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1.
Braz. j. biol ; 84: e249664, 2024. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1345558

ABSTRACT

Abstract The impact of antibiotics on growth, cocoon production was assessed in addition to isolation and characterization of bacteria associated with silkworm gut of infected larvae. Larval rearing was maintained at recommended conditions of temperature and humidity. Silkworm larvae showing abnormal symptoms were collected from the control group and dissected for gut collection. Bacteria were isolated from the gut content by spreading on agar plates and incubated at 37 °C for 48 hrs. Bacterial identification and phylogenetic analysis were carried out by 16S rRNA gene sequencing. The isolated bacteria were subjected to antimicrobial susceptibility test (disc diffusion methods) by using Penicillin (10 µg/mL), Tetracycline (30 µg/mL), Amoxicillin (25 µg/mL), Ampicillin (10 µg/mL), and Erythromycin (15 µg/mL). All isolated strains showed positive results for the catalase test. We isolated and identified bacterial strains (n = 06) from the gut of healthy and diseased silkworm larvae. Based on the 16S rRNA gene sequence, isolated bacteria showed close relation with Serratia, Bacillus, and Pseudomonas spp. Notably, 83.3% of strains were resistant to Penicillin, Tetracycline, Amoxicillin, Ampicillin, and Erythromycin but 16.6% showed antibiotic susceptibility to the above-mentioned commonly used antibiotics. Silkworm larvae fed on penicillin-treated leaves showed significant improvement in larval weight, larval length, and cocoon production. Significantly higher larval weight (6.88g), larval length (5.84cm), and cocoon weight (1.33g) were recorded for larvae fed on leaves treated with penicillin as compared to other antibiotics. Isolated bacterial strains showed close relation with Serratia spp., Bacillus spp. and Pseudomonas spp.


Resumo O impacto dos antibióticos no crescimento e na produção do casulo foi avaliado, além do isolamento e caracterização das bactérias associadas ao intestino de larvas infectadas do bicho-da-seda. A criação das larvas foi mantida nas condições recomendadas de temperatura e umidade. As larvas do bicho-da-seda com sintomas anormais foram coletadas do grupo controle e dissecadas para coleta do intestino. As bactérias foram isoladas do conteúdo intestinal por espalhamento em placas de ágar e incubadas a 37° C durante 48 horas. A identificação bacteriana e a análise filogenética foram realizadas pelo sequenciamento do gene 16S rRNA. As bactérias isoladas foram submetidas a teste de sensibilidade antimicrobiana (métodos de difusão em disco) com penicilina (10 µg / mL), tetraciclina (30 µg / mL), amoxicilina (25 µg / mL), ampicilina (10 µg / mL) e eritromicina (15 µg / mL). Todas as cepas isoladas apresentaram resultados positivos para o teste da catalase. Isolamos e identificamos cepas bacterianas (n = 06) do intestino de larvas de bicho-da-seda saudáveis e doentes. Com base na sequência do gene 16S rRNA, as bactérias isoladas mostraram estreita relação com Serratia, Bacillus e Pseudomonas spp. Notavelmente, 83,3% das cepas eram resistentes a penicilina, tetraciclina, amoxicilina, ampicilina e eritromicina, mas 16,6% mostraram suscetibilidade aos antibióticos comumente usados mencionados acima. As larvas do bicho-da-seda alimentadas com folhas tratadas com penicilina apresentaram melhora significativa no peso larval, comprimento larval e produção de casulo. Peso larval significativamente maior (6,88g), comprimento larval (5,84cm) e peso do casulo (1,33g) foram registrados para larvas alimentadas com folhas tratadas com penicilina, em comparação com outros antibióticos. Cepas bacterianas isoladas mostraram estreita relação com Serratia spp., Bacillus spp. e Pseudomonas spp.


Subject(s)
Animals , Bombyx , Anti-Bacterial Agents/pharmacology , Phylogeny , Bacteria/genetics , RNA, Ribosomal, 16S/genetics , Microbial Sensitivity Tests , Larva
2.
Braz. j. biol ; 84: e251747, 2024. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1355878

ABSTRACT

Abstract Fish is the main source of animal protein for human diet. The aim of this study was to find out prevalence of pathogenic bacteria of two selected economically important fish of Pakistan namely Mahseer (Tor putitora) and Silver carp (Hypophthalmichthys molitrix). Live fish samples from hatcheries and dead fish samples from different markets of study area were randomly collected. The fish samples were analyzed for isolation, identification and prevalence of bacteria. The isolated bacteria from study fish were identified through biochemical test and about 10 species of pathogenic bacteria were identified including the pathogenic bacteria to human and fish namely, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus iniae, Serratia spp. Citrobacter spp. Stenotrophomonas spp. Bacillus spp. and Salmonella spp. The bacterial percentage frequency of occurrence in Silver carp and Mahseer fish showed Pseudomonas aeruginosa 21.42%, Staphylococcus epidermidis 17.85%, Escherichia coli 11.90%, Staphylococcus aureus 9.52%, Citrobacter spp. 9.52%, Serratia spp. 8.33%, Streptococcus iniae 7.14%, Stenotrophomonas spp. 5.95%, Bacillus spp. 4.76% and Salmonella spp. 3.57%. The study revealed that Fish samples of Mahseer and Silver carp that were collected from markets have found more isolates (10 bacterial species) than did the fresh fish pond samples (03 bacterial species) of hatcheries. The occurrence of pathogenic bacteria in study fish showed risk factor for public health consumers.


Resumo O peixe é a principal fonte de proteína animal para a alimentação humana. O objetivo deste estudo foi descobrir a prevalência de bactérias patogênicas de dois peixes economicamente importantes selecionados do Paquistão, nomeadamente Mahseer (Tor putitora) e carpa prateada (Hypophthalmichthys molitrix). Amostras de peixes vivos de incubatórios e amostras de peixes mortos de diferentes mercados da área de estudo foram coletadas aleatoriamente. As amostras de peixes foram analisadas quanto ao isolamento, identificação e prevalência de bactérias. As bactérias isoladas dos peixes do estudo foram identificadas através de testes bioquímicos e cerca de 10 espécies de bactérias patogênicas foram identificadas incluindo as bactérias patogênicas para humanos e peixes, nomeadamente, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus iniae, Serratia spp. Citrobacter spp. Stenotrophomonas spp. Bacillus spp. e Salmonella spp. A porcentagem de freqüência de ocorrência bacteriana em carpa prateada e peixes Mahseer mostrou Pseudomonas aeruginosa 21,42%, Staphylococcus epidermidis 17,85%, Escherichia coli 11,90%, Staphylococcus aureus 9,52%, Citrobacter spp. 9,52%, Serratia spp. 8,33%, Streptococcus iniae 7,14%, Stenotrophomonas spp. 5,95%, Bacillus spp. 4,76% e Salmonella spp. 3,57%. O estudo revelou que as amostras de peixes de Mahseer e carpa prateada coletadas nos mercados encontraram mais isolados (10 espécies bacterianas) do que as amostras de peixes frescos (03 espécies bacterianas) de incubatórios. A ocorrência de bactérias patogênicas nos peixes do estudo apresentou fator de risco para consumidores de saúde pública.


Subject(s)
Humans , Animals , Carps , Pakistan , Bacteria , Ponds , Incidence
4.
Braz. J. Anesth. (Impr.) ; 73(3): 276-282, May-June 2023. tab, graf
Article in English | LILACS | ID: biblio-1439613

ABSTRACT

Abstract Background: Mobile phones in hospital settings have been identified as an important source of cross-contamination because of the low frequency with which mobile phones are cleaned by health workers and cyclical contamination of the hands and face. The aim of this study was to investigate whether the mobile phones of the anesthesia team at a teaching hospital are potential reservoirs of nosocomial bacteria. In addition, differences in device sanitization and hand hygiene habits between attending and resident anesthesiologists were correlated with mobile phone colonization. Methods: A prevalence study was conducted over a 6-month period from 2017 to 2018 that involved the collection of samples from the mobile phones of the anesthesiology team and culturing for surveillance. A questionnaire was administered to assess the mobile phone sanitization and hand washing routines of the anesthesia team in specific situations. Results: Bacterial contamination was detected for 86 of the 128 mobile phones examined (67.2%). A greater presence of Micrococcus spp. on devices was correlated with a higher frequency of mobile phone use (p = 0.003) and a lower frequency of sanitization (p = 0.003). The presence of bacteria was increased on the mobile phones of professionals who did not perform handwashing after tracheal intubation (p = 0.003). Conclusion: Hand hygiene and device sanitization habits were more important than the use behavior, as a higher presence of bacteria correlated with poorer hygiene habits. Furthermore, handwashing is the best approach to prevent serious colonization of mobile devices and the possible transmission of pathogens to patients under the care of anesthesiologists.


