Prevalence and molecular epidemiology of Cryptosporidium parvum in dairy calves in Punjab (India).

Cryptosporidium parvum is an important zoonotic protozoan parasite that infects the gastrointestinal tract of vertebrate animals and man. The current study was contemplated for molecular detection of Cryptosporidium species prevalent in dairy calves in Punjab, India. A total of 302 faecal samples were screened by modified Ziehl-Neelsen staining technique for the detection of Cryptosporidium oocysts. Molecular characterisation was done using PCR followed by sequence analysis of the representative isolates. An overall prevalence of 26.15 % was obtained with the highest prevalence obtained in 0-30 day old calves in both diarrhoeic and non-diarrhoeic animals. PCR analysis revealed the expected bands at 1,325 and 835 bp from all the isolates for primary and secondary/nested PCR respectively. Ten representative samples were sequenced in both directions. Phylogenetic analysis revealed the presence of C. parvum in all the samples. The high rate of calves infected with C. parvum can act as a great source of zoonotic cryptosporidiosis which indicates a potential risk of zoonotic transmission from animal to human beings in Punjab (India).