week 1

• What is the order that includes the family Enterobacteriaceae?


  Order Enterobacterales
• Which family includes the genera Salmonella, Escherichia, and Shigella?

  Family: Enterobacteriaceae
• What is the genus associated with the family Yersiniaceae?

  Genus: Yersinia
• What phylum do the Vibrionales belong to?

  Phylum: Proteobacteria
• Which genera are included in the order Campylobacterales?

  Genera: Campylobacter, Helicobacter
• What is the type genus of the family Vibrionaceae?


  Type genus: Vibrio
• What are the general morphological characteristics of Vibrio species?

  They are Gram negative straight/curved rods.
• What type of respiration do Vibrio species perform?

  They are facultative anaerobes.
• What biochemical characteristic is most common among Vibrio species?

  Most are oxidase positive.
• What is the G+C content and genome size of Vibrio species?

  G+C content is 47% with a genome size of 4-5 Mbp.
• What is the optimum growth temperature for Vibrio species?

  Optimum growth is at 30-35 ˚C.
• How do Vibrio species move?

  They are motile with a single polar flagella.
• In what type of environments do Vibrio species thrive?

  They thrive in marine and brackish water above 15 ˚C.
• What are the similarities between Vibrio species and members of Enterobacteriaceae?

  Both are gamma proteobacteria, Gram negative rods, and facultative anaerobes.
• How many species are there in the Vibrio genus?

  There are over 50 species.
• What are the three main species of Vibrio discussed?

  1. cholerae, V. parahaemolyticus, V. vulnificus
• What type of infections is V. cholerae primarily associated with?

  Waterborne infections.
• What type of infections does V. parahaemolyticus cause?

  Food (shellfish) infections.
• What type of infections is V. vulnificus associated with?

  Wound infections.
• How many O antigen serogroups does V. cholerae have?

  Over 200 O antigen serogroups.
• What is the nature of the disease caused by V. cholerae?

  It causes acute secretory diarrhoeal disease.
• How many countries is cholera endemic to?

  50 countries.
• What is the estimated number of individuals affected by cholera per year according to WHO?

  1. 5 million individuals.
• What are the symptoms of V. cholerae infection?

  Early vomiting and painless loss of copious watery diarrhea.
• What is the characteristic stool associated with V. cholerae infection?

  “Rice-water stool.”
• What can happen without treatment for severe cholera?

  It can kill about half of infected individuals.
• What are the steps during V. cholerae infection?

  1. Ingestion and passage through acidic stomach; 2. Colonisation of small intestine; 3. Production of CT; 4. Exit from host in mucus-associated aggregates.
• What is the critical colonisation factor for V. cholerae?

  Toxin co-regulated pilus (TCP).
• What is the role of cholera toxin (CT) in V. cholerae infection?


  It is responsible for secretory diarrhoea.
• What are the main clinical symptoms of V. parahaemolyticus infection?

  Watery diarrhoea, abdominal pain, nausea, and vomiting.
• What type of illness does V. parahaemolyticus typically cause?

  Typically a self-limiting illness.
• What are the two main types of infections caused by V. parahaemolyticus?

  1. Enteritis (shellfish-borne infections) and B. Soft tissue infections/septicaemia.
• What are the symptoms of soft tissue infections caused by V. parahaemolyticus?

  Swelling, pain, erythema, bullae, necrosis, and gangrene.
• What are the symptoms of septicaemia caused by V. parahaemolyticus?

  Fever, hypotension, bullae, pain in lower extremities, tachycardia, and shock.
• What are the virulence mechanisms of V. parahaemolyticus?

  Hemolysins and Type 3 secretion system (T3SS).
• What does the Kanagawa phenotype indicate in V. parahaemolyticus?

  Bile triggers expression of T3SS2 genes.
• What disease is associated with V. vulnificus?

  Wound infection and septicaemia.
• How can V. vulnificus be contracted?

  Through exposure to seawater or raw oysters.
• What is the estimated number of seafood-associated deaths in the USA caused by V. vulnificus?

  Responsible for over 95% of all seafood-associated deaths in the USA.
• What are the virulence factors of V. vulnificus?

  Hemolysin, proteases, and capsule.