Urogenital Pathogens Flashcards
What are the two most common infections of the urinary tract?
Pyelonephritis, Cystitis
What are the four most common Gram-positive pathogens of the urinary tract?
Staphylococcus, Streptococcus, Enterococcus, Corynebacterium
What are the most common Gram-negative pathogens of the urinary tract?
E. coli spp., Proteus spp., Klebsiella spp., Pseudomonas spp., Enterobacter spp.
How does cystitis occur?
Ascending urethra leads to a bladder infection (cystitis)
How does pyelonephritis occur?
Ascending ureter leads to a kidney infection (pyelonephritis)
What are three bacterial factors/virulence mechanisms used to accomplish infection?
- Attachment and colonization of mucosa of urethral orifice
- Transport up urethra
- Attachment of uroepithelium (fimbriae)
True or False: Female dogs should be catheterized if cystocentesis sample is not possible
False
How should you prepare a urine sample for testing?
The urine sample should be refrigerated and cultured within 6 hours
Special tubes with preservatives can maintain types and numbers of bacteria for up to 72 hours with refrigeration.
What are four general characteristics of Corynebacterium spp.?
Gram-positive, Facultative anaerobe, Obligate symbiotic bacteria (essential for host survival), Opportunistic pathogen
Which host is Corynebacterium spp. specific to?
Cattle
What two conditions does Corynebacterium spp. cause in cattle?
Urinary tract infections (especially older cows), Pyelonephritis
What is the order of virulence of Corynebacterium pilosum, Corynebacterium cystitidis, and Corynebacterium renale from most to least virulent?
C. cystitidis (most virulent) > C. renale > C. pilosum (least virulent)
Where does Corynebacterium spp. appear naturally in cattle?
Normal microbiota of the lower urogenital tract, Normal microbiota of prepuce of bulls
How many total cases of Corynebacterium spp. infections are fatal?
1/4-1/3 of infections
What are four clinical signs of Corynebacterium spp. infection?
Cystitis (frequent urination, straining), Polynephritis, Hematuria (from kidney lesions), Lack of kidney lobation (felt on rectal palpation)
What makes Corynebacterium spp. good at attacking the urogenital tract?
- Virulent Corynebacterium strains have fimbriae, which mediate binding to urethral epithelium and colonization.
- It makes urease which causes production of ammonia therefore mucosal inflammation
How can you diagnose Corynebacterium spp. infections?
Do a culture and isolation on a sterile urine sample
How are Corynebacterium spp. infections treated in the acute stage?
Antibiotics. These are only useful in acute stage because later it is more difficult to reach bacteria in pus
How are Corynebacterium spp. infections treated in the chronic stage?
You cannot treat in the chronic stage because kidneys are irreversibly damaged.
What is the most common bacterial cause of canine pyometra?
E. coli
What makes dogs susceptible to a pyometra?
In metestrus, there are high progesterone levels and decreased uterine defense mechanisms
What are the most common Gram-negative pathogens of the reproductive tract?
Taylorella equigenetalis, Brucella, Leptospira, Campylobacter
How are venereal diseases spread?
Sexual transmission
Examples include Taylorella equigenitalis in horses, Campylobacter fetus venerealis in cattle, Leptospira hardjo in cattle, Brucella in sheep.
What is the most common bacterial cause for equine endometriosis?
Streptococcus equi zooepidemicus
Which three bacterial genera are the most common causes of metritis in cattle?
Brucella, Leptospira, Campylobacter
What are four clinical manifestations of Streptococcus equi zooepidemicus?
- Endometritis
- Infectious abortion and placentitis
- Pneumonia
- Shipping fever
How can you prevent Streptococcus equi zooepidemicus?
It is very difficult as it is an opportunistic pathogen. Goal is to reduce stress.
What are three characteristics of Taylorella equigenitalis?
Gram-negative rod with capsule, Facultative anaerobe, Obligate symbiotic
What animal and area of the body is Taylorella equigenitalis selective for?
It is selective for the horse genital tract
What disease can Taylorella equigenitalis infection cause in horses?
