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1.
Proc Natl Acad Sci U S A ; 118(36)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34465619

RESUMO

The second plague pandemic started in Europe with the Black Death in 1346 and lasted until the 19th century. Based on ancient DNA studies, there is a scientific disagreement over whether the bacterium, Yersinia pestis, came into Europe once (Hypothesis 1) or repeatedly over the following four centuries (Hypothesis 2). Here, we synthesize the most updated phylogeny together with historical, archeological, evolutionary, and ecological information. On the basis of this holistic view, we conclude that Hypothesis 2 is the most plausible. We also suggest that Y. pestis lineages might have developed attenuated virulence during transmission, which can explain the convergent evolutionary signals, including pla decay, that appeared at the end of the pandemics.

2.
Microbiome ; 9(1): 180, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470652

RESUMO

BACKGROUND: Probiotics have been used to regulate the gut microbiota and physiology in various contexts, but their precise mechanisms of action remain unclear. RESULTS: By population genomic analysis of 418 Bifidobacterium longum strains, including 143 newly sequenced in this study, three geographically distinct gene pools/populations, BLAsia1, BLAsia2, and BLothers, were identified. Genes involved in cell wall biosynthesis, particularly peptidoglycan biosynthesis, varied considerably among the core genomes of the different populations, but accessory genes that contributed to the carbohydrate metabolism were significantly distinct. Although active transmission was observed inter-host, inter-country, inter-city, intra-community, and intra-family, a single B. longum clone seemed to reside within each individual. A significant negative association was observed between host age and relative abundance of B. longum, while there was a strong positive association between host age and strain genotype [e.g., single nucleotide polymorphisms in the arginine biosynthesis pathway]. Further animal experiments performed with the B. longum isolates via using a D-galactose-induced aging mouse model supported these associations, in which B. longum strains with different genotypes in arginine biosynthesis pathway showed divergent abilities on protecting against host aging possibly via their different abilities to modify the metabolism of gut microbes. CONCLUSIONS: This is the first known example of research on the evolutionary history and transmission of this probiotic species. Our results propose a new mechanistic insight for promoting host longevity via the informed use of specific probiotics or molecules. Video abstract.


Assuntos
Bifidobacterium longum , Microbioma Gastrointestinal , Probióticos , Sulfaleno , Envelhecimento , Animais , Galactose , Microbioma Gastrointestinal/genética , Humanos , Camundongos
3.
PLoS Negl Trop Dis ; 14(2): e0008046, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069325

RESUMO

Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou between 2001 and 2012, and compared them with 850 publicly available global isolates. We found that CNTP isolates from Hangzhou belonged to two distinctive lineages, named L3b and L9. Both lineages caused disease over a long time period with usually mild or moderate clinical symptoms. Within Hangzhou, the spread route of the L3b lineage was apparently from rural to urban areas, with aquatic food products being the most likely medium. Both lineages had been previously reported as causing local endemic disease in Latin America, but here we show that global spread of them has occurred, with the most likely origin of L3b lineage being in Central Asia. The L3b lineage has spread to China on at least three occasions. Other spread events, including from China to Thailand and to Latin America were also observed. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies: surveillance of V. cholerae should not be limited to ctxAB positive strains.


Assuntos
Cólera/epidemiologia , Cólera/microbiologia , Epidemias , Saúde Global , Vibrio cholerae/genética , China/epidemiologia , Análise por Conglomerados , DNA Bacteriano/genética , Regulação Bacteriana da Expressão Gênica , Variação Genética , Genômica , Humanos , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
4.
Nat Commun ; 11(1): 281, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941912

RESUMO

Yersinia pestis is transmitted from fleas to rodents when the bacterium develops an extensive biofilm in the foregut of a flea, starving it into a feeding frenzy, or, alternatively, during a brief period directly after feeding on a bacteremic host. These two transmission modes are in a trade-off regulated by the amount of biofilm produced by the bacterium. Here by investigating 446 global isolated Y. pestis genomes, including 78 newly sequenced isolates sampled over 40 years from a plague focus in China, we provide evidence for strong selection pressures on the RNA polymerase ω-subunit encoding gene rpoZ. We demonstrate that rpoZ variants have an increased rate of biofilm production in vitro, and that they evolve in the ecosystem during colder and drier periods. Our results support the notion that the bacterium is constantly adapting-through extended phenotype changes in the fleas-in response to climate-driven changes in the niche.


