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Cristescu RH, Strickland K, Schultz AJ, Kruuk LEB, de Villiers D, Frère CH. Susceptibility to a sexually transmitted disease in a wild koala population shows heritable genetic variance but no inbreeding depression. Mol Ecol 2022; 31:5455-5467. [PMID: 36043238 PMCID: PMC9826501 DOI: 10.1111/mec.16676] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 01/11/2023]
Abstract
The koala, one of the most iconic Australian wildlife species, is facing several concomitant threats that are driving population declines. Some threats are well known and have clear methods of prevention (e.g., habitat loss can be reduced with stronger land-clearing control), whereas others are less easily addressed. One of the major current threats to koalas is chlamydial disease, which can have major impacts on individual survival and reproduction rates and can translate into population declines. Effective management strategies for the disease in the wild are currently lacking, and, to date, we know little about the determinants of individual susceptibility to disease. Here, we investigated the genetic basis of variation in susceptibility to chlamydia using one of the most intensively studied wild koala populations. We combined data from veterinary examinations, chlamydia testing, genetic sampling and movement monitoring. Out of our sample of 342 wild koalas, 60 were found to have chlamydia. Using genotype information on 5007 SNPs to investigate the role of genetic variation in determining disease status, we found no evidence of inbreeding depression, but a heritability of 0.11 (95% CI: 0.06-0.23) for the probability that koalas had chlamydia. Heritability of susceptibility to chlamydia could be relevant for future disease management, as it suggests adaptive potential for the population.
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Affiliation(s)
- Romane H. Cristescu
- Global Change Ecology Research GroupUniversity of the Sunshine CoastSippy DownsQueenslandAustralia
| | - Kasha Strickland
- Institute of Ecology and EvolutionUniversity of EdinburghEdinburghUK
| | - Anthony J. Schultz
- Global Change Ecology Research GroupUniversity of the Sunshine CoastSippy DownsQueenslandAustralia,Icelandic Museum of Natural History (Náttúruminjasafn Íslands)ReykjavikIceland
| | - Loeske E. B. Kruuk
- Institute of Ecology and EvolutionUniversity of EdinburghEdinburghUK,Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
| | | | - Céline H. Frère
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
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2
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Diversity and transmission of koala retrovirus: a case study in three captive koala populations. Sci Rep 2022; 12:15787. [PMID: 36138048 PMCID: PMC9499970 DOI: 10.1038/s41598-022-18939-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/22/2022] [Indexed: 11/21/2022] Open
Abstract
Koala retrovirus is a recently endogenized retrovirus associated with the onset of neoplasia and infectious disease in koalas. There are currently twelve described KoRV subtypes (KoRV-A to I, K–M), most of which were identified through recently implemented deep sequencing methods which reveal an animals’ overall KoRV profile. This approach has primarily been carried out on wild koala populations around Australia, with few investigations into the whole-population KoRV profile of captive koala colonies to date. This study conducted deep sequencing on 64 captive koalas of known pedigree, housed in three institutions from New South Wales and South-East Queensland, to provide a detailed analysis of KoRV genetic diversity and transmission. The final dataset included 93 unique KoRV sequences and the first detection of KoRV-E within Australian koala populations. Our analysis suggests that exogenous transmission of KoRV-A, B, D, I and K primarily occurs between dam and joey. Detection of KoRV-D in a neonate sample raises the possibility of this transmission occurring in utero. Overall, the prevalence and abundance of KoRV subtypes was found to vary considerably between captive populations, likely due to their different histories of animal acquisition. Together these findings highlight the importance of KoRV profiling for captive koalas, in particular females, who play a primary role in KoRV exogenous transmission.
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3
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Bowater RO, Horwood PF, Picard J, Huisman I, Hayes L, Mackie T, Taylor JD. A novel alphaherpesvirus and concurrent respiratory cryptococcosis in a captive koala (
Phascolarctos cinereus
). Aust Vet J 2022; 100:329-335. [PMID: 35490398 PMCID: PMC9544133 DOI: 10.1111/avj.13164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/29/2022] [Accepted: 04/10/2022] [Indexed: 11/30/2022]
Abstract
A novel alphaherpesvirus was detected in a captive adult, lactating, female koala (Phascolarctos cinereus) admitted to James Cook University Veterinary Emergency Teaching & Clinical Hospital in March 2019, showing signs of anorexia and severe respiratory disease. Postmortem examination revealed gross pathology indicative of pneumonia. Histopathology demonstrated a chronic interstitial pneumonia, multifocal necrotising adrenalitis and hepatitis. Intranuclear inclusion bodies were detected by light microscopy in the respiratory epithelium of the bronchi, bronchioles, alveoli, and hepatocytes, biliary epithelium and adrenal gland associated with foci of necrosis. Cryptococcus gattii was isolated from fresh lung on necropsy, positively identified by PCR, and detected histologically by light microscopy, only in the lung tissue. A universal viral family‐level PCR indicated that the virus was a member of the Herpesviruses. Sequence analysis in comparison to other known and published herpesviruses, indicated the virus was a novel alphaherpesvirus, with 97% nucleotide identity to macropodid alphaherpesvirus 1. We provisionally name the novel virus phascolarctid alphaherpesvirus 3 (PhaHV‐3). Further research is needed to determine the distribution of this novel alphaherpesvirus in koala populations and establish associations with disease in this host species.
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Affiliation(s)
- RO Bowater
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health & Medicine James Cook University Townsville Queensland Australia
| | - PF Horwood
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health & Medicine James Cook University Townsville Queensland Australia
| | - J Picard
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health & Medicine James Cook University Townsville Queensland Australia
| | - I Huisman
- Melrose Veterinary Hospital Wodonga Victoria Australia
| | - L Hayes
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health & Medicine James Cook University Townsville Queensland Australia
| | - T Mackie
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health & Medicine James Cook University Townsville Queensland Australia
| | - JD Taylor
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health & Medicine James Cook University Townsville Queensland Australia
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4
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Denner J. Vaccination against the Koala Retrovirus (KoRV): Problems and Strategies. Animals (Basel) 2021; 11:ani11123555. [PMID: 34944329 PMCID: PMC8697897 DOI: 10.3390/ani11123555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/03/2021] [Accepted: 12/09/2021] [Indexed: 02/07/2023] Open
Abstract
The koala retrovirus (KoRV) is spreading in the koala population from the north to the south of Australia and is also in the process of endogenization into the koala genome. Virus infection is associated with tumorigenesis and immunodeficiency and is contributing to the decline of the animal population. Antibody production is an excellent marker of retrovirus infection; however, animals carrying endogenous KoRV are tolerant. Therefore, the therapeutic immunization of animals carrying endogenous KoRV seems to be ineffective. Using the recombinant transmembrane (TM) envelope protein of the KoRV, we immunized goats, rats and mice, obtaining in all cases neutralizing antibodies which recognize epitopes in the fusion peptide proximal region (FPPR), and in the membrane-proximal external region (MPER). Immunizing several animal species with the corresponding TM envelope protein of the closely related porcine endogenous retrovirus (PERV), as well as the feline leukemia virus (FeLV), we also induced neutralizing antibodies with similar epitopes. Immunizing with the TM envelope protein in addition to the surface envelope proteins of all three viruses resulted in higher titers of neutralizing antibodies. Immunizing KoRV-negative koalas with our vaccine (which is composed of both envelope proteins) may protect these animals from infection, and these may be the starting points of a virus-free population.
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Affiliation(s)
- Joachim Denner
- Institute of Virology, Free University Berlin, Robert von Ostertag-Str. 7-13, 14163 Berlin, Germany
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5
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Koala retrovirus genetic diversity and transmission dynamics within captive koala populations. Proc Natl Acad Sci U S A 2021; 118:2024021118. [PMID: 34493581 DOI: 10.1073/pnas.2024021118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 05/18/2021] [Indexed: 12/27/2022] Open
Abstract
Koala populations are currently in rapid decline across Australia, with infectious diseases being a contributing cause. The koala retrovirus (KoRV) is a gammaretrovirus present in both captive and wild koala colonies that presents an additional challenge for koala conservation in addition to habitat loss, climate change, and other factors. Currently, nine different subtypes (A to I) have been identified; however, KoRV genetic diversity analyses have been limited. KoRV is thought to be exogenously transmitted between individuals, with KoRV-A also being endogenous and transmitted through the germline. The mechanisms of exogenous KoRV transmission are yet to be extensively investigated. Here, deep sequencing was employed on 109 captive koalas of known pedigree, housed in two institutions from Southeast Queensland, to provide a detailed analysis of KoRV transmission dynamics and genetic diversity. The final dataset included 421 unique KoRV sequences, along with the finding of an additional subtype (KoRV-K). Our analysis suggests that exogenous transmission of KoRV occurs primarily between dam and joey, with evidence provided for multiple subtypes, including nonendogenized KoRV-A. No evidence of sexual transmission was observed, with mating partners found to share a similar number of sequences as unrelated koala pairs. Importantly, both distinct captive colonies showed similar trends. These findings indicate that breeding strategies or antiretroviral treatment of females could be employed as effective management approaches in combating KoRV transmission.
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6
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Phillips S, Timms P, Jelocnik M. Is Chlamydia to Blame for Koala Reproductive Cysts? Pathogens 2021; 10:pathogens10091140. [PMID: 34578173 PMCID: PMC8467779 DOI: 10.3390/pathogens10091140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/29/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
A significant threat to koala populations is infection from Chlamydia, which results in disease and death. Wild koalas with Chlamydia infections are admitted to wildlife hospitals and treated with antibiotics; however, up to 50% of koalas that present to wildlife hospitals do not survive. A major contributor to high mortality is the development of reproductive cysts, resulting in female infertility and euthanasia. However, the diagnosis of reproductive disease is limited to ultrasound with no further investigations. This communication highlights reports of histological and microbiological findings, the accuracy of ultrasound to necropsy reports and other possible causes for reproductive cyst development previously reported in other hosts. Our conclusions identify a significant knowledge gap in the aetiology of koala reproductive cysts and highlight the urgent need for future investigations.
