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Limitations of serial cloning in mammals: unresolved donor-cell genomic integrity challenges broad claims of cloning limits.

Wakayama et al. describe an extraordinary 20-year serial cloning study in mice, concluding that serial cloning in mammals is ultimately limited by the accumulation of genetic anomalies. However, their whole-genome sequencing (WGS) analysis characterized selected cloned animals but did not include matched genomic profiling of the corresponding cumulus cell (CC)-donor mice, the source CC populations, or developmental stages. Because each reconstructed embryo originated from a single CC nucleus and re-cloned animals were used to advance the lineage, pre-existing somatic variation could have entered the lineage and subsequently been propagated. Consequently, variants detected in later generations cannot be assigned definitively to pre-existing donor-cell mosaicism, donor-cell handling, somatic cell nuclear transfer manipulation, or early embryogenesis. Thus, the observed decline cannot be attributed exclusively to genetic lesions arising during repeated cloning, but the unresolved genomic status of the lineage-founding donor cells remains a plausible but unproven contributor. The study therefore demonstrates the transmission and propagation of genetic lesions through serial cloning more directly than it establishes that all initiating lesions arose because of repeated cloning. Paired genomic profiling of donor-cell populations, embryos, and offspring would help resolve the origins of accumulated genetic lesions and determine whether donor-cell screening could extend serial cloning.

Animals

Global emergence and transmission dynamics of carbapenemase-producing Citrobacter freundii sequence type 22 high-risk international clone: a retrospective, genomic, epidemiological study.

BACKGROUND: Carbapenemase-producing Citrobacter (CPC) species have recently been recognised as emerging pathogens associated with nosocomial infections in humans. The increased rate of Citrobacter freundii infections is a public health concern and there is a paucity of genomic data regarding its global transmission dynamics. We aimed to characterise the genetic features of CPC species, and their associated carbapenemase-encoding plasmids, obtained from hospitalised patients in China and from publicly available global data, with a particular focus on high-risk clones. METHODS: This was a retrospective, genomic epidemiological study of CPC species obtained from a tertiary hospital in Zhejiang Province, China, from March 5, 2013, to March 5, 2023. We used antimicrobial susceptibility testing, short-read and long-read whole-genome sequencing, phylogenomic analysis, and plasmid structure analysis. A global dataset of complete plasmid sequences encoding blaKPC, blaNDM, and blaIMP was constructed from the National Center for Biotechnology Information (NCBI) RefSeq database to provide insights into their diversity and distribution. All carbapenemase-producing Citrobacter freundii genomes from the NCBI GenBank database were incorporated in the comparative genomic analyses. Bayesian phylogeographical analysis and growth rate assays were carried out to characterise the high-risk C freundii sequence type (ST) 22 clone. FINDINGS: 1724 Citrobacter species isolates were collected from diverse clinical specimens, with 48 identified as CPC species. Citrobacter koseri (22 [46%] of 48) and C freundii (20 [42%]) were the predominant CPC species. Comparative analysis found C freundii carried significantly higher median numbers of plasmid replicons (5&#xb7;0 [IQR 3&#xb7;3-6&#xb7;0] vs 2&#xb7;0 [2&#xb7;0-3&#xb7;0]; p<0&#xb7;0001) and acquired antimicrobial resistance genes (12&#xb7;0 [7&#xb7;3-15&#xb7;8] vs 3&#xb7;0 [3&#xb7;0-5&#xb7;3]; p<0&#xb7;0001) than did C koseri. Molecular characterisation identified Inc-type plasmids, In823::Kl.pn.I3/In1589-like/In837-like integrons, Tn6296/Tn125/Tn5060 transposons, and insertion sequences (eg, IS26, IS3000, IS5, ISAba125, ISCR1), collectively facilitating the dissemination of carbapenemase genes. Global analysis of 3126 carbapenemase-encoding plasmids found epidemic plasmids with broad host ranges and global diversity. Phylogenetic investigation of predominant carbapenemase-encoding plasmids showed their persistence across geographical regions, temporal spans, and Enterobacterales species, exhibiting high genetic similarity to our clinical plasmids. A phylogenetic tree of 726 global carbapenemase-producing C freundii genomes showed that ST22 (227 [31&#xb7;3%]) represents the predominant multidrug-resistant clone across community, health-care, and environmental niches. Transmission across continents contributes to the global predominance of the ST22 clone, which carries a high load of resistance genes (median 15&#xb7;0 [IQR 11&#xb7;0-17&#xb7;0] vs 12&#xb7;0 [3&#xb7;0-16&#xb7;0]; p<0&#xb7;0001) and enhanced plasmid maintenance capacity (median replicons 5&#xb7;0 [IQR 4&#xb7;0-7&#xb7;0] vs 4&#xb7;0 [3&#xb7;0-6&#xb7;0]; p<0&#xb7;0001) relative to non-ST22 clones. INTERPRETATION: Our study provides evidence to suggest that Citrobacter species are emerging carriers of carbapenem-resistance genes. These findings provide insight into the population structure of CPC species and highlight C freundii ST22 as a prominent high-risk international clone. FUNDING: National Natural Science Foundation of China, National Health Commission Scientific Research Fund-Zhejiang Provincial Major Health Science and Technology Plan Project, Zhejiang Province Natural Science Foundation Project, Outstanding Youth Foundation of Jiangsu Province of China, the Priority Academic Program Development of Jiangsu Higher Education Institutions, and Postgraduate Research and Practice Innovation Program of Jiangsu Province.

