Occurrence of Arcobacter species in industrial dairy plants

The present study investigated the presence of Arcobacter spp. in industrial dairy plants. Between February and September 2013, pasteurized milk used for cheesemaking, processing and cleaning water, cheese and environmental samples from different plant sites, including surfaces in contact or not with food were sampled. A total of 126 samples were analyzed by cultural method and isolates were identified by multiplex PCR. Arcobacter spp. were isolated from 22 of 75 environmental samples (29.3%): of them 22.7% were surfaces in contact with food and 38.7% from other environmental surfaces. A total of 135 Arcobacter spp. isolates were obtained; of these, 129 and 6 were identified as A. butzleri and A. cryaerophilus, respectively. All food processing water and pasteurized milk samples were negative for Arcobacter species. We were not able to determine the primary source of contamination, but the isolation of both A. butzleri and A. cryaerophilus in surfaces in contact with food before and during manufacturing suggests that Arcobacter spp. are not or only partially affected by routine sanitizing procedures in the industrial dairy plants studied. The efficacy of sanitizing procedures should be evaluated and further studies are needed to determine whether certain Arcobacter strains persist for long periods of time in industrial dairy plants and whether they can survive in different types of cheese in case of post-processing contamination