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Pagliarani S, Johnston SD, Beagley KW, Palmieri C. Immunohistochemical characterization of the immune cell response during chlamydial infection in the male and female koala ( Phascolarctos cinereus) reproductive tract. Vet Pathol 2024; 61:621-632. [PMID: 38240274 PMCID: PMC11264539 DOI: 10.1177/03009858231225499] [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] [Indexed: 07/02/2024]
Abstract
Chlamydiosis is one of the main causes of the progressive decline of koala populations in eastern Australia. While histologic, immunologic, and molecular studies have provided insights into the basic function of the koala immune system, the in situ immune cell signatures during chlamydial infection of the reproductive tract in koalas have not been investigated. Thirty-two female koalas and 47 males presented to wildlife hospitals with clinical signs suggestive of Chlamydia infection were euthanized with the entire reproductive tract collected for histology; immunohistochemistry (IHC) for T-cell (CD3ε, CD4, and CD8α), B-cell (CD79b), and human leukocyte antigen (HLA)-DR markers; and quantitative real-time polymerase chain reaction (rtPCR) for Chlamydia pecorum. T-cells, B-cells, and HLA-DR-positive cells were observed in both the lower and upper reproductive tracts of male and female koalas with a statistically significant associations between the degree of the inflammatory reaction; the number of CD3, CD4, CD79b, and HLA-DR positive cells; and the PCR load. CD4-positive cells were negatively associated with the severity of the gross lesions. The distribution of immune cells was also variable according to the location within the genital tract in both male and female koalas. These preliminary results represent a step forward towards further exploring mechanisms behind chlamydial infection immunopathogenesis, thus providing valuable information about the immune response and infectious diseases in free-ranging koalas.
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Affiliation(s)
- Sara Pagliarani
- The University of Queensland, Gatton, QLD, Australia
- University of Guelph, Guelph, ON, Canada
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2
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Fernandez CM, Krockenberger MB, Ho SYW, Crowther MS, Mella VSA, Jelocnik M, Wilmott L, Higgins DP. Novel typing scheme reveals emergence and genetic diversity of Chlamydia pecorum at the local management scale across two koala populations. Vet Microbiol 2024; 293:110085. [PMID: 38581768 DOI: 10.1016/j.vetmic.2024.110085] [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: 10/18/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/08/2024]
Abstract
To overcome shortcomings in discriminating Chlamydia pecorum strains infecting the koala (Phascolarctos cinereus) at the local level, we developed a novel genotyping scheme for this pathogen to inform koala management at a fine-scale subpopulation level. We applied this scheme to two geographically distinct koala populations in New South Wales, Australia: the Liverpool Plains and the Southern Highlands to South-west Sydney (SHSWS). Our method provides greater resolution than traditional multi-locus sequence typing, and can be used to monitor strain emergence, movement, and divergence across a range of fragmented habitats. Within the Liverpool Plains population, suspected recent introduction of a novel strain was confirmed by an absence of genetic diversity at the earliest sampling events and limited diversity at recent sampling events. Across the partially fragmented agricultural landscape of the Liverpool Plains, diversity within a widespread sequence type suggests that this degree of fragmentation may hinder but not prevent spread. In the SHSWS population, our results suggest movement of a strain from the south, where diverse strains exist, into a previously Chlamydia-free area in the north, indicating the risk of expansion towards an adjacent Chlamydia-negative koala population in South-west Sydney. In the south of the SHSWS where koala subpopulations appear segregated, we found evidence of divergent strain evolution. Our tool can be used to infer the risks of strain introduction across fragmented habitats in population management, particularly through practices such as wildlife corridor constructions and translocations.
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Affiliation(s)
- Cristina M Fernandez
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia
| | - Mark B Krockenberger
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia; Sydney Infectious Diseases, The University of Sydney, 176 Hawkesbury Road, Westmead, NSW 2145, Australia
| | - Simon Y W Ho
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Mathew S Crowther
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Valentina S A Mella
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia; School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Martina Jelocnik
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia; Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
| | - Lachlan Wilmott
- NSW Department of Planning and Environment, Wollongong, NSW 2005, Australia
| | - Damien P Higgins
- Faculty of Science, Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia.
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3
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Simpson SJ, Higgins DP, Timms P, Mella VSA, Crowther MS, Fernandez CM, McArthur C, Phillips S, Krockenberger MB. Efficacy of a synthetic peptide Chlamydia pecorum major outer membrane protein vaccine in a wild koala (Phascolarctos cinereus) population. Sci Rep 2023; 13:15087. [PMID: 37699951 PMCID: PMC10497537 DOI: 10.1038/s41598-023-42296-7] [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: 06/23/2023] [Accepted: 09/07/2023] [Indexed: 09/14/2023] Open
Abstract
Chlamydiosis is a significant disease affecting Eastern Australian koala (Phascolarctos cinereus) populations, impacting individual animal welfare and fecundity and therefore influencing population dynamics. The aim of this study was to investigate the effect of a synthetic peptide vaccine based on 4 components of the Chlamydia pecorum major outer membrane protein (MOMP), over an 18-month period in a koala population severely impacted by chlamydiosis. Wild koalas were recruited into a vaccination or a placebo treatment group on a random allocation, then followed through a period of 18 months, with recapture at 6 monthly intervals. Vaccination did not alter clinical disease expression or chlamydial shedding from the ocular or urogenital sites. Vaccination did not stimulate a significant plasma anti-MOMP IgG response, when compared to the placebo group. There was no significant effect of vaccination on IFN-γ and IL-17A mRNA expression of peripheral blood lymphocytes when stimulated with rMOMP. We have demonstrated that a synthetic peptide vaccination against chlamydiosis is not an effective management tool in a koala population with a high prevalence of C. pecorum infection and related disease. The lack of antigenic response found in this study suggests that further research utilising a larger, full-length antigen is an avenue worth investigation if we are to consider vaccination as a part of a management strategy in diseased koala populations.
