8 - Infections and Defects in Mechanisms of Defense Flashcards
Communicability
Ability to spread from one person to another and cause disease
Infectivity
Pathogen’s ability to invade and mulitply in host
Virulence
Severity or harmfullness of a disease or poison
Toxigenicity
Ability to produce toxins (influences a pathogen’s virulence)
Portal of entry
Route by which a pathogen infects host
Prokaryotes
Lack nucleus, +/- O2, Gram +/- (gram- is more dangerous (outer membrane, porin channels)
Staphylococcus aureus
-Life threatenening, very virulent (resist phagocytosis, protien blockers, inhibit recognition by immune system)
-common nosocomial infection, common on normal skin and nasal passages
-Resist many antibiotics
Exotoxins
-Released from inside of pathogen
-damage host cell plasma membranes or interfere with protien synthesis
Endotoxins
Released from outer capsule
-activate inflammatory response, produce fever
Bacteremia
Presence of bacteria in blood
Septicemia
growth of bacteria in blood
Viral disease
-Most commong affliction of humans
-to replicate they must enter host cell, as such are self-limiting
-simple organism (DNA/RNA surrounded by Capsid envolope)
Cytopathic
Causing damage to living cells
Antigenic variation
ability to change viral antigen (spikes) yearly, results in dysfunction in adaptive immune response
E.g. seasonal flu
Fungal Infection
Eukaryotes, resist penicillin, simple division reproduction
Mycoses
Diseases caused by funghi
Dermatophytes
Funghi that invade skin, hair or nails
Tineas
Term for diseases caused by dermatophytes
E.g. tinea capitis (scalp infection)
Candida albicans
Most common cause of fungal infection
-found in normal human microbiome (skin, vagina, GI)
-Disseminated in immunocompromised, high mortality rates (30-40%)
Disseminated
Spread (on same person)
Parasitic Infections
-caused by unicellular protazoa
-Spread via vectors or contaminated food/water
Plasmodium malariae
Causes (malaria)
-occurs in RBCs, anemia within 48-72 hours
-RBC release cytokines (TNF-a/IL-1) = fever, chills, vomiting
Bactericidal
agent that kills other microorganisms
Bacteriostatic
agent that inhibts growth of other microorganisms