Department of Ecology and Evolution, Biophore, UNIL-Sorge, University of Lausanne , Lausanne, Switzerland.
Agroscope, Swiss Bee Research Centre , Bern, Switzerland.
Virulence. 2020 Dec;11(1):554-567. doi: 10.1080/21505594.2020.1768338.
is a bacterial pathogen that causes epidemic outbreaks of European foulbrood (EFB) in honey bee populations. The pathogenicity of a bacterium depends on its virulence, and understanding the mechanisms influencing virulence may allow for improved disease control and containment. Using a standardized assay, we demonstrate that virulence varies greatly among sixteen isolates from five European countries. Additionally, we explore the causes of this variation. In this study, virulence was independent of the multilocus sequence type of the tested pathogen, and was not affected by experimental co-infection with , a bacterium often associated with EFB outbreaks. Virulence was correlated with the growth dynamics of isolates in artificial medium, and with the presence of a plasmid carrying a gene coding for the putative toxin melissotoxin A. Our results suggest that some strains showed an increased virulence due to the acquisition of a toxin-carrying mobile genetic element. We discuss whether strains with increased virulence play a role in recent EFB outbreaks.
是一种细菌病原体，可导致欧洲蜜蜂种群中爆发流行病——欧洲幼虫腐臭病（EFB）。细菌的致病性取决于其毒力，了解影响毒力的机制可能有助于更好地控制和遏制疾病。使用标准化的测定方法，我们证明了来自五个欧洲国家的十六个分离株的毒力差异很大。此外，我们还探讨了这种变异的原因。在这项研究中，毒力与测试病原体的多位点序列类型无关，也不受与 EFB 爆发常相关的细菌 的实验性共同感染的影响。毒力与分离株在人工培养基中的生长动态相关，与携带编码假定毒素 melissotoxin A 的基因的质粒的存在相关。我们的结果表明，由于获得了携带毒素的可移动遗传元件，一些 菌株的毒力有所增加。我们讨论了毒力增加的菌株是否在最近的 EFB 爆发中发挥了作用。
