The horizontal transfer of Salmonella between the lesser mealworm (Alphitobius diaperinus) and poultry manure

Authors: Crippen, Tawni - Tc; Sheffield, Cynthia; Beier, Ross; Nisbet, David

Submitted to: Zoonoses and Public Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2017
Publication Date: 2/1/2018
Publication URL: http://handle.nal.usda.gov/10113/5832877
Citation: Crippen, T.L., Sheffield, C.L., Beier, R.C., Nisbet, D.J. 2018. The horizontal transfer of Salmonella between the lesser mealworm (Alphitobius diaperinus) and poultry manure. Zoonoses and Public Health. 65(1):e23-e33. https://doi.org/10.1111/zph.12404.
DOI: https://doi.org/10.1111/zph.12404

Interpretive Summary: Understanding of the entire pathway by which Salmonella enters into and is maintained in our food production systems is not known. At some point, certain poultry flocks can be contaminated with Salmonella and those bacteria have the possibility to be carried from the growing of chickens to the processing of meat for sale to the public. This study was specifically aimed at characterizing the movement of Salmonella between poultry litter and the beetles which infest many poultry houses. Our study suggests that a particular bacterial concentration is needed to support the movement of Salmonella between the litter and the beetles. Below that concentration, the movement was not significant. The data obtained will be used in correlation with facility management practices to develop strategies to decrease the spreading of Salmonella contributing to the contamination of poultry flocks.

Technical Abstract: There is a need to determine the nature and extent of residual reservoirs of Salmonella which contribute to perpetual contamination within poultry flocks. The dispersal of Salmonella between birds, litter, and beetles has been established, but the extent that these act as critical components in the epidemiology of Salmonella infection during broiler grow-out and flock rotation has not been well delineated, in particular the level of participation by the insect in interactions with chicken manure as agents of retention and dispersal. This study defines this route of transmission and provides empirical data on bacterial loads that facilitate Salmonella transfer. Results showed differential Salmonella transfer dependent on initial inoculation concentration. At 10**3 cfu/ml, only a small, but not significant, amount of Salmonella transferred, from both the entire beetle and just the bacteria carried internally, through the manure and back to uninfected beetles. At 10**5 – 10**7 cfu/ml, a significant acquisition and transfer occurred both internally and externally to the beetle over 4 and 24 h. The data obtained will be used in correlation with facility management practices to develop intervention strategies to mitigate the establishment of and spreading from reservoir Salmonella populations contributing to the preharvest contamination of poultry flocks.