Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-37417270

RESUMO

Two novel bacterial isolates were cultured from faecal samples of patients attending the Breast Care clinic at the Norwich and Norfolk University Hospital. Strain LH1062T was isolated from a 58-year-old female diagnosed with invasive adenocarcinoma with ductal carcinoma in situ. Strain LH1063T was isolated from a healthy 51-year-old female. Isolate LH1062T was predicted to be a potential novel genus most closely related to Coprobacillus, whilst LH1063T was predicted to be a novel species belonging to Coprobacter. Both strains were characterized by polyphasic approaches including 16S rRNA gene analysis, core-genome analysis, average nucleotide identity (ANI) comparisons and phenotypic analysis. Initial screening of the 16S rRNA gene of LH1062T returned a nucleotide identity of 93.4 % to Longibaculum muris. For LH1063T, nucleotide identity was a 92.6 % to Coprobacter secundus. Further investigations showed that LH1062T had a genome size of 2.9 Mb and G+C content of 31.3 mol %. LH1063T had a genome size of 3.3Mb and G+C content of 39.2 mol %. Digital DNA-DNA hybridization (dDDH) and ANI values of LH1062T with its closest relative, Coprobacillus cateniformis JCM 10604T, were 20.9 and 79.54 %, respectively. For LH1063T, the dDDH and ANI values with its closest relative, Coprobacter secundus 177T, were 19.3 and 77.81 %, respectively. Phenotypic testing confirmed that LH1062T could not be matched to a known validly published isolate in any database; thereby indicating a novel genus for which the name Allocoprobacillus gen. nov. is now proposed with LH1062T (=DSM 114537T=NCTC 14686T) being the type strain of the proposed novel species Allocoprobacillus halotolerans sp. nov. Strain LH1063T (=DSM 114538T=NCTC 14698T) fits within the genus Coprobacter and, it being the third species within this genus, the name Coprobacter tertius sp. nov. is proposed.


Assuntos
Ácidos Graxos , Microbioma Gastrointestinal , Humanos , Pessoa de Meia-Idade , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Composição de Bases , Filogenia , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Clostridiaceae/genética , Hibridização de Ácido Nucleico
2.
Cell Mol Life Sci ; 79(7): 386, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35760917

RESUMO

The gut microbiota plays a central role in regulating host metabolism. While substantial progress has been made in discerning how the microbiota influences host functions post birth and beyond, little is known about how key members of the maternal gut microbiota can influence feto-placental growth. Notably, in pregnant women, Bifidobacterium represents a key beneficial microbiota genus, with levels observed to increase across pregnancy. Here, using germ-free and specific-pathogen-free mice, we demonstrate that the bacterium Bifidobacterium breve UCC2003 modulates maternal body adaptations, placental structure and nutrient transporter capacity, with implications for fetal metabolism and growth. Maternal and placental metabolome were affected by maternal gut microbiota (i.e. acetate, formate and carnitine). Histological analysis of the placenta confirmed that Bifidobacterium modifies placental structure via changes in Igf2P0, Dlk1, Mapk1 and Mapk14 expression. Additionally, B. breve UCC2003, acting through Slc2a1 and Fatp1-4 transporters, was shown to restore fetal glycaemia and fetal growth in association with changes in the fetal hepatic transcriptome. Our work emphasizes the importance of the maternal gut microbiota on feto-placental development and sets a foundation for future research towards the use of probiotics during pregnancy.


Assuntos
Microbioma Gastrointestinal , Placenta , Animais , Bifidobacterium , Feminino , Desenvolvimento Fetal , Humanos , Camundongos , Nutrientes , Placenta/metabolismo , Gravidez
3.
Int J Syst Evol Microbiol ; 71(12)2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34919037

RESUMO

Four bacterial strains were isolated from two different colony sources of the wax moth Galleria mellonella. They were characterized by a polyphasic approach including 16S rRNA gene sequence analysis, core-genome analysis, average nucleotide identity (ANI) analysis, digital DNA-DNA hybridization (dDDH), determination of G+C content, screening of antibiotic resistance genes, and various phenotypic analyses. Initial analysis of 16S rRNA gene sequence identities indicated that strain GAL7T was potentially very closely related to Enterococcus casseliflavus and Enterococcus gallinarum, having 99.5-99.9 % sequence similarity. However, further analysis of whole genome sequences revealed a genome size of 3.69 Mb, DNA G+C content of 42.35 mol%, and low dDDH and ANI values between the genomes of strain GAL7T and closest phylogenetic relative E. casseliflavus NBRC 100478T of 59.0 and 94.5 %, respectively, indicating identification of a putative new Enterococcus species. In addition, all novel strains encoded the atypical vancomycin-resistance gene vanC-4. Results of phylogenomic, physiological and phenotypic characterization confirmed that strain GAL7T represented a novel species within the genus Enterococcus, for which the name Enterococcus innesii sp. nov. is proposed. The type strain is GAL7T (=DSM 112306T=NCTC 14608T).


