Academic literature on the topic 'Streptococcus uberis'
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Journal articles on the topic "Streptococcus uberis"
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ZADOKS, R. N., R. N. GONZÁLEZ, K. J. BOOR, and Y. H. SCHUKKEN. "Mastitis-Causing Streptococci Are Important Contributors to Bacterial Counts in Raw Bulk Tank Milk." Journal of Food Protection 67, no. 12 (December 1, 2004): 2644–50. http://dx.doi.org/10.4315/0362-028x-67.12.2644.
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The objective of this study was to probe the contribution of streptococci to the microbial quality of raw milk. Over a 5-month period, bulk tank milk samples from 48 New York State dairy farms were analyzed qualitatively for bacterial ecology and quantitatively for total bacterial, streptococcal, staphylococcal, and gram-negative bacterial counts. Linear regression analysis was used to determine the contribution of differential counts to total bacterial counts. Streptococci, staphylococci, and gram-negative bacteria accounted for 69, 3, and 3% of total bacterial count variability, respectively. Randomly selected Streptococcus isolates from each bulk tank milk sample were identified to species by means of the API 20 STREP identification system. The most commonly identified streptococcal species were Streptococcus uberis, Aerococcus viridans, and Streptococcus agalactiae, which were detected in 81, 50, and 31% of 48 bulk tank samples, respectively. For five herds, S. uberis isolates from bulk tank milk and individual cows were characterized by PvuII ribotyping. A farm-specific dominant ribotype was found in each bulk tank sample, and that ribotype was isolated from at least one cow within each herd of origin. Bacteriological and strain typing data indicate that control of streptococci, specifically mastitis-causing species, is important for improvement of the microbial quality of raw milk in New York State.
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Haenni, Marisa, Laure Galofaro, Mathilde Ythier, Marlyse Giddey, Paul Majcherczyk, Philippe Moreillon, and Jean-Yves Madec. "Penicillin-Binding Protein Gene Alterations in Streptococcus uberis Isolates Presenting Decreased Susceptibility to Penicillin." Antimicrobial Agents and Chemotherapy 54, no. 3 (January 11, 2010): 1140–45. http://dx.doi.org/10.1128/aac.00915-09.
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ABSTRACT Streptococcus uberis is an environmental pathogen commonly causing bovine mastitis, an infection that is generally treated with penicillin G. No field case of true penicillin-resistant S. uberis (MIC > 16 mg/liter) has been described yet, but isolates presenting decreased susceptibility (MIC of 0.25 to 0.5 mg/liter) to this drug are regularly reported to our laboratory. In this study, we demonstrated that S. uberis can readily develop penicillin resistance in laboratory-evolved mutants. The molecular mechanism of resistance (acquisition of mutations in penicillin-binding protein 1A [PBP1A], PBP2B, and PBP2X) was generally similar to that of all other penicillin-resistant streptococci described so far. In addition, it was also specific to S. uberis in that independent resistant mutants carried a unique set of seven consensus mutations, of which only one (Q554E in PBP2X) was commonly found in other streptococci. In parallel, independent isolates from bovine mastitis with different geographical origins (France, Holland, and Switzerland) and presenting a decreased susceptibility to penicillin were characterized. No mosaic PBPs were detected, but they all presented mutations identical to the one found in the laboratory-evolved mutants. This indicates that penicillin resistance development in S. uberis might follow a stringent pathway that would explain, in addition to the ecological niche of this pathogen, why naturally occurring resistances are still rare. In addition, this study shows that there is a reservoir of mutated PBPs in animals, which might be exchanged with other streptococci, such as Streptococcus agalactiae, that could potentially be transmitted to humans.
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REIDMILLER, JEFFREY S., WAYNE L. SMITH, MARY M. SAWYER, BENNIE I. OSBURN, JEFFERY L. STOTT, and JAMES S. CULLOR. "Antimicrobial Properties of the Chelating Agent EDTA on Streptococcal Bovine Mastitis Isolates." Journal of Food Protection 69, no. 6 (June 1, 2006): 1460–62. http://dx.doi.org/10.4315/0362-028x-69.6.1460.
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To determine the efficacy of the chelating agent EDTA on microbial growth, separate cultures of two streptococcal bovine mastitis isolates, Streptococcus agalactiae and Streptococcus uberis, were exposed to known concentrations of EDTA. Bacterial cultures of 108 CFU/ml were exposed to concentrations of EDTA ranging from 30 to 100 mM in an in-vitro-milk environment. Multiple replications of cultures exposed to EDTA were plated during a two-hour time course. A concentration of 100 mM EDTA resulted in a 90% reduction of S. agalactiae and a 99% reduction of S. uberis. Under these experimental conditions, EDTA treatments in cultures of both isolates exhibited from 1 to 2 log reductions suggesting that EDTA is a potentially effective antimicrobial against streptococcal isolates implicated in causing bovine mastitis.
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Varhimo, Emilia, Kirsi Savijoki, Jari Jalava, Oscar P. Kuipers, and Pekka Varmanen. "Identification of a Novel Streptococcal Gene Cassette Mediating SOS Mutagenesis in Streptococcus uberis." Journal of Bacteriology 189, no. 14 (May 18, 2007): 5210–22. http://dx.doi.org/10.1128/jb.00473-07.
