Which of the following is not correct about chlorhexidine as an antiseptic?
A. The mechanism is membrane disruption.
B. It is positively charged and reacts with the negatively charged microbial cell surface
C. It is bacteriostatic in low concentration and bactericidal in higher concentration.
D. Activity against gram positive and negative bacteria is the same
Answer: D
Chlorhexidine has better activity against gram positive bacteria than gram negative bacteria and fungi, because gram positive bacteria are more negatively charged and therefore react with the positively charged cholorhexidine better.