title: Addition of Maitake D-fraction reduces the effective dosage of vancomycin for the treatment of Listeria-infected mice.
abstract: Maitake D-fraction, beta1,6-glucan having beta1,3-branches, has been reported to activate the immune system of the host. To elucidate whether the D-fraction can reduce the clinical effective dosage of antibiotics in the treatment of opportunistic bacterial infection, we examined the effects of D-fraction on the treatment of Listeria monocytogenes-infected mice in combination with vancomycine (VCM), the only antibiotic used for methicillin-resistant Staphylococcus aureus (MRSA). Listeria-infection was introduced by its inoculation into the abdominal cavity of mice. Without treatment, all inoculated mice died within 3 days after the inoculation. In contrast, in the mice treated with combined therapy of D-faction (10 mg/kg per day) and VCM (10 mg/kg per day), the survival rate was maintained at 60% on the 10th day after the inoculation, which was superior to that of mice treated with VCM alone (10 mg/kg per day). To investigate the mechanism underlying the reinforcement of VCM treatment by the D-fraction, the activities of macrophages and splenic T cells of Listeria-infected mice were evaluated. In mice administered with both D-fraction and VCM, macrophages produced 2.7 times as much interleukin-1 as that of non-treated control mice. The bactericidal activity of splenic T cells was also enhanced by 2.6 times of that of non-treated control mice. These results indicate that D-fraction activates immuno-competent cells, induced cytokine production, and consequently enhanced the bactericidal activities of the splenic T cells against Listeria monocytogenes, suggesting the clinical benefit of D-fraction in the case of anti-bacterial treatment for patients with high risks.
authors.affiliation: Department of Microbial Chemistry, Kobe Pharmaceutical University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kodama
authors.forename: M
authors.initials: M
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Nanba
mesh_terms: D000005:Abdomen / Q000382:microbiology; D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000363:Agaricales / Q000737:chemistry*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001770:Blood Bactericidal Activity / Q000187:drug effects; D007167:Immunotherapy; D007375:Interleukin-1 / Q000096:biosynthesis; D008088:Listeriosis / Q000188:drug therapy*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010529:Peritoneal Cavity / Q000382:microbiology; D016019:Survival Analysis; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D014640:Vancomycin / Q000627:therapeutic use*
chemical_list: D000276:Adjuvants, Immunologic; D000900:Anti-Bacterial Agents; D007375:Interleukin-1; D014640:Vancomycin