[Element relationship and extension path of clinical evidence knowledge map with Chinese patent medicine].

This study aims to construct the element relationship and extension path of clinical evidence knowledge map with Chinese patent medicine, providing basic technical support for the formation and transformation of the evidence chain of Chinese patent medicine and providing collection, induction, and summary schemes for massive and disorganized clinical data. Based on the elements of evidence-based PICOS, the conventional construction methods of knowledge graph were collected and summarized. Firstly, the data entities related to Chinese patent medicine were classified, and entity linking was performed(disambiguation). Secondly, the study associated and classified the attribute information of the data entity. Finally, the logical relationship between entities was constructed, and then the element relationship and extension path of the knowledge map conforming to the characteristics of clinical evidence of Chinese patent medicine were summarized. The construction of the clinical evidence knowledge map of Chinese patent medicine was mainly based on process design and logical structure, and the element relationship of the knowledge map was expressed according to the PICOS principle and evidence level. The extension path crossed three levels(model layer, data layer application, and new evidence application), and the study gradually explored the path from disease, core evaluation indicators, Chinese patent medicine, core prescriptions, syndrome and treatment rules, and medical case comparison(evolution law) to new drug research and development. In this study, the top-level design of the construction of the clinical evidence knowledge map of Chinese patent medicine has been clarified, but it still needs the joint efforts of interdisciplinary disciplines. With the continuous improvement of the map construction technology in line with the characteristics of TCM, the study can provide necessary basic technical support and reference for the development of the TCM discipline.

High immigration rates critical for establishing emigration-driven diversity in microbial communities.

Unraveling the mechanisms governing the diversity of ecological communities is a central goal in ecology. Although microbial dispersal constitutes an important ecological process, the effect of dispersal on microbial diversity is poorly understood. Here, we sought to fill this gap by combining a generalized Lotka-Volterra model with experimental investigations. Our model showed that emigration increases the diversity of the community when the immigration rate crosses a defined threshold, which we identified as Ineutral. We also found that at high immigration rates, emigration weakens the relative abundance of fast-growing species and thus enhances the mass effect and increases the diversity. We experimentally confirmed this finding using co-cultures of 20 bacterial strains isolated from the soil. Our model further showed that Ineutral decreases with the increase of species pool size, growth rate, and interspecies interaction. Our work deepens the understanding of the effects of dispersal on the diversity of natural communities.

The trade-off between individual metabolic specialization and versatility determines the metabolic efficiency of microbial communities.

In microbial systems, a metabolic pathway can be either completed by one autonomous population or distributed among a consortium performing metabolic division of labor (MDOL). MDOL facilitates the system's function by reducing the metabolic burden; however, it may hinder the function by reducing the exchange efficiency of metabolic intermediates among individuals. As a result, the function of a community is influenced by the trade-offs between the metabolic specialization and versatility of individuals. To experimentally test this hypothesis, we deconstructed the naphthalene degradation pathway into four steps and introduced them individually or combinatorically into different strains with varying levels of metabolic specialization. Using these strains, we engineered 1,456 synthetic consortia and found that 74 consortia exhibited higher degradation function than both the autonomous population and rigorous MDOL consortium. Quantitative modeling provides general strategies for identifying the most effective MDOL configuration. Our study provides critical insights into the engineering of high-performance microbial systems.

Roles of sulfate-reducing bacteria in sustaining the diversity and stability of marine bacterial community.

Microbes play central roles in ocean food webs and global biogeochemical processes. Yet, the information available regarding the highly diverse bacterial communities in these systems is not comprehensive. Here we investigated the diversity, assembly process, and species coexistence frequency of bacterial communities in seawater and sediment across ∼600 km of the eastern Chinese marginal seas using 16S rRNA gene amplicon sequencing. Our analyses showed that compared with seawater, bacterial communities in sediment possessed higher diversity and experienced tight phylogenetic distribution. Neutral model analysis showed that the relative contribution of stochastic processes to the assembly process of bacterial communities in sediment was lower than that in seawater. Functional prediction results showed that sulfate-reducing bacteria (SRB) were enriched in the core bacterial sub-communities. The bacterial diversities of both sediment and seawater were positively associated with the relative abundance of SRB. Co-occurrence analysis showed that bacteria in seawater exhibited a more complex interaction network and closer co-occurrence relationships than those in sediment. The SRB of seawater were centrally located in the network and played an essential role in sustaining the complex network. In addition, further analysis indicated that the SRB of seawater helped maintain the high stability of the bacterial network. Overall, this study provided further comprehensive information regarding the characteristics of bacterial communities in the ocean, and provides new insights into keystone taxa and their roles in sustaining microbial diversity and stability in ocean.

