INRA, UR 406 Abeilles et Environnement, Site Agroparc, 84914 Avignon, France.
Bee Pathology Laboratory, Centro Apícola Regional, JCCM, 19180 Marchamalo, Spain.
Vet Microbiol. 2013 Mar 23;162(2-4):670-678. doi: 10.1016/j.vetmic.2012.09.012. Epub 2012 Sep 16.
The intestinal honey bee parasite Nosema ceranae (Microsporidia) is at the root of colony losses in some regions while in others its presence causes no direct mortality. This is the case for Spain and France, respectively. It is hypothesized that differences in honey bee responses to N. ceranae infection could be due to the degree of virulence of N. ceranae strains from different geographic origins. To test this hypothesis, we first performed a study to compare the genetic variability of an rDNA fragment that could reveal differences between two N. ceranae isolates, one from Spain and one from France. Then we compared the infection capacity of both isolates in Apis mellifera iberiensis, based on the anatomopathological lesions due to N. ceranae development in the honey bee midgut, N. ceranae spore-load in the midgut and the honey bee survival rate. Our results suggest that there is no specific genetic background of the two N. ceranae isolates, from Spain or France, used in this study. These results agree with the infection development, honey bee survival and spore-loads that were similar between honey bees infected with both N. ceranae isolates. Probably, differences in honey bee response to infection are more related to the degree of tolerance of honey bee subspecies or local hybrids to N. ceranae, or experimental conditions in the case of laboratory trials, than to differences between N. ceranae isolates. Further studies should be done to estimate the contribution of each of these factors on the response of the honey bees to infection.
肠道蜜蜂寄生虫蜜蜂微孢子虫（Nosema ceranae）（微孢子虫）是导致一些地区蜂群损失的根源，而在其他地区，其存在不会导致直接死亡。西班牙和法国就是这种情况。据推测，蜜蜂对蜜蜂微孢子虫感染的反应差异可能是由于来自不同地理起源的蜜蜂微孢子虫菌株的毒力程度不同。为了验证这一假设，我们首先进行了一项研究，比较了 rDNA 片段的遗传变异，该片段可能揭示来自西班牙和法国的两种蜜蜂微孢子虫分离株之间的差异。然后，我们根据蜜蜂微孢子虫在蜜蜂中肠发育引起的解剖病理学病变、中肠中的蜜蜂微孢子虫孢子负荷以及蜜蜂的存活率，比较了这两种分离株在 Iberian honey bee（Apis mellifera iberiensis）中的感染能力。我们的结果表明，在所研究的两个蜜蜂微孢子虫分离株（来自西班牙和法国的分离株）中，没有特定的遗传背景。这些结果与感染发展、蜜蜂存活率和孢子负荷一致，即感染两种蜜蜂微孢子虫分离株的蜜蜂相似。可能，蜜蜂对感染的反应差异更多地与蜜蜂亚种或当地杂种对蜜蜂微孢子虫的耐受程度有关，或者与实验室试验中的实验条件有关，而与蜜蜂微孢子虫分离株之间的差异无关。应进一步研究以估计这些因素中的每一个对蜜蜂对感染的反应的贡献。
