Articles de revues : « Enterococcus faecali »

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Maheux, Andrée F., Sébastien Bouchard, Ève Bérubé et Michel G. Bergeron. « Rapid molecular identification of fecal origin-colonies growing on Enterococcus spp.-specific culture methods ». Journal of Water and Health 15, n^o 2 (17 décembre 2016) : 239–50. http://dx.doi.org/10.2166/wh.2016.199.

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The mEI, Chromocult® enterococci, and m-Enterococcus culture-based methods used to assess water quality by the detection of Enterococcus spp. were first compared in terms of sensitivity using (1) 41 different type strains of Enterococcus spp. and (2) environmental colonies identified by 16S rRNA sequencing. Then, two specific-rtPCR assays targeting Enterococcus spp. and Enterococcus faecalis/faecium were tested for their ability to confirm the identity of putative enterococcal colonies. The mEI, Chromocult® enterococci, and m-Enterococcus methods detected β-glucosidase activity for 28 (68.3%), 32 (78.0%), and 12 (29.3%) of the 41 reference enterococcal strains tested, respectively. Analysis with environmental colonies showed that mEI and Chromocult® enterococci media had false positive rates of 4.3% and 5.0%, respectively. Finally, the two rtPCR assays showed a specificity of 100%. Only two (2/19) colonies of E. faecium isolated from mEI agar were not detected by the Enterococcus faecium rtPCR assay, for a sensitivity of 89.5%. Our results showed that Chromocult® enterococci medium recovered more E. faecalis/faecium cells than the two other methods. Thus, the use of Chromocult® enterococci combined with the Enterococcus faecalis/faecium rtPCR assay showed the best combination to decrease the high false-positive rate obtained when the entire Enterococcus genus is targeted.

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Kumurya, A. S., et B. Ega. « An Overview on Vancomycin Resistant Enterococcus faecalis ». UMYU Journal of Microbiology Research (UJMR) 6, n^o 1 (30 juin 2021) : 160–67. http://dx.doi.org/10.47430/ujmr.2161.033.

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There are over 15 species of the Enterococcus genus, 80-90% of clinical isolates as E. faecalis. The aim of this work is to review the current information on Vancomycin resistant Enterococcus fecalis. The study reviewed using electronic documents and hard copies from public libraries of relevant literatures relating to biology, epidemiology, drug resistance mechanism, treatment, and control of Enterococcus faecalis. The review revealed that Enterocuccus faecalis formerly known as Streptococcus faecalis is a Gram-positive commensal bacterium that inhabits the gastrointestinal tracts of healthy humans and other mammals. However, it can cause lifethreatening infections in humans, especially in the nosocomial environment, where there are naturally high levels of antibiotic resistance. Thus, Enterococci have proven to present a therapeutic challenge because of their resistance to many antimicrobial drugs, including cell-wall active agents; aminoglycosides, penicillin, ampicillin, and vancomycin.” The Enterococci have the capacity to acquire a wide variety of antimicrobial resistance factors through plasmid transfer by conjugation, which present serious problems in the management of patients with Enterococcal infections. In general, Enterococcal isolates with lowered susceptibility to vancomycin are categorized as vanA, vanB, and vanC, vanA and vanB pose the greatest threat because they are the most resistant genes.E. faecalis are also resistant to teicoplanin. Enterococcal strains that are vancomycin-dependent have been found, but are rare and less common than vancomycin-resistant strains (referred to as “vancomycin-resistant Enterococci” or “VRE”). The review, identified that although VRE infection possess the tendency to become endemic especially in very ill debilitated patients who have been exposed to broad spectrum antibiotics; and the immune-compromised, yet Vancomycin continues to be the drug of choice for serious life threatening infections as sepsis, pneumonia, and endocarditis. Keywords: Vancomycin-resistant Enterococci(VRE), Enterococcus faecalis, Resistance gene

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Cox, Christopher R., et Michael S. Gilmore. « Native Microbial Colonization of Drosophila melanogaster and Its Use as a Model of Enterococcus faecalis Pathogenesis ». Infection and Immunity 75, n^o 4 (12 janvier 2007) : 1565–76. http://dx.doi.org/10.1128/iai.01496-06.

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ABSTRACT Enterococci are commensal organisms of the gastrointestinal (GI) tracts of a broad range of mammalian and insect hosts, but they are also leading causes of nosocomial infection. Little is known about the ecological role of enterococci in the GI tract consortia. To develop a tractable model for studying the roles of these organisms as commensals and pathogens, we characterized the Drosophila melanogaster microflora and examined the occurrence of enterococci in the gastrointestinal consortium of Drosophila. In a survey of laboratory-reared Drosophila and wild-captured flies, we found that Drosophila was naturally colonized by representatives of five bacterial phyla. Among these organisms were several species of enterococci, including Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinaraum, and Enterococcus durans, as well as a previously detected but uncultured Enterococcus species. Drosophila could be cured of enterococcal carriage by antibiotic treatment and could be reassociated with laboratory strains. High-level colonization by a well-characterized strain expressing the enterococcal cytolysin was found to be detrimental to Drosophila compared to the effect of an isogenic, noncytolytic control. The anatomical distribution of enterococci in the Drosophila GI tract was determined by immunohistochemical staining of thin sections of naturally colonized and reassociated flies.

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Lauková, Andrea, Viola Strompfová, Jana Ščerbová et Monika Pogány Simonová. « Virulence Factor Genes Incidence among Enterococci from Sewage Sludge in Eastern Slovakia following Safety Aspect ». BioMed Research International 2019 (7 octobre 2019) : 1–5. http://dx.doi.org/10.1155/2019/2735895.

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The sewage sludges represent a potential health hazard because of the quantity of different microbiota detected in sewages. Among microbiota detected in sewages, also belong representatives of the phylum Firmicutes. In the past, environmental enterococci in addition to coliforms were widely used as indicators of faecal contamination. Regarding the enterococcal strains as potential pathogenic bacteria, their pathogenicity is mainly caused by production of virulence factors. Therefore, the aim of the study was to analyse incidence of virulence factors in enterococci from cows' dung water. Species identification of 24 enterococci using MALDI-TOF MS system allotted 23 strains to the species Enterococcus faecium with highly probable species identification and E. faecalis EEV20 with a score value meaning secure genus identification/probable species identification. Enterococci were absent of cytolysin A gene, hyaluronidase gene, and element IS gene. It can be concluded that they are not invasive which is very important from safety aspect. The most frequently detected gene was adhesin E. faecium (efaAfm, in 22 E. faecium strains and in one E. faecalis). Adhesin efaAfs gene was detected in E. faecalis EEV20 and in two E. faecium. GelE gene was present in three strains. E. faecium EF/EC31 was absent of virulence factor genes.

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Conwell, Michael, James S. G. Dooley et Patrick J. Naughton. « A Novel Biofilm Model System to Visualise Conjugal Transfer of Vancomycin Resistance by Environmental Enterococci ». Microorganisms 9, n^o 4 (9 avril 2021) : 789. http://dx.doi.org/10.3390/microorganisms9040789.

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Enterococci and biofilm-associated infections are a growing problem worldwide, given the rise in antibiotic resistance in environmental and clinical settings. The increasing incidence of antibiotic resistance and its propagation potential within enterococcal biofilm is a concern. This requires a deeper understanding of how enterococcal biofilm develops, and how antibiotic resistance transfer takes place in these biofilms. Enterococcal biofilm assays, incorporating the study of antibiotic resistance transfer, require a system which can accommodate non-destructive, real-time experimentation. We adapted a Gene Frame® combined with fluorescence microscopy as a novel non-destructive platform to study the conjugal transfer of vancomycin resistance in an established enterococcal biofilm.A multi-purpose fluorescent in situ hybridisation (FISH) probe, in a novel application, allowed the identification of low copy number mobile elements in the biofilm. Furthermore, a Hoechst stain and ENU 1470 FISH probe identified Enterococcus faecium transconjugants by excluding Enterococcus faecalis MF06036 donors. Biofilm created with a rifampicin resistant E. faecalis (MW01105Rif) recipient had a transfer efficiency of 2.01 × 10−3; double that of the biofilm primarily created by the donor (E. faecalis MF06036). Conjugation in the mixed enterococcal biofilm was triple the efficiency of donor biofilm. Double antibiotic treatment plus lysozyme combined with live/dead imaging provided fluorescent micrographs identifying de novo enterococcal vancomycin resistant transconjugants inside the biofilm. This is a model system for the further study of antibiotic resistance transfer events in enterococci. Biofilms promote the survival of enterococci and reduce the effectiveness of drug treatment in clinical settings, hence giving enterococci an advantage. Enterococci growing in biofilms exchange traits by means of horizontal gene transfer, but currently available models make study difficult. This work goes some way to providing a non-destructive, molecular imaging-based model system for the detection of antibiotic resistance gene transfer in enterococci.

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Weisser, Maja, Selja Capaul, Marc Dangel, Luigia Elzi, Esther Kuenzli, Reno Frei et Andreas Widmer. « Additive Effect of Enterococcus faecium on Enterococcal Bloodstream Infections : A 14-Year Study in a Swiss Tertiary Hospital ». Infection Control & ; Hospital Epidemiology 34, n^o 10 (octobre 2013) : 1109–12. http://dx.doi.org/10.1086/673145.

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We investigated whether an increase in enterococcal bloodstream infections (BSIs) depends on the emergence of Enterococcus faecium in an area with low vancomycin-resistant enterococci prevalence. From 1999 to 2012, a linear increase in E. faecium BSI rates (0.009 per 1,000 patient-days per year; P<.001) was noted. Enterococcus faecalis BSI rates remained stable.

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Dolka, Beata, Mariola Gołębiewska–Kosakowska, Krzysztof Krajewski, Piotr Kwieciński, Tomasz Nowak, Jarosław Szubstarski, Jarosław Wilczyński et Piotr Szeleszczuk. « Occurrence of Enterococcus spp. in poultry in Poland based on 2014–2015 data ». Medycyna Weterynaryjna 73, n^o 4 (2017) : 220–24. http://dx.doi.org/10.21521/mw.5680.

