TY - JOUR

T1 - Biofilm infections between Scylla and Charybdis: interplay of host antimicrobial peptides and antibiotics

AU - Черныш, Сергей Иванович

AU - Яковлев, Андрей Юрьевич

AU - Гордя, Наталья Александровна

AU - Тулин, Дмитрий Валентинович

N1 - Funding Information: This study was supported by a grant from the Russian Science Foundation (http://rscf.ru/, grant number 16-14-00048). The funder had no role in study design, data collection and analysis and decision to publish or preparation of the manuscript. The authors are grateful to Resource Centers “Development of molecular and cellular technologies”, “Chemical analysis and materials research” and “Culture collections of microorganisms” of St. Petersburg State University Research Park for technical assistance.

PY - 2018/4/9

Y1 - 2018/4/9

N2 - Purpose: The aim of this study is to improve the anti-biofilm activity of antibiotics. We hypothesized that the antimicrobial peptide (AMP) complex of the host’s immune system can be used for this purpose and examined the assumption on model biofilms. Methods: FLIP7, the AMP complex of the blowfly Calliphora vicina containing a combination of defensins, cecropins, diptericins and proline-rich peptides was isolated from the hemolymph of bacteria-challenged maggots. The complex interaction with antibiotics of various classes was studied in biofilm and planktonic cultures of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii by the checkerboard method using trimethyl tetrazolium chloride cell viability and crystal violet biofilm eradication assays supplemented with microscopic analysis. Results: We found that FLIP7 demonstrated: high synergy (fractional inhibitory concentration index <0.25) with meropenem, amikacin, kanamycin, ampicillin, vancomycin and cefotaxime; synergy with clindamycin, erythromycin and chloramphenicol; additive interaction with oxacillin, tetracycline, ciprofloxacin and gentamicin; and no interaction with polymyxin B. The interaction in planktonic cell models was significantly weaker than in biofilms of the same strains. The analysis of the dose-effect curves pointed to persister cells as a likely target of FLIP7 synergistic effect. The biofilm eradication assay showed that the effect also caused total destruction of S. aureus and E. coli biofilm materials. The effect allowed reducing the effective anti-biofilm concentration of the antibiotic to a level well below the one clinically achievable (2-3 orders of magnitude in the case of meropenem, ampicillin, cefotaxime and oxacillin). Conclusion: FLIP7 is a highly efficient host antimicrobial system helping antibiotics to overcome biofilm barriers through persisters’ sensitization and biofilm material destruction. It is promising for the treatment of biofilm infections as an adjuvant of various small-molecule antibiotics.

AB - Purpose: The aim of this study is to improve the anti-biofilm activity of antibiotics. We hypothesized that the antimicrobial peptide (AMP) complex of the host’s immune system can be used for this purpose and examined the assumption on model biofilms. Methods: FLIP7, the AMP complex of the blowfly Calliphora vicina containing a combination of defensins, cecropins, diptericins and proline-rich peptides was isolated from the hemolymph of bacteria-challenged maggots. The complex interaction with antibiotics of various classes was studied in biofilm and planktonic cultures of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii by the checkerboard method using trimethyl tetrazolium chloride cell viability and crystal violet biofilm eradication assays supplemented with microscopic analysis. Results: We found that FLIP7 demonstrated: high synergy (fractional inhibitory concentration index <0.25) with meropenem, amikacin, kanamycin, ampicillin, vancomycin and cefotaxime; synergy with clindamycin, erythromycin and chloramphenicol; additive interaction with oxacillin, tetracycline, ciprofloxacin and gentamicin; and no interaction with polymyxin B. The interaction in planktonic cell models was significantly weaker than in biofilms of the same strains. The analysis of the dose-effect curves pointed to persister cells as a likely target of FLIP7 synergistic effect. The biofilm eradication assay showed that the effect also caused total destruction of S. aureus and E. coli biofilm materials. The effect allowed reducing the effective anti-biofilm concentration of the antibiotic to a level well below the one clinically achievable (2-3 orders of magnitude in the case of meropenem, ampicillin, cefotaxime and oxacillin). Conclusion: FLIP7 is a highly efficient host antimicrobial system helping antibiotics to overcome biofilm barriers through persisters’ sensitization and biofilm material destruction. It is promising for the treatment of biofilm infections as an adjuvant of various small-molecule antibiotics.

KW - Antibiotics

KW - Biofilms

KW - Calliphora vicina

KW - Insect antimicrobial peptides

KW - Persisters

KW - Synergy

KW - insect antimicrobial peptides

KW - synergy

KW - CLINICAL PHARMACOKINETICS

KW - COMBINATION

KW - GRAM-NEGATIVE BACTERIA

KW - THERAPY

KW - persisters

KW - CRITICALLY-ILL PATIENTS

KW - antibiotics

KW - biofilms

UR - https://www.dovepress.com/getfile.php?fileID=41407

UR - http://www.scopus.com/inward/record.url?scp=85046337157&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/biofilm-infections-between-scylla-charybdis-interplay-host-antimicrobial-peptides-antibiotics

U2 - http://dx.doi.org/10.2147/idr.s157847

DO - http://dx.doi.org/10.2147/idr.s157847

M3 - Article

C2 - 29674848

VL - 11

SP - 501

EP - 514

JO - Infection and Drug Resistance

JF - Infection and Drug Resistance

SN - 1178-6973

ER -