Determination of Colistin Resistance by Simple Disk Diffusion Test Using Modified Mueller-Hinton Agar.

ABSTRACT:

Background

Colistin has become a last-resort antibiotic for the management of multidrug-resistant gram-negative bacteria. The disk diffusion test is cheap and easy to perform but may be unreliable for colistin susceptibility testing due to poor diffusion of the large colistin molecule. An improved agar diffusion test would increase the reliability of colistin susceptibility testing. This study aimed to modify Muller-Hinton agar (MHA) to improve colistin diffusion in agar.

Methods

MHA was modified by reducing the agar concentration from 100% to 30% and supplementing with protamine. We tested 60 gram-negative clinical isolates of Pseudomonas aeruginosa (N=27) and Acinetobacter calcoaceticus-baumannii complex (N=33). Disk diffusion test results were interpreted ba

SUBMITTER: Uwizeyimana JD 

PROVIDER: S-EPMC7054692 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature