Molecular characterization of clostridium difficile isolates by capillary gel electrophoresis-based PCR ribotyping

Abstract

Backgroud:

Clostridium difficile infection (CDI) is a global concern since the emergence of the hyper-virulent strain NAP1/BI/027. The incidence of CDI has been increasing and active surveillance of Clostridium difficile epidemiology is of paramount importance. In studying the epidemiology of CDI, PCR ribotyping is a very useful method in finding the genetic relatedness of outbreak and epidemic strains. Characterisation of Clostridium difficile isolates can help surveillance and active monitoring, hence reducing the chance of potential outbreaks.

Aim:

The aims of this study is to investigate the epidemiology of Clostridium difficile in Hong Kong in the year 2010, and that of a Clostridium difficile outbreak in 2011 by using capillary gel electrophoresis-based PCR ribotyping.

Results:

Among the 307 toxigenic isolates, 139 isolates (45.3%) were characterized as existing ribotypes. Ribotype 012 was the predominant ribotype (17.3%), followed by ribotype 002/0 (15.6%). A total of 144 isolates (46.9%) were characterized as new ribotypes. The remaining 24 isolates (7.8%) were characterized as of high resemblance of existing ribotypes. A total of 8/12 isolates (66.7%) of the outbreak strains were found to be ribotype 002/0.

Conclusion:

The predominant strains of Clostridium difficile in 2010 was ribotype 012. The 2011 outbreak in Kowloon Hospital was an outbreak of Clostridium difficile ribotype 002/0. Capillary gel electrophoresis-based PCR ribotyping was showed to be a useful tool in investigation of Clostridium difficile outbreaks and study of Clostridium difficile epidemiology.