PHENOTYPIC DETERMINATION OF INDUCIBLE CLINDAMYCIN RESISTANT AND METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS FROM CLINICAL ISOLATES OF KHYBER TEACHING HOSPITAL, PESHAWAR

Abstract

Methicillin Resistant Staphylococcus aureus (MRSA) is a major pathogen involved in nosocomial infections and to some extent, in community acquired infections. Among Macrolide Lincosamine Streptogramin B (MLSB) class of drugs, Clindamycin was vigorously preferred for treating staphylococcal infections in the past few decades but, some genetic factors i.e. erm and msrA genes contribute in developing Inducible Clindamycin Resistance (iCR). Sensitivity tests performed on a routine basis cannot detect inducible resistance and may result in the failure of Clindamycin to be used as an effective medication. This study aimed to detect the phenotype of MRSA and iCR S. aureus from the clinical samples of Khyber Teaching Hospital, Peshawar. A total of 204 samples were collected randomly from each gender, 130 (63.72%) samples were isolated as S. aureus, while 74 (36.27%) were other bacterial species. Double disk diffusion (D-test) was performed to detect iCR phenotype, and 80 (61.5%) isolates showed iCR, while 50 (38.4%) were negative in this regard. MRSA phenotype was determined by strains conferring resistance to Cefoxitin antibiotic, which resulted in 84 (64.6%) isolates of MRSA and 46 (35.3%) of Methicillin Sensitive Staphylococcus aureus (MSSA). Antibiogram analysis showed efficient antimicrobial activity by Tigecycline 129 (99.2%), Fusidic Acid 126 (96.9%), and Doxycycline 124 (95.3%), while the highest resistance pattern was recorded against Ciprofloxacin 31(23.8%) and Clindamycin 28(21.5%). Our study concludes that misuse of antibiotics should be avoided to inhibit the spread of MRSA, and implementation of D-test regularly in hospitals is crucial.