NURSING ANM AND GNM

NURSING EXAM QUESTIONS

MICROBIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which of the following bacteria stain poorly on Gram-stain:
A
Legionella pneumophilia
B
Staphylococcus aureus
C
Streptococcus pyogenes
D
Escherichia coli
Explanation: 

Detailed explanation-1: -Legionella stains poorly with Gram stain, stains positive with silver, and is cultured on charcoal yeast extract with iron and cysteine.

Detailed explanation-2: -INFECTIOUS AGENT. Gram-negative bacteria of the genus Legionella. Most cases of Legionnaires’ disease are caused by Legionella pneumophila, but all species of Legionella can cause disease.

Detailed explanation-3: -Legionella are poorly visualized with Gram stain. Silver stains such as Warthin-Starry or Dieterle stains are preferred.

Detailed explanation-4: -The Legionella bacterium is a small, aerobic, waterborne, gram-negative, unencapsulated bacillus that is nonmotile and oxidase and catalase positive. Legionella bacterium is a fastidious organism and will not grow anaerobically on a standard media.

There is 1 question to complete.