Potential Probiotic Escherichia coli 16 Harboring the Vitreoscilla Hemoglobin Gene Improves Gastrointestinal Tract Colonization and Ameliorates Carbon Tetrachloride Induced Hepatotoxicity in Rats
Figure 3
(a) Plate counts of fluorescent colonies in fecal samples of rats, following oral administration of E. coli 16 (pUC-gfp) and E. coli 16 (pUC8:16gfp) to respective groups of rats for the effects of antibiotic on the colonization process. (b) E. coli 16 strain transformed with pUC8:16gfp plasmid showed antimicrobial activity and expressed green fluorescent protein in fecal samples of Charles Foster rats. The plate (in the right side) showed antimicrobial activity under transmitted light and the same plate (in the left side) showed green fluorescent protein under ultraviolet light at 365 nm. The plate assay suggested that the transformants retained their antimicrobial activity even after passing through rat GI tract, and pUC8:16gfp plasmid did not affect the inherent antimicrobial activity of the E. coli. (c) Colony PCR for vgb gene in colonies showing fluorescence and antimicrobial activity in the plate. 1.5% agarose gel electrophoresis revealed 714 bp specific band of vgb gene (lanes: 2 and 3). Lane 1 represents 100 bp ladder; lane 4 represents plasmid pUC-gfp serving as negative control; lane 5 represents plasmid pUC8:16gfp serving as positive control for vgb gene.
