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1.
Lett Appl Microbiol ; 77(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38126115

RESUMEN

An important risk factor for cardiovascular disease is dyslipidemia, especially abnormal cholesterol levels. The relation between probiotics and cholesterol-lowering capability has been extensively studied. Lactobacillus acidophilus plays a significant role in affecting host health, and produces multitudinous metabolites, which have prohibitory functions against pathogenic microorganisms. In this study, we identified a cholesterol-lowering strain AM13-1, isolated from a fecal sample obtained from a healthy adult male, and performed comprehensive function analysis by whole-genome analysis and in vitro experiments. Genome analyses of L. acidophilus AM13-1 revealed that carbohydrate and amino acid transport, metabolism, translation, ribosomal structure, and biogenesis are abundant categories of functional genes. No virulence factors or toxin genes with experimentally verified were found in the genome of strain AM13-1. Besides, plenty of probiotic-related genes were predicted from the L. acidophilus AM13-1 genome, such as cbh, atpA-D, and dltD, with functions related to cholesterol-lowering and acid resistance. And strain AM13-1 showed high-efficiency of bile salt hydrolase activity and the capacity for removing cholesterol with efficiency rates of 70%. These function properties indicate that strain AM13-1 can be considered as a probiotic candidate for use in food and health care products.


Asunto(s)
Lactobacillus acidophilus , Probióticos , Humanos , Masculino , Lactobacillus acidophilus/genética , Lactobacillus acidophilus/metabolismo , Probióticos/metabolismo , Colesterol/metabolismo , Heces
2.
Brief Bioinform ; 22(4)2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-33333556

RESUMEN

African swine fever virus (ASFV) poses serious threats to the pig industry. The multigene family (MGF) proteins are extensively distributed in ASFVs and are generally classified into five families, including MGF-100, MGF-110, MGF-300, MGF-360 and MGF-505. Most MGF proteins, however, have not been well characterized and classified within each family. To bridge this gap, this study first classified MGF proteins into 31 groups based on protein sequence homology and network clustering. A web server for classifying MGF proteins was established and kept available for free at http://www.computationalbiology.cn/MGF/home.html. Results showed that MGF groups of the same family were most similar to each other and had conserved sequence motifs; the genetic diversity of MGF groups varied widely, mainly due to the occurrence of indels. In addition, the MGF proteins were predicted to have large structural and functional diversity, and MGF proteins of the same MGF family tended to have similar structure, location and function. Reconstruction of the ancestral states of MGF groups along the ASFV phylogeny showed that most MGF groups experienced either the copy number variations or the gain-or-loss changes, and most of these changes happened within strains of the same genotype. It is found that the copy number decrease and the loss of MGF groups were much larger than the copy number increase and the gain of MGF groups, respectively, suggesting the ASFV tended to lose MGF proteins in the evolution. Overall, the work provides a detailed classification for MGF proteins and would facilitate further research on MGF proteins.


Asunto(s)
Virus de la Fiebre Porcina Africana/genética , Variaciones en el Número de Copia de ADN , Evolución Molecular , Familia de Multigenes , Proteínas Virales/clasificación , Proteínas Virales/genética , Animales , Porcinos
3.
Brief Bioinform ; 22(2): 1297-1308, 2021 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-33757279

RESUMEN

The life-threatening coronaviruses MERS-CoV, SARS-CoV-1 and SARS-CoV-2 (SARS-CoV-1/2) have caused and will continue to cause enormous morbidity and mortality to humans. Virus-encoded noncoding RNAs are poorly understood in coronaviruses. Data mining of viral-infection-related RNA-sequencing data has resulted in the identification of 28 754, 720 and 3437 circRNAs encoded by MERS-CoV, SARS-CoV-1 and SARS-CoV-2, respectively. MERS-CoV exhibits much more prominent ability to encode circRNAs in all genomic regions than those of SARS-CoV-1/2. Viral circRNAs typically exhibit low expression levels. Moreover, majority of the viral circRNAs exhibit expressions only in the late stage of viral infection. Analysis of the competitive interactions of viral circRNAs, human miRNAs and mRNAs in MERS-CoV infections reveals that viral circRNAs up-regulated genes related to mRNA splicing and processing in the early stage of viral infection, and regulated genes involved in diverse functions including cancer, metabolism, autophagy, viral infection in the late stage of viral infection. Similar analysis in SARS-CoV-2 infections reveals that its viral circRNAs down-regulated genes associated with metabolic processes of cholesterol, alcohol, fatty acid and up-regulated genes associated with cellular responses to oxidative stress in the late stage of viral infection. A few genes regulated by viral circRNAs from both MERS-CoV and SARS-CoV-2 were enriched in several biological processes such as response to reactive oxygen and centrosome localization. This study provides the first glimpse into viral circRNAs in three deadly coronaviruses and would serve as a valuable resource for further studies of circRNAs in coronaviruses.


