STAPHYLOCOCCUS AUREUS Infection.pptx

STAPHYLOCOCCUS AUREUS Infection

1. STAPHYLOCOCCUS AUREUS Infection Amjad Khan Afridi Lecturer, Department of Health & Biological Sciences Abasyn University Peshawar Chapter # 4

2. STAPHYLOCOCCUS AUREUS BASIC CHARACTERISTICS Description The term ‘aureus’ is derived from Latin, which refers to the color of gold. Gram-positive round shape (coccus) in clusters. Non-motile. Non-spore-forming. Catalase: Positive. Coagulase: Positive Oxidase: Negative. Urease: Positive Facultatively anaerobic

3. Staphylococcus species 61 species Important S. aureus S. epidermidis S. saprophyticus S. pseudointermedius Others S. haemolyticus S. capitus S. hominis S. xylosis S. warneri

4. Ecology Staphylococcus aureus is a gram positive bacterium that is usually found in the nasal passages, mouth, throat etc. And on the skin of 15 to 40% of healthy humans, but can also survive in a wide variety of locations in the body. Commonly found in the environment (air, water & soil) .

5. General cultural and biochemical characteristics S. aureus is an aerobic and facultative anaerobic organism that forms fairly large yellow or white colonies on Nutrient agar media. The yellow color of the colonies is reported by carotenoids produced by the organism. The term ‘aureus’ is derived from Latin, which refers to the color of gold.

6. The organism is often haemolytic in blood agar due to production of haemolysins (alpha, beta, gamma). Leukocidin - hemolysis Nearly all isolates of S. aureus produce coagulase enzyme , that also helps in identification of the organism. The organism is able to grow in mannitol-salt agar medium containing 7.5% sodium chloride.

7. Epidemiology Normal microbiota Direct transmission Portal of Entry Hair follicle Break in skin Respiratory Complications Bacteremia Septicemia Abscess

8. PATHOGENESIS 1. Adherence Attached to the damaged sites ( Skin, mucosa, tissue etc.) At these sites, bacteria evade defence mechanisms of the host in the result colonize and cause tissue damaged. S. aureus produced disease by; 2. Entry 3. Multiplying in tissue 4. Releasing toxins

9. Clinical Syndromes Cutaneous Infections Folliculitis Boils/Furuncles Carbuncle Impetigo Deep Infections Osteomyelitis Endocarditis Toxin Shock syndrome Staphylococcal food Intoxication

10. 3. Toxic Shock Syndrome

11. 4. Staphylococcal Food Poisoning

12. Laboratory Diagnosis

13. Thank You 6 th April, 2022