Journal of Applied Microbiology, Vol.115, No.2, 546-554, 2013
The expression of adhesin EF-Tu in response to mucin and its role in Lactobacillus adhesion and competitive inhibition of enteropathogens to mucin
Aims: To analyse the expression of EF-Tu in Lactobacillus strains with response to mucin exposure and its role in interfering with adhesion of enteropathogens to mucin. Methods and Results: The Lactobacillus strains were analysed for their ability to adhere to immobilized mucin in microtiter plates. Lactobacillus delbrueckii M and Lactobacillus plantarum CS242 showed statistically significant adhesion to mucin, which was similar to Lactobacillus rhamnosus GG, the best binding probiotic strain. Lactobacillus rhamnosus GG, Lact.delbrueckii M, Lact.plantarum CS23 and Lact.plantarum CS242 were able to effectively antagonize the adhesion of Escherichia coli and Salmonella enterica serovar Typhi to mucin. In the presence of Lactobacillus adhesin - EF-Tu, the adhesion of Lact.delbrueckii M and the strains of Lact.plantarum to mucin was significantly inhibited. Similarly, EF-Tu also reduced the adhesion of enteropathogens to mucin. Furthermore, the relative fold change in gene expression analysis showed significant up-regulation of EF-Tu gene in the strains of Lact.plantarum and Lact.delbrueckii M when exposed to mucin for 3h. Conclusions: The study shows the significant role of EF-Tu in lactobacilli adhesion and enteropathogens inhibition. Significance and Impact of the Study: The study suggests EF-Tu as an important factor linked to the Lactobacillus adhesion as well as enteropathogen inhibition. Lactobacillus plantarum CS23 and Lact.plantarum CS242 can be used as potential probiotic strains.