Pseudomonas aeruginosa Morphology and Culture Characters

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is NOT a culture characteristic of Pseudomonas aeruginosa?

Grows anaerobically (correct)

Shows beta-hemolysis on blood agar

Produces sweet grape-like fruity odor

Gives greenish color to nutrient agar

What is the primary method for identifying Pseudomonas aeruginosa?

Fermentation test

Oxidase test (correct)

Catalase test

Gram staining

Which of the following is a virulence factor of Pseudomonas aeruginosa that causes tissue damage?

LPS

Exotoxin A (correct)

Pyoverdin

Pili

Which pigment is responsible for the nonfluorescent bluish color produced by Pseudomonas aeruginosa?

Pyocyanin Signup and view all the answers

What distinguishes the culture characteristics of Pseudomonas aeruginosa on nutrient agar?

$\beta$-hemolysis Signup and view all the answers

What type of bacteria are Pseudomonas aeruginosa based on their morphology?

Gram-negative rods Signup and view all the answers

How does P. aeruginosa become pathogenic?

By disrupting mucous membrane and skin Signup and view all the answers

What is a common clinical manifestation of P. aeruginosa infection in patients with severe burns?

Bacteremia Signup and view all the answers

Which antibiotic therapy is generally required to treat P. aeruginosa infections?

Aminoglycoside Signup and view all the answers

What is the most common predisposing factor for Moraxella catarrhalis infections?

Advanced age Signup and view all the answers

What is the color of Moraxella catarrhalis colonies on agar?

Grayish-white Signup and view all the answers

What is a characteristic of Moraxella catarrhalis in the laboratory diagnosis?

Non-motile Signup and view all the answers

Which treatment is effective for Moraxella catarrhalis infections?

Fluoroquinolones Signup and view all the answers

What is a common clinical infection caused by Moraxella catarrhalis?

Meningitis Signup and view all the answers

What is a characteristic of P. aeruginosa in laboratory diagnosis?

Oxidase positive Signup and view all the answers

What is a clinical manifestation of P. aeruginosa in pulmonary infection?

Necrotizing pneumonia in CF patients Signup and view all the answers

Study Notes

Characteristics of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a non-lactose fermenting gram-negative rod.
A primary method for identifying Pseudomonas aeruginosa is through its growth on cetrimide agar, leading to the formation of a distinct blue-green pigment.
A virulence factor that causes tissue damage is the production of elastase, which breaks down elastin in tissues.
The pigment responsible for the nonfluorescent bluish color is called pyocyanin.

Culture Characteristics

On nutrient agar, Pseudomonas aeruginosa typically presents as rough, greenish colonies due to pigment production.
Morphologically, Pseudomonas aeruginosa are bacilli, appearing as rod-shaped bacteria.
Pathogenicity occurs through adherence to surfaces, evasion of host immune responses, and production of biofilms.

Clinical Manifestations

Common clinical manifestations of Pseudomonas aeruginosa infections, especially in burn patients, include increased risk of sepsis and pneumonia.
A notable clinical manifestation in pulmonary infections is the production of a significant amount of mucus, leading to obstructive airway diseases.

Treatment and Antibiotic Resistance

Antipseudomonal antibiotics, such as piperacillin-tazobactam or meropenem, are generally required for treating Pseudomonas aeruginosa infections.
This organism tends to exhibit high levels of antibiotic resistance, necessitating susceptibility testing.

Moraxella catarrhalis Characteristics

The most common predisposing factor for Moraxella catarrhalis infections is underlying respiratory disease or conditions that affect the immune system.
Moraxella catarrhalis colonies appear opaque and often produce a creamy, white color on agar.
A characteristic laboratory diagnosis feature is that Moraxella catarrhalis is oxidase-positive and grows well on chocolate agar.
Effective treatment for Moraxella catarrhalis infections usually involves amoxicillin-clavulanate or other beta-lactam antibiotics.
Common clinical infections caused by Moraxella catarrhalis include otitis media and sinusitis.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the morphology and culture characteristics of Pseudomonas aeruginosa with this quiz presented by Professor Dina Moustafa Abou Rayia from the Medical Microbiology and Immunology Department. Test your knowledge on the gram-negative rods, motility, aerobic growth, and exopigment production of Pseudomonas aeruginosa.