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ABSTRACT Streptococci have been considered to lack the classical SOS response, defined by increased mutation after UV exposure and regulation by LexA. Here we report the identification of a potential self-regulated SOS mutagenesis gene cassette in the Streptococcaceae family. Exposure to UV light was found to increase mutations to antibiotic resistance in Streptococcus uberis cultures. The mutational spectra revealed mainly G:C→A:T transitions, and Northern analyses demonstrated increased expression of a Y-family DNA polymerase resembling UmuC under DNA-damaging conditions. In the absence of the Y-family polymerase, S. uberis cells were sensitive to UV light and to mitomycin C. Furthermore, the UV-induced mutagenesis was almost completely abolished in cells deficient in the Y-family polymerase. The gene encoding the Y-family polymerase was localized in a four-gene operon including two hypothetical genes and a gene encoding a HdiR homolog. Electrophoretic mobility shift assays demonstrated that S. uberis HdiR binds specifically to an inverted repeat sequence in the promoter region of the four-gene operon. Database searches revealed conservation of the gene cassette in several Streptococcus species, including at least one genome each of Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus mitis, Streptococcus sanguinis, and Streptococcus thermophilus strains. In addition, the umuC operon was localized in several mobile DNA elements of Streptococcus and Lactococcus species. We conclude that the hdiR-umuC-ORF3-ORF4 operon represents a novel gene cassette capable of mediating SOS mutagenesis among members of the Streptococcaceae.
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Jiang, Min, P. Ronald MacLachlan, Lorne A. Babiuk, Alexandra J. Bolton, and Andrew A. Potter. "The abp locus of Streptococcus uberis encodes a protein homologous to polar amino acid and opine binding proteins of Gram-negative bacteria." Canadian Journal of Microbiology 44, no. 8 (August 1, 1998): 784–88. http://dx.doi.org/10.1139/w98-058.
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A gene locus abp was identified immediately upstream of the CAMP factor gene cfu in Streptococcus uberis. An open reading frame capable of coding for a 277-residue protein was identified. On the basis of sequence characteristics, the abp gene product is potentially a polar amino acid and opine binding component of an ATP-binding cassette type (ABC-type) transport system similar to those of Gram-negative bacteria. This membrane protein is likely lipid modified at its amino terminus and was present in five S. uberis strains and one Streptococcus parauberis strain examined.Key words: bovine mastitis, Streptococcus uberis, amino acid transport.
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Almeida, Raúl A., Oudessa Kerro Dego, Susan I. Headrick, Mark J. Lewis, and Stephen P. Oliver. "Role of Streptococcus uberis adhesion molecule in the pathogenesis of Streptococcus uberis mastitis." Veterinary Microbiology 179, no. 3-4 (September 2015): 332–35. http://dx.doi.org/10.1016/j.vetmic.2015.07.005.
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Dmitriev, A., M. Bhide, and I. Mikula. "cpn60 Gene-Based Multiplex-PCR Assay for Simultaneous Identification of Streptococcal Species." Acta Veterinaria Brno 75, no. 2 (2006): 235–40. http://dx.doi.org/10.2754/avb200675020235.
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The cpn60 genes of Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis were sequenced and a certain polymorphism of cpn60 genes was revealed. Presumable species-specific pairs of primers were designed and their specificity was confirmed by PCR. Based on these data, the cpn60 gene-based multiplex-PCR assay was developed. It was found to be effective for simultaneous identification of S. agalactiae, S. dysgalactiae and S. uberis strains.
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Laven, Richard. "Disease Facts -Streptococcus uberis mastitis." Livestock 16, no. 3 (May 2011): 39–40. http://dx.doi.org/10.1111/j.2044-3870.2011.00037.x.
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Phuektes, Patchara, Glenn F. Browning, Garry Anderson, and Peter D. Mansell. "Multiplex polymerase chain reaction as a mastitis screening test for Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis in bulk milk samples." Journal of Dairy Research 70, no. 2 (May 2003): 149–55. http://dx.doi.org/10.1017/s0022029903006010.
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Effective diagnostic tools for screening herds for mastitis pathogens are important in development and monitoring of mastitis control programmes. A multiplex polymerase chain reaction (PCR) assay for simultaneous detection of Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis was used in preliminary studies to assess its applicability as an alternative method for monitoring mastitis caused by these organisms at the herd level. PCR was used to detect the presence of these organisms in bulk milk samples. Correlations with bulk milk somatic cell counts (BMCC), total bacteria counts and thermoduric bacteria counts were evaluated. A total of 176 bulk milk samples were collected from 42 herds on five consecutive occasions at approx. 10-d intervals. Str. uberis was the most common organism in these bulk milk samples. There was no relationship between presence of either Staph. aureus, Str. dysgalactiae or Str. uberis and BMCC, total bacteria counts or thermoduric bacteria counts. However, presence of Str. agalactiae was associated with high BMCC and total bacteria counts. The results of this study show that regular analysis of bulk milk using this multiplex PCR assay may be a useful tool for monitoring herd status with respect to Str. agalactiae, but is of less value for monitoring occurrence of Staph. aureus, Str. dysgalactiae and Str. uberis. Further investigations are needed to clarify the relationship between positive PCR results and the prevalence of infected cows in the herd.
