Methicillin resistance of staphylococci isolated from the skin of dogs with pyoderma.
OBJECTIVE
To determine the methicillin-resistant profile of staphylococcal isolates from the skin of dogs with pyoderma.


METHODS
90 dogs with pyoderma.


METHODS
Staphylococci isolated from dogs with pyoderma were tested for susceptibility to methicillin by use of a standard disk diffusion test with oxacillin disks. The DNA extracted from the isolates was tested for the mecA gene that encodes the penicillin-binding protein 2a (PBP2a) by use of a polymerase chain reaction (PCR) assay. The expression of PBP2a was determined with a commercial latex agglutination assay. Species of staphylococcal isolates were identified by use of morphologic, biochemical, and enzymatic tests.


RESULTS
Most of the isolated staphylococci were methicillin-susceptible, coagulase-positive Staphylococcus intermedius isolates. Whereas only 2 of 57 S. intermedius isolates were resistant to methicillin, approximately half of the isolates had the mecA gene and produced PBP2a. Staphylococcus schleiferi was the second most common isolate. Widespread resistance to methicillin was found among S. schleiferi isolates. More coagulase-negative S. schleiferi isolates were identified with mecA gene-mediated resistance to methicillin, compared with coagulase-positive S. schleiferi isolates.


CONCLUSIONS
The latex agglutination assay for the detection of PBP2a expression coupled with the PCR assay for the mecA gene may provide new information about emerging antimicrobial resistance among staphylococcal isolates.
Department of Comparative Medicine, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
Stephen A
SA
Kania
Nicola L
NL
Williamson
Linda A
LA
Frank
Rebecca P
RP
Wilkes
Rebekah D
RD
Jones
David A
DA
Bemis
D000818:Animals; D004283:Dog Diseases / Q000382:microbiology*; D004285:Dogs; D015870:Gene Expression; D007841:Latex Fixation Tests; D008712:Methicillin / Q000494:pharmacology*; D016106:Methicillin Resistance; D010068:Oxacillin; D046915:Penicillin-Binding Proteins / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011711:Pyoderma / Q000382:microbiology / Q000662:veterinary*; D013210:Staphylococcus / Q000187:drug effects* / Q000235:genetics
D046915:Penicillin-Binding Proteins; D008712:Methicillin; D010068:Oxacillin