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Chen CJ, Casteriano A, Green AC, Govendir M. A retrospective study on antibacterial treatments for koalas infected with Chlamydia pecorum. Sci Rep 2023; 13:12670. [PMID: 37542093 PMCID: PMC10403558 DOI: 10.1038/s41598-023-39832-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023] Open
Abstract
Chlamydiosis remains the leading infectious disease and is one of the key factors responsible for the dramatic reduction of koala populations in South-East Queensland (SEQ) and New South Wales (NSW) regions of Australia. Possible infection outcomes include blindness, infertility, painful cystitis, and death if left untreated. Studies have reported the treatment efficacy of chloramphenicol and doxycycline, which are the two most commonly administered treatments in diseased koalas, in clinical settings. However, none have directly compared the treatment efficacy of these antibacterials on koala survival. A retrospective study was essential to identify any relationships between the demographical information, and the animals' responses to the current treatment regimens. Associations were explored between six explanatory (sex; maturity; location; clinical signs, treatment; treatment duration) and two outcome variables (survival; post-treatment PCR). Results showed that female koalas had a statistical trend of lower odds of surviving when compared to males (OR = 0.36, p = 0.05). Koalas treated with chloramphenicol for ≥ 28 days had greater odds of surviving than when treated for < 28 days (OR = 8.8, p = 0.02), and those koalas administered doxycycline had greater odds of testing PCR negative when compared to chloramphenicol treatments (OR = 5.45, p = 0.008). There was no difference between the antibacterial treatments (chloramphenicol, doxycycline, and mixed/other) and the survival of koalas. Female koalas had greater odds of exhibiting UGT signs only (OR = 4.86, p < 0.001), and also greater odds of having both ocular and UGT clinical signs (OR = 5.29, p < 0.001) when compared to males. Of the koalas, 28.5% initially had no clinical signs but were PCR positive for C. pecorum. This study enables further understanding of the complex nature between chlamydial infection and response to antibacterial treatment.
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Affiliation(s)
- Chien-Jung Chen
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, Australia.
| | - Andrea Casteriano
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, Australia
| | - Alexandra Clare Green
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, Australia
| | - Merran Govendir
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, Australia
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2
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Limón-González MM, Hernández-Castro R, Martínez-Hernández F, Xicohtencatl-Cortes J, Ramírez-Alvarez H, Palomares-Resendiz EG, Díaz-Aparicio E. Genetic diversity of Chlamydia pecorum detected in sheep flocks from Mexico. Braz J Microbiol 2022. [DOI: https:/doi.org/10.1007/s42770-022-00682-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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3
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Silver LW, Cheng Y, Quigley BL, Robbins A, Timms P, Hogg CJ, Belov K. A targeted approach to investigating immune genes of an iconic Australian marsupial. Mol Ecol 2022; 31:3286-3303. [PMID: 35510793 PMCID: PMC9325493 DOI: 10.1111/mec.16493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 03/02/2022] [Accepted: 04/05/2022] [Indexed: 11/30/2022]
Abstract
Disease is a contributing factor to the decline of wildlife populations across the globe. Koalas, iconic yet declining Australian marsupials, are predominantly impacted by two pathogens, Chlamydia and koala retrovirus. Chlamydia is an obligate intracellular bacterium and one of the most widespread sexually transmitted infections in humans worldwide. In koalas, Chlamydia infections can present as asymptomatic or can cause a range of ocular and urogenital disease signs, such as conjunctivitis, cystitis and infertility. In this study, we looked at differences in response to Chlamydia in two northern populations of koalas using a targeted gene sequencing of 1209 immune genes in addition to genome‐wide reduced representation data. We identified two MHC Class I genes associated with Chlamydia disease progression as well as 25 single nucleotide polymorphisms across 17 genes that were associated with resolution of Chlamydia infection. These genes are involved in the innate immune response (TLR5) and defence (TLR5, IFNγ, SERPINE1, STAT2 and STX4). This study deepens our understanding of the role that genetics plays in disease progression in koalas and leads into future work that will use whole genome resequencing of a larger sample set to investigate in greater detail regions identified in this study. Elucidation of the role of host genetics in disease progression and resolution in koalas will directly contribute to better design of Chlamydia vaccines and management of koala populations which have recently been listed as “endangered.”
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Affiliation(s)
- Luke W Silver
- School of Life and Environmental Sciences, The University of Sydney, New South Wales, 2006, Australia
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, New South Wales, 2006, Australia
| | - Bonnie L Quigley
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia.,Provectus Algae Pty Ltd, 5 Bartlett Road, Noosaville, Queensland, 4566, Australia
| | - Amy Robbins
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia.,Endeavour Veterinary Ecology Pty Ltd, 1695 Pumicestone Road, Toorbul, Queensland, 4510, Australia
| | - Peter Timms
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia
| | - Carolyn J Hogg
- School of Life and Environmental Sciences, The University of Sydney, New South Wales, 2006, Australia
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, New South Wales, 2006, Australia
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4
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Limón-González MM, Hernández-Castro R, Martínez-Hernández F, Xicohtencatl-Cortes J, Ramírez-Alvarez H, Palomares-Resendiz EG, Díaz-Aparicio E. Genetic diversity of Chlamydia pecorum detected in sheep flocks from Mexico. Braz J Microbiol 2022. [DOI: https://doi.org/10.1007/s42770-022-00682-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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5
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Limón-González MM, Hernández-Castro R, Martínez-Hernández F, Xicohtencatl-Cortes J, Ramírez-Alvarez H, Palomares-Resendiz EG, Díaz-Aparicio E. Genetic diversity of Chlamydia pecorum detected in sheep flocks from Mexico. Braz J Microbiol 2022; 53:605-613. [PMID: 35119684 PMCID: PMC9151965 DOI: 10.1007/s42770-022-00682-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/13/2022] [Indexed: 02/06/2023] Open
Abstract
Chlamydia pecorum, an obligate intracellular bacterium, is associated with reproductive and systemic diseases in sheep, goats, pigs, cattle, and koalas. The main conditions include polyarthritis, conjunctivitis, enteritis, pneumonia, encephalomyelitis, orchitis, placentitis, and abortion. Even though there are several studies showing that C. pecorum infections are widely spread in the world, in Mexico there are no reports. During 2016, as part of a sheep restocking program in Mexico, sheep were imported from New Zealand. Briefly after their arrival in the herds in the State of Mexico, these sheep presented abortions during the last third of gestation. A total of 62 sheep vaginal swabs that had presented abortion from different municipalities of the State of Mexico were collected. Bacterial isolation was performed using L929 mouse fibroblasts, and molecular identification was achieved by 23S rRNA (Chlamydiaceae family) and ompA gene (species-specific) real-time polymerase chain reaction (PCR). In addition, the 16S rRNA subunit and ompA gene were amplified and sequenced. Seven of 62 samples were positive for C. pecorum by bacterial isolation, 23S rRNA, and ompA gene real-time PCR. The 16S rRNA subunit and ompA gene amplicons were purified and the nucleotide sequence was determined in both directions. The consensus sequences homology search was performed using BLASTn analysis and showed a 100% of homology with the C. pecorum 16S rRNA subunit and 99% with the C. pecorum ompA gene. The population structure analyses using ompA gene demonstrated 15 genetic populations or clusters of 198 sequences from GenBank and our sequences were in a particular genetic structure corresponding to genotype "O." Herein, we describe the presence of C. pecorum in sheep imported from New Zealand into Mexico. Genetic analysis of the ompA gene showed that the isolates belong to genotype O and are related to strains isolated from sheep, cattle, and koalas.
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Affiliation(s)
- M M Limón-González
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Coyoacán, 04510, Ciudad de México, Mexico.
| | - R Hernández-Castro
- Departamento de Ecología de Agentes Patógenos, Hospital General "Dr. Manuel Gea González", Tlalpan, 14080, Ciudad de México, Mexico
| | - F Martínez-Hernández
- Departamento de Ecología de Agentes Patógenos, Hospital General "Dr. Manuel Gea González", Tlalpan, 14080, Ciudad de México, Mexico
| | - J Xicohtencatl-Cortes
- Laboratorio de Bacteriología Intestinal, Hospital Infantil de México "Dr. Federico Gómez", Cuauhtémoc, 06720, Ciudad de México, Mexico
| | - H Ramírez-Alvarez
- Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, 54714, Cuautitlán Izcalli, Estado de México, Mexico
| | - E G Palomares-Resendiz
- Centro Nacional de Investigación Disciplinaria en Salud Animal e Inocuidad (CENID-SAI), Instituto Nacional de Investigaciones ForestalesAgrícolas y Pecuarias, Cuajimalpa, 05110, Ciudad de México, Mexico
| | - E Díaz-Aparicio
- Centro Nacional de Investigación Disciplinaria en Salud Animal e Inocuidad (CENID-SAI), Instituto Nacional de Investigaciones ForestalesAgrícolas y Pecuarias, Cuajimalpa, 05110, Ciudad de México, Mexico
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6
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White RT, Legione AR, Taylor-Brown A, Fernandez CM, Higgins DP, Timms P, Jelocnik M. Completing the Genome Sequence of Chlamydia pecorum Strains MC/MarsBar and DBDeUG: New Insights into This Enigmatic Koala ( Phascolarctos cinereus) Pathogen. Pathogens 2021; 10:1543. [PMID: 34959498 PMCID: PMC8703710 DOI: 10.3390/pathogens10121543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/17/2021] [Accepted: 11/24/2021] [Indexed: 12/30/2022] Open
Abstract
Chlamydia pecorum, an obligate intracellular pathogen, causes significant morbidity and mortality in livestock and the koala (Phascolarctos cinereus). A variety of C. pecorum gene-centric molecular studies have revealed important observations about infection dynamics and genetic diversity in both koala and livestock hosts. In contrast to a variety of C. pecorum molecular studies, to date, only four complete and 16 draft genomes have been published. Of those, only five draft genomes are from koalas. Here, using whole-genome sequencing and a comparative genomics approach, we describe the first two complete C. pecorum genomes collected from diseased koalas. A de novo assembly of DBDeUG_2018 and MC/MarsBar_2018 resolved the chromosomes and chlamydial plasmids each as single, circular contigs. Robust phylogenomic analyses indicate biogeographical separation between strains from northern and southern koala populations, and between strains infecting koala and livestock hosts. Comparative genomics between koala strains identified new, unique, and shared loci that accumulate single-nucleotide polymorphisms and separate between northern and southern, and within northern koala strains. Furthermore, we predicted novel type III secretion system effectors. This investigation constitutes a comprehensive genome-wide comparison between C. pecorum from koalas and provides improvements to annotations of a C. pecorum reference genome. These findings lay the foundations for identifying and understanding host specificity and adaptation behind chlamydial infections affecting koalas.
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Affiliation(s)
- Rhys T. White
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
| | - Alistair R. Legione
- Asia Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - Alyce Taylor-Brown
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
- Parasites and Microbes Programme, Wellcome Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Cristina M. Fernandez
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia; (C.M.F.); (D.P.H.)
| | - Damien P. Higgins
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia; (C.M.F.); (D.P.H.)
| | - Peter Timms
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
| | - Martina Jelocnik
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, Sunshine Coast, QLD 4557, Australia; (R.T.W.); (A.T.-B.); (P.T.)
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7
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Robbins A, Hanger J, Jelocnik M, Quigley BL, Timms P. Koala immunogenetics and chlamydial strain type are more directly involved in chlamydial disease progression in koalas from two south east Queensland koala populations than koala retrovirus subtypes. Sci Rep 2020; 10:15013. [PMID: 32929174 PMCID: PMC7490398 DOI: 10.1038/s41598-020-72050-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/18/2020] [Indexed: 02/02/2023] Open
Abstract
Chlamydial disease control is increasingly utilised as a management tool to stabilise declining koala populations, and yet we have a limited understanding of the factors that contribute to disease progression. To examine the impact of host and pathogen genetics, we selected two geographically separated south east Queensland koala populations, differentially affected by chlamydial disease, and analysed koala major histocompatibility complex (MHC) genes, circulating strains of Chlamydia pecorum and koala retrovirus (KoRV) subtypes in longitudinally sampled, well-defined clinical groups. We found that koala immunogenetics and chlamydial genotypes differed between the populations. Disease progression was associated with specific MHC alleles, and we identified two putative susceptibility (DCb 03, DBb 04) and protective (DAb 10, UC 01:01) variants. Chlamydial genotypes belonging to both Multi-Locus Sequence Typing sequence type (ST) 69 and ompA genotype F were associated with disease progression, whereas ST 281 was associated with the absence of disease. We also detected different ompA genotypes, but not different STs, when long-term infections were monitored over time. By comparison, KoRV profiles were not significantly associated with disease progression. These findings suggest that chlamydial genotypes vary in pathogenicity and that koala immunogenetics and chlamydial strains are more directly involved in disease progression than KoRV subtypes.
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Affiliation(s)
- Amy Robbins
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia.,Endeavour Veterinary Ecology Pty Ltd, 1695 Pumicestone Road, Toorbul, QLD, 4510, Australia
| | - Jonathan Hanger
- Endeavour Veterinary Ecology Pty Ltd, 1695 Pumicestone Road, Toorbul, QLD, 4510, Australia
| | - Martina Jelocnik
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia
| | - Bonnie L Quigley
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia
| | - Peter Timms
- Genecology Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia.
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8
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Quigley BL, Timms P. Helping koalas battle disease - Recent advances in Chlamydia and koala retrovirus (KoRV) disease understanding and treatment in koalas. FEMS Microbiol Rev 2020; 44:583-605. [PMID: 32556174 PMCID: PMC8600735 DOI: 10.1093/femsre/fuaa024] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/14/2020] [Indexed: 12/31/2022] Open
Abstract
The iconic Australian marsupial, the koala (Phascolarctos cinereus), has suffered dramatic population declines as a result of habitat loss and fragmentation, disease, vehicle collision mortality, dog attacks, bushfires and climate change. In 2012, koalas were officially declared vulnerable by the Australian government and listed as a threatened species. In response, research into diseases affecting koalas has expanded rapidly. The two major pathogens affecting koalas are Chlamydia pecorum, leading to chlamydial disease and koala retrovirus (KoRV). In the last eight years, these pathogens and their diseases have received focused study regarding their sources, genetics, prevalence, disease presentation and transmission. This has led to vast improvements in pathogen detection and treatment, including the ongoing development of vaccines for each as a management and control strategy. This review will summarize and highlight the important advances made in understanding and combating C. pecorum and KoRV in koalas, since they were declared a threatened species. With complementary advances having also been made from the koala genome sequence and in our understanding of the koala immune system, we are primed to make a significant positive impact on koala health into the future.
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Affiliation(s)
- Bonnie L Quigley
- Genecology Research Centre, University of the Sunshine Coast,
90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia
| | - Peter Timms
- Genecology Research Centre, University of the Sunshine Coast,
90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia
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Stokes HS, Martens JM, Jelocnik M, Walder K, Segal Y, Berg ML, Bennett ATD. Chlamydial diversity and predictors of infection in a wild Australian parrot, the Crimson Rosella (Platycercus elegans). Transbound Emerg Dis 2020; 68:487-498. [PMID: 32603529 DOI: 10.1111/tbed.13703] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022]
Abstract
Members of the Chlamydia genus are known to cause disease in both humans and animals. A variety of other species in the order Chlamydiales are increasingly being discovered and emerging as potential pathogens, yet there are scarce data on the diversity, prevalence and impacts of these pathogens in wild birds. To address this gap, we investigated which Chlamydiales species are present in a wild population of a common Australian parrot, the Crimson Rosella (Platycercus elegans). We collected cloacal swabs and serum from 136 individuals in south-eastern Australia, over two years, and tested several predictors of prevalence: age, sex, season and breeding status. We used multiple PCR assays to determine bacterial prevalence in cloacal swabs and a solid-phase ELISA to determine seroprevalence. We found Chlamydiales PCR prevalence of 27.7% (95% CI 20.2, 36.2) and identified at least two families (Chlamydiaceae and Parachlamydiaceae). Regarding known chlamydial avian pathogens, we found C. psittaci at 6.2% (95% CI 2.7, 11.8) and C. gallinacea at 4.6% (95% CI 1.7, 9.8) prevalence. We also identified at least two potentially novel Chlamydiales species, of unknown pathogenicity. Sex and breeding status predicted Chlamydiales PCR prevalence, with females more likely to be infected than males, and non-breeding birds more likely to be infected than breeding birds. Seroprevalence was 16% (95% CI 8.8, 25.9). Season and breeding status were strong predictors of seroprevalence, with highest seroprevalence in autumn and in non-breeding birds. Our results reveal a diversity of Chlamydiales species in this abundant wild host, and indicate that host-specific and temporal factors are associated with infection risk. Our findings suggest that wild parrots are a reservoir of both known and novel Chlamydiales lineages, of zoonotic and pathogenic potential.
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Affiliation(s)
- Helena S Stokes
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, Australia
| | - Johanne M Martens
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, Australia
| | - Martina Jelocnik
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Ken Walder
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Waurn Ponds, VIC, Australia
| | - Yonatan Segal
- Department of Jobs, Precincts and Regions, Attwood, VIC, Australia
| | - Mathew L Berg
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, Australia
| | - Andrew T D Bennett
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, Australia
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Fabijan J, Sarker N, Speight N, Owen H, Meers J, Simmons G, Seddon J, Emes RD, Tarlinton R, Hemmatzadeh F, Woolford L, Trott DJ. Pathological Findings in Koala Retrovirus-positive Koalas (Phascolarctos cinereus) from Northern and Southern Australia. J Comp Pathol 2020; 176:50-66. [PMID: 32359636 DOI: 10.1016/j.jcpa.2020.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/29/2020] [Accepted: 02/06/2020] [Indexed: 01/05/2023]
Abstract
Koala retrovirus (KoRV) infection shows differences in prevalence and load between northern and southern Australian koala populations; however, the effect of this on diseases such as lymphoma and chlamydial disease is unclear. This study compared clinicopathological findings, haematology and splenic lymphoid area of KoRV-positive koalas from northern (Queensland [Qld], n = 67) and southern (South Australia [SA], n = 92) populations in order to provide further insight into KoRV pathogenesis. Blood was collected for routine haematology and for measurement of KoRV proviral load by quantitative polymerase chain reaction (qPCR). Plasma samples were assessed for KoRV viral load by reverse transcriptase qPCR and conjunctival and cloacal swabs were collected for measurement of the load of Chlamydia pecorum (qPCR). During necropsy examination, spleen was collected for lymphoid area analysis. Lymphoma was morphologically similar between the populations and occurred in koalas with the highest KoRV proviral and viral loads. Severe ocular chlamydial disease was observed in both populations, but urinary tract disease was more severe in Qld, despite similar C. pecorum loads. No associations between KoRV and chlamydial disease severity or load were observed, except in SA where viral load correlated positively with chlamydial disease severity. In both populations, proviral and viral loads correlated positively with lymphocyte and metarubricyte counts and correlated negatively with erythrocyte and neutrophil counts. Splenic lymphoid area was correlated positively with viral load. This study has shown further evidence for KoRV-induced oncogenesis and highlighted that lymphocytes and splenic lymphoid tissue may be key sites for KoRV replication. However, KoRV infection appears to be highly complex and continued investigation is required to fully understand its pathogenesis.
