Clinical features: The bacteria causes disease most commonly in young children. . Acute pyogenic meningitis . Acute epiglottis . Pneumonia . Otitis media . Siusitis . Cellulitis . Acute pyogenic arthritis
Specimen: Cerebrospinal fluid, sputum, blood, pus Smear: Gram-negative short rods. Culture: Chocolate agar contain both X and V factor; blood agar contain only X factor. Satellitism test is used to identify H. influenzae in blood agar.
Methods: . Mix a loopful of haemophilus growth in 2ml of sterile saline. . Inoculate the bacteria suspension on a plate of blood agar using a sterile swab. . Streak a pure culture of S. aureus across the inoculated plate which provides V-factor for H. influenzae. . incubate the plate over night in a CO2 -enriched environment at 35- 37 Oc. . Look for growth and satellite colonies in next morning. NB: Colonies are largest nearest to the S. aureus column of growth. Serology: Quellung reaction (using specific antisera) Immunofluorescence stain