In vitro study on bacterial growth enhancement in the presence of TNF-?,IL-1? and IL-6 / 中国感染与化疗杂志

ABSTRACT

Objective To conduct an in vitro study of the growth of Pseudomonas aeruginosa,Staphylococcus aureus and Acin- etobacter spp.,and evaluate their response to various concentrations of tumor necrosis factor(TNF)-?,interleukin (IL)-1?, and IL-6.Methods To monitor the growth of bacteria incubated with the cytokines TNF?,IL-1?and IL-6 that were added to RPMI 1640 medium in various concentrations (10,50.100,500 pg,1 and 10 ng) at 2,4 to 6,8 and 16-18 h.The bacterial concentration was estimated when the mixtures of cytokines and specific neutralizing monoclonal antibodies (MoAbs) were in- cubated.Results We found that all three bacterial species showed concentration-dependent growth enhancement when incubated with one or more tested cytokines.Blockade by specific neutralizing cytokine significantly inhibited cytokine-induced growth. When compared with control,the 6 h growth response was maximal with IL-1?for Staphylococcus aureus and Acinetobacter spp.,and with IL-6 for Pseudomonas aeruginosa.Conclusions In this study we provide additional evidence for a newly de- scribed mechanism for bacterial proliferation in the presence of exaggerated and protracted inflammation.The effect that cyto kine-induced growth enhancement inhibited by specific neutralizing cytokine MoAbs may be useful for antimicrobial therapy.