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Affiliation(s)
- J Fabijan
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia.
| | - N Sarker
- School of Veterinary Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - N Speight
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - H Owen
- School of Veterinary Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - J Meers
- School of Veterinary Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - G Simmons
- School of Veterinary Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - J Seddon
- School of Veterinary Sciences, The University of Queensland, Gatton, Queensland, Australia
| | - R D Emes
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, UK
| | - R Tarlinton
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, UK
| | - F Hemmatzadeh
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - L Woolford
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - D J Trott
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
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11
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Fabijan J, Speight N, Boardman W, Hemmatzadeh F, Trott DJ, Woolford L. Haematological reference intervals of wild southern Australian koalas (Phascolarctos cinereus). Aust Vet J 2020; 98:207-215. [PMID: 32037511 DOI: 10.1111/avj.12923] [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] [Received: 07/24/2019] [Revised: 11/21/2019] [Accepted: 01/06/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Current haematology reference intervals (RIs) for koalas were developed in northern Australian koalas, using low numbers and/or individuals of unknown Chlamydia pecorum and koala retrovirus (KoRV) status. This study developed haematological RIs for wild, clinically healthy southern Australian koalas of known C. pecorum and KoRV infection status and investigated the effects of population, age and sex. METHODS Haematological RIs were determined for 138 clinically healthy South Australian koalas (Mount Lofty Ranges [MLR], n = 68; Kangaroo Island, n = 70) examined in April 2016 and February 2017, respectively. C. pecorum and KoRV status were determined by PCR. RESULTS RIs for southern koala haematological parameters were established for all koalas based on the finding that there were limited differences in haematological values in koalas with subclinical C. pecorum or KoRV infections (P > 0.05), except KoRV-infected koalas had a lower haematocrit than noninfected koalas. MLR koalas had significantly lower erythrocyte mass and leucocyte counts than Kangaroo Island koalas. Young koalas had significantly lower haemoglobin, haematocrit and higher mean cellular haemoglobin concentration and lymphocyte counts than adult koalas. MLR male koalas had elevated erythrocyte, leucocyte and neutrophil counts compared with MLR females. CONCLUSION The haematological RIs developed in this study are based on a large number of clinically healthy koalas, where subclinical C. pecorum and KoRV infections had no effect on haematological values and will be a valuable tool during clinical examination and disease investigation by veterinarians and researchers Australia-wide.
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Affiliation(s)
- J Fabijan
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, South Australia, Australia
| | - N Speight
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, South Australia, Australia
| | - Wsj Boardman
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, South Australia, Australia
| | - F Hemmatzadeh
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, South Australia, Australia
| | - D J Trott
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, South Australia, Australia
| | - L Woolford
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, South Australia, Australia
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EPIDEMIOLOGY OF CHLAMYDIA-INDUCED REPRODUCTIVE DISEASE IN MALE KOALAS (PHASCOLARCTOS CINEREUS) FROM SOUTHEAST QUEENSLAND, AUSTRALIA AS ASSESSED FROM PENILE URETHRAL SWABS AND SEMEN. J Wildl Dis 2020. [DOI: 10.7589/2019-03-062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Watchorn DJ, Whisson DA. Quantifying the interactions between koalas in a high-density population during the breeding period. AUSTRALIAN MAMMALOGY 2020. [DOI: 10.1071/am18027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A species’ social structure influences its patterns of gene flow and disease transmission. Knowledge of social structure therefore is critical for understanding conservation challenges and informing management strategies. We examined the social structure of 33 free-ranging koalas (Phascolarctos cinereus) in a high-density population (6.7 koalas per hectare) during the early and peak phase of the breeding period (August–December) at Cape Otway, Victoria. We used GPS and proximity loggers to quantify koala space use and interactions, and direct observations to determine behaviours associated with interactions. Our proximity loggers recorded 661 interactions (64% male–female, 28% male–male and 8% female–female). A peak in male–male interactions at the onset of the breeding period suggested that males may physically compete for mates at this time. Male–female interactions increased from the onset of the breeding period, and were mostly of short duration (median duration 5.5 min). From field observations of interactions, and the absence of pouch young in December, many of these interactions may have been unsuccessful copulation attempts. Space use and social network analyses revealed that most males had strong links (total interaction duration >30 min) with only one or two females, despite their spatial overlap and interactions with multiple females. Body mass did not influence a male’s mating success in terms of number of female mates. Our results contrast with those of a lower-density population in central eastern Queensland, suggesting that some aspects of koala social structure may be plastic relative to population density.
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Jelocnik M. Chlamydiae from Down Under: The Curious Cases of Chlamydial Infections in Australia. Microorganisms 2019; 7:microorganisms7120602. [PMID: 31766703 PMCID: PMC6955670 DOI: 10.3390/microorganisms7120602] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/16/2019] [Accepted: 11/21/2019] [Indexed: 12/13/2022] Open
Abstract
In Australia, the most researched and perhaps the most successful chlamydial species are the human pathogen Chlamydia trachomatis, animal pathogens Chlamydia pecorum and Chlamydia psittaci. C. trachomatis remains the leading cause of sexually transmitted infections in Australians and trachoma in Australian Indigenous populations. C. pecorum is globally recognised as the infamous koala and widespread livestock pathogen, whilst the avian C. psittaci is emerging as a horse pathogen posing zoonotic risks to humans. Certainly not innocuous, the human infections with Chlamydia pneumoniae seem to be less prevalent that other human chlamydial pathogens (namely C. trachomatis). Interestingly, the complete host range for C. pecorum and C. psittaci remains unknown, and infections by other chlamydial organisms in Australian domesticated and wildlife animals are understudied. Considering that chlamydial organisms can be encountered by either host at the human/animal interface, I review the most recent findings of chlamydial organisms infecting Australians, domesticated animals and native wildlife. Furthermore, I also provide commentary from leading Australian Chlamydia experts on challenges and future directions in the Chlamydia research field.
