National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, National Center for International Research on Tropical Diseases, Shanghai, 200025, China.
School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang, 310000, China.
BMC Microbiol. 2024 Sep 19;24(1):354. doi: 10.1186/s12866-024-03500-4.
Cryptosporidium spp. is a ubiquitous, globally distributed intestinal protozoan infecting humans and at least 260 animal hosts. Due to close human contact with pet dogs and identification of zoonotic Cryptosporidium species and subtypes in these animals, dog health is not only a veterinarian issue but also a public health issue. This study aimed to understand occurrence and genetic characterization at both genotype and subtype levels in pet dogs in Yunnan Province, China.
A total of 589 fresh fecal specimens were collected from adult pet dogs in the rural areas of eight cities/autonomous prefectures of Yunnan Province, China. 16 fecal specimens were positive for Cryptosporidium spp. by polymerase chain reaction (PCR) amplification and sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene, with an average occurrence rate of 2.7% (16/589) being observed. Three zoonotic Cryptosporidium species were identified: C. parvum (n = 7), C. suis (n = 5) and C. canis (n = 4). At the 60-kDa glycoprotein (gp60) locus, only three C. parvum and two C. canis specimens were successfully amplified and sequenced, with subtype IIaA17G2R1 (n = 3) and subtypes XXa4 (n = 1) and XXa5 (n = 1) being identified, respectively.
The present finding of three zoonotic Cryptosporidium species in dogs implied that dogs infected with Cryptosporidium spp. may pose a threat to human health. C. suis was identified in dogs in this study for the first time, expanding the host range of this species. Identification of C. parvum subtype IIaA17G2R1 and C. canis subtypes XXa4 and XXa5 will be helpful to explore the source attribution of infection/contamination and assess the transmission dynamics of C. parvum and C. canis in the investigated areas in the future.
隐孢子虫属是一种普遍存在且分布广泛的肠道原生动物，感染人类和至少 260 种动物宿主。由于人类与宠物狗密切接触，以及在这些动物中发现了人畜共患的隐孢子虫种和亚型，狗的健康不仅是兽医问题，也是公共卫生问题。本研究旨在了解中国云南省宠物犬中隐孢子虫属的发生情况和遗传特征，包括基因型和亚型水平。
从云南省八个城市/自治州农村地区的成年宠物犬中采集了 589 份新鲜粪便标本。通过聚合酶链反应（PCR）扩增和小亚基核糖体 RNA（SSU rRNA）基因序列分析，共检测到 16 份隐孢子虫属阳性粪便标本，总阳性率为 2.7%（16/589）。鉴定出三种人畜共患隐孢子虫种：小隐孢子虫（n=7）、猪隐孢子虫（n=5）和犬隐孢子虫（n=4）。在 60-kDa 糖蛋白（gp60）基因座，仅成功扩增和测序了三个小隐孢子虫和两个犬隐孢子虫标本，分别鉴定出亚型 IIaA17G2R1（n=3）和 XXa4（n=1）和 XXa5（n=1）亚型。
本研究在犬中发现了三种人畜共患隐孢子虫种，表明感染隐孢子虫属的犬可能对人类健康构成威胁。本研究首次在犬中鉴定出猪隐孢子虫，扩大了该种的宿主范围。鉴定出小隐孢子虫亚型 IIaA17G2R1 和犬隐孢子虫亚型 XXa4 和 XXa5 将有助于未来探索感染/污染的来源归因，并评估在调查地区小隐孢子虫和犬隐孢子虫的传播动态。
