Multi-locus variable number of tandem repeat analysis for rapid and accurate typing of virulent multidrug resistant Escherichia coli clones.

One hundred E. coli isolates from Norway (n = 37), Sweden (n = 24), UK (n = 20) and Spain (n = 19), producing CTX-M-type - (n = 84), or SHV-12 (n = 4) extended spectrum β-lactamases, or the plasmid mediated AmpC, CMY-2 (n = 12), were typed using multi-locus sequence typing (MLST) and multi-locus variable number of tandem repeat analysis (MLVA). Isolates clustered into 33 Sequence Types (STs) and 14 Sequence Type Complexes (STCs), and 58 MLVA-Types (MTs) and 25 different MLVA-Type Complexes (MTCs).

Characterization of Enterobacteriaceae producing OXA-48-like carbapenemases in the UK.

Objectives: To characterize UK clinical isolates of Enterobacteriaceae producing OXA-48-like carbapenemases and to compare their resistance plasmids.

Methods: Twenty-six enterobacteria producing OXA-48-like enzymes were studied. These were from 22 diverse hospitals in the UK.

Dissemination of pCT-like IncK plasmids harboring CTX-M-14 extended-spectrum β-lactamase among clinical Escherichia coli isolates in the United Kingdom.

IncK plasmids encoding CTX-M-14 extended-spectrum β-lactamase (ESBL) and highly related to plasmid pCT were detected in 13 of 67 (19%) human clinical isolates of Escherichia coli with a group 9 CTX-M-type ESBL from the United Kingdom and in 2 quality assurance isolates. None of these E. coli strains was related to the cattle strain from which pCT was originally characterized.

Characterization of plasmids encoding extended-spectrum β-lactamases and their addiction systems circulating among Escherichia coli clinical isolates in the UK.

Objectives: To characterize plasmids encoding extended-spectrum β-lactamases (ESBLs) from a recent UK collection of clinical Escherichia coli isolates.

Methods: The isolates comprised 118 ESBL producers referred from 54 laboratories. Plasmids were transferred by electroporation, and their incompatibility groups, associated addiction systems and resistance genes with the flanking genetic environments were identified by PCR or sequencing.

ISEcp1-mediated transposition of linked blaCTX-M-3 and blaTEM-1b from the IncI1 plasmid pEK204 found in clinical isolates of Escherichia coli from Belfast, UK.

Objectives: Linked bla(CTX-M-3)-bla(TEM-1b) genes, as found on the IncI1 plasmid pEK204 prevalent in Belfast, also occur on plasmids belonging to other rep types in Escherichia coli isolated from nursing-home residents in Belfast. We investigated the mechanisms for their joint dissemination among diverse plasmids.

Methods: Plasmid pEK204 was transferred by electroporation into E.

False extended-spectrum {beta}-lactamase phenotype in clinical isolates of Escherichia coli associated with increased expression of OXA-1 or TEM-1 penicillinases and loss of porins.

Objectives: Two clinical isolates of Escherichia coli, EC18 and EC21, were non-susceptible (MICs 4-16 mg/L) to cefpirome and cefepime, with marked synergy with clavulanate, yet were susceptible to cefotaxime and ceftazidime (MICs ≤ 1 mg/L). EC19, from the same patient as EC21, was susceptible to all four cephalosporins. We sought to characterize the molecular basis of resistance in isolates EC18 and EC21.

Phosphoethanolamine modification of lipid A in colistin-resistant variants of Acinetobacter baumannii mediated by the pmrAB two-component regulatory system.

Colistin resistance is rare in Acinetobacter baumannii, and little is known about its mechanism. We investigated the role of PmrCAB in this trait, using (i) resistant and susceptible clinical strains, (ii) laboratory-selected mutants of the type strain ATCC 19606 and of the clinical isolate ABRIM, and (iii) a susceptible/resistant pair of isogenic clinical isolates, Ab15/133 and Ab15/132, isolated from the same patient. pmrAB sequences in all the colistin-susceptible isolates were identical to reference sequences, whereas resistant clinical isolates harbored one or two amino acid replacements variously located in PmrB.

Variation in the genetic environments of bla(CTX-M-15) in Escherichia coli from the faeces of travellers returning to the United Kingdom.

Objective: The genetic surroundings of bla(CTX-M-15) in Escherichia coli recovered from faeces of travellers returning to the UK from overseas were compared with those among established UK strains to provide further insights into the spread of bla(CTX-M-15) in the UK.

Methods: From August 2006 to January 2008, 1031 faecal specimens were collected at the North West London NHS Trust from general practice patients with a clinical history of diarrhoea following recent international travel. Cefuroxime-resistant E.

Isolation of fluoroquinolone-resistant O25b:H4-ST131 Escherichia coli with CTX-M-14 extended-spectrum β-lactamase from UK river water.

Objectives: We analysed water sampled from the River Thames in London for Escherichia coli resistant to oxyimino-cephalosporins and/or fluoroquinolones, particularly seeking isolates with CTX-M extended-spectrum β-lactamases (ESBLs) and members of the clinically important O25b:H4-ST131 lineage.

Methods: River water was collected from three urban sites on the River Thames by the City of London Port Health Authority on two occasions 1 week apart. Coliforms and E.

Molecular epidemiology of fluoroquinolone-resistant ST131 Escherichia coli producing CTX-M extended-spectrum beta-lactamases in nursing homes in Belfast, UK.

Objectives: Between January 2004 and May 2006 Escherichia coli producing extended-spectrum β-lactamases (ESBLs) were isolated from the faeces of 118/294 residents from 16 nursing homes in Belfast. Of these, 58 isolates belonged to UK strain A, a variant of the international ST131 clone. Here we investigated the remaining 60 ESBL producers.

Cephalosporin resistance mechanisms in Escherichia coli isolated from raw chicken imported into the UK.

Objectives: We characterized mechanisms of resistance to oxyimino-cephalosporins in Escherichia coli isolated from raw chicken meat imported into the UK from South America, to ascertain whether this foodstuff contributes to the dissemination in the UK of extended-spectrum β-lactamase (ESBL)-producing E. coli belonging to the international uropathogenic ST131 clone.

Methods: Sampling and collection of imported raw chicken meat was performed in accordance with regulatory guidelines by the London Port Health Authority at Tilbury.

Real-time PCR for detection of the O25b-ST131 clone of Escherichia coli and its CTX-M-15-like extended-spectrum beta-lactamases.

CTX-M-15 has become the most prevalent extended-spectrum beta-lactamase amongst Escherichia coli in many countries during the past decade. Its dominance partly reflects the dissemination of an E. coli O25b:H4 ST131 clone that commonly produces this enzyme.

Rapid detection of the O25b-ST131 clone of Escherichia coli encompassing the CTX-M-15-producing strains.

Objectives: Recently, a CTX-M-15 extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli O25b-ST131 clone, belonging to the B2 phylogenetic group and with a high virulence potential, has been reported all over the world, representing a major public health problem. The present study was carried out to develop a rapid and simple detection assay that identifies members of this clone.

Methods: A total of 627 E.