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1.
Biochem Biophys Res Commun ; 597: 77-82, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35124463

RESUMO

Nowadays, a large number of databases have been developed gathering different types of therapeutic peptides including antimicrobial, antiviral and scorpion toxins peptides facilitating the searching for these molecules and their structural characteristics and pharmacology. Disintegrins, a family of small non-enzymatic and cysteine-rich proteins found in the snake venom may have a potential role in terms of novel therapeutic leads for cancer treatment. Despite their therapeutic effect, no database dedicated to disintegrins is available yet. Indeed, accessible information related to disintegrins are either scattered or fragmented in different databases from which it becomes extremely difficult to collect all the properties related to a particular disintegrin without exploring numerous databases available through distinct websites. Here, we propose DisintegrinDB as a first unique resource centralizing data related to disintegrins from snake venom. DisintegrinDB aims to facilitate the search on a given disintegrin and centralizes all the information on these peptides, helping researchers to retrieve all relevant related information.

2.
J Appl Microbiol ; 132(1): 279-289, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34252258

RESUMO

AIMS: Molecular characterization of extended-spectrum ß-lactamases (ESBLs) among Salmonella Kentucky and Typhimurium isolates: partial sequence analysis of the types of ß-lactamases found in these isolates, clonality, resistance and supposed emergence of ESBL-producing strains. METHODS AND RESULTS: A retrospective study surveyed the ESBLs occurring in a total of 1404 Salmonella Kentucky and Typhimurium isolates collected over a 5-year period in Tunisia. Antimicrobial susceptibility tests, ESBL phenotype determination (double-disc synergy) were performed. Polymerase chain reaction assays were used for the detection of ß-lactamase genes (blaTEM , blaSHV , blaOXA-1 and blaCTX-M ), class 1 and class 2 integrases (intI1 and intI2) and the 3' conserved segment (3'-CS) of class 1 integron (qacEΔ1+sul1). Sequencing of amplicons of ß-lactamase genes was performed. Percentage of 9.8 of the isolates (S. Kentucky = 117, S. Typhimurium = 20) were either resistant to penicillin and had decreased susceptibility to cefotaxime or had a positive double-disc synergy test result. Polymerase chain reaction detected that these isolates harboured one or more ß-lactamase genes (blaTEM , blaSHV , blaOXA-1 or blaCTX-M ). TEM-1, TEM-34, CTX-M15, CTX-M9 and CTX-M61 type ESBLs were identified through sequencing. The novel Salmonella cefotaxime-hydrolysing ß-lactamase, CTX-M61/TEM-34, detected in this study showed the emergence of new CTX-M-type ESBLs in Tunisia. There were found 33 different multidrug resistance (MDR) patterns. CONCLUSION: These findings highlighted the proliferation of ESBLs and MDR in Salmonella Kentucky and Typhimurium isolates from numerous regions and sources in Tunisia, indicating an emerging public health concern. SIGNIFICANCE AND IMPACT OF THE STUDY: For the first time CTX-M-61/TEM-34, a novel cefotaxime-hydrolysing ß-lactamase of Salmonella had been detected.


Assuntos
Salmonella enterica , beta-Lactamases , Antibacterianos/farmacologia , Cefotaxima/farmacologia , Kentucky , Estudos Retrospectivos , Salmonella , Salmonella enterica/genética , Sorogrupo , Tunísia , beta-Lactamases/genética
3.
Genomics ; 113(1 Pt 1): 317-330, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33279651

RESUMO

A new strain belonging to the genus Kocuria, designed PT10, was isolated from irradiated roots of the xerophyte Panicum turgidum. Isolate PT10 is a Gram-positive, coccoid, aerobic and ionizing-radiation (IR)-resistant actinobacterium. PT10 has shown an ability to survive under extreme conditions, such as gamma irradiation, desiccation and high concentration of hydrogen peroxide. Phenotypic, chemotaxonomic and comparative genome analyses support the assignment of strain PT10 (LMG 31102 = DSM 108617) as Kocuria rhizophila. The complete genome sequence of PT10 consists of one chromosome (2,656,287 bps), with a 70.7% G + C content and comprises 2481 protein-coding sequences. A total of 1487 proteins were identified by LC-MS/MS profiling. In silico analyses revealed that the proteome of the oxidation-tolerant PT10 possesses several features explaining its IR-resistant phenotype and many adaptive pathways implicated in response to environmental pressures - desiccation, cold, reactive oxygen species and other stressors.