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Li, Bin, Zhixin Wan, Zhenglei Wang, Jiakun Zuo, Yuanyuan Xu, Xiangan Han, Vanhnaseng Phouthapane, and Jinfeng Miao. "TLR2 Signaling Pathway Combats Streptococcus uberis Infection by Inducing Mitochondrial Reactive Oxygen Species Production." Cells 9, no. 2 (February 21, 2020): 494. http://dx.doi.org/10.3390/cells9020494.
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Mastitis caused by Streptococcus uberis (S. uberis) is a common and difficult-to-cure clinical disease in dairy cows. In this study, the role of Toll-like receptors (TLRs) and TLR-mediated signaling pathways in mastitis caused by S. uberis was investigated using mouse models and mammary epithelial cells (MECs). We used S. uberis to infect mammary glands of wild type, TLR2−/− and TLR4−/− mice and quantified the adaptor molecules in TLR signaling pathways, proinflammatory cytokines, tissue damage, and bacterial count. When compared with TLR4 deficiency, TLR2 deficiency induced more severe pathological changes through myeloid differentiation primary response 88 (MyD88)-mediated signaling pathways during S. uberis infection. In MECs, TLR2 detected S. uberis infection and induced mitochondrial reactive oxygen species (mROS) to assist host in controlling the secretion of inflammatory factors and the elimination of intracellular S. uberis. Our results demonstrated that TLR2-mediated mROS has a significant effect on S. uberis-induced host defense responses in mammary glands as well as in MECs.
Dissertations / Theses on the topic "Streptococcus uberis"
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Pryor, Shona Marie. "Bovine mastitis and ecology of Streptococcus uberis." The University of Waikato, 2008. http://hdl.handle.net/10289/2580.
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Bovine mastitis caused by Streptococcus uberis is a common problem in pasture-based dairying systems. This study examines both the ecology of S. uberis and infection of the bovine mammary gland on a New Zealand dairy farm. Initially, the REP-PCR strain typing method was developed and the potential of MALDI-TOF mass spectrometry evaluated as a strain typing method. While strain-specific mass spectra were obtained with MALDI-TOF mass spectrometry, the irreproducibility of spectra was its major downfall. With further work, this rapid method could be very useful for strain typing S. uberis on a large scale. Using optimised REP-PCR and anchored typing methods, multiple S. uberis strains were isolated and strain typed from the dairy environment, including farm races and paddocks, faeces, teat skin, the cow body and from intramammary infections. High strain diversity was observed in all sampled locations; however, some strains were found at more than one site, suggesting transmission may occur between the environment and cows. The most likely means of S. uberis distribution throughout the dairy farm was via excretion with faeces and, although not all cow faeces contained this pathogen, the gastrointestinal tract of some cows appeared to be colonised by specific strains, resulting in persistent shedding of this bacteria in the faeces. Infection of the mammary gland is likely to occur through contamination of the teat skin with highly diverse environmental strains of S. uberis. However, only one or two strains are generally found in milk from mastitis cases, suggesting that, although infection may arise from a random or opportunistic event, a strain selection process may take place. Intramammary challenge with multiple strains of S. uberis revealed that selection of a single infective strain can occur within the mammary gland. The predominance of one strain over others may be related to production of virulence factors allowing enhanced ability to establish in the gland and evade the immune response, or due to direct competition between strains through the production of antimicrobial factors such as bacteriocins. In addition to strain-specific factors, the individual cow and quarter response may play an important role in the development of infection and selection of the infective strain. Using results from this study, a model of S. uberis strain transmission has been proposed, which includes potential mechanisms of infection and persistence of S. uberis within the mammary gland.
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Gilchrist, Tamara Louise. "Genotypic and phenotypic characterisation of Streptococcus uberis." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2938/.
