title: Chitosan improves anti-biofilm efficacy of gentamicin through facilitating antibiotic penetration.
abstract: Antibiotic overuse is one of the major drivers in the generation of antibiotic resistant "super bugs" that can potentially cause serious effects on health. In this study, we reported that the polycationic polysaccharide, chitosan could improve the efficacy of a given antibiotic (gentamicin) to combat bacterial biofilms, the universal lifestyle of microbes in the world. Short- or long-term treatment with the mixture of chitosan and gentamicin resulted in the dispersal of Listeria monocytogenes (L. monocytogenes) biofilms. In this combination, chitosan with a moderate molecular mass (~13 kDa) and high N-deacetylation degree (~88% DD) elicited an optimal anti-biofilm and bactericidal activity. Mechanistic insights indicated that chitosan facilitated the entry of gentamicin into the architecture of L. monocytogenes biofilms. Finally, we showed that this combination was also effective in the eradication of biofilms built by two other Listeria species, Listeria welshimeri and Listeria innocua. Thus, our findings pointed out that chitosan supplementation might overcome the resistance of Listeria biofilms to gentamicin, which might be helpful in prevention of gentamicin overuse in case of combating Listeria biofilms when this specific antibiotic was recommended.
authors.affiliation: College of Science, Northwest A&F University, Yangling 712100, China. mhb1025@nwsuaf.edu.cn.
authors.forename: Haibo
authors.initials: H
authors.lastname: Mu
authors.affiliation: College of Science, Northwest A&F University, Yangling 712100, China. amin@nwsuaf.edu.cn.
authors.forename: Fan
authors.initials: F
authors.lastname: Guo
authors.affiliation: College of Science, Northwest A&F University, Yangling 712100, China. dawn@nwsuaf.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Niu
authors.affiliation: College of Science, Northwest A&F University, Yangling 712100, China. 2011015288@nwsuaf.edu.cn.
authors.forename: Qianjin
authors.initials: Q
authors.lastname: Liu
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China. shunchunwang@126.com.
authors.forename: Shunchun
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Science, Northwest A&F University, Yangling 712100, China. jduan@nwsuaf.edu.cn.
authors.forename: Jinyou
authors.initials: J
authors.lastname: Duan
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D048271:Chitosan / Q000494:pharmacology*; D005839:Gentamicins / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000502:physiology* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D008970:Molecular Weight; D011107:Polylysine / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D011107:Polylysine; D048271:Chitosan