EMERGING PATHOGEN ARCOBACTER SPP. IN FOOD OF ANIMAL ORIGIN

Abstract

7.1 Foreword The genus Arcobacter, previously classified as “aerotolerant campylobacter”, from 1991 is classified as a new genus member of the family of Campylobacteriaceae, belonging to the epsilon-proteobacteria. The genus Arcobacter contains eight described species: Arcobacter butzleri, A. cryaerophilus, A. nitrofigilis; A. skirrowii ,A. cibarius, A. thereius, A. halophilus and 46 A. mytili . The bacteria are Gram negative, non-sporeforming, motile, curved, occasionally straight, rods which may appear as spiral. The most important differences between Arcobacter and Campylobacter are the ability of Arcobacter to grow at 15-25°C and its marked aerotolerance. Arcobacter spp. have been considered as potential zoonotic foodborne and waterborne agents (. Arcobacter spp. can be found in meat (veal, beef, pork and poultry), milk and water. Nevertheless the real occurrence of these potential pathogens in food is largely unknown. 7.2 Objectives The aim of this study is to evaluate prevalence and distribution of Arcobacter spp. in food of animal origin (raw meat and milk) in Northern Italy and to test the antimicrobial susceptibility of collected strains. 7.3 Trial 1: Prevalence and Distribution of Arcobacter spp. In Veal Calves in Northern Italy In this study the prevalence and distribution of Arcobacter spp. in samples taken from feces and carcasses of healthy veal calves, raised in Northern Italy, were investigated. A membrane filtration technique with a non-selective blood agar was employed after enrichment in Arcobacter selective broth to isolate a wide range of Arcobacter spp. In addition, the same samples were tested at the species level by using a multiplex-PCR assay. Samples from feces (50 during a summer sampling, 50 during a winter sampling) and carcasses (50 during a summer sampling a 50 during a winter sampling) were collected at the slaughterhouse from 50 veal calves originating from five different farms. Of the fecal samples examined, 36 (72%) were found positive for at least one species of Arcobacter during summer sampling and 38 (76%) were found positive during winter sampling. Of the sampled carcasses examined, 50 (100%) were found positive for at least one species of Arcobacter in summer sampling and 20 (40%) in winter sampling. From feces, 23 (46%), 17 (34%) and 5 (10%) samples were found positive by m-PCR for A. cryaerophilus, A. skirrowii and A. butzleri, respectively in summer. On the other side in winter 15 (30%), 12 (24%) and 2 (8%) samples were found positive by m-PCR for A. cryaerophilus, A. skirrowii and A. butzleri, respectively. From carcasses, 47 (94%), 17 (34%) and 5 (10%) samples were positive for A. cryaerophilus, A. skirrowii and A. butzleri, respectively in summer sampling whereas 5 (10%), 4 (8%) and 8 (16%) samples were positive for A. cryaerophilus, A. skirrowii and A. butzleri, respectively in winter sampling . Some sampled carcasses (34% in summer and 6% in winter) and some fecal samples (18% both in summer and in winter) resulted contaminated with multiple…