16. Which of the following(s) is/ are oxidase-positive bacteria?
A. Vibrio
B. Neisseria
C. Pseudomonas
D. All of these
17. What is the order of reagents used in the Gram stain?
A. Crystal violet, iodine, safranin, decolorizer
B. Crystal violet, iodine, decolorizer, safranin
C. Safranin, crystal violet, decolorizer, iodine
D. Crystal violet, safranin, iodine, decolorizer
18. Gram staining was developed accidentally in 1884 by
A. Alexander Fleming
B. Hans Christian Gram
C. Joseph Christian Gram
D. Robert Gram
19. Which of the following organisms can be demonstrated with silver impregnation method?
A. Vibrios
B. Salmonella
C. Spirochaetes
D. Shigella
20. Which of the following(s) show(s) positive results for phenylalanine deaminase test?
A. Providencia
B. Proteus
C. Morganella
D. All of these