STREPTOCOCCI - PowerPoint PPT Presentation

streptococci n.
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STREPTOCOCCI

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  1. STREPTOCOCCI

  2. General character • Gram positive cocci arranged in chains • Catalase test negative • Fastidious • Facultative anaerobes • Penicillin sensitive (Streptococcus faecalis ) • Resistant to AG (GENTAMICIN )

  3. GROUP A STREPT STREPTOCOCCUS PYOGENES

  4. Most important pathogen • Distinguished by bacitracin test (sensitive) • Some are capsulated (hyaluronic acid)

  5. epidemiology • Acquired through infected respiratory droplet • Direct contact _ Skin , hand • Indirect contact _contaminated objects • Spread enhanced by poverty overcrowding poor ventilation

  6. Source of infection A - Patient with active disease – tonsillitis • Convalescent carriers – throat B - Asymptomatic carriers (20% -school children ) – throat • Prevalent in children – 3 – 8 yrs

  7. VIRULENCE FACTORES A- CELL ASSOCIATED 1- M protein (antiphagocytic) - originates from cytoplasmic membrane produces protective type specific abs 2- lipoteichoic acid adhesion factor for attachment 3- hyaluronic acid capsule - antiphagocytic

  8. 3- STREPTOKINASE (fibrinolysin) • Thrombotic disease – coronary thrombosis 4- DNAases A , B , C , D. • AntiDNAase B - DIAGNOSE SKIN infections 5- HYALURONIDASE – spread factor 6- LIPOPROTEINASE – opacity factor

  9. B- EXTRACELLULAR PRODUCTS B- EXTRACELLULAR PRODUCTS 1- SREPTOLYSINS OR HAEMOLYSIN • Streptolysin o antigenic , ASO , oxygen labile • Streptolysin s oxygen stable, non antigenic 2- Erythrogenic toxin (SPE ) • SUPERANTIGEN • Bacteriophage – 3 types , A – B- C . • SCARLET FEVER

  10. DISEASESA - SAPURATIVE A- SAPURATIVE 1- TONSILITIS / PHARINGITIS 2- PERITONSILAR ABSCESS(QUINSY) 3- OTITIS MEDIA 4- ADENITIS 5- IMPETIGO (PYODERMA) 6- SCARLET FEVER 7- CELLULITIS 8- PUERPERAL SEPSIS 9- INVASIVE SOFT TISSUE INFECTIOS NECROTISING FASCITIS , MYOSITIS , TSS 10 - BACTERIMIA

  11. B-NON SUPPURATIVE (DELAED SEQUELAE) B- NON- SUPPURATIVE (DELAYED SEQUELAE) 1- RHEUMATIC FEVER : autoimmune disease follows throat infection only recur (M – SEROTYPES) 2- ACUTE GLOMERULONEPHRITIS Ag – Ab complexes May follow both throat or skin infection NO recurrence

  12. LABORATORY DIAGNOSIS SPECIMEN THROAT SWAB PUS WOUND BLOOD ASPIRATES SERUM – SEROLOGY : ASO TITRE

  13. MICROSCOPY • GRAM – STAIN • GRAM-POSITIVE COCCI IN CHAIN • USELESS IN THROAT SWAB

  14. CULTURE - IDENTIFICATION • BLOOD-AGAR (AEROBIC- ANAEROBIC) • BETA- HAEMOLYSIS (COMPLETE ) • ID • BACITRACIN SENSITIVITY • LANCEFIELDS GROUPING (CELL WALL CHO-Ag) • STREPTEX

  15. SEROLOGY • ASO-TITRE • RHEUMATIC FEVER • ACUTE GLOMERULONEPHRITIS • Anti-DNAase B • RECENT GROUP -A INFECTIONS (SKIN)

  16. TREATMENT • PENICILLIN – 10 DAYS • ALLERGY- • ERYTHROMYCIN • CEPHALOSPORINS • CEPHRADIN • CEFUROXIME

  17. GROUP C AND G STREPT. • SORE THROAT • SKIN INFECTION • WOUND INFECTION • SOFT – TISSUE • GENITAL – INFECTION • CELLULITIS • SEPTICAEMIA