Assuntos
Enterococcus/classificação , Mariposas , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Enterococcus/isolamento & purificação , Ácidos Graxos/química , Mariposas/microbiologia , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Psychiatry Clin Neurosci ; 70(5): 218-26, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26864920

RESUMO

AIM: Atypical antipsychotic treatment (e.g. risperidone) has been found to improve social functioning more than standard antipsychotic treatment. However, it is unclear which specific social behaviors are implicated in this improvement. The current study employed an interactive puzzle game to examine how social behaviors contribute to the improvement of social functioning by comparing patients receiving risperidone with those receiving trifluoperazine. METHODS: Scores on the Positive and Negative Syndrome Scale, executive functioning, and social functioning were obtained from 24 patients with schizophrenia receiving either risperidone (n = 12) or trifluoperazine (n = 12), before their social behavior was measured in the interactive Tangrams Game. Immediately after the Tangrams Game, participants filled in two questionnaires measuring their interpersonal trust and rejection toward their game partner. RESULTS: Patients receiving risperidone showed more social engagement, cooperative behavior and interpersonal trust toward their game partners than those receiving trifluoperazine. Additional multivariate analysis of variance revealed that lower affiliative behavior was a function of positive symptoms; interpersonal trust had an impact on social engagement but executive functioning did not explain lower interpersonal trust or social disengagement. CONCLUSION: Improvement of social competence by risperidone might be related to the enhancement of both social behaviors and interpersonal trust as well as better symptom resolution.


Assuntos
Antipsicóticos/farmacologia , Relações Interpessoais , Risperidona/farmacologia , Esquizofrenia/tratamento farmacológico , Habilidades Sociais , Trifluoperazina/farmacologia , Confiança , Antipsicóticos/administração & dosagem , Humanos , Risperidona/administração & dosagem , Resultado do Tratamento , Trifluoperazina/administração & dosagem
5.
Emerg Microbes Infect ; 13(1): 2341968, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38590276

RESUMO

Clostridium perfringens causes multiple diseases in humans and animals. Its pathogenic effect is supported by a broad and heterogeneous arsenal of toxins and other virulence factors associated with a specific host tropism. Molecular approaches have indicated that most C. perfringens toxins produce membrane pores, leading to osmotic cell disruption and apoptosis. However, identifying mechanisms involved in cell tropism and selective toxicity effects should be studied more. The differential presence and polymorphisms of toxin-encoding genes and genes encoding other virulence factors suggest that molecular mechanisms might exist associated with host preference, receptor binding, and impact on the host; however, this information has not been reviewed in detail. Therefore, this review aims to clarify the current state of knowledge on the structural features and mechanisms of action of the major toxins and virulence factors of C. perfringens and discuss the impact of genetic diversity of toxinotypes in tropism for several hosts.


Assuntos
Toxinas Bacterianas , Infecções por Clostridium , Clostridium perfringens , Fatores de Virulência , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidade , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Humanos , Animais , Clostridium perfringens/genética , Clostridium perfringens/patogenicidade , Clostridium perfringens/metabolismo , Infecções por Clostridium/microbiologia
6.
Mol Metab ; 88: 102004, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39127167

