Inhibition of Shigella sonnei adherence to HT-29 cells by lactobacilli from Chinese fermented food and preliminary characterization of S-layer protein involvement.
In this study, seven lactobacilli with a high degree of antagonistic activity against three pathogens and good adherence to HT-29 cells were selected. The ability of these seven lactobacilli to inhibit adhesion of Shigella sonnei to intestinal mucosa was studied on cultured HT-29 cells. Lactobacilli were added simultaneously with, before or after S. sonnei to test for their effectiveness in exclusion, competition and displacement assays, respectively. Lactobacillus paracasei subp. paracasei M5-L, Lactobacillus rhamnosus J10-L and Lactobacillus casei Q8-L all exhibited significant inhibitory activity. In order to elucidate the inhibitory functions of S-layer proteins, the S-layer proteins were removed with 5 M LiCl from the M5-L, J10-L and Q8-L strains. Under such conditions, inhibition activity was decreased in all three strains, as revealed in exclusion, competition and displacement assays. SDS-PAGE analysis confirmed the presence of S-layer proteins with dominant bands of approximately 45 kDa. Further analysis of S-layer proteins revealed that the hydrophobic amino acids accounted for 40.5%, 41.5% and 43.8% of the total amino acid for the M5-L, J10-L and Q8-L strains, respectively. These findings suggest that the M5-L, J10-L and Q8-L strains possess the ability to inhibit S. sonnei adherence to HT-29 cells, and S-layer proteins are involved in this adhesion inhibition.
Zhang
Ying-Chun
YC
School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
Zhang
Lan-Wei
LW
Tuo
Yan-Feng
YF
Guo
Chun-Feng
CF
Yi
Hua-Xi
HX
Li
Jing-Yan
JY
Han
Xue
X
Du
Ming
M
D000596:Amino Acids / Q000032:analysis; D000898:Antibiosis; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000502:physiology*; D002681:China; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D005516:Food Microbiology; D019073:HT29 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology*; D007778:Lactobacillus / Q000302:isolation & purification / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000502:physiology*; D012764:Shigella sonnei / Q000502:physiology*; D018609:Tibet
D000596:Amino Acids; D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; C055764:S-layer proteins