Patients with Gram-negative nosocomial pneumonia have high plasma concentrations of lipopolysaccharide, interleukin-6, and tumor necrosis factor-alpha, but the antibiotic therapy evaluated did not significantly modify these concentrations.
The capacity of phagocytes to concentrate macrolide antibiotics was suggested by previous reports. In this study, we evaluated the capacity of Haemophilus influenzae type b culture supernatants (HICS) to induce polymorphonuclear leukocyte (PMNL) migration and macrolide antibiotic delivery. Using a Boyden multiwell chamber and a chemotaxis assay under agarose combined with a bioassay to measure antibiotic levels in agar, we demonstrated the chemotactic activity of HICS. Preincubation of PMNL with either erythromycin or azithromycin did not affect PMNL chemotaxis. By the agar diffusion test, we established that HICS increased the release of antibiotic from PMNL when compared with spontaneous release. Furthermore, we determined that the antibiotics remain bioactive after release. These results suggest that HICS may have a modulatory effect on transport and delivery of macrolide antibiotics by PMNL at the infection site.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.