Doctors at Bristol University found that individuals who had recently taken antibiotics showed increased resistance to subsequent antibiotic regimens. The researchers studied 3,000 people who had been given antibiotic treatments. The researchers took urine samples from patients who were prescribed antibiotics then tested the bacteria in the patients urine for antibiotic resistance. They found that the bacteria from patients who took antibiotics within two months of testing showed increased resistance to amoxicillin and trimethoprim (two antibiotics). When the antibiotic course was taken 12 months prior to taking the urine samples the influence on the antibiotic resistance of the urinary bacteria waned and the bacteria population resumed normal susceptibility to the drugs.
This is important for doctors who choose whether to prescribe antibiotics or not. Generally it is known (and Acronym Required has previously discussed) that the overuse of antibiotics creates a pool of antibiotic resistant bacteria in the environment. This exposes the human population as a whole to the increased risk of infections from of microbes that mutate and develop physiological abilities to resist the lethal affect of antibiotics. People sometimes think (and this was also discussed previously) that although they personally might be affected by their choice, not anyone else will, a misconception that allows them a certain nonchalance about whether they finish their prescription or not. If this study is repeated and the results are robust then it appears that there is an increased risk to individuals who take antibiotics, in addition to the increased risks to the population. This should add a cautionary note to patients and doctors about the dangers for individuals as well as populations of prescribing antibiotics overzealously. Though whether it changes behavior remains to be seen.
