Objective: To investigate the in vitro bacteriostatic action of Shenglin Baizhu powder (SBP) on Clostridium difficile

a major pathogen of antibiotic associated diarrhea (AAD). Method: The normal culture group (cultured on brain heart infusion) and cultured on adding medicine culture group (cultured on brain heart infusion adding a series dilution of with V/V: 1×10-1

10-2

10-3

and 10-4) were used to test the influences of SBP on in vitro growths of four clinic C. difficile isolates (NC-1

NC-2

SH182 and SH186) including two A+B+ stains and two A-B+ stains respectively

using continual exampling and spectrophotometry methods. Result: The modified brain heart infusion medium adding SBP decoction of whole dilution (V/V: 10-1

10-2

10-3 and 10-4) and of the 10-1 dilution significantly inhibited the growths of C. difficile NC-1 and C. difficile NC-2 respectively (P<0.05)

while modified BHI medium adding other series dilution SBP decoctions exhibited slight influences on all selective C. difficile strains by decreasing the bacterial CFU· mL-1 (colony forming units per milliliter) maximum. Conclusion: SBP has some bacteriostatic action to influence the growth of AAD pathogens.