Persistence of nosocomial bacteria on 2 biocidal fabrics based on silver under conditions of high relative humidity

How long can nosocomial pathogens survive on textiles? A systematic review

Aims: Healthcare-associated infections linked to contaminated textiles are rare but underline their potential role as a source for transmission. The aim of the review was to summarize the experimental evidence on the survival and persistence of the different types of nosocomial pathogens on textiles.

Methods: A literature search was performed on MedLine. Original data on the survival of bacteria, mycobacteria, and fungi and persistence of viruses on textiles were evaluated.

Results: The survival of bacteria at room temperature was the longest on polyester (up to 206 days), whereas it was up to 90 days for some species on cotton and mixed fibers. Only low inocula of 100 CFU were found on all types of textiles with a short survival time of ≤3 days. Most bacterial species survived better at elevated air humidity. The infectivity of viruses on textiles is lost much faster at room temperature, typically within 2–4 weeks.

Conclusions: Contaminated textiles or fabrics may be a source of transmission for weeks. The presence of pathogens on the coats of healthcare workers is associated with the presence of pathogens on their hands, demonstrating the relevance of textile contamination in patient care.

A novel comprehensive efficacy test for textiles intended for use in the healthcare setting

Soft surfaces, including textiles are found throughout healthcare settings. Pathogens can survive for long periods of time on textiles, and can be transferred to and from the skin. Antimicrobial fabrics are used as an engineering control to prevent infection. Efficacy testing standards have limitations, including single microorganism challenges, multiple fabric plies tested, and lengthy contact times. We developed a novel method that better models in-use conditions through testing standardized mixtures of pathogens and normal skin microorganisms, artificial soils, and a 15-min contact time. Reproducible growth of all microorganisms from frozen stocks was achieved using this method. A novel rechargeable, monitorable N-halamine cotton cellulose fabric, containing 5885 ± 98 ppm of active chlorine, was evaluated with the new method using PBS, artificial sweat, and artificial sweat plus 5% serum as soil. Pathogens tested included Acinetobacter baumannii, Candida albicans, Escherichia coli, vancomycin-resistant Enterococcus faecalis, methicillin-resistant Staphylococcus aureus, methicillin-susceptible Staphylococcus aureus, and Pseudomonas aeruginosa. Each was tested singly and in the presence of a representative normal skin flora mixture, including: Acinetobacter lwoffii, Corynebacterium striatum, Micrococcus luteus, and Staphylococcus epidermidis. When tested singly, all microorganisms were reduced by 3.00 log₁₀ or greater, regardless of artificial soil. In mixture, 4.00 log₁₀ or greater reductions were achieved for all microorganisms. These results suggest that the novel testing method can be used to provide more comprehensive and realistic efficacy information for antimicrobial textiles intended for use in healthcare. Furthermore, the N-halamine fabric demonstrated efficacy against multiple pathogens, singly and in mixtures, regardless of the presence of artificial soils.

Profile of environmental service managers and workers in Brazilian hospitals

INTRODUCTION

Contamination through the hands of professionals and surfaces is one of the main agents involved in health care-associated infections in health services. Flaws in the execution of hospital housekeeping can lead to the contamination of surfaces and health equipment though, representing a risk for patient safety and highlighting the need to maximize the quality of cleaning processes in these institutions.

OBJECTIVE

To describe the profile of managers and environmental service workers (ESWs) in Brazilian hospitals.

METHODS

A cross-sectional study was undertaken in January 2018, involving 155 participants, being 12 managers and 143 workers from the housekeeping team of two health institutions, being one private and the other public.

RESULTS

Most participants were female (86%), with a mean age of 45 years and primary education level, 52% being outsourced workers. The participants positively assessed their job satisfaction, satisfaction with training, basic knowledge and performance; nevertheless, situations were identified that were perceived as risks for patient safety and occupational health. The questions involving motivational incentives received the lowest scores.

CONCLUSION

Inconsistencies were found in the housekeeping professionals'. Preparation, indicating that the institutions studied do not value this type of service and that an investment policy in these workers' motivation is lacking.

Coping with low water activities and osmotic stress in Acinetobacter baumannii: significance, current status and perspectives

Multidrug resistant (MDR) pathogens are one of the most pressing challenges of contemporary health care. Acinetobacter baumannii takes a predominant position, emphasized in 2017 by the World Health Organization. The increasing emergence of MDR strains strengthens the demand for new antimicrobials. Possible targets for such compounds might be proteins involved in resistance against low water activity environments, since A. baumannii is known for its pronounced resistance against desiccation stress. Despite the importance of desiccation resistance for persistence of this pathogen in hospitals, comparable studies and precise data on this topic are rare and the mechanisms involved are largely unknown. This review aims to give an overview of the studies performed so far and the current knowledge on genes and proteins important for desiccation survival. 'Osmotic stress' is not identical to 'desiccation stress', but the two share the response of bacteria to low water activities. Osmotic stress resistance is in general studied much better, and in recent years it turned out that accumulation of compatible solutes in A. baumannii comprises some special features such as the bifunctional enzyme MtlD synthesizing the unusual solute mannitol. Furthermore, the regulatory pathways, as understood today, will be discussed.

Evaluation of antimicrobial persistent activity of alcohol-based hand antiseptics against bacterial contamination

The purpose of this study was to evaluate persistent activity of three alcohol-based antiseptics widely used in the clinical routine containing chlorhexidine, triclosan or mecetronium after hand disinfection. Four tests were used to evaluate the antimicrobial activity of antiseptics on: (i) resident microbiota; (ii) nutrient agar plates (NAP) subsequently inoculated with a test organism; and transient microbiota acquired by contact with dry hands (iii), or (iv) a wet inert surface that had been artificially contaminated. Four reference strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis) and an Acinetobacter baumannii strain responsible for a hospital outbreak were used as transient microbiota. Antimicrobial activity was calculated according to the CFUs reduction by reference to non-disinfected control hands. The antiseptics were applied according to European Standard EN1500. Solutions containing chlorhexidine or triclosan showed some persistent effects on transient microbiota on inert humid surfaces and NAP, but not on contaminated dry hands. Solutions containing mecetronium showed no persistent effect on transient flora in any of the trials. All alcohol-based antiseptics tested were more effective against resident flora than soap. No persistent activity was observed for A. baumannii in any of the trials. Chlorhexidine and triclosan are preferred when an antiseptic with persistent activity is desired, but a moist environment appears to be necessary for that antibacterial activity. Accordingly, relevant conclusions regarding the persistent activity of antiseptics for clinical practice and protection against bacterial contamination cannot be derived from this study for the alcoholic solutions tested.