A super-fine oil-and-water emulsion which is well known to destroy other microbes may assist in quelling other drug-resistant infections resulting in most of the deaths due to cystic fibrosis.
Cystic fibrosis is an inherited chronic lung disease characterised by mucus-clogged lungs that leave patients vulnerable to repeated, ever more serious respiratory infections.
''A key finding in the study is that we have a product that shows very good activity against a variety of bacteria that are very resistant to all known antibiotics. These really are superbugs,'' said John J. LiPuma, M.D., first and corresponding author of the study.
Nanoemulsions developed in the study consist of soybean oil, water, alcohol and surfactants forced by high-stress mechanical extrusion into droplets less than 400 nanometers in size.
These emulsions have already proved to be non-toxic, potent killers of bacteria such as Streptococcus pneumoniae, H. influenzae and gonorrhea, of viruses such as herpes simplex and influenza A, and of several fungi. Nanoemulsion treatments for cold sores and toenail fungus are in Phase 3 clinical trials.
''We have a product that looks like it could be safely administered to the lungs of people with cystic fibrosis,'' said LiPuma.
If future trials show that patients can tolerate effective doses of the nanoemulsion, this could be a major breakthrough in the treatment of cystic fibrosis, he said.
The novel physical mode of action the nanoemulsion appears to kill bacteria by disrupting their outer membranes - makes developing resistance unlikely, LiPuma says.
''Given that this technology works differently from antibiotic drugs, it provides a potential alternative for treatment in antibiotic-resistant bacteria. Since the material has already shown success in treating skin infections, we believe it has potential to treat antibiotic-resistant lung infections,'' said a co-author on the study.
If the technique proves safe and effective, people would inhale the nanoemulsion using a nebulizer and be able to reduce the severity and frequency of infections that spiral out of control due to resistance to current antibiotics.
In cell cultures in the lab, the scientists tested a nanoemulsion against 150 bacterial strains that attack cystic fibrosis patients.
The emulsion proved effective at killing all of them, including one-third that are resistant to many antibiotics and 13 percent that resist all antibiotics.
They then tested the nanoemulsion against several bacterial strains grown in biofilms and sputum, to more closely simulate conditions in a patient's body.
Antibiotics often can't penetrate biofilms and sputum unless given at high doses with unacceptable side effects.
''We saw, not surprisingly, that greater concentrations of nanoemulsion were required to kill the bacteria, but we saw no strains that were resistant,'' said LiPuma.
Whether humans can tolerate those concentrations well remains to be seen.
The study is published in the journal Antimicrobial Agents and Chemotherapy.