ECOLI Flashcards
Strain of Escherichia coli that causes infantile diarrhea?
Enteropathogenic E. coli (EPEC)
Which organism gives a mucoid colony under MacConkey Agar?
Klebsiella pneumoniae
It produces swarming motility and has a burnt chocolate odor.
Proteus spp.
All of the following genera are non-motile members of the family Enterobacteriaceae, except?
Proteus (motile, unlike Yersinia, Shigella, and Klebsiella)
What distinguishes Enteropathogenic E. coli (EPEC) from Enterohemorrhagic E. coli (EHEC)?
EHEC can cause hemolytic uremic syndrome (HUS).
What is the main pathogenic feature of Salmonella Typhi?
It invades and replicates within macrophages.
Produces a red pigment and gives a positive result for DNase.
Serratia marcescens
Which of the following is not H₂S positive?
Shigella dysenteriae
The causative agent of Bubonic Plague is?
Yersinia pestis
Which agar is highly selective for the isolation of Salmonella spp.?
HE agar (Hektoen Enteric Agar)
What organism is often associated with lobar pneumonia in elderly hospitalized patients?
Klebsiella pneumoniae
Which species produce a ‘stalactite pattern’ in broth cultures?
Yersinia pestis
What is a key distinguishing feature of Enterobacter species compared to E. coli?
Enterobacter is lactose-positive but indole-negative.
All of the organisms under Enterobacteriaceae are considered oxidase-negative except:
Plesiomonas shigelloides
An enteric organism that is acquired by eating improperly prepared and cooked or preserved food contaminated with human feces and produces dysentery?
Shigella spp.
Which of the following produces a ‘safety pin appearance’ on bipolar staining?
Yersinia
A pathogen documented as the cause of nursery outbreaks of neonatal meningitis and brain abscesses.
Citrobacter koseri
Why does Proteus mirabilis cause kidney stones?
It produces urease, raising urine pH and leading to calcium precipitation.
Which of the following is a selective medium for the isolation of Yersinia enterocolitica?
CIN agar
It may cause acute gastroenteritis or food poisoning.
Salmonella
What is the carbohydrate source of XLD Agar?
Xylose
All of the following sugars are detected in Triple Sugar Iron (TSI) Agar except:
Galactose
The additive that is added to the OF test for differentiating oxidation and fermentation?
Mineral oil
The end product of lysine decarboxylation is?
Cadaverine
