A new, quick method, using the resazurin dye test as a bacterial respiration indicator, has been developed to assay the antibacterial activity of various substances used as disinfectants against bacterial biofilm growth on clinical devices. Resazurin was used to measure the presence of active biofilm bacteria, after adding disinfectant, in relation to a standard curve generated from inocula in suspension of the same organism used to grow the biofilm. The biofilm was quantified indirectly by measuring the fluorescent, water-soluble resorufin product produced when resazurin is reduced by reactions associated with respiration. Four products used as disinfectants and the biofilm growth of five bacterial species on carriers made of materials commonly found in clinical devices were studied. Under test conditions, chlorhexidine, NaOCl, ethanol, and Perasafe at concentrations of 0.2, 0.01, 350, and 0.16 mg/ml, respectively, all produced 5-log reductions in biofilm cell numbers on the three different carriers. The redox-driven test depends on bacterial catabolism, for which reason resazurin reduction produces an analytic signal of the bacterial activity in whole cells, and therefore could be used for determining disinfectant efficacy in an assay based on the metabolic activity of microorganisms grown as biofilm or in suspension.

Over the last few years, the textile industry has developed different methods for obtaining fabrics and fibres with an antimicrobial action for use in hospital environments and for other purposes. This study evaluates the antimicrobial action of Bioactive®treated fabric (BTF), a commercially available textile containing silver for use in healthcare environments. Unlike other biocides used in hospital fabrics, the prolonged use of silver has not been related to the appearance of resistant bacteria or crossresistance to antibiotics, in spite of being extensively used in some treatments. Thirtythree hospital strains of bacteria were tested. This study showed the capacity of BTF for significantly reducing the number of microorganisms present, compared with the reduction observed in control fabrics (CF). The antimicrobial action of BTF was expressed as log 10 reduction (LR) from an initial inoculum of about 10 5 colony-forming units. According to the bacterial species, a LR of between 2.6 and 5.0, and 4.1 and 5.0 (5.0 indicating total inhibition of bacterial growth) were observed respectively after 24 and 48 hours for BTF. Acinetobacter strains were the most resistant to CF after 72 hours (0.8 LR). All the microorganisms, except two strains of Enterococcus faecalis, were totally inhibited after 72 hours on BTF.

This study investigated the use of a rapid bacterial toxicity test for detecting disinfectant residues released by disinfected materials. The test substances included an environmental disinfectant used in hospitals in high-risk areas, such as critical care units or emergency services, and three disinfectants used on clinical devices when a high level of disinfection is required. The test materials were polyurethane, polypropylene, glass, latex and cotton from different instruments and utensils used in hospitals. Of the four test disinfectants, o-phthalaldehyde (OPA) and 2-bromo-2-nitro-1,3-propanediol (BNP) showed the greatest inhibitory activity (as much as 300-fold greater than hydrogen peroxide in the case of OPA) according to the toxicity text. However, with the exception of hydrogen peroxide on latex, it was the most porous test materials, namely latex and cotton, that accumulated the least residue. BNP was the disinfectant that left the least residue on the five test materials, while the greatest residual concentration was left by hydrogen peroxide on latex (as much as 5 microg/cm2). The biotest used in this study permitted the detection of disinfectant residues released by different types of previously disinfected clinical materials, and can be adapted to simulate elution conditions similar to those existing in routine hospital practice.

Psychological disorders in people with extreme weight (low weight or obesity) should be taken into consideration by health professionals in order to practice an effective treatment to these patients. This study evaluates the association between body mass index (BMI) and psychological distress in 563 inhabitants of Málaga (South of Spain). Participants were classified in four categories of BMI: Underweight (BMI <18.5 Kg/m2), Normal weight (BMI 18.5–24.99 Kg/m2), Overweight (BMI 25.0–29.99 Kg/m2) and Obesity (BMI >30 Kg/m2). Psychological distress was measured with the Spanish version of the Derogatis’ Symptoms Checklist Revised (SCL-90-R). We observed a symmetric U-shaped relationship between weight status and psychological distress in all SCL-90-R dimensions (p for quadratic trend <0.001) for both men and women. Participants with extreme weight showed the worst psychological status, and participants with normal weight exhibited the best. We found no statistically significant differences between underweight and obese participants in 9 of the 10 SCL-90-R dimensions analyzed among men, and in 8 of the 10 dimensions among women. Underweight and obese participants showed no gender differences in psychological distress levels. Psychological treatment of Mediterranean people with extreme weight, should consider underweight and obese patients at the same level of psychological distress.

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