Molecular characterization of Cryptosporidium spp. from children in Kolkata, India

Abstract

The intracellular parasite Cryptosporidium is responsible for severe diarrhea in immunocompromised persons in developing countries. Few studies on the characterization of the parasite in India are available. In this study, molecular characterization of the parasite from diarrheic children was carried out by PCR-restriction fragment length polymorphism analysis. At least three genotypes were identified. Out of 40 positive samples, 35 were positive for C. hominis, 4 were positive for C. parvum, and 1 was positive for C. felis. This study clearly suggests that cryptosporidiosis in this region is caused largely by anthroponotic transmission.

FIG. 1.

Age-associated distribution of Cryptosporidium isolates in children. Age is represented in months.

FIG. 2.

Seasonal prevalence of Cryptosporidium in children in Kolkata, India. (A) Seasonal prevalence of Cryptosporidium hominis. (B) Seasonal prevalence of Cryptosporidium species other than Cryptosporidium hominis. Rainfall data were obtained from the Kolkata Meteorological Office.

FIG. 3.

RFLP analysis of PCR products. The VspI-and SspI-digested products of the SSU rRNA gene were fractionated on a 2% agarose gel and visualized by ethidium bromide staining. Lanes 1, 2, 5, 6, 8, 9, 10, 11, 12, 13, and 15 are C. hominis; lane 3 is C. felis; and lane 7 is C. parvum. The upper panel is VspI RFLP products, and the lower panel is SspI RFLP products. M, molecular weight marker.