title: Detection of Toxoplasma gondii oocysts in soils in northwestern China using a new semi-nested PCR assay.
abstract: BACKGROUND
  Toxoplasma gondii is a zoonotic pathogen that can infect a range of animals and humans. Ingestion of T. gondii oocysts in soil is a significant transmission route for humans and animals acquiring toxoplasmosis. In the present study, we developed a new semi-nested PCR method to determine T. gondii oocysts distribution in soils in northwestern China.
  
  
  RESULTS
  The one tube semi-nested PCR assay was developed to detect the oocysts of T. gondii in soil, targeting the repetitive 529 bp fragment of T. gondii genomic DNA. Then a total of 268 soil samples, including 148 samples from Gansu Province and 120 samples from Qinghai Province, northwestern China, were examined by the semi-nested PCR method. One third of the positive samples were sequenced. The sensitivity of the semi-nested PCR assay was 10(2)  T. gondii oocysts in 5 g soil sample. Investigation of soil samples from northwestern China showed that 34 out of 268 soil samples (12.69%) were T. gondii positive. Sequences of the partial 529 bp fragments varied from 0-1.2% among the sequenced samples. The prevalence of T. gondii oocysts in soil from cities (24/163) was slightly higher than that in soils from pasturing areas (10/105) (P = 0.21). Among the different regions in cities, the prevalence of T. gondii oocysts in soils from parks was 14.15%, whereas that in soils from schools was 19.05%.
  
  
  CONCLUSIONS
  The present study firstly reported the prevalence of T. gondii oocysts in soils in northwest China using a novel semi-nested PCR assay, which provided baseline data for the effective prevention and control of toxoplasmosis in this region.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Meng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ye
authors.forename: Yuan-Hua
authors.initials: YH
authors.lastname: Pu
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Yang
authors.forename: Jian-Xun
authors.initials: JX
authors.lastname: Luo
authors.forename: Nian-Zhang
authors.initials: NZ
authors.lastname: Zhang
authors.forename: De-Lin
authors.initials: DL
authors.lastname: Zhang
mesh_terms: D002681:China; D033661:Oocysts; D016133:Polymerase Chain Reaction / Q000379:methods*; D012987:Soil / Q000469:parasitology*; D014122:Toxoplasma / Q000302:isolation & purification*
chemical_list: D012987:Soil