Respiratory Infections

Question 1

Pneumocystis Jirovecii

Answer 1

Yeast-like fungus
HIV +ve
Fever, non-productive cough, night sweats, weight loss
Bilateral pulmonary infiltrates on CXR
Gomori’s methenamine silver stain - ‘flying saucer’ cysts/boat shaped organisms

Question 2

Strep. Pneumoniae

Answer 2

Alpha haemolytic gram +ve diplococci
Rusty sputum 
Optichin sensitive, catalase -ve
Quelling reaction, +ve urine Ag
Lobar pneumonia
Mx: amoxicillin or macrolide (mild-moderate) clarithromycin and co-amoxiclav or 2-3 weeks or cefuroxime (moderate-severe)
If HAP 1st: ciprofloxacin +/- vancomycin 2nd: piptazobactam + vancomycin 
Aspiration: cefuroxime and metronidazole

Question 3

S.Aureus

Answer 3

Beta haemolytic gram +ve cocci
Grape-like
Catalase +ve
Consolidation, cavitation or empyema
Post-viral infection 
CAP Mx: flucloxacillin
MRSA: vancomycin

Question 4

TB

Answer 4

Fever, cough, weight loss, night sweats
HIV+
Bihilar lymphadenopathy 
Ziehl-Neelson staining, acid-fast bacilli
Auramine-Rhodamine staining

Question 5

Legionella Pneumophilia

Answer 5

Aerobic gram -ve rod
Air conditioning units
Myalgia, confusion, rhabdomyolysis, abdominal pain 
Hyponatraemia
Buffered charcoal yeast extract agar
Urinary antigen +ve
Mx: macrolide and rifampicin

Question 6

Moraxella Catarrhalis

Answer 6

Gram -ve diplococci, aerobic
Chronic lung disease/COPD exacerbation
Can affect ears, eyes and CNS
Mx: amoxicillin or macrolide (mild - moderate), clarithromycin and co-amoxiclav or 2-3 weeks cefuroxime (moderate-severe)
HAP Mx: 1st: ciprofloxacin +/- vancomycin, 2nd: piptazobactam + vancomycin
Aspiration: cefuroxime + metronidazole

Question 7

Haemophilus Influenza

Answer 7

Gram -ve bacilli
Chocolate agar
Oxidase and catalase +ve
COPD/smoking
Mx: amoxicillin or macrolife (mild-moderate), clarithromycin + co-amoxiclav or 2-3 weeks cefuroxime (moderate-severe)
HAP Mx: 1st: ciprofloxacin +/- vancomycin, 2nd: piptazobactam + vancomycin
Aspiration: cefuroxime + metronidazole

Question 8

Mycoplasma Pneumoniae

Answer 8

Obligate intracellular bacteria
Cold-agglutinin test -> SJS
Mx: macrolide/tetracycline

Question 9

Chlamydia Pneumoniae

Answer 9

Obligate intracellular bacteria
Meningoencephalitis, arthritis, myocarditis, GBS
Mx: macrolide, tetracycline

Question 10

Chlamydia Psittaci

Answer 10

Bird handler

Mx: macrolife, tetracycline

Question 11

Bordatella Pertussis

Answer 11

Whooping cough in unvaccinated
Travellers
Mx: macrolife/tetracycline

Question 12

Klebsiella Pneumoniae

Answer 12

Alcoholism, elderly
Haemoptysis
Gram -ve rod, enterobacter
Mx: amoxicillin or macrolife (mild-moderate), clarithromycin + co-amoxiclav or 2-3 weeks cefuroxime
HAP 1st: ciprofloxacin +/- vancomycin, 2nd: piptazobactam + vancomycin
Aspiration: cefuroxime and metronidazole

Question 13

Pseudomonas Aerugenosa

Answer 13

CF
Mx: piperacillin + tazobactam
Ciprofloxacin + gentamicin