Presence of emerging Salmonella spp. serovars in pig farms: a risk to public health

The protection of consumers from emerging Salmonella spp.serovars depends on surveillance and control of the pathogen in food producing animals.Among them, pigs are the second most important species for transmitting emerging Salmonella spp.serovars pathogenic to consumers.Thus, a microbiological investigation of pig salmonellosis was undertaken in Central Greece examining samples collected from multiple carcass sites, aiming at the identification of prevalent serovars and their carcass location.For this purpose 492 tissue samples and 378 environmental swab samples were cultured following ISO 6579:2002.Twelve different serovars were isolated from feacal and tissue samples and two from the environmental samples, representing a total of 79 isolates.Among the identified serovars were the emerging monophasic Typhimurium serovars, S. enterica subsp.enterica ser.4,5, 12:i:-(16 isolates) and S. enterica subsp.enterica ser.4,12:i:-(7 isolates), the monophasic S. enterica subsp.enterica ser.6,7:k:-(6 isolates) and the rarer serovars of subspecies enterica subsp.diarizonae 61:k:1,5, and S. enterica subsp.houtenae 40:g,t:-(one isolate each).Of the remaining isolates, 37 were serovar Typhimurium, six (6) were serovars S. Bredeney (2 isolates), S. Agona, S. Derby, S. Infantis, S. Meleagridis, and S. Cerro and four were untypeable.Although serovar Typhimurium was the most prevalent one (37 isolates), the other serovars could also be considered of emerging public health importance, due to pork contamination.Thus, the pig appears in Greece as a possible source of human salmonellosis caused not only by commonly reported serovars, but also of rarer ones.