Microbial Pathogenesis
This term describes an infection where the pathogen (usually a virus) goes dormant within host tissues without active replication or symptoms but can reactivate during times of stress.
What is a latent infection?
This class of antibody is assembled as a dimer and is the predominant immunoglobulin found in body secretions like saliva, tears, and breast milk.
What is IgA?
Inactivated bacterial toxins used in vaccines to stimulate protective, neutralizing antibodies against diseases like tetanus and diphtheria are called this.
What are toxoids?
Inanimate objects such as doorknobs, syringes, surgical instruments, or towels that mediate the indirect transmission of pathogens are known as these.
What are fomites?
Flat, non-raised spots of skin discoloration measuring less than 0.5 cm in diameter are clinically defined as these.
What are macules?
This life-threatening condition occurs when bacteria actively reproduce and flourish in the bloodstream, triggering widespread vascular leakage and acute hypotension.
What is septicemia / septic shock?
A patient presents with a fever of 102°F, a heart rate of 110 bpm, severe muscle aches, and nausea, which two clinical of these observations would be classified as objective signs.
What are fever and heart rate?
All human cells in the body express these specific molecules on their cell surface so that the immune system is able to recognize self from non-self
What is major histocompatibility complex class I or MHC I molecules?
This population-level protection fails when community vaccination rates drop below a critical threshold, allowing highly contagious diseases like measles to trigger re-emergent epidemics
What is herd immunity?
A disease that is constantly present at a steady, predictable baseline level within a specific geographic population is classified as this.
What is an endemic disease?
Dermatophyte molds secrete this key virulence enzyme to break down and consume structural proteins in host skin, hair, and nails.
What is keratinase?
Prominent red streaks advancing along subcutaneous lymphatic channels from an infected wound toward regional lymph nodes indicate this clinical condition.
What is lymphangitis?
This exoenzyme produced by Streptococcus pyogenes acts as a "spreading factor" or "invasion factor" by digesting the hyaluronic acid that glues host tissue cells together.
What is hyaluronidase?
These two features of the adaptive immune system allow it to target unique individual pathogens and execute a faster, stronger secondary response upon re-exposure
What are specificity and memory?
An infant acquiring protective IgG antibodies across the placenta from its mother is an example of this specific classification of immunity.
What is natural or passive immunity?
Public health officials reporting 500 newly diagnosed cases of a viral illness in a county over one month are measuring new case counts using this specific epidemiological parameter.
What is incidence?
This clinical classification of bacterial skin infection is restricted to the hair follicles.
What is folliculitis?
Accumulations of fibrin, blood platelets, and bacterial cells on damaged heart valves during infective endocarditis are called these.
What are vegetations?
Unlike exotoxins, which are actively secreted proteins, these toxic lipopolysaccharide (LPS) molecules are released primarily when Gram-negative bacterial cells lyse.
What are endotoxins?
This constant "trunk" region at the base of an antibody molecule determines its class isotype and binds directly to receptors on phagocytic white blood cells.
What is the Fc region?
Inoculating a patient with weakened or killed pathogen antigens to deliberately stimulate their adaptive immune defenses and generate memory cells confers this type of immunity.
What is artificial active immunity?
A cockroach that picks up Salmonella on its feet from sewage and walks over exposed food acts as this type of vector.
What is a mechanical vector?
This bacterial genus dominates the lipid-rich, sebaceous regions of healthy human skin and is heavily implicated in the pathogenesis of acne.
What is Cutibacterium (or Propionibacterium)?
Staphylococcus epidermidis causes persistent catheter-related bloodstream infections primarily through its ability to synthesize this protective structure on plastic surfaces.
What is a biofilm?
Toxic Shock Syndrome toxin (TSST-1) induces life-threatening shock by non-specifically cross-linking these two different immune cell receptors on the macrophage and T cell, triggering an uncontrolled cytokine storm.
What are MHC Class II molecules and T-Cell Receptors (TCRs)?
While CD4+ T Helper cells recognize antigens presented on MHC Class II to orchestrate adaptive responses, CD8+ Cytotoxic T cells recognize antigens presented on MHC Class I to execute this function.
What is direct cell lysis or destruction of infected / abnormal host cells?
This class of vaccine contains weakened whole pathogens that establish a subclinical infection to stimulate both cellular and humoral immunity, but carries a slight risk of reversion to virulence.
What is a live attenuated vaccine?
Fifty guests developing staphylococcal food poisoning after eating the same contaminated potato salad at a single afternoon banquet represents this type of epidemic spread.
What is a point source epidemic?
This classification of bacterial skin infection bypasses the superficial epidermis and dermis to horizontally destroy the connective tissue wrapping muscle
What is necrotizing fasciitis?
During Gram-negative sepsis, cell lysis releases Lipid A, which binds to LBP and this specific pattern recognition receptor on host macrophages to trigger a cytokine storm.
What is Toll-Like Receptor 4 (TLR-4)?