Host Pathogen Interactions and Infectious Diseases / HX and PE Flashcards
components of the host pathogen interaction
host, pathogen, environment
t/f some pathogens are not very virulent, but the external environment can cause it to occur
false, the internal environment can cause the disease to occur
stages leading to infection
microbial encounter -> entry and microbial growth after entry -> avoidance of innate host defenses -> tissue invasion and tropism -> tissue damage -> transmission to new hosts
the simple presence of potentially pathogenic microbes in or on a host
colonization
attachment and growth of pathogens and avoidance of host defenses
infection
the result of activities of secreted toxins or toxic metabolites
disease
the measure of an organism’s capacity to cause disease and is a function of the pathogenic factors elaborated by microbes
virulence
t/f diseases produced are direct consequences of their route of entry into the body
true
t/f microbial entry doesn’t rely on presence of specific factors needed for persistence and growth in a tissue
false
most microbes anchor themselves to __
a tissue or tissue factor
types of microbial adherence
virus: ligands/adhesions g-: pili / fimbriae spirochetes: flagella s aureus: clumping factor a candida: als adhesions
host receptors of viruses
sialic acids, gangliosides, glycosaminoglycans, integrins, immunoglobulin superfamily, histocompatibility antigens, complement components receptor
growth in biofilms leads to __
- altered microbial metabolism
- production of extracellular virulence factors
- decreased susceptibility to antimicrobial agents and host defense molecules and cells
t/f changes and disruption of the indigenous microbiome have a strong and often fundamental impact on the progression of infection
true
host receptors for covid
ace2 receptors
drugs: barcitinib, umiifenovir, camostat mesylate
propensity of certain microbes to cause disease by infecting specific tissues
tropism
ex. c. diptheriae, n. meningitidis
receptor-ligand interactions clearly underlie __
- ability of certain viruses to enter cells
- viral capacity to penetrate into cells
- viral genetic elements that regulate gene expression
- pathways of viral spread in tissue
disease is a complex phenomenon resulting from
tissue invasion and destruction
toxin elaboration
host response
t/f most pathogens exit via the same round they enter
true
what is vector borne organism transmission
- direct contact with vector through blood meal
- indirect contact with organisms shed into environment
microorganims we encounter in our food or environment just passing through with little consequence. however regular encounters over time can lead to host adaptation or dependence
transient
microorganisms that inhabit the human body with host or microbe benefits
commensal
microbes that may or may not be a member of the indigenous biota but regularly causes disease in apparently normal individuals
pathogen
microbes that cause disease in immunocompromised
opportunistic pathogen
microbes encountered by accidental contact with animals, insects, or environment. deadly in humans, not readily transmissible from human to human
accidental pathogen
history that may identify microorganisms that pt might have contact
exposure history
example of birthplace related history
patient from samar developing schistosomiasis
___ are critical since new findings may appear as the illness progresses
serial exams
