Journal articles: '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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9

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.

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11

Sladek, Z., D. Rysanek, H. Ryznarova, and M. Faldyna. "The role of neutrophil apoptosis during experimentally induced Streptococcus uberismastitis ." Veterinární Medicína 51, No. 9 (March 27, 2012): 437–47. http://dx.doi.org/10.17221/5571-vetmed.

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The object of the study was to determine if apoptosis of neutrophils and their subsequent elimination from the mammary gland by macrophages are modulated by an infection of Streptococcus uberis. The experiments were carried out in 5 clinically normal Holstein × Bohemian Red Pied crossbred heifers, aged 14 to 18 months. Before the experimental infection mammary glands were stimulated by PBS as a control. The samples of cell populations were obtained by lavages of the mammary glands in 4 intervals (24, 48, 72 and 168 h) after the PBS and after the experimental infection. Flow cytometry was used to determine the Annexin V positive and propidium jodide negative neutrophils (Annexin V+/PI–). The light microscopy was used to determine apoptotic neutrophils and myeloperoxidase (MPO) positive macrophages. After PBS and S. uberis administration the total number of both Annexin V+/PI– neutrophils and karyopycnotic neutrophils peaked at 24 hours. The highest percentages of Annexin V+/PI– neutrophils were detected at 72 h after PBS and S. uberis, respectively. The highest percentages of karyopycnotic neutrophils were detected at 72 h after PBS and 168 h after S. uberis, respectively. The total number of MPO+ macrophages was the highest at 24 h after PBS and 72 h after S. uberis. The percentage of MPO+ macrophages was the highest at 72 h after PBS and S. uberis. The results of this study demonstrate that during experimental infection of the mammary gland by S. uberis, the apoptosis of neutrophils is modulated. Apoptosis of neutrophils and the subsequent phagocytosis of apoptotic neutrophils by macrophages were delayed. This may cause the transition of the acute inflammatory reaction to a chronic state.

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12

Heng, Nicholas C. K., Grace A. Burtenshaw, Ralph W. Jack, and John R. Tagg. "Ubericin A, a Class IIa Bacteriocin Produced by Streptococcus uberis." Applied and Environmental Microbiology 73, no. 23 (October 12, 2007): 7763–66. http://dx.doi.org/10.1128/aem.01818-07.

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ABSTRACT Streptococcus uberis, a causal agent of bovine mastitis, produces ubericin A, a 5.3-kDa class IIa (pediocin-like) bacteriocin, which was purified and characterized. The uba locus comprises two overlapping genes: ubaA (ubericin A precursor peptide) and ubaI (putative immunity protein). Ubericin A is the first streptococcal class IIa bacteriocin to be characterized.

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Vakanjac, Slobodanka, Vojislav Pavlovic, Vladimir Magas, Milos Pavlovic, Miloje Djuric, Milan Maletic, Svetlana Nedic, and Ivan Soco. "Investigations of efficacy of intramammary applied antimicrobials and glucocorticosteroides in the treatment of subclinical and clinical mastitis in cows." Veterinarski glasnik 67, no. 1-2 (2013): 15–27. http://dx.doi.org/10.2298/vetgl1302015v.

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Inflammation of the mammary gland, mastitis in cows, presents one of the most acute problems in intensive dairy production, inflicting huge economic losses. In the course of one year, 80 samples were taken at investigated farms from udder quarters of cows with clinical mastitis and 160 samples from udder quarters of cows with subclinical mastitis. The efficacy of three preparations, A, B, and C, was examined in the treatment of clinical and subclinical mastitis in cows. The investigations indicate that antibiotic preparation A (neomycin, polimixine B, oleandomycin and prednisolone) exhibited a greater efficacy in the treatment of clinical mastitis caused by Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Micrococcus sp., but a smaller efficacy in the treatment of subclinical mastitis caused by Staphylococcus aureus. Preparation B (amoxicillin, clavulanic acid and prednisolone) exhibited a higher efficacy in the treatment of clinical mastitis caused by Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Micrococcus, but a weaker effect in the treatment of subclinical mastitis caused by Staphylococcus aureus. Preparation C (procaine penicillin G, streptomycin, neomycin sulfate and prednisolone acetate) exihibited efficacy in the treatment of clinical and subclinical mastitis caused by Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Micrococcus, Staphylococcus aureus and Esherichie coli.

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Bolte, Josef, Yanchao Zhang, Nicole Wente, and Volker Krömker. "In Vitro Susceptibility of Mastitis Pathogens Isolated from Clinical Mastitis Cases on Northern German Dairy Farms." Veterinary Sciences 7, no. 1 (January 20, 2020): 10. http://dx.doi.org/10.3390/vetsci7010010.

