title: Clotrimazole and econazole inhibit Streptococcus mutans biofilm and virulence in vitro.
abstract: OBJECTIVE
  The aim of this study was to determine the inhibitory effect of eight antifungal drugs on S. mutans growth, biofilm formation and virulence factors.
  
  
  METHODS
  The actions of antifungal drugs on S. mutans were determined by recovery plates and survival kinetic curves. Biofilms were observed by scanning electron microscopy and the viable cells were recovered on BHI plates, meanwhile biofilms were stained by BacLight live/dead kit to investigate the biofilm viability. Bacteria/extracellular polysaccharides staining assays were performed to determine the EPS production of S. mutans biofilms. Acidogenicity and acidurity of S. mutans were determined using pH drop and acid tolerance assays, and the expression of ldh gene was evaluated using qPCR.
  
  
  RESULTS
  We found that clotrimazole (CTR) and econazole (ECO) showed antibacterial activities on S. mutans UA159 and S. mutans clinical isolates at 12.5 and 25mg/L, respectively. CTR and ECO could also inhibit S. mutans biofilm formation and reduce the viability of preformed biofilm. CTR and ECO affected the live/dead ratio and the EPS/bacteria ratio of S. mutans biofilms. CTR and ECO also inhibited the pH drop, lactate acid production, and acid tolerance. The abilities of CTR and ECO to inhibit S. mutans ldh expression were also confirmed.
  
  
  CONCLUSIONS
  We found that two antifungal azoles, CTR and ECO, had the abilities to inhibit the growth and biofilm formation of S. mutans and more importantly, they could also inhibit the virulence factors of S. mutans.
authors.affiliation: State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qiu
authors.affiliation: State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Ren
authors.affiliation: CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Huanqin
authors.initials: H
authors.lastname: Dai
authors.affiliation: CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China; Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Xuedong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China. Electronic address: liyuqing@scu.edu.cn.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Li
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D003022:Clotrimazole / Q000494:pharmacology*; D004464:Econazole / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D060888:Real-Time Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000187:drug effects* / Q000472:pathogenicity*; D037521:Virulence Factors
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D037521:Virulence Factors; D004464:Econazole; D003022:Clotrimazole
keywords: Biofilm; Cariogenic virulence; Clotrimazole; Econazole; Streptococcus mutans