S.pneumoniae

Question 1

Morphology of Strep pneumoniae

Answer 1

gram + lacet shaped diplococci
capsule
autolysis

Question 2

Culture of S pneumoniae

Answer 2

Blood agar-alpha haemolysis
Draughtman colonies( central plateau with elevated rim )at first small round colonies
optochin sensitive
smooth colonies (capsule production)

Question 3

pathogenicity of S pneumoniae

Answer 3

high invasiveness due to capsule=polysaccharide
capsule elicits B cell response
minimal toxicigenicity

Question 4

Identification and typing reaction for S pneumoniae

Answer 4

Quellung reaction( capsule swelling reaction)
pneumococci+ specific anti polysaccharide or polyvalent anti serum —-> capsule swells markedly

Question 5

Lobar pneumonia?

Answer 5

S pneumoniae infection—> outpouring of fibrinous exudate into alveoli followed by red cell and leukocytes—-> consolidation of lungs
via lymphatic drainage—> blood stream

Question 6

disease and clinical findings caused by S pneumoniae infection

Answer 6

Lobar pneumonia
Bacteremia Septicemia
Fever chills sharp pleural pain
Bloody or rusty sputum
bacteremic pneumonia—highest motality rate

Question 7

Complications of S pneumoniae

Answer 7

fq — Sinusitis,Otitis media, mastoiditis (SOM)
severe—bacteremia from pneumonia— meningitis, endocarditis,septic arthritis

Question 8

Specimen for S pneumoniae infection

Answer 8

Sputum
Laryngeal swab
Blood for bacteremia
CSF for meningitis

Question 9

Biochemical tests for differentiation of S. pneumoniae and S.viridans

Answer 9

Bile solubility test
Optocin sensitivity test
Inulin fermentation test
Mouse pathogenicity test

Question 10

Immunization of S.pneumoniae

Answer 10

Active immunization( combined vaccines of prevalent pneumococcal type)
Antigens(combined antigens of purified polysaccharides from main epidemic types)

PCV 2,4,6 months