Sterilization efficiency of pathogen-contaminated cottons in a laundry machine

Toward sustainable household laundry. Washing quality vs. environmental impacts

We tested the efficacy of standard soil removal and bacterial reduction from textile. A life cycle analysis for different washing cycles was also performed. The results show that washing at 40 °C and 10 g/L was the most effective and resulted in good removal of standard soiling. However, bacteria reduction was highest at 60 °C, 5 g/L and 40 °C, 20 g/L (> 5 log CFU/carrier). With the 40 °C, 10 g/L scenario, we approached the standard requirements for household laundry of ~ 4 log CFU/carrier reduction and good soil removal. Howsoever, life cycle analysis shows that washing at 40 °C and 10 g/L has a higher environmental impact than 60 °C and 5 g/L due to the significant contribution of the detergent. Reducing energy consumption and reformulation of detergents needs to be implemented in the household laundry to achieve sustainable washing without compromising the quality.

Evaluating infection risks and importance of hand hygiene during the household laundry process using a quantitative microbial risk assessment approach

BACKGROUND

Contaminated laundry contributes to infectious disease spread in residential and home health care settings. The objectives were to (1) evaluate pathogen transmission risks for individuals doing laundry, and (2) compare hand hygiene timing to reduce risks.

METHODS

A quantitative microbial risk assessment using experimental data from a laundry washing effectiveness study was applied to estimate infection risks from SARS-CoV-2, rotavirus, norovirus, nontyphoidal Salmonella, and Escherichia coli in 4 laundry scenarios: 1 baseline scenario (no hand hygiene event) and 3 hand hygiene scenarios (scenario 1: after moving dirty clothes to the washing machine, scenario 2: after moving washed clothes to the dryer, and scenario 3: hand hygiene events following scenario 1 and 2).

RESULTS

The average infection risks for the baseline scenario were all greater than 2 common risk thresholds (1.0×10-6and 1.0×10-4). For all organisms, scenario 1 yielded greater risk reductions (39.95%-99.86%) than scenario 2 (1.35%-55.25%). Scenario 3 further reduced risk, achieving 1.0×10-6(SARS-CoV-2) and 1.0×10-4risk thresholds (norovirus and E. coli).

CONCLUSIONS

The modeled results suggest individuals should reduce hand-to-facial orifice (eyes, nose, and mouth) contacts and conduct proper hand hygiene when handling contaminated garments. More empirical data are needed to confirm the estimated risks.

DATA AVAILABILITY STATEMENT

The data and code that support the findings of this study can be retrieved via a Creative Commons Zero v1.0 Universal license in GitHub at https://github.com/yhjung1231/Laundry-QMRAproject-2022.git DOI: http://doi.org/10.5281/zenodo.7122065.

Impact of antibacterial detergent on used-towel microbiomes at species-level and its effect on malodor control

The impact of antibacterial detergent on microbial exchanges and its subsequent effect on malodor in used towels were examined. Homogenization of microbiome among postwashed and indoor dried towels that was dominated by known malodor-producing bacteria. The microbial exchange was attenuated, and the abundance of malodor-producing bacteria was reduced in towels laundered with antibacterial detergent. Reduction of malodorous volatile organic compounds produced from towels laundered with antibacterial detergent.

Comparison of Survival of Healthcare Associated Bacteria on Materials used for Making White Coat

Healthcare-Associated Infections (HAIs) are of global concern in this present era and white coats play an important role in the transmission of HAIs. The most common healthcare-associated bacteria are Enterococcus species, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanni, Pseudomonas aeruginosa and Enterobacter species (ESKAPE bugs). These healthcare-associated bacteria are capable of surviving on white coats which could act as fomites in the transmission of HAIs. The purpose of this study was to compare the duration of survival of healthcare-associated bacteria on different materials used for making white coats. Materials like pure cotton, artificial cotton, cotton silk, spun and crepe were cut into swatches of 1cm2 size and sterilized by autoclaving. Five different bacteria isolated from clinical specimens were grown on 5 % sheep blood agar and bacterial suspensions were made in sterile physiological saline. The swatches were immersed in bacterial suspension and kept in petri plates at 25°C. The viable counts of bacteria were determined at definite time intervals by surface plate method. The present study shows that among the healthcare-associated bacteria, S.aureus survived the maximum up to 52 days. The duration of survival of S.aureus was significantly longer than P.aeruginosa and A.baumannii (p <0.05). A.baumannii survived only up to 20 days maximum. All the healthcare-associated bacteria significantly survived for the shortest duration of time on crepe. Therefore, crepe could be a better material used for making white coats.

