[Growth and Control of Catheter-related Bloodstream Infection Causing Bacteria in Nutrient Solutions]

Among healthcare-associated infections, catheter-related bloodstream infection (CRBSI) shows a high case fatality rate and is serious threat. CRBSI are a problem to be eradicated. This study was conducted to reveal the growth characteristics of the causative microorganisms of CRBSI and investigate relevant control methods. The effects of biotin on growth of Candida albicans (C. albicans) in the nutrient solutions were investigated. Upon comparing general solutions and biotin-containing solutions, C. albicans showed auxotrophy against biotin, resulting in significant proliferative potential. CRBSI is caused by biofilm formation in the catheter lumen and subsequent proliferation. The effect of biotin on the colonization of C. albicans in the catheter lumen was evaluated. Candida albicans colonization in the catheter lumen and subsequent proliferation were significantly higher than those in control solutions. To investigate methods for CRBSI control, effects on pathogenic microorganisms were examined by screening for nutrient solutions with antimicrobial activity, using a catheter-lumen contamination model. A commercially available solution (PLAS-AMINO^® injection; PA) containing the highest amount of sodium bisulfite was selected. Gram-positive or negative bacteria and C. albicans were used as the causative microorganisms of CRBSI in the study. Dripping PA into each catheter-lumen contamination model demonstrated bactericidal effects against all bacteria tested and strong growth-inhibitory effects on C. albicans. By using PA for contamination inside the catheter, sterilization and suppression of bacterial growth can be expected without having to remove central venous catheters and/or central venous access devices. This review provides valuable findings for the development of novel control methods for CRBSI.