Investigation On Human Infection And Obeserving On Genetic Variability Of Blastocystis Hominis In The South Coastol Areas Of Guangxi Province

Objective To investigate the speciality of hunman infection and variability of Blastocystis hominis in the south coastol areas of Guangxi province and analyse the genetic type for offering basis to prevent the intestinal diseases triggered by this hominis and research classify of this hominis.Methods Collecting fresh excrement of every investigated persons in every familes in the different villages of the south coastal of Guangxi province. Examinations were made by means of improved aether-amprodium sedimentation and microscopic examination. Separating and purifying the 37 human isolates and 3 animal isolates from the B.hominis positive excrement according to the distribution weight of different population size, gender, age, profession and nation. All the 40 islates are cultrued in vitro and the genetic DNA are extracted.37 genetic DNA are amplificated by the PCR reaction use the 7 known STS primers to identify the genotype.Results 1366 random samples in 11 regions has been examinate. The total infection rate of B.hominis was 26.35%. The infection rate of B. hominis in the 11 regions is between 5.13%-44.72%; the highest infection rate of 34.79% in age group is 0-9 group, while the lowest rate of 12.93% is 40-49 group, in the different occupation groups, the hihgest infaction rate of 40.80% is belonged to the Preschool Child, farmer has the lowest rate that is 21.19%. Bionomial distribution fit-suggested that there was remarkable family clustering of the infection.Ampificate the 37 human isolates genetic DNA by the PCR reaction and the results show that 12 isolates are subtype 1 occupy 32.43%,2 isolates are subtype 3 which occupy 5.41%, subtype 6 and subtype 7 which occupy 2.70% are all 1 isolate,3 isolates are subtype 7 occupy 8.11%, and mixed type has 6 isolates occupy 16.22%.12 of the isolates were unknown genotype B.h,which occupy 32.43% .2 of the 3 animal isolates belong to subtype 7 (66.67%). Another isolate was negative to all the 7 STS primers.Conclusion The infection rate of B. hominis of coastal areas in the south of Guangxi province is higher than that of other areas which has been reported. There were significant difference among the people of diferent areas, diferent ages and diferent occupations, and there were family clustering of infection. Simple subtype 1, simple subtype 3,simple subtype 6,simple subtype 7 and mixed subtype are exist-ed and subtype 1 is the dominant type in the area and subtype 2 is not existed.