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Affiliation(s)
- Martina Jelocnik
- Genecology Research Centre, University of the Sunshine Coast, Sippy Downs 4557, Australia
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Longitudinal study of wild koalas (Phascolarctos cinereus) reveals chlamydial disease progression in two thirds of infected animals. Sci Rep 2019; 9:13194. [PMID: 31519969 PMCID: PMC6744427 DOI: 10.1038/s41598-019-49382-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 08/23/2019] [Indexed: 01/12/2023] Open
Abstract
Chlamydial disease threatens many of Australia’s koala populations, and yet our understanding of chlamydial epidemiology and disease dynamics in koalas is limited by a lack of comprehensive, longitudinal population studies. To address this, we utilised longitudinal samples from a large-scale population study of wild koalas in south-east Queensland, to follow chlamydial infections over time and to investigate some of the drivers of disease progression. Our findings show, firstly, that almost two thirds of chlamydial infections progressed to disease, challenging the notion that chlamydial infections in koalas commonly remain chronic and asymptomatic. Secondly, disease progression at the urogenital tract site was associated with infection load, and urogenital tract shedding was significantly higher when koalas acquired a new infection. Thirdly, chronic chlamydial exposure was not necessary for pathogenic sequelae to develop, such as infertility and mortality. Fourthly, ompA-characterised strain sub-types may reflect tissue tropisms and pathogenicity, and the chlamydial status of some chronically infected koalas may be explained by reinfections with novel genotypes. Finally, successful antimicrobial treatment provided only short-term protection against reinfection and disease progression in susceptible koalas. These findings highlight the importance of identifying and preventing chlamydial infections in koalas, informing new population management strategies and research priorities.
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Altered immune parameters associated with Koala Retrovirus (KoRV) and Chlamydial infection in free ranging Victorian koalas (Phascolarctos cinereus). Sci Rep 2019; 9:11170. [PMID: 31371797 PMCID: PMC6673689 DOI: 10.1038/s41598-019-47666-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 07/18/2019] [Indexed: 01/29/2023] Open
Abstract
Koala Retrovirus (KoRV) has been widely speculated to cause immune suppression in koalas (Phascolarctos cinereus) and to underlie the koala's susceptibility to infectious disease, however evidence for immunomodulation is limited. The aim of this study is to determine whether immunophenotypic changes are associated with KoRV infection in free ranging Victorian koalas. qPCR was used to examine mRNA expression for Th1 (IFNγ), Th2-promoting (IL6, IL10) and Th17 (IL17A) cytokines, along with CD4 and CD8 in whole blood of koalas (n = 74) from Mt Eccles and Raymond Island in Victoria, Australia, with and without natural chlamydial infection. KoRV positive koalas had significantly lower levels of IL17A (p`0.023) and IFNγ (p = 0.044) gene expression along with a decreased CD4:CD8 gene expression ratio (p = 0.025) compared to negative koalas. No effect of chlamydial infection or combined effect of KoRV and chlamydial infection was detected in these populations. The decreased expression of IFNγ could make KoRV infected koalas more susceptible to persistent chlamydial infection, and a decrease in IL17A could make them more susceptible to gram negative bacterial, fungal and mycobacterial infection; but more tolerant of chlamydial infection.
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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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Fabijan J, Caraguel C, Jelocnik M, Polkinghorne A, Boardman WSJ, Nishimoto E, Johnsson G, Molsher R, Woolford L, Timms P, Simmons G, Hemmatzadeh F, Trott DJ, Speight N. Chlamydia pecorum prevalence in South Australian koala (Phascolarctos cinereus) populations: Identification and modelling of a population free from infection. Sci Rep 2019; 9:6261. [PMID: 31000763 PMCID: PMC6472425 DOI: 10.1038/s41598-019-42702-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 04/02/2019] [Indexed: 11/21/2022] Open
Abstract
Chlamydia pecorum is an established and prevalent infection that produces severe clinical disease in many koala populations, contributing to dramatic population declines. In wild South Australian koala populations, C. pecorum occurrence and distribution is unknown. Here, C. pecorum-specific real-time quantitative PCR (qPCR) was applied to ocular and urogenital swabs from targeted surveys of wild koalas from the mainland Mount Lofty Ranges (MLR) (n = 75) and Kangaroo Island (KI) (n = 170) populations. Historical data from 13,081 KI koalas (1997–2018) provided additional evidence for assessing the absence of C. pecorum infection. In the MLR population, 46.7% (CI: 35.1–58.6%) of koalas were C. pecorum positive by qPCR but only 4% had grade 3 clinical disease. MLR koala fertility was significantly reduced by C. pecorum infection; all reproductively active females (n = 16) were C. pecorum negative, whereas 85.2% of inactive females (n = 23) were positive (P < 0.001). KI koalas were C. pecorum negative and the population was demonstrated to be free of C. pecorum infection with 95% confidence. C. pecorum is a real threat for the sustainability of the koala and KI is possibly the last isolated, large C. pecorum-free population remaining in Australia. These koalas could provide a safeguard against this serious disease threat to an iconic Australian species.
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Affiliation(s)
- Jessica Fabijan
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia.
| | - Charles Caraguel
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia
| | - Martina Jelocnik
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, 4558, Queensland, Australia
| | - Adam Polkinghorne
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, 4558, Queensland, Australia
| | - Wayne S J Boardman
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia
| | - Elisa Nishimoto
- Kangaroo Island Veterinary Clinic, Kingscote, 5223, South Australia, Australia
| | - Greg Johnsson
- Kangaroo Island Veterinary Clinic, Kingscote, 5223, South Australia, Australia
| | - Robyn Molsher
- Department for Environment and Water, Adelaide, 5000, South Australia, Australia
| | - Lucy Woolford
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia
| | - Peter Timms
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, 4558, Queensland, Australia
| | - Greg Simmons
- School of Veterinary Sciences, The University of Queensland, Gatton, 4343, Queensland, Australia
| | - Farhid Hemmatzadeh
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia
| | - Darren J Trott
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia
| | - Natasha Speight
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, South Australia, Australia
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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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Fernandez CM, Schmertmann LJ, Higgins DP, Casteriano A, Irinyi L, Mella VSA, Crowther MS, Meyer W, Krockenberger MB. Genetic differences in Chlamydia pecorum between neighbouring sub-populations of koalas (Phascolarctos cinereus). Vet Microbiol 2019; 231:264-270. [PMID: 30853132 DOI: 10.1016/j.vetmic.2019.02.020] [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: 10/18/2018] [Revised: 02/04/2019] [Accepted: 02/11/2019] [Indexed: 01/09/2023]
Abstract
Chlamydiosis, caused by Chlamydia pecorum, is regarded as an important threat to koala populations. Across the koala's geographical range, disease severity associated with C. pecorum infection varies, with pathogen diversity and strain pathogenicity being likely important factors. To examine C. pecorum diversity on a sub-population level a Multi-Locus Sequence Typing (MLST) scheme, containing the housekeeping genes; gatA, oppA_3, hflX, gidA, enoA, hemN and fumC, was used to type strains from two sub-populations of koalas from the Liverpool Plains, NSW, Australia, with different disease expressions. Typing of samples from 2015 to 2017, revealed a significant association between sequence type ST 69 and clinical disease and a significant difference in sequence type frequencies between sub-populations. Sequence type ST 69 has previously been identified in both subclinical and clinically diseased koalas indicating that these markers alone are not illustrative of pathogenicity. However, recent emergence of this sequence type in a naïve population may explain the differing disease expressions. Sequence types ST 73 and ST 69 have been described in koalas across a broad geographic range, indicating multiple introduction events and/or a limited veracity of the MLST loci to explore fine scale epidemiological investigations, particularly those examining the interface between pathogenic strain and disease outcome.
