Articoli di riviste: "Escherichia coli O1113"

1

Vicente, H. I. G., L. A. do Amaral, A. P. Nunes e C. S. Lorenzon. "ESCHERICHIA COLI, PRODUTORAS DE SHIGATOXINAS DETECTADAS EM FEZES DE BOVINOS LEITEIROS". Arquivos do Instituto Biológico 77, n. 4 (dicembre 2010): 567–73. http://dx.doi.org/10.1590/1808-1657v77p5672010.

Testo completo

Abstract (sommario):

RESUMO Este trabalho teve como objetivo determinar a prevalência de Escherichia coli produtoras de Shigatoxinas (STEC) e E. coli dos sorogrupos O157, O111 e O113 em rebanhos leiteiros do Município de Jaboticabal, SP, Brasil. A presença de sequências gênicas stx1, stx2e eae foi detectada pela reação em cadeia da polimerase (PCR) em amostras de fezes. Todas as amostras stx e eae positivas foram submetidas a uma nova reação de PCR para detecção das sequências rfb O157, O111 e O113. Observou-se uma alta prevalência (72,16%) de sequências stx nas fezes dos bovinos, sendo que o perfil genotípico encontrado com maior frequência foi o stx1 associado à stx2. Os coeficientes de prevalência das sequências rfb O157, O111 e O113 foram, respectivamente, 14,77%, 0,2% e 30,83%. Animais de todos os rebanhos (100%) apresentaram em suas fezes STEC e E. coli O113 e os sorogrupos O157 e O111 foram observados em 60,0% e 10,0% dos rebanhos, respectivamente. Concluiu-se que a alta prevalência de STEC detectada em rebanho leiteiro evidenciada nas fezes de bovinos desempenham um papel importante na contaminação ambiental e podem oferecerrisco de agravo à saúde pública.

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Bettelheim, Karl A. "Non-O157 Verotoxin-Producing Escherichia coli: A Problem, Paradox, and Paradigm". Experimental Biology and Medicine 228, n. 4 (aprile 2003): 333–44. http://dx.doi.org/10.1177/153537020322800402.

Testo completo

Abstract (sommario):

The problems associated with identification and characterization of non-O157 verotoxin-producing Escherichia coli (VTEC) are discussed. The paradox of VTEC is that most reports of human illnesses are associated with serotypes such as O157:H7, O111:H– (nonmotile), O26:H11, and O113:H21, which are rarely found in domestic animals. However, those VTEC serotypes commonly found in domestic animals, especially ruminants, rarely cause human illnesses. When they cause human illnesses, the symptoms are similar to those caused by the serotypes E. coli O157:H7, O111:H–, O26:H11, and O113:H21. The impact of VTEC on human and animal health is also addressed. The VTEC and their toxicity are considered as a paradigm for emerging pathogens. The question on how such pathogens could arise from a basic commensal population is also addressed.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Paton, Adrienne W., e James C. Paton. "Molecular Characterization of the Locus Encoding Biosynthesis of the Lipopolysaccharide O Antigen of Escherichia coliSerotype O113". Infection and Immunity 67, n. 11 (1 novembre 1999): 5930–37. http://dx.doi.org/10.1128/iai.67.11.5930-5937.1999.

Testo completo

Abstract (sommario):

ABSTRACT Shiga toxigenic Escherichia coli (STEC) strains are a diverse group of organisms capable of causing severe gastrointestinal disease in humans. Within the STEC family, eae-positive STEC strains, particularly those belonging to serogroups O157 and O111, appear to have greater virulence for humans. However, in spite of beingeae negative, STEC strains belonging to serogroup O113 have frequently been associated with cases of severe STEC disease, including hemolytic-uremic syndrome (HUS). Western blot analysis with convalescent-phase serum from a patient with HUS caused by an O113:H21 STEC strain indicated that human immune responses were directed principally against lipopolysaccharide O antigen. Accordingly, the serum was used to isolate a clone expressing O113 O antigen from a cosmid library of O113:H21 DNA constructed in E. coli K-12. Sequence analysis indicated that the O113 O-antigen biosynthesis (rfb) locus contains a cluster of nine genes which may be cotranscribed. Comparison with sequence databases identified candidate genes for four glycosyl transferases, an O-acetyl transferase, an O-unit flippase, and an O-antigen polymerase, as well as copies of galE and gnd. Two additional, separately transcribed genes downstream of the O113 rfbregion were predicted to encode enzymes involved in synthesis of activated sugar precursors, one of which (designated wbnF) was essential for O113 O-antigen synthesis, and so is clearly a part of the O113 rfb locus. Interestingly, expression of O113 O antigen by E. coli K-12 significantly increased in vitro adherence to both HEp-2 and Henle 407 cells.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Paton, Adrienne W., e James C. Paton. "Direct Detection of Shiga Toxigenic Escherichia coliStrains Belonging to Serogroups O111, O157, and O113 by Multiplex PCR". Journal of Clinical Microbiology 37, n. 10 (1999): 3362–65. http://dx.doi.org/10.1128/jcm.37.10.3362-3365.1999.

Testo completo

Abstract (sommario):

Shiga toxigenic Escherichia coli (STEC) strains are a diverse group of organisms associated with severe gastrointestinal and systemic diseases in humans. Within the STEC family,eae-positive STEC strains, particularly those belonging to serogroups O157 and O111, appear to have greater virulence for humans. However, in spite of being eae negative, STEC strains belonging to serogroup O113 have frequently been associated with cases of severe STEC disease, including hemolytic-uremic syndrome (HUS). We have developed a modified multiplex PCR assay for detection of STEC strains belonging to these three serogroups in cultures of feces by using primers specific for portions of the genetic loci (rfb) encoding biosynthesis of the respective O antigen. These primers direct amplification of PCR products of 259, 406, and 593 bp for serogroups O157, O111, and O113, respectively. The assay was validated by testing 40 previously characterized STEC strains, with 100% agreement. It also detected STEC strains of the appropriate genotype in primary fecal cultures from 13 patients with HUS or bloody diarrhea. Thirty other primary fecal cultures from patients without evidence of STEC infection were negative.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Paton, Adrienne W., Matthew C. Woodrow, Robyn M. Doyle, Janice A. Lanser e James C. Paton. "Molecular Characterization of a Shiga ToxigenicEscherichia coli O113:H21 Strain Lacking eaeResponsible for a Cluster of Cases of Hemolytic-Uremic Syndrome". Journal of Clinical Microbiology 37, n. 10 (1999): 3357–61. http://dx.doi.org/10.1128/jcm.37.10.3357-3361.1999.

Testo completo

Abstract (sommario):

Shiga toxigenic Escherichia coli (STEC) strains are a diverse group of organisms capable of causing severe gastrointestinal disease in humans. Within the STEC family, certain strains appear to have greater virulence for humans. STEC strains carryingeae and belonging to serogroup O157 or O111 have been responsible for the vast majority of outbreaks of STEC disease reported to date. Here we describe a STEC O113:H21 strain lackingeae that was responsible for a cluster of three cases of hemolytic-uremic syndrome. This strain produces a single Stx2-related toxin and adheres efficiently to Henle 407 cells.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

ZHAO, TONG, SUZANA TKALCIC, MICHAEL P. DOYLE, BARRY G. HARMON, CATHY A. BROWN e PING ZHAO. "Pathogenicity of Enterohemorrhagic Escherichia coli in Neonatal Calves and Evaluation of Fecal Shedding by Treatment with Probiotic Escherichia coli". Journal of Food Protection 66, n. 6 (1 giugno 2003): 924–30. http://dx.doi.org/10.4315/0362-028x-66.6.924.

Testo completo

Abstract (sommario):

The pathogenicity and fecal shedding of enterohemorrhagic Escherichia coli (EHEC) O26:H11, O111:NM, and O157:H7 were compared in calves (<1 week of age) with or without prior treatment with probiotic bacteria (competitive exclusion E. coli). Three groups of 12 to 14 calves were used for these treatments. Half of the calves in each group were perorally administered 1010 CFU of probiotic bacteria per calf, and, 2 days thereafter, 108 CFU of a five-strain mixture with one of the three EHEC serotypes per calf were administered to each calf. None of the EHEC serotypes caused clinical disease, and neither gross nor microscopic lesions attributable to EHEC were detected in control or probiotic-treated calves at necropsy. In calves administered E. coli O157:H7, fecal shedding was greatly reduced (>6 log10 CFU/g) by 8 days after administration, and there was no significant difference (P > 0.05) in fecal shedding of E. coli O157:H7 between probiotic-treated and untreated control groups at that time. In contrast, control calves perorally administered E. coli of serotypes O111:NM or O26:H11 continued to shed substantial populations (102.1 to 106 CFU/g of feces and 102.5 to 104.9 CFU/g of feces, respectively) throughout 7 days postadministrationof EHEC. In both groups administered either E. coli O111:NM or O26:H11, significantly less (P < 0.05) EHEC was isolated from feces at 7 days postadministration of EHEC and at necropsy from the probiotic-treated group than from the untreated control group. Overall, neonatal calves shed in the feces from 1 to 7 days following peroral administration of EHEC greater populations of E. coli O111:NM and O26:H11 than E. coli O157:H7. In addition, treatment of calves with probiotic E. coli reduced fecal shedding of E. coli O111:NM and O26:H11 in most calves.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

TKALCIC, SUZANA, TONG ZHAO, BARRY G. HARMON, MICHAEL P. DOYLE, CATHY A. BROWN e PING ZHAO. "Fecal Shedding of Enterohemorrhagic Escherichia coli in Weaned Calves following Treatment with Probiotic Escherichia coli". Journal of Food Protection 66, n. 7 (1 luglio 2003): 1184–89. http://dx.doi.org/10.4315/0362-028x-66.7.1184.

