Stone "Microbetain" Georgia State University 

To understand more about Enterobacter aerogenes, we must go back in time to know more about it. As stated from the previous posts that this species is a bacterium of the family Enterobacteriacease. The first original name was Aerobacter aerogenes which later was involved in the genus Enterobacter in 1960. A decade later, was renamed to Klebsiella mobilis because of its motility by peritrichous flagella and it was associated with its genetics similarities to Klebsiella genus. After multiple studies on whole-genome sequencing of a multidrug-resistant clinical isolate which then concluded the scientific name as Enterobacter aerogenes. Five years after the name changed it was first announced that this bacterium caused a nationwide outbreak of hospital-acquired infections in Europe but mostly in France. It occurred by the process of septicemia where the bacteria enter the blood and caused severe infections in 378 patients at 25 hospitals (Georghiou et al. 1995). Which is now referred to as important multi-resistant bacterial pathogens for humans since the late 18^th century and three decades after it. The family Enterobacter is listed as the eight most common pathogen in the United States that is associated with healthcare infections. (Hidron et al. 2008)

E. aerogenes can be found in human and environmental settings such as wastes, chemicals, soil, and water. It is mostly found in the human gastrointestinal tract but does not harm healthy individuals. It causes infections from specific antibiotics treatment, cross-contamination of needle insertion into a peripheral vein and/or surgical procedures. Further studies concluded that E. aerogenes are capable to survive on stainless steel which involves the tools in treatments. As E. aerogenes continue to increase it led to causing major damage in healthcare facilities (CDC, 2008). According to the CDC, $45 billion is spent on treatment also a statistical data of approximately 100,000 Americans die each year from the infections of E. aerogenes. The type of infections that are caused by E. aerogenes is urinary tract infections (UTIs), gastrointestinal infections, respiratory infections, adult meningitis and skin, and soft tissue infections. The best way to get rid of the infection is to have proactive prevention practices like good hygiene. There are some antibiotics that may be susceptible to E. aerogenes. So overall, let us be safe and healthy to avoid these dangerous species. 

References:

Georghiou, P. R., Hamill, R. J., Wright, C. E., Versalovic, J., Koeuth, T. T., and Lupski, J. R. (1995). Molecular epidemiology of infections due to Enterobacter aerogenes: identification of hospital outbreak-associated strains by molecular techniques. Clin. Infect. Dis. 20, 84–94. doi: 10.1093/clinids/20.1.84

Hidron AI, Edwards JR, Patel J, Horan TC, Sievert DM, Pollock DA, Fridkin SK. NHSN annual update: antimicrobial-resistant pathogens associated with healthcare-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006–2007. Infect Control Hosp Epidemiol. 2008;29:996–1011. doi: 10.1086/591861.

Enterobacter aerogenes diet plan is being a heterotroph where it uses organic compounds as a carbon source. Both Escherichia coli and Enterobacter aerogenes can convert fermentation of glucose or other sugars into glucose. The difference is that E. coli is a mixed – acid fermentations while E.aerogenes is a butanediol fermentation. In the figures shown below are from the textbook where both bacteria undergo glycolysis to produce butanediol, ethanol, Co_2, and H₂. E. coli will produce an equal amount of Co₂ and H₂ on the other hand E.aerogenes will produce more Co₂ than H₂.

The optimal temperature it needs to maintain itself is approximately 37 °C. The pH for E. aerogenes ranges from 4.4 to 9.0, but the optimal pH is around 6.0 – 7.0. It does not produce spores to grow. Since it is an anaerobic facultative it can grow with or without oxygen. With the optimized growth condition, it can grow in around 16-18 hours with the process of binary fission. Binary fission is the process where the cell divides as it gets larger to twice of its minimum size to produce two equivalent cells.

Reference:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435039/

Enterobacter aerogenes is a microbe that is part of the family Enterobacteriaceae and genus Klebsiella. The microbe, E.aerogenes is a single cell Gram-negative, facultatively – anaerobic, rod-shaped bacterium. As a facultative anaerobe, the bacteria can survive in both aerobic and anaerobic. The genus Enterobacter can be found in the human intestinal tract, animals, plants, environment, and foods. E.aerogenes is commonly found in natural environments such as soil, water, and sewage. The measurement size of this bacteria is from 0.3 – 3.0 micrometer. E.aerogenes is motile by using flagella all around its membrane for movement in the environment. The cell wall contains an outer and inner layer encased by a plasma membrane. The outer membrane contains lipopolysaccharides in its outer leaflet and phospholipids in the inner leaflet. The peptidoglycan is thinner because Gram-positive have a bigger size than Gram-negative.   Enterobacter has a genome of approximately 5.6 megabases, with 5636 genes and 5518 proteins, and a G + C content of ~ 55% (Ren et al., 2010).

Figure 1. Genome size of Enterobacter

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3000252/

Atlanta Georgia, the land known as “The Peach State.” There are so many iconic events happened in Georgia such as the 1996 Summer Olympics, Coca-Cola first goes on sale in the late 19th century and also Jimmy Carter from Georgia elected as United States president. There are many fascinating things to do in Atlanta Georgia, one of the most common is Stone Mountain. As a Georgia resident since birth, I have been to Stone Mountain to spend time with family and/or friends. Things to do there are having picnics and also hike up the mountain which required cardio…  🙁  

So the site for this blog, I decided to go to Stone Mountain! It is also nearby my house with a 7 minutes drive.  

Before hiking up the mountain, this building is the Blue Star Memorial Highway which is marked to pay tribute to the U.S armed forces. 

This is the trail to hike up the mountain, but I failed due to hatred with cardio and allergies kicked into my nose.

After failing to hike the trail, I somehow walked my way from the trail to the Stone Mountain monument. 

Since there are many bacteria that occurs around the world. Most of the microorganisms that are in nature are Gram-negative, which I would like to discuss more about the genus Enterobacter which is Gram-negative and rod-shaped bacteria.