Screening of the traditional Chinese medicine with antibacterial activity against pan-drug resistant Klebsiella pneumoniae in vitro

ObjectiveTo screen the traditional Chinese medicine with antibacterial activity against pan-drug resistant Klebsiella pneumoniae, and explore its antibacterial mechanism in vitro.

MethodsAmong 60 traditional Chinese medicine granules, Chinese medicines with antibacterial activity against 28 pan-resistail strains were screened.The pH value of the antibacterial active liquid was adjusted to neutral, and the antibacterial effects were compared between before and after adjusting pH value.The minimum inhibitory concentration(MIC), minimum bactericidal concentration(MBC), combined bacteriostatic effects and changes of extracellular alkaline phosphatase(ALP) activity of these Chinese medicines with antibacterial activity were detected.

ResultsFour kinds of traditional Chinese medicine with antibacterial activity against pan-resistant bacteria were screened out, which included the Scutellariae Radix, Coptis Rhizoma, Ephedrae Herba and Spatholobi Coulis.The MIC of the Scutellariae Radix, Coptis Rhizoma, Ephedrae Herba and Spatholobi Caulis was 64 mg/mL, 64 mg/mL, 128 mg/mL, 128 mg/mL and 256 mg/mL, respectively.The MBC of the Scutellariae Radix, Coptis Rhizoma, Ephedrae Herba and Spatholobi Caulis was 128 mg/mL, 64 mg/mL, 128 mg/mL, 256 mg/mL and 512 mg/mL, respectively.The differences of the antibacterial effects in four kinds of traditional Chinese medicine between before and after adjusting pH value were not statistically significant(P>0.05).The FIC values of the combined application of Scutellariae Radix and Coptis Rhizoma were more than 2.With the increasing of the concentrations of four drugs, the concentrations of ALP increased, and the increasing degree of ALP concentration was more obvious after Scutellariae Radix and Coptis Rhizoma treated.

ConclusionScutellariae Radix, Coptis Rhizoma, Ephedrae Herba and Spatholobi Caulis have good antibacterial effect in vitro, the antibacterial mechanism of Scutellariae Radix and Coptis Rhizoma may be related to the increasing of membrane permeability, but the combination of Ephedrae Herba and Spatholobi Caulis has antagonistic effect.