New hope in the fight against antibiotic resistance

rsz_antibiotic

Imagine yourself cooking a meal or eating out at a restaurant. The next morning you wake up with a minor infection. Your stomach hurts and you can’t leave the bathroom, so you call off work. The illness doesn’t clear in 24 hours, so you go to the hospital. The doctor runs some tests and tells you have a bacterial infection. He writes you a script for some antibiotics and you go on your way. After taking the full course (always take the full course!), you’re back in the hospital with a more severe version of the initial illness. Turns out, the bad bacterium is antibiotic-resistant.

Antibiotics are ubiquitous. Everything from food to toothpaste to hand soap contains some form of antimicrobial compound. Advertisers promise us that these products will keep us bacteria free and safe from getting sick while the science says this is ineffective and naïve at best. Livestock remains the world’s largest consumer of antibiotics, even though recent studies suggest there is no added growth or health benefit when supplementing animal feed with antibiotics. Unfortunately for us, this culture of unlimited and inappropriate usage has led to the rise of antibiotic-resistant bacteria. The pipeline for new antibiotics has virtually dried up and effective alternative treatments using peptides or bacteriophage are proving difficult to bring into the clinic.

Just this past year, the World Health Organisation warned that the 21st century could be the beginning of a post-antibiotic era. Many early antibiotics are already useless and our most powerful antibiotics are growing more ineffective every day. What does this mean for us? Invasive and replacement surgeries would be difficult, if not impossible. Hospital visits would become longer and more deadly. Treatment would become more invasive and riskier.

The loss of antibiotics as a viable treatment option is one of the greatest challenges we will face in the 21st century. Possibly even the greatest. Why? A post-antibiotic era has the potential to send us back over 100 years into medical history where people young and old died of common bacterial infections, such as cholera or pneumonia. The bacterium that causes tuberculosis is continuing to develop resistance to our last-defence drugs and infections caused by methicillin-resistant Staphylococcus aureus, also known as MRSA, are common. Our healthcare systems are constantly being taxed by the challenges posed by these multidrug-resistant bacteria.

Texiobactin

But there is hope on the horizon. A paper recently published in Nature suggests that we are not without natural sources of antibiotics, even entirely new families of antibiotics. The publication’s authors revived an old pipeline, mining soil bacteria for antibiotics, using a powerful new tool that allows researchers to study previously unknown bacteria. This new antibiotic, texiobactin, is effective against Gram-positive bacteria (a group that includes the bacteria behind strep throat, scarlet fever, and tuberculosis) in laboratory studies on mice, significantly more effective than the similar acting antibiotic vancomycin. Texiobactin has a long road ahead before it will be approved for clinical use, but early results are encouraging. Most promising, the mechanism behind texiobactin means resistance will be very slow to develop. The compound attacks cell wall precursors that are highly conserved across all bacteria, so a radical change to these precursors or an enzyme able to modify texiobactin would need to develop before a bacterium could become resistant.

Even after more than a century of bacteriology, we are only able to culture about 1% of bacteria in a lab. The other 99% is an unknown frontier, as unknown to us as the far reaches of space. What promise do these bacteria hold? What benefits will we find in the unseen world? It will take a dedicated global effort to find the next major leap in bacterial treatment.

Antibiotics are not the final answer, but they are a useful tool. Increased funding for fundamental researchers who investigate life’s nuances and for those who are cleverly meeting the challenge of antibiotic-resistance is sorely needed. In addition, better public education on proper antibiotic usage, particularly from health ministries to doctor to patient, new regulations on antibiotic use and a more encouraging (even global) regulatory scheme for antibiotics and alternative treatments are all steps we will need to take if we wish to delay a post-antibiotic era. That era will come, but it is better it does when we have an alternative than when we aren’t prepared.

*Paul Bergen [2013] is doing a PhD in Pathology. Picture credit of the antibiotic cefalexin: Wiki Commons and Sage Ross.

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