Epizootiologic Role of Feeds in the Epidemiology of Salmonella Senftenberg Contamination in Commercial Layer Farms in Eastern Japan

Abstract

In total, 40 commercial layer farms and 32 replacement pullet farms with a combined population of 7.5 million adult layers and 6.6 million replacement pullets from six prefectures in eastern Japan were investigated for Salmonella Senftenberg contamination. We randomly collected 17,956 environmental samples, 5816 feed samples, and 218,470 egg samples from commercial layer farms; and 427 feed samples and 2896 environmental samples from replacement pullet farms. We monitored all samples for Salmonella. Samples were primarily enriched in Hajna tetrathinoate broth for 24 hr at 37 C followed by incubation in desoxycholate hydrogen sulfide lactose agar for 18 hr at 37 C. Salmonella colonies were confirmed and identified by biochemical tests and serotyped using Salmonella O and H antigens. We recorded 171 environmental samples (0.95%) and 10 feed samples (0.17%) that were positive for Salmonella spp. in which 36 environmental samples (0.20%) and six feed samples (0.10%) were identified as Salmonella Senftenberg. All Salmonella Senftenberg strains were isolated from nine replacement pullet farms. No Salmonella Senftenberg strains were isolated from adult layer farms and from eggs. Pulse field gel electrophoresis of BlnI-digested chromosomal DNA of 19 Salmonella Senftenberg isolates from feeds and environmental samples yielded a single identical DNA pattern. Traceback information showed that all positive feed samples were from a single feed source. Timeline studies showed that Salmonella Senftenberg contamination occurred first mostly in the feeds and then spread to the environment and other farms. This study demonstrated that the prevalence of Salmonella Senftenberg contamination in commercial layer facilities in eastern Japan is very low. Moreover, feed contamination played a major role in the epizootiology and spread of this pathogen in commercial poultry flocks. Given the resilient and persistent nature of this particular Salmonella serotype, routine monitoring and strict quality control measures at the feed level are recommended to prevent the colonization of poultry facilities with Salmonella Senftenberg that may lead to future outbreaks.

Survey of Salmonella Contamination in Chicken Layer Farms in Three Caribbean Countries

“…The need for good biosecurity practices and disinfection cannot be overem phasized, particularly between introducing new batches of birds to the pens to avoid residual contamination from the preceding flocks (17). The overall frequency of isolation of Salmonella from farm environments in the current study (17.8%) is within the range of 0.95 to 33.3% reported for other countries (6,34).…”

“…Adesiyun et al (1) used pulse-field gel electrophoresis to determine the relationships among Salmonella Enteritidis isolates recovered from each of the Caribbean countries studied. Salmonella serotypes differ among layer farms and countries (9,28,29,34), and all serotypes recovered in the present study have been documented previously in the Caribbean region (1,10,20).…”

“…Other researchers have recovered Salmonella from feeds provided for layers on farms at fre quencies of 0.1 to 5.6% (6,17,34), indicating that feed can serve as a vehicle for Salmonella transmission on poultry farms.…”

“…The frequency of isolation of Salmonella reported elsewhere has ranged from 4 to 12% in layer birds (3,16), from 0.95 to 33.3% for layer farm environments or litters (6,34), from 12.6 to 19.2% for imported day-old chicks (6,31), from 0.35 to 1.24% for hatching eggs (6), and from 13 to 29% for hatcheries (13,35). Rodents also have been documented as a potential source of Salmonella in layer farm environments (22,23,38).…”

Prevalência e susceptibilidade antimicrobiana de sorotipos de Salmonella spp. isolados de frangos vivos e carcaças no estado do Rio de Janeiro

“…Entretanto, surtos por esse sorotipo foram associados à ingestão de outros tipos de alimentos, como carne bovina, frutas e verduras (Jackson et al 2013), cereais de bebê (Rushdy et al 1998), manjericão (Zweifel & Stephan 2012) e pimenta preta (Van Doren et al 2013). Shirota et al (2012) relataram que Salmonella Senftenberg é um patógeno persistente, resiste a altas temperaturas, contaminando primeiro a ração, espalhando-se pelo ambiente e, posteriormente para as aves, sendo prudente o seu monitoramento na alimentação animal e na contaminação de produtos avícolas. Todavia, sua epidemiologia, ecologia e virulência são pouco conhecidas, necessitando de mais estudos (Shah et al 2017).…”