The Inhibition Of Conjugative R Plasmid Transfer By The Extrat Of Chinese Medicinal Materials In Vitro And In Vivo

Objective: To examine a possible influence of the extrat from edible alcohol of Chinese medicinal materials on the R plasmid transfer by conjugation from S.flexneri D15 R-plasmid Cm~R to E.coil 1485 Rif in vitro and in vivo.Methods:1. Make the extrat of 60 Chinese medicinal materials from edible alcohol seperately, and be sure their experimental concentration in vitro:determine the minimal inhibitory concentration(MIC)of the every kind of Chinese medicinal materials of S.flexneri D15 R-plasmid Cm~R and E.coii 1485 Rif separately, and then take the sub-minimal inhibitory concentration of two bacteria as the experimental concentration. 2. The experiment of the inhibition of conjugative R plasmid transfer in vitro and in vivo: (1)Screening the effective material of the inhibition of conjugative R plasmid transfer in vitro :coculture the extract of Chinese medicinal material (at the experimental concentration) S.flexneri D15 R-plasmid Cm~R and E.coil 1485 Rif twenty-four hours and forty-eight hours, and set seven control groups, and then calculate the transfer rate of R plasmid of every medicine and every control group and the inhibition rate of the effective medicine: the transfer rate(%)of R plasmid=number of transconjugants/number of recipient × 100 % the inhibition rate(%)=(1-number of transconjugants in the presence of the Chinese medicine/number of transconjugants in the absence of the Chinese medicine) ×100 %; (2)The experiment of the inhibition of conjugative R plasmid transfer in vivo of the effective medicine:inject the effective medicine(at the twice of the experimental concentration in vitro)...