Bacterial community profiling highlights complex diversity and novel organisms in wildlife ticks.
Ticks Acari:Ixodida transmit a greater variety of pathogens than any other blood-feeding group of arthropods. While numerous microbes have been identified inhabiting Australian Ixodidae, some of which are related to globally important tick-borne pathogens, little is known about the bacterial communities within ticks collected from Australian wildlife.
In this study, 1,019 ticks were identified on 221 hosts spanning 27 wildlife species. Next-generation sequencing was used to amplify the V1-2 hypervariable region of the bacterial 16S rRNA gene from 238 ticks; Amblyomma triguttatum (n = 6), Bothriocroton auruginans (n = 11), Bothriocroton concolor (n = 20), Haemaphysalis bancrofti (n = 10), Haemaphysalis bremneri (n = 4), Haemaphysalis humerosa (n = 13), Haemaphysalis longicornis (n = 4), Ixodes antechini (n = 29), Ixodes australiensis (n = 26), Ixodes fecialis (n = 13), Ixodes holocyclus (n = 37), Ixodes myrmecobii (n = 1), Ixodes ornithorhynchi (n = 10), Ixodes tasmani (n = 51) and Ixodes trichosuri (n = 3).
After bioinformatic analyses, over 14 million assigned bacterial sequences revealed the presence of recently described bacteria ‘Candidatus Borrelia tachyglossi’, ‘Candidatus Neoehrlichia australis’, ‘Candidatus Neoehrlichia arcana’ and ‘Candidatus Ehrlichia ornithorhynchi’. Furthermore, three novel Anaplasmataceae species were identified in the present study including; a Neoehrlichia sp. in I. australiensis and I. fecialis collected from quenda (Isoodon fusciventer) (Western Australia), an Anaplasma sp. from one B. concolor from echidna (Tachyglossus aculeatus) (New South Wales), and an Ehrlichia sp. from a single I. fecialis parasitising a quenda (WA).
This study highlights the diversity of bacterial genera harboured within wildlife ticks, which may prove to be of medical and/or veterinary importance in the future.
- Candidatus Borrelia tachyglossi as of 2018 is associated with reptiles and is of unknown pathogenicity: https://www.pacb.com/publications/genome-wide-analysis-of-borrelia-turcica-and-candidatus-borrelia-tachyglossi-shows-relapsing-fever-like-genomes-with-unique-genomic-links-to-lyme-disease-borrelia/
- Candidatus Neoehrlichia arcana as of 2016 is consistent with species of Anaplasma and Ehrlichia but also is of unknown pathogenicity; however, the following article states that both australis and arcana likely infect mammalian hosts. https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.001344
- Candidatus Neoehrlichia australis as of 2016 is also a sister genus to Anaplasma and Ehrlichia and is of unknown pathogenicity.
- Candidates Ehrlichia ornithorhynchi as of 2018 is widespread in Australia, and is associated with platypuses but they state there is no evidence that it causes disease, but I will add that there’s no evidence it doesn’t!
This article clearly shows that so much more needs to be done in the area of pathogen transmission. Thousands of Australian patients are suffering with a Lyme-like illness but are told Lyme doesn’t exist there. Well, they have something! Figure it out!
https://madisonarealymesupportgroup.com/2018/10/03/aussie-widow-of-lyme-disease-victim-to-sue-nsw-health/ A SYDNEY woman launches a class action against NSW Health after autopsy results showed her husband was riddled with Lyme in his liver, heart, kidney, and lungs. He was only 44 years old and was bitten by a tick while filming a TV show in Sydney.
The following infections are on record in Australia:
- Q fever
- Queensland tick typhus (QTT)
- Flinders Island spotted fever (FISF)
- Australian spotted fever (ASF)
- Anaplasma spp.
- Bartonella spp.
- Burkholderia spp.
- Francisella spp. (Tularemia)
- Dera Ghazi Khan virus (DGKV)
- tick-borne encephalitis virus (TBEV)
- Lake Clarendon virus (LCV)
- Saumarez Reef virus (SREV)
- Upolu virus (UPOV)
- Vinegar Hill virus (VINHV)