BACTERIAL PATHOGENESIS Flashcards
what is a pathogen?
an organism capable of causing disease
what are the areas of the body that SHOULD be microbe free?
blood, urine, CSF, muscles, glands, brains and inner ear
what does infectivity mean?
the organisms ability to infect you
what does pathogenicity mean?
the organisms ability to cause disease
what does virulence mean?
a measure of the degree of disease that a pathogen causes
what is infective dose?
the amount of pathogen required to cause an infection in the host
what are virulence factors?
molecules that enable a bacterium to colonise the host at a cellular level
give some examples of virulence factors?
fimbriaea, pili, outer membrane protein, flagella, siderophores, toxins, caosule, secreted molecules
what are siderophores?
Siderophores are small, high-affinity compounds that are secreted by microorganisms and serve primarily to transport iron across cell membranes
what are overt or strict pathogens?
ones that are only associated with human disease and are not found as members of the normal, healthy microbial flora
what are opportunistic pathogens?
those that are members of the normal flora that only cause disease when introduced into unprotected sites. there is a concern with this when normal defence mechanisms are compromised
what are facultative pathogens?
those that can grow and survive in the environment as well as the host
what are the 3 bacterial strategies of pathogens?
extracellular pathogens
toxin producing pathogens
intracellular pathogens
what is an endotoxin?
produced by gram negative bacteria, are cell-bound, heat stable, weakly toxic and have general symptoms of fever, diarrhea and vomiting
what are exotoxins?
proteins released extracelluarly produced by certai. gram positive and gram negative species. they are generally heat labile, have soecific targets and are highly toxic
