Detection of inducible clindamycin resistance among clinical isolates of staphylococcus aureus in a tertiary care hospital

About author
¹Nilima R. Patil*, ¹Ulhas S. Mali, ¹Sunanda A. Kulkarni, ¹Shivdas Mali, ²Vijay Mane, ³M. V. Ghorpade
¹Dept. of Microbiology, Bharati Vidyapeeth, University Dental College & Hospital, Wanlesswadi Sangli
²Department of Microbiology,MGMS Medical College, Navi Mumbai
³Department of Microbiology, KIMS, Karad, India

Abstract
The resistance to different antimicrobial agents among staphylococci is an increasing problem. Clindamycin (CL) is considered to be one of the alternative drug in these infections. Inducible clindamycin resistance cannot be detected by the routine conventional antimicrobial susceptibility test. This study demonstrates a simple, reliable method (double-disc diffusion test) for detecting inducible resistance to clindamycin in erythromycin-resistance (ER-R) isolates of S. aureus. Therefore, this study was undertaken to detect inducible clindamycin resistance among isolates of Staphylococcus aureus. To detect the prevalence of inducible clindamycin resistance among clinical isolates of Staphylococcus aureus in our hospital by Disk approximation test (D-test).  A total 450 isolates of Staphylococci aureus from various clinical samples were used in this study.  A total 135 (30%) isolates were resistant to Erythromycin. Out of these 84 isolates were MRSA and 51 were MSSA. Constitutive clindamycin resistance (cMLSB) was 03.55%, Inducible clindamycin resistance (iMLSB) was 11.11% and MS Phenotype was 15.33% in all isolates of Staphylococci aureus. Conclusion: – In conclusion the D–test is an easy, simple, test to perform along with routine susceptibility testing therefore D-test should be used as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance.
Key words: Staphylococcus, Constitutive clindamycin resistance, Inducible clindamycin resistance, MS Phenotype, D-test.