Asunto(s)
Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , ARN Circular/genética , SARS-CoV-2/genética , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/genética , Humanos
4.
J Appl Microbiol ; 134(12)2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38040628

RESUMEN

AIMS: Lactobacillus acidophilus has been extensively applied in plentiful probiotic products. Although several studies have been performed to investigate the beneficial characteristics and genome function of L. acidophilus, comparative genomic analysis remains scarce. In this study, we collected 74 L. acidophilus genomes from our gut bacterial genome collection and the public database and conducted a comprehensive comparative genomic analysis. METHODS AND RESULTS: This study revealed the potential correlation of the genomic diversity and niche adaptation of L. acidophilus from different perspectives. The pan-genome of L. acidophilus was found to be open, with metabolism, information storage, and processing genes mainly distributed in the core genome. Phage- and peptidase-associated genes were found in the genome of the specificity of animal-derived strains, which were related to the adaptation of the animal gut. SNP analysis showed the differences of the utilization of vitamin B12 in cellular of L. acidophilus strains from animal gut and others. CONCLUSIONS: This work provides new insights for the genomic diversity analysis of L. acidophilus and uncovers the ecological adaptation of the specific strains.


Asunto(s)
Lactobacillus acidophilus , Probióticos , Animales , Lactobacillus acidophilus/genética , Genoma Bacteriano , Genómica
5.
Biochemistry ; 61(24): 2870-2878, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36130198

RESUMEN

Bile acids are essential metabolites and signaling molecules in mammals. Primary bile acids are synthesized from cholesterol in the liver. At the same time, the microbiota in the mammalian gut has many interactions with bile acid, including various biotransformation processes such as 7-dehydroxylation and 3-epimerization. 7-Dehydroxylation is mediated by a bile acid-inducible (bai) operon, while 7-dehydroxylation and 3-epimerization are independently observed in only a few strains. Herein, we describe a novel microbe, Dorea sp. AM58-8, that can accomplish a two-step transformation and turn primary bile acids into both 3α secondary bile acids like deoxycholic acid and lithocholic acid, and 3ß secondary bile acids like isodeoxycholic acid and isolithocholic acid. We subsequently characterized BaiA, BaiB, BaiE, and their substrate profiles biochemically. The potential bai gene clusters in the metagenomes were further mined. Their evolution, potential functions, and possible regulatory pathways were predicted using bioinformatics based on our understanding of the 7-dehydroxylation pathway in Dorea sp. AM58-8. This study of Dorea sp. AM58-8 also helps us distinguish the inactive bacteria that seem to have the 7-dehydroxylation pathway proteins and discover the 7-dehydroxylation pathway in other mammalian gut microbes.


Asunto(s)
Bacterias , Ácidos y Sales Biliares , Animales , Operón , Mamíferos
6.
Bioinformatics ; 36(10): 2975-2979, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32096819

RESUMEN

MOTIVATION: Receptors on host cells play a critical role in viral infection. How phages select receptors is still unknown. RESULTS: Here, we manually curated a high-quality database named phageReceptor, including 427 pairs of phage-host receptor interactions, 341 unique viral species or sub-species and 69 bacterial species. Sugars and proteins were most widely used by phages as receptors. The receptor usage of phages in Gram-positive bacteria was different from that in Gram-negative bacteria. Most protein receptors were located on the outer membrane. The phage protein receptors (PPRs) were highly diverse in their structures, and had little sequence identity and no common protein domain with mammalian virus receptors. Further functional characterization of PPRs in Escherichia coli showed that they had larger node degrees and betweennesses in the protein-protein interaction network, and higher expression levels, than other outer membrane proteins, plasma membrane proteins or other intracellular proteins. These findings were consistent with what observed for mammalian virus receptors reported in previous studies, suggesting that viral protein receptors tend to have multiple interaction partners and high expressions. The study deepens our understanding of virus-host interactions. AVAILABILITY AND IMPLEMENTATION: phageReceptor is publicly available from: http://www.computationalbiology.cn/phageReceptor/index.html. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Bacteriófagos , Receptores Virales , Animales , Bacteriófagos/genética , Escherichia coli , Proteínas de la Membrana , Proteínas Virales
7.
Bioinformatics ; 36(10): 3251-3253, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32049310

