This page contains information specimen selection and collection for bacterial diseases.
General Bacteriology Considerations
Specimen Selection for Bacterial Diseases
General
Bacteriologic Considerations
Used correctly, microbiologic cultures
can identify etiologic agent(s) and
contribute key information towards a
diagnosis.
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However, improperly collected
microbiologic cultures may identify
contaminants or overgrow pathogens and
lead to erroneous diagnoses. Etiologic agents
can be missed because of improper transport medium, improper transport environment, or improper
preservation techniques. The value of microbiologic culture depends to a considerable degree on
the care and skill with which cultures are taken, stored and shipped to the laboratory. We offer
the following guidelines to optimize these procedures.
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Samples should be collected aseptically
and placed in sterile plastic bags (e.g., Whirl-pak) or heat sterilized containers. Seal tightly.
Do not use chemically disinfected containers, or plastic gloves or sleeves.
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Label all submissions with the location
(tissue) and species of origin. The same bacterial species may be highly significant or a
meaningless contaminant, depending on the tissue and/or species from which the sample was obtained.
Also, depending on the tissue/species of origin, different culture conditions may be necessary to
isolate and identify specific pathogens.
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Always specify the tests you want done, and the pathogens you suspect,
particularly in the case of specimens with normal bacterial flora (feces, intestinal contents, skin,
or oral mucus membranes). If we don't know what you're looking for, we may not inoculate the proper
media to find it.
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It is best to collect other samples before opening the gastrointestinal
tract. Tissue samples (lung, liver, spleen, kidney, etc.) should be 5 g or larger to allow surface
searing in the laboratory to reduce contaminants. Fecal samples should not be submitted in stoppered
tubes, as fermentation will dislodge the stoppers.
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Place each sample in a separate container. If the intestine is to be
cultured, tie off both ends of a segment and place it in a separate container.
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Except in the case of abortions, please separate samples that are to
be examined by different laboratory sections. If a specimen is to be examined by both the virology
and bacteriology sections, the specimen should be divided, each piece placed in a separate container,
and labelled with the source of the tissue and the desired laboratory service.
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Fluids for culture (e.g. body cavity fluids, pericardial fluid, joint
aspirates) should be submitted in a sealed sterile tube, in as large a volume as is available
(up to ~10 ml), since the concentration of organisms may be very low in these samples. Fluids may be
submitted in blood culture bottles or IsolatorĀ® tubes for highest sensitivity. Differentiating
contaminants from etiologic agents may be difficult from blood culture bottles, due to loss of
quantitation information. Fetal fluids (thoracic or peritoneal fluids, or heart blood) to be examined
for Leptospira sp. by FA test should be submitted in a sealed sterile tube to which 10%
buffered formalin is added at a rate of 1.5 ml per 20 ml fluid. Never submit fluid in syringes,
because they tend to leak in transit and contaminate packaging. Never submit fluids or other
specimens for bacteriologic culture in EDTA (purple top) VacutainerĀ® tubes, as EDTA is highly
toxic to many bacterial species.
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Milk samples should be submitted in screw top
tubes frozen or placed on ice packs. Less than 1 ml is required, and larger volumes are undesirable,
especially if the samples are frozen.
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Specimens for isolation of anaerobic pathogens
require special care. Anaerobic bacteria die in the presence of oxygen and should be shipped in an
anaerobic container, such as anaerobic swab or Port-a-CulĀ® system. Cultures for Clostridium
sp. in parenchymatous organs and intestines ordinarily provide no significant information concerning
the cause of death if the samples are taken more than one hour after death.
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Some specimens, such as porcine nasal swabs for Bordetella
sp. isolation must be delivered to the laboratory within 12 hours of collection. Fastidious organisms
such as Campylobacter spp. require special media for transport to the laboratory. Where there
is any doubt as to what samples to collect and how to transport them - - CALL THE LABORATORY FIRST!
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When collecting large numbers of samples (e.g. >30 milk samples for mastitis
diagnosis or fecal samples for Johne's disease diagnosis), call the laboratory for scheduling. This permits
the laboratory to have personnel and media available for prompt processing.
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Keep specimens cold from the time they are collected until they arrive at the
laboratory. Specimens should be shipped in insulated containers with a sufficient number of ice packs to
last 48 hours.Specimens arriving in the laboratory in a decomposed state will not be processed, since
processing and culture of these tissues lead to meaningless or erroneous results.
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For
cases where bacteremia is
suspected and blood culturing is
requested, blood culture systems
should be inoculated with the
proper amount of blood collected
aseptically. Single bottle blood
culture systems are recommended.
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Select samples judiciously! See the following list for guidelines, and call the
laboratory if questions remain.
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Different bacteriologic procedures take different times to complete; approximate culture
times are as follows:
|
Aerobic (culture and sensitivity) |
3 days |
|
Anaerobic |
7-10 days |
|
Listeria spp.cold enrichment |
7 days |
|
Mycology |
>2 weeks
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Mycoplasma
|
2 weeks
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Mycobacteria paratuberculosis
|
13 weeks
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Disease
|
Fees
|
Specimen
|
Remarks & Suggested Ancillary Testing
|
| Abortion |
fee schedule |
Dam: Placenta (cotyledon best in ruminants), vaginal swab, cervical mucus. Fetus: liver, lung kidney, stomach contents, thoracic fluid.
