News of a Nevada woman dying from an infection resistant to all kinds of antibiotics available in the United States has rocked the world of health care, showing that the matter of superbugs is much more urgent than previously thought.
Now, scientists from Oregon State University have developed a new potential weapon in the fight against antibiotic-resistant germs: a molecule neutralizing the bacteria’s ability to evade the antibiotic.
Key Molecule To Combat Resistance
The PPMO molecule, short for peptide-conjugated phosphorodiamidate morpholino oligomer, is hoped to inhibit an enzyme produced by bacteria known as NDM-1, which is instrumental in coding resistance — alongside other genes — to most if not all antibiotics.
"We're targeting a resistance mechanism that's shared by a whole bunch of pathogens," said microbiology professor and lead researcher Bruce Geller in a statement, only one PPMO is needed to fight resistance since the genes are shared across various bacteria types.
Here’s how it goes: the molecule would establish contact with the antibiotics, restoring its ability to fight NDM-1-expressing bacteria.
In their research, the team used the antibiotic meropenem, an ultra-broad spectrum medication from the carbapenem group. The drug emerged effective in treating mice infected with E. coli bacteria found to be positive with NDM-1.
Racing Against The Clock
According to Geller, the molecule will likely be tested in humans in around three years. And it’s a massive challenge ahead, given the difficulty of developing new drugs to stay a step ahead of the persistent bacteria.
The penicillin-type carbapenems had been the last line of defense against bacteria. NDM-1 becomes so important such that it annihilates carbapenems and forces doctors to use colistin — which has not been used in decades due to its kidney toxicity.
A PPMO can restore bacteria’s vulnerability to antibiotics again, reported Geller. It is also hoped that one day the NDM-1 enzyme can be targeted directly without going through antibiotics.
The findings were discussed in the Journal of Antimicrobial Chemotherapy.
Superbugs Can Be Asymptomatic, Too
Health experts have also warned about patients treated in hospitals overseas and potentially acquiring highly dangerous infections. The unnamed patient in Reno, Nevada, for instance, had inpatient exposure in Indian health centers before being treated in the United States. Practices in such hospitals may not be at par with those in the country, a factor that can contribute to superbug spread.
A separate study recently warned that the Carbapenem-resistant Enterobacteriaceae (CRE), which infects around 9,300 and kills about 600 of them in the United States, may be spreading silently and causing no symptoms in humans at all.
CRE seems to have more ways of evading antibiotics than what are currently identified by researchers, and that it may be proliferating more stealthily than current diagnostic and tracking methods can find.
The use of antibiotics in agriculture also plays a role in the ongoing campaign against superbugs. A new regulation from the FDA, taking effect this month, seeks to decrease this agricultural use of medically important antibiotics, and even farms themselves have begun taking steps to curb the widespread problem.