Practical Applications in Veterinary Microbiology Flashcards
COLLECTION OF SPECIMENS
* Tissue blocks (approx. __ x __ x __ ___)
* Abscesses - scraping of abscess ____ or ___ itself plus ____.
* Exudates (?) - collect aseptically by _____ syringe.
* Swab collection: use a _____-transport system, e.g. _________
4, 4, 2, cm, wall, wall, pus, joint fluids, endocardial fluid, etc., sterile, swab, Culturette
All tissues, organs, pus, must be maintained ____ (_________ temperature)
during shipment or transport. What is the exception to this?
cold, refrigerator
An exception is feces.
When feces is refrigerated the _____ drops, which may
kill some bacteria, such as _________. Feces should be placed in transport media (such as ?), and can then be transported at ____ temperature.
pH, Salmonella, Cary-Blair, 10% suspension, room
The use of ______ technique in collecting specimens cannot be overemphasized. Many pathogenic bacteria are fastidious and slow
growing. ____________ of specimens makes interpretation of results
difficult and may result in failure to isolate the ____ etiologic agent
aseptic, Contamination, true
Enteric bacteria rapidly ________ throughout the tissues after death.
Therefore, collection of specimens from an animal that has been dead for
an ________ period of time are often difficult to interpret. However, bone ______ or a ____ from dead animals may yield the causative organism.
disseminate, unknown, marrow, rib
Consider anything unknown to be potentially zoonotic.
Anything that will not grow routinely on an aerobic culture, you will have to ask for an ___________ culture.
Culture can be carried out for organisms such as ?
anaerobic
Clostridia (form spores and are aerotolerant),
Fusobacterium, Bacteroides, Peptostreptococcus (very sensitive to air), and many others.
Samples contaminated with normal flora, such as intestinal contents,
oropharyngeal swabs or washings, and skin, are not suitable because ___________ sites all contain ________ bacteria. _______
conditions must be maintained. Therefore, ___ and ____ should be
collected with a needle and syringe and the ____ expelled.
contaminated, anaerobic, Anaerobic, pus, fluids, air
If samples cannot reach the laboratory within 30 min., they should be transported in ?
an anaerobic transport system.
If swabs must be used they should be submitted in commercial ________ transport swabs and maintained at ___°C, if not processed ___________.
anaerobic, 4, immediately
Large pieces of tissue (___ X __ X __ ___) will usually maintain an ______
environment, but should be kept at __°C and processed ______. Smaller pieces of tissue (or other specimens) should be
maintained in an ______ transport ____ until processing can be done
6, 6, 6, cm, anaerobic, 4, ASAP, anaerobic, bag
The success of culture for anaerobes is heavily dependent on
* 1. Samples taken from a _____ or ______ dead animal.
* 2. Excluding ____ from the samples in _____, and maintaining at __°C.
* 3. Culture under _______ conditions ________.
living, recently, air, transit, 4, anaerobic, ASAP
In the case of Mastitis
* Culture - milk samples can easily be contaminated by organisms from _________
the udder, so it is essential that a good collection technique is used (* _____ few
mls of milk expressed and the sample collected from _______ the udder*).
* The collection should be made into ____ _________-necked bottles. Milk samples should not be submitted in _______ containers or “_____-_____”.
outside, first, within, sterile, narrow, nonsterile, whirl-bags
Never submit liquid samples in containers that can leak.
Urinary Tract Infections
* Specimens (usually urine) can be collected by ___________, _______, or ______.
Of these methods _________ is least likely to result in contamination of the specimen
cystocentesis, catheter, voided, cystocentesis
There are strict rules to follow regarding urine specimens. All specimens should
be _____________ if they cannot be cultured immediately. The specimen must be
cultured __________ ____ _____, even if kept at __________ temperature.
refrigerated, within 6 hrs, refrigerator
In private practice, the specimen should be inoculated to a _____ agar and ________ agar plate as follows: ___ μl (for cystocentesis and catheter specimens) or ___ μl (voided specimens) from a calibrated loop should be used to inoculate urine to the plates. The loop should be drawn down the _____ of the plate from ___ to _____, and then the loop should be streaked ____ and ___
through the ____ streak. After ___ hrs incubation, the colonies are counted and
the number of ____/ml is estimated. Most urinary tract infections will have a
bacterial burden of _____ than ____ CFU/ml. However, from a cystocentesis, any
number _____ CFU/ml is significant. If in doubt, the culture should be ______.
blood, MacConkey, 10, 1, center, top, bottom, back, forth, initial, 24, CFU, greater, 10^5, >10^3, repeated
The most common bacteria isolated from the urinary tract are ?
enterics (e.g. E. coli, enterococci, Proteus), as well as Pseudomonas, staphylococci, and occasionally yeasts. Anaerobes and filamentous fungi are rare.
Sterile loop and go through area a few times, streaking away from it. Do that 4 times.