Assuntos
Genes Bacterianos , Micrococcaceae/genética , Panicum/microbiologia , Tolerância a Radiação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Dessecação , Raios gama , Micrococcaceae/patogenicidade , Micrococcaceae/efeitos da radiação , Estresse Oxidativo
4.
Int J Mol Sci ; 23(3)2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35163319

RESUMO

Over the past 25 years, the powerful combination of genome sequencing and bioinformatics analysis has played a crucial role in interpreting information encoded in bacterial genomes. High-throughput sequencing technologies have paved the way towards understanding an increasingly wide range of biological questions. This revolution has enabled advances in areas ranging from genome composition to how proteins interact with nucleic acids. This has created unprecedented opportunities through the integration of genomic data into clinics for the diagnosis of genetic traits associated with disease. Since then, these technologies have continued to evolve, and recently, long-read sequencing has overcome previous limitations in terms of accuracy, thus expanding its applications in genomics, transcriptomics and metagenomics. In this review, we describe a brief history of the bacterial genome sequencing revolution and its application in public health and molecular epidemiology. We present a chronology that encompasses the various technological developments: whole-genome shotgun sequencing, high-throughput sequencing, long-read sequencing. We mainly discuss the application of next-generation sequencing to decipher bacterial genomes. Secondly, we highlight how long-read sequencing technologies go beyond the limitations of traditional short-read sequencing. We intend to provide a description of the guiding principles of the 3rd generation sequencing applications and ongoing improvements in the field of microbial medical research.


Assuntos
Bactérias/genética , Genoma Bacteriano/genética , Animais , Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Metagenômica/métodos , Epidemiologia Molecular , Sequenciamento Completo do Genoma/métodos
5.
Molecules ; 28(1)2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36615520

RESUMO

Snake venom contains a number of active molecules that have been shown to possess high anti-tumor activities; disintegrins are an excellent example among these. Their ability to interact and bind with integrins suggests that they could be very valuable molecules for the development of new cancer therapeutic approaches. However, in the absence of a clear Lysine-Threonine-Serine (KTS) Disintegrins Integrin interaction model, the exact compound features behind it are still unknown. In this study, we investigated the structural characteristics of three KTS-disintegrins and the interaction mechanisms with the α1ß1 integrin receptor using in silico bioinformatics approaches. Normal mode analysis showed that the flexibility of the KTSR motif and the C-terminal region play a key role and influence the KTS-Disintegrin-integrin interaction. Protein-protein docking also suggested that the interaction involving the KTSR motif is highly dependent on the residue following K21, S23 and R24. These findings contribute to a better understanding of the KTS-Disintegrin-Integrin structural differences and their interactions with α1ß1 receptors, which could improve the selection process of the best active molecules for antitumor therapies.


Assuntos
Desintegrinas , Venenos de Serpentes , Desintegrinas/química , Sequência de Aminoácidos , Venenos de Serpentes/química , Integrinas
6.
BMC Bioinformatics ; 22(1): 163, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33771096

RESUMO

BACKGROUND: Coronavirus Disease 2019 (COVID-19) is a viral pandemic disease that may induce severe pneumonia in humans. In this paper, we investigated the putative implication of 12 vaccines, including BCG, OPV and MMR in the protection against COVID-19. Sequences of the main antigenic proteins in the investigated vaccines and SARS-CoV-2 proteins were compared to identify similar patterns. The immunogenic effect of identified segments was, then, assessed using a combination of structural and antigenicity prediction tools. RESULTS: A total of 14 highly similar segments were identified in the investigated vaccines. Structural and antigenicity prediction analysis showed that, among the identified patterns, three segments in Hepatitis B, Tetanus, and Measles proteins presented antigenic properties that can induce putative protective effect against COVID-19. CONCLUSIONS: Our results suggest a possible protective effect of HBV, Tetanus and Measles vaccines against COVID-19, which may explain the variation of the disease severity among regions.