Subject(s)
Humans , Cross Infection/microbiology , Cross Infection/prevention & control , Cell Phone , Bacteria , Anesthesiologists , Hospitals, Teaching
5.
Univ. salud ; 25(1): A1-A6, ene.-abr. 2023. graf
Article in Spanish | LILACS, COLNAL | ID: biblio-1424733

ABSTRACT

Introducción: El riesgo de desarrollar cáncer gástrico varía entre continentes, países y regiones. A pesar de que existe una alta prevalencia de Helicobacter pylori su rol como patógeno o mutualista define el riesgo de cáncer gástrico en las regiones de Colombia. Objetivo: Discutir el rol de Helicobacter pylori en el riesgo de cáncer gástrico en Colombia. Materiales y métodos: Revisión de literatura mediante la búsqueda, en las bases de datos LILACS, SciELO, PubMed. Resultados: La coevolución del humano y de Helicobacter pylori; la virulencia de genes cagA, vacA; el tipo de respuesta inmune inflamatoria a Helicobacter pylori (Th1) o antinflamatoria (Th2) y la susceptibilidad humana a cáncer gástrico (IL1β, IL10), junto a la dieta y factores ambientales explican el papel de Helicobacter pylori como patógeno o mutualista asociado al riesgo de cáncer gástrico en Colombia. Conclusiones: Helicobacter pylori tiene un rol mutualista principalmente en poblaciones de bajo riesgo de cáncer gástrico (costas), no obstante, en poblaciones con alto riesgo de cáncer gástrico (andes), su papel como patógeno amerita la erradicación; única estrategia para mitigar la alta incidencia de este cáncer en Colombia.


Introduction: The risk to develop gastric cancer varies between continents, countries and regions. Although there is a high prevalence of Helicobater pylori, its role as either pathogen or mutualistic bacteria defines the risk of gastric cancer in Colombian regions. Objective: To discuss the role of Helicobacter pylori in the risk of gastric cancer in Colombia. Materials and methods: A literature review based on searching LILACS, SciELO, and PubMed databases. Results: Helicobacter pylori role as either a pathogen or mutualistic microorganism associated with gastric cancer risk in Colombia can be explained by analyzing elements such as: human and Helicobacter pylori coevolution; cagA and vacA gene virulence; inflammatory (Th1) or anti-inflammatory (Th2) responses induced by Helicobacter pylori; human susceptibility to gastric cancer (IL1β, IL10); diet; and environmental factors. Conclusions: Even though Helicobacter pylori has a mutualistic role in populations at low gastric cancer risk (coastal regions), its role as a pathogen in populations at higher risk (Andean regions) justifies its eradication as a key strategy to mitigate the incidence of this cancer in Colombia.


Introdução: O risco de desenvolver câncer gástrico varia entre continentes, países e regiões. Embora haja uma alta prevalência de Helicobacter pylori, seu papel como patógeno ou mutualista define o risco de câncer gástrico nas regiões da Colômbia. Objetivo: Discutir o papel do Helicobacter pylori no risco de câncer gástrico na Colômbia. Materiais e métodos: Revisão da literatura por meio da busca, nas bases de dados LILACS, SciELO e PubMed. Resultados: A coevolução de humanos e Helicobacter pylori; a virulência dos genes cagA, vacA; o tipo de resposta imune inflamatória ao Helicobacter pylori (Th1) ou anti-inflamatório (Th2) e a suscetibilidade humana ao câncer gástrico (IL1β, IL10), juntamente com a dieta e fatores ambientais explicam o papel do Helicobacter pylori como patógeno ou mutualista associado ao risco de câncer gástrico na Colômbia. Conclusões: Helicobacter pylori tem um papel mutualista principalmente em populações de baixo risco de câncer gástrico (litoral), porém, em populações com alto risco de câncer gástrico (andes), seu papel como patógeno justifica a erradicação; única estratégia para mitigar a alta incidência deste câncer na Colômbia.


Subject(s)
Humans , Bacteria , Neoplasms , Stomach Neoplasms , Carcinogens , Risk Factors , Helicobacter pylori
6.
Rev. cienc. salud (Bogotá) ; 21(1): 1-14, ene.-abr. 2023.
Article in Spanish | LILACS | ID: biblio-1427751

