Respiratory Cultures Flashcards
NF of upper respiratory tract
Strep mitis & other alpha strep, Staph aureus, Beta strep (not group A), H. influenzae, Strep pneumoniae, Moraxella catarrhalis, coag neg staph, Candida, Neisseria spp, non-hemolytic strep, Veillonella, bacteroides
Common cause of epiglottis
Haemophilus influenzae type B
Major concern in cystic fibrosis patients
Haemophilus influenzae, Staph aureus, Pseudomonas aeruginosa, Stenotrophomonas, Alcaligenes
Specimen collected for Bordetella pertussis
Nasopharyngeal swab using a calcium alginate swab
Media used for Bordetella pertussis
Boret-Gengou media, Regan-Low, modified Jones-Kendrick charcoal
Fl stain available, but if neg, must do culture
Cause of Vincent stomatitis or trench mouth
Severe cause of gingivitis. Caused by combined effect of anaerobes (Fusobacterium necophorum)
Purpose of PMN in sputum
PMNs suggest true sputum
Purpose of squamous epithelial cells in sputum
suggest only saliva & inadequate specimen
Significant findings on sputum gram stain
A disproportionate amount of any single type of bacterial morphology may be significant
Ex. gnr, gn diplococcic, gp diplococcic, or lack of bacteria
Organism that causes lobar pneumonia in a child
Strep pneumonia and H. influenzea type B
Organism that causes atypical pneumonia
Mycoplasma penumoniae
Cannot grow on culture - must Id by molecular amplification
Reason for SBA for isolation of beta hemolytic strep
Only blood agar that demonstrates valid reaction for hemolysis
What organism would be suspected from this sputum gram stain?
3+ gn diplococci 1+ gpc chains 1+ gp rods diptheroids >25 PMNS <10 epi
Moraxella catarrhalis
What organism would be suspected from this sputum gram stain?
4+ gpc chains & clusters 4+ gp rods 1+ gnr <25 PMN >10 epi
Saliva contamination, not acceptable specimen for culture
What organism would be suspected from this sputum gram stain?
4+ gp diplococci
2+ neg diplococci
>25 PMN
<10 epi
Strep pneumoniae
What organism would be suspected from this sputum gram stain?
3+ tiny gnr
2+ gpc
>25 PMN
<10 epi
Haemophilus influenzae
Moraxella catarrhalis biochemical tests
Oxidase +
glucose, maltose, sucrose, lactose =
DNase +
Tributryn +
Pathogenicity of Moraxella catarrhalis
Cause lower lobe pneumoniae
Screening for Group A beta Strep
Beta hemolysis around tiny pinpoint colony, confirm by antigen testing, bacitracin, PYR
What are you screening for on the choc plate in sputum culture
H. influenzae
What are you screening for on the blood agar plate in a sputum culture?
alpha hemolysis for Strep pneumonia, excess amount of Staph aureus, excess amount of yeast, hemolysis for group A beta Strep, presence or absence of normal flora
What are you screening for on the Mac plate in sputum culture?
Excess gram neg rod. Klebsiella pneumoniae
What must be done if the EIA screen for group A beta strep is neg
do culture
When will H. influenza grow on a blood agar plate?
If another organism gives it V factor. X factor is coming from the plate (satellitism)