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Streptococcus uberis is an important bovine mastitis pathogen, which places a significant financial burden upon the dairy industry. Determining the genetic diversity of a collection of field isolates and the mechanisms by which S. uberis colonises the host were the general aims of this project, in particular the determination of the basis for bacterial persistence despite antibacterial therapy. Multi-locus sequence typing identified high levels of recombination within the population, but also a single dominant clonal complex which comprised nearly all sequence types which were isolated from more than one animal. The dominant clonal complex also comprised isolates, derived, however, from both persistent and non-persistent infections, but RAPD typing demonstrated that these isolates can differ in genetic composition elsewhere in the genome. Whole genome sequencing of additional S. uberis isolates confirmed that despite significant homology between much of these genomes, novel genetic material was commonly obtained by phage insertion and horizontal gene transfer. Isolates with identical housekeeping sequences are thus highly likely to differ in their virulence gene repertoires. In this study, the potential for differentiating S. uberis isolates based instead upon protein profiles derived from mass spectrometry of disrupted whole cells was therefore also explored. Differentiation between small numbers of isolates was achieved after optimisation of this protocol, however, discriminatory ability and reproducibility were somewhat compromised when the technique was scaled up to analyse 50 Italian isolates. During the period of study, profile differences between persistent and non-persistent isolates could not be explored. Basic methods were thus also utilised in an attempt to identify factors which promoted bacterial survival in vitro; and a defined medium, representative of the udder environment, was optimised for this purpose. The use of this medium permitted the demonstration that S. uberis was reliant upon magnesium and manganese for proliferation and that, interestingly, the absence of iron did not inhibit bacterial growth. It was also shown that S. uberis had the ability to directly utilise casein, identifying a potential alternative pathway for the acquisition of essential nutrients from nutritionally-limited environments. It was also observed that to a limited extent S. uberis seemed to produce a siderophore. Although this remains to be confirmed, it may correlate with the observation that iron, although not essential for proliferation, improved the growth rate of the bacterium. It was also notable that most novel genes, identified from S. uberis genome sequences, exhibited functions for nutrient metabolism, demonstrating that flexibility in nutrient acquisition is central to the ability of the bacteria to adapt, permitting survival in vastly different environments. The use of the defined medium also demonstrated that S. uberis was able to form biofilms; this ability being variable depending on the growth conditions used and the isolate studied. Most significantly, under conditions representative of the mammary gland, there was an apparent trend for high levels of biofilm formation to correlate with isolates from persistent infections. Biofilm formation by Staphylococcus aureus is considered to be pivotal to the development of chronic mastitis, thus, biofilms may similarly play a role in S. uberis persistence. In an attempt to identify the molecular basis for S. uberis biofilm formation, genes with homology to those of the intercellular adhesion (ica) operon, well described for their involvement in Staphylococcus epidermidis and S. aureus biofilm formation, were identified in the genome sequence of S. uberis 0140J. A targeted mutagenesis protocol was optimised to ‘knock out’ these genes and observe the subsequent effects of these mutations on biofilm formation. During the course of this study, two of these potential biofilm genes (hasA and SUB 0809) were deleted from the S. uberis 0140J chromosome. Surprisingly, deletion of these genes did not retard subsequent biofilm formation, but instead biofilm formation was dramatically improved in the mutant strains. Characterisation of mastitis-causing S. uberis strains and a detailed understanding of the pathogenicity of the organism are required to further the development of a successful vaccine. The research presented in this thesis has increased the knowledge of these important research objectives and optimised techniques which will allow further advancement of knowledge in this field.
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Crowley, Rebecca Clare. "Molecular analysis of biofilm growth in streptococcus uberis." Thesis, University of Sussex, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488613.
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Streptococcus uberis is a major causative agent of bovine intramammary infections worldwide. S. uberis infections can persist for several months and resistance to antibiotic therapies has been observed. At present, the failure to bring S. uberis infections under control has been linked to the current lack of information with regards to S. uberis pathogenesis.
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Rapier, Christopher David. "Characterisation of the plasmin receptor of Streptococcus uberis." Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268981.
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Hossain, Muhammad Maqsud. "Bioinformatic analysis of Streptococcus uberis genes and genomes." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/37355/.
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Streptococcus uberis is a Gram-positive, catalase-negative member of the family Streptococcaceae and is an important environmental pathogen primarily responsible for a significant amount of bovine intramammary infections. This thesis describes the sequencing and comparison of multiple strains from clinical and sub-clinical infections. Following de novo assembly, these are compared to the single reference strain (0140J). The assemblies of strains sequenced with two technologies (Illumina and SOLiD) were compared. From these assemblies, annotation allowed the comparison of gene content, the pan and core genomes and gene gain/loss of coding sequences associated with clustered regularly interspaced short palindromic repeats (CRISPRs), prophage and bacteriocin production. Identification of sequence variants allowed identification of highly conserved and highly variant genes. Inferred intraspecies and interspecies (host-S. uberis) protein-protein interaction networks revealed pathways of bovine proteins enriched with potentially interacting pathogen proteins. These identified known and predicted pathways and also novel interaction partners. This was the first “whole-genome” comparison of multiple S. uberis strains isolated from clinical vs non-clinical intramammary infections including the type virulent vs non-virulent strains. These data allowed the first insight into potential evolutionary forces behind virulence differences.
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Denham, Emma Louise. "Molecular characterisation of lipoprotein processing in Streptococcus uberis." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/30496.
