12 - Spiral Bacteria

Question 1

1. List 3 species of Campylobacter that cause ovine/bovine abortion.
2. Name 2 species responsible for bovine infectious infertility.

Answer 1

1. Ovine/bovine abortion:

• C. fetus ss fetus
• C. jejuni
• Arcobacter cryoaerophila

2. Bovine infectious infertility (STD of bovines)

• C. fetus ss venerealis
• Arcobacter skirrowii

Question 2

1. Gram stain characteristic and morphology?
2. Motile or non-motile?
3. Oxygen requirements?
4. Preferred growth medium?
5. Fermenter or non-fermenter?
6. Oxidase + or -?
7. Commensal habitat?
8. Pathogenic habitat?

Answer 2

1. Gram negative, spiral shaped bacteria.
2. Motile
3. Microaerophile - 5% O2 maximum
4. Blood
5. Non-fermenter
6. Positive
7. GIT of animals - usually adults
8. Pathogens in:

• Reproductive tract
• GIT of young animals and humans

Question 3

1, What does C. fetus ss fetus cause and when does it occur?

2. How is it transmitted?
3. Very basic pathogenesis?
4. Is it zoonotic?

Answer 3

1. Sporadic abortion, often in late gestation, in:

• Sheep and goats
• Cattle, pigs and horses

2. Usually by fecal contamination on pasture or contaminated water
3. Ingestion leads to bacteremia - has a tropism for placenta - invades and kills fetus.

• Fetus often mummified
• Causes placentitis in sheep

4. Yes - causes septicemia in humans, usually immunocompromised

Question 4

Describe the pathogenesis of C. fetus ss fetus

Answer 4

Pathogenesis relies on serum resistance and avoiding phagocytosis.

Serums resistant due to S layer of surface

• Is like a capsule but is a high MW protein

S layer does not bind C3b - prevents phagocytosis by neutrophils

• S-layer mutant = reduced virulence
• shields LPS - potentially to reduce immunogenicity

Question 5

1. What disease is caused by C. fetus ss venerealis?
2. How is the disease spread?
3. What is the result of the infection?

Answer 5

1. Bovine venereal campylobacteriosis - BVC
2. Transmitted by infected bulls in normal mating

• Transmission by AI no longer a problem - semen is screened for it
• Organism located on glans penis and distal urethra of bulls
• causes an ascending infection in females: vagina → cervix → uterus → oviducts

3. Causes temporary infertility. Also causes abortion in about 10% of cows. Protective immunity eventually develops (via IgA in vaginal mucus and IgG in the uterus) - bacteria eventually cleared out and normal immunity is restored.

Question 6

Describe the pathogenesis of bovine venereal campylobacteriosis.

Answer 6

• C. fetus ss venerealis uses antigenic shifts in the S layer proteins to survive
  
  • S layer proteins = sapA
• sapA promoter is on an invertible segment
• Segment flips - uses protein gene cassettes to change S layer antigen
• Eventually the cow develops immunity to all of the S layer antigenic types
  
  • This is when the MO is cleared out and normal fertility is restored

Question 7

1, What 2 campylobacter species cause diarrhea in puppies?

2. Are they zoonotic?
3. What is a typical history in the disease process?
4. Which of the 2 can be shed by healthy animals?
5. Do the two species always act alone?

Answer 7

1. C. jejuni and C. upsaliensis
2. Yep
3. Puppies typically develop watery or bloody diarrhea after acquisition, followed by diarrhea in adults and/or children.
4. C. jejuni
5. Nope - can be part of a mixed infection with:

• Enteric virus
• Giardia
• Helminths
• etc.

Question 8

1. Is canine campylobacteriosis invasive?
2. What can be seen in gross pathology?

Answer 8

1. C. jejuni is invasive
2. Invasive = inflammatory process - on gross pathology see:

• Lesions of focal congestion
• Mucus production

Question 9

State which Campylobacter species is found in the following animals and whether or not it causes disease:

1. Birds
2. Pigs
3. Do these Campy species affect animals of all ages?
4. Do these Campy species affect humans?

Answer 9

1. C. jejuni - part of normal GIT flora, no disease association in poultry
2. C. coli - normal flora in pigs tf no disease
3. C. jejuni and C. coli can cause acute diarrhea in young animals but not older ones
4. Both cause acute diarrhea in humans - zoonotic.

Question 10

1. How is Campylobacter enteris acquired in man?
2. What is the incubation period in humans?
3. What are the symptoms?

Answer 10

1. Either direct contact or is foodborne:

• Poultry - broiler chickens = main source
• Raw meat
• Unpasteurized milk
• Untreated water
• Shellfish

2. About 3 days
3. Symptoms

• Severe abdominal pain
• Diarrhea - small volume, bloody, watery or both
• Fever, myalgia, malaise

Question 11

1. What media is used to grow Campy?
2. Temperature?
3. Atmosphere?
4. What do the colonies look like - size, appearance?
5. How else is Campy confirmed?
6. Is antimicrobial sensitivity testing possible?

