Lepper A W, Atwell J L, Lehrbach P R, Schwartzkoff C L, Egerton J R, Tennent J M
CSIRO Division of Animal Health, Animal Health Research Laboratory, Parkville, Vic., Australia.
Vet Microbiol. 1995 Jul;45(2-3):129-38. doi: 10.1016/0378-1135(94)00123-e.
Calves were vaccinated with cloned Moraxella bovis pili of serogroup C (experiment 1) or B (experiment 2) either as a monovalent formulation or as part of a multivalent preparation with pili of six other serogroups. Within 4 weeks of the second vaccine dose vaccinated calves and non-vaccinated controls were challenged via the ocular route with either virulent M. bovis strain Dal2d (serogroup C) or M. bovis strain 3WO7 (serogroup B) in experiments 1 and 2, respectively. Calves vaccinated with multivalent vaccines had significantly lower antibody titres than those vaccinated with monovalent preparations. Nevertheless, the levels of protection against infectious bovine keratoconjunctivitis (IBK) achieved with multivalent vaccines were 72% and 83% for the groups challenged with M. bovis strains of serogroups B and C, respectively. The serogroup C monovalent vaccine gave 100% protection against experimentally induced IBK and M. bovis isolates cultured from the eyes 6 days post-challenge were identified as belonging solely to serogroup C. Unexpectedly, only 25% protection was achieved against homologous strain challenge of calves that received the monovalent serogroup B vaccine. Furthermore, the majority of M. bovis isolates recovered from calves in this group belonged to serogroup C, as did half of those isolates cultured from the multivalent vaccinates. The remaining bacterial isolates from the latter group, together with all isolates from the non-vaccinated controls, belonged to serogroup B. Results are consistent with the hypothesis that derivatives of the serogroup B challenge inoculum had expressed serogroup C pilus antigen within 6 days of the challenge, possibly as a result of pilus gene inversion occurring in response to the presence of specific antibody in eye tissues and tears.
给犊牛接种C血清群（实验1）或B血清群（实验2）的克隆牛莫拉菌菌毛，接种形式为单价制剂，或作为包含其他六个血清群菌毛的多价制剂的一部分。在第二次接种疫苗后的4周内，在实验1和实验2中，分别通过眼内途径用强毒牛莫拉菌Dal2d菌株（C血清群）或牛莫拉菌3WO7菌株（B血清群）对接种疫苗的犊牛和未接种疫苗的对照进行攻毒。接种多价疫苗的犊牛的抗体滴度显著低于接种单价制剂的犊牛。然而，对于用B血清群和C血清群牛莫拉菌菌株攻毒的组，多价疫苗对传染性牛角膜结膜炎（IBK）的保护水平分别为72%和83%。C血清群单价疫苗对实验诱导的IBK提供了100%的保护，攻毒后6天从眼中培养的牛莫拉菌分离株被鉴定为仅属于C血清群。出乎意料的是，接种单价B血清群疫苗的犊牛对同源菌株攻毒仅获得了25%的保护。此外，该组中从犊牛分离出的大多数牛莫拉菌分离株属于C血清群，多价疫苗接种犊牛培养的分离株中有一半也属于C血清群。后一组中其余的细菌分离株以及未接种疫苗对照的所有分离株都属于B血清群。结果与以下假设一致：B血清群攻毒接种物的衍生物在攻毒后6天内表达了C血清群菌毛抗原，这可能是由于菌毛基因倒位响应眼组织和泪液中特异性抗体的存在而发生的。