Improving Rhamnolipids Biosynthesis in Pseudomonas sp. L01 through Atmospheric and Room-Temperature Plasma (ARTP) Mutagenesis.

Biosurfactants have significant applications in various industries, including microbial-enhanced oil recovery (MEOR). While the state-of-the-art genetic approaches can generate high-yield strains for biosurfactant production in fermenters, there remains a critical challenge in enhancing biosurfactant-producing strains for use in natural environments with minimal ecological risks. The objectives of this work are enhancing the strain's capacity for rhamnolipids production and exploring the genetic mechanisms for its improvement. In this study, we employed atmospheric and room-temperature plasma (ARTP) mutagenesis to enhance the biosynthesis of rhamnolipids in Pseudomonas sp. L01, a biosurfactant-producing strain isolated from petroleum-contaminated soil. Following ARTP treatment, we identified 13 high-yield mutants, with the highest yield of 3.45 ± 0.09 g/L, representing a 2.7-fold increase compared to the parent strain. To determine the genetic mechanisms behind the enhanced rhamnolipids biosynthesis, we sequenced the genomes of the strain L01 and five high-yield mutants. A comparative genomic analysis suggested that mutations in genes related to the synthesis of lipopolysaccharides (LPS) and the transport of rhamnolipids may contribute to the improved biosynthesis. To the best of our knowledge, this is the first instance of utilizing the ARTP approach to improve rhamnolipid production in Pseudomonas strains. Our study provides valuable insights into the enhancement of biosurfactant-producing strains and the regulatory mechanisms of rhamnolipids biosynthesis.

Assembly of Microbial Communities Engaging in Metabolic Division of Labor in a Diffusion-Limited Environment Is Governed by Metabolic Flux.

Metabolic division of labor (MDOL) represents one of the most commonly occurring interactions within natural microbial communities. Specifically, in a variety of MDOL systems engaged in hydrocarbon degradation, a sequential degradation is performed by several members with final products that are necessary for the growth of each member. In these MDOL systems, each strain catalyzes one or more specific reactions of a multistep metabolic pathway, whose end products are then allocated among the participants. While the benefit allocation is independent of metabolic flux in well-mixed environments, it remains unclear how the benefits are allocated when diffusion is limited. Here, we investigated how MDOL communities assemble in a diffusion-limited environment, by combining mathematical modeling with experimental inquiry using a synthetic consortium engaged in MDOL. Our model analysis in a diffusion-limited environment showed that, when the growth of all populations in the community relies on the final product that can only be produced by the last population, a diffusion gradient of the final products may create a bias favoring the member producing the final products, resulting in a higher relative abundance of the final product producer. Moreover, such asymmetric allocation of the final products is enhanced by both the lower diffusion rate and the higher metabolic flux (i.e., the higher yields of the final products) in the MDOL. Our results show that in a diffusively confined environment, metabolic flux constitutes a determining factor in the assembly of the MDOL community. Together, our findings are critical for a better understanding of how resource-sharing microbial communities are established and should assist in designing such communities for improved biomanufacturing and bioremediation.

Volatile compounds-induced environmental pH shifts mediate interspecific bacterial interactions over long-distance.

