This week in Biofilms and Microbiomes: Monday October 24, 2016
A round-up of what we read last week in the media's coverage of biofilms and microbiomes research.
Researchers at The Johns Hopkins University have developed a nanofiber-based novel coating that is capable of controlled and independent local delivery of two or more combinatorial antibiotics from the surface of various metallic implantable devices or prostheses. The coating can be potentially applied to any metallic implant, from prosthetic joints, rods, screws and plates to pacemakers, implantable defibrillators and dental hardware, and thus holds a great promise for effectively decreasing biofilm-associated infections in patients. Biofilm infections are a major complication associated with implantable medical devices and prostheses, which are exceedingly difficult to treat. In many cases of chronic infection, prostheses must be removed and patients placed on long courses of antibiotics before a new prosthesis can be implanted. To tackle these challenges, study’s senior author, Lloyd S. Miller, M.D., Ph.D., an associate professor of dermatology and orthopaedic surgery, teamed up with Hai-Quan Mao, Ph.D., a professor of materials science and engineering at the Johns Hopkins University Whiting School of Engineering, and over years of research, the team designed an electrospun composite coating comprised of poly(lactic-coglycolic acid) (PLGA) nanofibers embedded in a poly(ε-caprolactone) (PCL) film. By varying PLGA: PCL polymer ratios or by adjusting the load of antibiotics on different polymers, the researchers were able to control the delivery of two or more combinatorial antibiotics. The technology was tested in a mouse model where three different combinations of antibiotic (rifampin with vancomycin, daptomycin or linezolid) loaded coatings were highly effective in preventing infection of the bone-joint tissue and implant biofilm formation. In addition, bone loss often seen near infected joints was also absent in the mice that received pins with the antibiotic-loaded coating. The technology however, needs further research to test the efficacy and safety of the coating in humans. The study, published online in Proceedings of the National Academy of Sciences, was picked up by several media outlets, including Medical News Today, Science Daily, and Technology.org.
Migraine could be linked to the bacteria found in your mouth, reports a new study published in mSystems this week. The study, led by researchers at University of California San Diego School of Medicine, shows that the mouths of migraine sufferers harbor significantly more microbes with the ability to modify nitrates than people who do not get migraine headaches. This could be a possible explanation for why some people are more susceptible to enervating headaches and why some foods appear to act as triggers for migraines. Nitrates, found in foods such as processed meats and green leafy vegetables and in certain medicines, can be reduced to nitrites by bacteria found in the mouth. When circulating in the blood, these nitrites can then be converted to nitric oxide under certain conditions. Nitric oxide can aid cardiovascular health by improving blood flow and reducing blood pressure. However, roughly four in five cardiac patients who take nitrate-containing drugs for chest pain or congestive heart failure report severe headaches as a side effect. To uncover the links between diet, microbiome and migraine, the research team, led by Antonio Gonzalez, PhD and Embriette Hyde, PhD, sequenced bacteria found in 172 oral samples and 1,996 faecal samples from healthy participants, who had also reported whether they were affected by migraines. Significantly higher abundances of nitrate, nitrite, and nitric oxide reductase genes were detected in migraineurs versus nonmigraineurs in samples collected from the oral cavity and a slight but significant difference in fecal samples. However, in terms of bacterial community composition, the team did not find huge differences in either fecal or oral samples from the two sets. The next step will be looking at more defined groups of patients, separated into different types of migraines, to better understand the correlation between circulating nitric oxide and migraine status. The paper was widely publicized by media. Read the press coverage by Medscape, CNN, New York Daily News, and Science 2.