MDS PREP
What is the characteristic odor of cultures of proteus bacilli?
1) Fruity
2) Fishy or seminal
3) Sweet
4) Foul
General Microbiology Answer: 2Proteus bacilli are known for their characteristic swarming motility on agar and a distinctive odor, which is often described as fishy or seminal. This is due to the production of ammonia and indole as metabolic byproducts.
Which of the following describes the colony morphology of Bacillus anthracis on an agar plate?
1) Smooth and shiny
2) Irregularly round with a frosted glass appearance
3) Small and translucent
4) Large and mucoid
Bacillus anthracis colonies on an agar plate typically appear irregularly round with a frosted glass appearance.
The period from disease initiation to disease detection in non-infectious disease is called -
1. Incubation period
2. Serial interval
3. Latent period
4. Lag time
Microbiology
Answer: 3
Incubation period: This term is typically used for
infectious diseases and refers to the time between exposure to the
infectious agent and the onset of symptoms.
Serial interval: This refers to the time between
successive cases in a chain of transmission, specifically in infectious
diseases.
Latent period: This is the time from the initiation of
the disease process (or exposure to a risk factor) until the disease is
detectable or until symptoms appear. In non-infectious diseases, this period
can be significant, as the disease may be developing without any noticeable
symptoms.
Lag time: This term can refer to various delays in
processes but is not specifically defined in the context of disease
initiation and detection.
In concentrations usually applied for sterilization purposes, ethylene oxide is preferable to formaldehyde becuase it is
1. more readily polymerized to an active form
2. less toxic
3. less likely to form an explosive mixture with air
4. more penetrating
Microbiology
Answer: 4
In concentrations usually applied for sterilization purposes, ethylene oxide is preferable to formaldehyde becuase it is more penetrating
Which of the following is a characteristic microscopic feature of amoebic dysentery that distinguishes it from bacillary dysentery?
1) Presence of RBCs in the stool
2) Presence of pus cells in the stool
3) Presence of Charcot-Leyden crystals
4) Presence of ghost cells
The presence of Charcot-Leyden crystals is a characteristic microscopic feature of amoebic dysentery that distinguishes it from bacillary dysentery.
Which of the following statements is true regarding the hemolysis of Bacillus anthracis?
1) Strong hemolysis is observed
2) Hemolysis is absent or weak
3) Complete hemolysis is typical
4) Variable hemolysis depending on the strain
Hemolysis of Bacillus anthracis is typically absent or weak, depending on the strain.
What type of genome do Hepatitis B viruses have?
1) ssRNA
2) dsDNA
3) ssDNA
4) dsRNA
General Microbiology Answer: 2Hepatitis B viruses possess a double-stranded DNA (dsDNA) genome, which is unique among the hepatitis viruses. This dsDNA is partially double-stranded and circular, playing a crucial role in the virus life cycle and replication.
What is the unique feature of S. gallinarum-pullorum compared to other Salmonella species?
1) It is always motile.
2) It is always nonmotile.
3) It ferments mannitol.
4) It is always a pathogen in humans.
General Microbiology Answer: 2the unique feature of S. gallinarum-pullorum compared to other Salmonella species is that it is always nonmotile. This is in contrast to the typical motility of Salmonella species, which is conferred by the presence of flagella.