Microbiological diagnosis Flashcards
What are the major respiratory pathogens?
Sterp pneumoniaea , Haemophilus influenzae, Moraxella catarrhalis
Which organisms is usually present as a result of nasopharyngeal contamination?
Streptococcus viridans
Which organisms become pathogens after antibiotic treatment ?
Satphylococcus aureus, Escherichia cole
What is microscopy and culture used for ?
for analysis of sputum and blood, to observe sputum cells and bacteria after staining, culture to grow bacteria
What is BAL?
Broncho-alveolar lavage, type of sampling technique, usually in ventilated patients, bronchoscopy and catheter aspiration
What VAT ?
Ventilation associated pneumonia
How is blood sample analysed?
blood is inoculated in two bottles containing culture media, CO2 levels are picked up and the organisms are then analysed
What happens on day 1 and day 2 of testing?
Day 1 microscopically positive results are phoned, recommendation for treatment to start with, day 2 sensitivity test and identification tests, the treatment might need to be modified
Which organisms are not easily cultured?
Legionella pneumophyla, Mycoplasma pneumoniae, Chlamidia psittaci, Coxiella burnetti
Which antigens are present in urine?
Legionella, Pneumoccocal antigens
Which antigens are present in nasopharyngeal secretions?
viral antigens
What is latex agglutination?
Later particles covered in monoclonal antibodies that are specific, agglutination can be observed by naked eye
What id ELISA?
Enzyme -linked immunosorbet assay , monoclonal antibody at the bottom specific for antigens, second antibody linked to enzyme is added, if the binds the enzyme causes colour change
How is nucleic acid detection done?
By PCR polymerase chain reaction, there are modified versions such as real time PCR, nucleic acid amplification test
What is the requirement to be able to do PCR?
Throat flocket sway, different from the one used for culture
