Inducible Clindamycin Resistance in Clinical Isolates of Staphylococci

Abstract

Background: The increasing frequency of methicillin-resistant Staphylococcus aureus (MRSA) infections and the changing patterns of antimicrobial resistance have led to renewed interest in the use of macrolide-lincosamidestreptogramin B (MLSB) antibiotics to treat such infections. However, resistance to MLSB antibiotics has been reported to be mediated by the msrA gene coding for efflux mechanism and erm gene which encoding the enzymes conferring resistance to MLSB antibiotics. Routine antibiotic sensitivity tests for clindamycin may fail to detect inducible clindamycin resistance due to the presence of the erm gene thereby resulting in failure of treatment. Aim: This study was undertaken to detect the presence of inducible clindamycin resistance among clinical isolates of staphylococci. Materials and Methods: A total of 247 strains of staphylococci (S. aureus -158 and coagulasenegative staphylococci (CoNS) -89), isolated from various clinical samples were included in this study. The isolates were identified using conventional methods. Inducible clindamycin resistance was tested by D test as per the CLSI guidelines. Results: Of total 247 isolates included in this study 52(21.05%) were MRSA, 67(27.13%) were Methicillin Resistant Coagulase Negative Staphylococci (MR-CoNS). Inducible clindamycin resistance was detected in 13.46 % of 52 MRSA and 2.99% of 67 MR-CoNS. Conclusion: Staphylococcal isolates, particularly MRSA, must be tested routinely by the D-test before treatment so that the clindamycin drug is used effectively and for maximum clinical utility.

Methicillin- and Inducible Clindamycin-ResistantStaphylococcus aureusamong Patients with Wound Infection Attending Arba Minch Hospital, South Ethiopia

“…The increasing incidence of methicillin resistance among Staphylococci has led to renewed interest in the usage of macrolide-lincosamide-streptogramin B (MLSB) antibiotics to treat S. aureus infections, with clindamycin being the preferable agent due to its excellent pharmacokinetic properties [10, 11]. However, widespread use of MLSB antibiotics has led to an increase in the number of Staphylococcal strains acquiring resistance to MLSB antibiotics [12–14].…”