Prevalence and antimicrobial susceptibility pattern of Coagulase-negative Staphylococcus

Background: The vast majority of infections assumed to be caused by Coagulase-negative Staphylococcus (CoNS) are a significant consequence of hospitalization. Current antibiotic-prescribing practices, including preoperative antibiotic prophylaxis, have led to the selection of antibiotic-resistant organisms. The purpose of the present study is to provide a current scenario, species distribution in clinical specimens and antimicrobial susceptibility testing, mainly to screen for methicillin resistance, multi-drug resistant strains. Methodology: Total 113 isolates of Coagulase- negative Staphylococci were isolated from clinical specimens over a 6 month period in a non consecutive non random manner. Antimicrobial resisitance pattern to 20 antimicrobial agents were performed Results: Coagulase-negative Staphylococci consisting of 10 different species were isolated. Staphylococcus epidermidis (49), Staphylococcus haemolyticus (19), Staphylococcus hominis (11) were the most commonly isolated species. Antimicrobial susceptibility pattern revealed that they were all universally sensitive to vancomycin and linezolid. Methicillin resistance was noted among 48% of the isolates. Maximum resistance was seen with penicillin (91%) and least with Teicoplanin(3%) Conclusion: CoNS are a significant cause of nosocomial bacteremia and their susceptibility to beta-lactamase-stable penicillins is unpredictable. Hence the methicillin resistant CoNS which are also multidrug resistant act as a reservoir for drug resistance in hospitals. Low level glycopeptide resistance encountered in recent years limits its use. For all these reasons, accuracy and promptness in the detection of resistance pattern is of key importance to ensure appropriate antibiotic treatment in infected patients as well as control the spread of resistance in hospital environments.