title: Inhibition of Staphylococcus aureus by crude and fractionated extract from lactic acid bacteria.
abstract: Increasing levels of antibiotic resistance by Staphylococcus aureus have posed a need to search for non-antibiotic alternatives. This study aimed to assess the inhibitory effects of crude and fractionated cell-free supernatants (CFS) of locally isolated lactic acid bacteria (LAB) against a clinical strain of S. aureus. A total of 42 LAB strains were isolated and identified from fresh vegetables, fresh fruits and fermented products prior to evaluation of inhibitory activities. CFS of LAB strains exhibiting a stronger inhibitive effect against S. aureus were fractionated into crude protein, polysaccharide and lipid fractions. Crude protein fractions showed greater inhibition against S. aureus compared to polysaccharide and lipid fractions, with a more prevalent effect from Lactobacillus plantarum 8513 and L. plantarum BT8513. Crude protein, polysaccharide and lipid fractions were also characterised with glycine, mannose and oleic acid being detected as the major component of each fraction, respectively. Scanning electron microscopy revealed roughed and wrinkled membrane morphology of S. aureus upon treatment with crude protein fractions of LAB, suggesting an inhibitory effect via the destruction of cellular membrane. This research illustrated the potential application of fractionated extracts from LAB to inhibit S. aureus for use in the food and health industry.
authors.affiliation: School of Industrial Technology, Universiti Sains Malaysia, 11800, Penang, Malaysia.
authors.forename: C-B
authors.initials: CB
authors.lastname: Wong
authors.affiliation: Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, Malaysia.
authors.forename: B-Y
authors.initials: BY
authors.lastname: Khoo
authors.affiliation: Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, Malaysia.
authors.forename: S
authors.initials: S
authors.lastname: Sasidharan
authors.affiliation: Integrated Biosensor Laboratory, National Electronics and Computer Technology Center, Pathumthani 12120, Thailand Advanced Imaging Research Center, Faculty of Medicine, Chulalongkorn University, Pathumwan 10330, Bangkok, Thailand.
authors.forename: W
authors.initials: W
authors.lastname: Piyawattanametha
authors.affiliation: Division of Food Bioscience and Technology, Korea University, Seoul 136-701, South Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Integrated Biosensor Laboratory, National Electronics and Computer Technology Center, Pathumthani 12120, Thailand Advanced Imaging Research Center, Faculty of Medicine, Chulalongkorn University, Pathumwan 10330, Bangkok, Thailand.
authors.forename: N
authors.initials: N
authors.lastname: Khemthongcharoen
authors.affiliation: Analytical Department, Fisher Scientific Sdn Bhd, Shah Alam, 40400, Selangor, Malaysia.
authors.forename: M-Y
authors.initials: MY
authors.lastname: Ang
authors.affiliation: School of Industrial Technology, Universiti Sains Malaysia, 11800, Penang, Malaysia.
authors.forename: L-O
authors.initials: LO
authors.lastname: Chuah
authors.affiliation: School of Industrial Technology, Universiti Sains Malaysia, 11800, Penang, Malaysia.
authors.forename: M-T
authors.initials: MT
authors.lastname: Liong
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D005591:Chemical Fractionation; D045424:Complex Mixtures / Q000302:isolation & purification / Q000494:pharmacology*; D007778:Lactobacillus / Q000737:chemistry* / Q000302:isolation & purification; D008055:Lipids / Q000302:isolation & purification / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology; D011506:Proteins / Q000302:isolation & purification / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development*; D014675:Vegetables / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D045424:Complex Mixtures; D008055:Lipids; D011134:Polysaccharides; D011506:Proteins
keywords: anti-staphylococcal; antimicrobials; lactobacilli