Keratoconjunctivitis in mice inoculated with potential PhoQ inhibitors treated Sf9380.

A Mouse Sereny test shows the virulence of S. flexneri Sf9380. Mice inoculated with 1×108 CFUs display severe keratoconjunctivitis without purulence 24 hours post-infection, developed keratoconjunctivitis with purulence after 48 hours, and sustained the infection for 96 hours. Sf9380 cultured with a serial dilution of potential PhoQ inhibitors was inoculated into mice, at 1×108 CFUs per eye.The degree of keratoconjunctival inflammation in each of the six mice infected with Sf9380, ATCC 25922, DMSO, and Sf9380 pre-treated with different concentrations of potential PhoQ inhibitors 1, 2, 3 or 4 at 24, 48,72 and 96 hours (n = 6). Mouse Keratoconjunctivitis was rated as follows: −, no disease; ±, little keratoconjunctivitis; +, mild keratoconjunctivitis; ++, keratoconjunctivitis with some purulence; +++, fully developed keratoconjunctivitis with great purulence.(a)Inoculation of Sf9380 alone, served as the positive control for the Mouse Sereny.(b)ATCC 25922, an avirulent E. coli strain, served as a negative control for the Mouse Sereny test.(c)DMSO, Sf9380 treated with DMSO, the solvent of the potential PhoQ inhibitors, served as a control for the Mouse Sereny test.