title: Resistance to methicillin of coagulase-negative staphylococci (CNS) isolated from bovine mastitis.
abstract: The aim of this study was to determine the mechanisms of staphylococcal resistance to methicillin. CNS (n = 100 isolates) were prepared from the mammary inflammatory secretions of 86 cows from farms located in the Lublin region. Methicillin-resistant isolates constituted 20.0% of all CNS. Staphylococcus sciuri (n=8) and Staphylococcus xylosus (n=6) were most abundant, followed by Staphylococcus chromogenes (n=3), Staphylococcus haemolyticus (n=2) and Staphylococcus warned (n=1). The mecA gene was found in 50.0% of MRCNS (10.0% of all CNS isolates) belonging to two species: S. sciuri and S. xylosus. All mecA-positive isolates contained the protein of low affinity to penicillin (penicillin-binding protein 2a - PBP2a). The enzyme hydrolysing the beta-lactam ring in antibiotics was detected in 40.0% of MRCNS; 10.0% of MRCNS isolates were characterised by the presence of the mecA gene and ability to produce beta-lactamase. The remaining 20.0% of MRCNS isolates showing phenotypic resistance to methicillin were mecA gene-negative and were not able to produce beta-lactamase.
authors.affiliation: Department and Clinic of Animal Reproduction, Faculty of Veterinary Medicine, University of Life Sciences, Gleboka 30, 20-612 Lublin, Poland. mariolabochniarz@interia.pl
authors.forename: M
authors.initials: M
authors.lastname: Bochniarz
authors.affiliation: Department and Clinic of Animal Reproduction, Faculty of Veterinary Medicine, University of Life Sciences, Gleboka 30, 20-612 Lublin, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Wawron
authors.affiliation: Department and Clinic of Animal Reproduction, Faculty of Veterinary Medicine, University of Life Sciences, Gleboka 30, 20-612 Lublin, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Szczubial
mesh_terms: D000818:Animals; D002417:Cattle; D003030:Coagulase / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008414:Mastitis, Bovine / Q000382:microbiology*; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology*
chemical_list: D003030:Coagulase; D008712:Methicillin