Testo completo

Abstract (sommario):

The fecal shedding and pathogenicity of enterohemorrhagic E. coli (EHEC) O26:H11, EHEC O111:NM, and EHEC O157:H7 in weaned calves (8 to 10 weeks of age) were compared with and without treatment with a three-strain mixture of probiotic bacteria (competitive-exclusion E. coli). Three groups of 12 calves were each perorally given a five-strain mixture of one of the EHEC serotypes (1010 CFU of total bacteria per calf). Seventy-two hours later, six calves from each group were each administered 1010 CFU of probiotic bacteria. None of the EHEC serotypes caused significant clinical disease, although a few calves developed mild transient diarrhea or pyrexia. Gross or microscopic lesions attributable to EHEC were not detected in control or probiotic-treated calves at necropsy. For probiotic-treated calves given E. coli O157:H7 and for probiotic-treated calves given E. coli O111:NM, fecal shedding was reduced compared with that for untreated calves. For the probiotic-treated calves given E. coli O157:H7, the reductions in fecal shedding on days 8, 12, 14, 16, 20, 22, 28, and 30 after peroral administration were statistically significant (P < 0.05). For probiotic-treated calves given E. coli O111:NM, there were statistically significant reductions (P < 0.05) in fecal shedding on days 6, 8, 10, and 12. In contrast, there was no reduction in fecal shedding for calves administered E. coli O26:H11 and treated with the probiotic bacteria. In fact, calves in both the treated and the nontreated groups continued to shed large populations of E. coli O26:H11 throughout the 32-day trial. At necropsy, E. coli O157:H7 was isolated from five of six untreated calves and from only two of six probiotic-treated calves. E. coli O111:NM was isolated from four of six untreated calves at necropsy and from two of six probiotic-treated calves. However, E. coli O26:H11 was isolated from five of six untreated calves and from all six probiotic-treated calves. The results obtained in this study indicate that probiotic E. coli substantially reduced or eliminated fecal shedding of E. coli O157:H7 and E. coli O111:NM 8 to 30 days and 6 to 12 days after the administration of the probiotic culture, respectively, and reduced the persistence of E. coli O157:H7 in the gastrointestinal tract at necropsy (31 to 33 days after the administration of the probiotic culture). The probiotic E. coli did not reduce fecal shedding or gastrointestinal persistence of E. coli O26:H11.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

LIN, ANDREW, JULIE A. KASE, MICHELLE M. MOORE, INSOOK SON, NELLY TRAN, LAURIE M. CLOTILDE, KAREN JARVIS et al. "Multilaboratory Validation of a Luminex Microbead-Based Suspension Array for the Identification of the 11 Most Clinically Relevant Shiga Toxin–Producing Escherichia coli O Serogroups†". Journal of Food Protection 76, n. 5 (1 maggio 2013): 867–70. http://dx.doi.org/10.4315/0362-028x.jfp-12-468.

Testo completo

Abstract (sommario):

Rapid and high-throughput identification and serotyping of Shiga toxin–producing Escherichia coli (STEC) O serogroups is important for detecting, investigating, and controlling STEC infection outbreaks and removing hazardous products from commerce. A Luminex microbead-based suspension array has been developed to identify the 11 most clinically relevant STEC serogroups: O26, O45, O91, O103, O104, O111, O113, O121, O128, O145, and O157. Here we present results of a blinded multilaboratory collaborative study involving 10 participants from nine laboratories using 55 unknown strains. From the total 495 analyses, two false-positive and three false-negative results were obtained, indicating the assay to be a rapid, high-throughput, and robust method for identifying clinically relevant STEC serogroups.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Durso, Lisa M., James L. Bono e James E. Keen. "Molecular serotyping of Escherichia coli O111:H8". Journal of Microbiological Methods 69, n. 2 (maggio 2007): 381–83. http://dx.doi.org/10.1016/j.mimet.2007.01.016.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Santos, Maurílio F., Roger R. C. New, Gabrielle R. Andrade, Christiane Y. Ozaki, Osvaldo A. Sant'Anna, Lucia Mendonça-Previato, Luis R. Trabulsi e Marta O. Domingos. "Lipopolysaccharide as an Antigen Target for the Formulation of a Universal Vaccine against Escherichia coli O111 Strains". Clinical and Vaccine Immunology 17, n. 11 (22 settembre 2010): 1772–80. http://dx.doi.org/10.1128/cvi.00232-10.

Testo completo

Abstract (sommario):

ABSTRACT A promising approach to developing a vaccine against O111 strains of diarrheagenic Escherichia coli that exhibit different mechanisms of virulence is to target either the core or the polysaccharide chain (O antigen) of their lipopolysaccharide (LPS). However, due to structural variations found in both these LPS components, to use them as antigen targets for vaccination, it is necessary to formulate a vaccine able to induce a humoral immune response that can recognize all different variants found in E. coli O111 strains. In this study, it was demonstrated that, despite differences in composition of oligosaccharide repeat units between O111ab and O111ac LPS subtypes, antibodies against one O111 subtype can recognize and inhibit the adhesion to human epithelial cells of all categories of O111 E. coli (enteropathogenic E. coli [EPEC], enterohemorrhagic E. coli [EHEC], and enteroaggregative E. coli [EAEC]) strains regardless of the nature of their flagellar antigens, mechanisms of virulence, or O111 polysaccharide subtypes. These antibodies were also able to increase the clearance of different strains of O111 E. coli by macrophages. PCR analyses of the pathways involved in O111 LPS core biosynthesis showed that all EAEC strains have core type R2, whereas typical EPEC and EHEC have core type R3. In contrast, atypical EPEC strains have core types R2 and R3. In summary, the results presented herein indicate that the O111 polysaccharide and LPS core types R2 and R3 are antigen targets for panspecific immunotherapy against all categories of O111 E. coli.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Vicente, Hinig Isa Godoy, Luiz Augusto do Amaral e Aloysio de Mello Figueiredo Cerqueira. "Shigatoxigenic Escherichia coli serogroups O157, O111 and O113 in feces, water and milk samples from dairy farms". Brazilian Journal of Microbiology 36, n. 3 (settembre 2005): 217–22. http://dx.doi.org/10.1590/s1517-83822005000300003.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

TERAO, YOSHITAKA, TARO YONEKITA, NAOKI MORISHITA, TATSUYA FUJIMURA, TAKASHI MATSUMOTO e FUMIKI MORIMATSU. "Potential Rapid and Simple Lateral Flow Assay for Escherichia coli O111". Journal of Food Protection 76, n. 5 (1 maggio 2013): 755–61. http://dx.doi.org/10.4315/0362-028x.jfp-12-351.

Testo completo

Abstract (sommario):

We developed and evaluated a lateral flow assay (LFA) as a simple and rapid method for direct detection of Escherichia coli O111 in food after enrichment. When cell suspensions of 8 E. coli O111 strains and 77 non–E. coli O111 strains were tested with the LFA, the former all yielded positive results and the latter all yielded negative results. The minimum detection limits for the E. coli O111 strains were 1.8 × 103 to 5.6 × 105 CFU/ml of cell suspension, and the LFA was able to detect live cultures or those killed by autoclaving at nearly the same level of sensitivity. To evaluate the ability of LFA to detect its target in food, enrichment cultures of meat samples inoculated with 10-fold serial dilutions of E. coli O111 were tested with the LFA and PCR. Even when there were very few E. coli O111 cells in the meat samples (1.6 × 100 to 1.6 × 101 CFU/25 g of food), when they were cultured in modified E. coli broth with novobiocin for 22 h at 42°C, the LFA yielded positive results that corresponded to the PCR results. Although the LFA requires further evaluation and field study, these results suggest that this assay has sufficient sensitivity and specificity. This procedure can be completed with a one-step incubation after the test strip has been inserted into the sample after 22 h of culture, whereas the standard culture method requires multiple cultures, skilled personnel, a well-equipped laboratory, and 4 or 5 days. The speed and simplicity of this LFA make it suitable for use as part of routine screening assays in the food industry.

