Question

Antibiotic for gram positive and gram negative bacteria

Answer 1

Gram-positive bacteria retain the colour of the dye, whilst Gram-negative bacteria do not, and are instead coloured red or pink. Gram-negative bacteria are more resistant to antibodies and antibiotics than Gram-positive bacteria, because they have a largely impermeable cell wall.

Answer 2

Tetracyclines are broad-spectrum antibiotics, active against both Gram-positive and Gram-negative bacteria.