Assuntos
Proteínas de Bactérias/genética , Peste/microbiologia , Sifonápteros/microbiologia , Yersinia pestis/fisiologia , Animais , Biofilmes , Evolução Biológica , China , Clima , RNA Polimerases Dirigidas por DNA/genética , Reservatórios de Doenças , Ecossistema , Infestações por Pulgas , Variação Genética , Genoma Bacteriano , Interações Hospedeiro-Parasita , Interações Hospedeiro-Patógeno , Marmota/parasitologia , Fenótipo , Filogenia , Sciuridae/parasitologia , Seleção Genética , Sifonápteros/fisiologia , Yersinia pestis/genética
6.
ISME J ; 13(10): 2578-2588, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31235840

RESUMO

Humans have profoundly affected the ocean environment but little is known about anthropogenic effects on the distribution of microbes. Vibrio parahaemolyticus is found in warm coastal waters and causes gastroenteritis in humans and economically significant disease in shrimps. Based on data from 1103 genomes of environmental and clinical isolates, we show that V. parahaemolyticus is divided into four diverse populations, VppUS1, VppUS2, VppX and VppAsia. The first two are largely restricted to the US and Northern Europe, while the others are found worldwide, with VppAsia making up the great majority of isolates in the seas around Asia. Patterns of diversity within and between the populations are consistent with them having arisen by progressive divergence via genetic drift during geographical isolation. However, we find that there is substantial overlap in their current distribution. These observations can be reconciled without requiring genetic barriers to exchange between populations if long-range dispersal has increased dramatically in the recent past. We found that VppAsia isolates from the US have an average of 1.01% more shared ancestry with VppUS1 and VppUS2 isolates than VppAsia isolates from Asia itself. Based on time calibrated trees of divergence within epidemic lineages, we estimate that recombination affects about 0.017% of the genome per year, implying that the genetic mixture has taken place within the last few decades. These results suggest that human activity, such as shipping, aquatic products trade and increased human migration between continents, are responsible for the change of distribution pattern of this species.


Assuntos
Vibrioses/microbiologia , Vibrio parahaemolyticus/classificação , Vibrio parahaemolyticus/isolamento & purificação , Variação Genética , Genoma Bacteriano , Humanos , Filogenia , Frutos do Mar/microbiologia , Vibrio parahaemolyticus/genética
7.
Eur J Pharm Biopharm ; 140: 78-90, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31085313

RESUMO

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Authors. There were errors in the handling of the data of the BSA binding experiments, which affected the conclusion on the binding affinity of the different cocrystals to BSA. After rigorous discussion, the authors think further investigation should be performed in this project to get the precise results.

8.
Fitoterapia ; 134: 196-200, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30825579

RESUMO

Three undescribed 3(2H)-furanone derivatives, asperfuranones A-C (1-3), along with one known compound (4) were isolated from the Aspergillus sp. strain obtained from the intestines of centipede. Their structures were determined by NMR and MS spectroscopic analyses, and the absolute configurations were established by the Snatzke's sector rules, modified Mosher's method and electronic circular dichroism (ECD) calculation. Meanwhile, the application of the sector rules led to the reassignment of the absolute configurations of 4 and other seventeen previously reported analogues (5-21).


