Gram-Negative Cocci Diagnosis Quiz
39 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary medium used to culture a nasopharyngeal swab for diagnosing Neisseria meningitidis carriers?

  • Thayer-Martin medium (correct)
  • MacConkey agar
  • Chocolate agar
  • Blood agar

Gram-negative cocci can only appear in pairs.

False (B)

Name one serious infection caused by Gram-negative cocci.

Gonorrhea or meningitis

Gram-negative cocci typically appear as _____ shaped bacterial cells under the microscope.

<p>spherical</p> Signup and view all the answers

Match the following Gram-negative cocci with their associated disease:

<p>Neisseria gonorrhoeae = Gonorrhea Neisseria meningitidis = Meningitis Moraxella catarrhalis = Pneumonia</p> Signup and view all the answers

What characteristic staining property do Gram-negative cocci exhibit?

<p>They stain pink or red (D)</p> Signup and view all the answers

Gram-negative cocci can be found in various natural environments.

<p>True (A)</p> Signup and view all the answers

Which of the following is a key pathogenic Neisseria species responsible for gonorrhea?

<p>N.gonorrhoeae (D)</p> Signup and view all the answers

Neisseria species are typically Gram-positive cocci.

<p>False (B)</p> Signup and view all the answers

What is the shape commonly used to describe Neisseria species?

<p>coffee bean or kidney bean</p> Signup and view all the answers

Neisseria species require _______ media like blood agar for optimal growth.

<p>enriched</p> Signup and view all the answers

Match the Neisseria species with their disease association:

<p>N.gonorrhoeae = Gonorrhea N.meningitidis = Meningococcal disease</p> Signup and view all the answers

Which of the following is NOT a virulence factor of Neisseria species?

<p>Exotoxins (B)</p> Signup and view all the answers

CSF used for microbiological analysis typically contains exclusively lymphocytes.

<p>False (B)</p> Signup and view all the answers

What is one method used to diagnose Neisseria meningitidis?

<p>Gram staining</p> Signup and view all the answers

CSF for protein and glucose analysis is collected in tube ______.

<p>2</p> Signup and view all the answers

Which of the following statements accurately describes gram-negative cocci?

<p>They require aerobic conditions for optimal growth. (A)</p> Signup and view all the answers

Gram-negative cocci appear pink or red when subjected to Gram staining.

<p>True (A)</p> Signup and view all the answers

Name one species of medically important gram-negative cocci.

<p>Neisseria</p> Signup and view all the answers

Gram-negative cocci typically grow well on __________ agar.

<p>blood</p> Signup and view all the answers

Which media is used specifically to isolate and differentiate specific Gram-negative cocci species?

<p>Thayer-Martin agar (B)</p> Signup and view all the answers

Oxidase test is performed to determine the ability of bacteria to ferment carbohydrates.

<p>False (B)</p> Signup and view all the answers

What incubation temperature range is typically required for gram-negative cocci?

<p>35-37°C</p> Signup and view all the answers

Which test is NOT typically performed to confirm the species identification of Neisseria?

<p>Lactose fermentation (A)</p> Signup and view all the answers

Match the following gram-negative cocci species with their respective infections:

<p>N. gonorrhoeae = Gonorrhea N. meningitidis = Meningococcal disease M. catarrhalis = Respiratory infections A. baumannii = Multidrug-resistant infections</p> Signup and view all the answers

What color do gram-negative cocci appear when subjected to Gram staining?

<p>Pink or Red (B)</p> Signup and view all the answers

Gram-negative cocci require anaerobic conditions for optimal growth.

<p>False (B)</p> Signup and view all the answers

Name one pathogen related to the genus Neisseria.

<p>N. gonorrhoeae or N. meningitidis</p> Signup and view all the answers

Match the following biochemical tests with their purpose:

<p>Oxidase Test = Determines presence of cytochrome c oxidase Carbohydrate Utilization = Evaluates fermentation or oxidation of carbohydrates Antigen Detection = Provides rapid diagnosis of infections Antibody Detection = Measures immune response to specific bacteria</p> Signup and view all the answers

What is a key virulence factor of Neisseria species?

<p>Pili (A), Capsule (D)</p> Signup and view all the answers

Neisseria meningitidis can be diagnosed by collecting samples from the nasopharynx or cerebrospinal fluid.

<p>True (A)</p> Signup and view all the answers

What appearance do Neisseria species commonly exhibit under a microscope?

<p>Coffee bean or kidney bean shaped</p> Signup and view all the answers

Neisseria species require _______ media for optimal growth.

