Methicillin-resistant coagulase-negative staphylococci isolated from healthy horses in Japan.
OBJECTIVE
To determine patterns of methicillin-resistant staphylococci isolated from apparently healthy horses.


METHODS
44 horses from 8 riding clubs in Japan.


METHODS
Methicill in-resistant staphylococci were isolated from the skin or nares, using a selective medium containing a beta-(symboric) lactam antibiotic, ceftizoxime. Clonality of isolates was determined by use of pulsed-field gel electrophoresis. Detection of mecA, mecl, and mecR1 genes was accomplished by use of polymerase chain reactions.


RESULTS
Of the 44 horses, 13 (29.5%) yielded 15 isolates of methicillin-resistant staphylococci. The 15 isolates were identified as 6 species (Staphylococcus epidermidis, S lentus, S saprophyticus, S xylosus, S sciuri, and S haemolyticus). However, methicillin-resistant S aureus was seldom isolated. Each isolate contained the mecA gene and had a high resistance to beta-lactam antibiotics. Some isolates also were resistant to other antibiotics such as erythromycin and kanamycin.


CONCLUSIONS
Methicillin-resistant coagulase-negative staphylococci that were highly resistant to various antibiotics were isolated from apparently healthy horses in Japan. These organisms must be considered a potential threat to horses and veterinarians who care for them.
Yasuda
R
R
Department of Microbiology and Immunology, Faculty of Agriculture, Kobe University, Japan.
Kawano
J
J
Onda
H
H
Takagi
M
M
Shimizu
A
A
Anzai
T
T
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001431:Bacteriological Techniques / Q000379:methods / Q000662:veterinary; D002352:Carrier Proteins / Q000235:genetics; D003030:Coagulase / Q000032:analysis*; D017931:DNA Primers; D004587:Electrophoresis, Agar Gel / Q000662:veterinary; D016521:Electrophoresis, Gel, Pulsed-Field / Q000662:veterinary; D006602:Hexosyltransferases; D006736:Horses / Q000382:microbiology*; D007564:Japan; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D002267:Muramoylpentapeptide Carboxypeptidase / Q000235:genetics; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012097:Repressor Proteins / Q000235:genetics; D012867:Skin / Q000382:microbiology; D013210:Staphylococcus / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D003030:Coagulase; D017931:DNA Primers; C101640:MecI protein, Staphylococcus; D046915:Penicillin-Binding Proteins; D012097:Repressor Proteins; C101641:mecR1 protein, Staphylococcus aureus; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase