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1.
Bol. latinoam. Caribe plantas med. aromát ; 23(3): 401-409, mayo 2024. ilus, tab, graf
Artigo em Inglês | LILACS | ID: biblio-1538160

RESUMO

Bovine mastitis is a disease wi th far - reaching consequences for the dairy industry. Staphylococcus aureus is a pathogen that is especially resistant to antibiotics. The objective of this study was to evaluate the antimicrobial activity of the essential oils Lippia citriodora (Lam.), Thy mus vulgaris (L), and a mixture of the essential oils Lippia citriodora and Thymus vulgaris (50/50 v/v), against isolates of oxacillin - resistant Staphylococcus aureus (n=15) of positive cases of bovine mastitis. For the statistical analysis, the IBM SPSS s tatistical package was used. The mixture of essential oils ( Lippia citriodora and Thymus vulgaris (50/50 v/v)) obtained the most significant antimicrobial activity in relation to pure essential oils. It is therefore concluded that the mixture of these oils boosts their antimicrobial activity ( p <0.05). The minimum inhibitory and bactericidal concentration of this mixture for the total isolations was 12 µL/L and 25 µL/mL, respectively.


La mastitis bovina es una enfermedad de gran impacto para la industria lechera. El Staphylococcus aureus es uno de los principales patógenos, especialmente aquellos resistentes a los antibióticos. El objetivo de este estudio fue evaluar la actividad antimicrobiana de los aceites esenciales de Lippia citriodora (Lam.), Thymus vulgaris (L), y una mezcla de aceites esenciales de Lippia citriodora y Thymus vulgaris (50/50 v/v), frente a aislamientos clínicos de Staph ylococcus aureus oxacilino - resistentes (n=15) de mastitis bovina. Se utilizó p rograma estadístico IBM SPSS y se concluyó la diferencia significativa a un p <0.05. La mezcla de aceites esenciales ( Lippia citriodora y Thymus vulgaris (50/50 v/v)), obtuvo la m ayor actividad antimicrobiana en relación a los aceites esenciales puros, se concluye que la mezcla de estos aceites potencia su actividad antimicrobiana ( p <0.019). La concentración mínima inhibitoria y bactericida de esta mezcla fue del 12 µL/mL y 25 µL/m L, respectivamente, y puede ser una alternativa terapéutica.


Assuntos
Animais , Feminino , Bovinos , Óleos Voláteis/isolamento & purificação , Mastite Bovina/microbiologia , Mastite Bovina/terapia , Staphylococcus aureus/isolamento & purificação , Resistência Microbiana a Medicamentos , Colômbia
2.
Journal of Environmental and Occupational Medicine ; (12): 1207-1211, 2023.
Artigo em Chinês | WPRIM | ID: wpr-998779

RESUMO

There is a bidirectional interactive relationship between heavy metals and intestinal microorganisms. Single exposure to common heavy metals (Cd, Cr, As, Pb, etc.) may cause intestinal microecological damage and related diseases by losing the diversity and relative abundance of intestinal microorganisms. However, heavy metals in the environment are usually mixed exposure and an overall toxic effect is presented. Published studies have suggested a synergistic effect between most heavy metals, so the impact of mixed exposure on intestinal microorganisms is expected to be more significant than that of single exposure. Intestinal microorganisms are the first line of defense against heavy metals entering the body, and can reduce inflammation and oxidation caused by heavy metals via changing protein synthesis, intestinal PH, enzyme activity, etc. At the same time, the colonization of oral probiotics in the intestinal tract has a significant detoxification effect on heavy metals entering the body through synergy with intestinal microorganisms, which can promote the elimination of heavy metals, reduce the production of oxides and inflammatory mediators, reverse the changes in the relative abundance of intestinal microorganisms, and then reduce the damage of heavy metals to intestinal microecology. Therefore, probiotics may have better prospects than traditional heavy metal antidotes. In the future, more in-depth research on the mechanism of bidirectional interactive relationship between heavy metals and intestinal microorganisms is needed to provide new ideas for clinical heavy metal detoxification.

3.
Shanghai Journal of Preventive Medicine ; (12): 292-300, 2023.
Artigo em Chinês | WPRIM | ID: wpr-976259

RESUMO

Aerosol microorganisms are important constituents of aerosols. They participate in physical and chemical reactions in the air and are also closely related to disease transmission and human health. With the SARS-CoV-2 pandemic, aerosol microorganisms have become a public health topic of great concern. Studying the composition and influencing factors of the air microbiome therefore has significant public health implications. Due to the limitations of traditional technologies for sampling and determination, the aerosol microbiome has not been fully understood. However, with the development and maturity of high-throughput sequencing technology, the aerosol microbiome has shown promising research prospects. This article reviews the composition, characteristics, detection methods and influencing factors of aerosol microorganisms, providing basic knowledge for further research on the air microbiome. In-depth research on microbial aerosols has significant implications on urban air quality control, national security and public health.

4.
Shanghai Journal of Preventive Medicine ; (12): 253-257, 2023.
Artigo em Chinês | WPRIM | ID: wpr-976252

RESUMO

ObjectiveTo monitor the microbes in urban drinking water in Jiangxi from 2016 to 2020, to analyze the change in microbial qualification rate, and to provide a scientific basis for government decision-making. MethodsAccording to the Standard Examination Method for Drinking Water (GB/T 5750‒2006) and the Standards for Drinking Water Quality (GB 5749‒2006), the water samples were collected, tested and evaluated for hygienic safety. The chi-square test was used to compare the qualification rates among different water periods, water source types, water supply modes, water samples, treatment processes, and disinfection methods. ResultsA total of 10 584 water samples were collected and examined from 2016 to 2020,with a qualification rate of 97.72%. The qualified rate of the microbiological index increased gradually over the years. There was no statistically significant difference in the microbiological qualification rate of water samples monitored in different water periods (χ2=0.718,P=0.398), and the qualification rates were 97.85% and 97.60% in dry and abundant water periods respectively. There was a statistically significant difference in the qualification rates of water samples monitored in different water source types (χ2=79.560,P=0.398), with groundwater having a higher qualification rate of 98.83% than surface water (97.70%). The microbiological pass rate of water samples differed among different water supply methods (χ2=201.836,P<0.001). The microbiological pass rates of municipal centralized water supply, self-built centralized water supply and secondary water supply were 97.51%, 88.94% and 96.56% respectively. The microbiological pass rates of water samples differed among different treatment processes. There were differences in the qualification rates of the water samples between different treatment processes(χ2=855.034,P<0.001), with 98.22%, 67.19%, 95.60% and 53.13% of the conventionally treated, precipitated filtered, disinfected only and untreated water samples, respectively. The differences in the microbiological qualification rates of the monitored water samples between different disinfection methods were statistically significant (χ2=904.993,P<0.001). Chlorination disinfection, chlorine dioxide disinfection, other disinfection methods and non-disinfected water samples had the pass rates of 98.35%, 98.19%, 84.38% and 60.16%, respectively. ConclusionThe qualified rate of the microbiological index of drinking water in Jiangxi increases year by year, but there are still some drinking water without appropriate disinfectants and water quality treatment processes. There is still a need to strengthen the purification, disinfection and monitoring of drinking water.

5.
Journal of Environmental and Occupational Medicine ; (12): 480-485, 2023.
Artigo em Chinês | WPRIM | ID: wpr-972389

RESUMO

Accumulating studies suggest that, as the subway is one of the important means of transport in cities, airborne microorganisms in its system have potential effects on human health, but previous studies have mainly focused on some foreign cities. We reviewed the spatio-temporal distribution characteristics of airborne microorganisms in subway stations in different cities, including diurnal, weekly, and seasonal variations, and the distribution of microorganisms in different regions of the world. The factors affecting airborne microorganisms, such as human activities, temperature and humidity, ventilation, and particulate matter, were presented. The potential health effects were described. Although there was no significant risk of infection from using subway, many pathogens do exist in the air. The influence of microorganisms in subway air on health has become a public health problem that cannot be ignored.

6.
Chinese Journal of Biotechnology ; (12): 2719-2729, 2023.
Artigo em Chinês | WPRIM | ID: wpr-981228

RESUMO

To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.


Assuntos
Desnitrificação , Águas Residuárias , Oxidação Anaeróbia da Amônia , Nitrogênio , Oxirredução , Reatores Biológicos/microbiologia , Compostos de Amônio , Bactérias/genética , Microbiota , Esgotos
7.
Chinese Journal of Biotechnology ; (12): 1275-1289, 2023.
Artigo em Chinês | WPRIM | ID: wpr-981137

RESUMO

As human microbiome research advances, a large body of evidence shows that microorganisms are closely related to human health. Probiotics were discovered and used as foods or dietary supplements with health benefits in the last century. Microorganisms have shown broader application prospects in human health since the turn of the century, owing to the rapid development of technologies such as microbiome analysis, DNA synthesis and sequencing, and gene editing. In recent years, the concept of "next-generation probiotics" has been proposed as new drugs, and microorganisms are considered as "live biotherapeutic products (LBP)". In a nutshell, LBP is a living bacterial drug that can be used to prevent or treat certain human diseases and indications. Because of its distinct advantages, LBP has risen to the forefront of drug development research and has very broad development prospects. This review introduces the varieties and research advances on LBP from a biotechnology standpoint, followed by summarizing the challenges and opportunities for LBP clinical implementations, with the aim to facilitate LBP development.


Assuntos
Humanos , Probióticos , Suplementos Nutricionais , Bactérias , Desenvolvimento de Medicamentos , Biotecnologia
8.
Acta Pharmaceutica Sinica ; (12): 967-974, 2023.
Artigo em Chinês | WPRIM | ID: wpr-978761

RESUMO

A new siderophore chelate (1) and 8 known compounds were identified from the liquid co-cultures of the marine-derived Streptomyces sp. IMB18-531 and Cladosporium sp. IMB19-099 by a combination of chromatography methods, including C18 reversed-phase medium pressure chromatography, gel column chromatography and HPLC. Their structures were determined by spectroscopic analysis and chemical methods as aluminioxamine E (1), desferrioxamine E (2), ferrioxamine E (3), terragine E (4), capsimicin (5), cyclo(L-prolinyl-L-tyrosine) (6), anthranilic acid (7), (Z)-14-methylpentadec-9-enoic acid (8), and (Z)-hexadec-8-enoic acid (9). Compound 2 showed inhibitory activities against the expression of liver fibrosis related genes COL1A1, MMP2, and TIMP2. Compounds 5, 8, and 9 displayed antibacterial activities against methicillin-resistant Staphylococcus aureus, S. epidermidis and Bacillus subtilis, with MICs of 16-64 μg·mL-1. Compound 5 showed cytotoxicities against human pancreatic cancer MIA Paca-2 and human colon cancer HT-29 cell lines with IC50 of 2.9 and 6.3 μmol·L-1, respectively.

9.
Chinese Journal of Experimental Traditional Medical Formulae ; (24): 153-160, 2023.
Artigo em Chinês | WPRIM | ID: wpr-953935

RESUMO

ObjectiveTo study the effect of a microbial compound fertilizer on the growth, quality, and soil properties of Andrographis paniculata and provide a basis for its application in the cultivation and production of A. paniculata. MethodThrough five treatment tests in pots, the control group (CK, no fertilization), the treatment A group (chemical fertilization), the treatment B group (microbial fertilization at 2.5 g·kg-1 soil), the treatment C group (microbial fertilization at 7.5 g·kg-1 soil), and the treatment D group (microbial fertilization at 12.5 g·kg-1 soil) were established. The effects of a compound microbial fertilizer on the agronomic properties, the content of active ingredients, the number of rhizosphere soil bacteria, Actinomycetes, and fungi, and soil physicochemical properties of A. paniculata were studied. ResultAs compared with the CK group and the treatment A group, the plant height, leaf number, leaf area, and above-ground and below-ground fresh weight of A. paniculata were significantly increased after microbial fertilization, with differences in different growth periods. The effect of the compound microbial fertilizer on the content of andrographolide, dehydrated andrographolide, neandrographolide, and 14-deoxyandrographolide differed. The content of andrographolide significantly increased by 26.13% and 13.23% in the treatment C group, respectively, as compared with the CK group and the treatment A group (P<0.05). The content of neandrographolide increased with the increasing amount of microbial fertilizer, and the content in the treatment D group increased by 9.06% and 50.33%, respectively, as compared with the CK group and the treatment A group (P<0.05), which was the most obvious. The content of 14-deoxyandrographolide in the treatment B group significantly increased by 42.04% and 1.74%, respectively, as compared with the treatment A group and the CK group (P<0.05). The content of dehydrated andrographolide content in the treatment B group increased most significantly, significantly increasing by 11.73% and 27.74%, respectively, as compared with the CK group and the treatment A group (P<0.05). The soil pH of the treatment B, C, and D groups was higher than that of the CK group and the treatment A group. The content of total nitrogen and effective phosphorus increased most significantly in the treatment B group, and the content of fast-acting potassium increased most significantly in the treatment D group. The application of the compound microbial fertilizer increased the number of rhizosphere soil bacteria and Actinomycetes, which was significantly higher than that in the CK group and the treatment A group (P<0.05), and increased with the increase of applied amount. The number of fungi decreased with the increase of the compound microbial fertilizer application, which was significantly different from that in the CK group (P<0.05). The fungi/bacteria of all treatment groups were significantly lower than those of the CK group (P<0.05) and increased with the increase of microbial fertilizer application. ConclusionThe application of the compound microbial fertilizer transforms the plant-soil-microbial system in a benign direction, which is beneficial to the growth of A. paniculata and the accumulation of active ingredients.

10.
Sichuan Mental Health ; (6): 193-196, 2023.
Artigo em Chinês | WPRIM | ID: wpr-986739

RESUMO

There are a large number of microbial communities in human intestine, which play an important role in many physiological processes of the body. It has been found that intestinal microorganisms can act on brain diseases through brain-gut axis mechanism. The purpose of this paper is to summarize the mechanism of intestinal microorganisms in schizophrenia, bipolar disorder and depression, and to provide new ideas for the prevention and treatment of psychiatric disorders.

11.
Chinese Journal of Industrial Hygiene and Occupational Diseases ; (12): 317-320, 2023.
Artigo em Chinês | WPRIM | ID: wpr-986038

RESUMO

Occupational disease hazards in plywood manufacturing mainly include wood dust, formaldehyde, phenol, ammonia, noise, terpene, microorganisms, etc. The exposure is complex with multiple factors accompanied or coexisted. In the production process, these factors are exceeded, and mass occupational disease hazard events occurred among workers. Exposure to wood dust, formaldehyde, terpene, etc., put workers at increased risk of cancer. This article provides a review of this issue in order to provide a scientific basis for the prevention and control of occupational disease hazards in plywood manufacturing.


Assuntos
Humanos , Madeira/química , Doenças Profissionais/induzido quimicamente , Formaldeído/efeitos adversos , Terpenos , Poeira , Exposição Ocupacional/efeitos adversos
12.
International Eye Science ; (12): 1844-1848, 2023.
Artigo em Chinês | WPRIM | ID: wpr-996896

RESUMO

The ocular surface microbiota is a part of the human ocular surface microenvironment and is critical to its stability. Many studies have explored the composition of the ocular surface microbiota in health and disease, but the research results are different based on internal and external factors, and the relationship between microorganism dysbiosis and diseases also remains unclear. As the research on intestinal microorganisms and systemic diseases has intensified in recent years, ophthalmic researchers have been inspired to further explore the relationship between ocular surface microbiota and non-infectious ocular surface diseases. Therefore, this article will review the core microbiota of the normal ocular surface as well as alterations in ocular surface microbiota in ocular and systemic diseases, and discuss the possible mechanisms of diseases caused by microorganism dysbiosis, hoping to provide a reference for future studies in ocular surface microbiota.

