Microbiology: Antimicrobial Susceptibility Testing
25 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

Most bacteria can grow to some extent in the presence of ______

oxygen

The E-test uses rectangular plastic strips with the predefined, continuous and exponential gradient of ______ concentration.

antibiotic

Bacteria ______ is a biological activity wherein microorganisms multiply themselves in a predetermined culture media under laboratory conditions.

culture

Species that are naturally found in low ______ environments, such as in deep wounds or abscesses or the deep ocean, will typically grow best in the absence of oxygen.

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

The ______ test provides a direct quantification of antimicrobial susceptibility of microorganisms.

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

Cultivate means to ______ and help grow bacteria.

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

Minimum Inhibitory Concentration (MIC) is considered as the lowest concentration of an antimicrobial that inhibits the visible growth of a ______.

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

For example, Staph.epidermidis is a species that grows best on the ______ surface.

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

Streptococcus ______ can be found as normal flora in the nasopharynx of healthy individuals.

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

Some bacteria, such as ______ and Bacteroides, cannot grow in the presence of oxygen at all.

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

Aerotolerant organisms, like ______ and Lactobacillus, do not require oxygen for growth but can tolerate its presence.

<p>Strep.pyogenes</p> Signup and view all the answers

______ bacteria require oxygen for survival and are present in aerated moist soil containing organic carbon sources.

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

Obligate ______ are aerobic bacteria that compulsorily require oxygen for deriving energy, growth, reproduction, and cellular respiration.

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

The microorganism ______ can be found as normal flora in the nasopharynx of healthy individuals.

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

______ are aerobic bacteria that can grow in either aerobic or anaerobic conditions, switching from aerobic respiration to fermentation or anaerobic respiration if oxygen is absent.

<p>E.coli</p> Signup and view all the answers

Some bacteria, such as ______ and Mycobacterium tuberculosis, cannot grow in the absence of oxygen.

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

Facultative bacteria behave both aerobically and ______, according to the prevailing conditions.

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

In reduced environments, they acquire energy via ______ pathways.

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

The microaerophilic bacteria require ______ but in very low concentrations.

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

There are mainly three methods of cultivation of anaerobic bacteria such as an atmosphere free of ______.

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

An anaerobic jar is a container into which inoculated plates or tubes are placed inside the chamber, and anaerobic conditions are created by adding water to a gas generator envelope that is placed in the jar just before ______.

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

A candle jar is a container into which a lit candle is introduced before sealing the container's ______ lid.

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

The candle's flame burns until extinguished by ______ deprivation, which creates a carbon dioxide-rich, oxygen-poor atmosphere in the jar.

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

Openings in the side of an anaerobic box that is holding nine Petri plates supporting cultures are sealed by ______-like sleeves that allow for the handling of cultures inside the box.

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

Inoculated plates or tubes are placed inside the ______, and anaerobic conditions are created by adding water to a gas generator envelope.

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

Study Notes

Antimicrobial Susceptibility Testing

  • Epsilometer test (E-test) is a quantitative method that provides direct quantification of antimicrobial susceptibility of microorganisms.
  • It combines disk diffusion pattern with the determination of Minimum Inhibitory Concentration (MIC).
  • MIC is the lowest concentration of an antimicrobial that inhibits the visible growth of a microorganism.
  • E-test uses rectangular plastic strips with a predefined, continuous, and exponential gradient of antibiotic concentration.

Bacteria Culture and Cultivation

  • Cultivation of bacteria is a biological activity where microorganisms multiply themselves in a predetermined culture media under laboratory conditions.
  • Most bacteria can grow to some extent in the presence of oxygen, known as aerobic culture.
  • Species that are naturally found in low oxygen environments, such as in deep wounds or abscesses, will typically grow best in the absence of oxygen – anaerobic culture.
  • Examples of bacteria that can grow in aerobic culture include Staph. epidermidis, Staph. aureus, Streptococcus pneumoniae, Haemophilus influenza, and Moraxella catarrhalis.

Oxygen Requirements for Bacterial Growth

  • Microorganisms can be found as normal flora in the nasopharynx of healthy individuals.
  • Some bacteria cannot grow in the presence of oxygen at all, e.g. Fusobacterium and Bacteroides.
  • Some bacteria cannot grow in the absence of oxygen, e.g. Pseudomonas and Mycobacterium tuberculosis.
  • Some bacteria can grow in either aerobic or anaerobic conditions, switching from aerobic respiration to fermentation or anaerobic respiration if oxygen is absent, e.g. E. coli, Salmonella, Listeria, and Staphylococci.

Aerotolerant Organisms

  • Aerotolerant organisms are those that do not require oxygen for growth but can tolerate its presence.
  • An aerotolerant organism is classified as an anaerobe.
  • Examples of aerotolerant organisms include Strept. pyogenes (harmful) and Lactobacillus (beneficial).

Cultivation of Aerobic and Anaerobic Bacteria

  • Aerobic bacteria require oxygen for survival and are present in aerated moist soil containing organic carbon sources.
  • There are two main types of aerobic bacteria: obligate aerobes and facultative and microaerophile aerobes.
  • Obligate aerobes compulsorily require oxygen for energy, growth, and cellular respiration.
  • Facultative bacteria can behave both aerobically and anaerobically, depending on the prevailing conditions.
  • Microaerophilic bacteria require oxygen but in very low concentrations.
  • Anaerobic bacteria can be cultivated using an atmosphere free of oxygen, an anaerobic indicator, and an anaerobic jar with a catalyst.

Studying That Suits You

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

Quiz Team

Description

This quiz covers the principle of Epsilometer test (E test) and its application in determining antimicrobial susceptibility of microorganisms.

More Like This

Use Quizgecko on...
Browser
Browser