Bacti Final Exam
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- T or F: Transition Bacteria are true bacteria.
- True
- What four characteristics do transition bacteria share with fungi?
-
Extensive filamentation
Branching
Production of ariel hyphae
Tenacious colonies -
How do transition bacteria gram stain?
Are they acid fast? -
Gram positive
Yes, they're acid fast. - Are transition bacteria motile?
- Nope
- What is the common condition caused by Actinomyces bovis?
- Lumpy Jaw in cattle
- What kind of lesions are caused by A. bovis in Lumpy Jaw
- Necrotic lesions with pus
- Explain the procedure for examination of pus in a suspected A. bovis infection.
- Wash a small amount of pus to expose sulfur granules. Transfer the granules to a slide and treat with 10% NaOH. Crush the granules by applying gentle pressure to a coverslip.
- What causes poll evil and fistulous withers in horses?
- Actinomyces bovis
- How is pulmonary actinomycosis or visceral/abdominal actinomycosis contracted?
- By aspirating infectious material or swallowing it.
- What causes periodontal disease?
- Actinomyces viscosus. Gingivitis which leads to inflammation and vecrosis of the gingival tissue with the eventual loss of teeth.
- What causes canine pulmonary actinomycosis?
- Actinomyces viscosus
- Describe canine pulmonary actinomycosis
- This is caused by A. viscosus. The disease involves pyothorax with granulomatous lesions of thoracic tissues and accumulation of pleural and pericardial fluid containing sulfur granules.
- What is the best way to demonstrate presence of A. viscosus?
- Culture large amounts of purulent exudate.
- Describe the disease associated with A. viscosus common in hunting dogs
- A. viscosus can cause a skin disease that involves localized granulomatous abscess formation. Some sort of trauma is sustained and A. viscosus is spread from the oral cavity through licking to set up an infection.
- T or F: Actinomyces suis is the only species of Actinomyces that does NOT produce sulfur granules
- False
-
Which of the following does Actinomyces suis generally infect:
A. Lungs
B. Skin
C. Mammary glands
D. Nasal cavity - C. Mammary glands (with pus discarge, granuloma and sulfur granules)
- T or F: Nocardia asteroides are commensals in animals
- False - they are inhabitants of soil
- Which transition bacteria causes signs similar to distemper in dogs?
- Nocardia asteroides
- Describe the colony morphology of Nocardia asteroides
- Nocardia asteroides develops slowly on BA, are non-hemolytic and adhere to the agar. Colonies often develop a yellow-orange pigment. In mixed cultures of clinical material, other rapidly growing bacteria can easily obscure small colonies of Nocardia
- Ho can Nocardia be distinguished from mycobacteria?
- Nocardia has mycelial elements.
- T or F: Nocardia asteroides causes acute or chronic bovine mastitis.
- True
- Name two ways animals are infected with Nocardia and the type of disease each method causes
-
1. Inhalation of organisms results in the pulmonary form of the disease
2. Contamination of skin wounds results in subcutaneous abscesses - What might canine pulmonary nocardiosis be confused with?
- Pulmonary actinomycosis caused by A. viscosus.
- What causes lesions (observed at necropsy) described as "tomato soup?"
- Nocardia asteroides (and possibly Actinomyces viscosus?)
- Name three ways to distinguish Actinomyces and Nocardia apart
-
1. A. viscosus will not grow on Saubouraud agar while Nocardia will
2. Actinomyces and Nocardia infections are often associated with foreign bodies (I'm not sure how this is supposed to help in telling them apart...)
3. Nocardia infections are more often seen in immunocompromised hosts. - T or F: Draining an abscess is a bad idea...this can lead to spread of the infection.
- False. Bacteria are ina stationary phase when packed into a pus-filled abscess. Draining allows the bacteria to start growing again and antibiotics are effective on growing cells
- What causes dermatophilosis in domestic animals?
- Dermatophilus congolensis
- Describe the two morphologic forms of D. congolensis
-
1. Nonmotile, filamentous hyphae
2. Motile zoospores - What is the infectious form of D. congolensis? How does it become infectious?
- The motile zoospore. It's released when infected skin becomes wet.
- T or F: Dermatophilosis is commonly seen in pigs and horses, but is rare in cattle and cats.
- False. It is commonly seen in cattle and sheep, sometimes horses, and is rare in dogs, cats and pigs.
- In regards to Dermatophilosis, what are the two conditions called in sheep?
- "lumpy wool" and "strawberry foot rot"
-
How is dermatophilosis transmitted?
