title: Antimicrobial and antibiofilm potential of biosurfactants isolated from lactobacilli against multi-drug-resistant pathogens.
abstract: BACKGROUND
  Biosurfactants (BS) are amphiphilic compounds produced by microbes, either on the cell surface or secreted extracellularly. BS exhibit strong antimicrobial and anti-adhesive properties, making them good candidates for applications used to combat infections. In this study, our goal was to assess the in vitro antimicrobial, anti-adhesive and anti-biofilm abilities of BS produced by Lactobacillus jensenii and Lactobacillus rhamnosus against clinical Multidrug Resistant (MDR) strains of Acinetobacter baumannii, Escherichia coli, and Staphylococcus aureus (MRSA). Cell-bound BS from both L. jensenii and L. rhamnosus were extracted and isolated. The surface activities of crude BS samples were evaluated using an oil spreading assay. The antimicrobial, anti-adhesive and anti-biofilm activities of both BS against the above mentioned MDR pathogens were determined.
  
  
  RESULTS
  Surface activities for both BS ranged from 6.25 to 25 mg/ml with clear zones observed between 7 and 11 cm. BS of both L. jensenii and L. rhamnosus showed antimicrobial activities against A. baumannii, E. coli and S. aureus at 25-50 mg/ml. Anti-adhesive and anti-biofilm activities were also observed for the aforementioned pathogens between 25 and 50 mg/ml. Finally, analysis by electron microscope indicated that the BS caused membrane damage for A. baumannii and pronounced cell wall damage in S. aureus.
  
  
  CONCLUSIONS
  Our results indicate that BS isolated from two Lactobacilli strains has antibacterial properties against MDR strains of A. baumannii, E. coli and MRSA. Both BS also displayed anti-adhesive and anti-biofilm abilities against A. baumannii, E. coli and S. aureus. Together, these capabilities may open up possibilities for BS as an alternative therapeutic approach for the prevention and/or treatment of hospital-acquired infections.
authors.forename: Karthik
authors.initials: K
authors.lastname: Sambanthamoorthy
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Feng
authors.forename: Ruchi
authors.initials: R
authors.lastname: Patel
authors.forename: Sneha
authors.initials: S
authors.lastname: Patel
authors.forename: Chrysanthi
authors.initials: C
authors.lastname: Paranavitana
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000502:physiology; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D007778:Lactobacillus / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D013501:Surface-Active Agents / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D013501:Surface-Active Agents