Prevalence of Listeria Spp. and Listeria Monocytogenes in Cattle Farms in Cyprus using Bulk Tank Milk Samples

Abstract

Listeria monocytogenes is an important foodborne pathogen which causes listeriosis in humans and animals. Presence of Listeria spp. and L. monocytogenes in raw bovine milk could lead to the manufacture of contaminated products due to lack or insufficient pasteurization or cross-contamination. The purpose of this study was to record the prevalence of Listeria spp. and L. monocytogenes in all the Cypriot dairy farms, using bulk tank milk (BTM) samples. A total of 205 raw BTM samples were analyzed for Listeria spp. and L. monocytogenes. In addition a total viable count (TVC) was also performed in parallel in an attempt to correlate high TVC with the presence of Listeria. Results revealed a total of three samples (1.46%; 95% CI: 0.3–4.4%) positive for Listeria spp. two (0.98%; 95% CI: 0.04–3.72%), of which were successfully identified as L. monocytogenes. Molecular serotyping indicated that the two isolates were both 1/2a. This is the first report in Cyprus documenting the prevalence of Listeria spp. and L. monocytogenes in the raw BTM of all Cypriot dairy farms revealing a low prevalence in a reported asymptomatic population. Monitoring the prevalence is essential in an attempt to protect animal health and welfare as well as human health by reducing the risk of listeriosis through consumption of milk and dairy products. Practical Applications: There is an increasing need to better understand the prevalence of Listeria monocytogenes in the environment and food, given the rise of listeriosis in Europe, as reported by EFSA. Raw milk is an important exposure vehicle to humans either directly, through the consumption of unpasteurized products, or as a result of cross-contamination in food establishments. Previous detection studies have been published in Europe and throughout the world but never before a full prevalence study which records the results in bulk tank milk (BTM) following the sampling from all dairy herds in a country. In addition, this is the first report in Cyprus documenting the prevalence of L. monocytogenes in raw BTM, revealing a low prevalence in a reported asymptomatic population of cattle. Furthermore, the predominant serotypes are identified, providing useful epidemiological information for future studies in Cyprus and throughout the world.