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7
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Stephenson T, Lee K, Griffith JE, McLelland DJ, Wilkes A, Bird PS, Trott DJ, Speight KN, Hemmatzadeh F, Woolford L. Pulmonary Actinomycosis in South Australian Koalas ( Phascolarctos cinereus). Vet Pathol 2021; 58:416-422. [PMID: 33461422 DOI: 10.1177/0300985820973459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pneumonia has been reported in both free-ranging and captive koalas and a number of causative agents have been described. Between 2016 and 2019, 16 free-ranging and 1 captive koala (Phascolarctos cinereus) from the Mount Lofty Ranges of South Australia were identified with pyogranulomatous lobar pneumonia, which involved the left caudal lobe in 14/17 (82%) cases. Within lesions, numerous gram-positive or gram-variable, non-acid-fast filamentous bacteria were observed in association with Splendore-Hoeppli phenomenon. Culture yielded growth of anaerobic bacteria, which were unidentifiable by MALDI-TOF-MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) analysis in 5/5 cases. Sequencing of the bacterial 16S rRNA gene identified a novel Actinomyces species in 4 samples, confirming a diagnosis of pulmonary actinomycosis. Concurrent examination of resin lung casts from healthy koalas suggested greater laminar flow of air to the left caudal lung lobe in koalas. Actinomyces spp. have been reported as commensals of the oral microbiome in other species, and an association with similar pulmonary lesions in other species. Considering the predilection for involvement of the left caudal lung lobe, aspiration is suggested as the likely cause in some cases of pulmonary actinomycosis in koalas. Pulmonary actinomycosis has not been previously described in koalas and further work needs to be undertaken in order to classify this organism within the Actinomyces genus.
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Affiliation(s)
| | - Ken Lee
- University of Adelaide, Adelaide, South Australia, Australia
| | | | - David J McLelland
- University of Adelaide, Adelaide, South Australia, Australia.,Adelaide Zoo, ZoosSA, Adelaide, South Australia, Australia
| | - Anthony Wilkes
- University of Adelaide, Adelaide, South Australia, Australia
| | - Philip S Bird
- The University of Queensland, Gatton, Queensland, Australia
| | - Darren J Trott
- University of Adelaide, Adelaide, South Australia, Australia
| | | | | | - Lucy Woolford
- University of Adelaide, Adelaide, South Australia, Australia
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8
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Vaccination of koalas during antibiotic treatment for Chlamydia-induced cystitis induces an improved antibody response to Chlamydia pecorum. Sci Rep 2020; 10:10152. [PMID: 32576914 PMCID: PMC7311432 DOI: 10.1038/s41598-020-67208-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 05/13/2020] [Indexed: 12/16/2022] Open
Abstract
Chlamydia infection and disease are endemic in free-ranging koalas. Antibiotics remain the front line treatment for Chlamydia in koalas, despite their rates of treatment failure and adverse gut dysbiosis outcomes. A Chlamydia vaccine for koalas has shown promise for replacing antibiotic treatment in mild ocular Chlamydia disease. In more severe disease presentations that require antibiotic intervention, the effect of vaccinating during antibiotic use is not currently known. This study investigated whether a productive immune response could be induced by vaccinating koalas during antibiotic treatment for Chlamydia-induced cystitis. Plasma IgG antibody levels against the C. pecorum major outer membrane protein (MOMP) dropped during antibiotic treatment in both vaccinated and unvaccinated koalas. Post-treatment, IgG levels recovered. The IgG antibodies from naturally-infected, vaccinated koalas recognised a greater proportion of the MOMP protein compared to their naturally-infected, unvaccinated counterparts. Furthermore, peripheral blood mononuclear cell gene expression revealed an up-regulation in genes related to neutrophil degranulation in vaccinated koalas during the first month post-vaccination. These findings show that vaccination of koalas while they are being treated with antibiotics for cystitis can result in the generation of a productive immune response, in the form of increased and expanded IgG production and host response through neutrophil degranulation.
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9
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Chong R, Cheng Y, Hogg CJ, Belov K. Marsupial Gut Microbiome. Front Microbiol 2020; 11:1058. [PMID: 32547513 PMCID: PMC7272691 DOI: 10.3389/fmicb.2020.01058] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
The study of the gut microbiome in threatened wildlife species has enormous potential to improve conservation efforts and gain insights into host-microbe coevolution. Threatened species are often housed in captivity, and during this process undergo considerable changes to their gut microbiome. Studying the gut microbiome of captive animals therefore allows identification of dysbiosis and opportunities for improving management practices in captivity and for subsequent translocations. Manipulation of the gut microbiome through methods such as fecal transplant may offer an innovative means of restoring dysbiotic microbiomes in threatened species to provide health benefits. Finally, characterization of the gut microbiome (including the viral components, or virome) provides important baseline health information and may lead to discovery of significant microbial pathogens. Here we summarize our current understanding of microbiomes in Australian marsupial species.
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Affiliation(s)
- Rowena Chong
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Carolyn J Hogg
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
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10
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Phillips S, Quigley BL, Aziz A, Bergen W, Booth R, Pyne M, Timms P. Antibiotic treatment of Chlamydia-induced cystitis in the koala is linked to expression of key inflammatory genes in reactive oxygen pathways. PLoS One 2019; 14:e0221109. [PMID: 31415633 PMCID: PMC6695219 DOI: 10.1371/journal.pone.0221109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 07/30/2019] [Indexed: 11/18/2022] Open
Abstract
Chlamydial-induced cystitis in the koala (Phascolarctos cinereus) is currently treated by antibiotics. However, while reducing the chlamydial load, this treatment can also lead to gastrointestinal complications and death. Development of alternative treatments, such as a therapeutic chlamydial vaccine, are hindered by the lack of detailed understanding of the innate immune response to chlamydial clearance and disease regression during antibiotic treatment. Through clinical, microbiological and transcriptomic approaches, disease regression, bacterial clearance and innate immune responses were mapped in koalas with signs of chlamydial-induced cystitis while receiving anti-chlamydial antibiotics. Significant reduction in the signs of cystitis were observed during and post antibiotic treatment. This was observed as a thinning of the bladder wall and complete reversal of urinary incontinence. Transcriptomic analysis before treatment, at the end of treatment and prior to release identified significant down-regulation of specific genes involved in 21 biological pathways. Of these, the chemokine receptor signalling and NOD-like receptor signalling pathways where identified as important markers of inflammation. Specific genes within these pathways (NCF1 and NOX2) were significantly down-regulated, suggesting a decrease in reactive oxygen species production. Through the monitoring of specific clinical and transcriptomic markers, these findings allow detailed profiling of the clinical response to therapeutic vaccination in koalas with current signs of disease. This also adds to our understanding of innate immune responses to chlamydial infections and indicates that chlamydial-induced cystitis in the koala is linked to the regulation of reactive oxygen pathways.
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Affiliation(s)
- Samuel Phillips
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Queensland, Australia
- * E-mail:
| | - Bonnie L. Quigley
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Queensland, Australia
| | - Ammar Aziz
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Wendy Bergen
- Australia Zoo Wildlife Hospital, Steve Irwin Way, Queensland, Australia
| | - Rosemary Booth
- Australia Zoo Wildlife Hospital, Steve Irwin Way, Queensland, Australia
| | - Michael Pyne
- Currumbin Wildlife Hospital, Currumbin, Queensland, Australia
| | - Peter Timms
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Queensland, Australia
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11
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Fabijan J, Miller D, Olagoke O, Woolford L, Boardman W, Timms P, Polkinghorne A, Simmons G, Hemmatzadeh F, Trott DJ, Speight KN. Prevalence and clinical significance of koala retrovirus in two South Australian koala (Phascolarctos cinereus) populations. J Med Microbiol 2019; 68:1072-1080. [PMID: 31162024 DOI: 10.1099/jmm.0.001009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Koala retrovirus (KoRV-A) is 100 % prevalent in northern Australian (Queensland and New South Wales) koala populations, where KoRV-B has been associated with Chlamydia pecorum disease and the development of lymphosarcoma. In southern populations (Victoria and South Australia), KoRV-A is less prevalent and KoRV-B has not been detected in Victoria, while the current prevalence in South Australian populations is unknown but is thought to be low. This study aimed to determine (i) the prevalence of KoRV in the two largest South Australian koala populations [Kangaroo Island (KI) and Mount Lofty Ranges (MLR)], (ii) KoRV subtype and (iii) if an association between KoRV and C. pecorum exists. METHODOLOGY Wild koalas were sampled in KI ( n =170) between 2014 and 2017 and in MLR ( n =75) in 2016. Clinical examinations were performed, with blood collected for KoRV detection and typing by PCR. RESULTS KoRV prevalence was 42.4 % [72/170, 95 % confidence interval (CI): 34.9-49.8 %] in KI and 65.3 % (49/75, 95 % CI: 54.6-76.1 %) in MLR. Only KoRV-A, and not KoRV-B, was detected in both populations. In MLR, there was no statistical association between KoRV and C. pecorum infection (P =0.740), or KoRV and C. pecorum disease status ( P=0.274), although KoRV-infected koalas were more likely to present with overt C. pecorum disease than subclinical infection (odds ratio: 3.15, 95 % CI: 0.91-5.39). CONCLUSION KoRV-A is a prevalent pathogen in wild South Australian koala populations. Future studies should continue to investigate KoRV and C. pecorum associations, as the relationship is likely to be complex and to differ between the northern and southern populations.
