Healthcare Provider's FAQs

Why should you care about antibiotic resistance?

The effect of antibiotic usage impacts not only the individual, but also society. These drugs are the only therapeutic agents that are truly societal drugs, because the treatment of individuals can affect the family, the community and society at large. When treating an individual, we are not just targeting disease-causing organisms. We are also affecting the entire normal bacterial flora which are subsequently shed into the environment.

What is the association between antibiotic use and the emergence of resistance?

To date, our understanding of the relationship between antibiotic use and the emergence of resistance is based on several lines of evidence. First is the observed, correlated increase in antibiotic use and resistance development, coupled with our basic science understanding of resistance genes and their selection. More direct evidence comes from a study which examined the effect of low doses of antibiotics used as growth promotants in animals. Chickens raised from eggs were fed sub-therapeutic amounts of tetracycline in their feed. Within 24-36 hours the chickens were excreting tetracycline-resistant E.coli. As the number of weeks on tetracycline increased, other resistances in addition to that of tetracycline appeared in the E. coli strains. This finding paralleled results reported previously in which chronic use of ampicillin for urinary tract infections of British women was associated with a multi-drug resistant fecal flora. More recently, a Danish study correlated the amount of erythromcin used in different hospitals with the frequency of erythromycin resistance among staphylococci. Likewise, a study of mupirocin, a relatively new treatment for Staphylococcus aureus colonization of the nose and skin, demonstrated that as the amount of mupirocin use increased, there was a dramatic increase in resistance to mupirocin among methicillin-resistant staphylococci. While evidence is mounting, more research is needed to better understand the relationship between antibiotic use and the emergence of resistance.

Is antibiotic resistance inevitable?

Resistance problems emerge when the numbers of resistant bacterial infectious agents reach a high proportion. The development of resistance as a clinical problem is not inevitable. It is the steady use of the antibiotic and the continous selection that propels the rare resistant mutants to prominence in an environment. A resistance problem has arrived when you see that your patient has a resistant bacterial infection. The chance of finding a multiresistant pneumococcal infection in a child is probably millions of times greater now than it was 10 or 15 years ago.
The acquisition of resistance may be a rare event; an integration event may occur only once in 10 million bacteria. But once it has occurred, it can be selected and propagated. The reverse situation, loss of resistance gene(s), is not selectable. Moreover, when the new gene inserts into the chromosome or plasmid, it may cause changes which prevent it from coming out by the same way it went in. Therefore, the forward movement, the creation, development and selection of resistance which determines multidrug resistance, is a persistent problem precisely because its selection is so powerful, whereas its reversal is not. Moreover, loss will not emerge while continued antibiotic selection is present.

How can we reverse the drug resistance problem?

We must control the environmental densities of two major factors: the antibiotic and the resistance genes. Reduction of either component will lessen the generaton of antibiotic resistant bacteria. In this effort, we can evaluate shorter or rotating courses of use. Education of the consumer as well as the prescriber is critically important. We need to find new drugs which can circumvent the resistance mechanisms or which have new targets. We also have to consider how to use the new drugs once we have them. It appears that the most effective approach will be that which restores the susceptible microbial flora.

There is a need for a global surveillance system to monitor where the organisms are, where they are being transported, and what new ones appear. These data will greatly assist in our understanding of the spread of resistance. Increased understanding of the science of resistance, the approach to clinical problems, and how we can deal with resistance in line with the ecological considerations, will lead to a return of the susceptible strains, which will help us diminish and curtail the drug resistance problem.

This information from the Alliance for the Prudent Use of Antibiotics-APUA