Team combats antibiotic resistance with engineered viruses

March 2, 2009 by Anne Trafton

A new approach to fighting bacterial infections, developed at MIT and Boston University, could help prevent bacteria from developing antibiotic resistance and help kill those that have already become resistant.

Researchers from both schools have engineered a virus that knocks out bacterial defense systems, enhancing the effectiveness of antibiotics. The work is reported in the March 2 online issue of the Proceedings of the National Academy of Sciences.

Antibiotic-resistant bacteria pose a serious and growing health risk. The Centers for Disease Control and Prevention estimates that the antibiotic-resistant bacterium MRSA, or methicillin-resistant Staphylococcus aureus, causes approximately 94,000 infections and contributes to 19,000 deaths annually in the United States, through contact that can occur in a variety of locations, including schools, hospitals and homes.

New drugs are needed to combat these superbugs, but very few new antibiotics have been developed in the past few decades. "There are a lot of targets to go after, but people haven't been able to find the drugs," said Timothy Lu, lead author of the paper and an MD candidate in the Harvard-MIT Division of Health Sciences and Technology (HST).

Lu and James Collins, Howard Hughes Medical Institute investigator and professor of biomedical engineering at BU, took a new approach: engineering existing bacteriophages (viruses that infect bacteria) to attack specific targets. "It's much easier to modify phages than to invent a new drug," said Lu.

Lu, who completed his PhD at HST last year, won the $30,000 Lemelson-MIT Student Prize and the grand prize in the National Collegiate Inventors Competition in 2008 for his work with engineered bacteriophages.

The engineered viruses described in the PNAS paper attack the SOS system, a bacterial DNA repair system enlisted when bacteria are exposed to antibiotics that damage DNA, and other gene networks. Used in conjunction with traditional antibiotics, the viruses undermine bacterial defense systems and prevent resistance from developing.

The researchers tested their phages with three major classes of antibiotics (quinolones, beta-lactams and aminoglyclosides) and had good results with all three. In mice infected with bacteria, those treated with both engineered bacteriophage and antibiotics had an 80 percent survival rate, compared with 50 percent for mice treated with natural bacteriophages and antibiotics, 20 percent for mice treated only with antibiotics, and 10 percent for untreated mice.

"This work lays the groundwork for the development of a library of bacteriophages, each designed to attack different bacterial targets," said Lu.

In 2007, Lu and Collins demonstrated the successful creation of an engineered virus that could attack and destroy surface "biofilms" of harmful bacteria that can form on industrial and medical devices. Such viruses could be used in food processing plants, hospitals or other settings where dangerous bacteria can accumulate.

Source: Massachusetts Institute of Technology

Explore further: Researchers creating rapid diagnostic test for blood infections

Related Stories

Viruses join fight against harmful bacteria

September 23, 2015

In the hunt for new ways to kill harmful bacteria, scientists have turned to a natural predator: viruses that infect bacteria. By tweaking the genomes of these viruses, known as bacteriophages, researchers hope to customize ...

Root microbiome engineering improves plant growth

September 25, 2015

Humans have been breeding crops until they're bigger and more nutritious since the early days of agriculture, but genetic manipulation isn't the only way to give plants a boost. In a review paper published on September 25 ...

Antimicrobial film for future implants

September 23, 2015

The implantation of medical devices is not without risks. Bacterial or fungal infections can occur and the body's strong immune response may lead to the rejection of the implant. Researchers at Unit 1121 "Biomaterials and ...

Recommended for you

A long look back at fishes' extendable jaws

October 8, 2015

When it comes to catching elusive prey, many fishes rely on a special trick: protruding jaws that quickly extend their reach to snap up that next meal. Now, researchers reporting in the Cell Press journal Current Biology ...

New protein cleanup factors found to control bacterial growth

October 8, 2015

Biochemists have long known that crucial cell processes depend on a highly regulated cleanup system known as proteolysis, where specialized proteins called proteases degrade damaged or no-longer-needed proteins. These proteases ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.