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The present research study investigated the susceptibility of common mastitis pathogens—obtained from clinical mastitis cases on 58 Northern German dairy farms—to routinely used antimicrobials. The broth microdilution method was used for detecting the Minimal Inhibitory Concentration (MIC) of Streptococcus agalactiae (n = 51), Streptococcus dysgalactiae (n = 54), Streptococcus uberis (n = 50), Staphylococcus aureus (n = 85), non-aureus staphylococci (n = 88), Escherichia coli (n = 54) and Klebsiella species (n = 52). Streptococci and staphylococci were tested against cefquinome, cefoperazone, cephapirin, penicillin, oxacillin, cloxacillin, amoxicillin/clavulanic acid and cefalexin/kanamycin. Besides cefquinome and amoxicillin/clavulanic acid, Gram-negative pathogens were examined for their susceptibility to marbofloxacin and sulfamethoxazole/trimethoprim. The examined S. dysgalactiae isolates exhibited the comparatively lowest MICs. S. uberis and S. agalactiae were inhibited at higher amoxicillin/clavulanic acid and cephapirin concentration levels, whereas S. uberis isolates additionally exhibited elevated cefquinome MICs. Most Gram-positive mastitis pathogens were inhibited at higher cloxacillin than oxacillin concentrations. The MICs of Gram-negative pathogens were higher than previously reported, whereby 7.4%, 5.6% and 11.1% of E. coli isolates had MICs above the highest concentrations tested for cefquinome, marbofloxacin and sulfamethoxazole/trimethoprim, respectively. Individual isolates showed MICs at comparatively higher concentrations, leading to the hypothesis that a certain amount of mastitis pathogens on German dairy farms might be resistant to frequently used antimicrobials.

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ERYILDIZ, Canan, Şebnem BUKAVAZ, Şaban GÜRCAN, and Osman HATİPOĞLU. "Mikrobiyoloji Laboratuvarlarında Nadir İzole Edilen Bir Etken: Streptococcus uberis." Mikrobiyoloji Bulteni 51, no. 2 (April 15, 2017): 171–76. http://dx.doi.org/10.5578/mb.40378.

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Murdoch, David R., Lois M. Seawand, and Martin R. MacFarlane. "Human wound infection with streptococcus uberis." Clinical Microbiology Newsletter 19, no. 22 (November 1997): 174–75. http://dx.doi.org/10.1016/s0196-4399(00)89187-4.

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Shewmaker, P. Lynn, Alvin C. Camus, Tim Bailiff, Arnold G. Steigerwalt, Roger E. Morey, and Maria da Glória S. Carvalho. "Streptococcus ictaluri sp. nov., isolated from Channel Catfish Ictalurus punctatus broodstock." International Journal of Systematic and Evolutionary Microbiology 57, no. 7 (July 1, 2007): 1603–6. http://dx.doi.org/10.1099/ijs.0.64810-0.

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A streptococcal-like organism was associated with diseased Channel Catfish Ictalurus punctatus broodstock on four commercial aquaculture operations in the Mississippi Delta. Conventional biochemical testing, 16S rRNA gene sequence analysis and DNA–DNA hybridization distinguished the isolates from these fish from previously published Streptococcus species. Comparative 16S rRNA gene sequencing studies revealed that the isolates were phylogenetically most similar to Streptococcus iniae, Streptococcus uberis and Streptococcus parauberis with divergence ranging from 2.0 to 2.3 %. Streptococcus pyogenes, Streptococcus urinalis, Streptococcus dysgalactiae subsp. dysgalactiae and Streptococcus canis were included in the analysis and showed even greater differences (2.5–3.2 % divergence). DNA relatedness was 22 % or less to the most phylogenetically related species at the optimal temperature. These data suggest that the isolates represent a novel species of Streptococcus for which the name Streptococcus ictaluri sp. nov. is proposed. The type strain is 707-05T (=SO2-1108T=ATCC BAA-1300T=CCUG 52536T).

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OZ, HALIT H., and R. J. FARNSWORTH. "Influence of Addition of Newly Drawn Milk and Fluctuating Temperatures of Farm Bulk Tanks on Growth of Mastitis-Causing Bacteria." Journal of Food Protection 49, no. 1 (January 1, 1986): 54–57. http://dx.doi.org/10.4315/0362-028x-49.1.54.

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Effect of addition of newly drawn fresh milk of consecutive milkings on growth of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis in milk held at fluctuating temperatures of a farm bulk tank for 48 h was studied. There was a statistically insignificant effect of the addition of newly drawn fresh milk of consecutive milkings on the growth rate of S. aureus, S. epidermidis, S. agalactiae and S. uberis but there was a significant (p<0.001) growth enhancing effect on S. dysgalactiae. However, all the bacteria grew significantly (p< 0.001) in milk held at fluctuating temperatures of farm bulk tank for 48 h.

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Kabelitz, Tina, Etienne Aubry, Kira van Vorst, Thomas Amon, and Marcus Fulde. "The Role of Streptococcus spp. in Bovine Mastitis." Microorganisms 9, no. 7 (July 13, 2021): 1497. http://dx.doi.org/10.3390/microorganisms9071497.

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The Streptococcus genus belongs to one of the major pathogen groups inducing bovine mastitis. In the dairy industry, mastitis is the most common and costly disease. It not only negatively impacts economic profit due to milk losses and therapy costs, but it is an important animal health and welfare issue as well. This review describes a classification, reservoirs, and frequencies of the most relevant Streptococcus species inducing bovine mastitis (S. agalactiae, S. dysgalactiae and S. uberis). Host and environmental factors influencing mastitis susceptibility and infection rates will be discussed, because it has been indicated that Streptococcus herd prevalence is much higher than mastitis rates. After infection, we report the sequence of cow immune reactions and differences in virulence factors of the main Streptococcus species. Different mastitis detection techniques together with possible conventional and alternative therapies are described. The standard approach treating streptococcal mastitis is the application of ß-lactam antibiotics. In streptococci, increased antimicrobial resistance rates were identified against enrofloxacin, tetracycline, and erythromycin. At the end, control and prevention measures will be considered, including vaccination, hygiene plan, and further interventions. It is the aim of this review to estimate the contribution and to provide detailed knowledge about the role of the Streptococcus genus in bovine mastitis.

