20 Questions
What are the three types of antigens used to classify Enterobacteriaceae?
O (lipopolysaccharide) antigens, K (capsular) antigens, and H (flagellar) antigens
What are the shared characteristics of Enterobacteriaceae?
True & opportunistic pathogens, Gram-negative rods, Peritrichous flagella, Oxidase negative, Facultative organisms, Ferment glucose, and Reduce nitrate to nitrite
What are the key methods for species identification of Enterobacteriaceae?
Lactose fermentation, motility, IMViC tests (Indole, Methyl red, Voges-Proskauer, and Citrate utilization), H2S production, urease production, oxidase test, and API (Analytical Profile Index)
Which enteric bacteria are members of the normal intestinal microbiota but are considerably less common than E coli?
Proteus, Enterobacter, Klebsiella, Morganella, Providencia, Citrobacter, and Serratia species
In which circumstances do the enteric bacteria become pathogenic?
When they reach tissues outside of their normal intestinal or other less common normal microbiota sites
What is the natural habitat of Enterobacteriaceae?
The intestinal tract of humans and animals
Name two genera included in the family Enterobacteriaceae.
Escherichia, Shigella
What are the shared characteristics of Enterobacteriaceae?
Facultative anaerobes or aerobes, ferment a wide range of carbohydrates, possess a complex antigenic structure, and produce a variety of toxins and other virulence factors
Which enteric organism is part of the normal microbiota and incidentally causes disease?
Escherichia coli
Name two enteric gram-negative rods that may also be called coliforms.
Salmonella, Klebsiella
Enterobacteriaceae are classified by more than 150 different heat-stable somatic O antigens, more than 100 heat-labile K antigens, and more than 50 H antigens. (True/False)
True
Most gram-negative enteric bacteria produce exotoxins of clinical importance. (True/False)
True
The enteric bacteria generally do not cause disease and may even contribute to normal function and nutrition in the intestine. (True/False)
True
When clinically important infections occur, they are usually caused by E coli, while other enteric bacteria cause hospital-acquired infections. (True/False)
True
The most frequent sites of clinically important infection by Enterobacteriaceae include the urinary tract, biliary tract, and other sites in the abdominal cavity. (True/False)
True
The natural habitat of Enterobacteriaceae is primarily the skin of humans and animals.
False
All enteric organisms in the Enterobacteriaceae family are part of the normal microbiota and do not cause disease.
False
Enterobacteriaceae are strictly anaerobic and do not possess the ability to thrive in the presence of oxygen.
False
All members of the Enterobacteriaceae family share identical antigenic structures.
False
Enterobacteriaceae do not produce any toxins or virulence factors that contribute to their pathogenicity.
False
Test your knowledge on Enterobacteriaceae in this microbiology quiz. Explore the characteristics and significance of this diverse bacterial family.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
