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519400.9763Evaluation of the CosmosID Bioinformatics Platform for Prosthetic Joint-Associated Sonicate Fluid Shotgun Metagenomic Data Analysis. We previously demonstrated that shotgun metagenomic sequencing can detect bacteria in sonicate fluid, providing a diagnosis of prosthetic joint infection (PJI). A limitation of the approach that we used is that data analysis was time-consuming and specialized bioinformatics expertise was required, both of which are barriers to routine clinical use. Fortunately, automated commercial analytic platforms that can interpret shotgun metagenomic data are emerging. In this study, we evaluated the CosmosID bioinformatics platform using shotgun metagenomic sequencing data derived from 408 sonicate fluid samples from our prior study with the goal of evaluating the platform vis-à-vis bacterial detection and antibiotic resistance gene detection for predicting staphylococcal antibacterial susceptibility. Samples were divided into a derivation set and a validation set, each consisting of 204 samples; results from the derivation set were used to establish cutoffs, which were then tested in the validation set for identifying pathogens and predicting staphylococcal antibacterial resistance. Metagenomic analysis detected bacteria in 94.8% (109/115) of sonicate fluid culture-positive PJIs and 37.8% (37/98) of sonicate fluid culture-negative PJIs. Metagenomic analysis showed sensitivities ranging from 65.7 to 85.0% for predicting staphylococcal antibacterial resistance. In conclusion, the CosmosID platform has the potential to provide fast, reliable bacterial detection and identification from metagenomic shotgun sequencing data derived from sonicate fluid for the diagnosis of PJI. Strategies for metagenomic detection of antibiotic resistance genes for predicting staphylococcal antibacterial resistance need further development.201930429253
477710.9758Identification of Bacterial Strains and Development of anmRNA-Based Vaccine to Combat Antibiotic Resistance in Staphylococcus aureus via In Vitro and In Silico Approaches. The emergence of antibiotic-resistant microorganisms is a significant concern in global health. Antibiotic resistance is attributed to various virulent factors and genetic elements. This study investigated the virulence factors of Staphylococcus aureus to create an mRNA-based vaccine that could help prevent antibiotic resistance. Distinct strains of the bacteria were selected for molecular identification of virulence genes, such as spa, fmhA, lukD, and hla-D, which were performed utilizing PCR techniques. DNA extraction from samples of Staphylococcus aureus was conducted using the Cetyl Trimethyl Ammonium Bromide (CTAB) method, which was confirmed and visualized using a gel doc; 16S rRNA was utilized to identify the bacterial strains, and primers of spa, lukD, fmhA, and hla-D genes were employed to identify the specific genes. Sequencing was carried out at Applied Bioscience International (ABI) in Malaysia. Phylogenetic analysis and alignment of the strains were subsequently constructed. We also performed an in silico analysis of the spa, fmhA, lukD, and hla-D genes to generate an antigen-specific vaccine. The virulence genes were translated into proteins, and a chimera was created using various linkers. The mRNA vaccine candidate was produced utilizing 18 epitopes, linkers, and an adjuvant, known as RpfE, to target the immune system. Testing determined that this design covered 90% of the population conservancy. An in silico immunological vaccine simulation was conducted to verify the hypothesis, including validating and predicting secondary and tertiary structures and molecular dynamics simulations to evaluate the vaccine's long-term viability. This vaccine design may be further evaluated through in vivo and in vitro testing to assess its efficacy.202337189657
907620.9758ResiDB: An automated database manager for sequence data. The amount of publicly available DNA sequence data is drastically increasing, making it a tedious task to create sequence databases necessary for the design of diagnostic assays. The selection of appropriate sequences is especially challenging in genes affected by frequent point mutations such as antibiotic resistance genes. To overcome this issue, we have designed the webtool resiDB, a rapid and user-friendly sequence database manager for bacteria, fungi, viruses, protozoa, invertebrates, plants, archaea, environmental and whole genome shotgun sequence data. It automatically identifies and curates sequence clusters to create custom sequence databases based on user-defined input sequences. A collection of helpful visualization tools gives the user the opportunity to easily access, evaluate, edit, and download the newly created database. Consequently, researchers do no longer have to manually manage sequence data retrieval, deal with hardware limitations, and run multiple independent software tools, each having its own requirements, input and output formats. Our tool was developed within the H2020 project FAPIC aiming to develop a single diagnostic assay targeting all sepsis-relevant pathogens and antibiotic resistance mechanisms. ResiDB is freely accessible to all users through https://residb.ait.ac.at/.202133495705
