ABSTRACT
Salmonella infection causes serious economic losses, threatens food safety, and is one of the most important diseases threatening meat duck farming. The gut microbiome is critical in providing resistance against colonization by exogenous microorganisms. Studying the relationship between Salmonella and gut microbiota can help us better understand the threat of the pathogenic mechanism of Salmonella and provide a more scientific theoretical basis for its prevention and treatment. This study uses Salmonella Typhimurium as the research object and Cherry Valley meat duck as the model with which to study the impact of Salmonella infection on ducks. In this field trial, 2 × 108 CFUs Salmonella Typhimurium were administered to 3-day-old ducks. After infection, duck viscera were collected to detect the colonization of Salmonella, and cecal contents were collected to analyze the changes in gut microbiota. The results show that Salmonella Typhimurium can colonize ducks three days after infection and alter the gut microbiota composition, mainly by increasing the abundance of Ruminococcaceae and Lachnospiraceae. In conclusion, Salmonella Typhimurium infection significantly alters the intestinal microbiota of ducks and poses a serious public health risk.
ABSTRACT
Since Feb, 2013, more than 100 human beings had been infected with novel H7N9 avian influenza virus. As of May 2013, several H7N9 viruses had been found in retail live bird markets (LBMs) in Guangdong province of southern China where several human cases were confirmed later. However, the real avian influenza virus infection status especially H7N9 in Guangzhou remains unclear. Therefore, a cross-sectional study of avian influenza in commercial poultry farms, the wholesale LBM and retail LBMs in one district of Guangzhou was conducted from October to November, 2013. A total of 1505 cloacal and environmental samples from 52 commercial poultry farms, 1 wholesale LBM and 18 retail LBMs were collected and detected using real-time RT-PCR for type A, H7, H7N9 and H9 subtype avian influenza virus, respectively. Of all the flocks randomly sampled, 6 farms, 12 vendors of the wholesale LBM and 18 retail LBMs were type A avian influenza virus positive with 0, 3 and 11 positive for H9, respectively. The pooled prevalence and individual prevalence of type A avian influenza virus were 33.9% and 7.9% which for H9 subtype was 7.6% and 1.6%, respectively. None was H7 and H7N9 subtype virus positive. Different prevalence and prevalence ratio were found in different poultry species with partridges having the highest prevalence for both type A and H9 subtype avian influenza virus. Our results suggest that LBM may have a higher risk for sustaining and transmission of avian influenza virus than commercial poultry farms. The present study also indicates that different species may play different roles in the evolution and transmission of avian influenza virus. Therefore, risk-based surveillance and management measures should be conducted in future in this area.
