Arcobacter is an emerging foodborne pathogen about which relatively little is known, aside from the facts that the pathogen can be a cause of human gastroenteric illness and may diminish the shelf life of contaminated foods. A recent study published in the International Journal of Food Microbiology has attempted to expand upon the available knowledge about Arcobacter, revealing information related to food sources associated with the pathogen, its genetic diversity and traits, and its ability to form biofilms.

Researchers collected 220 samples from cockle, squid, shrimp, quail meat, rabbit meat, turkey meat, fresh cheese, spinach, Swiss chard, lettuce, and carrot, which were purchased from various retail outlets in Spain from May 2015–November 2015. Of the samples that were analyzed, 22.3 percent tested positive for Arcobacter; the pathogen was detected in samples from all tested food groups, but squid and turkey meat had the highest levels of contamination at 60 and 40 percent, respectively.

Although foods of animal origin and produce showed the lowest Arcobacter contamination levels, a species of the pathogen that had never been characterized before and possesses virulence genes was discovered in carrots. Additionally, all of the lettuces that tested positive for the pathogen were pre-packaged, and baby squid were found to be a major source of Arcobacter, indicating the importance of understanding Arcobacter persistence in ready-to-eat (RTE), raw, and lightly cooked foods. Cheese samples also tested positive for Arcobacter, but researchers hypothesize that it was likely due to cross-contamination.

The researchers were able to recover 83 isolates and identified 53 as A. butzlerii, 24 as A. cryaerophilus, three as A. thereius, two as A. skirrowii, and one as A. vitoriensis. Sequence typing analysis differentiated 68 individual sequence types (STs) for Acrobacter, 89.7 percent of which were novel, with five novel strains having a potential association with seafood. All of the Arcobacter isolates except one presented virulence-associated genes, with the highest incidence noted for A. butzleri, which is the most commonly associated strain with cases of human illness.

Regarding Arcobacter’s ability to form biofilms, 23.5 percent of isolates (19 isolates) were able to form biofilms on polystyrene (plastic), borosilicate (glass), and stainless steel surfaces. Additionally, glass enhanced the adhesion abilities of 84.2 percent of Arcobacter isolates.