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238 Tasks for the Veterinary Assistant

Sedi‐Stain. Some veterinary technicians prefer reading and PPE are of the utmost concern. The minimum PPE
the slide without any stain at all. If a stain is used, mix it are gloves, goggles or a face shield to catch splashes or
well with the urine by flicking the bottom of the tube prevent inhalation of infectious materials, and a lab coat
with a finger. to prevent contamination of clothing. Keep the work
Using a clean and labeled slide, pour or use a pipette area clean and uncluttered. Use disinfectant when the
to place a drop of urine on the center of the slide. Place work is completed leaving it on the surrounding surfaces
a coverslip over it to minimize the formation of bubbles to air dry.
under it. Place the slide next to the microscope with the Samples must be collected aseptically to prevent con-
patient’s medical record. Notify the veterinary techni- taminants being accidentally introduced into the sample.
cian the slide is ready to read. The veterinarian or veterinary technician will be collect-
Clean the refractometer and put it away. Discard any ing the sample and inoculating the mediums. The
remaining urine down the drain and flush the drain with assistant will gather the equipment needed, restraining
lots of cold water. If using reusable test tubes, clean them the patient, prepare the samples for shipping to the ref-
with hot soapy water and a small bottle brush, rinsing erence laboratory if not run in‐house and clean up.
well and drying upside down in a test tube rack. Discard When bacterial infections are suspected, the supplies
the micro‐test tube, if used, and the chemical strip. Put required are two sterile swabs, wax pencil for labeling
away the chemical assay strips. Clean and then disinfect the microscope slide, and Petri dishes with blood agar
the counter area. Remove and discard gloves in the haz- which is an all‐around bacterial growth medium. Bring
ardous waste container. all the necessary PPE for the personnel involved.
If the specimen is to be sent to a reference laboratory
for work‐up, the swabs to use are called culturettes.
Culturettes are sterile swabs in sterile plastic tubes. The
Learning Exercise swab is attached to the inside of the tube top. The top of
the tube with swab is removed, the sample is swabbed,
Take a look at the outside of the Chemstrip con- and the swab is reintroduced into the tube with the top
tainer. What does it test for and associate the securely replaced. Pressure is then applied over the end
color changes with each test.
of the tube. Crushing the end releases a liquid nutrient
media that soaks the tip of the cotton swab and keeps the
bacteria alive while in transit to the reference laboratory.
Fill out the appropriate requisition slip. The whole tube
Microbiology – Sample Collection is sent to the lab along with the unstained slide. Put the
slide in a slide container to keep it from breaking, then
Accurate diagnosis and the optimal choice of drugs for put the tube and slide container in a Ziploc bag with the
treatment begin with proper sample collection for requisition slip. Package the Ziploc in a box with an ice
microbiology testing. The goal is to collect a sample that pack and either call for pick‐up or ship the box to the lab.
contains the causative agent of disease. The identification If a fungal infection like ringworm is suspected, the
process and antibiotic sensitivity testing can then pro- PPE equipment will remain the same. The equipment
ceed to determine the course of treatment. required is the Wood’s light, 10% potassium hydroxide,
Most veterinary clinics approach the process in two a clean, labeled slide, coverslip, heat source and DTM or
ways. Preliminary diagnostic work can be done in‐house, other fungal culturing agar, sterile forceps, and an
such as the commonly used Gram stain to determine if alcohol‐soaked cotton ball.
the organism is Gram negative or positive and if it is a The veterinarian or the technician will secure the
rod or cocci‐type bacteria. The culture and sensitivity sample. The assistant will restrain the patient and then
can either be sent to a reference laboratory or be con- clean up and put the unused equipment away. Again,
ducted in‐house. A culture is where the sample is spread allow the disinfectant to air dry on the exam table.
upon an agar plate that has a medium that promotes the
growth of bacterial organisms. Once the bacteria has
grown, further isolation of the different colonies of Gram Stain
bacteria can be conducted on different mediums to rule Gram stain allows the technician or veterinarian to look
out bacterial strains and move closer to identification of at the sample under 100×. The stain will help determine
the bacteria. The sensitivity test indicates which antibi- if a bacterium is Gram positive (purple uptake of dye) or
otic would be of use against the identified pathogen. negative (red uptake of dye) and whether it is a rod or
The choice depends on the veterinarian’s preference, cocci. The stain consists of four solutions and may be
equipment available, and skills of the staff. performed from the original sample or later from growth
The potential for infection to staff handling these on the blood agar plate. The Gram reaction helps deter-
samples is high, so use of cautious laboratory techniques mine how to proceed with identification of the bacteria.