Staphylococcus Aureus

Staphylococcus aureus is also known as the golden staph

        Very frequently isolated in human pathology, especially during the suppuration, the staphylococcus bacteria are ubiquitous: they are in fact in the air, soil and water and they belong to the commensal flora of the skin and mucous membranes of the man and animals.
Staphylococcus aureus is a microorganism that has no special nutritional or environmental requirements for its development so that when strains enterotossigeni contaminate food, and if these are present in more favorable conditions (temperature between 10 and 40 ° C, pH above 4.8, aw greater than 0.86, low microbial flora antagonist, etc..), the organism can replicate and drop in the staphylococcal enterotoxins.

        The staphylococcus is, along with Pseudomonas and E. coli, the main agent of hospital infections. Particularly important for therapeutic implications is resistance to methicillin and other penicillinase-resistant penicillins, encoded by the gene meca. Recently, infections have been reported by MRSA strains with decreased sensitivity to glycopeptides, feared a prelude to the complete resistance to glycopeptides that has already occurred in some strains in the United States (VRSA, Vancomycin-resistant staphylococcus aureus).

Staphylococcus aureus is responsible for suppurative infections superficial and deep as well as syndromes associated with the action of toxins. Staphylococci belong to the family Micrococcaceae, which includes four genera: Micrococcus, Staphylococcus, Planococcus and Stomatococcus.

                               

Classifications of golden staph

1. The genus Micrococcus includes microcoques who are also regular guests of the skin and mucous membranes of man. They are almost always contaminants.
2. The genus Staphylococcus includes some thirty species: some have man as hosts, other animals, others are encountered both in humans and animals.
In humans, the species most commonly isolated are:
i. Staphylococcus aureus, the most pathogenic.
II. Staphylococcus epidermidis, often regarded as an opportunist.
III. Staphylococcus saprophyticus, responsible for urinary tract infections in young women.
IV. and to a lesser frequency, Staph haemolyticus, hominis Staph, and Staph auriculares capitis.

                               

        Staph aureus expresses characteristics that distinguish it from other staphylococci: coagulase related. In current bacteriological practice this character allows to differentiate between Staphylococcus aureus on the one hand and Staphylococcus coagulase negative (SCN) on the other.