The birth of antibiotic resistance

Feb ,16 2017

There are trillions of bacteria all around us. Bacteria were some of the first life forms to appear on earth. Even though, they consist only of a single cell, their total biomass is greater than all animals and plants in combination. They live virtually everywhere, on the ground, in the water, on our kitchen table, on our skin and even inside us. There are around ten times more bacteria cells inside us than our body own cells. Many of those bacteria are harmless or even beneficial, helping normal body functions like digestion or immunity.

There are bacteria that if allowed can cause infection, some can be minor inconveniences but other can be epidemics. Thankfully there are medicines designed to fight bacterial infection. Synthesized from chemicals or occurring natural in nature (mold for example), these antibiotics kill or neutralize bacteria by interrupting cell wall synthesis, or interfering with processes like protein synthesis, leaving human cells unharmed.

The deployment of antibiotics during the 20th century has rendered many dangerous diseases easily treatable. Today though, many antibiotics are becoming less effective. Not that the antibiotics lost their ability to fight, but the bacteria gained the ability to fight back and manipulate the system.

Just like many other microorganisms, individual bacteria can undergo random mutations, being many of those harmless or useless, but sometimes a single mutation can give a bacterium a way of survival. If this mutation gives to the bacterium an antibiotic resistance, it increases drastically the chance of the bacteria to survive. As the non-resistant bacteria are killed by the antibiotics, witch happens quite fast in a antibiotic rich environment like hospitals, there is more room and resources for the resistant ones to thrive, passing among themselves the mutated gene that help them to do so.

Reproduction is not the only way to share genetic information; some bacteria can release their DNA upon death to be picked up by other bacteria while others use a method called conjugation, connecting through pili and sharing their genes. Over time, antibiotic resistant gene proliferate, creating what we call today super bacteria.

How long it would take until these superbugs take over? In some bacteria like Klebsiella pneumoniae it’s already happened, some strains had already become resistant to a wide range of antibiotics, including penicillin, methicillin and even oxalillin.

The good news though, is that scientists are working to stay on step ahead of the bacteria, and although the development of new antibiotics is no longer viable, the world health organization has made priority the development of novel treatments.

Most important, curbing the excessive and unnecessary use of antibiotics, as for example minor infections that our body can resolve on its’ own and changing medical practice to prevent hospital spread infections, can have a major impact by simply keeping more non resistant bacteria alive as a competition to the resistant ones. In the war against superbugs, de-escalation might work better than an evolutionary arms race.