Microorganisms interact with each other through exchanging metabolites as well as signals molecules. This exchange typically depends on metabolites or signaling molecules diffusing in aqueous media within spatially connected habitats, and it only occurs within a short range. However, different microorganisms frequently live in spatially discontinuous micro-habitats without the connections of aqueous media. How microorganisms populating such spatially discontinuous micro-habitats interact remains poorly understood. Here, we show that a bacterial strain, Corynebacterium glutamicum ATCC13032T, produces high amounts of ammonia in its local habitat, which disperses over long distances (up to 12 cm) through the air. As a result, the pH of another spatially disconnected habitat increases, thus inducing the growth of an acid-sensitive strain (Glycocaulis alkaliphilus 6B-8T). We also show that ammonia-mediated long-distance interactions can be commonly found in various bacterial communities. In conclusion, our work demonstrates that bacteria growing in spatially discontinuous micro-habitats can interact with each other through gaseous diffusion of volatile compounds. This finding expands our understanding of the spatial scale at which bacteria can interact and provides new insights into how spatially separated species are connected to maximizing community-level commensalism.

Predicting microbial community compositions in wastewater treatment plants using artificial neural networks.

BACKGROUND: Activated sludge (AS) of wastewater treatment plants (WWTPs) is one of the world's largest artificial microbial ecosystems and the microbial community of the AS system is closely related to WWTPs' performance. However, how to predict its community structure is still unclear. RESULTS: Here, we used artificial neural networks (ANN) to predict the microbial compositions of AS systems collected from WWTPs located worldwide. The predictive accuracy R21:1 of the Shannon-Wiener index reached 60.42%, and the average R21:1 of amplicon sequence variants (ASVs) appearing in at least 10% of samples and core taxa were 35.09% and 42.99%, respectively. We also found that the predictability of ASVs was significantly positively correlated with their relative abundance and occurrence frequency, but significantly negatively correlated with potential migration rate. The typical functional groups such as nitrifiers, denitrifiers, polyphosphate-accumulating organisms (PAOs), glycogen-accumulating organisms (GAOs), and filamentous organisms in AS systems could also be well recovered using ANN models, with R21:1 ranging from 32.62% to 56.81%. Furthermore, we found that whether industry wastewater source contained in inflow (IndConInf) had good predictive abilities, although its correlation with ASVs in the Mantel test analysis was weak, which suggested important factors that cannot be identified using traditional methods may be highlighted by the ANN model. CONCLUSIONS: We demonstrated that the microbial compositions and major functional groups of AS systems are predictable using our approach, and IndConInf has a significant impact on the prediction. Our results provide a better understanding of the factors affecting AS communities through the prediction of the microbial community of AS systems, which could lead to insights for improved operating parameters and control of community structure. Video Abstract.

MiR-328-3p promotes TGF-ß1-induced proliferation, migration, and inflammation of airway smooth muscle cells by regulating the PTEN/Akt pathway.

BACKGROUND: Recent studies have shown that the up-regulation of microRNA miR-328-3p expression increases seasonal allergy and asthma symptoms in children, but the specific mechanism remains unclear. Therefore, the aim of this study was to explore the role and mechanism of -miR-328-3p in transforming growth factor (TGF)-ß1-induced airway smooth muscle cells (ASMCs). METHODS: The effect of TGF-ß1 on the expression of miR-328-3p in ASMCs was examined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cells proliferation, migration, and inflammatory factors in TGF-ß1-induced ASMCs were measured by cell counting kit-8 (CCK-8), transwell, and enzyme-linked immunosorbent assay (ELISA), respectively. Besides, TargetScan was used to predict phosphatase and tensin homolog (PTEN), the downstream target of miR-328-3p; double-luciferase reporter assay, western blot, and qRT-PCR were used to verify the targeting relationship between miR-328-3p and PTEN; western blot was also used to examine the effects of PTEN and miR-328-3p knockdown on the expression levels of PTEN, Akt, and p-Akt proteins. RESULTS: The expression of miR-328-3p was up-regulated in TGF-ß1-induced ASMCs. Knockdown of miR-328-3p significantly inhibited proliferation, migration, and inflammation of ASMCs induced by TGF-ß1 and decreased levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß. The dual--luciferase reporter assay results confirmed that PTEN was a target gene of miR-328-3p. Moreover, inhibition of PTEN expression reversed the inhibitory effect of low miR-328-3p expression on -TGF-ß1-induced ASMC's proliferation, migration, and inflammation. In comparison to the knockdown of miR-328-3p alone, the simultaneous knockdown of miR-328-3p with PTEN decreased PTEN protein expression levels and increased p-Akt/Akt ratio in TGF-ß1-induced ASMCs. CONCLUSION: Through regulating the expression of PTEN and the activity of Akt signaling pathway, miR-328-3p promotes TGF-ß1-induced proliferation, migration, and inflammation of ASMCs.

