NEET MDS Shorts
284998
MicrobiologyA classic example of delayed type IV hypersensitivity is the Mantoux tuberculin test in which skin induration indicates exposure to tuberculosis.
This reaction is called "delayed hypersensitivity" because it is mediated by sensitized CD4+ T lymphocytes which process antigens in association with class II HLA molecules and release lymphokines.
The lymphokines promote a reaction (especially mediated through macrophages) beginning in hours but reaching a peak in 2 to 3 days.
Hypersensitivity reactions with this mode of action include:
Granulomatous diseases (mycobacteria, fungi)
Tuberculin skin reactions
Transplant rejection
Contact dermatitis
Cytotoxic T lymphocyte (CTL) mediated responses: CD8+ T cells are generated and lyse specific cells. Class I HLA molecules play a role. Reactions with this mode include:
Neoplastic cell lysis
Transplant rejection
Virus-infected cell lysis
566910
MicrobiologyN-acetyl muramic is intermediate in the biosynthesis the cell wall
402725
Microbiology
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.
177456
MicrobiologyThe destruction of microorganisms on living tissues, as long as there is contact between the tissues and the antimicrobial agent, denotes antisepsis (option 2). Antisepsis refers to the application of antimicrobial agents to living tissues to reduce the possibility of infection, sepsis, or putrefaction.
Sterilization:
This is the process of completely eliminating all forms of microbial
life, including bacteria, viruses, fungi, and spores, from an object or
surface. Sterilization is typically achieved through methods such as
autoclaving (steam under pressure), dry heat, chemical sterilants, or
radiation. Sterilization is used for medical instruments, laboratory
equipment, and other items that must be free of all microorganisms.
Antisepsis:
Antisepsis refers to the application of antimicrobial agents to
living tissues to reduce the risk of infection, sepsis, or putrefaction.
Antiseptics are used on skin and mucous membranes to prevent infection
during surgical procedures, wound care, and other medical interventions.
Common antiseptics include alcohol, iodine solutions, and chlorhexidine.
Sanitization:
Sanitization is the process of reducing the number of microorganisms
on surfaces or objects to a level considered safe by public health
standards. This does not necessarily eliminate all microorganisms but
reduces them to a level that minimizes the risk of infection or disease.
Sanitization is commonly used in food service, public restrooms, and
other environments where hygiene is important.
321894
Microbiology
In concentrations usually applied for sterilization purposes, ethylene oxide is preferable to formaldehyde becuase it is more penetrating
282080
MicrobiologyThe minimum and maximum temperature for normal metabolic activity microorganisms that live on or within the human body is 20° C to 45°C
922413
MicrobiologyThe bacteria having the highest lipid Content in the cell wall Mycobacterium tuberculosis
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.