Specimen Examination and Interpretation

Question 1

What are the 3 considerations when looking at specimens?

Answer 1

• clinical history
• source and site
• direct smear (from source to slide)

Question 2

What is the general set of medium?

Answer 2

• blood agar
• macconkey agar
• CNA
• E broth

Question 3

Collect a colony from ______ only to determine gram stain

Answer 3

Blood agar

Question 4

Inoculate media for _______

Answer 4

Sensitivity testing

Question 5

The knowledge of the microbial etiology of infectious disease has ___, _____, and ______

Answer 5

Therapeutic, prognostic, and epidemiologic value

Question 6

What determines collection and handling techniques?

Answer 6

The type, location, and duration of disease

Question 7

What types of specimens are there?

Answer 7

• solids (tissues)
• liquids (transudates, exudates, milk, urine, etc)
• swabs (cotton or culturette with transport buffer)
• could be antemortem or postmortem
• could be collected for microbiology, serology, histology, toxicology, or combos

Question 8

General rules of collection

Answer 8

• avoid contamination
• obtain sufficient material (site and size)
• transport: consider packaging and speed

Question 9

Flora

Answer 9

• disease may be due to alteration of flora

- alterations in flora may be due to treatment

Question 10

Antisepsis

Answer 10

Solutions applied to living biological surfaces

- ex: chlorohexidine, hydrogen peroxide, isopropyl alcohol

Question 11

Decontamination

Answer 11

Solutions applied to environmental objects and surfaces to selectively destroy or inhibit microbes of interest
- ex: NaOH/HCl rotation

Question 12

Quantitation

Answer 12

To distinguish between normal flora and pathogens

- ex: tube dilutions and calibrated loops for milk, urine

Question 13

Microscopy

Answer 13

Use of direct exam and analysis of host cell types

Question 14

Swabs

Answer 14

• buffer: prevent desiccation, dilute inhibitors
• limitations: good for small volumes, but need 10^6 CFU for direct exam with recovery of only 10% (90% of specimen gets trapped in swab)
• indications for use: used with aerobes, faculatives, fungi, and viruses, exudates and secretions form skin/mucous membranes, anal and rectal
• contraindications: pus and supperative exudates, surgical specimens, mycobacterial specimens, anaerobes

Question 15

Specimen identification request forms must have

Answer 15

• signalment (age, sex, breed, names of owner and patient)
• source and site of specimen
• tentative or presumptive diagnosis
• date and hour of collection and receipt in lab
• history
• treatment to include type, dose, time last given, and duration

Question 16

What can be used to transport anaerobes?

Answer 16

A sterile syringe (expel the air and plug the tip)

Question 17

Tissues submitted for bacteriology should contain

Answer 17

A representative lesion and some normal tissue

Question 18

Is transport of specimens in enrichment broth recommended?

Answer 18

NO, want to minimize overgrowth of contaminants