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Affiliation(s)
- Jessica Fabijan
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Darren Miller
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Olusola Olagoke
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Lucy Woolford
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Wayne Boardman
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Peter Timms
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Adam Polkinghorne
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Greg Simmons
- School of Veterinary Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - Farhid Hemmatzadeh
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Darren J Trott
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - K Natasha Speight
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
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12
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Cristescu RH, Miller RL, Schultz AJ, Hulse L, Jaccoud D, Johnston S, Hanger J, Booth R, Frère CH. Developing noninvasive methodologies to assess koala population health through detecting Chlamydia from scats. Mol Ecol Resour 2019; 19:957-969. [PMID: 30681773 DOI: 10.1111/1755-0998.12999] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 11/13/2018] [Accepted: 01/14/2019] [Indexed: 01/17/2023]
Abstract
Wildlife diseases are a recognized driver of global biodiversity loss, have substantial economic impacts, and are increasingly becoming a threat to human health. Disease surveillance is critical but remains difficult in the wild due to the substantial costs and potential biases associated with most disease detection methods. Noninvasive scat surveys have been proposed as a health monitoring methodology to overcome some of these limitations. Here, we use the known threat of Chlamydia disease to the iconic, yet vulnerable, koala Phascolarctos cinereus to compare three methods for Chlamydia detection in scats: multiplex quantitative PCR, next generation sequencing, and a detection dog specifically trained on scats from Chlamydia-infected koalas. All three methods demonstrated 100% specificity, while sensitivity was variable. Of particular interest is the variable sensitivity of these diagnostic tests to detect sick individuals (i.e., not only infection as confirmed by Chlamydia-positive swabs, but with observable clinical signs of the disease); for koalas with urogenital tract disease signs, sensitivity was 78% with quantitative PCR, 50% with next generation genotyping and 100% with the detection dog method. This may be due to molecular methods having to rely on high-quality DNA whereas the dog most likely detects volatile organic compounds. The most appropriate diagnostic test will vary with disease prevalence and the specific aims of disease surveillance. Acknowledging that detection dogs might not be easily accessible to all, the future development of affordable and portable "artificial noses" to detect diseases from scats in the field might enable cost-effective, rapid and large-scale disease surveillance.
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Affiliation(s)
- Romane H Cristescu
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Russell L Miller
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Anthony J Schultz
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Lyndal Hulse
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, Australia
| | - Damian Jaccoud
- Diversity Arrays Technology, University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Stephen Johnston
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, Australia
| | - Jon Hanger
- Endeavour Veterinary Ecology, Toorbul, Queensland, Australia
| | - Rosie Booth
- Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia
| | - Céline H Frère
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
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13
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Detection and Differentiation of Two Koala Gammaherpesviruses by Use of High-Resolution Melt (HRM) Analysis Reveals Differences in Viral Prevalence and Clinical Associations in a Large Study of Free-Ranging Koalas. J Clin Microbiol 2019; 57:JCM.01478-18. [PMID: 30626662 DOI: 10.1128/jcm.01478-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/21/2018] [Indexed: 12/27/2022] Open
Abstract
The iconic koala (Phascolarctos cinereus) is host to two divergent gammaherpesviruses, phascolarctid gammaherpesviruses 1 and 2 (PhaHV-1 and -2), but the clinical significance of the individual viruses is unknown and current diagnostic methods are unsuitable for differentiating between the viruses in large-scale studies. To address this, we modified a pan-herpesvirus nested PCR to incorporate high-resolution melt analysis. We applied this assay in a molecular epidemiological study of 810 koalas from disparate populations across Victoria, Australia, including isolated island populations. Animal and clinical data recorded at sampling were analyzed and compared to infection status. Between populations, the prevalence of PhaHV-1 and -2 varied significantly, ranging from 1% to 55%. Adult and older animals were 5 to 13 times more likely to be positive for PhaHV-1 than juveniles (P < 0.001), whereas PhaHV-2 detection did not change with age, suggesting differences in how these two viruses are acquired over the life of the animal. PhaHV-1 detection was uniquely associated with the detection of koala retrovirus, particularly in females (P = 0.008). Both viruses were significantly associated (P < 0.05) with the presence of genital tract abnormalities (uterine/ovarian cysts and testicular malformation), reduced fertility in females, urinary incontinence, and detection of Chlamydia pecorum, although the strength of these associations varied by sex and virus. Understanding the clinical significance of these viruses and how they interact with other pathogens will inform future management of threatened koala populations.
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14
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Narayan E, Vanderneut T. Physiological Stress in Rescued Wild Koalas Are Influenced by Habitat Demographics, Environmental Stressors, and Clinical Intervention. Front Endocrinol (Lausanne) 2019; 10:18. [PMID: 30761085 PMCID: PMC6361754 DOI: 10.3389/fendo.2019.00018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/11/2019] [Indexed: 12/04/2022] Open
Abstract
Koalas are rescued from the wild often with incidence of burns from bushfire, injury from animal attacks, vehicle collision, and diseases. Exposure to environmental stressors (trauma and disease) could generate physiological stress and potentially impact the outcomes of clinical management intervention and rehabilitation of rescued wild koalas. It is important to quantify the stress physiology of wild koalas upon registering into clinical care. This study demonstrates the first report of physiological stress assessment in rescued wild koalas (n = 22) to determine the potential influences of habitat-specific demographics, stressor category, and clinical diagnosis. Fecal samples were collected from the koalas at rescue and routinely during hospitalization to provide a longitudinal assessment of the koala's stress response throughout clinical care. Fecal glucocorticoid metabolites (FCM) enzyme-immunoassay was used to index physiological stress non-invasively. Koalas were admitted with exposure to various categories of environmental trauma such as vehicle collision, dog attack, burns from forest fire (this also related to conditions such as copious drinking and flat demeanor), and other injury. The main disease diagnosed was chlamydial infections. In terms of environmental interactions, it was found that habitat-specific demographics, location where the rescued koala was found, especially the rural-urban fringe, influenced FCM levels. Furthermore, there was significant interaction between location, stressor category, and clinical diagnosis for mean FCM levels. However, these factors were not predictive of the clinical outcome (euthanized or released). Overall, the results provide invaluable insights into how wild koalas respond physiologically to environmental trauma and disease and how methods of care, husbandry, and treatment can be used to further reduce the impacts of stress with the ultimate aim of increasing the rehabilitation and future release of rescued koalas to revive the declining mainland populations.
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Affiliation(s)
- Edward Narayan
- School of Science and Health, Western Sydney University, Penrith, NSW, Australia
| | - Tayla Vanderneut
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
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Hulse LS, Hickey D, Mitchell JM, Beagley KW, Ellis W, Johnston SD. Development and application of two multiplex real-time PCR assays for detection and speciation of bacterial pathogens in the koala. J Vet Diagn Invest 2018; 30:523-529. [PMID: 29629645 PMCID: PMC6505923 DOI: 10.1177/1040638718770490] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Infectious diseases have contributed to the decline in the health of koala ( Phascolarctos cinereus) populations in the wild in some regions of Australia. Herein we report the development and validation of 2 multiplex real-time PCR (rtPCR) panels for the simultaneous detection of Mycoplasma spp., Ureaplasma spp., Bordetella bronchiseptica, and Chlamydia, including speciation and quantification of Chlamydia, in ocular, reproductive, and nasal swab samples in addition to semen and male urogenital and reproductive tissues, from koalas. Each rtPCR panel was developed for use as a single-tube reaction using pathogen-specific primers and fluorescently labeled probe sets. DNA extracted from reference strains and isolates was used for validation of sequence gene targets for the multiplex rtPCR panels. Each panel was shown to be sensitive and specific in detecting and differentiating the bacterial pathogens. The multiplex rtPCR panels were used to screen clinical samples from free-ranging and hospitalized koalas for multiple pathogens simultaneously. The multiplex rtPCR will improve turnaround time compared to individual-pathogen rtPCR methods used, to date, for confirmation of diagnosis and will provide the wildlife clinician with the ability to make treatment decisions more rapidly.
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Affiliation(s)
- Lyndal S. Hulse
- Lyndal S. Hulse, Wildlife
Biology Unit, School of Agriculture and Food Science, University of Queensland,
Gatton 4343, QLD, Australia.
