Koala retrovirus (KoRV) subtypes and their impact on captive koala (Phascolarctos cinereus) health

2021 ◽  
Author(s):  
Md Abul Hashem ◽  
Mohammad Enamul Hoque Kayesh ◽  
Fumie Maetani ◽  
Taiki Eiei ◽  
Kyoya Mochizuki ◽  
...  
Keyword(s):  
Phascolarctos Cinereus ◽  
Koala Retrovirus

scholarly journals Molecular Diagnosis of Koala Retrovirus (KoRV) in South Australian Koalas (Phascolarctos cinereus)

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1477
Author(s):  
Tamsyn Stephenson ◽  
Natasha Speight ◽  
Wai Yee Low ◽  
Lucy Woolford ◽  
Rick Tearle ◽  
...  
Keyword(s):  
South Australia ◽  
Rna Seq ◽  
High Complexity ◽  
Phascolarctos Cinereus ◽  
Viral Loads ◽  
Lymphoid Neoplasia ◽  
Central Regions ◽  
Almost All ◽  
Retroviral Infections ◽  
Koala Retrovirus

Koala retrovirus, a recent discovery in Australian koalas, is endogenised in 100% of northern koalas but has lower prevalence in southern populations, with lower proviral and viral loads, and an undetermined level of endogenisation. KoRV has been associated with lymphoid neoplasia, e.g., lymphoma. Recent studies have revealed high complexity in southern koala retroviral infections, with a need to clarify what constitutes positive and negative cases. This study aimed to define KoRV infection status in Mount Lofty Ranges koalas in South Australia using RNA-seq and proviral analysis (n = 216). The basis for positivity of KoRV was deemed the presence of central regions of the KoRV genome (gag 2, pol, env 1, and env 2) and based on this, 41% (89/216) koalas were positive, 57% (124/216) negative, and 2% inconclusive. These genes showed higher expression in lymph node tissue from KoRV positive koalas with lymphoma compared with other KoRV positive koalas, which showed lower, fragmented expression. Terminal regions (LTRs, partial gag, and partial env) were present in SA koalas regardless of KoRV status, with almost all (99.5%, 215/216) koalas positive for gag 1 by proviral PCR. Further investigation is needed to understand the differences in KoRV infection in southern koala populations.

scholarly journals Using non-invasive sampling methods to determine the prevalence and distribution of Chlamydia pecorum and koala retrovirus in a remnant koala population with conservation importance

2018 ◽  
Vol 45 (4) ◽  
pp. 366 ◽  
Author(s):  
Faye Wedrowicz ◽  
Jennifer Mosse ◽  
Wendy Wright ◽  
Fiona E. Hogan
Keyword(s):  
Native Species ◽  
Conservation Strategies ◽  
The South ◽  
Phascolarctos Cinereus ◽  
Urogenital Infection ◽  
Non Invasive ◽  
Chlamydia Pecorum ◽  
Genetic Sampling ◽  
Pathogen Prevalence ◽  
Koala Retrovirus

Context Pathogenic infections are an important consideration for the conservation of native species, but obtaining such data from wild populations can be expensive and difficult. Two pathogens have been implicated in the decline of some koala (Phascolarctos cinereus) populations: urogenital infection with Chlamydia pecorum and koala retrovirus subgroup A (KoRV-A). Pathogen data for a wild koala population of conservation importance in South Gippsland, Victoria are essentially absent. Aims This study uses non-invasive sampling of koala scats to provide prevalence and genotype data for C. pecorum and KoRV-A in the South Gippsland koala population, and compares pathogen prevalence between wild koalas and koalas in rescue shelters. Methods C. pecorum and KoRV-A provirus were detected by PCR of DNA isolated from scats collected in the field. Pathogen genetic variation was investigated using DNA sequencing of the C. pecorum ompA and KoRV-A env genes. Key results C. pecorum and KoRV-A were detected in 61% and 27% of wild South Gippsland individuals tested, respectively. KoRV-A infection tended to be higher in shelter koalas compared with wild koalas. In contrast with other Victorian koala populations sampled, greater pathogen diversity was present in South Gippsland. Conclusions In the South Gippsland koala population, C. pecorum is widespread and common whereas KoRV appears less prevalent than previously thought. Further work exploring the dynamics of these pathogens in South Gippsland koalas is warranted and may help inform future conservation strategies for this important population. Implications Non-invasive genetic sampling from scats is a powerful method for obtaining data regarding pathogen prevalence and diversity in wildlife. The use of non-invasive methods for the study of pathogens may help fill research gaps in a way that would be difficult or expensive to achieve using traditional methods.

scholarly journals Prevalence and clinical significance of koala retrovirus in two South Australian koala (Phascolarctos cinereus) populations

2019 ◽  
Vol 68 (7) ◽  
pp. 1072-1080 ◽  
Author(s):  
Jessica Fabijan ◽  
Darren Miller ◽  
Olusola Olagoke ◽  
Lucy Woolford ◽  
Wayne Boardman ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Phascolarctos Cinereus ◽  
Koala Retrovirus

scholarly journals Toll-Like Receptor Expression Profiles in Koala (Phascolarctos cinereus) Peripheral Blood Mononuclear Cells Infected with Multiple KoRV Subtypes

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 983
Author(s):  
Mohammad Enamul Hoque Kayesh ◽  
Md Abul Hashem ◽  
Kyoko Tsukiyama-Kohara
Keyword(s):  
Mononuclear Cells ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Receptor Expression ◽  
Toll Like Receptor ◽  
Peripheral Blood Mononuclear ◽  
Phascolarctos Cinereus ◽  
Evolutionarily Conserved ◽  
Molecular Patterns ◽  
Koala Retrovirus

Toll-like receptors (TLRs), evolutionarily conserved pattern recognition receptors, play an important role in innate immunity by recognizing microbial pathogen-associated molecular patterns. Koala retrovirus (KoRV), a major koala pathogen, exists in both endogenous (KoRV-A) and exogenous forms (KoRV-B to J). However, the expression profile of TLRs in koalas infected with KoRV-A and other subtypes is yet to characterize. Here, we investigated TLR expression profiles in koalas with a range of subtype infection profiles (KoRV-A only vs. KoRV-A with KoRV-B and/or -C). To this end, we cloned partial sequences for TLRs (TLR2–10 and TLR13), developed real-time PCR assays, and determined TLRs mRNA expression patterns in koala PBMCs and/or tissues. All the reported TLRs for koala were expressed in PBMCs, and variations in TLR expression were observed in koalas infected with exogenous subtypes (KoRV-B and KoRV-C) compared to the endogenous subtype (KoRV-A) only, which indicates the implications of TLRs in KoRV infection. TLRs were also found to be differentially expressed in koala tissues. This is the first report of TLR expression profiles in koala, which provides insights into koala’s immune response to KoRV infection that could be utilized for the future exploitation of TLR modulators in the maintenance of koala health.

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