Pseudomonas Quiz

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Questions and Answers

What does API stand for in the context of biochemical tests?

Analytical Profile Index (correct)

Analytical Power Identifier

Applied Profile Indicator

Acidic Profile Identification

What is a key identifying characteristic of Vibrio cholerae on TCBS agar?

Yellow colonies indicating sucrose fermentation (correct)

Greenish-blue colonies

Colorless colonies

No growth observed

Which of the following statements is true concerning Vibrio cholerae culture characteristics?

V.cholerae is non-hemolytic on blood agar

V.cholerae colonies are always large and colorless on MacConkey's agar

V.cholerae produces β-hemolytic colonies on blood agar (correct)

V.cholerae shows no growth in alkaline peptone water

After 18-24 hours of incubation, which result indicates the organism inoculated in the API 20NE strip?

Addition of reagents in appropriate tubes Signup and view all the answers

What is the microscopic morphology of Vibrios as identified under Gram staining?

Curved rods, Gram negative Signup and view all the answers

What biochemical test result is expected for Vibrio cholerae when growing on Kligler Iron Agar (KIA)?

Alkaline/Acidic slant and gas production Signup and view all the answers

Which of the following Vibrio species is known to be a common cause of gastroenteritis?

Vibrio parahaemolyticus Signup and view all the answers

What characteristic differentiates non-sucrose fermenting Vibrios on TCBS agar?

They produce greenish-blue colonies. Signup and view all the answers

What color indicates the presence of alkaline reaction in Kligler Iron Agar for Pseudomonas?

Red Signup and view all the answers

Which characteristic is NOT true for Pseudomonas aeruginosa colonies growing on Blood agar?

Non-hemolytic Signup and view all the answers

In the O-F test, what indicates an oxidative result for Pseudomonas aeruginosa?

Color change in oil-covered tube only Signup and view all the answers

What pigment is produced by Pseudomonas aeruginosa, giving it a blue color?

Pyocyanin Signup and view all the answers

Which nutrient medium does NOT support the growth of Pseudomonas aeruginosa?

Mannitol salt agar Signup and view all the answers

How do Pseudomonas aeruginosa colonies appear on MacConkey's agar?

Colourless and non-lactose fermenting Signup and view all the answers

Which result from the O-F test suggests that Alcaligens faecalis is non-saccharolytic?

No color change in both tubes Signup and view all the answers

What characteristic odor is associated with Pseudomonas aeruginosa colonies?

Fruity Signup and view all the answers

Study Notes

Pseudomonas

Gram-negative rods, strict aerobes, and motile
Non-fermenter
Oxidase positive
Produce acid from carbohydrates by oxidation in the presence of oxygen
Can grow in tap water, IV fluids, distilled water, antiseptics, detergents, and equipment
Colonies are medium to large in size, smooth, greenish (pyoverdin) pigment diffused into the medium, and have a fruity smell.
On blood agar, colonies are large, flat, and often hemolytic.
On MacConkey's agar, colonies are colourless and non-lactose fermenting.
Biochemical tests include KIA, Oxidase test, O-F test (oxidative-fermentative), and API 20NE identification.
KIA interpretation: results are typically alkaline/alkaline, no gas production, and no H2S production.
Oxidase test is positive in Pseudomonas aeruginosa.
O-F Test determines glucose metabolism by fermentation (anaerobic) or oxidation (aerobic) in gram-negative organisms.
API 20NE identification is a 20-biochemical test kit used to identify bacteria to the species level by identifying specific enzymes produced.

Vibrios

Gram-negative curved rods (comma-shaped)
Important species include Vibrio cholerae, Vibrio parahemolyticus, Vibrio alginolyticus, and Vibrio vulnificus.
Vibrio cholerae has a single flagellum at one end.
On TCBS agar, colonies of V. cholerae often produce yellow colonies indicating sucrose fermentation.
V. parahaemolyticus, V. mimicus, and V. vulnificus produce greenish-blue colonies on TCBS agar and do not ferment sucrose.
On MacConkey's agar, V. cholerae colonies are small, colourless, and non-lactose fermenting.
Grows in alkaline peptone water.
On blood agar, V. cholerae 01 and 0139 often produce beta-hemolytic colonies.
Biochemical tests include KIA, Oxidase test, and API 20NE identification.
KIA interpretation: results are usually alkaline/alkaline or alkaline/acidic, no gas production, and no H2S production.
Oxidase test is positive in V. cholerae.
API 20NE identification is used to identify bacteria to the species level using a 20-biochemical test kit.
Serological identification using specific antiserum can be used to identify V. cholerae. O1 and O139 serogroups are common. These serogroups have distinct antigens recognizable by serological tests, allowing for differentiation.
V. cholerae has 3 serotypes, Ogawa, Inaba, and Hikojima. Monovalent antisera are needed to differentiate these.

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Description

Test your knowledge on Pseudomonas, a significant Gram-negative bacterium. This quiz covers its characteristics, biochemical tests, and growth conditions. Perfect for students and professionals interested in microbiology.