Cystic Fibrosis Flashcards
Causal gene?
CFTR gene on chromosome 7
Result of genetic defect? Effect in lungs?
Electrolyte imbalance across organs
In lungs causes viscous bronchial secretions, more susceptible to infections
Main respiratory pathogens? (4)
1) P. aeruginosa
2) B. cenocepacia
3) S. aureus
4) H. influenzae
Other respiratory pathogens? (4)
1) Chlamydia
2) Aspergillus fumigatus
3) Influenza viruses
4) Mycoplasmas
Pseudomonas virulence factors? (3)
1) Biofilm formation
2) Rough lipopolysaccharide - Associates with surfaces and recognised as antigens (evasion), allows solubility
3) Antibiotic resistant
Pseudomonas phenotype?
Initially non-mucoid, the converts to mucoid at some point during infection
Treatment of pseudomonas biofilm?
Lung transplant
Patient groups with Burkholderia infections?
Cancer, CF patients - usually from attending hospital clinic
Burkholderia mortality?
16%
Outcomes of Burkholderia infection?
No reaction
Slow decline
Rapid decline
Burkholderia virulence factors?
1) Siderophores - Iron acquisition
2) Exotoxin A/S - Breakdown lipopolysaccharide as toxic
3) Grows intracellularly
Microbiology of CF infections?
Frustrated phagocyte syndrome - Phagocytes release proteases to breakdown biofilm, further damages lung tissue
Alginates respond well to Ca2+
Charged antibiotics penetrate slime slowly, allows production of protection factors
Pseudomonas can eliminate Burkholderia if colonising first, otherwise grow communally in different parts of lung
Mucoid cells to large to be engulfed by macrophages
