Creative Minds: Rapid Testing for Antibiotic Resistance

Ahmad Khalil

Ahmad (Mo) Khalil

The term “freeze-dried” may bring to mind those handy MREs (Meals Ready to Eat) consumed by legions of soldiers, astronauts, and outdoor adventurers. But if one young innovator has his way, a test that features freeze-dried biosensors may soon be a key ally in our nation’s ongoing campaign against the very serious threat of antibiotic-resistant bacterial infections.

Each year, antibiotic-resistant infections account for more than 23,000 deaths in the United States. To help tackle this challenge, Ahmad (Mo) Khalil, a researcher at Boston University, recently received an NIH Director’s New Innovator Award to develop a system that can more quickly determine whether a patient’s bacterial infection will respond best to antibiotic X or antibiotic Y—or, if the infection is actually viral rather than bacterial, no antibiotics are needed at all.

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Brain Scans Show Early Signs of Autism Spectrum Disorder

Unhappy baby

Source: Getty Images

For children with autism spectrum disorder (ASD), early diagnosis is critical to allow for possible interventions at a time when the brain is most amenable to change. But that’s been tough to implement for a simple reason: the symptoms of ASD, such as communication difficulties, social deficits, and repetitive behaviors, often do not show up until a child turns 2 or even 3 years old.

Now, an NIH-funded research team has news that may pave the way for earlier detection of ASD. The key is to shift the diagnostic focus from how kids act to how their brains grow. In their brain imaging study, the researchers found that, compared to other children, youngsters with ASD showed unusually rapid brain growth from infancy to age 2. In fact, the growth differences were already evident by their first birthdays, well before autistic behaviors typically emerge.

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Snapshots of Life: Virus Hunting with Carbon Nanotubes

H5N2 trapped in carbon nanotubes

Credit: Penn State University

The purple pods that you see in this scanning electron micrograph are the H5N2 avian flu virus, a costly threat to the poultry and egg industry and, in very rare instances, a health risk for humans. However, these particular pods are unlikely to infect anything because they are trapped in a gray mesh of carbon nanotubes. Made by linking carbon atoms into a cylindrical pattern, such nanotubes are about 10,000 times smaller than width of a human hair.

The nanotubes above have been carefully aligned on a special type of silicon chip called a carbon-nanotube size-tunable-enrichment-microdevice (CNT-STEM). As described recently in Science Advances, this ultrasensitive device is designed to capture viruses rapidly based on their size, not their molecular characteristics [1]. This unique feature enables researchers to detect completely unknown viruses, even when they are present in extremely low numbers. In proof-of-principle studies, CNT-STEM made it possible to collect and detect viruses in a sample at concentrations 100 times lower than with other methods, suggesting the device and its new approach will be helpful in the ongoing hunt for new and emerging viruses, including those that infect people.

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Portable System Uses Light to Diagnose Bacterial Infections Faster

PAD system

Caption: PAD system. Left, four optical testing cubes (blue and white) stacked on the electronic base station (white with initials); right, a smartphone with a special app to receive test results transmitted by the electronic base station.
Credit: Park et al. Sci. Adv. 2016

Every year, hundreds of thousands of Americans acquire potentially life-threatening bacterial infections while in the hospital, nursing home, or other health-care settings [1]. Such infections can be caused by a variety of bacteria, which may respond quite differently to different antibiotics. To match a patient with the most appropriate antibiotic therapy, it’s crucial to determine as quickly as possible what type of bacteria is causing his or her infection. In an effort to improve that process, an NIH-funded team is working to develop a point-of-care system and smartphone app aimed at diagnosing bacterial infections in a faster, more cost-effective manner.

The portable new system, described recently in the journal Science Advances, uses a novel light-based method for detecting telltale genetic sequences from bacteria in bodily fluids, such as blood, urine, or drainage from a skin abscess. Testing takes place within small, optical cubes that, when placed on an electronic base station, deliver test results within a couple of hours via a simple readout sent directly to a smartphone [2]. When the system was tested on clinical samples from a small number of hospitalized patients, researchers found that not only did it diagnose bacterial infections about as accurately and more swiftly than current methods, but it was also cheaper. This new system can potentially also be used to test for the presence of antibiotic-resistant bacteria and contamination of medical devices.

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Lyme Disease: Gene Signatures May Catch the Infection Sooner

Borrelia burgdoferi

Caption: Borrelia burgdorferi. Immunofluorescent antibodies bind to surface proteins on the bacterium that causes Lyme disease, producing fluorescent yellow, red, and green hues.
Credit: National Institute of Allergy and Infectious Diseases

Each year, thousands of Americans are bitten by deer ticks.These tiny ticks, common in and around wooded areas in some parts of the United States, can transmit a bacterium into the bloodstream that causes Lyme disease. Those infected experience fever, headache, stiff necks, body aches, and fatigue. A characteristic circular “target” red rash can mark the site of the tick bite, but isn’t always noticed. In fact, many people don’t realize that they’ve been bitten, and weeks can pass before they see a doctor. By then the infection has spread, sometimes causing additional rashes and/or neurological, cardiac, and rheumatological symptoms that mimic those of other conditions. All of this can make getting the right diagnosis frustrating, especially in areas where Lyme disease is rare.

Even when Lyme disease is suspected early on, the bacterium is unusually slow growing and present at low levels, so it can take a while before blood tests detect antibodies to confirm the condition. By then, knocking out the infection with antibiotics can be more challenging. But research progress continues to be made toward improving the diagnosis of Lyme disease.

An NIH-supported team recently uncovered a unique gene expression pattern in white blood cells from people infected with the Lyme disease-causing bacterium Borrelia burgdorferi [1]. This distinctive early gene signature, which persists after antibiotic treatment, is unique from other viral and bacterial illnesses studies by the team. With further work and validation, the test could one day possibly provide a valuable new tool to help doctors diagnose Lyme disease earlier and help more people get the timely treatment that they need.

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