Therapeutic Efficacy of Lysophosphatidylcholine in Severe Infections Caused by Acinetobacter baumannii

Abstract

ABSTRACTDue to the significant increase in antimicrobial resistance ofAcinetobacter baumannii, immune system stimulation to block infection progression may be a therapeutic adjuvant to antimicrobial treatment. Lysophosphatidylcholine (LPC), a major component of phospholipids in eukaryotic cells, is involved in immune cell recruitment and modulation. The aim of this study was to show if LPC could be useful for treating infections caused byA. baumannii. A. baumanniiATCC 17978 was used in this study. Levels of serum LPC and levels of the inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-10 were determined by spectrophotometric assay and enzyme-linked immunosorbent assay (ELISA), respectively, using a murine peritoneal sepsis model in which mice were inoculated with 5.3 log CFU/ml ofA. baumannii. The therapeutic efficacy of LPC againstA. baumanniiin murine peritoneal sepsis and pneumonia models was assessed for 48 h after bacterial infection. At early time points in the murine model of peritoneal sepsis caused byA. baumannii, LPC was depleted and was associated with an increase of inflammatory cytokine release. Preemptive therapy with LPC in murine peritoneal sepsis and pneumonia models markedly enhanced spleen and lung bacterial clearance and reduced the numbers of positive blood cultures and the mouse mortality rates. Moreover, treatment with LPC reduced proinflammatory cytokine production. These data demonstrate that LPC is efficacious as a preemptive treatment in experimental models of peritoneal sepsis and pneumonia caused byA. baumannii.