Micrococci Marphology: _ Gram +ve cocci Arrangement : Tetrades _ _ _ _ _ Non motile, non capsulated, non sporulated Habitat : May be normal present in upper respiratory tract Species : 1- M.varlans 2- M.luteus 3- M.roseus

Culture : - Stricking aerobic at 37°C incubation (24 hr) Grow on ordinary media Nutrient agar Blood agar and - on Mannitol salt agar grow given rose to rose or pink colonies except M.roseus. M.Roseus(pink)M.Luteus(white)M.Varlans(yellow) on the Blood agar

Disease: Acute endocarditis Urinary tract infection Mastitis Chest infection Resistance: Resistance to many antibiotics

Streptococci General character : 1- Morphology : _ Gram (+ve) cocci Arrangement : Chain _ _ Non motile, non sporulated, may be capsulated or not.

Culture character : _ Facultative anaerobic _ On fluid media →Sedment _ Grow very poor on ordinary media as dew drops like colonies, but growth inhanced in blood and glucose agar. Classification : 1-Brown`s classfication → depend up on degree of hemolysis * β- hemolytic (clear zone of hemolysis ) or ( complete ) e.g. S.pyogens [most pathogenic group ] * α – hemolytic (incomplete hemolysis) greenish colour in the blood agar e.g. (S.viridans _ S.pneumonia) [mield pathogenic group] *γ-haemolysis (non hemolytic group ) e.g. S.lactis mainly saprophytic.

2- Sherman`s classfication → depend up on the ability of microorgonism to grow at 10°C and 45°C * pyogenicgroup e.g. S.pyogenic - Not grow at 10,45°C but grow at 37°C - pathogenic - B- hemolytic * Entrococci group S.fecalis (E. fecalis) - grow at 10& 45°C - less pathogenic (present in the intestine) - highly resistance to alkaline, bile salts. & saline NaCl & resistance to Antibiotic * Lactic group: e.g. S.lactis - grow at 10°C but not at 45°C - non pathogenic - γ- hemolytic * Viridans or oral streptococcus S.viridans - grow at 45 °C & not 10°C - α – hemolytic

3- lance field classfication → depent on carbohydrate Antigen in the cell wall Group A, B,C,D,G, N, K, untypable group Group A : S.pyogens affect the human causing scarlet fever acute tonsilis – abcess – sore throat – otitis media puer peral sepsis and pyogenic infection Also cause post streptococcus disease as : - Rheumatic fever. - Rheumatic kidney. - Bovine mastitis in cattle. Group B : S.agalactia → mainly affect the bovine causing mastitis. Normal present in the infant & sepsis.

Group C: S.dysglactia → mastitis in cattle. Group D: S.faecalis (E. Faecalis) → endocarditis Urinary tract infection Group G,N,K : → animal strain Affect the animal + S.lactis, S.salivaris→ in saliva. untypable group: S.pneumonia → pneumonia in man. S.uberis → mastitis in cattle.

S.pyogens From group A&B haemolytic Morphology: As general characte Culture character : As general character + ß.hemolysis Biochemical test : As general characte Antibiotic sensitivity:Bactrian sensitive Serological test: * C-reactive protein (CRP): it is test used for diagnosis of post_streptococcal disease * Anti-streptolysin O (ASO): strept-pyogene → produce streptolysin O streptolysin S produce skin rash→ Erythrogenic toxin streptokinase (Fibrinolysin) streptolysin O → stimulated produce of specific antibody in the serum after 3-4 weeks from infiction, this test used to measure the ASO titre.

What is rheumatic fever ? It is autoimmune disease due to similaritybetween Ag on the heart muscle and on strep.,so the Ab-formed against strept. Will attact the heart → Carditis.

S.agalactia There are 2 important test to differentiale S.agalactia from other species CAMP test S.agalactia produce CAMP factor which help hemolysis of S.aureus. S.aureus also cause hemolysis, while at the function between staph. & strept. There is enhancement of haemolysis is occur by CAMP factor in the form of Triangular zone of haemolysis give the shape of arrow. - Sodum hippurate test : because S.agalactia cause hydrolysis of sodum hippurate. - Produce yellow pigment colonies(carotenoid pigment)

S.viridans Morphology: Gram +ve cocci, arrangement in short or long chain _ non motile, non sporulated –non capsulated. Normal flora: Upper Respiratory –throat –oral mouth. Culture: G GG Grow on sheep blood agar α haemolytic Greenish hemolytic. Temperature: Grow 10°C and not at 45°C

Biochemical testS.pneumoniaS.viridans +ve-ve Solubility in bile +ve with acid -ve Fermentation of inulin sR Sensitivity to optochin +veــــــ Pathogenicity to mice +veــــــ Quelling test

Pathogenicity - Mild - ability to infection weak. but may play the role opportunistic disease. Under certain condition & when the immunity low ↓ Disease 1- Dental caries 2- Endocarditis 3- Abcesses Mariam Abdelaziz