title: Antimicrobial action of water-soluble β-chitosan against clinical multi-drug resistant bacteria.
abstract: Recently, the number of patients infected by drug-resistant pathogenic microbes has increased remarkably worldwide, and a number of studies have reported new antibiotics from natural sources. Among them, chitosan, with a high molecular weight and α-conformation, exhibits potent antimicrobial activity, but useful applications as an antibiotic are limited by its cytotoxicity and insolubility at physiological pH. In the present study, the antibacterial activity of low molecular weight water-soluble (LMWS) α-chitosan (α1k, α5k, and α10k with molecular masses of 1, 5, and 10 kDa, respectively) and β-chitosan (β1k, β5k, and β10k) was compared using a range of pathogenic bacteria containing drug-resistant bacteria isolated from patients at different pH. Interestingly, β5k and β10k exhibited potent antibacterial activity, even at pH 7.4, whereas only α10k was effective at pH 7.4. The active target of β-chitosan is the bacterial membrane, where the leakage of calcein is induced in artificial PE/PG vesicles, bacterial mimetic membrane. Moreover, scanning electron microscopy showed that they caused significant morphological changes on the bacterial surfaces. An in vivo study utilizing a bacteria-infected mouse model found that LMWS β-chitosan could be used as a candidate in anti-infective or wound healing therapeutic applications.
authors: Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 540-950, Korea. schpark9@gnu.ac.kr.
authors: Seong-Cheol
authors: SC
authors: Park
authors: Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 540-950, Korea. always_shh@naver.com.
authors: Joung-Pyo
authors: JP
authors: Nam
authors: Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 540-950, Korea. mmoi@naver.com.
authors: Jun-Ho
authors: JH
authors: Kim
authors: Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 540-950, Korea. metingym@sunchon.ac.kr.
authors: Young-Min
authors: YM
authors: Kim
authors: Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 540-950, Korea. jwnah@sunchon.ac.kr.
authors: Jae-Woon
authors: JW
authors: Nah
authors: Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 540-950, Korea. jmk8856@sunchon.ac.kr.
authors: Mi-Kyeong
authors: MK
authors: Jang
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D048271:Chitosan / Q000737:chemistry* / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D051379:Mice; D008813:Mice, Inbred ICR; D008970:Molecular Weight; D014867:Water / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D014867:Water; D048271:Chitosan