13.
Chinese Journal of Infectious Diseases ; (12): 208-213, 2023.
Artigo em Chinês | WPRIM | ID: wpr-992532

RESUMO

Objective:To investigate the efficacy of metagenomic next generation sequencing (mNGS) in the etiological diagnosis of patients with spinal infection, so as to provide reference for timely diagnosis and treatment.Methods:A total of 40 patients with suspected spinal infection admitted to the Department of Infectious Diseases in Henan Provincial People′s Hospital from January 2020 to July 2022 were included. The results of tissue culture, histopathological examination and tissue mNGS detection were analyzed retrospectively. According to the clinical diagnose, the patients were divided into the spinal infection group (28 cases) and the non-spinal infection group (12 cases). The positive rate, sensitivity and specificity of mNGS and tissue culture in the pathogen detection of patients with spinal infection were compared. McNemar test was used for statistical analysis.Results:There were 23 males and 17 females in 40 patients. The positive rate of mNGS was higher than that of tissue culture (75.0%(30/40) vs 12.5%(5/40)), and the difference was statistically significant ( χ2=0.08, P<0.001). Based on clinical diagnostic criteria, the sensitivity of mNGS in the diagnosis of spinal infection was higher than that of tissue culture (82.1% vs 17.9%), with a statistically significant difference ( χ2=0.02, P<0.001), while the specificity compared to the tissue culture (33.3% vs 100.0%), the difference was not statistically significant ( P>0.05). Conclusions:mNGS has a high pathogen detection rate and sensitivity in the etiological diagnosis of patients with spinal infection, which could provide clinical guidance for the diagnosis and treatment of patients with spinal infection.

14.
Journal of Sun Yat-sen University(Medical Sciences) ; (6): 750-757, 2023.
Artigo em Chinês | WPRIM | ID: wpr-988720

RESUMO

High-level pathogenic microorganism laboratories are strategic scientific and technological forces of national biosafety, so it is significant to improve the policy and system management and strengthen the safety supervision. This paper reviewed the current status of management policy and system of high-level pathogenic microorganism laboratories, summarized the problems and challenges in terms of safety laws and regulations, supervision mechanism, hierarchical and classified management, standards and norms, legal person responsibility system, occupational access system and personnel training system. This paper also proposed targeted policy suggestions that might underlie the biosafety management of high-level pathogenic microorganism laboratories in China.

15.
Chinese Journal of Biochemistry and Molecular Biology ; (12): 507-515, 2023.
Artigo em Chinês | WPRIM | ID: wpr-1015653

RESUMO

Human RNase A (human RNase A) superfamily contains 13 members (RNase 1~RNase 13) with different biological activities. In addition to the conserved catalytic sequence, its protein structure also has a significant diversity of sequences, which determines that human ribonuclease A can exert biological functions other than ribonuclease activity. Human RNase A superfamily members are expressed in various immune cells such as eosinophils, neutrophils, monocytes, and macrophages and can be secreted to exert various biological functions, including anti-microbial activity, promote host defense, participate in angiogenesis and sperm maturation, etc. Some members of the human ribonuclease A superfamily can exert antimicrobial and antiparasitic activities through direct actions such as hydrolysis of viral RNA, inhibition of viral replication, destruction of bacterial cell walls, promotion of microbial aggregation, damage to parasitic cell membranes and mitochondrial membranes, and indirect actions mediated by host innate immune cells, thereby participating in host defense. This article reviews the antimicrobial (including viruses, bacteria, and fungi) and antiparasitic activities of human ribonuclease A and their mechanisms of action. It also prospects the prospects of human ribonuclease A as an active antimicrobial substance and innate immune molecule for the treatment of severe and drug-resistant microbial infections.

