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Bovine Mastitis (bovine + mastitis)
Selected AbstractsTotal and Differential Leucocyte Counts and Lymphocyte Subpopulations in Lymph, Afferent and Efferent to the Supramammary Lymph Node, During Endotoxin-Induced Bovine MastitisREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2007S Lun Contents Leucocyte trafficking in afferent and efferent mammary lymph and the supramammary lymph node in cows was examined during 4 h after intramammary infusion of endotoxin from Escherichia coli. Total and differential leucocyte counts were measured in milk, blood and lymph. The proportions of CD4+, CD8+, major histocompatibility complex (MHC) class II+ and IgM+ lymphocytes were examined in the lymph and lymph node. At post-infusion hour (PIH) 4, the flow rates of both lymph fluids had increased approximately eightfold. Total leucocyte concentration increased in afferent lymph, but decreased in efferent lymph. Neutrophils increased in afferent lymph at PIH 2 and in efferent lymph and milk at PIH 4. The predominant cell type in afferent lymph shifted from lymphocyte to neutrophil while lymphocyte was still at PIH 4 the predominant type in efferent lymph. Among the lymphocytes, B cells were predominant in afferent lymph and lymph node at PIH 4 while T cells, mainly CD4+ cells, were predominant in efferent lymph both at PIH 0 and PIH 4. The CD4 : CD8 ratio was higher in efferent lymph and the challenged lymph node than in afferent lymph and the control node, respectively. There was a significant difference in proportions of each lymphocyte subpopulation except for IgM+ cells, between afferent and efferent lymph after infusion. According to the results, there was already during the first hours of the immune response, a non-random trafficking of neutrophils and lymphocyte subpopulations resulting in a changed distribution of cells in afferent and efferent lymph and a difference in lymphocyte reactivity between the two lymph fluids. [source] Characterization of specific egg yolk immunoglobulin (IgY) against mastitis - causing Staphylococcus aureusJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2008Y.-H. Zhen Abstract Aims:, To evaluate the in vitro activity of egg yolk immunoglobulin (IgY) against mastitis-causing Staphylococcus aureus. Methods and Results:, Specific IgY was produced by immunizing hens with formaldehyde-killed Staph. aureus, using a bacterial strain known to cause mastitis. The IgY, of 94% purity, was obtained from yolks by water dilution, salt precipitations, ultrafiltration and gel filtration. ELISA indicated that the IgY produced was specific to the antigen and five Staph. aureus isolates obtained from mastitic cows. The growth of Staph. aureus was inhibited by specific IgY at concentrations from 1 to 10 mg ml,1 in a dose-dependent manner. The phagocytosis of Staph. aureus by milk macrophages was enhanced in the presence of specific IgY with the highest phagocytic percentage being 30% higher than that without IgY (P < 0·05). Conclusions:, The specific IgY against mastitis-causing Staph. aureus inhibited the growth of Staph. aureus and enhanced the phagocytosis of Staph. aureus by milk macrophages. Significance and Impact of the Study:, Specific IgY would be a potential treatment for bovine mastitis. [source] Virulence genes of bovine Staphylococcus aureus from persistent and nonpersistent intramammary infections with different clinical characteristicsJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2007M. Haveri Abstract Aims:, To screen putative virulence genes in Staphylococcus aureus causing persistent and nonpersistent bovine intramammary infections (IMI) with different clinical characteristics. To examine, whether a possible relationship exists between genetic profile and infection persistence, clinical signs of infection, clonal type determined by pulsed-field gel electrophoresis (PFGE), and antimicrobial resistance. Methods and Results:, One-hundred and sixty-one S. aureus isolates derived from bovine IMI, consisting of 17 different PFGE types, were screened by conventional and multiplex-polymerase chain reaction (PCR) for 24 virulence genes for haemolysins (hla-hlg), leukocidins (lukED, lukM), exfoliative toxins (eta, etb), enterotoxins (sea-seo, seu), toxic-shock syndrome toxin (tst), and genes encoding penicillin (blaZ) and methicillin resistance (mecA). The majority of S. aureus isolated at the onset of mastitis carried haemolysin genes (76·7,97·4%), lukED (96·6%), and at least one gene for pyrogenic toxin superantigen (PTSAg) (69·0%). Strains carrying PTSAg-encoding genes were more common among predominant PFGE types and in persistent IMI. Strains concomitantly possessing sed, sej, and blaZ, putatively plasmid-encoded, were typically found in connection with persistent IMI. Conclusions:, Our results suggest that certain genetic elements are over-representative in S. aureus isolates especially from persistent bovine mastitis. This phenomenon seems to be in connection with clonal type and is often concomitant with penicillin resistance. Significance and Impact of the Study:, This is the first study to investigate associations between a large number of bacterial factors and outcome of S. aureus mastitis. The finding that widespread clonal types of S. aureus causing bovine mastitis of low treatment response may harbour characteristic genes could be improved for strain-specific diagnostic purposes. [source] An overview of factors affecting the disposition of intramammary preparations used to treat bovine mastitisJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2006R. GEHRING The administration of antimicrobial drugs by the intramammary route offers a convenient option for the treatment of bovine mastitis. The goal of antimicrobial treatment is to achieve effective drug concentrations at the site of infection. Drug concentrations must also decrease to safe levels before the milk is harvested for human consumption. The rate of