| | - Danica Hickey
- School of Agriculture and Food Sciences, University
of Queensland, Gatton, Queensland, Australia (Hulse, Mitchell, Ellis,
Johnston)
- Institute of Health and Biomedical Innovation
(Hickey, Beagley), Faculty of Health, Queensland University of Technology,
Brisbane, Queensland, Australia
- School of Biomedical Sciences (Hickey, Beagley),
Faculty of Health, Queensland University of Technology, Brisbane, Queensland,
Australia
| | - Jessica M. Mitchell
- School of Agriculture and Food Sciences, University
of Queensland, Gatton, Queensland, Australia (Hulse, Mitchell, Ellis,
Johnston)
- Institute of Health and Biomedical Innovation
(Hickey, Beagley), Faculty of Health, Queensland University of Technology,
Brisbane, Queensland, Australia
- School of Biomedical Sciences (Hickey, Beagley),
Faculty of Health, Queensland University of Technology, Brisbane, Queensland,
Australia
| | - Kenneth W. Beagley
- School of Agriculture and Food Sciences, University
of Queensland, Gatton, Queensland, Australia (Hulse, Mitchell, Ellis,
Johnston)
- Institute of Health and Biomedical Innovation
(Hickey, Beagley), Faculty of Health, Queensland University of Technology,
Brisbane, Queensland, Australia
- School of Biomedical Sciences (Hickey, Beagley),
Faculty of Health, Queensland University of Technology, Brisbane, Queensland,
Australia
| | - William Ellis
- School of Agriculture and Food Sciences, University
of Queensland, Gatton, Queensland, Australia (Hulse, Mitchell, Ellis,
Johnston)
- Institute of Health and Biomedical Innovation
(Hickey, Beagley), Faculty of Health, Queensland University of Technology,
Brisbane, Queensland, Australia
- School of Biomedical Sciences (Hickey, Beagley),
Faculty of Health, Queensland University of Technology, Brisbane, Queensland,
Australia
| | - Stephen D. Johnston
- School of Agriculture and Food Sciences, University
of Queensland, Gatton, Queensland, Australia (Hulse, Mitchell, Ellis,
Johnston)
- Institute of Health and Biomedical Innovation
(Hickey, Beagley), Faculty of Health, Queensland University of Technology,
Brisbane, Queensland, Australia
- School of Biomedical Sciences (Hickey, Beagley),
Faculty of Health, Queensland University of Technology, Brisbane, Queensland,
Australia
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16
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Legione AR, Amery-Gale J, Lynch M, Haynes L, Gilkerson JR, Sansom FM, Devlin JM. Variation in the microbiome of the urogenital tract of Chlamydia-free female koalas (Phascolarctos cinereus) with and without 'wet bottom'. PLoS One 2018; 13:e0194881. [PMID: 29579080 PMCID: PMC5868818 DOI: 10.1371/journal.pone.0194881] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/12/2018] [Indexed: 12/21/2022] Open
Abstract
Koalas (Phascolarctos cinereus) are iconic Australian marsupials currently threatened by several processes, including infectious diseases and ecological disruption. Infection with Chlamydia pecorum, is considered a key driver of population decline. The clinical sign of 'wet bottom', a staining of the rump associated with urinary incontinence, is often caused by chlamydial urinary tract infections. However, wet bottom has been recorded in koalas free of C. pecorum, suggesting other causative agents in those individuals. We used 16S rRNA diversity profiling to investigate the microbiome of the urogenital tract of ten female koalas in order to identify potential causative agents of wet bottom, other than C. pecorum. Five urogenital samples were processed from koalas presenting with wet bottom and five were clinically normal. All koalas were negative for C. pecorum infection. We detected thirteen phyla across the ten samples, with Firmicutes occurring at the highest relative abundance (77.6%). The order Lactobacillales, within the Firmicutes, comprised 70.3% of the reads from all samples. After normalising reads using DESeq2 and testing for significant differences (P < 0.05), there were 25 operational taxonomic units (OTUs) more commonly found in one group over the other. The families Aerococcaceae and Tissierellaceae both had four significantly differentially abundant OTUs. These four Tissierellaceae OTUs were all significantly more abundant in koalas with wet bottom. This study provides the foundation for future investigations of causes of koala wet bottom, other than C. pecorum infection. This is of clinical relevance as wet bottom is often assumed to be caused by C. pecorum and treated accordingly. Our research highlights that other organisms may be causing wet bottom, and these potential aetiological agents need to be further investigated to fully address the problems this species faces.
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Affiliation(s)
- Alistair R. Legione
- Asia Pacific Centre for Animal Health, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Jemima Amery-Gale
- Asia Pacific Centre for Animal Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael Lynch
- Veterinary Department, Melbourne Zoo, Parkville, Victoria, Australia
| | - Leesa Haynes
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - James R. Gilkerson
- Centre for Equine Infectious Diseases, The University of Melbourne, Parkville, Victoria, Australia
| | - Fiona M. Sansom
- Asia Pacific Centre for Animal Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Joanne M. Devlin
- Asia Pacific Centre for Animal Health, The University of Melbourne, Parkville, Victoria, Australia
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Decline causes of Koalas in South East Queensland, Australia: a 17-year retrospective study of mortality and morbidity. Sci Rep 2017; 7:42587. [PMID: 28218272 PMCID: PMC5316976 DOI: 10.1038/srep42587] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 01/12/2017] [Indexed: 11/16/2022] Open
Abstract
Koala populations are in catastrophic decline in certain eastern Australian regions. Spanning from 1997–2013, a database derived from wildlife hospitals in southeast Queensland with N = 20,250 entries was classified by causes of morbidity and mortality. A total of 11 aetiologies were identified, with chlamydiosis, trauma, and wasting being most common. The clinical diagnosis at submission varied significantly over the observation period. Combinations of aetiologies were observed in 39% of koalas submitted, with chlamydiosis frequently co-occurring. Urogenital (cystitis 26.8%, bursitis 13.5%) and ocular (conjunctivitis 17.2%) chlamydiosis were the most frequently diagnosed representations of the infection. Approximately 26% of submissions comprised koalas involved in vehicle accidents that were otherwise healthy. Age and sex of the koala as well as season and submission period were compared for the case outcomes of ‘dead on arrival’, ‘euthanized’, or ‘released’ for the four most common clinical diagnoses using multinomial logistic regression models. Exploratory space-time permutation scans were performed and overlapping space-time clusters for chlamydiosis, motor vehicle traumas and wasting unveiled high risk areas for koala disease and injury. Our results suggest that these aetiologies are acting jointly as multifactorial determinants for the continuing decline of koalas.
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18
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Norris TA, Littnan CL, Gulland FMD, Baker JD, Harvey JT. An integrated approach for assessing translocation as an effective conservation tool for Hawaiian monk seals. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00788] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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19
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FitzGibbon SI, Gillett AK, Barth BJ, Taylor B, Ellis WA. Do koalas really get the blues? Critique of ‘Aversive behaviour by koalas (Phascolarctos cinereus) during the course of a music festival in northern New South Wales, Australia'. AUSTRALIAN MAMMALOGY 2017. [DOI: 10.1071/am16016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It is imperative that the reported results of scientific studies are based on sound data analyses and unbiased interpretation, especially where they may be used to guide government policy and regulation. A recent paper by Phillips (2016) evaluated the behavioural response of radio-collared koalas to an inaugural large music festival held in 2010 in northern New South Wales. The study concluded that six of seven koalas showed an aversive response. However, we regard the paper as misleading because it contains serious errors in the examination of koala home ranges and in the subsequent assessment of ‘aversive behaviour’ during the music festival. We conclude that Phillips’ paper is based on sufficient data to state that three, not six, of the koalas he studied displayed a short-term behavioural response to the music festival. These koalas temporarily moved outside of their estimated ranges during the festival period (10–80 m). Further, Phillips fails to report crucial ecological data regarding the high level of disease and mortality he recorded, which are presented in their entirety in the author’s prior, unpublished report. For the two deaths that are reported, no mention is made that these koalas had pre-existing disease. Rather, the author raises the possibility that the mortalities may have been related to festival-induced stress. The omission of such key data is prejudicial to the interpretation of results. The reported short-term impact of the festival upon some of the study animals is indeed noteworthy; however, it is apparent that the impact has been considerably overstated due to errors of analysis and the omission of critical ecological data. Our critique highlights our concerns by drawing on the author’s unpublished report as well as our own research at the same site over the past five years. Our aim is to ensure that debate over the impact of music festivals on wildlife is based on sound data analyses and unbiased interpretation, to provide guidance to relevant regulators and land managers.
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20
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Fiebig U, Keller M, Denner J. Detection of koala retrovirus subgroup B (KoRV-B) in animals housed at European zoos. Arch Virol 2016; 161:3549-3553. [PMID: 27638778 DOI: 10.1007/s00705-016-3064-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/12/2016] [Indexed: 12/14/2022]
Abstract
Many koalas carry an endogenous retrovirus, KoRV-A, in their genome. Recently, a second retrovirus, KoRV-B, was detected in koalas in Japanese and U.S. zoos. However, this virus is not endogenous, differs in the receptor binding site of the surface envelope protein, and uses a receptor different from that of KoRV-A. We describe here a KoRV-B found in koalas at zoos in Germany and Belgium that differs slightly from that found in the Los Angeles zoo.
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Affiliation(s)
- Uwe Fiebig
- Robert Koch Institute, Nordufer 20, D-13353, Berlin, Germany
| | - Martina Keller
- Robert Koch Institute, Nordufer 20, D-13353, Berlin, Germany
| | - Joachim Denner
- Robert Koch Institute, Nordufer 20, D-13353, Berlin, Germany.
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21
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Mackie JT, Gillett AK, Palmieri C, Feng T, Higgins DP. Pneumonia due to Chlamydia pecorum in a Koala (Phascolarctos cinereus). J Comp Pathol 2016; 155:356-360. [PMID: 27567271 DOI: 10.1016/j.jcpa.2016.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/06/2016] [Accepted: 07/22/2016] [Indexed: 11/27/2022]
Abstract
Chlamydiosis is a common infectious disease of koalas (Phascolarctos cinereus), but Chlamydia spp. have not yet been demonstrated to cause pneumonia in these animals. A juvenile male koala died following an episode of respiratory disease. At necropsy examination, the lung tissue was consolidated. Microscopical lesions in the lung included pyogranulomatous bronchopneumonia, proliferation of bronchiolar and alveolar epithelium and interstitial fibrosis. Hyperplastic bronchiolar epithelial cells contained aggregates of small basophilic punctate organisms, which were confirmed as chlamydiae by transmission electron microscopy and immunohistochemistry. Real-time polymerase chain reaction identified these as Chlamydia pecorum. This report provides the best evidence to date of chlamydial infection causing pneumonia in a koala, and the first evidence that C. pecorum is capable of infecting the bronchiolar epithelium of the koala.
