Abstract: Objective · To detect the virulence genes of Klebsiella pneumoniae isolated blood cultures, and analyze the clinical characteristics of the patients infected with hypervirulent Klebsiella pneumoniae (hvKP) or classic Klebsiella pneumoniae (cKP). Methods · A total of 80 Klebsiella pneumoniae strains isolated blood cultures in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine Oct. 2016 to Mar. 2018 were collected. String test was performed to determine hypermucoviscous Klebsiella pneumoniae (HMKP). The capsular serotypes were confirmedwzi sequencing. The 22 virulence genes, such as rmpA, magA, and aerobactin, were identifiedPCR. Multilocus sequence typing (MLST) was used to determine sequence type of these isolates. The clinical records were collected to analyze the characteristics of Klebsiella pneumoniae-infected patients. Results · The results of string test showed that 9 out of 80 Klebsiella pneumoniae strains were HMKP. The results of virulence gene detection showed that 10 strains were hvKP. Significant difference was found between hvKP and cKP in the detection rates of magA, allS, iucA, iroN, kfu, wcaG, rmpA2, iutA, pLVPK, silS and terW genes (PConclusion · cKP is the dominant type of the Klebsiella pneumoniae strains isolated blood cultures in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Most cKPs are K14.K64/ST11 and the infections are mainly hospital-acquired. The proportion of hvKP infected patients with liver abscess is high.

Key words: Klebsiella pneumoniae, blood culture, virulence gene, clinical characteristic