Assuntos
Aspergillus/química , Benzofuranos/química , Animais , Dicroísmo Circular , Camundongos , Estrutura Molecular , Células RAW 264.7
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 215: 307-312, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30851688

RESUMO

In this work, photoactivated oxidase mimetics was prepared by copolymerizing dicyandiamide with barbituric acid (BA) and characterized by X-ray diffraction pattern, Fourier transformed infrared spectrum, X-ray photoelectron spectroscopy, transmission electron microscopy, photoluminescence spectrum, diffuse reflectance spectrum. Experimental results and density functional theory calculation indicated that the substitution of nitrogen atoms by carbon atoms in tri-s-triazine structure due to the copolymerization of BA enhanced visible light absorption and weakened the barrier of photocarrier transfer. In the presence of visible light and oxygen, 3, 3', 5, 5'-tetramethylbenzidine was oxidized under the catalysis of photoactivated oxidase mimetics to produce a green colored product, which could be reduced by glutathione (GSH). Therefore, a facile method based on the photoactivated oxidase mimetic has been developed for colorimetric detection of GSH. The linear range for GSH was ranged from 2.0 to 50.0 µmol L-1 (R2 = 0.998) with the detection limit of 1.4 µmol L-1. The proposed method was applied to detect the cellular GSH with satisfactory results.


Assuntos
Barbitúricos/química , Colorimetria/métodos , Glutationa/análise , Guanidinas/química , Benzidinas/química , Biomimética , Glutationa/química , Glutationa/metabolismo , Células HeLa , Humanos , Limite de Detecção , Modelos Lineares , Processos Fotoquímicos , Reprodutibilidade dos Testes , Análise Espectral
10.
J Nanosci Nanotechnol ; 19(7): 4220-4227, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30764996

RESUMO

Boron- and phenyl-doped graphitic carbon nitride nanosheets (BPCN NSs) were prepared by thermal polymerization of cyanamide with 3-aminobenzeneboronic acid followed by ultrasonic exfoliation. BPCN NSs exhibited enhanced peroxidase-like activity and catalyzed the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and o-phenylenediamine by H2O2. A simple sensitive colorimetric senor was developed for H2O2 by utilizing TMB as the substrate and BPCN NSs as enzyme mimetic. The linear relations between the absorbance and H2O2 concentration over the range from 0 to 280 µmol L-1 and from 280 to 1000 µmol L-1 were obtained with the limit of detection of 1.0 µmol L-1 according to the 3σ rule. The colorimetric sensor was applied for the detection of H2O2 residue in simulated soaked foods with satisfied results. Finally, the portable test kits for H2O2 were prepared and applied for the semi-quantitative assay of H2O2 residues in soaked chicken feet.

11.
J Hazard Mater ; 358: 62-68, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29960935

RESUMO

The development of metal-free photocatalyst to make maximum use of the solar energy for photocatalytic disinfection is highly desired. Herein, boron-and phenyl-codoped graphitic carbon nitride was prepared by thermal polycondensation of cyanamide with 3-aminobenzeneboronic acid and applied as photocatalyst to inactivate Escherichia coli (E. coli). The photocatalysts exhibited the enhanced light responsive range over ultraviolet to near infrared light and 99.9% bacteria could be inactivated within 3 h with a low concentration of photocatalyst under the irradiation of simulated solar light. The disinfection mechanism was studied by scavenger experiments, indicating H2O2 was the main reactive species for the inactivation of bacteria. Finally, the photocatalyst was deposited on the surface of solid material and also exhibited strong disinfection performance. Taking advantage of excellent disinfection activity and low cytotoxicity, the photocatalyst showed a promising application in solar-driven photocatalytic disinfection in public place.


Assuntos
Ácidos Borônicos/química , Desinfecção/métodos , Grafite/química , Luz , Nitrilas/química , Catálise , Cianamida/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Grafite/efeitos da radiação , Nanoestruturas , Nitrilas/efeitos da radiação , Processos Fotoquímicos , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/farmacologia
12.
Org Lett ; 19(15): 4058-4061, 2017 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-28726414

RESUMO

Citrifurans A-D (1-4), metabolized by an Aspergillus sp., are unusual dimers of azaphilone and furanone derivatives. Michael addition was thought to be the pivotal procedure in their biosynthesis, and different addition sites generated two new different carbon skeletons. Their structures were elucidated on the basis of spectroscopic methods, single-crystal X-ray diffraction, chemical conversion, and electronic circular dichroism analyses. Compounds 1-3 showed moderate inhibitory activities against LPS-induced NO production in RAW 264.7 macrophages with IC50 values of 18.3, 22.6, and 25.3 µM, respectively.