Citrobacter freundii

1-Mb resolution array-based comparative genomic hybridization using a BAC clone set optimized for cancer gene analysis.

Array-based comparative genomic hybridization (aCGH) is a recently developed tool for genome-wide determination of DNA copy number alterations. This technology has tremendous potential for disease-gene discovery in cancer and developmental disorders as well as numerous other applications. However, widespread utilization of a CGH has been limited by the lack of well characterized, high-resolution clone sets optimized for consistent performance in aCGH assays and specifically designed analytic software. We have assembled a set of approximately 4100 publicly available human bacterial artificial chromosome (BAC) clones evenly spaced at approximately 1-Mb resolution across the genome, which includes direct coverage of approximately 400 known cancer genes. This aCGH-optimized clone set was compiled from five existing sets, experimentally refined, and supplemented for higher resolution and enhancing mapping capabilities. This clone set is associated with a public online resource containing detailed clone mapping data, protocols for the construction and use of arrays, and a suite of analytical software tools designed specifically for aCGH analysis. These resources should greatly facilitate the use of aCGH in gene discovery.

Cell Line, Tumor

A Restriction-Free Cloning Approach for Molecular Engineering of Plasmids.

Molecular cloning by PCR amplification using a highly processive, high-fidelity DNA polymerase represents a robust and versatile technique for the precise manipulation of nucleic acid sequences. This approach enables the insertion, replacement, or modification of specific DNA fragments within a cloning vector, thereby generating an accurate copy of a gene or viral segment for downstream applications, such as protein expression, site-directed mutagenesis, and structural or functional analyses. The use of processive, high-fidelity polymerases significantly reduces the occurrence of base substitution errors, ensuring sequence integrity throughout the amplification process. Traditionally, restriction enzymes have been employed to facilitate directional cloning; however, alternative methods allow for mutagenesis without the need for unique and specific restriction sites and can be applied to virtually any cloning or seamless DNA assembly strategy. In this chapter, we describe a restriction enzyme-free and ligation-free PCR-based protocol widely applicable to any circular vector. This method enables targeted mutagenesis of the chikungunya virus (CHIKV) genome, offering a fast, efficient, and reliable strategy for generating mutant constructs suitable for virological and molecular studies.

Cloning, Molecular

Gene Cloning, Expression, and Purification of Kunitz Trypsin Inhibitor from Glycine max Using Halo Tag.