Semi quantitative result
1-4, recorded in quadarant 1, etc.
Uterine Infections
* Abortions - the investigation should be comprehensive for all bacteria and fungi known to cause abortion in a particular animal species.
* Examples of bacterium that cause abortions are:
- hard to grow
- culture not very useful for most abortions unless ______ has been infected.
- fungal abortion –> __________is very evident
* Both maternal and fetal samples should be submitted when possible.
____ and __________-fixed samples for histopathology are essential if
ubiquitous organisms, such as Aspergillus fumigatus are to be identified.
Campylobacter sp., Brucella sp., Leptospira sp., H. somni, mycoplasmas, Listeria sp., A. pyogenes, Aspergillus sp.,
Zygomycetes and others.
fetus, histopath, Fresh, formalin
Preferred samples (fetus)
* ______ plus _________ (fixed and fresh) or uterine ______ (fresh).
** Fetal _______ contents (fresh), plus fetal lung, liver, kidney, and spleen (fixed and fresh).
* Midstream urine for ________: This sample needs to be centrifuged and examined by _____ microscopy immediately,
diluted and cultured in appropriate media, and/or blood collected for serology. Contact reference lab for details.
* Clotted blood samples for serology, at the time of abortion and 2 weeks later, should be sent to your Regional Laboratory, particularly for difficult to isolate agents such as Leptospira.
Placenta, cotyledons, discharge, stomach, leptospirosis, darkfield
Infertility
* Specimens:
* Uterine ______ or vaginal _____.
* ______ washings (_______) or ____. Submit urine (as above) if leptospirosis is suspected.
* Unless otherwise directed, examinations should cover:
* Cattle: Campylobacter fetus, and opportunistic aerobes (e.g. Haemophilus
somnus). A special transport medium is recommended for C. fetus.
Culture should be carried out within 4-6 hours of collection.
*** Mares: Coliforms (especially Klebsiella), other opportunist aerobes (such
as streptococci, fungi, and Taylorella equigenitalis).
* The laboratory should be notified if specimens are to be collected and
submitted for an infertility investigation. This will allow:
* Special _____ media to be prepared.
* Advice on the use of transport media for ?
discharge, mucus, Preputial, preferred, semen, selective, C. fetus.
often times happens in mares, often due to streptococci, klebsiella sometimes
go in with protected brush and ?
Blood Cultures
* The skin needs to be _________ and ______ prepped with antiseptic, such as ______
and ______. Once prepped, the skin should not be touched with the fingers.
** ____ blood samples should be collected, approximately __ hour apart*. The reason for this is two-fold: 1) the animal may not always be _____ and may only _____ be
shedding organisms into the blood; 2) to confirm any isolate obtained from ___ bottle is not a contaminant.
* Normally samples will be inoculated into aerobic and anaerobic bottles. However, lessthan 1% of blood isolates are anaerobic
and many labs have dispensed with doing
routine anaerobic cultures. There are two size blood culture bottles: adult and pediatric. Adult size requires 5-10 mls/bottle; the pediatric size requires about 1.5 ml/bottle. The pediatric size is useful for small animals.
* The bottles are examined for turbidity and gram-stained and cultured onto chocolate
agar. If there is no turbidity, blind subcultures are done at 48 hours and 7 days before
being discarded.
* Alternatively, lysis/centrifugation systems may be used. In this system the blood is added
to a tube containing an agent to lyse the red blood cells. The tube is then centrifuged
and the pellet of bacteria is resuspended and inoculated on to agar for culture. This
system has shown to be more sensitive, but isolates more contaminants, than culture
bottles. The ideal is to use both systems
shaved, aseptically, betadine, alcohol, Three, 1, septicemic, periodically, one
Johne’s Disease
* Cultural techniques may not be available, but specimens can be examined by the ____-_____ staining of smears. See PCR under “Non- culture diagnostic methods”.
* Specimens: Live animal - Scraping of ______ mucosa (detects ______ cases)
* Dead animal - _____ valve or other affected areas of ______ tract, ______ lymph nodes.
acid-fast, rectal, advanced, ileocecal, alimentary, mesenteric
Diarrhea/Dysentery
* _______, ______, and possibly _____ should be considered prime candidates for bacterial ______.
* Other possible agents are _____, yeasts, and agents that form toxins in foods
(e.g. S. aureus, Clostridium, and Bacillus; Shigella may cause gastroenteritis only in
primates.
* Enterotoxigenic __.___ is probably only of significance in neonates. However, E. coli
0157:H7 (causes bloody diarrhea and hemolytic uremia syndrome in humans) may be significant in adult cattle. The 0157:H7 strain can be screened for by failure to ferment sorbitol on sorbitol-MacConkey agar.
Campylobacter, Salmonella, Yersinia, gastroenteritis, Aeromonas, E. coli
