Plasmid transferability of KPC into a virulent K2 serotype Klebsiella pneumoniae
1 National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
2 Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
3 Division of Infectious Diseases, Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA
4 Department of Infectious Diseases, Veterans Affairs New Jersey Healthcare System, East Orange, NJ, USA
5 Rutgers New Jersey Medical School, 185 South Orange Avenue, Newark, New Jersey 07101, USA
BMC Infectious Diseases 2014, 14:176 doi:10.1186/1471-2334-14-176Published: 31 March 2014
KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with high mortality; however, their virulence determinants are not well defined.
We investigated the virulence and plasmid transferability among KPC-containing K. pneumoniae isolates.
KPC-2 and -3 were successfully conjugated and retained by a virulent K2 K. pneumoniae recipient isolate. Antimicrobial susceptibility testing showed KPC-2 and -3 donor strains were resistant to more than four classes of antibiotics while the K2 isolate was only initially resistant to ampicillin. After conjugation of KPC-2 and -3, the K2 K. pneumoniae transconjugants became resistant to all beta-lactams. Additionally, the KPC K2 K. pneumoniae transconjugants continued to retain its high serum resistance and murine lethality.
Conjugation and retainment of KPC by virulent K2 K. pneumoniae and the ability of the tranconjugants to maintain its high serum resistance and murine lethality after conjugation was demonstrated in this study. These findings are concerning for the potential of KPC-like genes to disseminate among virulent K. pneumoniae isolates.