STREPTOCOCCI General character l l l Gram positive

STREPTOCOCCI

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

GROUP A STREPTOCOCCUS PYOGENES

l l l Most important pathogen Distinguished by bacitracin test (sensitive) Some are capsulated (hyaluronic acid)

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

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

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

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

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

DISEASES A - 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

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

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

MICROSCOPY l GRAM – STAIN – GRAM-POSITIVE COCCI IN CHAIN – USELESS IN THROAT SWAB

CULTURE - IDENTIFICATION l l l BLOOD-AGAR (AEROBIC- ANAEROBIC) BETA- HAEMOLYSIS (COMPLETE ) ID – – – BACITRACIN SENSITIVITY LANCEFIELDS GROUPING (CELL WALL CHOAg) STREPTEX

SEROLOGY l ASO-TITRE – – l RHEUMATIC FEVER ACUTE GLOMERULONEPHRITIS Anti-DNAase B – RECENT GROUP -A INFECTIONS (SKIN)

TREATMENT l PENICILLIN – 10 DAYS l ALLERGY– – ERYTHROMYCIN CEPHALOSPORINS l l CEPHRADIN CEFUROXIME

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

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

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

CLINICAL PICTURE l l RESPIRATORY DISTRESS SYNDROME SEPTICAEMIA MENINGITIS MORTALITY :

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

DIAGNOSIS l l CLINICAL LATEX – AGGLUTINATION CULTURE ID – – CAMP – TEST STREPTEX (GROUPING)

INFECTIONS IN ADULTS l l l POST-PARTUM SEPSIS CHORIOAMNIONITIS IMMUNOCOMPROMISED – – SEPSIS CELLULITIS ARTHRITIS PNEUMONIA

TREATMENT PREVENTION l l l PENICILLIN OR AMPICILLIN + GENTAMICIN SCREEN- PREGNANT W. (35 -37 W) CARRIER – PROPHYLAXIES – IV- PENICILLIN – AT LABOUR

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

DISEASES l l l URINARY TRACT INFECTIONS ENDOCARDITIS WOUND INFECTIONS TREATMENT AMPICILLIN + GENTAMICIN VANCOMYCIN ( VRE )

ALPHA – HEMOLYTIC STREPTOCOCCI S. PNEUMONIAE VIRIDANS

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

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

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

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

TREATMENT , PREVENTION l CEFTRIXONE + VANCOMYCIN l PENICILLIN l ERYTHROMYCIN CLINDAMYCIN l l VACCIN

VIRIDANS l NORMAL FLORA – OROPHARYNX – SKIN – GIT

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