MAP, Johne\u2019s disease and the microbiome; current knowledge and future considerations

Chloe Matthews,Paul D. Cotter,Jim O’ Mahony

doi:10.1186/s42523-021-00089-1

Abstract

Mycobacterium avium subsp. paratuberculosis is the causative agent of Johne’s disease in ruminants. As an infectious disease that causes reduced milk yields, effects fertility and, eventually, the loss of the animal, it is a huge financial burden for associated industries. Efforts to control MAP infection and Johne’s disease are complicated due to difficulties of diagnosis in the early stages of infection and challenges relating to the specificity and sensitivity of current testing methods. The methods that are available contribute to widely used test and cull strategies, vaccination programmes also in place in some countries. Next generation sequencing technologies have opened up new avenues for the discovery of novel biomarkers for disease prediction within MAP genomes and within ruminant microbiomes. Controlling Johne’s disease in herds can lead to improved animal health and welfare, in turn leading to increased productivity. With current climate change bills, such as the European Green Deal, targeting livestock production systems for more sustainable practices, managing animal health is now more important than ever before. This review provides an overview of the current knowledge on genomics and detection of MAP as it pertains to Johne’s disease.

Highlights

Mycobacterium avium subsp. paratuberculosis and Johne’s disease Mycobacteria, which belong to the phylum Actinobacteria, are Gram-positive, acid-fast organisms that include a number of relevant human and animal pathogens such as Mycobacterium leprae, Mycobacterium tuberculosis and Mycobacterium avium subsp. paratuberculosis (MAP)
This study found that using whole genome sequencing (WGS) in conjunction with MIRU-VNTR led to better resolution
MAP was first reported to cause Johne’s disease (JD) in ruminants in the late 1800s. At that point it was described as intestinal tuberculosis and known as pseudotuberculous enteritis

Summary

Introduction

Mycobacterium avium subsp. paratuberculosis and Johne’s disease Mycobacteria, which belong to the phylum Actinobacteria, are Gram-positive, acid-fast organisms that include a number of relevant human and animal pathogens such as Mycobacterium leprae, Mycobacterium tuberculosis and Mycobacterium avium subsp. paratuberculosis (MAP). MAP, the focus of this review, is a slow-growing, rod-shaped, non-spore-former, with a unique complex lipid cell wall structure [1]. It is this complex cell wall structure that is in part responsible for its persistence in the environment and in the host. Infected animals can be classified into a number of distinct stages of silent, subclinical (greatest threat to eradication and control), clinical and advanced stages of disease. These categories are based on the presence and severity of clinical signs, the rate of environmental shedding and the likelihood of detection with current MAP diagnostic methods [4]. Animals that are infected with MAP, but have no evidence of disease and cannot be detected with current diagnostic methods, are said to be in the silent stage [5]

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Conclusion