Clindamycin-resistance in methicillin-resistant Staphylococcus aureus isolated from animals.
Clindamycin is widely used in veterinary medicine to treat a variety of bacterial infections. Resistance to clindamycin amongst staphylococci may be due to modification of the ribosomal target site. Resistance due to this mechanism is encoded by the erm genes, which may be either constitutively or inducibly expressed. Inducible expression of resistance is not usually demonstrable by routine laboratory susceptibility testing, however, a relatively simple double disc agar diffusion test (D-test) may be used to detect the presence of inducible resistance. Two hundred and eighty-five isolates of methicillin-resistant Staphylococcus aureus (MRSA) isolated from infections in animals were tested using the D-test for the presence of inducible clindamycin resistance. One hundred and seven (71%) of the strains tested demonstrated inducible resistance to clindamycin, which were not detected on initial susceptibility testing. It has been shown that there is potential for staphylococci to develop resistance to clindamycin whilst on treatment when inducible resistance mechanisms are present. Therefore, routine screening for inducible resistance may be prudent.
Rich
M
M
Microbiology Department, IDEXX Laboratories, Sandbeck Way, Wetherby, West Yorkshire LS22 7DN, UK. mick-rich@idexx.com
Deighton
L
L
Roberts
L
L
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002371:Cat Diseases / Q000382:microbiology; D002415:Cats; D002981:Clindamycin / Q000494:pharmacology* / Q000627:therapeutic use; D004283:Dog Diseases / Q000382:microbiology; D004285:Dogs; D024901:Drug Resistance, Multiple, Bacterial; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D002981:Clindamycin