OSPE STREPTOCOCCAL PHARINGITIS Flashcards
bacterial pharangitis
-temp more than 38
-sore throat
-tonsillar exudate/pus
-cervical adenopathy
-NO RUNNY NOSE(CORYZA)
viral pharyngitis
-cough
-runny nose(coryza)
-diarrhoea
COLLECTION OF SPECIMEN
- Throat swab- tonsils/posterior pharyngeal wall
- Serum
Transport medium: Pike’s medium
microscopy
Shape – Spherical and oval shape (cocci) Size – 0.5-1 micron (diameter) Arrangement of cells – Chains
Motility – Non-motile
No spores
Gram Staining reaction – Gram +ve
CULTURE REQUIREMENT for strep.pyogenes
Blood agar
-beta haemolytic
* Grey-white, circular, tiny
* Moist glistening, semi-transparent
-aerobic or facultatively anaerobic
-colonies seen after 24 hours at 35-37°C
* 5-10% CO2 during incubation promotes hemolysis on blood agar
Other CULTURE MEDIA f
- Liquid medium- Serum broth or Glucose broth
Reading: Granular turbidity with a powdery deposit without
any surface pellicle
Selective agar:
1. Selective media with crystal violet: resistant to crystal violet, normal flora is inhibited
2. Columbia agar
CATALASE TEST
Streptococcus pyogenes are slide and tube catalase test negative
-all strep are negative
other test
- Bacitracin sensitivity: clear zone of inhibition seen
- Failure to ferment ribose
- PYR Test: based on the activity of the enzyme
-ANTIGEN DETECTION TEST
-serological test
SEROLOGICAL TESTS
for rheumatic fever and glomerulonephritis strains
- Anti-Streptolysin O titre: ASO titres: higher than 200 indicate: prior streptococcal infection,
High levels in: acute rheumatic fever - Anti-Dnase B:
Titres higher than 300 are taken as significant
seen in: skin infection pyoderma - Streptozyme test: Convenient, sensitive and specific screening test, becomes positive after nearly all types of streptococcal infections, whether of the throat or the skin.
