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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Bee Research Laboratory » Research » Publications at this Location » Publication #410818

Research Project: Managing Honey Bees against Disease and Colony Stress

Location: Bee Research Laboratory

Title: Occurrence and distribution of two bacterial brood diseases (American and European foulbrood) in US honey bee colonies and resistance to antibiotics from 2015 to 2022

item Alburaki, Mohamed
item Abban, Samuel
item Evans, Jay
item Chen, Yanping - Judy

Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2024
Publication Date: 4/15/2024
Citation: Alburaki, M., Abban, S.K., Evans, J.D., Chen, Y. 2024. Occurrence and distribution of two bacterial brood diseases (American and European foulbrood) in US honey bee colonies and resistance to antibiotics from 2015 to 2022. Journal of Apicultural Research.

Interpretive Summary: Since its inception in 1891, the Bee Disease Diagnostic Service of the USDA-ARS Bee Research Laboratory (BRL) has been providing a free-of-charge disease diagnosis for beekeepers and other federal and state agencies across the U.S. In this report, we retrieved our historical disease diagnostic results obtained between 2015 and 2022 and conducted a full epidemiological assessment of the brood diseases across the states. We find consistent regional ‘hotspots’ for brood diseases across years, heavy annual variation, and regional concordance between the results from our diagnostic service of disease-symptomatic colonies versus public results from the National Honey Bee Health survey,which does not focus on symptomatic or failing colonies.

Technical Abstract: Here, we present a retrospective study on honey bee brood diseases in the USA. The Bee Disease Diagnostic Laboratory (BDDL) in the USDA-ARS Beltsville Bee Research Laboratory received a total of 4,790 brood samples between 2015 and 2022 from U.S. State Apiary Inspectors and beekeepers. Samples from 49 states were analyzed by microscopy for the presence and prevalence of two bacteria, Melissococcus plutonius and Paenibacillus larvae, causing European (EFB) and American (AFB) foulbrood diseases, respectively. Samples that tested positive for AFB were cultured and subjected to antibiotic susceptibility tests via the agar disc diffusion method to determine their resistance to tetracycline (Terramycin®) and tylosin (Tylan®) antibiotics. A comprehensive data analysis was conducted at multiple levels, including state, month, year, nationwide, and climate region. Among the 49 states examined, EFB was identified in 44 states, while AFB was found in 31 states. Infection levels varies across states, ranging from 0 % to 63.6% for EFB and from 0 % to 54.8 % for AFB. The national average of EFB (19.2%) was significantly (p < 0.001) higher than AFB (8.6%). Contrary to AFB, significant yearly increases (p < 0.001) were identified for EFB from 2015 to 2022. Furthermore, significant monthly variations were recorded for both brood diseases, with the highest occurrence of EFB observed from April to July. States with the lowest infection rates of both diseases were NV, ND, MS, AK, and AZ. The South U.S. climate region, which comprises six states, had the highest and lowest EFB and ABF infections, respectively. On a nationwide scale, the AFB resistance to tetracycline (38%) was significantly (p < 0.001) higher than the resistance to tylosin (27%).