Bacterial communities of house flies from dairy farms highlight their role as reservoirs, disseminators, and sentinels of microbial rhreats to human and animal health

Authors: NEUPANE, SARA - Kansas State University; PARK, YOONSEONG - Kansas State University; WATSON, D. WES - North Carolina State University; TROUT FRYXELL, REBECCA - University Of Tennessee; BURGESS, EDWIN - University Of Florida; Nayduch, Dana

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2024
Publication Date: 9/22/2024
Citation: Neupane, S., Park, Y., Watson, D., Trout Fryxell, R., Burgess, E.R., Nayduch, D. 2024. Bacterial communities of house flies from dairy farms highlight their role as reservoirs, disseminators, and sentinels of microbial rhreats to human and animal health. Insects. 15(9). Article 730. https://doi.org/10.3390/insects15090730.
DOI: https://doi.org/10.3390/insects15090730

Interpretive Summary: Adult house flies found in livestock operations pose significant challenges not only as nuisance pests but also as vectors of a wide range of microbial pathogens affecting both humans and animals. This study investigated bacterial community composition and diversity in female house flies and cattle manure collected from dairy cattle farms across three US states. The findings revealed that flies carried bacterial taxa acquired from their environment, capturing the entire bacterial microbiome from manure along with other taxa likely acquired from the animals. Taxa of potential pathogens were highly abundant in house flies, suggesting that flies pose a biosecurity risk in spreading microbes with human and animal importance both within dairy operations and potentially off site.

Technical Abstract: Adult house flies (Musca domestica L.) inhabiting dairy farms not only are nuisance pests but also harbor and disseminate bacteria. We examined the bacterial community composition, diversity, environmental sources, and prevalence in individual adult female house flies and cattle manure samples collected monthly from Florida, North Carolina, and Tennessee dairy farms between May and August 2021. Individual house flies carried diverse bacterial communities, encompassing all bacterial taxa (100%) identified in across manure samples, and additional species likely acquired from the animals. Bacterial community assemblage in house flies and manure samples within farms varied by month. Some taxa were differentially associated with either house flies (Corynebacterium, Acinetobacter, and Staphylococcus) or manure samples (Treponema, Succinivibrio, and Clostridia). House fly bacterial communities mostly contained specialist species originating from manure, with several taxa (Escherichia, Corynebacterium, Turicibacter) being potential pathogens of livestock and humans. These findings further support the role of house flies as carriers of cattle-associated bacteria, including pathogens, and their potential for disseminating these microbes among cattle and to neighboring environments. Since their bacterial communities pro-\vide a snapshot of their surrounding environment, house flies also serve as effective sentinels in xenosurveillance strategies.