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Streptococcus uberis is a common cause of bovine mastitis and the lipoprotein MtuA has been shown to be essential for growth in milk and virulence. The enzymes responsible for processing lipoproteins in other Gram positive bacteria are lipoprotein diacylglyceryl transferase (Lgt) which acts to anchor lipoproteins to the membrane and lipoprotein signal peptidase (Lsp) which cleaves the signal peptide. S. uberis mutants containing lesions in lgt and lsp uncovered several novel phenotypes. A number of additional proteins were shown to be present in extracellular fractions prepared from lgt- and lgt-/lsp- mutants when compared to the equivalent fraction prepared from wild type bacteria. Atypical processing of MtuA and other lipoproteins within the signal peptide was shown to occur, indicating the presence of an activity capable of shaving such proteins from the membrane in the absence of Lgt and Lsp activity. MtuA was shown to be released into the extracellular space by Wetern blot; the size closely resembled that of wild type protein in both the lgt- and lgt-/lsp- mutants. A metallopeptidase that can be inhibited by phosphoramidon and metal ion chelating agents may be responsible for the activity that results in these proteins being alternatively processed. MtuA in the lsp- mutant had a molecular weight that corresponded to full length MtuA and remained localised in the membrane as seen in the wild type. During late log phase a second form of MtuA with a lower molecular weight was detected. A mutant containing insertions in both lsp and the gene encoding the S. uberis homologue to the Enterococcus faecalis was studied. Enhanced expression of pheromone (eep) suggested that this metallopeptidase was also able to cleave the signal peptide of MtuA.
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Wirawan, Ruth E., and n/a. "An investigation into the antimicrobial repertoire of Streptococcus uberis." University of Otago. Department of Microbiology & Immunology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070312.142108.
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Streptococcus uberis, an environmental organism also associated with dairy animals, is a common and persistent cause of bovine mastitis. New approaches to control these infections need to be identified. One such strategy may be the application of bacteriocins; proteinaceous antimicrobials elaborated by bacteria that typically inhibit the growth of strains closely related to the producer organism. The well-characterized lactococcal bacteriocin nisin is the active ingredient in two commercial products currently in use for the prevention of mastitis. However, reports of resistance development have prompted the investigation of alternative bacteriocins to be used in conjunction with nisin in 'bacteriocin cocktails' designed to have more comprehensive inhibitory activity against mastitis pathogens. The bacteriocins of gram-positive bacteria have been divided into four distinct classes: (I) lantibiotics, (II) non-lantibiotic peptides, (III) large proteins, and (IV) circular peptides.
Although it has been known for more than twenty years that S. uberis commonly produce bacteriocin-like inhibitory substances (BLIS), none had been characterised prior to the present study. The first step in the current investigation was a survey of the BLIS activities of a set of fifteen S. uberis and S. bovis strains against a set of standard indicators as well as common gram-positive mastitis pathogens. Additional tests using a deferred antagonism agar plate-based assay showed that some of the BLIS activities were heat-sensitive and their production was influenced by the presence of either blood or a fermentable carbohydrate source in the test medium. On the basis of the results obtained from these tests it became apparent that S. uberis and S. bovis may commonly produce more than a single inhibitory agent.
S. uberis 42 became the focus of this study because (a) it had broad inhibitory activity against mastitis-associated bacteria, (b) it did not display cross-resistance to nisin, and (c) from the preliminary screening results it appeared to produce both heat-stable and heat-labile inhibitory agents. Acid extracts of S. uberis 42 cells yielded inhibitory activity that, when fractionated by reversed-phase HPLC, yielded a peptide of 3029 Da. Although this peptide was blocked to Edman degradation at position 2, following propanethiol-modification a 20-amino acid sequence was obtained. Degenerate primers to lantibiotic biosynthesis gene homologs were used to initiate inverse PCR and primer walking, ultimately yielding a 15-kb contiguous sequence encompassing 11 genes typical of those involved in lantibiotic synthesis, regulation and immunity. Due to the close similarities to nisin of the S. uberis 42 lantibiotic precursor (78%), and the organisation and composition of the locus, this inhibitor was named nisin U. Nucleotide sequences homologous to insertion sequences were detected in the vicinity of the nisin U locus, and indicate a possible mechanism of acquisition of this locus by S. uberis. The locus was detected in ten other S. uberis, and also in two S. agalactiae and two S. thoraltensis strains, and in one S. porcinus and one S. pluranimalium strain. The amino acid sequences of some of these differed in one or two amino acids, and these variants were named nisin U2 and nisin U3 accordingly. Nisin U, the two nisin U variants, and nisin A exhibited cross-immunity (i.e. all of the producer strains were insensitive to each form of nisin) and cross-inducibility (i.e. all of the producer strains displayed enhanced production when exposed to each form of nisin).
Nisin U did not contribute to the entire spectrum of inhibitory activity of S. uberis 42. Freeze thaw extracts of S. uberis 42 agar cultures yielded heat-labile inhibitory activity that was inhibitory to L. lactis A5, a producer of nisin Z. Subsequent purification by cation-exchange chromatography, gel filtration, and reversed-phase HPLC yielded a peptide of mass 7048 Da, which was resistant to Edman degradation. Digestion with chymotrypsin released an 819 Da peptide fragment of sequence NH₂-KAQAVIW-COOH. Tn916 mutagenesis of S. uberis 42 enabled the identification of the genetic locus of the inhibitor, comprising six genes potentially involved in its biosynthesis and immunity. The detection of a pair of flanking 159-bp direct repeats indicates possible acquisition of the locus by 'long target duplication'. The inhibitor was inferred to be a circular peptide, on the basis of its behaviour to Edman degradation, and by comparison of its locus with that of other circular bacteriocins. On the basis that the purified peptide appears to induce lysis in sensitive bacteria, although by an as-yet unidentified mechanism, the inhibitor was named uberolysin. The uberolysin structural gene was detected in eight other strains of S. uberis, however not all of these appeared to be producing active inhibitor.
