Knowledge gaps that hamper prevention and control ofMycobacterium aviumsubspeciesparatuberculosisinfection

Abstract

SummaryIn the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within-farm and farm-to-farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps. K E Y W O R D Scontrol, Johne's disease, Mycobacterium avium subspecies paratuberculosis, prevention

DISCONTOOLS supplement: Current research gaps for advancing control of infectious diseases in production animals

“…Barkema et al. () report that despite decades of implementing Johne's disease (JD) control programmes, eradication in a herd is still elusive and the disease continues to cause considerable losses to the livestock industry. Corroborated by the success of a JD vaccine in the Australian sheep industry, they argue that more effective diagnostic tests and development of a JD vaccine that prevents infection and shedding, but does not affect tuberculosis diagnostics, remain the most pressing gaps.…”

Capacity to Elicit Cytotoxic CD8 T Cell Activity Against Mycobacterium avium subsp. paratuberculosis Is Retained in a Vaccine Candidate 35 kDa Peptide Modified for Expression in Mammalian Cells

“…The inability to detect infected animals during the early (latent) stages of infection has led to the inadvertent spread of Ptb via introduction of latently infected animals into clean herds worldwide. Attempts to clear Map from livestock herds using management strategies and improved early diagnostic methods has not been successful (6)(7)(8)(9)(10). Thus, development of a Map livestock vaccine is urgently needed.…”

“…A major limitation of previous and ongoing endeavors has been the lack of methods to fully evaluate the immune response to candidate live and peptide-based vaccines. As a consequence, there has been a lingering question as to whether there is an age-related difference in susceptibility or immune-responsiveness to Map infection that confers long-lasting immunity in adult animals (6). We developed the reagents and methods needed to study the ex vivo Abbreviations: APC, antigen-presenting cells; pA, bovine growth hormone polyadenylation signal; CBS, calf bovine serum; CTL, cytotoxic T cells; cRPMI, complete culture medium; cDC, conventional dendritic cells; DMSO, dimethyl sulfoxide; EMEM, Eagle's minimal essential medium; EDTA, ethylenediaminetetraacetic acid; FBS, fetal bovine serum; GFP, green fluorescence protein; CMV, human cytomegalovirus; EF1α, human elongation factor 1 alpha promoter; HEK, human embryo kidney; HKB-11, human kidney/B cell hybrid; tPA, human tissue plasminogen activator signal peptide; Map, Mycobacterium avium subsp.…”

Mycobacterium avium Subspecies paratuberculosis DNA and Antibodies in Dairy Goat Colostrum and Milk

“…Although a causal role between MAP and Crohn's disease in humans has not been definitively established [7], a proactive approach in ensuring consumer confidence by addressing the issue is sensible [8,9]. Therefore, MAP control programs have been initiated in (at least) 22 countries [10].…”