Background & objectives: Streptococcus pneumoniae continues to be a major cause of morbidity and mortality in developing countries. The emerging resistance to some common antibiotics compounds the problem. There arises a need to monitor the resistance pattern and map serotype distribution in different geographic locations. The present study was undertaken to determine the serotype prevalence and antibiotic susceptibility of clinically significant S. pneumoniae isolated from a tertiary care hospital in south India.
Methods: A total of 150 clinical isolates from invasive and other clinically significant pneumococcal infections were serotyped and screened for susceptibility to commonly used antibiotics by standard and modified laboratory procedures.
Results: Majority (59.3%) of the isolates belonged to one or other of the serotypes 1, 6, 19, 5, 23 and 7. Serotype 1 was the commonest isolate from patients of meningitis and empyema followed by pneumonia. Nineteen isolates (12.6%) were nonvaccine type. Eleven (7.3%) isolates were relatively resistant to penicillin (minimum inhibitory concentration was between 0.1 and 1 microgram/ml) and 64 were resistant to one or more antibiotics. Resistance was distributed equally among the predominant serotypes.
Interpretation & conclusion: The common serotypes responsible for significant infections were similar to those reported in some other studies from India, with minor variations. Resistance to cotrimoxazole and tetracycline was predominant followed by chloramphenicol. Low level resistance to penicillin was observed but no isolate had absolute resistance. This calls for monitoring of resistance and mapping of serotype distribution from various parts of India.