Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 6 de 6
Filtrer
Plus de filtres










Base de données
Gamme d'année
1.
Infect Immun ; 92(6): e0010324, 2024 Jun 11.
Article de Anglais | MEDLINE | ID: mdl-38722168

RÉSUMÉ

Candida auris is an opportunistic fungal pathogen with high mortality rates which presents a clear threat to public health. The risk of C. auris infection is high because it can colonize the body, resist antifungal treatment, and evade the immune system. The genetic mechanisms for these traits are not well known. Identifying them could lead to new targets for new treatments. To this end, we present an analysis of the genetics and gene expression patterns of C. auris carbon metabolism, drug resistance, and macrophage interaction. We chose to study two C. auris isolates simultaneously, one drug sensitive (B11220 from Clade II) and one drug resistant (B11221 from Clade III). Comparing the genomes, we confirm the previously reported finding that B11220 was missing a 12.8 kb region on chromosome VI. This region contains a gene cluster encoding proteins related to alternative sugar utilization. We show that B11221, which has the gene cluster, readily assimilates and utilizes D-galactose and L-rhamnose as compared to B11220, which harbors the deletion. B11221 exhibits increased adherence and drug resistance compared to B11220 when grown in these sugars. Transcriptomic analysis of both isolates grown on glucose or galactose showed that the gene cluster was upregulated when grown on D-galactose. These findings reinforce growing evidence of a link between metabolism and drug tolerance. B11221 resists phagocytosis by macrophages and exhibits decreased ß-1,3-glucan exposure, a key determinant that allows Candida to evade the host immune system, as compared to B11220. In a transcriptomic analysis of both isolates co-cultured with macrophages, we find upregulation of genes associated with transport and transcription factors in B11221. Our studies show a positive correlation between membrane composition and immune evasion, alternate sugar utilization, and drug tolerance in C. auris.


Sujet(s)
Antifongiques , Candida auris , Virulence/génétique , Candida auris/génétique , Candida auris/effets des médicaments et des substances chimiques , Antifongiques/pharmacologie , Candidose/microbiologie , Candidose/immunologie , Résistance des champignons aux médicaments/génétique , Génome fongique , Humains , Macrophages/microbiologie , Macrophages/immunologie , Régulation de l'expression des gènes fongiques , Analyse de profil d'expression de gènes , Animaux
2.
J Ind Microbiol Biotechnol ; 47(11): 1005-1018, 2020 Nov.
Article de Anglais | MEDLINE | ID: mdl-33098066

RÉSUMÉ

Organic farming has become more prevalent in recent years as consumer demand for organic food and fiber has rapidly grown. Until recently, organic fertilizers and soil amendments have largely been based on the practices of returning crop residues, manures and related agricultural wastes back to crop production areas. One rapidly growing segment in commercial organic fertilizer development is the use of spent microbial biomass (SMB) from industrial fermentation processes. While SMB is widely accepted in many organic farming systems (OFS), little is known concerning the effectiveness, environmental impact, and influence on prokaryotic communities in soils receiving this treatment. In this study, a comparative analysis of bacterial communities associated with OFS and conventional farming systems was performed over a growing season for a field containing yellow dent corn (Zea mays). A statistically significant increase in microbial population α-diversity, along with a strong recruitment of Proteobacteria and Actinobacteria populations, was observed in soils treated with SMB when compared to areas in the field that utilized conventional farmer practices. These phyla are members of the copiotrophic subgroup, and considered a signature for the use of traditional organic fertilizers. These results provide valuable new information that SMB functions similarly to traditional organic fertilizers in promoting a high level of functional prokaryotic diversity and plant growth-promoting bacteria, but in contrast do not contribute directly to viable microorganisms in the soil due to the sterilization of SMB prior to land application.


Sujet(s)
Fermentation , Agriculture biologique , Microbiologie du sol , Actinobacteria , Agriculture/méthodes , Bactéries , Biomasse , Engrais/analyse , Fumier , Proteobacteria , Sol/composition chimique , Zea mays
3.
PLoS One ; 11(2): e0147707, 2016.
Article de Anglais | MEDLINE | ID: mdl-26845332

RÉSUMÉ

Adaptation is key for survival as vector-borne pathogens transmit between the arthropod and vertebrate, and temperature change is an environmental signal inducing alterations in gene expression of tick-borne spirochetes. While plasmids are often associated with adaptation, complex genomes of relapsing fever spirochetes have hindered progress in understanding the mechanisms of vector colonization and transmission. We utilized recent advances in genome sequencing to generate the most complete version of the Borrelia turicatae 150 kb linear megaplasmid (lp150). Additionally, a transcriptional analysis of open reading frames (ORFs) in lp150 was conducted and identified regions that were up-regulated during in vitro cultivation at tick-like growth temperatures (22°C), relative to bacteria grown at 35°C and infected murine blood. Evaluation of the 3' end of lp150 identified a cluster of ORFs that code for putative surface lipoproteins. With a microbe's surface proteome serving important roles in pathogenesis, we confirmed the ORFs expression in vitro and in the tick compared to spirochetes infecting murine blood. Transcriptional evaluation of lp150 indicates the plasmid likely has essential roles in vector colonization and/or initiating mammalian infection. These results also provide a much needed transcriptional framework to delineate the molecular mechanisms utilized by relapsing fever spirochetes during their enzootic cycle.


Sujet(s)
Borrelia/génétique , Vecteurs de maladies , Plasmides/génétique , Transcriptome , Animaux , Biologie informatique/méthodes , Cartographie de contigs , Modèles animaux de maladie humaine , Expression des gènes , Analyse de profil d'expression de gènes , Ordre des gènes , Maladie de Lyme/microbiologie , Souris , Annotation de séquence moléculaire , Cadres ouverts de lecture , Tiques/microbiologie
4.
FEMS Microbiol Lett ; 362(5)2015 Mar.
Article de Anglais | MEDLINE | ID: mdl-25743074

RÉSUMÉ

We sequenced and analyzed Shigella dysenteriae strain Sd1617 serotype 1 that is widely used as model strain for vaccine design, trials and research. A combination of next-generation sequencing platforms and assembly yielded two contigs representing a chromosome size of 4.34 Mb and the large virulence plasmid of 177 kb. This genome sequence is compared with other Shigella genomes in order to understand gene complexity and pathogenic factors.


Sujet(s)
Génome bactérien , Shigella dysenteriae/génétique , Shigella dysenteriae/pathogénicité , Virulence/génétique , Séquence nucléotidique , Cartographie chromosomique , Gènes bactériens , Données de séquences moléculaires , Plasmides , Shigella/génétique
5.
Genome Announc ; 2(5)2014 Sep 18.
Article de Anglais | MEDLINE | ID: mdl-25237017

RÉSUMÉ

The genome sequence of Flavobacterium psychrophilum strain CSF259-93, isolated from rainbow trout (Oncorhynchus mykiss), consists of a single circular genome of 2,900,735 bp and 2,701 predicted open reading frames (ORFs). Strain CSF259-93 has been used to select a line of rainbow trout with increased genetic resistance against bacterial cold water disease.

6.
Genome Announc ; 2(2)2014 Mar 27.
Article de Anglais | MEDLINE | ID: mdl-24675849

RÉSUMÉ

We report here the draft genome sequence of the novel homofermentative Enterococcus faecalis isolate CBRD01, which is capable of high lactic acid productivity and yields, with minimal nutritional requirements. The genome is 2.8 Mbp, with 37% G+C, and contains genes for two lactate dehydrogenase (LDH) enzymes found in related organisms.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE