MDS PREP
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.
What is the primary target of antibodies in neutralizing the action of exotoxins?
1) Cell wall components
2) Lipopolysaccharides
3) Protein components of the toxin
4) Enzymes involved in toxin production
General Microbiology Answer: 3
Antibodies neutralize exotoxins by binding to their protein components, preventing them from interacting with host cells and causing damage. This immune response is critical for protecting the host from the harmful effects of these toxins.
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.
The biologic standard used to test the efficiency of sterilization involves the use of
1. spores of Clostridium tetani
2. streptococcus pneumoniae
3 spores of a harmless bacillus
4. infectious hepatitis virus
Microbiology
Answer: 3
The biologic standard used to test the efficiency of sterilization typically
involves the use of spores of a harmless bacillus. This method is widely
recognized in the scientific community and is based on the principle that if a
sterilization process can effectively destroy the most heat-resistant
microorganisms, it is assumed to be capable of killing all other less resistant
microbes.
The choice of using spores of a harmless bacillus is rooted in the fact that
bacterial spores are the most heat-resistant forms of microbial life. Spores are
metabolically inactive, which makes them very hardy and capable of surviving in
adverse environmental conditions for extended periods. For sterilization
validation, scientists often employ a biological indicator that contains spores
of a known heat-resistant bacterium, such as Geobacillus stearothermophilus
(formerly Bacillus stearothermophilus) or Bacillus subtilis. These organisms are
chosen because they have well-characterized resistance profiles, and their
destruction indicates that the sterilization process has achieved the necessary
lethality to eradicate all microbial life forms, including vegetative bacteria,
fungi, and viruses.
Let's examine the other options provided:
1. Spores of Clostridium tetani: While C. tetani is a spore-forming bacterium,
its spores are not commonly used as a biological indicator for sterilization
efficiency. C. tetani is a pathogen that causes tetanus, a serious disease.
However, it is not typically used for this purpose because there are safer and
more universally accepted biological indicators available.
2. Streptococcus pneumoniae: S. pneumoniae is a bacterium that can cause
pneumonia and other infections, but it is not a spore-former. Moreover, it is
generally less resistant to heat and sterilization methods compared to
spore-forming bacteria. Thus, it is not suitable as a standard for testing
sterilization efficiency.
3. Spores of a harmless bacillus: As previously mentioned, this is the most
appropriate choice for a biologic standard in sterilization testing. These
spores serve as reliable and safe indicators of sterilization efficacy because
they mimic the resistance of pathogenic spores without posing the actual risk of
infection.
4. Infectious hepatitis virus: While viruses can be highly resistant to some
sterilization methods, they are generally more sensitive to heat than bacterial
spores. Moreover, using infectious viruses as biological indicators poses
significant biosafety risks and is not a standard practice in routine
sterilization testing. For viral resistance testing, specific viruses or
virus-like particles may be used, but these are not typically employed as the
primary biological indicators for sterilization validation due to the complexity
and high containment requirements of such testing.
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.
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 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.
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.