|
Histopathology, Virology, Serology Histopathology, Virology
|
| Abscess |
fee schedule |
Swab |
Anaerobic
See note 9 |
| Actinobacillosis or Actinomycosis |
fee schedule |
Exudate or lesion (sulfur granule if present) |
Anaerobic
See note 9 |
| Anthrax (B. anthracis) |
fee schedule |
Blood, spleen, or lymph node |
Necropsy contraindicated |
| Arthritis |
fee schedule |
Carcass, affected joint, synovial tissue, or joint fluid |
Anaerobic
See note 9 |
| Atrophic rhinitis (B. bronchiseptica) |
fee schedule |
Swabs, must arrive at the lab within 12 hours. |
Histopathology |
| Black leg (Clostridial myositis) |
fee schedule |
Entire carcass, Affected muscle |
Histopathology
See note 9 |
| Blood culture |
fee schedule |
Inoculated blood culture system. |
|
| Botulism |
fee schedule |
|
Call the laboratory |
| Brucellosis |
fee schedule |
See
abortion |
Serology |
|
Campylobacteriosis
Enteric:
Reproductive:
|
fee schedule |
Feces
See
abortion
|
Special transport media required |
| Caseous lymphadenitis (C. pseudotuberculosis) |
fee schedule |
Affected lymph node or swab of contents |
|
| Colibacillosis |
fee schedule |
Entire carcass, loop of duodenum, mesenteric lymph node |
|
| Corynebacterium equi
pneumonia |
fee schedule |
See
Rhodococcus equi |
|
| Contagious equine metritis (Taylorella equigenitalium) |
fee schedule |
Female: Cervical secretions
Male: Urethral fossa secretions |
Reportable disease. Call lab before collecting. |
| Dermatophilosis (Dermatophilus congolensis) |
fee schedule |
Scabs, purulent exudate |
Histopathology
|
| Enteritis |
fee schedule |
Entire carcass, loop of affected intestine, mesenteric lymph node |
Histopathology
E. coli typed by PCR |
| Enterotoxemia (Clostridium perfringens) |
fee schedule |
Intestines or intestinal contents. Thirty g required. Must be collected within 4
hours of death for interpretation of results. |
Histopathology
Typed by PCR |
| Erysipelas (Erysipelothrix rhusiopathia) |
fee schedule |
Entire carcass, Liver, heart, spleen, kidney, lymph node, affected joint. |
Histopathology |
| Glasser's disease (Hemophilus
polyserositis) |
fee schedule |
Entire carcass
Unopened joint and inflamed serosa |
Deliver immediately or freeze |
| Hemophilus pneumonia |
fee schedule |
Entire carcass
Thoracic fluid, lung, nasal swab |
Histopathology, Serology |
| Hemorrhagic bowel syndrome (Lawsonia
sp.) |
fee schedule |
Entire carcass, affected small intestine |
Histopathology, Serology, Molecular diagnostics |
| Johne's disease (Mycobacterium paratuberculosis) |
fee schedule |
Entire carcass
Rectal biopsy or large intestine/ileocecal valve, regional lymph node, feces
(2-10g) |
Histopathology, Serology |
| Leptospirosis (See abortion) |
fee schedule |
Entire carcass
Kidney, Urine |
Serology, Darkfield examination |
Listeriosis
CNS
Abortion |
fee schedule |
Entire carcass
1/2 cerebellum, pons, medulla
Fetal liver, kidney, spleen |
Histopathology |
| Malignant Edema |
fee schedule |
Entire carcass, Lesion |
See note 9, Histopathology |
| Mastitis |
fee schedule |
Milk. Use proper sample container half full or less. Call lab before submitting
large (>30) numbers of samples. |
Mycoplasma by specific request only |
Mycoplasma
- Arthritis
- Mastitis
- Pneumonia
|
fee schedule |
Entire carcass
Joint fluid
Milk
Entire carcass or affected lobe(s) |
Histopathology, Culture requires special media. Deliver immediately or freeze
samples. |
| Nocardiosis |
fee schedule |
Entire carcass, Lesion |
Histopathology |
| Pasteurellosis |
fee schedule |
Entire carcass, Affected lobe |
Histopathology |
| Pneumonia |
fee schedule |
Entire carcass, Affected lobe |
Histopathology, Virology, Serology |
| Polyarthritis |
fee schedule |
Entire carcass, Joint fluid |
Histopathology, Deliver immediately or freeze. |
| Polyserositis |
fee schedule |
Entire carcass, Joint fluid and affected serosa |
Histopathology, Deliver immediately or freeze. |
| Rhodococcus equi
pneumonia |
fee schedule |
Affected tissue, swab, or trans-tracheal aspirate |
Histopathology
Typed by PCR |
| Salmonellosis |
fee schedule |
Entire carcass, Loop of intestine/colon, feces, lymph nodes, spleen, and lungs |
Group typing at WADDL, forwarded to NVSL for speciation. |
| Strangles (Streptococcus equi) |
fee schedule |
Swab of exudate |
|
| Swine dysentery |
fee schedule |
Entire carcass, Colon |
Histopathology |
| Thromboembolic meningoencephalitis (Haemophilus somnus) |
fee schedule |
Affected organs, and 1/2 brain |
Histopathology, Serology |
| Trichomoniasis |
fee schedule |
Uterine exudate, preputial scrapings. |
Diamond's medium, Do not refrigerate or ship with ice packs |
| Tuberculosis |
fee schedule |
Culture not performed at WADDL, tissues sent to NVSL |
Histopathology |
| Tyzzer's Disease(Bacillus piliformis, now
Clostridium piliformis) |
fee schedule |
Culture not rewarding |
Histopathology, submit liver and gut in formalin |
| Ureaplasma |
fee schedule |
Vaginal swabs from affected cows |
Must reach laboratory within 4 days |
| Vibriosis |
fee schedule |
See
Campylobacter spp. |
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