Development of CpGP15 recombinant antigen of Cryptosporidium parvum for detection of the specific antibodies in cattle

• Published in: Parasitology international 2019-04, Vol.69, p.8-12
• Main Authors: Ichikawa-Seki, Madoka, Fereig, Ragab M., Masatani, Tatsunori, Kinami, Aiko, Takahashi, Yoko, Kida, Katsuya, Nishikawa, Yoshifumi
• Format: Article
• Language: English
• Subjects: Cattle; CpGP15; CpP23; Cryptosporidium parvum; ELISA; Japan
• ISSN: 1383-5769; 1873-0329
• DOI: 10.1016/j.parint.2018.10.013

The infection of neonatal calves with Cryptosporidium parvum can have a huge economic impact because diarrhea caused by the parasite sometimes results in death. A serodiagnostic system will be helpful in the diagnosis of C. parvum infection. CpP23 is commonly used as an antigen for enzyme-linked immunosorbent assay (ELISA); however, some positive sera show low reactivities, as shown in this study. Herein, we focused on three other antigens, CpGP15, CpP2 and CpGP60, in addition to CpP23, to detect C. parvum-specific antibodies in cattle sera. CpP23 and CpGP15 showed substantial ability to discriminate between positive (n = 10) and negative (n = 10) control cattle sera. Unlike our previous report, both the sensitivity and the specificity were 100% when the two antigens were employed for the ELISA. The newly developed ELISA was applied to a total of 344 sera obtained from 9 cattle farms. Two farms among them had suffered from C. parvum infections before, and were regarded as the C. parvum-positive farms. The positive rates of antibodies against CpP23 and CpGP15 in the C. parvum-positive farms were 42.7% and 49.8%, respectively, whereas the positive rate for either of the antigens was 63.0% in the farms. In contrast, 14.3% and 9.8% were positive for CpP23 and CpGP15 in the C. parvum-negative farms, respectively, whereas 18.8% was positive for either of the antigens. This study revealed that the ELISAs employing both of CpP23 and CpGP15 can avoid false-negative results and are useful for monitoring of the C. parvum infection in cattle farms. [Display omitted] •The recombinant CpP23 of C. parvum is used for serodiagnostic ELISA in cattle.•However, some positive sera show low reactivities against CpP23.•We focused on three other antigens, and the recombinant CpGP15 was useful.•No significant correlation was observed between the OD values of CpP23 and CpGP15.•The ELISAs employing both of CpP23 and CpGP15 can avoid false-negative results.