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Varcasia, Bianca, Francesco Tomassetti, Laura De Santis, Fabiola Di Giamberardino, Sarah Lovari, Stefano Bilei e Paola De Santis. "Presence of Shiga Toxin-Producing Escherichia coli (STEC) in Fresh Beef Marketed in 13 Regions of ITALY (2017)". Microorganisms 6, n. 4 (6 dicembre 2018): 126. http://dx.doi.org/10.3390/microorganisms6040126.

Testo completo

Abstract (sommario):

The aim of this study was to determine the prevalence of Shiga toxin-producing Escherichia coli in fresh beef marketed in 2017 in 13 regions of Italy, to evaluate the potential risk to human health. According to the ISO/TS 13136:2012 standard, 239 samples were analysed and nine were STEC positive, from which 20 strains were isolated. The STEC-positive samples were obtained from Calabria (n = 1), Campania (n = 1), Lazio (n = 2), Liguria (n = 1), Lombardia (n = 1) and Veneto (n = 3). All STEC strains were analysed for serogroups O26, O45, O55, O91, O103, O104, O111, O113, O121, O128, O145, O146 and O157, using Real-Time PCR. Three serogroups were identified amongst the 20 strains: O91 (n = 5), O113 (n = 2), and O157 (n = 1); the O-group for each of the 12 remaining STEC strains was not identified. Six stx subtypes were detected: stx1a, stx1c, stx2a, stx2b, stx2c and stx2d. Subtype stx2c was the most common, followed by stx2d and stx2b. Subtype stx2a was identified in only one eae-negative strain and occurred in combination with stx1a, stx1c and stx2b. The presence in meat of STEC strains being potentially harmful to human health shows the importance, during harvest, of implementing additional measures to reduce contamination risk.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Wang, Jiaying, Yan D. Niu, Jinding Chen, Hany Anany, Hans-W. Ackermann, Roger P. Johnson, Collins N. Ateba, Kim Stanford e Tim A. McAllister. "Feces of feedlot cattle contain a diversity of bacteriophages that lyse non-O157 Shiga toxin-producing Escherichia coli". Canadian Journal of Microbiology 61, n. 7 (luglio 2015): 467–75. http://dx.doi.org/10.1139/cjm-2015-0163.

Testo completo

Abstract (sommario):

This study aimed to isolate and characterize bacteriophages that lyse non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces. Of 37 non-O157 STEC-infecting phages isolated, those targeting O26 (AXO26A, AYO26A, AYO26B), O103 (AXO103A, AYO103A), O111 (AXO111A, AYO111A), O121 (AXO121A, AXO121B), and O145 (AYO145A, AYO145B) were further characterized. Transmission electron microscopy showed that the 11 isolates belonged to 3 families and 6 genera: the families Myoviridae (types rV5, T4, ViI, O1), Siphoviridae (type T5), and Podoviridae (type T7). Genome size of the phages as determined by pulsed-field gel electrophoresis ranged from 38 to 177 kb. Excluding phages AXO26A, AYO103A, AYO145A, and AYO145B, all other phages were capable of lysing more than 1 clinically important strain from serogroups of O26, O91, O103, O111, O113, O121, and O128, but none exhibited infectivity across all serogroups. Moreover, phages AYO26A, AXO121A, and AXO121B were also able to lyse 4 common phage types of STEC O157:H7. Our findings show that a diversity of non-O157 STEC-infecting phages are harbored in bovine feces. Phages AYO26A, AYO26B, AXO103A, AXO111A, AYO111A, AXO121A, and AXO121B exhibited a broad host range against a number of serogroups of STEC and have potential for the biocontrol of STEC in the environment.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Monteiro-Neto, Valério, Leila Carvalho Campos, Antonio José Piantino Ferreira, Tânia Aparecida Tardelli Gomes e Luiz Rachid Trabulsi. "Virulence properties of Escherichia coli O111:H12 strains". FEMS Microbiology Letters 146, n. 1 (17 gennaio 2006): 123–28. http://dx.doi.org/10.1111/j.1574-6968.1997.tb10181.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Torres, Alfredo G., Roberto C. Vazquez-Juarez, Christopher B. Tutt e J. Gerardo Garcia-Gallegos. "Pathoadaptive Mutation That Mediates Adherence of Shiga Toxin-Producing Escherichia coli O111". Infection and Immunity 73, n. 8 (agosto 2005): 4766–76. http://dx.doi.org/10.1128/iai.73.8.4766-4776.2005.

Testo completo

Abstract (sommario):

ABSTRACT The adherence of pathogenic Escherichia coli strains to intestinal epithelium is essential for initiation of infection. The cad operon encodes the lysine decarboxylase (LDC) system responsible for metabolizing lysine, and this operon has been proposed as an antivirulence mechanism in enteroinvasive E. coli and Shigella flexneri and as a factor mediating E. coli O157:H7 adherence. We sought to determine whether the LDC activity was present in a phylogenetically characterized collection of diarrheagenic E. coli (DEC) strains and to establish whether its expression was associated with their adherence to tissue culture cells. LDC activity was found in most of the pathogenic E. coli strains tested and was absent from Shiga toxin-producing E. coli (STEC) O111 strains (DEC pathotype 8). Analysis of the cad region in these O111 strains indicates that the operon has been rearranged and some of the genes are either missing or disrupted. A similar rearrangement was found in an E. coli O111:H8 strain recently isolated from an outbreak in Texas. Complementation of the LDC-negative strains with the cad operon in trans restored the LDC activity and resulted in a reduction in adherence to tissue culture cells. Initial analysis of the protein profiles on the surface of the O111 strains indicates that the LDC activity has an effect on the expression of the adhesin intimin. Cadaverine had a slight effect on LDC-negative strain adhesion but none on intimin expression. Our data suggest that this pathoadaptive mutation is an important mechanism to control functions potentially implicated in the pathogenesis of these organisms.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Zhao, Shaohua, David G. White, Beilei Ge, Sherry Ayers, Sharon Friedman, Linda English, David Wagner, Stuart Gaines e Jianghong Meng. "Identification and Characterization of Integron-Mediated Antibiotic Resistance among Shiga Toxin-Producing Escherichia coli Isolates". Applied and Environmental Microbiology 67, n. 4 (1 aprile 2001): 1558–64. http://dx.doi.org/10.1128/aem.67.4.1558-1564.2001.

Testo completo

Abstract (sommario):

ABSTRACT A total of 50 isolates of Shiga toxin-producing Escherichia coli (STEC), including 29 O157:H7 and 21 non-O157 STEC strains, were analyzed for antimicrobial susceptibilities and the presence of class 1 integrons. Seventy-eight (n = 39) percent of the isolates exhibited resistance to two or more antimicrobial classes. Multiple resistance to streptomycin, sulfamethoxazole, and tetracycline was most often observed. Class 1 integrons were identified among nine STEC isolates, including serotypes O157:H7, O111:H11, O111:H8, O111:NM, O103:H2, O45:H2, O26:H11, and O5:NM. The majority of the amplified integron fragments were 1 kb in size with the exception of one E. coli O111:H8 isolate which possessed a 2-kb amplicon. DNA sequence analysis revealed that the integrons identified within the O111:H11, O111:NM, O45:H2, and O26:H11 isolates contained the aadA gene encoding resistance to streptomycin and spectinomycin. Integrons identified among the O157:H7 and O103:H2 isolates also possessed a similaraadA gene. However, DNA sequencing revealed only 86 and 88% homology, respectively. The 2-kb integron of the E. coli O111:H8 isolate contained three genes, dfrXII,aadA2, and a gene of unknown function, orfF, which were 86, 100, and 100% homologous, respectively, to previously reported gene cassettes identified in integrons found inCitrobacter freundii and Klebsiella pneumoniae. Furthermore, integrons identified among the O157:H7 and O111:NM strains were transferable via conjugation to another strain of E. coli O157:H7 and to several strains of Hafnia alvei. To our knowledge, this is the first report of integrons and antibiotic resistance gene cassettes in STEC, in particular E. coliO157:H7.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Lima, Paulo Gomes de, Thalita Martins da Silva, Luciana Maria Ramires Esper, Alice Gonçalves Martins Gonzalez e Robson Maia Franco. "Viabilidade de Escherichia coli O153:H25, O113:H21 e O111:H8 (STEC não-O157) produtoras de toxina Shiga em queijo minas frescal". Ciência Rural 45, n. 1 (gennaio 2015): 52–57. http://dx.doi.org/10.1590/0103-8478cr20131678.

