Pathogenesis of microbial infections Flashcards
What type of parasite replicates within host cells?
obligate intracellular parasite
What type of parasite replicates outside of a cell?
facultative parasites
What is the most common bacteria in resident skin flora
Staph. epidermidis
What is the most common bacteria in transient skin flora
Staph. aureus
What is an opportunistic infection
when non-pathogenic organism acts as a pathogen
What is immunopathogenesis
primary cause of cell death in infections - killing of cells by host immune system
What is the difference between signs and symptoms
Symptoms are experienced, signs are measured
Like thirst, lethargy etc are symptoms of diabetes; high blood sugar is a sign of diabetes
What is the prodromal stage of a disease?
stage in which non-specific symptoms occur
What is a sporadic disease
disease which only occurs occasionally like tetanus
What is an endemic disease
disease continuously present in a population like chickenpox
What is an epidemic disease
disease has greater number of cases than normal in an area like SARS in 2003
What is a pandemic disease
epidemic disease with worldwide distribution like the flu pandemic
What is the difference between a latent and chronic infection
Latent: reactivation which is symptomatic or asymptomatic
Chronic: continued production of infectious organism
What is a nosocomial infection
Infection acquired in hospital
What does MRSA stand for
methicillin resistant Staph. aureus
What does VREF stand for
vancomycin resistant Enterococeus faeciais
What does CPE stand for
carbapenemase producing enterobacterieae
What are adhesins on the surface of a bacteria?
Proteins/glycolipids/polysaccharides which are on the surface of a bacteria which bind to receptors on the host cell surface
What are attachment factors and give an example
help concentrate viral particles at the cell surface, such as heparin sulfate proteoglycans
What is host range
different species of hosts a given pathogen can infect
What is tissue tropism
different tissues within an organism that are infected by the pathogen (eg rhinovirus affecting the resp. tract)
What is LD50
lethal dose 50; number of pathogens needed to kill 50% of hosts
What is ID50
infectious dose 50; number of pathogens needed to infect 50% of hosts
In which kind of bacteria are endotoxins present
in the cell walls of Gram-neg bacteria
In which kind of bacteria are exotoxins present
secreted by Gram-pos bacteria
What are superantigens?
toxins that stimulate the immune system; bind to MHCII molecules nonspecifically so activate a large number of T-cells
