The Research Of Genetype Of Treponema Pallidum And ITS Clinical Revalence

Objective:To investigate the epidemiological characteristics molecular epidem-iology of Treponema pallidum(TP) andi its clinical correlation contributes to the diagnosis,treatment and epidemic trend of syphilis.However,little related research about the molecular epidemiology of TP in Chongqing.This research is aimed to explore the genetype of TP and its association with clinical features.Method:Clincal specimens and medical history from two hundred and five patients were consecutively collected from patients from June 2010 to October 2013 in the first affiliated hospital of Chongqing Medical University,the people’s hospital of Chongqing(The previous campus of third people’s hospital of Chongqin-g),the first people’s hospital of Chongqing,the Chongqing City Center blood bank, the Centers for Disease Control of Chongqing and quarantine bureau of Chongqin-g.All specimens were screened by nested PCR targeted at TP polA gene.The acidic repeat protein(arp) gene,the T.pallidum repeat(tpr) gene family and TP0548 gene were amplified with the polA positive specimens above by semi-nested PCR,nested PCR and ordinary PCR,respectively.The number of repeats presented in the arp gene and the restriction fragment length polymorphism by MseI in the tpr gene were analyzed by electrophoresis and the sequence of TP0548 gene was analyzed by standard method.Then the strains were subtyped according to Pillay’s criteria and subtyping method targeted by three genes.Make analysis of the correlation of different genetypes with sero-resistance,syphilis recurrence and Jarisch-Her-xheimer reaction by Fisher’s exact test,respectively.Result:Out of 421 specimens with syphilis,163 specimens were positive by nested PCR targeted polA gene.Of 116 TP positive specimens subtyped by arp gene,5 subtype were found,including 14(77),13(14),12(11),15(11) and 16(3).While of 114 specimens subtyped by tpr gene,5 tpr subtypes consists of d(78),f(14),a(11), b(6) and g(5).117 positvie specimens subtyoed by TP0548 were devieded into four types,including f(82),c(14),d(13),g(8).By combining genetype of arp and tpr genes,7 subtypes were found,including 14d(50),14f and 13d(14 of each),15d(11),12a and 14b(6 of each),14a and 12g(5 of each),16d(3).While the genetyping method of three genes classified 9 genetype of two genes into 14 genetype of three genes,which includes 14d/f(45),14f/f(14),13d/d(10),15d/f(8),14b/c(6),12a/f,12g/f and 14d/c(5 of each),13d/g(4),15d/g,16d/f and 14a/f(3),14a/c(2),12a/g(1).There wa -s statistical difference of the correlation of molecular subtypes with sero-resistanc-e and Jarisch-Herxheimer reaction (x2=20.533,P=0.000046; x2=75,P=0.029),while no statistical difference of the correlation of genetypes with syphilis recurrence was found(x2=3, P=0.333).Conclusion:The incidence of sero-resistance in latent syphilis is highest, follo-wed by the second syphilis and primary syphilis.The predominate subtypes of Treponema pallidum in Chongqing is type 14,d and f.It is suggested that the sero-re-sistance be related with tpr gentype b and second syphilis with 14f/f be more likely to develop a Jarisch-Herxheimer reaction following benzathine penicillin treatment.