Standing on the Shoulders of Giants: Developing Antibiotics
Hannah Behrens, DPhil Infection, Immunology and Translational Medicine (m.2015)
Although first discovered in 1928, it was only during the Second World War that Penicillin was developed into a drug that could cure people of bacterial diseases. This started the “antibiotic era” and is considered to be one of the most important medical discoveries of the twentieth century. Antibiotics have since been saving us from otherwise fatal bacterial diseases.
Today, nearly a century later, on the same street where penicillin was first mass-produced, another significant step in the development of antimicrobial drugs is taking place: bacteriocins antibiotics.
Over the years, extensive (ab)use of antibiotics led to bacterial resistance. Furthermore, it was found that antibiotics can cause a problem called dysbiosis. Our body contains millions of bacteria, the so-called microbiome. They fulfil many important functions which includes fighting disease-causing bacteria. When an antibiotic kills all these bacteria there is a void that can be filled by the dangerous bacteria, leading to worse diseases than before the treatment (e.g. C. difficile infection).
The onset of dysbiosis is why bacteriocins may be critical to treating bacterial infections. Bacteriocins are very specific antibiotics that kill only one kind of bacteria each, leaving the remaining microbiome intact. They bind to unique molecules on the surfaces of bacteria, trick the bacteria to take them up by disguising themselves as nutrients and finally kill them. Like traditional antibiotics some bacteriocins target transcription and cell wall synthesis, others however poke holes in the bacterium’s membrane or degrade their genetic information, their DNA or RNA.
It is known that bacteriocins are potent antibiotics in mice and pigs (and in moths), more potent in fact than conventional commercial antibiotics. There seem to be very low levels of resistance to bacteriocins and in experiments where bacteria were exposed to bacteriocins repeatedly, resistance did not emerge.
The potential for bacteriocins is huge and the field eagerly anticipates the start of human trials; a significant step forward considering some bacteria are resistant to all 26 antibiotics on the market. One of the things that need to be known about any new medication before it is tested is how it works. This helps anticipate side effects. Therefore, my research focusses on unravelling the mechanism behind the most potent bacteriocin found to date: pyocin S5.
More specifically, I investigate how is pyocin S5 is so specific in finding its target cells? How does it get into target cells to kill? Where does the energy for the entry come from? And, can bacteria inactivate bacteriocins?
While these are very specific questions, answering them will (hopefully) be the first step to opening up the whole repertoire of bacteriocins for use in patients. If bacteriocins can prevent us from falling back into the pre-antibiotic era, their arrival could be as important as the discovery of penicillin was in Sir Alexander Flemings laboratory, close to a century ago.
During a winter evening last year, I found myself alone in an empty Kyiv park with my friend, Maria. We stood by a concrete pedestal where a statue of Vladimir Lenin was once mounted. It had obviously been torn down and the remains were scattered at our feet. Looking at the ruble, I made out […]
Nuclear power is a contentious political issue and it is something that most people hold a strong opinion on. Some people are against nuclear power as a result of the severe consequences of nuclear power plant disasters in Chernobyl and Fukushima (when 14m waves from a tsunami led to a major incident). These incidents have […]
I just got back from the swimming pool. When I was in the pool, I very vividly recalled my memories from my childhood when I used to swim competitively. Why did this distant, abstract experience feel so powerfully familiar? As I finished pondering this bizarre feeling, it occurred that I had been (thankfully) swimming without […]
I am a student in my 20s without any children or dependents. You could argue that there is no role in life granted more freedom than mine. In my position, you have the flexibility to choose how you spend your time and who you spend it with. You can spontaneously choose to meet a friend […]
Look at the image above. What do you think about this artwork? Any clue how much does this cost? Hold your heart, my friend, as it was auctioned for just $432,500. You might be wondering if the painting is embellished with riches of all sorts but no, it’s the painter who attracted this huge price […]