Answer 11

1. Selective media with antibiotics to suppress normal fecal flora growth.
2. 37 or 42 °C
3. Microaerophilic
4. Small, 1 - 2 mm in size, spreading colonies that look wet or mucousy
5. Confirm via

• Smear
• Gram stain - looks like a seagull in flight, diagnostic for Campy
• Campy API

6. Yep

Question 12

1. List 3 conditions caused by Helicobacter pylori in man?
2. Does it infect animals and what diseases does it cause?

Answer 12

1. H. pylori implicated in:

• Chronic active gastritis
• Gastric and duodenal ulcers
• Risk factor for gastric adenocarcinoma, lymphoma and gall bladder disease

2. There are many animal Helicobacter species - disease associattions still being defined.

Question 13

1. What are spirochetes?
2. Can they be Gram stained?
3. How is their structure different from other bacteria?
4. What are the 3 major classes of spirochetes?

Answer 13

1. Spiral, flexible, Gram negative rods
2. No. They have a Gram negative structure but a special silver stain is needed for identification.
3. They are arranged in spirals with an internal flagella

• Flagella originates at each end
• It curls around the body within the outer envelope

4. Classes:

• Borrelia
• Leptospira
• Brachyspira

Question 14

1. Where are Borrelia species found in the body?
2. How are they typically identified?

Answer 14

1. They are large spirochetes that live in blood
2. Are aerobic but difficult to isolate - ID’d via PCR

Question 15

1. For the following, state which species causes disease, how it is transmitted and what disease it causes:

• Birds
• Dogs and humans in North America

2. What two species are found in Europe and the UK? What sort of diseases do they cause?

Answer 15

1. Birds: Borrelia anserina

• Tick transmitted (species = Argus persicus)
• Causes fowl spirochetosis

Dogs and humans: Borrelia burgdorferi

• Tick transmitted (spp. = Ixodes, Hemophysalis)
• Causes Lyme disease

2. Borrelia afzellii, Borrelia garinii
   * Causes joint and CNS infections

Question 16

1. What is the incubation period?
2. What is the initial clinical sign?
3. What happens if the disease is not caught early?

Answer 16

1. 7 - 14 days, can range from 3 - 30 days
2. Skin sign - erythema migrans
   * Rash due to spirochetes multiplying in the skin
3. If caught at the skin stage, treat with antibiotics, rarely get sequelae. If not, second stage signs appear:

• Musculoskeletal signs - muscle and joint pains
• CNS signs rare
• Cardiac damage

Question 17

1. What are the typical clinical signs of Lyme Borreliosis in dogs?
2. What are 2 additional complications that can occur?
3. How is it diagnosed?

Answer 17

1. Typical clinical signs are a sudden onset of:

• Lethary, inappetance, fever
• Swollen LNs
• Inflammation in the joint space
  
  • Acute arthritis
  • Joint swelling

2. CNS infection (cervial pain, depression, anorexia, seizures) and glomerulonephritis (Lyme-specific immune complexes deposit in the kidney).

Question 18

What is the epidemiology of Lyme Borreliosis?

Answer 18

• Human encroachment into deer habitat
• Spread from deer and mice to humans and dogs via ticks
  
  • Infection rate in ticks = 10 - 60% depending on age
• Important factor = sprirochete migration in tick during feeding
  
  • Takes 24 - 48 hours to migrate from midgut to salivary glands
  • Short-term exposure - no infection
• Also intrauterine transmission in dogs

Question 19

1. What are the antibiotics used to treat Lyme disease?
2. How long is the animal usually treated?
3. Is antimicrobial therapy successful?
4. After treatment is started, how long does it take for clinical signs to resovle?

Answer 19

1. Doxycycline or amoxicillin
2. Usually 4 weeks - due to slow multiplication and in vivo persistence
3. Depends on stage of disease

• Successful for 1° disease
• Usually unsuccessful for 2° disease
  
  • Even if bacteria is killed, damage to animal is permanent

4. 24 - 48 hours

Question 20

1. What is the structure of Leptospira bacteria?
2. Oxygen requirements?
3. Survival tendencies?
4. How many pathogenic species are there?
5. Are they zoonotic?

Answer 20

1. Very fine, tightly coiled bacteria with hooked ends
2. Aerobic
3. Fastidious - eaily destroyed in the lab but survive in the environment “quite happily”
4. 8 pathogenic species with >200 serovars
   * Highly antigenically variable between the 8 pathogenic groups
5. Yes - transmission from rodents, domestic animals - carry the bacteria in their kidney therefore transmission via urine

Question 21

1. Which species of leptospirosa are most important in animals?

Which serogroup(s) is responsible for the following diseases?