Assuntos
Antígenos Virais/imunologia , SARS-CoV-2/química , Proteínas Virais/imunologia , Vacinas Virais/imunologia , Vacina BCG , COVID-19 , Vacinas contra COVID-19 , Simulação por Computador , Proteção Cruzada , Humanos , Conformação Proteica
7.
BMC Genomics ; 22(1): 540, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34261445

RESUMO

BACKGROUND: In Tunisia a first SARS-CoV-2 confirmed case was reported in March 03, 2020. Since then, an increase of cases number was observed from either imported or local cases. The aim of this preliminary study was to better understand the molecular epidemiology and genetic variability of SARS-CoV-2 viruses circulating in Tunisia and worldwide. METHODS: Whole genome sequencing was performed using NGS approach on six SARS. CoV-2 highly positive samples detected during the early phase of the outbreak. RESULTS: Full genomes sequences of six Tunisian SARS-CoV-2 strains were obtained from imported and locally transmission cases during the COVID-19 outbreak. Reported sequences were non-identical with 0.1% nucleotide divergence rate and clustered into 6 different clades with worldwide sequences. SNPs results favor the distribution of the reported Tunisian sequences into 3 major genotypes. These SNP mutations are critical for diagnosis and vaccine development. CONCLUSIONS: These results indicate multiple introductions of the virus in Tunisia and add new genomic data on SARS-CoV-2 at the international level.


Assuntos
COVID-19 , SARS-CoV-2 , Genoma Viral , Humanos , Pandemias , Filogenia , Tunísia/epidemiologia , Sequenciamento Completo do Genoma
8.
Extremophiles ; 25(1): 25-38, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33104875

RESUMO

A novel strain of the genus Promicromonospora, designated PT9T, was recovered from irradiated roots of the xerophyte Panicum turgidum collected from the Ksar Ghilane oasis in southern Tunisia. Strain PT9T is aerobic, non-spore-forming, Gram- positive actinomycete that produces branched hyphae and forms white to yellowish-white colonies. Chemotaxonomic features, including fatty acids, whole cell sugars and polar lipid profiles, support the assignment of PT9T to the genus Promicromonospora. The genomic relatedness indexes based on DNA-DNA hybridization and average nucleotide identity values revealed a significant genomic divergence between strain PT9T and all sequenced type strains of the taxon. Phylogenomic analysis showed that isolate PT9T was most closely related to Promicromonospora soli CGMCC 4.7398T. Phenotypic and phylogenomic analyses suggest that isolate PT9T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora panici sp. nov. is proposed. The type strain is PT9T (LMG 31103T = DSM 108613T).The isolate PT9T is an ionizing-radiation-resistant actinobacterium (D10 value = 2.6 kGy), with resistance to desiccation and hydrogen peroxide. The complete genome sequence of PT9T consists of 6,582,650 bps with 71.2% G+C content and 6291 protein-coding sequences. This genome will help to decipher the microbial genetic bases for ionizing-radiation resistance mechanisms including the response to oxidative stress.


Assuntos
Actinobacteria/classificação , Panicum/microbiologia , Filogenia , Radiação Ionizante , Actinobacteria/isolamento & purificação , Actinobacteria/efeitos da radiação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Raízes de Plantas/microbiologia , RNA Ribossômico 16S , Análise de Sequência de DNA , Tunísia
9.
Eur J Clin Microbiol Infect Dis ; 40(3): 597-606, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33030625