RESUMEN

MOTIVATION: Newly emerging influenza viruses keep challenging global public health. To evaluate the potential risk of the viruses, it is critical to rapidly determine the phenotypes of the viruses, including the antigenicity, host, virulence and drug resistance. RESULTS: Here, we built FluPhenotype, a one-stop platform to rapidly determinate the phenotypes of the influenza A viruses. The input of FluPhenotype is the complete or partial genomic/protein sequences of the influenza A viruses. The output presents five types of information about the viruses: (i) sequence annotation including the gene and protein names as well as the open reading frames, (ii) potential hosts and human-adaptation-associated amino acid markers, (iii) antigenic and genetic relationships with the vaccine strains of different HA subtypes, (iv) mammalian virulence-related amino acid markers and (v) drug resistance-related amino acid markers. FluPhenotype will be a useful bioinformatic tool for surveillance and early warnings of the newly emerging influenza A viruses. AVAILABILITY AND IMPLEMENTATION: It is publicly available from: http://www.computationalbiology.cn : 18888/IVEW. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Virus de la Influenza A , Gripe Humana , Orthomyxoviridae , Secuencia de Aminoácidos , Animales , Glicoproteínas Hemaglutininas del Virus de la Influenza , Humanos , Virus de la Influenza A/genética
8.
Bioinformatics ; 33(12): 1881-1882, 2017 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-28174895

RESUMEN

MOTIVATION: Previously, we developed a computational model to identify genomic co-occurrence networks that was applied to capture the coevolution patterns within genomes of influenza viruses. To facilitate easy public use of this model, an R package 'cooccurNet' is presented here. RESULTS: 'cooccurNet' includes functionalities of construction and analysis of residues (e.g. nucleotides, amino acids and SNPs) co-occurrence network. In addition, a new method for measuring residues coevolution, defined as residue co-occurrence score (RCOS), is proposed and implemented in 'cooccurNet' based on the co-occurrence network. AVAILABILITY AND IMPLEMENTATION: 'cooccurNet' is publicly available on CRAN repositories under the GPL-3 Open Source License ( http://cran.r-project.org/package=cooccurNet ). CONTACT: taijiao@ibms.pumc.edu.cn or pys2013@hnu.edu.cn. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Simulación por Computador , Genoma Viral , Genómica/métodos , Orthomyxoviridae/genética , Programas Informáticos , Evolución Molecular , Polimorfismo de Nucleótido Simple
9.
Bioinformatics ; 32(16): 2526-7, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27153622

RESUMEN

MOTIVATION: Timely surveillance of the antigenic dynamics of the influenza virus is critical for accurate selection of vaccine strains, which is important for effective prevention of viral spread and infection. RESULTS: Here, we provide a computational platform, called PREDAC-H3, for antigenic surveillance of human influenza A(H3N2) virus based on the sequence of surface protein hemagglutinin (HA). PREDAC-H3 not only determines the antigenic variants and antigenic cluster (grouped for similar antigenicity) to which the virus belongs, based on HA sequences, but also allows visualization of the spatial distribution and temporal dynamics of antigenic clusters of viruses isolated from around the world, thus assisting in antigenic surveillance of human influenza A(H3N2) virus. AVAILABILITY AND IMPLEMENTATION: It is publicly available from: http://biocloud.hnu.edu.cn/influ411/html/index.php CONTACTS: : yshu@cnic.org.cn or taijiao@moon.ibp.ac.cn.


