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Retracted: Inhibition of hepatitis C virus replication by intracellular delivery of multiple siRNAs by nanosomes.

Sustained antiviral responses of chronic hepatitis C virus (HCV) infection have improved recently by the use of direct-acting antiviral agen … lture using nanosomes without toxicity. Six siRNAs dramatically reduced HCV replication in both the replicon and infectious cell culture model. Repeated treatments with two siRNAs were better than a single siRNA treatment in minimizing the development of an escape mutant, resulting in rapid inhibition of viral replication. Systemic administration of combin …

A reporter system for Epstein-Barr virus (EBV) lytic replication: anti-EBV activity of the broad anti-herpesviral drug artesunate.

Epstein-Barr virus (EBV) is associated with severe human diseases. Therapies with conventional anti-herpesviral drugs are mostly ineffective so that novel drugs are urgently needed. As cell culture-based evaluation systems are required, a GFP (green fluorescent protein) reporter system was generated, which was conceived for an easy quantitation of lytic EBV replication and the analysis of EBV drug sensitivity. A reporter construct was generated on the basis of an EBV plasmid mini-replicon which enabled an episomal maintenance and selection of stably transfected Raji and 293T cell clones. Contr…

A cysteine-rich metal-binding domain from rubella virus non-structural protein is essential for viral protease activity and virus replication.

The protease domain within the RUBV (rubella virus) NS (non-structural) replicase proteins functions in the self-cleavage of the polyprotein … d Cys(1227) were required for the binding of Zn(2+). Corresponding mutational analyses using a RUBV replicon confirmed that these residues were necessary for both proteolytic activity of the NS protease and viability. The present study demonstrates that the CXXC(X)(48)CXC Zn(2+)-binding motif in the RUBV NS protease is critical for maintaining the structur …

Протеиновая киназа G фосфорилаты, переносимые комарами, флавивирус NS5.

Serine/threonine фосфорилирование неструктурного белка 5 (NS5) является одним из сохраняемых свойств флавивирусов, однако киназы, ответственные и функции, остаются неизвестными. Масс-спектрометрия использовалась для сравнения мест фосфориляции NS5 белков желтого вируса лихорадки (YFV) и вируса денге (DENV), двух флавивирусов, передаваемых комарами. Было выявлено семь фосфоропептидов ДЕНВ, однако в обоих вирусах был обнаружен только один сохранившийся объект для приема фосфора (трейнина 449 в ДЕНВ). Согласно прогнозам, этот участок является местом распознавания белковой киназы G (PKG) и строго

Совпадение в аннотации оригинала
Serine/threonine phosphorylation of the nonstructural protein 5 (NS5) is a conserved feature of flaviviruses, but the kinase(s) responsible … laviviruses. In contrast, in tick-borne flaviviruses, this residue is typically a histidine. A DENV replicon engineered to have the tick-specific histidine residue at this position is replication defective. We show that DENV NS5 purified from Escherichia coli is a substrate for PKG in vitro and facilitates the autophosphorylation of PKG as seen with cellul …

Mobile gene cassettes and integrons: moving antibiotic resistance genes in gram-negative bacteria.

In Gram-negative pathogens, multiple antibiotic resistance is common and many of the known resistance genes are contained in mobile gene cas … derivatives. Integron movement allows transfer of the cassette-associated resistance genes from one replicon to another or into another active transposon which facilitates spread of integrons that are transposition defective. Horizontal transfer of the resistance genes can be achieved when an integron containing one or more such genes is incorporated into …

"Strong incompatibility" between derivatives of the Streptomyces multi-copy plasmid pIJ101.

Some derivatives of pIJ101, a 8.9 kb Streptomyces multi-copy plasmid, can co-exist with each other at similar copy numbers but others are strongly incompatible. The DNA sequence, sti, which causes this "strong incompatibility" was localised on a DNA segment of about 200 bp which is not part of the essential replication region of pIJ101. The sti function is active only when the DNA fragment carrying it is present in the natural orientation with respect to the basic replicon region of pIJ101. Pairs of plasmids which either both possess sti in the correct orientation (Sti+) or both lack sti or ca…

Environmental occurrence of optrA-mediated linezolid resistance in Enterococcus isolates and genomic insights into Enterococcus faecium ST54 co-harboring optrA, poxtA, and cfr(D) genes.

