Microbiological Analysis of the Early Salmonella enteritidis Infection in Molted and Unmolted Hens

Abstract

A study was conducted in which the early kinetics (4 hr to 96 hr) of an infection by Salmonella enteritidis in older white leghorn hens was examined, and a molt was induced through withholding feed to determine its effect on the progression of this infection. Molted and unmolted hens were orally infected with 5-10 x 10(6) S. enteritidis on day 4 of the feed removal. At 4, 24, 48, 72, and 96 hr postinfection, liver, spleen, ileum, colon, cecum, and feces were removed from six hens per group and sampled for the presence of the challenge organism. By 24 hr postinfection, S. enteritidis was most prevalent in the cecum and feces of unmolted hens, and this prevalence continued throughout the experimental period. In molted hens, however, S. enteritidis could be detected in a high percentage (90-100%) of colon, cecum, and feces samples at 24 to 96 hr postinfection and in 67% or more of ileum samples at 48 to 96 hr postinfection, indicating a much wider distribution of the S. enteritidis along the intestinal tract than in unmolted hens. The numbers of S. enteritidis recovered from these alimentary samples were also significantly higher in molted than unmolted hens. S. enteritidis could not be detected in livers or spleens of either treatment group at 4 or 24 hr postinfection. At 48, 72, and 96 hr postinfection, 50% or more of the livers and spleens in both the molted and unmolted hens were positive for the challenge organism, but significantly more S. enteritidis was recovered from the organs of the molted hens at these three sampling times.(ABSTRACT TRUNCATED AT 250 WORDS)

Salmonella in Broiler Chickeens in Thailand with Special Reference to Contamination of Retail Meat with Salmonella Enteritidis.

“…Infected chickens excrete Salmonella in feces [8]. S. Enteritidis is highly infectious for chickens [10], however, our results have shown that the prevalence of S. Enteritidis (73% in 1-day-old chicks) fell to only 3% in 30-days-old chickens. This might be due to the continuous administration of amoxycillin dissolved in drinking water for 29 days.…”

Isolation ofSalmonella entericaSerovar Enteritidis from Houseflies (Musca domestica) Found in Rooms ContainingSalmonellaSerovar Enteritidis-Challenged Hens

“…This methodology has since been replaced in the U.S. with less-stressful diet regimens (35), while in Latin America and the Far East, responsible for more than 50% of egg production worldwide, feed withdrawal remains the primary method for molting flocks. Earlier studies have shown that feed withdrawal depresses cellular immunity in the birds (15,16), resulting in an increased severity of infection by Salmonella serovar Enteritidis (17,18,19,20,21) and dramatically increasing the susceptibility of hens to infection (17). In the present study, this increased susceptibility had no apparent impact on the transmission of Salmonella serovar Enteritidis to the recipient birds, as no birds were found to be colonized by the organism.…”

Bacteriological investigation of microorganisms (Salmonella sp. and other Enterobacteriaceae) in common quails (Coturnix coturnix) submitted to different forced-molting procedures

“…in none of the egg, fecal, or cloacal swab samples collected from all evaluated experimental groups. Despite the absence of Salmonella determined in the present study, several other authors demonstrated that laying hens submitted to forced molting by the method of feed fasting are more susceptible to this microorganism (Holt & Porter, 1992;Macriet al, 1997;Berchieri Jr., 2000;Holt, 2003;Berry, 2003).This was clearly shown in the study of Holt et al (1995). The authors induced molting in commercial layers using fasting and orally infected these birds after four days with SE (5-10 x 10 6 ).…”