CampylobacteriaceCampylobacteriaceaeae

CampylobacteriaceCampylobacteriaceaeae

CampylobacterCampylobacter HeliobacterHeliobacter

(Gram-negative curved rods)(Gram-negative curved rods)

Campylobacter• Gram(-), “curved”, small rods• Polar flagella• Non-fermentative

• Microaerophilic - grow best at 5% O2, 10% CO2 (capnophilic)

• Commensals of poultry, pigs, cattle, dogs, cats

Campylobacter Genera• Campylobacter sputorum:

– Normal oral flora of humans, cattle, pigs– Abscess, meningitis

• Campylobacter fetus:– Cattle, sheep– Septicemia, gastroenteritis, abortion,

meningitis• Campylobacter jejuni:

– Animals, humans– Gastroenteritis, septicemia, meningitis,

abortion, gastritis• Campylobacter coli:

– Pigs, poultry, bulls, sheep, birds– Gastroenteritis, septicemia, abortion,

meningitis

Campylobacter: Lab Culture Media

• Enteric species (C. jejuni, C. coli) best isolated at 420 C:– optimal growth temperature– suppress other enteric MOs

• Grow well on CBA, CHOC – 2 days, small, translucent colonies

• Poor growth on Mac• CampyBAP – Enriched, selective

– Brucella Agar base, 10% sheep blood

– Vancomycin, trimethoprim, polymyxin B, amphotericin B, cephalothin supress NF in stool

Campylobacter: Lab ID• Catalase(+) (except sputorum)• Oxidase(+)• Various growth requirements –

enriched media, microaerophilic, elevated temperature

• Serotyped by antigens:– Somatic O– Capsular K – Flagella H

Campylobacter : Virulence Factors

• Enterotoxin• Endotoxin• Adhesions• Survive phagocytosis• Ability to penetrate, invade, destroy

intestinal mucosal cells (edematous, bloody, ulceration, abscesses)

• Role of MO in causing disease poorly defined

Campylobacter: Infection• Most common cause of bacterial

gastroenteritis in USA, estimate ~2 M infections/year

• Mainly due to Campylobacter jejuni • Zoonotic infections, various animal

reservoirs (chicken, dog, cat)• Ingest contaminated milk, water,

poultry (50% of infections); contact with infected animal

• MO invades epithelium of small intestine, multiplies

• Causes acute enteritis, inflammatory response (may be responsible for many of disease symptoms)

Campylobacter: Gastroenteritis

• Symptoms 1-10 days after ingestion• Abdominal cramps, progress to crampy

pain, bloody diarrhea, chills, fever 3-6 days

• May have >10 bowel movements/day• Self-limited; replace fluids, electrolytes• Untreated patients may excrete MO

several months• Treat severe cases with erythromycin• Prevention by:

– Proper handling & preparation of food, especially poultry

– Drink pasteurized milk– Clean water supply

Campylobacter : Systemic Infection

• Usually Campylobacter fetus• Initial gastroenteritis, followed by

septicemia, spread to target organs• Debilitated or immunocompromised

individuals• Treat with aminoglycoside

(gentamycin)

Helicobacter pylori• Campylobacter-like MOs• Gram(-), small, “spiral”, rod • Ubiquitious, world-wide• Common in developing countries,

low socioeconomic groups• Person-to-person spread, fecal-

oral route• Lab culture: same media as

Campylobacter, may take 5 days• Differentiated from

Campylobacter by strong urease test (positive within 1-2 hrs.)

Helicobacter: Virulence Factors • Adhesions• Cytotoxin• Endotoxin• Flagella – highly motile, penetrate gastric mucus• Urease – NH3

raises stomach pH, cause cell damage, inflammation, access to cell nutrients, colonize stomach

• Mucinase –degrades mucus, expose epithelium to gastric acid

Helicobacter: Infection & Disease

• Peptic ulcers • Chronic, superficial

(type B) gastritis• Symptoms - nausea,

vomiting, anorexia, epigastric pain

• Association H. pylori and stomach carcinoma, possibly due to chronic inflammation

Helicobacter: Lab ID

• Tissue biopsy• Non-invasive urea breath test

– 14C labeled urea given orally

– Breath monitored for 14CO2

• Serology test for H. pylori antibody – indicates infection, possible etiology for peptic ulcer, gastritis

Helicobacter: Treatment

• Use of single antibiotic combined with bismuth (Pepto-Bismo) ineffective

• Combination therapy: beta-lactam (amoxicillin), macrolide (clarithromycin), a proton pump inhibitor (omeprazole), 7-10 days

• Eliminates MO and resolves pathology

Summary: Campylobacter, Helicobacter Infection

Class Assignment• Textbook Reading: Chapter 20

Campylobacter and Campylobacter-Like Species

• Key Terms• Learning Assessment Questions

Case Study - Campylobacter

• A mother and her 4-year-old son came to the local emergency room with a 1-day history of diarrhea and abdominal cramping.

• Both patients had low-grade fevers, and blood was grossly evident in the child’s stool specimen.

Case Study - Campylobacter

• The symptoms had developed 18 hours after the patients had consumed a dinner consisting of mixed green salad, chicken, corn, bread, and apple pie.

• Culture of blood samples was negative for organisms, but C. jejuni was isolated from stool specimens of both the mother and the child.

Case Study - Questions

• 1. Which food that they consumed is most likely responsible for these infections? What measures should be used to prevent these infections?

• 2. Name three Campylobacter species that have been associated with gastroenteritis. Name the species of Campylobacter that is most commonly associated with septicemia.

• 3. What diseases have been associated with H. pylori?