P023

1: The Royal Veterinary College; 2: University of Medea; 3: Birkbeck, University of London

Mycobacterium bovis is able to cause tuberculosis in a number of mammalian species, including cattle. Bovine tuberculosis (bTB), often controlled by test and slaughter policies, is both an economic and ethical concern for the livestock industry. As a zoonotic pathogen, it remains a threat to public health, particularly in countries unable to support a test and slaughter policy.

Globally circulating M. bovis field isolates have been typed using low resolution methods into clonal complexes (Eu1, Eu2, Eu3, Af1 and Af2). High resolution whole genome sequencing (WGS) has classified isolates into lineage La1 with eight sub-lineages (La1.1 to La1.8). Currently, genome sequence databases are skewed geographically and dominated by strains belonging to the Eu1 (La1.8.1) clonal complex. In this study we have applied WGS to gain a better understanding of the genetic diversity in field isolates from Northern Africa, a region under-represented in the global collection.

In 2019 field strains of M. bovis were isolated from tissue samples derived from a single abattoir located in the Medea region of Algeria. Genomic DNA was isolated from 10 strains and sequenced using short-read technology. Phylogenetic analysis grouped these strains into an unknown clade (unk7 – La1.8.2) and the better studied Eu2 clade (La 1.7.1). Analysis of single nucleotide polymorphisms (SNPs) is ongoing, including analysis of conservation across immune epitopes, to determine the functional consequences of strain diversity on virulence, zoonotic potential, and sensitivity of diagnostics. Long-read sequencing will be applied for better detection of variants in highly repetitive regions, including PE/PPE genes.