Lecture 5 - Fever and Cough: Pneumonia Flashcards
Diagnosing pneumonia in elderly?
increased respiratory rate (nociception and decreased air flow), crackles
Course of pneumonia?
streptococcus pneumoniae infiltrates nasopharynx, and then migrates to lower respiratory tract (also haemophilus influenza and staphylococcus aureus)
Risk factors of pneumonia?
<2, >65, chronic lung disease, smoking, immune dysfunction
Pneumococcal surface protein A?
binds epithelial cells and prevents depostion of C3b (C prevents complement)
Choline binding protein?
binds to immunoglobulin receptor on epithelial cells for transport
Pneumolysin?
lyses neutrophils and epithelial cells
Polysaccharide capsule?
prevents phagocytosis and complement deposition
Pili?
contribute to colonisation and cytokine production during invasion
Invasive pneumococcal disease?
seperate from pneumonia, invasion of CSF, joint fluid eetc.
Investigations?
CXR primarily, sputum sample for bacteria, PCR for viruses, streptococcal urinary antigen test
Penicillin resistance is increasing?
mediated by altered transpeptidase which REDUCES penicillin binding affinity - contributes to resis tance of other antibiotics
IV dosing?
more effective, important in meningitis cases cause by s. pneumoniae
Ribosome targets?
present in bacteria only so not to affect human cells - transpeptidation, peptidyl transferase, initiation, tRNA binding
Macrolides?
target transpeptidation, limited activity on gram negative, active for strep, staph, also chlamydia causes, used for penicillin allergic patients
Macrolide adverse effects?
GI upset (erythromycin agonist of motilin), sudden death (prolong QT leading to arrhythmia), interactions