Asunto(s)
Biología Computacional/métodos , Monitoreo Epidemiológico , Hemaglutininas , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/epidemiología , Análisis de Secuencia de ADN , Variación Antigénica , Antígenos Virales , ADN Viral , Glicoproteínas Hemaglutininas del Virus de la Influenza , Humanos , Virus de la Influenza A
10.
Front Microbiol ; 15: 1379500, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38873165

RESUMEN

Introduction: Faecalibacterium is one of the most abundant bacteria in the gut microbiota of healthy adults, highly regarded as a next-generation probiotic. However, the functions of Faecalibacterium genomes from cultured strains and the distribution of different species in populations may differ among different sources. Methods: We here performed an extensive analysis of pan-genomes, functions, and safety evaluation of 136 Faecalibacterium genomes collected from 10 countries. Results: The genomes are clustered into 11 clusters, with only five of them were characterized and validly nomenclated. Over 80% of the accessory genes and unique genes of Faecalibacterium are found with unknown function, which reflects the importance of expanding the collection of Faecalibacterium strains. All the genomes have the potential to produce acetic acid and butyric acid. Nine clusters of Faecalibacterium are found significantly enriched in the healthy individuals compared with patients with type II diabetes.. Discussion: This study provides a comprehensive view of genomic characteristic and functions and of culturable Faecalibacterium bacterium from human gut, and enables clinical advances in the future.

11.
Sci Rep ; 14(1): 1292, 2024 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-38221534

RESUMEN

The Illumina HiSeq platform has been a commonly used option for bacterial genome sequencing. Now the BGI DNA nanoball (DNB) nanoarrays platform may provide an alternative platform for sequencing of bacterial genomes. To explore the impact of sequencing platforms on bacterial genome assembly, quality assessment, sequence alignment, functional annotation, mutation detection, and metagenome mapping, we compared genome assemblies based on sequencing of cultured bacterial species using the HiSeq 2000 and BGISEQ-500 platforms. In addition, simulated reads were used to evaluate the impact of insert size on genome assembly. Genome assemblies based on BGISEQ-500 sequencing exhibited higher completeness and fewer N bases in high GC genomes, whereas HiSeq 2000 assemblies exhibited higher N50. The majority of assembly assessment parameters, sequences of 16S rRNA genes and genomes, numbers of single nucleotide variants (SNV), and mapping to metagenome data did not differ significantly between platforms. More insertions were detected in HiSeq 2000 genome assemblies, whereas more deletions were detected in BGISEQ-500 genome assemblies. Insert size had no significant impact on genome assembly. Taken together, our results suggest that DNBSEQ platforms would be a valid substitute for HiSeq 2000 for bacterial genome sequencing.


Asunto(s)
ADN , Genoma Bacteriano , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Bacterias/genética
12.
Nat Commun ; 15(1): 3396, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649355

RESUMEN

The incidence of young-onset colorectal cancer (yCRC) has been increasing in recent decades, but little is known about the gut microbiome of these patients. Most studies have focused on old-onset CRC (oCRC), and it remains unclear whether CRC signatures derived from old patients are valid in young patients. To address this, we assembled the largest yCRC gut metagenomes to date from two independent cohorts and found that the CRC microbiome had limited association with age across adulthood. Differential analysis revealed that well-known CRC-associated taxa, such as Clostridium symbiosum, Peptostreptococcus stomatis, Parvimonas micra and Hungatella hathewayi were significantly enriched (false discovery rate <0.05) in both old- and young-onset patients. Similar strain-level patterns of Fusobacterium nucleatum, Bacteroides fragilis and Escherichia coli were observed for oCRC and yCRC. Almost all oCRC-associated metagenomic pathways had directionally concordant changes in young patients. Importantly, CRC-associated virulence factors (fadA, bft) were enriched in both oCRC and yCRC compared to their respective controls. Moreover, the microbiome-based classification model had similar predication accuracy for CRC status in old- and young-onset patients, underscoring the consistency of microbial signatures across different age groups.


Asunto(s)
Edad de Inicio , Neoplasias Colorrectales , Microbioma Gastrointestinal , Humanos , Neoplasias Colorrectales/microbiología , Adulto , Masculino , Femenino , Persona de Mediana Edad , Anciano , Metagenoma , Metagenómica/métodos , Bacterias/clasificación , Bacterias/aislamiento & purificación , Bacterias/genética , Adulto Joven , Heces/microbiología , Estudios de Cohortes
13.
Heliyon ; 10(5): e27270, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38463766

