title: Plasmid transferability of KPC into a virulent K2 serotype Klebsiella pneumoniae.
abstract: BACKGROUND
  KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with high mortality; however, their virulence determinants are not well defined.
  
  
  METHODS
  We investigated the virulence and plasmid transferability among KPC-containing K. pneumoniae isolates.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.forename: Leung-Kei Kristopher
authors.initials: LK
authors.lastname: Siu
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA. dhuang82@hotmail.com.
authors.forename: David B
authors.initials: DB
authors.lastname: Huang
authors.forename: Tom
authors.initials: T
authors.lastname: Chiang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003227:Conjugation, Genetic / Q000235:genetics; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics*; D014774:Virulence / Q000235:genetics / Q000502:physiology; D037521:Virulence Factors / Q000235:genetics; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D037521:Virulence Factors; D001618:beta-Lactamases