Longitudinal Monitoring of Two Commercial Layer Flocks and Their Environments for Salmonella enterica Serovar Enteritidis and Other Salmonellae

Abstract

Between August 20, 2001, and September 17, 2002, 1429 samples including drag swabs, egg belt or egg rollout swabs, fan-blade swabs, rodent organ and intestinal pools, beetle (Alphitobius diaperinus) pools, housefly (Musca domestica) pools, chicken organ and intestinal pools, and egg pools were obtained for Salmonella culture from two flocks from two different commercial layer ranches. The two ranches were purposefully selected for the study based on their previous status of Salmonella Enteritidis isolation using environmental drag swabs in cooperation with practicing veterinarians. Salmonella sp. was isolated from 337 out of 979 (34.42%) non-egg samples. No Salmonella was isolated from 450 egg pools collected from either ranch. S. enteritidis was isolated from samples obtained from ranch 1 from manure drag swabs, 4/284 (1.4%); rodent organs, 1/24 (4.2%); and housefly pool cultures 1/21 (4.8%). Salmonella Enteritidis was isolated from ranch 2 from mouse organ and intestinal pool samples, 1/24 (4.2%). Salmonella group B was isolated from all sample types except the insects. There was a statistically significant difference in isolation rates among seven serogroups of Salmonella: groups B, C1, C2, D, E, K, and untypeable (Pearson chi-square 18.96, P = 0.002). Overall, statistically significant differences were observed with respect to Salmonella isolation among the types of samples taken (Pearson chi-square 118.54, P < 0.0001). Intensive monitoring for Salmonella Enteritidis can be used to optimize a Salmonella reduction program for an individual poultry biosecurity unit.

Salmonella in Belgian laying hens: An identification of risk factors

“…14 However, it should be mentioned that Belgium has many laying hens compared to 15 neighbouring countries (Quinet, 2005). The European survey was based on environmental 16 sampling which is considered to be an accurate and representative indicator for the presence 17 of Salmonella in layer flocks and for the probability that hens would lay contaminated eggs 18 (Henzler et al, 1994;Kinde et al, 2005). The persistence of the pathogen in the intestinal 19 tract is more important when infection occurs in young chicks, since bacterial clearance 20 occurs more efficiently in adults.…”

“…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…”

“…Although the proportion of flocks infected with Salmonella may significantly differ 2 depending on the type of sample that was used (Kinde et al, 2005), for the analyses in this 3 study we grouped the three dust-type samples to form the 'dust material' and the four faecal-4 type samples formed the 'faecal material' thus reducing the seven sample types to two for all 5 flocks. The 'dust material' and 'faecal material' were considered as positive (outcome=1) 6 when at least one of the dust or faecal samples respectively was positive.…”

A longitudinal study of environmental salmonella contamination in caged and free-range layer flocks

“…Longitudinal studies are an appropriate way to address these questions, but the requirements of resource and cooperation by producers over months or years tends to limit the number and scope of such investigations. Consequently, there are few reports that have examined the levels of salmonella in laying houses and hens in lay over an extended period of time (Davison et al ., 1999;Davies & Breslin, 2003b;Kinde et al ., 2005). The present report describes a longitudinal study conducted on several layer premises over a 12-month period.…”

Development and validation of a drag swab method using tampons and different diluents for the detection of members ofSalmonellain broiler houses

“…There are many different types of samples used to evaluate the microbiological status of poultry houses, including litter (Byrd et al, 1997), faeces (Voogt et al, 2001), chick paper (Kinde et al, 2005), chick fluff (Roy et al, 2002), dust (D'Aoust et al, 1992), foot covers (Caldwell et al, 1998) and drag swabs (Kingston, 1981). The use of gauze-based drag swabs (25 cm 2 ), first described by Kingston (1981), is a commonly cited method for environmental sampling of poultry houses.…”