SERPINE1 and meningitis: The cooperative effect of PAIs has been experimentally confirmed with the prototype strains 536, CFT073 and RS218 (Silver et al., 1980; Hacker et al., 1983; Brzuszkiewicz et al., 2006) by monitoring UTI, septicemia and meningitis mouse models using single-PAI and/or multiple-PAI deletion mutants (Schubert et al., 2002; Xie et al., 2006; Lloyd et al., 2009a; Tourret et al., 2010).