030 Pneumonia Flashcards
What is the mucociliary clearance elevator?
In the respiratory tract, particles are trapped in the mucus and brought out by the action of ciliary hairs that move mucus upwards. It is then coughed and spit out.
What disease is caused by the disruption to mucociliary clearance elevator?
Cystic fibrosis and other chronic illnesses
What is the mortality rate of community acquired pneumonia?
5-15%
How many cases of pneumonia are there per year in the UK?
1-3 cases / 1000 per year
What are the costs of CAP in pounds?
4-5 bn pounds
What are common extracellular causes of CAP?
H.influenza (10%), S.pneumoniae (>50%)
What are common intracellular causes of CAP?
L.pneumophilia (2%), M.pneumonia (10%), TB, Chlamydia pneumonia
What types of pneumonia can be treated using penicillin? How?
Penicillin can treat extracellular bacteria with a polysaccharide wall. It is not active against the atypicals. It works by inhibiting cell wall formation (penicillin binding proteins PBPs) which catalyzes the formation of the cross links that bridge peptidoglycan in the bacterial cell wall.
What is bacteraemia and what are its consequences?
Bacteremia occurs when bacteria invade the blood stream. This can be caused by the pneumonia through the lungs into the capillaries, or it can be caused by direct invasion from nasopharyngeal colonisation. This can lead to meningitis, death, and brain damage.
How is S. pneumonia able to evade the immune system?
S. pneumonia occurs in pairs and has a thick polysaccharide wall that can evade phagocytosis. This capsule also can undergo switching, to prevent detection by immune system. It produces IgA protease which cleaves anti-capsular IgA mucosal antibodies. It also has surface protein A which inhibits deposition of complement on bacterial surface.
What does the adhesin C-polysaccharide do, compared to the choline binding protein A?
Adhesin C-polysaccharide allow adhesion to the upper respiratory tract; choline binding protein A allows adhesion to the alveoli.
What is Pneumolysin and how does it invade body tisse?
Pneumolysin is an invasin that S.pneumonia can project. It activates the complement and TNF.
What are the virulence properties of S. pneumonia?
Polysacharride capsule; H2O2 production that damages epithelium and impairs mucociliary elevator, surface proteins, releasing toxins, and pneumococcal pilus that allow adherence.
What are characteristics of the polysaccharide capsules?
Polysaccharide capsules have 90 serotypes, though a limited are associated with disease. It is a major virulence determinant that causes adhesion and can undergo switching.
Name different investigation techniques used to detect pneumonia
Urine antigen samples, blood tests, cultures, PCR, serology, and histopathology
