This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
C. diphtheriae can be biochemically differentiated from C. pseudotuberculosis by 
Select and explain. 
A. Catalase test, B. Urease test, C. Oxidase test, D. Tellurite Reduction
B: Urease test
Answer: B: Urease test 
Explanation: -C. pseudotuberculosis is urease positive and is thus differentiated from C. diphtheriae. - C. pseudotuberculosis causes caseous lymphadenitis in sheep and goats. Corynebacterium - catalase positive. Oxidase positive organisms are: Pseudomonas aeruginosa Burkholderia species Vibrio Pasteurella multocida Brucella Neisseria Haemophilus spp Campylobacter Potassium tellurite agar (PTA) is the selective media used for C. diphtheriae.