ABSTRACT

Staphylococcus aureus y Staphylococcus epidermidis son los principales agentes etiológicos de las conjuntivitis bacterianas, que al tratarse con antibióticos de manera empírica, incrementan la resistencia antimicrobiana después de exposiciones repetidas. Se están buscando alternativas naturales para el tratamiento de infecciones bacterianas autolimitadas de la conjuntiva. Objetivo: determinar la actividad antimicrobiana de ocho extractos de las plantas frente a bacterias aisladas de pacientes con conjuntivitis bacterianas. Materiales y métodos: se tomaron muestras de 15 pacientes con conjuntivitis bacterianas. Se cultivaron en agar sangre y chocolate durante 24 h a 37 °C y se identificaron mediante el sistema automatizado vitek y pruebas de susceptibilidad antimicrobiana por el método de Kirby-Bauer. A cada aislamiento identificado con el género Staphylococcus se le evaluó su susceptibilidad frente a siete extractos: Ocimum basilicum, Sambucus nigra L., Delphinium elatum, Calendula officinalis, Bixa ore-llana (parte aérea y fruto independiente), Clinopodium brownei y Laurus nobilis, con un uso tradicional reportado para el tratamiento de infecciones oculares. Resultados: las bacterias aisladas con más frecuencia fueron S. epidermidis, S. hominis y S. aureus, las cuales presentaron resistencia antimicrobiana a oxacilina, tetraciclinas y eritromicina. Todos los aislamientos fueron inhibidos por los extractos de O. basilicum (cmi: >0.9 mg/mL) y L. nobilis (cmi: hasta 15 mg/mL). Conclusión: los extractos de C. officinalis y D. elatum tuvieron actividad antimicrobiana solo frente a los aislados con mayor sensibilidad antimi-crobiana. Los extractos etanólicos de O. basilicum y L. nobilis pueden ser una alternativa de tratamiento de las infecciones de la conjuntiva.


Staphylococcus aureus and Staphylococcus epidermidis are the primary etiological agents of bacterial conjunctivitis which are empirically treated with antibiotics. This results in an increase in antimicrobial resistance due to repeated exposure. Currently, natural treatment alternatives are being sought for self-limited bacterial infections of the conjunctiva. Objective: To determine the antimicrobial activity of eight extracts from Colombian plants against bacteria isolated from patients with bacterial conjunctivitis. Materials and methods: Samples were taken from 15 patients with bacterial conjunctivitis which were grown on blood and chocolate agar for 24 h at 37 °C. These samples were identified by the vitek automated system and antimicrobial susceptibility tests by the Kirby Bauer method. Each isolate identified with the genus Staphylococcus was evaluated for susceptibility to the following eight plant extracts of seven plant: Ocimum basilicum (basil), Sambucus nigra L. (elderberry), Delphinium elatum(belladonna), Calendula officinalis (marigold), Bixa orellana (annatto) (aerial part and independent fruit), Clinopodium brownei (pennyroyal), and Laurus nobilis (laurel), with traditional use previously reported for treating eye infections. Results: The most frequently isolated bacteria were S. epidermidis, S. hominis, and S. aureus, which exhibited antimicrobial resistance mainly to oxacillin, tetracyclines, and erythromycin. All isolates were inhibited by O. basilicum extracts (mic > 0.9 mg/mL) and L. nobilis (mic < 15 mg/mL). Conclusion: The extracts of C. officinalis y D. elatum showed antimicrobial activity only against isolates with higher antimicrobial sensitivity. Ethanolic extracts of O. basilicum y L. nobilis can be used as an alternative treatment for infections of the anterior segment of the eye.


Staphylococcus aureus e Staphylococcus epidermidis são os principais agentes etiológicos da conjuntivite bacteriana, estes são tratados empiricamente com antibióticos, causando aumento da resistência antimicrobiana após repetidas exposições aos mesmos. Atualmente, estão sendo estudadas alternativas naturais para o tratamento de infecções bacterianas autolimitadas da conjuntiva. Objetivo: determinar a atividade antimicrobiana de oito extratos de sete vegetais contra bactérias isoladas de pacientes com conjuntivite bacteriana. Materiais e métodos: foram retiradas amostras de 15 pacientes com conjuntivite bacteriana. As amostras foram cultivadas em ágar sangue e ágar chocolate por 24 horas a 37°C e os isolados foram identificados pelo sistema automatizado vitek, além de testes de susce-tibilidade antimicrobiana pelo método Kirby Bauer. Cada isolado identificado como sendo pertencente ao gênero Staphylococcus foi avaliado quanto à suscetibilidade a oito extratos vegetais: Ocimum basili-cum (manjericão), Sambucus nigra L. (sabugueiro), Delphinium elatum (belladona), Calendula officinalis(calêndula), Bixa orellana (urucum; parte aérea e fruto independente), Clinopodium brownei (poejo) e Laurus nobilis (louro), anteriormente relatados como uso tradicional para o tratamento de infecções ocu-lares. Resultados: as bactérias mais frequentemente isoladas foram S. epidermidis, S. hominis e S. aureus, que apresentaram resistência antimicrobiana principalmente à oxacilina, tetraciclinas e eritromicina. Todos os isolados foram inibidos por extratos de O. basilicum (cim: >0,9 mg/mL) e L. nobilis (cim: até 15 mg/mL). Conclusão: os extratos de C. officinalis e D. elatum apresentaram atividade antimicrobiana apenas contra os isolados com maior sensibilidade antimicrobiana. Os extratos etanólicos de O. basilicum e L. nobilis podem ser uma alternativa de tratamento para infecções conjuntivais.