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Bacteria of the genus Enterococcus are mainly commensals building natural microflora in the digestive tract of birds and mammals. They belong to the potentially pathogenic microorganisms. Among poultry, infections caused by enterococci were reported in chickens, turkeys, ducks and ostriches. The aim of this study was to evaluate the occurrence of enterococci in poultry in Poland, including identification of enterococcus species composition and determination of the age of birds. The analysis was based on data obtained from 2014 – 2015 from Division of Avian Diseases at Warsaw University of Life Sciences-SGGW and four veterinary laboratories in Poland: Lab – Vet, Tarnowo Podgórne; SLW Biolab, Ostróda; Vetdiagnostica, Solec Kujawski; Vet – Lab Brudzew. Seven enterococcal species were isolated from broiler chickens (CB), commercial layers (CL), and broiler breeder flocks (BB), nine from all poultry types (chickens, turkey, ducks and geese). The most often isolated enterococci from CB were E. faecalis (57%) > E. cecorum (7%) > E. faecium (5.2%) > E. hirae (3.6%) > E. gallinarum (2.5%) > E. casseliflavus (0.7%) > E. durans (0.2%). Seven Enterococcus species were isolated from sources associated with poultry, most often E. faecalis > E. faecium > E. cecorum > E. hirae. The differences in the occurrence of particular enterococcal species were observed between CB, BB and CL. The mean age at the time of isolation of E. cecorum was approx.: 3.6 weeks in CB, 27.5 weeks in BB, 33.3 weeks in CL, 12.9 weeks in turkeys, 3.6 weeks in ducks, 39.5 weeks in geese. E. faecalis and E. faecium dominated in samples obtained from hatching eggs, dead-in-shell embryos and from samples related to poultry environment. In conclusion, this study indicates the high prevalence of bacteria of the Enterococcus genus in poultry. The present findings demonstrate the differences in Enterococcus species between poultry groups, including with regard to age. In total 10 enterococcal species (E. faecalis, E. cecorum, E. hirae, E. faecium, E. gallinarum, E. casseliflavus, E. durans, E. avium E. thailandicus, E. aquimarinus) were detected in poultry, poultry environmental samples, hatching eggs and dead-in-shell embryos. Enterococcus faecalis and E. cecorum were found in all above-mentioned sources.

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KIM, YEONG BIN, HYUN JOO SEO, KWANG WON SEO, HYE YOUNG JEON, DONG KYU KIM, SHIN WOO KIM, SUK-KYUNG LIM et YOUNG JU LEE. « Characteristics of High-Level Ciprofloxacin-Resistant Enterococcus faecalis and Enterococcus faecium from Retail Chicken Meat in Korea ». Journal of Food Protection 81, n^o 8 (17 juillet 2018) : 1357–63. http://dx.doi.org/10.4315/0362-028x.jfp-18-046.

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ABSTRACTGenes encoding ciprofloxacin resistance in enterococci in animals may be transferred to bacteria in the animal gut and to zoonotic bacteria where they could pose a human health hazard. The objective of this study was to characterize antimicrobial resistance in high-level ciprofloxacin-resistant (HLCR) Enterococcus faecalis and Enterococcus faecium isolated from retail chicken meat. A total of 345 enterococci (335 E. faecalis and 10 E. faecium) were isolated from 200 chicken meat samples. Of these, 85 E. faecalis isolates and 1 E. faecium isolate were confirmed as HLCR enterococci. All 86 HLCR enterococci displayed gyrA-parC point mutations consisting of S83I-S80I (94.2%, 81 isolates), S83F-S80I (2.3%, 2 isolates), S83Y-S80I (2.3%, 2 isolates), and S83Y-S80F (1.2%, 1 isolate). Sixty-one (72.9%) of the 86 HLCR enterococci showed multidrug resistance to three to six classes of antimicrobial agents. Multilocus sequence typing revealed that E. faecalis had 17 different sequence types (ST) and E. faecium had 1 different ST, with ST256 observed most often (44 isolates, 51.8%). Although these results cannot exclude the possibility that pathotypes of enterococci isolated from chicken might represent transmission to or from humans, the foodborne HLCR E. faecalis indicated that the food chain is a potential route of enterococcal infection in humans.

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Tsiodras, Sotirios, Howard S. Gold, Eoin P. G. Coakley, Christine Wennersten, Robert C. Moellering et George M. Eliopoulos. « Diversity of Domain V of 23S rRNA Gene Sequence in Different Enterococcus Species ». Journal of Clinical Microbiology 38, n^o 11 (2000) : 3991–93. http://dx.doi.org/10.1128/jcm.38.11.3991-3993.2000.

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The highly conserved central loop of domain V of 23S RNA (nucleotides 2042 to 2628; Escherichia coli numbering) is implicated in peptidyltransferase activity and represents one of the target sites for macrolide, lincosamide, and streptogramin B antibiotics. DNA encoding domain V (590 bp) of several species ofEnterococcus was amplified by PCR. Twenty enterococcal isolates were tested, including Enterococcus faecium (six isolates), Enterococcus faecalis, Enterococcus avium, Enterococcus durans, Enterococcus gallinarum, Enterococcus casseliflavus (two isolates of each), and Enterococcus raffinosus, Enterococcus mundtii, Enterococcus malodoratus, andEnterococcus hirae (one isolate of each). For all isolates, species identification by biochemical testing was corroborated by 16S rRNA gene sequencing. The sequence of domain V of the 23S rRNA gene from E. faecium and E. faecalis differed from those of all other enterococci. The domain V sequences of E. durans and E. hirae were identical. This was also true for E. gallinarum and E. casseliflavus. E. avium differed from E. casseliflavus by 23 bases, from E. durans by 16 bases, and from E. malodoratus by 2 bases. E. avium differed fromE. raffinosus by one base. Despite the fact that domain V is considered to be highly conserved, substantial differences were identified between several enterococcal species.

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Jett, Bradley D., Rajeshwari V. Atkuri et Michael S. Gilmore. « Enterococcus faecalis Localization in Experimental Endophthalmitis : Role of Plasmid-Encoded Aggregation Substance ». Infection and Immunity 66, n^o 2 (1 février 1998) : 843–48. http://dx.doi.org/10.1128/iai.66.2.843-848.1998.

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ABSTRACT Enterococci have emerged as leading agents of nosocomial infection, yet relatively little is known about the pathogenesis of enterococcal disease. In previous studies, we developed an Enterococcus faecalis endophthalmitis infection model which provides unique opportunities to study the evolution of enterococcal disease by direct observation, as well as through sensitive electrophysiologic measures of organ function. The present study was designed to determine whetherE. faecalis possesses traits that permit its attachment to mammalian tissues during infection. It was also of interest to determine whether a plasmid-encoded adhesin, aggregation substance, contributes to enterococcal localization or otherwise mediates adherence to alternate sites. These studies found that, in this model, enterococci attach to membranous structures occurring within the vitreous but that this attachment or the course or severity of disease is unaffected by the aggregation substance phenotype.

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Gelsomino, Roberto, Marc Vancanneyt, Timothy M. Cogan et Jean Swings. « Effect of Raw-Milk Cheese Consumption on the Enterococcal Flora of Human Feces ». Applied and Environmental Microbiology 69, n^o 1 (janvier 2003) : 312–19. http://dx.doi.org/10.1128/aem.69.1.312-319.2003.

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ABSTRACT Enterococci are one of the major facultative anaerobic bacterial groups that reside in the human gastrointestinal tract. In the present study, the composition of the enterococcal fecal flora in three healthy humans was analyzed before, during, and after the daily consumption of ∼125 g of a raw-milk Cheddar-type cheese containing 3.2 × 104 enterococci/g of cheese. Enterococcal counts ranged between 1.4 × 102 and 2.5 × 108 CFU/g of feces and differed from subject to subject and from week to week. The cheese contained mainly Enterococcus casseliflavus and a small population of Enterococcus faecalis. Clonal relationships were determined by pulsed-field gel electrophoresis. Before and after consumption of the cheese, samples from humans contained mainly Enterococcus faecium, with some of the clones being resident. During consumption of the cheese, one particular transient clone of E. faecalis, clone Fs2, which was present in small numbers in the cheese, largely dominated the feces. Two clones of E. casseliflavus from the cheese were also found in the feces of one of the subjects during cheese consumption. These results suggest that a clone need not be present in a food in high numbers to establish itself in the intestine.

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Paul, Manisha, Prem Singh Nirwan et Preeti Srivastava. « Detection of high-level aminoglycoside resistance by disc diffusion and e-test amongst the enterococcus species isolated from various clinical samples in a tertiary care hospital ». International Journal of Research in Medical Sciences 7, n^o 9 (27 août 2019) : 3527. http://dx.doi.org/10.18203/2320-6012.ijrms20193941.

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Background: The emergence of Enterococcus species in causing nosocomial infections poses a therapeutic challenge to clinicians. Enterococci are intrinsically resistance to multiple antibiotics. Acquired resistance to commonly used antibiotics like Ampicillin, Vancomycin and Aminoglycosides have made the situation worse and difficult to treat serious Enterococcal infections. The present study aimed at detection of high-level aminoglycoside resistance by disc diffusion and E-test amongst the Enterococcus species isolated from various clinical samples in a tertiary care hospital.Methods: A total of 102 Enterococcus species isolated from various clinical samples and antimicrobial susceptibility was performed by Kirby Bauer disc diffusion method as per CLSI guidelines. E-test was done for all high level aminoglycoside resistance Enterococcus species isolated by disc diffusion test.Results: Among 102 isolates, 81 were E. faecalis, 18 were E. faecium and 3 were another Enterococcus. Their antimicrobial susceptibility pattern shows all isolates were sensitive to vancomycin, linezolid and teicoplanin with HLGR, HLSR detected in 40 and 38 isolates of E. faecalis, 17 and 13 isolates of E. faecium respectively by disc diffusion whereas by E-test it was detected in 44 and 40 in E. faecalis and 17 and 14 in E. faecium respectively. E. faecium is found to be more resistance to high level aminoglycoside than E. faecalis.Conclusions: Authors hereby conclude that Enterococci being the common cause of hospital acquired infections with their increasing resistance to multiple drugs and acquisition of HLAR; it must be routinely screened for various drugs to prevent drug resistance in hospital settings for serious Enterococcal infections.

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Figueras, M. J., I. Inza, F. Polo et J. Guarro. « Evaluation of the oxolinic acid - esculin - azide medium for the isolation and enumeration of faecal streptococci in a routine monitoring programme for bathing waters ». Canadian Journal of Microbiology 44, n^o 10 (1 octobre 1998) : 998–1002. http://dx.doi.org/10.1139/w98-096.

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m-Enterococcus agar (m-Ent) has been generally considered the reference medium for faecal streptococci in bathing waters. However, it shows several shortcomings, and therefore it is important to test newly developed media that can guarantee more precise results. In this sense, the recently described oxolinic acid - esculin - azide agar medium (OAA) and m-enterococccus agar (m-Ent) were comparatively evaluated for the detection of faecal streptococci from seawater and fresh water. The OAA medium showed a significantly higher relative recovery percentage and specificity for both types of water than m-Ent. A similar spectrum of species was recorded from both media, Enterococcus faecium being predominant in fresh water and Enterococcus faecalis, in seawater. The superior performance of the OAA medium in both types of bathing waters, added to the fact that it does not require the use of complementary confirmative tests, makes this medium an excellent candidate to be employed for monitoring programmes.Key words: faecal streptococci, water, monitoring, oxolinic acid - esculin - azide medium, m-enterococcus medium.

