title: Efficacy of metal ions and isothiazolones in inhibiting Enterobacter cloacae BF-17 biofilm formation.
abstract: Enterobacter cloacae is a nosocomial pathogen. The E. cloacae strain BF-17, with a high capacity for biofilm formation, was screened and identified from industrially contaminated samples, carried out in our laboratory. To develop an efficient strategy to deal with biofilms, we investigated the effects of metal ions, including Na⁺, K⁺, Ca⁺, Mg⁺, Cu⁺, and Mn⁺, and 3 isothiazolones, on elimination of E. cloacae BF-17 biofilm formation by using a 0.1% crystal violet staining method. The results revealed that higher concentrations of Na⁺ or K⁺ significantly inhibited E. cloacae BF-17 biofilm development. Meanwhile, Ca²⁺ and Mn²⁺ stimulated biofilm formation at low concentration but exhibited a negative effect at high concentration. Moreover, biofilm formation decreased with increasing concentration of Mg²⁺ and Cu²⁺. The isothiazolones Kathon (14%), 1,2-benzisothiazolin-3-one (11%), and 2-methyl-4-isothiazolin-3-one (10%) stimulated initial biofilm formation but not planktonic growth at low concentrations and displayed inhibitory effects on both biofilm formation and planktonic growth at higher concentrations. Unfortunately, the 3 isothiazolones exerted negligible effects on preformed or fully mature biofilms. Our findings suggest that Na⁺, K⁺, Mg²⁺, and isothiazolones could be used to prevent and eliminate E. cloacae BF-17 biofilms.
authors.affiliation: a Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology, South China (The Ministry-Province Joint Development), Guangzhou, Guangdong, 510070, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.forename: Long-Jie
authors.initials: LJ
authors.lastname: Li
authors.forename: Qing-Shan
authors.initials: QS
authors.lastname: Shi
authors.forename: You-Sheng
authors.initials: YS
authors.lastname: Ouyang
authors.forename: Yi-Ben
authors.initials: YB
authors.lastname: Chen
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Hu
mesh_terms: D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000502:physiology; D007477:Ions / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D010933:Plankton / Q000187:drug effects; D013844:Thiazoles / Q000494:pharmacology*
chemical_list: D007477:Ions; D008670:Metals; D013844:Thiazoles