Staphylococci

Definition

Staphylococcus is a type of bacteria that is assigned to the group of so-called spherical bacteria. They are about 0.1 micrometers in size and, as spherical bacteria, do not have their own active mobility. Staphylococci are gram-positive (this is a staining method to further classify bacteria).

They are usually present individually or together in the form of grape vines. Their optimum temperature for reproduction is approximately body temperature and their generation time, i.e. their division cycle, is about two hours. Staphylococci are only facultatively pathogenic. This means that they cause a “disease” when colonizing wounds. If they are on the skin or through food in our intestines, they do not cause disease.

Which staphylococci are there?

Staphylococci can be divided into two large groups using a special microbiological test. This test is used to examine the clumping behavior of the bacteria, more precisely whether they produce the enzyme coagulase. Staphylococcus epidermidis, for example, which can be detected on almost all human skin, is one of the staphylococci that do not produce coagulase.

There is also Staphylococcus haemolyticus, which is able to destroy erythrocytes, the red blood cells. Staphylococcus lugdunensis is another representative of coagulase-negative staphylococci. It is also found on the skin of humans, mainly in the intimate area near the anus.

The last known representative of staphylococci without coagulase enzyme is Staphylococcus saprophyticus. It is suspected that it is transmitted to humans upon contact with animals, especially cattle. The Staphylococcus aureus is a well-known main representative of the coagulase-positive Staphylococcus.

This is the potentially most dangerous form of Staphylococcus aureus, which in the meantime has gained unattractive notoriety as the so-called MRSA form. The MRSA form is a type of Staphylococcus aureus that can no longer be treated with a variety of antibiotics because it is resistant to those drugs. MRSA stands for “Methicillin-resistant Staphylococcus aureus”.

Staphylococcus aureus is the most pathogenic germ of the staphylococcal family. This germ is coagulase-positive. It owes its nickname aureus – golden to its appearance when growing on a Petri dish.

Here the colonies form a golden shimmering courtyard around the individual colonies. The germ causes the development of small abscesses or small boils in local infections of the skin. The pus contained in the colonies has a rather cheesy consistency, which also distinguishes this germ from other pathogens of the staphylococcus family.

Furthermore, Staphylococcus aureus is the germ that has become dubious in a variant resistant to antibiotics. This is the MRSA form – the “Meticillin-resistant Staphylococcus aureus” form. It can no longer be treated with the usual standard antibiotics, but requires special treatment that usually lasts longer than the treatment of normal Staphylococcus aureus.

If a generalized infection occurs, the germ can secrete a certain toxin, which can lead to multiple organ failure and ultimately to death. Staphylococcus epidermidis is, as its name suggests, a skin germ. It occurs physiologically on the skin of every human being and is only dangerous for humans in special cases.

Especially in hospitals, however, it can cause small local irritations and inflammations. If objects piercing the skin in this environment are not cleaned properly, the germs can get into the wound, multiply there and cause a local inflammatory reaction, in the worst case even with pus formation. In the worst case, bacteria can detach from the wound and travel with the bloodstream to the heart, where they then attack the heart valves and destroy them if necessary.