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Affiliation(s)
- Sarah J Simpson
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Damien P Higgins
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Peter Timms
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia
| | - Valentina S A Mella
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Mathew S Crowther
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Cristina M Fernandez
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Clare McArthur
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Samuel Phillips
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia
| | - Mark B Krockenberger
- Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia
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4
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Hulse L, Palmieri C, Beagley KW, Larkin R, Keeley T, Gosalvez J, Johnston SD. Investigation of pathology associated with Chlamydia pecorum infection in the male reproductive tract, and the effect on spermatogenesis and semen quality in the koala (Phascolarctos cinereus). Theriogenology 2022; 180:30-39. [DOI: 10.1016/j.theriogenology.2021.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/08/2021] [Accepted: 12/14/2021] [Indexed: 11/26/2022]
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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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Peel E, Cheng Y, Djordjevic JT, O’Meally D, Thomas M, Kuhn M, Sorrell TC, Huston WM, Belov K. Koala cathelicidin PhciCath5 has antimicrobial activity, including against Chlamydia pecorum. PLoS One 2021; 16:e0249658. [PMID: 33852625 PMCID: PMC8046226 DOI: 10.1371/journal.pone.0249658] [Citation(s) in RCA: 3] [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: 10/23/2020] [Accepted: 03/22/2021] [Indexed: 11/18/2022] Open
Abstract
Devastating fires in Australia over 2019-20 decimated native fauna and flora, including koalas. The resulting population bottleneck, combined with significant loss of habitat, increases the vulnerability of remaining koala populations to threats which include disease. Chlamydia is one disease which causes significant morbidity and mortality in koalas. The predominant pathogenic species, Chlamydia pecorum, causes severe ocular, urogenital and reproductive tract disease. In marsupials, including the koala, gene expansions of an antimicrobial peptide family known as cathelicidins have enabled protection of immunologically naïve pouch young during early development. We propose that koala cathelicidins are active against Chlamydia and other bacteria and fungi. Here we describe ten koala cathelicidins, five of which contained full length coding sequences that were widely expressed in tissues throughout the body. Focusing on these five, we investigate their antimicrobial activity against two koala C. pecorum isolates from distinct serovars; MarsBar and IPTaLE, as well as other bacteria and fungi. One cathelicidin, PhciCath5, inactivated C. pecorum IPTaLE and MarsBar elementary bodies and significantly reduced the number of inclusions compared to the control (p<0.0001). Despite evidence of cathelicidin expression within tissues known to be infected by Chlamydia, natural PhciCath5 concentrations may be inadequate in vivo to prevent or control C. pecorum infections in koalas. PhciCath5 also displayed antimicrobial activity against fungi and Gram negative and positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Electrostatic interactions likely drive PhciCath5 adherence to the pathogen cell membrane, followed by membrane permeabilisation leading to cell death. Activity against E. coli was reduced in the presence of 10% serum and 20% whole blood. Future modification of the PhciCath5 peptide to enhance activity, including in the presence of serum/blood, may provide a novel solution to Chlamydia infection in koalas and other species.
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Affiliation(s)
- Emma Peel
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Yuanyuan Cheng
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Julianne T. Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead, New South Wales, Australia
| | - Denis O’Meally
- Center for Gene Therapy, Beckman Research Institute of the City of Hope, Duarte, California, United States of America
| | - Mark Thomas
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Michael Kuhn
- Zoetis, Veterinary Medicine Research and Development, Kalamazoo, Michigan, United States of America
| | - Tania C. Sorrell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead, New South Wales, Australia
| | - Wilhelmina M. Huston
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
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7
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Hulse L, Beagley K, Larkin R, Nicolson V, Gosálvez J, Johnston S. The effect of Chlamydia infection on koala (Phascolarctos cinereus) semen quality. Theriogenology 2021; 167:99-110. [PMID: 33813053 DOI: 10.1016/j.theriogenology.2021.03.016] [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: 12/13/2020] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 01/06/2023]
Abstract
Although it is well established that chlamydial disease renders female koalas infertile, there has been limited research on its effects on male koala fertility, specifically sperm quality. This study determined whether chlamydial infection adversely affects semen quality of naturally infected koalas and spermatozoa recovered from Chlamydia negative koalas co-incubated in vitro with C. pecorum elementary bodies (EBs). Semen from 102 south-east Queensland sexually mature wild koalas exhibiting varying degrees of chlamydiosis and clinical signs of disease were assessed for semen quality and compared to 11 clinically healthy, Chlamydia-free captive male koalas. For in vitro studies, semen samples were collected from 6 Chlamydia-free captive koalas, and co-incubated over 24 h with high and low concentrations of C. pecorum EBs and sperm quality assessed. Wild koalas displaying severe signs of clinical disease with C. pecorum present in the semen had significantly greater sperm DNA damage (P = 0.0267). The total % of morphologically abnormal spermatozoa was highest in wild koalas that had severe signs of clinical disease but whose semen was negative for C. pecorum (P = 0.0328). This apparent contradiction is possibly associated with wild males having resolved the infection but still possessing underlining reproductive pathology. A higher incidence of loose head spermatozoa occurred in semen of wild koalas not infected with C. pecorum compared to those that were C. pecorum infected (P = 0.026). In vitro incubation of semen with C. pecorum significantly decreased sperm motility and viability over 24 h.
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Affiliation(s)
- Lyndal Hulse
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, 4343, Australia.
| | - Kenneth Beagley
- Centre for Immunology and Infection Control and School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, 300 Herston Road, Herston, Queensland, 4006, Australia
| | - Rebecca Larkin
- Moggill Koala Rehabilitation Centre (previously Known As Moggill Koala Hospital), 55 Priors Pocket Road, Moggill, Queensland, 4070, Australia
| | | | - Jaime Gosálvez
- Genetics Unit, Facultad de Biología, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049, Madrid, Spain
| | - Stephen Johnston
- School of Agriculture and Food Sciences, University of Queensland, Gatton, Queensland, 4343, Australia
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8
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Identification and Prevalence of Phascolarctid Gammaherpesvirus Types 1 and 2 in South Australian Koala Populations. Viruses 2020; 12:v12090948. [PMID: 32867109 PMCID: PMC7552032 DOI: 10.3390/v12090948] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 01/01/2023] Open
Abstract
To determine Phascolarctid gammaherpesviruses (PhaHV) infection in South Australian koala populations, 80 oropharyngeal swabs from wild-caught and 87 oropharyngeal spleen samples and swabs from euthanased koalas were tested using two specific PCR assays developed to detect PhaHV-1 and PhaHV-2. In wild-caught koalas, active shedding of PhaHV was determined by positive oropharyngeal samples in 72.5% (58/80) of animals, of which 44.8% (26/58) had PhaHV-1, 20.7% (12/58) PhaHV-2 and 34.5% (20/58) both viral subtypes. In the euthanased koalas, systemic infection was determined by positive PCR in spleen samples and found in 72.4% (63/87) of koalas. Active shedding was determined by positive oropharyngeal results and found in 54.0% (47/87) of koalas. Koalas infected and actively shedding PhaHV-1 alone, PhaHV-2 alone or shedding both viral subtypes were 48.9% (23/47), 14.9% (7/47) and 36.2% (17/47), respectively. Only 45.9% (40/87) were not actively shedding, of which 40.0% (16/40) of these had systemic infections. Both wild-caught and euthanased koalas actively shedding PhaHV-2 were significantly more likely to be actively shedding both viral subtypes. Active shedding of PhaHV-2 had a significant negative correlation with BCS in the euthanased cohort, and active shedding of PhaHV-1 had a significant positive relationship with age in both wild-caught and euthanased cohorts.
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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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10
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A Necropsy Study of Disease and Comorbidity Trends in Morbidity and Mortality in the Koala (Phascolarctos cinereus) in South-East Queensland, Australia. Sci Rep 2019; 9:17494. [PMID: 31767897 PMCID: PMC6877607 DOI: 10.1038/s41598-019-53970-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 11/05/2019] [Indexed: 12/11/2022] Open
Abstract
Koalas are an iconic Australian marsupial undergoing precipitous population reduction in South-East Queensland from complex interacting threats. To investigate the causes of death and the interaction of comorbidities with demography in South-East Queensland koalas, a large scale, high-throughput prospective necropsy survey was conducted spanning 2013–2016. During this period, 519 necropsies were conducted in 155 young/subadult koalas, 235 mature, 119 old koalas and 10 of unknown age. Similar numbers of males and females were assessed. Trauma and infectious disease at were the most common single diagnoses. However, comorbidity was frequent, including multicentric infection or infectious disease in combination with trauma or senescence. Female koalas had proportionally more reproductive chlamydiosis compared to males in which the ocular and urinary systems were more commonly affected. Comorbidity and disease were strongly associated with poor body condition, and trauma was associated with good body condition. Animals affected by motor vehicle trauma were often in better body condition than those affected by animal attack, tree fall or other causes of trauma. This study identified a higher frequency of infections and comorbidity then previously reported, confirming the complex nature of interacting threats to the koala population.
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Borthwick CR, Young LJ, Old JM. An Examination of the Development and Localization of Key Immune Cells in Developing Pouch Young of the Red‐Tailed Phascogale (
Phascogale calura
). Anat Rec (Hoboken) 2019; 302:1985-2002. [DOI: 10.1002/ar.24176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/23/2019] [Accepted: 01/29/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Casey R. Borthwick
- School of Science and HealthUniversity of Western Sydney Hawkesbury New South Wales Australia
| | - Lauren J. Young
- School of Science and HealthUniversity of Western Sydney Hawkesbury New South Wales Australia
| | - Julie M. Old
- School of Science and HealthUniversity of Western Sydney Hawkesbury New South Wales Australia
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12
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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: 20] [Impact Index Per Article: 4.0] [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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13
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Palmieri C, Hulse L, Pagliarani S, Larkin R, Higgins DP, Beagley K, Johnston S. Chlamydia pecorum Infection in the Male Reproductive System of Koalas ( Phascolarctos cinereus). Vet Pathol 2018; 56:300-306. [PMID: 30381016 DOI: 10.1177/0300985818806963] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Chlamydiosis is the most documented and serious disease of koalas, characterized by ocular, urinary, and reproductive lesions. Since little attention has been paid to the pathological effects of this infection in the male reproductive system, we aimed to determine the incidence and severity of reproductive pathology associated with chlamydial infection in male koalas submitted to koala hospitals in southeast Queensland. The entire reproductive tract from 62 sexually mature male koalas not suitable for rehabilitation was evaluated and 677 tissue samples were collected for histology, immunohistochemistry (IHC), and real-time polymerase chain reaction (qPCR). Lymphoplasmacytic inflammation was observed in 178 of 677 (26.3%) tissue samples from the upper and lower reproductive tract, mainly in the prostatic, penile, and membranous urethra. IHC was positive for the chlamydial antigen in 19 of 451 normal samples (4.2%) and 46 of 178 samples with inflammation (25.8%), located within the cytoplasm of epithelial cells of the epididymis, vas deferens, prostate, bulbourethral glands, and the prostatic membranous and penile urethra. Chlamydia pecorum was detected via qPCR in 319 of 451 normal samples (70.7%) and 159 of 178 samples with inflammation (89.3%), with the highest incidence in the penile urethra, prostate, membranous urethra, and bulbourethral glands. This study suggests that Chlamydia infection in the male reproductive tract is more widespread than originally thought. Furthermore, the male reproductive tract might be a reservoir for persistent chlamydial infections in koalas, with important implications for prophylactic strategies and epidemiology.
