Inducible clindamycin resistance in Staphylococcus aureus isolated from clinical samples.
OBJECTIVE
Clindamycin is commonly used in the treatment of erythromycin resistant Staphylococcus aureus causing skin and soft tissue infections. In vitro routine tests for clindamycin susceptibility may fail to detect inducible clindamycin resistance due to erm genes resulting in treatment failure, thus necessitating the need to detect such resistance by a simple D test on routine basis.


METHODS
247 Staphylococcus aureus isolates were subjected to routine antibiotic susceptibility testing including oxacillin (1ìg) by Kirby Bauer disc diffusion method. Inducible clindamycin resistance was detected by D test, as per CLSI guidelines on erythromycin resistant isolates.


RESULTS
36 (14.5%) isolates showed inducible clindamycin resistance, nine (3.6%) showed constitutive resistance while remaining 35 (14.1%) showed MS phenotype. Inducible resistance and MS phenotype were found to be higher in MRSA as compared to MSSA (27.6%, 24.3% and 1.6%, 4% respectively).


CONCLUSIONS
Study showed that D test should be used as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance.
Deotale
V
V
Department of Microbiology, Mahatma Gandhi Institute of Medical Sciences, Sevagram. Dist Wardha, M.S. - 442 102, India.
Mendiratta
D K
DK
Raut
U
U
Narang
P
P
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002981:Clindamycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*; D015533:Transcriptional Activation
D000900:Anti-Bacterial Agents; D002981:Clindamycin