Q. Each of the following statements concerning the Gram stain is correct except: Mycobacterium tuberculosis stains blue because it has a thick lipid layerEscherichia coli stains pink because it has a thin peptidoglycan layerStreptococcus pyogens stains blue because it has a thick peptidoglycan ...

Q. The identification of bacteria by serologic tests is based on the presence of specific antigens. Which of the following bacterial components is least likely to contain useful antigens? RibosomesCell wallCapsuleFlagella Answer: Ribosomes

Q. The cogulase test is used to differentiate Staphylococcus aureus from Staphylococcus epidermidisStreptococcus pyogens from Enterococcus faecalisStaphylococcus epidermidis from Neisseria meningitidisStreptococcus pyogens from Staphylococcus aureus Answer: Staphylococcus aureus from ...

Q. Which of the following bacteria has the lowest 50% infective dose (ID50)? Shigella sonneiCampylobacter jejuniSalmonella typhiVibrio cholerae Answer: Shigella sonnei