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Affiliation(s)
- Chiara Palmieri
- 1 School of Veterinary Science, The University of Queensland, Queensland, Australia
| | - Lyndal Hulse
- 2 School of Agriculture and Food Science, The University of Queensland, Queensland, Australia
| | - Sara Pagliarani
- 1 School of Veterinary Science, The University of Queensland, Queensland, Australia
| | - Rebecca Larkin
- 3 Ipswich Koala Protection Society, Mt Forbes, Queensland, Australia, formerly Environment Heritage and Protection, Queensland Government, Queensland, Australia
| | - Damien P Higgins
- 4 Sydney School of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Kenneth Beagley
- 5 Sciences, Faculty of Health, Institute of Health and Biomedical Innovation, School of Biomedical Queensland University of Technology, Brisbane, Queensland, Australia
| | - Stephen Johnston
- 2 School of Agriculture and Food Science, The University of Queensland, Queensland, Australia
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14
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Quigley BL, Carver S, Hanger J, Vidgen ME, Timms P. The relative contribution of causal factors in the transition from infection to clinical chlamydial disease. Sci Rep 2018; 8:8893. [PMID: 29891934 PMCID: PMC5995861 DOI: 10.1038/s41598-018-27253-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/25/2018] [Indexed: 12/21/2022] Open
Abstract
Chlamydia is a major bacterial pathogen in humans and animals globally. Yet 80% of infections never progress to clinical disease. Decades of research have generated an interconnected network linking pathogen, host, and environmental factors to disease expression, but the relative importance of these and whether they account for disease progression remains unknown. To address this, we used structural equation modeling to evaluate putative factors likely to contribute to urogenital and ocular chlamydial disease in the koala (Phascolarctos cinereus). These factors include Chlamydia detection, load, and ompA genotype; urogenital and ocular microbiomes; host sex, age, weight, body condition; breading season, time of year; location; retrovirus co-infection; and major histocompatibility complex class II (MHCII) alleles. We show different microbiological processes underpin disease progression at urogenital and ocular sites. From each category of factors, urogenital disease was most strongly predicted by chlamydial PCR detection and load, koala body condition and environmental location. In contrast, ocular disease was most strongly predicted by phylum-level Chlamydiae microbiome proportions, sampling during breeding season and co-infection with koala retrovirus subtype B. Host MHCII alleles also contributed predictive power to both disease models. Our results also show considerable uncertainty remains, suggesting major causal mechanisms are yet to be discovered.
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Affiliation(s)
- Bonnie L Quigley
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia
| | - Scott Carver
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia
| | - Jon Hanger
- Endeavour Veterinary Ecology, 1695 Pumicestone Road, Toorbul, Queensland, 4510, Australia
| | - Miranda E Vidgen
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, Australia
| | - Peter Timms
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, Queensland, 4556, 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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16
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Borel N, Polkinghorne A, Pospischil A. A Review on Chlamydial Diseases in Animals: Still a Challenge for Pathologists? Vet Pathol 2018; 55:374-390. [PMID: 29310550 DOI: 10.1177/0300985817751218] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chlamydiae have a worldwide distribution causing a wide range of diseases in human hosts, livestock, and companion animals as well as in wildlife and exotic species. Moreover, they can persist in their hosts as asymptomatic infections for extended periods of time. The introduction of molecular techniques has revolutionized the Chlamydia field by expanding the host range of known chlamydial species but also by discovering new species and even new families of bacteria in the broader order Chlamydiales. The wide range of hosts, diseases, and tissues affected by chlamydiae complicate the diagnosis such that standard diagnostic approaches for these bacteria are rare. Bacteria of the Chlamydiales order are small and their inclusions are difficult to detect by standard microscopy. With the exception of avian and ovine chlamydiosis, macroscopic and/or histologic changes might not be pathognomic or indicative for a chlamydial infection or even not present at all. Moreover, detection of chlamydial DNA in specimens in the absence of other methods or related pathological lesions questions the significance of such findings. The pathogenic potential of the majority of recently identified Chlamydia-related bacteria remains largely unknown and awaits investigation through experimental or natural infection models including histomorphological characterization of associated lesions. This review aims to summarize the historical background and the most important developments in the field of animal chlamydial research in the past 5 years with a special focus on pathology. It will summarize the current nomenclature, present critical thoughts about diagnostics, and give an update on chlamydial infections in domesticated animals such as livestock, companion animals and birds, as well as free-ranging and captive wild animals such as reptiles, fish, and marsupials.
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Affiliation(s)
- Nicole Borel
- 1 Department of Pathobiology, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
| | - Adam Polkinghorne
- 2 Centre for Animal Health Innovation, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Australia
| | - Andreas Pospischil
- 1 Department of Pathobiology, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland
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17
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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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18
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PREVALENCE AND PATHOLOGIC FEATURES OF CHLAMYDIA PECORUM INFECTIONS IN SOUTH AUSTRALIAN KOALAS (PHASCOLARCTOS CINEREUS). J Wildl Dis 2016; 52:301-6. [PMID: 26967132 DOI: 10.7589/2015-05-120] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chlamydia pecorum infection is highly prevalent in many koala ( Phascolarctos cinereus ) populations in the eastern states of Australia, causing ocular and urogenital tract disease. In contrast, the current prevalence of chlamydiosis in South Australian (SA) koalas is largely unknown, with few reports of clinical cases. We examined 65 SA rescued wild koalas at necropsy and collected ocular and urogenital swabs for the detection of C. pecorum by PCR. We detected C. pecorum in ocular or urogenital swabs from 57 koalas (88%), and 34 koalas were positive at both ocular and urogenital sites. Clinically overt chlamydial disease was present in only 12 (21%) positive koalas. Gross lesions were often externally inapparent as they affected the urogenital tract (n=5), and 24 infected koalas had microscopically evident lesions only. Lesions were predominantly mild and included conjunctivitis, cystitis, and urethritis. Reproductive tract disease was infrequently observed. We detected C. pecorum in 16 (28%) koalas with no evidence of chlamydial disease, suggesting the presence of subclinical carriers in this population. Based on these findings, chlamydiosis has a higher occurrence in SA koala populations than previously thought, but is most often mild and does not always result in overt clinical disease; inapparent and subclinical infections appear common. Further studies of the prevalence in wild-caught SA koalas are needed along with research into the host and bacterial factors that may influence disease outcome in these animals.
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19
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Black LA, Higgins DP, Govendir M. In vitro activity of chloramphenicol, florfenicol and enrofloxacin against Chlamydia pecorum isolated from koalas (Phascolarctos cinereus). Aust Vet J 2015; 93:420-3. [PMID: 26412342 DOI: 10.1111/avj.12364] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 04/12/2015] [Accepted: 05/04/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the in vitro susceptibilities of koala isolates of Chlamydia pecorum to enrofloxacin and chloramphenicol, which are frequently used to treat koalas with chlamydiosis, and florfenicol, a derivative of chloramphenicol. METHODS The in vitro susceptibilities were determined by culturing three stored isolates and seven clinical swabs of C. pecorum. Susceptibility testing was undertaken using cycloheximide-treated buffalo green monkey kidney cells in 96 well microtitre plates. RESULTS The minimum inhibitory concentrations (MICs) for all isolates were 0.25-0.50 µg/mL (enrofloxacin), 1-2 µg/mL (chloramphenicol), and 1-2 µg/mL (florfenicol). Minimum bactericidal concentration (MBC) values for five isolates were also determined and were within one two-fold dilution of MICs. The MICs and MBCs of these antimicrobials were within ranges previously reported for other chlamydial species. CONCLUSION When combined with previously published pharmacokinetic data, the in vitro susceptibility results support chloramphenicol as a more appropriate treatment option than enrofloxacin for koalas with chlamydiosis. The susceptibility results also indicate florfenicol may be an appropriate treatment option for koalas with chlamydiosis, warranting further investigation.