16.
Chinese Journal of Clinical Pharmacology and Therapeutics ; (12): 475-480, 2023.
Artigo em Chinês | WPRIM | ID: wpr-1014660

RESUMO

Autism spectrum disorder is a set of neurodevelopmental disorders with unclear etiology and pathogenesis and no cure. Studies have found that the gut microbiota plays a vital role in the occurrence and development of autism spectrum disorder. By supplementing with probiotics, diet management or fecal microbial transplantation, the balance of gut microbiota can be adjusted to improve the behaviors and symptoms of patients with autism spectrum disorder. This article reviews from the perspective of regulating the balance of gut microbiota to treat autism spectrum disorder, and aims to provide assistance for the research and treatment of autism spectrum disorder.

17.
Chinese Journal of Biotechnology ; (12): 4517-4533, 2023.
Artigo em Chinês | WPRIM | ID: wpr-1008039

RESUMO

Anaerobic granular sludge (AnGS), a self-immobilized aggregate containing various functional microorganisms, is considered as a promising green process for wastewater treatment. AnGS has the advantages of high volume loading rate, simple process and low excess sludge generation, thus shows great technological and economical potentials. This review systematically summarizes the recent advances of the microbial community structure and function of anaerobic granular sludge, and discusses the factors affecting the formation and stability of anaerobic granular sludge from the perspective of microbiology. Moreover, future research directions of AnGS are prospected. This review is expected to facilitate the research and engineering application of AnGS.


Assuntos
Esgotos/química , Eliminação de Resíduos Líquidos , Anaerobiose , Microbiota , Purificação da Água , Reatores Biológicos/microbiologia
18.
Artigo | IMSEAR | ID: sea-219337

RESUMO

Aim: Improper personal hygiene can facilitate the transmission of the pathogenic microorganisms found in environment and on people抯 hands via food to humans. The present study was undertaken to investigate the microbiological quality of different street food and determining the antibiotic susceptibility of the isolated microorganisms. Study Design: Collection of food samples for isolation of Pathogenic Microorganisms, to identify them by using Biochemical test, molecular test (16sr RNA typing), Antibiotic susceptibility was done by using different antibiotics against the isolates. Place and Duration of Study: Food samples were collected from street vendors of Sainkpuri area, work was done from December 2020 to April 2021 at Microbiology Department, St. Francis College for Women, Hyderabad. Methodology: Five samples of street food were collected in sterilized bottles, tested for the presence of microorganisms by following standard microbiological method used for isolation of microorganisms. The organisms were identified by carrying out various biochemical test according to Bergey抯 Manual of Systematic Bacteriology. The Molecular characterization was done based on 16sr RNA typing. Determining the sensitivity of the isolates against different Antibiotics by employing Kirby Bauer technique. Results: The organisms isolated from Manchuria and Ragada samples: Lactobacillus delbrueckii; Lactobacillus casei, Klebsiella pneumonia, Enterococcus faecalis and Vibrio spp respectively; Samosa and bonda: Staphylococcus aureus, Lactobacillus delbrueckii and Pantoea dispersa; Pani puri water: Staphylococcus aureus and Providencia vermicola. Antibiotic susceptibility tests showed that most of the isolated microorganisms were sensitive to Ciproflaxin. Conclusion: Hence the quality of street food is found to be low due to following factor: lack hygiene conditions in the food preparation, ingredients may also affect quality of the food, and presence of air borne microorganisms in the surrounding areas of service points.

