Enterobacteriaceae Flashcards
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Questions and Answers

To which class of Proteobacteria do Enterobacteriaceae belong?

Gamma (ɣ)

What is the Linnaean classification of Enterobacteriaceae?

Family

How many genera and species are in the Enterobacteriaceae?

51 genera with between 1 and 22 species per genus

Where are Enterobacteriaceae found?

<p>Ubiquitous (everywhere) in nature - both terrestrial and aquatic environments</p> Signup and view all the answers

How many chromosomes do Enterobacteriaceae have?

<p>Single chromosome</p> Signup and view all the answers

What is the size range of the single chromosome of Enterobacteriaceae?

<p>0.4 Mbp to 6.4 Mbp</p> Signup and view all the answers

Which have the bigger genome: endosymbionts or non-endosymbionts?

<p>Non-endosymbionts</p> Signup and view all the answers

Do endosymbionts have a lower or higher G+C content than others?

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

What is the definition of an endosymbiont?

<p>Any organism that lives within the body or cells of another, often in a mutualistic relationship</p> Signup and view all the answers

What is the definition of a non-endosymbiont?

<p>Organisms that can exist as free-living or in host</p> Signup and view all the answers

Approximately how many strains of Enterobacteriaceae contain extra-chromosomal DNA in the form of plasmids?

<p>Half of strains sequenced contained plasmids</p> Signup and view all the answers

Are Enterobacteriaceae Gram-negative?

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

Are Enterobacteriaceae oxidase positive?

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

Can Enterobacteriaceae ferment glucose?

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

Can Enterobacteriaceae reduce nitrate to nitrite?

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

What type of respiring organisms are Enterobacteriaceae?

<p>Facultative anaerobes</p> Signup and view all the answers

What type of respiratory bacteria are Enterobacteriaceae?

<p>Facultative anaerobes</p> Signup and view all the answers

Are Enterobacteriaceae motile and if so, how do they move?

<p>They are motile and move via peritrichous flagella</p> Signup and view all the answers

Where are Enterobacteriaceae naturally found?

<p>In the gastrointestinal tract of hosts and in the environment</p> Signup and view all the answers

How are Enterobacteriaceae bacteria usually spread?

<p>Through faecal to oral routes</p> Signup and view all the answers

Give the 4 key genera within the Enterobacteriaceae studied in lectures.

<p>Escherichia, Shigella, Salmonella, and Yersinia</p> Signup and view all the answers

What are the 5 routes of infection of Enterobacteriaceae?

<ol> <li>Ingestion through contaminated food/water 2. Endogenous (internal origin) 3. Person-to-person contact 4. Parenteral infection 5. Respiratory</li> </ol> Signup and view all the answers

Which 2 Enterobacteriaceae cause gastrointestinal infections?

<p>Salmonella and E. coli O157:H7</p> Signup and view all the answers

Which Enterobacteriaceae cause urinary tract infections and abdominal abscesses?

<p>Uropathogenic E. coli (UPEC)</p> Signup and view all the answers

Which strain of E. coli can be spread from person-to-person?

<p>E. coli K1</p> Signup and view all the answers

What are the 3 ways Enterobacteriaceae enter the body through parenteral routes?

<ol> <li>Injections/wounds 2. Surgery 3. Insect bites</li> </ol> Signup and view all the answers

Which member of Enterobacteriaceae can also enter the body through the respiratory route?

<p>Yersinia pestis</p> Signup and view all the answers

What disease does Y. pestis cause?

<p>Pneumonic plague</p> Signup and view all the answers

Study Notes

Enterobacteriaceae Overview

  • Belong to the Gamma (ɣ) class of Proteobacteria.
  • Classified as a family within the Linnaean taxonomy.

Genera and Species

  • Comprise 51 genera with 1 to 22 species per genus.
  • Ubiquitous in terrestrial and aquatic environments; often associated with animals, plants, or insects.

Genomic Characteristics

  • Have a single chromosome ranging in size from 0.4 Mbp to 6.4 Mbp.
  • Non-endosymbionts typically have larger genomes compared to endosymbionts.
  • Endosymbionts possess lower G+C content (20-29%) than other Enterobacteriaceae (39-60%).

Cellular and Biochemical Properties

  • Gram-negative, spore-forming rods (bacilli); oxidase negative.
  • Capable of fermenting glucose; gas production may vary.
  • Can reduce nitrate to nitrite with few exceptions.
  • Are facultative anaerobes, thriving in both aerobic and anaerobic conditions.

Motility and Natural Habitat

  • Most are motile, using peritrichous flagella; exceptions include Shigella and Klebsiella.
  • Naturally found in the gastrointestinal tracts of hosts (humans, animals, insects) and in the environment (soil, water, plants, food).

Transmission Routes

  • Commonly spread via fecal-oral routes.
  • Infection routes include gastrointestinal ingestion, endogenous infections (e.g., UTIs), person-to-person contact, parenteral methods (injections, surgery, bites), and respiratory droplets.

Key Genera and Infections

  • Main genera of study: Escherichia, Shigella, Salmonella, and Yersinia.
  • Salmonella and E.coli O157:H7 are notable for causing gastrointestinal infections.
  • Uropathogenic E.coli (UPEC) is associated with urinary tract infections and abdominal abscesses.
  • E.coli K1 strain can spread between individuals.

Parenteral Infection Routes

  • Enterobacteriaceae can enter through injections, surgical procedures, and insect bites.
  • Yersinia pestis can also spread via respiratory droplets, leading to pneumonic plague.

Specific Diseases

  • Yersinia pestis is the causative agent of pneumonic plague.

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Test your knowledge on Enterobacteriaceae with these flashcards. Explore key concepts including their classification, genera, and habitats. Perfect for students and professionals in the field of microbiology.

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