Detecting pathogenic bacteria and antibiotic resistance can use both culture-based and non-culture-based methods. Culture-based methods are able to identify the antibiotic resistance phenotype of the pathogenic bacteria, but the culturing process may only select the dominant strain and lose the information of the other strains. Non-culture-based methods including qPCR and sequencing can avoid the bias of selection, but it is challenging for those methods to identify whether an antibiotic resistance gene is intracellular or not. In our study investigating the distribution of Salmonella enterica in North Carolina water bodies after Hurricane Florence, we combined qPCR quantification and culture isolation. As a result, we found that culturable Salmonella enterica were less prevalent than the genetic marker ttrC of Salmonella enterica in those water bodies. In addition, the antibiotic genes inside the Salmonella enterica isolates were similar among flooded and unflooded water bodies. However, combining both methods was time-consuming, and a dominant strain of Salmonella enterica was still possible to be selected during culturing. To overcome these limitations, we propose a new pathogenic detection method for bacteria and antibiotic resistance genes, combining immunomagnetic beads and loop-mediated isothermal amplification (LAMP). Briefly, the target pathogen will first be bound and accumulated to the immunomagnetic beads. Then, the cells will be lysed and the DNA of the pathogen will be released. Finally, the existence of the target antibiotic resistance gene will be checked by LAMP. Because LAMP is robust to PCR inhibitors which are widely distributed in environmental samples, this method will be beneficial for reducing the time for sample pre-processing. This method is still in development. Once it is proved practical, it can be applied to antibiotic resistance surveillance in the water environment and shorten the time for getting the results from days to hours.

Surveillance of pathogenic bacteria and antibiotic resistance genes in water

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.