Eimeria spp. in captive-reared corncrakes (Crex crex): results of a GeneScan assay consistent with high prevalence of infection and extra-intestinal life stages

ABSTRACTEimeria crecis and Eimeria nenei have been detected in association with enteric disease (“coccidiosis”) in the corncrake (Crex crex: Family Rallidae, Order Gruiformes). Both parasite species are common in apparently healthy free-living corncrakes, but captive-bred juvenile birds reared for reintroduction appeared particularly susceptible to clinical coccidiosis. We investigated the occurrence and relative pathogenicity of these Eimeria species in this juvenile corncrake population and developed a diagnostic species-specific polymerase chain reaction (PCR) for their identification. PCR amplification and sequencing of 18S rDNA were performed on genomic DNA extracted from samples of corncrake intestine, liver and spleen. Sequences generated were used to design a GeneScan diagnostic PCR assay targeting a species-specific TTA indel located within the 18S rDNA – the results suggested this assay was more sensitive than the 18S rDNA/amplicon sequencing approach. Eimeria sp. DNA (consistent with Eimeria sp...