26. Which of the following determines the pathogenicity of Yersinia pestis?
A. V and W antigens
B. F1 envelope antigen
C. Production of pigmented colonies on haemin containing media
D. All of these
27. Enterobacter can be differentiated from Klebsiella by
A. ornithine positivity
B. motility
C. both (a) and (b)
D. none of these
28. In Yersinia pestis, the capsule is best demonstrated in cultures grown at
A. 25°C
B. 29°C
C. 37°C
D. 45°C
29. Which of the following can readily kill Salmonellae?
A. Moist heat at 55°C for 20 min
B. Moist heat at 55°C for 10 min
C. Moist heat at 55°C for 30 min
D. Moist heat at 55°C for 1 hr
30. Travelers diarrhea is caused by
A. enteropathogenic Escherichia coli (EPEC)
B. enteroinvasive E. coli (EIEC)
C. enterotoxigenic E. coli (ETEC)
D. enterohemorrhagic E. coli (EHEC)