Louro Manuel, Patrício Rui, Pereira André, Valença Andreia, Alves Margarida
Faculty of Veterinary Medicine, Lusófona University-Lisbon University Centre, Lisbon, Portugal.
Research in Veterinary Medicine (I-MVET), Faculty of Veterinary Medicine, Lusófona University-Lisbon University Centre, Lisbon, Portugal.
Front Vet Sci. 2025 Aug 25;12:1652362. doi: 10.3389/fvets.2025.1652362. eCollection 2025.
is a well-recognized etiologic agent of upper respiratory tract disease in tortoises. Although frequently reported in both captive and wild populations across Europe, its occurrence in Portugal had not been previously documented. This study aimed to investigate the presence of in apparently healthy captive tortoises in mainland Portugal and to evaluate potential host- and management-related factors associated with infection.
Oral swabs were collected from 84 tortoises of 13 species across 3 geographic regions. DNA extraction success and sample integrity were confirmed by partial amplification of the tortoise mitochondrial 12S rRNA gene in 92.9% of cases (78/84), which were then screened for using a species-specific PCR targeting the 16S rRNA gene.
The pathogen DNA was detected in 66.7% (52/78) of individuals. Phylogenetic analysis confirmed species identification, with all sequences forming a strongly supported monophyletic cluster together with reference sequences. A significant association was observed between tortoise genus and infection ( = 0.021), with exhibiting a significantly lower infection frequency than Testudo ( = 0.029). No statistically significant associations were observed regarding geographic region, housing origin, or group size. These results reveal a high frequency of infection in apparently healthy captive tortoises in Portugal, emphasizing its potential for silent transmission in group or mixed-species settings. Our findings support the inclusion of this pathogen in the differential diagnosis of respiratory disease in tortoises, even when clinical signs are absent and underscore the need for routine molecular surveillance and strengthened biosecurity practices to mitigate transmission risks and foster chelonian conservation efforts.
是陆龟上呼吸道疾病一种公认的病原体。尽管在欧洲的圈养和野生种群中均有频繁报道，但此前在葡萄牙尚未有其出现的记录。本研究旨在调查葡萄牙大陆表面健康的圈养陆龟中是否存在该病原体，并评估与感染相关的潜在宿主和管理因素。
从3个地理区域的13个物种的84只陆龟中采集口腔拭子。通过对陆龟线粒体12S rRNA基因进行部分扩增，在92.9%（78/84）的病例中确认了DNA提取成功和样本完整性，然后使用针对16S rRNA基因的种特异性PCR对其进行筛查。
在66.7%（52/78）的个体中检测到病原体DNA。系统发育分析证实了物种鉴定，所有序列与参考序列一起形成了一个得到有力支持的单系聚类。观察到陆龟属与感染之间存在显著关联（P = 0.021），与陆龟属相比，感染频率显著较低（P = 0.029）。在地理区域、饲养来源或群体大小方面未观察到统计学上的显著关联。这些结果揭示了葡萄牙表面健康的圈养陆龟中该病原体感染的高频率，强调了其在群体或混养环境中隐性传播的可能性。我们的研究结果支持将这种病原体纳入陆龟呼吸道疾病的鉴别诊断中，即使没有临床症状，并强调需要进行常规分子监测和加强生物安全措施，以降低传播风险并促进龟鳖保护工作。