RESUMO

We sought to determine the relative value of conventional molecular methods and whole-genome sequencing (WGS) for subtyping Salmonella enterica serovar Enteritidis recovered from 2000 to 2015 in Tunisia and to investigate the genetic diversity of this serotype. A total of 175 Salmonella Enteritidis isolates were recovered from human, animal, and foodborne outbreak samples. Pulsed-field gel electrophoresis (PFGE), multiple locus variable-number tandem repeat analysis (MLVA), and whole-genome sequencing were performed. Eight pulsotypes were detected for all isolates with PFGE (DI = 0.518). Forty-five Salmonella Enteritidis isolates were selected for the MLVA and WGS techniques. Eighteen MLVA profiles were identified and classified into two major clusters (DI = 0.889). Core genome multilocus typing (cgMLST) analysis revealed 16 profiles (DI = 0.785). Whole-genome analysis indicated 660 single-nucleotide polymorphism (SNP) divergences dividing these isolates into 43 haplotypes (DI = 0.997). The phylogenetic tree supported the classification of Salmonella Enteritidis isolates into two distinct lineages subdivided into five clades and seven subclades. Pairwise SNP differences between the isolates ranged between 302 and 350. We observed about 311 SNP differences between the two foodborne outbreaks, while only less or equal to 4 SNP differences within each outbreak. SNP-based WGS typing showed an excellent discriminatory power comparing with the conventional methods such as PFGE and MLVA. Besides, we demonstrate the added value of WGS as a complementary subtyping method to discriminate outbreak from non-outbreak isolates belonging to common subtypes. It is important to continue the survey of Salmonella Enteritidis lineages in Tunisia using WGS.


Assuntos
Tipagem Molecular , Infecções por Salmonella/microbiologia , Salmonella enteritidis/classificação , Sequenciamento Completo do Genoma , Animais , Eletroforese em Gel de Campo Pulsado , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Variação Genética , Humanos , Repetições Minissatélites/genética , Filogenia , Polimorfismo de Nucleotídeo Único , Infecções por Salmonella/epidemiologia , Salmonella enteritidis/genética , Salmonella enteritidis/isolamento & purificação , Sorogrupo , Tunísia/epidemiologia
10.
Genomics ; 112(1): 981-989, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31220587

RESUMO

Phosphogypsum (PG) is an acidic by-product from the phosphate fertilizer industry and it is characterized by a low nutrient availability and the presence of radionuclides and heavy metals which pose a serious problem in its management. Here, we have applied Illumina MiSeq sequencing technology and five bioinformatics pipelines to explore the phylogenetic communities in Tunisian PG. Taking One Codex as a reference method, we present the results of 16S-rDNA-gene-based metataxonomics abundances with four other alternative bioinformatics pipelines (MetaGenome Rapid Annotation using Subsystem Technology (MG-RAST), mothur, MICrobial Community Analysis (MICCA) and Quantitative Insights into Microbial Ecology (QIIME)), when analyzing the Tunisian PG. Importantly, based on 16S rDNA datasets, the functional capabilities of microbial communities of PG were deciphered. They suggested the presence of PG autochthonous bacteria valorizable into (1) removal of radioactive elements and toxic heavy metals, (2) promotion of plant growth, (3) oxidation and (4) reduction of sulfate. These bacteria can be explored further for applications in the bioremediation of by-products, like PG, by different processes.


Assuntos
Bactérias/metabolismo , Sulfato de Cálcio , Fósforo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Sulfato de Cálcio/química , Sulfato de Cálcio/metabolismo , Biologia Computacional , Sequenciamento de Nucleotídeos em Larga Escala , Microbiota , Fósforo/química , Fósforo/metabolismo , Análise de Sequência de DNA , Software , Tunísia
11.
Genomics ; 112(6): 4232-4241, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32650097

RESUMO

Computational approaches have been developed to prioritize candidate genes in disease gene identification. They are based on different pieces of evidences associating each gene with the given disease. In this study, 648 genes underlying genodermatoses have been compared to 1808 genes involved in other genetic diseases using a bioinformatic approach. These genes were studied at the structural, evolutionary and functional levels. Results show that genes underlying genodermatoses present longer CDS and have more exons. Significant differences were observed in nucleotide motif and amino-acid compositions. Evolutionary conservation analysis revealed that genodermatoses genes have less paralogs, more orthologs in Mouse and Dog and are less conserved. Functional analysis revealed that genodermatosis genes seem to be involved in immune system and skin layers. The Bayesian network model returned a rate of good classification of around 80%. This computational approach could help investigators working in the field of dermatology by prioritizing positional candidate genes for mutation screening.