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WANG, S. M., M. A. DEIGHTON, J. A. CAPSTICK, and N. GERRATY. "Epidemiological typing of bovine streptococci by pulsed-field gel electrophoresis." Epidemiology and Infection 123, no. 2 (October 1999): 317–24. http://dx.doi.org/10.1017/s0950268899002745.

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Pulsed-field gel electrophoresis (PFGE) was used to investigate the epidemiology of streptococcal mastitis in dairy cattle. The most prevalent streptococcal species, Streptococcus uberis (60–80% of streptococcal isolates), was highly heterogeneous, with different cows only rarely sharing the same pulsotype. S. agalactiae was rarely encountered, however all eight isolates from one farm generated identical PFGE profiles, which differed from those of all other isolates examined, confirming cow-to-cow transmission. Fifty-two isolates of S. dysgalactiae from 27 cows on 5 farms generated 6 different profiles. However, on individual farms, only one or two pulsotypes usually predominated. This species is generally regarded as an environmental pathogen but our data suggest that cow-to-cow transmission of S. dysgalactiae may occur. In spite of the variation in PFGE profiles of isolates from different cows, persistent infections in individual cows were usually caused by the same pulsotype of S. uberis or S. dysgalactiae.

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Wirawan, Ruth E., Nikolai A. Klesse, Ralph W. Jack, and John R. Tagg. "Molecular and Genetic Characterization of a Novel Nisin Variant Produced by Streptococcus uberis." Applied and Environmental Microbiology 72, no. 2 (February 2006): 1148–56. http://dx.doi.org/10.1128/aem.72.2.1148-1156.2006.

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ABSTRACT Streptococcus uberis is one of the principal causative agents of bovine mastitis. In this study, we report that S. uberis strain 42 produces a lantibiotic, nisin U, which is 78% identical (82% similar) to nisin A from Lactococcus lactis. The 15.6-kb nisin U locus comprises 11 open reading frames, similar in putative functionality but differing in arrangement from that of the nisin A biosynthetic cluster. The nisin U producer strain exhibits specific resistance (immunity) to nisin U and cross-resistance to nisin A, a finding consistent with the 55% sequence similarity of their respective immunity peptides. Homologues of the nisin U structural gene were identified in several additional S. uberis strains, and in each case cross-protective immunity was expressed to nisin A and to the other producers of nisin U and its variants. To our knowledge, this is the first report both of characterization of a bacteriocin by S. uberis, as well as of a member of the nisin family of peptides in a species other than L. lactis.

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Lämmler, C. "Biochemical and Serological Properties of Streptococcus uberis." Journal of Veterinary Medicine, Series B 38, no. 1-10 (January 12, 1991): 737–42. http://dx.doi.org/10.1111/j.1439-0450.1991.tb00937.x.

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Leigh, James A. "Activation of bovine plasminogen by Streptococcus uberis." FEMS Microbiology Letters 114, no. 1 (November 1993): 67–71. http://dx.doi.org/10.1111/j.1574-6968.1993.tb06552.x.

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Sherwin, Virginia E., Sharon A. Egan, Martin J. Green, and James A. Leigh. "Survival of Streptococcus uberis on bedding substrates." Veterinary Journal 276 (October 2021): 105731. http://dx.doi.org/10.1016/j.tvjl.2021.105731.

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Denham, E. L., P. N. Ward, and J. A. Leigh. "Lipoprotein Signal Peptides Are Processed by Lsp and Eep of Streptococcus uberis." Journal of Bacteriology 190, no. 13 (May 9, 2008): 4641–47. http://dx.doi.org/10.1128/jb.00287-08.

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ABSTRACT Lipoprotein signal peptidase (lsp) is responsible for cleaving the signal peptide sequence of lipoproteins in gram-positive bacteria. Investigation of the role of Lsp in Streptococcus uberis, a common cause of bovine mastitis, was undertaken using the lipoprotein MtuA (a protein essential for virulence) as a marker. The S. uberis lsp mutant phenotype displayed novel lipoprotein processing. Not only was full-length (uncleaved) MtuA detected by Western blotting, but during late log phase, a lower-molecular-weight derivative of MtuA was evident. Similar analysis of an S. uberis double mutant containing insertions disrupting both lsp and eep (a homologue of the Enterococcus faecalis “enhanced expression of pheromone” gene) indicated a role for eep in cleavage of lipoproteins in the absence of Lsp. Such a function may indicate a role for eep in maintenance of secretion pathways during disruption of normal lipoprotein processing.

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Almeida, Raúl A., Oudessa Kerro-Dego, and Agustín G. Rius. "Effect of heat stress on the interaction of Streptococcus uberis with bovine mammary epithelial cells." Journal of Dairy Research 85, no. 1 (February 2018): 53–56. http://dx.doi.org/10.1017/s0022029917000875.

