Abstract：
Hematophagous Stomoxys (stable) fly populations in dairy barns are sustained by a constant availability of cattle hosts and manure, which serve as major reservoirs of both zoonotic and opportunistic bacterial pathogens. However, the composition of the Stomoxys fly microbiota, the mechanisms by which flies acquire their microbiome, and the ability of potentially pathogenic bacteria to colonize and persist in fly hosts remain to be investigated. Here, we longitudinally collected fly and manure samples from two connected dairy facilities. High throughput 16S rRNA gene amplicon sequencing was then used to characterize and compare bacterial communities present on or within flies and in manure collected from the same facility, while culture-dependent methods were used to verify the viability of clinically relevant bacteria. Bacterial alpha diversity was overall higher in manure samples as compared to fly samples, with manure-associated bacterial communities being dominated by members of the Bacteroidales, Eubacteriales, and Oscillospirales. In contrast, flies harbored relatively low-complexity communities dominated by members of the Enterobacterales, Staphylococcales, and Lactobacillales. Clinically relevant bacterial strains, including Escherichia spp. and other taxa associated with mastitic cows housed in the same facilities, were detected in paired fly and manure samples but exhibited dramatically elevated abundances in fly samples as compared to manure samples. Viable colonies of Escherichia, Klebsiella, and Staphylococcus spp. were also readily isolated from fly samples, confirming that flies harbor culturable mastitis-associated bacteria. This study identifies biting flies as bona fide carriers of opportunistically pathogenic bacterial taxa on dairy farms.
OBJECTIVE: Disease prevention on dairy farms has significant implications for cattle health, food security, and zoonosis. Of particular importance is the control of bovine mastitis, which can be caused by diverse bacteria, including Klebsiella, Escherichia coli, Streptococcus, and Staphylococcus spp. Despite being one of the most significant and costly cattle diseases worldwide, the epidemiology of bovine mastitis is not well understood. This study provides parallel culture-independent and culture-dependent evidence to support the carriage of opportunistically pathogenic bacteria by Stomoxys flies on dairy farms. We further show that the fly microbiota is enriched in clinically relevant taxa-the vast majority of which can be traced to the manure habitats in which flies breed. Altogether, our results identify biting flies as underrecognized carriers of bacterial taxa associated with environmental bovine mastitis and other opportunistic infections in vertebrates and offer important insights into mechanisms of microbial acquisition by these and other medically important insects.
OBJECTIVE: Disease prevention on dairy farms has significant implications for cattle health, food security, and zoonosis. Of particular importance is the control of bovine mastitis, which can be caused by diverse bacteria, including Klebsiella, Escherichia coli, Streptococcus, and Staphylococcus spp. Despite being one of the most significant and costly cattle diseases worldwide, the epidemiology of bovine mastitis is not well understood. This study provides parallel culture-independent and culture-dependent evidence to support the carriage of opportunistically pathogenic bacteria by Stomoxys flies on dairy farms. We further show that the fly microbiota is enriched in clinically relevant taxa-the vast majority of which can be traced to the manure habitats in which flies breed. Altogether, our results identify biting flies as underrecognized carriers of bacterial taxa associated with environmental bovine mastitis and other opportunistic infections in vertebrates and offer important insights into mechanisms of microbial acquisition by these and other medically important insects.
摘要：
奶牛场中的吸血Stomoxys（稳定的）苍蝇种群通过持续不断的牛宿主和粪便来维持，它们是人畜共患和机会性细菌病原体的主要储库。然而,Stomoxys蝇微生物群的组成，苍蝇获取微生物组的机制，潜在致病菌在蝇宿主中定植和持续存在的能力仍有待研究。这里,我们从两个相连的乳品厂纵向收集了苍蝇和粪便样本。然后使用高通量16SrRNA基因扩增子测序来表征和比较苍蝇上或内部以及从同一设施收集的粪肥中存在的细菌群落。而培养依赖的方法用于验证临床相关细菌的活力。与苍蝇样品相比，粪便样品中的细菌α多样性总体较高，与粪肥相关的细菌群落由拟杆菌的成员主导，Eubacteriales,和螺旋管。相比之下,苍蝇具有相对低复杂性的群落，主要由肠杆菌的成员，葡萄球菌,和乳酸杆菌.临床相关细菌菌株，包括埃希氏菌。以及与饲养在同一设施中的乳牛相关的其他分类群，在配对的蝇和粪肥样品中检测到，但与粪肥样品相比，蝇样品中的丰度显着提高。大肠杆菌的活菌落，克雷伯菌属,和葡萄球菌属。也很容易从苍蝇样本中分离出来，确认苍蝇藏有可培养的乳腺炎相关细菌。这项研究确定了叮咬的苍蝇是奶牛场中机会致病性细菌分类群的真正携带者。
目的：奶牛场的疾病预防对牛的健康具有重要意义。粮食安全,和人畜共患病。特别重要的是控制牛乳腺炎，这可能是由多种细菌引起的，包括克雷伯菌,大肠杆菌,链球菌,和葡萄球菌属。尽管是世界上最重要和最昂贵的牛疾病之一，牛乳腺炎的流行病学尚不清楚。这项研究提供了平行的培养无关和培养依赖的证据，以支持Stomoxys蝇在奶牛场上携带机会致病菌。我们进一步表明，苍蝇的微生物群富含临床相关的分类群，其中绝大多数可以追溯到苍蝇繁殖的粪便栖息地。总之,我们的研究结果确定了叮咬蝇是与脊椎动物中环境牛乳腺炎和其他机会性感染相关的细菌分类群的未被识别的携带者，并为这些和其他医学上重要的昆虫获得微生物的机制提供了重要见解。
目的：奶牛场的疾病预防对牛的健康具有重要意义。粮食安全,和人畜共患病。特别重要的是控制牛乳腺炎，这可能是由多种细菌引起的，包括克雷伯菌,大肠杆菌,链球菌,和葡萄球菌属。尽管是世界上最重要和最昂贵的牛疾病之一，牛乳腺炎的流行病学尚不清楚。这项研究提供了平行的培养无关和培养依赖的证据，以支持Stomoxys蝇在奶牛场上携带机会致病菌。我们进一步表明，苍蝇的微生物群富含临床相关的分类群，其中绝大多数可以追溯到苍蝇繁殖的粪便栖息地。总之,我们的研究结果确定了叮咬蝇是与脊椎动物中环境牛乳腺炎和其他机会性感染相关的细菌分类群的未被识别的携带者，并为这些和其他医学上重要的昆虫获得微生物的机制提供了重要见解。
