PDF(Pubmed)
Abstract：
BACKGROUND: Infectious bovine keratoconjunctivitis (IBK) is a common cause of morbidity in cattle, resulting in significant economic losses. This study aimed to characterize the bovine bacterial ocular surface microbiome (OSM) through conjunctival swab samples from Normal eyes and eyes with naturally acquired, active IBK across populations of cattle using a three-part approach, including bacterial culture, relative abundance (RA, 16 S rRNA gene sequencing), and semi-quantitative random forest modeling (real-time polymerase chain reaction (RT-PCR)).
RESULTS: Conjunctival swab samples were obtained from eyes individually classified as Normal (n = 376) or IBK (n = 228) based on clinical signs. Cattle unaffected by IBK and the unaffected eye in cattle with contralateral IBK were used to obtain Normal eye samples. Moraxella bovis was cultured from similar proportions of IBK (7/228, 3.07%) and Normal eyes (1/159, 0.63%) (p = 0.1481). Moraxella bovoculi was cultured more frequently (p < 0.0001) in IBK (59/228, 25.88%) than Normal (7/159, 4.40%) eyes. RA (via 16 S rRNA gene sequencing) of Actinobacteriota was significantly higher in Normal eyes (p = 0.0045). Corynebacterium variabile and Corynebacterium stationis (Actinobacteriota) were detected at significantly higher RA (p = 0.0008, p = 0.0025 respectively) in Normal eyes. Rothia nasimurium (Actinobacteriota) was detected at significantly higher RA in IBK eyes (p < 0.0001). Alpha-diversity index was not significantly different between IBK and Normal eyes (p > 0.05). Alpha-diversity indices for geographic location (p < 0.001), age (p < 0.0001), sex (p < 0.05) and breed (p < 0.01) and beta-diversity indices for geographic location (p < 0.001), disease status (p < 0.01), age (p < 0.001), sex (p < 0.001) and breed (p < 0.001) were significantly different between groups. Modeling of RT-PCR values reliably categorized the microbiome of IBK and Normal eyes; primers for Moraxella bovoculi, Moraxella bovis, and Staphylococcus spp. were consistently the most significant canonical variables in these models.
CONCLUSIONS: The results provide further evidence that multiple elements of the bovine bacterial OSM are altered in the context of IBK, indicating the involvement of a variety of bacteria in addition to Moraxella bovis, including Moraxella bovoculi and R. nasimurium, among others. Actinobacteriota RA is altered in IBK, providing possible opportunities for novel therapeutic interventions. While RT-PCR modeling provided limited further support for the involvement of Moraxella bovis in IBK, this was not overtly reflected in culture or RA results. Results also highlight the influence of geographic location and breed type (dairy or beef) on the bovine bacterial OSM. RT-PCR modeling reliably categorized samples as IBK or Normal.
RESULTS: Conjunctival swab samples were obtained from eyes individually classified as Normal (n = 376) or IBK (n = 228) based on clinical signs. Cattle unaffected by IBK and the unaffected eye in cattle with contralateral IBK were used to obtain Normal eye samples. Moraxella bovis was cultured from similar proportions of IBK (7/228, 3.07%) and Normal eyes (1/159, 0.63%) (p = 0.1481). Moraxella bovoculi was cultured more frequently (p < 0.0001) in IBK (59/228, 25.88%) than Normal (7/159, 4.40%) eyes. RA (via 16 S rRNA gene sequencing) of Actinobacteriota was significantly higher in Normal eyes (p = 0.0045). Corynebacterium variabile and Corynebacterium stationis (Actinobacteriota) were detected at significantly higher RA (p = 0.0008, p = 0.0025 respectively) in Normal eyes. Rothia nasimurium (Actinobacteriota) was detected at significantly higher RA in IBK eyes (p < 0.0001). Alpha-diversity index was not significantly different between IBK and Normal eyes (p > 0.05). Alpha-diversity indices for geographic location (p < 0.001), age (p < 0.0001), sex (p < 0.05) and breed (p < 0.01) and beta-diversity indices for geographic location (p < 0.001), disease status (p < 0.01), age (p < 0.001), sex (p < 0.001) and breed (p < 0.001) were significantly different between groups. Modeling of RT-PCR values reliably categorized the microbiome of IBK and Normal eyes; primers for Moraxella bovoculi, Moraxella bovis, and Staphylococcus spp. were consistently the most significant canonical variables in these models.
CONCLUSIONS: The results provide further evidence that multiple elements of the bovine bacterial OSM are altered in the context of IBK, indicating the involvement of a variety of bacteria in addition to Moraxella bovis, including Moraxella bovoculi and R. nasimurium, among others. Actinobacteriota RA is altered in IBK, providing possible opportunities for novel therapeutic interventions. While RT-PCR modeling provided limited further support for the involvement of Moraxella bovis in IBK, this was not overtly reflected in culture or RA results. Results also highlight the influence of geographic location and breed type (dairy or beef) on the bovine bacterial OSM. RT-PCR modeling reliably categorized samples as IBK or Normal.
