Microbiology 3302 Spring 2013 – Getting Friendly with Bacteria

Hello fellow bacterial friends my name is Enterococcus Facecium, but you all can call me E. Facecium or Vancomycin- Resistant Enterococci (VRE). Before genomic DNA analysis showed a distinct genus classification would be applicable, I was affiliated with Group D Streptococcus until 1984 when I became part of the Enterococcus genus. My biggest attribute is that I’m a human pathogen that causes nosocomial bacteria, surgical wound infection, and urinary tract infection. The first time I made my rounds in clinical isolates was in Europe in the late 1980’s. Ever since then, I have been connected to various outbreaks of hospital- acquired or nosocomial contagions around the world. According to the CDC, the United States was linked to about 4% of healthcare- associated infections, from January 2006 to October 2007. When I’m not at hospitals causing hysteria, you can find me at gastrointestinal tract of a multitude of animals, sometimes you can even find me in oral cavities and vaginal tracts. My main home would probably be in soil, sewage and hospitals on various surfaces. I love the cold which propels me to operate in temperatures ranging from 10-45 degrees Celsius, in basic or acidic environments, and in environments which are isotonic and hypertonic. Although I’m known to cause harm in humans I also possess the ability to produce antibacterial peptides bacteriocins, which can be used in fermenting foods such as cheese and vegetables. I can also be used as a probiotic to out-compete deleterious bacteria in the gastrointestinal tract.

  1. 1.      My cell wall structure/Gram stain reaction:

E. faecium is a Gram-positive, spherical cell that can occur in pairs or chains. The colonies formed are 1-2 mm in length and appear wet. The cells are non-motile.

  1. 2.      My type of respiration:

It is a facultative anaerobe which means it can make ATP by aerobic respiration if     oxygen is present but will utilize fermentation if no oxygen is present.

  1. 3.      My type of metabolism:

Metabolism E. faecium lacks the Krebs’s cycle and respiratory chain and therefore it gains energy through fermentation.

  1. 4.      Where do I normally live/do I sometimes go on holidays (from a lake into someone’s intestine)

The microbe can survive for long periods of time in soil, sewage, and inside hospitals on a variety of surfaces. It can grow in temperatures ranging from 10 to 45 degrees Celsius, in basic or acidic environments, and in environments which are isotonic or hypertonic.

  1. 5.      Am I a pathogen? If not, am I useful for something?

E. faecium is considered a super-bug. It can colonize many organs of the body including the gastrointestinal tract and the skin, and can also survive for long periods on inanimate objects. This along with its multi-drug resistant characteristics makes it a particularly nasty pathogen.

6.   Do I have virulence factors?

Contributing to the virulence of E. faecium is the enterococcal surface protein (Esp). This protein allows the bacteria to aggregate and form bioflims. Strains with the Esp gene are normally found in clinical isolates and not found in strains that colonize the gut. Bioflim formation allows colonization of tubing used in hospitals and can lead to infections of the blood as well as urinary tract infections. Esp gene expression increased under increased temperature as well as a change to anaerobic condition. The regulation of the Esp gene in this way allows E. faecium to change its response when it enters a host.

7.   Who are my family members (My Genus) – Make friends with them on open lab

Enterococcus faecalis

8.     Who are my friends (In my classification tree) – Make friends with them on open lab:

Staphylococcus, Streptococcus, Bacillus and Clostridium.

9.      Do I have any pretty pictures of me/diagrams/movies

 

 

 

10.     Am I famous/in the news/notorious?

In the last two decades, particularly virulent strains of Enterococcus that are resistant to vancomycin (vancomycin-resistant Enterococcus, or VRE) have emerged in nosocomial infections of hospitalized patients, especially in the US.

 

 

Skerman, V.B.D., McGowan, V., and Sneath, P.H.A. (editors): “Approved lists of        bacterial names.” Int. J. Syst. Bacteriol. (1980) 30:225-420. Schleifer KH & Kilpper-Balz R (1984)

Mark M. Huycke, Daniel F. Sahm, and Michael S. Gilmore. “Multiple-Drug Resistant        Enterococci: The Nature of the Problem and an Agenda for the Future” EID (1998)

Schleifer, K.H., and Kilpper-Balz, R. “Transfer of Streptococcus faecalis and Streptococcus faecium to the genus Enterococcus nom. rev. as Enterococcus faecalis comb. nov. and Enterococcus faecium comb. nov.” Int. J. Syst. Bacteriol. (1984) 34:31-34.

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