506830.9757Ultrasensitive Label-Free Detection of Unamplified Multidrug-Resistance Bacteria Genes with a Bimodal Waveguide Interferometric Biosensor. Infections by multidrug-resistant bacteria are becoming a major healthcare emergence with millions of reported cases every year and an increasing incidence of deaths. An advanced diagnostic platform able to directly detect and identify antimicrobial resistance in a faster way than conventional techniques could help in the adoption of early and accurate therapeutic interventions, limiting the actual negative impact on patient outcomes. With this objective, we have developed a new biosensor methodology using an ultrasensitive nanophotonic bimodal waveguide interferometer (BiMW), which allows a rapid and direct detection, without amplification, of two prevalent and clinically relevant Gram-negative antimicrobial resistance encoding sequences: the extended-spectrum betalactamase-encoding gene blaCTX-M-15 and the carbapenemase-encoding gene blaNDM-5 We demonstrate the extreme sensitivity and specificity of our biosensor methodology for the detection of both gene sequences. Our results show that the BiMW biosensor can be employed as an ultrasensitive (attomolar level) and specific diagnostic tool for rapidly (less than 30 min) identifying drug resistance. The BiMW nanobiosensor holds great promise as a powerful tool for the control and management of healthcare-associated infections by multidrug-resistant bacteria.202033086716
376340.9755Staphylococcus epidermidis MSCRAMM SesJ Is Encoded in Composite Islands. Staphylococcus epidermidis is a leading cause of nosocomial infections in patients with a compromised immune system and/or an implanted medical device. Seventy to 90% of S. epidermidis clinical isolates are methicillin resistant and carry the mecA gene, present in a mobile genetic element (MGE) called the staphylococcal cassette chromosome mec (SCCmec) element. Along with the presence of antibiotic and heavy metal resistance genes, MGEs can also contain genes encoding secreted or cell wall-anchored virulence factors. In our earlier studies of S. epidermidis clinical isolates, we discovered S. epidermidis surface protein J (SesJ), a prototype of a recently discovered subfamily of the microbial surface component recognizing adhesive matrix molecule (MSCRAMM) group. MSCRAMMs are major virulence factors of pathogenic Gram-positive bacteria. Here, we report that the sesJ gene is always accompanied by two glycosyltransferase genes, gtfA and gtfB, and is present in two MGEs, called the arginine catabolic mobile element (ACME) and the staphylococcal cassette chromosome (SCC) element. The presence of the sesJ gene was associated with the left-hand direct repeat DR_B or DR_E. When inserted via DR_E, the sesJ gene was encoded in the SCC element. When inserted via DR_B, the sesJ gene was accompanied by the genes for the type 1 restriction modification system and was encoded in the ACME. Additionally, the SCC element and ACME carry different isoforms of the SesJ protein. To date, the genes encoding MSCRAMMs have been seen to be located in the bacterial core genome. Here, we report the presence of an MSCRAMM in an MGE in S. epidermidis clinical isolates.IMPORTANCES. epidermidis is an opportunistic bacterium that has established itself as a successful nosocomial pathogen. The modern era of novel therapeutics and medical devices has extended the longevity of human life, but at the same time, we also witness the evolution of pathogens to adapt to newly available niches in the host. Increasing antibiotic resistance among pathogens provides an example of such pathogen adaptation. With limited opportunities to modify the core genome, most of the adaptation occurs by acquiring new genes, such as virulence factors and antibiotic resistance determinants present in MGEs. In this study, we describe that the sesJ gene, encoding a recently discovered cell wall-anchored protein in S. epidermidis, is present in both ACME and the SCC element. The presence of virulence factors in MGEs can influence the virulence potential of a specific strain. Therefore, it is critical to study the virulence factors found in MGEs in emerging pathogenic bacteria or strains to understand the mechanisms used by these bacteria to cause infections.202032071265
583150.9754Development of a nucleic acid lateral flow immunoassay (NALFIA) for reliable, simple and rapid detection of the methicillin resistance genes mecA and mecC. The gene mecA and its homologue mecC confer methicillin resistance in Staphylococcus aureus and other staphylococci. Methicillin-resistant staphylococci (MRS) are considered resistant to all β-lactam antibiotics. To avoid the use of β-lactam antibiotics for the control of MRS infections, there is an urgent need for a fast and reliable screening assay for mecA and mecC that can easily be integrated in routine laboratory diagnostics. The aim of this study was the development of such a rapid detection method for methicillin resistance based on nucleic acid lateral flow immunoassay (NALFIA) technology. In NALFIA, the target sequences are PCR-amplified, immobilized via antigen-antibody interaction and finally visualized as distinct black bars resulting from neutravidin-labeled carbon particles via biotin-neutravidin interaction. A screening of 60 defined strains (MRS and non-target bacteria) and 28 methicillin-resistant S. aureus (MRSA) isolates from clinical samples was performed with PCR-NALFIA in comparison to PCR with subsequent gel electrophoresis (PCR-GE) and real-time PCR. While all samples were correctly identified with all assays, PCR-NALFIA was superior with respect to limits of detection. Moreover, this assay allowed for differentiation between mecA and mecC by visualizing the two alleles at different positions on NALFIA test stripes. However, since this test system only targets the mecA and mecC genes, it does not allow to determine in which staphylococcal species the mec gene is included. Requiring only a fraction of the time needed for cultural methods (i.e. the gold standard), the PCR-NALFIA presented here is easy to handle and can be readily integrated into laboratory diagnostics.201727569992
477860.9753DNA extraction of microbial DNA directly from infected tissue: an optimized protocol for use in nanopore sequencing. Identification of bacteria causing tissue infections can be comprehensive and, in the cases of non- or slow-growing bacteria, near impossible with conventional methods. Performing shotgun metagenomic sequencing on bacterial DNA extracted directly from the infected tissue may improve time to diagnosis and targeted treatment considerably. However, infected tissue consists mainly of human DNA (hDNA) which hampers bacterial identification. In this proof of concept study, we present a modified version of the Ultra-Deep Microbiome Prep kit for DNA extraction procedure, removing additional human DNA. Tissue biopsies from 3 patients with orthopedic implant-related infections containing varying degrees of Staphylococcus aureus were included. Subsequent DNA shotgun metagenomic sequencing using Oxford Nanopore Technologies' (ONT) MinION platform and ONTs EPI2ME WIMP and ARMA bioinformatic workflows for microbe and antibiotic resistance genes identification, respectively. The modified DNA extraction protocol led to an additional ~10-fold reduction of human DNA while preserving S. aureus DNA. Including the DNA sequencing and bioinformatics analyses, the presented protocol has the potential of identifying the infection-causing pathogen in infected tissue within 7 hours after biopsy. However, due to low number of S. aureus reads, positive identification of antibiotic resistance genes was not possible.202032076089
477470.9751Are antimicrobial resistance genes key targets to detect genetically modified microorganisms in fermentation products? As genetically modified microorganisms (GMM), commonly used by the food and feed industry to produce additives, enzymes and flavourings, are frequently harbouring antimicrobial resistance (AMR) genes as selection markers, health and environmental concerns were consequently raised. For this reason, the interest of the competent authorities to control such microbial fermentation products has strongly increased, especially since several recent accidental contaminations of unauthorized GMM, or associated recombinant DNA, in bacterial fermentation products intended for the European food and feed chain. However, no global screening strategy is currently available in enforcement laboratories to assess the presence of GMM harbouring AMR genes and/or the presence of full-length AMR genes. Moreover, the confidentiality of the related GMM dossiers strongly hampers the development of methods to perform such control. To overcome this issue, an analysis of related publicly available patents was performed in this study to identify all reported AMR genes. On this basis, the aminoglycoside adenyltransferase (aadD) gene, conferring a resistance to both kanamycin and neomycin, was identified as a key target to cover a large spectrum of GM bacteria. A real-time PCR method to screen for its potential presence as well as a nested-PCR method associated with a sequencing analysis to assess its full-length were developed to target this aadD gene. The performance of these new methods were successfully evaluated in terms of specificity, sensitivity and applicability, allowing their easy implementation in enforcement laboratories. Moreover, the integration of these newly developed methods to our very recently proposed strategy, initially targeting GMM carrying a chloramphenicol resistance gene, allows to drastically increase the detection spectrum of GM bacteria producing fermentation food and feed products. The data generated by the proposed strategy represents therefore a crucial support for the competent authorities, especially to evaluate potential risks for the food and feed safety.202032622259
