Choi BG, et al. Yonsei Med J. 2019 Feb;60(2):191-199. https://doi.org/10.3349/ymj.2019.60.2.191

In this work, the antibacterial activity of silver nanoparticles (AgNPs) synthesized using Areca catechu extracts against three species of antibiotic-susceptible and three species of resistant bacteria was investigated. The effects of this plant were more promising when compared with other medicinal plants tested. The hydrothermal extract of Areca catechu was mixed with silver nitrate to synthesize AgNPs. The synthesized particle characteristics were analyzed by UV–Vis spectrophotometry, scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FT-IR). Minimum inhibitory concentration and minimum bactericidal concentration tests were conducted to confirm antibacterial activity and the results showed that AgNPs synthesized using Areca catechu extracts effectively inhibited the growth of bacterial species. Moreover, the SEM images of the bacterial species treated with AgNPs synthesized with Areca catechu extracts showed that clusters of AgNPs were attached to the surface of the bacterial cell wall, which could induce destruction of the cell membranes. The results suggest that AgNPs synthesized with Areca catechu extracts have the potential to treat antibiotic-resistant bacteria known as the major cause of nosocomial infections.

Background: Human papillomavirus (HPV) is known to be more prevalent in spontaneous abortions than in elective terminations of pregnancy. More recently, placental infection with HPV was shown to be associated with spontaneous preterm delivery. However, no study has evaluated the prevalence of HPV infection in pregnant Korean females and its association with adverse pregnancy outcomes.Methods: We conducted a cross-sectional study of 311 females who gave birth at Korea University Medical Center. Our sample included 45 preterm deliveries, 50 cases of premature rupture of the membranes (PROM), 21 preeclampsia cases, and 8 gestational diabetes mellitus (GDM) patients. We used the Hybrid Capture II system to detect high-risk (HR)-HPV infection at six weeks postpartum.Results: The prevalence of HR-HPV infection was 14.1%. Women with HR-HPV infection had a higher incidence of PROM than those without HR-HPV. HR-HPV infection was associated with an increased risk of PROM (OR, 2.380; 95% CI, 1.103-5.134). The prevalence of preterm delivery, preeclampsia, or GDM was not different between the two groups.Conclusions: We observed a high prevalence of HR-HPV infection in pregnant women. Moreover, HR-HPV infection was associated with a risk of PROM at term. Further studies are needed to evaluate mechanisms by which HR-HPV infection induces PROM.

The aim of this study was to investigate the ability of hinokitiol to inhibit the formation of Candida biofilms. Biofilm inhibition was evaluated by quantification of the biofilm metabolic activity with XTT assay. Hinokitiol efficiently prevented biofilm formation in both fluconazole-susceptible and fluconazole-resistant strains of Candida species. We determined the expression levels of specific genes previously implicated in biofilm development of C. albicans cells by real-time RT-PCR. The expression levels of genes associated with adhesion process, HWP1 and ALS3, were downregulated by hinokitiol. Transcript levels of UME6 and HGC1, responsible for long-term hyphal maintenance, were also decreased by hinokitiol. The expression level of CYR1, which encodes the component of signaling pathway of hyphal formation-cAMP-PKA was suppressed by hinokitiol. Its upstream general regulator RAS1 was also suppressed by hinokitiol. These results indicate that hinokitiol may have therapeutic potential in the treatment and prevention of biofilm-associated Candida infections.

This paper investigated the antifungal and antibiofilm activity of silver nanoparticles synthesized with Lycopersicon esculentum extracts against Candida species. Lycopersicon esculentum extracts obtained by homogenization were mixed with silver nitrate to synthesize silver nanoparticles. Analysis of the particle characteristics by UV–Vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FT-IR) confirmed that the Lycopersicon esculentum extracts effectively served as reductants and capping agents. Minimum inhibitory concentration (MIC) tests were conducted to confirm antifungal activity against Candida species. In all the tested species, the silver nanoparticles inhibited the growth of Candida. Moreover, the SEM images of Candida species treated with silver nanoparticles synthesized using natural extracts of Lycopersicon esculentum showed that silver nanoparticles adhered to the surface of Candida, which induced pore formation in the membranes and prevented their normal growth. Ultimately, these abnormal forms of Candida were thought to be less able to form biofilms than normal Candida. The antifungal and antibiofilm activities of silver nanoparticles against Candida are expected to be utilized in various fields and contribute in particular to developments in nanomedicine.

Su Min Namkung, Jeong Su Choi, Ji Hyang Park, Man Gil Yang, Min Woo Lee, Suhng Wook Kim. Korean J Clin Lab Sci. 2017;49:220-6. https://doi.org/10.15324/kjcls.2017.49.3.220