Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece.
Institute of Veterinary Science, University of Liverpool, Neston, South Wirral, CH64 7TE, United Kingdom.
J Dairy Sci. 2019 Oct;102(10):9328-9344. doi: 10.3168/jds.2019-16287. Epub 2019 Aug 7.
Our objective was to evaluate the efficacy of a vaccine against staphylococcal mastitis in 5 dairy sheep farms, with 316 ewes in the vaccinated (V) group and 307 in the control (C) group studied throughout a lactation period. Two administrations of the vaccine were performed during the last stage of gestation of ewes. Starting 15 d after lambing and at monthly intervals thereafter, up to 9 milk samplings were performed for bacteriological and cytological examinations. Staphylococcal isolates recovered were examined for biofilm formation. Blood samples were collected for measurement of IgG poly-N-acetylglucosamine-specific antibodies. The most frequently isolated bacteria were staphylococci: 56.4 and 76.1%, respectively, of total isolates recovered from ewes of group V and C, respectively; staphylococci as causal agents of mastitis were isolated less frequently from V (5.3%) than in ewes in C (10.3%). Among mastitis-associated staphylococcal isolates recovered from V ewes, a smaller proportion was biofilm-forming than among ones from C: 53.2% versus 74.9% of isolates; biofilm-forming staphylococci as causal agents of mastitis were isolated less frequently from ewes in group V (2.3%) than in ewes in group C (6.0%). Anti-poly-N-acetylglucosamine-specific antibody values increased in V ewes and were higher than in C; a greater proportion of ewes with low antibody titers developed staphylococcal mastitis (41.4%) than of V ewes with high antibody titers (17.0%). Incidence risk of mastitis, staphylococcal mastitis, and biofilm-associated staphylococcal mastitis was smaller in V than in C: 36.7, 17.1, and 8.0% versus 44.3, 30.9, and 18.9%, respectively. The first case of staphylococcal mastitis occurred later in V than in C: third versus second sampling point. Overall, efficacy of the vaccine was 44.6% for staphylococcal mastitis, 57.7% for biofilm-associated staphylococcal mastitis, 33.1% for staphylococcal intramammary infection, and 51.5% for biofilm-associated staphylococcal intramammary infection. Nevertheless, vaccination should not be the only means for controlling mastitis; other udder health management measures should be included therein to improve control of the infection.
我们的目标是评估一种针对葡萄球菌乳腺炎的疫苗在 5 个奶绵羊场中的功效，其中 316 只接种疫苗（V）组的母羊和 307 只对照（C）组的母羊在整个哺乳期进行了研究。在母羊妊娠末期进行了两次疫苗接种。从产羔后 15 天开始，此后每月进行一次，共进行了 9 次牛奶采样进行细菌学和细胞学检查。回收的葡萄球菌分离株进行了生物膜形成检查。采集血液样本测量 IgG 多-N-乙酰葡糖胺特异性抗体。最常分离到的细菌是葡萄球菌：V 组和 C 组分别回收的总分离株中分别为 56.4%和 76.1%；从 V 组（5.3%）分离到的乳腺炎的葡萄球菌作为病原体比从 C 组（10.3%）分离到的葡萄球菌少。从 V 组的乳腺炎相关葡萄球菌分离株中，生物膜形成比例低于 C 组：53.2%比 74.9%的分离株；V 组（2.3%）中分离到的生物膜形成葡萄球菌作为乳腺炎的病原体比 C 组（6.0%）少。V 组母羊的抗多-N-乙酰葡糖胺特异性抗体值增加，且高于 C 组；低抗体滴度的母羊中，葡萄球菌乳腺炎的发病率（41.4%）高于高抗体滴度的 V 组（17.0%）。乳腺炎、葡萄球菌乳腺炎和生物膜相关葡萄球菌乳腺炎的发病率 V 组低于 C 组：分别为 36.7%、17.1%和 8.0%，44.3%、30.9%和 18.9%。V 组首次发生葡萄球菌乳腺炎的时间晚于 C 组：第三个采样点。总体而言，疫苗对葡萄球菌乳腺炎的功效为 44.6%，对生物膜相关葡萄球菌乳腺炎的功效为 57.7%，对葡萄球菌乳房内感染的功效为 33.1%，对生物膜相关葡萄球菌乳房内感染的功效为 51.5%。然而，疫苗接种不应是控制乳腺炎的唯一手段；应将其他乳房健康管理措施纳入其中，以改善对感染的控制。