907480.9750BacAnt: A Combination Annotation Server for Bacterial DNA Sequences to Identify Antibiotic Resistance Genes, Integrons, and Transposable Elements. Whole genome sequencing (WGS) of bacteria has become a routine method in diagnostic laboratories. One of the clinically most useful advantages of WGS is the ability to predict antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs) in bacterial sequences. This allows comprehensive investigations of such genetic features but can also be used for epidemiological studies. A plethora of software programs have been developed for the detailed annotation of bacterial DNA sequences, such as rapid annotation using subsystem technology (RAST), Resfinder, ISfinder, INTEGRALL and The Transposon Registry. Unfortunately, to this day, a reliable annotation tool of the combination of ARGs and MGEs is not available, and the generation of genbank files requires much manual input. Here, we present a new webserver which allows the annotation of ARGs, integrons and transposable elements at the same time. The pipeline generates genbank files automatically, which are compatible with Easyfig for comparative genomic analysis. Our BacAnt code and standalone software package are available at https://github.com/xthua/bacant with an accompanying web application at http://bacant.net.202134367079
843890.9750Virulence of Bacteria Colonizing Vascular Bundles in Ischemic Lower Limbs. BACKGROUND: We documented previously the presence of bacterial flora in vascular bundles, lymphatics, and lymph nodes of ischemic lower limbs amputated because of multifocal atheromatic changes that made them unsuitable for reconstructive surgery and discussed their potential role in tissue destruction. The question arose why bacterial strains inhabiting lower limb skin and considered to be saprophytes become pathogenic once they colonize deep tissues. Bacterial pathogenicity is evoked by activation of multiple virulence factors encoded by groups of genes. METHODS: We identified virulence genes in bacteria cultured from deep tissue of ischemic legs of 50 patients using a polymerase chain reaction technique. RESULTS: The staphylococcal virulence genes fnbA (fibronectin-binding protein A), cna (collagen adhesin precursor), and ica (intercellular adhesion) were present in bacteria isolated from both arteries and, to a lesser extent, skin. The IS256 gene, whose product is responsible for biofilm formation, was more frequent in bacteria retrieved from the arteries than skin bacteria. Among the virulence genes of Staphylococcus epidermidis encoding autolysin atlE, icaAB (intercellular adhesion), and biofilm insert IS256, only the latter was detected in arterial specimens. Bacteria cultured from the lymphatics did not reveal expression of eta and IS256 in arteries. The Enterococcus faecalis asa 373 (aggregation substance) and cylA (cytolysin activator) frequency was greater in arteries than in skin bacteria, as were the E. faecium cyl A genes. All Pseudomonas aeruginosa virulence genes were present in bacteria cultured from both the skin and arteries. Staphylococci colonizing arterial bundles and transported to tissues via ischemic limb lymphatics expressed virulence genes at greater frequency than did those dwelling on the skin surface. Moreover, enterococci and Pseudomonas isolated from arterial bundles expressed many virulence genes. CONCLUSIONS: These findings may add to the understanding of the mechanism of development of destructive changes in lower limb ischemic tissues by the patient's, but not hospital-acquired, bacteria, as well as the generally unsatisfactory results of antibiotic administration in these cases. More aggressive antibiotic therapy targeted at the virulent species should be applied.201626431369
5881100.9750A novel universal DNA labeling and amplification system for rapid microarray-based detection of 117 antibiotic resistance genes in Gram-positive bacteria. A rapid and simple DNA labeling system has been developed for disposable microarrays and has been validated for the detection of 117 antibiotic resistance genes abundant in Gram-positive bacteria. The DNA was fragmented and amplified using phi-29 polymerase and random primers with linkers. Labeling and further amplification were then performed by classic PCR amplification using biotinylated primers specific for the linkers. The microarray developed by Perreten et al. (Perreten, V., Vorlet-Fawer, L., Slickers, P., Ehricht, R., Kuhnert, P., Frey, J., 2005. Microarray-based detection of 90 antibiotic resistance genes of gram-positive bacteria. J.Clin.Microbiol. 