Stokes Helena S, Martens Johanne M, Jelocnik Martina, Walder Ken, Segal Yonatan, Berg Mathew L, Bennett Andrew T D
Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, VIC, Australia.
Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia.
Transbound Emerg Dis. 2021 Mar;68(2):487-498. doi: 10.1111/tbed.13703. Epub 2020 Jul 14.
Members of the Chlamydia genus are known to cause disease in both humans and animals. A variety of other species in the order Chlamydiales are increasingly being discovered and emerging as potential pathogens, yet there are scarce data on the diversity, prevalence and impacts of these pathogens in wild birds. To address this gap, we investigated which Chlamydiales species are present in a wild population of a common Australian parrot, the Crimson Rosella (Platycercus elegans). We collected cloacal swabs and serum from 136 individuals in south-eastern Australia, over two years, and tested several predictors of prevalence: age, sex, season and breeding status. We used multiple PCR assays to determine bacterial prevalence in cloacal swabs and a solid-phase ELISA to determine seroprevalence. We found Chlamydiales PCR prevalence of 27.7% (95% CI 20.2, 36.2) and identified at least two families (Chlamydiaceae and Parachlamydiaceae). Regarding known chlamydial avian pathogens, we found C. psittaci at 6.2% (95% CI 2.7, 11.8) and C. gallinacea at 4.6% (95% CI 1.7, 9.8) prevalence. We also identified at least two potentially novel Chlamydiales species, of unknown pathogenicity. Sex and breeding status predicted Chlamydiales PCR prevalence, with females more likely to be infected than males, and non-breeding birds more likely to be infected than breeding birds. Seroprevalence was 16% (95% CI 8.8, 25.9). Season and breeding status were strong predictors of seroprevalence, with highest seroprevalence in autumn and in non-breeding birds. Our results reveal a diversity of Chlamydiales species in this abundant wild host, and indicate that host-specific and temporal factors are associated with infection risk. Our findings suggest that wild parrots are a reservoir of both known and novel Chlamydiales lineages, of zoonotic and pathogenic potential.
衣原体属的成员已知会在人类和动物中引发疾病。衣原体目中的其他多种物种越来越多地被发现，并逐渐成为潜在病原体，但关于这些病原体在野生鸟类中的多样性、流行率和影响的数据却很少。为了填补这一空白，我们调查了澳大利亚常见鹦鹉深红玫瑰鹦鹉（Platycercus elegans）的野生种群中存在哪些衣原体物种。在两年时间里，我们从澳大利亚东南部的136只个体中采集了泄殖腔拭子和血清，并测试了几个流行率的预测因素：年龄、性别、季节和繁殖状态。我们使用多重PCR检测法来确定泄殖腔拭子中的细菌流行率，并使用固相ELISA来确定血清流行率。我们发现衣原体PCR流行率为27.7%（95%置信区间20.2, 36.2），并鉴定出至少两个科（衣原体科和副衣原体科）。关于已知的衣原体禽类病原体，我们发现鹦鹉热衣原体的流行率为6.2%（95%置信区间2.7, 11.8），鸡衣原体的流行率为4.6%（95%置信区间1.7, 9.8）。我们还鉴定出至少两种致病性未知的潜在新型衣原体物种。性别和繁殖状态可预测衣原体PCR流行率，雌性比雄性更易感染，非繁殖鸟类比繁殖鸟类更易感染。血清流行率为16%（95%置信区间8.8, 25.9）。季节和繁殖状态是血清流行率的有力预测因素，秋季和非繁殖鸟类的血清流行率最高。我们的结果揭示了这种丰富的野生宿主中衣原体物种的多样性，并表明宿主特异性和时间因素与感染风险相关。我们的研究结果表明，野生鹦鹉是具有人畜共患病和致病潜力的已知和新型衣原体谱系的宿主。
