Animal Age Affects the Gut Microbiota and Immune System in Captive Koalas (
            <i>Phascolarctos cinereus</i>
            )

Chen, Jiayan; Lv, Weijie; Zhang, Xueli; Zhang, Tianyou; Dong, Jing; Wang, Zhihui; Liu, Tingting; Zhang, Peng; Pyne, Michael; Dong, Guixin; Guo, Shining

doi:10.1128/spectrum.04101-22

Cited by 3 publications

(2 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One example of immunosenescence is the reduced antibody production and cell mediated responses (IFNγ) in geriatric patients following influenza vaccination 54 . In koalas, increased age, specifically 9 years and older, has been associated with a decrease in CD4 and CD8β responses 55 . The lack of immune response development in this study may be in part, therefore, a result of our study population demographics.…”

Section: Discussionmentioning

confidence: 99%

Efficacy of a synthetic peptide Chlamydia pecorum major outer membrane protein vaccine in a wild koala (Phascolarctos cinereus) population

Simpson,

Higgins,

Timms

et al. 2023

Sci Rep

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 99%

Efficacy of a synthetic peptide Chlamydia pecorum major outer membrane protein vaccine in a wild koala (Phascolarctos cinereus) population

Simpson,

Higgins,

Timms

et al. 2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…However, adult groups tend to have a higher level compared to older groups across all biomarkers, and this trend was further supported by the negative relationships found between age and stress level. This was expected because age has a significant impact on the koala immune system by influencing gut microbiota and host immune markers, increasing their susceptibility to C. pecorum (Chen et al, 2023). There is also a higher chance of disease as the koalas get older, but the increases cease as the koalas become old, i.e., there is a higher prevalence of C. pecorum infection in adult koalas than in older koalas (Nyari, et al, 2017).…”

Section: Agementioning

confidence: 99%

Testing the application of plasma glucocorticoids and their ratios as biomarkers of acute and chronic stress in rescued wild koala patients: a pilot study

Pan,

Pahuja,

Portas

et al. 2024

Preprint

View full text Add to dashboard Cite

Koalas (Phascolarctos cinereus) are one of the most iconic marsupial species endemic to Australia. However, their population is declining due to threats including habitat loss, disease, dog attacks, and vehicle collisions. These threats also serve as acute or chronic stressors that impact koala welfare and conservation. Cortisol is widely used as a biomarker to study stress in koalas. However, plasma cortisol concentration is less studied due to its limited ability to assess chronic stress and welfare concerns. Dehydroepiandrosterone sulphate (DHEAS) and dihydrotestosterone (DHT) are biomarkers that could potentially detect chronic stress due to their antagonising and inhibitory effects on cortisol. In this study, we used plasma cortisol and the ratio of DHEAS and DHT to cortisol to assess stress in rescued koalas (n = 10) admitted to RSPCA Queensland. Although no significant differences were found between koalas across all biomarkers and the ratios failed to detect chronic stressors, similar trends were found consistently, suggesting the potential use of the biomarkers to assess stress. Across all biomarkers, the highest medians were found in koalas with Chlamydia-related reproductive disease and oxalate nephrosis and the lowest medians were found in koalas with Chlamydia-related conjunctivitis. Higher medians were also found consistently in females (n = 3) and adult koalas. In addition, insignificant negative correlations were found across all biomarkers between age, weight, and body conditioning scores, except for the positive correlation between weight and cortisol and cortisol:DHT. Overall, the consistency of trends and the insignificant differences found across biomarkers in our study suggested that using a single biomarker to assess chronic stress is insufficient, especially for hospital-based studies limited by sample population. Thus, this pilot study provides first step towards developing a koala-specific allostatic load index based on multiple stress biomarkers to understand chronic stress in rescued koalas.

show abstract

Gut microbiota of captive common bottlenose dolphins Tursiops truncatus gilli: influence of age, sex, birthplace, and contacts with dolphinarium visitors

Popov,

Suvorova,

Krikunova

et al. 2024

Front. Mar. Sci.

View full text Add to dashboard Cite

Dolphins are aquatic mammals, whose role in microbial ecology is not fully understood. It is critical to study the microbiota of dolphins kept in captivity, as close contact with humans could unpredictably affect both human and animal health. In this study, we investigated the gut microbiota of 15 captive common bottlenose dolphins, and the relationship of microbial diversity and composition with animals’ age, sex, birthplace (dolphinarium or wildlife), and direct contacts with dolphinarium visitors using high-throughput V3-V4 16S rRNA amplicon sequencing. Based on acquired sequencing data we calculated and compared alpha and beta diversity indexes, as well as conducted differential abundance analysis of identified bacterial taxa to find multivariable associations with dolphins’ age period, sex, birthplace, and type of contact with humans with linear models. There was no association between gut microbiota composition and diversity and dolphins’ age period, sex, and birthplace. However, there were significant differences (q-value ≤ 0.00018) in the relative abundance of Edwardsiella genus in dolphins that were in contact only with dolphinarium staff in comparison to dolphins that apart from dolphinarium staff also had contact with dolphinarium visitors. These results show that dolphins born in wildlife and dolphinariums do not have significant differences in gut microbiota composition and the microbiota of captive dolphins can be affected by their contact with humans.

show abstract

Animal Age Affects the Gut Microbiota and Immune System in Captive Koalas ( Phascolarctos cinereus )

Cited by 3 publications

References 71 publications

Efficacy of a synthetic peptide Chlamydia pecorum major outer membrane protein vaccine in a wild koala (Phascolarctos cinereus) population

Efficacy of a synthetic peptide Chlamydia pecorum major outer membrane protein vaccine in a wild koala (Phascolarctos cinereus) population

Testing the application of plasma glucocorticoids and their ratios as biomarkers of acute and chronic stress in rescued wild koala patients: a pilot study

Gut microbiota of captive common bottlenose dolphins Tursiops truncatus gilli: influence of age, sex, birthplace, and contacts with dolphinarium visitors

Contact Info

Product

Resources

About