Linezolid-resistant Enterococcus species have emerged worldwide, with resistance mainly driven by plasmid-borne optrA, poxtA, and cfr genes. … bitory concentration to linezolid ranged from 0.5 to > 64 mg/L. Several virulence genes and plasmid replicons were observed, with gelE and rep9 being most prevalent, respectively. Ten isolates co-harbored the optrA and poxtA genes and belonged to the known sequence type (ST) 1221 (E. faecium) and ST283, ST253, ST234, and ST1230 (E. faecalis), as well as to …

Structure analysis of the telomere resolvase from the Lyme disease spirochete Borrelia garinii reveals functional divergence of its C-terminal domain.

Borrelia spirochetes are the causative agents of Lyme disease and relapsing fever, two of the most common tick-borne illnesses. A characteristic feature of these spirochetes is their highly segmented genomes which consists of a linear chromosome and a mixture of up to approximately 24 linear and circular extrachromosomal plasmids. The complexity of this genomic arrangement requires multiple strategies for efficient replication and partitioning during cell division, including the generation of hairpin ends found on linear replicons mediated by the essential enzyme ResT, a telomere resolvase. Us…

Tracing down the updates on Ebola virus surges: An update on anti-ebola therapeutic strategies.

Ebola virus (EBOV) related health complications have presented a great threat to the healthcare system in the endemic regions. The outbreaks … overview of diferent vaccination strategies: inactivated and DNA vaccines, virus-like particles and replicons, reverse genetic and recombinant approaches, entry, ion, and gene expression inhibitors, and some repurposed drugs. This data will help the scientific community to get a comprehensive overview of therapeutic interventions against Ebola that could b …

Whole-genome sequencing study of KPC-encoding Klebsiella pneumoniae isolated in Greek private laboratories from non-hospitalised patients.

OBJECTIVES: Greece is endemic for KPC-encoding Klebsiella pneumoniae; however, until now, reports have referred only to hospital isolates. In this study, seven KPC-encoding K. pneumoniae isolated in private laboratories from non-hospitalised patients were characterised. METHODS: Whole-genome sequencing was performed on an Illumina MiniSeq Sequencing System. Multilocus sequence typing (MLST) was performed using a BLAST-based approach, and antimicrobial resistance genes and plasmid replicons were identified using ResFinder and PlasmidFinder, respectively. The Rapid Annotation using Subsystem Te…

Flavonoids from Pterogyne nitens Inhibit Hepatitis C Virus Entry.

Hepatitis C virus (HCV) is one of the leading causes of liver diseases and transplantation worldwide. The current available therapy for HCV … These compounds were investigated for their anti-HCV activities using genotype 2a JFH-1 subgenomic replicons and infectious virus systems. Flavonoids 1 and 2 inhibited virus entry up to 45.0% and 78.7% respectively at non-cytotoxic concentrations. The mechanism of the flavonoid 2 block to virus entry was demonstrated to be by both the direct action on vir …

Preclinical evaluation of an anti-HCV miRNA cluster for treatment of HCV infection.

We developed a strategy to treat hepatitis C virus (HCV) infection by replacing five endogenous microRNA (miRNA) sequences of a natural miRN … by continuous expression of the anti-HCV miRNAs. Furthermore, the number of cells harboring HCV RNA replicons decreased dramatically by sustained expression of the anti-HCV miRNAs, suggesting that the vector is capable of curing cells of HCV. Delivery of AAV-HCV-miR-Cluster 5 to mice resulted in efficient transfer of the miRNA gene cluster and expression o …

Genetics of Borrelia burgdorferi.

The spirochetes in the Borrelia burgdorferi sensu lato genospecies group cycle in nature between tick vectors and vertebrate hosts. The current assemblage of B. burgdorferi sensu lato, of which three species cause Lyme disease in humans, originated from a rapid species radiation that occurred near the origin of the clade. All of these species share a unique genome structure that is highly segmented and predominantly composed of linear replicons. One of the circular plasmids is a prophage that exists as several isoforms in each cell and can be transduced to other cells, likely contributing to a…

Amidinoanthracyclines - a new group of potential anti-hepatitis C virus compounds.

