Detection of Neoehrlichia mikurensis in rodents on the basis of the groEL gene in Yunnan commensal rodent plague foci
The purpose of this study was to understand the prevalence of Neoehrlichia mikurensis in rodents in Yunnan commensal rodent plague foci.Lianghe Country,Mangshi City,and Mile City in Yunnan Province were chosen as sampling sites,where rodents were captured with dead-traps.The N.mikurensis groEL gene in rodent spleen samples was detected with nested PCR,and the positive products were sequenced with Sanger bidirectional assays.The infection rate of N.mikurensis a-mong plague foci,habitats,species,and sexes was compared with Chi-square tests or Fisher's exact probability method.Of 656 rodent spleen samples,12 N.mikurensis positive samples were detected in R.tanezumi,R.sladeni,N.confucianus,and B.bowersi.The positivity rate was 1.83%.No significant difference in the N.mikurensis positivity rate was observed a-mong plague foci,habitats,species,and sexes(P>0.05).Genetic evolution analysis of the groEL gene indicated that the se-quence similarity of nucleic acid sequences in 12 positive samples was 99.5%-100%,and the nucleic acid sequences of N.mikurensis were in the same branch,belonging to cluster Ⅳ.Thus,four species of rodents were found to have low frequency infection with N.mikurensis in Yunnan commensal rodent plague foci.