Hi, in reference to the below table: Why do some antibiotics gve different results on Gram -ve and Gram +ve organisms. How do different types of

Hi, in reference to the below table:

Why do some antibiotics gve different results on Gram -ve and Gram +ve organisms. How do different types of antibiotics act on the bacterial cell? What are their cellular targets?

Fyi the table contains the data from a Bauer-Kirby disc susceptibility test