<p>enriched</p> Signup and view all the answers

Match the following Neisseria species with their associated diseases:

<p>N.gonorrhoeae = Gonorrhea N.meningitidis = Meningococcal disease</p> Signup and view all the answers

Which species is known to cause meningitis?

<p>Neisseria meningitidis (C)</p> Signup and view all the answers

Gram-negative cocci have a thick peptidoglycan layer in their cell wall.

<p>False (B)</p> Signup and view all the answers

Name one morphological feature of Gram-negative cocci.

<p>They appear in pairs (diplococci) or clusters.</p> Signup and view all the answers

Gram-negative cocci are often identified by their characteristic _______ appearance, resembling a coffee bean.

<p>bean-shaped</p> Signup and view all the answers

Match each Gram-negative cocci species with their associated infection:

<p>Neisseria gonorrhoeae = Gonorrhea Neisseria meningitidis = Meningitis Moraxella catarrhalis = Sinusitis Neisseria lactamica = Bacterial Meningitis</p> Signup and view all the answers

Flashcards

Gram-negative cocci staining

Gram-negative cocci appear pink or red when Gram-stained due to their thin peptidoglycan layer and outer membrane.

Gram-negative cocci morphology

Gram-negative cocci can appear as pairs (diplococci), tetrads, or irregular clusters.

Gram-negative cocci fastidiousness

Gram-negative cocci need special culture media and growth conditions to thrive.

Neisseria meningitidis diagnosis

Nasopharyngeal swab cultures for Neisseria meningitidis (meningitis) require Thayer-Martin medium.

Signup and view all the flashcards

Gram-negative cocci clinical significance

Certain gram-negative cocci cause serious infections, especially in immunocompromised individuals.

Signup and view all the flashcards

Neisseria gonorrhoeae

A gram-negative coccus that causes gonorrhea.

Signup and view all the flashcards

Neisseria meningitidis

A gram-negative coccus that causes meningitis.

Signup and view all the flashcards

Neisseria Species

A genus of bacteria known for their pathogenic role in causing infections like gonorrhea and meningococcal disease.

Signup and view all the flashcards

Gram-negative diplococci

Neisseria bacteria are shaped like pairs of round cells, resembling coffee beans or kidney beans, and stain pink or red under a Gram stain.

Signup and view all the flashcards

Fastidious Bacteria

Neisseria species require specific growth conditions, like enriched media, to thrive.

Signup and view all the flashcards

Pili

Hair-like structures on the surface of Neisseria bacteria that help them attach to host cells.

Signup and view all the flashcards

Outer Membrane Proteins

Proteins located on the outer membrane of Neisseria that aid in evading the host's immune system.

Signup and view all the flashcards

Capsular Polysaccharide

A sugar-based coating surrounding some Neisseria species, providing protection against the host's immune system.

Signup and view all the flashcards

CSF Collection

Cerebrospinal fluid (CSF) is collected through a spinal tap for diagnosing Neisseria meningitidis.

Signup and view all the flashcards

Gram-negative cocci growth conditions

Gram-negative cocci need oxygen (aerobic) and often require enriched media like blood agar and chocolate agar to grow well.

Signup and view all the flashcards

Gram-negative cocci incubation

Gram-negative cocci typically need to be grown at 35-37°C with 5-10% CO2 to thrive.

Signup and view all the flashcards

Selective media for gram-negative cocci

Special media like Thayer-Martin agar helps isolate and differentiate certain species of gram-negative cocci.

Signup and view all the flashcards

Oxidase test for Gram-negative cocci

This test checks for cytochrome c oxidase, an enzyme present in many Gram-negative cocci, including Neisseria and Moraxella.

Signup and view all the flashcards

Carbohydrate utilization in Gram-negative cocci

This test looks at how a bacterium breaks down sugars.

Signup and view all the flashcards

Serological tests for Gram-negative cocci

These tests detect either bacterial antigens or antibodies in a patient's blood to help diagnose infections.

Signup and view all the flashcards

Gram-Negative Cocci

Spherical bacteria that stain pink or red with Gram stain, indicating a thin peptidoglycan layer and an outer membrane. They come in pairs, tetrads, or clusters.

Signup and view all the flashcards

What makes Gram-negative cocci hard to grow?

These bacteria are fastidious, meaning they require specialized media and growth conditions in the lab.

Signup and view all the flashcards

Where do Gram-negative cocci live?

They are widely distributed in nature and can colonize various sites in the human body.

Signup and view all the flashcards

What are some examples of Gram-negative cocci infections?

