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Clinical Microbiology Reviews Sep 2019The genus is a member of the ESKAPE group, which contains the major resistant bacterial pathogens. First described in 1960, this group member has proven to be more... (Review)
Review
The genus is a member of the ESKAPE group, which contains the major resistant bacterial pathogens. First described in 1960, this group member has proven to be more complex as a result of the exponential evolution of phenotypic and genotypic methods. Today, 22 species belong to the genus. These species are described in the environment and have been reported as opportunistic pathogens in plants, animals, and humans. The pathogenicity/virulence of this bacterium remains rather unclear due to the limited amount of work performed to date in this field. In contrast, its resistance against antibacterial agents has been extensively studied. In the face of antibiotic treatment, it is able to manage different mechanisms of resistance via various local and global regulator genes and the modulation of the expression of different proteins, including enzymes (β-lactamases, etc.) or membrane transporters, such as porins and efflux pumps. During various hospital outbreaks, the and complex exhibited a multidrug-resistant phenotype, which has stimulated questions about the role of cascade regulation in the emergence of these well-adapted clones.
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Enterobacter; Enterobacteriaceae Infections; Humans
PubMed: 31315895
DOI: 10.1128/CMR.00002-19 -
Future Microbiology Jul 2012Species of the Enterobacter cloacae complex are widely encountered in nature, but they can act as pathogens. The biochemical and molecular studies on E. cloacae have... (Review)
Review
Species of the Enterobacter cloacae complex are widely encountered in nature, but they can act as pathogens. The biochemical and molecular studies on E. cloacae have shown genomic heterogeneity, comprising six species: Enterobacter cloacae, Enterobacter asburiae, Enterobacter hormaechei, Enterobacter kobei, Enterobacter ludwigii and Enterobacter nimipressuralis, E. cloacae and E. hormaechei are the most frequently isolated in human clinical specimens. Phenotypic identification of all species belonging to this taxon is usually difficult and not always reliable; therefore, molecular methods are often used. Although the E. cloacae complex strains are among the most common Enterobacter spp. causing nosocomial bloodstream infections in the last decade, little is known about their virulence-associated properties. By contrast, much has been published on the antibiotic-resistance features of these microorganisms. In fact, they are capable of overproducing AmpC β-lactamases by derepression of a chromosomal gene or by the acquisition of a transferable ampC gene on plasmids conferring the antibiotic resistance. Many other resistance determinants that are able to render ineffective almost all antibiotic families have been recently acquired. Most studies on antimicrobial susceptibility are focused on E. cloacae, E. hormaechei and E. asburiae; these studies reported small variations between the species, and the only significant differences had no discriminating features.
Topics: Bacterial Proteins; Cross Infection; Drug Resistance, Bacterial; Enterobacter; Enterobacter cloacae; Enterobacteriaceae Infections; Humans; Molecular Typing; beta-Lactamases
PubMed: 22827309
DOI: 10.2217/fmb.12.61 -
Trends in Microbiology Jun 2021Enterobacter is a globally important pathogen. Here we clarify its taxonomy and review recent developments in its resistance to carbapenem and colistin, illustrating... (Review)
Review
Enterobacter is a globally important pathogen. Here we clarify its taxonomy and review recent developments in its resistance to carbapenem and colistin, illustrating that Enterobacter has a large arsenal of mechanisms to grow under antimicrobial pressure. Further studies are required to decipher colistin heteroresistance and understand why certain Enterobacter lineages have emerged clinically.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Carbapenems; Colistin; Drug Resistance, Multiple, Bacterial; Enterobacter; Humans; Microbial Sensitivity Tests
PubMed: 33431326
DOI: 10.1016/j.tim.2020.12.009 -
Infection Control : IC Mar 1985
Topics: Anti-Bacterial Agents; Disease Outbreaks; Drug Therapy, Combination; Enterobacter; Enterobacteriaceae; Enterobacteriaceae Infections; Humans
PubMed: 3845066
DOI: 10.1017/s0195941700062810 -
International Journal of Food... Feb 1997Enterobacter sakazakii, previously referred to as a yellow-pigmented Enterobacter cloacae was designated as a unique species in 1980. This reclassification was based on... (Review)
Review
Enterobacter sakazakii, previously referred to as a yellow-pigmented Enterobacter cloacae was designated as a unique species in 1980. This reclassification was based on differences from E. cloacae in DNA relatedness, pigment production and biochemical reactions. E. sakazakii has been implicated in a severe form of neonatal meningitis. Although studies have failed to identify an environmental source for the organism, dried-infant formula has been implicated in both outbreaks and sporadic cases of E. sakazakii meningitis. The high mortality rate (40-80%), the severity of the infection in infants, plus the scarcity of information on the ecology and pathogenicity of this organism warranted a review of the clinical and microbiological features of this putative foodborne pathogen.
Topics: Enterobacter; Enterobacteriaceae Infections; Food Microbiology; Humans; Infant; Infant Food; Meningitis, Bacterial
PubMed: 9039558
DOI: 10.1016/s0168-1605(96)01172-5 -
The Journal of Hospital Infection Apr 1988
Review
Topics: Bacteriophage Typing; Cephalosporins; Cross Infection; Disease Outbreaks; Drug Resistance, Microbial; Enterobacter; Enterobacteriaceae Infections; Humans; Sepsis; Serotyping
PubMed: 2899104
DOI: 10.1016/0195-6701(88)90098-9 -
The Journal of Antimicrobial... Feb 2020
Topics: Bacterial Proteins; Canada; Enterobacter; Enterobacteriaceae Infections; Humans; beta-Lactamases
PubMed: 31725164
DOI: 10.1093/jac/dkz438 -
Microbiology Spectrum Jun 2022Many species of bacteria change their morphology and behavior under external stresses. In this study, we report transient elongation and swimming motility of a novel...