Assuntos
Aspergillus/metabolismo , Furanos/química , Policetídeos/química , Animais , Benzopiranos/química , Sobrevivência Celular , Dimerização , Furanos/isolamento & purificação , Furanos/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , Óxido Nítrico/biossíntese , Pigmentos Biológicos/química , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Células RAW 264.7
13.
Anal Chim Acta ; 967: 59-63, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28390486

RESUMO

In this work, a new colorimetric biosensor for the assay of paraoxon was developed via the conventional iodine-starch color reaction and multi-enzyme cascade catalytic reactions. In the presence of acetylcholine chloride, acetylcholinesterase (AChE) and choline oxidase (ChO) catalyzed the formation of H2O2, which then activated horseradish peroxidase (HRP) to catalyze the oxidation of KI to produce an iodine-starch color reaction. Upon exposure to paraoxon, the catalytic activity of AChE was inhibited and less H2O2 generated, resulting in a decrease in the production of I2 and a drop in the intensity of solution color. This colorimetric biosensor showed high sensitivity for the assay of paraoxon with a limit of detection 4.7 ppb and was applied for the assay of paraoxon in spiked real samples. By employing the conventional iodine-starch color reaction, this biosensor has the potential of on-site assay of OPs residues in environmental samples.


Assuntos
Técnicas Biossensoriais , Colorimetria , Paraoxon/análise , Poluentes Químicos da Água/análise , Acetilcolina , Acetilcolinesterase , Oxirredutases do Álcool , Peróxido de Hidrogênio , Iodo , Praguicidas/análise , Amido
14.
Anal Chem ; 88(22): 11022-11027, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27779389

RESUMO

Colorimetric detection of biogenic amines, well-known indicators of food spoilage, plays an important role for monitoring of food safety. However, common colorimetric sensors for biogenic amines suffer from low color resolution or complicated design and intricate output for the end-users. Herein, we explored a simple but effective strategy for visual monitoring of biogenic amines with multiple color change based on hydrolysis-induced silver metallization reaction to tune the localized surface plasmon resonance (LSPR) adsorption of Au nanorods (NRs). The color change and blue shift of longitudinal LSPR peak of Au NRs were closely related to the concentration of biogenic amines. This strategy provided a simple, sensitive, robust, nondestructive, cost-effective, and user-friendly platform for in situ evaluating the freshness of foodstuffs.


Assuntos
Aminas/análise , Contaminação de Alimentos/análise , Ouro/química , Nanotubos/química , Prata/química , Adsorção , Colorimetria , Humanos , Hidrólise , Ressonância de Plasmônio de Superfície , Propriedades de Superfície
15.
Ann Clin Microbiol Antimicrob ; 15(1): 37, 2016 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-27245674

