1. Vibrios, Campylobacters and Associated Bacteria
General Characteristics: Gram-negative rods Widely distributed in nature

2. Vibrio cholerae General Characteristics Curved rods/ Comma-shaped
Aerobic
Grow at very high pH
Motile with polar flagellum
No spores

3. Vibrio cholerae

4. Vibrio cholerae Clinical Findings Cholera Incubation period: 1-4 days
S/S; nausea, vomiting, abdominal cramps, "rice water" stool (contains mucus, epithelial cells and large volume of vibrios), rapid fluid and electrolyte loss

5. Vibrio cholerae Pathology
Enterotoxin- causes hypersecretion of water and electrolytes
Attach to the microvilli
Pathogenic only to humans
Non-invasive

6. Vibrio cholerae Basis of classification: O antigen
V. cholerae strain O group 1 - causes classical cholera
Serotypes: Ogawa, Inaba, El Tor
V. cholerae non-O1 - causes cholera-like disease
*El Tor biotype cause milder diarrhea than the classic types

7. Vibrio cholerae Diagnostic Laboratory Tests Treatment
Dark-field or phase-contrast microscopy
Peptone or TCBS (Thiosulfate Citrate Bile salts Sucrose) agar
Treatment
Fluid and electrolyte replacement
Tetracycline

8. Vibrio cholerae Epidemiology, Prevention and Control
Mortality rate with treatment is 25-50%
Worldwide epidemics:
classical biotype
El Tor biotype was discovered
pandemic in Asia, Middle East, and Africa

9. Vibrio cholerae Endemic in India and Southeast Asia
Transmission: person-to-person contact (water, food, flies)
Carrier state: 3-4 weeks

10. Vibrio parahaemolyticus
Halophilic
Causes acute gastroenteritis
Transmission: ingestion of contaminated seafood
Incubation period: hrs
S/S: nausea, vomiting, abdominal cramps, fever, watery to bloody diarrhea
The disease subsides after 1-4 days with no treatment other than restoration of water and electrolytes
Occurs worldwide

11. Vibrio parahaemolyticus
TCBS Agar

12. Vibrio vulnificus Halophilic
Can cause skin lesions, enteritis, bacteremia

13. Camylobacter jejuni General Characteristics
Gram-negative rods with comma, S or "gull-wing" shapes
Motile with single polar flagellum
Do not form spores

14. Camylobacter jejuni

15. Camylobacter jejuni Campylobacter enteritis Clinical Findings
S/S: crampy abdominal pain, profuse diarrhea with blood, headache, malaise, and fever
Illness is self-limited to 5-8 days

16. Camylobacter jejuni Pathogenesis
Virulence factor: lipopolysaccharide with endotoxic activity
Invade the epithelium and produce inflammation that results in the appearance of RBC and WBC in stools

18. Helicobacter pylori Previously known as Campylobacter pylori
Spiral-shaped, gram-negative rod
Motile
Strong producer of urease
Grow at pH

19. Helicobacter pylori
It is present in the gastric mucosa of less than 20% of persons under age of 30 but increase in prevalence in elderly
Mode of transmission: person-to-person
Causes gastritis and appears to be important in the pathogenesis of duodenal (peptic) ulcer
H. pylori modifies the gastric mucus and further reduces the ability of acid to diffuse through the mucus

21. Camylobacter jejuni Diagnostic Laboratory Test
Microscopy: dark-field or phase-contrast
Culture: Skirrow's and Campy BAP medium
Epidemiology and Control
Mode of transmission: oral route from food (milk), drink, contact with infected animals, sexual activities