Fig. 3.

Bactericidal activity of T1-spanin and T1-endolysin against gram-negative bacteria. (A to F) Investigation of bacteriophage lytic activity against clinically isolated gram-negative bacteria. T1-spanin and T1-endolysin were transformed into clinical isolates (Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, and Acinetobacter spp.) as recipient strains by conjugation. For the clinical isolates of E. coli, a strain expressing the Tet repressor (which suppresses T1-spanin/T1-endolysin expression) was also prepared. Dilution series of the conjugated samples were prepared and spotted in 4-μl aliquots onto agar plates containing arabinose-supplemented M9 minimal medium. The resultant colonies were counted and plotted. All assays were performed in triplicate. The bars show the means of the 3 spot test results, and the error bars show the standard deviations.