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Affiliation(s)
- L A Black
- McMaster Building B14, Faculty of Veterinary Science, The University of Sydney, New South Wales, Australia
| | - D P Higgins
- McMaster Building B14, Faculty of Veterinary Science, The University of Sydney, New South Wales, Australia
| | - M Govendir
- McMaster Building B14, Faculty of Veterinary Science, The University of Sydney, New South Wales, Australia.
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20
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The prevalence and clinical significance of Chlamydia infection in island and mainland populations of Victorian koalas (Phascolarctos cinereus). J Wildl Dis 2015; 51:309-17. [PMID: 25588005 DOI: 10.7589/2014-07-176] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chlamydia infection is known to impact the health of koalas (Phascolarctos cinereus) in New South Wales (NSW) and Queensland, but the clinical significance of Chlamydia infections in Victorian koalas is not well described. We examined the prevalence of Chlamydia infection and assessed associated health parameters in two Victorian koala populations known to be Chlamydia positive. The same testing regimen was applied to a third Victorian population in which Chlamydia had not been detected. We examined 288 koalas and collected samples from the urogenital sinus and conjunctival sacs. Detection and differentiation of Chlamydia species utilized real-time PCR and high-resolution melting curve analysis. Chlamydia pecorum was detected in two populations (prevalences: 25% and 41%, respectively) but only from urogenital sinus swabs. Chlamydia was not detected in the third population. Chlamydia pneumoniae was not detected. Chlamydia pecorum infection was positively associated with wet bottom (indicating chronic urinary tract disease) in one Chlamydia-positive population and with abnormal urogenital ultrasound findings in the other Chlamydia-positive population. The prevalence of wet bottom was similar in all populations (including the Chlamydia-free population), suggesting there is another significant cause (or causes) of wet bottom in Victorian koalas. Ocular disease was not observed. This is the largest study of Chlamydia infection in Victorian koalas, and the results suggest the potential for epidemiologic differences related to Chlamydia infections between Victorian koalas and koalas in Queensland and NSW and also between geographically distinct Victorian populations. Further studies to investigate the genotypes of C. pecorum present in Victorian koalas and to identify additional causes of wet bottom in koalas are indicated.
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21
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Mathew M, Waugh C, Beagley KW, Timms P, Polkinghorne A. Interleukin 17A is an immune marker for chlamydial disease severity and pathogenesis in the koala (Phascolarctos cinereus). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 46:423-429. [PMID: 24915607 DOI: 10.1016/j.dci.2014.05.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 05/22/2014] [Accepted: 05/22/2014] [Indexed: 06/03/2023]
Abstract
The koala (Phascolarctos cinereus) is an iconic Australian marsupial species that is facing many threats to its survival. Chlamydia pecorum infections are a significant contributor to this ongoing decline. A major limiting factor in our ability to manage and control chlamydial disease in koalas is a limited understanding of the koala's cell-mediated immune response to infections by this bacterial pathogen. To identify immunological markers associated with chlamydial infection and disease in koalas, we used koala-specific Quantitative Real Time PCR (qrtPCR) assays to profile the cytokine responses of Peripheral Blood Mononuclear Cells (PBMCs) collected from 41 koalas with different stages of chlamydial disease. Target cytokines included the principal Th1 (Interferon gamma; IFNγ), Th2 (Interleukin 10; IL10), and pro-inflammatory cytokines (Tumor Necrosis Factor alpha; TNFα). A novel koala-specific IL17A qrtPCR assay was also developed as part of this study to quantitate the gene expression of this Th17 cytokine in koalas. A statistically significant higher IL17A gene expression was observed in animals with current chlamydial disease compared to animals with asymptomatic chlamydial infection. A modest up-regulation of pro-inflammatory cytokines, such as TNFα and IFNγ, was also observed in these animals with signs of current chlamydial disease. IL10 gene expression was not evident in the majority of animals from both groups. Future longitudinal studies are now required to confirm the role played by cytokines in pathology and/or protection against C. pecorum infection in the koala.
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Affiliation(s)
- Marina Mathew
- Institute of Health & Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove 4059, Brisbane, Australia
| | - Courtney Waugh
- Institute of Health & Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove 4059, Brisbane, Australia; Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Dr, Sippy Downs 4558, QLD, Australia
| | - Kenneth W Beagley
- Institute of Health & Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove 4059, Brisbane, Australia
| | - Peter Timms
- Institute of Health & Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove 4059, Brisbane, Australia; Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Dr, Sippy Downs 4558, QLD, Australia
| | - Adam Polkinghorne
- Institute of Health & Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove 4059, Brisbane, Australia; Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, 90 Sippy Downs Dr, Sippy Downs 4558, QLD, Australia.
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22
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Liddle V, Naranjo C, Bernays M. Anterior chamber collapse syndrome in a koala. Aust Vet J 2014; 92:179-82. [PMID: 24766050 DOI: 10.1111/avj.12166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2013] [Indexed: 12/01/2022]
Abstract
BACKGROUND Anterior chamber collapse syndrome has been recognised in various species and is associated with early-life ocular disease or trauma. It is important to differentiate this acquired condition from a congenital malformation. CASE REPORT An adult female koala (Phascolarctos cinereus) was referred for assessment of buphthalmos and severe keratitis of the right eye. The degree of keratitis obstructed examination of intraocular structures. Enucleation of the affected eye was performed and the histopathological diagnosis was anterior chamber collapse syndrome and secondary glaucoma. This case contributes to the limited information available in the literature on anterior chamber collapse syndrome, a disease unique in having secondary glaucoma with minimal or no inflammation. The case also expands the literature available on ocular disease in koalas. More specifically, this is the only reported case of glaucoma, of any aetiology, in the koala.
