[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]


NDM carbapenemases in the United Kingdom: an analysis of the first 250 cases

Anu Jain 1, Katie L Hopkins 1, Jane Turton 1, Michel Doumith 1, Robert Hill 1, Richard Loy 1, Daniele Meunier 1, Rachel Pike 1, David M. Livermore 1,2 and Neil Woodford 1,*

Author Affiliations: <SUP>1</SUP>Antimicrobial Resistance and Healthcare Associated Infections Reference Unit, Public Health England, London NW9 5EQ, UK <SUP>2</SUP>Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, UK

*Corresponding author. AMRHAI, PHE Reference Microbiology Services, 61 Colindale Avenue, London, NW9 5EQ, UK. Tel: +44 (0)20 8327 7255; E-mail: neil.woodford@phe.gov.uk

Received December 11, 2013. Revision requested January 28, 2014. Revision received March 4, 2014. Accepted March 6, 2014.


Abstract

Objectives

Gram-negative bacteria with diverse carbapenemases, including New Delhi metallo-β-lactamase (NDM) enzymes, have been increasingly recorded in the UK since 2007. We analysed patient data for NDM-positive isolates confirmed by the national reference laboratory from UK laboratories from February 2008 to July 2013.


Methods

Isolates resistant to carbapenems and with imipenem MICs reduced ≥8-fold by EDTA were tested by PCR for genes encoding acquired class B carbapenemases. MICs were determined by BSAC agar dilution methodology. When requested by the sender, or when they were members of apparent clusters, NDM-positive isolates were typed by variable number tandem repeat (VNTR) analysis or PFGE. Data provided by the sending laboratories were collated and reviewed.


Results

From February 2008 to July 2013 the reference laboratory confirmed 326 NDM-positive isolates from 250 patients, submitted by 83 laboratories. Most (85%, 213/250) patients were already hospitalized when the NDM-positive bacteria were detected, were male (61%, 152/250) and were aged >60 years (58%, 145/250). Travel history was available for only 40% of patients, but 52% (53/101) of these had documented healthcare contact within or travel to the Indian subcontinent. Most NDM-positive isolates (94%, 306/326) were Enterobacteriaceae with just 6% (20/326) non-fermenters; the predominant hosts were Klebsiella spp. (55%, 180/326) and Escherichia coli (25%, 80/326). Almost all NDM-positive isolates were resistant to multiple antibiotic classes, but 90% remained susceptible to colistin.


Conclusions

Gram-negative bacteria with NDM carbapenemases are a growing challenge, especially for elderly hospitalized patients, including those with healthcare contact in the Indian subcontinent, and leave few therapeutic options. UK outbreaks remain rare and contained.

Key words: MBLs ? meropenem ? Enterobacteriaceae ? Pseudomonas ? Acinetobacter


? Crown copyright 2014.

-
-------