Multiple antibiotic resistance iIndex of EscherichiaColi isolates in a tertiary hospital in south-west Nigeria

Abstract

Background: The effectiveness of available antibiotics is reducing as  microorganisms device means of evading its effects, resulting in the development of superbugs. Pathogens previously susceptible are becoming resistant, and spreading beyond the hospital environment. This change is a major concern for infection control and prevention and a huge economic burden for health care. This study aims to determine the drug sensitivity pattern of E. coli isolated in a tertiary hospital lab
Methodology: Gram negative bacilli, lactose fermenter, motile, indole positive,  glucose fermenter, gas producing isolate were identified as E.coli. Antimicrobial susceptibility testing to commonly prescribed antibiotics was carried out using the modified Kirby Bauer method and reported with the Clinical and Laboratory Standard Institute Interpretative chart. Mulitiple Antibiotic Resistance index was calculated as number of antibiotics to which isolate is resistant divided by the total number of antibiotics against which isolate was tested.
Result: Five hundred and twenty–seven isolates were identified, among which a high rate of resistance to cefuroxime (407), high rate of intermediate susceptibility to nalidixic acid (264) and high rate of sensitivity to ceftriaxone (388) was noted. Sixty percent of the isolates had an index 0.2. Of the 40% with Multiple Antibiotic Resistance index > 0.2, 61 % were from inpatient samples.
Conclusion: The high Multiple Antibiotic Resistance index of the E. coli isolates indicates previous exposure to antibiotics and development of resistance to commonly prescribed antibiotics, hence, antimicrobial susceptibility testing is imperative in selecting therapeutic options. Attention also needs be paid to effective infection control and prevention to curb its spread among individuals.