"Gram-negative." YourDictionary, n.d. Web. 18 December 2018. <https://www.yourdictionary.com/gram-negative>.
Gram-negative. (n.d.). Retrieved December 18th, 2018, from https://www.yourdictionary.com/gram-negative
Relating to a group of bacteria that do not change color when subjected to the laboratory staining method known as Gram's method or Gram's stain. Gram-negative bacteria have relatively thin cell walls and are generally resistant to the effects of antibiotics or the actions of the body's immune cells. Gram-negative bacteria include E. coli and the bacteria that cause gonorrhea, typhoid fever, rickettsial fever, cholera, syphilis, plague, and Lyme disease.