RESUMEN

The genus Bifidobacterium widely exists in human gut and has been increasingly used as the adjuvant probiotics for the prevention and treatment of diseases. However, the functional differences of Bifidobacterium genomes from different regions of the world remain unclear. We here describe an extensive study on the genomic characteristics and function annotations of 1512 genomes (clustered to 849 non-redundant genomes) of Bifidobacterium cultured from human gut. The distribution of some carbohydrate-active enzymes varied among different Bifidobacterium species and continents. More than 36% of the genomes of B. pseudocatenulatum harbored biosynthetic gene clusters of lanthipeptide-class-iv. 99.76% of the cultivated genomes of Bifidobacterium harbored genes of bile salt hydrolase. Most genomes of B. adolescentis, and all genomes of B. dentium harbored genes involved in gamma-aminobutyric acid synthesis. B. longum subsp. infantis were characterized harboring most genes related to human milk oligosaccharide utilization. Significant differences between the distribution of antibiotic resistance genes among different species and continents revealed the importance to use antibiotics precisely in the clinical treatment. Phages infecting Bifidobacterium and horizontal gene transfers occurring in genomes of Bifidobacterium were dependent on species and region sources, and might help Bifidobacterium adapt to the environment. In addition, the distribution of Bifidobacterium in human gut was found varied from different regions of the world. This study represents a comprehensive view of characteristics and functions of genomes of cultivated Bifidobacterium from human gut, and enables clinical advances in the future.

14.
Imeta ; 3(2): e174, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38882499

RESUMEN

The Lachnospiraceae family holds promise as a source of next-generation probiotics, yet a comprehensive delineation of its diversity is lacking, hampering the identification of suitable strains for future applications. To address this knowledge gap, we conducted an in-depth genomic and functional analysis of 1868 high-quality genomes, combining data from public databases with our new isolates. This data set represented 387 colonization-selective species-level clusters, of which eight genera represented multilineage clusters. Pan-genome analysis, single-nucleotide polymorphism (SNP) identification, and probiotic functional predictions revealed that species taxonomy, habitats, and geography together shape the functional diversity of Lachnospiraceae. Moreover, analyses of associations with atherosclerotic cardiovascular disease (ACVD) and inflammatory bowel disease (IBD) indicated that several strains of potentially novel Lachnospiraceae species possess the capacity to reduce the abundance of opportunistic pathogens, thereby imparting potential health benefits. Our findings shed light on the untapped potential of novel species enabling knowledge-based selection of strains for the development of next-generation probiotics holding promise for improving human health and disease management.

15.
IEEE Trans Med Imaging ; PP2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39120989

RESUMEN

Diagnosing malignant skin tumors accurately at an early stage can be challenging due to ambiguous and even confusing visual characteristics displayed by various categories of skin tumors. To improve diagnosis precision, all available clinical data from multiple sources, particularly clinical images, dermoscopy images, and medical history, could be considered. Aligning with clinical practice, we propose a novel Transformer model, named Remix-Former++ that consists of a clinical image branch, a dermoscopy image branch, and a metadata branch. Given the unique characteristics inherent in clinical and dermoscopy images, specialized attention strategies are adopted for each type. Clinical images are processed through a top-down architecture, capturing both localized lesion details and global contextual information. Conversely, dermoscopy images undergo a bottom-up processing with two-level hierarchical encoders, designed to pinpoint fine-grained structural and textural features. A dedicated metadata branch seamlessly integrates non-visual information by encoding relevant patient data. Fusing features from three branches substantially boosts disease classification accuracy. RemixFormer++ demonstrates exceptional performance on four single-modality datasets (PAD-UFES-20, ISIC 2017/2018/2019). Compared with the previous best method using a public multi-modal Derm7pt dataset, we achieved an absolute 5.3% increase in averaged F1 and 1.2% in accuracy for the classification of five skin tumors. Furthermore, using a large-scale in-house dataset of 10,351 patients with the twelve most common skin tumors, our method obtained an overall classification accuracy of 92.6%. These promising results, on par or better with the performance of 191 dermatologists through a comprehensive reader study, evidently imply the potential clinical usability of our method.

