Multidrug-Resistant Aeromonas hydrophila in Retail Fish Markets: Prevalence, Survival and Public Health Implications

Abstract

Aeromonas hydrophila is a widespread opportunistic pathogen commonly associated with aquatic environments and is responsible for infections in fish and other aquatic organisms. This study investigated during January to February 2025, the prevalence, survival ability and antibiotic resistance of Aeromonas hydrophila isolated from local fish markets in and around Salem, Tamil Nadu. The bacterium was detected in 33.29% out of 48 fish samples obtained, indicating a significant level of contamination, while 20% of Musca domestica samples (1/5), also tested positive, suggesting their role as potential mechanical vectors. Antibiotic susceptibility profiling revealed that the potential isolate (CS1) showed resistant to ampicillin, amoxyclav, cephalexin, cefazolin, methicillin, oxacillin and vancomycin, indicating the presence of multidrug resistant strains. Survival studies showed that Aeromonas hydrophila could adhere to and persist on commonly used market surfaces such as stainless steel, wood, iron and thermocol. It also exhibited tolerance to a wide range of pH and temperature conditions. Experiments with common Indian cooking ingredients demonstrated varying inhibitory effects and several disinfectants and antiseptics were effective against the isolates. These findings highlight Aeromonas hydrophila contamination may cause public health issues such as gastrointestinal tract infections, septicemia, peritonitis in specifically in immunosuppressive persons. Emphasize the need for improved hygiene and handling practices in fish markets.