Soybean Kunitz Trypsin Inhibitor (SKTI) is one of the most extensively studied protease inhibitors, with applications in pest management, medicine, the food processing industry, and the leather industry. In this study, SKTI was cloned into the pFN29A Flexi vector containing a barnase gene. Genomic DNA was isolated from tender soybean leaves, and SKTI was amplified by PCR to obtain a 671&#xa0;bp product. After cloning, an internal 380&#xa0;bp sequence was amplified using specific primers to confirm that the cloned sequence was a functional SKTI, as non-functional SKTI genes also exist in Glycine max. The amplified PCR product, containing an AsiSI site at the 5' end and a PmeI site at the 3' end, was cloned into the pFN29A vector. The resulting colonies were screened by colony PCR, and the insert sequence was confirmed by Sanger sequencing. The recombinant protein, containing a His-tag, Halo-tag, and a TEV protease cleavage site, was expressed in Escherichia coli BL21 cells. Maximum expression was achieved 5&#xa0;h after induction with 0.5&#xa0;mM IPTG at 37&#xa0;&#xb0;C. The expressed SKTI was purified using affinity chromatography on HaloLink resin, and the bound SKTI was cleaved with HaloTEV protease to obtain pure SKTI. The purified inhibitor effectively inhibited bovine trypsin, with an IC&#x2085;&#x2080; of 0.6&#x2009;&#xb1;&#x2009;0.003&#xa0;&#xb5;g/&#xb5;l, yielding 1.6&#xa0;mg per gram of bacterial pellet. The 24&#xa0;kDa inhibitor remained stable up to a temperature of 50&#xa0;&#xb0;C. Kinetic analysis revealed that recombinant SKTI competitively inhibits trypsin, with a K&#x1d62; value of 14&#xa0;&#xb5;M.

Cloning, Molecular

Infectious Clone Development of Zucchini Green Mottle Mosaic Virus Infecting Medicinal Plant Trichosanthes kirilowii and Establishment of a Serological Assay System.

Trichosanthes kirilowii has long been cultivated for application in traditional Chinese medicine. In this study, we identified two isolates of zucchini green mottle mosaic virus (ZGMMV; species Tobamovirus cucurbitae) from T. kirilowii plants. We determined the complete genome sequences of the ZGMMV isolates named ZGMMV-GL-1 and ZGMMV-GL-2. Each ZGMMV genome was 6,517 nucleotides in length, with only a single nucleotide variation detected between two sequences. Sequence analysis revealed that the ZGMMV isolates from this study shared 88.07 to 91.62% nucleotide identity with five other ZGMMV isolates deposited in GenBank. Phylogenetic analysis indicated that ZGMMV isolates can be clustered into two distinct groups; our two isolates shared the highest sequence similarity with the ZGMMV isolate from Nanning (GenBank accession number MF066176) and clustered within Group II. The coat protein (CP) gene was cloned from ZGMMV-infected T. kirilowii samples, and the CPZGMMV was expressed using the pET28(a) vector. Specific polyclonal antiserum CPZGMMV was generated by immunizing rabbits with the purified protein, and its sensitivity was determined to be satisfactory. Leveraging the high accuracy and sensitivity of the CPZGMMV antiserum, we developed a rapid, precise, and scalable diagnostic method for ZGMMV. We then constructed the full-length cDNA clones (ZGMMV-GL-1 and ZGMMV-GL-2). Additionally, the ZGMMV cDNA infectious clones from T. kirilowii were also able to infect Nicotiana benthamiana and Cucumis sativus systemically, inducing rough-textured and curled leaves in N. benthamiana and mosaic symptoms in C. sativus and T. kirilowii. In this study, we produced an antiserum against the ZGMMV CP and developed a sensitive, rapid, and reliable diagnostic assay, which lays a technical foundation for the detection and monitoring of ZGMMV. Therefore, the establishment of the ZGMMV infectious clone facilitates further research on viral protein functions, plant-pathogen interactions, and the formulation of effective ZGMMV management strategies.

Nicotiana benthamiana

The voice clone intelligibility benefit in noise in middle-aged listeners.

