Vibrios

• What is the order of the family Vibrionaceae?

  Vibrionales
• What are the general morphological and biochemical characteristics of Vibrionales?

  • Gram negative straight/curved rods
  • Facultative anaerobes
  • Oxidase positive (most)
  • Catalase positive
  • Nitrate reductase positive
  • Requirement for NaCl for growth
  • G+C content 47%; 4-5 Mbp genome
  • Two chromosomes
  • Optimum growth at 30-35ºC
  • Motile (single polar flagella)
  • Aquatic organisms, thrive in marine and brackish water
• How many genera are included in the family Vibrionaceae?

  Four genera
• What is the G+C content of Vibrionales?

  47%
• What is the typical genome size of Vibrionales?

  1. 5 Mbp
• What type of flagella do Vibrionales have?

  Single polar flagella
• What are the similarities between Vibrionales and Enterobacteriaceae?

  Both are gamma proteobacteria, gram negative rods, and facultative anaerobes
• What are the differences between Vibrionales and Enterobacteriaceae?

  Vibrionales have two chromosomes and a single polar flagella
• What are the two main O antigen serogroups of Vibrio cholerae?

  O1 and O139
• What is the primary mode of transmission for cholera?

  Waterborne and person-to-person
• What is the impact of Vibrio cholerae O1 on public health?

  It causes acute secretory diarrhoeal disease and is endemic to 50 countries
• What are the symptoms of cholera infection?

  Early vomiting and painless watery diarrhoea known as rice water stool
• What is the incubation period for Vibrio cholerae infection?

  Short incubation period of approximately 12 hours
• What is the role of the cholera toxin in Vibrio cholerae pathogenesis?

  It is responsible for inducing secretory diarrhoea

  
• What are the steps during Vibrio cholerae infection?

  1. Ingestion and passage via acidic stomach
  2. Colonisation of small intestine (distal region)
  3. Production of cholera toxin (CT) to induce secretory diarrhoea
  4. Exit from host in mucus-associated aggregates

  
• What is the main clinical symptom of Vibrio parahaemolyticus enteritis?

  Watery diarrhoea
• How does Vibrio parahaemolyticus typically enter the body?

  Through wounds or skin lesions
• What are the common symptoms of Vibrio parahaemolyticus infection?

  Abdominal pain, nausea, and vomiting
• What are the virulence mechanisms of Vibrio parahaemolyticus?

  Hemolysins and type 3 secretion system (T3SS)
• What is the main virulence factor of Vibrio vulnificus?

  Hemolysin
• What are the routes of infection for Vibrio vulnificus?

  Wound infection/septicaemia and food-borne illnesses

  
• What is the significance of Vibrio vulnificus in seafood consumption?

  Responsible for approximately 95% of all seafood-associated deaths in the USA
• What are the key virulence factors of Vibrio vulnificus?

  • Hemolysin (encoded by vvhA and vvhB)
  • Proteases (e.g., VVP and RtxA)
  • Capsule (hides bacterium from immune response)
• What are the diseases caused by pathogenic Vibrio species?

  • V. cholerae: Intestinal pathology
  • V. parahaemolyticus: Enteritis and soft tissue infections
  • V. vulnificus: Wound infections and food-borne illnesses

  
• What is the infectious dose for Vibrio species?

  Varies by species
• What is the habitat or vehicle for Vibrio species?

  Aquatic environments, particularly marine and brackish waters