The FINANCIAL -- A new study published in Nature Communications, led by scientists at the University of Liverpool in collaboration with the University of Salford, finds evidence that as bacteria adapt to the human body, they can sometimes become more susceptible to antibiotics and therefore easier to kill.
Antibiotic medications are used to kill bacteria, which can cause illness and disease. They have made a major contribution to human health. Many diseases that once killed people can now be treated effectively with antibiotics. However, some bacteria have become resistant to commonly used antibiotics.
Antibiotic resistant bacteria are bacteria that are not controlled or killed by antibiotics. They are able to survive and even multiply in the presence of an antibiotic. Most infection-causing bacteria can become resistant to at least some antibiotics. Bacteria are increasingly becoming antibiotic-resistant, making infections such as pneumonia, tuberculosis harder to treat, leading to increased medical costs, prolonged hospital stays and higher mortality.
Pseudomonas aeruginosa is a species of bacteria that is able to survive in harsh environments. It is found widely in soil and stagnant water, and can infect humans and plants. It does not usually cause illness in healthy people, but is described as an ‘opportunistic’ organism, causing serious infection when our normal defences are weakened. It is a major cause of lung infections, particularly in patients with cystic fibrosis.
Researchers aimed to establish how the bacteria adapted to the environment of the lungs and whether this process impacted on bacterial resistance to antibiotic treatment.
Using models of long-term lung infection, the team identified mutations that appeared in the bacterial DNA over the course of infection and which led to changes in the ability of Pseudomonas to survive in the lungs. The mutations enabled the bacteria to attach to lung cells more effectively, and to resist defence molecules produced by the host immune system.
Importantly however, the same changes also made Pseudomonas more susceptible to antibiotics, raising hopes that even bacteria that are well adapted to the lung environment could be combatted with conventional antibiotics. The new study, published today (July 6 2018), sheds new light on how bacterial pathogens can change over the course of a single infection within a patient.