Research with younger adults showed that cloned voices are more intelligible than human voices in noise, with a benefit of 13.4%. This study tested whether this benefit extends to 40 middle-aged listeners (45-65&#x2009;years), as this population may show emerging difficulties with speech-in-noise. Participants recognised sentences by ten human voices and ten voice clones in four noise levels. Cloned voices were 11.8% more intelligible, with benefits enhanced at the two most severe noise levels (15.9% at -6 dB and 17.5% at -3 dB), suggesting cloned speech enhanced perception in middle-aged listeners, potentially by reducing listening effort and compensating for emerging age-related auditory-cognitive decline.

Humans

Cloning, Transformation, and Reporter Gene Analysis of the SalT Promoter in Barley (Hordeum vulgare).

Constitutive gene expression can lead to pleiotropic effects. Therefore, spatial or temporal restriction of expression via specific promoters provides a more targeted approach. This study aimed to clone the SalT promoter and analyze its activity in transgenic barley using GFP and GUS reporter genes. The T-DNA constructs carrying the SalT promoter were introduced into barley cv. Golden Promise, and transgenic plants were confirmed through PCR, hygromycin selection, and Southern hybridization. Both constructs, SalT-GFP and SalT-GUS, were transformed in barley cv. Golden Promise. Here, we characterized the expression pattern of the SalT promoter in barley and utilized it to drive the expression of reporter genes GFP and GUS. The SalT promoter was isolated from rice genomic DNA, cloned into the pNos-AB-M vector, and confirmed through PCR and restriction analysis. Subsequently, GFP and GUS genes were cloned under the SalT promoter in the same vector. The constructs were then subcloned into the p6U vector for plant expression. Agrobacterium-mediated genetic transformation of barley cultivar "Golden Promise" was conducted, resulting in successful integration of the transgenes. Callus induction, regeneration, and root formation efficiency were assessed, demonstrating the potential of the SalT promoter to drive gene expression during various stages of plant development. Molecular analyses, including PCR and Southern hybridization, confirmed the presence and integration of transgenes in the barley genome. Furthermore, GFP fluorescence and GUS staining analyses revealed strong expression of the respective genes under control of the SalT promoter in different plant tissues. This study provides insights into the application of the SalT promoter for genetic manipulation and functional characterization in barley, offering opportunities for crop improvement and biotechnological applications.

Hordeum

Construction of an infectious clone of Spodoptera frugiperda densovirus and its biological characteristics.

Densoviruses are highly pathogenic to their insect hosts and have great potential for biocontrol. Spodoptera frugiperda densovirus (SfDV) was isolated from diseased larvae of Spodoptera frugiperda, while its biological functions remain unclear. Herein, we successfully constructed an infectious clone of SfDV. The S. frugiperda larvae transfected with the infectious clone exhibited anorexia, stunted growth, and reduced activity. Histopathological analysis further showed that the epidermis, fat body and trachea were infected instead of muscle and midgut tissues. Transmission electron microscopy (TEM) revealed that numerous virions of about 22&#x202f;nm were distributed within both the nucleoplasm and cytoplasm of epidermal cells. Moreover, many virions were also found contained within vesicles in the cytoplasm. The replication kinetics of the rescued SfDV (rSfDV) was similar to that of the parental SfDV. The median lethal dose (LD50) and median lethal time (LT50) values of rSfDV were 6.63&#x202f;&#xd7;&#x202f;107 viral genome copies (vgc), 5.23&#x202f;d, respectively, which were also comparable to those of the parental SfDV. Taken together, the infectious clone of SfDV provides an important tool for further exploring the genome function, pathogenesis, and interactions with its hosts.

Animals

Aire mediates tolerance to insulin through thymic trimming of high-affinity T cell clones.

