Within-host diversity of MRSA antimicrobial resistances (AMR)
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Project description:ObjectivesMRSA is a major antimicrobial resistance (AMR) pathogen. The reservoir of infecting isolates is colonization, which is the site of evolutionary selection. The aim was to identify if AMRs in colonizing MRSA populations diversified and potential mechanisms of resistance gene transfer in vivo.MethodsNasal swabs from 38 MRSA carriers admitted to hospital were plated and 20 individual colonies from each patient tested for phenotypic antibiotic susceptibility and genetically for lineage, carriage of four prophages and three plasmid families. Free bacteriophages were detected in swabs as well as their capacity for transducing resistance genes.ResultsNine (24%) patients carried phenotypic AMR variants and 24 (63%) carried prophage and plasmid variants. If a single colony was selected for testing, the probability of detecting all AMR in that patient was 87%. Sixty-four different AMR and mobile genetic element (MGE) profiles were detected, mostly in the MRSA CC22 background (where CC stands for clonal complex), with up to 8 profiles per patient. Nearly half of the patients carried detectable free bacteriophages and phages successfully transduced resistance genes between laboratory and patient isolates in vitro. WGS showed MRSA core genomes were stable, while AMR and MGEs varied.Conclusions'Clouds' of MRSA variants that have acquired or lost AMR and MGEs are common in nasal colonizing populations and bacteriophages may play an important role in gene transfer. Accurate estimation of AMR and genetic variability has implications for diagnostics, epidemiology, antimicrobial stewardship and understanding the evolutionary selection of AMR in colonizing populations.
| S-EPMC4500776 | biostudies-literature
Project description:Antimicrobial resistance (AMR) is an increasing challenge for therapy and management of bacterial infections. Currently, antimicrobial resistance detection relies on phenotypic assays, which are performed independently of species identification. On the contrary, phenotypic prediction from molecular data using genomics is gaining interest in clinical microbiology and might become a serious alternative in the future. Although, in general protein analysis should be superior to genomics for phenotypic prediction, no untargeted proteomics workflow specifically related to AMR detection has been proposed so far. In this study, we present a universal proteomics workflow to detect the bacterial species and antimicrobial resistance related proteins in the absence of secondary antibiotic cultivation in less than 4 h from a primary culture. The method was validated using a sample cohort of 7 bacterial species and 11 AMR determinants represented by 13 protein isoforms which resulted in a sensitivity of 92 % (100 % with vancomycin inference) and a specificity of 100 % with respect to AMR determinants. This proof-of concept study demonstrates the high potential of untargeted proteomics for clinical microbiology.
2021-11-25 | PXD022425 | Pride
Project description:Glycoproteomics is likely to identify Mtb virulence factors because glycoproteins on the bacterial cell envelope are used by mycobacteria to enter the primary human host cell, the macrophage. It has been proposed that Mtb interacts with mannose receptors on host cells via mannosylated proteins to enter the macrophages. Despite the vital importance of these proteins in Mtb pathogenesis, our current knowledge of Mtb glycoproteins is still limited, and only a few secreted and cell wall-associated glycoproteins have to date been described. Previous studies have used laboratory strains as model systems to study glycosylation in Mtb. However, only a few sub-groups within the genetically conserved MTBC appear to cause extensive outbreaks with different clinical presentation and AMR. In this study, we employed qualitative and quantitative mass spectrometry and bioinformatics to explore the glycoproteomic patterns of clinical isolates from four lineages of the MTBC, lineages 3, 4, 5 and 7, to investigate the role of protein glycosylation in Mtb adaptation, survival and AMR.
