This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
True about corynebacterium diphtheriae ? 
Select and explain. 
A. Schick test is done for resistance, B. Gram positive organism, C. Schick test is an intramuscular test, D. Most impoant treatment is antibiotic
B: Gram positive organism
Answer: B: Gram positive organism 
Explanation: Ans. is 'b' i.e., Gram positive organism Corynebacterium diphtheriae is a gram positive bacillus. Schick test was an intradermal test which was used for susceptibility. Administration of diphtherial antitoxin is the most impoant element in the treatment of respiratory diphtheria. The primary goal of antibiotic therapy is to eradicate C. diphtheriae. Drugs currently used are erythromycin or procaine penicillin G. alternatives are rifampicin or clindamycin.