Insulin is a central autoantigen in the pathogenesis of T1D, and thymic epithelial cell expression of insulin under the control of the Autoimmune Regulator (Aire) is thought to be a key component of maintaining tolerance to insulin. In spite of this general working model, direct detection of this thymic selection on insulin-specific T cells has been somewhat elusive. Here, we used a combination of highly sensitive T cell receptor transgenic models for detecting thymic selection and sorting and sequencing of Insulin-specific CD4+ T cells from Aire-deficient mice as a strategy to further define their selection. This analysis revealed a number of unique t cell receptor (TCR) clones in Aire-deficient hosts with high affinity for insulin/major histocompatibility complex (MHC) ligands. We then modeled the thymic selection of one of these clones in Aire-deficient versus wild-type hosts and found that this model clone could escape thymic negative selection in the absence of thymic Aire. Together, these results suggest that thymic expression of insulin plays a key role in trimming and removing high-affinity insulin-specific T cells from the repertoire to help promote tolerance.

Animals

IMAGE cDNA clones, UniGene clustering, and ACeDB: an integrated resource for expressed sequence information.

In this study we describe a new information resource that provides integrated access to information on IMAGE (integrated molecular analysis of genomes and their expression) cDNA library clones and derived expressed sequence tags (ESTs). We have developed an automated procedure that collates data from various public sources into a single ACeDB database. This database is a valuable tool for electronic cloning experiments and gene expression studies. It allows researchers to find information about cDNA libraries, plate addresses, insert sizes, and sequence data for IMAGE clones, the assignment of ESTs to UniGene clusters, and the chromosomal location of those genes in an efficient, graphically oriented manner.

Cloning, Molecular

Genomic characterization of KPC-2 and NDM coproducing carbapenem-resistant Klebsiella pneumoniae in a hospital: discovery of ST1869 clone and a novel hybrid plasmid.

UNLABELLED: To characterize the plasmid architecture and molecular background of KPC-NDM coproducing carbapenem-resistant Klebsiella pneumoniae (KN-CRKP) in a South China hospital. Five KN-CRKP isolates were collected, including three from one patient. All underwent Illumina sequencing; two (ST11 and ST1869) additionally had Nanopore sequencing. Antimicrobial susceptibility testing strain sequence types, conjugation assays, resistance gene profiling, plasmid typing, genetic structure comparison, core-genome single nucleotide polymorphisms (SNPs) analysis, and plasmid clustering were performed. All isolates exhibited an imipenem minimum inhibitory concentration (MIC) of &#x2265;128 &#xb5;g/mL and harbored multiple resistance genes. One isolate (1/5) belonged to ST1869 and co-harbored blaKPC-2 and blaNDM-5. The blaNDM-5-carrying plasmid was a novel IncI1/X3 fusion plasmid that also carried blaCMY-42. Unlike several IncX3 plasmids carrying blaNDM in publicly available KN-CRKP genomes from South China, this IncI1/X3 hybrid lacked a complete conjugative transfer system. ST11 was the predominant clone (4/5), co-harboring blaKPC-2 and blaNDM-1. A rare genetic structure, &#x394;ISKpn6-blaKPC-2-ISKpn28, was identified on IncFII plasmids carrying blaKPC-2. Plasmid clustering analysis of 126 comparative KN-CRKP genomes showed diverse sequence types and plasmid backgrounds associated with the KPC/NDM co-production pattern. The observed plasmid diversity and structural variation in KN-CRKP support continued genomic surveillance, with particular attention to the ST1869 clone, the novel IncI1/X3 hybrid plasmid harboring blaNDM-5 and blaCMY-42, and the rare "&#x394;ISKpn6-blaKPC-2-ISKpn28" genetic structure. Expanded genomic data on KN-CRKP are needed to further elucidate its resistance mechanisms and plasmid evolutionary trajectories. IMPORTANCE: The co-production of KPC and NDM carbapenemases in Klebsiella pneumoniae poses a formidable threat to clinical antimicrobial therapy, as these enzymes confer resistance to virtually all &#x3b2;-lactam agents, including carbapenems. Here, we report novel genomic features of KN-CRKP in South China, including the emergence of the ST1869 clone, a unique IncI1/X3 hybrid plasmid harboring blaNDM-5 and blaCMY-42, and the rare &#x394;ISKpn6-blaKPC-2-ISKpn28 genetic structure. These findings substantially expand current understanding of plasmid evolution and resistance gene dissemination in this region. The identification of diverse resistance mechanisms and clonal backgrounds supports enhanced genomic surveillance and infection-control awareness for pan-resistant Enterobacterales.

