Lecture 27: Highly Regulated Bacteria Flashcards
What is the causative agent of contagious equine metritis
Taylorella equigenitalis
Taylorella equigenitalis are gram __ rods
Negative
Taylorella equigenitalis is catalase, oxidase, and phosphatase ___
Positive
T or F: Taylorella equigenitalis grows on MacConkey agar
False
What is pathogenesis of contagious equine metritis
- Semen and pre-ejaculatory fluids contaminated
- Enter uterus and replicate
- Induce acute endometritis
- Mononuclear cells, plasma cells and neutrophils migrate to uterine lumen
- Produces profuse mucopurulent exudate
What are some clinical findings with contagious equine metritis in mares
- Copious mucopurulent vaginal discharge
- Temporary infertility
Contagious equine metritis can be spread to foals aka ___transmission
Vertical
What signs do stallions show with contagious equine metritis
Usually asymptomatic carriers
How is contagious equine metritis transmitted
- Venereal most common
- Infected semen
- Contaminated instructment
In untreated stallions T. Equigenitalis can persist for ___ to ___
Months to years
Foals born to infected mares with T. Equigenitalis may become ___
Long-term asymptomatic carriers
What samples do you use to dx contagious equine metritis in mares
Swabs from vaginal discharge, clittoral fossa, sinuses, cervix
What samples do you use to dx contagious equine metritis in stallions
Swab from Urethral fossa, sinus, distal urethra, external surface of penis, prepuce, pre-ejaculatory fluid
When taking samples for contagious equine metritis the horses can not be on systemic antibiotics for at least ___ days or topical antibiotics for __ days
7 days, 21 days
Sample from suspected contagious equine metritis should be transported in ___medium
Amines
What is the gold standard to dx contagious equine metritis
- Chocolate agar
- Timoney’s medium
What is tx for contagious equine metritis
- Wash external genital with 2% chlorine iodine
- Nitrofurazone
- Silver sulfadiazine
Repeat for 5 days
How do you prevent contagious equine metritis
- Strict import/export testing requirements
- Quarantine
- Hygienic measures
Where is brucellosis endemic
Yellowstone national park
Brucellosis is found in wild __ and ___
Bison and elk
Brucellosis is transmissible to __ and __ through contact with ___fetuses and infected carriers
Cattle and humans
Aborted fetuses
What is a select agent
Infectious agent with potential for use in bioterrorism
Brucellosis is a gram ___ aerobic coccobacilli
Negative
Pathogenic strains of brucellosis have __
LPS
Brucellosis is catalase, oxidase and urease ___ except B. Ovid which is oxidase and urease ___
Positive, negative
What are reservoirs for brucellosis
Various wild, feral and domestic animals
Brucellae are shed with __
Aborted fetuses
Brucellae infect mammary glands and therefore are fond in ___
Raw milk
What humans are at greatest risk for brucellosis
- Consume unpasteurized milk
- Direct contact with infected animals
- Lab or researchers
Animals are infected with brucellosis by
- Ingestion of contaminated fetal tissues and fluids
- Direct contact with MM
- Cut in the skin
- Contaminated equipment or feed
- Transplacental
What is pathogenesis for brucellosis
- Rapidly phagocytosed by leukocytes and macrophages
- Bacteria survive inside phagocytic cells
- Multiply in monocyte-macrophage cells
- Spread to reproductive organs
What is the causative agent of bovine brucellosis
B. Abortus
What does B. Abortus cause
Abortion, infertility, reduced milk yieldw
What is causative agent of canine brucellosis
B. Canis
What does B. Canis cause
Low virulence, abortions occasionally seen in kennel settings
What is the causative agent of swine brucellosis
B. Suis
What does B. Suis cause
Abortion, infertility, orchitis, arthritis
What is the causative agent of brucellosis in goat and sheep
B. Melitensis
What does B. Melitensis cause
Abortion, orchitis, arthritis
B. Melitensis is transmitted in ___ and ___
Milk products, fresh cheeses
What is the most dangerous zoonotic brucellosis spp
B. Melitensis
What is the causative agent of brucellosis in sheep
B. Ovis
What does B. Ovis cause
Abortion
What is gold standard to dx brucellosis
- Brucella milk ring test
What agar is used to culture brucellosis
Columbia agar supplemented with 5% serum
Tested for brucellosis, what test is this and what does it indicate
Brucella milk ring test
Blue rings are positive
What is tx for brucellosis
Infected animals can’t be cured- no tx available
How do you prevent brucellosis
- Vaccine
- Hygienic measures after abortion
- For vets: safe handling, PPE
What is the causative agent of Coxiellosis/ Q fever
Coxiella burnetii
Coxiella burnetii is ___ to environmental stress
Resistant
Coxiella burnetii is a zoonotic pathogen that infects __, __ and __
Goat, sheep and cattle
Coxiella burnetii is a obligate ___
Intracellular
What are the two antigenic phases of coxiellosis
- Phase 1- virulent
- Phase 2- a virulent
What are the two distinct cell types for Coxiella burnetii
- Small cell variant
- Large cell variant
What is small cell variant
Metabolically inactive form and environmentally stable
What is large cell variant
Metabolically active form
Coxiella burnetii is highly infectious a __ bacterium can cause infection in humans
Single
Coxiella burnetii has an ID50 <__
10
What is ID50
Number of organism required for infection in 50% of test subjects
Coxiella proliferates in the ___ of infected animals and causes ___
Uterus and mammary glands, causing late term abortion
How is coxiella transmitted
Exposure via inhalation of aerosols usually from parturient sheep, goats and cattle
Coxiella has high numbers in __ fluid
Amniotic
Coxiella can be excreted in __, ___ or ___
Milk, urine, feces
What is pathogenesis of coxiella
- Multiples in acidified phagolysosomes
- Localizes to genital tract and mammary glands
What is the main virulence factor for coxiella
Type 4 secretion system
What are some clinical findings of coxiella in goats
- Reproductive failure
- Abortions and stillbirths
- Infertility
- Weak newborns
- Low birth weights
What are som clinical findings of coxiella in ruminants
- Infertility
- Weak offspring
- Carrier state
What is the most sensitive and fast way to dx coxiellosis
PCR
What is tx for coxiellosis
Tetracycline prior to parturition
How do you prevent coxiellosis
- Good husbandry
- Proper disposal of birth products