Detection of Salmonella enterica Carrying a Putative qacA Biocide Resistance Gene in a River in Bali, Indonesia.

Abstract Salmonella enterica is the cause of foodborne diseases like salmonellosis which become major health issues in middle-income countries. However, the awareness about the presence of this pathogen in rivers from people is still low. This research aims to discover the presence of S. enterica and biocide resistance gene ( qacA ) in the river with high human activities in Bali. We conducted surveillance of S. enterica in Badung River from July 2022 until January 2023 by taking out the water with modified moore swab’s method. Isolated and detection of S. enterica and qacA gene was conducted by conventional and molecular methods. We found 15 out of 86 colonies from water samples were detected S. enterica serovar Typhimurium and 6 samples out from 86 colonies positive with qacA gene that provide resistance to biocide Thus bacteria was detected in the river’s part with human activities such as fishing, picnic, sport and waste disposal. S. enterica could be found in rivers with human activities and this pathogen starts to have resistance genes to biocide. Therefore, it is necessary to increase people’s awareness of the existence of S. enterica .