Bacteria

Bacteria are tiny one-celled organisms on, in, and all around us. There are trillions to be found, they have many different forms and purposes, and of course our species routinely interacts with these microorganisms. This can range from the innocuous (causing the smell associated with body odor) to the lethal infections (such as tetanus, typhoid fever, cholera, and tuberculosis).

Bacterial DNA can evolve like any other DNA, but bacteria can also acquire DNA sequences from their surroundings and can share DNA with other bacteria (that do not have to be the same species). The threat of antibiotic resistant bacteria means we should all care very greatly about what sequences of DNA we place into the environment.

Specifically, bacteria are acquiring the genes to resist the compounds used to kill them off by sheer force of nature; bathing an environment in antibiotics creates an opportunity for bacteria to attain the DNA to resist the antibiotic used within that environment. Repeated on vast scales and in many different places there are arising bacteria engrained with DNA sequences to make them resistant to many forms of antibiotics. This is currently the situation in most modern hospitals, where antibiotic applications are ubiquitous.

The FDA website outlines the rise of antibiotic-resistant bacteria. I found a 2004 article that concluded:

Antibacterial household cleaning products do not seem to reduce the number of infections among household residents, an expected finding because viruses, not bacteria, account for most household infections.

The FDA currently requests Americans not use antibacterial soaps, but the potential public health concerns partnered with on-going research could provide initiative for dramatically changing the marketing of these goods. Likewise for antibiotics used in agriculture. The alternative is a situation where the body of antibiotics unravels rather quickly. Take Tuberculosis (TB): it could easily reverse the downward trend demonstrated in the American Lung Association paper going from lows of under 800 TB deaths in the US in 2000 back up to tens of thousands of TB deaths in the 1950s (for reference CDC stats show AIDS responsible for over 13,000 deaths in 2004.).