RESUMO

BACKGROUND: Recent advances have significantly expanded our understanding of the gut microbiome's influence on host physiology and metabolism. However, the specific role of certain microorganisms in gestational health and fetal development remains underexplored. OBJECTIVE: This study investigates the impact of Bifidobacterium breve UCC2003 on fetal brain metabolism when colonized in the maternal gut during pregnancy. METHODS: Germ-free pregnant mice were colonized with or without B. breve UCC2003 during pregnancy. The metabolic profiles of fetal brains were analyzed, focusing on the presence of key metabolites and the expression of critical metabolic and cellular pathways. RESULTS: Maternal colonization with B. breve resulted in significant metabolic changes in the fetal brain. Specifically, ten metabolites, including citrate, 3-hydroxyisobutyrate, and carnitine, were reduced in the fetal brain. These alterations were accompanied by increased abundance of transporters involved in glucose and branched-chain amino acid uptake. Furthermore, supplementation with this bacterium was associated with elevated expression of critical metabolic pathways such as PI3K-AKT, AMPK, STAT5, and Wnt-ß-catenin signaling, including its receptor Frizzled-7. Additionally, there was stabilization of HIF-2 protein and modifications in genes and proteins related to cellular growth, axogenesis, and mitochondrial function. CONCLUSIONS: The presence of maternal B. breve during pregnancy plays a crucial role in modulating fetal brain metabolism and growth. These findings suggest that Bifidobacterium could modify fetal brain development, potentially offering new avenues for enhancing gestational health and fetal development through microbiota-targeted interventions.


Assuntos
Bifidobacterium breve , Encéfalo , Microbioma Gastrointestinal , Animais , Feminino , Camundongos , Bifidobacterium breve/metabolismo , Encéfalo/metabolismo , Gravidez , Microbioma Gastrointestinal/fisiologia , Feto/metabolismo , Vida Livre de Germes , Desenvolvimento Fetal , Camundongos Endogâmicos C57BL
7.
NPJ Biofilms Microbiomes ; 10(1): 85, 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39277573

RESUMO

The gut microbiota of infants in low- to middle-income countries is underrepresented in microbiome research. This study explored the faecal microbiota composition and faecal cytokine profiles in a cohort of infants in a rural province of Cambodia and investigated the impact of sample storage conditions and infant environment on microbiota composition. Faecal samples collected at three time points from 32 infants were analysed for microbiota composition using 16S rRNA amplicon sequencing and concentrations of faecal cytokines. Faecal bacterial isolates were subjected to whole genome sequencing and genomic analysis. We compared the effects of two sample collection methods due to the challenges of faecal sample collection in a rural location. Storage of faecal samples in a DNA preservation solution preserved Bacteroides abundance. Microbiota analysis of preserved samples showed that Bifidobacterium was the most abundant genus with Bifidobacterium longum the most abundant species, with higher abundance in breast-fed infants. Most infants had detectable pathogenic taxa, with Shigella and Klebsiella more abundant in infants with recent diarrhoeal illness. Neither antibiotics nor infant growth were associated with gut microbiota composition. Genomic analysis of isolates showed gene clusters encoding the ability to digest human milk oligosaccharides in B. longum and B. breve isolates. Antibiotic-resistant genes were present in both potentially pathogenic species and in Bifidobacterium. Faecal concentrations of Interlukin-1alpha and vascular endothelial growth factor were higher in breast-fed infants. This study provides insights into an underrepresented population of rural Cambodian infants, showing pathogen exposure and breastfeeding impact gut microbiota composition and faecal immune profiles.


Assuntos
Bifidobacterium , Citocinas , Diarreia , Fezes , Microbioma Gastrointestinal , RNA Ribossômico 16S , População Rural , Humanos , Fezes/microbiologia , Lactente , Camboja , Citocinas/metabolismo , RNA Ribossômico 16S/genética , Feminino , Masculino , Diarreia/microbiologia , Bifidobacterium/genética , Bifidobacterium/isolamento & purificação , Dieta , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Shigella/genética , Shigella/isolamento & purificação , Bacteroides/genética , Bacteroides/isolamento & purificação , Klebsiella/genética , Klebsiella/isolamento & purificação , Aleitamento Materno , DNA Bacteriano/genética , Sequenciamento Completo do Genoma , Leite Humano/microbiologia , Leite Humano/química
8.
Nat Commun ; 14(1): 1349, 2023 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-36906612

