Scientists discover new mechanisms that bacteria use to protect themselves from antibiotics

Researchers at the University of Birmingham have identified new mechanisms used by bacteria to resist infection-fighting antibiotics.

Antibiotic resistance happens when bacteria evolve mechanisms to withstand the drugs which are used to treat infections.

The team of experts at the University’s Institute of Microbiology and Infection focussed their research on E. coli, which can cause urinary and blood stream infections.

Using novel experimental approaches, involving whole genome DNA sequencing never previously applied in this area of research, the team identified mechanisms or ‘strategies’ that bacteria use to protect themselves from antibiotics.

Senior author Professor David Grainger said: “We investigated a gene found in bacteria that is involved in resistance to multiple antibiotics.

“Although we have known about this gene for many decades, the ‘nuts and bolts’ of how it provides resistance to antibiotics has been difficult to pick apart.

“Our research identified previously unknown roles for this gene in controlling processes that provide drug resistance.
“We found two completely unexpected mechanisms that bacteria use to protect themselves from antibiotics. One protected their DNA from the harmful effects of fluoroquinolone antibiotics, and the other prevented doxycyline getting inside bacteria.”

Dr Prateek Sharma, who did much of the experimental work, adds: “The resistance mechanisms that we identified are found in many different species of bacteria therefore, our research could lead to the discovery of molecules that could be developed into new drugs that can treat bacterial infections.”

The study, published today in Nature Communications, was the result of a decade-long research project carried out by the University.

Co-author Professor Laura Piddock concludes: “Antibiotics underpin modern medical, veterinary and farming practices world-wide. However, the efficacy of antibiotics is decreasing as more bacteria become resistant.

“Research such as ours that provides greater understanding of drug resistance mechanisms is vital if we are to address the global crisis of antibiotic resistance.”

For more information contact Emma McKinney, Communications Manager (Health Science), University of Birmingham, on 0121 414 6681.

• The University of Birmingham is ranked amongst the world’s top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 5,000 international students from over 150 countries.
• Sharma et al (2017). ‘The multiple antibiotic resistance operon of enteric bacteria controls DNA repair and outer membrane integrity’. Nature Communications. DOI: 0.1038/s41467-017-01405-7
• The research was funded by the Biotechnology and Biological Sciences Research Council (grant BB/N014200/1). Biotechnology and Biological Sciences Research Council is one of seven research councils that work together as Research Councils UK (RCUK). It is funded by the government's Department for Business, Energy and Industrial Strategy (BEIS). It invested £469 million in world-class bioscience in 2016-17. We support around 1600 scientists and 2000 research students in universities and institutes across the UK.
• About 700,000 people die every year from drug-resistant infections
• If we do not act now, antimicrobial resistance (AMR) could be responsible for 10million deaths per year and $100trillion of lost production, globally, by 2050
• $40billion is needed over 10 years to take global action. This represents about 0.05% of what G20 countries spend on healthcare, currently
• AMR reduces the effectiveness of antibiotics. Without antibiotics there can be no treatments for common or complicated infections: chemotherapy for cancer, cystic fibrosis, heart transplant, joint replacement surgery