Genetic characterization and biofilm formation of potentially pathogenic foodborne Arcobacter isolates

Various species of the genus Arcobacter are regarded as emerging food pathogens and can be cause of human gastroenteric illness, among others. In order to gain knowledge on the risk associated with the presence of arcobacters in retail foods, this study aimed to determine their presence in a variety of products; to evaluate the genetic diversity and the occurrence of virulence and biofilm-associated genes in the isolated strains; and to assess their biofilm activity on polystyrene, borosilicate and stainless steel. Arcobacters were detected in the 22.3% of the analysed samples and the 83 recovered isolates were identified as A. butzleri (n = 53), A. cryaerophilus (n = 24), A. skirrowii (n = 2), A. thereius (n = 3) and A. vitoriensis (n = 1). They were isolated from virtually all tested food types, but mostly from squids and turkey meat (contamination levels of 60% and 40%, respectively). MLST differentiated 68 STs, most of which were novel (89.7%) and represented by a single strain (86.9%). Five novel STs were detected in various isolates derived from seafood, and the statistical analysis revealed their potential association with that type of food product (p < 0,001). All the isolates except one harboured virulence-associated genes and the highest incidence was noted for A. butzleri. Nineteen isolates (23.5%) were able to form biofilms on the different surfaces tested and, of note; glass enhanced the adhesion ability of the majority of them (84.2%). The results highlight the role that common food products can have in the transmission of Arcobacter spp., the pathogenic potential of the different species, and the survival and growth ability of several of them on different food contact surfaces. Therefore, the study provides interesting information regarding the risk arcobacters may pose to human health and the food industry.