There are two main types of bacteria, and these categories reflect the microbes' biology and their vulnerability to different antibiotics.

In comparison to Gram negative bacteria, the periplasmic space of Gram positive bacteria is smaller in volume and the cell wall is much thicker, ranging from 15 and 80 nanometers.

Colonization of the oropharynx by Pseudomonas aeruginosa and enteric gram-negative bacilli in acutely ill or debilitated patients, alcoholics, diabetics, and persons with chronic bronchitis may lead ...

If they’re positive, it means bacteria were present. Because of the staining technique used, gram-positive bacteria will appear purple under a microscope and gram-negative bacteria will appear pink.

Of the 55 (14% of 383) positive follow-up blood cultures, 43 (78%) grew gram-positive cocci, and eight (15%) grew gram-negative bacilli. The presence of fever on the day of follow-up blood ...