A. Dipping sheep
B. Trees and brush in the enclosure
C. Biting insects
D. Direct contact
E. All of the above - E. All of the above
- Name four things that breach the protection of the skin and contribute to Dermatophilosis.
-
1. Prolonged wetting by rain
2. High humidity
3. High temperature
4. Parasites - Describe how zoospores penetrate the skin and cause infection in dermatophiolosis.
- They are chemotactically responsive to C02 diffusing out of skin. They germinate and a hyphal branch penetrates the epidermis. Hyphae branch out laterally and invade hair or wool follicles. the dermis is not invaded. Neutrophils collect beneath the infected epidermis and a serous exudate accumulates and leaks to the surface. A new layer of epidermis is formed as the older layer above deteriorates, which forms a thick scab. Infection of newly forming epidermis occurs from organisms already in the follicular sheath.
- What drug combination has been shown to be effective in treating dermatophilosis?
- A single large dose of penicillin/streptomycin.
- T or F: Streptomyces are common animal pathogens
- False - they are very rare as pathogens in animals.
- What causes soil to smell like damp earth?
- The production of a number of volatile substances by Streptomyces.
- T or F: Streptomyces are strict aerobes.
- True
- What genus of bacteria is the largest source of naturally occurring antibiotics?
- Streptomyces
-
Match:
1. Nystatin
2. Tetracycline
3. Amphotericin B
4. Erythromycin
5. Streptomycin
a. S. aureofaciens
b. S. erythreus
c. S. nouresii
d. S. nodosus
e. S. griseus -
1 - c
2 - a
3 - d
4 - b
5 - e -
Mech of action:
Erythromycin - Inhibit 50S ribosome function
-
Mech. of action:
Streptomycin - Inhibit 30S ribosome function
-
Mech. of action:
Tetracycline - Inhibit binding of amino-acyl RNAs to ribosomes
-
Mech. of action:
Amphotericin B - Inactivate membranes containing sterols
-
Mech. of action:
Nystatin - Inactivate membranes containing sterols
- T or F: Facultative intracellular parasites may multiply in environments totally devoid of host cells.
- True
-
A. Obligate intracellular parasite
B. Facultative intracellular parasite
Choose A or B for each of the following:
1. Chlamydia
2. Brucellosis
3. tuberculosis
4. Rickettsia
5. Johne's disease -
1. A
2. B
3. B
4. A
5. B - Name four steps to phagocytosis/endocytosis
-
1. Recognition and adhesion - to professional or non-professional phagocytes. Generally receptor-mediated.
2. Endocytosis: generation of phagocytic vacuole (endosome or phagosome)
3. Phagosome-Lysosome fusion
4. Degranulation and killing -
Choose one word in the parenthesis:
The respiratory burst is an oxygen (independent/dependent) mechanism. - Dependent
-
Select the oxygen independent killing mechanisms (more than one answer may be correct):
A. Respiratory burst
B. Proteases
C. Defensins - B & C are oxygen independent.
- What five parts come together to form an activated NADPH oxidase complex?
- Fp, P22, Gp91, p67 & p47
-
Most animals with chronic granulomatous disease have mutations in:
A. p47
B. p67
C. Fp
D. Gp91
E. P22 - A. p47
- What gets phosphorylated several times in an active NADPH oxidase complex?
- p47
-
Starting with a Superoxide molecule (from NADPH Oxidase), match each Reactive Oxygen Species with the intermediate(s) it needs to get there.
1. Hydroxyl Radical
2. Hypochlorite
3. Hydrogen Peroxide
4. Singlet Oxygen
A -
1 - C
2 - B
3 - D
4 - A -
Which of the following are not vector-borne?
A. Ehrlichia
B. Coxiella
C. Rochalimaea
D. Rickettsia - B. Coxiella - it is spread by direct contact (inhalation), usually in aerosol form
- Ehrlichia is an (obligate intracellular/obligate extracellular) parasite.
- Obligate intracellular
-
Fill in the blank:
Ehrlichia live inside cytoplasmic vacuoles, where they divide by binary fission to form clusters of bacteria called __________. - morulae
- In what vector do many Ehrlichia species spend part of their normal life cycle?
- An arthropod host, most commonly a hard-shell tick.
- Rickettsia have a functional cell membrane impermeable to __________ and inorganic ______________.
-
sucrose
electrolytes - T or F: LPS in Rickettsia is not toxic as in E. coli
- True - the Rickettsia have a modified LPS that is not toxic
- The Rickettsia divide by _____________.