Testo completo

Abstract (sommario):

A existência de um reservatório animal é de grande importância na transmissão de Escherichia coli, produtora de toxina shiga (STEC) aos humanos. Epidemiologicamente, o sorotipo O157:H7 tem sido o mais envolvido em surtos de doença humana causada por STEC, porém surtos envolvendo STEC não pertencentes ao sorogrupo O157 (STEC não-O157) têm sido descritos. Inúmeros trabalhos constatam uma elevada ocorrência destes microrganismos em fezes de bovinos no Brasil, entretanto, pouco se sabe sobre a transmissão destes aos produtos de origem animal em nosso país. Neste trabalho, foi avaliada a viabilidade de E.coli O153:H25; O113:H21 e O111:H8 em Queijo Minas Frescal (QMF), produzido com inóculos de STEC não O157: H7 e armazenados a 8ºC. Realizaram-se contagens de E. coli e psicrotróficos totais após o processamento do queijo e com intervalos de sete e quinze dias. Foi observado aumento nas contagens de E. coli STEC não O157: H7 e psicrotróficos totais logo após o processamento do QMF, bem como durante o armazenamento a 8ºC, temperatura máxima recomendada pela legislação brasileira. Demonstra-se que, caso haja contaminação da matéria-prima com STEC não O157: H7 (deste estudo), o processamento do QMF não elimina os microrganismos e a temperatura máxima recomendada pela legislação não inibe a multiplicação bacteriana, mantendo-se o risco à população. Reforça-se, portanto, a atenção à qualidade da matéria-prima, das ferramentas de qualidade no campo e na indústria de alimentos para garantir a inocuidade do produto final

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Wang, Lei, Heather Curd, Wenjia Qu e Peter R. Reeves. "Sequencing of Escherichia coli O111 O-Antigen Gene Cluster and Identification of O111-Specific Genes". Journal of Clinical Microbiology 36, n. 11 (1998): 3182–87. http://dx.doi.org/10.1128/jcm.36.11.3182-3187.1998.

Testo completo

Abstract (sommario):

Shiga toxin (Stx)-producing Escherichia coli strains of serogroup O111 are the most frequently isolated non-O157 strains causing outbreaks of gastroenteritis with hemolytic-uremic syndrome. The O111 O-antigen gene cluster had been cloned and about half of it has been sequenced; we have now sequenced the remainder of the gene cluster, which is 12.5 kb in length and which comprises 11 genes. On the basis of sequence similarity, we have identified all the O-antigen genes expected, including five sugar biosynthetic pathway genes, three transferase genes, the O-unit flippase gene, and the O-antigen polymerase gene. By PCR testing with E. coli strains representing all 166 O-antigen forms, some randomly selected gram-negative bacteria, and Salmonella enterica serovar Adelaide, we showed that four O-antigen genes are highly specific to O111. This work provides the basis for a sensitive test for the rapid detection of E. coli O111. This is important both for decisions related to patient care, because early treatment may reduce the risk of life-threatening complications, and for the detection of sources of contamination.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

DebRoy, Chitrita, Elisabeth Roberts, James Kundrat, Michael A. Davis, Connie E. Briggs e Pina M. Fratamico. "Detection of Escherichia coli Serogroups O26 and O113 by PCR Amplification of the wzx and wzy Genes". Applied and Environmental Microbiology 70, n. 3 (marzo 2004): 1830–32. http://dx.doi.org/10.1128/aem.70.3.1830-1832.2004.

Testo completo

Abstract (sommario):

ABSTRACT PCR-based assays for detecting enterohemorrhagic Escherichia coli serogroups O26 and O113 were developed by targeting the wzx (O-antigen flippase) and the wzy (O-antigen polymerase) genes found in the O-antigen gene cluster of each organism. The PCR assays were specific for the respective serogroups, as there was no amplification of DNA from non-O26 and non-O113 E. coli serogroups or from other bacterial genera tested. Using the PCR assays, we were able to detect the organisms in seeded apple juice inoculated at concentration levels as low as ≤10 CFU/ml. The O26- and O113-specific PCR assays can potentially be used for typing E. coli O26 and O113 serogroups; these assays will offer an advantage to food and environmental microbiology laboratories in terms of identifying these non-O157 serogroups by replacing antigen-based serotyping.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Karama, Musafiri, e Carlton L. Gyles. "Virulence Profiling of Shiga Toxin-Producing Escherichia coli O111:NM Isolates from Cattle". Applied and Environmental Microbiology 79, n. 13 (19 aprile 2013): 4164–65. http://dx.doi.org/10.1128/aem.00294-13.

Testo completo

Abstract (sommario):

ABSTRACTShiga toxin-producingEscherichia coli(STEC) O111:NM is an important serotype that has been incriminated in disease outbreaks in the United States. This study characterized cattle STEC O111:NM for virulence factors and markers by PCR. Major conclusions are that STEC O111:NM characterized in this study lacksstx2and the full spectrum ofnlegene markers, and it has an incomplete OI-122.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

DESMARCHELIER, PATRICIA M. "Enterohemorrhagic Escherichia coli—The Australian Perspective†". Journal of Food Protection 60, n. 11 (1 novembre 1997): 1447–50. http://dx.doi.org/10.4315/0362-028x-60.11.1447.

Testo completo

Abstract (sommario):

Food borne transmission of hemolytic uremic syndrome (HUS) was first reported in Australia in 1995 when an outbreak of HUS due to Escherichia coli O111 occurred following the consumption of locally produced mettwurst. Federal and state health and food authorities responded rapidly to bring the outbreak under control. Longer-term responses include the introduction by regulatory authorities of a code of practice for uncooked fermented comminuted meat products, the provision of government and industry funds to support the implementation of this code, and research into the ecology and epidemiology of enterohemorrhagic Escherichia coli and the safe production of meat. In addition, general awareness has increased, and activities in food safety control among all sectors has been stimulated. The pattern of EHEC serotypes in the Australian human and animal populations appears different from that in countries in the Northern Hemisphere. Serotype O157:H7 is not the predominant serotype isolated. Other serotypes, including O111, are more common and possess a variety of virulence-associated determinants. Research into food safety and EHEC is therefore aimed at the development of detection methods more appropriate for the Australian situation. Additional research objectives include determining both the prevalence of EHEC in meat and the meat animal population and farming and handling practices that influence EHEC carriage and transmission. These activities will contribute to an assessment of the hazards presented by EHEC in Australia and recommendations for their control.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

KANKI, MASASHI, KAZUKO SETO e YUKO KUMEDA. "Simultaneous Immunomagnetic Separation Method for the Detection of Escherichia coli O26, O111, and O157 from Food Samples". Journal of Food Protection 77, n. 1 (1 gennaio 2014): 15–22. http://dx.doi.org/10.4315/0362-028x.jfp-13-225.

Testo completo

Abstract (sommario):

We performed a simultaneous immunomagnetic separation (IMS) assay on Shiga toxin–producing Escherichia coli (STEC) serogroups O26, O111, and O157 with immunobeads coated with O26, O111, or O157 antibodies that were simultaneously added to an aliquot of food culture. We also compared the usefulness of CHROMagar STEC medium against various selective isolation agars designed to test for the three serogroups. Samples of sliced beef, ground beef, and radish sprout were artificially contaminated with STEC O26, O111, and O157 strains after incubation in enrichment broth and were subjected to conventional and simultaneous IMS assays. Simultaneous IMS did not affect the sensitivity of target cell detection. For STEC O26, O111, and O157 inoculated into the enriched samples of sliced beef and radish sprout, the detection ability of CHROMagar STEC was similar to or exceeded that of other isolation agars. However for STEC O157 inoculated into ground beef cultures, cefixime tellurite sorbitol MacConkey agar (CT-SMAC) was the superior detection medium. The performance of simultaneous IMS combined with CT-SMAC and CHROMagar STEC detection is similar to that of the Japanese standard method for isolating E. coli O26, O111, and O157. However, the proposed approach involves the same time, materials, and labor costs as the standard E. coli O157 reference procedure but allows detection of three E. coli serotypes rather than a single strain.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Luck, Shelley N., Luminita Badea, Vicki Bennett-Wood, Roy Robins-Browne e Elizabeth L. Hartland. "Contribution of FliC to Epithelial Cell Invasion by Enterohemorrhagic Escherichia coli O113:H21". Infection and Immunity 74, n. 12 (18 settembre 2006): 6999–7004. http://dx.doi.org/10.1128/iai.00435-06.

Testo completo

Abstract (sommario):

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) O113:H21 can invade epithelial cells. In this study, we found that invasion but not adherence was inhibited by anti-FliCH21 specific antibodies. In addition, deletion of fliCH21 from EHEC O113:H21 resulted in an eightfold decrease in invasion that was restored upon transcomplementation with fliCH21 but not with fliCH6 . These results suggested that FliC plays an important role in the pathogenesis of infections caused by EHEC O113:H21 by allowing bacteria to penetrate the intestinal epithelium.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Akarsu, Eyup S., e Soner Mamuk. "Escherichia coli lipopolysaccharides produce serotype-specific hypothermic response in biotelemetered rats". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 292, n. 5 (maggio 2007): R1846—R1850. http://dx.doi.org/10.1152/ajpregu.00786.2006.

