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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Invasive Species and Pollinator Health » Research » Publications at this Location » Publication #409527
Research Project: Conduct Longitudinal Studies on Colony Performance and Explore Near-term Effects of Nutritional and Agrochemical Stressors on Honey Bee Health

Location: Invasive Species and Pollinator Health

Title: Inactivation of Nosema spp. with zinc phthalacyonine

Author
item YURTTAS, ASIYE - Istanbul Health And Technology University
item KHAN, ZAEEMA - Sabanci University
item ELGUN, TUBGA - Biruni University
item Mayack, Christopher
item CINAR, KAMIL - Gebze Technical University

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2024
Publication Date: 2/11/2024
Citation: Yurttas, A.G., Khan, Z., Elgun, T., Mayack, C.L., Cinar, K. 2024. Inactivation of Nosema spp. with zinc phthalacyonine. Journal of Invertebrate Pathology. 203. https://doi.org/10.1016/j.jip.2024.108074.
DOI: https://doi.org/10.1016/j.jip.2024.108074

Interpretive Summary: Vairimorpha (Nosema) is a fungal pathogen that is globally distributed and is implicated as a key disease in the most recent decline of honey bee health. There is no effective treatment on the market for the spore stage of the pathogen and this is the stage in which it is dispersed to further infect other honey bees. Consequently, the spores can potentially contaminate beekeeping equipment. We therefore tested a large molecule (Zinc phthalacyonine) that can be activated by light to increase its potency against microorganisms and can serve as an alternative treatment to antibiotics to determine its effectiveness in killing Nosema spores. We found that the treatment itself within 1 hour was effective at reducing the number of viable spores and when used under light conditions the potency increased with a 80 percent reduction in the number of viable spores. Our results suggest that this new treatment method may be particularly beneficial for treating Nosema spores, which can help reduce the spread of this pathogen and potentially improve the health of the honey bee. Further investigation is needed to determine if this treatment can be used on live adult honey bees to reduce Nosema spores, but it is promising because the light required to activate the treatment compound can easily pass through honey bee tissue.

Technical Abstract: Most honey bee diseases, such as Vairimorpha (Nosema), cannot be rapidly and definitively diagnosed in a natural setting, consequently there is typically the spread of these diseases through shared and re-use of beekeeping equipment. Furthermore, there are no viable treatment options available for Nosema spores to aid in managing the spread of this bee disease. We therefore aimed to develop a new treatment method using novel ZnPc as a photosensitizer for the photodynamic inactivation of Nosema spores as a method that could be used for the decontamination of beekeeping equipment. Nosema spores were propagated for in vitro testing using caged Apis mellifera honey bees. The ZnPc treatment was encapsulated with a liposome, characterized, and then used as a treatment for the freshly harvested Nosema spores, under light and dark conditions, in-vitro, in 96-well plates. In the dark treatment, after 30-min, the ZnPc 100 µM treatment, caused a 30% Nosema mortality, while this increased to 80% at the same concentration after the light treatment. The high rate of anti-spore effects, in a short period of time, supports the notion that this could be an effective treatment for managing honey bee Nosema infections in the future. Our results also suggest that the photo activation of the treatment could be applied in the field setting and this would increase the sterilization of beekeeping equipment against Nosema.