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Affiliation(s)
- J T Mackie
- Vepalabs, Woolloongabba, Queensland, Australia.
| | - A K Gillett
- Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia
| | | | - T Feng
- School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - D P Higgins
- School of Life and Environmental Sciences, Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
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22
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Mangar C, Armitage CW, Timms P, Corcoran LM, Beagley KW. Characterisation of CD4 T cells in healthy and diseased koalas (Phascolarctos cinereus) using cell-type-specific monoclonal antibodies. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 60:80-90. [PMID: 26905635 DOI: 10.1016/j.dci.2016.02.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/16/2016] [Accepted: 02/16/2016] [Indexed: 06/05/2023]
Abstract
The koala (Phascolarctos cinereus) is an arboreal herbivorous marsupial that is an Australian icon. Koalas in many parts of Australia are under multiple threats including habitat destruction, dog attacks, vehicular accidents, and infectious diseases such as Chlamydia spp. and the koala retrovirus (KoRV), which may contribute to the incidence of lymphoma and leukaemia in this species. Due to a lack of koala-specific immune reagents and assays there is currently no way to adequately analyse the immune response in healthy, diseased or vaccinated animals. This paper reports the production and characterisation of the first anti-koala CD4 monoclonal antibody (mAb). The koala CD4 gene was identified and used to develop recombinant proteins for mAb production. Fluorochrome-conjugated anti-CD4 mAb was used to measure the levels of CD4(+) lymphocytes collected from koala spleens (41.1%, range 20-45.1%) lymph nodes (36.3%, range 19-55.9%) and peripheral blood (23.8%, range 17.3-35%) by flow cytometry. Biotin-conjugated anti-CD4 mAb was used for western blot to determine an approximate size of 52 kDa for the koala CD4 molecule and used in immunohistochemistry to identify CD4(+) cells in the paracortical region and germinal centres of spleen and lymph nodes. Using the anti-CD4 mab we showed that CD4 cells from vaccinated, but not control, koalas proliferated following in vitro stimulation with UV-inactivated Chlamydia pecorum and recombinant chlamydial antigens. Since CD4(+) T cells have been shown to play a pivotal role in clearing chlamydial infection in both human and mouse infections, using this novel antibody will help determine the role CD4(+) T cells play in protection against chlamydial infection in koalas and also enhance our knowledge of how KoRV affects the koala immune system.
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Affiliation(s)
- Chandan Mangar
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), P.O Box 4059, Kelvin Grove, Queensland, Australia
| | - Charles W Armitage
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), P.O Box 4059, Kelvin Grove, Queensland, Australia
| | - Peter Timms
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), P.O Box 4059, Kelvin Grove, Queensland, Australia; Faculty of Science, Health, Education and Engineering, University of Sunshine Coast (USC), P.O Box, 4556, Sippy Downs, Queensland, Australia
| | - Lynn M Corcoran
- The Walter Eliza Hall Institute of Medical Research, 1G Royal Parade, 3052, The University of Melbourne, Parkville, Victoria, Australia
| | - Kenneth W Beagley
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), P.O Box 4059, Kelvin Grove, Queensland, Australia.
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23
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THE PARADOX OF EUTHANIZING KOALAS (PHASCOLARCTOS CINEREUS) TO SAVE POPULATIONS FROM ELIMINATION. J Wildl Dis 2015; 51:833-42. [PMID: 26280878 DOI: 10.7589/2014-12-278] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Koala (Phascolarctos cinereus) populations in the wild are in sharp decline in Australia due to deforestation, road accidents, dog attacks, and disease from infection with sexually transmitted Chlamydia spp. Severely diseased koalas that are captured are euthanized for humane reasons because antibiotics are not effective. Paradoxically, we propose that euthanizing more koalas could help to increase koala population numbers. We investigated the potential impact of systematically euthanizing diseased koalas. Using data from a well-studied koala population, and an individual-based computer simulation model, we predict that such a program would result in a larger population of koalas after 7 yr than would exist without the program. If terminally diseased and sterile koalas are euthanized and other infected captured koalas are given antibiotics, chlamydial infection could be eliminated and population growth observed after 4 yr. The practical implementation of such a program would be facilitated with further development of tools to diagnose infection and internal disease in the field.
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24
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Fiebig U, Dieckhoff B, Wurzbacher C, Möller A, Kurth R, Denner J. Induction of neutralizing antibodies specific for the envelope proteins of the koala retrovirus by immunization with recombinant proteins or with DNA. Virol J 2015; 12:68. [PMID: 25925265 PMCID: PMC4429407 DOI: 10.1186/s12985-015-0296-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 04/07/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The koala retrovirus (KoRV) is the result of a transspecies transmission of a gammaretrovirus with fatal consequences for the new host. Like many retroviruses, KoRV induces lymphoma, leukemia and an immunodeficiency that is associated with opportunistic infections in the virus-infected animals. We recently reported the induction of neutralizing antibodies by immunization with the recombinant ectodomain of the transmembrane envelope protein p15E of KoRV. Since the neutralization titers of the p15E-specific sera were only moderate, we investigated the use of the surface envelope protein gp70 to induce neutralizing antibodies. FINDINGS We immunized rats and goats with the recombinant gp70 protein of the KoRV, an unglycosylated protein of 52kD (rgp70/p52) or with the corresponding DNA. In parallel we immunized with recombinant rp15E or with a combination of rp15E and rgp70/p52. In all cases binding and neutralizing antibodies were induced. The gp70-specific sera had titers of neutralizing antibodies that were 15-fold higher than the p15E-specific sera. Combining rp15E and rgp70/p52 did not significantly increase neutralizing titers compared to rgp70/p52 alone. High titers of neutralizing antibodies specific for gp70 were also induced by immunization with DNA. Since KoRV and PERV are closely related, we investigated cross-neutralization of the antisera. The antisera against p15E and gp70 of PERV and KoRV inhibited infection by both viruses. CONCLUSION The envelope proteins of the KoRV may therefore form the basis of an effective preventive vaccine to protect uninfected koalas from infection and possibly an immunotherapeutic treatment for those already infected.
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Affiliation(s)
- Uwe Fiebig
- Robert Koch-Institute, Nordufer 20, D-13353, Berlin, Germany.
| | | | | | | | - Reinhard Kurth
- Robert Koch-Institute, Nordufer 20, D-13353, Berlin, Germany.
| | - Joachim Denner
- Robert Koch-Institute, Nordufer 20, D-13353, Berlin, Germany.
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25
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Abts KC, Ivy JA, DeWoody JA. Immunomics of the koala (Phascolarctos cinereus). Immunogenetics 2015; 67:305-21. [PMID: 25761531 DOI: 10.1007/s00251-015-0833-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 02/19/2015] [Indexed: 12/20/2022]
Abstract
The study of the koala transcriptome has the potential to advance our understanding of its immunome--immunological reaction of a given host to foreign antigens--and to help combat infectious diseases (e.g., chlamydiosis) that impede ongoing conservation efforts. We used Illumina sequencing of cDNA to characterize genes expressed in two different koala tissues of immunological importance, blood and spleen. We generated nearly 600 million raw sequence reads, and about 285 million of these were subsequently assembled and condensed into ~70,000 subcomponents that represent putative transcripts. We annotated ~16% of these subcomponents and identified those related to infection and the immune response, including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), major histocompatibility complex (MHC) genes, and koala retrovirus (KoRV). Using phylogenetic analyses, we identified 29 koala genes in these target categories and report their concordance with currently accepted gene groups. By mapping multiple sequencing reads to transcripts, we identified 56 putative SNPs in genes of interest. The distribution of these SNPs indicates that MHC genes (34 SNPs) are more diverse than KoRV (12 SNPs), TLRs (8 SNPs), or RLRs (2 SNPs). Our sequence data also indicate that KoRV sequences are highly expressed in the transcriptome. Our efforts have produced full-length sequences for potentially important immune genes in koala, which should serve as targets for future investigations that aim to conserve koala populations.
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Affiliation(s)
- Kendra C Abts
- Department of Forestry and Natural Resources, Purdue University, 195 Marsteller St, West Lafayette, IN, 47907, USA,
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26
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Khan SA, Waugh C, Rawlinson G, Brumm J, Nilsson K, Gerdts V, Potter A, Polkinghorne A, Beagley K, Timms P. Vaccination of koalas (Phascolarctos cinereus) with a recombinant chlamydial major outer membrane protein adjuvanted with poly I:C, a host defense peptide and polyphosphazine, elicits strong and long lasting cellular and humoral immune responses. Vaccine 2014; 32:5781-6. [PMID: 25196393 DOI: 10.1016/j.vaccine.2014.08.037] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/26/2014] [Accepted: 08/15/2014] [Indexed: 01/08/2023]
Abstract
Chlamydial infections are wide spread in koalas across their range and a solution to this debilitating disease has been sought for over a decade. Antibiotics are the currently accepted therapeutic measure, but are not an effective treatment due to the asymptomatic nature of some infections and a low efficacy rate. Thus, a vaccine would be an ideal way to address this infectious disease threat in the wild. Previous vaccine trials have used a three-dose regimen; however this is very difficult to apply in the field as it would require multiple capture events, which are stressful and invasive processes for the koala. In addition, it requires skilled koala handlers and a significant monetary investment. To overcome these challenges, in this study we utilized a polyphosphazine based poly I:C and a host defense peptide adjuvant combined with recombinant chlamydial major outer membrane protein (rMOMP) antigen to induce long lasting (54 weeks) cellular and humoral immunity in female koalas with a novel single immunizing dose. Immunized koalas produced a strong IgG response in plasma, as well as at mucosal sites. Moreover, they showed high levels of C. pecorum specific neutralizing antibodies in the plasma as well as vaginal and conjunctival secretions. Lastly, Chlamydia-specific lymphocyte proliferation responses were produced against both whole chlamydial elementary bodies and rMOMP protein, over the 12-month period. The results of this study suggest that a single dose rMOMP vaccine incorporating a poly I:C, host defense peptide and polyphosphazine adjuvant is able to stimulate both arms of the immune system in koalas, thereby providing an alternative to antibiotic treatment and/or a three-dose vaccine regime.
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Affiliation(s)
- Shahneaz Ali Khan
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia.
| | - Courtney Waugh
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia; Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia.
| | - Galit Rawlinson
- Lone Pine Koala Sanctuary, Fig Tree Pocket, QLD 4519, Australia.
| | - Jacqui Brumm
- Lone Pine Koala Sanctuary, Fig Tree Pocket, QLD 4519, Australia.
| | - Karen Nilsson
- Lone Pine Koala Sanctuary, Fig Tree Pocket, QLD 4519, Australia.
| | - Volker Gerdts
- Vaccine and Infectious Disease Organizations, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada.
| | - Andrew Potter
- Vaccine and Infectious Disease Organizations, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada.
| | - Adam Polkinghorne
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia; Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia.
| | - Kenneth Beagley
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia.
| | - Peter Timms
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia; Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia.
