Project description:<p><strong>Background</strong></p><p>Antibiotic treatment has a well-established detrimental effect on the gut bacterial composition, but effects on the fungal community are less clear. Bacteria in the lumen of the gastrointestinal tract may limit fungal colonization and invasion. Antibiotic drugs targeting bacteria are therefore seen as an important risk factor for fungal infections and induced allergies. However, antibiotic effects on gut bacterial-fungal interactions, including disruption and resilience of fungal community compositions, were not investigated in humans. We analysed stool samples collected from 14 healthy human participants over three months following a 6-day antibiotic administration. We integrated data from shotgun metagenomics, metatranscriptomics, metabolomics, and fungal ITS2 sequencing. </p><p><strong>Results</strong></p><p>While the bacterial community recovered mostly over three months post treatment, the fungal community was shifted from mutualism at baseline to competition. Half of the bacterial-fungal interactions present before drug intervention had disappeared three months later. During treatment, fungal abundances were associated with the expression of bacterial genes with functions for cell growth and repair. By extending the metagenomic species approach, we revealed bacterial strains inhibiting the opportunistic fungal pathogen Candida albicans. We demonstrate in vitro how C. albicans pathogenicity and host cell damage might be controlled naturally in the human gut by bacterial metabolites such as propionate or 5-dodecenoate.</p><p><strong>Conclusions</strong></p><p>We demonstrate that antibacterial drugs have long-term influence on the human gut mycobiome. While bacterial communities recovered mostly 30-days post antibacterial treatment, the fungal community was shifted from mutualism towards competition.</p><p><br></p><p><strong>Linked data:</strong></p><p>Metagenomics has been submitted to NCBI SRA repository as projects PRJNA573821, PRJNA573905 and PRJNA579284.</p>
Project description:Drosophila melanogaster larvae and filamentous fungi both utilise organic material. Here they compete for resources. Filamentous fungi can defend themselves and their substrate from predation respectively competition by the production and excretion of secondary metabolites, including substances with antibiotic and insecticidal properties. To analyse the traits that enables D. melanogaster larvae to reduce the harmful effects of fungal secondary metabolites and to develop on fungal infested substrate we confronted larvae with a toxin-producing wild type of Aspergillus nidulans, with a toxin-production-impaired mutant strain of A. nidulans, and with sterigmatocystin, a highly toxic metabolite of A. nidulans. Early first instar larvae were transferred to breeding substrate inhabited by fungal colonies respectively inoculated with the purified mycotoxin or controls. After 3, 6, 12, and 24 hours of confrontation larvae were collected and samples prepared for whole transcriptome shotgun sequencing.
Project description:Antibiotic resistance genes expressed in the upper respiratory tract of patients infected with influenza viruses were associated with the microbial community and microbial activities. Interactions between the host systemic responses to influenza infection and ARG expression highlight the importance of antibiotic resistance in viral-bacterial co-infection.
Project description:Antibiotic resistance genes expressed in the upper respiratory tract of patients infected with influenza viruses were associated with the microbial community and microbial activities. Interactions between the host systemic responses to influenza infection and ARG expression highlight the importance of antibiotic resistance in viral-bacterial co-infection.
Project description:Antibiotic resistance genes expressed in the upper respiratory tract of patients infected with influenza viruses were associated with the microbial community and microbial activities. Interactions between the host systemic responses to influenza infection and ARG expression highlight the importance of antibiotic resistance in viral-bacterial co-infection.
Project description:In a given bacterial population, antibiotic treatment kills a large portion of the population, while a small, tolerant subpopulation survives. Tolerant cells disrupt the efficacy of antibiotic treatment and increase the likelihood that a population gains antibiotic resistance. Antibiotic tolerance is different from resistance because tolerant cells cannot grow and replicate in the presence of the antibiotic, but when the antibiotic is removed, they begin to propagate. When a population becomes resistant, the antibiotic becomes ineffective, which is a major health concern. Since antibiotic tolerance often leads to antibiotic resistance, we have taken a systems biology approach to examine how regulatory networks respond to antibiotic stress so that cells can survive and recover after antibiotic treatment. We have compared gene expression with and without ampicillin in E. coli.
Project description:Protein post-translational modifications (PTMs) play crucial roles in various biological processes across prokaryotes and eukaryotes. Lysine acetylation (Kac), which is observed in different bacteria species and is known to be a dynamic and reversible PTM involved in numerous physiological functions. However, limited research has been conducted to explore the connection between Kac and bacterial antibiotic resistance. In this investigation, we employed advanced 4D label-free quantitative proteomics technology to examine the differential expression of Kac-modified proteins in Staphylococcus aureus strains: one susceptible to erythromycin (Ery-S) and another induced to be resistant (Ery-R). Our systematic analysis identified a total of 1808 acetylated proteins with 6791 specific Kac sites. Notably, we quantified 1907 of these sites across 483 proteins. A total of 548 Kac sites were affected by erythromycin pressure on 316 acetylated proteins. Functional analyses uncovered a notable presence of differentially acetylated proteins (DAPs) within pathways associated with ribosome assembly, glycolysis, and lysine biosynthesis. Moreover, our findings indicate a significant acetylation of ribosomal proteins in antibiotic-resistant strains, implying a potential regulatory role of this modification in translation processes. Further investigations using polysome profiling experiments revealed that Kac modification of ribosomal and ribosome-associated proteins can maintain translation in response to antibiotic stress. Our data provides support for the link between protein lysine acetylation and bacterial antibiotic resistance, highlighting the potential involvement of ribosome translation. These findings collectively unveil a novel mechanism that enhances our understanding of bacterial antibiotic resistance and offer valuable insights for the development of antibiotic treatment strategies.
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:Co-occurrence of fungicide and antibiotic enhances toxicity, alters bacterial communities, and increases antibiotic resistance
Project description:Bacterial evolution of antibiotic resistance frequently has deleterious side effects on microbial growth, virulence, and susceptibility to other antimicrobial agents. However, it is unclear how these trade-offs could be utilized for manipulating antibiotic resistance in the clinic, not least because the underlying molecular mechanisms are poorly understood. Using laboratory evolution, we demonstrate that clinically relevant resistance mutations in Escherichia coli constitutively rewire a large fraction of the transcriptome in a repeatable and stereotypic manner. Strikingly, lineages adapted to functionally distinct antibiotics and having no resistance mutations in common show a wide range of parallel gene expression changes that alter oxidative stress response, iron homeostasis, and the composition of the bacterial outer membrane and cell surface. These common physiological alterations are associated with changes in cell morphology and enhanced sensitivity to antimicrobial peptides. Finally, the constitutive transcriptomic changes induced by resistance mutations are largely distinct from those induced by antibiotic stresses in the wild-type. This indicates a limited role for genetic assimilation of the induced antibiotic stress response during resistance evolution. Our work suggests that diverse resistance mutations converge on similar global transcriptomic states that shape genetic susceptibility to antimicrobial compounds.