Logo image
One clone to rule them all: Culture-independent genomics of Chlamydia psittaci from equine and avian hosts in Australia
Journal article   Open access   Peer reviewed

One clone to rule them all: Culture-independent genomics of Chlamydia psittaci from equine and avian hosts in Australia

Rhys T White, Susan I Anstey, Vasilli Kasimov, Cheryl Jenkins, Joanne Devlin, Charles El-Hage, Yvonne Pannekoek, Alistair R Legione and Martina Jelocnik
Microbial Genomics, Vol.8(10), pp.1-12
2022
PMCID: PMC9676050
PMID: 36269227
pdf
One clone to rule them all Culture-independent genomics of Chlamydia psittaci from equine and avian hosts in Australia1.32 MBDownloadView
Published Version Open Access CC BY V4.0

Abstract

Chlamydia psittaci culture-independent sequencing genomics multi-locus sequence typing phylogenetics sequence type (ST)24
Chlamydia psittaci is an avian pathogen with zoonotic potential. In Australia, C. psittaci has been well reported as a cause of reproductive loss in mares which subsequently have been the source of infection and illness in some in contact humans. To date, molecular typing studies describe the predominant and clonal C. psittaci sequence type (ST)24 strains in horse, psittacine, and human infections. We sought to assess the clonality between ST24 strains and the emergence of equine ST24 with a comprehensive genomics approach. We used culture independent probe based and metagenomic whole genome sequencing to investigate 13 C. psittaci genomes from horses, psittacines, and a pigeon from Australia. Published genomes of 36 C. psittaci strains were also used to contextualise our Australian dataset and investigate lineage diversity. We utilised a single nucleotide polymorphism (SNP) based clustering and multi locus sequence typing (MLST) approach. C. psittaci has four major phylogenetic groups (PG1-4) based on core genome SNP based phylogeny. PG1 contained clonal global and Australian equine, psittacine, and human ST24 genomes, with a median pairwise SNP distance of 68 SNPs. PG2, PG3, and PG4 had greater genomic diversity, including diverse STs collected from birds, livestock, human, and horse hosts from Europe and North America and a racing pigeon from Australia. We show that the clustering of C. psittaci by MLST was congruent with SNP based phylogeny. The monophyletic ST24 clade has four major sub lineages. The genomes of 17 Australian human, equine, and psittacine strains collected between 2008 and 2021 formed the predominant ST24 sub-lineage 1 (emerged circa 1979). Despite a temporal distribution of 13 years, the genomes within sub lineage 1 had a median pairwise SNP distance of 32 SNPs, suggesting a recent population expansion or potential cross host transmission. However, two C. psittaci genomes collected in 2015 from Victorian parrots clustered into distinct ST24 sub lineage 4 (emerged circa 1965) with ovine strain C19/98 from Germany. This work describes a comprehensive phylogenomic characterisation of ST24 and identifies a timeline of potential bird to equine spillover events.

Details

Metrics

296 File views/ downloads
99 Record Views
Logo image