No bacteriocins closely resembling the two reported in this thesis have been demonstrated previously to be produced by members of the genus Streptococcus. The remarkable diversity in the structures, activity spectra and basic modes of action of these two bacteriocins produced by a single strain of S. uberis, combined with the observation of apparent greater heterogeneity in properties of a preliminary sampling of BLIS-producing strains, indicates that these bacteria may be an important source of novel antimicrobials of potential value for the treatment of mixed bacterial infections and for minimising potential resistance development.
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Copsey, Sarah Denise. "Characterisation of a metal-ion dependent repressor in Streptococcus uberis." Thesis, University of Sussex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426229.
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Khan, Izhar-ul-Haq. "Identification and further characterization of Streptococcus uberis and Streptococcus parauberis isolated from bovine milk samples." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964881799.
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Vinha, Rita Bronze. "Utilização intramamária de benzilpenicilina procaínica na terapêutica de mamites por Streptococcus uberis." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2020. http://hdl.handle.net/10400.5/20242.
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Dissertação de Mestrado Integrado em Medicina VeterináriaStreptococcus uberis é um agente etiológico de mamites, ubiquitário no ambiente das vacas sendo considerado ambiental, porém com alguma componente contagiosa. Atualmente, é considerado um dos agentes mais preocupantes, que produz mamites tanto subclínicas como clínicas graves e, frequentemente, associadas a contagens de células somáticas (CCS) elevadas. Estas infeções acarretam uma grande dificuldade no processo de cura e as medidas clássicas de controlo de mamites não se demonstram eficazes contra este agente, pois dispõe de vários fatores de virulência. Deste modo, o estudo apresentado visa avaliar a eficácia de várias terapêuticas à base de benzilpenicilina procaínica intramamária (IMM), com diferentes durações, e a vantagem de associar um antibiótico sistémico, neste caso a ampicilina. De forma a proceder a este trabalho, desde dia 16 de setembro de 2019 até 18 de fevereiro de 2020, foram recolhidas amostras de leite de vacas com sinais de mamite, tais como quartos mamários edemaciados e/ou tumefactos e/ou alterações no leite, de várias explorações leiteiras pertencentes à Proleite. Todas as vacas identificadas microbiologicamente com S. uberis foram submetidas a um dos três protocolos terapêuticos em estudo: benzilpenicilina procaínica IMM durante sete dias, uma terapia combinada com ampicilina intramuscular durante cinco dias e outra apenas com administração IMM num período de cinco dias. Assim, através das taxas de cura clínica, analisadas pela CCS, foi percetível que tanto a terapia combinada (57,1%) como o tratamento IMM de sete dias (54,5%) proporcionaram uma taxa de cura razoável, ao contrário da terapêutica IMM de cinco dias (25%). A fase produtiva do animal poderá ter tido alguma influência nas taxas de cura atingidas, já que se verificou que apenas 42,1% das vacas multíparas atingiu a cura clínica. Também a duração destas infeções poderá ter sido limitante, uma vez que somente 35,7% das vacas com IIM prolongada apresentaram cura clínica. Após a aplicação de qualquer protocolo terapêutico foi visível uma diminuição nas células somáticas presentes no leite das vacas afetadas, todavia estas mantêm-se em valores elevados. Quanto à epidemiologia, confirmou-se que S. uberis é bastante prevalente (5,8%), está associado a elevados valores de células somáticas e foi, também, percetível que 77,3% destas mamites ocorrem num período próximo da secagem, que os animais com uma fase produtiva mais avançada são mais suscetíveis (86,4%) e que são normalmente infeções já subclínicas e de longa duração (63,5%).
ABSTRACT - Intramammary use of procaine benzylpenicillin in the treatment of Streptococcus uberis mastitis - Streptococcus uberis is an etiologic agent of mastitis, that is ubiquitous in the environment of cows, so it is considered as an environmental agent, however with a contagious component. Currently, it is considered one of the most worrying agents, which produces both subclinical and severe clinical mastitis, frequently associated with high somatic cell counts (SCC). These infections are known by the problematic healing process and most of the classic control measures do not demonstrate any use against this agent, because it can exhibit several virulence factors. In this way, the study presented aims to evaluate the effectiveness of various therapies based on intramammary (IMM) procaine benzylpenicillin, with different durations and to know the advantage of associating a systemic antibiotic, in this case ampicillin. In order to proceed with the study, from September 16, 2019 to February 18, 2020, milk samples from cows with signs of mastitis, such as swollen teats and/or changes in milk, from various types of dairy farms belonging to Proleite, were collected. All infections microbiologically identified with S. uberis were subjected to one of the three therapeutic protocols under study: procaine benzylpenicillin IMM for seven days, a combination therapy with intramuscular ampicillin for five days and another one with only IMM administration for five days. Thus, trough the clinical cure rates, analyzed by the SCC, it was shown that both, the combination therapy (57,1%) and the seven-day IMM treatment (54,5%), had a reasonable cure rate, in contrast to the five-day IMM therapy (25%). The animal’s productive stage may have some influence on the cure rates achieved, which has been verified because only 42,1% of the multiparous cows achieved the clinical cure. The duration of these infections may also have been a limitation, since only 35,7% of the cows with prolonged IMI showed a clinical cure. After the application of any therapeutic protocol, a reduction in the somatic cells present in the milk of the affected cows was detected, however these remain in high values. Regarding epidemiology, it was confirmed that it is a very prevalent agent (5,8%) and that is associated with high values of somatic cells. It was also noticeable that 77,3% of the S. uberis mastitis occurred close to the drying period, that animals with a more advanced productive stage are more susceptible (86,4%) and that these infections are mostly already subclinical and long lasting (63,5%).