Assuntos
Dermatopatias Genéticas/genética , Animais , Teorema de Bayes , Bovinos , Cães , Evolução Molecular , Genoma Humano , Genômica , Humanos , Camundongos , Motivos de Nucleotídeos , Estrutura Secundária de Proteína , Proteínas/genética , Ratos
12.
Biochem Biophys Res Commun ; 527(3): 702-708, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32410735

RESUMO

The spread of COVID-19 caused by the SARS-CoV-2 outbreak has been growing since its first identification in December 2019. The publishing of the first SARS-CoV-2 genome made a valuable source of data to study the details about its phylogeny, evolution, and interaction with the host. Protein-protein binding assays have confirmed that Angiotensin-converting enzyme 2 (ACE2) is more likely to be the cell receptor through which the virus invades the host cell. In the present work, we provide an insight into the interaction of the viral spike Receptor Binding Domain (RBD) from different coronavirus isolates with host ACE2 protein. By calculating the binding energy score between RBD and ACE2, we highlighted the putative jump in the affinity from a progenitor form of SARS-CoV-2 to the current virus responsible for COVID-19 outbreak. Our result was consistent with previously reported phylogenetic analysis and corroborates the opinion that the interface segment of the spike protein RBD might be acquired by SARS-CoV-2 via a complex evolutionary process rather than a progressive accumulation of mutations. We also highlighted the relevance of Q493 and P499 amino acid residues of SARS-CoV-2 RBD for binding to human ACE2 and maintaining the stability of the interface. Moreover, we show from the structural analysis that it is unlikely for the interface residues to be the result of genetic engineering. Finally, we studied the impact of eight different variants located at the interaction surface of ACE2, on the complex formation with SARS-CoV-2 RBD. We found that none of them is likely to disrupt the interaction with the viral RBD of SARS-CoV-2.


Assuntos
Betacoronavirus/química , Peptidil Dipeptidase A/química , Glicoproteína da Espícula de Coronavírus/química , Sequência de Aminoácidos , Enzima de Conversão de Angiotensina 2 , Sítios de Ligação , COVID-19 , Infecções por Coronavirus , Humanos , Simulação de Acoplamento Molecular , Pandemias , Filogenia , Pneumonia Viral , Domínios Proteicos , Estrutura Terciária de Proteína , SARS-CoV-2
13.
BMC Microbiol ; 20(1): 322, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33096980

RESUMO

BACKGROUND: Whole-genome sequencing using high throughput technologies has revolutionized and speeded up the scientific investigation of bacterial genetics, biochemistry, and molecular biology. Lactic acid bacteria (LABs) have been extensively used in fermentation and more recently as probiotics in food products that promote health. Genome sequencing and functional genomics investigations of LABs varieties provide rapid and important information about their diversity and their evolution, revealing a significant molecular basis. This study investigated the whole genome sequences of the Enterococcus faecium strain (HG937697), isolated from the mucus of freshwater fish in Tunisian dams. Genomic DNA was extracted using the Quick-GDNA kit and sequenced using the Illumina HiSeq2500 system. Sequences quality assessment was performed using FastQC software. The complete genome annotation was carried out with the Rapid Annotation using Subsystem Technology (RAST) web server then NCBI PGAAP. RESULTS: The Enterococcus faecium R.A73 assembled in 28 contigs consisting of 2,935,283 bps. The genome annotation revealed 2884 genes in total including 2834 coding sequences and 50 RNAs containing 3 rRNAs (one rRNA 16 s, one rRNA 23 s and one rRNA 5 s) and 47 tRNAs. Twenty-two genes implicated in bacteriocin production are identified within the Enterococcus faecium R.A73 strain. CONCLUSION: Data obtained provide insights to further investigate the effective strategy for testing this Enterococcus faecium R.A73 strain in the industrial manufacturing process. Studying their metabolism with bioinformatics tools represents the future challenge and contribution to improving the utilization of the multi-purpose bacteria in food.


