Identification and Characterization ofChlamydia abortusIsolates from Yaks in Qinghai, China

Abstract

Recently, the yak population has exhibited reproductive disorders, which are considered to be associated withChlamydia abortus(C. abortus) in Qinghai, China. In this study, a total of 9 aborted fetuses (each from a different herd) and 126 vaginal swab samples from the 9 herds were collected and analyzed.C. abortusDNA was detected from all of the 9 aborted fetuses and 30 of the 126 vaginal swab samples (23.81%) from yak cows in the selected herds. FourC. abortusstrains were isolated from embryonated egg yolk sacs inoculated with foetal organ suspensions. The isolatedC. abortusstrains were further identified, which showed identical restriction profiles with theC. abortusreference strain usingAluI restriction enzyme in the RFLP test. Moreover, the isolatedC. abortusstrains andC. abortus-positive vaginal swab samples were genotyped by multiple loci variable number tandem repeat analysis and all belonged to the genotype 2 group. These findings suggested thatC. abortusplayed a substantial role in yak abortion in Qinghai, China.