Campylobacter Flashcards
What is the characteristic shape of Campylobacter bacteria?
S-shaped or spirally curved rods (one or more spirals)
What is the Gram stain reaction of Campylobacter?
Gram-negative
How does Campylobacter move?
Motile by a single polar flagellum at one or both ends
What are the oxygen requirements of Campylobacter?
Microaerophilic (3%-5% CO₂), can be aerobic or anaerobic
What is the oxidase test result for Campylobacter?
Oxidase positive
Can Campylobacter ferment carbohydrates?
No, it does not use carbohydrates
How many Campylobacter species are recognized?
18 species, but only 2 are frankly pathogenic for animals
Which Campylobacter species are pathogenic for animals?
Campylobacter fetus (2 subspecies) and C. jejuni
Where are non-pathogenic Campylobacter species typically found?
On mucous membranes of the genital and intestinal tracts
Campylobacter is a Gram-positive bacterium. (T/F)
False (it’s Gram-negative)
Campylobacter can ferment glucose. (T/F)
False (does not use carbohydrates)
All Campylobacter species are pathogenic. (T/F)
False (only 2 species are frankly pathogenic)
Campylobacter is oxidase positive. (T/F)
True
Campylobacter has peritrichous flagella. (T/F)
False (has single polar flagellum at one or both ends)
How many subspecies does Campylobacter fetus have?
Two: C. fetus subsp. fetus and C. fetus subsp. venerealis
(Bovine Genital Campylobacteriosis) is caused by
C. fetus subsp. venerealis
Where is C. fetus subsp. venerealis found in asymptomatic bulls?
Preputial cavity
How is C. fetus subsp. venerealis transmitted in cattle?
Venereally through infected bull semen
(C. fetus subsp. venerealis) At what gestation stage do abortions typically occur?
5-8 months
(C. fetus subsp. venerealis) What are the placental characteristics in infected cows
Hemorrhagic and edematous
(C. fetus subsp. venerealis) What reproductive issue arises from uterine infection?
Metritis leading to infertility
Where is C. fetus subsp. fetus commonly found?
Intestines of cattle/sheep and genital tracts
How is C. fetus subsp. fetus transmitted?
Ingestion (direct or via fomites)
What is a key pathological feature of C. fetus subsp. fetus in aborted fetuses?
Necrotic foci in fetal liver
What samples are used for culture?
Cervical mucus, preputial secretions, fetal stomach contents
Why must clinical samples be fresh?
Organism dies rapidly when exposed to air/sunlight
What filtration size captures Campylobacter?
0.65 μm membrane filter
How is C. fetus visualized in fetal stomach contents?
Dark-field/phase microscopy or negative staining
What molecular method detects subsp. venerealis in semen?
PCR
What agar base is used for culture?
Brucella agar with antibiotics
What atmospheric conditions are required for growth?
10% CO₂, 5% O₂, 85% N₂
Which antibody classes are involved in systemic immunity?
IgM and IgG
What is the immunodominant antigen in C. fetus?
99-kDa S-layer protein
Which subspecies infects humans?
subsp. fetus (not venerealis)
FAT detects C. fetus in preputial washings. (T/F)
True
subsp. venerealis is zoonotic. (T/F)
False (only subsp. fetus)
C. fetus can survive weeks in dry environments. (T/F)
False (dies within hours unprotected
Where is Campylobacter jejuni commonly found?
As a commensal in intestinal tracts of domestic/wild animals and birds
Which animals commonly carry C. jejuni?
Poultry, dogs, cats, birds
What are the key virulence factors of C. jejuni?
Adhesins
Endotoxin (LPS)
Cytotoxin
Enterotoxin
How does C. jejuni colonize the intestine?
Via flagella and adhesins
What is unique about C. jejuni’s survival mechanism?
Can survive in phagosomes
(C. jejuni) How does the enterotoxin cause diarrhea?
Activates adenylate cyclase
(C. jejuni) What toxin Causes tissue destruction and abscess formation
cytotoxin
(C. jejuni) What are the main clinical signs in infected mammals?
Diarrhea and enterocolitis
Which species are affected by C. jejuni-induced abortion?
Bitches, ewes, cows
(C. jejuni) What poultry disease does it cause?
Avian infectious hepatitis
(C. jejuni) What lesions are seen in poultry livers?
Hemorrhagic and necrotic changes
(C. jejuni) Why is treatment often impractical?
Because it’s primarily a commensal
C. jejuni enterotoxin is identical to cholera toxin. (T/F)
False (similar mechanism but different toxin)
C. jejuni can cause mastitis in cows. (T/F)
True
The cytotoxin promotes fluid secretion. (T/F)
False (enterotoxin does; cytotoxin causes tissue damage)
C. jejuni is always pathogenic. (T/F)
False (often commensal)
What type of bacteria are Helicobacters?
Gram-negative, spiral/curved, motile, microaerophilic rods
Where are Helicobacter species typically found?
In the stomach or intestines of animals/humans
How do Helicobacters survive in the stomach?
By living beneath the mucus layer (pH ~7.4) and producing urease
What key enzyme allows Helicobacter to neutralize stomach acid?
Urease (breaks urea → ammonia + CO₂)
Name two major toxins produced by H. pylori.
VacA (vacuolating cytotoxin) and CagA (cytotoxin-associated gene)
What motility structure is critical for colonization of H. pylori.?
Flagella
What human diseases does H. pylori cause?
Chronic gastritis
Peptic ulcers
Gastric adenocarcinoma
Which Helicobacter species commonly infects dogs/cats?
H. heilmannii
What media are used for culture of H. pylori?
Skirrow’s medium and chocolate agar + antibiotics
How can Helicobacter be visualized diagnostically?
Phase microscopy of gastric mucosa scrapings
Can pet Helicobacter species infect humans?
Yes (zoonotic potential)
Helicobacter was previously classified as Campylobacter. (T/F)
True
H. pylori infection confers lifelong immunity. (T/F)
False (no protective immunity)
H. heilmannii causes gastritis in humans. (T/F)
True (rare zoonotic cases)
Feco-oral is the only transmission route. (T/F)
False (also oral-oral)