  18. GROUP-B STREPTOCOCCUS(SREPT. AGALACTIAE) • RESERVOIR- COLON (RECTUM) • 10-40 % FEMALE . CARRIER (VAGINA) • 70% - NEOBORN – COLONISED DURING BIRTH • < 1% GET INVIASIVE INFECTION

  19. DISEASES A – EARLY ONSET (24 – 48 h ) RISK – FACTORS RUPTURED MEMBRANES (>18h PREMATURITY PROM (< 37 WEEKS) MULTIPLE BIRTH (TWINS) LOW BIRTH WEIGHT

  20. CLINICAL PICTURE • RESPIRATORY DISTRESS SYNDROME • SEPTICAEMIA • MENINGITIS • MORTALITY :

  21. B- LATE – ONSET HOSPITAL- AQUIRED (NOSOCOMIAL) MENNGITIS IN FULL – TERM NEONAT. BETTER PROGNOSIS MORTALITY

  22. DIAGNOSIS • CLINICAL • LATEX – AGGLUTINATION • CULTURE • ID • CAMP – TEST • STREPTEX (GROUPING)

  23. INFECTIONS IN ADULTS • POST-PARTUM SEPSIS • CHORIOAMNIONITIS • IMMUNOCOMPROMISED • SEPSIS • CELLULITIS • ARTHRITIS • PNEUMONIA

  24. TREATMENTPREVENTION • PENICILLIN OR AMPICILLIN + GENTAMICIN • SCREEN- PREGNANT W. (35-37 W) • CARRIER – PROPHYLAXIES • IV- PENICILLIN – AT LABOUR

  25. GROUP – D STREPT.NORMAL INTESTINAL FLORA A- ENTEROCOCCI GROW IN 40% BILE-ACID,6.5% NACL PENICILLIN RESISTENT AMPICILLIN SENSITIVE - E. FAECALIS : 80% - 90% INFECTI. - E. FAECIUM : MANY AMPICILLIN R. B- NON-ENTEROCOCCI PENICILLIN SENSETIVE STREPT . BOVIS

  26. DISEASES • URINARY TRACT INFECTIONS • ENDOCARDITIS • WOUND INFECTIONS TREATMENT AMPICILLIN + GENTAMICIN VANCOMYCIN ( VRE )

  27. ALPHA – HEMOLYTICSTREPTOCOCCI S.PNEUMONIAE VIRIDANS

  28. PNEUMONIA BACTEREMIA MENINGITIS SEPTIC ARTHRITIS PERITONITIS OTITIS MEDIA SINUSITIS CONJUNCTIVITIS BRONCITIS S.PNEUMONIAE

  29. GRAM POSITIVE DIPLOCOCCI • POLYSACCHARIDE CAPSULES (85) • ANTIPHAGOSITIC • OPSONIZING ANTIBODIES • ANTCAPSULAR AB. ARE PROTECTIVE • PNEUMOLYSIN

  30. RISK FACTORS • CEREBRAL IMPAIRMENT • VIRAL INFECTION • OLD AGE • HEART FAILURE • SPLENECTOMY • SCA , MULTIPLE MYLOMA , HIV • SKULL FRACTURE

  31. DIAGNOSIS SPUTUM , BLOOD , CSF • MICROSCOPY • QUELLUNG REACTION • BILE SOLUBLE • OPTOCHIN SENSETIVE • BLOOD CULTURE + IN 15% • LATEX AGGLUTINATION • SENSETIVITY TEST

  32. CEFTRIXONE + VANCOMYCIN PENICILLIN ERYTHROMYCIN CLINDAMYCIN VACCIN TREATMENT , PREVENTION

  33. VIRIDANS • NORMAL FLORA • OROPHARYNX • SKIN • GIT

  34. ENDOCARDITISFEVER , ANEMIA , HEART MURMUR • S. MUTANS –POLYSACCHARIDES (DEXTRAN) – DENTAL CARIES • S.SANGUIS • S.SALIVARIUS • S.MITIS • S. BOVIS ( CA. COLON ) • S.INTERMEDIUS ( MILLERI) • DENTAL , BRAIN , ABDOMINAL ABSCESSES