Previous studies discovered that L. monocytogenes and Francisella species mutants hyperactivated the inflammasome as a consequence of bacteriolysis in the host cytosol (8, 10); hence, we hypothesized that our bacteriolysis mutants would also induce pyroptosis in macrophages. Holin-lysin and ΔyvcK strains were used as positive controls, since lysis of these strains triggers the AIM2 inflammasome (8). The Δhly strain induces undetectable levels of cell death because it cannot access the cytosol to be recognized by AIM2 (8). Infections with pdhC::Tn and yvcJ::Tn mutants induced significantly higher levels of caspase-1- and AIM2-dependent cell death in macrophages in comparison to wild-type results as expected (Fig. 3 and Fig. S5A). Like that seen with the ΔyvcK mutants (8), yvcJ::Tn mutant intracellular replication was partially caspase-1 dependent, as indicated by a moderate rescue in intracellular replication in caspase-1-deficient macrophages (Fig. S5B). Unlike that seen with the ΔyvcK and yvcJ::Tn mutants, pdhC::Tn mutant intracellular replication was not rescued in caspase-1-deficient macrophages, suggesting that the intracellular growth defect of these mutants is independent of induction of host cell death (Fig. S5C). Additionally, despite delivering plasmid and chromosomal DNA to the cytosol (Fig. 1A and Fig. S2C), infections with the other bacteriolysis mutants induced cell death at levels indistinguishable from those seen with the wild-type strain (Fig. 3). These mutants also did not induce caspase-3/caspase-7 (caspase-3/7)-dependent apoptosis in macrophages as an alternative to pyroptosis (Fig. S5D). In contrast to previous reports demonstrating a consistent link between bacteriolysis and inflammasome activation (8, 10), our data suggest that cytosolic bacteriolysis alone may be insufficient to trigger the inflammasome or that L. monocytogenes possesses additional strategies to avoid inflammasome activation.