Characterization and Antibiotic Susceptibility of Coagulase Negative Staphylococci from Patients Admitted In Dr.Prabhakar Kore Hospital and MRC with Special Reference to Methicillin Resistance

Abstract

INTRODUCTION: ABSTRACT: CONS inhabitants of skin and mucous membranes are known to be opportunistic pathogens causing infections in immuno compromised hosts or in patients with medical devices such as intravascular and peritoneal dialysis, catheters, prosthetic heart valves and orthopaedic prosthesis. Today it is well established beyond doubt as the causative agents of various diseases. They cause infections like septicemia, endocarditis, osteomyelitis, urinary tract infection and peritonitis. This study has been undertaken with a view to a speciate the CONS, and also to detect the production of slime and beta-lactamase. As slime is one of the virulence marker, slime is believed to make the micro organism insusceptible to antibiotics. We have taken the CONS isolated from various clinical specimens like pus, urine, blood, endotracheal tip, cervical swab, pleural fluid, amniotic fluid and CSF during one year period. Antibiotic sensitivity pattern studied with special reference to methicilline. MATERIAL AND METHODS The present study was undertaken at the Department of Microbiology, J N Medical College, Belgaum during the period from 01-01-09 to 01-01-10. A total of 120 CONS were isolated from various clinical samples were included in the study. CONS were isolated based on, which showed gram positive cocci in cluster with pus cells on gram stain, pure growth on culture media. Slide coagulase and tube coagulase negative were taken. All these were speciated according to the Kloos and Schleifer flow chart. These isolates were also tested for slime production by tube method and beta- lactamase production by chromogenic cephalosporin method using nitrocefin disk. IX Antibiomicrobial sensitivity testing was performed by Kirby Bauer disc diffusion method on Muller-Hilton agar plate. RESULTS Out of 120 isolates, 78 ( 65.5% ) were S.epidermidis, 18 ( 15% ) S.saprophyticus, 12 ( 10.83% ) S.haemolyticus, 04 ( 3.33% ) S.sciuri, 02( 1.67% ) each of S.hominis, S.xylosus and S.cohnii and 01 ( 0.83% ) S.simulans. The majority of the isolates were from pus/wound discharge 58( 48.33% ) followed by blood 27( 22.50% ) and urine 23 ( 19.17% ) . Out of 120, 67 ( 55.83% ) were slime producing organisms. S.epidermidis showed maximum slime production. 45( 37.5% ) isolates showed beta-lactamase production. 48( 40% ) species showed resistance to methicillin. Most of the species showed resistance to penicillin 90( 75.17% ) followed by ampicillin 87( 72.5% ) and gentamycin 68( 56.66% ) . CONCLUSION: This study concludes that CONS isolated from clinical specimen showed more resistant to penicillin, ampicillin, gentamycin even to methicillin. This has become a serious clinical and epidemiological problem, as resistance to methicillin implies resistance to all β-lactum drugs.