Testo completo

Abstract (sommario):

We investigated whether LPS-induced hypothermia develops in a serotype-specific manner in biotelemetered conscious rats. Two different Escherichia coli serotypes of LPSs were injected at a dose of 250 μg/kg ip. E. coli O55:B5 LPS elicited an initial hypothermia and subsequent fever, but E. coli O111:B4 LPS caused more potent monophasic hypothermia. Serum tumor necrosis factor (TNF)-α levels were dramatically elevated at the initial phase of the hypothermia induced by both LPSs. This elevation tended to subside at the nadir of E. coli O55:B5 LPS-induced response but progressively increased at the nadir of E. coli O111:B4 LPS hypothermia. Serum IL-10 levels were moderately elevated at the initial phase of the hypothermia and persisted at the same level at the nadir of each LPS-induced response. No change was observed at the serum IL-18 levels. A selective cyclooxygenase (COX)-1 enzyme inhibitor, valeryl salicylate (20 mg/kg sc), abolished the hypothermia without any effect on the elevated cytokine levels. Another COX-1-selective inhibitor, 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole (SC-560; 1 mg/kg sc) inhibited hypothermic responses as well. Meanwhile, cytokine levels were also reduced by SC-560 treatment. These findings suggest that LPS-induced hypothermia may have serotype-specific characteristics in rats. E. coli O111:B4 LPS has more potent hypothermic activity than E. coli O55:B5 LPS; that may presumably be related to its higher or sustained capability to release antipyretic cytokines, such as TNF-α. COX-1 enzyme may be involved in the generation of the hypothermia, regardless of the type of LPS administered.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Blanco, Jorge, Miguel Blanco, Jesus E. Blanco, Azucena Mora, Enrique A. Gonzalez, Maria I. Bernardez, Maria P. Alonso et al. "Verotoxin-Producing Escherichia coli in Spain: Prevalence, Serotypes, and Virulence Genes of O157:H7 and Non-O157 VTEC in Ruminants, Raw Beef Products, and Humans". Experimental Biology and Medicine 228, n. 4 (aprile 2003): 345–51. http://dx.doi.org/10.1177/153537020322800403.

Testo completo

Abstract (sommario):

In Spain, as in many other countries, verotoxin-producing Escherichia coli (VTEC) strains have been frequently isolated from cattle, sheep, and foods. VTEC strains have caused seven outbreaks in Spain (six caused by E. coli O157:H7 and one by E. coli O111:H– [nonmotile]) in recent years. An analysis of the serotypes indicated serological diversity. Among the strains isolated from humans, serotypes O26:H11, O111:H–, and O157:H7 were found to be more prevalent. The most frequently detected serotypes in cattle were O20:H19, O22:H8, O26:H11, O77:H41, O105:H18, O113:H21, O157:H7, O171:H2, and OUT (O untypeable):H19. Different VTEC serotypes (e.g., O5:H–, O6:H10, O91:H–, O117:H–, O128:H–, O128:H2, O146:H8, O146:H21, O156:H–, and OUT:H21) were found more frequently in sheep. These observations suggest a host serotype specificity for some VTEC. Numerous bovine and ovine VTEC serotypes detected in Spain were associated with human illnesses, confirming that ruminants are important reservoirs of pathogenic VTEC. VTEC can produce one or two toxins (VT1 and VT2) that cause human illnesses. These toxins are different proteins encoded by different genes. Another virulence factor expressed by VTEC is the protein intimin that is responsible for intimate attachment of VTEC and effacing lesions in the intestinal mucosa. This virulence factor is encoded by the chromosomal gene eae. The eae gene was found at a much less frequency in bovine (17%) and ovine (5%) than in human (45%) non-O157 VTEC strains. This may support the evidence that the eae gene contributes significantly to the virulence of human VTEC strains and that many animal non-O157 VTEC strains are less pathogenic to humans.

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Morabito, Stefano, Helge Karch, Patrizia Mariani-Kurkdjian, Herbert Schmidt, Fabio Minelli, Edouard Bingen e Alfredo Caprioli. "Enteroaggregative, Shiga Toxin-ProducingEscherichia coli O111:H2 Associated with an Outbreak of Hemolytic-Uremic Syndrome". Journal of Clinical Microbiology 36, n. 3 (1998): 840–42. http://dx.doi.org/10.1128/jcm.36.3.840-842.1998.

Testo completo

Abstract (sommario):

Shiga toxin-producing Escherichia coli O111:H2 strains from an outbreak of hemolytic-uremic syndrome showed aggregative adhesion to HEp-2 cells and harbored large plasmids which hybridized with the enteroaggregative E. coli probe PCVD432. These strains present a novel combination of virulence factors and might be as pathogenic to humans as the classic enterohemorrhagic E. coli.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Tarr, Cheryl L., e Thomas S. Whittam. "Molecular Evolution of the Intimin Gene in O111 Clones of Pathogenic Escherichia coli". Journal of Bacteriology 184, n. 2 (15 gennaio 2002): 479–87. http://dx.doi.org/10.1128/jb.184.2.479-487.2002.

Testo completo

Abstract (sommario):

ABSTRACT Intimin is an important virulence factor in two groups of enteric pathogens: enteropathogenic Escherichia coli (EPEC), which is a major cause of infant diarrhea in the developing world, and enterohemorrhagic E. coli (EHEC), which has caused large food-borne outbreaks of hemorrhagic colitis in the United States and other developed countries. Intimin is encoded on a 35-kb pathogenicity island called the locus of enterocyte effacement (LEE). At least five antigenic types have been described for the highly variable gene, and each type is generally characteristic of particular evolutionary lineages. We determined the nucleotide sequences of intimin and other LEE genes in two O111 clones that have not been amenable to typing. The sequences from both O111:H8 and O111:H9 differed from the Int-β that is typical of other clones in the same evolutionary lineage. The sequence from the O111:H8 strains was a mosaic of divergent segments that alternately clustered with Int-α, Int-β, or Int-γ. The sequence from the O111:H9 clone consistently showed a close relationship with that from E2348/69, a distantly related strain that expresses Int-α. The results suggest that there have been multiple acquisitions of the LEE in the EHEC 2/EPEC 2 clonal lineage, with a recent turnover in either O111:H8 or its close relatives. Amino acid substitutions that alter residue charge occurred more frequently than would be expected under random substitution in the extracellular domains of intimin, suggesting that diversifying selection has promoted divergence in this region of the protein. An N-terminal domain that presumably functions in the periplasm may also be under positive selection.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Hornitzky, Michael A., Kim Mercieca, Karl A. Bettelheim e Steven P. Djordjevic. "Bovine Feces from Animals with Gastrointestinal Infections Are a Source of Serologically Diverse Atypical Enteropathogenic Escherichia coli and Shiga Toxin-Producing E. coli Strains That Commonly Possess Intimin". Applied and Environmental Microbiology 71, n. 7 (luglio 2005): 3405–12. http://dx.doi.org/10.1128/aem.71.7.3405-3412.2005.

Testo completo

Abstract (sommario):

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) cells were isolated from 191 fecal samples from cattle with gastrointestinal infections (diagnostic samples) collected in New South Wales, Australia. By using a multiplex PCR, E. coli cells possessing combinations of stx 1, stx 2, eae, and ehxA were detected by a combination of direct culture and enrichment in E. coli (EC) (modified) broth followed by plating on vancomycin-cefixime-cefsulodin blood (BVCC) agar for the presence of enterohemolytic colonies and on sorbitol MacConkey agar for the presence of non-sorbitol-fermenting colonies. The high prevalence of the intimin gene eae was a feature of the STEC (35 [29.2%] of 120 isolates) and contrasted with the low prevalence (9 [0.5%] of 1,692 fecal samples possessed STEC with eae) of this gene among STEC recovered during extensive sampling of feces from healthy slaughter-age cattle in Australia (M. Hornitzky, B. A. Vanselow, K. Walker, K. A. Bettelheim, B. Corney, P. Gill, G. Bailey, and S. P. Djordjevic, Appl. Environ. Microbiol. 68:6439-6445, 2002). Forty-seven STEC serotypes were identified, including O5:H−, O8:H19, O26:H−, O26:H11, O113:H21, O157:H7, O157:H− and Ont:H− which are known to cause severe disease in humans and 23 previously unreported STEC serotypes. Serotypes Ont:H− and O113:H21 represented the two most frequently isolated STEC isolates and were cultured from nine (4.7%) and seven (3.7%) animals, respectively. Fifteen eae-positive E. coli serotypes, considered to represent atypical EPEC, were identified, with O111:H− representing the most prevalent. Using both techniques, STEC cells were cultured from 69 (36.1%) samples and EPEC cells were cultured from 30 (15.7%) samples, including 9 (4.7%) samples which yielded both STEC and EPEC. Culture on BVCC agar following enrichment in EC (modified) broth was the most successful method for the isolation of STEC (24.1% of samples), and direct culture on BVCC agar was the most successful method for the isolation of EPEC (14.1% samples). These studies show that diarrheagenic calves and cattle represent important reservoirs of eae-positive E. coli.

