Search

The infant gut microbiome is increasingly recognized as a reservoir of antibiotic resistance genes, yet the assembly of gut resistome in infants and its influencing factors remain largely unknown. We characterized resistome in 4132 metagenomes from 963 infants in six countries and 4285 resistance genes were observed. The inherent resistome pattern of healthy infants (N = 272) could be distinguished by two stages: a multicompound resistance phase (Months 0-7) and a tetracycline-mupirocin-β-lactam-dominant phase (Months 8-14). Microbial taxonomy explained 40.7% of the gut resistome of healthy infants, with Escherichia (25.5%) harboring the most resistance genes. In a further analysis with all available infants (N = 963), we found age was the strongest influencer on the resistome and was negatively correlated with the overall resistance during the first 3 years (p

[Objective] To address the shortcomings of existing accounting that only focuses on traditional natural resources, and to further enrich and develop China’s unique natural resource balance sheet accounting theory, this study explored the compilation of a natural resource balance sheet that incorporates environmental capacity resources. [Methods] This study closely integrates China’s pollutant emission control practices to analyze the theory of natural resource balance sheet accounting by incorporating environmental capacity resources. Considering that water can serve as both a resource carrier and an environmental capacity carrier, this study took water in Shanxi Province as an example to compile a balance sheet for water resources in the province from 2018 to 2020. [Results] (1) China’s practice of pollutant emission control provides practical feasibility for incorporating environmental capacity resources into accounting. (2) After incorporating environmental capacity resources into the natural resource balance sheet, natural resource asset accounting is comprised of two major categories: traditional natural resource assets and environmental capacity resource assets. Natural resource liability accounting encompasses two categories: resource overuse liabilities and ecological damage liabilities. Environmental damage liabilities are classified as environmental capacity resource overuse liabilities. （3） From 2018 to 2020, Shanxi Province used an accumulated excess of water environmental capacity resources assets of 4.225 billion yuan, with a closing (cumulative) value of the water asset liability balance of 7.973 billion yuan. During the study period, Shanxi Province utilized water environmental capacity resources assets totaling 54.750 billion yuan, accounting for 53% of the water asset value used during the same period. [Conclusion] It is possible to compile a natural resource balance sheet that includes environmental capacity resources. The accounting theory of natural resource balance sheets should be closely linked to China’s natural resource management practices. Integrating with the total natural resource use control system represents a feasible breakthrough for the accounting theory of natural resource balance sheets.

Mathematical models have many applications in infectious diseases: epidemiologists use them to forecast outbreaks and design containment strategies; systems biologists use them to study complex processes sustaining pathogens, from the metabolic networks empowering microbial cells to ecological networks in the microbiome that protects its host. Here, we (1) review important models relevant to infectious diseases, (2) draw parallels among models ranging widely in scale. We end by discussing a minimal set of information for a model to promote its use by others and to enable predictions that help us better fight pathogens and the diseases they cause.

Targeted metagenomic sequencing is an emerging strategy to survey disease- specific microbiome biomarkers for clinical diagnosis and prognosis. However, this approach often yields inconsistent or conflicting results owing to inadequate study power and sequencing bias. We introduce Taxa4Meta, a bioinformatics pipeline explicitly designed to compensate for technical and demographic bias. We designed and validated Taxa4Meta for accurate taxonomic profiling of 16S rRNA amplicon data acquired from different sequencing strategies. Taxa4Meta offers significant potential in identifying clinical dysbiotic features that can reliably predict human disease, validated comprehensively via reanalysis of individual patient 16S data sets. We leveraged the power of Taxa4Meta's pan-microbiome profiling to generate 16S-based classifiers that exhibited excellent utility for stratification of diarrheal patients with Clostridioides difficile infection, irritable bowel syndrome, or inflammatory bowel diseases, which represent common misdiagnoses and pose significant challenges for clinical management. We believe that Taxa4Meta represents a new 'best practices' approach to individual microbiome surveys that can be used to define gut dysbiosis at a population-scale level., Introduction Targeted metagenomic sequencing is commonly used for the identification of disease-causing bacteria, archaea, and fungi. In addition, 16S rRNA gene surveys are increasingly being adopted as diagnostic tools to [...]