MiR-328-3p promotes TGF-B1-induced proliferation, migration, and inflammation of airway smooth muscle cells by regulating the PTEN/Akt pathway

Background: Recent studies have shown that the up-regulation of microRNA miR-328-3p expression increases seasonal allergy and asthma symptoms in children, but the specific mechanism remains unclear. Therefore, the aim of this study was to explore the role and mechanism of -miR-328-3p in transforming growth factor (TGF)-β1-induced airway smooth muscle cells (ASMCs). Methods: The effect of TGF-β1 on the expression of miR-328-3p in ASMCs was examined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cells proliferation, migration, and inflammatory factors in TGF-β1-induced ASMCs were measured by cell counting kit-8 (CCK-8), transwell, and enzyme-linked immunosorbent assay (ELISA), respectively. Besides, TargetScan was used to predict phosphatase and tensin homolog (PTEN), the downstream target of miR-328-3p; double-luciferase reporter assay, western blot, and qRT-PCR were used to verify the targeting relationship between miR-328-3p and PTEN; western blot was also used to examine the effects of PTEN and miR-328-3p knockdown on the expression levels of PTEN, Akt, and p-Akt proteins. Results: The expression of miR-328-3p was up-regulated in TGF-β1-induced ASMCs. Knockdown of miR-328-3p significantly inhibited proliferation, migration, and inflammation of ASMCs induced by TGF-β1 and decreased levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β. The dual--luciferase reporter assay results confirmed that PTEN was a target gene of miR-328-3p. Moreover, inhibition of PTEN expression reversed the inhibitory effect of low miR-328-3p expression on -TGF-β1-induced ASMC’s proliferation, migration, and inflammation (AU)

pH and Nitrate Drive Bacterial Diversity in Oil Reservoirs at a Localized Geographic Scale.

Oil reservoirs are one of the most important deep subsurface biospheres. They are inhabited by diverse microorganisms including bacteria and archaea with diverse metabolic activities. Although recent studies have investigated the microbial communities in oil reservoirs at large geographic scales, it is still not clear how the microbial communities assemble, as the variation in the environment may be confounded with geographic distance. In this work, the microbial communities in oil reservoirs from the same oil field were identified at a localized geographic scale. We found that although the injected water contained diverse exogenous microorganisms, this had little effect on the microbial composition of the produced water. The Neutral Community Model analysis showed that both bacterial and archaeal communities are dispersal limited even at a localized scale. Further analysis showed that both pH and nitrate concentrations drive the assembly of bacterial communities, of which nitrate negatively correlated with bacterial alpha diversity and pH differences positively correlated with the dissimilarity of bacterial communities. In contrast, the physiochemical parameters had little effect on archaeal communities at the localized scale. Our results suggest that the assembly of microbial communities in oil reservoirs is scale- and taxonomy-dependent. Our work provides a comprehensive analysis of microbial communities in oil reservoirs at a localized geographic scale, which improves the understanding of the assembly of the microbial communities in oil reservoirs.

Response of Microbial Communities on Cathode with Different Potentials in a Single-Chamber Reactor.