- binary fission
- Are Rickettsia ever found outside a cell?
- Yes, but only briefly. They are released following host cell lysis.
- How do Rickettsia enter non-professional phagocytes?
- By direct penetration or by phagocytosis
- Once in a phagolysosome, the Rickettsia penetrate the phagosome membrane and are seen where?
- Free in the cytoplasm
- T or F: The Rickettsia are not very good at passing through cell membranes.
- False
- T or F: Rickettsia can grow without living cells
- False
- What is the major substrate for energy (ATP) production in Rickettsiae?
- glutamate
- What is the second-most important ATP-yielding substrate?
- glutamine
- T or F: Rickettsia can exchange internal ADP for host ATP
- True
- What are three end products of metabolism in Rickettsia?
- NH4, CO2, and aspartate
-
What causes:
Canine Salmon Poisioning - Neorickettsia helminthoeca
-
What causes:
Q-Fever - Coxiella burnettii
-
What causes:
Canine ehrlichiosis
What carries the organism? -
Ehrlichia canis
Brown dog tick -
What causes:
Rocky Mountain Spotted Fever - R. rickettsii
-
What causes:
Scrub Typhus -
R. tsutsugamushi
("Chigger") -
What causes:
Brill-Zinsser disease - Rickettsia prowazekii
-
What causes:
Endemic Typhus - R. typhi or R. mooseri
-
What causes:
Equine ehrlichiosis - Ehrlichia equi
-
What causes:
Potomac horse fever - Ehrlichia ristcii
-
What causes:
Anaplasmosis (4 species) -
A. marginale
A. caudatum
A. centrale
A. ovis - T or F: Rocky Mountain Spotted Fever (caused by what?) is a disease of mainly humans.
- True. RMSF is caused by R. rickettsii
- What is the target cell of Rickettsia?
- Cells other than RBC's - primarily endothelium
- How is epidemic Typhus spread?
-
Human --> Louse --> Human
Tick --> Human
Tick --> Dog - What antibiotics work against Rickettsia?
- Intracellular active antibiotics - tetracycline (doxcycline)
- What is the target cell of Ehrlichia?
- WBC's
-
What are the clinical signs with Canine Ehrlichia?
What is another name for this disease? -
Tropical Canine Pancytopenia
Pancytopenia (esp. thrombocytopenia), epistaxis, hypergammaglobinemia, lymphadenopathy, increased RBC sedimentation rate - What time of the year does Potomac Horse Fever occur?
- Summer months
- What are the clinical symptoms of Potomac Horse Fever?
- anorexia, fever, depression, explosive diarrhea, leukopenia, dehydration and terminal shock
- Ehrlichia risticii is antigenically related to ___________ and __________.
- E. sennetsu and Neorickettsia helminthoeca
- T or F: E. risticii has been shown to be present in trematodes infecting fresh water snails
- True
- T or F: New information suggests that horses contract Potommac Horse Fever through biting arthropods such as ticks
- False - This is the old view. New information suggests that horses may become infected through ingesting of infected trematodes of fresh water snails
- What are the two forms of Human Ehrlichiosis and what are their causative agents?
-
Monocytic: Ehrlichia chaffeensis
Granulocytic: Anaplasma phagocytophilia - Name five ways Coxiella burnetti differs from Rickettsia.
-
1. Arthropod vector not necessary
2. Usually stable outside host cells
3. No rash
4. Infects fixed macrophages rather than endothelia
5. Grows within phagolysosomes as well as free in the cytoplasm -
What is the common name of the zoonotic human disease caused by Coxiella burnettii and what are it's symptoms?
Who is at risk for contracting this disease? -
Q-fever
Pneumonia, acute illness: headache, fever, dry cough, chest pain, muscle aches, liver inflammation,
Veterinarians and slaughterhouse workers at risk -
What is the target cell of Anaplasma marginale?
How is this related to the symptoms of infection? - RBC - symptoms associated with severe anemia, depression, inapetance, fever, dehydration, may die from hypoxia when handled.
- Is anaplasmosis a disease of younger or older animals?
- Older
-
What are two symptoms of Hemobartonellosis in cats?
What other diseases are usually associated with Hemobartonellosis? -
hemolytic anemia and fever
Cats showing signs usually are concurrently infected with feline leukemia or other immunosuppressive diseases. - How are anaplasmosis and hemobartonellosis diagnosed?
- Find organisms in blood smear stained with Giemsa stain.
- What disease is Eperythrozoonosis essentially identical to?
- Hemobartonellosis
- Name five species of Eperythrozoan and some symptoms they cause.
