How Antibiotic Resistance Spreads and Arises

How antibiotic resistance happens and spreadsThis infograph from CDC’s, Antibiotic resistance threats in the United States, 2013 is a very simplified illustration on how antibiotic resistance happens and how antibiotic resistance spreads in a community. Bottom line: Simply using antibiotics creates resistance. These drugs should only be used to treat infections.

(click on the image on the right for a larger view)

How Antibiotic Resistance Arises

1. Where there are lots of germs there will be some that are resistant to certain antibiotics, either naturally or acquired.

2. Antibiotics kill bacteria causing the infection, as well as good bacteria protecting the body from infection

3. The drug-resistant bacteria are now allowed to grow and take over. They will thrive because there are less other bacteria to compete for nutrients or space.

4. Some bacteria give their drug-resistance to other bacteria, causing more problems.

Suggested reading: How bacteria Acquire Resistance

How Antibiotic Resistance Spreads

It is becoming more clear that the misuse of antibiotics in Food animals is an important factor of the antibiotic resistant problems we are facing today.

  1. Animals get antibiotics and develop resistant bacteria in their guts
  2. Drug-resistant bacteria can remain on meat products from animals. When not cooked or handled properly, the bacteria can spread to humans.
  3. Fertilizer or water containing animal feces and drug-resistant bacteria is used on food crops.
  4. Drug-resistant bacteria in the animal feces can remain on crops and be eaten. These bacteria can remain in the human gut.

But also the (mis)use of antibiotics in healthcare is promoting antibiotic resistance:

  1. George gets antibiotics and develops resistant bacteria in his gut. (this is mainly because antibiotics are sometime prescribed without properly evaluation their effectiveness on the infectious agent)
  2. George stays at home and in the general community. Spreads resistant bacteria.
  3. George gets care at a hospital, nursing home or other inpatient care facility
  4. Resistant germs spread directly to other patients or indirectly on unclean hands of healthcare providers.
  5. Resistant bacteria spread to other patients from surfaces within the healthcare facility.
  6. Patients go home and can further spread the resistant bacteria.

Suggested reading: The spread of Antimicrobial Resistance