Methicillin resistance in staphylococci isolated from subclinical mastitis in sheep.
One hundred ovine milk samples were subjected to bacteriological analysis to detect staphylococci. Twenty-four staphylococcal strains isolated were characterised for methicillin resistance with disk diffusion test (DDT) after incubation at 24 and 48 h, oxacillin agar screen test, Minimal Inhibitory Concentration (MIC), nitrocefin test for beta-lactamase production and PCR for the mecA gene. Nine staphylococcal strains resulted resistant in DDT; some differences in the halo diameter at double incubation period were noted; eight of these strains were resistant in MIC test; just one strain was positive to oxacillin agar screen test. All strains were mecA negative by PCR and positive by nitrocefin test. On the basis of these results methicillin-resistant strains can be classified as beta-lactamase hyperproducers.
Corrente
M
M
Department of Health and Animal Well-being, Faculty of Veterinary Medicine of Bari, Valenzano, Italy.
Greco
G
G
Madio
A
A
Ventriglia
G
G
D000818:Animals; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics; D002511:Cephalosporins / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D006602:Hexosyltransferases; D005779:Immunodiffusion; D007202:Indicators and Reagents / Q000378:metabolism; D008413:Mastitis / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D008892:Milk / Q000382:microbiology; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D002352:Carrier Proteins; D002511:Cephalosporins; D004269:DNA, Bacterial; D007202:Indicators and Reagents; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D001618:beta-Lactamases; C021720:nitrocefin