Abstract: Objective　To investigate the prevalence and genotypes of Cryptosporidium spp. and Giardia lamblia in dogs and cats from a pet hospital in Shanghai Municipality. Methods　A total of 145 fresh fecal samples were collected from pet dogs and cats in a pet hospital in Shanghai Municipality during the period from November 2021 to June 2022, including 99 dog fecal samples and 46 cat fecal samples. The small subunit ribosomal ribonucleic acid (SSU rRNA) gene of Cryptosporidium and the triose phosphate isomerase (TPI) gene of G. lamblia were amplified using nested PCR assay, and the positive amplification products were sequenced from both directions. The sequence assembly was performed using the software Clustal X 2.1, and sequence alignment was conducted using BLAST. A phylogenetic tree was created with the Neighbor⁃Joining method using MEGA 11.0 to identify parasite species or genotype. Results　The overall prevalence of Cryptosporidium and G. lamblia was 20.00% (29/145) in 145 pet dog and cat fecal samples, with the prevalence of 0.69% (1/145) and 19.31% (28/145) in Cryptosporidium and G. lamblia, respectively. G. lamblia was only detected in dog fecal samples, with prevalence of 18.18% (18/99), while the detection rates of Cryptosporidium and G. lamblia were 2.17% (1/46) and 21.74% (10/46) in cat fecal samples. Nucleotide sequence analysis showed that one Cryptosporidium positive sample was characterized as C. felis, and 28 G. lamblia positive samples were all characterized as Giardia assemblage A, which showed 100% sequence homology with human isolates of Giardia. Phylogenetic analysis revealed that the sequences obtained in this study belonged to the same branch with the reported Giardia assemblage A. Conclusions　Cryptosporidium and G. lamblia infection was prevalent in pet dogs and cats from the study pet hospital in Shanghai Municipality, and there is a zoonotic risk for the species and genotype. Intensified surveillance of Cryptosporidium and Giardia infection is recommended in pets and their owners, and improved management of pet keeping is required.

Key words: Cryptosporidium, Giardia lamblia, Small subunit ribosomal ribonucleic acid, Triose phosphate isomerase, Genotype, Pet animal

摘要： ［摘要］　目的　了解上海市某宠物医院犬、猫隐孢子虫和蓝氏贾第鞭毛虫（简称贾第虫）感染情况，并对感染虫种或基因型进行分析。方法　2021年11月至2022年6月，采集在上海市某宠物医院就诊的犬、猫新鲜粪便样本145份（犬粪99份、猫粪46份）。采用巢式PCR方法分别扩增隐孢子虫核糖体小亚基rRNA（SSU rRNA）基因和贾第虫磷酸丙糖异构酶（triosephosphate isomerase，TPI）基因，对阳性产物进行双向测序，利用Clustal X 2.1 软件对测序结果进行拼接，采用BLAST软件进行分析比对，使用MEGA 11.0软件基于邻接法构建系统发育进化树，鉴定寄生虫虫种或基因型。结果　共检测145份犬、猫粪便样本，隐孢子虫和贾第虫总检出率为20.00%（29/145）；其中隐孢子虫检出率为0.69%（1/145），贾第虫检出率为19.31%（28/145）。在犬粪便样本中仅检测到贾第虫，检出率为18.18%（18/99）；在猫粪便样本中，隐孢子虫和贾第虫检出率分别为2.17%（1/46）和21.74%（10/46）。经核苷酸序列分析，1份隐孢子虫阳性样本鉴定为猫隐孢子虫；28份贾第虫阳性样本均为贾第虫集聚体A，与人源贾第虫序列同源性为100%。系统进化树构建结果表明，获得的贾第虫基因序列与人源贾第虫集聚体A属同一分支。结论　上海市某宠物医院就诊的犬和猫存在隐孢子虫和贾第虫感染，相关虫种和基因型均有人兽共患风险，有必要加强宠物及其饲养者隐孢子虫和贾第虫感染监测，并加强宠物饲养管理。

关键词: 隐孢子虫, 蓝氏贾第鞭毛虫, 核糖体小亚基rRNA, 磷酸丙糖异构酶, 基因型, 宠物