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Affiliation(s)
- Cristina M Fernandez
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Hospital, Faculty of Medicine and Health, Westmead Clinical School, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia; The Westmead Institute for Medical Research, 176 Hawkesbury Road, 2145, Westmead, NSW, Australia; Sydney School of Veterinary Science, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Laura J Schmertmann
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Hospital, Faculty of Medicine and Health, Westmead Clinical School, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia; The Westmead Institute for Medical Research, 176 Hawkesbury Road, 2145, Westmead, NSW, Australia; Sydney School of Veterinary Science, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Damien P Higgins
- Sydney School of Veterinary Science, The University of Sydney, Sydney, 2006, NSW, Australia; Marie Bashir Institute for Emerging Infectious diseases and Biosecurity, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia
| | - Andrea Casteriano
- Sydney School of Veterinary Science, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Laszlo Irinyi
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Hospital, Faculty of Medicine and Health, Westmead Clinical School, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia; The Westmead Institute for Medical Research, 176 Hawkesbury Road, 2145, Westmead, NSW, Australia
| | - Valentina S A Mella
- School of Life and Environmental Sciences, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Mathew S Crowther
- School of Life and Environmental Sciences, The University of Sydney, Sydney, 2006, NSW, Australia
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Westmead Hospital, Faculty of Medicine and Health, Westmead Clinical School, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia; The Westmead Institute for Medical Research, 176 Hawkesbury Road, 2145, Westmead, NSW, Australia; Marie Bashir Institute for Emerging Infectious diseases and Biosecurity, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia
| | - Mark B Krockenberger
- Sydney School of Veterinary Science, The University of Sydney, Sydney, 2006, NSW, Australia; Marie Bashir Institute for Emerging Infectious diseases and Biosecurity, The University of Sydney, 176 Hawkesbury road, 2145, Westmead, NSW, Australia.
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Nyari S, Booth R, Quigley BL, Waugh CA, Timms P. Therapeutic effect of a Chlamydia pecorum recombinant major outer membrane protein vaccine on ocular disease in koalas (Phascolarctos cinereus). PLoS One 2019; 14:e0210245. [PMID: 30615687 PMCID: PMC6322743 DOI: 10.1371/journal.pone.0210245] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 12/19/2018] [Indexed: 12/29/2022] Open
Abstract
Chlamydia pecorum is responsible for causing ocular infection and disease which can lead to blindness in koalas (Phascolarctos cinereus). Antibiotics are the current treatment for chlamydial infection and disease in koalas, however, they can be detrimental for the koala’s gastrointestinal tract microbiota and in severe cases, can lead to dysbiosis and death. In this study, we evaluated the therapeutic effects provided by a recombinant chlamydial major outer membrane protein (MOMP) vaccine on ocular disease in koalas. Koalas with ocular disease (unilateral or bilateral) were vaccinated and assessed for six weeks, evaluating any changes to the conjunctival tissue and discharge. Samples were collected pre- and post-vaccination to evaluate both humoral and cell-mediated immune responses. We further assessed the infecting C. pecorum genotype, host MHC class II alleles and presence of koala retrovirus type (KoRV-B). Our results clearly showed an improvement in the clinical ocular disease state of all seven koalas, post-vaccination. We observed increases in ocular mucosal IgA antibodies to whole C. pecorum elementary bodies, post-vaccination. We found that systemic cell-mediated immune responses to interferon-γ, interleukin-6 and interleukin-17A were not significantly predictive of ocular disease in koalas. Interestingly, one koala did not have as positive a clinical response (in one eye primarily) and this koala was infected with a C. pecorum genotype (E’) that was not used as part of the vaccine formula (MOMP genotypes A, F and G). The predominant MHC class II alleles identified were DAb*19, DAb*21 and DBb*05, with no two koalas identified with the same genetic sequence. Additionally, KoRV-B, which is associated with chlamydial disease outcome, was identified in two (29%) ocular diseased koalas, which still produced vaccine-induced immune responses and clinical ocular improvements post-vaccination. Our findings show promise for the use of a recombinant chlamydial MOMP vaccine for the therapeutic treatment of ocular disease in koalas.
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Affiliation(s)
- Sharon Nyari
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Rosemary Booth
- Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia
| | - Bonnie L. Quigley
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Courtney A. Waugh
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Peter Timms
- University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- * E-mail:
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Phillips S, Robbins A, Loader J, Hanger J, Booth R, Jelocnik M, Polkinghorne A, Timms P. Chlamydia pecorum gastrointestinal tract infection associations with urogenital tract infections in the koala (Phascolarctos cinereus). PLoS One 2018; 13:e0206471. [PMID: 30383822 PMCID: PMC6211709 DOI: 10.1371/journal.pone.0206471] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 10/12/2018] [Indexed: 11/21/2022] Open
Abstract
Background Chlamydia infects multiple sites within hosts, including the gastrointestinal tract (GIT). In certain hosts, gastrointestinal infection is linked to treatment avoidance and self-infection at disease susceptible sites. GIT C. pecorum has been detected in livestock and koalas, however GIT prevalence rates within the koala are yet to be established. Methods Paired conjunctival, urogenital and rectal samples from 33 koalas were screened for C. pecorum and C. pecorum plasmid using 16S rRNA and CDS5-specific quantitative PCR assays, respectively. Amplicon sequencing of 359 bp ompA fragment was used to identify site-specific genotypes. Results The overall C. pecorum prevalence collectively (healthy and clinically diseased koalas) was 51.5%, 57.6% and 42.4% in urogenital, conjunctival and gastrointestinal sites, respectively. Concurrent urogenital and rectal Chlamydia was identified in 14 koalas, with no cases of GIT only Chlamydia shedding. The ompA genotype G dominated the GIT positive samples, and genotypes A and E’ were dominant in urogenital tract (UGT) positive samples. Increases in C. pecorum plasmid per C. pecorum load (detected by PCR) showed clustering in the clinically diseased koala group (as assessed by scatter plot analysis). There was also a low correlation between plasmid positivity and C. pecorum infected animals at any site, with a prevalence of 47% UGT, 36% rectum and 40% faecal pellet. Conclusions GIT C. pecorum PCR positivity suggests that koala GIT C. pecorum infections are common and occur regularly in animals with concurrent genital tract infections. GIT dominant genotypes were identified and do not appear to be related to plasmid positivity. Preliminary results indicated a possible association between C. pecorum plasmid load and clinical UGT disease.
