There’s no denying that we’re in the midst of a global antibiotic crisis. According to the World Health Organization (WHO), if we don’t tackle the ever-growing problem soon, we’re on a one-way journey towards a post-antibiotic era, in which normally treatable infections become killers.
There are a number of ways that we could approach the dire situation, such as reducing the use of antibiotics in intensive livestock production, performing tests on patients to ensure the correct antibiotic is used, encouraging completion of the prescribed course of treatments, encouraging hand hygiene and other infection control measures in clinical settings, to name a few. But ultimately, we’re still going to need to come up with effective antibiotic alternatives, preferably those which don’t encourage the development of resistance.
Realizing that the race is on, scientists across the globe have been working hard to achieve this, and a few promising therapies could be in the pipeline, such as using viruses (phages) to attack bacteria, or self-assembling “ninja polymers.” Now, researchers from the University of Bern have developed an innovative new antibiotic alternative that has yielded promising results in animal studies.
As described in the journal Nature Biotechnology, their new compounds are composed of tiny, naturally occurring fatty molecules called lipids. These join together to form nanoparticles known as liposomes which mimic the membranes of our own cells. These liposomes effectively act as bait for the toxins produced by various bacterial pathogens, sequestering them away from our vulnerable cells. Normally, these toxins punch holes in our cells, causing them to leak out their contents and die. However, toxins bound to the liposomes are blocked from being able to do this and are therefore rendered harmless.
“The toxins are fatally attracted to the liposomes,” explains lead researcher Eduard Babiychuk, “and once they are attached, they can be eliminated easily without danger for the host cells.”
The team tested out their liposomes on mice with septicemia (infection that has spread to the blood stream) caused by two medically important bacterial pathogens: Staphylococcus aureus and Streptococcus pneumonia. They found that administering the liposomes 10 hours after infection rescued the mice from the life-threatening condition, without the need for additional antibiotic therapy. Untreated mice, on the other hand, died within 24 to 33 hours.
Because the liposomes don’t target the bacteria themselves, they place little selection pressure on the pathogens and therefore do not encourage the development of resistance, which is a crucially important feature.
The researchers envisage that these liposomes could either be used alone or in conjunction with antibiotics to combat infections. Because liposomes are already used in drug delivery systems, hopefully it won’t be too long before human clinical trials can begin. In fact, they plan to conduct a study as soon as next year in severely ill patients with pneumococcal pneumonia.
[Via University of Bern, Nature Biotechnology, gizmag and Genetic Engineering & Biotechnology News]