Quinine sulfate and bacterial invasion

Background: As many patients who receive antimalarial drugs for treatment of noninfectious, inflammatory diseases are also immunosuppressed and might have a concomitant bacterial infection, we studied the effectiveness of these drugs against bacterial infections, to find out whether they could protect against (and even treat) such conditions and obviate the need for an additional antibiotic drug. Methods: Effect of QS on bacterial growth: Escherichia coli (E. coli) HB101 pRI203 were cultured overnight at 37 C in TSB and inoculated (approx 1 107 cells /ml) in MEM in the presence of QS at various concentrations (0, 50 and 100 M). The effect of QS at concentration of 50 and 100 M on the entry process of E. coli HB101 pRI203 into HeLa cells was studied under different experimental conditions: 1. QS was incubated with 3 105 HeLa cells for 60 min at 37 C prior to infection. 2. QS was added to HeLa cell monolayers during the infection period. Results: QS showed no antibacterial activity after 24 h of incubation. The invasive efficiency of the bacteria was significantly inhibited at a dose-dependent manner, when QS was added to HeLa cells for 60 min at 37 C prior to infection (condition 1), and to a lesser extent when added during the period of infection (condition 2). Conclusions: Although the antimalarials are generally regarded as being inactive against most extracellular bacterial species, our results indicate that QS significantly inhibited the internalization/ invasion efficacy of E. coli in the host cells. Background Antimalarial drugs were first discovered in the seventeenth century [1], two and one-half centuries before the causative agent of malaria was identified. As no other drug before it, quinine, the first antimalarial agent derived from the cinchona tree, helped to shape today's world by enabling explorers and colonists from Europe to survive in tropical countries and to build their colonial empires Published: 22 October 2002 Annals of Clinical Microbiology and Antimicrobials 2002, 1:5 Received: 14 September 2002 Accepted: 22 October 2002 This article is available from: http://www.ann-clinmicrob.com/content/1/1/5 © 2002 Wolf et al; licensee BioMed Central Ltd. This article is published in Open Access: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.