Treatment - Penicillin G benzathine, erythromycin, tetracyclines and cephalosporin. The agent is Corynebacterium diphtheria which is a gram positive rod, pleomorphic and produces catalase. There are three biotypes - gravis, intermedius and mitis. Toxigenicity is related to a lysogenic phage that codes for the tox gene. Diphtheria toxin contains both an active subunit A, which catalyzes toxic activity, and subunit B which mediates receptor binding and membrane translocation of subunit A. Toxin biosynthysis is enhanced by the presence of iron that is regulated by siderophore.
Transmission is by respiratory or cutaneous discharge.
Symptoms - Sore throat, fever and pharyngitis or tonsillitis. Treatment - Penicillin and erythromycin. DTP - Diphtheria, Tetanus, and Pertussis. It is a gram negative, aerobic, non motile coccobacilli, with pili and is very fastidious. It is pathogenic especially to he young.