-
E. coccoides, E. suis, E. ovis, E. felis, E. wenyoni
Anemia, fever, weak piglets, organisms on RBC or free in plasma - How does one encounter Chlamydia?
- Direct contact with infectious agent - no arthropod vector necessary
- How does the life cycle of Chlamydia differ from Rickettsia?
-
Chlamydia has two life cycle forms:
Elementary bodies which are infective and reticulate or initial bodies which are non-infectious -
With Chlamydia, which of these would be found outside a host cell?
A. Elementary bodies
B. Reticulate bodies - A. Elementary bodies - these are the infectious forms and can survive extracellularly to infect new hosts
- What cell types does Chlamydia have an affinity for?
- Epithelial cells of mucous membranes and phagocytes
- T or F: Chlamydia is found free within the cytoplasm, as in Rickettsia
- False
- Where do the reticulate bodies of Chlamydia develop?
- Within endosomes - Chlamydia is not free in the cytoplasm
- Name three virulence factors of Chlamydia.
-
1. Attach to sialic acid receptors of eye, throat or genitalia
2. Persistance at body sites that are immunologically privledged
3. Unique cell wall - T or F: Birds with psittacosis will always show signs
- False - many have latent infections with no clinical signs
- List some symptoms of avian psittacosis.
- Anorexia, yellowish-green diarrheal feces (stains on bird), mucopurulent nasal discharge, eyes pasted shut with discharge, emaciated and dehydrated
- What is a frequent source of psittacosis infection in a flock (esp. for younger birds)?
- Birds that have recovered from psittacosis which continue to shed organisms and contaminate the environment for a long time.
- What other problems can be caused by psittacosis in mammals?
-
1. Abortion (sheep, cattle)
2. Encephalomyelitis (cattle, dogs)
3. Pneumonia (cats, dogs, mice, horses, sheep, goats, cattle)
4. Polyarthritis (sheep, cattle, horses)
5. Conjunctivitis (guinea pigs, hamsters, sheep)
6. Enteritis (cattle, hare, muskrat) -
What are three symptoms of psittacosis infection in humans?
What other disease is almost indistinguishable from human psittacosis?
In recent years, where have most human psittacosis cases come from? -
Fever, headache and pneumonia
Viral pneumonia
Most recent cases from handling infected turkeys - What is the treatment of choice for psittacosis? What drug is ineffective?
- Chlorotetracycline is the best drug to use. Penicillin is ineffective.
-
What human disease is characterized by keratoconjunctivitis, corneal scarring, blindness and occurs in warm climates in countries with poor hygiene?
What is the etilogical agent of this disease? -
Trachoma - an ancient disease
C. trachomatis, serotypes A, B and C -
What is the most common human STD caused by?
What kind of infections occur in men? Women? -
C. trachomatis (serotypes Ba, D-K)
Male: non-gonococcal urethritis
Female: cervicitis, salpingitis, PID -
What human disease is characterized by:
low grade fever, malaise, lymphadenopathy, anorexia, weight loss, nausea, vomiting, sore throat, splenomegaly, occasional papular eruptions, erythema, thrombocytopenia, purpura. - Cat Scratch fever - Bartonella
- What does Arcanobacterium pyogenes cause in sheep and pigs (one disease specifically in boars)?
-
Sheep - with Fusobacterium necrophorum, causes heel abscesses
Pigs - causes jaw abscesses
Boars - associated with orchitis and epididymitis - What transition bacteria produces the hemolytic exotoxin pyolysin (PLO)?
- A. pyogenes
- Name four groups of transition bacteria
-
Actinomyces
Nocardia
Dermatophilus
Streptomyces - Why do obligate or strict anaerobes not tolerate oxygen?
- Oxygen is inherently unstable. Strict anaerobes lack superoxide dismutase, catalase, and peroxidases to deal with reactive oxygen species.
- Give some examples of reducing agents and what these agents do in an anaerobic medium.
-
Sulfhydryl compunds - thioglycolate
Metallic iron
They absorb oxygen and reduce H2O2. - T or F: The higher the Eh, the better the reducing environment.
- False - The LOWER the Eh, the better the reducing environment.
- What prevents the growth of anaerobes, A. increasing p[O2] (increasing redox potential - more positive value), or B. decreasing p[O2] (decreasing redox postential - more negative value
- A.
- T or F: Methylene blue turns colorless as the dye becomes oxidized.
- False - the dye turns colorless when reduced. This is a way to measure the redox potential electrochemically.
