How do bacteria cause infection?

Anthony L. Komaroff, MD
Internal Medicine
In order to cause disease, the pathogen or a disease-causing microbe entering the body must reproduce in sufficient numbers before it is overwhelmed by the body's immune response. Bacteria replicate using their own resources through a process called binary fission, in which one bacterium divides into two. Bacteria are noted for their adaptability; once a bacterium arrives in a suitable environment, it can divide and multiply very fast. Escherichia coli, a common intestinal bacterium, can divide every 20 minutes. Unlike viruses, most, but not all, bacteria operate outside cells. One example of a bacterium that can enter cells is the organism that causes leprosy.

Continue Learning about Bacterial Infections

Bacterial Infections

Bacterial Infections

Bacterial infections like typhoid, strep throat and some sexually transmitted diseases are infections caused by different types of bacteria. These infections are often treated with doctor-prescribed antibiotics. Either viruses or ...

bacteria can cause infections, so it’s important to get examined by a doctor to make sure you’re prescribed the correct medication.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.