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G., Hemalatha, Bhaskaran K., Sowmiya M., Anusheela Howlader et Sethumadhavan K. « A study on virulence factors and antimicrobial resistance pattern among enterococci isolated from various clinical specimens from a tertiary care hospital ». International Journal of Research in Medical Sciences 5, n^o 7 (24 juin 2017) : 2969. http://dx.doi.org/10.18203/2320-6012.ijrms20172971.

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Background: Enterococci, adult faeces commensal are important nosocomial pathogens. E. faecalis is the most common cause of infection, followed by E. faecium. In the past two decades, they have developed resistance to many commonly used antimicrobial agents. Understanding virulence factors and monitoring antimicrobial resistance among Enterococci is essential for controlling the spread of bacterial resistance and important for epidemiological surveillance within the hospital environment. The aim of the study is to evaluate antibiotic resistance and virulence factors exhibited by Enterococcus sp.Methods: One hundred consecutive isolates of Enterococci isolated from different clinical samples of patients attending AVMC and H, a tertiary care center at Pondicherry in a period of 20 months were included in the study. Enterococcus sp were identified as per standard conventional bacteriologic methods and detected for the production of virulence factors such as Hemolysin production, Gelatinase production. Antimicrobial susceptibility testing was carried out by disc diffusion method and MIC of vancomycin and teicoplanin was determined by E-test strips.Results: Among 100 Enterococcal isolates included in the study, 81% were E. faecalis and 19% were E. faecium which were isolated from urine (44%), Pus (51%) and others specimen (5%, which includes blood 80% and drain tube 20%). In this study, overall 15% of E. faecalis and 1% of E. faecium showed hemolysin production and Gelatinase was produced by 6% of E. faecalis and 4% of E. faecium. Majority of E. faecalis and E. faecium strains isolated in our study, had increased sensitivity were to be exhibited for Linezolid, Vancomycin followed by high level gentamycin and high degree of resistance to penicillin, ciprofloxacin and cotrimoxazole. Analyzing the results of MIC of vancomycin and teicoplanin, 5 isolates were classified phenotypically as VanB phenotype that possess only moderate to high levels of vancomycin resistance and one isolate obtained from drain tube which showed MIC of vancomycin as 120µg/ml and teicoplanin 16µg/ml was grouped into VanA.Conclusions: Though the prevalence of vancomycin resistant Enterococcci (VRE) is very low in our study, yet regular monitoring of vancomycin resistance is very crucial for early detection, treatment, application of preventive and control measures and most importantly to check the spread of virulent multidrug resistant Enterococcus species.

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KuKanich, Kate S., et Brian V. Lubbers. « Review of Enterococci Isolated from Canine and Feline Urine Specimens from 2006 to 2011 ». Journal of the American Animal Hospital Association 51, n^o 3 (1 mai 2015) : 148–54. http://dx.doi.org/10.5326/jaaha-ms-6070.

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Canine and feline urine culture reports and medical records were reviewed at a veterinary teaching hospital from 2006 to 2011 for enterococcal growth, coinfections, antimicrobial resistance, urine sediment findings, clinical signs, and concurrent conditions. Of all of the urine specimens with significantly defined colony-forming units/mL, Enterococcus (E.) faecalis was the only enterococci isolated from cats and predominated (77.4%) in dogs followed by E. faecium (12.9%), E. durans (3.2%), and other Enterococcus spp. (6.5%). The majority of specimens with significant enterococcal growth resulted in complicated urinary tract infections in 83.9% of dogs and 81.8% of cats. Specimens with only enterococcal growth were more common than those mixed with other bacterial species. Cocci were observed in urine sediments of 8 out of 8 cats and 21 out of 25 dogs with available concurrent urinalyses. Pyuria was noted in 5 out of 8 feline and 15 out of 25 canine urine sediments, and pyuria in dogs was associated with growth of only enterococci on aerobic urine culture. Multidrug resistance was identified in 6 out of 11 cats and 7 out of 31 dogs, and E. faecium isolates from dogs were 4.5× more likely to be multidrug resistant than E. faecalis.

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KOBAYASHI, N., MD MAHBUB ALAM, Y. NISHIMOTO, S. URASAWA, N. UEHARA et N. WATANABE. « Distribution of aminoglycoside resistance genes in recent clinical isolates of Enterococcus faecalis, Enterococcus faecium and Enterococcus avium ». Epidemiology and Infection 126, n^o 2 (avril 2001) : 197–204. http://dx.doi.org/10.1017/s0950268801005271.

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Aminoglycoside modifying enzymes (AMEs) are major factors which confer aminoglycoside resistance on bacteria. Distribution of genes encoding seven AMEs was investigated by multiplex PCR for 279 recent clinical isolates of enterococci derived from a university hospital in Japan. The aac(6′)-aph(2″), which is related to high level gentamicin resistance, was detected at higher frequency in Enterococcus faecalis (42·5 %) than in Enterococcus faecium (4·3 %). Almost half of E. faecalis and E. faecium isolates possessed ant(6)-Ia and aph(3′)-IIIa. The profile of AME gene(s) detected most frequently in individual strains of E. faecalis was aac(6′)-aph(2″)+ant(6)-Ia+aph(3′)-IIIa, and isolates with this profile showed high level resistance to both gentamicin and streptomycin. In contrast, AME gene profiles of aac(6′)-Ii+ant(6)-Ia+aph(3′)-IIIa, followed by aac(6′)-Ii alone, were predominant in E. faecium. Only one AME gene profile of ant(6)-Ia+aph(3′)-IIIa was found in Enterococcus avium. The ant(4′)-Ia and ant(9)-Ia, which have been known to be distributed mostly among Staphylococcus aureus strains, were detected in a few enterococcal strains. An AME gene aph(2″)-Ic was not detected in any isolates of the three enterococcal species. These findings indicated a variety of distribution profiles of AME genes among enterococci in our study site.

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MARTÍN, MARÍA, JORGE GUTIÉRREZ, RAQUEL CRIADO, CARMEN HERRANZ, LUIS M. CINTAS et PABLO E. HERNÁNDEZ. « Genes Encoding Bacteriocins and Their Expression and Potential Virulence Factors of Enterococci Isolated from Wood Pigeons (Columba palumbus) ». Journal of Food Protection 69, n^o 3 (1 mars 2006) : 520–31. http://dx.doi.org/10.4315/0362-028x-69.3.520.

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Samples of the intestinal content and carcasses of wood pigeons (Columba palumbus) were evaluated for enterococci with antimicrobial activity. Enterococcus faecium comprised the largest enterococcal species with antagonistic activity, followed by Enterococcus faecalis and Enterococcus columbae. PCR amplification of genes coding bacteriocins and determination of their nucleotide sequence, and the use of specific antipeptide bacteriocin antibodies and a noncompetitive indirect enzyme-linked immunosorbent assay, permitted characterization of enterococci coding that described bacteriocins and their expression. The efaAfm determinant was the only virulence gene detected in E. faecium, whereas E. faecalis showed a larger number of virulence determinants, and E. columbae did not carry any of the virulence genes examined. Although all E. faecalis isolates manifested a potent direct antimicrobial activity, no activity was detected in supernatants of producer cells. Purification of the antagonistic activity of E. columbae PLCH2 showed multiple chromatographic fragments after matrix-assisted laser desorption–ionization time-of-flight mass spectrometry analysis, suggesting the active peptide(s) had not yet purified to homogeneity. Bacteriocinogenic E. faecium and E. columbae isolates may be considered hygienic for production of enterocins and potentially safe due to their low incidence of potential virulence genes and susceptibility of most relevant clinical antibiotics. However, the presence among the enterococci of E. faecalis strains with a potent antagonistic activity and multiple virulence factors is an issue that must be considered further.

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Su, Rina, Yunzhi Peng, Zhanli Wang, Hui Yu et Qi Wu. « Identification of two novel type II topoisomerase mutations in Enterococcus spp. isolated from a hospital in China ». Archives of Biological Sciences, n^o 00 (2021) : 34. http://dx.doi.org/10.2298/abs210628034s.

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Type II topoisomerases, including DNA gyrase (GyrA) and topoisomerase IV (ParC), contribute to fluoroquinolone resistance in Enterococcus spp. This study investigated the mutational status of the quinolone resistance-determining regions (QRDRs) of GyrA and ParC in the clinical isolates of enterococci from a hospital in Baotou, China. We analyzed 110 enterococcal isolates, including 57 Enterococcus faecalis and 53 Enterococcus faecalis faecium. The resistance rates of E. faecalis and E. faecium to ciprofloxacin were 63.16% and 84.91%, respectively. We found that 32 samples of E. faecalis and 42 of E. faecium had single or combined mutations in gyrA and/or parC, which were all resistant to ciprofloxacin. Only two ciprofloxacin-resistant E. faecalis isolates had no mutation. No mutations in gyrA and parC genes in all ciprofloxacin-susceptible isolates were found. Ciprofloxacin minimal inhibitory concentrations (MICs) in the mutation group were significantly higher than those of the nonmutation group, indicating that mutations in the QRDRs of gyrA and parC were correlated with MIC elevation. Two novel substitutions (GyrA Ser83Phe and ParC Ser80Leu) of E. faecalis were identified herein. Three-dimensional modeling revealed that these novel amino acid substitutions could disrupt the water/metal-ion bridge and decrease the interaction between the enzymes and ciprofloxacin. The data showed a diversity of mutation types in QRDRs of type II topoisomerases whose association with fluoroquinolone resistance in clinical isolates of enterococci warrants further investigation.

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Bera, Shyamsundar, Sonia Mehta, Manisha Bhatt Dwivedi, Varsha A. Singh, Rajdeep Paul et Sumi Nongrum. « Study on vancomycin-resistant enterococci in faecal samples from non-hospitalized individuals at MMIMSR, Haryana, India ». Bangladesh Journal of Medical Science 18, n^o 2 (25 mars 2019) : 334–39. http://dx.doi.org/10.3329/bjms.v18i2.40705.

