Genotyping Of Treponema Pallidum In Xinjiang

Objective:To understand the epidemic characteristics of Treponema pallidum genotypes in Xinjiang.Methods:204 cases of syphilis diagnosed by clinical diagnosis and laboratory syphilis serology from June 2016 to December 2017 were collected.Whole blood specimens were collected intravenously and stored at low temperature for later use.The whole blood genomic DNA kit was used to extract the genomic DNA of the blood specimens,and the DNA concentration was measured with a spectrophotometer;the positive samples were screened using the Tp specific gene PloA amplified by ordinary PCR,and the two positive genes were selected from the positive specimens screened out.The method was used to further amplify the gene of interest gene(arp)and treponemal gene family(tpr)used for genotyping.The arp gene repeat sequence number and tpr gene fragment polymorphism were analyzed by agarose gel electrophoresis.Sex,to analyze and determine the Tp genotype.RESULTS: A total of 27 cases of Tp-specific gene polA were screened in 204 specimens,and the positive detection rate was 13%(27/204).Further,in27 positive specimens,26 cases of arp gene were amplified,the positive detection rate was96%(26/27),tpr gene was 23 cases,and the positive detection rate was 85%(23/27).Among them,10 cases(38%,10/26),14 subtypes(31%,8/26)and 16 subtypes(8 cases,31%,8/26)were found after arp classification.After tpr typing,subtype b showed 13 cases(56%,13/23)and d subtype(31%,10/23).After the two genes arp and tpr were completely subtyped,there were 23 genotypes that could be fully typed,6 genotypes were 14b(26%,6/23),and 5 were 14d(22%,5/23),15 d type 4 cases(17%,4/23),16 d type 3 cases(13%,3/23),15 b type 3 cases(13%,3/23),type 16 b 2 cases(8%,2/23).Conclusion:The genotypes of Treponema pallidum in Xinjiang determined by two genotyping methods were14 b,14d,15 d,16d,15 b and 16 b,respectively,and 14 b and 14 d accounted for the main advantage.However,due to the limited sample size,it is still necessary to further expand the sample size to find more genotypes.