Objective:To study the effects of Streptococcus pneumoniae(S.pn)capsular polysaccharide(CPS)on acute otitis media of C57BL/6 mice. Methods:TIGR4Δcps strain was built by homologous replacement construction. Wild TIGR4(5 μl/ear)or TIGR4Δcps was respectively inoculated into bilateral ear cavity by puncturing the tympanic membrane;an equal amount of sterile phosphate buffered saline(PBS)was injected into the control group. The status of mice was detected every day;inflammation of middle ear epithelia that deal ...