Fig. 2
Cpl-1 endolysin retains its antibacterial activity against antibiotic-resistant pneumococcal isolates in human blood and human cerebrospinal fluid. A Blood obtained from healthy volunteers was spiked with penicillin-resistant AMR 19,000, or penicillin- and erythromycin-resistant AMR 12,116 and AMR 68,715, which was subsequently treated with 5.0 µM endolysin cpl-1 or protein buffer as a negative control. B Turbidity reduction assay with the same isolates in pooled human cerebrospinal fluid. In A, bars show the mean ± standard deviation of three biological replicates (n = 3). In B, datapoints show one biological replicate (n = 1) every 5 min. Log10(CFU/mL) were analyzed by means of a two-tailed, paired t-test; LOD indicates the limit of detection (200 CFU/mL); * indicates p < 0.05, ** indicates p < 0.01 and *** indicates p < 0.001