Role of darkling beetles (Alphitobius diaperinus) in spreading and maintaining Salmonella Enteritidis and Campylobacter jejuni in chicken flocks

Authors: BARUA, SUBARNA - Auburn University; BAILEY, MATTHEW - Auburn University; ZHONG, KEVIN - Auburn University; IDUU, NNEKS - Auburn University; DORMITORIO, TERESA - Auburn University; MACKLIN, KEN - Auburn University; BOURASSA, DIANNA - Auburn University; PRICE, STUART - Auburn University; HAUCK, RUEDIGER - Auburn University; KREHLING, JAMES - Auburn University; KITCHENS, STEVE - Auburn University; KYRIAKIS, CONSTANTIONS - Auburn University; Buhr, Richard - Jeff; WANG, CHENGMING - Auburn University

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/23/2023
Publication Date: 7/10/2023
Citation: Barua, S., Bailey, M.A., Zhong, K., Iduu, N., Dormitorio, T., Macklin, K., Bourassa, D.V., Price, S., Hauck, R., Krehling, J., Kitchens, S., Kyriakis, C., Buhr, R.J., Wang, C. 2023. Role of darkling beetles (Alphitobius diaperinus) in spreading and maintaining Salmonella Enteritidis and Campylobacter jejuni in chicken flocks. Poultry Science Association Meeting Abstract. 102(E-Suppl.1): 288, p.139.

Interpretive Summary:

Technical Abstract: Salmonella and Campylobacter are common foodborne pathogens found in chickens, but the exact mechanisms of how these pathogens persist in the flocks are still not fully understood. The darkling beetle (Alphitobius diaperinus) is a resilient and abundant insect pest in housing poultry, and may play a role in spreading and maintaining pathogens. In this study, four groups of SPF Leghorn chickens (n=50) were inoculated with 10^8 Salmonella Enteritidis and 10^8 C. jejuni, and housed in four BSL-2 rooms in containers with autoclaved bedding and beetles (n=200). The fecal, litter and beetle samples were collected weekly for bacterial isolation and PCRs. Phase-I (Weeks 1-3): the infected chickens remained in the containers for three weeks and were then euthanized while beetles and litter remained in the container (group-A), beetles were removed and litter remained in the container (group-B), beetles remained and litter was removed (group-C), and beetles and litter were removed (group-D). Phase-II (Weeks 5-7): after one-week, autoclaved bedding was added to containers in groups C and D and new SPF chickens (n=50) were introduced into the containers and kept for three weeks. Phase-III (Weeks 8-25): all chickens were euthanized, and the litter and/or beetles remained in the containers for seventeen weeks. In phase-I, both pathogens were identified in all groups of chickens, beetles and litter except for the absence of Salmonella in beetles of group B. The positivity of Campylobacter (128/150) was significantly higher than Salmonella (58/150) in feces (Chi- square, p<10 ), and the detection rate of Campylobacter was significantly higher in feces than in beetles (128/150 vs. 7/16, p<10 ). In phase-II, Salmonella was only detected in chickens of groups A and B, and in litter of groups B and C while Campylobacter was found in chickens of groups A, B, D, and litter of groups A, B and C. In Phase-III, Salmonella was identified in beetle of group A, and litter of groups A, B and C while Campylobacter was positive in litter of groups A and B. The positivity of both pathogens in litter was significantly higher than in feces in phase-II, and higher than in beetles in phases II and III (p<0.007). Sixty-nine days after the infected chickens were removed, Salmonella was still detectable in beetles. In addition, both Salmonella and Campylobacter were detectable up to 127 days (the end of the experiment) in litter after the infected chickens were removed. This study suggested that Salmonella and Campylobacter can be transmitted via beetles and litter to new flocks in successive rearing cycles, and there should be intensive control programs for the exclusion of these insects during poultry litter management between flocks.