Bacterial infections and illnesses can be painful and time-consuming to cure. Our physicians provide us with a prescription for an antibiotic where the label says, “Take until bottle is empty.” Antibiotics help us cure most of our symptoms, but mutations occurring in bacteria inevitably make them resistant to the old drugs we’re so used to taking.
Kim Lewis and Losee Ling from Northeastern University in Boston, Massachusetts and the University of Bonn in Germany may have found an effective antibiotic that bacteria have yet to resist. This study, published on January 8 in Nature, presents researchers with new techniques and potential for learning more about “unculturable bacteria”—bacteria that scientists can’t grow on a petri dish in a laboratory.
Breaking down walls
The new antibiotic described, teixobactin, prevents bacteria from creating a “cell wall”, which is a bacteria’s safety blanket. Without a cell wall, bacteria cannot support themselves structurally and they become susceptible to viruses. Teixobactin latches on to the molecule “lipid II”, which creates the building blocks for a cell wall. By attaching itself to this molecule, lipid II can’t release the cell wall. A bacterium senses that it has no protection, so it undergoes lysis, a self-destruct mechanism for the whole organism. Without any protection, a bacterium is better off dead than weak and vulnerable.
To test how effectively teixobactin can kill bacteria, they injected mice infected by Staphylococcus aureus (S. aureus), the bacteria that causes skin infections, respiratory diseases, and food poisoning in humans. They also injected it into mice infected with Mycobacterium tuberculosis (M. tuberculosis), the main cause of tuberculosis. Lewis and Ling found that all the mice survived while the bacteria were dead and gone.
Clinical trials for humans are expected to be two or more years away.
Resisting resistance
What makes teixobactin so unique was that it was found and developed in ground soil. Lewis and Ling used an item called an iChip that provides blocks of soil sourced from various locations with nutrients, so when bacteria develop a colony, the researchers can take it back to the lab and analyze it further. This is different from the usual technique for antibiotic creation, where bacteria are grown and raised on a petri dish.
This new technique provides a unique look on how pharmaceutical companies and researchers can improve antibiotic creation. By looking at more natural sources and raising them in their environment rather than in a lab, we can find new antibiotics like teixobactin to eliminate the strongest bacterial infections.
Other researchers, such as Dr. John Conly quoted in a January 7 Globe and Mail article on the bacteria, contend that resistance is inevitable, contrary to the researchers’ claims. In either case, new sources of antibiotics at least enlarge our arsenal.
