NEET MDS Shorts
918567
MicrobiologyThe 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.
807531
MicrobiologyThe 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.
624867
Microbiology
Dry heat sterilization of paper points without incineration is accomplished at 160°C for 2hours
651993
MicrobiologyThe most pronounced effect on the oral microflora of a reduction in rate of salivary flow is a shift towards a more acidogenic microflora
865021
MicrobiologyThe bacterial population in the gingival sulcus or the pocket that influences the course of periodontal disease has essentially the same organisms found in the healthy sulcus
323444
MicrobiologySoaps typically have the narrowest effective antimicrobial range among the listed compounds. They are primarily effective against certain bacteria and viruses but may not be as potent against a broader spectrum of pathogens compared to glutaraldehyde or alcohols like 70% isopropanol.
733146
MicrobiologyThe 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.
541056
Microbiology
Infectious hepatitis (Hepatitis A virus): While HAV is
resistant to some environmental conditions, it is generally less resistant
than HBV.
Mumps virus: This is an enveloped virus and is not
particularly resistant to environmental factors.
Influenza virus: This is also an enveloped virus and is
susceptible to heat and many disinfectants.
Serum hepatitis (Hepatitis B virus): HBV is known for
its resilience. It can survive outside the body for long periods and is
resistant to many disinfectants and physical agents, making it one of the
more resistant viruses.
In summary, the correct answer is indeed 4. serum hepatitis
(Hepatitis B virus), as it is more resistant to chemical and physical
agents