Microbes use both organic and inorganic compounds as electron donors, with different electronic potentials, to produce energy required for growth in environments. Conventional studies on the effects of different electron donors on microbial community has been extensively studied with a set cathode potential. However, it remains under-researched how a microbial community response to the different redox potentials in different environments. Here, we incubated a lake sediment in a single-chamber reactor equipped with three working electrodes, i.e., with potentials of - 0.29 V, - 0.05 V versus standard hydrogen electrode and open-circuit, respectively. Results reveal that the structure of bacterial communities was highly similar for all closed-circuit electrodes (- 0.29 V, - 0.05 V), while differing significantly from those on open-circuit electrodes. We also show that specific bacteria were preferentially enriched by different electrode potentials, i.e., Pseudomonas and Rhodobacter preferentially grew on - 0.05 V and - 0.29 V cathode potentials, Azospirillum and Bosea preferentially grew on - 0.05 V; while Ferrovibrio, Hydrogenophaga, Delftia, and Sphingobium preferentially grew on - 0.29 V. In addition, microorganisms selectively enriched on open-circuit electrodes possess higher connectivity and closer relationship than microorganisms selectively enriched on closed-circuit electrode.

Metabolic profiling of petroleum-degrading microbial communities incubated under high-pressure conditions.

While pressure is a significant characteristic of petroleum reservoirs, it is often overlooked in laboratory studies. To clarify the composition and metabolic properties of microbial communities under high-pressure conditions, we established methanogenic and sulfate-reducing enrichment cultures under high-pressure conditions using production water from the Jilin Oilfield in China. We utilized a metagenomics approach to analyze the microbial community after a 90-day incubation period. Under methanogenic conditions, Firmicutes, Deferribacteres, Ignavibacteriae, Thermotogae, and Nitrospirae, in association with the hydrogenotrophic methanogen Archaeoglobaceae and acetoclastic Methanosaeta, were highly represented. Genomes for Ca. Odinarchaeota and the hydrogen-dependent methylotrophic Ca. Methanosuratus were also recovered from the methanogenic culture. The sulfate-reducing community was dominated by Firmicutes, Thermotogae, Nitrospirae, Archaeoglobus, and several candidate taxa including Ca. Bipolaricaulota, Ca. Aminicenantes, and Candidate division WOR-3. These candidate taxa were key pantothenate producers for other community members. The study expands present knowledge of the metabolic roles of petroleum-degrading microbial communities under high-pressure conditions. Our results also indicate that microbial community interactions were shaped by syntrophic metabolism and the exchange of amino acids and cofactors among members. Furthermore, incubation under in situ pressure conditions has the potential to reveal the roles of microbial dark matter.

Type IV pili trigger episymbiotic association of Saccharibacteria with its bacterial host.

Recent characterization of the obligate episymbiont Saccharibacteria (TM7) belonging to the candidate phyla radiation (CPR) has expanded the extent of microbial diversity. However, the episymbiotic lifestyle of TM7 is still underexploited due to the deficiency of cultivated representatives. Here, we describe gene-targeted TM7 cultivation guided by repurposing epicPCR (emulsion, paired isolation, and concatenation PCR) to capture in situ TM7‒host associations. Using this method, we obtained a novel Saccharibacteria isolate TM7i and its host Leucobacter aridicollis J1 from Cicadae Periostracum, the castoff shell of cicada. Genomic analyses and microscopic characterizations revealed that TM7i could bind to J1 through twitching-like motility mediated by type IV pili (T4P). We further showed that the inhibition of T4P extrusion suppressed the motility and host adherence of TM7i, resulting in its reduced growth. However, the inactivation of T4P had little effect on the growth of TM7i that had already adhered to J1, suggesting the essential role of T4P in host recognition by TM7i. By capturing CPR‒host association and elaborating the T4P-dependent episymbiotic association mechanism, our studies shed light on the distinct yet widespread lifestyle of CPR bacteria.

Single-Cell-Based High-Throughput Cultivation and Functional Characterization of Biosurfactant-Producing Bacteria from Soil and Oilfield-Produced Water.