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Heat stress (HS) negatively affects milk production and has been associated with decreased immune function, and increased rate of intramammary infections (IMI). Research has shown that HS affects gene expression, cell cycle, and cell metabolism in bovine mammary epithelial cells (BMEC). Since BMEC are an initial target of mastitis pathogens, we studied adherence to and internalisation of S. uberis into HS-BMEC, as well as the effect that this interaction has on host cells by measuring HS-BMEC viability and membrane integrity. Results reported in this Research Communication showed that HS reduced cell viability and induced membrane damage. However, these pathological changes, as well as the rate of adherence and internalisation of S. uberis into BMEC, were augmented when S. uberis was cocultured with HS-BMEC. These results may help to understand the pathogenesis of S. uberis IMI as well as the increased susceptibility of mammary glands to IMI in cows subjected to HS.

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Abd El-Aziz, Norhan K., Ahmed M. Ammar, Hend M. El Damaty, Rehab A. Abd Elkader, Hosam A. Saad, Waleed El-Kazzaz, and Eman Khalifa. "Environmental Streptococcus uberis Associated with Clinical Mastitis in Dairy Cows: Virulence Traits, Antimicrobial and Biocide Resistance, and Epidemiological Typing." Animals 11, no. 7 (June 22, 2021): 1849. http://dx.doi.org/10.3390/ani11071849.

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Mastitis remains a serious problem for dairy animals. The misappropriation of antimicrobial agents helps accelerate resistance, which poses a serious challenge in controlling environmental S. uberis infection. Here, we study the virulence attributes, antimicrobial and biocide resistance, and epidemiological typing of S. uberis recovered from bovine clinical mastitis in dairy farms of diverse hygienic interventions in Egypt. The overall S. uberis infection rate was 20.59%; all were multidrug-resistant (MDR). The sua gene was the most frequent virulence gene (42.02%), followed by pauA (40.57%), cfu (21.73%), skc (20.28%), and opp (11.59%). The erm(B) gene served as the predominant antimicrobial-resistant gene (75.36%), followed by fexA (52.63%) and tet(M), blaZ, and aac(6′)aph(2″) genes (46.38% each). Of note, 79.71%, 78.26%, and 18.84% of S. uberis isolates harbored qacED1, qacC/D, and qacA/B genes, respectively. All analyzed isolates were S. uberis type I by their unique RFLP–PCR pattern. In conclusion, the sustained presence of pauA and sua genes throughout the investigated farms contributes to a better understanding of the bacterium’s pathogenicity. Furthermore, MDR coupled with the existence of biocide resistance genes indicates the importance of S. uberis surveillance and the prudent use of antimicrobials in veterinary clinical medicine to avoid the dissemination of antimicrobial resistance.

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Sherwin, Virginia E., Morena Santi, Olivia Walker, Natalie D. Pickwell, Tracey J. Coffey, James A. Leigh, and Sharon A. Egan. "PCR-Based Direct Detection of Streptococcus uberis from Subclinical and Clinical Dairy Cattle Milk Samples." Veterinary Medicine International 2020 (December 8, 2020): 1–9. http://dx.doi.org/10.1155/2020/8828624.

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Streptococcus uberis is one of the leading causes worldwide of mastitis in the dairy industry, with the most likely sources of infection attributed to environmental reservoirs such as contaminated bedding materials. Early detection of those cases most likely to progress to clinical disease would lead to improved animal welfare, a critical component of overall health and productivity. A multiplex PCR-based diagnostic test was developed for detection of S. uberis directly from milk and targeting two genes previously identified as important for intramammary colonisation and persistence in dairy cattle. Results indicated the threshold for detection directly from milk was 20,000 CFU/ml and this was achieved without the need for preenrichment. In addition, S. uberis could be identified from milk samples collected during intramammary challenge studies, prior to clinical signs of infection and at much lower detection limits. The PCR test developed for confirmation of the presence of S. uberis directly from infected milk has potential value as a diagnostic test to identify early infection and/or to confirm that antibiotic therapy has been successful.

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Petinaki, Efthymia, Véronique Guérin-Faublée, Vianney Pichereau, Corinne Villers, Adeline Achard, Brigitte Malbruny, and Roland Leclercq. "Lincomycin Resistance Gene lnu(D) in Streptococcus uberis." Antimicrobial Agents and Chemotherapy 52, no. 2 (December 17, 2007): 626–30. http://dx.doi.org/10.1128/aac.01126-07.

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ABSTRACT Streptococcus uberis UCN 42, isolated from a case of bovine mastitis, was intermediately resistant to lincomycin (MIC = 2 μg/ml) while remaining susceptible to clindamycin (MIC = 0.06 μg/ml) and erythromycin. A 1.1-kb SacI fragment was cloned from S. uberis UCN 42 total DNA on plasmid pUC 18 and introduced into Escherichia coli AG100A, where it conferred resistance to both clindamycin and lincomycin. The sequence analysis of the fragment showed the presence of a new gene, named lnu(D), that encoded a 164-amino-acid protein with 53% identity with Lnu(C) previously reported to occur in Streptococcus agalactiae. Crude lysates of E. coli AG100A containing the cloned lnu(D) gene inactivated lincomycin and clindamycin in the presence of ATP and MgCl2. Mass spectrometry experiments demonstrated that the lnu(D) enzyme catalyzed adenylylation of clindamycin. A domain conserved in deduced sequences of lincosamide O-nucleotidyltransferases Lnu(A), Lnu(C), LinAN2, and Lin(D) and in the aminoglycoside nucleotidyltransferase ANT(2′′) was identified.

