18. Global Surveillance of Clostridioides difficile Demonstrates High Prevalence in Non-Healthcare Settings

Background Clostridioides difficile is a Gram-positive, spore-forming, toxin-producing organism that is the leading cause of healthcare-associated infections. However, past studies have isolated C. difficile spores from the community, suggesting an environmental reservoir that may play a role in transmission. This study aimed to examine the prevalence and strain types of C. difficile isolated from the United States (US) and internationally. Methods From 2014 to 2017, environmental swabs were collected from public areas, healthcare settings, and shoe soles. Samples were considered positive for C. difficile following growth on CCFA plates and confirmatory PCR testing for toxin genes and fluorescent PCR ribotyping (RT). The rate of C. difficile positivity and associated RT distribution were compared between settings, including shoe soles which were investigated for their potential role in environmental transmission. Results A total of 11,986 unique isolates were obtained primarily from the US (n=11,002; 92%) in addition to 11 other countries including Taiwan (n=200) and India (n=187). Samples were categorized as being from outdoor environments (n=2,992), private residences (n=2,772), shoe soles (n=1,420), public buildings (n=1,104) or acute care settings (n=3,698). Worldwide C. difficile sample positivity was 26% and was similar between US and non-US sampling sites. In the US, private residences (26.2%) and outdoor environments (24.1%) had the highest positivity rate compared to public buildings (17.2%). In a Texas sub-analysis (n=8,571), positivity rates were highest from outdoor samples (27%) and were similar between private residences (24%) and healthcare buildings (24%). The most prevalent RTs overall were F014-020 (16.4%), F106 (14.9%), and FP310 (11%). Shoe soles had the highest positivity rate (45%) with similar RT distribution between shoe soles and environmental samples. Conclusion Using a worldwide sample, 26% of environmental samples tested positive for toxigenic C. difficile strains from healthcare and non-healthcare sites. Community stewardship efforts will be needed to reduce the risk of CDI in vulnerable patients. Shoe sole sampling may be an ideal surveillance tool to test for emerging epidemic strains. Disclosures Kevin W. Garey, Pharm.D., M.S., FASHP, Summit Therapeutics (Research Grant or Support)

TRIBOLOGICAL CHARACTERISTICS OF POLYURETHANES USED FOR THE SOLES OF FOOTWEAR

The inability to take into account the type of base material (floor, pavement, soil), as well as the inability to take into account the variable friction conditions – load, intermediary medium (water, loose abrasive, sand or other soil particles), sliding velocity, and ambient temperature – is a significant limitation the use of friction methods and devices used so far in the footwear industry to precisely anticipate the behavior of the bottom materials in the actual operating conditions of the footwear. These limitations prompted the authors to adapt a tribological tester for this purpose, used in the area of construction and operation of machines and material engineering. A research methodology was developed and, in order to verify it, measurements of the coefficient of friction and wear of polyurethane used for shoe soles in combination with a raw and varnished wooden substrate were carried out. The obtained test results are characterized by diversity, which proves the high research resolution of the developed method. It allows determining the coefficient of friction of associations influencing the slip of the footwear and the wear and tear that determines the length of use of the footwear.

3D Printing in Fiber-Device Technology

Recent advances in additive manufacturing enable redesigning material morphology on nano-, micro-, and meso-scale, for achieving an enhanced functionality on the macro-scale. From non-planar and flexible electronic circuits, through biomechanically realistic surgical models, to shoe soles individualized for the user comfort, multiple scientific and technological areas undergo material-property redesign and enhancement enabled by 3D printing. Fiber-device technology is currently entering such a transformation. In this paper, we review the recent advances in adopting 3D printing for direct digital manufacturing of fiber preforms with complex cross-sectional architectures designed for the desired thermally drawn fiber-device functionality. Subsequently, taking a recursive manufacturing approach, such fibers can serve as a raw material for 3D printing, resulting in macroscopic objects with enhanced functionalities, from optoelectronic to bio-functional, imparted by the fiber-devices properties. Graphic abstract

Women With Impact: Taking One Small Step into the Universe

Out of 1,578 cataloged and named craters on the Moon, only 32 are named after women. That is a scant 2%. To highlight the underrepresentation of women in science, the author created two connected art projects. The initial project, Women With Impact, is a series of drawings of Moon craters named after women. Building on this oeuvre is One Small Step, a participatory project that invites prominent female astronomers to perform a meditative walk while wearing 3D-printed shoe soles that create a small Moon crater with each step.

