Thursday, 20 August 2015

Identification of Bacteria

Identification of Bacteria

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Which of the following is commonly used as Gram's decolouriser?

a. Ethyl alcohol
b. Methyl alcohol
c. Acetone
d. A mixture of ethyl alcohol and acetone

Production of acetoin can be detected by which of the following tests?

a. Citrate test
b. Voges-Proskauer test
c. Methyl red test
d. Indole test

The production of sufficient acid by fermentation of glucose leads to decrease in pH such that pH of the medium falls below 4.5. Which of the following test can detect it?

a. Indole test
b. Methyl red test
c. Citrate utilization test
d. Voges-Proskauer test

Which of the following inference(s) indicate(s) the ability of an organism to utilize citrate as a sole source of carbon in Simmon's citrate medium?

a. Blue colour
b. Appearance of growth
c. Both (a) and (b)
d. None of these

The organisms that can be acid-fast stained is__________

a. Nocardia
b. Tubercle bacilli
c. Lepra bacilli
d. all of these

The primary stain of Gram's method is__________

a. Safranin
b. Phenolpthalene
c. Crystal violet
d. Methyl red

At what concentration of sulphuric acid, Nocardia resists decolourization?

a. 0.5% sulphuric acid
b. 5% sulphuric acid
c. 10% sulphuric acid
d. 8% sulphuric acid

The gram-negative organisms is__________

a. Actinomyces
b. Bacillus
c. Clostridium
d. None of these

Catalase production is negative in which of the following?

a. Streptococcus
b. Salmonella
c. Proteus
d. Staphylococcus

Which of the following is a substitute for crystal violet used in gram-staining procedure?

a. Methylene blue
b. Bromocresol green
c. Safranin
d. Phenolpthalene

What is the colour of gram -postive bacteria on a gram staining?

a. Purple         
b. Pink
c. Colourless    
d. Green

What is the colour of gram-negative bacteria on a gram staining?

a. Purple          
b. Pink
c. Green           
d. Colourless

Which of the following is a primary stain for acid fast staining of mycobacteria?

a. Crystal violet
b. Carbol fuchsin
c. Geimsa
d. Methylene blue

The deinococci are gram-positive cocci and rods that are distinctive in their unusually great resistance to__________

a. radiation
b. desiccation
c. both (a) and (b)
d. extreme temperatures

Which of the following shows a positive urease test?

a. Proteus
b. Klebsiella
c. Both (a) and (b)
d. None of these

Which of the following(s) is/ are oxidase-positive bacteria?

a. Vibrio
b. Neisseria
c. Pseudomonas
d. All of these

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

Gram staining was developed accidentally in 1884 by__________

a. Alexander Fleming
b. Hans Christian Gram
c. Joseph Christian Gram
d. Robert Gram

The process of Gram staining is based on the ability of bacterial cell wall__________

a. To retain the safranin dye
b. To retain the crystal violet dye during solvent treatment.
c. To retain part of both dyes
d. None of above

Which of the following organisms can be demonstrated with silver impregnation method?

a. Vibrios         
b. Salmonella
c. Spirochaetes           
d. Shigella

Which of the following(s) show(s) positive results for phenylalanine deaminase test?

a. Providencia
b. Proteus
c. Morganella

d. All of these
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