RESUMO

Preterm infants with very low birthweight are at serious risk for necrotizing enterocolitis. To functionally analyse the principles of three successful preventive NEC regimens, we characterize fecal samples of 55 infants (<1500 g, n = 383, female = 22) longitudinally (two weeks) with respect to gut microbiome profiles (bacteria, archaea, fungi, viruses; targeted 16S rRNA gene sequencing and shotgun metagenomics), microbial function, virulence factors, antibiotic resistances and metabolic profiles, including human milk oligosaccharides (HMOs) and short-chain fatty acids (German Registry of Clinical Trials, No.: DRKS00009290). Regimens including probiotic Bifidobacterium longum subsp. infantis NCDO 2203 supplementation affect microbiome development globally, pointing toward the genomic potential to convert HMOs. Engraftment of NCDO 2203 is associated with a substantial reduction of microbiome-associated antibiotic resistance as compared to regimens using probiotic Lactobacillus rhamnosus LCR 35 or no supplementation. Crucially, the beneficial effects of Bifidobacterium longum subsp. infantis NCDO 2203 supplementation depends on simultaneous feeding with HMOs. We demonstrate that preventive regimens have the highest impact on development and maturation of the gastrointestinal microbiome, enabling the establishment of a resilient microbial ecosystem that reduces pathogenic threats in at-risk preterm infants.


Assuntos
Microbioma Gastrointestinal , Recém-Nascido Prematuro , Lactente , Recém-Nascido , Humanos , Feminino , RNA Ribossômico 16S/genética , Ecossistema , Intestinos , Fezes/microbiologia , Bifidobacterium longum subspecies infantis/genética
9.
Microb Genom ; 9(7)2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37428148

RESUMO

The human skin microbiome represents a variety of complex microbial ecosystems that play a key role in host health. Molecular methods to study these communities have been developed but have been largely limited to low-throughput quantification and short amplicon-based sequencing, providing limited functional information about the communities present. Shotgun metagenomic sequencing has emerged as a preferred method for microbiome studies as it provides more comprehensive information about the species/strains present in a niche and the genes they encode. However, the relatively low bacterial biomass of skin, in comparison to other areas such as the gut microbiome, makes obtaining sufficient DNA for shotgun metagenomic sequencing challenging. Here we describe an optimised high-throughput method for extraction of high molecular weight DNA suitable for shotgun metagenomic sequencing. We validated the performance of the extraction method, and analysis pipeline on skin swabs collected from both adults and babies. The pipeline effectively characterised the bacterial skin microbiota with a cost and throughput suitable for larger longitudinal sets of samples. Application of this method will allow greater insights into community compositions and functional capabilities of the skin microbiome.


Assuntos
Metagenômica , Microbiota , Adulto , Humanos , DNA Bacteriano/genética , Metagenômica/métodos , Peso Molecular , Análise de Sequência de DNA/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , RNA Ribossômico 16S/genética , Bactérias/genética , Microbiota/genética , DNA
10.
Nat Microbiol ; 8(6): 1160-1175, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37231089

RESUMO

Clostridium perfringens is an anaerobic toxin-producing bacterium associated with intestinal diseases, particularly in neonatal humans and animals. Infant gut microbiome studies have recently indicated a link between C. perfringens and the preterm infant disease necrotizing enterocolitis (NEC), with specific NEC cases associated with overabundant C. perfringens termed C. perfringens-associated NEC (CPA-NEC). In the present study, we carried out whole-genome sequencing of 272 C. perfringens isolates from 70 infants across 5 hospitals in the United Kingdom. In this retrospective analysis, we performed in-depth genomic analyses (virulence profiling, strain tracking and plasmid analysis) and experimentally characterized pathogenic traits of 31 strains, including 4 from CPA-NEC patients. We found that the gene encoding toxin perfringolysin O, pfoA, was largely deficient in a human-derived hypovirulent lineage, as well as certain colonization factors, in contrast to typical pfoA-encoding virulent lineages. We determined that infant-associated pfoA+ strains caused significantly more cellular damage than pfoA- strains in vitro, and further confirmed this virulence trait in vivo using an oral-challenge C57BL/6 murine model. These findings suggest both the importance of pfoA+ C. perfringens as a gut pathogen in preterm infants and areas for further investigation, including potential intervention and therapeutic strategies.


