PBL: Respiratory Cultures Flashcards Preview

Liz's Microbiology Module 2 > PBL: Respiratory Cultures > Flashcards

Flashcards in PBL: Respiratory Cultures Deck (50):
1

List the anatomical areas of the respiratory tract

- Upper: Nasal, sinus, nasopharnyx, oropharynx, epiglottis, larynx
- Lower: Trachea, bronchi, alveoli (last 2 are in the lungs)

2

Which anatomic regions of the respiratory region are sterile?

Lower: trachea, bronchi, alveoli (last 2 are in the lungs)

3

List the organisms most commonly found as "normal flora" in upper respiratory tract specimens

- Streptococcus Viridans
- S. pneumoniae
- S. pyogenes
- Corynebacterium spp
- Neisseria spp
- CoNS
- Micrococcus spp
- Rothia spp
- Haemophilus spp
- Aggregatibacter aphrophilus
- Moraxella spp
- Anaerobes (Veillonella spp, Fusobacterium spp, Prevotella spp, Porphymonas spp, Parvimonas micra)

4

List the common general symptoms of pneumonia

- Fever, chills
- Malaise
- Dyspnea
- Thick, purulent sputum

5

What is pneumonia?

Inflammation of the lungs detected via physical examination of CXR

6

What are the characteristic signs of pneumonia?

Inflammation → fluid buildup in alveolar sacs
- Physical examination: decreased or abnormal breath sounds (crackles)
- CXR infiltrates: fluid buildup in alveolar sacs

7

Relationship of positive blood cultures and pneumonia

S. pneumoniae infection occurs w/ 30% positive blood cultures?

8

Discuss the vaccines which are available for the prevention of respiratory infections

- Pneumococal conjugate vaccine (PCV)
- Pneumococcal polysaccharide vaccine (PPSV23)

9

List the most common bacterial pathogen in HIV patients

M. avium

10

List the most common bacterial pathogen(s) in cystic fibrosis patients

- Pseudomonas aeruginosa (most often isolated)
- Burkholderia cepacia

11

List the most common bacterial pathogen that causes "walking pneumonia" in young adults

Mycoplasma pneumoniae

12

What are the 3 most common upper respiratory tract pathogens?

- Cryptococcus neoformans
- Streptococcus pneumoniae
- Moraxella catarrhalis

13

List the most common bacterial pathogen(s) in the throat (pharyngitis)

- Streptococcus pyogenes (Group A/Beta hemolytic)
- Streptococcus pneumoniae
- Neisseria spp (N. gonorrhoeae and N. meningitidis)
- Haemophilus influenzae

14

List the most common anaerobic pathogen(s) causing aspiration pneumonia

- Fusobacterium spp (GNR)
- Prevotella spp (GNR)
- Porphymonas spp (GNR)
- Veillonella (GNC)
- Peptostreptococcus anaerobius (GPC)

15

List the common bacterial pathogen(s) that are community acquired

- Streptococcus pneumoniae (most common cause of bacterial pneumonia)
- Haemophilus influenzae
- Legionella pneumophilia

16

List the most common bacterial pathogen that are nosocomial acquired

Klebsiella pneumoniae

17

Prevents engulfment and drying out

Polysaccharide capsule

18

Which organisms have a polysaccharide capsule?

- H. influenzae
- Streptococcus pneumoniae
- Neisseria meningitidis
- Pseudomonas aeruginosa
- Bordetella pertussis
- Klebsiella pneumoniae
- Cryptococcus spp

19

Which organisms are intracellular?

- Mycobacteirum tuberculosis
- Chlamydophila pneumoniae

20

Which organisms should be considered agents of bioterrorism if isolated from respiratory culture?

