Macgowan A, Macnaughton E. Medicine 2017; 45: 622–628

Some bacteria are inherently resistant to antibiotics, but others acquire methods to avoid destruction through evolutionary selection processes. The means by which resistance is transferred from one bacteria to another involves the transfer of genetic material by either direct contact between the cells, transfer via a virus or the uptake of raw DNA from the surrounding environment. Studies show that the use of antibiotics allows resistant bacteria to flourish both in individuals and the wider community. In the case of Streptococcus pneumoniae, antibiotic resistant bacteria have been shown to persist in the respiratory tract for up to a year.

S. pneumonia is frequently found in the oral environment. A review (Evidence summary: the relationship between oral health and pulmonary disease, BDJ 2017; 222: 527–533) has shown that there is evidence for a link between the presence of plaque and the development of pneumonia.

The tendency of older people for complex, multiple medical problems puts them at particular risk of chest infection. An increasingly ineffective pool of available antibiotics decreases the options for treatment but highlights the importance of maintaining good oral hygiene in at risk patients. However, research and development of new antibiotics and further education for prescribers is needed.