Enterobacteriaceae is a large family of Gram-negative bacteria. It was first proposed by Rahn in 1936, and now includes over 30 genera and more than 100 species. Its classification above the level of family is still a subject of debate, but one classification places it in the order Enterobacterales of the class Gammaproteobacteria in the phylum Pseudomonadota. In 2016, the description and members of this family were emended based on comparative genomic analyses by Adeolu et al.
Enterobacterales is an order of Gram-negative, non-spore forming, facultatively anaerobic, rod-shaped bacteria with the class Gammaproteobacteria. The type genus of this order is Enterobacter.
Enterobacter is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae. It is the type genus of the order Enterobacterales. Several strains of these bacteria are pathogenic and cause opportunistic infections in immunocompromised hosts and in those who are on mechanical ventilation. The urinary and respiratory tracts are the most common sites of infection. The genus Enterobacter is a member of the coliform group of bacteria. It does not belong to the fecal coliforms group of bacteria, unlike Escherichia coli, because it is incapable of growth at 44.5 °C in the presence of bile salts. Some of them show quorum sensing properties.
Enterobacter cloacae is a clinically significant Gram-negative, facultatively-anaerobic, rod-shaped bacterium.
Pantoea is a genus of Gram-negative bacteria of the family Erwiniaceae, recently separated from the genus Enterobacter. This genus includes at least 20 species. Pantoea bacteria are yellow pigmented, ferment lactose, are motile, and form mucoid colonies. Some species show quorum sensing ability that could drive different gene expression, hence controlling certain physiological activities. Levan polysaccharide produced by Pantoea agglomerans ZMR7 was reported to decrease the viability of rhabdomyosarcoma (RD) and breast cancer (MDA) cells compared with untreated cancer cells. In addition, it has high antiparasitic activity against the promastigote of Leishmania tropica.
Pantoea agglomerans is a Gram-negative bacterium that belongs to the family Erwiniaceae.
Cronobacter sakazakii, which before 2007 was named Enterobacter sakazakii, is an opportunistic Gram-negative, rod-shaped, pathogenic bacterium that can live in very dry places, otherwise known as xerotolerance. C. sakazakii utilizes a number of genes to survive desiccation and this xerotolerance may be strain specific. The majority of C. sakazakii cases are adults but low-birth-weight preterm neonatal and older infants are at the highest risk. The pathogen is a rare cause of invasive infection in infants, with historically high case fatality rates (40–80%).
Ensifer is a genus of nitrogen-fixing bacteria (rhizobia), three of which have been sequenced.
Pluralibacter gergoviae is a Gram-negative, motile, facultatively-anaerobic, rod-shaped bacterium. P. gergoviae is of special interest to the cosmetics industry, as it displays resistance to parabens, a common antimicrobial agent added to cosmetic products.
Cronobacter is a genus of Gram-negative, facultatively anaerobic, oxidase-negative, catalase-positive, rod-shaped bacteria of the family Enterobacteriaceae. Several Cronobacter species are desiccation resistant and persistent in dry products such as powdered infant formula. They are generally motile, reduce nitrate, use citrate, hydrolyze esculin and arginine, and are positive for L-ornithine decarboxylation. Acid is produced from D-glucose, D-sucrose, D-raffinose, D-melibiose, D-cellobiose, D-mannitol, D-mannose, L-rhamnose, L-arabinose, D-trehalose, galacturonate and D-maltose. Cronobacter spp. are also generally positive for acetoin production and negative for the methyl red test, indicating 2,3-butanediol rather than mixed acid fermentation. The type species of the genus Cronobacter is Cronobacter sakazakii comb. nov.
Azospirillum brasilense is a well studied, nitrogen-fixing (diazotroph), genetically tractable, Gram-negative, alpha-proteobacterium bacterium, first described in Brazil by the group of Johanna Döbereiner and then receiving the name "brasilense". A. brasilense is able to fix nitrogen in the presence of low oxygen levels, making it a microaerobic diazotroph. An isolate from the genus Azospirillum was isolated from nitrogen poor soils in the Netherlands in 1925, however the species A. brasilense was first described in 1978 in Brazil, since this genus is widely found in the rhizospheres of grasses around the world where it confers plant growth promotion. Whether growth promotion occurs through direct nitrogen flux from the bacteria to the plant or through hormone regulation is debated. The two most commonly studied strains are Sp7 and Sp245, both are Brazilian isolates isolated from Tropical grasses from Seropedica, Brazil.
Cronobacter malonaticus, formerly considered a subspecies of Cronobacter sakazakii, is a bacterium. Its type strain is CDC 1058-77T.
Bradyrhizobium yuanmingense is a species of legume-root nodulating, endosymbiont nitrogen-fixing bacterium, associated with Lespedeza and Vigna species. Its type strain is CCBAU 10071(T).
Enterobacter cowanii is a Gram-negative, motile, facultatively-anaerobic, rod-shaped bacterium of the genus Enterobacter. The species is typically associated with natural environments and is found in soil, water, and sewage. E. cowanii is associated with plant pathogens that exhibit symptoms of severe defoliation and plant death. This species, originally referred to as NIH Group 42, was first proposed in 2000 as a potential member of the family Enterobacteriaceae. The name of this species honors S. T. Cowan, an English bacteriologist, for his significant contributions to the field of bacterial taxonomy.
Citrobacter youngae is a Gram-negative species of bacteria.
Azospirillum is a Gram-negative, microaerophilic, non-fermentative and nitrogen-fixing bacterial genus from the family of Rhodospirillaceae. Azospirillum bacteria can promote plant growth.
Scandinavium is a genus of Gram-negative, facultative anaerobic, oxidase-negative, rod-shaped, motile bacteria of the family Enterobacteriaceae. It contains a single species, Scandinavium goeteborgense. The type strain of the species is S. goeteborgenseCCUG 66741T = CECT 9823T = NCTC 14286T and its genome sequence is publicly available in DNA Data Bank of Japan, European Nucleotide Archive and GenBank under the accession number LYLP00000000.
Pluralibacter is a genus of Gram negative bacteria from the family of Enterobacteriaceae. The genus consists of two species, P. gergoviae and P. pyrinus. Both species were originally classified in the genus Enterobacter but were reclassified into the novel genus Pluralibacter in 2013.
Pluralibacter pyrinus is a Gram-negative, motile, facultatively-anaerobic, rod-shaped bacterium. P. pyrinus is the causitive agent of brown leaf spot disease of pear trees.
Niallia is a genus of Gram-Positive rod-shaped bacteria in the family Bacillaceae from the order Bacillales. The type species of this genus is Niallia circulans.
