5

 Arrangement of cocci in pair or long chains  Non-spore forming, non-motile  Capsule, slime layers  Facultative anaerobes  Catalase(-), peroxidase(+)  Small, non-pigmented, glistening colonies  Fastidious in nutrition, drying, heat, disinfectants

1. Hemolysis type incomplete hemolysis S.pneumoniae, S.viridans α complete hemolysis S.pyogenes, S.agalactiae β non hemolysis E.faecalis γ

2. Lancefield group

1. Characteristic  β-hemolysis  bacitracin sensitive  Most strong pathogenicity Hemolytic Streptococcus to human.  Streptococcus infection’s 90% (produce a large variety of toxins in vivo)  young school aged children’s infection rate is the most high

좌 : S.pyogenes / 우 : S.agalactiae

2. Virulence Factor  Cell surface antigen (C carbohydrate)  Lipoteichoic acid  M protein  Hyaluronic acid  C5a protease

3. Major Extracellular Toxins  streptolysins  streptolysin O (SLO) : oxygen sensitivity  streptolysin S (SLS) : oxygen-stable  erythrogenic toxin (pyogenic toxin) 4. Major Extracellular Enzymes  streptokinase  hyaluronidase

5. Disease impetigo pyodermapapules

erysipelaspharyngitisnecrotizing myositis

Scarlet feverToxic shock syndrom

6. Treatment and Prevention  Anti-microbic therapy  Most S.pyogenes is very sensitive to penicillin  Patients with group A infections must be isolated and high level precautions be practiced  rheumatic fever  acute glomerulonephritis

1. Characteristic  β-hemolysis  Normal flora of humans and other mammals  In vagina, pharynx, large intestine of human  associated with cattle (causes bovine mastitis)  main virulence factor : polysaccharide antiphagocytic capsule

2. Diagnosis  CAMP test, hippurate hydrolysis test

3. Disease  bovine mastitis  neonatal pneumonia, sepsis, meningitis  endocarditis 4. Treatment and Prevention  Treatment : penicillin G, vancomycin, cephalosporins  Prevention : Pregnant women in the third trimester should be screened for colonization.

Group D Streptococci EnterococciE.faecalisE.faeciumE.durans Non- Enterococci S.bovisS.equinus

1. Group D Enterococci  Normal colonists of the human large intestine.  Multi-drug-resistant strains → vancomycin-resistant Enterococcus (VRE) → serious nomocomial opportunists  E.faecalis : Elderly patients undergoing surgery  E.faecium : Neonatal meningitis  Combined therapy with ampicillin and aminoglycoside 2. Group D Non-Enterococci  Starch hydrolysis  6.5% salt sensitive

 Common flora of domestic animals  Isolated from human upper respiratory  β-hemolysis  Compromised patients  → bacteremia  → dissenminated deep-seated infections  S.equisimilis

 residents of the oral cavity, nasopharynx, genital tract, skin  α-hemolysis : S.mitis, S.mutans, S.milleri, S.saliarus, S.sanguis  subacute endocarditis : rheumatic fever, valve surgery  dental caries : S.mutans, S.sanguis

1. Characteristic  normal flora in the nasopharynx  60~70% of all bacterial pneumonias  α-hemolysis  smooth or mucoid colony in blood agar, Small lancet-shaped  5~10% CO 2, lack catalase and peroxidase  Delicate, Not survive out of habitat  Capsule → Virulence↑ : Quellung test  soluble to bile  autolysis : dome, smooth shape → flat, rough shape

2. Diagnosis  Blood culture, sputum, pleural fluid, spinal fluid  Gram stain  Quellung test  Optochin test : alpha hemolytic streptococci (-), but, Streptococcus pneumoniae (+)

3. Disease  pharynx → lung → bronchiole & alveoli → inflammatory response → the release of a torrent of edematous fluids into the lungs → drown in his own secretion → lobar pneumonia  in young children (under 2 years) : otitis media, meningitis

4. Treatment and Prevention  penicillin G, penicillin V (drug sensitive test)  cephalosporins, vancomycin, quinolones, erythromycin  polyvalent vaccine (capsular antigen) : sickle cell anemia, lack of spleen, congestive heart failure, lung disease, diabetes, kidney disease, advanced age  conjugate vaccine → recommened for children 2 to 23 months as preventive  therapy for otitis media and meningitis

You want to differentiate between The Viridans Group and S.pneumoniae. Which method should you choose? ① Hemolysis pattern ② Bacitracin test ③ Optochin test ④ Urease test ⑤ Motility

Which disease is occurred by S. agalactiae? ① meningitis ② scarlet fever ③ rheumatic fever ④ acute glomerulonephritis ⑤ erysipelas

What is NOT feature of Lancefield group A streptococcus? ① Most strong pathogenicity Hemolytic Streptococcus to human. ② Gram positive. ③ β-hemolysis ④ CAMP test positive ⑤ bacitracin sensitive

Which of the following disease is/are caused by S.pneumoniae? ① otitis media ② subacute endocarditis ③ meningitis ④ rheumatic fever ⑤ dental caries

Which is NOT the Group D streptococcus? ① Streptococcus bovis ② Enterococcus faecalis ③ Enterococcus durans ④ Streptococcus equinus ⑤ Streptococcus agalactiae