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ZADOKS, R. N., B. E. GILLESPIE, H. W. BARKEMA, O. C. SAMPIMON, S. P. OLIVER, and Y. H. SCHUKKEN. "Clinical, epidemiological and molecular characteristics of Streptococcus uberis infections in dairy herds." Epidemiology and Infection 130, no. 2 (April 2003): 335–49. http://dx.doi.org/10.1017/s0950268802008221.

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A longitudinal observational study (18 months) was carried out in two Dutch dairy herds to explore clinical, epidemiological and molecular characteristics of Streptococcus uberis mastitis. Infections (n=84) were detected in 70 quarters of 46 cows. Bacterial isolates were characterized at strain level by random amplified polymorphic DNA (RAPD) fingerprinting. Persistent infections were usually attributable to one strain, while recurrent infections could be caused by different strains. When multiple quarters of a cow were infected, infections were mostly caused by one strain. In each herd, multiple strains were identified yet one strain predominated. The majority of all infections were subclinical, and infections attributed to predominant strains were more chronic than infections attributed to other strains. Epidemiological and molecular data suggest infection from environmental sources with a variety of S. uberis strains as well as within-cow and between-cow transmission of a limited number of S. uberis strains, with possible transfer of bacteria via the milking machine.

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Janevsкi, Aleksandar, Iskra Cvetkovikj, Sanja Kiprijanovska, Aleksandar Dimovski, Katarina Davalieva, Ljupco Angelovski, Miroslav Kjosevski, and Dine Mitrov. "Prevalence of Subclinical Mastitis Pathogens in Small Dairy Farms in Republic of North Macedonia." Macedonian Veterinary Review 43, no. 1 (March 1, 2020): 23–30. http://dx.doi.org/10.2478/macvetrev-2020-0010.

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AbstractSubclinical mastitis is an asymptomatic udder infection distributed worldwide with enormous losses in the dairy industry. The study’s objective was to determine the presence of this pathological condition in small dairy farms in the R. of N. Macedonia and to identify the most common associated bacteria. Milk samples were obtained from 96 dairy cows (378 udder quarters) in seven dairy farms, in 3 consecutive samplings 24–72 hours apart. The samples were cultured on routine bacteriological growth media and incubated for 24–48 hours. The isolates were identified by AximaiD Plus MALDITOF MS Platform. Subclinical mastitis was found in 49 animals (51%) and 104 infected quarters (27%). The most frequent isolated bacteria on cow level were Streptococcus uberis (19.4%), Staphylococcus haemolyticus (13.4%), Staphylococcus aureus (7.4%) and Staphylococcu ssimulans (7.4%). On quarter level, the most isolated pathogen was Streptococcus uberis (35.6%) followed by Staphylococcu shaemolyticus and Staphylococcus aureus (10.3% and 9.2% respectively). Subclinical mastitis was found to be highly present in the selected small dairy farms. The most prevalent bacteria identified in the dairy farms (Streptococcus uberis, Staphylococcus aureus and coagulase–negative staphylococci) indicate that poor management and udder health practices, inadequate milking procedures and lack of mastitis control strategies greatly contribute to occurrence and persistence of subclinical mastitis.

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Kerro Dego, Oudessa, Raul Almeida, Susan Ivey, and Getahun E. Agga. "Evaluation of Streptococcus uberis Surface Proteins as Vaccine Antigens to Control S. uberis Mastitis in Dairy Cows." Vaccines 9, no. 8 (August 5, 2021): 868. http://dx.doi.org/10.3390/vaccines9080868.

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There is no effective vaccine against Streptococcus uberis mastitis in dairy cows. Objectives of this study were (1) to extract S. uberis surface proteins (SUSP) and determine immunoreactivity in vitro and (2) immunogenicity and efficacy in vivo. SUSP was extracted from S. uberis, and their immunoreactivity was tested by western blot. In total, 26 Jersey dairy cows were randomly divided into four groups. Groups 1, 2, and 3 were vaccinated subcutaneously with 4 mg, 1 mg, and 100 μg of SUSP, respectively, with Freund’s incomplete adjuvant. Group 4 (control) was injected with placebo. S. uberis UT888 was infused into two contralateral quarters of each cow during early lactation. Somatic cell count (SCC), bacteria count in milk, and mastitis were monitored. Our results show that SUSP contains multiple protein bands, that ranged from 10 to 100 kDa. All vaccinates showed an increased anti-SUSP IgG antibody. The SCC of all experimentally infected quarters increased after challenge but slightly decreased after day 3 with no significant difference among groups. Milk bacterial count was significantly (p < 0.05) reduced in high and medium doses vaccinated groups than low and control groups. In conclusion, SUSP vaccine is immunogenic and showed a promising efficacy to control bovine S. uberis mastitis.

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Thomas, Funmilola Clara, William Mullen, Riccardo Tassi, Adela Ramírez-Torres, Manikhandan Mudaliar, Tom N. McNeilly, Ruth N. Zadoks, Richard Burchmore, and P. David Eckersall. "Mastitomics, the integrated omics of bovine milk in an experimental model of Streptococcus uberis mastitis: 1. High abundance proteins, acute phase proteins and peptidomics." Molecular BioSystems 12, no. 9 (2016): 2735–47. http://dx.doi.org/10.1039/c6mb00239k.

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Collins, Robert A., Keith R. Parsons, Terry R. Field, and A. John Bramley. "Histochemical localization and possible antibacterial role of xanthine oxidase in the bovine mammary gland." Journal of Dairy Research 55, no. 1 (February 1988): 25–32. http://dx.doi.org/10.1017/s0022029900025814.

