A New Era for Antibiotic Resistance Testing
The world as we know it is journeying down a terrifying path. With antibiotic resistance at an all time high, we are heading toward the apocalyptic scenario of a dystopian film director’s dreams—one where minor cuts and scrapes are life threatening; urinary tract infections, sexually transmitted diseases. and food poisoning can no longer be effectively treated. Candida runs rampant due to antibiotics wiping out healthy gut bacteria.
By 2050, resistant bugs (or “superbugs”) are projected to wipe out 10 million people annually worldwide.
Global antibiotic consumption grew by 30 percent between 2000 and 2010, mainly because in some countries you can acquire antibiotics without a prescription. The Center for Disease Dynamics, Economics and Policy (CDDEP), a non-profit group headquartered in Washington DC, has used scientific literature and national and regional surveillance systems to calculate the rate of antibiotic resistance for 12 types of bacteria in 39 countries. They’ve also observed trends in antibiotic use in 69 countries over the past 10 years or longer.
Their report lists improving sanitation as one method of preventing antibiotic resistance in countries that do not yet police antibiotics as effectively as others. For instance, in Nicaragua, you can stroll into a pharmacy and easily buy antibiotics without a doctor’s note. And elsewhere, there are loose rules when it comes to antibiotics in agriculture and hospitals.
As a global issue, we must also face the solution globally. That is, according to Timothy Walsh, a medical microbiologist at Cardiff University. Walsh says that we need to tackle the antibiotic issue as a collective.
“We can pour as much money and sentiment and goodwill into the front end of the problem as we want,” he says, “but unless we start to have international action and accountability, we’re going to just keep on making the same mistakes over and over again.”
The growing threat of antibiotic-resistant infections is grounded in two issues: little investment in the development of new antibiotics and accelerated bacterial evolution due to the overuse of antibiotics in healthcare and agriculture. Bacteria are evolving faster than science.
Studying antibiotic resistance becomes interesting when, instead of challenging results, you challenge methodology. This is a complex issue due to the variability in the modes of testing resistance, as well as the inconsistencies in the results.
Current methods for testing resistance to antibiotics do not reflect the actual and varying environments in the body! Can a lab be conducive to the human organism? Can a petri dish really create the same environment needed to accurately predict how bacteria fight to survive?
Inaccurate testing methods can create inaccurate outcomes—and those results then inform our physical health. This could explain why antibiotics are ineffective in some patients despite lab tests that show otherwise.
So how do we test for antibiotic susceptibility? The testing is standardized and looks for bacterial growth on Mueller–Hinton Broth (MHB), a microbiological growth medium. However, UC Santa Barbara biologist Michael Mahan and his lab have been utilizing a culture medium called LPM, a medium that more accurately depicts the intracellular conditions where bacteria replicate in the human body.
“We are not petri plates, and we need to revisit the way antibiotics are developed, tested, and prescribed,” Mahan says.
In a nutshell: standard lab testing is accurate in a dish, in vitro, but may not work for people, in vivo. Findings show that bacteria were more resistant to some antibiotics with LPM, although they were shown to be susceptible by traditional testing. This also shows that using the wrong antibiotic, although deemed acceptable for certain illnesses, can further promote resistance.
“Even in our most advanced hospitals, high drug doses are given to infected patients without knowing that the body’s environment may render bacteria inherently resistant to the very antibiotics prescribed to control them,” Mahan says.
So how do we bridge the gap between lab and human body?
Bigger, Better Antibiotics
Another interesting route Mahan takes is to explain how traditional testing might exclude effective antibiotics from consideration. Wait a minute! I thought the anti-antibiotic movement was to decrease the use of antibiotics, not create more of them?
What Mahan is noting is that if we are not going to stop antibiotic use completely, we can at least use ones that are safer and more effective for our bodies. These new culture tests will incorporate methods that better mimic the environments that trigger resistance in the body.
Mahan goes on to explain how pharmaceutical companies hold large, ‘chemical libraries’ containing “millions of chemical compounds that were excluded as antibiotics on petri plates (MHB); they may work well to fight infections…but they were never tested since standard petri plates ruled them out.” The bottom line: screening these compounds using other media, such as the LPM, could create more effective antibiotics.
The Fine Line
This shift in paradigm and methodology requires us to step on the fine line between two thought groups: one that fights to eradicate antibiotics and one that is willing to live in a world of antibiotics that are better tested and better suited for our particular condition. We are faced with new challenges, perhaps opportunities, to improve antibiotic susceptibility testing and as a consequence, reduce the growing resistance throughout the world. We are also faced with the global need to come together as a collective consciousness and demand better for our bodies. Are we willing to say no to standardized testing, which is too limited to be effective?