Subject(s)
Humans , Patients , Staphylococcus , Bacteria , Bacterial Infections , Plant Extracts , Eye Infections , Conjunctivitis, Bacterial , Conjunctivitis , Anti-Bacterial Agents
7.
Chinese Journal of Industrial Hygiene and Occupational Diseases ; (12): 247-254, 2023.
Article in Chinese | WPRIM | ID: wpr-986023

ABSTRACT

Objective: To explore the composition of bacteria in lower respiratory tract of patients with pneumoconiosis and dust exposure, and to compare and analyze the difference and correlation between them. Methods: From May 2020 to January 2021, a prospective multicenter cross-sectional study was conducted to select patients with pneumoconiosis who underwent bronchoalveolar lavage treatment at the Respiratory and Critical Care Medical Department of the 920th Hospital of the Joint Support Force and the Respiratory Department of Tongren Hospital in Kunming, as well as the population of dust recipients. A total of 24 patients with pneumoconiosis (pneumoconiosis group) were included, and 16 dust exposed individuals (dust exposed group) were used as controls. Two groups of patients' alveolar lavage fluid were collected. The 16SrRNA gene V3-V4 sequencing technology and bioinformatics analysis platform were used to measure and analyze the differences in microbial structure composition and associations between bacterial communities. Results: Compared with the dust exposed group, the top 5 bacterial phyla in the alveolar lavage fluid level of patients with pneumoconiosis were the same, followed by Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Actinobacteria. Compared with the dust exposure group, the pneumoconiosis group patients belong to the top 5 genera of horizontal flora abundance, which are different. The dust exposure group is respectively: Pseudomonas, Proctor, Streptococcus, Achromobacter, and Neisseria. The pneumoconiosis group is respectively: Pseudomonas, Achromobacter, Streptococcus, Ralstonia, and Proctor. The Alpha diversity analysis results showed that compared with the dust exposed group, the level of bacterial diversity in the pneumoconiosis group was difference (P<0.05), and there was no statistically significant difference in bacterial evenness (P>0.05) ; Beta diversity showed differences in microbial community structure between the two groups (P<0.05 ). Single factor microbial association network analysis showed that there was a high correlation between Firmicutes and Bacteroidetes in the pneumoconiosis and dust exposed groups and other species, showing a positive correlation; The correlation between Proteobacteria and other species is high, showing a negative correlation. Conclusion: The structure and relative abundance of bacteria in lower respiratory tract were different between patients with pneumoconiosis and dust exposure, and the diversity of bacteria in lower respiratory tract increased in patients with pneumoconiosis, which may be related to disease status.


Subject(s)
Humans , Cross-Sectional Studies , Prospective Studies , Pneumoconiosis , Bacteria/genetics , Dust , Respiratory System
8.
Journal of Peking University(Health Sciences) ; (6): 124-132, 2023.
Article in Chinese | WPRIM | ID: wpr-971284

ABSTRACT

OBJECTIVE@#To investigate the gut microbiota in newly diagnosed IgA nephropathy patients with chronic kidney disease (CKD) stages 1-2 and the association between the gut microbiota and the clinical risk factors of IgA nephropathy.@*METHODS@#Fresh fecal samples were collected from nineteen newly diagnosed IgA nephropathy patients with CKD stages 1-2 and fifteen age- and sex-matched healthy controls. Fecal bacterial DNA was extracted and microbiota composition were characterized using 16S ribosomal RNA (16S rRNA) high-throughput sequencing for the V3-V4 region. The Illumina Miseq platform was used to analyze the results of 16S rRNA high-throughput sequencing of fecal flora. At the same time, the clinical risk factors of IgA nephropathy patients were collected to investigate the association between the gut microbiota and the clinical risk factors.@*RESULTS@#(1) At the phylum level, the abundance of Bacteroidetes was significantly reduced (P=0.046), and the abundance of Actinobacteria was significantly increased (P=0.001). At the genus level, the abundance of Escherichia-Shigella, Bifidobacte-rium, Dorea and others were significantly increased (P < 0.05). The abundance of Lachnospira, Coprococcus_2 and Sutterella was significantly reduced (P < 0.05). (2) There was no significant difference in the abundance of gut microbiota between the newly diagnosed IgA nephropathy patients and the healthy control group (P>0.05), but there were differences in the structure of the gut microbiota between the two groups. The results of LEfSe analysis showed that there were 16 differential bacteria in the newly diagnosed IgA nephropathy patients and healthy controls. Among them, the abundance of the newly diagnosed IgA nephropathy patients was increased in Enterobacteriales, Actinobacteria, Escherichia-Shigella, etc. The healthy control group was increased in Bacteroidetes and Lachnospira. (3) The result of redundancy analysis (RDA) showed that Bifidobacterium was positively correlated with serum IgA levels, 24-hour urinary protein levels and the presence of hypertension. Lachnoclostridium was positively correlated with the presence of hypertension. Escherichia-Shigella was positively correlated with urine red blood cells account. Bifidobacterium was positively correlated with the proliferation of capillaries. Faecalibacterium was positively correlated with cell/fibrocytic crescents. Ruminococcus_2 was positively correlated with mesangial cell proliferation, glomerular segmental sclerosis and renal tubular atrophy/interstitial fibrosis.@*CONCLUSION@#The gut microbiota in the newly diagnosed IgA nephropathy patients with CKD stages 1-2 is different from that of the healthy controls. Most importantly, some gut bacteria are related to the clinical risk factors of IgA nephropathy. Further research is needed to understand the potential role of these bacteria in IgA nephropathy.


Subject(s)
Humans , Gastrointestinal Microbiome , RNA, Ribosomal, 16S/genetics , Glomerulonephritis, IGA , Bacteria/genetics , Risk Factors , Renal Insufficiency, Chronic
9.
Acta Academiae Medicinae Sinicae ; (6): 317-321, 2023.
Article in Chinese | WPRIM | ID: wpr-981270

ABSTRACT

Blood stream infection (BSI),a blood-borne disease caused by microorganisms such as bacteria,fungi,and viruses,can lead to bacteremia,sepsis,and infectious shock,posing a serious threat to human life and health.Identifying the pathogen is central to the precise treatment of BSI.Traditional blood culture is the gold standard for pathogen identification,while it has limitations in clinical practice due to the long time consumption,production of false negative results,etc.Nanopore sequencing,as a new generation of sequencing technology,can rapidly detect pathogens,drug resistance genes,and virulence genes for the optimization of clinical treatment.This paper reviews the current status of nanopore sequencing technology in the diagnosis of BSI.


Subject(s)
Humans , Nanopore Sequencing , Sepsis/diagnosis , Bacteremia/microbiology , Bacteria , Blood Culture/methods
10.
Chinese Journal of Biotechnology ; (12): 2719-2729, 2023.
Article in Chinese | WPRIM | ID: wpr-981228

ABSTRACT

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.


Subject(s)
Denitrification , Wastewater , Anaerobic Ammonia Oxidation , Nitrogen , Oxidation-Reduction , Bioreactors/microbiology , Ammonium Compounds , Bacteria/genetics , Microbiota , Sewage
11.
Chinese Journal of Biotechnology ; (12): 2449-2464, 2023.
Article in Chinese | WPRIM | ID: wpr-981211

ABSTRACT

The CRISPR/Cas systems comprising the clustered regularly interspaced short palindromic repeats (CRISPR) and its associated Cas protein is an acquired immune system unique to archaea or bacteria. Since its development as a gene editing tool, it has rapidly become a popular research direction in the field of synthetic biology due to its advantages of high efficiency, precision, and versatility. This technique has since revolutionized the research of many fields including life sciences, bioengineering technology, food science, and crop breeding. Currently, the single gene editing and regulation techniques based on CRISPR/Cas systems have been increasingly improved, but challenges still exist in the multiplex gene editing and regulation. This review focuses on the development and application of multiplex gene editing and regulation techniques based on the CRISPR/Cas systems, and summarizes the techniques for multiplex gene editing or regulation within a single cell or within a cell population. This includes the multiplex gene editing techniques developed based on the CRISPR/Cas systems with double-strand breaks; or with single-strand breaks; or with multiple gene regulation techniques, etc. These works have enriched the tools for the multiplex gene editing and regulation and contributed to the application of CRISPR/Cas systems in the multiple fields.


Subject(s)
Gene Editing , CRISPR-Cas Systems/genetics , Bacteria/genetics , Archaea , Bioengineering
12.
Chinese Journal of Biotechnology ; (12): 2015-2026, 2023.
Article in Chinese | WPRIM | ID: wpr-981186

ABSTRACT

PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.


