Dataset Information

Myxosporean parasites in Australian frogs: Importance, implications and future directions.

ABSTRACT: Myxosporean parasites have been identified in amphibians around the world yet very little is known about their diversity, biology and host impact. Several species of Australian frogs have recently been shown to be affected by myxosporidiosis caused by two new Cystodiscus species. In this manuscript, we review what is known about the myxosporean parasites Cystodiscus australis and Cystodiscus axonis that produce myxospores in gallbladders of Australian frogs and Myxobolus fallax and Myxobolus hylae that produce spores in gonads and the potential impact of these parasites on the conservation of Australian frogs. By doing so, we aim to highlight the importance of amphibian myxosporean parasites, suggest directions for future research and argue that the lessons learned about these parasites in Australia are directly transferable to amphibians around the world.

SUBMITTER: Hartigan A

PROVIDER: S-EPMC3862533 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Myxosporean parasites in Australian frogs: Importance, implications and future directions.

Hartigan Ashlie A Phalen David N DN Slapeta Jan J

International journal for parasitology. Parasites and wildlife 20130104

Myxosporean parasites have been identified in amphibians around the world yet very little is known about their diversity, biology and host impact. Several species of Australian frogs have recently been shown to be affected by myxosporidiosis caused by two new Cystodiscus species. In this manuscript, we review what is known about the myxosporean parasites Cystodiscus australis and Cystodiscus axonis that produce myxospores in gallbladders of Australian frogs and Myxobolus fallax and Myxobolus hyl ...[more]

PMID: 24533318

Similar Datasets

Project description:Myxosporean parasites Cystodiscus axonis and C. australis are pathogens of native and exotic Australian frog species. The pathology and ecological outcomes of infection with these parasites were investigated in this study. Gliosis was correlated to Cystodiscus axonis plasmodia in the brains of (9/60) tadpoles and (3/9) adult endangered Green and golden bell frogs using ordinal regression. Severe host reactions to C. axonis (haemorrhage, necrosis, and vasulitis) were observed in the brains of threatened Southern bell frogs (8/8), critically endangered Booroolong frogs (15/44) and Yellow spotted bell frogs (3/3). Severe brain lesions were associated with behavioural changes, neurological dysfunction, and spontaneous death. Both C. axonis and C. australis develop in the bile ducts of tadpoles, the plasmodia were significantly associated with biliary hyperplasia, inflammation and the loss of hepatocytes in (34/72) Green and golden bell frog tadpoles using ordinal regression. These lesions were so severe that in some cases 70% of the total liver was diseased. Normal liver function in tadpoles is necessary for metamorphosis, metabolism, and immune function. We postulate that this extensive liver damage would have significant host health impacts. Severe hepatic myxosporidiosis was more prevalent in tadpoles examined in autumn and winter (overwintered), suggestive of delayed metamorphosis in infected tadpoles, which would have serious flow-on effects in small populations. We compared the sensitivity of histopathology and species-specific PCR in the detection of C. australis and C. axonis. PCR was determined to be the most sensitive method (detection limit 1 myxospore equivalent of ribosomal DNA). Histology, however, had the advantage of assessing the impact of the parasite on the host. It was concluded that these parasites have the potential for significant ecological impacts, because of their high prevalence of infection and their ability to cause disease in some frogs.

Project description:BACKGROUND:The injured trauma survivor screen (ITSS) has been shown to predict posttraumatic stress disorder (PTSD) and depression risk at 1 month after traumatic injury. This study explored the ability of the ITSS to predict chronic distress after injury, as well as the impact of combining the ITSS with an additional screening measure. METHODS:Patients were enrolled following admission to a Level I trauma center. Baseline measurements were collected during initial hospitalization, and follow-up measures were collected an average of 6.5 months after injury. Receiver operating characteristic (ROC) curve analyses were run to determine predictive accuracy, controlling for participants who had mental health intervention and for those who experienced additional potentially psychologically traumatic events since their injury event. RESULTS:Utilizing a cut score of 2, the ITSS PTSD scale had a sensitivity of 85.42%, specificity of 67.35%, negative predictive value (NPV) of 91.9% and positive predictive value (PPV) of 51.4%. The combined PTSD risk group (risk positive on the baseline ITSS and the PTSD checklist for the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) had a sensitivity of 72.92%, specificity of 81.63%, NPV of 88.2%, and PPV of 61.6%. Also using a cut score of 2, the ITSS Depression Scale had a sensitivity of 72.50%, specificity of 70.29%, NPV of 91.1%, and PPV of 37.9%. CONCLUSION:The nine-item ITSS, which takes approximately 5 minutes to administer, is a stable screening tool for predicting those most at risk for PTSD and/or depression 6 months after admission to a Level I trauma center following traumatic injury. The combined PTSD risk group data provide evidence that symptom evaluation by a psychologist can improve specificity. These results further inform the recommendation of the American College of Surgeons Committee on Trauma regarding PTSD and depression screening in trauma centers. LEVEL OF EVIDENCE:Prognostic study, level III.

Dataset Information

Myxosporean parasites in Australian frogs: Importance, implications and future directions.

Publications

Myxosporean parasites in Australian frogs: Importance, implications and future directions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets