Misidentification of Aeromonas veronii biovar sobria as Vibrio alginolyticus by the Vitek system

Abstract

Aims: To find the cause of misidentification of aeromonads when using the Vitek system. Methods and Results: Two Aeromonas veronii biovar sobria isolates were misidentified as Vibrio alginolyticus by the Vitek system. Both strains' identification was confirmed by biochemical testing, API 20E/20NE kits and/or 16S RFLP analysis. Thirty-one known Aeromonas species were tested by the Vitek system using 0AE45 and 0AE85% saline in the suspension medium. It was not clear whether low salinity causes misidentification of Aeromonas species more frequently. Conclusions: The specified reaction time may be inappropriately short for some critical biochemical tests of some strains. An ingenious reading strategy regarding incubation time is necessary to improve identification of Aeromonas species by the Vitek system. Significance and Impact of the Study: To our knowledge, this is the first report of misidentification of A. veronii biovar sobria as V. alginolyticus in the Vitek system.

Evaluation of Two Miniaturized Systems, MicroScan W/A and BBL Crystal E/NF, for Identification of Clinical Isolates of Aeromonas spp

“…The tendency of miniaturized biochemical identification systems to confuse Aeromonas isolates with Vibrio isolates noticed in our study was already known (2,19). In our case, MicroScan misidentified eight isolates (10.8%) as Vibrio fluvialis, results similar to those reported by Vivas et al (21).…”

Detection of hemolytic strains of Aeromonas hydrophila and A. sobria along with other Aeromonas spp. from fish and fishery products by multiplex PCR

“…The few contradictory results obtained by conventional biochemical tests and multiplex PCR assay in respect of A. hydrophila were analyzed in detail. There were reports that biochemical confirmation at times lacks specificity for some strains of bacterial pathogens (Park et al 2003;Beaz-Hidalgo et al 2010) and it need not be the same for all species. In this work, four isolates of A. hydrophila biochemically confirmed did not show the presence of hemolysin gene, ahh1 in the multiplex PCR assay.…”

Molecular Detection and Characterization of Furunculosis and Other Aeromonas Fish Infections

“…Some other authors have also reported poor results from the API systems and discrepancies with traditional tube testing when identifying Aeromonas strains isolated from fish (Godoy et al, 2010;Han et al, 2011;Joseph & Carnahan, 1994;and references therein). Some methods may even misidentify Aeromonas strains as Vibrio species (Park et al, 2003;Soler et al, 2003b). To avoid this confusion, Chacón and colleagues designed a specific probe based on a fragment of the glycerophospholipid-cholesterol acyltransferase (GCAT) gene that is able to hybridize with all Aeromonas species but not with strains from other genera .…”

“…the "A. hydrophila" complex (including A. hydrophila, A. bestiarum and A. salmonicida and also latter A. popoffii), the "Aeromonas caviae" complex (including A. caviae, A. media and A. eucrenophila) and "Aeromonas sobria" complex (including A. sobria, A. veronii, A. jandaei and A. trota) (Abbott et al, 1992;2003;Borrell et al, 1998;Kozińska et al, 2002;Martin-Carnahan & Joseph, 2005;Martínez-Murcia et al, 2005). In the descriptions of new Aeromonas species, the mandatory criteria of identifying differential phenotypic tests from other existing Aeromonas species has been fulfilled (Figueras et al, 2011b and references therein).…”

“…Miniaturized commercial identification systems, such as API (20E, 20NE), Vitek, Biolog GN Microplates, BBL Crystal or MicroScan Walk/Away are also routinely used in ichthyopathology laboratories, but are not always able to identify Aeromonas species precisely (Figueras, 2005;Joseph & Carnahan, 1994;Kozińska et al, 2002;Park et al, 2003;Soler et al, 2003a). The mentioned systems normally tend to identify all Aeromonas strains as A. hydrophila (Figueras, 2005;Soler et al, 2003b).…”