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Affiliation(s)
- Vl Liddle
- Animal Eye Services, Underwood, Queensland, Australia
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23
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Maher I, Griffith J, Lau Q, Reeves T, Higgins D. Expression profiles of the immune genes CD4, CD8β, IFNγ, IL-4, IL-6 and IL-10 in mitogen-stimulated koala lymphocytes (Phascolarctos cinereus) by qRT-PCR. PeerJ 2014; 2:e280. [PMID: 24688858 PMCID: PMC3961157 DOI: 10.7717/peerj.280] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 01/29/2014] [Indexed: 11/20/2022] Open
Abstract
Investigation of the immune response of the koala (Phascolarctos cinereus) is needed urgently, but has been limited by scarcity of species-specific reagents and methods for this unique and divergent marsupial. Infectious disease is an important threat to wild populations of koalas; the most widespread and important of these is Chlamydial disease, caused by Chlamydia pecorum and Chlamydia pneumoniae. In addition, koala retrovirus (KoRV), which is of 100% prevalence in northern Australia, has been proposed as an important agent of immune suppression that could explain the koala's susceptibility to disease. The correct balance of T regulatory, T helper 1 (Th1) and Th2 lymphocyte responses are important to an individual's susceptibility or resistance to chlamydial infection. The ability to study chlamydial or KoRV pathogenesis, effects of environmental stressors on immunity, and the response of koalas to vaccines under development, by examining the koala's adaptive response to natural infection or in-vitro stimulation, has been limited to date by a paucity of species- specific reagents. In this study we have used cytokine sequences from four marsupial genomes to identify mRNA sequences for key T regulatory, Th1 and Th2 cytokines interleukin 4 (IL-4), interleukin 6 (IL-6), interleukin 10 (IL-10) and interferon gamma (IFNγ) along with CD4 and CD8β. The koala sequences used for primer design showed >58% homology with grey short-tailed opossum, >71% with tammar wallaby and 78% with Tasmanian devil amino acid sequences. We report the development of real-time RT-PCR assays to measure the expression of these genes in unstimulated cells and after three common mitogen stimulation protocols (phorbol myristate acetate/ionomycin, phorbol myristate acetate/phytohemagglutinin and concanavalin A). Phorbol myristate acetate/ionomycin was found to be the most effective mitogen to up-regulate the production of IL-4, IL-10 and IFNγ. IL-6 production was not consistently up-regulated by any of the protocols. Expression of CD4 and CD8β was down-regulated by mitogen stimulation. We found that the reference genes GAPDH and 28s are valid for normalising cytokine expression by koala lymphocytes after mitogen stimulation.
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Affiliation(s)
- Iona E. Maher
- Faculty of Veterinary Science, The University of Sydney, NSW, Australia
| | | | - Quintin Lau
- Faculty of Veterinary Science, The University of Sydney, NSW, Australia
| | - Thomas Reeves
- Faculty of Veterinary Science, The University of Sydney, NSW, Australia
| | - Damien P. Higgins
- Faculty of Veterinary Science, The University of Sydney, NSW, Australia
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24
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Liddle VL. Electroretinography in the normal koala (Phascolarctos cinereus). Vet Ophthalmol 2013; 18 Suppl 1:74-80. [DOI: 10.1111/vop.12133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Vicki L. Liddle
- Animal Eye Services; Shop 14 ‘Springwood Centre’ Cnr Logan & Lexington Rds Underwood Qld 4119 Australia
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25
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Kollipara A, Polkinghorne A, Wan C, Kanyoka P, Hanger J, Loader J, Callaghan J, Bell A, Ellis W, Fitzgibbon S, Melzer A, Beagley K, Timms P. Genetic diversity of Chlamydia pecorum strains in wild koala locations across Australia and the implications for a recombinant C. pecorum major outer membrane protein based vaccine. Vet Microbiol 2013; 167:513-22. [DOI: 10.1016/j.vetmic.2013.08.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/08/2013] [Accepted: 08/12/2013] [Indexed: 11/29/2022]
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26
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Conjunctivitis Associated with Chlamydia pecorum in Three Koalas (Phascolarctos cinereus) in the Mount Lofty Ranges, South Australia. J Wildl Dis 2013; 49:1066-9. [DOI: 10.7589/2013-03-066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Preliminary characterisation of tumor necrosis factor alpha and interleukin-10 responses to Chlamydia pecorum infection in the koala (Phascolarctos cinereus). PLoS One 2013; 8:e59958. [PMID: 23527290 PMCID: PMC3602058 DOI: 10.1371/journal.pone.0059958] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/20/2013] [Indexed: 01/16/2023] Open
Abstract
Debilitating infectious diseases caused by Chlamydia are major contributors to the decline of Australia's iconic native marsupial species, the koala (Phascolarctos cinereus). An understanding of koala chlamydial disease pathogenesis and the development of effective strategies to control infections continue to be hindered by an almost complete lack of species-specific immunological reagents. The cell-mediated immune response has been shown to play an influential role in the response to chlamydial infection in other hosts. The objective of this study, hence, was to provide preliminary data on the role of two key cytokines, pro-inflammatory tumour necrosis factor alpha (TNFα) and anti-inflammatory interleukin 10 (IL10), in the koala Chlamydia pecorum response. Utilising sequence homology between the cytokine sequences obtained from several recently sequenced marsupial genomes, this report describes the first mRNA sequences of any koala cytokine and the development of koala specific TNFα and IL10 real-time PCR assays to measure the expression of these genes from koala samples. In preliminary studies comparing wild koalas with overt chlamydial disease, previous evidence of C. pecorum infection or no signs of C. pecorum infection, we revealed strong but variable expression of TNFα and IL10 in wild koalas with current signs of chlamydiosis. The description of these assays and the preliminary data on the cell-mediated immune response of koalas to chlamydial infection paves the way for future studies characterising the koala immune response to a range of its pathogens while providing reagents to assist with measuring the efficacy of ongoing attempts to develop a koala chlamydial vaccine.
