ABSTRACT
Objective To screen and prepare a broad-spectrum monoclonal antibody against Strep-tococcus pneumoniae ( S. pneumoniae) surface protein A ( PspA) and to evaluate its potential in clinical prac-tice. Methods Hybridoma cells were screened and inoculated into the abdominal cavities of BALB/c mice to prepare antibodies in ascites. Monoclonal antibodies were obtained by ammonium sulfate precipitation and protein A affinity chromatography and then identified by SDS-PAGE and Western blot. Their specificity, iso-forms and killing activities in vitro were analyzed. Results A broad-spectrum monoclonal antibody that rec-ognized PspA subclasses 2, 3 and 4 was obtained. Its in vitro killing rate against S. pneumoniae reached 40. 3％. Conclusions A broad-spectrum monoclonal antibody that could specifically bind to PspA was suc-cessfully prepared with a strong in vitro killing activity. This study provided reference for clinical diagnosis of S. pneumoniae-related diseases, quality assessment of S. pneumoniae vaccines and further research on mono-clonal antibody therapeutics.