Campylobacter and Helicobacter Flashcards
Campylobacter
- thin
- curved
- gram-negative rod
- oxidase-positive
- nonfermenting
- microaerophilic
Virulence Campylobacter
-factors that regulate adhesion, motility, and invasion into intestinal mucosa are poorly defined
C. jejuni
- host: poultry (birds and mammals )
- Gastroenteritis
- extraintestinal infections
- Guillain-Barré syndrome
- reactive arthritis
- Diarrhea is common
- SOURCE OF ISOLATION: FECES
- 32042 C
C. coli
- host: Pigs
- Gastroenteritis, extraintestinal infections
C. fetus
- host: Cattle, sheep
- Vascular infections (septicemia, endocarditis, septic thrombophlebitis)
C. upsaliensis
- Host: dogs cats
- Gastroenteritis, extraintestinal infections, Guillain-barre syndrome
Guillain Barre syndrome
-autoimmune disease caused by antigenic cross-reactivity between oligosaccharides in bacterial capsule and glycosphingolipids on the surface of neural tissues
Acute enteritis
- most common disease
- diarrhea
- fever
- malaise
- abdominal pain
Zoonotic infection
-improperly prepared poultry is a common source of human infections
Is person to person spread usual
-No
Infections are acquired by
-ingestion of contaminated food, unpasteurized milk, or contaminated water
Diagnosis of Campylobacter
- antigens on stool
- specimen is moderately sensitive
Gastroenteritis treatment
- infection is self-limited and is managed by fluid and electrolyte replacement
Severe gastroenteritis and septicemia treatment
-treated with erythromycin or azithromycin
how can gastroenteritis be prevented?
-proper preparation of food and consumption of pasteurized milk; preventing contamination of water supplies also controls infection
Helicobacter
- curved
- gram-negative rods
- microaerophilic
- hydrogenase, oxidase, catalase, urease-positive
H. pylori
- host: Humans, primates, pigs
- Gastritis, peptic ulcers, gastric adenocarcinoma, mucosa-associated lymphoid tissue B-cell lymphomas
- Never diarrhea
- Source of isolation : Gastric and duodenal biopsy specimens
- 35-24 C
H. cinaedi
- host: humans, hamsters
- Gastroenteritis, septicemia, proctocolitis
H. fenneliae
- host: humans
- Gastroenteritis, septicemia, proctocolitis
Virulence Helicobacter
- Urease production at very high levels is typical of gastric helicobacters (e.g., H. pylori) and uncommon in intestinal helicobacters (important diagnostic test for H. pylori)
- Multiple factors contribute to gastric colonization, inflammation, alteration of gastric acid production, and tissue destruction
Disease Helicobacter
-H. pylori is an important cause of acute and chronic gastritis, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma
Epidemiology Helicobacter
-Infections are common, particularly in people in a low socioeconomic class or in developing nations
-Humans are the primary reservoir
-Person-to-person spread is important
(typically fecal-oral)
Diagnosis helicobacter
- microscopy
- urease test sensitive and specific
- Culture requires incubation in microaerophilic conditions; growth is slow; relatively insensitive unless multiple biopsies are cultured
Treatment, prevention, and control Helicobacter
- H. pylori infections. Combined therapy with a proton pump inhibitor (e.g., omeprazole), a macrolide (e.g., clarithromycin), and a β-lactam (e.g., amoxicillin) for 2 weeks has had a high success rate
- Prophylactic treatment of colonized individuals has not been useful and potentially has adverse effects, such as predisposing patients to adenocarcinomas of the lower esophagus
- No vaccine