Certain species can cause serious infections like gonorrhea (Neisseria gonorrhoeae) and meningitis (Neisseria meningitidis).

Signup and view all the flashcards

What is a Thayer-Martin medium?

A specialized media used to culture Neisseria meningitidis from nasopharyngeal swabs.

Signup and view all the flashcards

Gram-Negative Cocci Growth Requirements

Gram-negative cocci need oxygen (aerobic) and often require enriched media like blood agar and chocolate agar to grow well.

Signup and view all the flashcards

Oxidase Test

Detects cytochrome c oxidase, an enzyme found in many gram-negative cocci, including Neisseria and Moraxella.

Signup and view all the flashcards

Moraxella catarrhalis

An opportunistic pathogen that can cause respiratory infections, especially in immunocompromised individuals.

Signup and view all the flashcards

Neisseria Species: Pathogens

Neisseria gonorrhoeae causes gonorrhea, while Neisseria meningitidis leads to meningococcal disease. These are important bacterial culprits of infections.

Signup and view all the flashcards

Neisseria Morphology

Neisseria are Gram-negative diplococci, meaning they are pairs of round bacteria that stain pink/red. They have a characteristic 'coffee bean' or 'kidney bean' shape.

Signup and view all the flashcards

Neisseria Growth Needs

Neisseria are picky eaters (fastidious), requiring specialized media like blood agar or chocolate agar to grow well.

Signup and view all the flashcards

Neisseria Virulence Factors

Pili, outer membrane proteins, and capsular polysaccharides are key features that help Neisseria cause disease.

Signup and view all the flashcards

CSF: First Tube Analysis

The first tube of CSF collected for microbiological analysis typically contains a high number of cells, mainly polymorphs (white blood cells).

Signup and view all the flashcards

Study Notes

Gram-Negative Cocci: Medically Relevant Diagnosis

  • Gram-negative cocci are spherical bacteria that stain pink or red in Gram staining.
  • They have a thin peptidoglycan layer and an outer membrane.
  • They can appear in pairs (diplococci), tetrads, or irregular clusters.
  • This morphological variability helps in species identification.
  • Gram-negative cocci are fastidious and require specialized culture media and growth conditions for optimal growth in the laboratory.
  • Thayer-Martin medium is a selective medium used to cultivate Neisseria species.
  • Common species include Neisseria gonorrhoeae and Neisseria meningitidis, responsible for gonorrhea and meningitis, respectively.
  • Moraxella catarrhalis causes respiratory infections.
  • Acinetobacter baumannii produces multidrug-resistant infections.
  • Neisseria species are usually Gram-negative diplococci, often described as coffee bean-shaped.
  • Neisseria species are typically grown on enriched media like blood agar or chocolate agar and require 5-10% CO2.
  • Key pathogenic species include Neisseria gonorrhoeae which is the causative agent of gonorrhea and Neisseria meningitidis which is responsible for causing meningococcal disease.
  • Neisseria species are characterized by Pili, outer membrane proteins, and capsular polysaccharides.
  • Methods for diagnosing Neisseria meningitidis include sample collection from nasopharynx or cerebrospinal fluid (CSF), Gram staining to observe characteristic Gram-negative diplococci, and culture-based identification using selective media like modified Thayer-Martin agar and biochemical tests.
  • CSF for microbiological analysis typically includes numerous polymorphs.
  • Neisseria gonorrhoeae is identified through culture on Thayer-Martin medium to distinguish it from other bacteria which may show overgrowth when grown on chocolate agar.
  • The oxidase test identifies bacteria that produce cytochrome c oxidase, helping differentiate between Gram-negative groups. Oxidase-positive bacteria include Neisseria, Pseudomonas, and Vibrio.
  • Neisseria gonorrhoeae do not grow on blood agar.
  • Moraxella catarrhalis culture grows well on blood agar or chocolate agar, exhibiting smooth, grayish, and non-hemolytic colonies.
  • Moraxella catarrhalis is characterized by Gram-negative diplococci, with a 'coffee bean' morphology under the microscope.
  • Moraxella catarrhalis is identified using biochemical tests including catalase, oxidase, and DNase tests.
  • Gonorrhea is sexually transmitted.
  • The mode of transmission of Neisseria meningitidis is droplets.

Studying That Suits You

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

Quiz Team

Related Documents

Gram-Negative Cocci Medically Relevant Diagnosis PDF

Description

Test your knowledge about the medically relevant Gram-negative cocci. This quiz covers their identification, growth conditions, and the diseases they cause. Enhance your understanding of bacteria such as Neisseria and Moraxella through this focused assessment.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser