Antibiotic resistance: Reprogramming bacteria turns them sensitive to drugs

A two-pronged approach where antibiotic resistance in selected bacteria is deleted and other bacteria are made more sensitive to drugs has been developed by Israeli researchers.

Using bacterial viruses called phages, which transfer "edited" DNA into resistant bacteria, the team led by professor Udi Qimron of the Department of Clinical Microbiology and Immunology at TAU's Sackler Faculty of Medicine, could eliminate the genes that cause antibiotic resistance as well as deliver protection against lethal phages.

"We managed to devise a way to restore antibiotic sensitivity to drug-resistant bacteria, and also prevent the transfer of genes that create that resistance among bacteria," said professor Qimron.

"Since there are only a few pathogens in hospitals that cause most of the antibiotic-resistance infections, we wish to specifically design appropriate sensitization treatments for each one of them," he said and added, "We will have to choose suitable combinations of DNA-delivering phages that would deliver the DNA into pathogens, and the suitable combination of 'killing' phages that could select the re-sensitized pathogens."

Earlier, research had revealed that bacteria could be sensitised to certain antibiotics and that these bacteria could be picked by specific chemical agents.

Qimron's strategy harnesses the gene editing tool CRISPR-Cas to achieve the results.

Qimron and his team are now poised to apply the CRISPR/phage system on pseudomonas aeruginosa -- one of the world's most prevalent antibiotic-resistant pathogens involved in hospital-acquired infections.

The research is published in PNAS.

No new drugs

At its annual assembly in Geneva last week, the World Health Organization approved a global action plan to slow the rapid, extensive spread of antibiotic resistance around the world and spur development of new drugs.

Only two new antibiotics have been approved since 2009. Big pharma is not interested as the returns are low.

The future of antibacterial drug discovery depends largely on discovery and research taking place within academia, research institutes and small and medium enterprises.

Recently researchers from the University of Buffalo engineered colonies of the bacteria Escherichia coli (E coli) to produce antibiotics that work against drug-resistant bacteria. The team made more than 40 new analogs of erythromycin — three of which killed erythromycin-resistant bacteria in lab experiments.

Globally, antibiotic use has risen by 36% during the last decade. Prescription of drugs for a wide range of viral infections as also availability over the counter, and overuse in veterinary medicine, has led to development of drug resistant strains of microbes.