new approach for designing a potentially vaccine candidate against urinary tract infection by using protein display on lactobacillus surface

The prevalence of Urinary Tract Infection [UTI] is really high in the world. Escherichia coli is a major agent of UTI. One of the strategies for decreasing UTI infections is vaccine development. As the attachment is a really important stage in colonization and infection, attachment inhibition has an applied strategy. FimH protein is a major factor during bacterial colonization in urinary tract and could be used as a vaccine. Thus, it was considered in this research as a candidate antigen. The sequences of fimH and acmA genes were used for designing a synthetic gene. It was cloned to pET23a expression vector and transformed to E. coli [DE3] Origami. To confirm the expression of recombinant protein, SDS-PAGE and western blotting methods were used. Subsequently, recombinant protein was purified. On the other hand, Lactobacillus reuteri was cultured and mixed with FimH / AcmA recombinant protein. The rate of protein localization on lactobacillus surface was assessed using ELISA method. It was showed that the recombinant protein was expressed in E. coli [DE3] Origami and purified by affinity chromatography. Moreover, this protein could be localized on lactobacillus surface by 5 days. In current study, a fusion recombinant protein was prepared and displayed on L. reuteri surface. This strain could be used for animal experiment as a competitor against Uropathogenic E. coli [UPEC]. Using manipulated probiotics strains instead of antibiotic therapy could decrease the antibiotic consumption and reduce multi-drug resistant strains

Identification and biological activity of potential probiotic bacterium isolated from the stomach mucus of breast-fed lamb

The lactic acid bacterium E isolated from the stomach mucus of breast-fed lamb was identified by sequencing of 16S rDNA fragment and species-specific PCR as Lactobacillus reuteri. Its potential antimicrobial activity and ability to modulate immune system in vitro and in vivo was determined. The growth inhibition of potential pathogens decreased from Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica ser. Minnesota to Escherichia coli. The lowest inhibition activity was observed in the case of Candida albicans. The ability of L. reuteri E to modulate biological activities of human and mouse mononuclear cells was estimated in vitro and in vivo, respectively. The production of IL-1β by monocytes in vitro was significantly induced by L. reuteri E (relative activity 2.47). The ability to modulate biological activities of mononuclear cells by living L. reuteri E cells in vitro in comparison to disintegrated L. reuteri E cells in vivo differed. For example lysozyme activity in vitro was inhibited while in vivo was stimulated (relative activities 0.30 and 1.83, respectively). The peroxidase activity in vitro was stimulated while in vivo was inhibited (relative activities 1.53 and 0.17, respectively). Obtained results indicate that L. reuteri E is potential candidate to be used in probiotic preparations for animals and/or human.