Morphologic, Host Specificity, and Molecular Characterization of a HungarianCryptosporidium meleagridisIsolate

Abstract

This study was undertaken in order to characterize Cryptosporidium meleagridis isolated from a turkey in Hungary and to compare the morphologies, host specificities, organ locations, and small-subunit RNA (SSU rRNA) gene sequences of this organism and other Cryptosporidium species. The phenotypic differences between C. meleagridis and Cryptosporidium parvum Hungarian calf isolate (zoonotic genotype) oocysts were small, although they were statistically significant. Oocysts of C. meleagridis were successfully passaged in turkeys and were transmitted from turkeys to immunosuppressed mice and from mice to chickens. The location of C. meleagridis was the small intestine, like the location of C. parvum. A comparison of sequence data for the variable region of the SSU rRNA gene of C. meleagridis isolated from turkeys with other Cryptosporidium sequence data in the GenBank database revealed that the Hungarian C. meleagridis sequence is identical to a C. meleagridis sequence recently described for a North Carolina isolate. Thus, C. meleagridis is a distinct species that occurs worldwide and has a broad host range, like the C. parvum zoonotic strain (also called the calf or bovine strain) and Cryptosporidium felis. Because birds are susceptible to C. meleagridis and to some zoonotic strains of C. parvum, these animals may play an active role in contamination of surface waters not only with Cryptosporidium baileyi but also with C. parvum-like parasites.

Characterization of Cryptosporidium meleagridis of Human Origin Passaged through Different Host Species

“…Nor were there apparent differences in animals experimentally infected with TU1867 compared to those infected with C. parvum genotype 1 (piglets and calves) (1), or genotype 2 (pigs, calves, and mice) (27). We do not believe that propagation of TU1867 in piglets had influenced the spectrum of infectivity to other animal species, as other investigators have been able to infect a range of animals with C. meleagridis (21). While natural infections with C. meleagridis have not been reported so far in chicken, rodents, cattle, or swine, the infectivity (number of oocysts required to induce infections) and virulence (intensity of infection or disease and distribution in the gut) suggest that they are more than likely to occur, much as seen in humans.…”

“…Our data supports and extends previous reports describing host-range studies. Darabus reported the passage of one C. meleagridis isolate originally isolated from chickens into mice, rabbits, rats, and cattle (6), and later, Sreter et al (21) reported the passage of a second isolate from turkeys into mice then into chickens.…”

Cryptosporidium meleagridis: Infectivity in Healthy Adult Volunteers

“…[3][4][5] Cryptosporidium meleagridis was originally isolated from a turkey and has subsequently been found in other avian species, including parrots, red-legged partridges, and chickens. [6][7][8][9] The infection has been experimentally established in immunosuppressed mice, 9,10 and C. meleagridis isolated from a human has been successfully passaged in chickens, mice, gnotobiotic piglets, and calves. 11 In those animals, the infectivity and virulence of C. meleagridis was similar to that of C. parvum .…”

High Applicability of a Novel Method for gp60-Based Subtyping of Cryptosporidium meleagridis

“…meleagridis was first described in turkeys (10). In 1999, Xiao et al (11) amplified and sequenced the complete C. meleagridis small subunit (SSU) rRNA gene, and later Sréter et al (12) combined the traditional classification methods with studies of host specificity and SSU rRNA gene sequence similarity to confirm its taxonomic status.…”