Vibrio, Aeromonas & Plesiomonas Flashcards
What environments are Vibrio primarily found in?
Aquatic environments including fresh water, brackish or estuarine water, marine or salt water
What devastating diarrheal illness is caused by Vibrio cholerae?
Cholera
Name one species of Vibrio associated with gastrointestinal illnesses.
V. cholerae
What clinical manifestations are associated with infections from Vibrio species?
Range from mild gastroenteritis to cholera and from simple wound infections to fatal septicemia
Which Vibrio species are most commonly identified in clinical laboratories?
- V. cholerae (O1 and non-O1)
- V. parahaemolyticus
- V. vulnificus
- V. alginolyticus
How is cholera primarily spread?
Through contaminated water
What are the key characteristics of stools in acute cases of cholera?
Described as ‘rice-water’ with large amounts of watery diarrhea flecked with small pieces of mucous
What is the primary treatment for cholera?
Administration of oral intravenous fluids and antibiotics
What are the ideal specimens for diagnosing Vibrio infections?
Body fluids, pus, and tissues
What type of agar is commonly used to isolate pathogenic Vibrio species?
MacConkey agar and blood agar
What is a unique characteristic of Vibrio bacteria’s morphology?
Gram-negative curved bacteria
What is the most commonly used selective media for the growth of vibrios?
Thiosulfate citrate bile salts sucrose agar (TCBS)
What biochemical test is used for presumptive identification of Vibrio species?
Oxidase activity test
What is the oxidase status of Vibrio species?
Oxidase positive
What is a defining characteristic of Aeromonas species?
Facultatively anaerobic
What is the most common clinical manifestation of Aeromonas infections?
Gastroenteritis
What type of bacteria is Aeromonas hydrophila?
Small Gram-negative bacilli
What is the characteristic appearance of Aeromonas colonies on culture media?
Large, round, raised, opaque with a smooth and often mucoid surface
What is the sole species in the genus Plesiomonas?
Plesiomonas shigelloides
How is Plesiomonas shigelloides primarily transmitted?
Ingestion of contaminated water or food
What is a unique biochemical characteristic of Plesiomonas shigelloides?
Ability to ferment inositol
What is the primary method for differentiating Plesiomonas from Aeromonas?
Susceptibility to O/129
What is the significance of the string test in Vibrio identification?
Mucoid ‘stringing’ observed following emulsification of colonies in 0.5% sodium desoxycholate
