Isolation of Salmonella and Campylobacter Strains from Superficial Irrigation Water, Soil, and Vegetables Samples from Small Agriculture Fields around the Capital of Chile

Introduction:  In Chile and around the world, people prefer to buy their vegetables from farmers market and the possibility of these vegetables has been contaminated with pathogenic microorganisms constitutes a risk to human health. The isolation of these two pathogens in vegetables, irrigation water and soil where they are produced could explain that the contamination on the final product could come from its origin.

Purpose: Isolate Salmonella and Campylobacter in irrigation water samples, leafy vegetables, and agriculture soils in small farms on the vicinity of the capital city of Santiago.

Methods: Samples are taken every two months along one year in six different points surrounding Santiago city. These points previously indicated the presence of enteric Salmonella isolated from superficial irrigation water creek, genotypically related to isolates from human patients. The points are distributed in an agricultural production area of 145 hectares. The samples correspond to superficial irrigation water, soil, and leafy vegetables within a radius of five kilometers from the creek. All samples were analyzed using ISO 6579-2 for Salmonella and FDA BAM for Campylobacter.

Results: There has been no isolation from the superficial irrigation water samples. From the 130 samples of soil, only one was positive for Salmonella spp. In vegetables, from 650 samples only two were positive for Salmonella spp. and 21 for Campylobacter spp.

Significance: The consumption of raw leafy vegetables from small farmers is very frequent and the preference for this type of food is increasing all over the world. This study shows that must be considered as a potentially vehicle for the transmission of pathogenic bacteria to the population. Being able to assess the level of contamination in the small agricultural production area and establish the source from this contamination is important to be able to adopt the corresponding control measures at the farms markets.