Major infection of ear:
i) acute otitis media
ii) Chronic suppurative otits media
iii) otitis externa
Causative organisms: S. pyogens, H. influenzae, Moraxellacatarrhalis, M. pneumoniae, P. aeruginosa, S. aureus, coliform bacilli
Mode of infection:
-Organisms spreads to middle ear via the Eustachian tube from Nasopharynx,
-As long as eardrum remains intact, infected exudates cant be collected in the swabs
-In such case throat swab may give provisional diagnosis
Specimen: swabs taken from external auditary meatus
Transport media: Amies charcoal transport media
Culture
: take two swabs if possible, one for culture and next for gram stain
-Nature of organisms in gram stain gives presumptive idea of causative agents
-Culture aerobically on MA and BA plates and SDA for fungal growth
- On SDA place 50 unit disc of Nystatin and incubate at 35-37°C for Candidia and at 28°C for Aspergillus
- On plates observe for the colony characteristics and perform different biochemical tests and identify the organism
- For fungi perform lactophenol cotton blue cellophane tape method to observe the fungal spores
- For Candida, Gram staining and Germ tube test: +ve
CONTAMINANT:
– Coagulase negative staphylococci, Diptheroid bacilli
– Should be ignored.
Treatment: Amoxycillin, Amoxy Clav, Erythromycin, Ofloxacin
