Otti Oliver, Schmid-Hempel Paul
Experimental Ecology, Institute of Integrative Biology-Zurich (IBZ), ETH Zurich, 8092 Zurich, Switzerland.
J Invertebr Pathol. 2007 Oct;96(2):118-24. doi: 10.1016/j.jip.2007.03.016. Epub 2007 Mar 31.
Nosema bombi is an obligate intracellular parasite that infects different bumblebee species at a substantial, though variable, rate. To date its pathology and impact on host fitness are not well understood. We performed a laboratory experiment investigating the pathology and fitness effects of this parasite on the bumblebee Bombus terrestris. We experimentally infected one group of colonies with N. bombi spores at the start of the worker production, while a second uninfected group of colonies served as controls. During colony development we collected live workers for dissections to measure infection intensities. In parallel, we measured several life history traits, to investigate costs to the host. We succeeded in infecting 11 of 16 experimental colonies. When infection occurred at an early stage of colony development, virtually all individuals were infected, with spores being found in a number of tissues, and the functional fitness of males and young queens was reduced to zero. Further, the survival of workers from infected colonies and infected males were reduced. With such severe effects, N. bombi appears to decrease its opportunities for transmission to the next host generation.
熊蜂微孢子虫是一种专性细胞内寄生虫，它以相当高但有所变化的比率感染不同种类的熊蜂。迄今为止，其病理学以及对宿主健康状况的影响尚未得到充分了解。我们进行了一项实验室实验，研究这种寄生虫对熊蜂（Bombus terrestris）的病理学和健康状况影响。在工蜂开始产生时，我们用熊蜂微孢子虫孢子对一组蜂群进行实验性感染，而另一组未感染的蜂群作为对照。在蜂群发育过程中，我们收集活的工蜂进行解剖以测量感染强度。同时，我们测量了几个生活史特征，以研究对宿主的代价。我们成功感染了16个实验蜂群中的11个。当在蜂群发育早期发生感染时，几乎所有个体都被感染，在许多组织中都发现了孢子，雄性和年轻蜂王的功能健康状况降至零。此外，来自受感染蜂群的工蜂和受感染雄性的存活率降低。由于有如此严重的影响，熊蜂微孢子虫似乎减少了其传播到下一代宿主的机会。