摘要：
背景：传染性牛角膜结膜炎（IBK）是牛发病的常见原因，造成重大经济损失。这项研究旨在通过正常眼睛和自然获得的眼睛的结膜拭子样本来表征牛细菌眼表微生物组（OSM），使用三部分方法在牛种群中活跃IBK，包括细菌培养,相对丰度(RA，16SrRNA基因测序），和半定量随机森林建模(实时聚合酶链反应(RT-PCR))。
结果:结膜拭子样品获自基于临床体征单独分类为正常(n=376)或IBK(n=228)的眼睛。使用未受IBK影响的牛和具有对侧IBK的牛的未受影响的眼睛来获得正常眼睛样品。从类似比例的IBK（7/228，3.07％）和正常眼（1/159，0.63％）（p=0.1481）培养牛莫拉氏菌。在IBK（59/228，25.88％）中，与正常（7/159，4.40％）眼相比，在IBK（59/228，25.88％）中培养了更多（p<0.0001）。正常眼放线菌群的RA(通过16SrRNA基因测序)显著较高(p=0.0045)。在正常眼中，在RA显着较高（分别为p=0.0008，p=0.0025）的情况下检测到了变异棒状杆菌和固定棒状杆菌（放线菌）。在IBK眼中，在显着较高的RA中检测到Roshianassimurium（放线菌）（p<0.0001）。Alpha多样性指数在IBK和正常眼之间没有显着差异（p>0.05）。地理位置的Alpha-多样性指数(p<0.001)，年龄（p<0.0001），性别（p<0.05）和品种（p<0.01）以及地理位置的β-多样性指数（p<0.001），疾病状态（p<0.01），年龄（p<0.001），性别(p<0.001)和品种(p<0.001)组间差异显著。RT-PCR值的建模可靠地对IBK和正常眼睛的微生物组进行了分类；博沃氏菌的引物，牛莫拉氏菌,和葡萄球菌属。一直是这些模型中最重要的规范变量。
结论：结果提供了进一步的证据，表明牛细菌OSM的多种元素在IBK的背景下发生了变化，表明除了牛莫拉氏菌外，还有多种细菌的参与，包括波克莫拉菌和纳氏梭菌，在其他人中。放线菌RA在IBK中发生改变，为新的治疗干预提供可能的机会。虽然RT-PCR建模为牛莫拉氏菌参与IBK提供了有限的进一步支持，这没有在文化或RA结果中得到明确反映.结果还强调了地理位置和品种类型（乳制品或牛肉）对牛细菌OSM的影响。RT-PCR建模可靠地将样品分类为IBK或正常。
结果:结膜拭子样品获自基于临床体征单独分类为正常(n=376)或IBK(n=228)的眼睛。使用未受IBK影响的牛和具有对侧IBK的牛的未受影响的眼睛来获得正常眼睛样品。从类似比例的IBK（7/228，3.07％）和正常眼（1/159，0.63％）（p=0.1481）培养牛莫拉氏菌。在IBK（59/228，25.88％）中，与正常（7/159，4.40％）眼相比，在IBK（59/228，25.88％）中培养了更多（p<0.0001）。正常眼放线菌群的RA(通过16SrRNA基因测序)显著较高(p=0.0045)。在正常眼中，在RA显着较高（分别为p=0.0008，p=0.0025）的情况下检测到了变异棒状杆菌和固定棒状杆菌（放线菌）。在IBK眼中，在显着较高的RA中检测到Roshianassimurium（放线菌）（p<0.0001）。Alpha多样性指数在IBK和正常眼之间没有显着差异（p>0.05）。地理位置的Alpha-多样性指数(p<0.001)，年龄（p<0.0001），性别（p<0.05）和品种（p<0.01）以及地理位置的β-多样性指数（p<0.001），疾病状态（p<0.01），年龄（p<0.001），性别(p<0.001)和品种(p<0.001)组间差异显著。RT-PCR值的建模可靠地对IBK和正常眼睛的微生物组进行了分类；博沃氏菌的引物，牛莫拉氏菌,和葡萄球菌属。一直是这些模型中最重要的规范变量。
结论：结果提供了进一步的证据，表明牛细菌OSM的多种元素在IBK的背景下发生了变化，表明除了牛莫拉氏菌外，还有多种细菌的参与，包括波克莫拉菌和纳氏梭菌，在其他人中。放线菌RA在IBK中发生改变，为新的治疗干预提供可能的机会。虽然RT-PCR建模为牛莫拉氏菌参与IBK提供了有限的进一步支持，这没有在文化或RA结果中得到明确反映.结果还强调了地理位置和品种类型（乳制品或牛肉）对牛细菌OSM的影响。RT-PCR建模可靠地将样品分类为IBK或正常。
