SHORT REPORT: IDENTIFICATION OF ECHINOCOCCUS SPECIES FROM A YAK IN THE QINGHAI-TIBET PLATEAU REGION OF CHINA

Abstract. The species identification of an echinococcal lesion in the liver of a yak in the Qinghai-Tibet plateau region of China, where both Echinococcus granulosus and E. multilocularis are present, was difficult to determine because of the atypical appearance of the lesion. Polymerase chain reaction−based mitochondrial genotyping allowed us to discriminate the Echinococcus species. Nucleotide sequences of the cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) genes amplified from the echinococcal lesion demonstrated that the yak was infected with the E. granulosus G1 genotype (sheep strain). The canine intestinal tapeworms Echinococcus granulosus and E. multilocularis are important zoonotic pathogens that cause serious disease in humans.1,2 In general, E. granulosus produces unilocular cysts in liver and lungs of ungulates and humans, whereas E. multilocularis causes alveolar cystic le-sions in rodents and humans. The liver of susceptible inter-mediate hosts is the most common site of development for both parasites and the causative species is often misidentified when the metacestode is poorly developed in unsuitable in