Outbreak of Citrobacter freundii carrying VIM-1 in an Italian Hospital, identified during the carbapenemases screening actions, June 2012

Int J Infect Dis. 2013 Sep;17(9):e714-7. doi: 10.1016/j.ijid.2013.02.007. Epub 2013 Mar 23.

Abstract

Objective: The identification of patients colonized or infected with carbapenemase-producing Enterobacteriaceae (CPE), in order to control and prevent the global spread of multidrug-resistant (MDR) pathogens.

Methods: From June 1 to June 15, 2012, eight Citrobacter freundii strains with reduced susceptibility to carbapenems were isolated from rectal swabs of hospitalized patients during active screening following the detection of a Klebsiella pneumoniae carbapenemase (KPC) -positive patient on the ward. All isolates were analyzed phenotypically and molecularly by PCR and sequencing. Genotype clustering was performed by multilocus sequence typing (MLST) analysis.

Results: The isolates showed high rates of multidrug resistance profile. A phenotypic assay for carbapenemase production suggested the presence of metallo-β-lactamase (MBL). The blaVIM-1 gene was detected in all imipenem-resistant C. freundii isolates. MLST showed that the C. freundii isolates shared the same sequence type (ST). Phylogenetic analysis revealed a strict relationship with an ST5C. freundii isolate from a diarrhea patient in China.

Conclusions: Our findings showed that the active surveillance program for CPE was useful, not only for the detection of KPC-producers, but also to identify and control the spread of other MDR pathogens that could expand the spectrum of circulating MDR pathogens.

Keywords: Citrobacter freundii; Italy; MLST; VIM-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology
  • Citrobacter freundii / classification
  • Citrobacter freundii / drug effects
  • Citrobacter freundii / genetics*
  • Cross Infection / epidemiology*
  • Cross Infection / microbiology
  • Disease Outbreaks*
  • Enterobacteriaceae Infections / epidemiology*
  • Enterobacteriaceae Infections / microbiology
  • Female
  • Hospitals
  • Humans
  • Italy / epidemiology
  • Male
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Phylogeny
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • VIM-1 metallo-beta-lactamase
  • beta-Lactamases