E-Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2021

Surveillance of antimicrobial resistant microorganisms across different reservoirs through culture-based techniques (#225)

Thanavit Jirapanjawat 1 2 , Paul Cordero 1 2 , Rachael Lappan 1 2 , Laura Perlaza-Jimenez 1 2 , Chris Greening 1 2
  1. Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
  2. Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Victoria, Australia

An emergence of antimicrobial resistance has become a major public health concern since the discovery of the first antibiotic. It is important to monitor and reduce the spread of antimicrobial resistant genes between reservoirs to prevent the development of multidrug resistant microorganisms. The Greening lab as a part of the Centre to Impact Antimicrobial Resistance has developed and optimised a surveillance program to detect antimicrobial resistance from diverse samples through standardised cultivation techniques and antimicrobial susceptibility testing. Samples from agricultural lands and products, wastewaters, and urbanised areas were serially diluted and plated onto selective culture media. We have isolated 81 pathogenic and non-pathogenic strains from the selective culture plates and these isolates were identified through Sanger sequencing of the universal 16S rRNA gene. Susceptibility to antimicrobials was tested using Sensititreā„¢ plates, which contain a range of antimicrobial agents at different concentrations in a 96-well plate format. Our results demonstrate that several Gram-negative infectious strains from families including the Enterobacteriaceae, Aeromonadaceae, and Pseudomonadaceae, exhibit multidrug resistance, especially against cefazolin, ampicillin, polymyxin B, colistin, and gentamicin. We also detected numerous Gram-positive strains, including from the Streptococcaceae, Staphylococcaceae, and Bacillaceae families, to express antimicrobial resistance especially against clindamycin and tigecycline. The 81 isolated strains have been subject to whole genome sequencing, which will aid in linking phenotypes to genotypes. Overall, our protocol provides a cost-effective and time-efficient approach to early detect antimicrobial resistance. This will help prevent the spread of resistant genes in the environment and impede the development of superbugs.