Biosurfactants are a group of surface-active compounds that can be produced by diverse microorganisms. They have been widely used in various industrial fields. Reducing production costs, improving efficiency, and collecting more diverse producing strains have become major challenges in the biosurfactant industry. These challenges could be overcome by screening for more diverse and efficient biosurfactant-producing strains. The conventional methods for the isolation and functional characterization of microorganisms are laborious and biased toward fast-growing or strongly competitive microorganisms. Here, we established a high-throughput approach of single-cell-based cultivation and functional characterization of biosurfactant-producing bacteria (SCCBB). This approach combines single-cell cultivation with the detection of optical distortions. Using this approach, we isolated 431 strains with biosurfactant production potential from petroleum-contaminated soil and oilfield-produced water. The surfactant production capabilities of the strains were subsequently validated using surface tension measurements, TLC, and CMC measurements. To investigate the industrial production potential, we optimized the production conditions of a representative glycolipids-producing strain, Pseudomonas sp. L01, using response surface methodology (RSM). Optimal conditions yielded a crude biosurfactant yield of 8.43 g/L in a flask. Our work provides a high-throughput approach to the isolation and screening of biosurfactant-producing bacteria, as well as other functional bacteria in a wide range of fields.

The Roles of the Two-Component System, MtrAB, in Response to Diverse Cell Envelope Stresses in Dietzia sp. DQ12-45-1b.

Two-component systems (TCSs) act as common regulatory systems allowing bacteria to detect and respond to multiple environmental stimuli, including cell envelope stress. The MtrAB TCS of Actinobacteria is critical for cell wall homeostasis, cell proliferation, osmoprotection, and antibiotic resistance, and thus is found to be highly conserved across this phylum. However, how precisely the MtrAB TCS regulates cellular homeostasis in response to environmental stress remains unclear. Here, we show that the MtrAB TCS plays an important role in the tolerance to different types of cell envelope stresses, including environmental stresses (i.e., oxidative stress, lysozyme, SDS, osmotic pressure, and alkaline pH stresses) and envelope-targeting antibiotics (i.e., isoniazid, ethambutol, glycopeptide, and ß-lactam antibiotics) in Dietzia sp. DQ12-45-1b. An mtrAB mutant strain exhibited slower growth compared to the wild-type strain and was characterized by abnormal cell shapes when exposed to various environmental stresses. Moreover, deletion of mtrAB resulted in decreased resistance to isoniazid, ethambutol, and ß-lactam antibiotics. Further, Cleavage under targets and tagmentation sequencing (CUT&Tag-seq) and electrophoretic mobility shift assays (EMSAs) revealed that MtrA binds the promoters of genes involved in peptidoglycan biosynthesis (ldtB, ldtA, murJ), hydrolysis (GJR88_03483, GJR88_4713), and cell division (ftsE). Together, our findings demonstrated that the MtrAB TCS is essential for the survival of Dietzia sp. DQ12-45-1b under various cell envelope stresses, primarily by controlling multiple downstream cellular pathways. Our work suggests that TCSs act as global sensors and regulators in maintaining cellular homeostasis, such as during episodes of various environmental stresses. The present study should shed light on the understanding of mechanisms for bacterial adaptivity to extreme environments. IMPORTANCE The multilayered cell envelope is the first line of bacterial defense against various extreme environments. Bacteria utilize a large number of sensing and regulatory systems to maintain cell envelope homeostasis under multiple stress conditions. The two-component system (TCS) is the main sensing and responding apparatus for environmental adaptation. The MtrAB TCS highly conserved in Actinobacteria is critical for cell wall homeostasis, cell proliferation, osmoprotection, and antibiotic resistance. However, how MtrAB works with regard to signals impacting changes to the cell envelope is not fully understood. Here, we found that in the Actinobacterium Dietzia sp. DQ12-45-1b, a TCS named MtrAB is pivotal for ensuring normal cell growth as well as maintaining proper cell morphology in response to various cell envelope stresses, namely, by regulating the expression of cell envelope-related genes. Our findings should greatly advance our understanding of the adaptive mechanisms responsible for maintaining cell integrity in times of sustained environmental shocks.

Even allocation of benefits stabilizes microbial community engaged in metabolic division of labor.

Microbial communities execute metabolic pathways to drive global nutrient cycles. Within a community, functionally specialized strains can perform different yet complementary steps within a linear pathway, a phenomenon termed metabolic division of labor (MDOL). However, little is known about how such metabolic behaviors shape microbial communities. Here, we derive a theoretical framework to define the assembly of a community that degrades an organic compound through MDOL. The framework indicates that to ensure community stability, the strains performing the initial steps should hold a growth advantage (m) over the "private benefit" (n) of the strain performing the last step. The steady-state frequency of the last strain is then determined by the quotient of n and m. Our experiments show that the framework accurately predicts the assembly of our synthetic consortia that degrade naphthalene through MDOL. Our results provide insights for designing and managing stable microbial systems for metabolic pathway optimization.

