The Genus Aeromonas : Biochemical Characteristics, Atypical Reactions, and Phenotypic Identification Schemes

Abstract

A total of 193 strains representing 14 different Aeromonas genomospecies were evaluated for 63 phenotypic properties to create useful tables for the reference identification of mesophilic aeromonads. Only 9 of 62 biochemical tests (14%) yielded uniform results, and the fermentation of certain carbohydrates was found to be linked to specific species. A number of unusual or aberrant properties for the genus Aeromonas were also detected in the collection of 428 strains (193 in the phenotypic study, 235 in a retrospective review). These tests included susceptibility to the vibriostatic agent, fermentation of m-inositol and D-xylose, hydrolysis of urea, and the lack of cytochrome oxidase activity. Fermentation of melibiose was linked to raffinose fermentation in all Aeromonas species except A. jandaei. Keys are provided for clinical laboratories choosing to identify aeromonads to species level based upon initial Møeller decarboxylase and dihydrolase reactions. In addition, several new tests were identified that help to separate members of the A. caviae complex (A. caviae, A. media, and A. eucreonophila).

Multilocus sequence typing revealed a clonal lineage of Aeromonas hydrophila caused motile Aeromonas septicemia outbreaks in pond-cultured cyprinid fish in an epidemic area in central China

“…Aeromonas genus-specific polymerase chain reaction (PCR) detection was carried out as previously described (Lee et al, 2002). All isolates were positively amplified and were further confirmed as members of the genus Aeromonas in terms of motility, positive reactions for both oxidase and catalase, fermentation of glucose and resistance to O/129 on a 150 μg disk (Abbott et al, 2003). To further identify the species of these isolates, the gyrB gene was amplified and sequenced with previously described primers (Yáñez et al, 2003).…”

“…We found that A. hydrophila was responsible for these MAS Aquaculture 432 (2014) 1-6 outbreaks. A. hydrophila isolates were previously studied to be phenotypically, serologically, and genetically diverse (Abbott et al, 2003;Aguilera-Arreola et al, 2005;Szczuka and Kaznowski, 2004;Thomas et al, 1990). Thus, we used a recently developed precise method of multilocus sequence typing (MLST) to evaluate the population structure of MAS outbreak isolates of A. hydrophila.…”

Identification error of Aeromonas aquariorum: A causative agent of septicemia

“…We previously reported that Aeromonas septicemia 34 occurred frequently in hospitalized patients with underlying diseases including malignancy in 35 Japan (Morinaga, et al, 2011). Phenotypical differentiation of the genus Aeromonas or its 36 species has been recognized to be difficult because of the non-uniform biochemical reactions, 37and can lead to misidentification (Abbott, Cheung, & Janda, 2003; Aravena-Roman, Harnett, 38 Riley, Inglis, & Chang, 2011; Figueras, 2005; Figueras, Beaz-Hidalgo, Senderovich, Laviad, 39 & Halpern, 2011). The acid production from arabinose and the production of urocanic acid 40 and sodium dodecyl sulfate have been proposed for discriminating A. aquariorum from other 41 species (Esteve, Alcaide, & Blasco, 2012), but the molecular identification has been 42 emphasized as an alternative method for the correct identification (Figueras, Beaz-Hidalgo, 43 Collado, & Martínez-Murcia, 2011; Puthucheary, Puah, & Chua, 2012).…”

Prevalence of Hemolytic and Enterotoxigenic Aeromonas Spp. in Healthy and Diseased Freshwater Food Fishes as Assessed by Multiplex PCR

“…Bin Kingombe et al (1999) reported that the detection of the ampicilin-sensitive A. trota is relatively low in food samples. Moreover, most often these strains are conventionally identified correctly to the genus level, but incorrectly to the species level, due to lack of biochemical tests in distinguishing these species (Abbott et al, 2003) or the difference in the prevalence are related to geographical distribution. However, the prevalence of one or more toxin gene, as observed in this study, among these isolates cannot be underestimated, as harbouring any of these toxin genes may be hazardous (Bin Kingombe et al, 2010).…”