Fredrik Westerlund
Photo Peter Sandin

Culture-free identification of antibiotic resistance

Bacteria becoming resistant to antibiotics is a growing problem in society. In April 2014, the World Health Organization (WHO) classified antibiotic resistance as a global problem.

The WHO warned that in the near future we may face a situation where we can no longer treat diseases that have been treatable for almost a century. New methods for diagnosing antibiotic resistance are therefore of great interest, both to speed up the deployment of the right medical treatment and to understand how resistance develops and limit its spread.

In clinics, resistance is traditionally identified by culturing bacteria in the presence of antibiotics, a process that takes days to complete. The goal of my research project, supported by the Torsten Söderberg Foundation, is to develop a method that makes it possible to predict resistance without culturing.

Resistance is often caused by genes localized on plasmids, pieces of DNA that are not part of the chromosomal DNA of the bacterium. Through our method, based on modern nanotechnology where plasmids can be studied one by one, we aim to be able to characterize the plasmid content of patient samples without culture.

We hope that the method can be used to predict whether a patient is carrying resistant bacteria within an hour of sampling. This will allow doctors to start treatment of infected patients more quickly and avoid giving antibiotics to patients who are not infected. Rapid identification of resistant bacteria is especially important for weak patients, such as those with severe blood infections (sepsis) or premature babies.

Fredrik Westerlund
research assistant Chalmers University of Technology