16.
Front Microbiol ; 15: 1366744, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38638907

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) is increasingly recognized for its global prevalence and potential progression to more severe liver diseases such as non-alcoholic steatohepatitis (NASH). The gut microbiota plays a pivotal role in the pathogenesis of NAFLD, yet the detailed characteristics and ecological alterations of gut microbial communities during the progression from non-alcoholic fatty liver (NAFL) to NASH remain poorly understood. Methods: In this study, we conducted a comparative analysis of gut microbiota composition in individuals with NAFL and NASH to elucidate differences and characteristics. We utilized 16S rRNA sequencing to compare the intestinal gut microbiota among a healthy control group (65 cases), NAFL group (64 cases), and NASH group (53 cases). Random forest machine learning and database validation methods were employed to analyze the data. Results: Our findings indicate a significant decrease in the diversity of intestinal flora during the progression of NAFLD (p < 0.05). At the phylum level, high abundances of Bacteroidetes and Fusobacteria were observed in both NAFL and NASH patients, whereas Firmicutes were less abundant. At the genus level, a significant decrease in Prevotella expression was seen in the NAFL group (AUC 0.738), whereas an increase in the combination of Megamonas and Fusobacterium was noted in the NASH group (AUC 0.769). Furthermore, KEGG pathway analysis highlighted significant disturbances in various types of glucose metabolism pathways in the NASH group compared to the NAFL group, as well as notably compromised flavonoid and flavonol biosynthesis functions. The study uncovers distinct microbiota characteristics and microecological changes within the gut during the transition from NAFL to NASH, providing insights that could facilitate the discovery of novel biomarkers and therapeutic targets for NAFLD.

17.
Heliyon ; 10(9): e30495, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38765070

RESUMEN

Vaginitis, characterized by pathogenic invasion and a deficiency in beneficial lactobacilli, has recognized lactobacilli supplementation as a novel therapeutic strategy. However, due to individual differences in vaginal microbiota, identifying universally effective Lactobacillus strains is challenging. Traditional methodologies for probiotic selection, which heavily depend on extensive in vitro experiments, are both time-intensive and laborious. The aim of this study was to pinpoint possible vaginal probiotic candidates based on whole-genome screening. We sequenced the genomes of 98 previously isolated Lactobacillus strains, annotating their genes involved in probiotic metabolite biosynthesis, adherence, acid/bile tolerance, and antibiotic resistance. A scoring system was used to assess the strains based on their genomic profiles. The highest-scoring strains underwent further in vitro evaluation. Consequently, two strains, Lactobacillus crispatus LG55-27 and Lactobacillus gasseri TM13-16, displayed an outstanding ability to produce d-lactate and adhere to human vaginal epithelial cells. They also showed higher antimicrobial activity against Gardnerella vaginalis, Escherichia coli, Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa compared to reference Lactobacillus strains. Their resilience to acid and bile environments highlights the potential for oral supplementation. Oral and vaginal administration of these two strains were tested in a bacterial vaginosis (BV) rat model at various doses. Results indicated that combined vaginal administration of these strains at 1 × 106 CFU/day significantly mitigated BV in rats. This research offers a probiotic dosage guideline for vaginitis therapy, underscoring an efficient screening process for probiotics using genome sequencing, in vitro testing, and in vivo BV model experimentation.

18.
Mol Plant Microbe Interact ; 26(11): 1294-301, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23883359

RESUMEN

Dickeya zeae is the causal agent of rice foot rot and maize stalk rot diseases, which could cause severe economic losses. The pathogen is known to produce two phytotoxins known as zeamine and zeamine II which are also potent antibiotics against both gram-positive and gram-negative bacteria pathogens. Zeamine II is a long-chain aminated polyketide and zeamine shares the same polyketide structure as zeamine II, with an extra valine derivative moiety conjugated to the primary amino group of zeamine II. In this study, we have identified a gene designated as zmsK encoding a putative nonribosomal peptide synthase (NRPS) by screening of the transposon mutants defective in zeamine production. Different from most known NRPS enzymes, which are commonly multidomain proteins, ZmsK contains only a condensation domain. High-performance liquid chromatography and mass spectrometry analyses showed that the ZmsK deletion mutant produced only zeamine II but not zeamine, suggesting that ZmsK catalyzes the amide bond formation by using zeamine II as a substrate to generate zeamine. We also present evidence that a partially conserved catalytic motif within the condensation domain is critical for zeamine production. Furthermore, we show that deletion of zmsK substantially decreased the total antimicrobial activity and virulence of D. zeae. Our findings provide a new insight into the biosynthesis pathway of zeamines and the virulence mechanisms of the bacterial pathogen D. zeae.