Subject(s)
Hydrolases/metabolism , Bacteria/metabolism , Hydrolysis , Polyethylene Terephthalates/metabolism
13.
Chinese Journal of Biotechnology ; (12): 1976-1986, 2023.
Article in Chinese | WPRIM | ID: wpr-981183

ABSTRACT

Although polyurethane (PUR) plastics play important roles in daily life, its wastes bring serious environmental pollutions. Biological (enzymatic) degradation is considered as an environmentally friendly and low-cost method for PUR waste recycling, in which the efficient PUR-degrading strains or enzymes are crucial. In this work, a polyester PUR-degrading strain YX8-1 was isolated from the surface of PUR waste collected from a landfill. Based on colony morphology and micromorphology observation, phylogenetic analysis of 16S rDNA and gyrA gene, as well as genome sequence comparison, strain YX8-1 was identified as Bacillus altitudinis. The results of high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) showed that strain YX8-1 was able to depolymerize self-synthesized polyester PUR oligomer (PBA-PU) to produce a monomeric compound 4, 4'-methylene diphenylamine. Furthermore, strain YX8-1 was able to degrade 32% of the commercialized polyester PUR sponges within 30 days. This study thus provides a strain capable of biodegradation of PUR waste, which may facilitate the mining of related degrading enzymes.


Subject(s)
Polyurethanes/chemistry , Polyesters/chemistry , Chromatography, Liquid , Phylogeny , Tandem Mass Spectrometry , Bacteria/metabolism , Biodegradation, Environmental
14.
Chinese Journal of Biotechnology ; (12): 1963-1975, 2023.
Article in Chinese | WPRIM | ID: wpr-981182

ABSTRACT

Polyurethane (PUR) plastics is widely used because of its unique physical and chemical properties. However, unreasonable disposal of the vast amount of used PUR plastics has caused serious environmental pollution. The efficient degradation and utilization of used PUR plastics by means of microorganisms has become one of the current research hotspots, and efficient PUR degrading microbes are the key to the biological treatment of PUR plastics. In this study, an Impranil DLN-degrading bacteria G-11 was isolated from used PUR plastic samples collected from landfill, and its PUR-degrading characteristics were studied. Strain G-11 was identified as Amycolatopsis sp. through 16S rRNA gene sequence alignment. PUR degradation experiment showed that the weight loss rate of the commercial PUR plastics upon treatment of strain G-11 was 4.67%. Scanning electron microscope (SEM) showed that the surface structure of G-11-treated PUR plastics was destroyed with an eroded morphology. Contact angle and thermogravimetry analysis (TGA) showed that the hydrophilicity of PUR plastics increased along with decreased thermal stability upon treatment by strain G-11, which were consistent with the weight loss and morphological observation. These results indicated that strain G-11 isolated from landfill has potential application in biodegradation of waste PUR plastics.


Subject(s)
Plastics/metabolism , Polyurethanes/chemistry , RNA, Ribosomal, 16S , Bacteria/genetics , Biodegradation, Environmental
15.
Chinese Journal of Biotechnology ; (12): 1949-1962, 2023.
Article in Chinese | WPRIM | ID: wpr-981181

ABSTRACT

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.


Subject(s)
Polyethylene/metabolism , Bacteria/metabolism , Plastics/metabolism , Biodegradation, Environmental , Microbial Consortia
16.
Chinese Journal of Biotechnology ; (12): 1621-1632, 2023.
Article in Chinese | WPRIM | ID: wpr-981158

ABSTRACT

The widespread of tigecycline resistance gene tet(X4) has a serious impact on the clinical efficacy of tigecycline. The development of effective antibiotic adjuvants to combat the looming tigecycline resistance is needed. The synergistic activity between the natural compound β-thujaplicin and tigecycline in vitro was determined by the checkerboard broth microdilution assay and time-dependent killing curve. The mechanism underlining the synergistic effect between β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli was investigated by determining cell membrane permeability, bacterial intracellular reactive oxygen species (ROS) content, iron content, and tigecycline content. β-thujaplicin exhibited potentiation effect on tigecycline against tet(X4)-positive E. coli in vitro, and presented no significant hemolysis and cytotoxicity within the range of antibacterial concentrations. Mechanistic studies demonstrated that β-thujaplicin significantly increased the permeability of bacterial cell membranes, chelated bacterial intracellular iron, disrupted the iron homeostasis and significantly increased intracellular ROS level. The synergistic effect of β-thujaplicin and tigecycline was identified to be related to interfere with bacterial iron metabolism and facilitate bacterial cell membrane permeability. Our studies provided theoretical and practical data for the application of combined β-thujaplicin with tigecycline in the treatment of tet(X4)-positive E. coli infection.


