ANALYSIS OF K26 GENE AND ITS-1 SEQUENCE POLYMORPHISMS IN THE REEMERGING CASE OF VISCERAL LEISHMANIASIS IN BEIJING
Objective To understand the molecular genetic background of the reported case of reemerging visceral leishmaniasis in Beijing.Methods The PCR was used to amplify the hydrophilic acylated surface protein B(K26)gene and internal transcribed spacer 1(ITS-1)sequence of ribosomal DNA.The amplified fragments were cloned and sequenced to analyze their genetic polymorphisms and to construct phylogenetic trees to determine the causative parasitic species in the infected patient and its genetic relationships.Results The K26 gene yielded a 626 bp amplicon,which exhibited significant differences in length compared to domestic epidemic strains.The amino acid sequence of this amplicon consisted of a repetitive arrangement of a 14-amino-acid motif,but amino acid substitutions were observed at certain positions.Phylogenetic analysis of the K26 sequence revealed that the Beijing strain was closely related to Leishmania infantum strains from France and Spain but distant from those in other regions of China,such as Xinjiang,Sichuan,and Hebei.Moreover,phylogenetic analysis of a 314 bp fragment amplified from the ITS-1 sequence also showed that the Beijing strain belonged to the same branch as L.infantum strains.Conclusion These results indicate that the infection in this patient was caused by L.infantum,with the strain having some differences from those in other endemic areas in China.
国家科技期刊平台
NSTL
万方数据
