[Isolation of Cryptosporidium parvum oocysts from fecal samples--the combination of ether extraction and discontinuous sucrose gradients]

Molecular detection and prevalence of Cryptosporidium spp. infections in two types of domestic farm animals in the Qinghai-Tibetan Plateau Area (QTPA) in China

The objective of this study was to determine the prevalence of Cryptosporidium species infections in young cattle and sheep in the north-eastern part of the Qinghai-Tibetan Plateau Area (QTPA), north-western China. A total number of 454 faecal samples (389 from cattle and 65 from sheep) were collected and investigated to determine the prevalence of Cryptosporidium spp. oocysts. Cryptosporidium spp. infections detected in cattle (n = 56 positive samples) and sheep (n = 4 positive samples) were as following: C. andersoni (16/56, 28.6%) was the dominant species, followed by C. canis (9/56, 16.1%), C. bovis (9/56, 16.1%), C. hominis (8/56, 14.3%), C. struthionis (7/56, 12.5%), C. ryanae (5/56, 8.9%), and C. serpentis (2/56, 3.6%). Two Cryptosporidium species were detected in sheep: C. parvum (2/4) and C. canis (2/4). There were no mixed infections. C. hominis, C. struthionis, and C. serpentis are reported in domestic animals for the first time at the QTPA of China and our results indicate an anthropozoonotic transmission of C. hominis. The identification of Cryptosporidium spp. in domestic animals warrants better care of the farm animals in order to avoid contamination in vulnerable animal and human populations.

Diagnosis of bovine cryptosporidiosis by indirect immunofluorescence assay using monoclonal antibody

Two hybridoma cell lines against Cryptosporidium parvum oocysts (VRI-CN91) were produced. The isotype of these 2 monoclonal antibodies (mAbs) was IgG2b (1E7.2) and and IgM (C6). Enzyme immuno-transfer blotting analysis showed that 1E7.2 reacted specifically to 36 kDa protein and C6 reacted to 67 and 70 kDa proteins. C. parvum was bound specifically to the surface region of oocysts by these mAbs. No cross-reactivity was observed with tachyzoites of Toxoplasma gondii and oocysts of Eimeria zuernii, E. bovis and E. canadensis of bovine origin. The indirect immunofluorescence assay (IIF) using mAb C6 was successful with counterstain. With the IIF using mAb C6, oocysts appeared as 3 to 5 microns spherical objects fluorescing bright apple green against a reddish dark background. The IIF using mAb C6 was agreed in specificity and sensitivity with those of a commercial diagnostic kit. These results demonstrated that the produced mAbs were specific to C. parvum and that the mAb C6 could be used for diagnosis of cryptosporidiosis.