Plasmids

Molecular Cloning and Reverse Genetics.

This chapter describes a detailed molecular biology protocol for introducing specific point mutations into the chikungunya virus (CHIKV) genome using a reverse genetics strategy. The method utilizes an overlapping PCR-based approach to generate a mutated DNA fragment, which is then cloned into a pre-engineered CHIKV infectious clone plasmid. The protocol covers all major steps, from the initial PCRs to create the mutated insert to its digestion and ligation into the vector. It also includes procedures for bacterial transformation, colony screening via PCR and Sanger sequencing to confirm the mutation, and plasmid purification via miniprep. The document is structured with a clear introduction, a list of all required reagents and equipment, and a step-by-step methods section.

Cloning, Molecular

Construction and Segmental Reconstitution of Full-Length Infectious Clones of Milk Vetch Dwarf Virus.

The construction of infectious clones (ICs) is essential for studying viral replication, pathogenesis, and host interactions. Milk vetch dwarf virus (MDV), a nanovirus with a multipartite, single-stranded DNA genome, presents unique challenges for IC development due to its segmented genome organization. To enable functional analysis of its genome, we constructed full-length tandem-dimer-based ICs for all eight MDV genomic segments. Each segment was cloned into a binary vector and co-delivered into Nicotiana benthamiana, Nicotiana tabacum, Vicia faba, and Vigna unguiculata plants via Agrobacterium-mediated inoculation. Systemic infection was successfully reconstituted in all host plants, with PCR-based detection confirming the presence of all viral segments in the infected leaves of nearly all tested plants. Segmental accumulation in infected plants was quantified using qPCR, revealing non-equimolar distribution across hosts. This study establishes the first complete IC system for MDV, enabling reproducible infection, replication analysis, and quantitative segment profiling. It provides a foundational tool for future molecular investigations into MDV replication, host interactions, and viral movement, advancing our understanding of nanovirus biology and transmission dynamics.

Nicotiana

Cloning and validating systems for high throughput molecular recording.

Molecular recording technologies record and store information about cellular history. Lineage tracing is one form of molecular recording and produces information describing cellular trajectories during mammalian development, differentiation and maintenance of adult stem cell niches, and tumor evolution. Our molecular recorder technology utilizes CRISPR-Cas9 barcode editing to generate mutations in genomically integrated, engineered DNA cassettes, which are read out by single-cell RNA sequencing and used to produce high-resolution lineage trees. Here, we describe optimized cloning and validation procedures to construct the molecular recorder lineage tracing system. We include information on considerations of technology design, cloning procedures, the generation of lineage tracing cell lines, and time course experiments to assess their performance.

Cloning, Molecular

A Novel Approach to Engineering Tomato Spotted Wilt Virus Infectious Clones by Disarming Key Nodes in Antiviral Defenses.

Tomato spotted wilt virus (TSWV) is an economically devastating pathogen that rapidly overcomes genetic resistance in major crops. Reverse genetic systems are crucial for investigating plant-virus interactions and resistance-breaking mechanisms, and developing these tools for segmented ambisense RNA viruses remains a crucial challenge. Current TSWV clones rely on extensively modified Asian isolates requiring co-delivery of multiple replication helpers and viral silencing suppressors. Streamlining these systems for regionally significant strains with minimal genetic alterations is essential. Here, we developed the first infectious clone of a U.S. TSWV isolate (PA01). Three binary plasmids contain cDNAs for the antigenomic L and S segments, as well as the genomic M segment, with enhanced GFP replacing NSs on the S segment. Co-delivery of the cucumovirus 2b alone or in combination with tombusvirus P19 or begomovirus AL2 achieved a high proportion of systemically infected Nicotiana benthamiana and Capsicum annuum plants. In N. tabacum, co-delivering the Caenorhabditis elegans cell death suppressor CED-9 or using NahG transgenic plants produced 30 to 33% systemically infected plants. Co-delivery of 2b boosted infection levels in NahG plants to 62%. These data indicate that in addition to the antiviral RNA-silencing machinery, additional host defense pathways influence TSWV rescue and systemic infection from cDNA. [Formula: see text] Copyright &#xa9; 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Tospovirus

Cloning of human DING: Developmental expression and downregulation by EtOH in-utero.