Assuntos
Clostridium perfringens , Doenças do Recém-Nascido , Lactente , Recém-Nascido , Humanos , Animais , Camundongos , Clostridium perfringens/genética , Recém-Nascido Prematuro , Estudos Retrospectivos , Virulência/genética , Genômica
11.
iScience ; 23(7): 101336, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32683312

RESUMO

The underlying health-driving mechanisms of Bifidobacterium during early life are not well understood, particularly how this microbiota member may modulate the intestinal barrier via programming of intestinal epithelial cells (IECs). We investigated the impact of Bifidobacterium breve UCC2003 on the transcriptome of neonatal murine IECs. Small IECs from two-week-old neonatal mice administered B. breve UCC2003 or PBS (control) were subjected to global RNA sequencing, and differentially expressed genes, pathways, and affected cell types were determined. We observed extensive regulation of the IEC transcriptome with ∼4,000 genes significantly up-regulated, including key genes linked with epithelial barrier function. Enrichment of cell differentiation pathways was observed, along with an overrepresentation of stem cell marker genes, indicating an increase in the regenerative potential of the epithelial layer. In conclusion, B. breve UCC2003 plays a central role in driving intestinal epithelium homeostatic development during early life and suggests future avenues for next-stage clinical studies.

12.
Cell Rep Med ; 1(5): 100077, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32904427

RESUMO

Supplementation with members of the early-life microbiota as "probiotics" is increasingly used in attempts to beneficially manipulate the preterm infant gut microbiota. We performed a large observational longitudinal study comprising two preterm groups: 101 infants orally supplemented with Bifidobacterium and Lactobacillus (Bif/Lacto) and 133 infants non-supplemented (control) matched by age, sex, and delivery method. 16S rRNA gene profiling on fecal samples (n = 592) showed a predominance of Bifidobacterium and a lower abundance of pathobionts in the Bif/Lacto group. Metabolomic analysis showed higher fecal acetate and lactate and a lower fecal pH in the Bif/Lacto group compared to the control group. Fecal acetate positively correlated with relative abundance of Bifidobacterium, consistent with the ability of the supplemented Bifidobacterium strain to metabolize human milk oligosaccharides into acetate. This study demonstrates that microbiota supplementation is associated with a Bifidobacterium-dominated preterm microbiota and gastrointestinal environment more closely resembling that of full-term infants.


Assuntos
Bifidobacterium/fisiologia , Microbioma Gastrointestinal/fisiologia , Recém-Nascido Prematuro/metabolismo , Recém-Nascido Prematuro/fisiologia , Lactobacillus/fisiologia , Metaboloma/fisiologia , Bifidobacterium/genética , Aleitamento Materno/métodos , Suplementos Nutricionais/microbiologia , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Humanos , Lactente , Recém-Nascido , Lactobacillus/genética , Estudos Longitudinais , Leite Humano/microbiologia , Probióticos/administração & dosagem , RNA Ribossômico 16S/genética
13.
Anim Microbiome ; 1: 12, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-32021965

RESUMO

BACKGROUND: Clostridium perfringens is a key pathogen in poultry-associated necrotic enteritis (NE). To date there are limited Whole Genome Sequencing based studies describing broiler-associated C. perfringens in healthy and diseased birds. Moreover, changes in the caecal microbiome during NE is currently not well characterised. Thus, the aim of this present study was to investigate C. perfringens virulence factors linked to health and diseased chickens, including identifying putative caecal microbiota signatures associated with NE. RESULTS: We analysed 88 broiler chicken C. perfringens genomes (representing 66 publicly available genomes and 22 newly sequenced genomes) using different phylogenomics approaches and identified a potential hypervirulent and globally-distributed clone spanning 20-year time-frame (1993-2013). These isolates harbored a greater number of virulence genes (including toxin and collagen adhesin genes) when compared to other isolates. Further genomic analysis indicated exclusive and overabundant presence of important NE-linked toxin genes including netB and tpeL in NE-associated broiler isolates. Secondary virulence genes including pfoA, cpb2, and collagen adhesin genes cna, cnaA and cnaD were also enriched in the NE-linked C. perfringens genomes. Moreover, an environmental isolate obtained from farm animal feeds was found to encode netB, suggesting potential reservoirs of NetB-positive C. perfringens strains (toxinotype G). We also analysed caecal samples from a small sub-set of 11 diseased and healthy broilers for exploratory microbiome investigation using 16S rRNA amplicon sequencing, which indicated a significant and positive correlation in genus Clostridium within the wider microbiota of those broilers diagnosed with NE, alongside reductions in beneficial microbiota members. CONCLUSIONS: These data indicate a positive association of virulence genes including netB, pfoA, cpb2, tpeL and cna variants linked to NE-linked isolates. Potential global dissemination of specific hypervirulent lineage, coupled with distinctive microbiome profiles, highlights the need for further investigations, which will require a large worldwide sample collection from healthy and NE-associated birds.

