Transmission Network of Deer-Borne Mycobacterium bovis Infection Revealed by a WGS Approach.

Lorraine Michelet,Maria Laura Boschiroli,Cyril Conde,Franck Biet,Thierry Cochard,Maxime Branger

doi:10.3390/microorganisms7120687

Abstract

Bovine tuberculosis (TB) is a zoonotic disease, mainly caused by Mycobacterium bovis. France was declared officially TB free in 2001, however, the disease persists in livestock and wildlife. Among wild animals, deer are particularly susceptible to bovine TB. Here, a whole genome sequence (WGS) analysis was performed on strains with the same genetic profile—spoligotype SB0121, Multiple Loci VNTR Analysis (MLVA) 6 4 5 3 11 2 5 7—isolated from different types of outbreaks, including from deer or cattle herds, or zoological or hunting parks where the presence of infected deer was a common trait in most of them. The results of the phylogeny based on the SNP calling shows that two sub-clusters co-exist in France, one related to deer bred to be raised as livestock, and the other to hunting parks and zoos. The persistence over almost 30 years of sporadic cases due to strains belonging to these clusters highlights the deficiency in the surveillance of captive wildlife and the need for better monitoring of animals, especially before movement between parks or herds.

Highlights

Bovine tuberculosis, mainly caused by Mycobacterium bovis, is an important re-emergent zoonotic disease in Europe [1]
An epidemiological link exists between these three cases: the wild boars belonged to the same hunting park and the fallow deer, found infected but in another animal park, was originally issued from the same hunting park as that of the wild boar cases
This genotype has been circulating in France for the last 30 years, such strains have been isolated sporadically which clearly shows that there is a lack of appropriate surveillance in animal parks

Summary

Introduction

Bovine tuberculosis (bTB), mainly caused by Mycobacterium bovis, is an important re-emergent zoonotic disease in Europe [1]. France has been officially bTB free (OTF) since 2001, the persistence of the disease in livestock and its occurrence in some areas of wildlife are matters of great concern [2]. This ancient disease is no longer considered just a cattle-borne problem, but a concern for multihost communities that include wildlife species such as wild boar (Sus scrofa), red deer (Cervus elaphus), and badgers (Meles meles) [3]. In Europe, red and fallow deer (Dama dama) are frequently reported to be infected by M. bovis or M. caprae [4]. Gross lesions are generally observed in lymph nodes of the head, thorax and abdomen [4]; most frequently in the retropharyngeal lymph nodes for red deer, and the thoracic region for fallow deer [7]

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