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Background: Enterococci, formerly classified with fecal streptococci, have been recognized to be of fecal origin since the beginning of this century. Method: This study was undertaken to determine the prevalence of stool colonization with vancomycin resistant Enterococcus (VRE) and also to evaluate the risk factors for colonization with vancomycin resistant Enterococcus among non- Hospitalized individuals at MMIMSR, Mullana.Test was performed for VRE isolates collected over a period of 6 months (Oct2015- March 2016). Faecal samples were collected by using sterile container from non- hospitalized individuals then to Cultures using Mac Conkey and Blood agar. After presumptive diagnosis as an enterococcus spp, 50 Enterococcal isolates were then again cultured on special VRE screen agar media to identify vancomycin resistant Enterococcus. Result: The results were further supported by modified Kirby-bauer disk diffusion method with vancomycin (30μg) as per CLSI guideline. A total of 29 (58%) Enterococcus faecalis and 21 (42%) Enterococcus faecium were detected among the faecal isolates and 2 (4%) were VRE. According to CLSI guideline isolates showing diameter of zone of inhibition ≤16mm were considered among the VRE. Chronic diseases, previous hospital stay (more than 15 days) and repeatedly antibiotic consumption was found to be significant risk factor for non-hospitalized individuals. Conclusion: There is need for programs to promote greater attention about antibiotics usage in the general population. Education of Health care workers with implementation and observation of hand-washing practices constitutes a very effective step in preventing the spread Prolonged use of vancomycin drug should not be recommended by the physician. Bangladesh Journal of Medical Science Vol.18(2) 2019 p.334-339

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Gaspar, Frédéric, Neuza Teixeira, Lionel Rigottier-Gois, Paulo Marujo, Christina Nielsen-LeRoux, Maria Teresa Barreto Crespo, Maria de Fátima Silva Lopes et Pascale Serror. « Virulence of Enterococcus faecalis dairy strains in an insect model : the role of fsrB and gelE ». Microbiology 155, n^o 11 (1 novembre 2009) : 3564–71. http://dx.doi.org/10.1099/mic.0.030775-0.

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Despite the existence of various virulence factors in the Enterococcus genus, enterococcal virulence is still a debated issue. A main consideration is the detection of the same virulence genes in strains isolated from nosocomial or community-acquired infections, and from food products. The goal of this study was to evaluate the roles of two well-characterized enterococcal virulence factors, Fsr and gelatinase, in the potential virulence of Enterococcus faecalis food strains. Virulence of unrelated Enterococcus isolates, including dairy strains carrying fsr and gelE operons, was compared in the Galleria mellonella insect model. E. faecalis dairy strains were able to kill larvae and were as virulent as strain OG1RF, one of the most widely used for virulence studies. In contrast, Enterococcus durans and Enterococcus faecium strains were avirulent or poorly virulent for G. mellonella. To evaluate the role of fsrB and gelE in virulence of E. faecalis dairy strains, both genes were deleted independently in two strains. The ΔfsrB and ΔgelE deletion mutants both produced a gelatinase-negative phenotype. Although both mutations significantly attenuated virulence in G. mellonella, the ΔfsrB strains were more strongly attenuated. These results agree with previous findings suggesting the involvement of fsrB in the control of other cell functions relevant to virulence. Our work demonstrates that the presence of functional fsrB, and to a lesser extent gelE, in dairy enterococci should be considered with caution.

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Krawczyk, Beata, Paweł Wityk, Mirosława Gałęcka et Michał Michalik. « The Many Faces of Enterococcus spp.—Commensal, Probiotic and Opportunistic Pathogen ». Microorganisms 9, n^o 9 (7 septembre 2021) : 1900. http://dx.doi.org/10.3390/microorganisms9091900.

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Enterococcus spp. are Gram-positive, facultative, anaerobic cocci, which are found in the intestinal flora and, less frequently, in the vagina or mouth. Enterococcus faecalis and Enterococcus faecium are the most common species found in humans. As commensals, enterococci colonize the digestive system and participate in the modulation of the immune system in humans and animals. For many years reference enterococcal strains have been used as probiotic food additives or have been recommended as supplements for the treatment of intestinal dysbiosis and other conditions. The use of Enterococcus strains as probiotics has recently become controversial due to the ease of acquiring different virulence factors and resistance to various classes of antibiotics. Enterococci are also seen as opportunistic pathogens. This problem is especially relevant in hospital environments, where enterococcal outbreaks often occur. Their ability to translocate from the gastro-intestinal tract to various tissues and organs as well as their virulence and antibiotic resistance are risk factors that hinder eradication. Due to numerous reports on the plasticity of the enterococcal genome and the acquisition of pathogenic microbial features, we ask ourselves, how far is this commensal genus from acquiring pathogenicity? This paper discusses both the beneficial properties of these microorganisms and the risk factors related to their evolution towards pathogenicity.

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Lin, Yu-Tzu, Sung-Pin Tseng, Wei-Wen Hung, Chen-Chia Chang, You-Han Chen, Ya-Ting Jao, Yen-Hsu Chen, Lee-Jene Teng et Wei-Chun Hung. « A Possible Role of Insertion Sequence IS1216V in Dissemination of Multidrug-Resistant Elements MESPM1 and MES6272-2 between Enterococcus and ST59 Staphylococcus aureus ». Microorganisms 8, n^o 12 (30 novembre 2020) : 1905. http://dx.doi.org/10.3390/microorganisms8121905.

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Sequence type 59 (ST59) is the dominant type of community-associated methicillin-resistant Staphylococcus aureus (MRSA) in Taiwan. Previously, we reported that ST59 MRSA harbors enterococcal IS1216V-mediated multidrug-resistant composite transposons MESPM1 or MES6272-2. The MES were found to have a mosaic structure, largely originating in enterococci and partly native to S. aureus. The current study aimed to track the origin of the MES and how they disseminated from enterococci to ST59 S. aureus. A total of 270 enterococcal isolates were analyzed, showing that two ST64 Enterococcus faecalis isolated in 1992 and 11 clonal complex 17 Enterococcus faecium harbored MESPM1-like and MES6272-2-like structures, respectively. Sequence analysis revealed that ST64 E. faecalis strain N48 acquired the MESPM1-like structure on the plasmid pEflis48. The pEflis48 harbored the enterococci-originated region (erythromycin, kanamycin, and streptomycin resistances) and the S.aureus-originated region (chloramphenicol resistance) of MESPM1 but was separated by the replication region of the plasmid. Homologous recombination between the two direct repeats of IS1216V resulted in excision of the replication region of the plasmid to regenerate MESPM1. The p4780-1 and pV19 of E. faecium carried MES6272-2-like structures with IS1216V, albeit with multiple insertions by other insertion sequences. The findings show that IS1216V plays important roles in bidirectional gene transfer of multidrug resistance between enterococci and S. aureus.

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Gião, Joana, Célia Leão, Teresa Albuquerque, Lurdes Clemente et Ana Amaro. « Antimicrobial Susceptibility of Enterococcus Isolates from Cattle and Pigs in Portugal : Linezolid Resistance Genes optrA and poxtA ». Antibiotics 11, n^o 5 (3 mai 2022) : 615. http://dx.doi.org/10.3390/antibiotics11050615.

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Enterococci are part of the commensal gut microbiota of mammals, with Enterococcus faecalis and Enterococcus faecium being the most clinically relevant species. This study assesses the prevalence and diversity of enterococcal species in cattle (n = 201) and pig (n = 249) cecal samples collected in 2017. Antimicrobial susceptibility profiles of E. faecium (n = 48) and E. faecalis (n = 84) were assessed by agar and microdilution methods. Resistance genes were screened through PCR and nine strains were analyzed by Whole Genome Sequencing. A wide range of enterococci species was found colonizing the intestines of pigs and cattle. Overall, the prevalence of resistance to critically important antibiotics was low (except for erythromycin), and no glycopeptide-resistant isolates were identified. Two daptomycin-resistant E. faecalis ST58 and ST93 were found. Linezolid-resistant strains of E. faecalis (n = 3) and E. faecium (n = 1) were detected. Moreover, oxazolidinone resistance determinants optrA (n = 8) and poxtA (n = 2) were found in E. faecalis (ST16, ST58, ST207, ST474, ST1178) and E. faecium (ST22, ST2138). Multiple variants of optrA were found in different genetic contexts, either in the chromosome or plasmids. We highlight the importance of animals as reservoirs of resistance genes to critically important antibiotics.

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Goel, Varun, Dinesh Kumar, Rajendra Kumar, Purva Mathur et Sarman Singh. « Community Acquired Enterococcal Urinary Tract Infections and Antibiotic Resistance Profile in North India ». Journal of Laboratory Physicians 8, n^o 01 (janvier 2016) : 050–54. http://dx.doi.org/10.4103/0974-2727.176237.

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ABSTRACT Background: Urinary tract infections (UTIs) remain a major problem both in hospitalized and outdoor patients. Multidrug-resistant enterococci are emerging as a major nosocomial pathogen with increasing frequency. However, the incidence of community-acquired enterococcal infections and species prevalent in India is not thoroughly investigated. Objectives: This study aims to estimate the burden of community-acquired UTIs seen at a tertiary care hospital and to identify the Enterococcus species isolated from these patients. The study also aims to determine the antibiotic susceptibility pattern with reference to high-level aminoglycosides and vancomycin. Materials and Methods: Semi-quantitative cultures from a total of 22,810 urine samples obtained from patients seen at various Outpatient Departments were analyzed. From them 115 nonduplicate isolates of enterococci were obtained as significant pure growth (>105 cfu/ml) and speciated. Antibiotic susceptibility was performed by Kirby–Bauer disc diffusion method. Vancomycin resistance screening was performed by the vancomycin screen agar method recommended by Clinical and Laboratory Standards Institute and confirmed by determination of minimum inhibitory concentration by agar dilution method. Results: Of 115 enterococcal isolates, 61 were identified as Enterococcus faecalis, 42 as Enterococcus faecium, 3 each as Enterococcus dispar, and Enterococcus pseudoavium. High-level gentamicin resistance (HLGR) was higher in E. faecium (47.6%) than E. faecalis (32.7%) and HLSR also showed the same pattern with 47.6% and 27.9% resistance, respectively. Vancomycin resistant enterococci accounted for 11.3% of the isolates, and out of them 53.8% were E. faecium by agar dilution method. Conclusion: High rate of resistance to antibiotics of penicillin group and aminoglycosides was observed in our tertiary care hospital even in community acquired UTIs. Hence, there is an urgent need for more rational and restricted use of antimicrobials.

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CHINGWARU, W., S. F. MPUCHANE et B. A. GASHE. « Enterococcus faecalis and Enterococcus faecium Isolates from Milk, Beef, and Chicken and Their Antibiotic Resistance ». Journal of Food Protection 66, n^o 6 (1 juin 2003) : 931–36. http://dx.doi.org/10.4315/0362-028x-66.6.931.

