Prevalence and genotyping of Cryptosporidium spp. and Giardia lamblia in dogs and cats from a pet hospital in Shanghai Municipality

Abstract

To investigate the prevalence and genotypes of Cryptosporidium spp. and Giardia lamblia in dogs and cats from a pet hospital in Shanghai Municipality. 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. 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. 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.