DETECTION OF PARASITES AND COLIFORM BACTERIA IN VEGETABLES FROM FRESH-FOOD MARKETS IN NAKHON NAYOK PROVINCE, THAILAND

Abstract

Food-borne infectious diseases from parasites and bacteria are major global public health problems. A common source of food-borne infectious pathogens is fresh vegetable. In this study, sedimentation technique and the Most Probable Number (MPN) method was used to identify parasites and quantify coliform bacteria and Escherichia coli respectively in fresh vegetable (celery, coriander, leek, lettuce, and peppermint) samples (n = 375) from a fresh food market each located in four districts (Ban Na, Mueang, Ongkharak, and Pak Phli) of Nakhon Nayok Province, Thailand. Overall prevalence of parasite contaminated vegetables was 36%, celery with the highest (60%) and lettuce the lowest (13%) value; Ascaris lumbricoides was most predominant parasite; and Ongkharak District had the highest prevalence (78%). Nine percent of samples were contaminated with <3 MPN/g coliform bacteria and 65% with >1,100 to ≤2,400 MPN/g (highest value of the technique); highest prevalence of coliform bacteria and E. coli were found in lettuce. Consumers should be made aware of the risk of contracting parasitic/bacterial infection from fresh vegetables if not properly prepared, and, at the same time, local health authorities should monitor fresh vegetables (and other food products) supply chain from farm to market to minimize risk of contracting food-borne diseases.