Population Dynamics of Salmonella enterica Serotypes in Commercial Egg and Poultry Production

Abstract

ABSTRACTFresh and processed poultry have been frequently implicated in cases of human salmonellosis. Furthermore, increased consumption of meat and poultry has increased the potential for exposure toSalmonella enterica. While advances have been made in reducing the prevalence and frequency ofSalmonellacontamination in processed poultry, there is mounting pressure on commercial growers to prevent and/or eliminate these human pathogens in preharvest production facilities. Several factors contribute toSalmonellacolonization in commercial poultry, including the serovar and the infectious dose. In the early 1900s,Salmonella entericaserovars Pullorum and Gallinarum caused widespread diseases in poultry, but vaccination and other voluntary programs helped eradicate pullorum disease and fowl typhoid from commercial flocks. However, the niche created by the eradication of these serovars was likely filled byS.Enteritidis, which proliferated in the bird populations. While this pathogen remains a significant problem in commercial egg and poultry production, its prevalence among poultry has been declining since the 1990s. Coinciding with the decrease ofS.Enteritidis,S.Heidelberg andS.Kentucky have emerged as the predominant serovars in commercial broilers. In this review, we have highlighted bacterial genetic and host-related factors that may contribute to such shifts inSalmonellapopulations in commercial poultry and intervention strategies that could limit their colonization.