Survey of Antibiotic Resistant Bacteria in Lake Gyeongpo, Korea

The emergence and spread of antibiotic-resistant bacteria have been increasing with anthropogenic contamination. Understanding the prevalence and distribution of these resistant bacteria in environments is crucial for effectively managing anthropogenic pollutants. Lake Gyeongpo in the Gangwon Province of South Korea is known for its diverse ecological features and human interactions. The lake is exposed to pollutants from non-point sources, including urban areas, agricultural practices, and recreational activities, which can introduce antibiotics and foster antibiotic resistance in bacteria. The present study investigates Lake Gyeongpo as a potential reservoir for antibiotic-resistant bacteria in a natural eco-system. A total of 203 bacterial isolates were collected from six sampling locations in Lake Gyeongpo during May, July, and November 2022. Most isolates were tax-onomically identified as Pseudoalteromonas , Bacillus , Shewanella , and Vibrio spp.; their abundance showed a spatiotemporal distribution. An antibiotic susceptibility test was conducted on 75 isolates using the disk diffusion method with six drugs according to the CLSI guideline; 42 isolates were resistant to one or more antibiotics. Among these, 15 isolates were identified as multi-drug resistant bacteria. This finding suggests the potential anthropogenic impact on Lake Gyeongpo and provides valuable insights into the dissemination of antibiotic resistance caused by anthropogenic pollutants.