Carbapenem-non-susceptible Enterobacteriaceae in Europe : conclusions from a meeting of national experts

The emergence and global spread of carbapenemase-producing Enterobacteriaceae is of great concern to health services worldwide. These bacteria are often resistant to all beta-lactam antibiotics and frequently co-resistant to most other antibiotics, leaving very few treatment options. The epidemiology is compounded by the diversity of carbapenem-hydrolysing enzymes and the ability of their genes to spread between different bacterial species. Difficulties are also encountered by laboratories when trying to detect carbapenemase production during routine diagnostic procedures due to an often heterogeneous expression of resistance. Some of the resistance genes are associated with successful clonal lineages which have a selective advantage in those hospitals where antimicrobial use is high and opportunities for transmission exist; others are more often associated with transmissible plasmids. A genetically distinct strain of Klebsiella pneumoniae sequence type (ST) 258 harbouring the K. Pneumoniae carbapenemases (KPC) has been causing epidemics of national and international proportions. It follows the pathways of patient referrals, causing hospital outbreaks along the way. Simultaneously, diverse strains harbouring New Delhi metallo-beta-lactamase (NDM-1) are repeatedly being imported into Europe, commonly via patients with prior medical exposure in the Indian subcontinent. Since the nature and scale of carbapenem-non-susceptible Entrobacteriaceae as a threat to hospital patients in Europe remains unclear, a consultation of experts from 31 countries set out to identify the gaps in diagnostic and response capacity, to index the magnitude of carbapenem-non-susceptibility across Europe using a novel five-level staging system, and to provide elements of a strategy to combat this public health issue in a concerted manner.peer-reviewe

Draft genome sequence of Proteus mirabilis NO-051/ 03, representative of a multidrug-resistant clone spreading in Europe and expressing the CMY-16 AmpC-type β-lactamase

Proteus mirabilis NO-051/03, representative of a multidrug-resistant clone expressing the CMY-16 AmpC-type β-lactamase and circulating in Europe since 2003, was sequenced by a MiSeq platform using a paired-end approach. The genome was assembled in 100 scaffolds with a total length of 4,197,318 bp. Analysis of the draft genome sequence revealed the presence of several acquired resistance determinants to β-lactams, aminoglycosides, phenicols, tetracyclines, trimethoprim, and sulfonamides, of one plasmid replicon, and of a type I-E clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein (Cas) adaptive immune system

CTX-M and Plasmid-mediated AmpC-Producing Enterobacteriaceae, Singapore

10.3201/eid1006.030726Emerging Infectious Diseases1061172-117

Characterization of two new CTX-M-25-group extended-spectrum β-lactamase variants identified in Escherichia coli isolates from Israel.

OBJECTIVES: We characterized two new CTX-M-type extended-spectrum β-lactamase (ESBL) variants in Escherichia coli isolates from stool samples of two elderly patients admitted at the Tel Aviv Sourasky Medical Center, Israel. Both patients underwent treatment with cephalosporins prior to isolation of the E. coli strains. METHODS: ESBLs were detected by the double-disk synergy test and PCR-sequencing of β-lactamase genes. The bla(CTX-M) genes were cloned into the pCR-BluntII-TOPO vector in E. coli TOP10. The role of amino-acid substitutions V77A and D240G was analyzed by site-directed mutagenesis of the bla(CTX-M-94) and bla(CTX-M-100) genes and comparative characterization of the resulting E. coli recombinants. MICs of β-lactams were determined by Etest. Plasmid profiling, mating experiments, replicon typing and sequencing of bla(CTX-M) flanking regions were performed to identify the genetic background of the new CTX-M variants. RESULTS: The novel CTX-M β-lactamases, CTX-M-94 and -100, belonged to the CTX-M-25-group. Both variants differed from CTX-M-25 by the substitution V77A, and from CTX-M-39 by D240G. CTX-M-94 differed from all CTX-M-25-group enzymes by the substitution F119L. Glycine-240 was associated with reduced susceptibility to ceftazidime and leucine-119 with increased resistance to ceftriaxone. bla(CTX-M-94) and bla(CTX-M-100) were located within ISEcp1 transposition units inserted into ∼93 kb non-conjugative IncFI and ∼130 kb conjugative IncA/C plasmids, respectively. The plasmids carried also different class 1 integrons. CONCLUSIONS: This is the first report on CTX-M-94 and -100 ESBLs, novel members of the CTX-M-25-group

SHV Lactamase Engineering Database: a reconciliation tool for SHV β-lactamases in public databases

<p>Abstract</p> <p>Background</p> <p>SHV β-lactamases confer resistance to a broad range of antibiotics by accumulating mutations. The number of SHV variants is steadily increasing. 117 SHV variants have been assigned in the SHV mutation table (<url>http://www.lahey.org/Studies/</url>). Besides, information about SHV β-lactamases can be found in the rapidly growing NCBI protein database. The SHV β-Lactamase Engineering Database (SHVED) has been developed to collect the SHV β-lactamase sequences from the NCBI protein database and the SHV mutation table. It serves as a tool for the detection and reconciliation of inconsistencies, and for the identification of new SHV variants and amino acid substitutions.</p> <p>Description</p> <p>The SHVED contains 200 protein entries with distinct sequences and 20 crystal structures. 83 protein sequences are included in the both the SHV mutation table and the NCBI protein database, while 35 and 82 protein sequences are only in the SHV mutation table and the NCBI protein database, respectively. Of these 82 sequences, 41 originate from microbial sources, and 22 of them are full-length sequences that harbour a mutation profile which has not been classified yet in the SHV mutation table. 27 protein entries from the NCBI protein database were found to have an inconsistency in SHV name identification. These inconsistencies were reconciled using information from the SHV mutation table and stored in the SHVED.</p> <p>The SHVED is accessible at <url>http://www.LacED.uni-stuttgart.de/classA/SHVED/</url>. It provides sequences, structures, and a multisequence alignment of SHV β-lactamases with the corrected annotation. Amino acid substitutions at each position are also provided. The SHVED is updated monthly and supplies all data for download.</p> <p>Conclusions</p> <p>The SHV β-Lactamase Engineering Database (SHVED) contains information about SHV variants with reconciled annotation. It serves as a tool for detection of inconsistencies in the NCBI protein database, helps to identify new mutations resulting in new SHV variants, and thus supports the investigation of sequence-function relationships of SHV β-lactamases.</p