Baseline analysis of Mycoplasma mycoides subsp. mycoides antigens as targets for a DIVA assay for use with a subunit vaccine for contagious bovine pleuropneumonia.

BACKGROUND: Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia in cattle. A prototype subunit vaccine is being developed, however, there is currently no diagnostic test that can differentiate between infected cattle and those vaccinated with the prototype subunit vaccine. This study characterized Mmm proteins to identify potential antigens for use in differentiating infected from vaccinated animals. RESULTS: Ten Mmm antigens expressed as recombinant proteins were tested in an indirect ELISA using experimental sera from control groups, infected, and vaccinated animals. Data were imported into R software for analysis and drawing of the box and scatter plots while Cohen's Kappa assessed the level of agreement between the Mmm antigens. Two vaccine antigens (MSC_0499 and MSC_0776) were superior in detecting antibodies in sera of animals vaccinated with the subunit vaccines while two non-vaccine antigens (MSC_0636 and LppB) detected antibodies in sera of infected animals showing all clinical stages of the disease. Sensitivity and specificity of above 87.5% were achieved when the MSC_0499 and MSC_0636 antigens were tested on sera from vaccinated and infected animals. CONCLUSIONS: The MSC_0499 and MSC_0776 antigens were the most promising for detecting vaccinated animals, while MSC_0636 and LppB were the best targets to identify infected animals. Further testing of sera from vaccinated and infected animals collected at different time intervals in the field should help establish how useful a diagnostic test based on a cocktail of these proteins would be.

Prevalence of contagious caprine pleuro-pneumonia in pastoral flocks of goats in the Rift Valley region of Kenya.

A cross-sectional survey was conducted between the months of March 2014 and March 2015 to determine the prevalence of contagious caprine pleuropneumonia in goat populations in pastoral flocks in three sub-counties of the Rift Valley region. A total of 432 serum samples were collected from goats from 54 flocks and tested for the presence of antibodies against mycoplasma capricolum subspecies capripneumoniae (mccp) using monoclonal antibody-based competitive enzyme-linked immuno-sorbent assay. Sero-prevalence recorded for Turkana West was 63.9%, Kajiado Central was 48.6%, while Pokot East was 29.2% which was statistically significant (χ2 = 34.997; P = 0.000) in the study sites. The results of this study confirmed that CCPP is widespread and endemic in the pastoral production systems studied in the Rift Valley region. The results confirmed that regions sharing international boundaries are at a higher risk of CCPP hence the need for a unified cross-border approach to disease control measures in the border areas.