Clonal dissemination of multilocus sequence type 11 Klebsiella pneumoniae carbapenemase - producing K. pneumoniae in a Chinese teaching hospital.

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae has disseminated rapidly in China. We aimed to analyze the molecular epidemiology of four KPC-producing K. pneumoniae strains isolated from a suspected clonal outbreak during a 3-month period and to track the dissemination of KPC-producing K. pneumonia retrospectively. We created antimicrobial susceptibility profiles using an automated broth microdilution system and broth microdilution methods. We screened carbapenemase and KPC phenotypes using the modified Hodge test and meropenem-boronic acid (BA) disk test, respectively. We identified β-lactamase genes with PCR and sequencing. We investigated clonal relatedness for epidemiological comparison using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). All isolates expressed multidrug resistance and yielded positive results for the modified Hodge and meropenem-BA disk tests. The isolates all carried blaKPC -2 , and coproduced CTX-M-type extended-spectrum β-lactamase. PFGE and MLST showed that the isolates were clonally related. The PFGE patterns of these isolates had ≥90% similarity. We found a single clone, sequence type (ST) 11, and its typical dissemination mode resembled clonal spread. The dissemination of KPC-producing K. pneumoniae is clonally related and there is probable local transmission of a successful ST11 clone.

Sun K ，Chen X ，Li C ，Yu Z ，Zhou Q ，Yan Y ... -  《-》

Emergence of clonally related Klebsiella pneumoniae isolates of sequence type 258 producing plasmid-mediated KPC carbapenemase in Norway and Sweden.

Samuelsen Ø ，Naseer U ，Tofteland S ，Skutlaberg DH ，Onken A ，Hjetland R ，Sundsfjord A ，Giske CG ... -  《-》

A nosocomial outbreak of KPC-2-producing Klebsiella pneumoniae in a Chinese hospital: dissemination of ST11 and emergence of ST37, ST392 and ST395.

In China, Klebsiella pneumoniae carbapenemase (KPC) -producing K. pneumoniae isolates have been identified. However, little is known about the spread and outbreak of KPC-producing enterobacterial pathogens. In this study, 48 non-duplicated KPC-producing isolates were analysed for genetic relatedness by pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility by E-test, and sequence type (ST) by multilocus sequence typing. S1-PFGE and Southern blot were used for plasmid profiling, and PCR and subsequent sequencing were performed to determine the effects of genetic background on the blaKPC gene. From December 2011 to June 2012, an outbreak of the KPC-2-producing K. pneumoniae was observed. The 48 isolates of K. pneumoniae are categorized into eight PFGE types (A1, A2, A3, A4, B, C, D and E). The predominant pathogens of the outbreak were strains with PFGE types A1, A2 and A3, which all belong to ST11. Furthermore, ST37, ST392 and ST395 KPC-2-producing K. pneumoniae isolates have also been sporadically identified. The blaKPC-2 -carrying plasmids vary in size from 30 to 220 kb. The genetic environments of the blaKPC-2 gene for most strains were consistent with the genetic structure of blaKPC-2 on the plasmid pKP048. In conclusion, the dissemination and outbreak of KPC-2-producing K. pneumoniae isolates in this study appeared to be clonal, and ST11 K. pneumoniae was the predominant clone attributed to the outbreak. This is the first study to report the emergence and spread of KPC-producing K. pneumoniae ST392 and ST395 worldwide. Our findings suggest that horizontal transfer of Tn3-based transposons might mediate the spread of blaKPC-2 gene between different K. pneumoniae clones in China.

Yang J ，Ye L ，Guo L ，Zhao Q ，Chen R ，Luo Y ，Chen Y ，Tian S ，Zhao J ，Shen D ，Han L ... -  《-》

An outbreak of infection due to beta-Lactamase Klebsiella pneumoniae Carbapenemase 2-producing K. pneumoniae in a Greek University Hospital: molecular characterization, epidemiology, and outcomes.

Souli M ，Galani I ，Antoniadou A ，Papadomichelakis E ，Poulakou G ，Panagea T ，Vourli S ，Zerva L ，Armaganidis A ，Kanellakopoulou K ，Giamarellou H ... -  《-》

ST11, the dominant clone of KPC-producing Klebsiella pneumoniae in China.

Qi Y ，Wei Z ，Ji S ，Du X ，Shen P ，Yu Y ... -  《-》