Assuntos
Infecções Bacterianas/veterinária , Bacteriocinas/genética , Enterococcus faecium/genética , Peixes/microbiologia , Animais , Fermentação , Água Doce , Genoma Bacteriano , Sequenciamento de Nucleotídeos em Larga Escala , Lactobacillales/genética , Filogenia , Sequenciamento Completo do Genoma
14.
J Hum Genet ; 65(4): 397-410, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31911611

RESUMO

Molecular diagnosis of rare inherited palmoplantar keratoderma (PPK) is still challenging. We investigated at the clinical and genetic level a consanguineous Tunisian family presenting an autosomal dominant atypical form of transgrediens and progrediens PPK to better characterize this ultrarare disease and to identify its molecular etiology. Whole-exome sequencing (WES), filtering strategies, and bioinformatics analysis have been achieved. Clinical investigation and follow up over 13 years of this Tunisian family with three siblings formerly diagnosed as an autosomal recessive form of Mal de Melela-like conducted us to reconsider its initial phenotype. Indeed, the three patients presented clinical features that overlap both Mal de Meleda and progressive symmetric erythrokeratoderma (PSEK). The mode of inheritance was also reconsidered, since the mother, initially classified as unaffected, exhibited a similar expression of the disease. WES analysis showed the absence of potentially functional rare variants in known PPKs or PSEK-related genes. Results revealed a novel heterozygous nonsynonymous variant in cadherin-12 gene (CDH12, NM_004061, c.1655C > A, p.Thr552Asn) in all affected family members. This variant is absent in dbSNP and in 50 in-house control exomes. In addition, in silico analysis of the mutated 3D domain structure predicted that this variant would result in cadherin-12 protein destabilization and thermal instability. Functional annotation and biological network construction data provide further supporting evidence for the potential role of CDH12 in the maintenance of skin integrity. Taken together, these results suggest that CDH12 gene is a potential candidate gene for an atypical presentation of an autosomal dominant form of transgrediens and progrediens PPK.


Assuntos
Caderinas , Transtornos Cromossômicos , Eritroceratodermia Variável , Genes Dominantes , Mutação de Sentido Incorreto , Adulto , Idoso , Proteínas Relacionadas a Caderinas , Caderinas/química , Caderinas/genética , Transtornos Cromossômicos/genética , Transtornos Cromossômicos/patologia , Simulação por Computador , Eritroceratodermia Variável/genética , Eritroceratodermia Variável/patologia , Feminino , Humanos , Masculino , Domínios Proteicos , Pele/patologia , Sequenciamento do Exoma
15.
Genomics ; 111(6): 1802-1814, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30529640

RESUMO

Here, we report the genomic features and the bioremediation potential of Halomonas desertis G11, a new halophilic species which uses crude oil as a carbon and energy source and displays intrinsic resistance to salt stress conditions (optimum growth at 10% NaCl). G11 genome (3.96 Mb) had a mean GC content of 57.82%, 3622 coding sequences, 480 subsystems and 64 RNA genes. Annotation predicted 38 genes involved in osmotic stress including the biosynthesis of osmoprotectants glycine-betaine, ectoine and osmoregulated periplasmic glucans. Genome analysis revealed also the versatility of the strain for emulsifying crude oil and metabolizing hydrocarbons. The ability of G11 to degrade crude oil components and to secrete a glycolipid biosurfactant with satisfying properties was experimentally confirmed and validated. Our results help to explain the exceptional capacity of G11 to survive at extreme desertic conditions, and highlight the metabolic features of this organism that has biotechnological and ecological potentialities.


Assuntos
Genes Bacterianos , Halomonas/genética , Anotação de Sequência Molecular , Petróleo/microbiologia , Tensoativos , Biodegradação Ambiental , Clima Desértico , Halomonas/metabolismo , Petróleo/metabolismo , Tunísia
16.
Biochem Biophys Res Commun ; 496(4): 1025-1032, 2018 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-29382529

