When bacteria is on the human body in the absence of disease, it is called a colonizer. However, people can get infected from pathogenic bacteria from food, water, abrasions and other wounds and even from colonizing bacteria if it gets into a normally sterile part of the body.hen bacteria is on the human body in the absence of disease, it is called a colonizer. However, people can get infected from pathogenic bacteria from food, water, abrasions and other wounds and even from colonizing bacteria if it gets into a normally sterile part of the body.