Staphylococcus

Staphylococcus

What is Staphylococcus? • Staphylococcus is a group of bacteria that can cause a multitude of diseases as a result of infection of various tissues of the body. • Staphylococcus is more familiarly known as Staph (pronounced "staff"). Staph-related illness can range from mild and requiring no treatment to severe and potentially fatal.

Characteristics of S.Coccus • 1-Gram Positive. 

• 2-Catalase Positive. • • 3-Spherical. • • 4-Arranged in Clusters. 

Habitats 

commonly found in air and water and on the skin and upper part of the human pharynx and mucosa. The nose is the main habitat for S.aureus and S.epidermidis.

Infection • They can cause illness directly by infection, or indirectly through products they make, such as the toxins responsible for food poisoning and toxic shock syndrome(TSS) . • Staphylococci generally resist host defenses.

STAPHYLOCOCCUS They contain more than 30 species, However ; 1)Staphylococcus aureus. 2)Staphylococcus epidermidis. 3)Staphylococcus saprophyticus. Are the most spread and important species.

1) S.Aureus • They are true food poisoning • It grows best at 37°C and can grow between 6 and 48°C. • grows best in the presence of oxygen but can grow an-aerobically (absence of oxygen). • Humans, and animals are the main reservoir of this organism.

Some Diseases caused by S.Aureus 1) Abscess. 2)boils. 3)osteomyelitis. 4)Post-operative wound infection. 5)Food poisoning. 

Treatment Generally no specific treatment is needed except for fluid replacement when diarrhoea and vomiting are severe.  Preventive measures 1)Thorough hand washing. 2) Proper use of tasting spoons and ladles. 3) Not keeping high-risk foods at room temperature but above 60°C if served hot, 4°C if cold. 4) Not drinking untreated water supplies or unpasteurised milk. 5) Thorough cooking of meat and meat products. 

2)Staphylococcus Epidermidis • It is coagulase-negative cocci and part of our normal flora. • It is a true opportunistic pathogen. • It is one of the leading pathogens of nosocomial infections, particularly associated with foreign body infections.

3) Staphylococcus saprophyticus • It is often implicated in urinary tract infections. • It is rarely found in healthy humans but is commonly isolated from animals and their carcasses. • It is a coagulase-negative species of Staphylococcus bacteria

Diagnosis • Clinical: Generally, a Gram stain of exudate from a lesion can demonstrate the characteristic Gram-positive cocci arranged in clusters. • Laboratory: Isolation techniques employ blood agar or Bacteriophage testing may be utilized.

Staph culture: golden S. aureus and white S. epidermidis colony.

Gram positive S. aureus, light microscope, Magn. ~ 100x

Preventive measures 1) Thorough hand washing. 2) Proper use of tasting spoons and ladles. 3) Not keeping high-risk foods at room temperature but above 60°C if served hot, 4°C if cold. 4) Not drinking untreated water supplies or unpasteurised milk. 5) Thorough cooking of meat and meat products. 6) Keep skin clean as possible. 7) Fast treating of wounds using antiseptic. 

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