43, 2291-2302.) was improved by additional oligonucleotides. A total of 244 oligonucleotides (26 to 37 nucleotide length and with similar melting temperatures) were spotted on the microarray, including genes conferring resistance to clinically important antibiotic classes like β-lactams, macrolides, aminoglycosides, glycopeptides and tetracyclines. Each antibiotic resistance gene is represented by at least 2 oligonucleotides designed from consensus sequences of gene families. The specificity of the oligonucleotides and the quality of the amplification and labeling were verified by analysis of a collection of 65 strains belonging to 24 species. Association between genotype and phenotype was verified for 6 antibiotics using 77 Staphylococcus strains belonging to different species and revealed 95% test specificity and a 93% predictive value of a positive test. The DNA labeling and amplification is independent of the species and of the target genes and could be used for different types of microarrays. This system has also the advantage to detect several genes within one bacterium at once, like in Staphylococcus aureus strain BM3318, in which up to 15 genes were detected. This new microarray-based detection system offers a large potential for applications in clinical diagnostic, basic research, food safety and surveillance programs for antimicrobial resistance.201525451460
9078110.9748MetaCherchant: analyzing genomic context of antibiotic resistance genes in gut microbiota. MOTIVATION: Antibiotic resistance is an important global public health problem. Human gut microbiota is an accumulator of resistance genes potentially providing them to pathogens. It is important to develop tools for identifying the mechanisms of how resistance is transmitted between gut microbial species and pathogens. RESULTS: We developed MetaCherchant-an algorithm for extracting the genomic environment of antibiotic resistance genes from metagenomic data in the form of a graph. The algorithm was validated on a number of simulated and published datasets, as well as applied to new 'shotgun' metagenomes of gut microbiota from patients with Helicobacter pylori who underwent antibiotic therapy. Genomic context was reconstructed for several major resistance genes. Taxonomic annotation of the context suggests that within a single metagenome, the resistance genes can be contained in genomes of multiple species. MetaCherchant allows reconstruction of mobile elements with resistance genes within the genomes of bacteria using metagenomic data. Application of MetaCherchant in differential mode produced specific graph structures suggesting the evidence of possible resistance gene transmission within a mobile element that occurred as a result of the antibiotic therapy. MetaCherchant is a promising tool giving researchers an opportunity to get an insight into dynamics of resistance transmission in vivo basing on metagenomic data. AVAILABILITY AND IMPLEMENTATION: Source code and binaries are freely available for download at https://github.com/ctlab/metacherchant. The code is written in Java and is platform-independent. COTANCT: ulyantsev@rain.ifmo.ru. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.201829092015
6010120.9748The role of two families of bacterial enzymes in putrescine synthesis from agmatine via agmatine deiminase. Putrescine, one of the main biogenic amines associated to microbial food spoilage, can be formed by bacteria from arginine via ornithine decarboxylase (ODC), or from agmatine via agmatine deiminase (AgDI). This study aims to correlate putrescine production from agmatine to the pathway involving N-carbamoylputrescine formation via AdDI (the aguA product) and N-carbamoylputrescine amidohydrolase (the aguB product), or putrescine carbamoyltransferase (the ptcA product) in bacteria. PCR methods were developed to detect the two genes involved in putrescine production from agmatine. Putrescine production from agmatine could be linked to the aguA and ptcA genes in Lactobacillus hilgardii X1B, Enterococcus faecalis ATCC 11700, and Bacillus cereus ATCC 14579. By contrast Lactobacillus sakei 23K was unable to produce putrescine, and although a fragment of DNA corresponding to the gene aguA was amplified, no amplification was observed for the ptcA gene. Pseudomonas aeruginosa PAO1 produces putrescine and is reported to harbour aguA and aguB genes, responsible for agmatine deiminase and N-carbamoylputrescine amidohydrolase activities. The enzyme from P. aeruginosa PAO1 that converts N-carbamoylputrescine to putrescine (the aguB product) is different from other microorganisms studied (the ptcA product). Therefore, the aguB gene from P. aeruginosa PAO1 could not be amplified with ptcA-specific primers. The aguB and ptcA genes have frequently been erroneously annotated in the past, as in fact these two enzymes are neither homologous nor analogous. Furthermore, the aguA, aguB and ptcA sequences available from GenBank were subjected to phylogenetic analysis, revealing that gram-positive bacteria harboured ptcA, whereas gram-negative bacteria harbour aguB. This paper also discusses the role of the agmatine deiminase system (AgDS) in acid stress resistance.201021404211
