Campylobacter

Question 1

what are the characteristics of Campylobacter?

Answer 1

• gram-negative, curved S-shaped rod
• motile with a single polar flagellum at one or both ends
• microaerophilic (ensures its survival in reduced-oxygen environments)

Question 2

true or false: campylobacter is a zoonotic pathogen

Answer 2

true; can be infected via direct handling of animals, slaughter houses, contaminated feces, contamination of water, raw milk, and under cooked meet

Question 3

what type of waters are sources of campylobacter species

Answer 3

tap, bore, and pond waters

Question 4

what can ingestion of a sufficient-dose of organisms via the oral-gastric route, lead to?

Answer 4

one or more gastrointestinal and/or extragastrointestinal illnesses

Question 5

when do campylobacter species peak?

Answer 5

in the summer time

Question 6

what is the significance of Abattoir workers?

Answer 6

abattoir workers have developed antibody responses to campylobacter during their employment.
long-term workers shed C. jejuni but are asymptomatic, this is unlike new workers who commonly develop clinical signs of C. jejuni gastroenteritis during their first weeks

Question 7

what are the clinical manifestations of campylobacter?

Answer 7

1. brain abscess meningitis
2. miller-fisher syndrome
3. Guillain-Barre syndrome
4. Bacteremia, Septicemia, Endocarditis, Myocarditis
5. hepatitis
6. IBS?

Question 8

what is the most common clinical manifestation of campylobacter?

Answer 8

gastroenteritis

Question 9

what species of campylobacter cause majority of gastroenteritis?

Answer 9

C. jejuni (responsible for 90% of cases with gastroenteritis)

Question 10

what is the incubation period before symptoms of gastroenteritis show up?

Answer 10

24-72 hours, then acute diarrhea occurs and may be accompanied by fever, chills, headache, and abdominal cramping

Question 11

what are rare clinical manifestation?

Answer 11

brain abscesses, periodontitis

Question 12

significance of Guillain-Barre syndrome and Miller Fisher syndrome

Answer 12

• it is the most extensively studied extraintestinal manifestation associated with Campylobacter infection

Question 13

Symptoms of Guillain-Barre and Miller Fisher syndrome:

Answer 13

generally begin with motor and sensory deficits in the lower extremities and spread to the upper extremities - can lead to the need for ventilator support

Question 14

what is the main difference between Miller Fisher and Guillain-Barre syndrome?

Answer 14

patients with MFS: first nerve groups to be affected by paralysis are those in the head, resulting in difficulty controlling eye muscles and balance

patients with GBS: paralysis typically begins in the legs

Question 15

Inflammatory Bowel Diseases (IBD):

Answer 15

• chronic inflammatory conditions of the GI tract including Crohn’s disease and ulcerative colitis
• patients with these diseases have lesions that occur at different sites along the GI tract
• evidence that Campylobacter infection may play a role

Question 16

Esophageal Diseases:

Answer 16

• include gastroesophageal reflux disease (GERD), Barrett’s esophagus (BE), and esophageal adenocarcinoma
• bacterial composition of the esophagus differ between healthy individuals and those with GERD or BE
• possible mechanism could be that there is a strong esophageal immune response and inflammation in people whose esophagus is colonized with C. conisus could be causing symptoms

Question 17

Bacteremia/Septicemia:

Answer 17

• most cases occur in those who are immunocompromised
• of these patients, 10-15% will die within 30 days of diagnosis
• generally associated with C. jejuni, C. coli, and C. fetus

Question 18

describe the epidemiology of Campy

Answer 18

• population-level immunity influences the prevalence
• Campy is endemic in developing countries, where infection is usually limited to children which could lead to life long protective immunity
• adults in developing countries have asymptomatic campy but shed the bacteria
• in the developed world, the most common reported source of Campy infection is poultry products and water
• in canada infection rates vary by region

Question 19

what are the main steps of campy molecular pathogenesis?

Answer 19

1. motility
2. adhesion
3. protein secretion and invasion
4. actin polymerization and endocytosis
5. toxin production

Question 20

what are the virulence factors of campy?

Answer 20

• CiaB: an exported virulence factor
• Type IV secretion apparatus: encoded on a large plasmid known as pVir
• flagellar export apparatus: may also be used to export virulence factors

Question 21

what toxin does Campy release?

Answer 21

produces a tripartite complex toxin called cytolethal distending toxin (CDT)

Question 22

what genes encode for the tripartite complex CDT toxin?

Answer 22

cdtA, cdtB and cdtC

Question 23

what does cdtA, B and C do?

Answer 23

• CdtA and CdtC binds to the cell membrane and facilitates entry of CdtB
• CdtB is translocated into the cytoplasm and is transported via the Golgi apparatus to the ER and from there reaches the nucleus
• CdtB causes DNA damage and arrest the mitosis cell cycle of the cell
• leads to cell death, which increases permeability of the epithelium and results in diarrhea

Question 24

summary of Campy:

Answer 24

• campylobacter is a very common foodborne bacterial pathogen in the developing and the developed world
• post-acute sequelae may occur such as GBS or possible IBD after initial infections is cleared
• good kitchen and hand hygiene are key to stopping infection