Antibiotic resistance profiles of Escherichia coli and Salmonella spp. isolated from chicken meat sold in traditional markets in Gresik District, East Java']Java, Indonesia

Background: Antibiotic resistance in the poultry industry poses a global threat. The occurrence of resistance in humans can occur through foodstuffs of animal origin, one of which is chicken meat, which is sold in traditional markets. Traditional markets are synonymous with dirty environments and poor sanitation and hygiene. Aim: The purpose of this study was to determine the contamination of Escherichia coli and Salmonella spp. and antibiotic resistance in chicken meat from traditional markets in the Gresik District. Methods: The samples were collected by random sampling following the general procedures of the FDA guidelines for meat sample handling. The samples were then transported in a cold box containing ice packs at approximately 4 degrees C. Laboratory testing was conducted at the Veterinary Public Health Laboratory, Faculty of Veterinary Medicine, Wijaya Kusuma University, Surabaya. Samples were cultured on selective MacConkey Agar and Salmonella Shigella Agar, followed by Gram staining, biochemical tests, and antibiotic susceptibility testing on Mueller Hinton Agar using the Clinical and Laboratory Standards Institute (CLSI, 2022) guidelines. Results: The results of antibiotic resistance to E. coli showed resistance to amoxicillin 75% (47/61), ampicillin 75% (47/61), oxytetracycline 59% (36/61), streptomycin 49% (30/61), sulfonamide trimethoprim 44% (27 /61), ciprofloxacin 29% (18/61), gentamicin 27% (17/61), chloramphenicol 13% (8/61), and azithromycin 3% (2/61), while Salmonella spp. showed antibiotic resistance oxytetracycline 84% (27/32), azithromycin 65% (21/32), sulfonamide trimethoprim 53% (17/32), ampicillin 43% (14/32), streptomycin 34% (11/32), amoxicillin 31% (10/32), ciprofloxacin 15% (5/32), gentamicin 12% (4/32), and chloramphenicol 9% (3/32). Antibiotics that have experienced multidrug resistance (MDR) against E. coli bacteria by 42% (26/61) and Salmonella spp. by 43% (14/32). Conclusion: This study found high levels of antibiotic resistance in E. coli and Salmonella spp. isolated from chicken meat sold in traditional markets in Gresik District, with the highest resistance observed against amoxicillin, ampicillin, and oxytetracycline. MDR was detected in 42% of E. coli and 43% of Salmonella spp. isolates. These findings suggest the potential misuse of antibiotics in poultry production and underscore the need for better surveillance, hygiene control in markets, and responsible antibiotic use to prevent the transmission of resistant bacteria to humans.