INTRODUCTION: An estimated 15-20% of women consume alcohol (EtOH) during pregnancy. Women with alcohol use in early pregnancy are likely to have a child with fetal alcohol spectrum disorders (FASD). Recently, we reported neuroprotective effects of human DING (a member of the DING family of phosphatases) against EtOH-mediated toxicity in rats and in human fetal cortical neurons in vitro. Now, we report the sequencing and developmental expression patterns of endogenous DING in human fetal brain. METHODS: DING cDNA was cloned from human U87MG astrocytoma cells with primers specific to the plant DING gene and known prokaryotic DING genes. This cDNA was used to prepare antibodies. The full-length human DING gene p38hu (1095 nucleotide bases) is flanked by the first initiating codon, ATG, and the last, stop codon, TAA. Post-mortem fetal tissues and maternal blood were collected during pregnancy between 8 and 37 weeks' gestation. The developmental, spatial, and temporal expression of DING protein in fetal brain tissue was analyzed by immunohistochemistry. Developmental expression of DING in fetal brain and placenta was quantified by qWestern blots. DING promoter expression was assayed by ddPCR. Statistical analysis included ANOVA. RESULTS: Sequencing revealed different-sized genomic DNA clones. The anti-DING antibody detected proteins ranging in size from 35 to 40 kDa, and high molecular weight precursor protein in fetal brain and placenta. DING protein was present in fetal brain at early stages and its level was increased at later gestational ages. The DING promoter was expressed in fetal brain, neurospheres, and fetal brain-derived exosomes. DING levels were reduced in samples exposed to maternally consumed alcohol. CONCLUSIONS: Because DING is neuroprotective, its reduced expression in fetuses exposed to alcohol may suggest a mechanism that contributes to the pathogenesis of FASD, which could lead to the development of therapeutic tools aimed at preventing, ameliorating or reversing this prevalent group of syndromes that are implicated in as many as 5% of births world-wide.

DING gene cloning

Emergence of a Novel, Phenotypically Difficult-to-Detect Vancomycin-Resistant Enterococcus faecium Clone (ST117/CT7799).

A significant increase of vancomycin-resistant Enterococcus faecium (VREfm) infections was observed in South-Eastern Austria since 2024. The prolonged outbreak is caused by a novel vanB-VREfm clone (ST117/CT7799, "VREfmstyr"). This study characterizes the atypical difficult-to-detect resistance phenotype and assesses the genomic relatedness of the isolates. Patient and outbreak characteristics were investigated including whole genome sequencing of the isolates. Sensitivity of broth microdilution (BMD), gradient tests (GT), disk diffusion (DD), and automated susceptibility testing (VITEK2) was compared. The performance of commercial screening media was evaluated. From sporadic detections in early 2024 case numbers began to rise during the year. In 30/31 (97%) of all cases, intra-hospital transmission was considered likely and an association with invasive procedures was identified in most cases. Core genome multilocus sequence typing revealed only six allelic differences between VREfmstyr isolates collected in a 12-month period, all belonging to the E. faecium ST117/CT7799 lineage. BMD detected vancomycin resistance (MIC&#x2009;>&#x2009;4&#x2009;mg/L) in no more than 16/31 (52%) of isolates after 24&#x2009;h incubation, while GT and DD misclassified all isolates. Only prolonged incubation improved the performance of these assays. VITEK2 analysis, however, correctly classified all 31 isolates. Of four commercially available VRE-screening agars, only one was capable of detecting VREfmstyr after 24&#x2009;h incubation. The emergence and clonal dissemination of VREfm ST117/CT7799 reveals a serious diagnostic gap as commonly used diagnostic algorithms fail to reliably detect this resistance phenotype. Our findings should help to further evaluate the true geographical distribution and clinical significance of this novel VREfm clone.

Enterococcus faecium