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Burach F, Pospischil A, Hanger J, Loader J, Pillonel T, Greub G, Borel N. Chlamydiaceae and Chlamydia-like organisms in the koala (Phascolarctos cinereus)—Organ distribution and histopathological findings. Vet Microbiol 2014; 172:230-40. [DOI: 10.1016/j.vetmic.2014.04.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/24/2014] [Accepted: 04/26/2014] [Indexed: 11/28/2022]
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A 5-year Chlamydia vaccination programme could reverse disease-related koala population decline: Predictions from a mathematical model using field data. Vaccine 2014; 32:4163-70. [DOI: 10.1016/j.vaccine.2014.05.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 05/09/2014] [Accepted: 05/15/2014] [Indexed: 11/19/2022]
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Heterogeneity of koala retrovirus isolates. FEBS Lett 2013; 588:41-6. [PMID: 24239536 DOI: 10.1016/j.febslet.2013.10.046] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/27/2013] [Accepted: 10/31/2013] [Indexed: 11/21/2022]
Abstract
Koala retrovirus (KoRV) is a gammaretrovirus which may induce immune suppression, leukemia and lymphoma in koalas. Currently three KoRV subgroups (A, B, and J) have been reported. Our phylogenetic analysis suggests that KoRV-B and KoRV-J should be classified as the same subgroup. In long terminal repeat (LTR), a KoRV-B isolate has four 17 bp tandem repeats named direct repeat (DR)-1, while a KoRV-J isolate (strain OJ-4) has three 37 bp tandem repeats named DR-2. We also found that the promoter activity of the KoRV-J strain OJ-4 is stronger than that of original KoRV-A, suggesting that KoRV-J may replicate more efficiently than KoRV-A.
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Denner J, Young PR. Koala retroviruses: characterization and impact on the life of koalas. Retrovirology 2013; 10:108. [PMID: 24148555 PMCID: PMC4016316 DOI: 10.1186/1742-4690-10-108] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 10/07/2013] [Indexed: 11/16/2022] Open
Abstract
Koala retroviruses (KoRV) have been isolated from wild and captive koalas in Australia as well as from koala populations held in zoos in other countries. They are members of the genus Gammaretrovirus, are most closely related to gibbon ape leukemia virus (GaLV), feline leukemia virus (FeLV) and porcine endogenous retrovirus (PERV) and are likely the result of a relatively recent trans-species transmission from rodents or bats. The first KoRV to be isolated, KoRV-A, is widely distributed in the koala population in both integrated endogenous and infectious exogenous forms with evidence from museum specimens older than 150 years, indicating a relatively long engagement with the koala population. More recently, additional subtypes of KoRV that are not endogenized have been identified based on sequence differences and host cell receptor specificity (KoRV-B and KoRV-J). A specific association with fatal lymphoma and leukemia has been recently suggested for KoRV-B. In addition, it has been proposed that the high viral loads found in many animals may lead to immunomodulation resulting in a higher incidence of diseases such as chlamydiosis. Although the molecular basis of this immunomodulation is still unclear, purified KoRV particles and a peptide corresponding to a highly conserved domain in the envelope protein have been shown to modulate cytokine expression in vitro, similar to that induced by other gammaretroviruses. While much is still to be learned, KoRV induced lymphoma/leukemia and opportunistic disease arising as a consequence of immunomodulation are likely to play an important role in the stability of koala populations both in the wild and in captivity.
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31
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Identification of a novel subgroup of Koala retrovirus from Koalas in Japanese zoos. J Virol 2013; 87:9943-8. [PMID: 23824806 DOI: 10.1128/jvi.01385-13] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We identified a new subgroup of koala retrovirus (KoRV), named KoRV-J, which utilizes thiamine transport protein 1 as a receptor instead of the Pit-1 receptor used by KoRV (KoRV-A). By subgroup-specific PCR, KoRV-J and KoRV-A were detected in 67.5 and 100% of koalas originating from koalas from northern Australia, respectively. Altogether, our results indicate that the invasion of the koala population by KoRV-J may have occurred more recently than invasion by KoRV-A.
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Polkinghorne A, Hanger J, Timms P. Recent advances in understanding the biology, epidemiology and control of chlamydial infections in koalas. Vet Microbiol 2013; 165:214-23. [PMID: 23523170 DOI: 10.1016/j.vetmic.2013.02.026] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 02/24/2013] [Indexed: 11/16/2022]
Abstract
The koala (Phascolarctos cinereus) is recognised as a threatened wildlife species in various parts of Australia. A major contributing factor to the decline and long-term viability of affected populations is disease caused by the obligate intracellular bacteria, Chlamydia. Two chlamydial species infect the koala, Chlamydia pecorum and Chlamydia pneumoniae, and have been reported in nearly all mainland koala populations. Chlamydial infections of koalas are associated with ocular infections leading to blindness and genital tract infections linked to infertility, among other serious clinical manifestations. Diagnosis can be based on clinical presentation alone, however, it is complicated by the observation that many koala chlamydial infections occur with no overt signs of clinical disease. Instead, accurate diagnosis requires detailed clinical assessment and confirmatory testing by a range of PCR-based assays. Antibiotic treatment for koala chlamydial infection is possible, however, results on its success are mixed. A more practical solution for the protection of diseased populations is the application of a koala Chlamydia vaccine, with recent trials indicating promising results. Interestingly, molecular epidemiology studies of koala C. pecorum infections and recent comparative genomic analyses of koala C. pneumoniae have revealed potential differences in their origin that will have wider ramifications for our understanding of human chlamydial infections and host adaptation of the chlamydiae. This review summarises changes to the taxonomy of koala chlamydial infections and recent advances in our understanding of the epidemiology, diagnosis, treatment, control and evolution of Chlamydia infections in this iconic wildlife species.
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Affiliation(s)
- Adam Polkinghorne
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, Brisbane 4059, Australia.
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33
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Construction and characterization of an infectious molecular clone of Koala retrovirus. J Virol 2013; 87:5081-8. [PMID: 23427161 DOI: 10.1128/jvi.01584-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Koala retrovirus (KoRV) is a gammaretrovirus that is currently endogenizing into koalas. Studies on KoRV infection have been hampered by the lack of a replication-competent molecular clone. In this study, we constructed an infectious molecular clone, termed plasmid pKoRV522, of a KoRV isolate (strain Aki) from a koala reared in a Japanese zoo. The virus KoRV522, derived from pKoRV522, grew efficiently in human embryonic kidney (HEK293T) cells, attaining 10(6) focus-forming units/ml. Several mutations in the Gag (L domain) and Env regions reported to be involved in reduction in viral infection/production in vitro are found in pKoRV522, yet KoRV522 replicated well, suggesting that any effects of these mutations are limited. Indeed, a reporter virus pseudotyped with pKoRV522 Env was found to infect human, feline, and mink cell lines efficiently. Analyses of KoRV L-domain mutants showed that an additional PPXY sequence, PPPY, in Gag plays a critical role in KoRV budding. Altogether, our results demonstrate the construction and characterization of the first infectious molecular clone of KoRV. The infectious clone reported here will be useful for elucidating the mechanism of endogenization of the virus in koalas and screening for antiretroviral drugs for KoRV-infected koalas.
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Kollipara A, Wan C, Rawlinson G, Brumm J, Nilsson K, Polkinghorne A, Beagley K, Timms P. Antigenic specificity of a monovalent versus polyvalent MOMP based Chlamydia pecorum vaccine in koalas (Phascolarctos cinereus). Vaccine 2013; 31:1217-23. [DOI: 10.1016/j.vaccine.2012.12.057] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 12/17/2012] [Accepted: 12/20/2012] [Indexed: 10/27/2022]
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35
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Kollipara A, George C, Hanger J, Loader J, Polkinghorne A, Beagley K, Timms P. Vaccination of healthy and diseased koalas (Phascolarctos cinereus) with a Chlamydia pecorum multi-subunit vaccine: Evaluation of immunity and pathology. Vaccine 2012; 30:1875-85. [DOI: 10.1016/j.vaccine.2011.12.125] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 12/22/2011] [Accepted: 12/23/2011] [Indexed: 01/08/2023]
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36
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Wan C, Loader J, Hanger J, Beagley K, Timms P, Polkinghorne A. Using quantitative polymerase chain reaction to correlate Chlamydia pecorum infectious load with ocular, urinary and reproductive tract disease in the koala (Phascolarctos cinereus). Aust Vet J 2011; 89:409-12. [PMID: 21933169 DOI: 10.1111/j.1751-0813.2011.00827.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Complex interactions between Chlamydia pecorum infection, the immune response and disease exist in the koala. We used quantitative polymerase chain reaction to investigate the relationship between C. pecorum infectious load and ocular and urogenital tract disease. Chlamydia pecorum shedding was generally higher in animals with chronic, active disease than in animals with inactive disease. The absence of ocular disease was generally associated with low levels of shedding, but relatively high levels of shedding in the urogenital tract were detected in some koalas without clinical disease signs. These results suggest a complex disease pathogenesis and clinical course in C. pecorum-infected koalas.