RESUMO

Scorpion envenoming and its treatment is a public health problem in many parts of the world due to highly toxic venom polypeptides diffusing rapidly within the body of severely envenomed victims. Recently, 38 AahII-specific Nanobody sequences (Nbs) were retrieved from which the performance of NbAahII10 nanobody candidate, to neutralize the most poisonous venom compound namely AahII acting on sodium channels, was established. Herein, structural computational approach is conducted to elucidate the Nb-AahII interactions that support the biological characteristics, using Nb multiple sequence alignment (MSA) followed by modeling and molecular docking investigations (RosettaAntibody, ZDOCK software tools). Sequence and structural analysis showed two dissimilar residues of NbAahII10 CDR1 (Tyr27 and Tyr29) and an inserted polar residue Ser30 that appear to play an important role. Indeed, CDR3 region of NbAahII10 is characterized by a specific Met104 and two negatively charged residues Asp115 and Asp117. Complex dockings reveal that NbAahII17 and NbAahII38 share one common binding site on the surface of the AahII toxin divergent from the NbAahII10 one's. At least, a couple of NbAahII10 - AahII residue interactions (Gln38 - Asn44 and Arg62, His64, respectively) are mainly involved in the toxic AahII binding site. Altogether, this study gives valuable insights in the design and development of next generation of antivenom.


Assuntos
Mapeamento de Epitopos/métodos , Modelos Químicos , Simulação de Acoplamento Molecular , Venenos de Escorpião/química , Escorpiões , Anticorpos de Domínio Único/química , Animais , Sítios de Ligação , Epitopos/química , Nanopartículas/química , Ligação Proteica , Análise de Sequência de Proteína/métodos , Homologia de Sequência de Aminoácidos
17.
J Transl Med ; 16(1): 158, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29879995

RESUMO

BACKGROUND: A family history of breast cancer has long been thought to indicate the presence of inherited genetic events that predispose to this disease. In North Africa, many specific epidemio-genetic characteristics have been observed in breast cancer families when compared to Western populations. Despite these specificities, the majority of breast cancer genetics studies performed in North Africa remain restricted to the investigation of the BRCA1 and BRCA2 genes. Thus, comprehensive data at a whole exome or whole genome level from local patients are lacking. METHODS: A whole exome sequencing (WES) of seven breast cancer Tunisian families have been performed using a family-based approach. We focused our analysis on BC-TN-F001 family that included two affected members that have been sequenced using WES. Relevant variants identified in BC-TN-F001 have been confirmed using Sanger sequencing. Then, we conducted an integrative analysis by combining our results with those from other WES studies in order to figure out the genetic transmission model of the newly identified genes. Biological network construction and protein-protein interactions analyses have been performed to decipher the molecular mechanisms likely accounting for the role of these genes in breast cancer risk. RESULTS: Sequencing, filtering strategies, and validation analysis have been achieved. For BC-TN-F001, no deleterious mutations have been identified on known breast cancer genes. However, 373 heterozygous, exonic and rare variants have been identified on other candidate genes. After applying several filters, 12 relevant high-risk variants have been selected. Our results showed that these variants seem to be inherited in a family specific model. This hypothesis has been confirmed following a thorough analysis of the reported WES studies. Enriched biological process and protein-protein interaction networks resulted in the identification of four novel breast cancer candidate genes namely MMS19, DNAH3, POLK and KATB6. CONCLUSIONS: In this first WES application on Tunisian breast cancer patients, we highlighted the impact of next generation sequencing technologies in the identification of novel breast cancer candidate genes which may bring new insights into the biological mechanisms of breast carcinogenesis. Our findings showed that the breast cancer predisposition in non-BRCA families may be ethnic and/or family specific.


Assuntos
Neoplasias da Mama/genética , Sequenciamento do Exoma , Predisposição Genética para Doença , Alelos , Neoplasias da Mama/epidemiologia , Família , Feminino , Genes Neoplásicos , Estudos de Associação Genética , Variação Genética , Humanos , Masculino , Linhagem , Mapas de Interação de Proteínas , Tunísia
18.
Brief Bioinform ; 16(2): 355-64, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24990350

