Klebsiella aerogenes,[2] previously known as Enterobacter aerogenes, is a Gram-negative, oxidase-negative, catalase-positive, citrate-positive, indole-negative, rod-shaped bacterium.[3] Capable of motility via peritrichous flagella,[4] it is approximately one to three microns in length.
| Klebsiella aerogenes | |
|---|---|
Scientific classification 
| |
| Domain: | Bacteria |
| Phylum: | Pseudomonadota |
| Class: | Gammaproteobacteria |
| Order: | Enterobacterales |
| Family: | Enterobacteriaceae |
| Genus: | Klebsiella |
| Species: | K. aerogenes
|
| Binomial name | |
| Klebsiella aerogenes Tindall et al., 2017
| |
| Synonyms | |
| |
| Gram | negative |
|---|---|
| Shape | rods |
| Hemolysis | negative |
| Oxidase | negative |
| Catalase | positive |
| Indole | negative |
| Citrate | positive |
Klebsiella aerogenes is a nosocomial, pathogenic bacterium that causes opportunistic infections of most types. Infections are generally sensitive to antibiotics designed for this bacteria class, though complicated by inducible resistance mechanisms,[5] particularly lactamase; infections accordingly become quickly resistant to standard antibiotics during treatment, necessitating a change in antibiotic to avoid worsening of the sepsis.
Some infections caused by K. aerogenes result from specific antibiotic treatments, venous catheter insertions, and/or surgical procedures. It is generally found in the human gastrointestinal tract and does not generally cause disease in healthy individuals. It has been found to live in various wastes, hygiene chemicals, and soil. It also has some commercial significance; experiments using molasses as the substrate have produced hydrogen gas.
K. aerogenes is an outstanding hydrogen producer. It is an anaerobic facultative and mesophilic bacterium that can consume different sugars, and—unlike the cultivation of strict anaerobes—there is no requirement to remove all oxygen from the fermenter. Along with a short doubling time, it has a high hydrogen productivity and evolution rate. Furthermore, its hydrogen production is not inhibited at high hydrogen partial pressures. Its hydrogen yield is lower than that of such strict anaerobes as Clostridia: strictly anaerobic bacteria produce a theoretical maximum of 4 mol H2/mol glucose, while such facultative anaerobic bacteria as K. aerogenes theoretically yield a maximum of 2 mol H2/mol glucose.[6]
K. aerogenes may spoil maple sap and syrup.[7]
Owing to diverse metabolites—acids and alcohols—produced by such a strain in conjunction with its ability to utilize different sugars, the metabolism and growth of K. aerogenes can vary significantly with the conditions.[8]
Biochemical identification test results
edit| Identification Method[9] | Test Result |
|---|---|
| Motility | Positive |
| Indole | Negative |
| Methyl Red | Negative |
| VP | Positive |
| Citrate (Simmons) | Positive |
| Nitrate Reduction | Negative |
| Hydrogen Sulfide (TSI) | Negative |
| Urea Hydrolysis | Negative |
| Oxidase | Negative |
| Phenylalanine Deaminase | Negative |
| Eosin-methylene blue | Positive |
| Glucose Fermentation | Acid/Gas |
| Lactose Fermentation | Acid/Gas |
| Sucrose Fermentation | Acid/Gas |
| Mannitol Fermentation | Acid/Gas |
| Growth in KCN | Positive |
| Ornithinine Decarboxylase | Positive |
| Gelatin Hydrolysis (22 °C) | Negative |
References
edit- ^ Breed, R.; Conn, H. (1936). "The Status of the Generic Term Bacterium Ehrenberg 1828". Journal of Bacteriology. 31 (5): 517–518. doi:10.1128/jb.31.5.517-518.1936. PMC 543738. PMID 16559906.
- ^ Tindall, B. J.; Sutton, G.; Garrity, G. M. (2017). "Enterobacter aerogenes Hormaeche and Edwards 1960 (Approved Lists 1980) and Klebsiella mobilis Bascomb et al. 1971 (Approved Lists 1980) share the same nomenclatural type (ATCC 13048) on the Approved Lists and are homotypic synonyms, with consequences for the name Klebsiella mobilis Bascomb et al. 1971 (Approved Lists 1980)". International Journal of Systematic and Evolutionary Microbiology. 67 (2): 502–504. doi:10.1099/ijsem.0.001572. PMID 27902205.
- ^ Sanders, W.E; Sanders, C.C (1997). "Enterobacter spp.: pathogens poised to flourish at the turn of the century". Clinical Microbiology Reviews. 10 (2): 220–41. doi:10.1128/CMR.10.2.220. PMC 172917. PMID 9105752.
- ^ "Morphological Characteristics of Enterobacter aerogenes". Archived from the original on 2017-07-05. Retrieved 2017-05-07.
- ^ Jones, Ronald N.; Baquero, Fernando; Privitera, Gaetano; Inoue, Matsuhisa; Wiedemann, Bernd (1997). "Inducible β-lactamase-mediated resistance to third-generation cephalosporins". Clinical Microbiology and Infection. 3 (s1): s7–s20. doi:10.1111/j.1469-0691.1997.tb00643.x. ISSN 1469-0691.
- ^ Asadi, Nooshin; Zilouei, Hamid (March 2017). "Optimization of organosolv pretreatment of rice straw for enhanced biohydrogen production using Enterobacter aerogenes". Bioresource Technology. 227: 335–344. Bibcode:2017BiTec.227..335A. doi:10.1016/j.biortech.2016.12.073. PMID 28042989.
- ^ MICROBES INVOLVED IN FOOD SPOILAGE Authors: Gabriel Chavarria, Julia Neal, Parul Shah, Katrina Pierzchala, Bryant Conger
- ^ Asadi, Nooshin; Karimi Alavijeh, Masih; Zilouei, Hamid (2018-05-03). "Biological hydrogen production by Enterobacter aerogenes: Structural analysis of treated rice straw and effect of substrate concentration". International Journal of Hydrogen Energy. 43 (18): 8718–8728. Bibcode:2018IJHE...43.8718A. doi:10.1016/j.ijhydene.2018.03.137. ISSN 0360-3199.
- ^ Farmer, J J; Davis, B R; Hickman-Brenner, F W; McWhorter, A; Huntley-Carter, G P; Asbury, M A; Riddle, C; Wathen-Grady, H G; Elias, C (1985-01-01). "Biochemical identification of new species and biogroups of Enterobacteriaceae isolated from clinical specimens". Journal of Clinical Microbiology. 21 (1): 46–76. doi:10.1128/JCM.21.1.46-76.1985. ISSN 0095-1137. PMC 271578. PMID 3881471.
External links
edit- Enterobacter Infections at eMedicine
- "Klebsiella aerogenes". NCBI Taxonomy Browser. 548.
- Type strain of Klebsiella aerogenes at BacDive - the Bacterial Diversity Metadatabase