Staphylococcus Aureus

How does coagulase aid in the survival of Staph Aureus

It is an enzyme that causes blood clotting and the bacteria will use coagulase to form a clot around itself

As a pathogen Staphylococcus aureus utilizes Protein A, along with a host of other proteins and surface factors to aid its survival and, thus, virulence. How does Protein A help aid this infection.

Protein A helps inhibit phagocytic engulfment and acts as an immunological disguise.

Of the Clinical Manifestations of Staphylococcus Aureus, What is most common?

Foliculitis

How long can Staph Aureus survive with H2O

3 weeks.

What can Staphylococcus Aureus cause: Clinical Manifestations

Abcesses Pyogenic infections Food poisoning Scalded skin syndrome Toxic Shock Foliculitis

What disease is an example of the Pyogenic Mechanism of disease with Staph Aureus

Abscess-- Skin infections, and Sepsis

Treatment of Staphylococcus Aureus

Antimicrobial intervention is necessary; --90% S. aureus isolates have plasmids that code β Lactamase making it resistant to Penicillin --- Metacillin Resistent S. aureus (MRSA) - 50% of isolates in US ---Vancomyosin-2% of S. aureus are resistant Resistant strains to penecilin and Methicillin ***Between 10% and 30% of these patients will die from S . Aureus

Mechanism of Disease-Staphylococcus Aureus

Can be Toxin Mediated and Pyogenic.

Because Staphylococcus Aureus is aerobic, it contains what enzyme to protect itself from toxic forms of oxygen?

Catalase

Name the exotoxin responsible for Food intoxification leading to vomiting and Diarhea

Enterotoxin

Name the exotoxin responsible for Scalded Skin Syndrome

Exfoliatin

Staphylococcus Aureus Prevention

No Vaccine. Wash hands, keep wounds covered, be sanitary. intranasal antibiotics for carriers.

___________Most important cause of hospital acquired pneumonia septicemia and surgical infections

S. aureus

Main Biological features of Staphylococcus Aureus

Spherical, Clusters, Gram Positive Catalase and Coagulase Positive, is Aerobic, found on skin, but can also be anaerobic, and perform fermentaion allowing it to move into deep tissues. non motile, non spore forming.

One Virulent factor for Staph Aureus is staphyloxanthin, how does this increase the ability for Staph Aureus to cause disease.

This pigment enhances the pathogenicity of the organism by preventing white blood cells from killing the bacteria

What are the ways that Staph Aureus uses toxins as a mechanism of disease

Toxi Shock Syndrome: Peptidoglycan Behaves like LPS Food Poisoning--Toxins; Enterotoxin Scalded Skin--Toxins--Exfoliatin--Destroys Desmosomes

S. aureus is distinguished from the others-Staph Epidermidis and Saprophyticus- primarily by ______.

coagulase

Most pathogenic staphylococci, such as Staphylococcus aureus, will ferment____.

mannitol

Transmission of Staphylococcus Aureus

mucosal layer inside nose, skin, --30% carriers --Disease is caused by the combination of heavy contamination and debilitated immune response - Severe Necrotizing disease aka Flesh eating disorder-seen in homeless and drug users food-food intoxification