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28
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Lau Q, Canfield PJ, Higgins DP. Expression and in vitro upregulation of MHCII in koala lymphocytes. Vet Immunol Immunopathol 2012; 147:35-43. [PMID: 22551982 DOI: 10.1016/j.vetimm.2012.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/06/2012] [Accepted: 04/10/2012] [Indexed: 11/16/2022]
Abstract
Understanding and measuring immune activity of the koala (Phascolarctos cinereus), is important to studies of the epidemiology and impact of the widespread chlamydial and koala retroviral (KoRV) infections that occur in this iconic but increasingly threatened species. To explore the interaction of disease and immunity, and to assess the potential for use of class II major histocompatibility complex (MHCII) upregulation as an indicator of lymphocyte activation in in vitro immune assays, we have investigated the expression of MHCII in koala lymphocytes by flow cytometry. MHCII expression was upregulated in mitogen stimulated B lymphocytes in vitro but no such increase was detected in vivo in free-living koalas with active inflammation. In assessing phenotypic baseline data of captive koalas, we have identified that MHCII is expressed predominantly on circulating B lymphocytes (85.7 ± 2.4%) but on very few T lymphocytes (3.4 ± 1.9%), even following activation, and suggest that the latter finding might be compensated by the greater absolute numbers of peripheral blood B lymphocytes in this species relative to many eutherian species.
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Affiliation(s)
- Quintin Lau
- Faculty of Veterinary Science, The University of Sydney, B14 McMaster Building, Camperdown, NSW 2006, Australia
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29
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Higgins DP, Beninati T, Meek M, Irish J, Griffith JE. Within-population diversity of koala Chlamydophila pecorum at ompA VD1-VD3 and the ORF663 hypothetical gene. Vet Microbiol 2011; 156:353-8. [PMID: 22118784 DOI: 10.1016/j.vetmic.2011.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 10/31/2011] [Accepted: 11/02/2011] [Indexed: 11/19/2022]
Abstract
Infection of koalas by Chlamydophila pecorum is very common and causes significant morbidity, infertility and mortality. Fundamental to management of the disease is an understanding of the importance of multi-serotype infection or pathogen virulence in pathogenesis; these may need consideration in plans involving koala movement, vaccination, or disease risk assessment. Here we describe diversity of ompA VD1-3, and ORF663 hypothetical gene tandem repeat regions, in a single population of koalas with diverse disease outcomes. We PCR amplified and sequenced 72 partial ompA segments and amplified 25 tandem repeat segments (ORF663 hypothetical gene) from C. pecorum obtained from 62 koalas. Although several ompA genotypes were identified nationally, only one ompA genotype existed within the population studied, indicating that severe chlamydial disease occurs commonly in free-ranging koalas in the absence of infection by multiple MOMP serotypes of C. pecorum. In contrast, variation in tandem repeats within the ORF663 hypothetical gene was very high, approaching the entire range reported for pathogenic and non-pathogenic C. pecorum of European ruminants; providing an impetus for further investigation of this as a potential virulence trait.
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Affiliation(s)
- D P Higgins
- Faculty of Veterinary Science, B14, University of Sydney, Australia.
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GOVENDIR M, HANGER J, LOADER JJ, KIMBLE B, GRIFFITH JE, BLACK LA, KROCKENBERGER MB, HIGGINS DP. Plasma concentrations of chloramphenicol after subcutaneous administration to koalas (Phascolarctos cinereus) with chlamydiosis. J Vet Pharmacol Ther 2011; 35:147-54. [DOI: 10.1111/j.1365-2885.2011.01307.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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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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Higgins DP, Hemsley S, Canfield PJ. Association of uterine and salpingeal fibrosis with chlamydial hsp60 and hsp10 antigen-specific antibodies in Chlamydia-infected koalas. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2005; 12:632-9. [PMID: 15879024 PMCID: PMC1112079 DOI: 10.1128/cdli.12.5.632-639.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Infection by Chlamydia pneumoniae or Chlamydia pecorum commonly causes chronic, fibrotic disease of the urogenital tracts of female koalas. Studies of humans have associated titers of serum immunoglobulin G (IgG) against chlamydial hsp60 and hsp10 antigens with chronic infection, salpingeal fibrosis, and tubal infertility. To determine whether a similar relationship exists in Chlamydia-infected koalas, samples were collected opportunistically from 34 wild female koalas and examined by gross pathology and histopathology, PCR, and immunohistochemistry for Chlamydia spp. and enzyme-linked immunosorbent assay for serological responses to chlamydial hsp10 and hsp60 antigens. Greater anti-hsp titers occurred in Chlamydia-infected koalas with fibrous occlusion of the uterus or uterine tube than in other Chlamydia-infected koalas (for hsp10 IgG, P = 0.005; for hsp60 IgG, P = 0.001; for hsp10 IgA, P = 0.04; for hsp60 IgA, P = 0.09). However, as in humans, some koalas with tubal occlusion had low titers. Among Chlamydia-infected koalas with tubal occlusion, those with low titers were more likely to have an active component to their ongoing uterine or salpingeal inflammation (P = 0.007), such that the assay predicted, with 79% sensitivity and 92% specificity, tubal occlusion where an active component of inflammation was absent. Findings of this study permit advancement of clinical and epidemiological studies of host-pathogen-environment interactions and pose intriguing questions regarding the significance of the Th1/Th2 paradigm and antigen-presenting and inflammation-regulating capabilities of uterine epithelial cells and the roles of latency and reactivation of chlamydial infections in pathogenesis of upper reproductive tract disease of koalas.
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Affiliation(s)
- Damien P Higgins
- Faculty of Veterinary Science, B01, University of Sydney, Sydney, NSW 2006, Australia.