- Bacillus anthracis
- Yersinia pestis (plague)
- Francisella tularensis
- Mycobacterium tuberculosis (mult-drug resistant)

21

Which specimens should avoid exposure to usual flora of the upper respiratory tract (*should be sterile)

- Transtracheal
- Lung biopsy
- FIne needle aspirate

22

Strep screens
- Specimen type

- Throat swab of tonsillar areas
- Posterior pharynx

23

Strep screens
- Media to set up

BAP

24

Routine lower respiratory specimens
- Specimen type

- Expectorated and induced sputum
- Endotracheal aspirate
- BAL
- Bronchial washings
- Bronch brushes

25

Routine lower respiratory specimens
- Media to set up

- BAP
- CHOC
- MAC
- CNA
- Direct smear

26

Sterile respiratory specimens
- Specimen type

- Transtracheal aspirates
- Lung aspirates

27

Sterile respiratory specimens
- Media to set up

- ABAP
- PEA
- BAP
- CHOC
- MAC
- CNA
- Direct smear

28

Legionella cultures
- Specimen type

- Biopsy/autopsy tissues
- Pleural fluids
- Transtracheal aspirations
- Sputum or other respiratory specimens
- Blood

29

Legionella cultures
- Media to set up

- Buffered charcoal yeast extract agar (BCYE)
- Buffered charcoal yeast extract agar w/ cephalothin, colistin, vancomycin, cycloheximide (BCYE selective)
- 5% SBAP

30

Bordetella pertussis cultures
- Specimen type

Swab of posterior nasopharynx
- NOTE: no cotton swabs!

31

Bordetella pertussis cultures
- Media to set up

- BAP
- Regan-Lowe
- Charcoal agar (Bordet-Gengou)
- Possible Gram stain or use of FA reagents

32

C. diphtheriae cultures
- Specimen type for respiratory infections

Throat and nose, preferably posterior nasopharynx specimens

33

C. diphtheriae cultures
- Specimen type for cutaneous infections

Culture skin area as well as nose and throat

34

C. diphtheriae cultures
- Media to set up

- BAP
- CHOC
- Tinsdale (black colonies)
- Gram stain
- Catalase
- CHOs
- Nitrate broth
- Urea agar

35

Actinomyces
- Specimen type

Various (slow grower → 2 weeks)

36

Actinomyces
- Media to set up

ABAP

37

Cystic fibrosis patient w/ B. cepacia
- Specimen type

Sputum

38

Cystic fibrosis patient w/ B. cepacia
- Media to set up

- PC (used specifically for B. cepacia)
- MSA (some strains can oxidize mannitol)
- BAP
- CHOC
- MAC
- CNA
- Direct Gram stain by request

39

MRSA
- Specimen type

Nasal swab

40

MRSA
- Media to set up

- Oxacillin screening plates (Growth vs. No growth)
- MSA
- CHROM agar (MRSA selective)

41

Significance of Rapid Ag testing in diagnosis of strep throat

POC test that uses enzyme immunoassays or latex agglutination to identify group A strep Ags
- HIGH specificity
- LOW sensitivity

42

Discuss the reasoning for quantitation of organisms in respiratory tract specimens

- Quantitation of fresh sputum is indicative of probable pathogens based on how much bacteria is found
- Pathogens are usually found in higher quantities than oropharyngeal flora
- Proper collection and quantitation of culture is very helpful in providing information that would aid in the physician helping the patient, such as recognizing superinfections, or preforming antimicrobial susceptibility testing

43

What indicates a good collection of a respiratory specimen?

- Dust macrophages
- Ciliated epithelium
---- If found in URT, indicates contamination
- WBCs (indicates infection)

44

Evaluation of Gram-stained direct smears of sputum
- Bartlett's method

Assign + and - values; +2 if > 25 WBC; +1 if 10-25 WBCs; +1 if mucus seen; -2 if > 25 epis; -1 if 10-25 epis

45

Evaluation of Gram-stained direct smears of sputum
- Bartlett's criteria for acceptability

Any positive score (sum of + and - values assigned)

46

Evaluation of Gram-stained direct smears of sputum
- Murray and Washington's method

Average number of epi/LPF

47

Evaluation of Gram-stained direct smears of sputum
- Murray and Washington's criteria for acceptability

< 10 EPI/LPF

48

List the bacteria that cause aspiration pneumonia

Mouth flora

49

Epiglottis is caused by...

Haemophilus influenzae

50

Ear/sinus infections is caused by...

Moraxella catarrhalis