Boonmee Thummanoon, Sinpoo Chainarong, Laokulsiri Kasidet, Piyaphonsakon Gaokaew, Panngom Kamonporn, Disayathanoowat Terd, Pettis Jeffery S, Chaimanee Veeranan
Department of Agro-Industrial Biotechnology, Maejo University Phrae Campus, Phrae, 54140, Thailand.
Bee Protection Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand.
Sci Rep. 2025 Jul 24;15(1):26975. doi: 10.1038/s41598-025-11303-4.
Nosema ceranae is a widespread microsporidian parasite that primarily affects adult honeybees (Apis mellifera) but has also been reported to infect honeybee larvae. It has been considered as a main cause of colony losses. This study evaluated the anti-microsporidian activity of atmospheric non-thermal plasma against N. ceranae, which could provide a new technology for controlling Nosema disease. Argon and helium plasma substantially decreased N. ceranae spores, with the maximal reductions of 96.55% and 96.05%, respectively. Also, plasma activated water (PAW) generated by argon gas affected spores by a 50.51-77.14% of reduction, with HO concentrations ranging from 50 to 200 mg/L, depending on the plasma exposure time. Therefore, the effect of HO on the inactivation of N. ceranae spores was evaluated. The results showed that HO concentration up to 100 mg/L reduced spore numbers by approximately 42.64-49.75%. HO levels remained stable for up to 6 days, followed by a reduction of 50-80% in argon-generated PAW and 33.33-80% in helium-generated PAW by day 14. Moreover, this study demonstrated that both direct plasma and PAW treatments resulted in a significant reduction in the number of N. ceranae spores infecting adult bees, especially on day 14 after inoculation (71.88-87.42% of reduction). To elucidate the anti-N. ceranae activity of gas plasma and PAW, we performed an integrity of cell membrane and scanning electron microscopy analysis. The results of the cell membrane tests and microscopy reveal much about how these two methods could work, both plasma discharge and PAW. However, the development of plasma devices and PAW, as well as their safety for honeybees should be further investigated for effective control of N. ceranae and other pathogens in honeybees.
蜜蜂微孢子虫是一种广泛传播的微孢子虫寄生虫，主要影响成年蜜蜂（西方蜜蜂），但也有报道称其会感染蜜蜂幼虫。它被认为是蜂群损失的主要原因之一。本研究评估了大气非热等离子体对蜜蜂微孢子虫的抗微孢子虫活性，这可为防治微孢子虫病提供一种新技术。氩气和氦气等离子体显著减少了蜜蜂微孢子虫孢子，最大减少率分别为96.55%和96.05%。此外，氩气产生的等离子体活化水（PAW）对孢子有影响，减少率为50.51%-77.14%，羟基（HO）浓度范围为50至200毫克/升，这取决于等离子体暴露时间。因此，评估了羟基对蜜蜂微孢子虫孢子失活的影响。结果表明，羟基浓度高达100毫克/升时，孢子数量减少了约42.64%-49.75%。羟基水平在长达6天内保持稳定，随后在第14天时，氩气产生的PAW中羟基水平降低了50%-80%，氦气产生的PAW中降低了33.33%-80%。此外，本研究表明，直接等离子体处理和PAW处理均导致感染成年蜜蜂的蜜蜂微孢子虫孢子数量显著减少，尤其是在接种后第14天（减少率为71.88%-87.42%）。为阐明气体等离子体和PAW的抗蜜蜂微孢子虫活性，我们进行了细胞膜完整性和扫描电子显微镜分析。细胞膜测试和显微镜检查的结果揭示了这两种方法（等离子体放电和PAW）的作用方式。然而，为有效控制蜜蜂微孢子虫和蜜蜂中的其他病原体，应进一步研究等离子体装置和PAW的开发及其对蜜蜂的安全性。