Hepatitis C virus (HCV) infections represent one of the major and still unresolved health problems because current therapy is effective in o … on of the active helicase complex. Selected amidinoanthracyclines were tested in the subgenomic HCV replicon system. These experiments confirmed the antiviral activity of two selected inhibitors (EC(50) values below 0.2 mum with selectivity indices of 19 and 33) and proved that they may be considered as potential anti-HCV drugs.

A five-amino-acid deletion of the eastern equine encephalitis virus capsid protein attenuates replication in mammalian systems but not in mosquito cells.

Eastern equine encephalitis virus (EEEV) is a human and veterinary pathogen that causes sporadic cases of fatal neurological disease. We previously demonstrated that the capsid protein of EEEV is a potent inhibitor of host cell gene expression and that this function maps to the amino terminus of the protein. We now identify amino acids 55 to 75, within the N terminus of the capsid, as critical for the inhibition of host cell gene expression. An analysis of stable EEEV replicons expressing mutant capsid proteins corroborated these mapping data. When deletions of 5 to 20 amino acids within this …

The M1 and NP proteins of influenza A virus form homo- but not heterooligomeric complexes when coexpressed in BHK-21 cells.

The nucleoprotein (NP) and matrix protein (M1) are the most abundant structural proteins of influenza A virus. M1 forms a protein layer beneath the viral envelope and NP constitutes the protein backbone of the ribonucleoproteins (RNPs). In order to elucidate the functions of these proteins in virus assembly we have expressed NP and M1 in BHK-21 cells using Semliki Forest virus replicons and analysed their molecular interactions. We found that both M1 and NP engaged in extensive homooligomerization reactions soon after synthesis. However, there was no detectable heterooligomerization taking pla…

Molecular evolution of multiply-antibiotic-resistant staphylococci.

Methicillin-resistant Staphylococcus aureus (MRSA) is an intractable nosocomial pathogen. The chemotherapeutic intransigence of this organis … insertion sequences. Clinical staphylococci commonly carry one or more plasmids, ranging from small replicons that are phenotypically cryptic or contain only a single resistance gene, to larger episomes that possess several such determinants and sometimes additionally encode systems that mediate their own conjugative transmission and the mobilization of ot …

Glycerol-Based Cryopreservation of Sinorhizobium/Ensifer Strains from Sweet Acacia (Vachellia farnesiana [L.] Wight & Arn.).

The genus Sinorhizobium (Ensifer) exhibits remarkable metabolic versatility and adaptive capacity, establishing effective nitrogen-fixing symbioses with diverse legume crops, including the pioneer shrub Vachellia farnesiana. This association is crucial for ecological restoration in arid and nutrient-deficient Mexican dryland ecosystems and for the remediation of contaminated sites. However, the prolonged preservation of specialized native strains through continuous serial subculturing risks genomic instability and the loss of extrachromosomal replicons harboring essential nod, nif, and heavy m…

Identification of NDM-1 producing and colistin resistant Klebsiella pneumoniae ST11: A highly drug-resistant strain detected in intensive care unit of a Greek tertiary care hospital.

The spread of NDM-1-harboring Klebsiella pneumoniae is a worldwide concern. In this study the whole-genome sequence (WGS) of a carbapenem- and colistin-resistant K. pneumoniae 838Gr strain is presented. This strain was isolated from a urine sample of a patient in the Intensive Care Unit (ICU) at Volos Hospital, Greece. The initial assembly produced 224 contigs with a combined genome size of 5,561,803 bp and a GC content of 57.21%. The K. pneumoniae strain carried IncR, IncFIA, IncC, and repB (R1701) replicons. Multilocus sequence typing (MLST) analysis revealed that the isolate belonged to the…

Curing of a field strain of Salmonella enterica serovar Infantis isolated from poultry from its highly stable pESI like plasmid.

Salmonella enterica serovar Infantis (S. infantis) is an important emerging pathogen, associated with poultry and poultry products and related to an increasing number of human infections in many countries. A concerning trend among S. infantis isolates is the presence of plasmid-mediated multidrug resistance. In many instances, the genes responsible for this resistance are carried on a megaplasmid known as the plasmid of emerging S. infantis (pESI) or pESI like plasmids. Plasmids can be remarkably stable due to the presence of multiple replicons and post-segregational killing systems (PSKs), wh…