UAMS MICROBIOLOGY EXAM 4
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS (GRADED A+)
||UPDATED 2026
Microbiology: Clinical Specimen Suitability for Gram Stain
Which primary clinical specimens are appropriate for routine Gram stain
examination and preliminary evaluation?
✔✔ Abscess / Wound aspirates or exudates (evaluates PMNs, mixed
anaerobes/aerobes)
✔✔ Sputum / Lower respiratory specimens (evaluates specimen quality via
epithelial cell vs. WBC ratios)
✔✔ Normally sterile body fluids (e.g., CSF, pleural, joint, or peritoneal fluid via
cytospin)
✔✔ Urethral discharge / Exudate (specifically for screening Neisseria
gonorrhoeae / GC in males)
✔✔ Stool (specifically for assessing the presence of fecal WBCs / inflammatory
response)
How are cells and bacteria enumerated
Cells (10X)
Bacteria (100X)
1-10 = few=1+
11-24 = moderate= 2+
>= 25 = many = 3+
,Inappropriate Gram Stain Specimens
Throat
Rectal
Vaginal
Stool (unless looking for PMN, Campy, Staph)
Acridine Orange Stain
Stains nucleic acids of living or dead cells.
Prepare slide and fix with methanol.
Flood with stain, rinse and examine under 40X.
Bacteria / Yeast will fluoresce orange.
Common Pathogens of CSF
H. flu
S. pneumo
N. meningitidis
GBS
Listeria
Coag- Staph
CSF Rhinorrhea
CSF leak through nasal passages from:
trauma / tumors
, Stool Media and Incubation
BAP, MAC/EMB, HE, SS, XLD, GN Broth, Campy
CIN (Yersinia)
TCBS (Vibrio)
SMAC (E. coli 0157:H7)
Incubate in air at 37.
Genital Smears look for:
Clue cells
GNDC (male urethral)
Yeast
Genital Culture Media and Incubation
BAP, MTM
Todd Hewitt / Carrot Broth (GBS)
HBT or V agar (Gardnerella)
MAC/EMB (Enterics)
Incubate in CO2 at 37
Genital Pathogens
N. gonorrhoeae
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS (GRADED A+)
||UPDATED 2026
Microbiology: Clinical Specimen Suitability for Gram Stain
Which primary clinical specimens are appropriate for routine Gram stain
examination and preliminary evaluation?
✔✔ Abscess / Wound aspirates or exudates (evaluates PMNs, mixed
anaerobes/aerobes)
✔✔ Sputum / Lower respiratory specimens (evaluates specimen quality via
epithelial cell vs. WBC ratios)
✔✔ Normally sterile body fluids (e.g., CSF, pleural, joint, or peritoneal fluid via
cytospin)
✔✔ Urethral discharge / Exudate (specifically for screening Neisseria
gonorrhoeae / GC in males)
✔✔ Stool (specifically for assessing the presence of fecal WBCs / inflammatory
response)
How are cells and bacteria enumerated
Cells (10X)
Bacteria (100X)
1-10 = few=1+
11-24 = moderate= 2+
>= 25 = many = 3+
,Inappropriate Gram Stain Specimens
Throat
Rectal
Vaginal
Stool (unless looking for PMN, Campy, Staph)
Acridine Orange Stain
Stains nucleic acids of living or dead cells.
Prepare slide and fix with methanol.
Flood with stain, rinse and examine under 40X.
Bacteria / Yeast will fluoresce orange.
Common Pathogens of CSF
H. flu
S. pneumo
N. meningitidis
GBS
Listeria
Coag- Staph
CSF Rhinorrhea
CSF leak through nasal passages from:
trauma / tumors
, Stool Media and Incubation
BAP, MAC/EMB, HE, SS, XLD, GN Broth, Campy
CIN (Yersinia)
TCBS (Vibrio)
SMAC (E. coli 0157:H7)
Incubate in air at 37.
Genital Smears look for:
Clue cells
GNDC (male urethral)
Yeast
Genital Culture Media and Incubation
BAP, MTM
Todd Hewitt / Carrot Broth (GBS)
HBT or V agar (Gardnerella)
MAC/EMB (Enterics)
Incubate in CO2 at 37
Genital Pathogens
N. gonorrhoeae
