Effect of per oral administration of the ŽP strain, a new potential probiotic, on rats

Abstract

Bacterial antimicrobial resistance is worldwide rising and is already reaching worrisome levels, hence WHO released the priority bacterial pathogen list for research and development of new antimicrobial agents. ŽP strain, a new Nissle 1917 based antimicrobial strain harbors a bacteriocin, colicin ColE7, bacterial conjugationbased “kill” – “anti-kill” antimicrobial system. In previous studies the efficiency of ColE7 bacterial conjugation-based antimicrobial system was shown against different Escherichia coli strains. In this study its effect after the per oral administration of the ŽP strain, on the host, namely on rats of both sexes was studied. The following parameters were analyzed weight, histology of intestine, spleen and Peyer’s patches, blood biochemistry, hematology and microbicide activity of leukocytes and peritoneal macrophages. Our results showed that when administered at a dose of 5 × 108 CFU in the drinking water the ŽP strain is safe and responsible for control and maintenance of an adequate local and non-specific immune response and can also improve the performance of animals in terms of weight gain. Hence our results indicate that it is a promising probiotic.