Outbreaks caused by Klebsiella pneumoniae producing carbapenemases and other β-lactamases have been reported. Four neonates admitted to a neonatal intensive care unit (NICU) in a Chinese hospital developed respiratory infection while receiving intensive care. In all four cases, multidrug-resistant K. pneumoniae was isolated from multiple respiratory specimens, leading to additional characterization of these organisms and investigation of the local environment in the NICU. Multiple β-lactamase genes, including blaTEM-1, blaIMP-4, blaDHA-1 and blaCTX-M-14, as well as the quinolone resistance gene qnrB4, were harboured by transferable plasmids from all four clinical isolates. Furthermore, PFGE confirmed that three of the four clinical isolates from the patients and three K. pneumoniae isolates collected from the hands of health-care workers and an incubator in the NICU belonged to the same PFGE cluster, indicating that an outbreak due to multidrug-resistant K. pneumoniae carrying blaIMP-4 and blaDHA-1 occurred in this NICU. As far as is known, this is the first report of the co-existence of blaIMP-4 and blaDHA-1 in the same K. pneumoniae isolate. These data suggest that additional precautions are needed to prevent outbreaks of infection caused by multidrug-resistant K. pneumoniae resulting from environmental exposure in NICUs.
BradfordP. A., BratuS., UrbanC., VisalliM., MarianoN., LandmanD., RahalJ. J., BrooksS., CebularS., QualeJ.2004; Emergence of carbapenem-resistant Klebsiella species possessing the class A carbapenem-hydrolyzing KPC-2 and inhibitor-resistant TEM-30 β-lactamases in New York City. Clin Infect Dis 39:55–60 [View Article][PubMed]
CaiJ. C., ZhouH. W., ZhangR., ChenG.-X.2008; Emergence of Serratia marcescens, Klebsiella pneumoniae, and Escherichia coli isolates possessing the plasmid-mediated carbapenem-hydrolyzing β-lactamase KPC-2 in intensive care units of a Chinese hospital. Antimicrob Agents Chemother 52:2014–2018 [View Article][PubMed]
ChenL.-R., ZhouH.-W., CaiJ.-C., ZhangR., ChenG.-X.2009; Combination of IMP-4 metallo-β-lactamase production and porin deficiency causes carbapenem resistance in a Klebsiella oxytoca clinical isolate. Diagn Microbiol Infect Dis 65:163–167 [View Article][PubMed]
EspedidoB., IredellJ., ThomasL., ZelynskiA.2005; Wide dissemination of a carbapenemase plasmid among Gram-negative bacteria: implications of the variable phenotype. J Clin Microbiol 43:4918–4919 [View Article][PubMed]
LiuY., ZhangB., CaoQ., HuangW., ShenL., QinX.2009; Two clinical strains of Klebsiella pneumoniae carrying plasmid-borne blaIMP-4, blaSHV-12, and armA isolated at a pediatric center in Shanghai, China. Antimicrob Agents Chemother 53:1642–1644 [View Article][PubMed]
MaltezouH. C.2009; Metallo-β-lactamases in Gram-negative bacteria: introducing the era of pan-resistance?. Int J Antimicrob Agents 33:405.e1–405.e7 [View Article][PubMed]
MendesR. E., BellJ. M., TurnidgeJ. D., YangQ., YuY., SunZ., JonesR. N.2008; Carbapenem-resistant isolates of Klebsiella pneumoniae in China and detection of a conjugative plasmid (blaKPC-2 plus qnrB4) and a blaIMP-4 gene. Antimicrob Agents Chemother 52:798–799 [View Article][PubMed]
PelegA. Y., FranklinC., BellJ. M., SpelmanD. W.2005; Dissemination of the metallo-β-lactamase gene blaIMP-4 among Gram-negative pathogens in a clinical setting in Australia. Clin Infect Dis 41:1549–1556 [View Article][PubMed]
RobicsekA., StrahilevitzJ., SahmD. F., JacobyG. A., HooperD. C.2006; qnr prevalence in ceftazidime-resistant Enterobacteriaceae isolates from the United States. Antimicrob Agents Chemother 50:2872–2874 [View Article][PubMed]
RobledoI. E., AquinoE. E., VázquezG. J.2011; Detection of the KPC gene in Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii during a PCR-based nosocomial surveillance study in Puerto Rico. Antimicrob Agents Chemother 55:2968–2970 [View Article][PubMed]
SouliM., GalaniI., AntoniadouA., PapadomichelakisE., PoulakouG., PanageaT., VourliS., ZervaL., ArmaganidisA.other authors2010; An outbreak of infection due to β-lactamase Klebsiella pneumoniae carbapenemase 2-producing K. pneumoniae in a Greek university hospital: molecular characterization, epidemiology, and outcomes. Clin Infect Dis 50:364–373 [View Article][PubMed]
SteinmannJ., KaaseM., GatermannS., PoppW., SteinmannE., DammanM., PaulA., SanerF., BuerJ., RathP.2011; Outbreak due to a Klebsiella pneumoniae strain harbouring KPC-2 and VIM-1 in a German university hospital, July 2010 to January 2011. Euro Surveill 16:19944[PubMed]
TenoverF. C., ArbeitR. D., GoeringR. V., MickelsenP. A., MurrayB. E., PersingD. H., SwaminathanB.1995; Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol 33:2233–2239[PubMed]
WalshT. R., TolemanM. A., PoirelL., NordmannP.2005; Metallo-β-lactamases: the quiet before the storm?. Clin Microbiol Rev 18:306–325 [View Article][PubMed]