title: Seroprevalence and genetic characterization of Toxoplasma gondii in cancer patients in Anhui Province, Eastern China.
abstract: BACKGROUND
  Recent studies have indicated the predominance of Toxoplasma gondii genotype Chinese 1 in animals in China. However, little is known of the genetic features of the parasite in humans. This study aims to determine the prevalence of anti-T. gondii antibodies based on which the genetic character of the parasite was identified in cancer patients in China.
  
  
  METHODS
  A total of 1014 serum samples with malignant neoplasms were collected from six tertiary-care hospitals (HAUCM, APH, HAMU, XAH, FHH and HBMC) from January, 2012 to August, 2013. Antibodies against T. gondii were examined by enzyme-linked immunosorbent assay (ELISA). Blood samples were subsequently used for PCR assay to detect T. gondii DNA (gra6). The DNA positive samples were subjected to genotyping using a multiplex multilocus nested PCR-RFLP at 10 loci, including sag1, sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1 and apico. Samples from the patients were anonymous and only data with regard to age and gender was available at sample collection.
  
  
  RESULTS
  Overall, 8.38% (85/1014) of the examined patients showed positive antibodies against T. gondii. Among them, 61 (6.02%) were seropositive only for IgG, 16 (1.58%) were only for IgM, and 8 (0.79%) were found to be positive for both IgG and IgM. The seroprevalence of antibodies to Toxoplasma ranged from 5.8% to 11.0%, without regional difference (χ(2) = 4.764, P = 0.445). No significant differences of the positive rates of T. gondii infection were noted in genders (male, 8.96%; female, 7.45%) (χ(2) = 0.707, P = 0.400) and in ages (χ(2) = 1.172, P = 0.947). Of 1014 DNA samples, 36 (3.55%) were positive for T. gondii by nested PCR at gra6 locus and nine gave rise to complete genotyping results. All samples with achieved PCR-RFLP genotyping showed a common genetic character of type Chinese 1 (ToxoDB#9).
  
  
  CONCLUSIONS
  Seroprevalence of toxoplasmosis in immunosuppressed individuals is rarely reported in China and we presented a positive rate of 8.38% in cancer patients. Toxoplasma genomic DNA genotyping demonstrated a common genetic character of Chinese 1, indicating a possible pathogenic origin of animals in human infection.
authors.affiliation: Clinical Laboratory, the First Affiliated Hospital of Anhui University of Chinese Medicine, 230031, Hefei, Anhui Province, China. azywl1985@126.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Parasitology, Provincial Laboratory of Microbiology & Parasitology and the Key Laboratory of Zoonoses Anhui, Anhui Medical University, 230032, Hefei, Anhui Province, China. 305120198@qq.com.
authors.forename: Liu-yuan
authors.initials: LY
authors.lastname: He
authors.affiliation: Department of Medical Technology, Anhui Medical College, 230601, Hefei, Anhui Province, China. 87139376@qq.com.
authors.forename: De-di
authors.initials: DD
authors.lastname: Meng
authors.affiliation: Clinical Laboratory, Anhui Tumour Hospital, West Campus of Affiliated Provincial Hospital of Anhui Medical University, 230022, Hefei, Anhui Province, China. 104597894@qq.com.
authors.forename: Zhao-wu
authors.initials: ZW
authors.lastname: Chen
authors.affiliation: Clinical Laboratory, the First People's Hospital, 230061, Hefei, Anhui Province, China. 308878279@qq.com.
authors.forename: He
authors.initials: H
authors.lastname: Wen
authors.affiliation: Department of Medical Technology, Anhui Medical College, 230601, Hefei, Anhui Province, China. 396841874@qq.com.
authors.forename: Gong-si
authors.initials: GS
authors.lastname: Fang
authors.affiliation: Department of Parasitology, Provincial Laboratory of Microbiology & Parasitology and the Key Laboratory of Zoonoses Anhui, Anhui Medical University, 230032, Hefei, Anhui Province, China. 345052511@qq.com.
authors.forename: Qing-li
authors.initials: QL
authors.lastname: Luo
authors.affiliation: Clinical Laboratory, the First Affiliated Hospital of Anhui University of Chinese Medicine, 230031, Hefei, Anhui Province, China. hkq1510@163.com.
authors.forename: Kai-quan
authors.initials: KQ
authors.lastname: Huang
authors.affiliation: Department of Parasitology, Provincial Laboratory of Microbiology & Parasitology and the Key Laboratory of Zoonoses Anhui, Anhui Medical University, 230032, Hefei, Anhui Province, China. shenjilong53@126.com.
authors.forename: Ji-long
authors.initials: JL
authors.lastname: Shen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000913:Antibodies, Protozoan / Q000097:blood; D002681:China / Q000453:epidemiology; D005260:Female; D005838:Genotype; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D016133:Polymerase Chain Reaction / Q000379:methods; D016036:Seroepidemiologic Studies; D014122:Toxoplasma / Q000235:genetics*; D014123:Toxoplasmosis / Q000453:epidemiology / Q000469:parasitology*
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M