Abstract: To clarify the taxonomic status of four Sarcoptes isolates from rabbits and swine in China, the cytochrome oxidase subunit I (COI) gene from these specimens was sequenced and compared with the homologous genes of other fourteen Sarcoptes isolates from other countries deposited in GenBank. The results of sequence analysis indicated that the lengths of COI genes in the four Sarcoptes isolates were all 1 427 bp. There was no insert or deletion. The base composition was obviously A+T biased, averaging 73%. Homology analysis indicated that the identity levels of nucleotide of COI genes among the four isolates from China ranged from 99.1% to 100.0%, while the homology of COI gene between the Sarcoptes isolated from China and the Sarcoptes isolates from human in Australia and those from other animals abroad ranged from 98.4% to 99.6%. The phylogenetic analysis showed that the relationships among Sarcoptes isolates from China and the Sarcoptes isolates from human in Australia and other animals abroad were close. Homology and phylogenetic analysis indicated that the Sarcoptes isolates from China and the Sarcoptes isolates from human in Australia and other animals abroad are conspecific.

Key words: Sarcoptes, rabbit, swine, cytochrome oxidase subunit I (COI), sequence analysis, phylogenetic analysis, China