Gli stili APA, Harvard, Vancouver, ISO e altri

30

WIGHT, J. P., P. RHODES, P. A. CHAPMAN, S. M. LEE e P. FINNER. "Outbreaks of food poisoning in adults due to Escherichia coli O111 and campylobacter associated with coach trips to northern France". Epidemiology and Infection 119, n. 1 (agosto 1997): 9–14. http://dx.doi.org/10.1017/s0950268897007620.

Testo completo

Abstract (sommario):

Thirty-seven out of 48 people on a coach excursion to northern France developed gastrointestinal symptoms within 4 days of the trip. Twenty-six had stool samples positive for Escherichia coli O111, 8 were also positive for Campylobacter species, and 1 was positive for campylobacter alone. Strains of E. coli were positive for the effacing and attaching protein (eaeA) gene, but negative for other E. coli virulence genes, and therefore belonged to the enteropathogenic E. coli (EPEC) group. Twenty-two out of 37 people in a second party which followed the same itinerary 2 weeks later also became ill. One had a stool sample positive for E. coli O111. Analytical epidemiology suggested that the source of infections was a restaurant in northern France at which both parties had eaten.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

EKIRI, ABEL B., DOUGLAS LANDBLOM, DAWN DOETKOTT, SUSAN OLET, WEILIN L. SHELVER e MARGARET L. KHAITSA. "Isolation and Characterization of Shiga Toxin–Producing Escherichia coli Serogroups O26, O45, O103, O111, O113, O121, O145, and O157 Shed from Range and Feedlot Cattle from Postweaning to Slaughter". Journal of Food Protection 77, n. 7 (1 luglio 2014): 1052–61. http://dx.doi.org/10.4315/0362-028x.jfp-13-373.

Testo completo

Abstract (sommario):

Cattle are the main reservoirs for Shiga toxin–producing Escherichia coli (STEC) strains. E. coli O26, O45, O103, O111, O121, O145, and O157 are among the STEC serogroups that cause severe foodborne illness and have been declared as adulterants by the U.S. Department of Agriculture, Food Safety and Inspection Service. The objectives of this study were (i) to estimate the prevalence of non-O157 STEC and E. coli O157 in naturally infected beef cows and in steer calves at postweaning, during finishing, and at slaughter and (ii) to test non-O157 STEC isolates for the presence of virulence genes stx1, stx2, eaeA, and ehlyA. Samples were collected from study animals during multiple sampling periods and included fecal grabs, rectal swabs, and midline sponge samples. Laboratory culture, PCR, and multiplex PCR were performed to recover and identify E. coli and the virulence genes. The prevalence of non-O157 STEC (serogroups O26, O45, O103, O111, O121, O113, and O145) fecal shedding ranged from 8% (4 of 48 samples) to 39% (15 of 38 samples) in cows and 2% (1 of 47 samples) to 38% (9 of 24 samples) in steer calves. The prevalence of E. coli O157 fecal shedding ranged from 0% (0 of 38 samples) to 52% (25 of 48 samples) in cows and 2% (1 of 47 samples) to 31% (15 of 48 samples) in steer calves. In steer calves, the prevalence of non-O157 STEC and E. coli O157 was highest at postweaning, at 16% (15 of 96 samples) and 23% (22 of 96 samples), respectively. Among the 208 non-O157 STEC isolates, 79% (164 isolates) had stx1, 79% (165 isolates) had stx2, and 58% (121 isolates) had both stx1 and stx2 genes. The percentage of non-O157 STEC isolates encoding the eaeA gene was low; of the 165 isolates tested, 8 (5%) were positive for eaeA and 135 (82%) were positive for ehlyA. Findings from this study provide further evidence of non-O157 STEC shedding in beef cows and steer calves particularly at the stage of postweaning and before entry into the feedlot.

Gli stili APA, Harvard, Vancouver, ISO e altri

32

BROOKS, BRIAN W., CHERYL L. LUTZE-WALLACE, BURTON BLAIS, MARTINE GAUTHIER e MYLÈNE DESCHÊNES. "Monoclonal Antibodies to Lipopolysaccharide O Antigens of Enterohemorrhagic Escherichia coli Strains in Serogroups O26, O45, O103, O111, O121, and O145". Journal of Food Protection 78, n. 7 (1 luglio 2015): 1252–58. http://dx.doi.org/10.4315/0362-028x.jfp-14-597.

Testo completo

Abstract (sommario):

Non-O157 enterohemorrhagic Escherichia coli in priority serogroups O26, O45, O103, O111, O121, and O145 are increasingly recognized as important human pathogens. In the present study, a panel of monoclonal antibodies (MAbs) to the lipopolysaccharide O antigens of E. coli in serogroups O26, O45, O103, O111, O121, and O145 was produced. The specificity was evaluated by examining the reactivity of the MAbs with 50 E. coli strains and 42 non–E. coli bacteria, and several MAbs highly specific for E. coli strains in each of the six non-O157 priority serogroups were identified. The use of these highly specific MAbs may be of considerable value for determining whether an E. coli isolate belongs to one of the six priority non-O157 serogroups, for developing specific detection assays for these organisms, and for characterizing the lipopolysaccharide O antigens of isolates in these serogroups.

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Shen, Songhai, Mariola Mascarenhas, Kris Rahn, James B. Kaper e Mohamed A. Karmal. "Evidence for a Hybrid Genomic Island in Verocytotoxin-Producing Escherichia coli CL3 (Serotype O113:H21) Containing Segments of EDL933 (Serotype O157:H7) O Islands 122 and 48". Infection and Immunity 72, n. 3 (marzo 2004): 1496–503. http://dx.doi.org/10.1128/iai.72.3.1496-1503.2004.

Testo completo

Abstract (sommario):

ABSTRACT Genomic O island 122 (OI-122) of the verocytotoxin-producing Escherichia coli (VTEC) strain EDL933 contains four putative virulence genes, Z4321, Z4326, Z4332, and Z4333. However, strain CL3 (serotype O113:H21) contains only Z4321, not the other three genes. To determine whether Z4321 is part of a different genomic island in CL3, a region of 27,293 bp up- and downstream of Z4321 was sequenced and found to contain elements of two different EDL933 genomic islands (OI-48 and OI-122) and a Yersinia pestis-like hemolysin/adhesin gene cluster. The region contained OI-48 genes Z1635, Z1636, and Z1637 at the left terminus and Z1641, Z1642, Z1643, and Z1644 at the right. The middle portion consisted of OI-48 gene Z1640, which was separated into three fragments by genomic segments including the Y. pestis cluster and EDL933 OI-122 genes Z4322, Z4321, and Z4318. In a PCR investigation of 36 VTEC strains of different serotypes, intact Z1640 was present in strains of serotypes O157:H7, O26:H11, O103:H2, O111:NM, and O145:NM, which are associated with hemolytic uremic syndrome and outbreaks. In contrast, fragmented Z1640 was seen in strains of nonepidemic serotypes, such as O91:H21 and O113:H21, and in animal serotypes that have not been associated with human disease, indicating that Z1640 might be a virulence gene.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Bettelheim, K. A., e P. N. Goldwater. "Outbreak of Shiga Toxin-Producing Escherichia coli O111:H8 Infection". Clinical Infectious Diseases 39, n. 1 (1 luglio 2004): 148. http://dx.doi.org/10.1086/421781.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Rivera-Betancourt, Mildred, e James E. Keen. "Murine Monoclonal Antibodies Specific for Lipopolysaccharide of Escherichia coli O26 and O111". Applied and Environmental Microbiology 66, n. 9 (1 settembre 2000): 4124–27. http://dx.doi.org/10.1128/aem.66.9.4124-4127.2000.

Testo completo

Abstract (sommario):

ABSTRACT Monoclonal antibody (MAb) 12F5 reacted with 35 Escherichia coli O26 isolates and cross-reacted with 1 of 365 non-E. coli O26 isolates. MAb 15C4 reacted with 30 E. coliO111 strains and 8 Salmonella O35 strains (possessing identical O antigen) but not with 362 other bacterial strains. Lipopolysaccharide immunoblots confirmed MAb O-antigen specificity.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Arikè Salifou, Chakirath Folakè, Cyrille Boko, Isidore Houaga, Raoul Agossa, Isabelle Ogbankotan, Christie Agonsè Gnonnandé Adèle Ahokpossi, Benoit A. Mehoba, Bernadette M. Konsaka, Serge Gbênagnon Ahounou e Issaka Youssao Abdou Karim. "Prevalence of shiga toxin-producing Escherichia coli O157, O26 and O111 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Benin". Journal of Applied Biosciences 152 (31 agosto 2020): 15667–75. http://dx.doi.org/10.35759/jabs.152.6.

