Effects of bile salt deconjugation by probiotic strains on the survival of antibiotic-resistant foodborne pathogens under simulated gastric conditions.
This study was designed to evaluate the effects of bile acid deconjugation by probiotic strains on the antibiotic susceptibility of antibiotic-sensitive and multiple antibiotic-resistant Salmonella Typhimurium and Staphylococcus aureus. Eight probiotic strains, Bifidobacterium  longum B6, Lactobacillus acidophilus ADH, Lactobacillus brevis KACC 10553, Lactobacillus casei KACC 12413, Lactobacillus paracasei ATCC 25598, Lactobacillus rhamnosus GG, Leuconostoc mesenteroides KACC 12312, and Pediococcus acidilactici  KACC 12307, were used to examine bile acid tolerance. The ability to deconjugate bile acids was evaluated using both thin-layer chromatography and high-performance liquid chromatography. The antibiotic susceptibility testing was carried out to determine the synergistic inhibitory activity  of deconjugated bile acids. L. acidophilus, L. brevis, and P. acidilactici showed the most tolerance to the conjugated bile acids. P. acidilactici deconjugated glycocholic acid and glycodeoxycholate from 3.18 and 3.09 mM to the detection limits, respectively. The antibiotic  susceptibility of selected foodborne pathogens was increased by increasing the concentration of deconjugated bile acids. The study results are useful for understanding the relationship between bile acid deconjugation by probiotic strains and antibiotic susceptibility in the presence of deconjugated  bile acids, and they may be useful for designing new probiotic-antibiotic combination therapy based on bile acid deconjugation.
Medical and Bio-Material Research Center and Department of Biomaterials Engineering, Kangwon National University, Chuncheon, Gangwon, Republic of Korea.
Xinlong
X
He
Yunyun
Y
Zou
Youngjae
Y
Cho
Juhee
J
Ahn
D000898:Antibiosis; D001644:Bifidobacterium / Q000378:metabolism / Q000502:physiology*; D001647:Bile Acids and Salts / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000378:metabolism / Q000502:physiology*; D007934:Leuconostoc / Q000378:metabolism / Q000502:physiology*; D019936:Probiotics; D012486:Salmonella typhimurium / Q000187:drug effects / Q000254:growth & development*; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development*
D001647:Bile Acids and Salts