2. Interstitial nephritis in dogs
3. Weil’s Disease / leptrospirosal jaundice
4. Disease in cattle

Answer 21

1. Leptospira interrogans, Leptospria borgpetersenii
2. L. interrogans serovar canicola
3. L. interrogans serovar icterohemorrhagiae
4. Several serovars:

• L. interrogans serovar pomona
  
  • non-host-specific
• L. interrogans serovar hardjo/hardjobovis
  
  • host adapted to cattle
• L. borgpetersenii serovar hardjo/hardjobovis

Question 22

1. What is the epidemiology of host-adapted Leptospira serovars?
2. What is the epidemiology of non-host-adapted serovars?

Answer 22

1. Host-adapted

• Disease is mild and sporadic
• Venereal transmission - lifelong colonization of the urinary tract
• Serovars
  
  • hardjo in cows
  • bratislava, tarassovi in pigs

2. Non-host-adapted

• Catastrophic infections - abortion storms, death of adults
• Carrier state breif
• Serovars
  
  • pomona in cows, pigs
  • canicola in dogs

Question 23

What is the epidemiology of Leptospira in humans in the following environments?

1. Temperate climates
2. Tropical climates
3. Urban environment

Answer 23

1. Few serovars - infection via direct contact with infected farm animals

• Urine aerosols in milking parlors
• MIlk of infected cows

2. Many serovars in humans and domestic animals, may reservoirs - exposure via environmental contamination
3. Rodent-borne leptospirosis - frequently misdiagnosed

Question 24

What is the pathogenesis of Leptospirosis infections?

Answer 24

• Enters through cuts/abrasions or conjuctiva
• Evades local defenses
• Produce bacteremia
  
  • Shorter in host-adapted strains
  • Longer in non-host-adapted strains
• Proliferate in liver, kidneys, spleen, meninges
• Host antibodies eliminate bacteria from everywhere except:
  
  • Brain
  • Eyes
  • Kidneys
• Multiply in PCTs
• Excreted in urine - days to life

Question 25

For cattle, name the common host and non-host-adapted serovars and summarize the common clinical signs seen with disease.

Answer 25

Host-adapted = L. hardjo * Sporadic abortions * Infertility * Mild clinical signs Non-host adapted = L. pomona * Fever * Icterus * Hemoglobinuria * Abortion storms

Question 26

For pigs, name the common host and non-host-adapted serovars and summarize the common clinical signs seen with disease.

Answer 26

Host-adapted: L. bratislava * Similar to L. hardjo in cattle * Sporadic abortions, infertility, mild clinical signs Non-host-adapted: L. pomona * Similar to L. pomona in cattle * Fever, icterus, abortion storms

Question 27

For horses, name the common host and non-host-adapted serovars and summarize the common clinical signs seen with disease.

Answer 27

Host-adapted: L. bratislava * Mild, sporadic infections in adults * Late-term abortions Non-host-adapted: L. pomona, L. kennewicki * Fever, icterus, abortion

Question 28

For dogs, name the common host and non-host-adapted serovars and summarize the common clinical signs seen with disease.

Answer 28

Host-adapted: L. bratislava * Mild disease * Infertility * Weak pups Non-host-adapted: * High fever, myalgia, bloody vomit * Signs of shock * DIC, petechial hemorrhage * Renal localization - leptospiruria 2 weeks post-infection * Acute nephritis → chronic nepthritis → renal failure

Question 29

1. Morphology? 2. Oxygen requirements? 3. Media for growth? 4. Where do they live? 5. Do they cause disease? 6. How are they identified to host species?

Answer 29

1. Large spirochetes 2. Anaerobic 3. Grow on blood 4. Large intestine of animals and birds 5. Yes - inflammation, diarrhea, dysentery * Dysentery = small volume bloody diarrhea with tissue inflammation 6. Hemolysis, API, size, sugars, indole

Question 30

Name 3 species of Brachyspira of veterinary importance, their hosts and what diseases are caused.

Answer 30

1. B. hyodysenteriae * Dysentery in pigs 2. B. pilosicoli * Colonic spirochetosis (diarrhea) * Pigs, chickens, humans 3. B. alvinpulli * Colonic spirochetosis in poultry

Question 31

1. Morphology? 2. Hemolysis? 3. Disease?

Answer 31

1. Large, Gram negative spirochete with 7 - 14 filaments originating from each end 2. Beta hemolysis on blood agar after 48 hours in anaerobic conditions 3. Several serogroups - infects LI of pigs - causes dystentery

Question 32

1. Morphology? 2. Hemolysis? 3. Disease? 4. Characteristic histology?

Answer 32

1. Gram negative spirochete, smaller than B. hyodysteneriae, 4 - 5 filaments overlapping centrally 2. Less hemolytic cf. B. hyodystenteriae 3. Several serovars, causes diarreha - not bloody cf. B. hyodystenteriae * Pigs, chickens, dogs, humans 4. Colonizes colonic epithelium to give a false brush border - not invasive