Antibiotic Resistance Crisis Discussion Questions

According to the text and information in Figure 1, how long after the introduction of antibiotics is resistance often reported?

Within a decade. Penicillin was successful in controlling bacterial infections in the 1940’s. By the 1950s however, penicillin resistance became a clinical problem. The same trend was seen with nearly every antibiotic. Resistance was also seen within a couple years for some of the antibiotics.

What impact does horizontal gene transfer have on the evolution of resistance? How does it enable diverse groups of bacteria to become resistant? 

In bacteria genes can be inherited from both relatives and non-relatives through plasmids. This process is horizontal gene transfer and can allow antibiotic resistance to be transferred among different species. Through HGT two bacteria that are different species are able to share genes with each other. The sex pilus can join the cytoplasm, transferring genes, of two unrelated bacteria.

How often are antibiotics inappropriately prescribed, and how can this lead to resistance?

Studies show that in 30-50% of cases the choice of agent and duration of antibiotic therapies are incorrect. An additional 30-60% of antibiotics prescribed in the ICU were found to be not needed, inappropriate or suboptimal. This leads to resistance because it supports genetic alterations (changes in gene expression, horizontal gene transfer and metagenesis). These changes can increase virulence, and the increased mutagenesis and HGT promotes antibiotic resistance and spread.

 What are the majority of antibiotics (80%) in America used for?

The majority of antibiotics in America is used in animals, to promote their growth and prevent infection. This improves the health of the animals causing larger yields and a higher quality product.

How do resistant bacteria from farm animals reach consumers?

The resistance bacteria from farm animals reaches the consumers when the antibiotics used in livestock are ingested by humans eating that meat. High rates of antibiotic resistance were found in the intestinal microbes of both the farm animals and the consumers. This primarily occurs through meat products. Antibiotics are used in food producing animals kills bacteria, allowing antibiotic resistant bacteria to flourish. These are transmitted to humans via food supply and can cause infections leading to adverse health consequences.

Why aren’t pharmaceutical companies producing as many new antibiotic drugs currently as in previous years?

The development of new antibiotics has been stalled due to economic and regulatory obstacles. 15/18 of the largest pharmaceutical companies abandoned the antibiotic field. It is not considered economically wise for the pharmaceutical industries. They are only used for a short period of time, curative and not as profitable as the drugs used for chronic illnesses. Antibiotics are also low cost compared to chronic illness treatments. There is also the problem that bacterial evolution is unpredictable, and resistance can develop to the new antibiotics rapidly, preventing profit. Because of this pharmaceutical companies fear the potential lack of return on millions of US dollars. 

Obtaining regulatory approval is also an obstacle. Standards for clinical trial made by the FDA have made antibiotic clinical trials challenging. Performing trials with a placebo is unethical.

What can be said about death rates from MRSA when compared to other causes of death?

MRSA kills more Americans every year than HIV, AIDS, Parkinson’s disease, emphysema and homicide combined. In the US, 11,285 deaths per year were due to MRSA alone. 

Why are hospital acquired infections often antibiotic resistant?

They commonly occur in hospitals due to the clustering of vulnerable patients, invasive procedures and high rates of antibiotic use. Two million Americans per year develop hospital acquired infections. This results in 99,000 deaths mostly due to antibacterial resistant pathogens. Sepsis and pneumonia alone were found to be responsible for the deaths of 50,000 Americans.