Genetic characterization of Cryptosporidium spp. among patients with gastrointestinal complaints

Aim: This study investigated subtypes of Cryptosporidium in patients with gastrointestinal complaints in Tehran, Iran. Background: Cryptosporidium, an intracellular protozean parasite, is among the major causative agents of gastroenteritis disorders in humans. It also causes water-borne and food-borne outbreaks of diarrheal diseases. Patients and methods: A total of 1685 fecal samples were collected from patients with gastrointestinal complaints who had been referred to clinical laboratories Tehran, Iran. The primary diagnosis was established by the detection of oocysts using the modified Ziehl-Neelsen staining method and following that, the positive microscopically samples were selected for sequence analysis of the partial 60 kDa glycoprotein (gp60) gene. Results: Out of 1685 collected samples, 7 (0.4 %) were positive for Cryptosporidium oocysts. Sequence analysis of gp60 gene in seven Cryptosporidium isolates revealed that two subtype families were identified, IIa and IId. Five (of 7) isolates belonged to the subtype family IIa and the remaining two isolates belonged to IId. Two sub-types were recognized within the subtype family II,a including IIaA16G2R1 (3/5), IIaA17G1R1 (2/5), while IIdA17G1d was the only subtype within IId subtype family. Conclusion: The predominance of zoonotic subtype families of C. parvum species (IIa, IId) in this study highlights the importance of zoonotic transmission of cryptosporidiosis in the country.