The Study Of Antibacterial Metabolite Of Lactobacillus Plantarumand It's Clinical Application

Objective: The aim of this study is to investigate the antibacterial production of Lactobacillus plantarum and it's characterization.In order to define the role of probiotics in treatment of infectious diseases and their interaction with antibiotics,we test the culture supernatant's antimicrobial activity combined with antibiotics and detect the susceptibility of Lactobacillus plantarum to commonly used antibiotics,such as Penicillin,Clindamycin,Vancomycin,et al.Methods: First,we inoculated the Lactobacillus plantarum into the de Man Rogosa Sharpe(MRS)broth.After centrifugation and ultrafiltration,the antibacterial spectrum of the culture supernatant and it's antimicrobial activity combined with Meropenem or Ceftazidime was determined by the agar well diffusion method.Then,through heating,catalase and different p H treatments,the stability and characterization of the antagonists was detected.Finally,we define the drug susceptibility to antibiotics by Broth Microdilution Susceptibility Testing.Results: The inhibition zone indicated that the culture supernatant of Lactobacillus plantarum had antibacterial activity against selected strains of Pseudomonas aeruginosa,Escherichia coli,Klebsiella pneumonia,Acinetobacter baumannii,Staphylococcus aureus,Enterococcus faecalis,that isolated from clinical samples.The combination of the culture supernatant and Meropenem or Ceftazidime could promote the antibiotics' activity.And the antibacterial activity remained despite the treatment of catalase and heating,but abolished when the p H was adjusted to 5 or above.The result of Broth Microdilution Susceptibility Testing indicated that the strain in this experiment was sensitive to Penicillin and Clindamycin,but resistant to other antibiotics.Conclusions: The culture supernatant of Lactobacillus plantarum has antibacterial substance with a range of inhibitory activity against part of Gram-positive and Gram-negative bacteria isolated from clinical samples.When combined with antibiotics,the culture supernatant can improve the antimicrobial activity of the antibiotics.Though the inhibitor is inactive when p H is elevated,its activity cannot be explained by lactic acid or other acid production of the Lactobacillus plantarum.Concluded from the drug susceptibility,the application of the Lactobacillus plantarum will be suppressed by antibiotics and then be inactive.