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SummaryXanthine oxidase (XO) was demonstrated to be present in the teat canal and secretory tissue of the bovine mammary gland by histochemical techniques. Homogenates of these tissues were able to replace XO in an antibacterial assay with Streptococcus uberis. The action of XO on its substrate hypoxanthine was shown to provide an essential component for anti-streptococcal activity mediated by lactoperoxidase. A mechanism is proposed whereby the interaction of XO, lactoperoxidase and thiocyanate may provide antibacterial activity in the teat canal.

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Monistero, Valentina, Antonio Barberio, Paola Cremonesi, Bianca Castiglioni, Stefano Morandi, Desiree C. K. Lassen, Lærke B. Astrup, et al. "Genotyping and Antimicrobial Susceptibility Profiling of Streptococcus uberis Isolated from a Clinical Bovine Mastitis Outbreak in a Dairy Farm." Antibiotics 10, no. 6 (May 28, 2021): 644. http://dx.doi.org/10.3390/antibiotics10060644.

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Streptococcus uberis, an environmental pathogen responsible also for contagious transmission, has been increasingly implicated in clinical mastitis (CM) cases in Europe. We described a 4-month epidemiological investigation of Strep. uberis CM cases in an Italian dairy farm. We determined molecular characteristics and phenotypic antimicrobial resistance of 71 Strep. uberis isolates from dairy cows with CM. Genotypic variability was investigated via multiplex PCR of housekeeping and virulence genes, and by RAPD-PCR typing. Antimicrobial susceptibility was assessed for 14 antimicrobials by MIC assay. All the isolates carried the 11 genes investigated. At 90% similarity, two distinct clusters, grouping 69 of the 71 isolates, were detected in the dendrogram derived from the primer ERIC1. The predominant cluster I could be separated into two subclusters, containing 38 and 14 isolates, respectively. Strep. uberis strains belonging to the same RAPD pattern differed in their resistance profiles. Most (97.2%) of them were resistant to at least one of the drugs tested, but only 25.4% showed a multidrug resistance phenotype. The highest resistance rate was observed for lincomycin (93%), followed by tetracycline (85.9%). This study confirmed a low prevalence of β-lactam resistance in Strep. uberis, with only one isolate showing resistance to six antimicrobial classes, including cephalosporins.

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36

Taylor, D. L., P. N. Ward, C. D. Rapier, J. A. Leigh, and L. D. Bowler. "Identification of a Differentially Expressed Oligopeptide Binding Protein (OppA2) in Streptococcus uberis by Representational Difference Analysis of cDNA." Journal of Bacteriology 185, no. 17 (September 1, 2003): 5210–19. http://dx.doi.org/10.1128/jb.185.17.5210-5219.2003.

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ABSTRACT Streptococcus uberis is an increasingly significant cause of intramammary infection in the dairy cow, presently responsible for approximately 33% of all cases of bovine mastitis in the United Kingdom. Following experimentally induced infection of the lactating mammary gland, S. uberis is found predominantly in the luminal areas of secretory alveoli and ductular tissue, indicating that much of the bacterial growth occurs in residual and newly synthesized milk. With the objective of identifying potential virulence determinants in a clinical isolate of S. uberis, we have used representational difference analysis of cDNA to identify genes that show modified expression in milk. We have identified a number of differentially expressed genes that may contribute to the overall pathogenicity of the organism. Of these, a transcript encoding a putative oligopeptide binding protein (OppA) was further characterized. We have found that S. uberis possesses two oppA-like open reading frames, oppA1 and oppA2, which are up-regulated to different degrees following growth in milk. Mutants lacking either oppA1 or oppA2 are viable and have an increased resistance to the toxic peptide derivative aminopterin; however, only mutants lacking oppA1 display a lower rate of growth in milk. In addition, expression of the oppA genes appears to be coordinated by different mechanisms. We conclude that the oppA genes encode oligopeptide binding proteins, possibly displaying different specificities, required for the efficient growth of S. uberis in milk.

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Zadoks, R. N., H. G. Allore, H. W. Barkema, O. C. Sampimon, Y. T. Gröhn, and Y. H. Schukken. "Analysis of an Outbreak of Streptococcus uberis Mastitis." Journal of Dairy Science 84, no. 3 (March 2001): 590–99. http://dx.doi.org/10.3168/jds.s0022-0302(01)74512-2.

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Schaufuss, P., R. Sting, W. Schaeg, and H. Blobel. "Isolation and Characterization of Hyaluronidase from Streptococcus uberis." Zentralblatt für Bakteriologie 271, no. 1 (May 1989): 46–53. http://dx.doi.org/10.1016/s0934-8840(89)80052-0.

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Almeida, R. A., and S. P. Oliver. "Antiphagocytic Effect of the Capsule of Streptococcus uberis." Journal of Veterinary Medicine, Series B 40, no. 1-10 (January 12, 1993): 707–14. http://dx.doi.org/10.1111/j.1439-0450.1993.tb00195.x.

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40

Wolter, Wilfried. "Besonderheiten und strategische Bekämpfung von Streptococcus-uberis-Mastitiden." veterinär spiegel 22, no. 02 (June 2012): 75–80. http://dx.doi.org/10.1055/s-0031-1298526.

