Infectious bovine keratoconjunctivitis vaccine development

Abstract

Infectious bovine keratoconjunctivitis is a common and highly contagious ocular disease affecting cattle worldwide. The tremendous economic losses attributable to this disease warrant continued investigation into methods of prevention. Multiple virulence factors have been linked to the primary aetiologic agent, Moraxella bovis. Efforts to develop an efficacious vaccine have primarily focused upon the use of surface pili or cytolysin to stimulate host immunity; however, M. bovis possesses other virulence determinants that include proteases, fibrinolysins, phospholipases and other cell surface components such as outer membrane proteins. These potentially conserved antigens provide additional possibilities for vaccine development. Examination of appropriate antigen presentation is necessary to attain an adequate immune response. Further, the potential for antigenic diversity as well as epitope conversion requires continuous epidemiological surveillance of isolates recovered from outbreaks. Current work targeting conserved immunogens provides hope for efficacious vaccines that when used in tandem with proper management may control, if not prevent, infectious bovine keratoconjunctivitis.

A Randomized Clinical Trial Evaluating a Farm‐of‐Origin Autogenous Moraxella bovis Vaccine to Control Infectious Bovine Keratoconjunctivis (Pinkeye) in Beef Cattle

“…The response to the vaccine therefore may not have been protective. There is no consensus about the immunoglobins and antigens needed to induce a protective immune response . The results of the meta‐analysis suggest that, despite good evidence that M. bovis is a cause of IBK, M. bovis autogenous vaccines consistently fail to offer protection.…”

Serologic cross‐reactivity of AustralianMoraxella bovisto vaccinal bacterin strains as determined by competitive ELISA

“…In conclusion, because of the pilin variability between groups, the vaccine will not protect against infection with all strains in Australia, but there are no more efficacious vaccines currently commercially available. Data has been published on cytolysin based vaccines, and while these vaccines are likely to be cross protective against all serogroups of Moraxella bovis , the protection afforded is also incomplete 32 . The impact of vaccination on the national incidence of disease is unknown, but this will be influenced by the proportion of producers who elect to use the vaccine.…”

Type‐IV pili spectroscopic markers: Applications in the quantification of piliation levels inMoraxella boviscells by a FT‐IR ANN‐based model

“…In a previous work we demonstrated that this could be due to the piliation loss that occurs as a consequence of the shear forces generated in cell environments when they are grown in mechanically stirred bioreactors [15]. Therefore, in M. bovis vaccine production, it is crucial to monitor cell-bound pili levels during bacterial growth to verify whether the bacterial cells produced maintain their immunogenic properties [11,15,17]. Consequently, we tested if piliation levels of samples withdrawn from stirred bioreactors could be estimated by the FT-IR ANN-based system developed.…”

“…After several vaccines trials it was demonstrated that prophylaxis relies so far largely on vaccines formulated with whole highly piliated M. bovis cells [11,12]. Rapid and reliable detection and quantification of the piliated phenotype in M. bovis is crucial to guarantee the efficacy of vaccine formulations and also important for any study of pathogenicity and epidemiology of IBK [11]. Current techniques for identifying piliated or nonpiliated cells include electron microscopy, slide agglutination (SA), tandem-crossed immunoelectrophoresis (TCIE) and immunological tests such as immunodiffusion and enzyme-linked immunosorbent assay (ELISA) [16][17][18].…”

“…The piliated phenotype of M. bovis is the only form able to cause persistent ocular infection and disease, while the nonpiliated form appears to be nonpathogenic in cattle [10]. After several vaccines trials it was demonstrated that prophylaxis relies so far largely on vaccines formulated with whole highly piliated M. bovis cells [11,12]. Rapid and reliable detection and quantification of the piliated phenotype in M. bovis is crucial to guarantee the efficacy of vaccine formulations and also important for any study of pathogenicity and epidemiology of IBK [11].…”