Quantifying pathogen infection risks from household laundry practices

Aims

Contaminated laundry can spread infections. However, current directives for safe laundering are limited to healthcare settings and not reflective of domestic conditions. We aimed to use quantitative microbial risk assessment to evaluate household laundering practices (e.g., detergent selection, washing and drying temperatures, and sanitizer use) relative to log₁₀ reductions in pathogens and infection risks during the clothes sorting, washer/dryer loading, folding and storing steps.

Methods and Results

Using published data, we characterized laundry infection risks for respiratory and enteric pathogens relative to a single user contact scenario and a 1.0 × 10⁻⁶ acceptable risk threshold. For respiratory pathogens, risks following cold water wash temperatures (e.g. median 14.4℃) and standard detergents ranged from 2.2 × 10⁻⁵ to 2.2 × 10⁻⁷. Use of advanced, enzymatic detergents reduced risks to 8.6 × 10⁻⁸ and 2.2 × 10⁻¹¹ respectively. For enteric pathogens, however, hot water, advanced detergents, sanitizing agents and drying are needed to reach risk targets.

Significance and Impact of the Study

Conclusions provide guidance for household laundry practices to achieve targeted risk reductions, given a single user contact scenario. A key finding was that hand hygiene implemented at critical control points in the laundering process was the most significant driver of infection prevention, additionally reducing infection risks by up to 6 log₁₀.

Laundry Hygiene and Odor Control: State of the Science

Laundering of textiles—clothing, linens, and cleaning cloths—functionally removes dirt and bodily fluids, which prevents the transmission of and reexposure to pathogens as well as providing odor control. Thus, proper laundering is key to controlling microbes that cause illness and produce odors. The practice of laundering varies from region to region and is influenced by culture and resources. This review aims to define laundering as a series of steps that influence the exposure of the person processing the laundry to pathogens, with respect to the removal and control of pathogens and odor-causing bacteria, while taking into consideration the types of textiles. Defining laundering in this manner will help better educate the consumer and highlight areas where more research is needed and how to maximize products and resources. The control of microorganisms during laundering involves mechanical (agitation and soaking), chemical (detergent and bleach), and physical (detergent and temperature) processes. Temperature plays the most important role in terms of pathogen control, requiring temperatures exceeding 40°C to 60°C for proper inactivation, while detergents play a role in reducing the microbial load of laundering through the release of microbes attached to fabrics and the inactivation of microbes sensitive to detergents (e.g., enveloped viruses). The use of additives (enzymes) and bleach (chlorine and activated oxygen) becomes essential in washes with temperatures below 20°C, especially for certain enteric viruses and bacteria. A structured approach is needed that identifies all the steps in the laundering process and attempts to identify each step relative to its importance to infection risk and odor production.

Silver Nanostars-Coated Surfaces with Potent Biocidal Properties

Bacterial proliferation on certain surfaces is of concern as it tends to lead to infectious health problems. Nanotechnology is offering new options for engineering antimicrobial surfaces. Herein, the antibiofilm and biocidal properties of star-shaped silver nanoparticles (AgNSs) in suspension and as coating surfaces were studied. AgNSs and spherical silver nanoparticles (AgNPs) (used for comparison purposes) were synthesized using reported methods. Glass disks (9 mm diameter) were covered with AgNSs using deposition by centrifugation. Minimum inhibitory concentrations (MICs) of AgNSs and AgNPs were determined against several reference strains and multidrug-resistant isolates and their antibiofilm activity was assessed against preformed biofilms of Pseudomonas aeruginosa and Staphylococcus aureus by both Live/Dead staining and atomic force microscopy (AFM). The antimicrobial properties of AgNSs-coated surfaces were evaluated by the “touch test” method on agar, and also Live/Dead staining and AFM. The MIC values of the AgNSs were 2–4 times lower than those of the AgNPs. Biofilms treated with AgNSs at a concentration equal to the MIC were not significantly affected, although they exhibited more dead cells than the non-treated biofilms. The biocidal activity of AgNSs-coated surfaces was attested, since no growth on agar nor viable cells were observed after contact of the inoculated bacteria with the coated surface for 6 and 24 h. Thus, AgNSs show greater potential as a surface coating with biocidal effects than used as suspension for antimicrobial purposes.