Biofilm Inhibition, Antibacterial and Antiadhesive Properties of a Novel Biosurfactant from Lactobacillus paracasei N2 against Multi-Antibiotics-Resistant Pathogens Isolated from Braised Fish.

This study aimed to assess the antibiotic susceptibility and biofilm formation ability of
pathogens isolated from braised fish as well as characterize and evaluate the antibacterial, antiadhesive,
and antibiofilm activities of the biosurfactant from Lactobacillus paracasei subsp. tolerans N2
against these pathogens. The susceptibility of six pathogens isolated from braised fish (Escherichia
coli EM2, Staphylococcus aureus SA1, Salmonella enteritidis PE1, Pseudomonas aeruginosa CT3, Yersinia
enterolitica MH5, Proteus mirabilis MR2, and Klebsiella pneumoniae AG5) to 16 antibiotics revealed
multiple resistances with an MAR index greater than 0.3. These pathogens were able to form biofilms
with S. aureus SA1, which showed the highest ability. Using biochemical and elemental analyses,
FTIR, GC-MS, 1H NMR and high-resolution mass spectrometry, the biosurfactant was characterized
as a novel glycolipoprotein made of two congeners of mass 482.28 and 507.27 m/z, respectively. They
showed bactericidal and antiadhesive activities against all pathogens. The biosurfactant inhibited
biofilm formation by these pathogens and eradicated mature biofilms.