MDS PREP
What type of antibodies are known as "coproantibodies"?
1) IgA
2) IgM
3) IgG
4) Antibodies found in feces
General Microbiology Answer: 4Copro antibodies are antibodies found in feces These are typically IgA antibodies that are produced in response to infections in the gastrointestinal tract, including typhoid fever. They can be detected in stool samples and are used in diagnostic tests.
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.
The first person becoming sick in an epidemic is called -
1. Primary case
2. Source of infection
3. Reservoir of infection
4. Index case
Microbiology
Answer: 4
The first recognized case in an epidemic outbreak is termed as the index case. Although both the index case and primary case appear to be the same yet they differ slightly. The term primary case refers to the person who first brings a disease into a group of people.
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.
Which medium is suitable for the transport of Salmonella and Shigella?
1) Cary-Blair medium
2) Thiosulfate-citrate-bile salts-sucrose (TCBS) agar
3) Hektoen enteric (HE) agar
4) Blood agar
General Microbiology Answer: 1the medium suitable for the transport of Salmonella and Shigella is Cary-Blair mediumx. This medium is designed to maintain the viability of these organisms during transport and is selective for enteric pathogens by inhibiting the growth of other non-target bacteria. TCBS agar and HE agar are used for the selective isolation and growth of these organisms, while blood agar is a general purpose medium used for various bacteria.
Selective medium for streptococcus mutans?
1 mac conkey medium
2 mitis salivarius bacitracin agar
3 neutrient agar
4 tellurite medium
Microbiology
Answer: 2
Colonies of E. coli serotype O157:H7 appear on Mac Conkey Sorbitol Agar as colourless colonies non-sorbitol fermenter. Others E. coli, sorbitol fermenters, give red colonies and gram-negative non-sorbitol fermenters appear translucent.
Which of the following statements is true about the colony morphology and cultural characteristics of Anthrax bacilli?
1) Anthrax bacilli are motile and produce a turbidity in broth.
2) The Medusa head appearance is seen in non-virulent strains of anthrax bacilli.
3) Virulent capsulated strains form smooth colonies.
4) The inverted fir tree appearance is characteristic of Anthracoid bacilli.
The Medusa head appearance is characteristic of virulent strains of anthrax bacilli, not non-virulent strains.
Which of the following is considered as a disadvantage in the application of dry heat as a sterilizing agent?
1. Requires excessive time
2. Does not destroy hepatitis viruses
3. Dulls instrument cutting edges
4. All of the above
Microbiology
Answer: 1