Aeromonas

Abstract

Ae.ro.mo' nas . Gr. n. aer air, gas; Gr. n. monas unit, monad; M.L. fem. n. Aeromonas gas(‐producing) monad. Proteobacteria / Gammaproteobacteria / Aeromonadales / Aeromonadaceae / Aeromonas Cells straight, coccobacillary to bacillary with rounded ends, 0.3–1.0 × 1.0–3.5 µm. Occur singly, in pairs, or rarely in short chains. Gram negative. Most species are motile by a single, polar flagellum of 1.7 µm wavelength; peritrichous flagella may be formed on solid media in young cultures and lateral flagella occur in some species. Facultatively anaerobic. Chemoorganotrophic, displaying oxidative and fermentative metabolism of D ‐glucose. Acid and often acid with gas produced from many carbohydrates, especially D ‐glucose. Nitrate is reduced to nitrite. A variety of exoenzymes such as arylamidases, amylase, DNase, esterases, peptidases, and other hydrolytic enzymes are produced. Main cellular fatty acids are hexadecanoic acid (C 16:0 ), hexadecenoic acid (C 16:1 ), and octadecenoic acid (C 18:1 ). Usually oxidase positive and catalase positive . Optimum growth temperature varies between 22°C and 37°C; growth temperature can range from 0 to 45°C, and some species do not grow at 35°C. Generally resistant to 150 μg of the vibriostatic agent 2,4 diamino‐6, 7‐diisopropylpteridine (0/129) . Occur in fresh, brackish, tap, well, and chlorinated water, as well as biosolids and sewage. Some of the species have been associated with disease in a wide variety of warm‐blooded and cold‐blooded animals, including humans, domestic animals, frogs, fresh and salt water fish, and invertebrates. The phylogenetic position of Aeromonas , as determined by 16S rRNA gene sequence analysis, is in the Gammaproteobacteria , with its closest relatives in the families Vibrionaceae and Enterobacteriaceae . 16S rDNA sequences (signature sequences) have been determined for nearly all validly named species and are deposited in GenBank, EMBL, or RDP databases (Table BXII.γ180). The mol % G + C of the DNA is : 57–63. Type species : Aeromonas hydrophila (Chester 1901) Stanier 1943, 213 ( Bacillus hydrophilus Chester 1901 , 235.)

Three species ofAeromonas(A. dhakensis, A. hydrophila and A. jandaei) isolated from freshwater crocodiles (Crocodylus siamensis) with pneumonia and septicemia

“…All isolates were Gram‐negative and rod‐shaped. According to online Bergey's Manual of Systematic Archaea and Bacteria (Martin‐Carnahan and Joseph ), all isolates were identified as Aeromonas by being positive for catalase, oxidase, lysine decarboxylase, arginine dihydrolase and d ‐glucose, and negative for ornithine decarboxylase, urease, citrate and lactose (Table ). Aeromonads can be differentiated from Enterobacteriaceae by the oxidase test, for which aeromonads are positive.…”

“…The grown colonies were subjected to Gram staining followed by microscopy. Biochemical identification of the isolates was performed in accordance with Bergey's Manual of Determinative Bacteriolo gy (9th edn., Martin‐Carnahan and Joseph ).…”

Seasonal and spatial patterns of microbial diversity along a trophic gradient in the interconnected lakes of the Osterseen Lake District, Bavaria

“…The high abundance of Aeromonas and Acinetobacter still point to the eu-mesotrophic past of the lake, even though the phosphate concentrations of <5 μg/L at the time of sampling seem to indicate oligotrophic nutrient conditions. Both genera are frequently found in fresh and brackish waters, but also in waste water (Towner et al, 1991 ; Martin-Carnahan and Joseph, 2005 ). Many species within those genera are known pathogens, although due to the limited length of the sequence reads there is no conclusive evidence whether the OTUs found in this lake are pathogenic.…”

Host Matters: Medicinal Leech Digestive-Tract Symbionts and Their Pathogenic Potential

“…In contrast to highly specialized symbiotic bacteria that must live in close association with their host, Aeromonas spp. can succeed in a wide range of habitats ( Martin-Carnahan and Joseph, 2005 ). A. veronii is capable of proliferating as a symbiont in digestive tracts of leeches and zebrafish ( Bates et al, 2007 ; Roeselers et al, 2011 ; Nelson and Graf, 2012 ), subsisting as free-living cells within aquatic environments, and causing diseases in fish and mammals ( Janda and Abbott, 2010 ; Beaz-Hidalgo and Figueras, 2013 ; Hossain et al, 2014 ).…”