Morphological and molecular characteristics of a single oocyst for the identification of Eimeria species in domestic rabbits (Oryctolagus cuniculus f. domesticus)

Abstract

Coccidiosis caused by Eimeria is one of the most common diseases in domestic rabbits (Oryctolagus cuniculus f. domesticus), with 11 Eimeria species in domestic rabbits recognized internationally. To identify Eimeria species more accurately, a method based on the molecular characteristics of a single oocyst with multiple gene loci was established by combining morphological and molecular biology. The results showed that the total infection rate of Eimeria in domestic rabbits was 44.2 % (152/344). Ten Eimeria species were identified in domestic rabbits based on morphological characteristics, namely Eimeria vejdovskyi (39.5 %, 136/344), E. magna (18.0 %, 62/344), E. perforans (17.4 %, 60/344), E. intestinalis (12.5 %, 43/344), E. media (11.9 %, 41/344), E. coecicola (4.4 %, 15/344), E. irresidua (3.8 %, 13/344), E. exigua (2.6 %, 9/344), E. stiedai (2.3 %, 8/344), and E. piriformis (1.5 %, 5/344). The molecular biological identification of Eimeria in domestic rabbits was conducted through single oocyst selection and nested polymerase chain reaction amplification with multiple gene loci. We obtained the sequences of the 18S rRNA, ITS-1 and COI gene loci of E. magna, E. perforans, E. vejdovskyi, E. media, E. intestinalis, and E. coecicola. The results showed that the molecular biology and morphological identification results of single oocysts were consistent and could be used for the molecular identification of Eimeria at the single oocyst level. This study provides an efficient tool for identification of Eimeria in domestic rabbits and the population genetic study of Eimeria in domestic rabbits.