Probiotic Lactobacillus casei expressing porcine antimicrobial peptide PR39 elevates antibacterial activity in the gastrointestinal tract

Lei Zhang, Dian Guo, Yangxin Liu, Yilan Shao, Yufeng Wang, Yigang Xu, Yanping Jiang, Wen Cui, Yijing Li, Lijie Tang
2016 Canadian Journal of Microbiology (print)  
16 PR39, a 4.7-kDa proline-rich antimicrobial peptide, acts as a cationic host defense peptide. In 17 addition to killing bacteria, PR39 mediates inflammatory reactions, including cell 18 proliferation, migration, wound healing, and angiogenesis. Here, we examined the 19 antibacterial effects of this peptide. The synthetic gene fragment PR39 was inserted into the 20 secretory expression vector plasmid pPG:612 of Lactobacillus casei, yielding the 21 recombinant strain pPG:612-PR39/L. casei 393.
more » ... PR39/L. casei 393. In vitro antibacterial tests showed that 22 expression of the PR39 peptide in recombinant L. casei resulted in antibacterial activity 23 against Escherichia coli and Salmonella, but had only minor antibacterial effects in 24 Staphylococcus aureus. In addition, BALB/c mice fed the recombinant pPG:612-PR39/L. 25 casei 393 grew better and had increased peripheral blood lymphocyte percentages, white 26 blood cell numbers, and spleen indices compared with those of the control group. Scanning 27 electron microscopy showed that jejunum and duodenum villus height, crypt depth, and the 28 ratio of V/C in the intestinal villi also increased. Moreover, mice fed the recombinant strain 29 showed significantly lower mortality rates than the control group when challenged with the 30
doi:10.1139/cjm-2016-0130 pmid:27718591 fatcat:ijpkbnzqszgxhgk6vwyq7n57ea