Molecular Characterization and Zoonotic Significance of Cryptosporidium spp. and Giardia duodenalis in Asymptomatic Adult Stray Cats and Dogs in Turkey

Background: Cryptosporidium species and Giardia duodenalis are important protozoan parasites due to their wide host range and potential as zoonotic diseases. These parasites, responsible for Cryptosporidiosis and Giardiasis, are significant health concerns and have garnered attention from both the public and veterinary fields. Pets, such as dogs and cats, are susceptible to these infections and play a crucial role in transmitting these protozoans to humans. This study was conducted to determine the prevalence, species, genotypes and zoonotic significance of Cryptosporidium and Giardia in asymptomatic adult stray cats and dogs. Methods: Fecal samples from 75 adult stray animal, 42 dogs and 33 cats, were collected in Diyarbakýr city, southeastern Anatolia, Turkey. Direct immunofluorescence test was used to confirm the presence of G. duoenalis cysts and cryptosporidium spp. oocysts in collected fecal samples. Microscopic analysis was used to count the number of cysts/oocysts per gram as specified by the manufacturer. Molecular confirmation was done with Polymerase chain reaction (PCR) using Giardia SSU-rDNA and Cryptosporidium spp. SSU rRNA gene. The secondary PCR products of all positive samples were sequenced in one directions on an automated sequencer. Nucleotide sequence analysis was performed by BLAST alignment using the National Center for Biotechnology Information database. Result: The prevalence of Cryptosporidium was 7.14% in 42 cats and 9.09% in 33 dogs. The prevalence of G. duodenalis was 23.80% in cats and 54.54% in dogs. The average number of Cryptosporidium spp. oocysts per gram of cat and dog feces was 1866.3 and 1813.3, respectively. The average number of G. duodenalis cysts per gram of cat and dog feces was 1011.6 and 4786, respectively. All Cryptosporidium isolates were determined as C. canis in dogs and C. felis in cats. C. canis and C. felis isolates identified in the study, MT329018.1 and MN696800.1, AF159113.1 and KM977642.1 showed similarity with Genbank number, respectively. Assemblages A, E, C, D were found in dogs and assemblages A and E in cats in the result of the sequence of 130 bp gene fragments obtained from G. duodenalis isolates. This study sequence analysis of G. duodenalis cat isolates identified assemblages A (50%/10) and E (50%/10). In this study, assemblage E was the most common genotype isolated in dogs (38.8%), followed by Assemblage C (27.7%), Assemblage D (16.6%) and Assemblage A (15.5%). Assemblage A, which has zoonotic importance, was detected in cats and dogs, while assemblage E in cats and dogs was reported for the first time in Turkey.