Submitted to: Avian Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/16/2003
Publication Date: 7/20/2004
Citation: Johannsen, S.A., Griffith, R.W., Wesley, I.V., Scanes, C.G. 2004. Salmonella enterica serovar typhimurium colonization of the crop in the domestic turkey: influence of probiotic and prebiotic treatment (lactobacillus acidophilus and lactose). Avian Diseases. 48(2):279-286. Interpretive Summary: Salmonellosis a major cause of human gastrointestinal illness with an estimated 1.3 million cases reported in the U.S. annually. Salmonella enterica serovar Typhimurium (ST) infections are predominantly (~ 96%) caused by consumption of contaminated food, with poultry meat implicated as the primary source. Chickens and turkeys harbor ST in their intestine as asymtomatic carriers and shed the organism in their feces. The crop of poultry is a source for Salmonella contamination because it can rupture during slaughter and potentially contaminate the carcass. We developed a model for ST colonization of the crop in the turkey, which uses ST administration by oral gavage prior to the period of subjective night, quantification of ST in the crop wall and ingesta together with immunohistochemistry of the crop wall. The model can be employed to examine the effectiveness of various paradigms, such as feeding lactose in combination with Lactobacillus acidophilus to decrease crop pH and thus to reduce salmonella in the turkey crop.
Technical Abstract: Acute colonization of the crop of the domestic turkey by Salmonella enterica serovar Typhimurium was examined. The influences of pre-harvest probiotic and prebiotic treatment with lactobaccilli and lactose on crop colonization with ST were also investigated. Prior to Salmonella challenge, poults received 2.5% lactose and Lactobacillus acidophilus (1.9 x 10**9 organisms/liter) in the only source of drinking water from one-day-old to termination. At three-weeks-old, turkey poults were challenged with ST (1.7 x 10**8 CFU/ml) before their natural nocturnal fast to determine the potential effects of supplementation on crop colonization when it was engorged and subsequently undergoing emptying. Crop ingesta and tissue were collected at time points 30 minutes, 4-, 8-, and 24-hours post challenge and ST levels determined. High levels of ST were detected in the crop. For instance, the poults not receiving lactose or Lactobacilli, 30 minutes following ST challenge, there were 4.4 x 10**7 colony forming units in the crop ingesta and 5.3 x 10**5 in the crop wall. Ingesta ST levels dropped dramatically to 1.0 x 10**6 CFU after 4 hours as the crop emptied. Crop wall ST levels were steady during the nocturnal crop evacuation. Immunohistochemical staining demonstrated ST in close association with the crop epithelium. Treatment with lactose and L. acidophilus supplementation did not reduce ST colonization.