The objectives of the study were to investigate the distribution of cphA-related genes (cphA) encoding a CphA metallo-β-lactamase (MBL) among 51 consecutive Aeromonas blood isolates and to compare different phenotypic methods for detecting CphA. The presence of cphA was detected by PCR. Four phenotypic methods, the imipenem-EDTA combined disc test, imipenem-EDTA MBL Etest, agar dilution test and modified Hodge test (MHT), were used to detect imipenem susceptibility and MBL production. The results showed that 35 (69 %) blood isolates had cphA. All (100 %) of 16 Aeromonas aquariorum isolates and 12 Aeromonas veronii isolates, and 4 (80 %) of 5 Aeromonas hydrophila isolates, carried cphA, but none of 15 Aeromonas caviae isolates did. With the standard inocula, irrespective of the presence or absence of cphA, all but one (50, 98 %) isolates were susceptible to imipenem tested by disc diffusion, Etest and agar dilution (104 c.f.u. spot inocula), and did not exhibit MBL production by the imipenem-EDTA combined disc test and MBL Etest. By the agar dilution test using large inocula (107 c.f.u.), 34 (97 %) of 35 cphA+ isolates had imipenem MICs of ≥16 µg ml−1, higher than the susceptible breakpoint (4 µg ml−1), and demonstrated positive results for the MHT, while one cphA+ and all 17 cphA− isolates had imipenem MICs of ≤4 µg ml−1. In conclusion, the distribution of cphA among aeromonads is species-specific, found in A. aquariorum, A. veronii and A. hydrophila, and the MHT may be a phenotypic screening test for CphA production.
Aravena-RománM.,
HarnettG. B.,
RileyT. V.,
InglisT. J.,
ChangB. J.2011; Aeromonas aquariorum is widely distributed in clinical and environmental specimens and can be misidentified as Aeromonas hydrophila
. J Clin Microbiol 49:3006–3008 [View Article][PubMed]
BalsalobreL. C.,
DropaM.,
LincopanN.,
MamizukaE. M.,
MattéG. R.,
MattéM. H.2009; Detection of metallo-β-lactamases-encoding genes in environmental isolates of Aeromonas hydrophila and Aeromonas jandaei
. Lett Appl Microbiol 49:142–145 [View Article][PubMed]
CLSI2009; Performance Standards for Antimicrobial Susceptibility Testing; 19th Informational Supplement. M100-S19. Wayne, PA: Clinical and Laboratory Standards Institute;
CLSI2010; Methods for Antimicrobial Dilution and Disk Susceptibility Testing of Infrequently Isolated or Fastidious Bacteria; Approved Guideline M45-A2. Wayne, PA: Clinical and Laboratory Standards Institute;
FiguerasM. J.,
AlperiA.,
SaavedraM. J.,
KoW. C.,
GonzaloN.,
NavarroM.,
Martínez-MurciaA. J.2009; Clinical relevance of the recently described species Aeromonas aquariorum
. J Clin Microbiol 47:3742–3746 [View Article][PubMed]
FosseT.,
Giraud-MorinC.,
MadinierI.2003; [Phenotypes of beta-lactam resistance in the genus Aeromonas]. Pathol Biol (Paris) 51:290–296 (in French) [View Article][PubMed]
ItohH.,
KuwataG.,
TateyamaS.,
YamashitaK.,
InoueT.,
KataokaH.,
IdoA.,
OgataK.,
TakasakiM.other authors1999; Aeromonas sobria infection with severe soft tissue damage and segmental necrotizing gastroenteritis in a patient with alcoholic liver cirrhosis. Pathol Int 49:541–546 [View Article][PubMed]
LamyB.,
LaurentF.,
KodjoA.2010; Validation of a partial rpoB gene sequence as a tool for phylogenetic identification of aeromonads isolated from environmental sources. Can J Microbiol 56:217–228 [View Article][PubMed]
MassiddaO.,
RossoliniG. M.,
SattaG.1991; The Aeromonas hydrophila cphA gene: molecular heterogeneity among class B metallo-β-lactamases. J Bacteriol 173:4611–4617[PubMed]
MouësC. M.,
VosM. C.,
van den BemdG. J.,
StijnenT.,
HoviusS. E.2004; Bacterial load in relation to vacuum-assisted closure wound therapy: a prospective randomized trial. Wound Repair Regen 12:11–17 [View Article][PubMed]
MukhopadhyayC.,
BhargavaA.,
AyyagariA.2003; Aeromonas hydrophila and aspiration pneumonia: a diverse presentation. Yonsei Med J 44:1087–1090[PubMed][CrossRef]
NeuwirthC.,
SieborE.,
RobinF.,
BonnetR.2007; First occurrence of an IMP metallo-β-lactamase in Aeromonas caviae: IMP-19 in an isolate from France. Antimicrob Agents Chemother 51:4486–4488 [View Article][PubMed]
RossoliniG. M.,
ZanchiA.,
ChiesurinA.,
AmicosanteG.,
SattaG.,
GuglielmettiP.1995; Distribution of cphA or related carbapenemase-encoding genes and production of carbapenemase activity in members of the genus Aeromonas
. Antimicrob Agents Chemother 39:346–349[PubMed][CrossRef]
RossoliniG. M.,
WalshT.,
AmicosanteG.1996; The Aeromonas metallo-β-lactamases: genetics, enzymology, and contribution to drug resistance. Microb Drug Resist 2:245–252 [View Article][PubMed]
Sánchez-CéspedesJ.,
FiguerasM. J.,
AspirozC.,
AldeaM. J.,
ToledoM.,
AlperíA.,
MarcoF.,
VilaJ.2009; Development of imipenem resistance in an Aeromonas veronii biovar sobria clinical isolate recovered from a patient with cholangitis. J Med Microbiol 58:451–455 [View Article][PubMed]
SegatoreB.,
MassiddaO.,
SattaG.,
SetacciD.,
AmicosanteG.1993; High specificity of cphA-encoded metallo-β-lactamase from Aeromonas hydrophila AE036 for carbapenems and its contribution to β-lactam resistance. Antimicrob Agents Chemother 37:1324–1328[PubMed][CrossRef]
TalaveraB. M. M.,
BenassiF. O.,
von SpechtM. H.,
QuirogaM. I.,
GarcíaM. A.,
PucciarelliA. B.,
ZubreskiE.,
LaczeskiM. E.,
GutkindG.2006; Susceptibilities to carbapenems and presence of cphA gene on food-borne Aeromonas
. Braz Arch Biol Technol 49:677–682 [View Article]
WuC. J.,
WuJ. J.,
YanJ. J.,
LeeH. C.,
LeeN. Y.,
ChangC. M.,
ShihH. I.,
WuH. M.,
WangL. R.,
KoW. C.2007; Clinical significance and distribution of putative virulence markers of 116 consecutive clinical Aeromonas isolates in southern Taiwan. J Infect 54:151–158 [View Article][PubMed]
YongD.,
LeeK.,
YumJ. H.,
ShinH. B.,
RossoliniG. M.,
ChongY.2002; Imipenem-EDTA disk method for differentiation of metallo-β-lactamase-producing clinical isolates of Pseudomonas spp. and Acinetobacter spp. J Clin Microbiol 40:3798–3801 [View Article][PubMed]