4761130.9748Antimicrobial resistance and biofilm formation of penile prosthesis isolates: insights from in-vitro analysis. BACKGROUND: Inflatable penile prostheses (IPPs) have been shown to harbor biofilms in the presence and absence of infection despite exposure to various antimicrobials. Microbes persisting on IPPs following antibiotic exposure have not been adequately studied to assess biofilm formation capacity and antibiotic resistance. AIM: In this study, we aimed to assess these properties of microbes obtained from explanted infected and non-infected IPPS using an in vitro model. METHODS: 35 bacterial isolates were grown and tested against various single-agent or multiple agent antibiotic regimens including: bacitracin, cefaclor, cefazolin, gentamicin, levofloxacin, trimethoprim-sulfamethoxazole, tobramycin, vancomycin, piperacillin/tazobactam, gentamicin + piperacillin/tazobactam, gentamicin + cefazolin, and gentamicin + vancomycin. Zones of inhibition were averaged for each sample site and species. Statistics were analyzed with Holm's corrected, one-sample t-tests against a null hypothesis of 0. Isolates were also allowed to form biofilms in a 96-well polyvinyl plate and absorbance was tested at 570 nm using a microplate reader. OUTCOMES: Resistance was determined via clinical guidelines or previously established literature, and the mean and standard deviation of biofilm absorbance values were calculated and normalized to the optical density600 of the bacterial inoculum. RESULTS: Every species tested was able to form robust biofilms with the exception of Staphylococcus warneri. As expected, most bacteria were resistant to common perioperative antimicrobial prophylaxis. Gentamicin dual therapy demonstrated somewhat greater efficacy. STRENGTHS AND LIMITATIONS: This study examines a broad range of antimicrobials against clinically obtained bacterial isolates. However, not all species and antibiotics tested had standardized breakpoints, requiring the use of surrogate values from the literature. The microbes included in this study and their resistance genes are expectedly biased towards those that survived antibiotic exposure, and thus reflect the types of microbes which might "survive" in vivo exposure following revisional surgery. CLINICAL TRANSLATION: Despite exposure to antimicrobials, bacteria isolated during penile prosthesis revision for both infected and non-infected cases exhibit biofilm forming capacity and extensive antibiotic resistance patterns in vitro. These microbes merit further investigation to understand when simple colonization vs re-infection might occur. CONCLUSIONS: Although increasing evidence supports the concept that all IPPs harbor biofilms, even in the absence of infection, a deeper understanding of the characteristics of bacteria that survive revisional surgery is warranted. This study demonstrated extensive biofilm forming capabilities, and resistance patterns among bacteria isolated from both non-infected and infected IPP revision surgeries. Further investigation is warranted to determine why some devices become infected while others remain colonized but non-infected.202540062463
5070140.9748Sequence-specific DNA solid-phase extraction in an on-chip monolith: Towards detection of antibiotic resistance genes. Antibiotic resistance of bacteria is a growing problem and presents a challenge for prompt treatment in patients with sepsis. Currently used methods rely on culturing or amplification; however, these steps are either time consuming or suffer from interference issues. A microfluidic device was made from black polypropylene, with a monolithic column modified with a capture oligonucleotide for sequence selective solid-phase extraction of a complementary target from a lysate sample. Porous properties of the monolith allow flow and hybridization of a target complementary to the probe immobilized on the column surface. Good flow-through properties enable extraction of a 100μL sample and elution of target DNA in 12min total time. Using a fluorescently labeled target oligonucleotide related to Verona Integron-Mediated Metallo-β-lactamase it was possible to extract and detect a 1pM sample with 83% recovery. Temperature-mediated elution by heating above the duplex melting point provides a clean extract without any agents that interfere with base pairing, allowing various labeling methods or further downstream processing of the eluent. Further integration of this extraction module with a system for isolation and lysis of bacteria from blood, as well as combining with single-molecule detection should allow rapid determination of antibiotic resistance.201728734608
