Klebsiella pneumoniae liver abscess in Taiwan is not caused by a clonal spread strain.

In Taiwan, the incidence of pyogenic liver abscess caused by Klebsiella pneumoniae has been increasing over the past 2 decades. Although most of the patients have no concurrent biliary tract disease, diabetes mellitus is thought to be an important risk factor for the disease. The incidence of metastatic infections in K. pneumoniae liver abscess, such as endogenous endophthalmitis and other extrahepatic infections, is also higher than that in liver abscess caused by other microbes. Furthermore, the incidence of metastatic infections in K. pneumoniae liver abscess in Taiwan is higher than Western countries. The reasons why K. pneumoniae liver abscess is so common in Taiwan and why diabetes mellitus is a risk factor for the disease are not clear. In this study, blood isolates from 40 patients with K. pneumoniae liver abscess treated at the Taipei Veterans General Hospital from 1995 through 2000 were randomly selected for study. Pulsed-field gel electrophoresis, ribotyping, and serotyping were used for cluster analysis. A total of 15 strains were of serotype K1 and 25 strains were of a serotype other than K1. No major cluster or a closely related strain of K. pneumoniae was found. In conclusion, the results obtained from pulse-field gel electrophoresis and ribotyping of K. pneumoniae isolates do not suggest that liver abscess in Taiwan is primarily caused by a single genetically related strain.