Isolation and Virulence Gene Profiling of Arcobacter spp. from Seafood and Its Environment

Arcobacter spp. are emerging microaerophilic human pathogens associated with food-borne outbreaks worldwide. The present study reports the incidence and virulence gene characterization of Arcobacter spp. from seafood. Using the selective isolation method, a total of 112 arcobacters were isolated from 43 samples out of the 123 samples screened, comprising 71 finfish, 29 crustaceans, 13 molluscan and 10 water samples. The overall incidence of Arcobacter spp. was 34.96%, with highest in water (50%), followed by mollusca (46.15%), finfish (33.8%), and cephalopods (27.59%). The isolates were confirmed by polymerase chain reaction using Arcobacter genus and species-specific primers. Among 112 Arcobacter isolates, 62 were identified as A. butzleri, 17 as A. skirrowii, 14 as A. cryaerophilus and 19 as other arcobacters. Selected isolates (n = 52) comprising 19 A. butzleri, 17 A. skirrowii, and 14 A. cryaerophilus were screened for the presence of seven putative virulence genes, among which, ciaB was predominantly present in 94% of the isolates, whereas hecB was found absent in all test isolates. More than one virulence gene was present in 94% of the isolates screened. These findings suggest the pathogenic potential of seafood isolates of arcobacters, which further necessitates the need for detailed investigations on their molecular virulence mechanisms.