Effect of d-mannose on fimbriae of bacterial isolates from chicken carcasses

Genetic Basis of Salmonella Enteritidis Pathogenesis in Chickens

Salmonella Enteritidis (SE) is the predominant cause of the food-borne salmonellosis in humans, in part because this serotype has the unique ability to contaminate chicken eggs without causing discernible illness in the infected birds. Attempts to develop effective vaccines and eradicate SE from chickens are undermined by significant limitations in our current understanding of the genetic basis of pathogenesis of SE in this reservoir host. In this chapter, we summarize the infection kinetics and provide an overview of the current understanding of genetic factors underlying SE infection in the chicken host. We also discuss the important knowledge gaps that, if addressed, will improve our understanding of the complex biology of SE in young chickens and in egg laying hens.

Evaluation of the effects of a mixture of organic acids and duration of storage on the survival of salmonella on turkey carcasses

Samples from turkey carcasses previously inoculated with Salmonella Enteritidis 33/66 were subjected to the effect of various mixtures of equal parts of organic acid solutions (acetic, ascorbic, citric, lactic, and tartaric acids). The first part of the study concerned analysis of the influence of the mixtures of organic acids over 15 or 30 min on Salmonella Enteritidis on turkey carcasses. Turkey breast samples were inoculated with Salmonella Enteritidis at 3.7, 2.7, 1.7, 0.7, and 0.07 log CFU. The antibacterial effectiveness of the organic acids differed depending on the initial population of Salmonella on the turkey carcasses. Salmonella was most sensitive to mixtures of equal parts of 1% ascorbic, 1% citric, and 1% tartaric acids. The second part of the study involved determining the influence the organic acid mixtures had on survival of Salmonella Enteritidis on turkey meat stored at 4°C for 2, 4, or 6 days. The level of Salmonella was determined using a most-probable-number method. Salmonella Enteritidis was inoculated into a nutrient broth, incubated at 37°C for 24 h, and then added to the diluent in which the turkey breast samples were immersed for 5 min. The initial Salmonella level of the control samples of turkey breast following immersion was determined in each analysis. After storage at 4°C, turkey samples were transferred to the organic acid solutions for 15 min. Stainless steel templates were used to swab 50 cm(2) of the turkey breast samples. During storage at 4°C, the Salmonella level in the meat samples decreased. The largest decrease occurred at 4°C after 6 days with equal parts of 1% acetic acid, 1% lactic acid, and 1% tartaric acid. Thus, treatment of raw turkey breasts with a mixture of organic acids is a promising option for reducing the risk of the presence of Salmonella.