LAUSR

Objective: To understand the etiological characteristics of the patients with fever of unknown origin in Guizhou province through the isolation and identification of Leptospira interrogans and provide evidence for the control, prevention and treatment of human leptospirosis. Methods: Blood and urine samples were collected from patients with fever symptoms in Qiandongnan, an epidemic area, in Guizhou. The suspected Leptospira strains were primarily identified using pathogenic Leptospira specific G1/G2-PCR, and subsequently identified by using Leptospira serogroups specific PCR. The Leptospira strains were then genotyped with multiple locus sequence typing. MLST data based cluster analysis on the isolates and Leptospira reference strains of common serogroups were analyzed by using software NTsys 2.10e. Results: Three suspected strains of Leptospira 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 Leptospira 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 Leptospira grippotyphosa, while strain 17BX003 and 17AJX008 were typed as ST96, the same as serogroup badaviae. Conclusion: There are leptospirosis cases in epidemic area of Guizhou in high incidence season, grippotyphosa and bataviae are the newly discovered serogroups of Leptospira in Guizhou.