3- microbiology of respiratory tract Flashcards
what are the 3 important components for disease? (another triangle thing)
susceptible host, virulent pathogen, favorable environment = if lack any of these then disease
what are the 6 components of chain of infection? (geography thing)
- susceptible host (elderly, infants, immunocompromised)
- portal of entry (mouth, eyes, cuts)
- mode of transmission (contact, droplets (sneeze, speak, cough))
- portal of exit (mouth, cuts, feces, bodily fluids)
- reservoir (people, animals, water, food, soil)
- agent (bacteria, virus, parasites, funghi)
what is a colonisation?
presence of microbe in human body without inflammatory response
*means doesn’t need antibiotic
what is a bacteraemia?
presence of viable bacteria in blood
what is infection?
inflammation due to viable bacteria in blood
what is sepsis?
dysregulated host response due to infection
what is importance if it says colonies in question?
it’s a trick - make sure to not prescribe antibiotics when colony as colony is just presence of microbe but not actually causing inflammatory response
*unless in immune compromised/CF
what are some common bacteria causing community acquired pneumonia? (from highest incidence to lowest incidence)
- streptococcus pneumoniae = typical
- haemophilus influenzae
- mycoplasma pneumoniae = atypical
- chlamydia pneumoniae = atypical
- legionella species = atypical
what are common hospital acquired pneumonia and Ventilator-Associated Pneumonia?
- staphylococcus aureus
- pseudomonas aeruginosa
- e.coli
*a bunch more in notes but just picked these - ones with more gram negatives
what is common fungal infection in lungs?
aspergillus
what are some common viral infections in adults?
- influenza viruses
- rhinoviruses
- coronavirus
what is involved in diagnosing infections? (sam as like everything else)
- history
- examination
- investigations (radiology, biochemistry, immunology etc)
- tests (blood, stool, urine, wound, tissue cultures)
- serology
what is problem with serology test? why is it not that useful for someone who is acutely ill?
takes a long time for body to form antibodies
what is
a) sinusitis?
b) rhinitis?
c) pharyngitis?
d) epiglottitis?
e) laryngitis?
inflammation of:
a) paranasal sinuses
b) nose
c) pharynx, tonsils, uvula
d) epiglottis, superior larynx
e) larynx
what is the important aspects of inflammation that are good to think about for different locations e.g. pleuritic chest pain, coughing, short of breath, maybe sputum?
calor (heat), rubor (redness), tumor (swelling) , dolor (pain) , functio laesa (loss of function)
how long does blood culture and PCR take? what is the significance of this?
blood test about 2 days and PCR about 6-24 hours but often lab doesn’t run every day so logistics mean maybe only done once or so a week
= means that you can’t just wait until diagnosis before doing something, need to treat as go along and with little bits and pieces your told
what are the key things to do for microbiology?
- identify what particular infection for particular patient
- determine colonisation vs infection for interpreting test results
- identify organism with name & characteristics and with correct tests
- choose treatment - with antibiotic guide & formulation, adverse effects
- prevent infection = vaccines, drugs
what are people have unusual host response?
- old people
- immunosuppressed
- some drugs, genetic
what are characteristics of unusual microbe that make difficult infection?
- virulence expression
- latency – intracellular
- predilection (preference) for certain sites
what are the different classes of beta lactams?
- Penicillin
- Flucloxacillin
- Amoxicillin
- Cephalosporins
- Piperacillin/tazobactam
- carbapenems
does flucloxacillin work for methicillin resistant?
no
why is it bad for people with penicillin allergies?
because it means they might have to use drugs such as quinolones which is bad with lots of bad side effects
= that’s why it’s important to test if actually allergic cause you don’t want to give someone bad drug unless you really need to
what are important things to think about when picking what antibiotic to give?
- dose, route, frequency, cost
- age, body composition
- with food/without food
- if they can access treatment
how many days of antibiotics is suitable?
5 days
what is risk factor clue for question of community acquired penumonia?
smoker
what are clinical symptoms of community acquired pneumonia?
- cough
- increased sputum
- dyspnoea
- chest pain
- fever
what is seen on chest xray in community acquired pneumonia?
chest xray with infiltrates
what is temperature and results found from examination of community acquired pneumonia?
temperature 38.0, left base crackles