Inducible clindamycin resistance in clinical isolates of staphylococci in a rural hospital

Authors:Kalpana Date , Dr Mamta Choudhary , Dr Vilas Thombare
Int J Biol Med Res. 2012; 3(3): 1912 - 1915.  |  PDF File

Abstract

The increasing frequency of Methicillin resistant Staphylococcus aureus (MRSA) infections and the changing patterns in antimicrobial resistance have led to renewed interest in the use of macrolide lincosamide–streptogramin B (MLSB) antibiotics to treat such infections Therapeutic failure to clindamycin has been reported due to mechanisms which confer resistance constitutively, or by the presence of low level inducers which can lead to therapeutic failure. This study was undertaken to detect the presence of inducible clindamycin resistance among clinical isolates of staphylococci. Inducible clindamycin resistance was tested by the clindamycin disc induction test (D test) as per the CLSI recommendations. A total of 140 strains of staphylococci (Staphylococcus aureus-70 and CONS -70), isolated from various clinical samples at our institution, were included in this study. The isolates were identified using conventional methods. Of total 140 isolates included in this study 19(13.57%) were MRSA, 51(36.42%) were Methicillin Sensitive Staphylococcus Aureus (MSSA), 19(13.57%) were Methicillin Resistant Coagulase Negative Staphylococci (MRCONS) and 51(36.42%) were Methicillin Sensitive Coagulase Negative Staphylococci (MSCONS). Inducible clindamycin resistance was detected in 10.52% of 19 MRSA, 5.26% of 19 MRCONS and 3.92% of 51 MSCONS isolates and in none of the 51 MSSA. In our setting, clindamycin can be used for the treatment of infections due to staphylococci, but we recommend that staphylococci isolates, particularly MRSA, should be tested by the D-test before treatment so that the drug is used effectively and for maximum clinical utility.