Antibacterial Properties of <i>Pseudomonas aeruginosa</i> Immunotype 1 Lipopolysaccharide-Specific Monoclonal Antibody (MAb) in a Murine Thigh Infection Model: Combined Effects of MAb and Ceftazidime

J-STAGE
  • Akiyama Moritoshi
    Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
  • Oishi Kazunori
    Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
  • Tao Misao
    Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
  • Matsumoto Keizo
    Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
  • Pollack Matthew
    Department of Medicine, Uniformed Services University of the Health Sciences, F. Edward Hebert School of Medicine

抄録

A murine monoclonal antibody (MAb) specific for the Pseudomonas aeruginosa immunotype 1 (It-1) lipopolysaccharide (LPS) O-side chain was evaluated in terms of its in vitro bactericidal opsonophagocytic activity and in vivo bacterial killing in a mouse thigh infection model. An immunoglobulin (Ig) G2a MAb Ld3-2F2, specific for It-1 LPS, mediated in vitro complement-dependent opsonophagocytic killing at a concentration of 10μg/ml. MAb-mediated, complement-dependent killing also occurred in the absence of neutrophils at serum concentrations in excess of 20%. A remarkable synergy was observed in opsonophagocytic assays between MAb Ld3-2F2 (0.5μg/ml) and ceftazidime (1/4 MIC). The administration of MAb Ld3-2F2 at a level of 1μg resulted in a significant decrease in the number of bacteria in the thigh muscles of normal mice, while 100μg of the same MAb was required for one log of reduction in the number of bacteria at the same site in neutropenic mice. The combined therapy with MAb Ld3-2F2 and ceftazidime provided a significant reduction in the density of bacteria in the thigh muscle at 9hr post-infection in normal and neutropenic mice as compared with those after treatment alone or with no treatment (P< 0.01). These favorable in vitro and in vivo interactions of an LPS-specific IgG MAb and ceftazidime strongly support their potential for use in therapy, combined with an LPS-reactive MAb and parenteral antipseudomonas β-lactam antibiotics in the therapy of systemic Pseudomonas infections in normal and neutropenic hosts.

収録刊行物

詳細情報 詳細情報について

問題の指摘

ページトップへ