Molecular Characterization of Optochin Resistant Strep pneumoniae

Out of 1500 nasopharyngeal swab samples collected from patients who were admitted to different maternity clinics in Dhaka city, 111 optochin resistant strains were isolated. As a confirmatory test of Streptococcus pneumoniae, i.e., Bile solubility was checked. A total of 37 optochin resistant bile soluble isolates were obtained, designated as optochin resistant bile soluble S. pneumoniae as other - hemolytic streptococci are not bile soluble. For further identification, bile soluble isolates were subjected to PCR of the lytA gene specific for S. pneumonia an 32 (87%) isolates were found to be lytA positive. Thus, it can be suggested that for confirmatory identification of S. pneumoniae, bile solubility test together with PCR of lytA gene should be carried out in routine microbilogical investigation. Antimicrobial susceptibility test revealed multiple drug resistance among the organisms. About 64.86% were resistant to more than three agents (multi drug resistant). Higher MIC values were obtained for azithromycin (256 microg/ml), erythromycin (256 microg/ml) and ciprofloxacin (8 microg/ml) considering the CLSI break point.