The aim of the study was to speciate the CoNS isolates from various clinical samples and to study their antibiotic susceptibility pattern. Over a period of 18 months from December 2013 to May 2015, 142 Coagulase negative staphylococcal isolates grown in pure culture from various clinical samples were isolated and identified by standard procedure. Speciation of CoNS was done using novobiocin resistance test, urease activity, ornithine decarboxylase, pyrrolidonyl arylamidase and aerobic acid production from mannose. Out of 142 isolates, 56.3% were S. hemolyticus, 26.8% S. epidermidis, 5.6% S. warneri, 4.9% S. saprophyticus and 3.5% S. schleiferi sub sp schleiferi. Isolation of CoNS from urine, blood, conjunctival swab and pus were 62%, 12.7%, 7.8%% and 6.3% respectively. Antibiotic susceptibility testing showed maximum resistance to penicillin (91.6%). No resistance was noted against linezolid and vancomycin. Methicillin resistance was noted in 73.9% % of the isolates; 7% of isolates showed erythromycin induced clindamycin resistance. 45% of the total CoNS isolates were found to be multidrug resistant. The increasing recognition of pathogenic potential of CoNS and emergence of drug resistance amongst them denotes the need to adopt simple laboratory procedures to identify and understand the diversity of staphylococci isolated from clinical material.

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