8. Transmission of bubonic plague is by
A.rat flea
B.inhalation
C.ingestion
D.all of these

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9. The bacteria, which is more resistant to adverse environmental conditions, is
A.S sonnei
B.S dysenteriae
C.S flexneri
D.S boydii

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10. The reaction(s) that is/are usually positive in Escherichia coli, is/ are
A.Glucose fermentation
B.Indole reaction
C.Methyl red reaction
D.All of these

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11. An enrichment medium for the isolation of Shigella is
A.Alkaline peptone water
B.Terathionate broth
C.Selenite F broth
D.none of these

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12. In Widal test the significant titres for H agglutinins is
A.1:50 or more
B.1:100 ormore
C.1:200 or more
D.1:400 or more

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13. Heat-labile enterotoxin of Escherichia coli activates
A.guanylate cyclase
B.adenylate cyclase
C.both (a) and (b)
D.none of these

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14. Heat-stable enterotoxin of Escherichia coli activates
A.adenylate cyclase
B.guanylate cyclase
C.both of the above
D.none of these

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