MDS PREP
The chemical nature of bacterial exotoxins is, a
1. low molecular weight polypeptide
2. lipopolysaccharide complex
3. protein
4. complex carbohydrate
Microbiology
Answer: 2
The chemical nature of bacterial exotoxins is, a
lipopolysaccharide complex
What is the characteristic appearance of Bacillus anthracis in gelatin stab culture?
1) Smooth liquefaction
2) Inverted fir tree appearance
3) No liquefaction
4) Uniform turbidity
The inverted fir tree appearance is characteristic of Bacillus anthracis in gelatin stab culture.
Which of the following is NOT a characteristic of anthracoid bacilli?
1) Generally motile
2) Non-capsulated
3) Grow in long chains
4) Pathogenic to laboratory animals
Anthracoid bacilli are generally non-motile and non-capsulated, and they do not grow in long chains.
What is the purpose of using aluminum hydroxide as an adjuvant in the hepatitis B vaccine?
1) To increase the immunogenicity of the vaccine
2) To prevent bacterial contamination
3) To enhance the stability of the vaccine
4) To reduce the amount of antigen needed for immunization
General Microbiology Answer: 1
Aluminum hydroxide is used as an adjuvant in the hepatitis B vaccine to increase the immunogenicity of the vaccine, enhancing the body's immune response to the antigen.
Which of the following is a distinguishing feature of orthomyxoviruses?
1) Single linear RNA
2) 80-120 nm in size
3) Hemolysin present
4) Cytoplasmic replication
General Microbiology Answer: 2Orthomyxoviruses, which include the influenza viruses, are characterized by their single-stranded RNA genome. This feature distinguishes them from other virus families that may have different types of genetic material. Orthomyxoviruses are distinguished by their single linear RNA genome, which is essential for their replication and pathogenicity.
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
General Microbiology Answer: 3
Amoebic dysentery, caused by the protozoan parasite Entamoeba histolytica, is characterized by the presence of ghost cells in the stool. Ghost cells are the remnants of red blood cells that have been phagocytosed by the amoeba. These cells are ingested and their cytoplasm is removed, leaving only the cell membrane, which gives them a "ghost-like" appearance under the microscope. This feature helps distinguish amoebic dysentery from bacillary dysentery, which is caused by bacteria such as Shigella species. Bacillary dysentery typically shows the presence of white blood cells (pus cells) and red blood cells in the stool, but not ghost cells.
Which of the following is NOT a direct method for diagnosing tuberculosis?
1) Smear examination
2) ELISA
3) Culture methods
4) Nucleic acid technology
General Microbiology Answer: 2ELISA: While ELISA (Enzyme-Linked Immunosorbent Assay) can be used to detect antibodies to the tuberculosis bacterium, it is not a direct method for diagnosing active TB infection. Direct methods include smear examination, culture, and nucleic acid technology, which detect the actual presence of the bacteria in the patient sample.
What is the correct color coding for bio-medical waste that requires incineration or deep burial?
1) Red
2) Yellow
3) Blue/white translucent
4) Black
General Microbiology Answer: 2
Yellow is the designated color for bio-medical waste that is considered hazardous and requires incineration or deep burial. This classification helps in the proper disposal of infectious and potentially harmful materials.