14.
Microb Genom ; 5(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31553300

RESUMO

Clostridium perfringens is a major enteric pathogen known to cause gastroenteritis in human adults. Although major outbreak cases are frequently reported, only limited whole-genome sequencing (WGS) based studies have been performed to understand the genomic epidemiology and virulence gene content of outbreak-associated C. perfringens strains. We performed phylogenomic analysis on 109 C. perfringens isolates (human and food) obtained from disease cases in England and Wales between 2011 and 2017. Initial findings highlighted the enhanced discriminatory power of WGS in profiling outbreak C. perfringens strains, when compared to the current Public Health England referencing laboratory technique of fluorescent amplified fragment length polymorphism analysis. Further analysis identified that isogenic C. perfringens strains were associated with nine distinct care-home-associated outbreaks over the course of a 5-year interval, indicating a potential common source linked to these outbreaks or transmission over time and space. As expected, the enterotoxin cpe gene was encoded in all but 4 isolates (96.3 %; 105/109), with virulence plasmids encoding cpe (particularly pCPF5603 and pCPF4969 plasmids) extensively distributed (82.6 %; 90/109). Genes encoding accessory virulence factors, such as beta-2 toxin, were commonly detected (46.7 %; 51/109), and genes encoding phage proteins were also frequently identified. Overall, this large-scale genomic study of gastroenteritis-associated C. perfringens suggested that three major cpe-encoding (toxinotype F) genotypes underlie these outbreaks: strains carrying (1) pCPF5603 plasmid, (2) pCPF4969 plasmid and (3) chromosomal-cpe strains. Our findings substantially expanded our knowledge on type F C. perfringens involved in human-associated gastroenteritis, with further studies required to fully probe the dissemination and regional reservoirs of this enteric pathogen, which may help devise effective prevention strategies to reduce the food-poisoning disease burden in vulnerable patients, such as the elderly.


Assuntos
Clostridium perfringens , Enterotoxinas/genética , Microbiologia de Alimentos , Gastroenterite , Cromossomos Bacterianos/genética , Clostridium perfringens/classificação , Clostridium perfringens/genética , Clostridium perfringens/patogenicidade , Surtos de Doenças , Inglaterra/epidemiologia , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Genes Bacterianos/genética , Humanos , Filogenia , Plasmídeos/genética , Virulência/genética , País de Gales/epidemiologia
15.
Toxins (Basel) ; 11(9)2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31546794

RESUMO

Clostridium perfringens toxinotype D, toxinotype E, and gastroenteritis-linked BEC/CPILE-positive strains have never been reported in healthy children. We isolated, whole-genome sequenced and bioinformatically characterised three C. perfringens isolates-type D (IQ1), type E (IQ2) and BEC/CPILE-positive (IQ3), recovered from the stools of three healthy two-year-olds, which were further compared to 128 C. perfringens genomes available from NCBI. The analysis uncovered a previously under-described putative toxin gene alv (alveolysin) encoded by isolates IQ2 and IQ3, which appeared to be a clade-specific trait associated with strains from domestic animals. A plasmid analysis indicated that the iota-toxin was encoded on a near-intact previously described plasmid pCPPB-1 in type E strain IQ2. The BEC genes becA and becB were carried on a near-identical pCPOS-1 plasmid previously associated with Japanese gastroenteritis outbreaks. Furthermore, a close phylogenetic relatedness was inferred between the French C. perfringens type E isolates cp515.17 and newly sequenced IQ2, suggesting geographical links. This study describes novel C. perfringens isolates from healthy individuals which encode important toxin genes, indicating the potential spread of these veterinary and clinically important strains and mobile genetic elements, and highlights areas for future research.


Assuntos
Clostridium perfringens/genética , Fezes/microbiologia , Toxinas Bacterianas/genética , Sequência de Bases , Pré-Escolar , Infecções por Clostridium/microbiologia , Clostridium perfringens/isolamento & purificação , Genômica , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único
16.
Emerg Microbes Infect ; 7(1): 141, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30082713

RESUMO

Clostridium perfringens, a rapid-growing pathogen known to secrete an arsenal of >20 virulent toxins, has been associated with intestinal diseases in both animals and humans throughout the past century. Recent advances in genomic analysis and experimental systems make it timely to re-visit this clinically and veterinary important pathogen. This Review will summarise our understanding of the genomics and virulence-linked factors, including antimicrobial potentials and secreted toxins of this gut pathogen, and then its up-to-date clinical epidemiology and biological role in the pathogenesis of several important human and animal-associated intestinal diseases, including pre-term necrotising enterocolitis. Finally, we highlight some of the important unresolved questions in relation to C. perfringens-mediated infections, and implications for future research directions.


