12 - Spiral Bacteria Flashcards
1
Q
- List 3 species of Campylobacter that cause ovine/bovine abortion.
- Name 2 species responsible for bovine infectious infertility.
A
- Ovine/bovine abortion:
- C. fetus ss fetus
- C. jejuni
- Arcobacter cryoaerophila
- Bovine infectious infertility (STD of bovines)
- C. fetus ss venerealis
- Arcobacter skirrowii
2
Q
- Gram stain characteristic and morphology?
- Motile or non-motile?
- Oxygen requirements?
- Preferred growth medium?
- Fermenter or non-fermenter?
- Oxidase + or -?
- Commensal habitat?
- Pathogenic habitat?
A
- Gram negative, spiral shaped bacteria.
- Motile
- Microaerophile - 5% O2 maximum
- Blood
- Non-fermenter
- Positive
- GIT of animals - usually adults
- Pathogens in:
- Reproductive tract
- GIT of young animals and humans
3
Q
1, What does C. fetus ss fetus cause and when does it occur?
- How is it transmitted?
- Very basic pathogenesis?
- Is it zoonotic?
A
- Sporadic abortion, often in late gestation, in:
- Sheep and goats
- Cattle, pigs and horses
- Usually by fecal contamination on pasture or contaminated water
- Ingestion leads to bacteremia - has a tropism for placenta - invades and kills fetus.
- Fetus often mummified
- Causes placentitis in sheep
- Yes - causes septicemia in humans, usually immunocompromised
4
Q
Describe the pathogenesis of C. fetus ss fetus
A
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
5
Q
- What disease is caused by C. fetus ss venerealis?
- How is the disease spread?
- What is the result of the infection?
A
- Bovine venereal campylobacteriosis - BVC
- 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
- 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.
6
Q
Describe the pathogenesis of bovine venereal campylobacteriosis.
A
- 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
7
Q
1, What 2 campylobacter species cause diarrhea in puppies?
- Are they zoonotic?
- What is a typical history in the disease process?
- Which of the 2 can be shed by healthy animals?
- Do the two species always act alone?
A
- C. jejuni and C. upsaliensis
- Yep
- Puppies typically develop watery or bloody diarrhea after acquisition, followed by diarrhea in adults and/or children.
- C. jejuni
- Nope - can be part of a mixed infection with:
- Enteric virus
- Giardia
- Helminths
- etc.
8
Q
- Is canine campylobacteriosis invasive?
- What can be seen in gross pathology?
A
- C. jejuni is invasive
- Invasive = inflammatory process - on gross pathology see:
- Lesions of focal congestion
- Mucus production
9
Q
State which Campylobacter species is found in the following animals and whether or not it causes disease:
- Birds
- Pigs
- Do these Campy species affect animals of all ages?
- Do these Campy species affect humans?
A
- C. jejuni - part of normal GIT flora, no disease association in poultry
- C. coli - normal flora in pigs tf no disease
- C. jejuni and C. coli can cause acute diarrhea in young animals but not older ones
- Both cause acute diarrhea in humans - zoonotic.
10
Q
- How is Campylobacter enteris acquired in man?
- What is the incubation period in humans?
- What are the symptoms?
A
- Either direct contact or is foodborne:
- Poultry - broiler chickens = main source
- Raw meat
- Unpasteurized milk
- Untreated water
- Shellfish
- About 3 days
- Symptoms
- Severe abdominal pain
- Diarrhea - small volume, bloody, watery or both
- Fever, myalgia, malaise
11
Q
- What media is used to grow Campy?
- Temperature?
- Atmosphere?
- What do the colonies look like - size, appearance?
- How else is Campy confirmed?
- Is antimicrobial sensitivity testing possible?
A
- Selective media with antibiotics to suppress normal fecal flora growth.
- 37 or 42 °C
- Microaerophilic
- Small, 1 - 2 mm in size, spreading colonies that look wet or mucousy
- Confirm via
- Smear
- Gram stain - looks like a seagull in flight, diagnostic for Campy
- Campy API
- Yep
12
Q
- List 3 conditions caused by Helicobacter pylori in man?
- Does it infect animals and what diseases does it cause?
A
- H. pylori implicated in:
- Chronic active gastritis
- Gastric and duodenal ulcers
- Risk factor for gastric adenocarcinoma, lymphoma and gall bladder disease
- There are many animal Helicobacter species - disease associattions still being defined.
13
Q
- What are spirochetes?
- Can they be Gram stained?
- How is their structure different from other bacteria?
- What are the 3 major classes of spirochetes?
A
- Spiral, flexible, Gram negative rods
- No. They have a Gram negative structure but a special silver stain is needed for identification.
- They are arranged in spirals with an internal flagella
- Flagella originates at each end
- It curls around the body within the outer envelope
- Classes:
- Borrelia
- Leptospira
- Brachyspira
14
Q
- Where are Borrelia species found in the body?
- How are they typically identified?
A
- They are large spirochetes that live in blood
- Are aerobic but difficult to isolate - ID’d via PCR
15
Q
- For the following, state which species causes disease, how it is transmitted and what disease it causes:
- Birds
- Dogs and humans in North America
- What two species are found in Europe and the UK? What sort of diseases do they cause?
A
- Birds: Borrelia anserina
- Tick transmitted (species = Argus persicus)
- Causes fowl spirochetosis
Dogs and humans: Borrelia burgdorferi
- Tick transmitted (spp. = Ixodes, Hemophysalis)
- Causes Lyme disease
- Borrelia afzellii, Borrelia garinii
* Causes joint and CNS infections