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Affiliation(s)
- Samuel Phillips
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
- * E-mail:
| | - Amy Robbins
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, Australia
| | - Joanne Loader
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, Australia
| | | | | | - Martina Jelocnik
- Animal Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
| | - Adam Polkinghorne
- Animal Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
| | - Peter Timms
- Genecology Research Centre, Faculty of Science, Health, Education and Engineering, The University of the Sunshine Coast, Queensland, Australia
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Madden D, Whaite A, Jones E, Belov K, Timms P, Polkinghorne A. Koala immunology and infectious diseases: How much can the koala bear? DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 82:177-185. [PMID: 29382557 DOI: 10.1016/j.dci.2018.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/24/2018] [Accepted: 01/24/2018] [Indexed: 06/07/2023]
Abstract
Infectious diseases are contributing to the decline of the iconic Australian marsupial, the koala (Phascolarctos cinereus). Infections with the obligate intracellular bacteria, Chlamydia pecorum, cause debilitating ocular and urogenital-tract disease while the koala-retrovirus (KoRV) has been implicated in host immunosuppression and exacerbation of chlamydial pathogenesis. Although histological studies have provided insight into the basic architecture of koala immune tissues, our understanding of the koala immune response to infectious disease has been limited, until recently, by a lack of species-specific immune reagents. Recent advances in the characterisation of key immune genes have focused on advancing our understanding of the immune response to Chlamydia infection, revealing commonalities in disease pathologies and immunity between koalas and other hosts and paving the way for the development of a koala Chlamydia vaccine. This review summarises these recent findings and highlights key aspects of the koala immune system requiring further attention with particular regard to their most prominent infectious diseases.
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Affiliation(s)
- Danielle Madden
- Animal Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs 4556, Australia.
| | - Alessandra Whaite
- Animal Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs 4556, Australia.
| | - Elizabeth Jones
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, NSW 2006, Australia.
| | - Katherine Belov
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, NSW 2006, Australia.
| | - Peter Timms
- Animal Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs 4556, Australia.
| | - Adam Polkinghorne
- Animal Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs 4556, Australia.
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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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Nyari S, Waugh CA, Dong J, Quigley BL, Hanger J, Loader J, Polkinghorne A, Timms P. Epidemiology of chlamydial infection and disease in a free-ranging koala (Phascolarctos cinereus) population. PLoS One 2017; 12:e0190114. [PMID: 29281731 PMCID: PMC5744985 DOI: 10.1371/journal.pone.0190114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 12/10/2017] [Indexed: 12/01/2022] Open
Abstract
Chlamydial disease continues to be one of the main factors threatening the long-term survival of the koala (Phascolarctos cinereus). Despite this, large epidemiological studies of chlamydial infection and disease in wild koala populations are lacking. A better understanding of the prevalence, transmission and pathogenesis is needed to improve control measures, such as the development of vaccines. We investigated the prevalence of Chlamydia pecorum infection and disease in 160 koalas in a peri-urban wild population in Queensland, Australia and found that 31% of koalas were Chlamydia PCR positive and 28% had clinically detectable chlamydial disease. Most infections were at the urogenital site (27%; both males and females) with only 14% at the ocular site. Interestingly, we found that 27% (4/15) of koalas considered to be sexually immature (9–13 months) were already infected with C. pecorum, suggesting that a significant percentage of animals are infected directly from their mother. Ocular infection levels were less prevalent with increasing age (8% in koalas older than 4 years), whereas the prevalence of urogenital tract infections remained high into older age (26% in koalas older than 4 years), suggesting that, after mother-to-young transmission, C. pecorum is predominantly a sexually transmitted infection. While 28% of koalas in this population had clinically detectable chlamydial disease (primarily urogenital tract disease), many PCR positive koalas had no detectable disease and importantly, not all diseased animals were PCR positive. We also observed higher chlamydial loads in koalas who were C. pecorum infected without clinical disease than in koalas who were C. pecorum infected with clinical disease. These results shed light on the potential mechanisms of transmission of C. pecorum in koalas and also guide future control measures, such as vaccination.
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Affiliation(s)
- Sharon Nyari
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Courtney A. Waugh
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Jianbao Dong
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Bonnie L. Quigley
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Jonathan Hanger
- Endeavour Veterinary Ecology, Toorbul, Queensland, Australia
| | - Joanne Loader
- Endeavour Veterinary Ecology, Toorbul, Queensland, Australia
| | - Adam Polkinghorne
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Peter Timms
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
- * E-mail:
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Guo W, Jelocnik M, Li J, Sachse K, Polkinghorne A, Pannekoek Y, Kaltenboeck B, Gong J, You J, Wang C. From genomes to genotypes: molecular epidemiological analysis of Chlamydia gallinacea reveals a high level of genetic diversity for this newly emerging chlamydial pathogen. BMC Genomics 2017; 18:949. [PMID: 29212448 PMCID: PMC5717833 DOI: 10.1186/s12864-017-4343-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 11/21/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chlamydia (C.) gallinacea is a recently identified bacterium that mainly infects domestic chickens. Demonstration of C. gallinacea in human atypical pneumonia suggests its zoonotic potential. Its prevalence in chickens exceeds that of C. psittaci, but genetic and genomic research on C. gallinacea is still at the beginning. In this study, we conducted whole-genome sequencing of C. gallinacea strain JX-1 isolated from an asymptomatic chicken, and comparative genomic analysis between C. gallinacea strains and related chlamydial species. RESULTS The genome of C. gallinacea JX-1 was sequenced by single-molecule, real-time technology and is comprised of a 1,059,522-bp circular chromosome with an overall G + C content of 37.93% and sequence similarity of 99.4% to type strain 08-1274/3. In addition, a plasmid designated pJX-1, almost identical to p1274 of the type strain, except for two point mutations, was only found in field strains from chicken, but not in other hosts. In contrast to chlamydial species with notably variable polymorphic membrane protein (pmp) genes and plasticity zone (PZ), these regions were conserved in both C. gallinacea strains. There were 15 predicted pmp genes, but only B, A, E1, H, G1 and G2 were apparently intact in both strains. In comparison to chlamydial species where the PZ may be up to 50 kbp, C. gallinacea strains displayed gene content reduction in the PZ (14 kbp), with strain JX-1 having a premature STOP codon in the cytotoxin (tox) gene, while tox gene is intact in the type strain. In multilocus sequence typing (MLST), 15 C. gallinacea STs were identified among 25 strains based on cognate MLST allelic profiles of the concatenated sequences. The type strain and all Chinese strains belong to two distinct phylogenetic clades. Clade of the Chinese strains separated into 14 genetically distinct lineages, thus revealing considerable genetic diversity of C. gallinacea strains in China. CONCLUSIONS In this first detailed comparative genomic analysis of C. gallinacea, we have provided evidence for substantial genetic diversity among C. gallinacea strains. How these genetic polymorphisms affect C. gallinacea biology and pathogenicity should be addressed in future studies that focus on phylogenetics and host adaption of this enigmatic bacterial agent.