Testo completo

Abstract (sommario):

Objectives: The study aimed to search for E. coli O157 and non-O157 in milk, meat and faeces of cattle, sheep and pigs slaughtered in Cotonou. Methodology and Results: One hundred and Seventy-Five (175) samples including 25 meat, 25 faeces per species and 25 milk from cattle were analysed for E. coli O157; O26 and O111 and the virulence genes were identified by PCR. The SAS software (1998) and the bilateral Z test were used to calculate and compare the identification frequencies. E. coli O157 was identified in 4% of cattle faeces, 4% of sheep faeces, and 20% of beef and, in 20% of milk samples. E. coli O26 was identified in 12% of cattle faeces and, in 8% of beef samples. E. coli O111 was identified at frequencies of 8%, and 12% in faeces of sheep and pigs, respectively. The eae gene was detected in 4% of beef, ovine meat, milk, pig faeces and in sheep faeces. stx1 was detected in 8% of milk, and in 4% of bovine and sheep faeces. The strains possessing the gene were all of E. coli O157 with the exception of one from pig faeces identified as O111. Conclusions and application of findings: The presence of these serogroups of E. coli with virulence genes poses a real food safety problem in Benin. This study findings must be taken into account for risk assessment and management related to the consumption of food of animal origin. Keywords: Benin, E. coli O157, O26, O111, faeces, meat, milk

Gli stili APA, Harvard, Vancouver, ISO e altri

37

dos Santos, Luis Fernando, Kinue Irino, Tânia Mara Ibelli Vaz e Beatriz Ernestina Cabilio Guth. "Set of virulence genes and genetic relatedness of O113 : H21 Escherichia coli strains isolated from the animal reservoir and human infections in Brazil". Journal of Medical Microbiology 59, n. 6 (1 giugno 2010): 634–40. http://dx.doi.org/10.1099/jmm.0.015263-0.

Testo completo

Abstract (sommario):

Escherichia coli strains of serotype O113 : H21 are commonly described as belonging to a Shiga toxin (Stx)-producing E. coli (STEC) pathotype worldwide. Albeit this STEC serotype is frequently identified among cattle and other domestic animals, to the best of our knowledge no human infections associated with STEC O113 : H21 have been registered in Brazil to date. Here, we report the virulence profile and genetic relatedness of a collection of O113 : H21 E. coli strains mainly isolated from the animal reservoir aimed at determining their potential as human pathogens. The strains from the animal reservoir (n=34) were all classified as STEC, whereas the few isolates recovered so far from human diarrhoea (n=3) lacked stx genes. Among the STEC, the stx 2d-activatable gene was identified in 85 % of the strains that also carried lpfA O113, iha, saa, ehxA, subAB, astA, cdt-V, espP, espI and epeA; the human strains harboured only lpfA O113, iha and astA. All the strains except one, isolated from cattle, were genetically classified as phylogenetic group B1. High mass plasmids were observed in 25 isolates, but only in the STEC group were these plasmids confirmed as the STEC O113 megaplasmid (pO113). Many closely related subgroups (more than 80 % similarity) were identified by PFGE, with human isolates clustering in a subgroup separate from most of the animal isolates. In conclusion, potentially pathogenic O113 : H21 STEC isolates carrying virulence markers in common with O113 : H21 clones associated with haemolytic uraemic syndrome cases in other regions were demonstrated to occur in the natural reservoir in our settings, and therefore the risk represented by them to public health should be carefully monitored.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Louie, M., S. Read, A. E. Simor, J. Holland, L. Louie, K. Ziebell, J. Brunton e J. Hii. "Application of Multiplex PCR for Detection of Non-O157 Verocytotoxin-Producing Escherichia coli in Bloody Stools: Identification of Serogroups O26 and O111". Journal of Clinical Microbiology 36, n. 11 (1998): 3375–77. http://dx.doi.org/10.1128/jcm.36.11.3375-3377.1998.

Testo completo

Abstract (sommario):

Primers were designed to amplify sequences of verocytotoxin genes and eaeA genes of Escherichia coli O26:H11, O111:H8, and O157:H7 in a multiplex PCR assay. This assay successfully detected E. coli O26:H11 in bloody stool specimens in which other enteric pathogens were not detected by culture-based methods. Rapid assays to detect non-O157:H7 verocytotoxin-producingE. coli is important to improve methods for the etiologic diagnosis of hemorrhagic colitis.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

MASANA, M. O., B. A. D'ASTEK, P. M. PALLADINO, L. GALLI, L. L. DEL CASTILLO, C. CARBONARI, G. A. LEOTTA, E. VILACOBA, K. IRINO e M. RIVAS. "Genotypic Characterization of Non-O157 Shiga Toxin–Producing Escherichia coli in Beef Abattoirs of Argentina". Journal of Food Protection 74, n. 12 (1 dicembre 2011): 2008–17. http://dx.doi.org/10.4315/0362-028x.jfp-11-189.

Testo completo

Abstract (sommario):

The non-O157 Shiga toxin–producing Escherichia coli (STEC) contamination in carcasses and feces of 811 bovines in nine beef abattoirs from Argentina was analyzed during a period of 17 months. The feces of 181 (22.3%) bovines were positive for non-O157 STEC, while 73 (9.0%) of the carcasses showed non-O157 STEC contamination. Non-O157 STEC strains isolated from feces (227) and carcasses (80) were characterized. The main serotypes identified were O178:H19, O8:H19, O130:H11, and O113:H21, all of which have produced sporadic cases of hemolytic-uremic syndrome in Argentina and worldwide. Twenty-two (7.2%) strains carried a fully virulent stx/eae/ehxA genotype. Among them, strains of serotypes O103:[H2], O145:NM, and O111:NM represented 4.8% of the isolates. XbaI pulsed-field gel electrophoresis pattern analysis showed 234 different patterns, with 76 strains grouped in 30 clusters. Nine of the clusters grouped strains isolated from feces and from carcasses of the same or different bovines in a lot, while three clusters were comprised of strains distributed in more than one abattoir. Patterns AREXSX01.0157, AREXBX01.0015, and AREXPX01.0013 were identified as 100% compatible with the patterns of one strain isolated from a hemolytic-uremic syndrome case and two strains previously isolated from beef medallions, included in the Argentine PulseNet Database. In this survey, 4.8% (39 of 811) of the bovine carcasses appeared to be contaminated with non-O157 STEC strains potentially capable of producing sporadic human disease, and a lower proportion (0.25%) with strains able to produce outbreaks of severe disease.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Minami, S. B., H. Takegoshi, Y. Shinjo e K. Kaga. "Secondary, profound, sensorineural hearing loss after recovery from haemolytic uraemic syndrome due to enterohaemorrhagic Escherichia coli, and subsequent cochlear implantation, in two Japanese children". Journal of Laryngology & Otology 127, n. 3 (14 febbraio 2013): 306–10. http://dx.doi.org/10.1017/s0022215113000145.

Testo completo

Abstract (sommario):

AbstractObjectives:To describe two cases of profound hearing loss secondary to enterohaemorrhagic Escherichia coli infection, and to report the efficacy of subsequent cochlear implantation.Results:The first case was a four-year-old girl admitted to hospital with Escherichia coli O157 infection and haemolytic uraemic syndrome. Mild hearing loss was confirmed five months after discharge, progressing to profound loss three months later. At the age of seven years, she underwent cochlear implantation, with remarkable improvement in speech perception and production. The second case was a three-year-old boy admitted with haemolytic uraemic syndrome caused by Escherichia coli O111 infection. One year after disease onset, profound hearing loss was confirmed. Cochlear implantation at the age of five years produced significant recovery of auditory function.Conclusion:This study represents the first published report of secondary hearing loss after recovery from haemolytic uraemic syndrome caused by enterohaemorrhagic Escherichia coli. It indicates that cochlear implantation can restore hearing function in such patients.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Wang, Lei, e Peter R. Reeves. "The Escherichia coli O111 and Salmonella enterica O35 Gene Clusters: Gene Clusters Encoding the Same Colitose-Containing O Antigen Are Highly Conserved". Journal of Bacteriology 182, n. 18 (15 settembre 2000): 5256–61. http://dx.doi.org/10.1128/jb.182.18.5256-5261.2000.

Testo completo

Abstract (sommario):

ABSTRACT O antigen is part of the lipopolysaccharide present in the outer membrane of gram-negative bacteria. Escherichia coli andSalmonella enterica each have many forms of O antigen, but only three are common to the two species. It has been found that, in general, O-antigen genes are of low GC content. This deviation in GC content from that of typical S. enterica or E. coli genes (51%) is thought to indicate that the O-antigen DNA originated in species other than S. enterica or E. coli and was captured by lateral transfer. The O-antigen structure of Salmonella enterica O35 is identical to that of E. coli O111, commonly found in enteropathogenicE. coli strains. This O antigen, which has been shown to be a virulence factor in E. coli, contains colitose, a 3,6-dideoxyhexose found only rarely in theEnterobacteriaceae. Sequencing of the O35-antigen gene cluster of S. enterica serovar Adelaide revealed the same gene order and flanking genes as in E. coli O111. The divergence between corresponding genes of these two gene clusters at the nucleotide level ranges from 21.8 to 11.7%, within the normal range of divergence between S. enterica and E. coli. We conclude that the ancestor of E. coli andS. enterica had an O antigen identical to the O111 and O35 antigens, respectively, of these species and that the gene cluster encoding it has survived in both species.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Bielaszewska, Martina, Marina Fell, Lilo Greune, Rita Prager, Angelika Fruth, Helmut Tschäpe, M. Alexander Schmidt e Helge Karch. "Characterization of Cytolethal Distending Toxin Genes and Expression in Shiga Toxin-Producing Escherichia coli Strains of Non-O157 Serogroups". Infection and Immunity 72, n. 3 (marzo 2004): 1812–16. http://dx.doi.org/10.1128/iai.72.3.1812-1816.2004.