5161150.9747Genomic analysis of contaminant Stenotrophomonas maltophilia, from placental swab culture, carrying antibiotic resistance: a potential hospital laboratory contaminant. Acute chorioamnionitis has been considered as reflective of amniotic fluid infection. Standard microbiological work ups for causative microorganism of intra-amniotic infection is based on microbial identification. However, frequency of positive placental culture is varied depending on placental sampling techniques, contaminations, methods of microbiologic work ups or comprehensive microbiologic work ups. In this report, we performed a hybrid whole genome sequencing of a proven bacterial contaminant obtained from placental culture in a patient with preterm labor and acute chorioamnionitis. This is to unveil genetic characterization of contaminant Stenotrophomonas maltophilia habouring antibiotic resistance genes. Stenotrophomonas maltiphilia was proven to be bacterial contaminant since Ureaplasma urealyticum was subsequently demonstrated in amniotic fluid by 16 S rRNA gene Sanger sequencing. Cultivation results from other sources were no growth. We identified Stenotrophomonas maltiphilia strain RAOG732 which carried several antibiotic resistance genes, including aminoglycoside, fluoroquiolone and beta-lactam. Biofilm production genes were also identified in this genome. We firstly utilized a hybrid sequencing approach to investigate the genome of S. maltiphilia in the patient with preterm and acute chorioamnionitis, a proven bacterial laboratory contaminant. The analysis provided several antibiotic resistance-associated and genes biofilm-associated genes. The detection of S. maltiphilia raised the awareness of the colonization of biofilm-producing bacteria in hospitals, where surveillance for decontamination is necessary.202540594762
3770160.9747Detection of mobile genetic elements associated with antibiotic resistance in Salmonella enterica using a newly developed web tool: MobileElementFinder. OBJECTIVES: Antimicrobial resistance (AMR) in clinically relevant bacteria is a growing threat to public health globally. In these bacteria, antimicrobial resistance genes are often associated with mobile genetic elements (MGEs), which promote their mobility, enabling them to rapidly spread throughout a bacterial community. METHODS: The tool MobileElementFinder was developed to enable rapid detection of MGEs and their genetic context in assembled sequence data. MGEs are detected based on sequence similarity to a database of 4452 known elements augmented with annotation of resistance genes, virulence factors and detection of plasmids. RESULTS: MobileElementFinder was applied to analyse the mobilome of 1725 sequenced Salmonella enterica isolates of animal origin from Denmark, Germany and the USA. We found that the MGEs were seemingly conserved according to multilocus ST and not restricted to either the host or the country of origin. Moreover, we identified putative translocatable units for specific aminoglycoside, sulphonamide and tetracycline genes. Several putative composite transposons were predicted that could mobilize, among others, AMR, metal resistance and phosphodiesterase genes associated with macrophage survivability. This is, to our knowledge, the first time the phosphodiesterase-like pdeL has been found to be potentially mobilized into S. enterica. CONCLUSIONS: MobileElementFinder is a powerful tool to study the epidemiology of MGEs in a large number of genome sequences and to determine the potential for genomic plasticity of bacteria. This web service provides a convenient method of detecting MGEs in assembled sequence data. MobileElementFinder can be accessed at https://cge.cbs.dtu.dk/services/MobileElementFinder/.202133009809
9073170.9747EpitoCore: Mining Conserved Epitope Vaccine Candidates in the Core Proteome of Multiple Bacteria Strains. In reverse vaccinology approaches, complete proteomes of bacteria are submitted to multiple computational prediction steps in order to filter proteins that are possible vaccine candidates. Most available tools perform such analysis only in a single strain, or a very limited number of strains. But the vast amount of genomic data had shown that most bacteria contain pangenomes, i.e., their genomic information contains core, conserved genes, and random accessory genes specific to each strain. Therefore, in reverse vaccinology methods it is of the utmost importance to define core proteins and core epitopes. EpitoCore is a decision-tree pipeline developed to fulfill that need. It provides surfaceome prediction of proteins from related strains, defines core proteins within those, calculate their immunogenicity, predicts epitopes for a given set of MHC alleles defined by the user, and then reports if epitopes are located extracellularly and if they are conserved among the core homologs. Pipeline performance is illustrated by mining peptide vaccine candidates in Mycobacterium avium hominissuis strains. From a total proteome of ~4,800 proteins per strain, EpitoCore predicted 103 highly immunogenic core homologs located at cell surface, many of those related to virulence and drug resistance. Conserved epitopes identified among these homologs allows the users to define sets of peptides with potential to immunize the largest coverage of tested HLA alleles using peptide-based vaccines. Therefore, EpitoCore is able to provide automated identification of conserved epitopes in bacterial pangenomic datasets.202032431712
