The antimicrobial peptide — a fragment of a larger protein found in certain insects — helped speed wound healing and clear infections in mice infected with Acinetobacter baumannii, the most common systemic infection in soldiers who have burns or blast wounds.
“This is a bacteria to which resistance develops very, very fast. When soldiers get injuries like blast injuries or burns, they are taken to military hospitals. These bugs (the bacteria) are all over these hospitals,” said Laszlo Otvos of Temple University in Philadelphia, whose findings were published in the Journal of Antimicrobial Chemotherapy.
“It is so bad that about 40 percent of gowns worn by healthcare workers (in military hospitals) are infected,” Otvos said in a telephone interview.
“About 30 to 40 percent of soldiers admitted to these hospitals who have blast or burn infections do get infected,” Otvos said, adding that it also infects civilian hospitals.
Current antibiotics, such as imipenem, a drug in the powerful carbapenem class used for hard-to-treat infections, or the older antibiotic colistin rapidly lose efficacy due to high rates of antimicrobial resistance. And colistin is highly toxic.
Otvos and colleagues set out to find something better. They developed a group of peptide drugs inspired by proteins in insects used to fight certain microbes.
“We optimized these. We put together all the best properties. I also made a few changes so the peptide would not decompose in the body,” Otvos said.
The result is a compound called A3-APO.
They tested this in mice with burn wounds infected with Acinetobacter baumannii bacteria taken from a Canadian soldier who had returned from Afghanistan.
When given as a shot, the therapy worked better at clearing bacterial counts in the blood and the injury site than colistin or imipenem.
The peptide also protected open wounds from bacteria in the environment.
“We have a more effective compound than anything else and a less toxic one,” Otvos said.
The drug also appears to have some effect on multi-drug resistant strains of E. coli infections.
Otvos has formed a small biotech company called Pepthera LLC based in Pennsylvania to develop the drug and has been in discussions with the U.S. Defense Department about testing the compound in people.
Khaleej Times