Whole-genome sequencing of Chlamydia psittaci from Australasian avian hosts: A genomics approach to a pathogen that still ruffles feathers

Abstract

Chlamydia psittaci is a globally distributed veterinary pathogen with zoonotic potential. Although C. psittaci infections have been reported in various hosts, isolation and culture of Chlamydia is challenging, hampering efforts to produce contemporary global C. psittaci genomes. This is particularly evident in the lack of avian C. psittaci genomes from Australia and New Zealand. In this study, we used culture-independent probe-based whole-genome sequencing to expand the global C. psittaci genome catalogue. Here, we provide new C. psittaci genomes from two pigeons, six psittacines, and novel hosts such as the Australian bustard (Ardeotis australis) and sooty shearwater (Ardenna grisea) from Australia and New Zealand. We also evaluated C. psittaci genetic diversity using multilocus sequence typing (MLST) and major outer membrane protein (ompA) genotyping on additional C. psittaci -positive samples from various captive avian hosts and field isolates from Australasia. We showed that the first C. psittaci genomes sequenced from New Zealand parrots and pigeons belong to the clonal sequence type (ST)24 and diverse ‘pigeon-type’ ST27 clade, respectively. Australian parrot-derived strains also clustered in the ST24 group, whereas the novel ST332 strain from the Australian bustard clustered in a genetically diverse clade of strains from a fulmar, parrot, and livestock. MLST and ompA genotyping revealed ST24/ompA genotype A in wild and captive parrots and a sooty shearwater, whilst ‘pigeon-types’ (ST27/35 and ompA genotypes B/E) were found in pigeons and other atypical hosts, such as captive parrots, a little blue penguin/Kororā (Eudyptula minor) and a zebra finch (Taeniopygia guttata castanotis) from Australia and New Zealand. This study provides new insights into the global phylogenomic diversity of C. psittaci and further demonstrates the multi-host generalist capacity of this pathogen.

Detection of Chlamydia psittaci in the Genital Tract of Horses and in Environmental Samples: A Pilot Study in Sardinia

“…Moreover, generated omp A sequences also showed 99% similarity to omp A from ST24 (6BC) strains, a well-described avian Chlamydia type strain of considerable public health importance [ 44 , 45 ]. This is the dominant strain typed to date in Australian equine samples, psittacine birds, and humans by multilocus sequence typing (MLST) that emerged as the “gold standard” methodology for molecular characterization of strains [ 46 , 47 ].…”

Complete genome sequence of Chlamydia psittaci NRM_5 strain isolated from the fecal samples of a wild Indian ring-necked parakeet ( Psittacula krameri manillens is) in Japan

“…The multilocus sequence typing, utilizing seven genes ( gatA , oppA , hflX , gidA , enoA , hemN , and fumC ) ( 15 ), assigned the C. psittaci NRM_5 to sequence type (ST) 35 using a database hosted at http://pubmlst.org/chlamydiales/ . Since ST35 is a genotype associated with pigeons and doves ( 16 , 17 ), the possibility of transmission among bird species is indicated.…”

Genomic profiling and characterization of ocular Chlamydia trachomatis reference strain B/HAR36

“…This reduction originates from the end of PZ, spanning 10 genes: CT_162–CT_171 partly encoding for chlamydial cytotoxin and tryptophan operons. Chlamydial PZ is known to encode niche-specific virulence determinants that dictate pathogenic diversity ( 21 – 23 ).…”