- As Eh falls below ______mV, anaerobes can grow.
- +150
- List four conditions that can lead to lowered Eh values.
-
1. Loss of vascular supply to tissues
2. Trauma, foreign bodies, pressure from casts
3. Acid production by aerobes and facultative anaerobes
4. Tissue necrosis from trauma, infection or surgical manipulation. - List some aerotolerant anaerobic bacteria.
-
Gram positive non-sporeforming bacilli
Actinomyces bovis
Actinomyces viscosus
Actinomyces suis - List some obligate anaerobes of veterinary importantce.
-
Gram negative, non-sporeforming bacilli
Bacteroides melanigenicus, Bacteroides nodosus, Bacteroides fragilis
Bacteroides nodosus, Fusobacterium necrophorum - Name some of the gram positive sporeforming bacilli anaerobes.
-
Clostridium, including:
-perfringens
-hemolyticum
-novyi
-chauvoei
-septicum
-colinum
-tetani
-botulinum - T or F: Most anaerobic infections are mixed infections
- True - usually the aerobic bacteria cause damage first, setting up the right conditions for an anaerobic infection
- Do aerobes or anaerobes make up the majority of normal flora?
- Anaerobes
- Which Clostridia is non-motile?
- C. perfringens
- What is the habitat of the Clostridia?
- Free-living, widely distributed in the soil.
- Which Clostridia group is not responsible for any animal diseases?
- Group 1
- Which Clostridia groups hydrolyze gelatin?
- Groups 2 and 4
- Which Clostridia groups have teminal spores?
- Groups 3 & 4
- What Clostridium species of veterinary importance is in Group 4 (terminal spores, gelatin hydrolyzed)?
- C. tetani
-
What causes "blackleg" in ruminants? (Also known as gas gangrene or myositis)
How is the organism encountered? -
Clostridium chauvoei
-Normal inhabitant of the soil
-Ingestion of the organism or its spores
-Entry into deep trauma or puncture wounds
-Sometimes no external wounds, entry unclear
-Entry as teeth are lost in young cattle - Describe the pathogenesis of blackleg in ruminants.
- Organism is carried from intestine via lymphatics to the blood and is seeded into liver and muscle. It remains dormant until the tissue is damaged from trauma or other infection. Starts producing toxins. Anaerobiosis is required for spore germination. This disease usually affects the most robust young animals because of aggressive behavior (butting, etc.)
- What causes the majority of tissue damage in Clostridium infections?
- alpha-toxin
- What are the signs of malignant edema and what is the etiologic agent?
-
Clostridium septicum causes malignant edema.
-Large, expanding swellings, edema, fever and death in a few hours or in 1-2 days.
-Tissues filled with large amounts of gelatinous exudate (dissolved muscle and CT)
-no gas produced, generally - What disease does Clostridium hemolyticum cause? What other agent is implicated in this disease?
-
Red Water disease of cattle - hemoglobinuria
Disease associated with liver flukes causeing infarcts which allow for anaerobiosis, then toxin production locally which spreads systemically. - What are the two types of Clostridium novyi and what do they cause?
-
Type A - gas gangrene in man, cattle sheep and "big head" in rams
Type B - Black disease in sheep and cattle -
What else is Black Disease known as?
What infection is it very similar to?
What causes the damage? -
Necrotic hepatitis
Similar to C. hemolyticum infections, but no liver flukes
Dame is done by lecithinase, a toxin - What causes Ulcerative Enteritis or Quail Disease?
- Clostridium colinum
- What causes inactivity, sluggishness, anorexia, inability to move in later stages, death occurs in 1-2 days, with diffuse necrosis of the liver?
- Clostridium colinum - ulcerative enteritis or Quail Disease
-
What does Clostridium spiroforme cause?
What are the symptoms? -
Entertoxemia of rabbits and lab rodents.
Diarrhea w/perianal staining, massively dialated cecum, necrotic villous epithelium, prominent infiltrate of inflammatory cells in lamina propria.
Caused by Iota toxin -
What is Tyzzer's disease caused by?
Who does it affect? -
Clostridium piliformis
Necrotizing helpatitis and hemorrhagic enteritis in domestic, lab and wild animals. Generally high mortality. - How is Tyzzers disease transmitted?
- Ingestion of spores in feces contaminated with Clostridium piliformis.
- What are the clinical signs associated with Tyzzer's disease?
- Acute onset, profuse diarrhea, melena, anal bleeding, depression, anorexia, rough hair coat
-
What does Clostridium difficile cause?