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The occurrence and antibiotic resistance of enterococci, especially Enterococcus faecalis and Enterococcus faecium, in milk, beef, and chicken in Gaborone, Botswana, were studied. Enterococci were isolated from these sources with the use of bile esculin agar and identified with API 20 Strep kits. Antibiotic resistance was determined by the disk diffusion method. The antibiotics tested were vancomycin, teicoplanin, ampicillin, tetracycline, and cephalothin. Among the 1,467 enterococci isolated from the samples, E. faecalis (46.1%) and E. faecium (29.0%) were found to be the predominant species. Other enterococcal species made up 25% of the isolates. More than 96 and 97% of the E. faecalis and E. faecium isolates, respectively, were found to be resistant to ampicillin. Almost 34, 27.3, and 22.4% of the E. faecalis isolates from milk, beef, and chicken, respectively, were also resistant to cephalothin. The percentages of E. faecium isolates that were found to be resistant to cephalothin were 32.8, 16.9, and 17.3% for milk, beef, and chicken, respectively. Resistance to vancomycin was widespread. It was found that 18.8, 7.8, and 13.1% of the E. faecalis isolates from milk, beef, and chicken samples, respectively, were resistant to vancomycin. In contrast, 32.8, 24.7, and 30.7% of the E. faecium isolates from milk, beef, and chicken samples, respectively, were resistant to vancomycin. Isolates that were resistant to multiple drugs were found in relatively large numbers.

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Ke, Danbing, Maurice Boissinot, Ann Huletsky, François J. Picard, Johanne Frenette, Marc Ouellette, Paul H. Roy et Michel G. Bergeron. « Evidence for Horizontal Gene Transfer in Evolution of Elongation Factor Tu in Enterococci ». Journal of Bacteriology 182, n^o 24 (15 décembre 2000) : 6913–20. http://dx.doi.org/10.1128/jb.182.24.6913-6920.2000.

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ABSTRACT The elongation factor Tu, encoded by tuf genes, is a GTP binding protein that plays a central role in protein synthesis. One to three tuf genes per genome are present, depending on the bacterial species. Most low-G+C-content gram-positive bacteria carry only one tuf gene. We have designed degenerate PCR primers derived from consensus sequences of the tuf gene to amplify partial tuf sequences from 17 enterococcal species and other phylogenetically related species. The amplified DNA fragments were sequenced either by direct sequencing or by sequencing cloned inserts containing putative amplicons. Two different tufgenes (tufA and tufB) were found in 11 enterococcal species, including Enterococcus avium,Enterococcus casseliflavus, Enterococcus dispar, Enterococcus durans, Enterococcus faecium, Enterococcus gallinarum, Enterococcus hirae, Enterococcus malodoratus, Enterococcus mundtii, Enterococcus pseudoavium, andEnterococcus raffinosus. For the other six enterococcal species (Enterococcus cecorum, Enterococcus columbae, Enterococcus faecalis, Enterococcus sulfureus, Enterococcus saccharolyticus, andEnterococcus solitarius), only the tufA gene was present. Based on 16S rRNA gene sequence analysis, the 11 species having two tuf genes all have a common ancestor, while the six species having only one copy diverged from the enterococcal lineage before that common ancestor. The presence of one or two copies of thetuf gene in enterococci was confirmed by Southern hybridization. Phylogenetic analysis of tuf sequences demonstrated that the enterococcal tufA gene branches with the Bacillus, Listeria, andStaphylococcus genera, while the enterococcaltufB gene clusters with the generaStreptococcus and Lactococcus. Primary structure analysis showed that four amino acid residues encoded within the sequenced regions are conserved and unique to the enterococcaltufB genes and the tuf genes of streptococci and Lactococcus lactis. The data suggest that an ancestral streptococcus or a streptococcus-related species may have horizontally transferred a tuf gene to the common ancestor of the 11 enterococcal species which now carry two tuf genes.

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Komenkova, T. S., et E. A. Zaitseva. « Modern View on Enterococcus faecalis and Enterococcus faecium Resistance Mechanisms to Antibiotics ». Antibiotics and Chemotherapy 65, n^o 11-12 (13 février 2021) : 38–48. http://dx.doi.org/10.37489/0235-2990-2020-65-11-12-38-48.

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Enterococci are currently becoming one of the major causative agents of various infectious diseases. Enterococcus faecalis and E.faecium are the most common species causing enterococcal infections. Both species exhibit natural low-level resistance to aminoglycosides, cephalosporins, quinolones, clindamycin, and co-trimoxazole. In addition, the peculiarities of their genome make it easy to acquire resistance to other antibiotics widely used in clinical practice, through mutations or by horizontal gene transfer. The review represents current knowledge about the mechanisms of enterococcal resistance to the most commonly used antibiotics.

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Shepard, Brett D., et Michael S. Gilmore. « Differential Expression of Virulence-Related Genes in Enterococcus faecalis in Response to Biological Cues in Serum and Urine ». Infection and Immunity 70, n^o 8 (août 2002) : 4344–52. http://dx.doi.org/10.1128/iai.70.8.4344-4352.2002.

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ABSTRACT Enterococci rank among leading causes of nosocomial bacteremia and urinary tract infection and are also a leading cause of community acquired subacute endocarditis. Limited evidence suggests that biological cues in serum and urine may play an important role in modulating enterococcal virulence at sites of infection. To determine the extent to which biological cues affect enterococcal virulence-associated gene expression, we used quantitative real-time PCR to compare mRNA levels in Enterococcus faecalis cultures grown in serum or urine to that achieved in laboratory medium. Both environment- and growth phase-specific variations were observed, demonstrating the occurrence of as-yet-uncharacterized mechanisms for control of gene expression in E. faecalis that may play an important role in vivo.

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Jonas, Brandie M., Barbara E. Murray et George M. Weinstock. « Characterization of emeA, anorA Homolog and Multidrug Resistance Efflux Pump, inEnterococcus faecalis ». Antimicrobial Agents and Chemotherapy 45, n^o 12 (1 décembre 2001) : 3574–79. http://dx.doi.org/10.1128/aac.45.12.3574-3579.2001.

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ABSTRACT We hypothesized that multidrug resistance efflux pumps (MDRs) may be contributing to the drug resistance of enterococci. We recently identified potential MDR-encoding genes in the Enterococcus faecalis V583 genome. Among the putative MDRs, we found a gene that encodes a NorA homolog and have characterized this enterococcal MDR in the present study. A mutant from which the enterococcal NorA homolog has been deleted has reduced resistance to several NorA substrates. Complementation of the deletion mutant with the wild-type gene verified the involvement of this enterococcal gene in resistance to ethidium bromide (EtBr) and norfloxacin. Known MDR inhibitors (reserpine, lansoprazole, and verapamil) inhibit the efflux of EtBr and norfloxacin in wild-type strain OG1RF. A fluorescence assay with EtBr allowed us to quantitate the efflux capability of the enterococcal NorA pump. On the basis of these results, we have named this enterococcal gene emeA (enterococcal multidrug resistance efflux).

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Huescas, C. G. Y., R. I. Pereira, J. Prichula, P. A. Azevedo, J. Frazzon et A. P. G. Frazzon. « Frequency of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) in non-clinical Enterococcus faecalis and Enterococcus faecium strains ». Brazilian Journal of Biology 79, n^o 3 (septembre 2019) : 460–65. http://dx.doi.org/10.1590/1519-6984.183375.

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Abstract The fidelity of the genomes is defended by mechanism known as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) systems. Three Type II CRISPR systems (CRISPR1- cas, CRISPR2 and CRISPR3-cas) have been identified in enterococci isolates from clinical and environmental samples. The aim of this study was to observe the distribution of CRISPR1-cas, CRISPR2 and CRISPR3-cas in non-clinical strains of Enterococcus faecalis and Enterococcus faecium isolates from food and fecal samples, including wild marine animals. The presence of CRISPRs was evaluated by PCR in 120 enterococci strains, 67 E. faecalis and 53 E. faecium. It is the first report of the presence of the CRISPRs system in E. faecalis and E. faecium strains isolated from wild marine animal fecal samples. The results showed that in non-clinical strains, the CRISPRs were more frequently detected in E. faecalis than in E. faecium. And the frequencies of CRISPR1-cas and CRISPR2 were higher (60%) in E. faecalis strains isolated from animal feces, compared to food samples. Both strains showed low frequencies of CRISPR3-cas (8.95% and 1.88%). In conclusion, the differences in the habitats of enterococcal species may be related with the results observe in distribution of CRISPRs systems.

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Romero-Saavedra, F., D. Laverde, E. Kalfopoulou, C. Martini, R. Torelli, D. Martinez-Matamoros, M. Sanguinetti et J. Huebner. « Conjugation of Different Immunogenic Enterococcal Vaccine Target Antigens Leads to Extended Strain Coverage ». Journal of Infectious Diseases 220, n^o 10 (9 juillet 2019) : 1589–98. http://dx.doi.org/10.1093/infdis/jiz357.

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Abstract Enterococci have emerged as important nosocomial pathogens due to their resistance to the most commonly used antibiotics. Alternative treatments or prevention options are aimed at polysaccharides and surface-related proteins that play important roles in pathogenesis. Previously, we have shown that 2 Enterococcus faecium proteins, the secreted antigen A and the peptidyl-prolyl cis-trans isomerase, as well as the Enterococcus faecalis polysaccharide diheteroglycan, are able to induce opsonic and cross-protective antibodies. Here, we evaluate the use of glycoconjugates consisting of these proteins and an enterococcal polysaccharide to develop a vaccine with broader strain coverage. Diheteroglycan was conjugated to these 2 enterococcal proteins. Rabbit sera raised against these glycoconjugates showed Immunoglobulin G titers against the corresponding conjugate, as well as against the respective protein and carbohydrate antigens. Effective opsonophagocytic killing for the 2 sera was observed against different E. faecalis and E. faecium strains. Enzyme-linked immunosorbent assays against whole bacterial cells showed immune recognition of 22 enterococcal strains by the sera. Moreover, the sera conferred protection against E. faecalis and E. faecium strains in a mouse infection model. Our results suggest that these glycoconjugates are promising candidates for vaccine formulations with a broader coverage against these nosocomial pathogens and that the evaluated proteins are potential carrier proteins.

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Huebner, Johannes, Alexander Quaas, Wolfgang A. Krueger, Donald A. Goldmann et Gerald B. Pier. « Prophylactic and Therapeutic Efficacy of Antibodies to a Capsular Polysaccharide Shared among Vancomycin-Sensitive and -Resistant Enterococci ». Infection and Immunity 68, n^o 8 (1 août 2000) : 4631–36. http://dx.doi.org/10.1128/iai.68.8.4631-4636.2000.

