Neutralization-sensitive epitopes are conserved among geographically diverse isolates of Cryptosporidium parvum.

Isolates of Cryptosporidium parvum from New York, Florida, Brazil, Mexico, and Peru were examined for the presence of two sporozoite surface epitopes originally identified in an Iowa isolate by neutralizing monoclonal antibodies (MAbs) 18.44 and 17.41. Immunofluorescence microscopy and immunoblotting demonstrated the presence of both epitopes on all isolates. Incubation of DEAE-cellulose-purified sporozoites of the New York, Florida, Brazil, and Mexico isolates with MAb 18.44 or 17.41 significantly neutralized their infectivity for 4- to 6-day-old BALB/c mice. The results indicate that two neutralization-sensitive epitopes are conserved on geographically diverse C. parvum isolates.