The Role of Mice in the Epizootiology of Salmonella enteritidis Infection on Chicken Layer Farms

Abstract

A microbiological survey of 10 mice-infested poultry farms was conducted to determine the role of mice in the epizootiology of S. enteritidis infection. Five of the farms were rated as clean of S. enteritidis and five as contaminated based on culture results of environmental samples for S. enteritidis. Of 2103 environmental samples and 715 mice and rats tested, 5.1% and 16.2%, respectively, were culture-positive for S. enteritidis. On contaminated farms, S. enteritidis was isolated from 24.0% of the mice and 7.5% of the environmental samples, which represented 75.3% of all Salmonella isolations from mice but only 18.0% of Salmonella isolations from environmental samples on these farms. S. enteritidis was not detected in mice on clean farms. Phage types 13a and 14b were the two most frequently isolated phage types from mice and environmental samples. Although only a single phage type was isolated from single free-standing poultry houses, multiple phage types were isolated from multi-house complexes. A bacterial count from the feces of one mouse yielded 2.3 x 10(5) S. enteritidis bacteria per fecal pellet. S. enteritidis persisted at least for 10 months in an infected mouse population.

Salmonella in Belgian laying hens: An identification of risk factors

“…24 At last, other risk factors which were not considered in the present study are important to 1 mention. For example, it could be useful to build a model taking into account flock 2 characteristics (type of breed, number of flocks on the farm, multi-age farm or not), farm 3 management (control of pest access, visitors allowed or not, feed composition and feeding 4 practices, drinking water), cleaning and disinfecting practices related with the contamination 5 status of the previous flock in the same hen house ( ( Henzler & Opitz, 1992;Kinde et al, 6 1996;Shirota et al, 2000;Garber et al, 2003;Liebana et al, 2003;Kinde et al, 2005). 7…”

Emergence of Salmonella epidemics: The problems related to Salmonella enterica serotyp Enteritidis and multiple antibiotic resistance in other major serotypes

“…Several authors have suggested that S. Enteritidis was introduced into poultry flocks by rodents where it is endemic since in the distant past it was used as a rodenticide [51,71]. S. Enteritidis was first used to control rodent populations during the Yersinia pestis outbreak in San Francisco in 1895 and then occasionally in Europe until 1960 [127].…”

An Epidemiological Analysis of Salmonella Enteritidis Contamination in a Rat-Infested Chicken Layer Farm, an Egg Processing Facility, and Liquid Egg Samples by Pulsed-Field Gel Electrophoresis

“…The important role of mice in the dissemination and persistence of S. Enteritidis on poultry farms has been described in the past [5]. Recently, definitive molecular evidence for the involvement of several wildlife species in the maintenance of S. Enteritidis infection in layer farms was demonstrated [10].…”

“…A major factor in this increase has been attributed to consumption of undercooked eggs and egg products such as liquid egg, contaminated with S. Enteritidis [4]. Rodents, dirty environment, recent poultry farming practices, chicks, pullets, and feeds have all been considered as major sources for contamination with S. Enteritidis in chicken layer farms [5,7,[17][18][19]. In Japan, liquid egg is commonly used in making egg custard products.…”