School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia.
Bioproperties Pty Ltd, Ringwood, Victoria, Australia.
Environ Microbiol Rep. 2024 Jun;16(3):e13265. doi: 10.1111/1758-2229.13265.
Role of dust in Salmonella transmission on chicken farms is not well characterised. Salmonella Typhimurium (ST) infection of commercial layer chickens was investigated using a novel sprinkling method of chicken dust spiked with ST and the uptake compared to a conventional oral infection. While both inoculation methods resulted in colonisation of the intestines, the Salmonella load in liver samples was significantly higher at 7 dpi after exposing chicks to sprinkled dust compared to the oral infection group. Infection of chickens using the sprinkling method at a range of doses showed a threshold for colonisation of the gut and organs as low as 1000 CFU/g of dust. Caecal content microbiota analysis post-challenge showed that the profiles of chickens infected by the sprinkling and oral routes were not significantly different; however, both challenges induced differences when compared to the uninfected negative controls. Overall, the study showed that dust sprinkling was an effective way to experimentally colonise chickens with Salmonella and alter the gut microbiota than oral gavage at levels as low as 1000 CFU/g dust. This infection model mimics the field scenario of Salmonella infection in poultry sheds. The model can be used for future challenge studies for effective Salmonella control.
粉尘在鸡场沙门氏菌传播中的作用尚未得到充分描述。本研究采用新型撒粉法将沙门氏菌 Typhimurium（ST）接种于鸡粉尘中，对商业蛋鸡进行感染，并与传统口服感染进行了比较。两种接种方法均导致了肠道定植，但在暴露于撒粉粉尘的雏鸡中，在 7dpi 时肝脏样本中的沙门氏菌负荷明显高于口服感染组。用撒粉法对鸡进行一系列剂量的感染实验表明，粉尘中 1000CFU/g 沙门氏菌即可达到肠道和器官定植的阈值。感染后盲肠内容物的微生物组分析表明，撒粉和口服感染途径的鸡的菌群特征没有显著差异；然而，与未感染的阴性对照组相比，这两种感染途径都有差异。总的来说，本研究表明，粉尘撒粉是一种有效的方法，可以在鸡中定植沙门氏菌，并改变肠道微生物群，而口服灌胃的效果不如粉尘撒粉，在 1000CFU/g 粉尘的水平下就能实现这一效果。该感染模型模拟了家禽舍中沙门氏菌感染的田间情况。该模型可用于未来的挑战研究，以实现有效的沙门氏菌控制。
