General Principles Flashcards
endogenous flora
normal flora
Organisms commonly found in the mouth, nose and oropharynx:
Staphylococcus aureus Staphylococcus epidermidis Peptostreptococci sp. alpha and non-hemolytic streptococci anaerobic streptococci, bacteroides Candida albicans
otitis media
obstruction of eustachian tube
sinusitis
obstruction of sinus openings
pneumonia
obstruction of small airways, especially after influenza
Organisms not commonly found in the mouth, nose and oropharynx; indicative of disease or carrier state
beta-hemolytic streptococci (S. pyogenes)
Hemophilus influenza (type B)
Neisseria meningitidis
Obligate intracellulars
viruses, chlamydiae, rickettsiae
routes of transmission
direct spread
contaminated water, food or soil
vertical (prenatally or perinatally)
zoonotic
High virulence
capable of causing disease in a normal host
Low virulence
capable of causing disease only in hosts with low resistance or impaired defenses
Bacteria that use exotoxins
diphtheria pseudomonas streptococcus vibrio cholera clostridia (botulism, tetanus) staphylococcus (TSS)
Bacteria that use endotoxins (cell walls) - associated with DIC, septic shock
E. coli
Neisseria (meningococci, gonococci)
Things that use capsules
many pyogenic bacteria
H. influenza, pneumococci, Neisseria
Phagocytosis and opsonization are important in the defense against organisms with?
capsules
Nonspecific immune response
phagocytosis
antibody-mediated immune responses
antibody enhances phagocytosis and NK cell activity
complement, opsonization
IgM, IgG, and IgA
Cellular immune responses
for intracellular organisms (viruses, rickettsia, etc.)
for persistent organisms which cannot be phagocytized (TB, fungi, parasites)
Patterns of Tissue Destruction/Pathology
- Suppurative inflammation
- Mononuclear and Granulomatous inflammation
- Cytopathic-Cytoproliferative inflammation
- Necrotizing inflammation
- Chronic inflammation and scarring
Suppurative inflammation
exuberant neutrophilic response, possible abscesses
Pseudomembranes form when?
fibrinopurulent exudates are in the presence of epithelial necrosis
Mononuclear inflammation
predominately mononuclear infiltrate: lymphocytes and monocytes
Granulomatous inflammation
specialized cell-mediated (hypersensitivity type IV) reaction to chronic intracellular infection
ex. mycobacterium tuberculosis
Morphology of granulomas
consists of a collection of epithelioid macrophages surrounded by a mantle of lymphocytes
caseous necrosis
granuloma with a necrotic center
examples of non-caseating granulomatous inflammation
Histoplasmosis, Blastomycosis
Cytopathic-Cytoproliferative Inflammation
primarily viruses
ex. herpes and papilloma viruses
Necrotizing inflammation
organisms have virulence factors that directly destroy cells
few inflammatory cells seen in response to necrosis
Chronic inflammation and scarring
chronic damage replaced by scar tissue
may be associated with cancer formation
If you have an inability to produce immunoglobulin you are susceptible to?
encapsulated organisms
If you have a lack of cellular immunity you are susceptible to?
intracellular organisms such as viruses and rickettsia
If you have a lack of neutrophil function you are susceptible to?
Staph and Strep
If you have a lack of phagocytic clearing mechanisms (no spleen) you are susceptible to?
encapsulated organisms
Nosocomial infections results from failure to?
limit the exposure to virulent organisms
not allow virulent organisms to go where they don’t belong
What types of patients may not show typical signs and symptoms of pathogenic organisms?
patients who have an altered immune response or vascular insufficiency
