Complete Sequencing of pNDM-HK Encoding NDM-1 Carbapenemase from a Multidrug-Resistant Escherichia coli Strain Isolated in Hong Kong

BACKGROUND: The emergence of plasmid-mediated carbapenemases, such as NDM-1 in Enterobacteriaceae is a major public health issue. Since they mediate resistance to virtually all β-lactam antibiotics and there is often co-resistance to other antibiotic classes, the therapeutic options for infections caused by these organisms are very limited. METHODOLOGY: We characterized the first NDM-1 producing E. coli isolate recovered in Hong Kong. The plasmid encoding the metallo-β-lactamase gene was sequenced. PRINCIPAL FINDINGS: The plasmid, pNDM-HK readily transferred to E. coli J53 at high frequencies. It belongs to the broad host range IncL/M incompatibility group and is 88803 bp in size. Sequence alignment showed that pNDM-HK has a 55 kb backbone which shared 97% homology with pEL60 originating from the plant pathogen, Erwina amylovora in Lebanon and a 28.9 kb variable region. The plasmid backbone includes the mucAB genes mediating ultraviolet light resistance. The 28.9 kb region has a composite transposon-like structure which includes intact or truncated genes associated with resistance to β-lactams (bla(TEM-1), bla(NDM-1), Δbla(DHA-1)), aminoglycosides (aacC2, armA), sulphonamides (sul1) and macrolides (mel, mph2). It also harbors the following mobile elements: IS26, ISCR1, tnpU, tnpAcp2, tnpD, ΔtnpATn1 and insL. Certain blocks within the 28.9 kb variable region had homology with the corresponding sequences in the widely disseminated plasmids, pCTX-M3, pMUR050 and pKP048 originating from bacteria in Poland in 1996, in Spain in 2002 and in China in 2006, respectively. SIGNIFICANCE: The genetic support of NDM-1 gene suggests that it has evolved through complex pathways. The association with broad host range plasmid and multiple mobile genetic elements explain its observed horizontal mobility in multiple bacterial taxa

Evolution and spread of a multidrug-resistant Proteus mirabilis clone with chromosomal AmpC-type cephalosporinases in Europe

Proteus mirabilis isolates obtained in 1999 to 2008 from three European countries were analyzed; all carried chromosomal AmpC-type cephalosporinase bla CMY genes from a Citrobacter freundii origin (bla CMY-2-like genes). Isolates from Poland harbored several bla CMY genes (bla CMY-4, bla CMY-12, bla CMY-14, bla CMY-15, and bla CMY-38 and the new gene bla CMY-45), while isolates from Italy and Greece harbored bla CMY-16 only. Earlier isolates with bla CMY-4 or bla CMY-12, recovered in France from Greek and Algerian patients, were also studied. All isolates showed striking similarities. Their bla CMY genes resided within ISEcp1 transposition modules, named Tn6093, characterized by a 110-bp distance between ISEcp1 and bla CMY, and identical fragments of both C. freundii DNA and a ColE1-type plasmid backbone. Moreover, these modules were inserted into the same chromosomal site, within the pepQ gene. Since ColE1 plasmids carrying ISEcp1 with similar C. freundii DNA fragments (Tn6114) had been identified earlier, it is likely that a similar molecule had mediated at some stage this DNA transfer between C. freundii and P. mirabilis. In addition, isolates with bla CMY-12, bla CMY-15, and bla CMY-38 genes harbored a second bla CMY copy within a shorter ISEcp1 module (Tn6113), always inserted downstream of the ppiD gene. Sequence analysis of all mobile bla CMY-2-like genes indicated that those integrated in the P. mirabilis chromosome form a distinct cluster that may have evolved by the stepwise accumulation of mutations. All of these observations, coupled to strain typing data, suggest that the bla CMY genes studied here may have originated from a single ISEcp1-mediated mobilization-transfer-integration process, followed by the spread and evolution of a P. mirabilis clone over time and a large geographic area. Copyright © 2011, American Society for Microbiology. All Rights Reserved

Occurrence of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in the European survey of carbapenemase-producing Enterobacteriaceae (EuSCAPE): a prospective, multinational study

The members of the European Survey on Carbapenemase-Producing Enterobacteriaceae, (EuSCAPE) Working Group are: Portugal—Manuela Caniça and Vera ManageiroBACKGROUND: Gaps in the diagnostic capacity and heterogeneity of national surveillance and reporting standards in Europe make it difficult to contain carbapenemase-producing Enterobacteriaceae. We report the development of a consistent sampling framework and the results of the first structured survey on the occurrence of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in European hospitals. METHODS: National expert laboratories recruited hospitals with diagnostic capacities, who collected the first ten carbapenem non-susceptible clinical isolates of K pneumoniae or E coli and ten susceptible same-species comparator isolates and pertinent patient and hospital information. Isolates and data were relayed back to national expert laboratories, which made laboratory-substantiated information available for central analysis. FINDINGS: Between Nov 1, 2013, and April 30, 2014, 455 sentinel hospitals in 36 countries submitted 2703 clinical isolates (2301 [85%] K pneumoniae and 402 (15%) E coli). 850 (37%) of 2301 K pneumoniae samples and 77 (19%) of 402 E coli samples were carbapenemase (KPC, NDM, OXA-48-like, or VIM) producers. The ratio of K pneumoniae to E coli was 11:1. 1·3 patients per 10 000 hospital admissions had positive clinical specimens. Prevalence differed greatly, with the highest rates in Mediterranean and Balkan countries. Carbapenemase-producing K pneumoniae isolates showed high resistance to last-line antibiotics. INTERPRETATION: This initiative shows an encouraging commitment by all participants, and suggests that challenges in the establishment of a continent-wide enhanced sentinel surveillance for carbapenemase-producing Enterobacteriaeceae can be overcome. Strengthening infection control efforts in hospitals is crucial for controlling spread through local and national health care networks.European Centre for Disease Prevention and Controlinfo:eu-repo/semantics/publishedVersio