Comparison Of Standard Mueller–Hinton Agar And Modified Mueller–Hinton Agar In Antibiotic Sensitivity Testing Of Escherichia Coliabstract

Abstract

Introduction: Antimicrobial resistance is a global health problem that occurs when microorganisms no longer respond effectively to antimicrobial drugs, resulting in persistent infections and an increased risk of disease transmission. Escherichia coli is one of the bacterial species commonly used in antimicrobial susceptibility testing. Mueller–Hinton Agar (MHA) is widely used as a standard medium for antimicrobial susceptibility testing because it supports bacterial growth and allows the formation of inhibition zones. However, the availability and cost of standard media may become limitations in some laboratory settings. Therefore, modified MHA using locally available and affordable nutritional ingredients may serve as an alternative medium.

Objective: This study aimed to compare the suitability of standard MHA and modified MHA for antimicrobial susceptibility testing of E. coli.

Method: This study used a qualitative experimental design. Modified MHA was prepared using nutritional ingredients consisting of beef extract, casein hydrolysate, agar, and corn extract. E. coli was inoculated onto the standard and modified MHA media. Bacterial growth and the formation of inhibition zones were then observed and compared descriptively.

Result: The results showed that the modified MHA containing beef extract, casein hydrolysate, agar, and corn extract was able to support the growth of E. coli. In addition, inhibition zones were observed in the antimicrobial susceptibility testing, indicating that the modified medium could support antimicrobial susceptibility testing of E. coli.

Conclusion: Modified MHA prepared from relatively accessible and affordable nutritional ingredients has potential as an alternative medium for antimicrobial susceptibility testing of E. coli. However, further quantitative studies are needed to compare inhibition-zone diameters between modified and standard MHA and to determine the equivalence of antimicrobial susceptibility testing results.

Keywords: Mueller–Hinton Agar, modified medium, Escherichia coli, antimicrobial susceptibility testing, antimicrobial resistance