MDS PREP
What is the principle behind the Prausnitz and Kustner experiment demonstrating IgE-mediated type I hypersensitivity?
1) Injection of allergen into a non-allergic person causes an allergic reaction.
2) Transfer of serum containing allergen-specific IgE from an allergic person to a non-allergic person induces an allergic reaction.
3) Introduction of allergen-specific T cells into a non-allergic person induces an allergic reaction.
4) Exposure of a non-allergic person to high doses of an allergen induces tolerance.
General Microbiology Answer: 2the Prausnitz and Kustner experiment demonstrated Transfer of serum containing allergen-specific IgE from an allergic person to a non-allergic person induces an allergic reaction. This experiment showed that the allergic state is mediated by a serum component, which we now know is the immunoglobulin E (IgE), and that it can be passively transferred from one individual to another.
Which of the following statements about the fermentation of sugars by Anthracoid bacilli is true?
1) Anthracoid bacilli ferment glucose, maltose, lactose, and sucrose, producing acid and gas.
2) Anthracoid bacilli do not ferment glucose but ferment maltose, lactose, and sucrose.
3) Anthracoid bacilli only ferment glucose.
4) Anthracoid bacilli ferment glucose, maltose, and lactose, but not sucrose.
Anthracoid bacilli ferment glucose, maltose, lactose, and sucrose, producing acid and gas.
The main tool for detection of "cases" of tuberculosis is -
1. Sputum examination
2. Mantoux test
3. Chest X-ray
4. All of the above
Microbiology
Answer: 1
The main tool for the detection of "cases" of tuberculosis is 1.
Sputum examination.
Explanation of Each Option:
Sputum examination: This is the primary method for
diagnosing active pulmonary tuberculosis. Sputum samples are collected and
examined for the presence of Mycobacterium tuberculosis through
microscopy (e.g., acid-fast bacilli staining) and culture methods. It is
considered the gold standard for confirming active TB cases.
Mantoux test: Also known as the tuberculin skin test,
this test is used to determine if a person has been exposed to the
tuberculosis bacteria. However, it does not diagnose active TB; rather, it
indicates whether a person has been infected with the bacteria at some
point.
Chest X-ray: While chest X-rays are important for
identifying lung abnormalities associated with tuberculosis and can support
the diagnosis, they are not definitive for detecting the bacteria itself.
They are often used in conjunction with sputum examination.
Which of the following is NOT a causative agent of dentoalveolar abscess?
1) Prevotella intermedia
2) P. melaninogenicus
3) Porphyromonas gingivalis
4) Fusobacterium nucleatum
General Microbiology Answer: 2Prevotella intermedia and P. melaninogenicus (now known as Aggregatibacter actinomycetemcomitans) are both anaerobic bacteria that can be found in the oral cavity and are involved in the pathogenesis of periodontal diseases, including dentoalveolar abscesses. Fusobacterium nucleatum is another anaerobic bacterium commonly found in dental plaque and is associated with various oral infections, including dentoalveolar abscesses.
What is the recommended storage condition for both recombinant and plasma-derived hepatitis B vaccines?
1) At room temperature
2) In a refrigerator
3) In a freezer
4) At 4°C to 8°C
General Microbiology Answer: 4
oth recombinant and plasma-derived hepatitis B vaccines should be stored at temperatures between 4°C and 8°C to maintain their efficacy and stability. Proper storage is crucial to ensure the vaccines remain effective when administered.
What is the purpose of the puncture-proof container in bio-medical waste management?
1) To contain sharps
2) To hold non-infectious waste
3) To store chemicals used for disinfection
4) To transport pathological waste
General Microbiology Answer: 1
The purpose of the puncture-proof container in bio-medical waste management is to contain sharps, preventing injuries and contamination.
There are some enzymes that cause protein to coagulate rather than to produce simpler compund These are known as
1. lab enzymes
2. coagulase
3. proteolytic enzymes
4. wenmycin
Microbiology
Answer: 1
There are some enzymes that cause protein to coagulate rather than to produce simpler compund These are known as lab enzymes
1. Coagulase:
Definition: Coagulase is an enzyme produced by certain
bacteria, most notably Staphylococcus aureus. It catalyzes the
conversion of fibrinogen (a soluble plasma protein) into fibrin (an
insoluble protein), leading to the clotting of blood.
Function: The production of coagulase is a virulence
factor for Staphylococcus aureus, as it helps the bacteria evade
the host's immune system by forming a protective clot around the bacterial
cells. This clot can shield the bacteria from phagocytosis and other immune
responses.
Clinical Relevance: Coagulase is used in laboratory
tests to differentiate between pathogenic Staphylococcus aureus (coagulase-positive)
and non-pathogenic staphylococci (coagulase-negative).
2. Proteolytic Enzymes:
Definition: Proteolytic enzymes, also known as
proteases or peptidases, are enzymes that catalyze the breakdown of proteins
into smaller peptides or amino acids by cleaving the peptide bonds between
amino acids.
Function: These enzymes play crucial roles in various
biological processes, including digestion, protein turnover, cell signaling,
and immune responses. They are found in many organisms, including humans,
where they are involved in the digestion of dietary proteins in the stomach
and small intestine.
Types: Proteolytic enzymes can be classified based on
their mechanism of action (e.g., serine proteases, cysteine proteases,
aspartic proteases, and metalloproteases) and their substrate specificity.
Wenmycin is an antibiotic that is derived from the
bacterium Streptomyces wenyangensis. It belongs to the class of
compounds known as macrolide antibiotics, which are
characterized by their large lactone ring structure. Wenmycin has been studied
for its antimicrobial properties, particularly against certain types of
bacteria.
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.