Contagious equine metritis (CEM) which is a reportable venereal disease
True or False: Contagious equine metritis (CEM) is reportable
True
How can you diagnose CEM?
- Bacteriological isolation is gold standard
- PCR testing is more sensitive
- No reliable serologic test available
How can you treat CEM?
It can be treated with a combo of topical and systemic antibiotics, but it’s not always effective
Which of these venereal diseases are reportable?
All are reportable
Which of these venereal diseases are zoonotic?
Brucellosis, campylobacteriosis, and leptospirosis are zoonotic
What are three general characteristics of Brucella?
Gram-negative, Obligate aerobe (most species), No capsule and non-motile with no flagella
True or False: Brucellosis is zoonotic
True
What are the three most common pathogenic species of Brucella?
Brucella abortus, Brucella melitensis, and Brucella canis
True or False: Cats can get brucellosis
False
Which bacterial species commonly causes brucellosis in cattle?
Brucella abortus. It is referred to as Bang’s disease
What is the treatment and prevention method for brucellosis?
There is no treatment in any species. Vaccination for brucellosis is not permitted in Canada
What is the pathogenesis of brucellosis?
- Brucella invades through the oral mucosa (Brucella canis) or through ingestion of aborted fetuses (Brucella abortus)
- Brucella invades host cells including professional phagocytes and then survive and replicate within them.
What is the main clinical sign for Brucella canis infections in dogs?
Mostly reproductive disturbances (abortions or testicular abnormalities)
How can you diagnose Brucella canis in dogs?
- Culture (gold standard)
- Serologic testing (most common but many false positives)
What are three general characteristics of Leptospira?
Gram-negative, Obligate aerobe, Spiral shaped spirochete
What host specificity does Leptospira have?
None really, it’s not very host specific, but there usually is one host that acts as reservoir
How is Leptospira transmitted?
Direct through mucosa (oral, urine, venereal), Indirect (contaminated food or water)
What is the pathogenesis of Leptospira?
- Penetrates intact mucous membranes (mouth, nose and eyes)
- Replicates in kidney, liver, spleen, CNS, eyes and genital tract
- Persists in kidney and can be shed in urine for weeks
What are the three clinical signs of leptospirosis?
I. Peracute phase: Leptospiremia is present, leading to sudden death.
II. Acute leptospirosis: Hepatic and renal failure do not have time to develop (fever, shivering, muscle weakness, vomiting, dehydration and shock, and tachypnea)
III. Subacute leptospirosis: Intrahepatic cholestasis and necrosis of the liver may result in acholic feces and renal failure.
How can you prevent leptospirosis?
- Vaccination (except in horses)
- Limited exposure to stagnant water and to potential carriers
How can you diagnose leptospirosis?
- Culture (gold standard but sensitivity is low)
- Immunofluorescence (higher sensitivity)
- Diagnosis is mostly based on ELISA and MAT
What can leptospirosis cause in horses?
Abortions (horses are incidental hosts for this disease so usually serious disease does not occur)
Which Leptospira species is host specific to cattle?
Leptospira hardjo
What does Leptospira hardjo cause in cattle?
Sporadic abortions and infertility
What clinical signs does Leptospira pomona cause in cattle?
Icterus, Hemoglobinemia, Hemoglobinuria
Campylobacter is Gram-_____________
Negative
What does Campylobacter cause in cattle?
Enzootic sterility
How is Campylobacter fetus venerealis transmitted?
It is transmitted venereally from bulls (carriers) to cows
Where does Campylobacter fetus venerealis replicate?
In the vagina (25% of cases cause vaginitis)
How is Campylobacter fetus fetus transmitted?
Oral transmission (not venereal transmission)
Where does Campylobacter fetus fetus replicate?
In the GI tract of cattle and sheep.
What can Campylobacter fetus fetus cause in cattle?
Bacteremia (occasionally causes abortions)
True or False: Listeria monocytogenes is host specific
False
Which body system does Listeria monocytogenes target?
The central nervous system
What animals can Listeria monocytogenes affect?
Cattle, sheep, goats, rodents and humans
What main clinical sign does Listeria monocytogenes cause?
Abortion in 2nd half of pregnancy in most mammals
