title: Morphologic and microbiologic features of nasal cavity and middle ear in germfree, defined-flora, conventional, and chronic respiratory disease-affected rats.
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques; D002908:Chronic Disease; D003470:Culture Media; D013296:Streptococcus pneumoniae / Q000302:isolation & purification
chemical_list: D003470:Culture Media