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Jayarao, B. M., B. J. Bassam, G. Caetano-Anollés, P. M. Gresshoff, and S. P. Oliver. "Subtyping of Streptococcus uberis by DNA amplification fingerprinting." Journal of Clinical Microbiology 30, no. 5 (1992): 1347–50. http://dx.doi.org/10.1128/jcm.30.5.1347-1350.1992.

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42

Matthews, K. R., R. A. Almeida, and S. P. Oliver. "Bovine mammary epithelial cell invasion by Streptococcus uberis." Infection and Immunity 62, no. 12 (1994): 5641–46. http://dx.doi.org/10.1128/iai.62.12.5641-5646.1994.

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Mihklepp, K., K. Kivirand, D. Juronen, A. Lõokene, and T. Rinken. "Immunodetection of Streptococcus uberis pathogen in raw milk." Enzyme and Microbial Technology 130 (November 2019): 109360. http://dx.doi.org/10.1016/j.enzmictec.2019.109360.

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Pecka-Kiełb, E., M. Vasil, A. Zachwieja, W. Zawadzki, J. Elečko, F. Zigo, J. Illek, and Z. Farkašová. "An effect of mammary gland infection caused by Streptococcus uberis on composition and physicochemical changes of cows’ milk." Polish Journal of Veterinary Sciences 19, no. 1 (March 1, 2016): 49–55. http://dx.doi.org/10.1515/pjvs-2016-0007.

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Abstract An effect of mammary gland infection caused by Streptococcus uberis on the changes in cows’ milk composition and its physicochemical properties was examined. The study was conducted in the herd of Slovak Pied breed cattle (with a share of HF blood), in 2nd and 3rd lactation, after 4th month of milking. Milk samples were collected from a quarter milking. The samples were subjected to microbiological analysis, basic milk composition, total bacteria count, somatic cell count and physicochemical properties were examined. Also analyses of protein fractions share and fatty acids profile were conducted. An effect of bacterial infection of the mammary gland bring an increase (P<0.01) in somatic cell count was observed in this study. Milk samples contaminated with S. uberis were characterized by higher (P<0.05) total bacteria count and total protein compared to milk samples collected from non-infected mammary gland. The level of κ-casein was significantly (P<0.05) decreased in cows with subclinical mastitis caused by S. uberis. Significant (P<0.05) reduction in the share of C13:0 acid, and an increased level of C18:0, C18:1n7t and CLA were observed in milk contaminated with S. uberis compared to healthy cows’ milk. It should be concluded that S. uberis causes the increase in total bacteria count, SCC and the decrease in κ-casein level, which significantly affects deterioration of technological quality of cows’ milk.

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Shome, Bibek Ranjan, Mani Bhuvana, Susweta Das Mitra, Natesan Krithiga, Rajeswari Shome, Dhanikachalam Velu, Apala Banerjee, Sukhadeo B. Barbuddhe, Krishnamshetty Prabhudas, and Habibar Rahman. "Molecular characterization of Streptococcus agalactiae and Streptococcus uberis isolates from bovine milk." Tropical Animal Health and Production 44, no. 8 (May 16, 2012): 1981–92. http://dx.doi.org/10.1007/s11250-012-0167-4.

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Leelahapongsathon, Kansuda, Ynte Hein Schukken, Tanu Pinyopummintr, and Witaya Suriyasathaporn. "Comparison of transmission dynamics between Streptococcus uberis and Streptococcus agalactiae intramammary infections." Journal of Dairy Science 99, no. 2 (February 2016): 1418–26. http://dx.doi.org/10.3168/jds.2015-9950.

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Ward, Philip N., Terence R. Field, William G. F. Ditcham, Emmanuelle Maguin, and James A. Leigh. "Identification and Disruption of Two Discrete Loci Encoding Hyaluronic Acid Capsule Biosynthesis GeneshasA, hasB, and hasC inStreptococcus uberis." Infection and Immunity 69, no. 1 (January 1, 2001): 392–99. http://dx.doi.org/10.1128/iai.69.1.392-399.2001.

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ABSTRACT The hyaluronic acid capsule of Streptococcus uberis has been implicated in conferring resistance to phagocytosis by bovine neutrophils. Construction of a bank of random insertion mutants ofS. uberis (strain 0140J) was achieved using the pGh9::ISS1 mutagenesis system (22). Phenotypic screening of approximately 5,000 clones enabled the isolation of 11 acapsular mutants. Southern hybridization indicated that two mutants carried a lesion within a group of genes similar to those involved in the assembly of the hyaluronic acid capsule found in the group AStreptococcus (GAS) has operon. The DNA sequence flanking the points of insertion confirmed the presence of homologues of GAS hasA and hasB in S. uberis. The DNA sequence flanking the ISS1 insertion in another mutant identified a homologue of hasC inS. uberis. The GAS hasABC operon structure was not conserved in S. uberis, and two discrete loci comprising homologues of either hasAB or hasCwere identified. Disruption of S. uberis hasA orhasC resulted in the complete cessation of hyaluronic acid capsule production. Correspondingly, these mutants were found to have lost their resistance to phagocytosis by bovine neutrophils. The bactericidal action of bovine neutrophils on S. uberis0140J was shown unequivocally to depend upon the capsule status of the bacterium.

