Attack bac

Antibiotic-resistant superbugs infect at least 2 million people annually in the United States, kill 23,000, and increase healthcare costs by an estimated $20 billion to $35 billion. Without new innovations the world is heading toward a post-antibiotic era in which common infections, once easily treatable with antibiotics, can once again kill, according to the World Health Organization.

But new research into viruses offers hope of a solution. Researchers at the European Molecular Biology Laboratory in Hamburg, Germany, developed a method that uses viruses called bacteriophages to destroy an antibiotic-resistant bacterium. Bacteriophages attack only bacteria and pose no health risk to humans.

Scientists know that bacteriophages use enzymes to destroy bacterial cell walls; but, until now, they did not know how these enzymes were activated. The current research demonstrates that the bacteriophages usurp the bacterium’s ability to read DNA and use it to multiply. The enzymes undergo a shift in shape that switches them from “standby” to “demolition” mode. They are then enabled to break down the bacterium cell wall, causing the bacterium to explode and spew out the virus, freeing it to find new bacterium hosts to destroy.

The researchers conclude that the shape shift in the enzymes is likely a common maneuver that can be used to design a variety of bacteriophages to fight antibiotic-resistant bacteria.

Listen and learn

Adults may have more difficulty learning a new language than children because they try too hard. Children often become as fluent as native speakers within months, but adults have difficulty learning the grammar of a foreign language.

For the first time the underlying reason for this phenomenon has been demonstrated in a study led by researchers at MIT’s Department of Brain and Cognitive Sciences: Language circuits in the brains of children appear to be soft-wired until adolescence, and hardwired adult brains have trouble building a new circuit for language acquisition. The more highly developed cognitive skills of adults get in the way of learning certain elements of language.

The researchers divided the adult participants into two groups and encouraged the first to try hard to learn an artificial language. They told the other group to listen while coloring (a distracting activity). The group instructed to try hard had much more difficulty learning grammatical units. That prompted lead researcher Amy Finn to say, “When it comes to learning language, trying is not always best.” —J.B.

Prevention intervention

Although some researchers have said half of Alzheimer’s cases could be prevented, 28 percent is the more likely figure, according to new research published in the journal Lancet Neurology this month.

The researchers looked at seven risk factors formerly believed to cause as many as half of Alzheimer’s cases: diabetes, midlife hypertension, midlife obesity, physical inactivity, depression, smoking, and low educational attainment. Previous studies, though, did not take into account that risk factors often overlap. For example, people with diabetes are frequently obese and also suffer from hypertension. When the researchers adjusted for co-occurrence of the risk factors, the percentage of preventable cases dropped from 50 percent to 28 percent.

Nonetheless, assuming intervention begins soon enough, and these factors actually cause Alzheimer’s, even as little as a 10 percent per decade reduction in the prevalence of each of the seven risk factors could reduce the incidence 8.3 percent worldwide by 2050. —J.B.