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ABSTRACT Enterococci are important nosocomial pathogens that are increasingly difficult to treat due to intrinsic and acquired resistance to antibiotics, including vancomycin. A recently described capsular polysaccharide (CP) isolated from Enterococcus faecalis 12030 was used to evaluate the potential efficacy of active or passive immunotherapy regimens as adjunctive treatments. Evaluation of protective efficacy was carried out in immunocompetent mice challenged intravenously (i.v.) with live enterococci. In nonimmune mice, i.v. inoculations resulted in high levels of bacteria in kidneys, spleens, and livers 5 days after challenge. Mice immunized with four 10-μg doses of CP antigen/mouse were protected against challenge with the homologous E. faecalis strain. High-titer opsonic immunoglobulin G was also induced by immunizing rabbits with the purified CP, and passive transfer of this antiserum to mice produced significantly lower bacterial counts in organs than did normal rabbit serum or sterile saline. Antibodies to the polysaccharide isolated from E. faecalis 12030 were protective againstEnterococcus faecalis OG1RF and against two serologically related, vancomycin-resistant Enterococcus faecium clinical isolates. Antibodies to this CP antigen were also effective as a therapeutic reagent in mice when passive therapy was initiated 48 h after live bacterial challenge. These data indicate that CP antigens from enterococci are potential targets of protective antibodies and that these antibodies may be useful for prophylaxis and treatment of enterococcal infections.

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Palmer, Kelli L., Karen Carniol, Janet M. Manson, David Heiman, Terry Shea, Sarah Young, Qiandong Zeng et al. « High-Quality Draft Genome Sequences of 28 Enterococcus sp. Isolates ». Journal of Bacteriology 192, n^o 9 (5 mars 2010) : 2469–70. http://dx.doi.org/10.1128/jb.00153-10.

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ABSTRACT The enterococci are low-GC Gram-positive bacteria that have emerged as leading causes of hospital-acquired infection. They are also commensals of the gastrointestinal tract of healthy humans and most other animals with gastrointestinal flora and are important for food fermentations. Here we report the availability of draft genome sequences for 28 enterococcal strains of diverse origin, including the species Enterococcus faecalis, E. faecium, E. casseliflavus, and E. gallinarum.

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Macovei, Lilia, et Ludek Zurek. « Ecology of Antibiotic Resistance Genes : Characterization of Enterococci from Houseflies Collected in Food Settings ». Applied and Environmental Microbiology 72, n^o 6 (juin 2006) : 4028–35. http://dx.doi.org/10.1128/aem.00034-06.

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ABSTRACT In this project, enterococci from the digestive tracts of 260 houseflies (Musca domestica L.) collected from five restaurants were characterized. Houseflies frequently (97% of the flies were positive) carried enterococci (mean, 3.1 ï¿½ 103 CFU/fly). Using multiplex PCR, 205 of 355 randomly selected enterococcal isolates were identified and characterized. The majority of these isolates were Enterococcus faecalis (88.2%); in addition, 6.8% were E. faecium, and 4.9% were E. casseliflavus. E. faecalis isolates were phenotypically resistant to tetracycline (66.3%), erythromycin (23.8%), streptomycin (11.6%), ciprofloxacin (9.9%), and kanamycin (8.3%). Tetracycline resistance in E. faecalis was encoded by tet(M) (65.8%), tet(O) (1.7%), and tet(W) (0.8%). The majority (78.3%) of the erythromycin-resistant E. faecalis isolates carried erm(B). The conjugative transposon Tn916 and members of the Tn916/Tn1545 family were detected in 30.2% and 34.6% of the identified isolates, respectively. E. faecalis carried virulence genes, including a gelatinase gene (gelE; 70.7%), an aggregation substance gene (asa1; 33.2%), an enterococcus surface protein gene (esp; 8.8%), and a cytolysin gene (cylA; 8.8%). Phenotypic assays showed that 91.4% of the isolates with the gelE gene were gelatinolytic and that 46.7% of the isolates with the asa1 gene aggregated. All isolates with the cylA gene were hemolytic on human blood. This study showed that houseflies in food-handling and -serving facilities carry antibiotic-resistant and potentially virulent enterococci that have the capacity for horizontal transfer of antibiotic resistance genes to other bacteria.

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Andrews Jr., Robert E., Wesley S. Johnson, Abby R. Guard et Jonathan D. Marvin. « Survival of enterococci and Tn916-like conjugative transposons in soil ». Canadian Journal of Microbiology 50, n^o 11 (1 novembre 2004) : 957–66. http://dx.doi.org/10.1139/w04-090.

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The persistence of Enterococcus faecalis, fecal enterococci from swine waste, and Tn916-like elements was determined following inoculation into autoclaved and native soil microcosms. When cells of E. faecalis CG110 (Tn916) were inoculated into native microcosms, enterococcal viability in the soil decreased approximately 5 orders of magnitude (4.8 × 105CFU/g soil to < 10 CFU/g) after 5 weeks. In autoclaved microcosms, the viability of E. faecalis decreased by only 20% in 5 weeks. In contrast, the content of Tn916, based on PCR of DNA extracts from soil microcosms, decreased by about 20% in both native and autoclaved microcosms. Similar results were obtained when the source of fecal enterococci and Tn916-like elements was swine waste. Because the concentration of Tn916-independent E. faecalis DNA (the D-alanine D-alanine ligase gene), based on PCR, decreased to nearly undetectable levels (at least 3 orders of magnitude) after 5 weeks in the native microcosms, the evidence suggests Tn916 stability in the soil results from en masse transfer of the transposon to the normal soil microflora and not survival of E. faecalis DNA in the soil system. Results from denaturing gradient gel electrophoresis suggest that multiple forms of Tn916 occur in swine waste, but only forms most like Tn916 exhibit stability in the soil.Key words: Tn916, Enterococcus faecalis, soil, antibiotic resistance, conjugation, transposon.

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Adeniji, Oluwaseun Ola, Nolonwabo Nontongana et Anthony Ifeanyin Okoh. « Prevalence of Class 1 Integron and In Vitro Effect of Antibiotic Combinations of Multidrug-Resistant Enterococcus Species Recovered from the Aquatic Environment in the Eastern Cape Province, South Africa ». International Journal of Molecular Sciences 24, n^o 3 (3 février 2023) : 2993. http://dx.doi.org/10.3390/ijms24032993.

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Enterococci are regarded as a better indication of faecal pollution in freshwater and marine waters. Their levels in seawater are positively connected with swimming-related gastrointestinal disorders. This study used an Enterococcus-specific polymerase chain reaction (PCR) to characterize the isolates. Classes 1 and 2 integrons were examined for environmental Enterococcus isolates using a standard biological procedure. All strains were assessed against a panel of 12 antibiotics from various classes using disc diffusion methods. The microdilution method was used to work out the minimum inhibitory concentration (MIC) according to the CLSI guiding principles. The combination therapy of the resistant drugs was evaluated using a checkerboard assay and a time-dependent test for assessing their bactericidal or bacteriostatic activity. The gene diversity of the tested organisms was analyzed with the aid of Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR. In total, 57 Enterococcus spp. environmental samples were recovered, in which Enterococcus faecalis (33.33%) and Enterococcus faecium (59.65%) were the dominant species. Resistance to linezolid, ciprofloxacin, erythromycin, gentamicin, vancomycin, rifampicin, and tetracycline was prevalent. Fifty (50) strains tested positive for class 1 integron, more frequent in Enterococcus faecium and Enterococcus faecalis isolates, with no gene cassette array discovered. A combination of gentamicin (MIC 4 µg/mL) with vancomycin (MIC 256 µg/mL) antibiotics against Enterococcus faecalis showed antibacterial activity. In contrast, the combination of ciprofloxacin (1 µg/mL) with Ampicillin (16 µg/mL) antibiotics against Enterococcus faecalis showed a bacteriostatic effect. The ERIC-PCR analysis pointed out that most of the assessed isolates have close genetic similarities.

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Yangzom, Tsering, et T. Shanti Kumar Singh. « Study of vancomycin and high-level aminoglycoside-resistant Enterococcus species and evaluation of a rapid spot test for enterococci from Central Referral Hospital, Sikkim, India ». Journal of Laboratory Physicians 11, n^o 03 (juillet 2019) : 192–99. http://dx.doi.org/10.4103/jlp.jlp_5_19.

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Abstract BACKGROUND: Enterococcus is an important pathogen, and with its emergence of resistance to multiple antimicrobials, the management of infection is becoming increasingly difficult. AIM: The aim of the study is to determine the prevalence, antibiotic resistance, and risk factors associated with enterococcal infection or colonization. MATERIALS AND METHODS: In this prospective study, samples from inpatients were screened for resistant enterococci. Antibiotic susceptibility testing was performed using the disc diffusion method and minimum inhibitory concentration by the agar dilution method. A modification of a test tube method of sodium chloride-esculin hydrolysis to a spot test was evaluated for its rapidity and reliability in the presumptive diagnosis of enterococci. STATISTICAL ANALYSIS USED: Fisher's exact test was used for continuous (Student's t-test) and categorical variables. Multivariate analysis was performed with logistic regression using IBM SPSS 20.0 software (Armonk, NY, USA). RESULTS: Enterococcus species were isolated from 182 samples: Enterococcus faecalis (68.7%), Enterococcus faecium (20.9%), Enterococcus gallinarum (6%), and Enterococcus durans (4.4%). Maximum resistance was to ciprofloxacin (59.3%) and least to linezolid (0.5%). The isolation rate of vancomycin-resistant enterococci (VRE) was 13.7%; 30.2% and 20.9% were of high-level gentamicin and streptomycin, respectively. All 182 Enterococcus species gave positive results within 30–60 min by the rapid spot test. CONCLUSIONS: Overall, high-level aminoglycoside resistance (HLAR) was observed more than glycopeptide resistance. Surveillance strategies need to be upgraded and implemented in order to prevent the emergence and further spread of not only VRE but also HLAR enterococci in the hospital. The spot test gave reliable and rapid results in presumptive identification of enterococci.

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Baldassarri, L., R. Creti, L. Montanaro, G. Orefici et C. R. Arciola. « Pathogenesis of Implant Infections by Enterococci ». International Journal of Artificial Organs 28, n^o 11 (novembre 2005) : 1101–9. http://dx.doi.org/10.1177/039139880502801107.