RESUMO

BACKGROUND: Small colony variants (SCVs), constituting a slow-growing subpopulation of bacteria that facilitates persistence in lethal environmental conditions, are able to revert to the phenotype of rapid growth for further proliferation and transmission. Salmonella enterica serotype Typhimurium is one of the most important foodborne pathogens. This study investigated the genetic mechanisms how SCVs induced by streptomycin reverted to the fast-growing phenotype and the phenotypic changes of SCVs among their complete life cycle in S. Typhimurium. METHODS: Salmonella Typhimurium SCVs were obtained by streptomycin treatment and their revertants were collected in the absence of antibiotics. The fitness, antimicrobial susceptibility, biofilm formation, and the biofilm-related genes expression were analyzed in comparison to their wild type strain, and the whole genome sequencing was performed to identify the genetic changes in the life cycle of S. Typhimurium SCVs. RESULTS: Small colony variants were characterized by an increased antimicrobial resistance to streptomycin (64-fold), imipenem (twofold), and gentamicin (fourfold). A significant increase in biofilm production with higher expression of csgB was observed in SCVs (P < 0.01). The genetic alterations of all SCVs occurred in ubiE gene (coenzyme Q8 and menaquinone synthesis) with frameshift mutations. However, all fast-growing revertants again lost the trait of increased biofilm production (P > 0.05), in which two modes of the genetic changes for reversing to the rapidly growing form were observed: four revertants harbored a secondary mutation in ubiE, which reinstated most of the amino acid sequence of the ubiE, and other four revertants harbored a mutation in prfB. CONCLUSIONS: Salmonella Typhimurium could switch to the phenotype of SCVs under the treatment of streptomycin by a mutation in ubiE, partially combined with increased production of biofilm, and these SCVs could escape from growth restriction by a compensatory mutation in prfB or a new mutation in ubiE. These findings may contribute to establishing phenotype-directed treatments against SCVs of S. Typhimurium.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Biofilmes/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Salmonella typhimurium/efeitos dos fármacos , Estreptomicina/farmacologia , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Mutação da Fase de Leitura , Variação Genética , Gentamicinas/farmacologia , Sequenciamento de Nucleotídeos em Larga Escala , Imipenem/farmacologia , Metiltransferases/genética , Metiltransferases/metabolismo , Testes de Sensibilidade Microbiana , Fatores de Terminação de Peptídeos/genética , Fatores de Terminação de Peptídeos/metabolismo , Fenótipo , Salmonella typhimurium/genética , Salmonella typhimurium/crescimento & desenvolvimento
16.
Sci Rep ; 6: 22704, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26940047

RESUMO

Lactobacillus delbrueckii subsp. bulgaricus is one of the most widely used starter culture strains in industrial fermented dairy manufacture. It is also common in naturally fermented dairy foods made using traditional methods. The subsp. bulgaricus strains found in naturally fermented foods may be useful for improving current industrial starter cultures; however, little is known regarding its genetic diversity and population structure. Here, a collection of 298 L. delbrueckii strains from naturally fermented products in Mongolia, Russia, and West China was analyzed by multi-locus sequence typing based on eight conserved genes. The 251 confirmed subsp. bulgaricus strains produced 106 unique sequence types, the majority of which were assigned to five clonal complexes (CCs). The geographical distribution of CCs was uneven, with CC1 dominated by Mongolian and Russian isolates, and CC2-CC5 isolates exclusively from Xinjiang, China. Population structure analysis suggested six lineages, L1-L6, with various homologous recombination rates. Although L2-L5 were mainly restricted within specific regions, strains belonging to L1 and L6 were observed in diverse regions, suggesting historical transmission events. These results greatly enhance our knowledge of the population diversity of subsp. bulgaricus strains, and suggest that strains from CC1 and L4 may be useful as starter strains in industrial fermentation.


Assuntos
Biota , Microbiologia de Alimentos , Variação Genética , Lactobacillus delbrueckii/classificação , Lactobacillus delbrueckii/genética , China , Genótipo , Lactobacillus delbrueckii/isolamento & purificação , Mongólia , Tipagem de Sequências Multilocus , Filogeografia , Federação Russa , Análise de Sequência de DNA
17.
Virus Res ; 215: 65-71, 2016 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-26811903

RESUMO

Many pathogens trigger caspase-1-mediated innate immune responses. Avian leukosis virus subgroup J (ALV-J) causes serious immunosuppression and diverse tumors in chicks. The caspase-1 inflammasome mechanism of response to ALV-J invading remains unclear. Here we investigated the expression of caspase-1, the inflammasome adaptor NLRP3, IL-1ß and IL-18 in response to ALV-J infection in the liver of chick. We found caspase-1 mRNA expression was elevated at 5 dpi and peaked at 7 dpi in ALV-J infected animals. Corresponding to this, the expressions of NLRP3 and proinflammatory cytokines IL-1ß and IL-18 were significantly increased at 5 or 7 dpi. In addition, caspase-1 protein expression and inflammatory cell infiltration were induced after virus infection. These results indicated that ALV-J infection could trigger the caspase-1- mediated inflammatory response in chicks. Thus, an understanding of the inflammatory responses can provide a better insight into the pathogenicity of ALV-J and a possible anti-virus target for ALV-J infection.


