Project description:This project shows that the use of antibiotics targeting gram-positive, anaerobic bacteria can improve patient's health by removing the main nutritional sources of classic pathogens. These antibiotics, traditionally not used in CF therapy, target anaerobes that efficiently degrade mucus providing metabolic products that feed and stimulate the expression of virulence factors in Pseudomonas. They work as keystone groups sustaining the stability of the entire microbial community, and their control drives a decrease in Pseudomonas abundance and virulence.
Project description:<p>The study of antimicrobial resistance (AMR) in infectious diarrhea has generally been limited to cultivation, antimicrobial susceptibility testing and targeted PCR assays. When individual strains of significance are identified, whole genome shotgun (WGS) sequencing of important clones and clades is performed. Genes that encode resistance to antibiotics have been detected in environmental, insect, human and animal metagenomes and are known as "resistomes". While metagenomic datasets have been mined to characterize the healthy human gut resistome in the Human Microbiome Project and MetaHIT and in a Yanomani Amerindian cohort, directed metagenomic sequencing has not been used to examine the epidemiology of AMR. Especially in developing countries where sanitation is poor, diarrhea and enteric pathogens likely serve to disseminate antibiotic resistance elements of clinical significance. Unregulated use of antibiotics further exacerbates the problem by selection for acquisition of resistance. This is exemplified by recent reports of multiple antibiotic resistance in Shigella strains in India, in Escherichia coli in India and Pakistan, and in nontyphoidal Salmonella (NTS) in South-East Asia. We propose to use deep metagenomic sequencing and genome level assembly to study the epidemiology of AMR in stools of children suffering from diarrhea. Here the epidemiology component will be surveillance and analysis of the microbial composition (to the bacterial species/strain level where possible) and its constituent antimicrobial resistance genetic elements (such as plasmids, integrons, transposons and other mobile genetic elements, or MGEs) in samples from a cohort where diarrhea is prevalent and antibiotic exposure is endemic. The goal will be to assess whether consortia of specific mobile antimicrobial resistance elements associate with species/strains and whether their presence is enhanced or amplified in diarrheal microbiomes and in the presence of antibiotic exposure. This work could potentially identify clonal complexes of organisms and MGEs with enhanced resistance and the potential to transfer this resistance to other enteric pathogens.</p> <p>We have performed WGS, metagenomic assembly and gene/protein mapping to examine and characterize the types of AMR genes and transfer elements (transposons, integrons, bacteriophage, plasmids) and their distribution in bacterial species and strains assembled from DNA isolated from diarrheal and non-diarrheal stools. The samples were acquired from a cohort of pediatric patients and controls from Colombia, South America where antibiotic use is prevalent. As a control, the distribution and abundance of AMR genes can be compared to published studies where resistome gene lists from healthy cohort sequences were compiled. Our approach is more epidemiologic in nature, as we plan to identify and catalogue antimicrobial elements on MGEs capable of spread through a local population and further we will, where possible, link mobile antimicrobial resistance elements with specific strains within the population.</p>
| phs001260 | dbGaP
Project description:Genomic epidemiology of antimicrobial resistance in bacteria
Project description:The overall goal of this investigation was to investigate X-content of sex-biased genes in several nematode species. The following species of nematode were investigated: *C. elegans, *N2; *C. brenneri, *PB2801; *C. briggsae, *AF16; *C. remanei*, PB4641; *P. **pacificus, *PS312*.* Genomic DNA sequencing data was used to assign X and autosomal - linkage to unassembled sequencing contigs. Male and female RNA seq data was then generated and used to determine sex-biased expression. For both DNA and RNA experiments, 50bp paired-end (DNA) or single-end (RNA) reads were generated on the Illumina HiSeq 2500. Sequencing lanes were multiplexed. Genomic DNA was isolated from 50-100 hand-picked young adult worms. At least two replicates for each sex were prepared. DNA was sheared via sonication and 350-500 bp sequencing libraries were prepared following the Illumina protocol. Total RNA was isolated from at least 1000 hand-picked L4/young adult worms (*C. **elegans, *N2) or J4/young adult worms (*P. pacificus, *PS312*). *PolyA beads were used to enrich for mRNA. Stranded RNAseq libraries were prepared via incorporation of dUTPs during cDNA synthesis, following the protocol detailed in Parkhomchuk et al, 2009. DNAseq and RNAseq reads were aligned to the appropriate WS228 reference genomes.
Project description:The overall goal of this investigation was to investigate X-content of sex-biased genes in several nematode species. The following species of nematode were investigated: *C. elegans, *N2; *C. brenneri, *PB2801; *C. briggsae, *AF16; *C. remanei*, PB4641; *P. **pacificus, *PS312*.* Genomic DNA sequencing data was used to assign X and autosomal - linkage to unassembled sequencing contigs. Male and female RNA seq data was then generated and used to determine sex-biased expression. For both DNA and RNA experiments, 50bp paired-end (DNA) or single-end (RNA) reads were generated on the Illumina HiSeq 2500. Sequencing lanes were multiplexed. Genomic DNA was isolated from 50-100 hand-picked young adult worms. At least two replicates for each sex were prepared. DNA was sheared via sonication and 350-500 bp sequencing libraries were prepared following the Illumina protocol. Total RNA was isolated from at least 1000 hand-picked L4/young adult worms (*C. **elegans, *N2) or J4/young adult worms (*P. pacificus, *PS312*). *PolyA beads were used to enrich for mRNA. Stranded RNAseq libraries were prepared via incorporation of dUTPs during cDNA synthesis, following the protocol detailed in Parkhomchuk et al, 2009. DNAseq and RNAseq reads were aligned to the appropriate WS228 reference genomes. DNA sequencing data (2-3 replicates) from male and female YA worms are included along with RNAseq data from C.elegans YA hermaphrodites and P.pacificus YA males and hermaphrodites.
Project description:Summary statistics for Malaria Genomic Epidemiology Network, "A novel locus of resistance to severe malaria in a region of ancient balancing selection", Nature (2015)
Project description:The human gut is colonized by trillions of microorganisms that influence human health and disease through the metabolism of xenobiotics, including therapeutic drugs and antibiotics. The diversity and metabolic potential of the human gut microbiome have been extensively characterized, but it remains unclear which microorganisms are active and which perturbations can influence this activity. Here, we use flow cytometry, 16S rRNA gene sequencing, and metatranscriptomics to demonstrate that the human gut contains distinctive subsets of active and damaged microorganisms, primarily composed of Firmicutes, which display marked temporal variation. Short-term exposure to a panel of xenobiotics resulted in significant changes in the physiology and gene expression of this active microbiome. Xenobiotic-responsive genes were found across multiple bacterial phyla, encoding novel candidate proteins for antibiotic resistance, drug metabolism, and stress response. These results demonstrate the power of moving beyond DNA-based measurements of microbial communities to better understand their physiology and metabolism. RNA-Seq analysis of the human gut microbiome during exposure to antibiotics and therapeutic drugs.