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Enterococci are commensals of human and animal intestinal tract that have emerged in the last decades as a major cause of nosocomial infections of bloodstream, urinary tract and in infected surgical sites. Enterococcus faecalis is responsible for ca. 80% of all enterococcal infections while Enterococcus faecium accounts for most of the others; among the most relevant risk factors for development of enterococcal infections is the presence of implanted devices. The pathogenesis of such infections is poorly understood, but several virulence factors have been proposed. Among them, the ability to form biofilm has recently been shown to be one of the most prominent features of this microorganism, allowing colonization of inert and biological surfaces, while protecting against antimicrobial substances, and mediating adhesion and invasion of host cells and survival within professional phagocytes. Biofilm formation has been shown to be particularly important in the development of prosthetic valve enterococcal endocarditis and stent occlusion. Enterococci are also able to express other surface factors that may support colonization of both inert and biological surfaces, and that may be involved in the invasion of, and survival within, the host cell.

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Alexandrova, Natalya A., Maya I. Zaslavskaya, Irina V. Soloveva, Anna G. Tochilina et Irina V. Belova. « EVALUATION OF ANTI-CANDIDA ACTIVITY OF METABOLITES OF ENTEROCOCCAL CLINICAL ISOLATES ». Russian Clinical Laboratory Diagnostics 64, n^o 11 (15 novembre 2019) : 690–92. http://dx.doi.org/10.18821/0869-2084-2019-64-11-690-692.

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When studying the effect of the metabolic products of clinical isolates of enterococci on the viability of Candida albicans, it was found that metabolites of all tested strains of Enterococcus faecium, E. faecalis had a fungistatic effect. At the same time a reliable fungicidal effect is a strain-specific feature. It is better to use the method of delayed antagonism on double-layer agar to assess the antifungal effect of enterococcal metabolism products.

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Khairy, Rasha MM, Mahmoud Shokry Mahmoud, Mona Abdel Monem Esmail et Aya Nabil Gamil. « First detection of vanB phenotype-vanA genotype vancomycin-resistant enterococci in Egypt ». Journal of Infection in Developing Countries 13, n^o 09 (30 septembre 2019) : 837–42. http://dx.doi.org/10.3855/jidc.10472.

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Introduction: Enterococci have emerged in last two decades as serious hospital acquired pathogens particularly vancomycin resistant strains (VRE). The study aimed to identify the prevalence of enterococcal isolation from hospital infections and colonization as well as determine vancomycin resistance phenotypes and genotypes. Methods: Sixty enterococcus isolates were isolated from patients, health care workers and hospital environment, identified and tested for antimicrobial susceptibility. Enterococcus species were identified by Real-time PCR and vancomycin resistance was assessed by agar dilution method and Real-time PCR. Results; out of 300 samples (20%) were enterococci (53.3% were E. faecium, 31.7% E. faecalis and 10% other enterococci). Among of them 40/60 (66, 6%) were isolated from infections and 33.3% were isolated from colonization. multiple drug resistance was reported in (100%) of isolates, while (95%) and (45%) of isolates were resistant to vancomycin and ticoplanin respectively. VanA phenotype, vanA genotype was identified in (47.4%) of isolates, while vanB phenotype, vanA genotype was identified in (33.3%) of vancomycin resistant isolates. Conclusion; VanB phenotype-vanA genotype was identified in (33.3%) of vancomycin resistant enterococcal isolates. To our knowledge it is the first identified incidence of such strains in Egypt and Africa.

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Hayes, Joshua R., Linda L. English, Peggy J. Carter, Terry Proescholdt, Kyung Y. Lee, David D. Wagner et David G. White. « Prevalence and Antimicrobial Resistance of Enterococcus Species Isolated from Retail Meats ». Applied and Environmental Microbiology 69, n^o 12 (décembre 2003) : 7153–60. http://dx.doi.org/10.1128/aem.69.12.7153-7160.2003.

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ABSTRACT From March 2001 to June 2002, a total of 981 samples of retail raw meats (chicken, turkey, pork, and beef) were randomly obtained from 263 grocery stores in Iowa and cultured for the presence of Enterococcus spp. A total of 1,357 enterococcal isolates were recovered from the samples, with contamination rates ranging from 97% of pork samples to 100% of ground beef samples. Enterococcus faecium was the predominant species recovered (61%), followed by E. faecalis (29%), and E. hirae (5.7%). E. faecium was the predominant species recovered from ground turkey (60%), ground beef (65%), and chicken breast (79%), while E. faecalis was the predominant species recovered from pork chops (54%). The incidence of resistance to many production and therapeutic antimicrobials differed among enterococci recovered from retail meat samples. Resistance to quinupristin-dalfopristin, a human analogue of the production drug virginiamycin, was observed in 54, 27, 9, and 18% of E. faecium isolates from turkey, chicken, pork, and beef samples, respectively. No resistance to linezolid or vancomycin was observed, but high-level gentamicin resistance was observed in 4% of enterococci, the majority of which were recovered from poultry retail meats. Results indicate that Enterococcus spp. commonly contaminate retail meats and that dissimilarities in antimicrobial resistance patterns among enterococci recovered from different meat types may reflect the use of approved antimicrobial agents in each food animal production class.

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TEMPLER, S. P., P. ROHNER et A. BAUMGARTNER. « Relation of Enterococcus faecalis and Enterococcus faecium Isolates from Foods and Clinical Specimens ». Journal of Food Protection 71, n^o 10 (1 octobre 2008) : 2100–2104. http://dx.doi.org/10.4315/0362-028x-71.10.2100.

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Clinical Enterococcus faecalis (n = 65) and Enterococcus faecium (n = 12) blood isolates from three Swiss hospitals were characterized with testing for resistance to antimicrobial agents, pulsed-field gel electrophoresis (PFGE), and the occurrence of virulence factors. Phenotypic determination of resistance to antimicrobial agents resulted in 20% of E. faecalis isolates showing a triple resistance against chloramphenicol, tetracycline, erythromycin, and seven isolates (two E. faecalis and five E. faecium) exhibiting a multiresistance against five or more antimicrobials. One isolate each of E. faecalis and E. faecium showed vancomycin resistance. All isolates contained at least two of the nine tested virulence genes (agg, gelE, cyl, esp, efaAfs, efaAfm, cpd, cob, and ccf ). Phylogenetic analysis of the PFGE profiles identified several small clusters within E. faecalis isolates, one of which included isolates of all three hospitals. Fifty-six (73%) isolates occurred as unique, patient-specific clones. Several PFGE types were associated with shared features in their resistance patterns, indicating spread between and within wards. Finally, enterococci from this study and previous isolates from cheeses were examined by PFGE typing. The comparison of PFGE profiles from human and food isolates resulted in clusters of genetically strong related strains, which suggests high similarities of the enterococcal community composition of these two environments. A possible spread of the enterococcal isolates through the food supply cannot be excluded.

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Abril, Ana G., Marcos Quintela-Baluja, Tomás G. Villa, Pilar Calo-Mata, Jorge Barros-Velázquez et Mónica Carrera. « Proteomic Characterization of Virulence Factors and Related Proteins in Enterococcus Strains from Dairy and Fermented Food Products ». International Journal of Molecular Sciences 23, n^o 18 (19 septembre 2022) : 10971. http://dx.doi.org/10.3390/ijms231810971.

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Enterococcus species are Gram-positive bacteria that are normal gastrointestinal tract inhabitants that play a beneficial role in the dairy and meat industry. However, Enterococcus species are also the causative agents of health care-associated infections that can be found in dairy and fermented food products. Enterococcal infections are led by strains of Enterococcus faecalis and Enterococcus faecium, which are often resistant to antibiotics and biofilm formation. Enterococci virulence factors attach to host cells and are also involved in immune evasion. LC-MS/MS-based methods offer several advantages compared with other approaches because one can directly identify microbial peptides without the necessity of inferring conclusions based on other approaches such as genomics tools. The present study describes the use of liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS) to perform a global shotgun proteomics characterization for opportunistic pathogenic Enterococcus from different dairy and fermented food products. This method allowed the identification of a total of 1403 nonredundant peptides, representing 1327 proteins. Furthermore, 310 of those peptides corresponded to proteins playing a direct role as virulence factors for Enterococcus pathogenicity. Virulence factors, antibiotic sensitivity, and proper identification of the enterococcal strain are required to propose an effective therapy. Data are available via ProteomeXchange with identifier PXD036435. Label-free quantification (LFQ) demonstrated that the majority of the high-abundance proteins corresponded to E. faecalis species. Therefore, the global proteomic repository obtained here can be the basis for further research into pathogenic Enterococcus species, thus facilitating the development of novel therapeutics.

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KNUDTSON, LINDA M., et PAUL A. HARTMAN. « Antibiotic Resistance Among Enterococcal Isolates from Environmental and Clinical Sources ». Journal of Food Protection 56, n^o 6 (1 juin 1993) : 489–92. http://dx.doi.org/10.4315/0362-028x-56.6.489.

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Antibiotic resistance among enterococci and fecal streptococci was examined by testing 149 isolates from pork, water, and clinical material, as well as 50 strains of 13 known species, for resistance to 27 different antimicrobial agents. Tests were performed by using the MicroScan Pos MIC type 6 panels. Pork isolates exhibited less resistance than either water or clinical isolates to most antibiotics, although a larger proportion of pork isolates than others was resistant to tetracycline. Comparisons of antimicrobial-resistance patterns between enterococcal species revealed that Enterococcus faecium was most resistant to β-lactam antimicrobials, especially ampicillin, whereas Enterococcus faecalis seemed to be the most resistant to the synergistic effects of antimicrobial combinations. Vancomycin resistance was observed in one Enterococcus hirae isolate from water. Enterococcal isolates from any of the sources tested did not show multiple resistance to antibiotics (such as gentamicin, ampicillin, streptomycin, and vancomycin) used to treat serious infections caused by gram-positive cocci.

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Ben Said, Leila, Raoudha Dziri, Nadia Sassi, Carmen Lozano, Karim Ben Slama, Imen Ouzari, Carmen Torres et Naouel Klibi. « Species distribution, antibiotic resistance and virulence traits in canine and feline enterococci in Tunisia ». Acta Veterinaria Hungarica 65, n^o 2 (juin 2017) : 173–84. http://dx.doi.org/10.1556/004.2017.018.

