Shared Flashcard Set

Details

Opportunistic respiratory pathogens
Exam 6 Material
26
Medical
Graduate
12/05/2010

Additional Medical Flashcards

 


 

Cards

Term
Which opportunistic pathogen is a motile aerobe and Gram-negative?
Definition
pseudomonas aeruginosa
Term
What is the practical application for pseudomonas aeruginosa?
Definition
Since it subsides on almost anything, it can be used in toxic waste clean-up.
Term
On culture, what unique characteristics exist from pseudomonas?
Definition
It forms green colonies and has a sweet grape-like odor.
Term
What contributes to the diversity of infections caused by pseudomonas aeruginosa?
Definition
Genotype diversity due to large deletions, insertions, and inversions of gene islands or plasmids that insert in the tRNA loci.
Term
What is the produced by pseudomonas aeruginosa that functions like a capsule and promotes adherence?
Definition
alginate
Term
What are the three major extracellular products produced by pseudomonas aeruginosa?
Definition
exotoxin A, quorum sensing, type III secretion systems
Term
What is the mechanism of exotoxin A produced by pseudomonas?
Definition
ADP-ribosylation of EF2
Term
What is the Exotoxin A receptor?
Definition
alpha2-macroglobulin/LDL-receptor related protein
Term
Which pseudomonas TS3 effector causes lysis of host cells?
Definition
ExoU
Term
What is the mechanism of ExoS?
Definition
It's a GAP/ADP ribosyltransferase, inactivating cell function.
Term
What is the mechanism of ExoY?
Definition
It's adenylate cyclase, increasing cAMP production.
Term
How does quorum sensing work?
Definition

 

P. aeruginosa produces auto-inducters called homoserine lactones, which are diffusible. As bacteria reaches a certain density in an area, these auto-inducers act as signals and jump-start virulence factors .

Term
Defiency of what immune component makes them susceptible to P. aeruginosa infections?
Definition
neutrophils (normally, neutrophil phagocytosis of pseudomonas is effective)
Term
In chronic P. aeruginosa infections, what provides protection against phagocytosis and opsonization?
Definition
the alginate capsule
Term
What is alginate comprised of?
Definition
mannose and glucuronic acid
Term
When is alginate induced in nature?
Definition
Induced to prevent dehydration
Term
Biofilms are responsible for what percent of human infections?
Definition
90%
Term
In which situations are Pseudomonas aeruginosa biofilm formations common?
Definition
chronic wound infections and CF patients
Term
What is the most common, serious inherited disease among Caucasians?
Definition
Cystic Fibrosis
Term
What is a possible reason for the selective advantage of the CFTR mutation?
Definition
It's a mechanism of resistance against cholera and E.coli
Term
Which classes of CFTR mutations are the most serious?
Definition
Classes I, II, and III
Term
What is the common sequelae of the impaired mucociliary clearance in CF patients?
Definition
The thickened mucus traps bacteria but can't expel, recruiting neutrophils and creating an inflammatory response that leads to tissue destruction and bronchiectasis (progressive pulmonary dysfunction)
Term
For treating chronic CF infections, what two measures carry "strong" recommendations?
Definition
inhaled tobramycin and DNase
Term
Is azithromycin use strongly recommended, recommended, or not recommended in treating chronic CF infections?
Definition
recommended
Term
What three drugs are strongly recommended AGAINST when treating chronic CF infections?
Definition
oral corticosteroids, inhaled corticosteroids, and oral anti-staphylococcal antibiotics
Term
What was the major recommendation of the ELITE trial?
Definition
Do not give tobramycin for more than 28 days
Supporting users have an ad free experience!