Clonal dissemination of KPC-2 producing Klebsiella pneumoniae ST11 clone with high prevalence of oqxAB and rmtB in a tertiary hospital in China: results from a 3-year period

Abstract

BackgroundCarbapenemase-producing Klebsiella pneumoniae (CPKP) strains have emerged as a major problem for healthcare systems. The aim of this study was to determine the circulating clones and analyze the clinical and molecular characteristics of CPKP in our hospital.MethodsA total of 74 carbapenemase producers collected from our hospital from 2012 to 2014 were analyzed for the prevalence of extended-spectrum β-lactamase (ESBLs), plasmid-mediated quinolone resistance genes (PMQRs), exogenously acquired 16S rRNA methyltransferase (16S-RMTase), and plasmid-mediated AmpC enzyme (pAmpCs) by PCR and DNA sequencing. The sequence types (STs) of the carbapenemase producers were analyzed by multi-locus sequence typing (MLST). And Pulsed-field gel electrophoresis (PFGE) was performed to investigate the genetic relationship of KPC-2 producing strains. Clinical data were retrieved from the medical records.ResultsKPC-2 (n = 72) was the predominant enzyme followed by NDM-1 (n = 2); The genes blaCTX-M, blaSHV, blaTEM-1, blaDHA-1, rmtB, armA, oqxA, oqxB, and qnrB were present in 29 (39.2 %), 27 (36.5 %), 46 (62.2 %), 2 (2.7 %), 25 (33.8 %), 1 (1.4 %), 60 (81.1 %) and 56 (75.7 %), 6 (8.1 %) isolates, respectively. MLST analysis revealed 10 different STs. The most dominant ST was ST11 (78.4 %, 58/74), followed by ST15 (8.1 %, 6/74). PFGE patterns of the KPC-2 producing K. pneumoniae isolates exhibited clonal dissemination of ST11 and ST15 clones as well as a genetic diversity of the remaining strains.ConclusionThe intra- and inter-hospital cross-transmission of KPC-2-producing K. pneumoniae ST11 co-carrying oqxAB and rmtB in our hospital strongly suggested that rapid identification of colonized or infected patients and screening of carriers is quite necessary to prevent a scenario of endemicity.

An Outbreak of Infections Caused by a Klebsiella pneumoniae ST11 Clone Coproducing Klebsiella pneumoniae Carbapenemase-2 and RmtB in a Chinese Teaching Hospital

“…KPC-2-RmtB-positive K. pneumoniae strains are widespread and have replaced KPC-KP strains in some hospitals. [2831] Similarly, coproduction of bla KPC-2 and rmtB was detected in most of the 17 KPC-KP isolates in our study, and these isolates displayed resistance to all antimicrobial agents tested except for colistin and cotrimoxazole. Furthermore, bla KPC-2 and rmtB were located on a transferable plasmid and were transferred by conjugation into a recipient E. coli J53 strain, indicating that these genes may be mobilized into bacterial strains that lack these genes.…”

The rapid spread of carbapenem-resistant Enterobacteriaceae

“…rmtB is a 16s rRNA methylase conferring high level aminoglycoside resistance that is commonly found on IncF, IncA/C, IncK, and IncN plasmids [Kang 2008, Yu 2010]. These plasmids are common in Enterobacteriaceae and indeed rmtB was found in 34% (25/74) of K. pneumoniae ST11 isolates from China in 2012 to 2014 with 97% (72/74) positive for bla KPC-2 and the remainder (2/74) positive for bla NDM-1 [Cheng 2016]. Quinolone resistance genes oqxA , oqxB , and qnrB were also common in 81% (60/74), 76% (56/74), and 8 % (6/74) of isolates, respectively [Cheng 2016].…”

“…These plasmids are common in Enterobacteriaceae and indeed rmtB was found in 34% (25/74) of K. pneumoniae ST11 isolates from China in 2012 to 2014 with 97% (72/74) positive for bla KPC-2 and the remainder (2/74) positive for bla NDM-1 [Cheng 2016]. Quinolone resistance genes oqxA , oqxB , and qnrB were also common in 81% (60/74), 76% (56/74), and 8 % (6/74) of isolates, respectively [Cheng 2016]. rmtF is a novel 16S rRNA methyltransferase which was found to confer high aminoglycoside resistance in Enterobacteriaceae isolates collected from 2009 to 2011 in India and the United Kingdom [Hidalgo 2013].…”

Klebsiella pneumoniae co-producing KPC and RmtG, finally targeting Switzerland

“…In this regard, carbapenem-resistant K. pneumoniae strains of clonal complex 258 (CC258 that includes ST11, ST258, ST340 and ST437) that produce KPC-type carbapenemases have disseminated worldwide and have been often responsible for nosocomial outbreaks (Woodford et al, 2011). Worryingly, the co-occurrence of 16S rRNA methyltransferases, such as ArmA, RmtB, RmtD, and RmtG enzymes, that confer high-level and broad-spectrum resistance towards aminoglycosides has been increasingly reported among KPC-producing K. pneumoniae in recent years (Cerdeira et al, 2016;Cheng et al, 2016;Quiles et al, 2015). Once KPC and a 16S rRNA methyltransferase are co-produced, it almost leads to pandrug resistance.…”