ID1 Flashcards
2 examples of colonizing pathogens
streptococcus pneumoniae- can cause disease or colonize
bordetella pertussis- obligate pathogen; always causes disease
4 different types of physical barriers
skin-stratified squamous epithelium
respiratory tract- ciliated columnar epithelium
GI tract- columnar epithelium with mucous secretions
genitourinary tract- squamous and columnar epithelia; “urinary” epithelium
opportunistic pathogens
require an opportunity, such as immunosuppresion to cause a disease
–>true opportunists rarely cause disease in normal hosts
2 examples of opportunistic pathogens
1) pneumocytis jirovecci-
widely disseminated in human populations
2) CMV
2 types of invasion
tissue
intracellular
2 types of intracellular invaision
active–penetrates host cells on its own power
endocytosis/phagocytosis- take advantage of cellular machinery to be internalized
2 types of virulence factors
toxins
capsule-polysaccharide
adhesions
2 types of toxins
1) endotoxin- LPS–on cell wall of gram negative
2) exotoxin- secreted proteins that may mimic intracellular signaling molecules
capsule
polysachharide that prevents phagocytosis in several bacterial pathogens and is a poor immunogen
adhesions
allow adherence to cell surfaces or ECM
–modulation of surface adhesions may be involved in transition between colonization and invasion
two more viruelnce factors
enzymes
nutritonal factors
types of enzymes that are virulence factors
proteases, collagenases, phospholipases
–>disurpt cells and tissues
nutritional factors
iron binding proteins like ferritin, transferrin, and lacto ferrin sequester iron from bacteria and prevent growth
hepicidin-takes signals from dietary absorption and inflammatory signals and influences host-pathogen balance
types of acute suppurative inflammation
pneumonia
endocarditis
pyelonephritis
cellular responses to infectious agents
acute suppurative mononuclear granulomatous chronic inflam and scarring cytopathic/cytoprofliferative necrotizing
stages of acute bacterial pneumonia
edema-exudate
acute inflammation-PMN, platelets, complement cascade, coagulation
consolidation-red & grey
resolution (macrophages clear out what is in lungs)
endocarditis
infection of heart valve
two types of endocarditis
acute (rapidly progressive)–stephylococcus aureus
subacute (indolent)-SBE- oral strains of streptococci
acute endocarditis
staph aureus
–multiple virulence factors encoded by genetic “pathogenicity island”–>induced coordinately by a peptide secreted by bacterium
types of vegetation in endocarditis
rheumatic
infectious
marantic (non-bacterial)
autoimmune
staph aurueus endocarditis steps
seeding of bacteria on to fibrin deposited on valve
- ->local destruction of tissue with a massive PMN infiltrate
- ->inflam lesions can erode into vlave ring, cause hemodynamic decompnesation and rapid death
pyelonephritis
bacterial infection of kidney
what is pylonephritis associated with?
anatomic abnormalities or the urinary collecting system
–can become chronic and destroy the kidney
gram neg rods
E.Coli pyelonephritis
facultative (anaerobic/aerobic) enteric gram negative bacillus
causes UTI–>ascending urinary tract infection–>inflammation in interstitum and renal tubules
