Economic burden attributable to Clostridioides difficile infections in South Korea: a nationwide propensity score-matched study.

BACKGROUND: Clostridioides (Clostridium) difficile is an important pathogen that causes diarrhoea in patients who take antibacterial drugs. Considering the limited medical resources, it is necessary to prioritize the management of threats caused by antibiotic use and the spread of germs, but there are little available data, especially for C. difficile infections in South Korea. AIMS: In this study, we analysed the hospital length of stay (LOS) and the increase in medical costs due to C. difficile infections. METHODS: Propensity score-matched experimental (hospitalized patients with C. difficile infection)-control (hospitalized patients without C. difficile infection) studies were conducted to estimate the increase in the LOS and medical costs associated with C. difficile infections. The data were obtained from the National Health Insurance Service-National Sample Cohort from 2006 to 2015. Reliable results were obtained by actively calibrating various confounding variables of demographic characteristics, disease severity, and information on healthcare facilities. FINDINGS: The C. difficile-attributable increase in LOS and hospitalization costs were 36.9 days and 8298 USD, respectively, per infection case. CONCLUSION: This study quantified the considerable burden associated with C. difficile infections in South Korea.

Bioactivity-guided separation of anti-acidogenic substances against Streptococcus mutans UA 159 from Polygonum cuspidatum.

OBJECTIVES: The aim of this study was to separate the anti-acidogenic substances against Streptococcus mutans UA 159 from Polygonum cuspidatum. MATERIAL AND METHODS: The anti-acidogenic substances were separated by a series of liquid-liquid fractionations followed by normal-phase silica gel liquid chromatography, based on high-performance liquid chromatography and glycolytic pH-drop assay. The effectiveness of the separated substances on the acidogenicity of Streptococcus mutans UA 159 was examined using sodium fluoride as a positive control. The chemical composition and quantities of the components of the substances was also assessed by qualitative-quantitative chromatographic analysis. RESULTS: Among the substances separated from P. cuspidatum, F3 showed the strongest inhibitory effect on the acidogenicity of S. mutans UA 159 in a dose-dependent manner without displaying any bactericidal activity. F3 decreased the acidogenicity of S. mutans even at 12.5 microg ml(-1) (P < 0.05). F3 consisted mainly of resveratrol and emodin (C(14)H(12)O(3) and C(14)H(4)O(2)(OH)(3)CH(3), respectively), which made up approximately 60% of the weight of F3. CONCLUSION: F3 can be considered as a promising agent for controlling the acidogenicity of S. mutans and subsequent dental caries formation.