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Book chapters on the topic "Streptococcus uberis"
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Kitt, A. J., and J. A. Leigh. "The Auxotrophic Nature of Streptococcus uberis." In Streptococci and the Host, 647–50. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4899-1825-3_151.
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Lincoln, R. A., and J. A. Leigh. "Characterization of a Novel Plasminogen Activator from Streptococcus uberis." In Streptococci and the Host, 643–45. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4899-1825-3_150.
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Field, T. R., P. M. Norton, A. P. Bland, and J. A. Leigh. "Changes in Bovine Neutrophils Induced by the Capsule of Streptococcus uberis." In Streptococci and the Host, 957–60. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4899-1825-3_225.
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Berger, U. K., C. Haldemann, and W. Schaeren. "Epidemiological and microbiological characteristics of Streptococcus uberis as mastitis pathogen in Swiss dairy herds." In Udder Health and Communication, 349. Wageningen: Wageningen Academic Publishers, 2011. http://dx.doi.org/10.3920/978-90-8686-742-4_67.
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Simjee, S., J. Amedeo, and A. M. Barletta. "Use of Tylan 200® for the treatment of mastitis caused by Staphylococcus aureus and/or Streptococcus uberis." In Udder Health and Communication, 295. Wageningen: Wageningen Academic Publishers, 2011. http://dx.doi.org/10.3920/978-90-8686-742-4_51.
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Simjee, S., J. Amedeo, A. M. Barletta, and A. Pridmore. "Effect of the combination of Tylan 200® & Penicillin G in the treatment of mastitis caused by Staphylococcus aureus and/or Streptococcus uberis." In Udder Health and Communication, 294. Wageningen: Wageningen Academic Publishers, 2011. http://dx.doi.org/10.3920/978-90-8686-742-4_50.
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Shoaib, Muhammad, Amjad Islam Aqib, Muhammad Aamir Naseer, Zeeshan Ahmad Bhutta, Wanxia PU, Qaisar Tanveer, Iqra Muzammil, Muhammad Fakhar-e-Alam Kulyar, Muhammad Salman Younas, and Muhammad Hammad. "Etiology of Bovine Mastitis." In Mastitis [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98543.
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Mastitis in dairy animals is the primary concern of dairy farmers, which is the most common disease that causes huge economic losses in the dairy industry. The economic losses due to mastitis are from a reduction in milk yield, condemnation of milk with antibiotic residues, veterinary treatment costs, and death. In addition, some mastitis pathogens also cause serious human diseases associated with the contamination of milk or milk products with bacteria or their toxins. Bovine mastitis is mainly caused by a wide range of environmental and contagious bacterial mastitis pathogens. Contagious pathogens are those whose main reservoir is the infected udder. Contagious pathogens mainly spread among animals during milking process whereas environmental pathogens spread from environment to udder at any time. The source of the environmental pathogens is the surrounding environment of an animal. The major contagious pathogens include Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. and the minor contagious pathogens include Corynebacterium bovis and others. Major environmental pathogens include coliform bacteria (Escherichia coli, Klebsiella spp., Enterobacter spp. and Citrobacter spp.), environmental streptococci (Strep. dysgalactiae, Strep. uberis). This chapter covers detailed review of published data on contagious and environmental pathogens responsible for bovine mastitis.
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Tolosa Fulasa, Tadele, and Feyissa Begna Deressa. "Bovine Mastitis in Ethiopia." In Mastitis [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99235.
