IIaA13G2R1 is the most common Cryptosporidium parvum Subtype among Calves with diarrhea in Türkiye

Cryptosporidium spp., an intracellular extra cytoplasmic localized protozoan, is one of the leading infectious agents in the etiology of neonatal diarrheal syndrome of ruminants. Cryptosporidiosis is a common disease seen all over the world. However molecular epidemiologic studies are limited on distribution of Cryptosporidium parvum subtypes in the world. To date, nearly 20 subtypes of C. parvum have been described. Gene sequence analysis of the glycoprotein 60 structural protein (GP60) is used to identify subtypes. It is reported that the GP60 gene sequence shows a high degree of genetic polymorphism among the strains. In this study, it was aimed to determine the subtypes of C. parvum parasite in cow and calf stool samples by using GP60 gene sequence analysis. A total of 109 stool samples from calves (< 30 days) found to be Cryptosporidium spp. positive by Kinyoun Acid Fast staining were further studied for subtyping. Samples were obtained from farms in 2 regions of Türkiye (Burdur/Yesilova and Aydin provinces). DNA isolation from feces was done with the QIAamp Stool Mini Kit. Cryptosporidium specie identification was done by 18S gene sequences analysis. Nested PCR was performed to amplify GP60 gene and sequences of amplicons were used to identify subtypes. The repeat regions at the serine residue in the GP60 sequences were used to define the subtypes. The results of C. parvum subtyping study showed that IIaA13G2R1 subtype was the most common subtype. IIaA13G2R1 was detected in 73% (80/109) of 109 stool samples followed by IIaA14G1R1 with 15 samples (14%), IIaA2R1 with 12 samples (11%), and IIaA16R1 and IIaA5G1R1 subtypes with one sample each (1%). In subtype studies based on the GP60 sequence, IIaA15G2R1 was found to be the most common in the world, however this subtype was not found among our samples. In our study, IIaA13G2R1 subtype was the most common subtype detected, which is also the most common subtype in Türkiye. In our study, two new subtypes were found, IIaA2R1 and IIaA5G1R1 subtypes. These subtypes were defined for the first time in the world. The subtype IIaA16R1 was to be new in Türkiye. Molecular epidemiology studies are important for better understanding the dissemination of subtypes and IIaA13G2R1 is the most common subtype in Türkiye and the IIaA15G2R1 the most common subtype in the world were absent among our samples.