Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia.
Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia.
Sci Rep. 2023 Sep 12;13(1):15087. doi: 10.1038/s41598-023-42296-7.
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.
衣原体病是一种严重影响澳大利亚东部考拉（Phascolarctos cinereus）种群的疾病，影响动物个体的福利和繁殖力，从而影响种群动态。本研究的目的是在衣原体病严重影响的考拉种群中，调查基于衣原体 pecorum 主要外膜蛋白（MOMP）的 4 种成分的合成肽疫苗在 18 个月期间的效果。野生考拉随机分配到疫苗或安慰剂治疗组，然后进行为期 18 个月的随访，每 6 个月重新捕获一次。疫苗接种并未改变临床疾病表现或眼部或泌尿生殖道的衣原体脱落。与安慰剂组相比，疫苗接种并未刺激出显著的血浆抗 MOMP IgG 反应。用 rMOMP 刺激外周血淋巴细胞时，疫苗接种对 IFN-γ 和 IL-17A mRNA 表达没有显著影响。我们已经证明，针对衣原体病的合成肽疫苗在考拉种群中对衣原体 pecorum 感染和相关疾病的高流行率并不是一种有效的管理工具。本研究中发现的缺乏抗原反应表明，如果我们将疫苗接种作为患病考拉种群管理策略的一部分，那么利用更大的全长抗原进行进一步研究是值得考虑的。
