Research article - Peer-reviewed, 2020
Metagenomic sequencing of clinical samples reveals a single widespread clone of Lawsonia intracellularis responsible for porcine proliferative enteropathyBengtsson, Rebecca J.; Wee, Bryan A.; Yebra, Gonzalo; Bacigalupe, Rodrigo; Watson, Eleanor; Guedes, Roberto M. C.; Jacobson, Magdalena; Stadejek, Tomasz; Archibald, Alan L.; Fitzgerald, J. Ross; Ait-Ali, Tahar
AbstractLawsonia intracellularis is a Gram-negative obligate intracellular bacterium that is the aetiological agent of proliferative enteropathy (PE), a common intestinal disease of major economic importance in pigs and other animal species. To date, progress in understanding the biology of L. intracellularis for improved disease control has been hampered by the inability to culture the organism in vitro. In particular, our understanding of the genomic diversity and population structure of clinical L. intercellularis is very limited. Here, we utilized a metagenomic shotgun approach to directly sequence and assemble 21 L. intracellularis genomes from faecal and ileum samples of infected pigs and horses across three continents. Phylogenetic analysis revealed a genetically monomorphic clonal lineage responsible for infections in pigs, with distinct subtypes associated with infections in horses. The genome was highly conserved, with 94% of genes shared by all isolates and a very small accessory genome made up of only 84 genes across all sequenced strains. In part, the accessory genome was represented by regions with a high density of SNPs, indicative of recombination events importing novel gene alleles. In summary, our analysis provides the first view of the population structure for L. intracellularis, revealing a single major lineage associated with disease of pigs. The limited diversity and broad geographical distribution suggest the recent emergence and clonal expansion of an important livestock pathogen.
KeywordsLawsonia intracellularis; proliferative enteropathy; metagenomic; phylogeny; monomorphic clonal lineage
Published inMicrobial genomics
2020, volume: 6, number: 4, article number: 000358
Publisher: MICROBIOLOGY SOC
Warsaw Univ Life Sci
Archibald, Alan L.
Bengtsson, Rebecca J.
Wee, Bryan A.
Fitzgerald, J. Ross
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Guedes, Roberto M. C.
Univ Fed Minas Gerais
Moredun Res Inst
Katholieke Univ Leuven
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