American Society for Microbiology
Soil and water are suggested to represent pivotal niches for the transmission of Listeria monocytogenes to plant material, animals and the food chain. In the present study, 467 soil and 68 water samples were collected in 12 distinct geological and ecological sites in Austria during 2007-2009. Listeria spp. was present in 30% and 26% of the investigated soil and water samples respectively. Generally, the most dominant species in soil and water samples were L. seeligeri, L. innocua and L. ivanovii. The human and animal pathogenic L. monocytogenes was exclusively isolated from 6% soil samples in region A (mountainous region) and B (meadow). Distinct ecological preferences were observed for L. seeligeri and L. ivanovii, which were more often isolated from wildlife reserves region C (Lake Neusiedl) and from sites in the proximity to wild and domestic ruminants (region A). The higher L. monocytogenes detection and antibiotic resistances in region A and B could be explained by the proximity to agricultural land and urban environment. L. monocytogenes multi-locus sequence typing corroborated this evidence since sequence type (ST) ST37, ST91, ST101, and ST517 were repeatedly isolated from regions A and B over several months. A higher L. monocytogenes detection and strain variability was observed during flooding of the river Schwarza (region A) and Danube (region B) in September 2007, indicating dispersion via watercourses.
FoodWorld 