[1] Guangzhou Med Univ, Dept Pathol, Affiliated Hosp 3, 63 Duobao Rd, Guangzhou 510150, Peoples R China
[2] Guangzhou Med Univ, Clin Sch 3, Guangzhou 510150, Peoples R China
[3] Guangdong Higher Educ Inst, Key Lab Reprod & Genet, Guangzhou 510150, Peoples R China
[4] Wake Forest Sch Med, Dept Microbiol & Immunol, Winston Salem, NC 27157 USA