Staphylococcus epidermidis 09005509

external image purple-staph.jpgStaphylococcusepidermidis belongs to the:

Kingdom: Bacteria

Phylum: Firmicutes

Class: Cocci

Order: Bacillales

Family: Staphylococcaceae

Genus: Staphylococcus

Species: S. epidermidis


Source: Gillen, A. (2009). http://www.answersingenesis.org/articles/aid/v4/n1/genesis-of-mrsa
Date accessed: 27/02/11

Features

S. epidermidis is a small (~ 1 µm in diameter) Gram-positive, coagulase-negative bacterium. These bacteria grow in grape-like clusters and appear as round, cocci, organisms under the microscope as shown in figure 1. S. epidermidis grows by aerobic respiration (converting oxygen to carbon dioxide) or by fermentation (splitting complex organic compounds into simple substances). This microorganism is non-pathogenic can be found on human skin and is a part of our normal skin flora.

external image Staphylococcus%20epidermidis%20fig1.jpg












Figure 1
Source: Smith, A. and Hussey M (2005). http://archive.microbelibrary.org/asmonly/details_print.asp?id=2029&lang=
Date accessed: 27/02/11


History

S. epidermidiswas first discovered by Friedrich Julius Rosenbach in 1884 and was originally named Staphylococcus albus. He distinguished the difference between S.epidermidis and S. aureus.


Illness

S. epidermidis is a true opportunistic pathogen; it is harmless to a healthy person but debilitates a person whose immune system has been weakened by a disease or drug treatment. The most susceptible to the infection are newborns, elderly, intravenous drug users and people with catheters.

Most strains of S. epidermidis do not cause illness however if it does cause illness it is usually arises from hospital environments, as this bacteria can contaminate. It can cause infection on biomaterials such as catheters, prosthetic valves, joint prosthesis, vacular prosthesis, postoperative wounds, cerebrospinal fluid shunts and venous catheters.


Symptoms

S. epidermidis can cause infections in a wide variety of locations in the body. Wherever the site of the infection, the symptoms may be common, such as fever, fatigue, pain or tenderness at the site of an implant, rapid breathing, rapid heart beat and sweating.


Biofilm

S. epidermidis can produce a biofilm, where these microorganisms adhere on solid surfaces forming a complex attachment, enclosed by a slime layer, an adhesive polysaccharide, which is excreted by the cells.

Biofilms can protect pathogens from disinfectants inside humans. Basically, helping the pathogen cause diseases; releasing microorganisms or microbial products which can have an affect on the immune system.


Resistance and Treatment

S. epidermidis is a major concern for people with catheters or artificial appliances as biofilms can form and become resistant to antibiotics. Staphylococcus is a main biofilm-forming organism which can be found impairing prosthetic devises and in wounds, creating diseases such as endocarditis. Due to the resistance of antibiotics, the treatment often results in the removal of the implanted medical device/biomaterial which is infected with S. epidermidis.

However, the faster the diagnosis, means less time form the biofilm to originate and more effective the antibiotic therapy treatment.


Current research external image images?q=tbn:ANd9GcSOeAfMnQHk1NG7B5TA1f6Ol3vpBh4MJyyKS4XTNrOXLP5OcBci

Currently research laboratories are testing the sensitivity of the bacteria, S. epidermidis, to

different antibiotics. It is one of the most popular subject of research.


Source: Anon. (2011). The Retroscope. http://www.retroscope.eu/wordpress/staphylococcus-epidermidis/
Date accessed: 29/03/11

Gram Staining Procedure

Animation

http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/prostruct/images/gram_stain_11.swf


References

Anon. (2011). Bacteria Genomes-Staphylococcus Epidermidis. http://www.ebi.ac.uk/2can/genomes/bacteria/Staphylococcus_epidermidis.html Date accessed: 08/03/11

Bukhari, M., (2004). Staphylococcus epidermidis. http://web.uconn.edu/mcbstaff/graf/Student%20presentations/S%20epidermidis/sepidermidis.html Date accessed: 08/03/11

O'gara, J.P and Humhreys, H. (2001) Staphylococcus epidermidis biofilms: importance and implications Vol. 50, pp. 582-587.