Assuntos
Vírus da Leucose Aviária/patogenicidade , Caspase 1/análise , Genótipo , Inflamação/patologia , Fígado/patologia , Animais , Vírus da Leucose Aviária/genética , Perfilação da Expressão Gênica , Interleucina-18/análise , Interleucina-1beta/análise , Proteína 3 que Contém Domínio de Pirina da Família NLR/análise , RNA Mensageiro/análise , Fatores de Tempo
18.
Planta ; 243(2): 459-71, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26474992

RESUMO

MAIN CONCLUSION: The meta-QTL and candidate genes will facilitate the elucidation of molecular bases underlying agriculturally important traits and open new avenues for functional markers development and elite alleles introgression in maize breeding program. A large number of QTLs attributed to grain productivity and other agriculturally important traits have been identified and deposited in public repositories. The integration of fruitful QTL becomes a major issue in current plant genomics. To this end, we first collected QTL for six agriculturally important traits in maize, including yield, plant height, ear height, leaf angle, stay-green, and maize rough dwarf disease resistance. The meta-analysis method was then employed to retrieve 113 meta-QTL. Additionally, we also isolated candidate genes for target traits by the bioinformatic technique. Several candidates, including some well-characterized genes, GA3ox2 for plant height, lg1 and lg4 for leaf angle, zfl1 and zfl2 for flowering time, were co-localized with established meta-QTL intervals. Intriguingly, in a relatively narrow meta-QTL region, the maize ortholog of rice yield-related gene GW8/OsSPL16 was believed to be a candidate for yield. Leveraging results presented in this study will provide further insights into the genetic architecture of maize agronomic traits. Moreover, the meta-QTL and candidate genes reported here could be harnessed for the enhancement of stress tolerance and yield performance in maize and translation to other crops.


Assuntos
Resistência à Doença/genética , Locos de Características Quantitativas , Zea mays/genética , Cromossomos de Plantas , Biologia Computacional , Genes de Plantas , Zea mays/crescimento & desenvolvimento , Zea mays/virologia
20.
PLoS One ; 10(2): e0117912, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25658111

RESUMO

Bifidobacteria are well known for their human health-promoting effects and are therefore widely applied in the food industry. Members of the Bifidobacterium genus were first identified from the human gastrointestinal tract and were then found to be widely distributed across various ecological niches. Although the genetic diversity of Bifidobacterium has been determined based on several marker genes or a few genomes, the global diversity and evolution scenario for the entire genus remain unresolved. The present study comparatively analyzed the genomes of 45 type strains. We built a robust genealogy for Bifidobacterium based on 402 core genes and defined its root according to the phylogeny of the tree of bacteria. Our results support that all human isolates are of younger lineages, and although species isolated from bees dominate the more ancient lineages, the bee was not necessarily the original host for bifidobacteria. Moreover, the species isolated from different hosts are enriched with specific gene sets, suggesting host-specific adaptation. Notably, bee-specific genes are strongly associated with respiratory metabolism and are potential in helping those bacteria adapt to the oxygen-rich gut environment in bees. This study provides a snapshot of the genetic diversity and evolution of Bifidobacterium, paving the way for future studies on the taxonomy and functional genomics of the genus.


Assuntos
Bifidobacterium/genética , Evolução Molecular , Variação Genética , Adaptação Fisiológica , Animais , Abelhas/microbiologia , Bifidobacterium/fisiologia , Trato Gastrointestinal/microbiologia , Genômica , Interações Hospedeiro-Patógeno , Humanos , Filogenia
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