MDS PREP
The minimum and maximum temperature for normal metabolic
activity microorganisms that live on or within the human body is
1 50 C
to 300 C
2 200 C to 450
C
3. 300 C to 400
C
4. 15 C to 600
C
Microbiology Answer: 2
The minimum and maximum temperature for normal metabolic activity microorganisms that live on or within the human body is 20° C to 45°C
What is the typical color of Salmonella colonies on MacConkey agar, except for Sh. Sonnei?
1) Colorless
2) Pink
3) Red
4) Yellow
General Microbiology Answer: 1Salmonella species, excluding Shigella sonnei, which is lactose non-fermenting, will ferment lactose in MacConkey agar, turning the colonies pink due to the formation of acidic end-products
What is the primary mode of action of exotoxins?
1) Enzymatic
2) Non-enzymatic
3) Structural disruption
4) Inhibition of protein synthesis
General Microbiology Answer: 1
The primary mode of action of exotoxins is enzymatic, as they often act as enzymes that modify or damage host cell functions.
Which of the following is the correct Lancefield group for Streptococcus pyogenes?
1) A
2) B
3) C
4) D
Streptococcus pyogenes is classified as Lancefield group A.
What is a key characteristic of the colonies formed by Streptococcus pneumoniae?
1) Dome-shaped
2) Initially dome-shaped, later draughtsman colonies
3) Granular turbidity with a powdery deposit
4) Not typically seen in culture
Streptococcus pneumoniae colonies are initially dome-shaped and later develop draughtsman colonies.
What is the effect of Actinomycin D on orthomyxoviruses?
1) Stimulates multiplication
2) Inhibits multiplication
3) No effect
4) Enhances stability
General Microbiology Answer: 2Actinomycin D is an antibiotic that inhibits RNA synthesis. In the case of orthomyxoviruses, it effectively inhibits their multiplication by preventing the transcription of viral RNA, thereby blocking the virus ability to replicate. Actinomycin D inhibits the multiplication of orthomyxoviruses by blocking RNA synthesis, which is crucial for viral replication.
What is the primary mechanism of action of the PCR test in diagnosing HIV infection?
1) Amplification of viral RNA or DNA
2) Detection of specific antibodies to HIV
3) Detection of the HIV virus directly
4) Measurement of the immune response to the virus
General Microbiology Answer: 1
The primary mechanism of action of the PCR test in diagnosing HIV infection is the amplification of viral RNA or DNA, allowing for the detection of the virus.
What is the commonest subtype of Hepatitis B virus in Thailand?
1) Subtype A
2) Subtype B
3) Subtype C
4) Subtype E
General Microbiology Answer: 4
Subtype B is the most common subtype of Hepatitis B virus found in Thailand, linked to increased risks of chronic infection.