What species does it affect? - Pseudomembranous enterocolitis of lab animals, esp. guinea pigs and hamsters on anibiotics that develop an overgrowth of this organism which produces toxin.
- Where is Clostridium perfringens found?
-
Everywhere! Air, soil, dust, manure, waters of streams, lakes, rivers, vegetables, milk, cheese, canned food, fresh meat, seafood, mollusks, constantly present in human and animal intestinal contents.
Type A most common, Type B, C, D, and E less common in intestinal tracts. - Describe the alpha toxin produced by C. perfringins.
- -Alpha - principal lethal toxin produced in varying amounts by all C.perfringens - Phospholipase C
- Describe the beta toxing produced by C. perfringins
- -Beta - produced by types B, C & F, heat labile, produces profuse diarrhea, causes inflammation of the intestine and loss of the mucosa and causes enteritis in cattle, sheep and humans
- Describe the Theta toxin produced by Clostridium perfringens.
- Theta is a lethal, hemolytic necrotizing toxin produced by strains A, B, C, D, E
- Describe the Iota toxin produced by Clostridium perfringens.
- Iota is produced only by Strain E and like Epsilon toxin, is synthesized as a protoxin and activated by proteolysis
- Describe the kappa, lambda, and Mu toxins produced by Clostridium perfringens.
-
Kappa - collagenase
Lambda - gelatinase (denatured collagen collagenase)
Mu - hyaluronidase - What causes "yellow lamb disease" (enterotoxemia in nursing lambs and horses) and what are its clinical signs?
-
C. perfringens Type A
Signs are depression, pale mucous membranes, anemia, icterus, and hemoglobinuria, death within 6-12 hours of symptoms - What does C. perfringens Type B cause?
- Lamb desentery (not in US or Austrailia) - infection occurs in the first few days of life, transmitted from dam or soil, Beta toxin - hemorrhagic ulceration of small intestine.
- What does C. perfringens Type C cause?
- hemorrhagic and necrotic enteritis in many species (mainly in England)
- What percent of Clostridial wound infections are caused by C. perfringens? What is the name of this infection?
- 90% are caused by C. perfringens. Called Clostridial Anaerobic Cellulitis
- Which Clostridial species are non-invasive>
- C. tetani and C. botulinum
- T or F: C. perfringens can cause food borne infection in humans.
- True - This causes diarrhea and entertoxemia from actual infection. The organism grows in the intestinal tract and produces toxin during sporulation (not vegetative growth)
- Name the three types of toxins in Clostridium tetani.
-
1. tetanolysin - a hemolysin
2. tetanospasmin - potent A-B neurotoxin
3. non-spasmogenic toxin - What is the mechanism of action of Tetanospasmin?
- It is passed to the major nerves - binds to gangliosides at neuromuscular junctions. It blocks inhibitory transmitters presynaptically.
- What Clostridium botulinum toxin types are most common in animals?
-
Types C and D
C - botulism in cattle, sheep, turtles, chickens
D - botulism in cattle with phosphate deficiency - T or F: The C. botulinum toxins are the most potent toxins known.
- True - 1 ug is lethal to man, 1 mg = 120 lethal mouse doses
- What is the mechanism of action for C. botulinum toxin?
- Spores germinate in food, toxin is produced in the food or intestine and is absorbed in the lymphatics and bloodstream. It binds to the GM1 ganglioside at the neuromuscular junctions of peripheral nerves. It acts presynaptically to inhibit the release of the neurotransmitter Ach - results in flaccid paralysis.
- Describe neonatal botulism.
- Spores are ingested (raw honey) and the cells multiply in the large bowel because indigenous microflora is not yet fully formed.
-
Name two genera of gram negative non-sporeforming anaerobic rods.
Where are these found?
What do they infect? -
Bacteroides and Fusobacterium
Normal inhabitants of the alimentary tract of humans and animals, also found in feces of some animals and humans.
Infect damaged tissue (the necrosis provides anaerobiosis) in animals kept in filthy, manure-laden surroundings - T or F: Fusobacterium is a secondary invader.
- True
- What is responsible for calf diphtheria - necrotic foci in the mouth, larynx and trachea, foot rot in cattle and sheep, and "bull nose" in boars.
- Fusobacterium necrophorum
- What is an obligate parasite of the hooves of sheep, cattle and goats?
- Bacteroides nodosus
- What is the primary cause of contagious foot rot and what allows it to enter the epidermis?
-
Bacteroides nodosus
Fusobacterium damages the epidermis enough to allow penetration and multiplication of B. nodosus. - What is a virulence factor of Bacteriodes nodosus?
