title: Letter: Avirulent corynebacteria.
mesh_terms: D000328:Adult; D002648:Child; D003353:Corynebacterium diphtheriae / Q000302:isolation & purification / Q000472:pathogenicity*; D004165:Diphtheria / Q000382:microbiology; D006801:Humans; D014069:Tonsillitis / Q000382:microbiology; D014774:Virulence