title: Increasing prevalence and dissemination of NDM-1 metallo-β-lactamase in India: data from the SMART study (2009).
abstract: OBJECTIVE
  To investigate the β-lactamase background of ertapenem non-susceptible isolates for the presence of the most commonly detected carbapenemase genes, bla(KPC), bla(OXA-48) and bla(VIM), and the newly described bla(NDM-1).
  
  
  METHODS
  Two hundred and thirty-five ertapenem-non-susceptible (MIC ≥ 0.5 mg/L) isolates of Enterobacteriaceae from the worldwide Study for Monitoring Antimicrobial Resistance Trends (SMART) 2009 programme were screened using a multiplex PCR for the presence of bla(KPC), bla(OXA-48), bla(VIM) and bla(NDM-1) genes. Extended-spectrum β-lactamase (ESBL) and AmpC genes (bla(ESBL) and bla(AmpC)) were identified using the Check-MDR CT101 microarray. DNA sequencing was performed to identify the bla(ESBL), bla(KPC) and bla(NDM-1) genes. Molecular typing was also performed to genetically characterize these isolates.
  
  
  RESULTS
  Sixty-six isolates (28%) had a carbapenemase gene, with bla(NDM-1) identified in 33 isolates including 2 isolates carrying both bla(NDM-1) and bla(OXA-48); other carbapenemase genes found included bla(KPC) (n = 23), bla(VIM) (n = 7) and bla(OXA-48) (n = 3). All bla(NDM-1)-carrying isolates were from patients in India and comprised five different species. With the exception of one isolate carrying only bla(NDM-1), all bla(NDM-1) carbapenemase-possessing isolates carried additional β-lactamases in various combinations: bla(ESBL) and bla(AmpC) (n = 18); bla(ESBL) (n = 10); bla(ESBL), bla(AmpC) and bla(OXA-48) (n = 2); and bla(AmpC) (n = 2). Except for bla(OXA-48)-carrying isolates, novel multilocus sequence types or enterobacterial repetitive intergenic consensus PCR patterns were observed along with clonal dissemination within and among sites.
  
  
  CONCLUSIONS
  A range of carbapenemase genes, associated with diverse ESBLs and/or AmpC backgrounds, were found among Enterobacteriaceae isolated during the study. Many of these ertapenem non-susceptible strains were clonally related and carried various combinations of β-lactamases.
authors.affiliation: International Health Management Associates, Inc., Schaumburg, IL 60173, USA. clascols@ihmainc.com
authors.forename: Christine
authors.initials: C
authors.lastname: Lascols
authors.forename: Meredith
authors.initials: M
authors.lastname: Hackel
authors.forename: Steven H
authors.initials: SH
authors.lastname: Marshall
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Hujer
authors.forename: Sam
authors.initials: S
authors.lastname: Bouchillon
authors.forename: Robert
authors.initials: R
authors.lastname: Badal
authors.forename: Daryl
authors.initials: D
authors.lastname: Hoban
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bonomo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000201:enzymology / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D014644:Genetic Variation; D006801:Humans; D007194:India / Q000453:epidemiology; D046228:Microarray Analysis; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D001618:beta-Lactamases / Q000235:genetics*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1