4775180.9747Safety assessment of dairy microorganisms: the Lactobacillus genus. Lactobacilli are Gram positive rods belonging to the Lactic Acid Bacteria (LAB) group. Their phenotypic traits, such as each species' obligate/facultative, homo/heterofermentation abilities play a crucial role in souring raw milk and in the production of fermented dairy products such as cheese, yoghurt and fermented milk (including probiotics). An up to date safety analysis of these lactobacilli is needed to ensure consumer safety. Lactobacillus genus is a heterogeneous microbial group containing some 135 species and 27 subspecies, whose classification is constantly being reshuffled. With the recent use of advanced molecular methods it has been suggested that the extreme diversity of the Lactobacillus genomes would justify recognition of new subgeneric divisions. A combination of genotypic and phenotypic tests, for example DNA-based techniques and conventional carbohydrate tests, is required to determine species. Pulsed-Field gel Electrophoresis (PFGE) has been successfully applied to strains of dairy origin and is the most discriminatory and reproducible method for differentiating Lactobacillus strains. The bibliographical data support the hypothesis that the ingestion of Lactobacillus is not at all hazardous since lactobacillemia induced by food, particularly fermented dairy products, is extremely rare and only occurs in predisposed patients. Some metabolic features such as the possible production of biogenic amines in fermented products could generate undesirable adverse effects. A minority of starter and adjunct cultures and probiotic Lactobacillus strains may exceptionally show transferable antibiotic resistance. However, this may be underestimated as transferability studies are not systematic. We consider that transferable antibiotic resistance is the only relevant cause for caution and justifies performing antibiotic-susceptibility assays as these strains have the potential to serve as hosts of antibiotic-resistance genes, with the risk of transferring these genes to other bacteria. However, as a general rule, lactobacilli have a high natural resistance to many antibiotics, especially vancomycin, that is not transferable. Safety assessment requirements for Lactobacillus strains of technological interest should be limited to an antibiotic profile and a study to determine whether any antibiotic resistance(s) of medical interest detected is (or are) transferable. This agrees with the recent EFSA proposal suggesting attribution of a QPS status for 32 selected species of lactobacilli.200817889388
9742190.9747BOCS: DNA k-mer content and scoring for rapid genetic biomarker identification at low coverage. A single, inexpensive diagnostic test capable of rapidly identifying a wide range of genetic biomarkers would prove invaluable in precision medicine. Previous work has demonstrated the potential for high-throughput, label-free detection of A-G-C-T content in DNA k-mers, providing an alternative to single-letter sequencing while also having inherent lossy data compression and massively parallel data acquisition. Here, we apply a new bioinformatics algorithm - block optical content scoring (BOCS) - capable of using the high-throughput content k-mers for rapid, broad-spectrum identification of genetic biomarkers. BOCS uses content-based sequence alignment for probabilistic mapping of k-mer contents to gene sequences within a biomarker database, resulting in a probability ranking of genes on a content score. Simulations of the BOCS algorithm reveal high accuracy for identification of single antibiotic resistance genes, even in the presence of significant sequencing errors (100% accuracy for no sequencing errors, and >90% accuracy for sequencing errors at 20%), and at well below full coverage of the genes. Simulations for detecting multiple resistance genes within a methicillin-resistant Staphylococcus aureus (MRSA) strain showed 100% accuracy at an average gene coverage of merely 0.515, when the k-mer lengths were variable and with 4% sequencing error within the k-mer blocks. Extension of BOCS to cancer and other genetic diseases met or exceeded the results for resistance genes. Combined with a high-throughput content-based sequencing technique, the BOCS algorithm potentiates a test capable of rapid diagnosis and profiling of genetic biomarkers ranging from antibiotic resistance to cancer and other genetic diseases.201931173943