Differences in Propagation and Isolation of Wild Type Iowa Strain and Luciferase Iowa Strain Cryptosporidium Parvum

Abstract

Cryptosporidium parvum, a coccidian parasite in the phylum Apicomplexa, is the second leading infectious agent responsible for causing diarrhea in children younger than five years old in resource-limited countries. It also causes disease in calves and other mammals and is a major cause of economic loss in agriculturally important livestock species. There are currently no consistently effective parasite-specific pharmaceuticals available for treating or preventing the infection besides a P23 vaccine. Therefore, Cryptosporidium parvum was genetically modified by others to express the Luciferase gene to help researchers rapidly and efficiently test multiple potential anti-cryptosporidial drugs and therapies. These genetically modified organisms are also aiding in the study of gene expression, with the ability to identify the slightest changes in transcription, and the role(s) of genes thought to be involved in pathogenesis. In the present study the Luciferase Cryptosporidium parvum (Nluc-Cp) or Wild type Iowa strain Cryptosporidium parvum (WT- Cp) were used to infect Holstein bull calves to determine the level of propagation and recoverability of each after isolation procedures. It was hypothesized that the propagation and isolation of Nluc-Cp versus WT-Cp in neonatal calves would be the same. It was found that the Nluc-Cp calves were healthier and propagated fewer oocysts than WT-Cp. Further, Nluc-Cp proved difficult to isolate based on the self-adherent nature of the oocysts which resulted in clumping and reduced recovery.