- It produces keratin degrading proteases
- What bacteria is implicated in periodontal disease and pulmonary infections following dental surgery?
- Bacteriodes melaninogenicus
- What is the most common anaerobic infection in humans, found in 80-90% of all cases of peritonitis?
- Bacteroides fragilis
- Where is Campylobacter normally found?
- In the reproductive and alimentary tracts of humans and animals.
-
Match:
1. Campylobacter fetus var venerealis
2. Campylobacter fetus var fetus
a. Sheep and cattle repro tract
b. Bovine retract -
1 - b
2 - a - How do cows encounter Campylobacter fetus var venerealis?
- Through coitus or AI
- T or F: A bull will show signs of C. fetus var Venerealis
- False - infections in bulls are inapparent
- T or F: A cow infected with C. fetus var Venerealis will become sterile.
- False - they will be infertile for weeks-months, but will regain fertility in ~5 months.
- T or F: A vaccine exists to protect bulls agains C. fetus var Venerealis.
- True
- How are sheep exposed to C. fetus var Fetus? What does it cause?
- Organism enters through ingestion. The bacteremia eventually localizes in the placenta and causes late-term abortions.
-
Name that bacteria:
Found in the mouth of stressed, overcrowded piglets ~2 weeks after weaning. Affected pigs don't thrive, develop lesions in the lower ileum and cecum (proliferating epithelia), loss of villi and development of polyp-like mas -
Campylobacter mucosalis
Campylobacter hyointestinalis -
What causes Porcine Proliferative Enteritis?
What kind of lesions does it produce? -
Lawsonia intracellularis
Enlarged intestinal crypts containing immature epithelial cells and an absence of goblet cells. Numerous bacteria are located in the affected cells. - What are important reservoirs for Campylobacter jejuni?
- Milk, minced meat, dogs, cats, and poultry.
- T or F: Campylobacter jejuni is not very pathogenic for humans.
- False - it is a frank pathogen of humans and 500 organisms can cause enteritis.
- What causes most non-foodborne illness in children playing with diarrheal pets, usually puppies?
- Campylobacter jejuni
- What is Campylobacter jejuni frequently misdiagnosed for?
- Appendicitis
- Where are all species of the Pseudomonads found?
- Aquatic habitats and soil
-
Which is the mammalian-host adapted?
a. P. mallei
b. P. pseudomallei
c. P. aeruginosa - a. P. mallei is mammalian-host adapted
- Which of the Pseudomonads are not motile?
- P. mallei
- Who is P. mallei an obligate parasite of?
- Horses, mules and donkeys
- Are Pseudomonads intracellular or extracellular pathogens?
- Extracellular
- How do Pseudomonads escape phagocyte killing (2 ways)?
-
-slimy capsule
-cytolytic exotoxins toxic to neutrophils - How does Pseudomonas aeruginosa resist phagocyte killing?
-
It produces alginate, a polysaccharide coating (viscous gel) which protects it from phagocytes.
It uses green pyocanin pigment as a virulence factor - What organism causes a greenish pus?
- P. aeruginosa - from the pyoverdin and pyocyanin pigments
- What causes "Green Wool" or "Fleece Rot" in sheep?
- P. aeruginosa
- What causes devastating losses in minks and chinchillas in the form of hemorrhagic pneumonia?
- Pseudomonas aeruginosa
-
What is "Glanders" caused by?
What species does it affect primarily?
What are its clinical signs? -
Pseudomonas mallei
Horses, or those that eat infected horse meat.
Nodular abscesses in lymphatics, become thickened and lyse discharing sticky exudate in ulcers at skin surface (farcy). Eventually spreads to the lungs where it forms similar lesions. Can also occur in liver and spleen. - T or F: Glanders (caused by Pseudomonas aeruginosa) is zoonotic.
- True - Especially with stablehands and veterinarians
-
What is meliodosis caused by?
What species does it affect? -
Pseudomonas pseudomallei
Causes a glanders-like disease mainly in rodents. - T or F: Pseudomonas are easily treated with many antibiotics
- False - Many Pseudomonas demonstrate multiple drug resistance, especially aeruginosa
- What is the only species of Moraxella of veterinary importance?
- M. bovis
- What does Moraxella bovis cause?
- Infectious bovine keratoconjunctivitis
- What is distinctive about the colonies of Moraxella bovis on BA?
- They pit the surface
-
Where is Moraxella generally found?
When does it cause disease? -
In the nares/conjunctiva of normal animals.
