The in vitro study of gentamicin combined with trisodium citrate for locking solution in preventing catheter-related bloodstream infection

Abstract

Objective To predict the effectiveness of gentamicin combined with trisodium citrate for locking solution in preventing catheter-related bloodstream infection. Methods This is a retrospective study,ten kinds of common pathogens in catheter-related bloodstream infections were selected from medical intensive care unit (n=9) and cardiac care unit (n=1) between July 2011 and July 2012,and the diffusion method was used to analyze the inhibitory effect of gentamicin combined with trisodium citrate against tested pathogens. Results When trisodium citrate was tested alone,a certain antimicrobial activity could be detected from 10% trisodium citrate,only Staphylococcus aureus and Staphylococci haemolyticus were inhibited,and then Enterococcus faecium was inhibited by 30% trisodium citrate.Compared with trisodium citrate,gentamicin showed stronger antimicrobial activity.Staphylococcus aureus,Staphylococci haemolyticus,Enterococcus faecium and Escherichia coli could be inhibited by 0.32 g/L gentamicin and the antimicrobial activity was enhanced by increasing concentrations.The maximum activity was in 5 g/L gentamicin with 7-17 mm diameters.However,the antimicrobial activity of gentamicin didn′t increase when combined with trisodium citrate,especially in 4% trisodium citrate,the Staphylococci haemolyticus was not inhibited by all of the combinations with any concentration of gentamicin.In 0.32 g/L gentamicin,only the combination with 50% trisodium citrate could inhibit the four kinds of pathogens (Staphylococcus aureus,Staphylococci haemolyticus,Enterococcus faecium and Escherichia coli) with 8-21 mm diameters,while in 1 g/L,2 g/L,and 5 g/L gentamicin,these pathogens could be inhibited by the combination with only 10% trisodium citrate,and the diameters were 5-24 mm,12-27 mm,and 17-28 mm,respectively. Conclusion Based on the data,gentamicin combined with trisodium citrate lock solution may play an important role in preventing catheter-related bloodstream infections caused by Gram-positive bacteria and Escherichia coli.(Chin J Lab Med,2013,36:743-747) Key words: Gentamicins; Citric acid; Catheter-related infections; In vitro