School of Veterinary Medicine, Azabu University, Fuchinobe 1-17-71, Chuo-ku Sagamihara-shi, Kanagawa, Japan.
School of Veterinary Medicine, Azabu University, Fuchinobe 1-17-71, Chuo-ku Sagamihara-shi, Kanagawa, Japan.
Vet Microbiol. 2020 Jan;240:108547. doi: 10.1016/j.vetmic.2019.108547. Epub 2019 Dec 4.
Infection of cattle by bovine leukemia virus (BLV) causes significant economic losses in terms of milk and meat production in many countries. Because the gut microbiota may be altered by immunomodulation resulting from viral infections, we hypothesized that latent BLV infection would change the gut (i.e., rumen and hindgut) microbiota of infected cattle. In this study, we compared the gut microbiota of 22 uninfected and 29 BLV-infected Holstein-Friesian cows kept on the same farm, by 16S rRNA amplicon sequence analysis of fecal samples. First, we found that the fecal microbial diversity of BLV-infected cows differed slightly from that of uninfected cows. According to differential abundance analysis, some bacterial taxa associated with ruminal fermentation, such as Lachnospiraceae and Veillonellaceae families, were enriched in the fecal microbiota of uninfected cows. Second, the virus propagation ability of BLV strains was examined in vitro, and the correlation of the fecal microbiota with this virus propagation ability was analyzed. Higher virus propagation was shown to lead to less diversity in the microbiota. Differential abundance analysis showed that one bacterial taxon of genus Sanguibacteroides was negatively correlated with the virus propagation ability of BLV strains. Considering these results, BLV infection was speculated to decrease energy production efficiency in the cows via modification of rumen and hindgut microbiota, which partly relies on the virus propagation ability of BLV strains. This may explain the secondary negative effects of BLV infections such as increased susceptibility to other infections and decreased lifetime milk production and reproductive efficiency.
牛白血病病毒（BLV）感染会降低牛奶和肉类产量，给许多国家造成巨大的经济损失。由于病毒感染可能会导致肠道微生物群发生免疫调节变化，我们假设潜伏的 BLV 感染会改变感染牛的肠道（即瘤胃和后肠）微生物群。在这项研究中，我们通过对粪便样本的 16S rRNA 扩增子序列分析，比较了 22 头未感染和 29 头 BLV 感染的荷斯坦-弗里生奶牛的肠道微生物群。首先，我们发现 BLV 感染牛的粪便微生物多样性与未感染牛略有不同。根据差异丰度分析，一些与瘤胃发酵相关的细菌类群，如 Lachnospiraceae 和 Veillonellaceae 科，在未感染牛的粪便微生物群中富集。其次，我们在体外检测了 BLV 株的病毒增殖能力，并分析了粪便微生物群与这种病毒增殖能力的相关性。较高的病毒增殖能力导致微生物群的多样性降低。差异丰度分析表明，一个属于 Sanguibacteroides 属的细菌类群与 BLV 株的病毒增殖能力呈负相关。考虑到这些结果，BLV 感染可能通过改变瘤胃和后肠微生物群来降低奶牛的能量产生效率，这部分依赖于 BLV 株的病毒增殖能力。这可以解释 BLV 感染的一些次要负面影响，如增加对其他感染的易感性、降低终生产奶量和繁殖效率。