It is an opportunistic pathogen that causes disease when stressed or dealing with a concurrent viral or mycoplasma disease. - T or F: Moraxella is spread from dam to calf and also between other animals.
- False - No correlation has been shown between disease in calf and dam, or that spread is direct between animals.
- What are the symptoms of infectious bovine keratoconjuntivitis (caused by Moraxella bovis)?
- One or both eyes involved, excessive weeping of eye and closure due to pain, white or cloudy cornea, blood vessels extending into cornea from sclera when healing, lose weight, possible blindness
- What are two virulence factors of Moraxella bovis?
-
Pili (adhesion mediated agar pitting)
Hemolysin - lysis of RBCs and bovine corneal epitheal cells - What are three species of Francisella?
-
novicida
philomiragia
tularensis - What does Francisella require?
- Cysteine or cystine
- What are the methods of entry for Franciscella?
-
Ingestion
Inhalation
Entry into minute skin abrasions
Tick bite - Which organism is highly virulent for rabbits (<10 organisms kills in 10 days)?
- Francisella
- What are the signs of Francisella infection in rabbits?
- Systemic plague-like disease, multiple necrotic lesions in spleen and liver - granulomas
- What are the forms of Francisella infection in humans and what are some signs of each?
-
*Pneumonic-inhalation, no local lesions, respiratory granulomas, fever, myalgia
*Ulceroglandular-papule at sight of entry, then ulcer, regional lymphadenitis and fever
*Oculoglandular-entry via conjunctiva, conjuctivitis, cervical lymphadenopathy
*Typoidal form-ingestion of infected meat, diarrhea, abdominal cramps and fever - usually septicemic
*Systemic form-blood entry, multiple organ involvement, granulomatous lesions, necrosis - What are two virulence factors for Francisella?
-
Capsule (polysaccharide)
Acid phosphatase? - What drug should Francisella be treated with?
-
Streptomycin
Tetracycline (2nd choice) - What organism is the leading cause of abortion and sterility in domesticated livestock?
- Brucella
-
For each Brucella, is it a restricted or unrestricted host range?
1. ovis
2. abortus
3. suis
4. canis
5. melitensis -
1. restricted
2. unrestricted
3. unrestricted
4. restricted
5. unrestricted - T or F: Brucella is a zoonosis and is on the CDC Select Agent List
- True
- Where does the Brucella organism divide?
- In the endoplasmic reticulum.
- What is present in high concentrations in the uterus of cattle, sheep goats and swine that stimulates the growth of Brucella abortus/suis?
- Erythritol
- T or F: 45 states have now been declared Brucella-free due to aggressive vaccination programs.
- True
- What are the strains of Brucella that cause disease in humans, and what are the clinical signs with infection?
-
abortus, suis, melitensis, canis
flu-like fever, undulant fever - Name three important species of Hemophilus.
-
parasuis
somnus
paragallinarum - What three bacteria are part of the HAP group?
-
Hemophilus
Actinobacillus
Pasteurella - What is significant about the name Hemophilus?
-
Named because of requirement for growth factors in blood (factors X and V)
Factor X - heme or porphyrins
Factor V - NAD - What is the normal habitat of Hemophilus and how is it transmitted?
-
Part of the normal flora of mucous membranes or respiratory tract, mouth and sometimes vagina in many species including humans.
Transmitted generally via respiratory route. - What causes swine influenza? What is a predisposing factor?
-
Hemophilus parasuis
A predisposing factor is concurrent viral infection. - What causes Glassers disease and what are the clinical signs?
-
H. parasuis
fibrinous inflammation of the serous surfaces of the pericardium, pleura, peritoneum, joints and meninges
has no viral involvement
symptoms depend on tissues infected - swollen joints, lameness, bronchitis, pleuritis, fever, meningitis -
What causes Thromboembolic Meningoencephalitis (TEME)?
Signs? -
H. somnus - most important disease caused by this organism
Abortion, infertility, arthritis, weakness, fever, dyspnea, staggering, erratic behavior
somnolence: paralysis and sudden death - What causes foul Coryza?
-
H. Paragallinarum - serious and widespread disease of chickens
often associated with Newcastle virus or mycoplasma infection
resp. transmission and contaminated water - What causes wooden tongue?
- A. lignieresii
- What are the primary contagious pathogens causing bovine mastitis?
- S. agalactiae, S. aureus, Mycoplasma
- What are the primary environmental pathogens causing bovine mastitis?
- Coliform bacteria, strep (other than s. agalactiae), Pseudomonas and Arcanobacterium