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Affiliation(s)
- C Wan
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Brisbane, Australia
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37
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Marsh J, Kollipara A, Timms P, Polkinghorne A. Novel molecular markers of Chlamydia pecorum genetic diversity in the koala (Phascolarctos cinereus). BMC Microbiol 2011; 11:77. [PMID: 21496349 PMCID: PMC3101125 DOI: 10.1186/1471-2180-11-77] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 04/18/2011] [Indexed: 01/16/2023] Open
Abstract
Background Chlamydia pecorum is an obligate intracellular bacterium and the causative agent of reproductive and ocular disease in several animal hosts including koalas, sheep, cattle and goats. C. pecorum strains detected in koalas are genetically diverse, raising interesting questions about the origin and transmission of this species within koala hosts. While the ompA gene remains the most widely-used target in C. pecorum typing studies, it is generally recognised that surface protein encoding genes are not suited for phylogenetic analysis and it is becoming increasingly apparent that the ompA gene locus is not congruent with the phylogeny of the C. pecorum genome. Using the recently sequenced C. pecorum genome sequence (E58), we analysed 10 genes, including ompA, to evaluate the use of ompA as a molecular marker in the study of koala C. pecorum genetic diversity. Results Three genes (incA, ORF663, tarP) were found to contain sufficient nucleotide diversity and discriminatory power for detailed analysis and were used, with ompA, to genotype 24 C. pecorum PCR-positive koala samples from four populations. The most robust representation of the phylogeny of these samples was achieved through concatenation of all four gene sequences, enabling the recreation of a "true" phylogenetic signal. OmpA and incA were of limited value as fine-detailed genetic markers as they were unable to confer accurate phylogenetic distinctions between samples. On the other hand, the tarP and ORF663 genes were identified as useful "neutral" and "contingency" markers respectively, to represent the broad evolutionary history and intra-species genetic diversity of koala C. pecorum. Furthermore, the concatenation of ompA, incA and ORF663 sequences highlighted the monophyletic nature of koala C. pecorum infections by demonstrating a single evolutionary trajectory for koala hosts that is distinct from that seen in non-koala hosts. Conclusions While the continued use of ompA as a fine-detailed molecular marker for epidemiological analysis appears justified, the tarP and ORF663 genes also appear to be valuable markers of phylogenetic or biogeographic divisions at the C. pecorum intra-species level. This research has significant implications for future typing studies to understand the phylogeny, genetic diversity, and epidemiology of C. pecorum infections in the koala and other animal species.
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Affiliation(s)
- James Marsh
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
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38
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Simmons G, Young P, McKee J, Meers J, MIZUNO T. The Epidemiology of Koala Retrovirus. ACTA ACUST UNITED AC 2011. [DOI: 10.2743/jve.15.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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39
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Mitchell CM, Hovis KM, Bavoil PM, Myers GSA, Carrasco JA, Timms P. Comparison of koala LPCoLN and human strains of Chlamydia pneumoniae highlights extended genetic diversity in the species. BMC Genomics 2010; 11:442. [PMID: 20646324 PMCID: PMC3091639 DOI: 10.1186/1471-2164-11-442] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 07/21/2010] [Indexed: 11/28/2022] Open
Abstract
Background Chlamydia pneumoniae is a widespread pathogen causing upper and lower respiratory tract infections in addition to a range of other diseases in humans and animals. Previous whole genome analyses have focused on four essentially clonal (> 99% identity) C. pneumoniae human genomes (AR39, CWL029, J138 and TW183), providing relatively little insight into strain diversity and evolution of this species. Results We performed individual gene-by-gene comparisons of the recently sequenced C. pneumoniae koala genome and four C. pneumoniae human genomes to identify species-specific genes, and more importantly, to gain an insight into the genetic diversity and evolution of the species. We selected genes dispersed throughout the chromosome, representing genes that were specific to C. pneumoniae, genes with a demonstrated role in chlamydial biology and/or pathogenicity (n = 49), genes encoding nucleotide salvage or amino acid biosynthesis proteins (n = 6), and extrachromosomal elements (9 plasmid and 2 bacteriophage genes). Conclusions We have identified strain-specific differences and targets for detection of C. pneumoniae isolates from both human and animal origin. Such characterisation is necessary for an improved understanding of disease transmission and intervention.
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Affiliation(s)
- Candice M Mitchell
- Faculty of Science and Technology, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland 4059, Australia
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40
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Carey AJ, Timms P, Rawlinson G, Brumm J, Nilsson K, Harris JM, Beagley KW. ORIGINAL ARTICLE: A Multi-Subunit Chlamydial Vaccine Induces Antibody and Cell-Mediated Immunity in Immunized Koalas (Phascolarctos cinereus): Comparison of Three Different Adjuvants. Am J Reprod Immunol 2010; 63:161-72. [DOI: 10.1111/j.1600-0897.2009.00776.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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41
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The marsupial CD8 gene locus: molecular cloning and expression analysis of the alpha and beta sequences in the gray short-tailed opossum (Monodelphis domestica) and the tammar wallaby (Macropus eugenii). Vet Immunol Immunopathol 2008; 129:14-27. [PMID: 19135263 DOI: 10.1016/j.vetimm.2008.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 11/28/2008] [Accepted: 12/01/2008] [Indexed: 11/22/2022]
Abstract
In eutherian mammals, CD8 is a key receptor of cytotoxic T cells and plays a pivotal role in the recognition and elimination of infected host cells by cell-mediated cytotoxicity. Here, we report the molecular cloning and expression analysis of CD8alpha and CD8beta cDNAs in two marsupial species, the gray short-tailed opossum and the tammar wallaby. The opossum and tammar CD8 sequences share a high degree of amino acid identity of 63% (CD8alpha) and 57% (CD8beta) to each other as well as 36-45% (CD8alpha) and 38-41% (CD8beta) with their eutherian counterparts. In addition, many of the signature features of eutherian CD8alpha and CD8beta are preserved in both marsupials including the two invariant cysteines that form the intra-chain disulphide bond in the extracellular IgSfV domain and the two hinge region cysteines involved in dimerisation between the two subunits. The p56(lck) binding motif in the cytoplasmic tail of the CD8alpha subunit is also conserved. Interestingly, the opossum CD8alpha and the tammar CD8beta sequences have a truncated cytoplasmic tail. RT-PCR analysis of CD8alpha and CD8beta transcripts in the tissues of the adult opossum and tammar showed broad tissue expression with a high level of expression observed in the lymphoid tissues of both marsupials. Furthermore, RT-PCR analysis of CD8alpha and CD8beta transcripts in the immune tissues of tammar young over the first 120 days of pouch life revealed a pattern of expression analogous to the maturation of the lymphoid tissues. This is the first report confirming the presence of CD8 in the tissues of a marsupial and will provide the tools to further analyse T cell subsets in this unique group of mammals.
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Fiebig U, Hartmann MG, Bannert N, Kurth R, Denner J. Transspecies transmission of the endogenous koala retrovirus. J Virol 2007; 80:5651-4. [PMID: 16699047 PMCID: PMC1472152 DOI: 10.1128/jvi.02597-05] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The koala retrovirus (KoRV) is a gammaretrovirus closely related to the gibbon ape leukemia virus and induces leukemias and immune deficiencies associated with opportunistic infections, such as chlamydiosis. Here we characterize a KoRV newly isolated from an animal in a German zoo and show infection of human and rat cell lines in vitro and of rats in vivo, using immunological and PCR methods for virus detection. The KoRV transmembrane envelope protein (p15E) was cloned and expressed, and p15E-specific neutralizing antibodies able to prevent virus infection in vitro were developed. Finally, evidence for immunosuppressive properties of the KoRV was obtained.
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Affiliation(s)
- Uwe Fiebig
- Robert Koch Institute, Nordufer 20, D-13353 Berlin, Germany
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43
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Markey B, Wan C, Hanger J, Phillips C, Timms P. Use of quantitative real-time PCR to monitor the shedding and treatment of chlamydiae in the koala (Phascolarctos cinereus). Vet Microbiol 2006; 120:334-42. [PMID: 17178441 DOI: 10.1016/j.vetmic.2006.11.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 11/15/2006] [Accepted: 11/21/2006] [Indexed: 11/29/2022]
Abstract
The aim of this study was to monitor chlamydial shedding patterns in clinically affected koalas before, during and following treatment using quantitative real-time PCR. Swab samples were obtained from 14 koalas presented for treatment at the Australian Wildlife Hospital. Four of these animals were followed over a period of 8-9 weeks. Primers were designed based on the consensus signature sequence of the 16S rRNA chlamydial gene. Additional primers were designed based on the sequence of the koala beta-actin gene and used to normalize chlamydial values when comparing results from different swab samples. Chlamydial 16S rRNA gene copy number was highest in swab samples from clinically affected sites. Daily injections of chloramphenicol resulted in a marked and rapid reduction in the numbers of chlamydiae being shed from all sites. In general, chlamydial copy number was no longer detectable by the end of the 2nd week of treatment. No evidence of relapse of infection was detected at 2 weeks after the cessation of treatment. In contrast, topical chloramphenicol treatment of the eyes required a longer treatment period and had little effect on the shedding of chlamydiae from other sites of the body. Further studies are required to confirm the efficacy of a shorter treatment period.
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Affiliation(s)
- Bryan Markey
- School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
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44
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Tarlinton R, Meers J, Hanger J, Young P. Real-time reverse transcriptase PCR for the endogenous koala retrovirus reveals an association between plasma viral load and neoplastic disease in koalas. J Gen Virol 2005; 86:783-787. [PMID: 15722540 DOI: 10.1099/vir.0.80547-0] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Koala retrovirus (KoRV) is a newly described endogenous retrovirus and is unusual in that inserts comprise a full-length replication competent genome. As koalas are known to suffer from an extremely high incidence of leukaemia/lymphoma, the association between this retrovirus and disease in koalas was examined. Using quantitative real-time reverse transcriptase PCR it was demonstrated that KoRV RNA levels in plasma are significantly increased in animals suffering from leukaemia or lymphoma when compared with healthy animals. Increased levels of KoRV were also seen for animals with clinical chlamydiosis. A significant positive association between viral RNA levels and age was also demonstrated. Real-time PCR demonstrated as much as 5 log variation in KoRV proviral DNA levels in genomic DNA extracted from whole blood from different animals. Taken together these data indicate that KoRV is an active endogenous retrovirus and suggests that it may be causally linked to neoplastic disease in koalas.