2019-03-25 | PXD009676 | Pride
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) transmission in the hospital setting has been a frequent subject of investigation using bacterial genomes, but previous approaches have not yet fully utilised the extra deductive power provided when multiple pathogen samples are acquired from each host. Here, we used a large dataset of MRSA sequences from multiply-sampled patients to reconstruct colonisation of individuals in a high-transmission setting in a hospital in Thailand. We reconstructed transmission trees for MRSA. We also investigated transmission between anatomical sites on the same individual, finding that this either occurs repeatedly or involves a wide transmission bottleneck. We examined the between-subject bottleneck, finding considerable variation in the amount of diversity transmitted. Finally, we compared our approach to the simpler method of identifying transmission pairs using single nucleotide polymorphism (SNP) counts. This suggested that the optimum threshold for identifying a pair is 39 SNPs, if sensitivities and specificities are equally weighted.
| S-EPMC6954020 | biostudies-literature
Project description:HEK293T cells were transfected with the Rbp1-amr or slow (R729H-amr) α-amanitin resistant subunit of RNA Pol II and selected with α-amanitin 24 hours after transfection for additional 24 hours. Total RNA was extracted and global changes in gene expression were determined using microarray chips. MiRNAs are transcribed by RNA pol II but the transcriptional features influencing their synthesis are poorly defined. Here we report that a TATA-box in miRNA and a subset of protein-coding genes is associated with increased sensitivity to a slow rate of transcription elongation. We also show that promoters driven by TATA-box or NF-κB elicit high transcription re-initiation rate, but paradoxically lower levels of miRNA. Interestingly, miRNA synthesis was converted to a more productive mode by decreasing initiation rate, but less productive when the re-initiation rate increased. This phenomenon was found to be associated with a delay in miR-146a induction by NF-κB. We also demonstrate that miRNAs are remarkably strong pause sites. Our findings suggest that lower efficiency of miRNA synthesis directed by the TATA-box or NF-κB is a consequence of frequent transcription initiation that lead to Pol II crowding at pause sites, thereby increasing the chance of collision and premature termination. These findings highlight the importance of the transcription initiation mechanism for miRNA synthesis, and have implications for TATA-box promoters in general. HEK293T cells were transfected with plasmids directing the expression of α-amanitin-resistant variants of Pol II (Rpb1-amr and R749H-amr). α-amanitin was added and RNA was prepared 24 and 48 h later, respectively. The data provided is from 3 Rpb1-amr vs 3 R749H-amr (6 samples).
2013-07-01 | E-GEOD-48163 | biostudies-arrayexpress
Project description:Antimicrobial resistance (AMR) is one of the major challenges that humans are facing this century. Understanding the mechanisms behind the rise of AMR is crucial to tackle this global threat. Among the triggers of phenotypic antimicrobial resistance, the contribution of transition metals has been understudied in Mycobacterium abscessus (Mabs), a fast-growing non-tuberculous mycobacterium known for its extreme AMR levels. Deeper understanding of the effects of transition metal ions will be beneficial for our knowledge in AMR and the discovery of potential therapeutic targets. Here, we investigated the impact of transition metal ions, nickel, cobalt and copper on the physiology and drug susceptibility of Mabs.
2024-09-13 | GSE243031 | GEO
Project description:Effect of two different antimicrobial materials, functionalized graphene oxide (GOX), and AGXX® coated on cellulose fibers, on the growth and transcriptome of the clinical MRSA strain S. aureus 04-02981. In addition, we investigated the effect of a third material as a combination of GOX and AGXX® fibers on S. aureus 04-02981
2020-04-22 | GSE149013 | GEO
Project description:Herein, we used C. acnes as a model to elucidate the antimicrobial machinery of the TH17 subset. We generated C. acnes-specific antimicrobial TH17 clones (AMTH17) with varying antimicrobial activity against C. acnes, to enable us to study mechanisms by which TH17 cells kill bacteria. We show that C. acnes-induced AMTH17 clones represent a subset of CD4+ TEM and TEMRA cells. RNA-seq analysis of AMTH17 indicate transcripts encoding antimicrobial molecules such as GNLY, GZMB, PRF1 and histone H2B, whose expression correlates with killing activity. Additionally, we validated that AMTH17-mediated killing is a general mechanism that can target C. acnes and other bacterial species. Scanning electron microscopy reveal that AMTH17s can release T cell extracellular traps composed of lysine and arginine-rich histones such as H2B and H4 that entangle C. acnes. This study identifies a functionally distinct subpopulation of TH17 cells with an ability to secrete antimicrobial proteins and form extracellular T cell traps to capture and kill bacteria.
2021-12-01 | GSE144852 | GEO