Multiple antibiotic resistance indexing of non-fermenting gram-negative bacilli

Abstract

Objective: The multiple antibiotic resistance (MAR) indexing and finding multidrug-resistant (MDR) bacteria will help to indicate the origin from the high risk of contamination where the antibiotics are often used. Hence, this study was carried out to give the MAR index of non-fermenting Gram-negative bacilli in a tertiary care hospital which would help our infection control team also. Methods: Drug resistance was tested using Kirby-Bauer disc diffusion method. MAR index was calculated using the formula, a/b (where, a=number of antibiotics to which the organism was resistant and b=total number of antibiotics to which the organism was tested). Results: Of 240 Gram-negative non-fermenters isolated, 117 (49%) strains were >0.2 of MAR index, 95 (81%) was from inpatient department. 73 (62%) were hospitalized for more than 3 days, 44 (38%) was from surgery department. 49 (42%) was wound specimen. Out of 117 multiple antibiotic resistant isolates, 99 (85%) were MDR isolates. Conclusion: Nearly 51% prevalence of isolates >0.2 MAR index shows that the source of contamination can still be brought up down by proper surveillance and management with proper usage of surface and skin disinfectants, especially in surgery ward where the MAR index has indicated more usage of antibiotics.