Enterobacter aerogenes

From MicrobeWiki, the student-edited microbiology resource

A Microbial Biorealm page on the genus Enterobacter aerogenes

Classification

Higher order taxa

Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacteriales; Enterobacteriaceae; Enterobacter

Species

Enterobacter aerogenes

Description and significance

The Enterobacteriaciae family includes genera of Escherichia, Shilgella, Salmonella, Enterobacter, Klebsiella, Serratia, Proteus, and others. The gram-negative bacteria reside is soil, water, dairy products and inhabits a natural flora in the gastrointestinal tract of animals as well as humans. The rod shaped bacteria exists in a variety of sizes; are not spore forming; are both motile (with peritrichous flagella) or nonmotile; grow both aerobically and anaerobically; are active biochemically; ferment (versus oxidize) D-glucose as well as other sugars, often with gas production; reduce nitrate to nitrite; contain the enterobacter common antigen; and have a 39-59% guanine-plus-cytosine (G + C) content of DNA (2).

The genus Enterobacter has four species- E. cloacae, E. aerogenes, E. hafniae, and E. agglomerans. The genus is more specifically a nosocomial opportunistic pathogen and is sought out to be one of the many key causes for extraintestinal infections next to E. coli. Infections commonly attributed to E. aerogenes are respiratory, gastrointesntinal, and urinary tract infections, specifically cystits, in addition to wound, bloodstream, and central nervous system infections (1,2, 3).

In the clinical setting, Enterobacter aerogenes and Enterobacter cloacae are the most frequently isolated in samples of infected hospitalized patients. The majority of the infections are etiologically due to inadvertent transfer of bacteria during surgery or prolonged treatment in hospitals in patients who use venous or urethral catheters. Enterobacteriaceae may account for 80% of clinically significant isolates of gram-negative bacilli and 50% bacilli clinically significant bacteria in clinical microbiology laboratories. Additionally, they account for nearly 50% of septicemia cases and more than 70% of urinary and intestinal tract infections, thus creating an importance to target the causes of these nosocomial infections (2).

Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?

Cell structure and metabolism

Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.

Ecology

Enterobacter are found in the soil, water, dairy products, and in the intestines of animals as well as humans. They are most frequently found in the gastrointestinal tract and are studied in clinical sites in stool samples.

Pathology

Enterobacter aerogenes causes disease in humans through inadvertent bacteria transfer in hospital settings. A portion of enteric bacteria like E. aerogenes are opportunistic and only infect those who already have suppressed host immunity defenses. Infants, the elderly, and those who are in the terminal stages of other disease or are immunosuppressed are prime candidates for such infections (_).

Additionally, E. aerogenes as well as other enteric bacteria, is known to have drug-resistant characteristics. There has been some success in dealing with infections through antibiotics, however, the fast development of multidrug resistence has become an increasingly growing problem. (_ lil paper). These multiresistant strains have caused outbreaks in intensive care units (ICUs) in Belgium, France, Austria, and the United States and has further become more emergent than its sister species E. cloacea (_ 3 ncbi). Research has shown that E. aerogenes is resistant to ampicillin and it has been more recently discovered that it is resistant to imipenem (_,_).

Application to Biotechnology

Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

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References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

This page was created by Tiffany M. Liu, a student of Professor Rachel Larsen at the University of California, San Diego.