A Pilot Study on the Contamination of Assistance Dogs’ Paws and Their Users’ Shoe Soles in Relation to Admittance to Hospitals and (In)Visible Disability

(1) Background: People with disabilities may benefit from an assistance dog (AD). Despite regulations that prohibit the denial of ADs to public places, this still occurs on a regular basis. The main argument for denial of access is that dogs compromise hygiene with their presence, which could cause a health hazard. Meanwhile, people are allowed to walk into and out of public places freely. (2) Objective: As a pilot study, to investigate the number of Enterobacteriaceae and the presence of Clostridium difficile bacteria on the paws of ADs and pet dogs (PDs) as well as the shoe soles of their users and owners. With the results, an assessment can be made as to whether measures are required to reduce environmental contamination (e.g., in hospitals). (3) Methods: In total, 25 ADs, 25 PDs, and their 50 users/owners participated in the study. Each participant walked their dog for 15–30 min prior to the sampling of the front paws. Each PD owner or AD user filled out a general questionnaire about the care of their dogs, and AD users were asked to fill out an additional questionnaire on their experiences regarding the admittance of their ADs to public places (in particular, hospitals). Dutch hospitals were questioned on their protocols regarding the admittance of ADs and their visitor numbers, including the percentage of AD users, to put these numbers into perspective. (4) Results: Dog paws were more often negative for Enterobacteriaceae compared to shoe soles (72% and 42%, respectively) and also had significantly lower bacterial counts (mean of 3.54log10 and 5.03log10 colony-forming units (CFUs), respectively; p < 0.05). This was most distinct in the comparison between PDs and their owners (3.75log10 and 5.25log10 CFUs; p < 0.05); the numbers were similar between ADs and their users (3.09log10 and 4.58log10 CFUs; p = 0.2). C. difficile was found on one (4%) AD user’s shoe soles. Moreover, 81% of AD users had been denied access with their current AD once or several times, the main reason being hygiene. The results of the visibly and invisibly disabled were significantly different. The number of AD users as opposed to the total number of hospital visitors was 0.03% in one hospital and is estimated to be 0.02% in the Netherlands. (5) Conclusions: The general hygiene of dogs’ paws is far better than that of shoe soles, mostly demonstrated by the better general hygiene of PD paws compared with their owners’ shoe soles; ADs and their users had comparable levels of general hygiene. In addition, the number of AD users amongst the total number of hospital visitors in the Netherlands is very limited. Thus, hygiene measures to reduce any contamination due to dog paws do not seem necessary.

Analysis of the dependence of stresses and deformations on the surfaces of shoe soles of different thicknesses and materials

For this study, three-dimensional models of the soles of work shoes of different thicknesses and consisting of different materials were created. These models were analyzed to obtain the distribution of stress and strain on their surfaces. To build the model, we used experimental data on the shape and size of the sole, as well as the properties of specific materials used in the manufacture of soles for work shoes used in agriculture. The goal was to determine the most suitable material, that is, which of the materials has the most suitable characteristics for the sole, has the best wear resistance when used in agriculture. We noticed a significant reduction in deformations on the surface of the sole with an increase in the thickness of the sole, as well as when using two-component casting of the sole from a combination of materials: low-density EVA and flexible PU, medium-density EVA and soft PVC. This indicates their advantages and maximum suitability.

Studies of carboxylated nitrile butadiene rubber/butyl reclaimed rubber (XNBR/BRR) blends for shoe soles application

Rising environmental issues and huge disposal of rubber waste have resulted in an increased interest in the usage of reclaimed rubber (RR) to produce sustainable and environmental friendly applications. In this study, incorporation of butyl reclaimed rubber into carboxylated nitrile butadiene rubber (XNBR/BRR) was carried out where the loadings of each XNBR and BRR were varied. The rubber was cured with sulphur during the melt mixing using a two-roll mill. This study is aimed to investigate the applied BRR loading towards the physical and mechanical properties of the XNBRcompounds. The results appeared that the optimum cure time (T90) increased and curing rate index (CRI) showed that a faster curing reaction with the increase in the content of BRR where the T90 had an increment of 89% while the CRI was faster by 89%. As for the crosslink density which indicates the density of chains or segments in polymer network, it decreased about 20% with increasing level of BRR. Also, the compression set which refers to the ability of rubber to resist permanent deformation, had an increase of 73% as the loading ratio of BRR increased. These results were obtained due to the low molecular weight of the BRR where the high shear and temperature during the reclamation process severely breaks down the molecular chains of the BRR into shorter segments. With the results obtained, it is shown that reclaimed rubber has the potential for further development and could increase the interest of researchers all around the world in the incorporation of reclaimed rubber for footwear application.