Species distribution, Antibiotic sensitivity pattern and methicillin resistance of coagulase negative staphylococci isolated from various clinical samples at a tertiary care hospital

Abstract

Introduction: Coagulase negative staphylococci (CoNS) which were formerly regarded as contaminants of clinical samples, these undoubtedly need more recognition as their pathogenic potential is being increasingly understood and can cause serious human infections. They are causing problems to clinicians because of their drug resistance. Susceptibility testing should be done an isolate considered to be a cause of infection because of the resistance of these organisms to a wide spectrum of antimicrobial agents. Materials and Methods: Total One hundred strains of CoNS were isolated from 1486 clinical Samples processed (blood – 320, urine – 518, exudates – 522 and body fluids-126.Out of 100 CoNS were isolated from blood (35), urine (33), exudates (29), and body fluids (3) samples collected from both outpatients and inpatients of our Hospital. The organisms were identified and speciation was done by standard biochemical reactions. Antibiotic susceptibility testing was done by Kirby-Bauer disk diffusion method. Results: Out of total 100 strains of CoNS isolated, majority were in the age group of 15- 45 years (43%). Maximum isolates were from females 54(54%) than males 46 (46%). Maximum CoNS were isolated from blood (35%), followed by urine (33%), exudates (29%) and body fluids (3%). Most common species isolated was S. epidermidis (45%), followed by S. saprophyticus (22%), S. haemolyticus (13%), S. xylosus (5%), S. lugdunensis (4%), S. hominis (4%), S. capitis (4%) and S. cohnii (3%). Methicillin resistance was found in (61%) strains. Linezolid, Amikacin, Doxycycline, Gentamicin, Erythromycin, Norfloxacin and Ciprofloxacin were found to be the most effective antibiotics. Conclusion: S. epidermidis was the predominant species isolated. The most effective antibiotics were Linezolid and Amikacin. Keywords: S. epidermidis, Linezolid and Amikacin.