Ch. 39: Sample Collection and Handling Flashcards
What are the two common collection methods of microbiology sample collection?
Aspiration and swabbing (Imprints may also be an option)
The specific collection method depends on what?
The location of the sample area/lesion and the testing desired
What collection method is the least suitable method and why?
Sterile cotton swabs; contamination risk is high and cotton can inhibit microbial growth
Sterile cotton swabs aren’t likely to be able to collect what bacteria?
Anaerobic; oxygen an be trapped in the fibers, making the recovery of anaerobic bacteria less likely
What collection is preferred over sterile cotton swabs?
Rayon or Dacron swabs
What must be used if there are delays in processing samples?
A rayon swab in a transport media (Culturette) to preserve the quality
Samples that are to be immediately processed an usually be collected using what?
Sterile cotton swabs; but this is not preferred
The best results can be obtained if specimens are collected from sites that would normally be ______.
Sterile
What sample collection sites will not yield the best results due to the contamination of the area?
Ear or fecal samples
What technique must be used when collecting samples for microbiology testing?
Aseptic technique
What is the required data needed prior to collecting microbiology samples?
- Owner’s name
- Clinic’s name
- Address
- Phone number
- Species
- Patient name
- Age
- Sex
- Number of animals dead or affected
- Duration of the problem
- Major signs observed
What is the most common cause of diagnostic failure with microbiology samples?
Specimen contamination
When collecting dermatophyte specimens for culture, what is the proper technique?
Clean the skin lesion to remove some of the surface contamination, and collect specimens from the lesion periphery
What are the best samples ( likely to contain viable organisms) for dermatophyte culture?
Broken hair shafts and dry skin scales
How can hairs be collected?
Plucking or a toothbrush can be used
If using a toothbrush to collect sample hairs, what is the proper technique?
Obtain a new human toothbrush and brush the suspected lesion for 1-2 minutes
For fungal testing, hair, nails, and skin can be put in what container?
A paper envelope
With respiratory diseases, where are viruses often present?
Nasal and pharyngeal secretions
When collecting samples for viral specimens, what should be the method of collection?
Mucosal scrapings rather than swabs of secretions should be taken
What tool is useful for mucosal scrapings?
Sterile wooden tongue depressors
Viral specimens should also be collected for what indirect studies?
Serology, hematology, histology, and bacteriology
Viral diseases are often complicated by what that act as secondary invaders?
Pathogenic bacteria
Specimens for histology testing should be contained in what?
10% Formalin, should contain a thin section of tissue
Is it okay for histology specimens to be frozen?
No, this causes tissue artifacts that may be difficult to differentiate from a pathologic process
