Portable Device for Quick Detection of Viable Bacteria in Water.

(1) Background: Access to clean water is a very important factor for human life. However, pathogenic microorganisms in drinking water often cause diseases, and convenient/inexpensive testing methods are urgently needed. (2) Methods: The reagent contains 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and phenazine methosulfate (PMS) and can react with succinate dehydrogenase within bacterial cell membranes to produce visible purple crystals. The colorimetric change of the reagent after reaction can be measured by a sensor (AS7262). (3) Results: Compared with traditional methods, our device is simple to operate and can provide rapid (i.e., 5 min) semi-quantitative results regarding the concentration of bacteria within a test sample. (4) Conclusions: This easy-to-use device, which employs MTT-PMS reagents, can be regarded as a potential and portable tool for rapid water quality determination.

Plasma-activated medium as adjuvant therapy for lung cancer with malignant pleural effusion.

This study compared effects of plasma-activated medium (PAM) with effects of conventional clinical thermal therapy on both lung cancer cells and benign cells for management of malignant pleural effusion (MPE). For MPE treatment, chemotherapy, photodynamic therapy, and thermal therapy are used but caused systemic side effects, patient photosensitivity, and edema, respectively. Recent studies show that plasma induces apoptosis in cancer cells with minor effects on normal cells and is cost-effective. However, the effects of plasma on MPE have not been investigated previously. This study applied a nonthermal atmospheric-pressure plasma jet to treat RPMI medium to produce PAM, carefully controlled the long-life reactive oxygen and nitrogen species concentration in PAM, and treated the cells. The influence of PAM treatment on the microenvironment of cells was also checked. The results indicated that PAM selectively inhibited CL1-5 and A549 cells, exerting minor effects on benign mesothelial and fibroblast cells. In contrast to selective lethal effects of PAM, thermal therapy inhibited both CL1-5 and benign mesothelial cells. This study also found that fibroblast growth factor 1 is not the factor explaining why PAM can selectively inhibit CL1-5 cells. These results indicate that PAM is potentially a less-harmful and cost-effective adjuvant therapy for MPE.

Rapid detection of biofilm with modified alcian blue staining: In-vitro protocol improvement and validation with clinical cases.

For chronic wounds, biofilm infection is a critical issue because it can tip the scales toward an unhealing state. Biofilm-based wound therapy has been extensively advocated. However, point-of-care biofilm diagnosis still largely relies on clinical judgment. In this study, we aimed to develop a rapid tool for diagnosing wound biofilm presence by alcian blue staining. First, we sought to optimize alcian blue staining using a colorimetric-based approach to detect the biofilm, specifically targeting polysaccharides in the extracellular polymeric substances. Among examined transfer membranes and cationic detergents at various concentrations, we selected a positively charged nylon transfer membrane for sample loading, and 1% cetyl trimethyl ammonium chloride (CTAC) as the blocking solution. After sample loading and blocking, the membrane was immersed in alcian blue solution for staining, followed by immersion in 1% CTAC to decrease background noise. Each step required only 30 seconds, and the whole procedure was completed within a few minutes. In the second part of this study, we enrolled 31 patients with chronic wounds to investigate the predictive validity of biofilm detection for unhealed wounds at a 1-month follow-up visit. Among the 18 cases with positive wound biofilm staining, 15 wounds (83.3%) were not healed at the 1-month follow-up visit. Only three unhealed wounds (30%) produced in negative staining cases. This finding indicates that biofilm infection is associated with poor healing outcome for chronic wounds. Moreover, our staining results correlated well with the clinical microbiological culture assessment (83.9% consistency; 95.2% sensitivity, and 60% specificity). In conclusion, the modified alcian blue staining protocol used here represents a rapid and sensitive procedure for detecting biofilm in chronic wounds. This technique provides a practical point-of-care approach for detection of wound biofilm, the implementation of which may improve clinical outcomes for chronic wound patients. Additional studies are required to validate this method.