2 research outputs found
Natural antimicrobial peptide complexes in the fighting of antibiotic resistant biofilms: Calliphora vicina medicinal maggots
Biofilms, sedimented microbial communities embedded in a biopolymer matrix cause vast
majority of human bacterial infections and many severe complications such as chronic
inflammatory diseases and cancer. Biofilms' resistance to the host immunity and antibiotics
makes this kind of infection particularly intractable. Antimicrobial peptides (AMPs) are a ubiquitous
facet of innate immunity in animals. However, AMPs activity was studied mainly on
planktonic bacteria and little is known about their effects on biofilms. We studied structure
and anti-biofilm activity of AMP complex produced by the maggots of blowfly Calliphora
vicina living in environments extremely contaminated by biofilm-forming germs. The complex
exhibits strong cell killing and matrix destroying activity against human pathogenic antibiotic
resistant Escherichia coli, Staphylococcus aureus and Acinetobacter baumannii biofilms as
well as non-toxicity to human immune cells. The complex was found to contain AMPs from
defensin, cecropin, diptericin and proline-rich peptide families simultaneously expressed in
response to bacterial infection and encoded by hundreds mRNA isoforms. All the families
combine cell killing and matrix destruction mechanisms, but the ratio of these effects and
antibacterial activity spectrum are specific to each family. These molecules dramatically
extend the list of known anti-biofilm AMPs. However, pharmacological development of the
complex as a whole can provide significant advantages compared with a conventional onecomponent
approach. In particular, a similar level of activity against biofilm and planktonic
bacteria (MBEC/MIC ratio) provides the complex advantage over conventional antibiotics.
Available methods of the complex in situ and in vitro biosynthesis make this idea practicable.Russian Science Foundation, grant № 16-14-0004