19.
Chinese Journal of Experimental Traditional Medical Formulae ; (24): 92-99, 2022.
Artigo em Chinês | WPRIM | ID: wpr-942333

RESUMO

Continuous cropping obstacle is the bottleneck of medicinal plant cultivation, which seriously affects the quality and yield of medicinal materials. The research on the mechanism of continuous cropping obstacle has evolved from soil physical and chemical properties and allelopathy in the 1970s to the changes of rhizosphere microenvironment and plant response mechanism at present. According to the available studies in this field and our previous research work, we systematically analyzed the mechanism of rhizosphere exudate-mediated microbial community reconstruction in the soil of the medicinal plants in continuous cropping. Specifically, rhizosphere exudates, providing the carbon source and energy for microbial growth, act as inducers or repellents to induce microbial growth or transfer, thereby changing the physicochemical properties (such as acidity) of rhizosphere soil and further altering the structure of rhizosphere microbial community. Further, we comprehensively discussed the ways of synergism between rhizosphere exudates and soil microorganisms in causing harm to the medicinal plants in continuous cropping. That is, rhizosphere exudates mediate the infection of the rhizosphere by pathogenic microorganisms, increase the susceptibility of the nearby plants, inhibit the defense of the host plants, and protect the pathogens to occupy the dominant niche. The synergistic interaction results in the release of more pathogenic factors such as mycotoxins by rhizosphere pathogens, enhanced toxicity of rhizosphere allelochemicals, and deterioration of soil physical and chemical properties. This paper summarizes the role of interaction between rhizosphere exudates and soil microorganisms in the formation of continuous cropping obstacles, aiming to provide a new research idea for revealing the formation mechanism as well as the theoretical support for overcoming continuous cropping obstacles of medicinal plants.

20.
Journal of Environmental and Occupational Medicine ; (12): 1102-1109, 2022.
Artigo em Chinês | WPRIM | ID: wpr-960531

RESUMO

Background Domestic waste classification is one of the major livelihood projects in China. With the introduction of the Shanghai Household Waste Management Regulation in 2019, the work of domestic waste classification has been carried out nationwide, yet its potential risks especially those derived from microorganisms are not clear. Objective To investigate the microbial characteristics of the domestic waste in typical residential areas in Shanghai, and provide a theoretical basis for health protection during the domestic waste classification process in Shanghai and throughout China. Methods Dry and wet waste from a typical residential community in Shanghai were collected during 2019–2020. Microbial colonies were counted in domestic waste and analyzed for growth patterns. Then through 16S rRNA sequencing using lllumina PE250, hierarchical clustering analysis was conducted to reveal the similarity and dissimilarity of community compositions in different domestic waste groups, alpha diversity was estimated to reflect the richness and diversity of bacterial communities, principal co-ordinates analysis of unweighted UniFrac distance was performed to estimate the beta diversity, and linear discriminant analysis effect size (LEfSe) was used to find features differentially represented among domestic waste groups. Results In the chosen typical residential community of this study, the numbers of microorganisms in waste were quite different, with lower numbers of microorganisms in dry waste than the numbers in wet waste. In addition, different growth curves of microorganisms were shown for different seasons, and the peak baterial colony numbers were 200 CFU·cm−2, 6×105 CFU·mL−1, 10 CFU·cm−2, and 2×106 CFU·mL−1 for summer dry waste, summer wet waste, winter dry waste, and winter wet waste, respectively. The results of 16S RNA demonstrated significant differences in α and β diversity indicators among different waste groups, and the difference in waste classifications was larger than the difference of the same classification of waste in different seasons. The main compositions of bacterial colonies in domestic waste was Proteobacteria, followed by Firmicute and Bacteroidota. The clustering analysis showed that the microbial composition in summer dry waste was close to that in winter dry waste, while other groups were quite different. In total 48 differential bacterial taxa were found at the level of genus including Pseudomonas and Pantoea. Conclusion Different seasons and different classifications of domestic waste present varied microbial characteristics, with different potential pathogenic microorganisms. Together with other related studies, we suggest that different measures should be taken for different domestic wastes to prevent and control the health hazards associated with waste classification.

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