1621. Emergence of VIM-producing Aeromonas caviae in Israeli hospitals
Session: Poster Abstract Session: Multidrug-Resistant Gram Negative Rods
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Background:

Aeromonas species are globally distributed in the aquatic environment. Resistance to carbapenems 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 caviaeisolated from human samples from two hospitals.

Methods:

Carbapenem-resistant Aeromonas (CRA) spp. were isolated from rectal surveillance cultures using CHROMagar™ KPC media.  Bacterial identification was done by dnaJ sequencing.  Antimicrobial susceptibility testing was done by agar dilution and via the VITEK-2 system.  Detection of metallo-β-lactamase and other β-lactamase genes was done by PCR. Molecular typing was done by PFGE.  The location of the blaVIM gene was determined by plasmid transformation into the E. coli DH10B strain, S1-nuclease analysis and Southern blot.  The genetic environment of the blaVIMgene was determined by sequencing.

Results:

Four CRA isolates were identified in hospital 1 and one in hospital 2 in 2012-2013, all from surveillance cultures.  Carbapenem MIC ranges were 0.5-8 µg/ml for ertapenem and imipenem and 0.25-8 µg/ml for meropenem.  All isolates were resistant to gentamicin and susceptible to amikacin and ciprofloxacin.  All isolates were positive by the modified Hodge test and showed synergy between ertapenem and EDTA.  All isolates were Aeromonas caviae, comprising 4 different PFGE types.  The carbapenemase genes were blaVIM-1 and blaVIM-35; other carbapenemase genes, including cphA, were not identified.  The blaVIMgene was located on a class 1 integron.  It was detected by Southern blot on a ~25-kb plasmid in all isolates, although transformation was successful in only one.  This plasmid was non-typeable by replicon typing.

Conclusion:

This study is the first report of a plasmid-borne blaVIM gene in Aeromonas isolated from human samples and the first report of VIM-producing gram-negative bacteria in Israel.  These findings are alarming as this species may spread via water or sewage systems within the hospital or out to the community.  Although clinical infection due to Aeromonas spp. is rare, the presence of the gene on mobile elements is of concern due to the potential for dissemination to other clinically important gram-negative pathogens.

Amos Adler1, Marc V. Assous2, Svetlana Paikin3, Anastasia Shulman1, Sarah Hillel2, Rima Aronov3, Yehuda Carmeli1 and Mitchell J. Schwaber, MD1, (1)National Center for Infection Control, Tel Aviv, Israel, (2)Shaare Zedek Medical Center, Jerusalem, Israel, (3)Laniado Hospital, Netanya, Israel

Disclosures:

A. Adler, None

M. V. Assous, None

S. Paikin, None

A. Shulman, None

S. Hillel, None

R. Aronov, None

Y. Carmeli, None

M. J. Schwaber, None

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