Aeromonas

Abstract Ae.ro.mo'nas. Gr. n. aer air, gas; Gr. n. monas unit, monad; M.L. fem. n. Aeromonas gas(‐producing) monad. 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.) Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus Aeromonas is: correct name (last update, February 2025) * . LPSN classification: Bacteria / Pseudomonadati / Pseudomonadota / Gammaproteobacteria / Aeromonadales / Aeromonadaceae / Aeromonas The genus Aeromonas can also be recovered in the Genome Taxonomy Database (GTDB) as g__Aeromonas (version v220) ** . GTDB classification: d__Bacteria / p__Pseudomonadota / c__Gammaproteobacteria / o__Enterobacterales / f__Aeromonadaceae / g__Aeromonas * Meier‐Kolthoff et al. ( 2022 ). Nucleic Acids Res , 50 , D801 – D807 ; DOI: 10.1093/nar/gkab902 ** Parks et al. ( 2022 ). Nucleic Acids Res , 50 , D785 – D794 ; DOI: 10.1093/nar/gkab776