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In order to investigate the possible role of dogs and cats in the carriage and potential dissemination of resistant enterococci, seventy faecal samples from dogs and cats were tested for enterococci. Fifty-eight enterococci were recovered. Isolates were identified as Enterococcus faecium (n = 31) and E. faecalis (n = 14) E. durans (n = 6), E. casseliflavus (n = 2), E. hirae and E. gallinarum (2 isolates each). Enterococcal isolates showed resistance to ciprofloxacin (n = 35), erythromycin (n = 31), tetracycline (n = 25), kanamycin (n = 15), streptomycin (n = 13), pristinamycin (n = 11), gentamicin (n = 10), chloramphenicol (n = 8), and linezolid (n = 6). The gene erm(B) was detected in 22 out of 31 erythromycin-resistant enterococci. All tetracycline-resistant enterococci carried tet(M) and/or tet(L) genes. The gene aac(6′)-Ie-aph(2″)-Ia was identified in five of high-level gentamicin-resistant isolates, the genes aph(3′)-IIIa and/or aac(6′)-Ie-aph(2″)-Ia in eleven high-level kanamycin-resistant isolates and the gene ant(6)-Ia in eleven high-level streptomycin-resistant isolates. Only one strain harboured cat(A) gene, and five strains contained vat(E) or vat(D) genes. Virulence genes gel(E) (21 strains), esp (11 strains) and cylA/cylB (5 strains) were detected. High genetic diversity was demonstrated among E. faecium isolates by pulsed-field gel electrophoresis (PFGE). Dogs and cats can be carriers of antibiotic-resistant enterococci in their faeces that could shed into the household environment.

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Schell, Celia M., Ana P. Tedim, Mercedes Rodríguez-Baños, Mónica D. Sparo, Sabina Lissarrague, Juan A. Basualdo et Teresa M. Coque. « Detection of β-Lactamase-Producing Enterococcus faecalis and Vancomycin-Resistant Enterococcus faecium Isolates in Human Invasive Infections in the Public Hospital of Tandil, Argentina ». Pathogens 9, n^o 2 (20 février 2020) : 142. http://dx.doi.org/10.3390/pathogens9020142.

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The study’s aim was to analyze the population structure of enterococci causing human invasive infections in a medium-sized Argentinian Hospital coincidental with a 5 year-period of increased recovery of antibiotic resistant enterococci (2010–2014). Species identification (biochemical testing/MALDI-TOF-MS), antimicrobial susceptibility (disk-diffusion) and clonal relatedness (PFGE/MLST/BAPS) were determined according to standard guidelines. β-lactamase production was determined by a nitrocefin test and confirmed by PCR/sequencing. The isolates were identified as Enterococcus faecalis and Enterococcus faecium at a 2:1 ratio. Most of the E. faecalis isolates, grouped in 25 PFGE-types (ST9/ST179/ST236/ST281/ST388/ST604/ST720), were resistant to high-levels (HLR) of gentamicin/streptomycin. A ST9 clone (bla+/HLR-gentamicin) was detected in patients of different wards during 2014. E. faecium isolates were grouped in 10 PFGE-types (ST25/ST18/ST19/ST52/ST792), with a low rate of ampicillin resistance. Five vancomycin-resistant E. faecium, three vanA (ST792/ST25) and two vanB (ST25) were detected. The ST25 clone carried either vanA or vanB. The recovery of a bla+-ST9-E. faecalis clone similar to that described in the late 1980s in Argentina suggests the possibility of a local hidden reservoir. These results reflect the relevance of local epidemiology in understanding the population structure of enterococci as well as the emergence and spread of antimicrobial resistance in predominant enterococcal clonal lineages.

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MACOVEI, LILIA, BRETT MILES et LUDEK ZUREK. « Potential of Houseflies To Contaminate Ready-to-Eat Food with Antibiotic-Resistant Enterococci† ». Journal of Food Protection 71, n^o 2 (1 février 2008) : 435–39. http://dx.doi.org/10.4315/0362-028x-71.2.435.

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It was shown previously that houseflies in fast-food restaurants commonly carry antibiotic-resistant and potentially virulent enterococci. In this study, the potential of field-collected houseflies to contaminate ready-to-eat (RTE) food with enterococci was assessed by laboratory bioassays. Houseflies were collected with a sweep net in a cattle feedlot and exposed in groups of 5, 10, 20, and 40 to a beef patty (from an RTE hamburger) for 0.5, 1.0, 3.0, and 24 h. The exposure of RTE food to flies resulted in 100% contamination with enterococci in all bioassays, regardless of the number of houseflies and the length of exposure time. In addition, with the increasing number of houseflies as well as with the increasing time exposure, the concentration of enterococci in RTE food increased. Even a short time exposure (0.5 h) resulted in food contamination, ranging from 3.1 × 103 CFU/g (5 houseflies) to 8.4 × 104 CFU/g (40 houseflies). The analysis of 23 randomly selected enterococcal isolates from RTE food after the fly exposure revealed a single species, Enterococcus faecalis. In contrast, four Enterococcus species, including E. faecalis (57.1%), E. gallinarum (19.1%), E. hirae (14.3%), and E. faecium (9.5%), represented 21 randomly selected and identified isolates from houseflies. Phenotypic screening showed that E. faecalis isolates from RTE food were resistant to ciprofloxacin (17.4%), tetracycline (13.0%), erythromycin (13.0%), and chloramphenicol (4.3%). This study demonstrates a great potential of houseflies from a cattle feedlot to contaminate RTE food with enterococci in a short time.

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Tendolkar, Preeti M., Arto S. Baghdayan, Michael S. Gilmore et Nathan Shankar. « Enterococcal Surface Protein, Esp, Enhances Biofilm Formation by Enterococcus faecalis ». Infection and Immunity 72, n^o 10 (octobre 2004) : 6032–39. http://dx.doi.org/10.1128/iai.72.10.6032-6039.2004.

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ABSTRACT Enterococci play a dual role in human ecology. They serve as commensal organisms of the gastrointestinal tract and are also leading causes of multiple antibiotic-resistant hospital-acquired infection. Many nosocomial infections result from the ability of microorganisms to form biofilms. The molecular mechanisms involved in enterococcal biofilm formation are only now beginning to be understood. Enterococcal surface protein, Esp, has been reported to contribute to biofilm formation by Enterococcus faecalis. Recent studies have shown that enterococci form biofilms independently of Esp expression. To precisely determine what role Esp plays in E. faecalis biofilm formation, Esp was expressed on the cell surface of genetically well-defined, natively Esp-deficient strains, and isogenic Esp-positive and Esp-deficient strains were compared for their biofilm-forming ability. The results show that Esp expression leads to a significant increase in biofilm formation, irrespective of the strain tested. The contribution of Esp to biofilm formation was found to be most pronounced in the presence of 0.5% (wt/vol) or greater glucose. These results unambiguously define Esp as a key contributor to the ability of E. faecalis to form biofilms.

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Fioriti, Simona, Gianluca Morroni, Sonia Nina Coccitto, Andrea Brenciani, Alberto Antonelli, Vincenzo Di Pilato, Ilaria Baccani et al. « Detection of Oxazolidinone Resistance Genes and Characterization of Genetic Environments in Enterococci of Swine Origin, Italy ». Microorganisms 8, n^o 12 (17 décembre 2020) : 2021. http://dx.doi.org/10.3390/microorganisms8122021.

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One hundred forty-five florfenicol-resistant enterococci, isolated from swine fecal samples collected from 76 pig farms, were investigated for the presence of optrA, cfr, and poxtA genes by PCR. Thirty florfenicol-resistant Enterococcus isolates had at least one linezolid resistance gene. optrA was found to be the most widespread linezolid resistance gene (23/30), while cfr and poxtA were detected in 6/30 and 7/30 enterococcal isolates, respectively. WGS analysis also showed the presence of the cfr(D) gene in Enterococcus faecalis (n = 2 isolates) and in Enterococcus avium (n = 1 isolate). The linezolid resistance genes hybridized both on chromosome and plasmids ranging from ~25 to ~240 kb. Twelve isolates were able to transfer linezolid resistance genes to enterococci recipient. WGS analysis displayed a great variability of optrA genetic contexts identical or related to transposons (Tn6628 and Tn6674), plasmids (pE035 and pWo27-9), and chromosomal regions. cfr environments showed identities with Tn6644-like transposon and a region from p12-2300 plasmid; cfr(D) genetic contexts were related to the corresponding region of the plasmid 4 of Enterococcus faecium E8014; poxtA was always found on Tn6657. Circular forms were obtained only for optrA- and poxtA-carrying genetic contexts. Clonality analysis revealed the presence of E. faecalis (ST16, ST27, ST476, and ST585) and E. faecium (ST21) clones previously isolated from humans. These results demonstrate a dissemination of linezolid resistance genes in enterococci of swine origin in Central Italy and confirm the spread of linezolid resistance in animal settings.

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Alder, Jeff, Tongchaun Li, Donghui Yu, Larry Morton, Jared Silverman, Xi-Xian Zhang, Ian Critchley et Grace Thorne. « Analysis of Daptomycin Efficacy and Breakpoint Standards in a Murine Model of Enterococcus faecalis and Enterococcus faecium Renal Infection ». Antimicrobial Agents and Chemotherapy 47, n^o 11 (novembre 2003) : 3561–66. http://dx.doi.org/10.1128/aac.47.11.3561-3566.2003.

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ABSTRACT Daptomycin efficacy against clinical isolates of Enterococcus faecalis, Enterococcus faecium, and a lab-derived daptomycin-resistant isolate of E. faecalis was investigated in a mouse model of renal infection. The daptomycin MICs against these enterococci ranged from 0.5 to 50 μg/ml. The objective of this study was to determine the relationship between the MICs of drugs against E. faecalis and E. faecium and the level of daptomycin exposure needed to evaluate the drug's efficacy. Correlating the required therapeutic exposures of mice with the exposures achieved clinically allowed us to project enterococcal breakpoint values. Mice pretreated with carrageenan were infected intravenously with 3 × 108 to 4 × 108 CFU of E. faecalis or E. faecium. Daptomycin (5 to 50 mg of drug/kg of body weight) or saline control was administered 4 h postinfection and continued once daily for 2 days (three total doses). On day 4, infected kidneys were harvested, homogenized, and dilution plated. Efficacy was defined as a ≥2-log10 (99%) reduction in bacterial burden in infected kidneys. At clinically relevant dosages and exposures (area under the curve, 400 to 600 μg · hr/ml), daptomycin demonstrated similar and marked efficacy against all clinical enterococcal isolates tested. Daptomycin achieved efficacy with comparable doses against both vancomycin-sensitive (MIC, ≤4 μg/ml) and -resistant enterococcal strains tested. Efficacy was also established against the lab-derived daptomycin-resistant E. faecalis isolate. In this murine renal infection model, clinically relevant exposures of daptomycin were effective against E. faecalis and E. faecium strains for which MICs were ≤8 μg/ml. These murine efficacy data for daptomycin, along with surveillance data and human pharmacokinetic exposures achieved, suggest a breakpoint concentration value of ≤8 μg/ml (susceptible) and ≥16 μg/ml (resistant) for daptomycin against E. faecium and E. faecalis.

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