A study has added to the evidence of Arcobacter being detected in food products but the significance of the findings are still unclear.

Several species of Arcobacter are seen as emerging foodborne pathogens and may cause gastrointestinal illness. Tracking the infection source and transmission routes of Arcobacter is a step towards assessing the risk related to these pathogens.

Consumption of contaminated drinking water or undercooked and raw foods seems to be the main transmission source of Arcobacter, said the study published in the International Journal of Food Microbiology.

The infectious dose, or amount needed to make people sick, is not clear and the incidence appears to be low, possibly because events are not routinely investigated. Studies on the pathogen have been going on for at least 20 years.

A total of 220 samples were analyzed and Arcobacter was detected in 49 of them. The most abundant type was Arcobacter butzleri, which is most often associated with human illness, but other species were found, such as Arcobacter cryaerophilus.

Samples including cockle, squid, shrimp, quail, rabbit and turkey meat, fresh cheese, spinach, Swiss chard, lettuce and carrots, were purchased from different retail shops and supermarkets in Vitoria-Gasteiz, Spain, from May to November 2015. 

Seafood and carrot findings
Arcobacters were mostly detected in seafood products and turkey meat. Foods of animal and vegetable origin showed lower contamination levels.

Irati Martinez-Malaxetxebarria, a researcher at the University of the Basque Country, said the bacteria had genes that could give it the capacity to cause infections in humans.

“All the lettuces that tested positive were pre-packed. That makes you think a bit, because often when we buy processed foods we don’t pay attention to their degree of cleanliness. We also detected a species in carrots that had never been characterized before and which also possesses virulence genes,” she said.

Baby squid were a major source of Arcobacter, so eating these products raw could be a significant source of infection, said researchers.

It was also found in a piece of fresh cheese but scientists said this was probably because of cross-contamination.

Martinez said it was the first time the presence of Arcobacter species in fresh Burgos cheese and carrots had been reported.

“We also noted seafood, especially squid, as a significant source of adherent Arcobacter. These findings should be taken into consideration for their possible food safety implications, as Burgos cheese is a ready-to-eat product, and carrots and seafood are often consumed only lightly cooked or raw,” she said.

Future studies on the survival and growth of Arcobacter on products, especially ready to eat ones, may help assess the implications of the findings for food safety.

Results highlight the role that food products can have in the transmission of Arcobacter, the pathogenic potential of the different species, and the survival and growth ability of several of them on different food contact surfaces. All the isolates except one harbored virulence-associated genes and 19 isolates were able to form biofilms on the different surfaces tested.

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