Determination of Inducible Clindamycin Resistance Amongst Clinical Isolates of Methicillin-Resistant Staphylococcus aureus in Kaduna, Nigeria

Abstract

For quite a long time, mainly due to fewer treatment options, Clindamycin have been regarded as an alternative drug to effectively manage all Staphylococcus aureus infections. Strains with inducible clindamycin resistance (iMLSB phenotype) raise concerns because therapeutic failure may occur during treatment. Clindamycin is mostly regarded in treating serious infections that cannot be treated by other antibiotics, as it may cause colitis or mild diarrhea. A double disc diffusion test (D-test) for detecting inducible resistance to clindamycin in erythromycin-resistant methicillin-resistant S. aureus was performed by placing a 15µg erythromycin disc in proximity to a 2µg clindamycin disc in adjacent positions. For erythromycin-resistant isolates, D-test can help to determine whether clindamycin could be used as a therapeutic option (reported as susceptible when the D-test is negative or reported as resistant when the D-test is positive). Twenty (20) out of the 30 (thirty) isolates collected were confirmed to be determined by D-test as per CLSI guidelines. Fifteen (15) isolates were D-test Negative, 5 were resistant to both Erythromycin and Clindamycin, and none was D-test positive. D-test should be included as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance in staphylococci for the optimum treatment of patients.