Asunto(s)
Antiinfecciosos/metabolismo , Enterobacteriaceae/enzimología , Macrólidos/metabolismo , Oryza/microbiología , Péptido Sintasas/genética , Poliaminas/metabolismo , Secuencia de Aminoácidos , Antiinfecciosos/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cromatografía Líquida de Alta Presión , Enterobacteriaceae/genética , Enterobacteriaceae/patogenicidad , Germinación , Macrólidos/química , Espectrometría de Masas , Datos de Secuencia Molecular , Oryza/fisiología , Péptido Sintasas/metabolismo , Fenotipo , Enfermedades de las Plantas/microbiología , Raíces de Plantas/microbiología , Raíces de Plantas/fisiología , Brotes de la Planta/microbiología , Brotes de la Planta/fisiología , Poliaminas/química , Estructura Terciaria de Proteína , Semillas/microbiología , Semillas/fisiología , Alineación de Secuencia , Eliminación de Secuencia , Virulencia
19.
Int J Syst Evol Microbiol ; 63(Pt 5): 1817-1823, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23002044

RESUMEN

Two Lactobacillus strains, designated LY-73(T) and LY-30B, were isolated from a dairy beverage, sold in Shenzhen market, China. The two isolates were Gram-positive, non-spore-forming, non-motile, facultatively anaerobic rods that were heterofermentative and did not exhibit catalase activity. Sequencing of the 16S rRNA, pheS and rpoA genes revealed that the two isolates shared 99.5, 99.8 and 99.9 % sequence similarity, which indicates that they belong to the same species. Phylogenetic analysis demonstrated clustering of the two isolates with the genus Lactobacillus. Strain LY-73(T) showed highest 16S rRNA gene sequence similarities with Lactobacillus harbinensis KACC 12409(T) (97.73%), Lactobacillus perolens DSM 12744(T) (96.96 %) and Lactobacillus selangorensis DSM 13344(T) (93.10 %). Comparative analyses of their rpoA and pheS gene sequences indicated that the novel strains were significantly different from other Lactobacillus species. Low DNA-DNA reassociation values (50.5 %) were obtained between strain LY-73(T) and its phylogenetically closest neighbours. The G+C contents of the DNA of the two novel isolates were 56.1 and 56.5 mol%. Straight-chain unsaturated fatty acids C18 : 1ω9c (78.85 and 74.29 %) were the dominant components, and the cell-wall peptidoglycan was of the l-Lys-d-Asp type. Based on phenotypic characteristics, and chemotaxonomic and genotypic data, the novel strains represent a novel species of the genus Lactobacillus, for which the name Lactobacillus shenzhenensis sp. nov. is proposed, with LY-73(T) ( = CCTCC M 2011481(T) = KACC 16878(T)) as the type strain.


Asunto(s)
Bebidas/microbiología , Productos Lácteos/microbiología , Fermentación , Lactobacillus/clasificación , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Microbiología de Alimentos , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Datos de Secuencia Molecular , Peptidoglicano/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
20.
Trends Microbiol ; 31(1): 76-91, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36008191

RESUMEN

Cardiovascular disease (CVD) is a health problem worldwide, and elevated cholesterol levels are a key risk factor for the disease. Dysbiotic gut microbiota has been shown to be associated with CVD development. However, the beneficial effects of healthy microbiota in decreasing cholesterol levels have not been summarized. Herein, we begin by discussing the potential mechanisms by which the gut microbiota reduces cholesterol levels. We further sketch the application of probiotics from the genera Lactobacillus and Bifidobacterium in reducing cholesterol levels in clinical studies. Finally, we present the cholesterol-lowering function of beneficial commensal microbes, such as Akkermansia and Bacteroides spp., as these microbes have potential to be the next-generation probiotics (NGPs). The information reviewed in this paper will help people to understand how the gut microbiome might alter cholesterol metabolism and enable the development of NGPs to prevent and treat CVD.


Asunto(s)
Enfermedades Cardiovasculares , Microbioma Gastrointestinal , Hipercolesterolemia , Microbiota , Probióticos , Humanos , Enfermedades Cardiovasculares/prevención & control , Colesterol/farmacología , Colesterol/uso terapéutico , Hipercolesterolemia/tratamiento farmacológico , Probióticos/uso terapéutico
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