Open Access Research article

Seroepidemiology of Klebsiella pneumoniae colonizing the intestinal tract of healthy chinese and overseas chinese adults in Asian countries

Yi-Tsung Lin12, L Kristopher Siu3, Jung-Chung Lin4, Te-Li Chen12, Chih-Peng Tseng1, Kuo-Ming Yeh4, Feng-Yee Chang5 and Chang-Phone Fung12*

Author Affiliations

1 Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan

2 Institute of Clinical Medicine, School of Medicine, National Yang Ming University, Taipei, Taiwan

3 Division of Infectious Diseases, National Health Research Institutes, Maoli, Taiwan

4 Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, and National Defense Medical Center, Taipei, Taiwan

5 Centers for Disease Control, Taipei, Taiwan

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BMC Microbiology 2012, 12:13  doi:10.1186/1471-2180-12-13

Published: 19 January 2012



Capsular serotypes K1 and K2 of Klebsiella pneumoniae are thought to the major virulence determinants responsible for liver abscess. The intestine is one of the major reservoirs of K. pneumoniae, and epidemiological studies have suggested that the majority of K. pneumoniae infections are preceded by colonization of the gastrointestinal tract. The possibility of fecal-oral transmission in liver abscess has been raised on the basis of molecular typing of isolates. Data on the serotype distribution of K. pneumoniae in stool samples from healthy individuals has not been previously reported. This study investigated the seroepidemiology of K. pneumoniae isolates from the intestinal tract of healthy Chinese in Asian countries. Stool specimens from healthy adult Chinese residents of Taiwan, Japan, Hong Kong, China, Thailand, Malaysia, Singapore, and Vietnam were collected from August 2004 to August 2010 for analysis.


Serotypes K1/K2 accounted for 9.8% of all K. pneumoniae isolates from stools in all countries. There was no significant difference in the prevalence of K1/K2 isolates among the countries excluding Thailand and Vietnam. The antimicrobial susceptibility pattern was nearly the same in K. pneumoniae isolates. The result of pulsed-field gel electrophoresis revealed no major clonal cluster of serotype K1 isolates.


The result showed that Chinese ethnicity itself might be a major factor predisposing to intestinal colonization by serotype K1/K2 K. pneumoniae isolates. The prevalent serotype K1/K2 isolates may partially correspond to the prevalence of K. pneumoniae liver abscess in Asian countries.