Kim Lewis

Newly discovered antibiotic kills pathogens without resistance

by Greg St. Martin

For years, pathogens’ resis­tance to antibi­otics has put them one step ahead of researchers, which is causing a public health crisis, according to Uni­ver­sity Dis­tin­guished Pro­fessor Kim Lewis. But in new research, Lewis and his col­leagues present a newly dis­cov­ered antibi­otic that elim­i­nates pathogens without encoun­tering any detectable resistance—a finding that chal­lenges long-​​held sci­en­tific beliefs and holds great promise for treating chronic infec­tions like tuber­cu­losis and those caused by MRSA.

The research, which is making headlines around the world, was pub­lished Wednesday in the journal Nature.

North­eastern researchers’ pio­neering work to develop a novel method for growing uncul­tured bac­teria led to the dis­covery of the antibi­otic, called teixobactin, and Lewis’ lab played a key role in ana­lyzing and testing the com­pound for resis­tance from pathogens. Lewis, who is the paper’s lead author, said this marks the first dis­covery of an antibi­otic to which resis­tance by muta­tions of pathogens have not been identified.


Slava Epstein, professor of biology

Lewis and North­eastern biology pro­fessor Slava Epstein co-​​authored the paper with col­leagues from the Uni­ver­sity of Bonn in Ger­many, Novo­Bi­otic Phar­ma­ceu­ti­cals in Cam­bridge, Mass­a­chu­setts, and Selcia Lim­ited in the United Kingdom.

The research team says teixobactin’s dis­covery presents a promising new oppor­tu­nity to treat chronic infec­tions caused by staphy­lo­coccus aureus, or MSRA, that are highly resis­tant to antibi­otics, as well as tuber­cu­losis, which involves a com­bi­na­tion of ther­a­pies with neg­a­tive side effects.

The screening of soil microor­gan­isms has pro­duced most antibi­otics, but only 1 per­cent of them will grow in the lab, and this lim­ited resource was over­mined in the 1960s, Lewis explained. He and Epstein spent years seeking to address this problem by tap­ping into a new source of antibi­otics beyond those cre­ated by syn­thetic means: uncul­tured bac­teria, which make up 99 per­cent of all species in external envi­ron­ments. They devel­oped a novel method for growing uncul­tured bac­teria in their nat­ural envi­ron­ment, which led to the founding of Novo­Bi­otic. Their approach involves the iChip, a minia­ture device Epstein’s team cre­ated that can iso­late and help grow single cells in their nat­ural envi­ron­ment and thereby pro­vides researchers with much improved access to uncul­tured bac­teria. Novo­Bi­otic has since assem­bled about 50,000 strains of uncul­tured bac­teria and dis­cov­ered 25 new antibi­otics, of which teixobactin is the latest and most inter­esting, Lewis said.

The antibi­otic was dis­cov­ered during a rou­tine screening for antimi­cro­bial mate­rial using this method. Lewis then tested the com­pound for resis­tance devel­op­ment and did not find mutant MSRA or Mycobac­terium tuber­cu­losis resis­tant to teixobactin, which was found to block sev­eral dif­ferent tar­gets in the cell wall syn­thesis pathway.

Our impres­sion is that nature pro­duced a com­pound that evolved to be free of resis­tance,” Lewis said. “This chal­lenges the dogma that we’ve oper­ated under that bac­teria will always develop resis­tance. Well, maybe not in this case.”

Gerard Wright, a pro­fessor in the Depart­ment of Bio­chem­istry and Bio­med­ical Sci­ences at McMaster Uni­ver­sity and who was not involved in this research, exam­ined the team’s work in a sep­a­rate article for Nature pub­lished in con­cert with the new research paper. In his article, Wright noted that while it remains to be seen whether other mech­a­nisms for resis­tance against teixobactin exist in the envi­ron­ment, the team’s work could lead to iden­ti­fying “other ‘resistance-​​light’ antibiotics.”

(The researchers’) work offers hope that inno­va­tion and cre­ativity can com­bine to solve the antibi­otics crisis,” Wright wrote.

Going for­ward, the research team hopes to develop teixobactin into a drug.

In 2013, Lewis revealed ground­breaking research in a sep­a­rate paper pub­lished by Nature that pre­sented a novel approach to treat and elim­i­nate MRSA—the so-​​called “superbug” that infects 1 mil­lion Amer­i­cans annu­ally. Lewis and his team dis­cov­ered a way to destroy the dor­mant per­sister cells, which are key to the suc­cess of chronic infec­tions caused by MRSA.

Lewis said this latest research lays new ground to advance his inno­v­a­tive work on treating MRSA and other chronic infections.

Originally published in news@Northeastern on January 7, 2015.

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