Characterization and Antibiotic Susceptibility Pattern of Nonfermenters

Abstract

INTRODUCTION : ABSTRACT Nonfermenters are being isolated from various clinical specimens. Although frequently considered as contaminants, the pathogenic potential has been proved beyond doubt by their frequent isolation from clinical material and their association with disease. Most of the Nonfermenters are resistant to routinely used antibiotics. This study has been undertaken with a view to know the incidence of pathogenic nonfermentative gram negative bacilli from various clinical specimens like pus, urine, sputum, blood, aural swabs, nasal swabs, CSF, wounds, endotracheal aspirates etc. during one year period. Sensitivity of the organisms to antimicrobial agents has also been tested and the results reported. MATERIAL AND METHODS : The present study was undertaken at the Department of Microbiology, J.N Medical college, Belgaum during the period from 01/01/2007 to 01/01/2008. A total of 130 nonfermenters isolated from clinical samples such as pus, sputum, urine, blood, ear swab, catheter tip and pleural fluid were included in the study. Isolates from clinical samples which gave an alkaline/alkaline ( K/K ) or alkaline/neutral ( K/N ) reaction on Triple sugar iron agar. All these were identified by a battery of tests as per standard laboratory techniques. Antimicrobial sensitivity testing was performed on the 130 isolates by Kirby bauer disc diffusion method on Muellor Hinton Agar plate using standard antimicrobial agents. RESULTS : Out of 130 isolates, 107( 82.3% ) were Pseudomonas aeruginosa, 20( 15.4% ) were Acinetobacter baumanii, 1( 0.76% ) each of A.lwofii, B.psudomallei and IX Moraxella were isolated. The majority of the isolates were isolated from pus/wound discharge ( 78) followed by blood ( 30) , urine ( 11) , sputum ( 6) and 2 each from catheter tip and ear swab. Out of 107 isolates of P.aeruginosa 96.2% were sensitive to Meropenem, 50% to Ciprofloxacin, 49.5% to Amikacin. Isolates were least sensitive to Ampicillin, doxycycline, Cefotaxime and Piperacillin. A.baumanii was more sensitive Meropenem ( 96.2% ) followed by Ciprofloxacin ( 45% ) , Doxycycline ( 35% ) and Amikacin( 25% ) . CONCLUSION : This study shows that Nonfermenters are isolated from clinical specimens frequently and are resistant to most of the routinely used antibiotics showing that these organisms need to be taken seriously and identified and not just regarded as contaminants.