MDS PREP
What is the primary reservoir for prions?
1) Bacteria
2) Viruses
3) Proteinaceous particles
4) Nucleic acids
General Microbiology Answer: 3Prions are infectious agents composed solely of protein. They do not have nucleic acids like DNA or RNA and are responsible for several neurodegenerative diseases. The primary reservoir for prions is thus the proteinaceous particles themselves.
What is the size range of adenoviruses?
1) 50-100 nm
2) 70-75 nm
3) 100-150 nm
4) 200-300 nm
General Microbiology Answer: 2Adenoviruses are medium-sized viruses that typically range from 70 to 90 nanometers in diameter, with the most common size being around 70-75 nm. They are known for causing respiratory infections and conjunctivitis
What type of differentiation is associated with a diphtheria bacilli that ferments glycogen and starch?
1) Gravis
2) Intermedius
3) Mitis
4) Avirulent
Diphtheria bacilli that ferment glycogen and starch are classified as Mitis.
Most viruses are
1. never destroyed by the application of moist heat
2 easily destroyed by the application of moist heat
3 difficult to destroy by the application of moist heat
4 never destroyed because they are not living
Microbiology
Answer: 2
The bacteria having the highest lipid Content in the cell wall
1 Staphylococcus aureus
2 Escherichia coli
3 Mycobacterium tuberculosis
4 Leptotrichia buccali
Microbiology
Answer: 3
The bacteria having the highest lipid Content in the cell wall Mycobacterium tuberculosis
What is the principle behind the oxidase test used to identify bacteria?
1) The presence of specific antigens
2) The activity of certain bacterial oxidases
3) The growth of bacteria on selective media
4) The presence of enzymes that hydrolyze certain sugars
General Microbiology Answer: 2
The oxidase test is based on the presence of cytochrome c oxidase in bacteria. This enzyme catalyzes the oxidation of certain substrates, leading to a color change in the test medium, which indicates a positive result for oxidase activity.
What is the primary target of antibodies in neutralizing the action of exotoxins?
1) Cell wall components
2) Lipopolysaccharides
3) Protein components of the toxin
4) Enzymes involved in toxin production
General Microbiology Answer: 3
Antibodies neutralize exotoxins by binding to their protein components, preventing them from interacting with host cells and causing damage. This immune response is critical for protecting the host from the harmful effects of these toxins.
The term cold sterilization has been employed to refer to
1. physical methods of sterilization
2. prolonged exposure to 20� C
3. exposure to low temperature steam
4. chemical disinfection
Microbiology
Answer: 4
chemical disinfection is cold strelization