Distribution of multiple antibiotic resistance index in a setting where fluoroquinolones and â- lactams are used arbitrarily.

Abstract

Antimicrobial resistance is a public health issue globally. Unregulated use of antimicrobials is rife in our setting, and multiple antibiotic (MAR) index is an inexpensive surveillance tool to monitor antimicrobial resistance in an environment. The study aimed to determine the MAR index among Gram negative bacilli from various locations in a tertiary hospital as well as the effect of concurrent ESBL production and ciprofloxacin resistance on MAR index. A total of 254 non-repetitive Gram-negative bacilli recovered from various clinical specimens were used. The isolates were identified and disc susceptibility tests as well as phenotypic detection of extended spectrum â-lactamase were performed on all isolates using standard techniques. MAR index was calculated using a formula. A total of 234 (92.13%) of the isolates had MAR index >0.2. The MAR index of Pseudomonas aeruginosa was significantly higher than Escherichia coli, Proteus mirabilis and Raoultella ornithinilytica (p<0.05). The prevalence of ESBL production was higher among those that were ciprofloxacin resistant compared with those that were ciprofloxacin susceptible, with only that among E. coli reaching statistical significance (p=0.0007). The MAR index of E. coli isolates was significantly higher for ESBL-producing and ciprofloxacin resistant strains (p<0.001), ESBL-producing but ciprofloxacin susceptible strains (p<0.05), and ESBL-non-producing ciprofloxacin resistant strains (p<0.05) than for ciprofloxacin susceptible and non-ESBL producing strains. Isolates from the ICU had a significantly (p<0.05) higher MAR index than isolates from the Children's Emergency Ward, Labor Ward, Out-patient Department, and Surgical Ward. Antimicrobial agents are misused in the environments where more than 90% of the isolates come from. Only among E. coli strains was a significant correlation between ESBL production and ciprofloxacin resistance seen. Isolates recovered from ICU had a higher mean MAR index. We recommended the implementation of an antibiotic stewardship program.