[Isolation and identification of in patients with fever of unknown origin in Guizhou province].

To understand the etiological characteristics of the patients with fever of unknown origin in Guizhou province through the isolation and identification of and provide evidence for the control, prevention and treatment of human leptospirosis. Blood and urine samples were collected from patients with fever symptoms in Qiandongnan, an epidemic area, in Guizhou. The suspected strains were primarily identified using pathogenic specific G1/G2-PCR, and subsequently identified by using serogroups specific PCR. The strains were then genotyped with multiple locus sequence typing. MLST data based cluster analysis on the isolates and reference strains of common serogroups were analyzed by using software NTsys 2.10e. Three suspected strains of were isolated from human blood samples, the isolation rate was 8.６%, which were designated as strain 17BX002, 17BX003 and 17AJX008. Strain 17BX002 was further identified as serogroup grippotyphosa by using serogroup specific PCR, while the other two strains were negative (excluded as iterohaemorrhagiae, sejroe, canicola, autumnalis, grippotyphosa and hebdomadis). MLST genotyping showed that strain 17BX002 was typed as ST106, most closely clustered with grippotyphosa, while strain 17BX003 and 17AJX008 were typed as ST96, the same as serogroup badaviae. There are leptospirosis cases in epidemic area of Guizhou in high incidence season, grippotyphosa and bataviae are the newly discovered serogroups of in Guizhou.