Assuntos
Infecções por Clostridium/microbiologia , Clostridium perfringens/fisiologia , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Clostridium perfringens/genética , Clostridium perfringens/patogenicidade , Humanos , Virulência
17.
Front Microbiol ; 8: 2485, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29312194

RESUMO

Clostridium perfringens is an important cause of animal and human infections, however information about the genetic makeup of this pathogenic bacterium is currently limited. In this study, we sought to understand and characterise the genomic variation, pangenomic diversity, and key virulence traits of 56 C. perfringens strains which included 51 public, and 5 newly sequenced and annotated genomes using Whole Genome Sequencing. Our investigation revealed that C. perfringens has an "open" pangenome comprising 11667 genes and 12.6% of core genes, identified as the most divergent single-species Gram-positive bacterial pangenome currently reported. Our computational analyses also defined C. perfringens phylogeny (16S rRNA gene) in relation to some 25 Clostridium species, with C. baratii and C. sardiniense determined to be the closest relatives. Profiling virulence-associated factors confirmed presence of well-characterised C. perfringens-associated exotoxins genes including α-toxin (plc), enterotoxin (cpe), and Perfringolysin O (pfo or pfoA), although interestingly there did not appear to be a close correlation with encoded toxin type and disease phenotype. Furthermore, genomic analysis indicated significant horizontal gene transfer events as defined by presence of prophage genomes, and notably absence of CRISPR defence systems in >70% (40/56) of the strains. In relation to antimicrobial resistance mechanisms, tetracycline resistance genes (tet) and anti-defensins genes (mprF) were consistently detected in silico (tet: 75%; mprF: 100%). However, pre-antibiotic era strain genomes did not encode for tet, thus implying antimicrobial selective pressures in C. perfringens evolutionary history over the past 80 years. This study provides new genomic understanding of this genetically divergent multi-host bacterium, and further expands our knowledge on this medically and veterinary important pathogen.

18.
Genome Biol Evol ; 9(10): 2707-2714, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29044436

RESUMO

Clostridium species (particularly Clostridium difficile, Clostridium botulinum, Clostridium tetani and Clostridium perfringens) are associated with a range of human and animal diseases. Several other species including Clostridium tertium, Clostridium cadaveris, and Clostridium paraputrificum have also been linked with sporadic human infections, however there is very limited, or in some cases, no genomic information publicly available. Thus, we isolated one C. tertium strain, one C. cadaveris strain and three C. paraputrificum strains from preterm infants residing within neonatal intensive care units and performed Whole Genome Sequencing (WGS) using Illumina HiSeq. In this report, we announce the open availability of the draft genomes: C. tertium LH009, C. cadaveris LH052, C. paraputrificum LH025, C. paraputrificum LH058, and C. paraputrificum LH141. These genomes were checked for contamination in silico to ensure purity, and we confirmed species identity and phylogeny using both 16S rRNA gene sequences (from PCR and in silico) and WGS-based approaches. Average Nucleotide Identity (ANI) was used to differentiate genomes from their closest relatives to further confirm speciation boundaries. We also analysed the genomes for virulence-related factors and antimicrobial resistance genes, and detected presence of tetracycline and methicillin resistance, and potentially harmful enzymes, including multiple phospholipases and toxins. The availability of genomic data in open databases, in tandem with our initial insights into the genomic content and virulence traits of these pathogenic Clostridium species, should enable the scientific community to further investigate the disease-causing mechanisms of these bacteria with a view to enhancing clinical diagnosis and treatment.


Assuntos
Clostridium tertium/classificação , Clostridium tertium/genética , Clostridium/classificação , Clostridium/genética , Clostridium/isolamento & purificação , Clostridium/patogenicidade , Clostridium tertium/isolamento & purificação , Clostridium tertium/patogenicidade , Fezes/microbiologia , Genoma Bacteriano , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Filogenia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA