Inducible clindamycin resistance among Staphylococcus aureus isolates from skin and soft tissue infections: a study from Brunei Darussalam

Kavitha PRABHU, Terrence Rohan CHINNIAH, Rashidah PPHA AHMAD, Noor Amalina ABU BAKAR, Julaini SAFAR,

Microbiology Laboratory, Department of Laboratory Services, RIPAS Hospital, Brunei Darussalam

ABSTRACT

Introduction: Clindamycin is one of the important antibiotics in treating Staphylococcal soft tissue infections. Clinical failure of clindamycin therapy has been reported to be due to inducible clindamycin resistance which cannot be detected by routine in-vitro antibiotic susceptibility testing. This study was undertaken to detect the presence of inducible clindamycin resistance among Staphylococcus aureus (S. aureus) isolates and its association with methicillin resistance. Materials and Methods: D zone test was performed by incorporating it in the routine antibiotic susceptibility test for all S. aureus isolates and methicillin resistance was detected by doing cefoxitin disk diffusion test according to Clinical Laboratory Standard Institute (CLSI) guidelines 2014. Results: Forty four among 56 erythromycin resistant S. aureus isolates were inducible clindamycin resistant (78.6%). It was also observed that percentages of inducible resistance and constitutive clindamycin resistance were higher amongst MRSA as compared to MSSA (60.7%, 7.1% and 9.9%, 2.4% respectively). Conclusion: Clinical laboratories should perform D zone test routinely to guide the clinicians about the inducible clindamycin resistance in S. aureus isolates and to prevent therapeutic failure.

Keywords: Clindamycin resistance, D zone test, Methicillin resistant staphylococcus aureus

Correspondence author: Kavitha PRABHU. Division of Microbiology, Department of Pathology and Laboratory Services, RIPAS Hospital, Brunei Darussalam. Tel: +673 8798489

Brunei Int Med J. 2015; 11 (5): 235-240