(A) Survival percentage of 3-4 dpf zebrafish embryos (n ≥156) upon infection with S. pneumoniae T4 alone or its isogenic PLY mutant, T4Δply. Injection with E3 growth medium served as mock control. *** denotes P < 0.0005 and **** denotes P < 0.0001 by Mantel Cox test. Exact P values are shown in Appendix Table S4. 