Emergence of VIM-producing Aeromonas caviae in Israeli hospitals

J Antimicrob Chemother. 2014 May;69(5):1211-4. doi: 10.1093/jac/dkt505. Epub 2014 Jan 2.

Abstract

Objectives: Resistance to carbapenems in Aeromonas species is rare and mediated mostly by the chromosomal cphA gene. Our aims were to describe the molecular characteristics of the first cases of VIM-producing Aeromonas caviae isolated from human samples.

Methods: Carbapenem-resistant Aeromonas (CRA) spp. were isolated from rectal surveillance cultures. Bacterial identification was done by dnaJ sequencing. Detection of metallo-carbapenemase and other β-lactamase genes was done by PCR. Molecular typing was done by PFGE. The genetic environment of the blaVIM gene was determined by sequencing.

Results: Five CRA were isolated from surveillance cultures in 2010-13; four were from Shaare Zedek Medical Center and one was from Laniado Hospital. All five isolates were identified as A. caviae and comprised four different pulsotypes. MICs ranged from 0.5 to 8 mg/L for imipenem and from 0.25 to 8 mg/L for meropenem. All isolates were resistant to gentamicin, susceptible to amikacin and ciprofloxacin (except one), and were positive for carbapenemase production in the modified Hodge and Carba NP tests. The carbapenemase genes blaVIM-1 and blaVIM-35 were located inside a class I integron with two different sizes to its variable region.

Conclusions: This is the first report of blaVIM in A. caviae from human samples and the first report of VIM-producing Gram-negative bacteria in Israel. This finding is alarming as this species may spread via water or sewage systems. Although infection due to Aeromonas spp. is rare, the presence of the gene on a mobile element is of concern due to the potential for dissemination to clinically important Gram-negative pathogens.

Keywords: Aeromonas spp.; VIM carbapenemases; integrins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aeromonas caviae / enzymology*
  • Aeromonas caviae / genetics*
  • Aeromonas caviae / isolation & purification
  • Anti-Bacterial Agents / pharmacology
  • Cross Infection / epidemiology
  • Cross Infection / microbiology*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Gram-Negative Bacterial Infections / epidemiology
  • Gram-Negative Bacterial Infections / microbiology*
  • Hospitals
  • Humans
  • Interspersed Repetitive Sequences
  • Israel / epidemiology
  • Microbial Sensitivity Tests
  • Sequence Analysis, DNA
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • DNA, Bacterial
  • beta-Lactamases