IntroductionS. aureus is a Gram positive bacterium which is responsible for a wide range of infections. This pathogen has also the ability to adhere to biotic or abiotic surface such as central venous catheter (CVC) and to produce a biofilm. The aim of this study was to evaluate the effect of hexadecyltrimethyl ammonium bromide (HTAB) and Hexadecylbetainate chloride (HBC) on Staphylococcus aureus adherence to the catheter tubing and on bacteria growth.MethodsBroth microdilution method was used to determine the Minimal Inhibitory Concentration (MIC). The detection of slime production was done by Congo Red Agar method, and the adherence of bacteria to the catheter tubing was evaluated by the enumeration of bacteria on plate counts.ResultsThe results of this study showed that the MICs of HTAB were ranged from 0.125 to 0.5 µg/mL, and those of HBC fluctuated between 2 to 8 µg/mL. HTAB and HBC inhibited bacteria adhesion on the surface of the catheter tubing.ConclusionThis study showed that HTAB and HBC can prevent the adherence of S. aureus strains to the surface of catheter tubing, suggesting that they could be used to prevent the risk of catheter related bloodstream infections.

Background: Enterobacteriaceae are one of the most predominant pathogen in surgical site infections. In recent years we oberved increase in resistance among bacteria from surgical site infections. The aim of this study was to evaluate antimicrobial suceptibility pattern of Enterobacteriaceae isolates from surgical site infections, the biofilm formation and the production of OXA-48 carbapenemase.Methods: A total of 41 Enterobacteriaceae (19 Escherchia coli, 8 Enterobacter sp., 9 Citrobacter sp., and 5 Serratia sp. ) clinical isolates were collected from patients with SSI in Hôpital Saint Joseph (Kinshasa) for diagnostic purposes. The pus samples were cultured and the antibiotic susceptibility profile of the isolates were determined by disk-diffusion method following Clinical and Laboratory Standards Institute 2012 recommendations. OXA-48-producing Enterobacteriaceae were detected using ChromaticTM OXA-48 chromogenic medium. Crystal Violet Staining Method was used to assess the ability of bacteria strains to form a biofilm. Results: All Enterobacteriacea isolates studied were biofilm producers and highly resistant to the majority of antibiotics tested. E. coli, Enterobacter sp., Citrobacter sp., and Serratia sp. were 100 % resistant cefotaxime, imipenem, and amoxicillin-clavulanic acid, and ampicillin. Serratia sp. isolates were 100% and 80% sensitive to norfloxacine and amikacine respectively. There was relationship between antibiotic resistance and biofilm production. E. coli, Enterobacter sp., and Citrobacter sp. strains were all OXA-48 producers.Conclusion: The results of the present study demonstrate the emergence of multidrug resistant organisms, the correlation between antibiotic resistance- biofilm formation and OXA-48 production. These results suggest the implementation of antimicrobial resistance survey programm in order to prevent and combat the spread of multidrug resistant organisms in hospital and community in Democratic Republic of Congo.