Presence of Listeria, Arcobacter, and Campylobacter spp. in dairy farms in Spain.

Bacteria from genera Listeria, Campylobacter and Arcobacter are potentially zoonotic pathogens for humans and they may be detected in dairy cattle farms. In this study the presence of these bacteria was considered in dairy cattle farms in Galicia (northwest of Spain). In the first part of the study, bulk tank milk samples were collected to determine the herd prevalences of Listeria spp. in 98 dairy farms. Additionally 83 silage samples and 97 faeces samples of lactating cows were collected. L. monocytogenes was detected in 6.1%, 9.3% and 6.0% of these samples, respectively. With regard to Campylobacter spp. and Arcobacter spp., 254 faecal samples were collected on 89 dairy farms. Campylobacter spp. was found with a herd prevalence of 36%. It was also confirmed in 20.5% of dairy cattle faecal samples. Arcobacter spp. was isolated in 68.5% of the farms and in 41.7% of faecal samples, with A. cryaerophilus being the most frequently identified species. The results related to the prevalence of the bacteria included in this study confirm their presence in high numbers in different types of biological samples from dairy farms, and suggest that more epidemiological studies regarding this bacteria need to be performed.