Title : Clinical and microbiological characteristics of Klebsiella 1 pneumoniae liver abscess in China 2 3 Running title : Klebsiella pneumoniae liver abscess in China

26 Background: Klebsiella pneumoniae has been the dominant pathogens for liver 27 abscesses in several Asian countries. Although the prevalence of K. pneumoniae liver 28 abscess (KLA) in mainland China is increasing recently, the clinical and 29 microbiological characteristics of KLA in China have not been elucidated. 30 Methods: Clinical and microbiology characteristics of consecutive 45 patients 31 with KLA from a tertiary teaching hospital in China between Jun 2008 and June 2012 32 were retrospectively evaluated. 33 Results: Vast majority of the strains were susceptible to main antimicrobial 34 agents. Most of K. pneumoniae strains from pyogenic liver abscess (PLA) patients 35 belonged to K1/K2 serotype (68.9% for K1 serotype and 20% for K2 serotype). All K. 36 pneumoniae strains were rmpA positive, and 68.9% of these strains were magA 37 positive. Overall, 57.8% (26/45) of K. pneumoniae strains belonged to ST23. 38 Twenty-five of 26 ST23 K. pneumoniae isolates (96.2%) from PLA patients were 39 magA-positive and K1 serotype. Only 28.9% (13/45) of KLA isolates exhibited 40 hypermucoviscous phenotype, which is clinically used as the characteristic of 41 hypervirulent K. pneumoniae (hvKP). The size of liver abscess caused by K. 42 pneumoniae with hypermucoviscosity was larger than that caused by cKP. There was 43 no significant association between the microbiological characteristics including 44 serotypes, magA and rmpA genotypes, and STs with the metastatic infection and 45 prognosis of KLA. 46 Conclusions: Neither the serotypes, magA and rmpA genotypes, nor the STs of K. 47 pneumoniae were associated with the metastatic infection and prognosis of KLA. 48 However, further studies with larger sample are needed in the future. 49 50