Development of a qPCR to diagnose the genus Eimeria in sheep and goats

Abstract Coccidiosis of sheep and goats is caused by protozoa in the genus Eimeria. These protozoa mainly affect young animals, causing a decrease in production and consequent economic losses. Routine diagnosis is made through morphological observation of the oocysts, which has several limitations. The objective of the present study was to develop a real-time PCR (qPCR) technique for the diagnosis of Eimeria spp. in sheep and goats. For this purpose, the 18S rRNA region of the DNA of these parasites was selected because it is a region with low variability among Eimeria spp. The qPCR technique was developed using SYBR Green, resulting in a PCR with high sensitivity, and the ability to amplify samples containing only one oocyst of an Eimeria spp. There was no cross-reaction with other intestinal protozoa, such as Blastocystis, Microsporidia, Cryptosporidium, and Giardia duodenum. The repeatability test showed that the coefficient of variation was less than 2%. This indicated that this method has good sensitivity, specificity, and reproducibility. Thus, the feasibility of using qPCR in the diagnosis of the genus Eimeria was demonstrated in this study. This technique was less laborious and required less skill and diagnostic training compared with the micromorphometry technique conventionally used for this diagnosis.