what if i told you there were trillionsof tiny bacteria all around you? it's true. microorganisms called bacteriawere some of the first life forms to appear on earth. though they consist of only a single cell, their total biomass is greater thanthat of all plants and animals combined. and they live virtually everywhere: on the ground, in the water, on your kitchen table, on your skin,
even inside you. don't reach for the panic button just yet. although you have 10 timesmore bacterial cells inside you than your body has human cells, many of these bacteriaare harmless or even beneficial, helping digestion and immunity. but there are a few bad applesthat can cause harmful infections, from minor inconveniencesto deadly epidemics. fortunately, there are amazing medicinesdesigned to fight bacterial infections.
synthesized from chemicals oroccurring naturally in things like mold, these antibiotics killor neutralize bacteria by interrupting cell wall synthesis or interfering with vital processeslike protein synthesis, all while leaving human cells unharmed. the deployment of antibioticsover the course of the 20th century has rendered many previouslydangerous diseases easily treatable. but today, more and moreof our antibiotics are becoming less effective.
did something go wrongto make them stop working? the problem is not with the antibioticsbut the bacteria they were made to fight, and the reason lies in darwin's theoryof natural selection. just like any other organisms, individual bacteriacan undergo random mutations. many of these mutationsare harmful or useless, but every now and then,one comes along that gives its organism an edge in survival. and for a bacterium,
a mutation making it resistantto a certain antibiotic gives quite the edge. as the non-resistant bacteriaare killed off, which happens especially quicklyin antibiotic-rich environments, like hospitals, there is more room and resourcesfor the resistant ones to thrive, passing along only the mutated genesthat help them do so. reproductionisn't the only way to do this. some can release their dna upon deathto be picked up by other bacteria,
while others use a methodcalled conjugation, connecting through pilito share their genes. over time, the resistantgenes proliferate, creating entire strainsof resistant super bacteria. so how much time do we havebefore these superbugs take over? well, in some bacteria,it's already happened. for instance, some strandsof staphylococcus aureus, which causes everything fromskin infections to pneumonia and sepsis, have developed into mrsa,
becoming resistantto beta-lactam antibiotics, like penicillin, methicillin,and oxacillin. thanks to a gene that replaces the proteinbeta-lactams normally target and bind to, mrsa can keep makingits cell walls unimpeded. other super bacteria, like salmonella, even sometimes produce enzymeslike beta-lactams that break down antibiotic attackersbefore they can do any damage, and e. coli, a diverse group of bacteria that contains strains that causediarrhea and kidney failure,
can prevent the function of antibiotics, like quinolones, by activelybooting any invaders that manage to enter the cell. but there is good news. scientists are working to stayone step ahead of the bacteria, and although developmentof new antibiotics has slowed in recent years, the world health organization has made ita priority to develop novel treatments. other scientists are investigatingalternate solutions,
such as phage therapyor using vaccines to prevent infections. most importantly, curbing the excessiveand unnecessary use of antibiotics, such as for minor infectionsthat can resolve on their own, as well as changing medical practiceto prevent hospital infections, can have a major impact by keeping morenon-resistant bacteria alive as competition for resistant strains. in the war against super bacteria,deescalation may sometimes work better than an evolutionary arms race.