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Ethiopia is located in tropical region and livestock production represents a major national resource and forms an integral part of the Agricultural production system and livelihood of the society. Dairy farming being one of the agricultural production in Ethiopia, is practiced mainly as an extensive type of management system, which involves smallholder farmers in rural areas and semi-intensive and intensive managements in per urban and urban areas. Despite a large number of milking cows, there is low milk production because of many factors, including low genetic potential of indigenous breeds, extensive and poor husbandry practices, and widespread livestock diseases. Among the dairy cows’ diseases, mastitis is prevalent in the dairy production system incurring high economic losses and social burden. Several reports on mastitis in Ethiopia are present but are scattered. We focused on reviewing articles published in indexed journals reporting bovine mastitis to summarize its common etiologies, prevalence, and risk factors in Ethiopia. The common pathogens reported from different parts of Ethiopia are Staphylococcus aureus (Staph. aureus), non-aureus staphylococci, Streptococcus spp. (Strep. agalactiae, Strep. dysgalactiae, Strep. uberis), coliforms (E. coli, Klebsiella pneumonae), Trueperella pyogenes and Mannheimia haemolytica (M. haemolytica), Pseudomonas aeruginosa (P. aeroginosa), Enterobater aerogenes, Bacillus species, Micrococcus species. Staphylococcus aureus and E. coli are the most common isolates from clinical mastitis (CM). Staphylococcus aureus is also the most frequently isolated pathogen from sub-clinical mastitis (SCM). Sub-clinical mastitis which usually ranges from 25.4% to 73.3%, is highly prevalent than the clinical cases of mastitis which ranges from 3.2% to 26.5%. Several mastitis risk factors were reported. These were breed of animals, parity number, stage of lactation, presence of teat/udder lesion and hygiene measure of the farms. Thus, it is essential to plan and implement control measures including maintenance of good dairy farm environment, udder and milking hygiene at farm level; regular monitoring of udder health with special attention to exotic, crossbred and lactating cows and culling of older cows. Isolation, characterization and conducting antibacterial sensitivity test should be integral part of mastitis control strategy for effective control of the mastitis causing pathogens.
Conference papers on the topic "Streptococcus uberis"
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Upadhyay, Shivanck, and Gene R. Pesola. "Streptococcus Uberis, An Unusual Cause Of Community Acquired Pneumonia." In American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California. American Thoracic Society, 2012. http://dx.doi.org/10.1164/ajrccm-conference.2012.185.1_meetingabstracts.a6119.
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Pinto, Vanessa Arantes, Gabriela Santos Alencar, Adriano Favero, Hugo Franciscon, and Fagner Luiz Da Costa Freitas. "POTENCIAL MICROBIOLÓGICO DO SYZYGIUM AROMATICUM (L). SOBRE MICRORGANISMOS DE IMPORTÂNCIA NA MEDICINA VETERINÁRIA." In I Congresso On-line Nacional de Clínica Veterinária de Pequenos Animais. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1920.
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Introdução: O fenômeno de resistência a antimicrobianos está se mostrando um grande problema na saúde, ameaçando tanto a população humana como animal. Devido a isso, a descoberta de novos compostos com capacidade antimicrobiana torna-se imprescindível, e os fitoterápicos têm se mostrado uma alternativa promissora na terapia complementar. O óleo essencial (OE) de Syzygium aromaticum (Cravo da Índia), apresenta potencial capacidade antibacteriana e antifúngica devido às altas concentrações de Eugenol. Objetivos: Avaliar o potencial antimicrobiano do óleo essencial de Syzygium aromaticum (L). contra microrganismos de importância na Medicina veterinária. Materiais e métodos: Foram testadas as bactérias gram positivas: S. aureus LB 25923, S. aureus B24, S. aureus NP 38, Streptococcus uberis, S. agalactiae, Enterococcus faecalis e S. epidermidis; as gram negativas: Pseudomonas aeruginosa ATCC 27853 e E. coli ATCC 25922; e os fungos: C. tropicalis e C. gattii 179. Utilizou-se a técnica de disco difusão (Kirby-bauer) aplicando 10µL de OE, e posteriormente, para os patógenos que apresentaram o halo inibitório, determinou-se, aplicando 15µL de OE, a concentração inibitória mínima (CIM), concentração bactericida mínima (CBM) e concentração fungicida mínima (CFM) através da microdiluição seriada utilizando leitor de ELISA e corante resazurina. Resultados: Todos os microrganismos apresentaram halo inibitório. Com relação aos valores de CIM e CBM para as bactérias, obteve-se, respectivamente: S. aureus LB25923 (18,75% e 18,75%), S. aureus B 24 (4,94% e 4,94%) S. aureus NP 38 (3,64% e 3,64%) Streptococcus uberis (2,60% e 3,125%) S. agalactiae (5,20 %, 5,20%), Enterococcus faecalis (5,20% e 6,25%), S. epidermidis (3,38% e 4,42%), Pseudomonas aeruginosa ATCC 27853 (2,09% e 2,09%), E. coli ATCC 25922 (10,41% e 10,41%). Os resultados de CIM e CFM obtidos para os fungos foram respectivamente: C. tropicalis (1,82% e 1,82%) e C. gattii 179 (5,27% e 5,27%). Conclusão: O óleo essencial de Syzygium aromaticum possui considerável potencial antimicrobiano “in vitro”, e dessa forma, pode ser considerado uma possível alternativa para as terapias sintéticas de tratamento das doenças infecciosas bacterianas e fúngicas encontradas na rotina clínica.
Reports on the topic "Streptococcus uberis"
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Nelson, Corwin, Donald C. Beitz, and John Lippolis. Activation of Vitamin D3 in Bovine Mastitis Caused by Streptococcus uberis. Ames (Iowa): Iowa State University, January 2009. http://dx.doi.org/10.31274/ans_air-180814-951.
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