Garlanda 6 Flashcards
CAP is with which species
S. pneumoniae S. aureus Influenza A and B Adenovirus Parainfluenza virus 1-4 Respiratory syncitial virus (children) Human metapneumovirus (children) Hantavirus Sars-cov2 H. influenza L. pneumophilia
Infection of lung and pleura in immunocompromised pts is due to
Pneumocytis jirovecii CMV M. avium intracellular complex Aspergillus species (neutropenic) Nocardia
Atypical pneumonia agents
Mycoplasma pneumonia
Legionella pneumophilia
Chlamydophylia pneumonia
Top 5 bacteria to cause influenza co infections
S. pneumonia P. aeruginosa Chlamydophilia H. influenza S.aureus (MRSA)
Top 5 viruses to cause influenza co infections
Respiratory syncitial virus parainfluenza virus hMPV (metapneunovirus) Parainfluenza virus 3 Coronavirus
what is difficult about diagnosis of respiratory infections
- sample collection of lower respiratory specimens is contaminated with oropharyngeal flora (expectorate sputum)
- you need to always check to exclude the presence of squamous cells
- No single test detects all potential respiratory pathogens
3 categories of tests in CLIA (clinical lab improvement amendements)
waived test
test of moderate complexity
tests of highest complexity
Reference standard for influenza diagnosis
immunochromatographic dipstick. Can yeild result in 15 mins, but have limited specificity compared to RT-PCR or viral culture.
What identifies latent TB, and has a positive rxn in pts with BCG
tuberculin skin test (PPD)
INF gamma test is for what TB
IGRA/QUANTIferron can be used for latent, is an ELISA based whole blood test that used peptides from 3 TB antigens
Chest X ray in TB is for which stage of TB
to identify people with active disease
How to confirm active TB
acid fast cells and cord in sputum(CSF, urine, biopsies), or fluorescence auramine-rhodamine staining
Gold standard for TB
culture in liquid medium for 1-2 weeks, with DNA probe hybridization, or NAAT
Note that solid media is positive after 4-8 weeks, while liquid media is positive after 10-14 days
What is Xpert MTB/RIF
a molecular test that ids both M tuberculosis and rifampicin resistance in a single test in less than 2 hours
What is drug sensitivity testing
after culture isolation, definition of minimal inhibitory concentration on liquid culture
Pseudomonads are
aerobic gram negative bacilli, gammaproteobacteria. Found in soil, decaying organic matter, moist environment, they grow everywhere in hospitals, are oppertunistic pathogens
How do you diagnose aspergillosis?
Which lab test can you ask for?
presence of septate hyphae and distinctive conidia in pt samples, and detection of galactomannan antigens in blood in confirmatory
How do you diagnose cryptocoocus neoformans
id the fungus in pt sample, as encapsulated yeast or fungal antigens in CSF or lung
GMS (gomori methenamine silver) stain and immunofluoresence analysis
dx for legionella and pneumococcus is done via
immunoassays for antigens in urine
cons of immunochromatographic dipstick tests for influenza
limited sensitivity
false negatives
what mutation is present for rifampicin resistant TB strains
rpoB in 95% of cases
T/F P. aeruginosa is rarely part of the normal human microbiota
T
How does P aeruginosa infect ppl
it breaches skin or mucous membranes
- mainly infects burn victims and cystic fibrosis pts
DX of P aeruginosa
with colony morphology and beta hemolysis and green pigmentation
what kind of bacteria are moraxella, acinetobacter, stenotrophomonas, and what shape are they
pseudomonades, plump bacilli or diplocci
THEY ARE RESISTANT TO ANTIBIOTICS
who do moraxella, acinetobacter, stenotrophomonas infect
they are oppertunistics, and affect pts on broad spectrum antibiotics, respiratory ventilation, and immunosuppressed
Moraxella catarrhalis causes infection of
sinuses, bronchi, ears, lungs
stenotrophomonas causes
nosocomial infections, bacteremia, pneumonia
Acinetobacter grows where? And infects?
Gram positive with high G+C [ ]
grows in soil, water, sewage
infects medical devices, to resp, urinary, CNS
burkholderia cepacia is found where? Causes what infection?
gram neg aerobic bacilli; fagellated Bproteobacterium can decompose organic molecules infects CF pts In chronic granulomatous dx causes RESPIRATORY infection causes UTI, bacteremia in catheter contamination pt to pt spread resistant to many antimicrobials Found in soil and water
Legionella
gram neg aerobic bacilli
inhabitants of freshwater protozoa
humans inhale bacteria
T/F majority of ppl are exposed to P jiroveci by 5 yo
T
most common cause of bacterial infections of the CNS in <3 months
S agalactiae
common cuase of bacterial infection of CNS in >3 months
S pneumoniae
How do people get infected by listeria monocytogenes
by contaminated food and drink, its a gram pos bacillua, an intracellular parasite
grows in macrophages/liver/gall bladder
can cause meningitis in immunosuppresed
causes premature delivery, micarriage, still birth of new born
the most common cause of meningitis in ppl under 20 is due to
neisseria meningitidis (also causes partial hearing loss)
dx for H influenzae type B
- specimen collection: needle aspiration for sinusitis or otitis, CSF, blood
- microscopic exam
- antigen detection: agglutination test
- culture
three main enteroviruses
(75% of viral meningitis and encephalitis)
poliovirus, coxsackie virus, echovirus
neonatal herpes is due to which type
HSV2
bacterial agents that can cuase meningitis with cleat fluid
M tb
L monocytogenes
spirochetes (leptospira, borrelia, treponema)
brucella
fungal agents that can cuase meningitis with cleat fluid
cryptococcus spp
