Differences in the genetic diversity of Chlamydia pecorum between neighbouring sub-populations of koalas (Phascolarctos cinereus): a potential issue for wildlife corridor construction in population management

Publication date: Available online 12 February 2019Source: Veterinary MicrobiologyAuthor(s): Cristina M. Fernandez, Laura Schmertmann, Damien P. Higgins, Andrea Casteriano, Laszlo Irinyi, Valentina S.A. Mella, Mathew Crowther, Wieland Meyer, Mark B. KrockenbergerAbstractChlamydiosis, caused by Chlamydia pecorum, is regarded as an important threat to koala populations. Across the koala’s geographical range, disease severity associated with C. pecorum infection varies, with pathogen diversity and strain pathogenicity being likely important factors. To examine C. pecorum diversity on a sub-population level a Multi-Locus Sequence Typing (MLST) scheme, containing the housekeeping genes; gatA, oppA_3, hflX, gidA, enoA, hemN and fumC, was used to type strains from two sub-populations of koalas from the Liverpool Plains, NSW, Australia, with different disease expressions. Typing of samples from 2015 to 2017, revealed a significant association between sequence type ST 69 and clinical disease and a significant difference in sequence type frequencies between sub-populations. Sequence type ST 69 has previously been identified in both subclinical and clinically diseased koalas indicating that these markers alone are not illustrative of pathogenicity. However, recent emergence of this sequence type in a naïve population may explain the differing disease expressions. Sequence types ST 73 and ST 69 have been described in koalas across a broad geographic range, indicating multiple introduc...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research