One of the most significant medical achievements in human medicine during the 20th century was the discovery and introduction of antibiotics. However, a short time after the introduction of new antibiotic compounds, resistant bacteria were discovered. Antimicrobial resistance is a global threat and challenge, and it is estimated that resistant bacteria were responsible for the death of 25,000 people in the European Union, Iceland and Norway in 2007. Bacteria acquire resistance either by de novo mutations or by taking up DNA from the environment, a process known as horizontal gene transfer. Resistance genes are ubiquitous, and are found in the environment and in the human normal flora, including the oral microbiota. The normal flora constitutes a reservoir of resistance genes, with the possibility of transferring genes to pathogenic bacteria. The use of antibiotics selects for resistant bacteria and may stimulate horizontal gene transfer. The increase in bacterial resistance calls for a more conscious prescription and use of antibiotics, which should be restricted to evidence-based knowledge demonstrating their usefulness to the patient.

Oral mikroflora – et reservoir av antibiotikaresistensgener?
Valen H, Scheie AA, Petersen F
Aktuel Nordisk Odontologi 2017: 42: 43-59.