Sodium houttuyfonate inhibits virulence related motility of Pseudomonas aeruginosa / 中国中药杂志

Sodium houttuyfonate (SH) is a derivative of effective component of a Chinese material medica, Houttuynia cordata, which is applied in anti-infection of microorganism. But, the antimicrobial mechanisms of SH still remain unclear. Here, we firstly discovered that SH effectively inhibits the three types of virulence related motility of.Pseudomonas aeruginosa, i.e., swimming, twitching and swarming. The plate assay results showed that the inhibitory action of SH against swimming and twitching in 24 h and swarming in 48 h is dose-dependent; and bacteria nearly lost all of the motile activities under the concentration of 1 x minimum inhibitory concentration (MIC) (512 mg x L(-1) same as azithromycin positive group (1 x MIC, 16 mg x L(-1)). Furthermore, we found that the expression of structural gene flgB and pilG is down-regulated by SH, which implies that inhibitory mechanism of SH against motility of P. aeruginosa may be due to the inhibition of flagella and pili bioformation of P. aeruginosa by SR Therefore, our presented results firstly demonstrate that SH effectively inhibits the motility activities of P. aeruginosa, and suggest that SH could be a promising antipseudomonas agents in clinic.

Effect of sodium houttuyfonate in enhancing imipenem's activity against Pseudomonas aeruginosa biofilms / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the resistant effect of houttuyfonate sodium (SH) combined with imipenem (IMP) against Pseudomonas aeruginosa (Pa) biofilms.</p><p><b>METHOD</b>The two-fold dilution method was used to examine the minimum inhibitory concentration (MIC) of the tested drug. The crystal violet staining was applied to detect the effect of the combination of 1/2MIC, 1MIC, 2MIC of SH, single IMP, 1/2MIC of SH and IMP of various concentrations on the clearance rate of adherent bacteria, growth of biofilms and alginate production. Fluorescein diacetate (FDA)-propidium iodide (PI) doubling staining assay was employed to observe the bacterial viability and morphological changes after membrane dispersion of each drug group.</p><p><b>RESULT</b>Sodium houttuyfonate could enhance the effect of IMP against pseudomonas aeruginosa biofilms. Particularly, the combination group with the concentration of 2MIC showed the highest effect, with P < 0.001 compared with the negative control group. The above results were proved by the bacterial viability and biofilm morphology under fluorescence microscope.</p><p><b>CONCLUSION</b>After being combined with imipenem, sodium houttuyfonate shows a higher effect against biofilms. It is expected that the combination of the two drugs could improve the clinical efficacy of associated infections.</p>

Advances in the study of synergistic effect of anti-biofilm agents / 药学学报

Biofilms are communities of surface-associated bacteria or fungi embedded in a self-produced extracellular polymeric matrix that are notoriously difficult to be eradicated and are sources of many recalcitrant infections. Treatment for biofilm infection with any individual drug is always less effective, while the combinations of different types of drugs are superior to monotherapy concerning the removing of biofilms. This paper focus on research progress in recent years for synergistic effect of drugs in combination against biofilms formed by Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Candida albicans.

Effects of houttuyfonate sodium on eliminating adhesion of Psedomonas aeruginosa and forming biofilms / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of houttuyfonate sodium (HS) on eliminating adhesion of Psedomonas aeruginosa (Pa) and forming biofilms.</p><p><b>METHOD</b>Pa biofilms were established in 96-hold plates. MTT assay was used to evaluate the changes in metabolism of biofilms and assess the minimum eliminating concentration and minimum biofilm inhibitory concentration for adherent Pa. The colony counting method was used to observe the effect of HS on Pa adhesion and biomass in biofilms. SEM was employed to examine the effect of HS on adhesion of tested Pa and morphology of biofilms.</p><p><b>RESULT</b>MEC80 and MEC50 of HS for adherent Pa was 500 mg x L(-1) and 125 mg x L(-1), respectively. Meanwhile, its SMIC80 for either early or mature biofilms of Pa was 500 mg x L(-1), and SMIC50 for early and mature biofilms of Pa were 31.25, 1.95 mg x L(-1), respectively. At the concentration of 250 mg x L(-1), the number of viable bacteria in the state of adhesion and in initial and mature biofilms decreased significantly, compared with the control group (P < 0.05). The number of bacteria on adherent carriers notably reduced under SEM. Following the continuous administration, there were no visible biofilms on carriers in the mature biofilm phase, with the biomass remarkably shrinking and the bacterial morphology changing from bacillus into coccobacillus.</p><p><b>CONCLUSION</b>HS displayed powerful effect on eliminating adherent Pa, and can inhibit Pa biofilm from being formed through continuous administration.</p>

On the Reform of Experimental Teaching of Microbiology for Pharmacy Speciality / 微生物学通报

The authors helpfully discuss the design idea,experimental module design,examination methods,and experiment textbook construction in experimental teaching of microbiology,and conduct further researches on the basic skill training,verifying experiment,integrative experiment,and investigative experiment in the course. This study aims to enhance effects of the experimental teaching,to cultivate high potential talents who can master essential knowledge and skills,and creatively carry out scientific research.