Antimicrobial effect of sodium houttuyfonate on Staphylococcus epidermidis and Candida albicans biofilms

OBJECTIVE： To study antimicrobial effect of Sodi- um houttuyfonate （SH） on Staphylococcus epider- midis （SE） and Candida albicans （CA）. METHODS： The prepared strain broths （OD600=0.05） containing SE and CA were firstly used to test the minimal inhibitory concentrations （MICs） of SH, azithromycin （AZM） and fluconazole （FLU） by mi- cro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with differ- ent concentrations by crystal violet staining meth- od. At last, the treated biofilms of SE and CA by 2× MIC agents were observed by scanning electronic microscope. RESULTS： The MlCs of SE and CA were 256 and 1024 μg/mL, respectively. After the 1st, 2nd and3rd day of medications, the suppressions of biofilm were about 60% （P〈0.01）, 76% （P=0.000） and 75% （P=0.000） by 2×MIC SH, the suppressions of biofilm were about 90% （P=0.000）, 88% （P=0.000） and 90% （P=0.000） by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole. CONCLUSION： SH had widely anti-pathogenic ef- fect on pathogenic biofilm formation of either bac- teria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular poly- meric substances, and was more active to inhibit the growth of CA than SE.

Effect of sodium houttuyfonate on symptom pattern of lung-Qi deficiency in rats induced by bacterialbiofilm infection

OBJECTIVE: To investigate the in vivo inhibitory effects of sodium houttuyfonate(SH) on symptom pattern of Qi-deficiency in rats induced by infection of bacterial biofilm on rat respiratory tract.METHODS: Symptom pattern is a term used in Traditional Chinese Medicine(TCM) to define a cluster of symptoms in a medical condition. Based on the pattern, TCM therapies are administered. The symptom pattern used in this study was lung-Qi deficiency pattern identified in rats, which was induced by nasal intubation drip of Pseudomonas aeruginosa(P. aeruginosa)(two strains) to form bacterial biofilm on airway combined with stimulation of cold and fatigue. We measured the variations of the symptoms of the pattern, weight, spleen and thymus index, blood gas, lung bronchial tissue pathology and cytokine of rat in different treatments and control groups.RESULTS: The rats of SH-treatment groups had not showed typical symptoms comparing with model group in the early stage of infection. The weight,spleen and thymus index of the SH-treatment groups were significantly higher comparing with untreated model group. The SH-treatment groups also showed higher O2 partial pressure and lower CO2 partial pressure than model group. Furthermore, we found that the bronchopulmonary section of SH-treatment groups not showed typical pathogenic variation in model group. The comparison of cytokine concentration in different groups indicated that SH could prevent the over-production of cytokine to reduce the inflammation occurrence.CONCLUSION: In the early stage of airway infection by biofilm of P. aeruginosa, application of SH can prevent the occurrence of lung-Qi deficiency pattern.