In this study, we evaluated the biotransformation mechanisms of lincomycin (LIN) and three fluoroquinolone antibiotics (FQs), ciprofloxacin (CFX), norfloxacin (NFX), and ofloxacin (OFX), which regularly enter aquatic environments through human activities, by different ammonia-oxidizing microorganisms (AOM). The organisms included a pure culture of the complete ammonia oxidizer (comammox) Nitrospira inopinata, an ammonia oxidizing archaeon (AOA) Nitrososphaera gargensis, and an ammonia-oxidizing bacterium (AOB) Nitrosomonas nitrosa Nm90. The removal of these antibiotics by the pure microbial cultures and the protein-normalized biotransformation rate constants indicated that LIN was significantly co-metabolically biotransformed by AOA and comammox, but not by AOB. CFX and NFX were significantly co-metabolized by AOA and AOB, but not by comammox. None of the tested cultures transformed OFX effectively. Generally, AOA showed the best biotransformation capability for LIN and FQs, followed by comammox and AOB. The transformation products and their related biotransformation mechanisms were also elucidated. i) The AOA performed hydroxylation, S-oxidation, and demethylation of LIN, as well as nitrosation and cleavage of the piperazine moiety of CFX and NFX; ii) the AOB utilized nitrosation to biotransform CFX and NFX; and iii) the comammox carried out hydroxylation, demethylation, and demethylthioation of LIN. Hydroxylamine, an intermediate of ammonia oxidation, chemically reacted with LIN and the selected FQs, with removals exceeding 90%. Collectively, these findings provide important fundamental insights into the roles of different ammonia oxidizers and their intermediates on LIN and FQ biotransformation in nitrifying environments including wastewater treatment systems.

Background & aimsAlthough Clostridioides difficile infection (CDI) is known to involve the disruption of the gut microbiota, little is understood regarding how mucus-associated microbes interact with C difficile. We hypothesized that select mucus-associated bacteria would promote C difficile colonization and biofilm formation.MethodsTo create a model of the human intestinal mucus layer and gut microbiota, we used bioreactors inoculated with healthy human feces, treated with clindamycin and infected with C difficile with the addition of human MUC2-coated coverslips.ResultsC difficile was found to colonize and form biofilms on MUC2-coated coverslips, and 16S rRNA sequencing showed a unique biofilm profile with substantial cocolonization with Fusobacterium species. Consistent with our bioreactor data, publicly available data sets and patient stool samples showed that a subset of patients with C difficile infection harbored high levels of Fusobacterium species. We observed colocalization of C difficile and F nucleatum in an aggregation assay using adult patients and stool of pediatric patients with inflammatory bowel disease and in tissue sections of patients with CDI. C difficile strains were found to coaggregate with F nucleatum subspecies in vitro; an effect that was inhibited by blocking or mutating the adhesin RadD on Fusobacterium and removal of flagella on C difficile. Aggregation was shown to be unique between F nucleatum and C difficile, because other gut commensals did not aggregate with C difficile. Addition of F nucleatum also enhanced C difficile biofilm formation and extracellular polysaccharide production.ConclusionsCollectively, these data show a unique interaction of between pathogenic C difficile and F nucleatum in the intestinal mucus layer.

In this study, triple sheets of R60702 zirconium (Zr) alloy are joined together using the resistance‐spot‐welding process. The nugget formation mechanism and microstructure of the weld joint in three equal‐thickness sheets of R60702 Zr alloy are studied. In the results, it is revealed that the initial nugget forms at the top of the intermediate sheet, and subsequently expands both radially and axially until a complete nugget is formed. The fusion zone (FZ) exhibits a martensitic microstructure, while the heat‐affected zone (HAZ) consists of two regions: coarse‐grain HAZ and fine‐grain HAZ. The hardness in the FZ is higher than that of the HAZ and the base metal. Furthermore, the tensile‐shear force and fracture mode of the weld nuggets are also studied. The weld joints exhibit a maximum tensile‐shear load of 5.7 kN under the following welding parameters: welding current of 14 kA, welding time of 150 ms, and welding force of 3.6 kN. Three failure modes are identified interface fracture, partial button fracture, and button fracture. [ABSTRACT FROM AUTHOR]