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24 Cards in this Set
- Front
- Back
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general characteristics of pseudomonads
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opportunistic pathogens, foind in soil, decaying organic matter, vegetatation and water, reservoirs in hospital.
aerobic, non-fermenting, gram-negative rods with polar flagella. can tell from enterobacteriaceae by oxidase positive |
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physiology and structure of Pseudomanas aeruginosa
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strict aerobe, non-fermenting, rod shaped cell, simple growth requirements, can be pigmented and capsulated
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epdiemiology of P. aeruginosa
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ubiquitous, seoncmost common etiologic agen on nonsocomial infections, opportunistic, multipole drug resistance
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pathogenesis of P. aerouginosa
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affect mainly immunocompromised patients, quorum sensing regulates virulence factors
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structural virulence factors P. aeruginosa
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capsule - adhesion, inhibits antibiotic killing
pili - adhesion LPS - endotoxin activity during sepisis pyocyanin - mediated tissue damage through production of toxic oxygen radicals |
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toxins and enzyme virulence factors P. aeruginosa
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exotoxin A - inhibitor of portein synthesis (similar to diptheria)
exotoxin S and T - AB toxin with ADP - ribosyltransferase activity (not the most important) |
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diagnosis P. aeruginosa
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grows simple media, requires many suseptibility tests
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treatment of P. aeruginosa
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combination of antibiotics generally necessary
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general characteristics of Haemophilus
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non-motile, facultative anaerobic, oxidae positive, gram negative rods, need complex growth requirements, normal flora of upper respiratory tract
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tybe b strains of H. influenzae
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responsible for most serious systemic infections. is a capsular antigen
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H. influenzae
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present in almost all individuals. high infections, spread can be controlled by vaccine or prphylactic treatment with rifampicin for children under age of 4
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syndroms from encapsulated H. influenzae
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meningitis in children two months to 3 years. epiglotitis, airway obstruction
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syndroms form non-encapsulated H. influenzae
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acute or chronic otitis (second most common causes except for strep. pneumoniae)
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adults usually get infections from what form of H. influenzae
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non-encapsulated
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pathogenesis of encapsulated H. influenzae
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encapsulated - tybe b capsular polysaccharide is critcal determinant virulence. initially in nasopharynx, spreads to CNS
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pathogenesis of non-encapsulated H. influenzae
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localized infections, colonize the host cells surfaces using pili and cell surface protens
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virulence factors of H. infleunzae
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polysaacharide capsule - major virulence factor
outermembrane proteins - maemagluttinins pili LPS IgA protease Rhamnolipid - heat stable hemolysin phospholipase C - heat labiel hemolysin |
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diagnosis of H. influenzae
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test colonies for morphology, growth requirements (chocolate aguar that provides speical blood products)
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treatment of H. influenzae
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serious infections - cepholosporin
less severe - ampicillin or chloramphenicol |
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prevention and control of H. influenzae
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prophylaxis for close contact -rifampin
new effective PRP protien conjecated vaccins that childrens immune systems will respond well to |
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biofilm
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biologically active population of microorganisms that is attached to a surface and enclosed by an extracellular matrics
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clinical relevance of biofilms
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cause persistent and chronic infections
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possible reasons for increased resistance to antimicrobials with respect to biofilms
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reduced microbial activity
reduced pentration of the antimicrobials microbial stress response effective persister cells accumulate acquired resistance: increased conjugative plasmid transfer in the biofilm |
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treatment of biofilms
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concentration of antimicrobials may need to be higher, certain categories of antibiotics may be more effective
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