[1] It is a quantitative description of the amount of change occurring in processes investigated by evolutionary biology, but the formal concept is often extended to other areas of research.
The evolutionary arms race between the rapidly evolving virulence factors of the bacteria and the treatment practices of modern medicine requires evolutionary biologists to understand the mechanisms of resistance in these pathogenic bacteria, especially considering the growing number of infected hospitalized patients.
The evolved virulence factors pose a threat to patients in hospitals, who are immunocompromised from illness or antibiotic treatment.
One of the virulence factors of C. difficile that largely constitutes its resistance to antibiotics is its toxins: enterotoxin TcdA and cytotoxin TcdB.
[6] Combating the threat of the rapid spread of CDIs is therefore dependent on hospital sanitation practices removing spores from the environment.
A study published in the American Journal of Gastroenterology found that to control the spread of CDIs glove use, hand hygiene, disposable thermometers and disinfection of the environment are necessary practices in health facilities.
[7] The virulence of this pathogen is remarkable and may take a radical change at sanitation approaches used in hospitals to control CDI outbreaks.
[1] This is natural selection at work, but the pressure is coming from man-made activity such as building roads or hunting.
[citation needed] Populations of cliff swallows in Nebraska have displayed morphological changes in their wings after many years of living next to roads.
[6] This began by humans and wolves sharing the same area, with a pressure to coexist eventually leading to their domestication.
[9] An unintended consequence of this selection is that domesticated dogs also tend to have heritable diseases depending on what specific breed they encompass.