The Bacterial MtrAB Two-Component System Regulates the Cell Wall Homeostasis Responding to Environmental Alkaline Stress.

Throughout the course of evolution, bacteria have developed signal transduction tools such as two-component systems (TCSs) to meet their demands to thrive even under the most challenging environmental conditions. One TCS called MtrAB is commonly found in Actinobacteria and is implicated in cell wall metabolism, osmoprotection, cell proliferation, antigen secretion, and biosynthesis of secondary metabolites. However, precisely how the MtrAB TCS regulates the bacterial responses to external environments remains unclear. Here, we report that the MtrAB TCS regulates the cell envelope response of alkali-tolerant bacterium Dietzia sp. strain DQ12-45-1b to extreme alkaline stimuli. We found that under alkaline conditions, an mtrAB mutant exhibited both reduced growth and abnormal morphology compared to the wild-type strain. Electrophoretic mobility shift assay analysis showed that MtrA binds the promoter of the mraZ gene critical for cell wall homeostasis, suggesting that MtrA directly controls transcription of this regulator. In conclusion, our findings demonstrate that MtrAB TCS is involved in controlling the bacterial response to alkaline stimuli by regulating the expression of the cell wall homeostasis regulator MraZ in Dietzia sp. DQ12-45-1b, providing novel details critical for a mechanistic understanding of how cell wall homeostasis is controlled. IMPORTANCE Microorganisms can be found in most extreme environments, and they have to adapt to a wide range of environmental stresses. The two-component systems (TCSs) found in bacteria detect environmental stimuli and regulate physiological pathways for survival. The MtrAB TCS conserved in Corynebacterineae is critical for maintaining the metabolism of the cell wall components that protects bacteria from diverse environmental stresses. However, how the MtrAB TCS regulates cell wall homeostasis and adaptation under stress conditions is unclear. Here, we report that the MtrAB TCS in Dietzia sp. DQ12-45-1b plays a critical role in alkaline resistance by modulating the cell wall homeostasis through the MtrAB-MraZ pathway. Thus, our work provides a novel regulatory pathway used by bacteria for adaptation and survival under extreme alkaline stresses.

[Clinical evidence analysis report of Chinese patent medicine in 2020].

The present study collected, collated, analyzed, and evaluated randomized controlled trial(RCT) of Chinese patent medicine published in Chinese and English journals in 2020, and summarized clinical evidence of Chinese patent medicine in stages, providing references for follow-up clinical research and evidence transformation and application. On the basis of the collection in the Traditional Chinese Medicine(TCM) Clinical Evidence Database System(EVDS), CNKI, Wanfang, SinoMed, Cochrane Library, PubMed, and EMbase were searched for RCTs of Chinese patent medicine published in 2020, and their research characteristics and methodological quality were analyzed and evaluated. A total of 1 285 research papers on Chinese patent medicine(1 257 in Chinese/28 in English) were included, involving 146 054 patients and 639 Chinese patent medicines, including 526 oral drugs, 68 injections, and 45 external drugs. A total of 412 diseases in 23 types were involved, which were dominated by circulatory system diseases and respiratory system diseases, specifically, cerebral infarction and angina pectoris. The sample size ranged from 20 cases to 2 673 cases, and 57.67% of RCTs had samples sizes less than 100. Single-center trials were the main ones, and multi-center trials only accounted for 4.75%(n=61). In terms of methodological quality, 52.91% of the RCTs had unclear descriptions or incorrect application of randomization methods, and the implementation of allocation concealment and blinding methods has not been paid much attention. In conclusion, compared with the conditions in 2019, the number of RCTs published in 2020 has decreased, and the research interest in respiratory diseases has increased, while the quality control in the process of research design and implementation has not been improved. Therefore, it is necessary to strengthen the methodological training of researchers and promote the output of high-quality research evidence.