Cryptosporidium parvum life cycle in suckling mice: a Nomarski interference-contrast study of a human-derived strain.
Cryptosporidiosis has emerged as one of the life-threatening opportunistic enteric infections in HIV-infected persons. To date, Cryptosporidium parvum is known to infect man via person-to-person or zoonotic transmission. We studied the sequential stages of the life cycle of C. parvum by Normarski interference-contrast microscopy in fresh gut specimens of newborn mice, infected with a strain derived from an AIDS patient with cryptosporidial diarrheal enteritis. Many 4- to 5-day-old suckling BALB/C mice were orally inoculated with 1 x 10(6) oocysts, obtained by acid flocculation of the patient's stools. The animals were sacrificed from 4 to 96 h post-infection and the ileum was examined microscopically. All stages of the asexual life cycle of C. parvum, from excysted sporozoites in the intestinal lumen through the development of type II mature meronts, 12- to 72-h post-infection, were documented by extemporaneous microscopic evaluation of fresh gut samples. The sexual cycle, characterized by the appearance of micro- and macrogametocytes, followed by a zygote developing into a sporulated oocyst, was documented as early 48-h post-infection. Our Nomarski interference-contrast observations on the life cycle of C. parvum yielded data comparable with those originally published by Current and Reese, and confirm the results of previous electron microscopic studies performed by several other authors.
Scaglia
M
M
Department of Infectious Diseases, University-IRCCS San Matteo, Pavia, Italy.
Bruno
A
A
Chichino
G
G
Atzori
C
C
Cevini
C
C
Gatti
S
S
D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000469:parasitology; D000818:Animals; D000831:Animals, Newborn; D003457:Cryptosporidiosis / Q000150:complications / Q000469:parasitology; D016785:Cryptosporidium parvum / Q000254:growth & development*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008858:Microscopy, Phase-Contrast