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Abd, Abdul-Hadi Abbass. "Immunological Response of Bovine Mammary Cell Lines in Mastitis and Milk Hygiene." Iraqi Journal of Veterinary Medicine 36, no. 1 (June 30, 2012): 1–13. http://dx.doi.org/10.30539/iraqijvm.v36i1.515.

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Mammary adherent cells (MAC-T) were infected with six isolates of Streptococcus uberis (S. uberis). Three isolates were cases of mastitis in dairy cows and belonged to clonal complex 5, 143, which is associated with virulence and three were from cows with no clinical or laboratory evidence of mastitis. All these isolates belonged to clonal complex 86 which contains strains of low virulence. After incubation at 37oC for 24 h, there were no significant differences in the number of adherent or internalized S. uberis between mastitis (M) and non- mastitis (NM) isolates (p> 0.05).The levels of tumour necrosis factor (TNF-α), measured in treated MAC-T cells supernatant with S. uberis by ELISA, were significantly elevated in cultures infected with NM isolates compared with M isolates, after 10h (p>0.05) and 24h (p>0.001) respectively. Expression of TNF-α, TLR2, TLR4 and NFkB genes were examined by Real-Time PCR. There are highly significant differences in the timing of expression. The levels of TNF-α mRNA increased 36 fold after 6 hour of infecting cells with M strains, but not in NM strains of S. uberis. These results suggest a vital role for TNF-α, in the defence against S. uberis in the bovine mammary glands.

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Vander Elst, Niels, Sara B. Linden, Rob Lavigne, Evelyne Meyer, Yves Briers, and Daniel C. Nelson. "Characterization of the Bacteriophage-Derived Endolysins PlySs2 and PlySs9 with In Vitro Lytic Activity against Bovine Mastitis Streptococcus uberis." Antibiotics 9, no. 9 (September 19, 2020): 621. http://dx.doi.org/10.3390/antibiotics9090621.

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Bovine mastitis, an infection of the cow’s mammary gland, is frequently caused by Streptococcus uberis and causes major economic losses in the dairy industry. The intramammary administration of antibiotics currently remains the predominant preventive and therapeutic measure. These antimicrobial compounds, of which some are considered critical in human health care, are frequently applied as dry therapy resulting in their consistent overuse. Therefore, the use of antibiotics in the dairy sector is being questioned. We here identified two endolysins, i.e., PlySs2 and PlySs9, respectively derived from Streptococcus suis serotype-2 and -9 prophages, with lytic activity against S. uberis in an in vitro setting. Both endolysins gave clear lysis zones in spot-on-plate assays and caused a reduction of the optical density in a turbidity reduction assay. In depth characterization identified PlySs9 as the more potent endolysin over PlySs2 with a lower MIC value and about one additional log of killing. PlySs2 and PlySs9 were challenged to a panel of subclinical and clinical S. uberis milk isolates and were both able to lyse all strains tested. Molecular dissection of these endolysins in catalytic and cell wall binding subdomains resulted in major loss of killing and binding activity, respectively. Taken together, we here propose PlySs2 and PlySs9 as candidate compounds to the current antimicrobial arsenal known against bovine mastitis-causing S. uberis as future add-on or replacement strategy to the currently used intramammary antibiotics.

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Loures, Rafael Ambrósio, Ulisses De Pádua Pereira, Glei Dos Anjos de Carvalho-Castro, Gláucia Frasnelli Mian, Dircéia Aparecida da Costa Custódio, Juliana Rosa da Silva, and Geraldo Márcio da Costa. "Genetic diversity and virulence genes in Streptococcus uberis strains isolated from bovine mastitis." Semina: Ciências Agrárias 38, no. 4Supl1 (August 25, 2017): 2595. http://dx.doi.org/10.5433/1679-0359.2017v38n4supl1p2595.

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Mastitis is one of the most common and costly infectious diseases in dairy cattle worldwide. This is a multifactorial illness caused by different microorganisms, including virus, yeasts, algae, parasites, and several species of bacteria. Among these bacteria, Streptococcus uberis is an important environmental pathogen that is responsible for a large range of clinical and subclinical mammary infections, especially in intensively managed herds. Despite the increasing importance of this pathogen in the etiology of bovine mastitis, data on its virulence and diversity in Brazilian dairy herds are scarce. The aims of the present study were to investigate the virulence characteristics of S. uberis isolated from bovine mastitis and to assess the molecular epidemiology of the Brazilian isolates using pulsed-field gel electrophoresis (PFGE). In this work, 46 strains of S. uberis isolated from bovine mastitis from 26 Brazilian dairy herds were evaluated regarding their genetic diversity by PFGE using with the SmaI enzyme. Additionally, the presence of the virulence genes skc and pauA, which encode plasminogen activators, and the gene sua, which encodes an adhesion molecule in mammary epithelial cells, were assessed by PCR. Our results showed a high genetic diversity in the population, displaying many different patterns in the PFGE analysis. A high proportion of strains was positive for virulence genes in the sampled population (sua [100%], pauA [91%], and skc [91%]). The high frequency of skc, pauA, and sua genes among the studied strains suggests the importance of these virulence factors, possibly helping S. uberis in the colonization of the bovine mammary gland. Surveys of the genetic and molecular characteristics of this pathogen can improve our knowledge of bacterial activity and identify molecules that have roles in the establishment of the infection. This might help in the development of more effective measures to control and prevent bovine mastitis.

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Journal articles on the topic 'Streptococcus uberis'

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