RESUMO

The discipline of bioinformatics has developed rapidly since the complete sequencing of the first genomes in the 1990s. The development of many high-throughput techniques during the last decades has ensured that bioinformatics has grown into a discipline that overlaps with, and is required for, the modern practice of virtually every field in the life sciences. This has placed a scientific premium on the availability of skilled bioinformaticians, a qualification that is extremely scarce on the African continent. The reasons for this are numerous, although the absence of a skilled bioinformatician at academic institutions to initiate a training process and build sustained capacity seems to be a common African shortcoming. This dearth of bioinformatics expertise has had a knock-on effect on the establishment of many modern high-throughput projects at African institutes, including the comprehensive and systematic analysis of genomes from African populations, which are among the most genetically diverse anywhere on the planet. Recent funding initiatives from the National Institutes of Health and the Wellcome Trust are aimed at ameliorating this shortcoming. In this paper, we discuss the problems that have limited the establishment of the bioinformatics field in Africa, as well as propose specific actions that will help with the education and training of bioinformaticians on the continent. This is an absolute requirement in anticipation of a boom in high-throughput approaches to human health issues unique to data from African populations.


Assuntos
Biologia Computacional/educação , África , Biologia Computacional/história , Educação , Genômica , História do Século XX , História do Século XXI , Humanos , Internet/provisão & distribuição , Universidades
19.
J Med Microbiol ; 73(2)2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38314675

RESUMO

Introduction. Infection caused by Mycobacterium tuberculosis (M. tb) is still a leading cause of mortality worldwide with estimated 1.4 million deaths annually.Hypothesis/Gap statement. Despite macrophages' ability to kill bacterium, M. tb can grow inside these innate immune cells and the exploration of the infection has traditionally been characterized by a one-sided relationship, concentrating solely on the host or examining the pathogen in isolation.Aim. Because of only a handful of M. tb-host interactions have been experimentally characterized, our main goal is to predict protein-protein interactions during the early phases of the infection.Methodology. In this work, we performed an integrative computational approach that exploits differentially expressed genes obtained from Dual RNA-seq analysis combined with known domain-domain interactions.Results. A total of 2381 and 7214 genes were identified as differentially expressed in M. tb and in THP-1-like macrophages, respectively, revealing different transcriptional profiles in response to infection. Over 48 h of infection, the host-pathogen network revealed 25 016 PPIs. Analysis of the resulting predicted network based on cellular localization information of M. tb proteins, indicated the implication of interacting nodes including the bacterial PE/PPE/PE_PGRS family. In addition, M. tb proteins interacted with host proteins involved in NF-kB signalling pathway as well as interfering with the host apoptosis ability via the potential interaction of M. tb TB16.3 with human TAB1 and M. tb GroEL2 with host protein kinase C delta, respectively.Conclusion. The prediction of the full range of interactions between M. tb and host will contribute to better understanding of the pathogenesis of this bacterium and may provide advanced approaches to explore new therapeutic targets against tuberculosis.


Assuntos
Mycobacterium tuberculosis , Humanos , Mycobacterium tuberculosis/genética , Mapas de Interação de Proteínas , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Patógeno/genética , Macrófagos , Análise de Sequência de RNA
20.
Database (Oxford) ; 20242024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38204360

RESUMO

There is growing evidence that comprehensive and harmonized metadata are fundamental for effective public data reusability. However, it is often challenging to extract accurate metadata from public repositories. Of particular concern is the metagenomic data related to African individuals, which often omit important information about the particular features of these populations. As part of a collaborative consortium, H3ABioNet, we created a web portal, namely the African Human Microbiome Portal (AHMP), exclusively dedicated to metadata related to African human microbiome samples. Metadata were collected from various public repositories prior to cleaning, curation and harmonization according to a pre-established guideline and using ontology terms. These metadata sets can be accessed at https://microbiome.h3abionet.org/. This web portal is open access and offers an interactive visualization of 14 889 records from 70 bioprojects associated with 72 peer reviewed research articles. It also offers the ability to download harmonized metadata according to the user's applied filters. The AHMP thereby supports metadata search and retrieve operations, facilitating, thus, access to relevant studies linked to the African Human microbiome. Database URL:  https://microbiome.h3abionet.org/.


Assuntos
Metadados , Microbiota , Humanos , Metagenoma , Bases de Dados Factuais , Metagenômica , Microbiota/genética
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