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Higgins DP, Hemsley S, Canfield PJ. Immuno-histochemical Demonstration of the Role of Chlamydiaceae in Renal, Uterine and Salpingeal Disease of the Koala, and Demonstration of Chlamydiaceae in Novel Sites. J Comp Pathol 2005; 133:164-74. [PMID: 16045922 DOI: 10.1016/j.jcpa.2005.04.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Accepted: 04/09/2005] [Indexed: 11/23/2022]
Abstract
Numerous bacteria, including Chlamydophila pecorum and Chlamydophila pneumoniae, are known to occur in diseased sites in koalas. In the present study the significance of such organisms was investigated by demonstrating their distribution in situ, in tissues collected opportunistically from wild koalas. Chlamydiaceae were demonstrated in epithelial cells and macrophages in association with pyogranulomatous pyelonephritis (8/11 kidneys), focal interstitial nephritis (3/21), and active inflammation and fibrosis of the entire upper female reproductive tract (10/10). In one case of pyelonephritis, Gram-positive cocci were also demonstrated in association with Chlamydiaceae and, in another, haematogenous filamentous bacteria appeared to be the sole aetiological agent. Three cases of chlamydial metritis were also superficially co-infected by a mixture of other bacteria. Chlamydiaceae were also demonstrated in pulmonary alveolar macrophages and epithelial cells in association with pneumonitis, and in hepatic and splenic macrophages in one koala. The study illustrated the prominent role of Chlamydiaceae in renal disease and disease of the uterus, uterine tube and ovarian bursa, with implications for pathogenesis and therapy. In addition, macrophages appeared to be a potential site of latent persistence from which systemic spread of infection might occur.
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Affiliation(s)
- D P Higgins
- Faculty of Veterinary Science, B01, University of Sydney, NSW 2006, Australia
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Cisternas PA, Armati PJ. Immune system cell markers in the northern brown bandicoot, Isoodon macrourus. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2000; 24:771-782. [PMID: 10906390 DOI: 10.1016/s0145-305x(00)00030-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This is the first study to report the presence of T and B lymphocyte markers and antigen presenting-like molecules in a marsupial bandicoot. Intra-cytoplasmic markers for CD3 and CD5, as well as surface Thy-1.1 and CD1a molecules were located in lymphocytes of T dependent regions of immuno-lymphoid tissue in the northern brown bandicoot using immunohistochemical techniques. Similarly, intra-cytoplasmic domains of CD79a, CD79b molecules and surface IgG molecules enabled characterisation of B lymphocytes and plasma cells. The phenotypic expression of these molecules parallels findings in eutherians, suggesting firstly the conservation of lineage epitopes for T and B subsets and secondly, the potential for similar functional properties of immune system cells between marsupials and eutherians. In addition, the presence of MHC class II and CD1a molecules on dendritic-like cells may indicate similar mechanisms for antigen processing and presentation as reported in eutherians. The use of such immune system cell markers will enable functional studies to characterise the marsupial immune system as well as ontogeny studies of immune competence.
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Affiliation(s)
- P A Cisternas
- School of Biological Sciences, Building AO8, The University of Sydney, NSW 2006, Sydney, Australia.
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Abstract
This review summarizes the dramatic changes that have occurred in the taxonomy of bacteria known as Chlamydia. Best known for the diseases they cause in humans, these intracellular bacteria also comprise many species that are responsible for a wide variety of clinically and economically important diseases in livestock and companion animals. The old taxonomy grouped most of these species into C. psittaci because systematic methods for routinely distinguishing them were not available. DNA-based testing methods are now available that distinguish different chlamydial families, genera, and species. This summary reviews these tests and a number of oligonucleotide primers that distinguish these groups using PCR and PCR-RFLP. DNA-based methods are also being used to discover new families of chlamydia-like bacteria, at least one of which is responsible for abortion in cattle (Waddlia chondrophila). This review summarizes the pathogenic roles of the Chlamydiaceae, new families, and individual species within the order Chlamydiales. These discoveries create opportunities for veterinarians to carry out epidemiological studies of chlamydiae that previously were not possible.
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Affiliation(s)
- K D Everett
- Department of Medical Microbiology and Parasitology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
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Canfield PJ, Hemsley S. The roles of histology and immunohistology in the investigation of marsupial disease and normal lymphoid tissue. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2000; 24:455-471. [PMID: 10785271 DOI: 10.1016/s0145-305x(00)00009-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This review acquaints scientists with current information related to the application of histology and immunohistology to the studies of normal lymphoid tissues and specific diseases in marsupials. Histological examination of tissue is a necessary prerequisite for immunohistological examination because it establishes tissue structure and detects specific areas of disease which allow the selection of smaller areas for immunohistological examination. Information is provided on the basic techniques of histology. Immunohistology (immunohistochemistry) refers to the identification of antigenic determinants of specific substances (proteins) by the application of antibodies to histological sections. Information is provided on a technique for enzyme based, avidin-biotin enhanced immunohistology, and on antibodies that can be used to mark disease agents or marsupial tissues and cells. A summary is provided of the available information on studies of the histology and immunohistology of normal marsupial lymphoid tissue (thymus, spleen, lymph nodes and mucosa associated lymphoid tissue), and of selected marsupial diseases such as chlamydiosis and lymphosarcoma in koalas.
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Affiliation(s)
- P J Canfield
- Department of Veterinary Anatomy and Pathology, University of Sydney, NSW 2006, Australia.
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Connolly JH, Canfield PJ, Obendorf DL. Gross, histological and immunohistochemical features of mucormycosis in the platypus. J Comp Pathol 2000; 123:36-46. [PMID: 10906254 DOI: 10.1053/jcpa.2000.0384] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nine male and five female adult free-living platypuses, obtained in a prospective capture-release study from northern Tasmania, exhibited gross features of cutaneous mycosis caused by Mucor amphibiorum. The lesions were present on the hind limbs (six cases), front limbs (four), tail (five), dorsal trunk (three) and ventral trunk (one). They varied in size, and ranged from raised red nodules or plaques, which sometimes exuded purulent material, to ulcerated lesions with central cavitation, red exuding centres and raised epidermal margins. Older lesions were covered either partly or fully by thickened and irregular epidermis. Histological examination of skin biopsies revealed discrete, poorly encapsulated granulomas, or more commonly a diffuse granulomatous or pyogranulomatous inflammation. Inflammatory cells consisted of neutrophils or eosinophils, sparse plasma cells and lymphocytes, many macrophages and occasional multinucleated giant cells. Fibrovascular tissue was diffusely and irregularly scattered in the granulomatous regions. Sphaerules characteristic of M. amphibiorum infection were observed in all lesions. The cutaneous distribution of the lesions and the natural history of the platypus indicated that entry of M. amphibiorum may have been via superficial skin wounds. T cells were the predominant infiltrating lymphoid cells in the diffuse lesions, indicating the importance of the cell-mediated response to infection.
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Affiliation(s)
- J H Connolly
- Department of Veterinary Anatomy and Pathology, University of Sydney, NSW, 2006, 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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