Microbiological Diagnosis of Chest Infection-LRTI Flashcards
what diagnostic techniques can be used to test a patient for respiratory tract infection
Microscopy and culture of sputum and blood
Antigen detection methods
Nucleic acid amplification (PCR)
Serology (antibody measurement)
after taking a microscopy and culturing sputum what major respiratory pathogens can be looked for in the culture
strep pneumoniae
haemophilus influenzae
moraxella catarrhalis
what stain would you uses to test for TB
ZN or Auramine phenol stain
how may you distinguish a culture containing TB
it would be a Acid and Alcohol fast bacilli
To get an accurate reading how long would you have to wait to see if a culture had TB
weeks- extended culture
what is a Bronchio-alveolar lavage
a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then collected for examination. It is typically performed to diagnose lung disease.
blood cultures often have too few organisms in the blood to see on microscopy what can be done to overcome this
Blood inoculated into two bottles containing culture media and incubated
what are microorganisms that are not easily cultured (“atypical causes”)
Legionella pneumophila
Mycoplasma pneumoniae
Chlamydia psittaci (birds)
Coxiella burnetti (Q fever)
what are non-culture methods of demonstrating the presence of an organism (antigen)
detect it immunologically in urine or nasopharyngeal secretions
what does Agglutination mean
the clumping together in suspension of antigen-bearing cells, microorganisms, or particles in the presence of specific antibodies
what is Immunofluorescence
is a powerful technique that utilizes fluorescent-labeled antibodies to detect specific target antigens
what antigens can usually be detected in urine
Legionella
Pneumococcal
what are some common respiratory viruses
Influenza A and B Adenovirus RSV Parainfluenza viruses Metapneumovirus Coronavirus Rhinovirus
when doing antibody detection what is IgM a marker of
marker of current infection
when doing antibody detection what is IgG a marker of
represents previous infection