change of drug concentrations in the milk and udder tissues over time is dependent on the physicochemical characteristics of the drug and how these interact with the biological environment, affecting the rate and extent of absorption, distribution and elimination. Studies reported in the literature have identified various pathophysiological and pharmaceutical factors that may influence these processes. This review summarizes current understanding of factors affecting the disposition of drugs following intramammary administration. Areas of incomplete knowledge requiring further research have been identified. [source] Inhibition of bacteriophage K proliferation on Staphylococcus aureus in raw bovine milkLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2005S. O'Flaherty Abstract Aims:, To assess the ability of staphylococcal bacteriophage K to inhibit Staphylococcus aureus in raw milk. Methods and Results:, The ability of bacteriophage (phage) to replicate in milk is important in situations where phage might be used as a therapeutic for bovine mastitis. Phage K was able to replicate normally, leading to elimination of the host culture in milk, which had been previously heat-treated. When raw milk was used under identical conditions, the phages were unable to replicate. Phage adsorption assays were performed and these demonstrated that adsorption of phage was significantly reduced in the raw milk while it was restored in the heat-treated sample (86·50% compared with 99·96% adsorption respectively). When confocal microscopy with a Live/Dead Bac light staining system was employed, it was observed that in raw milk S. aureus formed clusters associated with fat globules, while in heat-treated milk, bacterial agglutination had not occurred. Conclusions:, Raw milk inhibits staphylococcal phage K proliferation. Significance and Impact of the Study:, This observation has implications for the exploitation of staphylococcal therapeutic phage in milk. [source] Bacteriocin production of probiotic Lactobacillus gasseri LA39 isolated from human feces in milk-based mediaANIMAL SCIENCE JOURNAL, Issue 5 2008Kensuke ARAKAWA ABSTRACT The use of bacteriocins from Lactobacillus gasseri, a probiotic lactic acid bacterium, as bio-preservatives in the food industry and animal formulations has been limited because few strains of Lb. gasseri are cultivated and produce a bacteriocin in natural media such as milk and milk-based media. By the determination of the growth-supplements to milk among the 47 nutrients, Lb. gasseri JCM1131T, LA39 and LA158 isolated from human feces were successfully cultured in reconstituted skim milk and cheese whey using proteose peptone as a nutrient supplement, where Lb. gasseri LA39 produced a useful bacteriocin, gassericin A, with effective growth-inhibiting activity against Gram-positive food-borne pathogens. The data suggest these developed low-cost safe media supporting enough production of bacteriocins by the probiotic Lb. gasseri LA39 could be used to improve the safe bio-preservation of foods and therapy of bovine mastitis, and extra cheese whey produced by cheese making industry is reused in the cultivation for probiotics effectively. [source] Characterisation of isolates of Staphylococcus aureus from acute, chronic and subclinical mastitis in cows in NorwayAPMIS, Issue 9 2000TORE Tollersrud Eighty-six Staphylococcus aureus isolates from cases of bovine mastitis were characterised biochemically and with respect to serotype, multilocus enzyme electrophoresis genotypes, antibiotic sensitivity, and production of enterotoxins A through D (SEA-D) and toxic shock syndrome toxin-1 (TSST-1). The samples were obtained from 81 different cows from 79 Norwegian dairy herds in 10 different counties in southern Norway. There was an equal representation of isolates from cases of acute, chronic and subclinical mastitis. Multilocus enzyme electrophoresis using 13 genetic loci showed that 69 of 86 isolates had the same electrophoretic type. This common electrophoretic type comprised isolates that differed in the expression of other phenotypical characteristics studied. Fifty-eight percent of the isolates produced one or more enterotoxins, predominantly a combination of SEC and TSST-1. Capsular serotyping revealed that 95% of the isolates belonged to serotype 8. No correlation was found between the factors studied and the clinical classification of mastitis. It appears that the majority of S. aureus isolates recovered from cases of bovine mastitis in Norway are genetically closely related and express common phenotypical characteristics. [source] Genetic relatedness between group B streptococci originating from bovine mastitis and a human group B streptococcus type V cluster displaying an identical pulsed-field gel electrophoresis patternCLINICAL MICROBIOLOGY AND INFECTION, Issue 9 2006I. C. M. Oliveira Abstract Twenty isolates of group B streptococcus (GBS) were recovered from the milk of cows with bovine mastitis on three farms located in the south and south-east of Brazil between 1987 and 1988. These isolates were characterised by molecular methods and compared with a collection of 103 human GBS isolates from colonised and infected patients in the same region between 1980 and 2003. Some of the bovine isolates shared identical or similar pulsed-field gel electrophoresis (PFGE) patterns with a PFGE clone of human GBS type V. In addition, these bovine and human isolates also possessed the same ribotype. Multilocus sequence typing (MLST) of representative isolates confirmed the genetic relationship between the human and bovine GBS isolates with identical PFGE patterns, which clustered in the same ST-26 clonal complex. These data support the hypothesis that some bovine GBS strains are related closely to human isolates and may infect humans, or vice versa. Further comparative genomic analyses of GBS isolates from bovine and human origins are required to investigate this hypothesis further. [source] | |||||||||||||