October 9, 2013

Three foreign-born United States citizens have won the 2013 Nobel Prize in Chemistry for their work in designing powerful computer models that are widely used to study an amazing variety of complex chemical interactions. The winner are Austrian-born Martin Karplus of Harvard University and the University of Strasbourg; South African-born Michael Levitt of Stanford University School of Medicine; and Israeli-born Arieh Warshel of the University of Southern California, Los Angeles.

Developing new drugs is only one application of this pioneering work. “Today the computer is just as important a tool for chemists as the test tube. Simulations are so realistic that they predict the outcome of traditional experiments,” the Nobel Committee said. “The work of Karplus, Levitt and Warshel is ground-breaking in that they managed to make Newton’s classical physics work side-by-side with the fundamentally different quantum physics. Previously, chemists had to choose to use either or.” Quantum physics is the study of the smallest known units of matter and their activity. Using programs based on Karplus, Levitt, and Warshel’s models, researchers can study the behavior of large molecules as well as the atoms and electrons in them.

“Chemical reactions occur at lightning speed,” the Nobel Committee explained. “In a fraction of a millisecond, electrons jump from one atomic nucleus to the other. Classical chemistry has a hard time keeping up; it is virtually impossible to experimentally map every little step in a chemical process. Aided by the methods now awarded with the Nobel Prize in Chemistry, scientists let computers unveil chemical processes, such as a catalyst’s purification of exhaust fumes or the photosynthesis in green leaves.”

September 19, 2013

Infections caused by superbugs could kill hundreds of thousands, if not millions of Americans, if medical and public health professionals as well as ordinary citizens do not combat the threat posed by these antibiotic-resistant bacteria. That is the conclusion of the authors of a new report, Antibiotic Resistance Threats in the United States, 2013, released by the Centers for Disease Control and Prevention (CDC) in Atlanta. In an effort to call attention to the problem, CDC officials have established a new rating system that provides “a snapshot of the burdens and threats posed by antibiotic-resistant germs having the most impact on human health.” CDC officials said urgent steps are needed to prevent some infections from becoming essentially untreatable. “Without urgent action now, more patients will be thrust back to a time before we had effective drugs,” said CDC Director Thomas Frieden.

So-called superbugs are bacteria with the ability to overcome medications and other substances that might kill them or interfere with their growth. Each year, more than 2 million Americans develop antibiotic-resistant infections; some 23,000 of these people die, according to the CDC. The main reason for the rise of the superbugs is the widespread use of antibiotics. Up to 50 percent of all antibiotics prescribed for Americans are unnecessary or inappropriate. For example, people often request and doctors prescribe antibiotics to treat the common cold or flu. However, these infections are caused by viruses, which cannot be controlled by antibiotics. Even more worrisome is the amount of antibiotics used to promote growth and prevent and treat infections in livestock–up to 80 percent of all antibiotics used in the United States. Human ingest these antibiotics by eating meat. The more an antibiotic is used, the more quickly it can develop resistance, the CDC emphasized.

Bacteria, such as these Streptococcus cells, cause many diseases, including ear infections, strep throat, and pneumonia. ((c) Oliver Meckes/Science Source from Photo Researchers)

The CDC rating system includes three threat levels–concerning, serious, and urgent–based on seven factors. These include how common a bacterium is, how easily it spreads, the number of people it infects or kills, and the availablity of antibiotics to combat it. Three superbugs made the “urgent” list in the new report: CRE bacteria, Clostridium difficile (C-Diff), and Neisseria gonorrhoeae.

The CRE family of bacteria includes E. coli, which can cause serious illness or even death. E. coli is often found on improperly washed vegetables. Some CRE bacteria are already resistant to antibiotics.

C-Diff kills up to 14,000 people and causes 250,000 hospitalizations each year. It is often acquired in hospitals in which the staff has failed to maintain sanitary standards. These bacteria are also resistant to many antibiotics. 

Neisseria gonorrhoeae is the drug-resistant form of the bacterium that causes gonorrhea, a sexually transmitted disease and the second most commonly reported infection in the United States, according to the CDC.

The CDC report listed four major steps to fight antibiotic resistance:

• Preventing infections (through immunizations, safe food handling, and handwashing);
• Tracking bacterial infections (to determine factors that contribute to their spread);
• Improving the use of antibiotics (using them only when necessary and appropriate);
• Developing new antibiotics and diagnostic tests (to track the spread of resistance and quickly distinguish between illnesses caused by bacteria and viruses).

Additional World Book articles:

• Sanitation
• Handwashing: The First Line of Defense Against Disease (a special report)
• The War on Superbugs (a special report)