Subject(s)
Humans , Tigecycline/pharmacology , Escherichia coli/metabolism , Reactive Oxygen Species/therapeutic use , Plasmids , Anti-Bacterial Agents/metabolism , Escherichia coli Infections/microbiology , Bacteria/genetics , Microbial Sensitivity Tests
17.
Chinese Journal of Biotechnology ; (12): 1363-1373, 2023.
Article in Chinese | WPRIM | ID: wpr-981143

ABSTRACT

The CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR associated proteins) system is an adaptive immune system of bacteria and archaea against phages, plasmids and other exogenous genetic materials. The system uses a special RNA (CRISPR RNA, crRNA) guided endonuclease to cut the exogenous genetic materials complementary to crRNA, thus blocking the infection of exogenous nucleic acid. According to the composition of the effector complex, CRISPR-Cas system can be divided into two categories: class 1 (including type Ⅰ, Ⅳ, and Ⅲ) and class 2 (including type Ⅱ, Ⅴ, and Ⅵ). Several CRISPR-Cas systems have been found to have very strong ability to specifically target RNA editing, such as type Ⅵ CRISPR-Cas13 system and type Ⅲ CRISPR-Cas7-11 system. Recently, several systems have been widely used in the field of RNA editing, making them a powerful tool for gene editing. Understanding the composition, structure, molecular mechanism and potential application of RNA-targeting CRISPR-Cas systems will facilitate the mechanistic research of this system and provide new ideas for developing gene editing tools.


Subject(s)
CRISPR-Cas Systems/genetics , RNA/genetics , Bacteria/genetics , Gene Editing , Archaea
18.
Chinese Journal of Biotechnology ; (12): 1290-1303, 2023.
Article in Chinese | WPRIM | ID: wpr-981138

ABSTRACT

Live biotherapeutic products (LBPs) refer to the living bacteria derived from human body intestinal gut or in nature that can be used to treat the human disease. However, the naturally screened living bacteria have some disadvantages, such as deficient therapeutic effect and great divergence, which fall short of the personalized diagnosis and treatment needs. In recent years, with the development of synthetic biology, researchers have designed and constructed several engineered strains that can respond to external complex environmental signals, which speeded up the process of development and application of LBPs. Recombinant LBPs modified by gene editing can have therapeutic effect on specific diseases. Inherited metabolic disease is a type of disease that causes a series of clinical symptoms due to the genetic defect of some enzymes in the body, which may cause abnormal metabolism the corresponding metabolites. Therefore, the use of synthetic biology to design LBPs targeting specific defective enzymes will be promising for the treatment of inherited metabolic defects in the future. This review summarizes the clinic applications of LBPs and its potential for the treatment of inherited metabolic defects.


Subject(s)
Humans , Bacteria/genetics , Gene Editing , Metabolic Diseases/therapy
19.
Chinese Journal of Biotechnology ; (12): 1275-1289, 2023.
Article in Chinese | WPRIM | ID: wpr-981137

ABSTRACT

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.


Subject(s)
Humans , Probiotics , Dietary Supplements , Bacteria , Drug Development , Biotechnology
20.
West China Journal of Stomatology ; (6): 208-217, 2023.
Article in English | WPRIM | ID: wpr-981114

ABSTRACT

OBJECTIVES@#This study aimed to analyze the bacteria in dental caries and establish an optimized dental-ca-ries diagnosis model based on 16S ribosomal RNA (rRNA) data of oral flora.@*METHODS@#We searched the public databa-ses of microbiomes including NCBI, MG-RAST, EMBL-EBI, and QIITA and collected data involved in the relevant research on human oral microbiomes worldwide. The samples in the caries dataset (1 703) were compared with healthy ones (20 540) by using the microbial search engine (MSE) to obtain the microbiome novelty score (MNS) and construct a caries diagnosis model based on this index. Nonparametric multivariate ANOVA was used to analyze and compare the impact of different host factors on the oral flora MNS, and the model was optimized by controlling related factors. Finally, the effect of the model was evaluated by receiver operating characteristic (ROC) curve analysis.@*RESULTS@#1) The oral microbiota distribution obviously differed among people with various oral-health statuses, and the species richness and species diversity index decreased. 2) ROC curve was used to evaluate the caries data set, and the area under ROC curve was AUC=0.67. 3) Among the five hosts' factors including caries status, country, age, decayed missing filled tooth (DMFT) indices, and sampling site displayed the strongest effect on MNS of samples (P=0.001). 4) The AUC of the model was 0.87, 0.74, 0.74, and 0.75 in high caries, medium caries, low caries samples in Chinese children, and mixed dental plaque samples after controlling host factors, respectively.@*CONCLUSIONS@#The model based on the analysis of 16S rRNA data of oral flora had good diagnostic efficiency.


Subject(s)
Humans , Child , Bacteria/genetics , Dental Caries/microbiology , Dental Caries Susceptibility , Microbiota/genetics , RNA, Ribosomal, 16S
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