Testo completo

Abstract (sommario):

ABSTRACT We identified cytolethal distending toxin and its gene (cdt) in 17 of 340 non-O157 Shiga toxin-producing Escherichia coli (STEC) strains (serotypes O73:H18, O91:H21, O113:H21, and O153:H18), all of which were eae negative. cdt is either chromosomal and homologous to cdt-V (serotypes O73:H18, O91:H21, and O113:H21) or plasmidborne and identical to cdt-III (serotype O153:H18). Among eae-negative STEC, cdt was associated with disease (P = 0.003).

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Luck, Shelley N., Vicki Bennett-Wood, Rachael Poon, Roy M. Robins-Browne e Elizabeth L. Hartland. "Invasion of Epithelial Cells by Locus of Enterocyte Effacement-Negative Enterohemorrhagic Escherichia coli". Infection and Immunity 73, n. 5 (maggio 2005): 3063–71. http://dx.doi.org/10.1128/iai.73.5.3063-3071.2005.

Testo completo

Abstract (sommario):

ABSTRACT The majority of enterohemorrhagic Escherichia coli (EHEC) strains associated with severe disease carry the locus of enterocyte effacement (LEE) pathogenicity island, which encodes the ability to induce attaching and effacing lesions on the host intestinal mucosa. While LEE is essential for colonization of the host in these pathogens, strains of EHEC that do not carry LEE are regularly isolated from patients with severe disease, although little is known about the way these organisms interact with the host epithelium. In this study, we compared the adherence properties of clinical isolates of LEE-negative EHEC with those of LEE-positive EHEC O157:H7. Transmission electron microscopy revealed that LEE-negative EHEC O113:H21 was internalized by Chinese hamster ovary (CHO-K1) epithelial cells and that intracellular bacteria were located within a membrane-bound vacuole. In contrast, EHEC O157:H7 remained extracellular and intimately attached to the epithelial cell surface. Quantitative gentamicin protection assays confirmed that EHEC O113:H21 was invasive and also showed that several other serogroups of LEE-negative EHEC were internalized by CHO-K1 cells. Invasion by EHEC O113:H21 was significantly reduced in the presence of the cytoskeletal inhibitors cytochalasin D and colchicine and the pan-Rho GTPase inhibitor compactin, whereas the tyrosine kinase inhibitor genistein had no significant impact on bacterial invasion. In addition, we found that EHEC O113:H21 was invasive for the human colonic cell lines HCT-8 and Caco-2. Overall these studies suggest that isolates of LEE-negative EHEC may employ a mechanism of host cell invasion to colonize the intestinal mucosa.

Gli stili APA, Harvard, Vancouver, ISO e altri

44

KASE, JULIE A., ANNA MAOUNOUNEN-LAASRI e ANDREW LIN. "Rapid Identification of Shiga Toxin–Producing Escherichia coli O Serogroups from Fresh Produce and Raw Milk Enrichment Cultures by Luminex Bead–Based Suspension Array". Journal of Food Protection 79, n. 9 (1 settembre 2016): 1623–29. http://dx.doi.org/10.4315/0362-028x.jfp-16-070.

Testo completo

Abstract (sommario):

ABSTRACT The U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) Chapter 4a describes a Luminex microbead–based suspension array used to screen colonies for 11 clinically relevant Shiga toxin–producing Escherichia coli (STEC) serogroups: O26, O45, O91, O103, O104, O111, O113, O121, O128, O145, and O157. We evaluated the usefulness of this method to identify STEC-positive enrichment samples before agar plating. Twelve E. coli strains were added to three types of fresh produce (bagged baby spinach, alfalfa sprouts, and cilantro) at levels near the detection limit of the test. A subset of these strains (six O serogroups) was similarly evaluated in raw milk. For comparison, portions of each of the 168 enrichment cultures were analyzed for serogroup by a real-time PCR assay and a Bio-Plex 200 assay with the bead-based suspensions. No false-positive results were obtained. Of the 112 samples with a reported cycle threshold (CT) value, 101 undiluted, diluted, or extracted enrichment cultures also produced ratios above 5.0 in the Bio-Plex assay. When PCR CT values approached or were greater than 35, Bio-Plex detection became less reliable. Using undiluted or extracted enrichment cultures resulted in a significantly larger number of positive results. With the same enrichment material prepared for real-time PCR analysis as described in the BAM Chapter 4a, the STEC microbead-based suspension array can accurately screen food enrichment cultures.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Leuvenink, J., A. Bouter, J. H. Marcelis e J. Verhoef. "Characterization and specification of monoclonal antibodies against Escherichia coli O111 and E. coli J5". Antonie van Leeuwenhoek 51, n. 5-6 (1985): 589–90. http://dx.doi.org/10.1007/bf00404576.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Stevenson, Gordon, Manuela Dieckelmann e Peter R. Reeves. "Determination of Glycosyltransferase Specificities for the Escherichia coli O111 O Antigen by a Generic Approach". Applied and Environmental Microbiology 74, n. 4 (21 dicembre 2007): 1294–98. http://dx.doi.org/10.1128/aem.02660-07.

Testo completo

Abstract (sommario):

ABSTRACT We describe a bacterial strain developed to facilitate the determination of glycosyltransferase (GT) specificities for O antigens of known structure and gene cluster sequence. For proof of principle for the approach, the strain was used to determine the specificity of the Escherichia coli O111 O-antigen GT genes.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

ENACHE, ELENA, EMILY C. MATHUSA, PHILIP H. ELLIOTT, D. GLENN BLACK, YUHUAN CHEN, VIRGINIA N. SCOTT e DONALD W. SCHAFFNER. "Thermal Resistance Parameters for Shiga Toxin–Producing Escherichia coli in Apple Juice". Journal of Food Protection 74, n. 8 (1 agosto 2011): 1231–37. http://dx.doi.org/10.4315/0362-028x.jfp-10-488.

Testo completo

Abstract (sommario):

The purpose of the present study was to determine the heat resistance of six non-O157 Shiga toxin–producing Escherichia coli (STEC) serotypes in comparison to E. coli O157:H7 in single-strength apple juice without pulp. The thermal parameters for stationary-phase and acid-adapted cells of E. coli strains from serogroups O26, O45, O103, O111, O121, O145, and O157:H7 were determined by using an immersed coil apparatus. The most heat-sensitive serotype in the present study was O26. Stationary-phase cells for serotypes O145, O121, and O45 had the highest D56°C-value among the six non-O157 serotypes studied, although all were significantly lower (P < 0.05) than that of E. coli O157:H7. At 60°C E. coli O157:H7 and O103 demonstrated the highest D-values (1.37 ± 0.23 and 1.07 ± 0.03 min, respectively). The D62°C for the most heat-resistant strain belonging to the serotype O145 was similar (P > 0.05) to that for the most resistant O157:H7 strain (0.61 ± 0.17 and 0.60 ± 0.09 min, respectively). The heat resistance for stationary-phase cells was generally equal to or higher than that of acid-adapted counterparts. Although E. coli O157:H7 revealed D-values similar to or higher than the individual six non-O157 STEC serotypes in apple juice, the z-values for most non-O157 STEC tested strains were greater than those of E. coli O157:H7. When data were used to calculate heat resistance parameters at a temperature recommended in U.S. Food and Drug Administration guidance to industry, the D71.1°C for E. coli O157:H7 and non-O157 STEC serotypes were not significantly different (P > 0.05).

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Seyahian, E. Abril, Gisela Oltra, Federico Ochoa, Santiago Melendi, Ricardo Hermes, James C. Paton, Adrienne W. Paton et al. "Systemic effects of Subtilase cytotoxin produced by Escherichia coli O113:H21". Toxicon 127 (marzo 2017): 49–55. http://dx.doi.org/10.1016/j.toxicon.2016.12.014.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Šafařikova, M., e I. Šafařik. "Immunomagnetic separation of Escherichia coli O26, O111 and O157 from vegetables". Letters in Applied Microbiology 33, n. 1 (luglio 2001): 36–39. http://dx.doi.org/10.1046/j.1472-765x.2001.00941.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

50

HORNITZKY, MA, KA BETTELHEIM e SP DJORDJEVIC. "The isolation of enterohaemorrhagic Escherichia coli O111:H-from Australian cattle". Australian Veterinary Journal 78, n. 9 (settembre 2000): 636–37. http://dx.doi.org/10.1111/j.1751-0813.2000.tb11941.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Articoli di riviste sul tema "Escherichia coli O1113"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili