Raw vegetables as a vehicle for pathogens and antimicrobial resistances in the Indian food-chain

Introduction: Antimicrobial resistance (AMR) has arisen as one of the fronting threats to public health. It possesses a multidimensional (social, economic, and environmental) challenge encompassing the food production system, influencing human and animal health. Antibiotics and antibiotic-resistant pathogenic bacteria are present in the environment naturally more important, anthropogenically influenced. Resistances can disseminate via raw vegetables consumption to human. But studies integrating the environment into health risks assessment by AMR transmission are rare, esp. in the south Asian region.

Goals: The study aims to investigate the role of vegetables in AMR spread by an agroecosystem exploration from a One Health perspective in Ahmedabad, India. This abstract focus on (resistant) human pathogenic bacteria in soil and raw vegetable.

Materials & Methods: A total of 312 samples were collected from peri-urban agricultural farms from 08/2022-05/2023. It comprises most frequently produced and raw consumed vegetables (spinach, spring onion, green garlic, coriander, radish) and the respective soils. Analysis of indicator bacteria in crops for human consumption as recommended by WHO (E. coli, Salmonella, Klebsiella, Pseudomonas) followed cultural standard procedures. AST pattern of the isolates were done by Kirby-Bauer disk diffusion technique using Muller Hinton Agar and CLSI guidelines. Microbiome and resistance genes analysis are recently ongoing.

Results: The microbiological assessment recorded that both soil and vegetable samples had considerable levels of microbial contamination, with highest loads of Salmonella (86.5% positive vegetable samples), and lowest of E. coli (6.4%). The corresponding soil samples were positive from 96.15%, and 14.7%.

AMR patterns of isolated shows multidrug resistance to at least 4 antibiotics in 36.4% of E. coli and 81% of Salmonella. 32.6% of Klebsiella but no Pseudomonas showed multidrug resistances.

Summary: The study shows the importance of microbiological assessment in agroecosystems in a country like India, one of the largest producers of fresh vegetables. Resistant pathogens found pose a certain health risk for consumers.