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Affiliation(s)
- Weina Guo
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
- College of Animal Science, Anhui Science and Technology University, Maanshan, Anhui China
| | - Martina Jelocnik
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD Australia
| | - Jing Li
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
| | - Konrad Sachse
- Institute of Bioinformatics, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Adam Polkinghorne
- Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD Australia
| | - Yvonne Pannekoek
- Department of Microbiology, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Jiansen Gong
- Poultry Institute, Chinese Academy of Agricultural Sciences, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu China
| | - Jinfeng You
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
| | - Chengming Wang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu 225009 People’s Republic of China
- College of Veterinary Medicine, Auburn University, Auburn, AL USA
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Immunization of a wild koala population with a recombinant Chlamydia pecorum Major Outer Membrane Protein (MOMP) or Polymorphic Membrane Protein (PMP) based vaccine: New insights into immune response, protection and clearance. PLoS One 2017; 12:e0178786. [PMID: 28575080 PMCID: PMC5456371 DOI: 10.1371/journal.pone.0178786] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/18/2017] [Indexed: 12/11/2022] Open
Abstract
We assessed the effects of two different single-dose anti-Chlamydia pecorum (C. pecorum) vaccines (containing either Major Outer Membrane Protein (3MOMP) or Polymorphic Membrane Protein (Pmp) as antigens) on the immune response of a group of wild koalas. Both vaccines elicited a systemic humoral response as seen by the production of anti-chlamydial IgG antibodies in more than 90% of vaccinated koalas. A mucosal immune response was also observed, with an increase in Chlamydia-specific mucosal IgG and/or IgA antibodies in some koalas post-vaccination. Both vaccines elicited a cell-mediated immune response as measured by the production of the cytokines IFN-γ and IL-17 post-vaccination. To determine the level of protection provided by the vaccines under natural conditions we assessed C. pecorum infection loads and chlamydial disease status of all vaccinated koalas pre- and post-vaccination, compared to a non-vaccinated cohort from the same habitat. The MOMP vaccinated koalas that were infected on the day of vaccination showed significant clearance of their infection at 6 months post-vaccination. In contrast, the number of new infections in the PMP vaccine was similar to the control group, with some koalas progressing to disease. Genotyping of the ompA gene from the C. pecorum strains infecting the vaccinated animals, identified genetic variants of ompA-F genotype and a new genotype ompA-O. We found that those animals that were the least well protected became infected with strains of C. pecorum not covered by the vaccine. In conclusion, a single dose vaccine formulated with either recombinant PmpG or MOMP can elicit both cell-mediated and humoral (systemic and mucosal) immune responses, with the MOMP vaccine showing clearance of infection in all infected koalas. Although the capability of our vaccines to stimulate an adaptive response and be protective needs to be fully evaluated, this work illustrates the necessity to combine epitopes most relevant to a large panel of variable strains with an efficient adjuvant.
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28
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Legione AR, Patterson JLS, Whiteley P, Firestone SM, Curnick M, Bodley K, Lynch M, Gilkerson JR, Sansom FM, Devlin JM. Koala retrovirus genotyping analyses reveal a low prevalence of KoRV-A in Victorian koalas and an association with clinical disease. J Med Microbiol 2017; 66:236-244. [PMID: 28266284 DOI: 10.1099/jmm.0.000416] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Koala retrovirus (KoRV) is undergoing endogenization into the genome of koalas in Australia, providing an opportunity to assess the effect of retrovirus infection on the health of a population. The prevalence of KoRV in north-eastern Australia (Queensland and New South Wales) is 100 %, whereas previous preliminary investigations in south-eastern Australia (Victoria) suggested KoRV is present at a lower prevalence, although the values have varied widely. Here, we describe a large study of free-ranging koalas in Victoria to estimate the prevalence of KoRV and assess the clinical significance of KoRV infection in wild koalas. METHODOLOGY Blood or spleen samples from 648 koalas where tested for KoRV provirus, and subsequently genotyped, using PCRs to detect the pol and env genes respectively. Clinical data was also recorded where possible and analysed in comparison to infection status. RESULTS The prevalence of KoRV was 24.7 % (160/648). KoRV-A was detected in 141/160 cases, but KoRV-B, a genotype associated with neoplasia in captive koalas, was not detected. The genotype in 19 cases could not be determined. Genomic differences between KoRV in Victoria and type strains may have impacted genotyping. Factors associated with KoRV infection, based on multivariable analysis, were low body condition score, region sampled, and 'wet bottom' (a staining of the fur around the rump associated with chronic urinary incontinence). Koalas with wet bottom were nearly twice as likely to have KoRV provirus detected than those without wet bottom (odds ratio=1.90, 95 % confidence interval 1.21, 2.98). CONCLUSION Our findings have important implications for the conservation of this iconic species, particularly regarding translocation potential of Victorian koalas.
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Affiliation(s)
- Alistair R Legione
- Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Jade L S Patterson
- Veterinary Department, Melbourne Zoo, Parkville, Victoria, Australia.,Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Pam Whiteley
- Wildlife Health Surveillance Victoria, The University of Melbourne, Werribee, Victoria, Australia.,Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Simon M Firestone
- Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Megan Curnick
- Australian Wildlife Health Centre, Healesville Sanctuary, Healesville, Victoria, Australia.,Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Kate Bodley
- Veterinary Department, Melbourne Zoo, Parkville, Victoria, Australia
| | - Michael Lynch
- Veterinary Department, Melbourne Zoo, Parkville, Victoria, Australia.,Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - James R Gilkerson
- Centre for Equine Infectious Diseases, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Fiona M Sansom
- Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Joanne M Devlin
- Asia Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
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A non-invasive tool for assessing pathogen prevalence in koala (Phascolarctos cinereus) populations: detection of Chlamydia pecorum and koala retrovirus (KoRV) DNA in genetic material sourced from scats. CONSERV GENET RESOUR 2016. [DOI: 10.1007/s12686-016-0574-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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