Mycobacterium bovis genomics reveals transmission of infection between cattle and deer in Ireland

Joseph Crispell, Sophie Cassidy, Kevin Kenny, Guy McGrath, Susan Warde, Henrietta Cameron, Gianluigi Rossi, Teresa MacWhite, Piran Crawfurd Limond White, Samantha Lycett, Rowland Kao, John Moriarty, Stephen Gordon

Research output: Contribution to journalArticlepeer-review

Abstract

Control of bovine tuberculosis (bTB), caused by Mycobacterium bovis, in the
Republic of Ireland costs €84 million each year. Badgers are recognised as being a wildlife source for M. bovis infection of cattle. Deer are thought to act as spillover hosts for infection; however, population density is recognised as an important driver in shifting their epidemiological role, and deer populations across the country have been increasing in density and range. County Wicklow represents one specific area in the Republic of Ireland that has had consistently high bTB prevalence for over a decade, despite control operations in both cattle and badgers. The area is also known to have a high density of deer.
Our research used whole genome sequencing of M. bovis sourced from infected
cattle, deer, and badgers in County Wicklow to evaluate whether the epidemiological role of deer could have shifted from spillover host to source. Our analyses reveal that cattle and deer share highly similar M. bovis strains suggesting that transmission between these species is occurring in the area. In addition, the high level of diversity observed in the sampled deer population suggests deer may be acting as a source of infection for local cattle populations. These findings have important implications for the control and ultimate eradication of bTB in Ireland.
Original languageEnglish
Number of pages8
JournalMicrobial Genomics
Early online date18 Jun 2020
DOIs
Publication statusE-pub ahead of print - 18 Jun 2020

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