Cystic Fibrosis Canada-funded Dr. Miguel Valvano recently published a study that details a new mechanism of antibiotic resistance. The majority of work in the area of antibiotic resistance has focused on the bacterial cells themselves; Dr. Valvano’s team’s work is novel because they discovered a new way that bacteria defend against antibiotics, which occurs even before the antibiotics reach their intended bacterial target.
People with cystic fibrosis (CF) have chronic lung infections, which are often treated with inhaled antibiotics. Over time, bacteria in the lungs can become resistant to antibiotics, making lung infections difficult to treat. One type of bacteria, Burkholderia cenocepacia, is of particular concern, as it causes serious lung infections in people with CF, and is also highly resistant to a wide variety of drugs. Due to the highly antibiotic-resistant nature of Burkholderia cenocepacia, it is an ideal bacteria to study in order to understand how antibiotic resistance works.
Dr. Valvano’s team found that Burkholderia cenocepacia secretes small proteins, lipocalins, when exposed to antibiotics. Bacterial lipocalins interfere with antibiotic effectiveness by binding to the drugs, capturing them before they are able to reach the bacteria. Since antibiotics do not reach the bacteria, they are unable to effectively kill it, and the chronic infection in the person’s lungs remains. The investigators also showed that many different bacteria, in addition to Burkholderia cenocepacia, secrete lipocalins.
Along with this finding, Dr. Valvano’s team discovered that bacterial lipocalins bind more strongly to fat-soluble vitamins, like vitamin E, than to antibiotics. Therefore, fat-soluble vitamins provide a possible clinical tool to combat antibiotic resistance, since they could ‘soak up’ the lipocalins before they have a chance to bind the antibiotics, increasing the chances that antibiotics will reach the bacteria. This finding opens new opportunities for more effective treatment.
To read more about the study, please click here.
Dr. Miguel Valvano is a Chair in Microbiology and Infectious Diseases at Queen’s University Belfast, UK, and was a former Tier I Canada Research Chair in Infectious Diseases and Microbial Pathogenesis in the University of Western Ontario, Canada. He has dedicated his research career to understanding how bacteria cause disease. (http://publish.uwo.ca/~mvalvano/)