Cryptosporidium ubiquitum n. sp. in animals and humans

Abstract

A new species, Cryptosporidium ubiquitum, previously identified as the Cryptosporidium cervine genotype and infrequently as the cervid, W4 or genotype 3 genotype, is described. In published studies this genotype was reported in wild and domesticated ruminants, rodents, carnivores and primates including humans. In the present study oocysts were found in feces from a captive prehensile-tailed porcupine and her infant. Oocysts from the porcupine were transmitted to 4 boer goats. Oocysts from the goats were transmitted to a calf (calf 1) and oocysts from calf 1 were transmitted to gerbils and BALB/c mouse pups. Calf 2 housed near calf 1 became contaminated and excreted oocysts of C. ubiquitum. Oocysts collected from calf 2 were transmitted to a calf 3. When calf 2 stopped excreting C. ubiquitum oocysts it was challenged with oocysts of C. parvum and became infected, indicating a lack of cross-species immunity. Oocysts of C. ubiquitum from calf 1 measured 4.71-5.32 microm x 4.33-4.98 microm (mean=5.04 microm x4.66 microm) with a length/width shape index of 1.08 (n=50). Purified PCR products of the SSU rRNA, actin and COWP genes were sequenced and analysis of the 3 unlinked loci demonstrated the new species to be distinct from all other species and also demonstrated a lack of recombination, providing further evidence of species status. Based on morphological, molecular and biological data, this geographically widespread parasite infectious for a wide range of mammalian hosts is recognized as a new species and is named C. ubiquitum.