Carbapenemase-Producing Escherichia coli among Humans and Backyard Animals

Background: The rapidly increasing dissemination of carbapenem-resistant Enterobacteriaceae (CRE) in both humans and animals poses a global threat to public health. However, the transmission of CRE between humans and animals has not yet been well studied. Objectives: We investigated the prevalence, risk factors, and drivers of CRE transmission between humans and their backyard animals in rural China. Methods: We conducted a comprehensive sampling strategy in 12 villages in Shandong, China. Using the household [residents and their backyard animals (farm and companion animals)] as a single surveillance unit, we assessed the prevalence of CRE at the household level and examined the factors associated with CRE carriage through a detailed questionnaire. Genetic relationships among human- and animal-derived CRE were assessed using whole-genome sequencing–based molecular methods. Results: A total of 88 New Delhi metallo-β-lactamases –type carbapenem-resistant Escherichia coli (NDM-EC), including 17 from humans, 44 from pigs, 12 from chickens, 1 from cattle, and 2 from dogs, were isolated from 65 of the 746 households examined. The remaining 12 NDM-EC were from flies in the immediate backyard environment. The NDM-EC colonization in households was significantly associated with a) the number of species of backyard animals raised/kept in the same household, and b) the use of human and/or animal feces as fertilizer. Discriminant analysis of principal components (DAPC) revealed that a large proportion of the core genomes of the NDM-EC belonged to strains from hosts other than their own, and several human isolates shared closely related core single-nucleotide polymorphisms and blaNDM genetic contexts with isolates from backyard animals. Conclusions: To our knowledge, we are the first to report evidence of direct transmission of NDM-EC between humans and animals. Given the rise of NDM-EC in community and hospital infections, combating NDM-EC transmission in backyard farm systems is needed. https://doi.org/10.1289/EHP525

Progress on the Preparation of Nano-hydroxyapatite and its Application in Water Treatment

This is an article in the field of ceramics and composites. Hydroxyapatite (HAP) has excellent ion exchange performance, shows good adsorption capacity for heavy metal ions, harmful anions, and organics in wastewater, and will not cause secondary pollution in the process of wastewater treatment. Thus, it is a promising green adsorbent. Due to its small size and large specific surface area, nano-hydroxyapatite (nHAP) exposes more adsorption sites, showing supreme adsorption capacity. It is a tendency to produce nHAP composites of strong adsorption capacity, easy for solid-liquid separation and regeneration, and low-cost. This article reviews the recent research progress of nano-HAP and its composites as adsorbents for wastewater treatment, and prospects the application of them as adsorbents

Predominant T-cell epitopes of SARS-CoV-2 restricted by multiple prevalent HLA-B and HLA-C allotypes in Northeast Asia

Since the outbreak of novel coronavirus pneumonia (COVID-19), numerous T-cell epitopes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteome have been reported. However, most of the identified CD8+ T-cell epitopes have been restricted primarily by HLA-A allotypes. The epitopes restricted by HLA-B and HLA-C allotypes are limited. This study focuses on the screening of T-cell epitopes restricted by 13 prevalent HLA-B and 13 prevalent HLA-C allotypes, which cover over 70% and 90% of the Chinese and Northeast Asian populations, respectively. Totally, 67 HLA-B restricted and 53 HLA-C restricted epitopes were validated as immunogenic epitopes with a herd predominance rate by peptide-PBMCs ex vivo coculture experiments using the PBMCs from convalescent Chinese cohort. In addition, 26 transfected cell lines expressing indicated HLA-B or HLA-C allotype were established, and used in the competitive peptide binding assays to define the affinities and cross-restriction of each validated epitope binding to HLA-B or HLA-C allotypes. These data will facilitate the design of T-cell-directed vaccines and SARS-CoV-2-specific T-cell detection tools tailored to the Northeast Asian population. The herd test of functionally validated T-cell epitopes, and the competitive peptide binding assay onto cell line array expressing prevalent HLA allotypes may serve as an additional criterion for selecting T-cell epitopes used in vaccine

Shape Optimization Design of Brackets Connecting Girders of an Internal Bulkhead and Pressure Hull Under External Pressure

In order to decrease the local high stress in the brackets which connect to the horizontal and vertical girders of an internal bulkhead and submersible pressure shell, the mathematical models for the shape optimization of the brackets are proposed. In the study, stress analysis of the pressure hull structure including an internal bulkhead and brackets with coarse mesh is firstly conducted, then the submodeling technique is further employed to analyze the refinement stress distribution of the brackets with refined mesh. The boundary shapes of the brackets are assumed as the design variables while the maximum stress of the bracket is treated as objective function to be minimized in the shape optimization problem. The proposed mathematical model is solved by using analysis code Hyperworks/Optistruct and optimal shapes of the brackets are obtained. Results of the shape optimization show that the optimized bracket types can effectively reduce the level of stress. Therefore, the proposed method can be referred to similar structure designs.</jats:p