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Affiliation(s)
- Rachael Tarlinton
- Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, University of Queensland, St Lucia 4072, Queensland, Australia
| | - Joanne Meers
- School of Veterinary Science, University of Queensland, St Lucia 4072, Queensland, Australia
| | - Jon Hanger
- Dreamworld, Coomera, Queensland, Australia
| | - Paul Young
- Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, University of Queensland, St Lucia 4072, Queensland, Australia
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45
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Bodetti TJ, Hengstberger K, Johnston S, Timms P. Evaluation of tetracycline, erythromycin, penicillin and streptomycin for decontaminating koala semen contaminated in vitro with chlamydiae. Vet Rec 2003; 153:588-91. [PMID: 14640326 DOI: 10.1136/vr.153.19.588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Semen from seven koalas was extended in a tris-citrate glucose diluent containing one of four antibiotics at different concentrations and then contaminated with a standard concentration of chlamydiae. These semen preparations were then tested for residual chlamydial viability by an in vitro cell culture assay, and any detrimental effect of the antibiotics on the motility and viability of the sperm was assessed. Penicillin at 25 iu/ml or more, erythromycin at 1000 microg/ml or more and tetracycline at 200 microg/ml or more were highly effective at rendering the chlamydiae non-viable, but streptomycin showed no antichlamydial activity. There was a significant reduction of the motility of spermatozoa extended in diluents containing erythromycin (P < 0.05), but spermatozoa incubated with tetracycline up to concentrations of 200 microg/ml were not affected.
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Affiliation(s)
- T J Bodetti
- School of Life Sciences, Queensland University of Technology, Brisbane, Australia
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46
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Devereaux LN, Polkinghorne A, Meijer A, Timms P. Molecular evidence for novel chlamydial infections in the koala (Phascolarctos cinereus). Syst Appl Microbiol 2003; 26:245-53. [PMID: 12866851 DOI: 10.1078/072320203322346092] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chlamydia-related disease has a detrimental effect on Australia's free-range koala (Phascolarctos cinereus) populations. The chlamydial species responsible for ocular, urogenital and respiratory disease in the koala have previously been identified as Chlamydophila pecorum and Chlamydophila pneumoniae. Epizootiology studies have therefore used species specific PCR assays to detect chlamydial infections. In the current study, we used a broad range PCR amplification and cloning strategy to identify all strains of Chlamydiales in the koala. Sequencing of 16S rRNA gene PCR products, cloned from Chlamydiales--order positive swab samples identified nine novel koala Chlamydiales genotypes, including multiple novel chlamydial genotypes present in a single sample. The novel koala genotypes are clustered together with other Chlamydia-like bacteria within a second lineage separate from the known Chlamydiaceae species. Two new primer sets UKC-A and UKC-B were designed to detect five of the nine novel Chlamydiales and were applied to swab samples collected from two wild koala populations. Using these new UKC PCR assays, UKC-A type Chlamydiales sequences were more prevalent (72%; 18/25) compared to UKC-B (24%; 6/25). UKC sequences were most commonly found as dual infections with C. pecorum. This report provides the first description of additional members of the order Chlamydiales infecting the koala.
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Affiliation(s)
- Lisa N Devereaux
- Centre for Molecular Biotechnology, School of Life Sciences, Queensland University of Technology, Brisbane, Australia
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47
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Jackson M, White N, Giffard P, Timms P. Epizootiology of Chlamydia infections in two free-range koala populations. Vet Microbiol 1999; 65:255-64. [PMID: 10223324 DOI: 10.1016/s0378-1135(98)00302-2] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The prevalence of Chlamydia pecorum and Chlamydia pneumoniae infections in two free-range koala populations was assessed using genus-specific PCR combined with species-specific DNA probe hybridisation. Population A had a very high overall level of chlamydial infection (85%) with significantly more of these infections being due to C. pecorum (73%) compared to C. pneumoniae (24%). The second population had a much lower prevalence of infection (10%) with equal levels of both species. An important finding of this study was that. while five of 24 C. pecorum-infected koalas had clinical signs of the disease (both ocular and urogenital sites), none out of seven C. pneumoniae-infected koalas had signs of clinical disease. This suggests that C. pecorum may be the more pathogenic of the two chlamydial species infecting this host. The level of infection (assessed by intensity of the specific hybridisation signal) also differed between chlamydial species, with C. pecorum infections ranging from low to high grade whereas C. pneumoniae infections were always low grade. When the age of infected koalas was examined, 58% of young, sexually immature koalas were found to have C. pecorum infections, increasing to 100% of koalas in the older age groups. This suggests that, in this population at least, young koalas are readily infected with C. pecorum from their mothers. While the infection levels with C. pneumoniae were too low to be statistically significant, again, sexually immature koalas were found to be infected. The recent separation of chlamydial infections in koalas into two species is beginning to indicate different epizootiologies for koala C. pecorum compared to koala C. pneumoniae.
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Affiliation(s)
- M Jackson
- Centre for Molecular Biotechnology, School of Life Sciences, Queensland University of Technology, Brisbane, Australia
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Wardrop S, Fowler A, O'Callaghan P, Giffard P, Timms P. Characterization of the koala biovar of Chlamydia pneumoniae at four gene loci--ompAVD4, ompB, 16S rRNA, groESL spacer region. Syst Appl Microbiol 1999; 22:22-7. [PMID: 10188275 DOI: 10.1016/s0723-2020(99)80024-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Koalas are infected with two species of Chlamydia, C. pecorum and C. pneumoniae. While it is known that significant genetic diversity occurs in the C. pecorum strains infecting koalas, very little is known about the C. pneumoniae strains that infect this host. In the current study, 10 isolates of koala C. pneumoniae were analysed at four gene loci and found to be different to both the human and horse C. pneumoniae strains at all loci (biovar differences ranging from 0.3% at groESL up to 9.0% at ompAVD4). All koala biovar isolates studied were found to be 100% identical at ompAVD4 (all 10 isolates) and at ompB (all three isolates) gene. This lack of allelic polymorphisms at ompAVD4 has now been observed for koala C. pneumoniae, human C. pneumoniae, guinea pig inclusion conjuctivitis C. psittaci and feline conjuctivitis C. psittaci and may be correlated to a lack of antibody response to the chlamydial major outer membrane protein (MOMP) in these same strain/host combinations. This study also provides the first documented case of natural C. pneumoniae infection causing a severe and extended respiratory episode in a captive koala population. This captive episode is in contrast to most free-range observations in which koala C. pneumoniae is rarely documented as causing respiratory, ocular or urogenital tract disease.
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Affiliation(s)
- S Wardrop
- Centre for Molecular Biotechnology, School of Life Sciences, Queensland University of Technology, Brisbane, Australia
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Johnston SD, O'Boyle D, Frost AJ, McGowan MR, Tribe A, Higgins D. Antibiotics for the preservation of koala (Phascolarctos cinereus) semen. Aust Vet J 1998; 76:335-8. [PMID: 9631702 DOI: 10.1111/j.1751-0813.1998.tb12362.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM To determine the normal microbial flora of the koala ejaculate and prepuce in order to select appropriate antibiotics for addition into diluents designed for the preservation of semen. PROCEDURE Bacteriological samples of the koala prepuce (n = 12) and ejaculate (n = 20) were submitted for microbial culture and sensitivity testing. Microbial flora of ejaculates collected by electroejaculation and artificial vagina were compared. The effects of varying concentrations of penicillin G and gentamicin on sperm motility and on the growth of bacteria in diluted semen stored at room temperature and 16 degrees C over a 24 h period were investigated. RESULTS A range of bacteria was isolated from the koala prepuce and ejaculate. The predominant organisms in semen collected by electroejaculation and artificial vagina were Corynebacterium spp, none of which could be assigned to any recognised species. The addition of penicillin G and gentamicin to a PBS-based diluent at dose rates of 1000 to 2000 IU/mL and 100 to 200 micrograms/mL respectively, resulted in no adverse effect on sperm motility over a 24 h incubation period. Penicillin G (1000 IU/mL) and gentamicin (100 micrograms/mL) prevented growth of bacterial contaminants in diluted koala semen. CONCLUSION By controlling the growth of bacteria in extended koala semen, penicillin G and gentamicin are likely to lengthen the period by which spermatozoa can be stored at 16 degrees C and reduce the possibility of disease transmission during artificial insemination procedures.
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Affiliation(s)
- S D Johnston
- Division of Animal Health and Production, School of Veterinary Science and Animal Production, University of Queensland
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Martin JL, Cross GF. Comparison of the omp I gene of Chlamydia psittaci between isolates in Victorian koalas and other animal species. Aust Vet J 1997; 75:579-82. [PMID: 9293340 DOI: 10.1111/j.1751-0813.1997.tb14198.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE The objective of this study is to compare the strain of chlamydia causing genital infection in koalas from Victoria with isolates from other animal species. DESIGN Polymerase chain reaction and restriction enzyme analysis has been used to compare various Chlamydia psittaci isolates from a range of animals and disease syndromes. The isolates used in this study include isolates from three birds, three from aborted sheep, one from polyarthritis, one from bovine abortion, one from feline pneumonitis, three porcine isolates from faeces, polyarthritis and abortion, and three urogenital isolates from Victorian koalas. PROCEDURE Two polymerase chain reactions were performed, each amplifying a different region of the omp 1 gene. The first polymerase chain reaction amplified a 144 bp segment of the gene which was then digested with the restriction enzyme EcoR I. The second polymerase chain reaction amplified a larger 1070 bp region of the omp 1 gene which was digested with two restriction enzymes Alu I and Nde II. RESULTS AND CONCLUSIONS The results obtained have confirmed that variation in DNA sequence of various animal chlamydia isolates does occur. They have also shown that it is possible to classify isolates, based on their restriction enzyme profiles, into distinct groups.
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Affiliation(s)
- J L Martin
- Department of Microbiology, Monash Medical School, Alfred Hospital, Prahran, Victoria
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