by Kate Eglan-Garton

Created on: July 06, 2011   Last Updated: July 08, 2011

Staphylococcus is a specific type of bacterial infection that can attack the human body at any time.  Although there are more than 20 species of Staphylococcus, only two interact with humans according to Bergey’s Manual (2001) on systematic bacteriology.  

The first type is called Staphylococcus aureus and is a common bacterium that measures about 1 micrometer in diameter and are perfectly shaped round cells.  They are yellowish in color and form in clusters.  Prone to grow in the nasal passages, they can be responsible for pus-forming infections that cause respiratory problems.  Less common areas of the body where they can be found are the skin, gastrointestinal tract and oral cavity. 

Cellulitis is the name given to Staphylococcus aureus that infects more than one layer of skin.  Penetrating deep into the skin area, this particular infection is more common than most people realize.  Because it is centralized in one area, it can be treated but only after the underlying problem of a weak immune system has been addressed.

Because most of the Staph infections that people find themselves with are localized and do not spread throughout the body, treatment with antibiotics usually clears up the strain.  However, methicillin-resistant Staph aureus (MRSA) can be contracted that spreads in tissues, hides in cell membranes and damage host tissues.  Once thought of as being contained in clinic settings and community associated, MRSA is becoming more widespread.  There is no antibiotic to date that has any permanent affect on this strain of Staphylococcus aureus.

The Staphylococcal disease of MRSA can be found in hospitals where invasive surgical procedures have taken place or even in public.  Community Associated infections can be acquired from another person that does not even realize that they are ill.  Called CA-MRSA, this type of infection is growing quickly in society.

The second type of bacteria that is related to Staphylococcus aureus yet different is known as Staphylococcus epidermidis.  Found in patients that have catheters, heart valves or other type of foreign object placed inside the body for extended periods of time.  Instead of building grape-like clusters that stay in one spot, the Staphylococcus epidermidis chooses to take on another form.  This bacterium is able to create a biofilm on the prosthetic device that is a slimy secretion of acid. 

MRSA and Staphylococcus epidermidis can both enter other areas of the body through the blood or even bones.  These types of Staph are very hard to treat because of the resistance to antimicrobial drugs and vaccines.

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