L4: DIAGNOSTIC BACTERIOLOGY Flashcards
Laboratory Procedures performed in Clinical Microbiology Laboratory
- Microscopic ID
- Culture Isolation and ID
- Detection of Ag from the agent using Immunoassays
- Molecular Methods
Specimen should be collected from the ____ of infection
actual site
Include throat cultures, nasopharyngeal cultures, oral cavity
Respiratory Tract
Specimen of choice for LRT
SPUTUM
Respiratory Tract.
PMNs: ___
Epith cell: ___
PMNs: >25/lpf
Epith cell: <10/lpf
____ are preferred over rectal swab
Stool specimen
Culture to diagnose Gastroenteritis
Gastrointestinal Tract
should be use to enhance the growth of the
pathogen, while inhibiting Normal Flora
Enrichment Media
Requested to diagnose UTI
Urine
Urine. Specimen of choice:
CLEAN CATCH MIDSTREAM SPECIMEN
Urine. If patient cannot void 🡪 _____
CATHETERIZED SPECIMEN
Urine. Infants and Young children 🡪 _____
SUPRAPUBIC ASPIRATION
should be performed in all Urine Samples
Colony Count
positive urine culture:
> 100,000 CFUs/mL
presence of bacteria in the Blood
BACTEREMIA
TRANSIENT BACTEREMIA – ____
NORMAL FLORA
sporadically discharged from extravascular abscesses into the blood
Intermittent Bacteremia
constant release of bacteria into the blood
Continuous Bacteremia
Highest conc of bacteria in the blood 🡪 ___
Before the fever spikes
2 or 3 venipuncture sites, __ hour apart
1 hour apart
Cleaning of the skin prior for collection of blood: ___ Alcohol, ___ Iodine (left 1min)
70% Alcohol, 2% Iodine (left 1min)
____ ml blood is collected from adults during Phlebotomy,
10 ml
during Phlebotomy, ____ml is collected from from children
1-5ml
Cerebrospinal Fluid. Collected by lumbar puncture (____ Lumbar vert)
3rd-4th Lumbar vert
Cerebrospinal Fluid. 3 tubes
TT1
TT2
TT3
Cerebrospinal Fluid. 3 tubes. TT1🡪___
chemistry/immunology
Cerebrospinal Fluid. 3 tubes. TT2🡪___
Microbiology
Cerebrospinal Fluid. 3 tubes. TT3🡪___
Hematology
Cerebrospinal Fluid Specimen should be screened IMMEDIATELY for the presence of bacteria using ____
Gram stain
DELAYS must be avoided in processing CSF result 🡪 _____
HIGH MORTALITY
Generally preferred to collect specimens using SYRINGE and NEEDLE to
aspirate (avoid NF and high chance of ANAEROBES)
Wound Culture and Abscesses
result from animal bites, burns, ulcer and traumatic wound
Exogenous wound
bacterial sources within the patient (cellulitis, dental infections, septic arthritis)
Endogenous wound
______ limit: collection 🡪 Lab reception
2 hour limit
Specimen Transport. With delay, use _____ (increase the viability of the pathogen up to 72 hours), and refrigerate the specimen
STUART’S MEDIUM
For transport of Stool specimen:
CARY-BLAIR medium
MORE PREFERRED than cotton swab
Ca-Alginate or Dacron swab
Specimen not collected properly and accordingly 🡪 NOTIFY ______
PHYSICIAN or NURSE
Upon receipt of the specimen in the lab 🡪 ______ should be done
GROSS EXAMINATION
For anaerobic culture 🡪 make sure to use ____
ANAEROBIC TRANSPORT MEDIUM
specimen is mixed with saline then view under the microscope
Saline Mount
dissolves keratin to make fungal elements more visible
KOH preparation
to detect capsules
India Ink
Gram Stain primary stain
Crystal Violet
capsular swelling, detect capsular Ag
Neufeld (quelling) reaction
Gram Stain. Mordant
Iodine
Gram Stain. Decolorizing agent
Alcohol/Acetone
Gram Stain. Counter stain
Safranin
Use to stain Mycobacteria (walls are thick and waxy)
Acid Fast Stain
Acid Fast Stain. Hot method:
Ziehl Neelsen
Acid Fast Stain. Cold method:
Kinyoun
Fluorescent Stains
Rhodamine Stains
Acridine orange
Calcofluor white
stain Mycobacteria
Rhodamine Stains
useful to demonstrate small amount of
bacteria in blood cultures, CSF, Urthral smears
Acridine orange
Fluorescent Stains for fungi
Calcofluor white
Mixture of nutrient needed by microorganisms
Culture Media