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Medically important · PDF file Staphylococcus epidermidis, S.saprophyticus S. capitis .. Opportunistic and nosocomial ( immunocompromised patients) S.epidermidis: skin, hair follicules

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  • Medically important cocci

  • Pyogenic bacteria

    • Staphylococcus (family Micrococcaceae)

    • Streptococcus (family Streptococcaceae)

    • Neisseria (family Neisseriaceae)

  • Staphylococci

    • Skin and mucous membrane

    • Pathogen for human and animals

    • Gram positive cocci

    • Facultative aero-anaerobi

    • Appearing in clusters, short chains and diplococci

    • Lack flagella and spore

    • Some contains capsule

  • Staphylococci I. Generals: 30 species

    – S.saprophyticus

    – S.epidermidis( S.slbus)

    = Staphylococcus aureus

  • Staphylococcus aureus

    • Spherical 1µ

    • In clusters after cultivation on solid media

  • cultivation

    • 37 0C ( 10-46 0C )

    • Aero-anaerobic ( O2 and CO2)

    • NaCl (7.5-10%)

    • Heat (600C to 1h)

    • Antibiotics and antiseptics

  • Enzymes of S.aureus

    • Coagulase (97%)

    • Hyaluronidase (spreading factor)

    • Fibrinolysine (35%)

    • DNAase

    • Lipase

    • Catalase

    • Penicillinase (more than 75%)

  • Toxins of S.aureus

    • Hemolysins (α- Hemolysine , β hemolysine , δ hemolysine , γ hemolysine )

    • Leukucidin

    • Enterotoxin (A-F) 50%S.aureus (resist to boiling for 30min)

    • Exfoliative toxin (SSSS)

    • TSST

  • Pathogenicity

    A. Staphylococcus aureus

    A.1 Localized infections

    – Cutaneous (folliculitis, furuncle, impetigo,carbuncle,blepharitis, panaris)

    – ORL (sinusite, otitis, Pneumonia)

    – Septicemia ,osteomyelitis,endocarditis,polyarthritis,meningitis, toxemia

    A.2 Toxic infections

    – Toxic shock syndrom – SSSS(staphylococcal scalded skin syndrom) – Food intoxication (1-8h) vomiting ,diarrhea, nausea, self limited

  • Site of pathogenicity

  • abcès

    folliculitis

    furuncle

    Abcess

    folliculitis

  • Osteomyelitis

  • Chronic osteomyelitis

  • STAPHYLOCOCCIC TOXINFECTIONS

    I. STAPHYLOCOCCAL SCALDED SKIN SYNDROME

    – (SSSS) – : S. aureus produce exfoliative toxin – Fever – Generalised eruptions (cutaneous + mucous)

  • Scarlatine staphylococcique

    Toxic shock

    Impétigo bulleux

    SSSS

    Impétigo

  • Non supurative infetions of toxic origin

    SSSS

    Impétigo bulleux

    EXFOLIATINE

  • Staphylococcus aureus Pathogenicity

    SSSS

  • STAPHYLOCOCCIC TOXEMIA

    • III - Staphylococcal toxic shock syndrom

    – 5-10 % mortality

    – TSST-1

    – 20-30 % portal of entry vaginal

    – Character hyper-absorbant to certain tampons.

  • staphylococcal toxic shock

    – Staphylococcal toxic shock syndrome

    • High fever

    • hypotension

    • Profound cutaneous nodules

    • Myalgia

    • Cardiac and tubular complications

    • S.aureus TSST1

  • B. Other staphylococci( coagulase negative

    Staphylococcus epidermidis, S.saprophyticus S. capitis ….. Opportunistic and nosocomial ( immunocompromised patients)

    S.epidermidis: skin, hair follicules and mucous membrane (UTI,Endocardits, Bacteremia)

    S.saprophyticus: skin, intestine and vagina( esp UTI)

    Mode of transmission: -surgery -catheter -Instruments _truama

  • Direct biologic diagnosis

    – Gram staining

    – Gram positive cocci

    Catalase + (differentiate from strept)

  • Direct biologic diagnosis

    Identification Aspect of colonies Coagulase

    S. aureus golden Positive

    S. albus white Négative

    S.Saprophyticus Variable

    – ANTIBIOGRAMME

  • Color of colonies Golden white Vulnerable

    Anaerobic + - -

    Aerobic + w w

    Manitol fermentation + - w*

    sensitive to lysostaphin + - -

    sensitive to novobiocin + + -

    β- hemolysis(α-toxin) + - -

    Coagulase + - -

    Test S.aures S. epdermidis S.saprophyticus

    تجرید انواع استافیلوکوک ھای عمده ازنگاه کلینیکی

    * Weak

  • Treatment

    • Multidrug resistant

    • Penicilline, Gentamicine, Tetracycline, Methicilin,Quinolones, Erythromycine, Sulfamides, Cephalosporines, Rifampicin

  • Epidemiology

    • Main reservoir are human and abcess

    • Careful hygiene and adequate cleansing of surgical incisions and burns

    • Isolation of people with open lesions

    • Handwashing, proper disposal of infectious dressings and discharges.