Many species of bacteria change their morphology and behavior under external stresses. In this study, we report transient elongation and swimming motility of a novel Enterobacter sp. strain, SM1_HS2B, in liquid broth under a standard growth condition. When growing in the Luria-Bertani medium, HS2B cells delay their cell division and elongate. Although transient over a few hours, the average cell length reaches over 10 times that of the stationary-state cells. The increase is also cumulative following repeated growth cycles stimulated by taking cells out of the exponential phase and adding them into fresh medium every 2 hours. The majority of the cells attain swimming motility during the exponential growth phase, and then they lose swimming motility over the course of several hours. Both daughter cells due to division of a long swimming cell retain the ability to swim. We confirm that the long HS2B cells swim with rigid-body rotation along their body axis. These findings based on microscopic observation following repeated cycles of growth establish HS2B as a prototype strain with sensitive dependence of size and motility on its physical and biochemical environment. Bacteria undergo morphological changes in order to cope with external stresses. Among the best-known examples are cell elongation and hyperflagellation in the context of swarming motility. The subject of this report, SM1_HS2B, is a hyperswarming strain of a newly identified species of enterobacteria, noted as Enterobacter sp. SM1. The key finding that SM1_HS2B transiently elongates to extreme length in fresh liquid medium offers new insights on regulation in bacterial growth and division. SM1_HS2B also manifests transient but vigorous swimming motility during the exponential phase of growth in liquid medium. These properties establish HS2B as a prototype strain with sensitive dependence of size and motility on its physical and biochemical environment. Such a dependence may be relevant to swarming behavior with a significant environmental or physiological outcome.
Topics: Bacterial Proteins; Cell Division; Enterobacter; Flagella
PubMed: 35647691
DOI: 10.1128/spectrum.02078-21 -
International Journal of Systematic and... Dec 2018An Enterobacter strain, WCHECL1597, was recovered from the urine of a patient in China in 2016. Phylogenetic analysis based on its 16S rRNA gene sequence indicated the...
An Enterobacter strain, WCHECL1597, was recovered from the urine of a patient in China in 2016. Phylogenetic analysis based on its 16S rRNA gene sequence indicated the strain belongs to the genus Enterobacter, while multi-locus sequence analysis of the rpoB, gyrB, infB and atpD housekeeping genes revealed that the strain was distinct from any previously described Enterobacter species. The whole genome sequence of strain WCHECL1597 had a 79.81-91.49 % average nucleotide identity to those of type strains of all known Enterobacter species. In silico DNA-DNA hybridization values between strain WCHECL1597 and the type strains of all known Enterobacter species ranged from 22.8 to 45.2 %. The major cellular fatty acids of strain WCHECL1597 were C16 : 0, C17 : 0cyclo and C18 : 1ω7c, which are in the quantitative range of other Enterobacter species while differentiated by the relatively higher amount (12.3 %) of iso-c16 : 1 I/C14 : 0 3-OH. The genomic DNA G+C content was 55.2 mol%. Strain WCHECL1597 could be distinguished from all known Enterobacter species by its ability to ferment inositol but with a negative l-rhamnose and d-mannitol reaction. Genotypic and phenotypic characteristics from this study indicate that strain WCHECL1597 represents a novel species of the genus Enterobacter, for which the name Enterobactersichuanensis sp. nov. is proposed. The type strain is WCHECL1597 (=GDMCC1.1217=CCTCC AB 2017104=KCTC 52994).
Topics: Bacterial Typing Techniques; Base Composition; China; DNA, Bacterial; Enterobacter; Fatty Acids; Genes, Bacterial; Humans; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Urine
PubMed: 30387707
DOI: 10.1099/ijsem.0.003089 -
MicrobiologyOpen Sep 2019A novel oligotrophic bacterium, designated strain CCA6, was isolated from leaf soil collected in Japan. Cells of the strain were found to be a Gram-negative,...
A novel oligotrophic bacterium, designated strain CCA6, was isolated from leaf soil collected in Japan. Cells of the strain were found to be a Gram-negative, non-sporulating, motile, rod-shaped bacterium. Strain CCA6 grew at 10-45°C (optimum 20°C) and pH 4.5-10.0 (optimum pH 5.0). The strain was capable of growth in poor-nutrient (oligotrophic) medium, and growth was unaffected by high-nutrient medium. The major fatty acid and predominant quinone system were C and ubiquinone-8. Phylogenetic analysis based on 16S rRNA gene sequences indicated strain CCA6 presented as a member of the family Enterobacteriaceae. Multilocus sequence analysis (MLSA) based on fragments of the atpD, gyrB, infB, and rpoB gene sequences was performed to further identify strain CCA6. The MLSA showed clear branching of strain CCA6 with respect to Enterobacter type strains. The complete genome of strain CCA6 consisted of 4,476,585 bp with a G+C content of 54.3% and comprising 4,372 predicted coding sequences. The genome average nucleotide identity values between strain CCA6 and the closest related Enterobacter type strain were <88.02%. Based on its phenotypic, chemotaxonomic and phylogenetic features, strain CCA6 (=HUT 8142 =KCTC 62525 ) can be considered as a novel species within the genus Enterobacter with the proposed name Enterobacter oligotrophica.
Topics: Bacterial Proteins; Bacterial Typing Techniques; Base Composition; Cluster Analysis; Cytosol; DNA, Bacterial; DNA, Ribosomal; Enterobacter; Fatty Acids; Hydrogen-Ion Concentration; Japan; Locomotion; Multilocus Sequence Typing; Phylogeny; Quinones; RNA, Ribosomal, 16S; Soil Microbiology; Temperature
PubMed: 31066221
DOI: 10.1002/mbo3.843