Anti-Adenoviral Effect of Human Argonaute 2 Alone and in Combination with Artificial microRNAs.

During infection, adenoviruses inhibit the cellular RNA interference (RNAi) machinery by saturating the RNA-induced silencing complex (RISC) of the host cells with large amounts of virus-derived microRNAs (mivaRNAs) that bind to the key component of the complex, Argonaute 2 (AGO2). In the present study, we investigated AGO2 as a prominent player at the intersection between human adenovirus 5 (HAdV-5) and host cells because of its ability to interfere with the HAdV-5 life cycle. First, the ectopic expression of AGO2 had a detrimental effect on the ability of the virus to replicate.

Inhibition of adenovirus replication by CRISPR-Cas9-mediated targeting of the viral E1A gene.

DNA-targeting CRISPR-Cas systems are able to cleave dsDNA in mammalian cells. Accordingly, they have been employed to target the genomes of dsDNA viruses, mostly when present in cells in a non-replicative state with low copy numbers. However, the sheer amount of viral DNA produced within a very short time by certain lytically replicating viruses potentially brings the capacities of CRISPR-Cas systems to their limits.

Bacterial-like nitric oxide synthase in the haloalkaliphilic archaeon Natronomonas pharaonis.

Bacterial nitric oxide (NO) synthases (bNOS) play diverse and important roles in microbial physiology, stress resistance, and virulence. Although bacterial and mammalian NOS enzymes have been well-characterized, comparatively little is known about the prevalence and function of NOS enzymes in Archaea. Analysis of archaeal genomes revealed that highly conserved bNOS homologs were restricted to members of the Halobacteria.

Freezing from the inside: Ice nucleation in Escherichia coli and Escherichia coli ghosts by inner membrane bound ice nucleation protein InaZ.

Ice nucleation (IN) active bacteria such as Pseudomonas syringae promote the growth of ice crystals more effectively than any material known. Using the specialized ice nucleation protein (INP) InaZ, P. syringae-the well studied epiphytic plant pathogen-attacks plants by frost damage and, likewise fascinating, drives ice nucleation within clouds when airborne in the atmosphere by linkage to the Earth's water cycle.

virus , a Novel Halovirus Related to PhiH1 and PhiCh1.

The unexpected lysis of a large culture of strain S9 was found to be caused by a novel myovirus, designated ChaoS9. Virus purification from the culture lysate revealed a homogeneous population of caudovirus-like particles. The viral genome is linear, dsDNA that is partially redundant and circularly permuted, has a unit length of 55,145 nt, a G + C% of 65.

Complete Genome Sequence of the Model Halovirus PhiH1 (ΦH1).

The halophilic myohalovirus (ΦH) was first described in 1982 and was isolated from a spontaneously lysed culture of strain R1. Until 1994, it was used extensively as a model to study the molecular genetics of haloarchaea, but only parts of the viral genome were sequenced during this period. Using Sanger sequencing combined with high-coverage Illumina sequencing, the full genome sequence of the major variant (phiH1) of this halovirus has been determined.

The Viral Gene ORF79 Encodes a Repressor Regulating Induction of the Lytic Life Cycle in the Haloalkaliphilic Virus ϕCh1.

In this study, we describe the construction of the first genetically modified mutant of a halovirus infecting haloalkaliphilic By random choice, we targeted ORF79, a currently uncharacterized viral gene of the haloalkaliphilic virus ϕCh1. We used a polyethylene glycol (PEG)-mediated transformation method to deliver a disruption cassette into a lysogenic strain of the haloalkaliphilic archaeon bearing ϕCh1 as a provirus. This approach yielded mutant virus particles carrying a disrupted version of ORF79.

Functional display of ice nucleation protein InaZ on the surface of bacterial ghosts.

In a concept study the ability to induce heterogeneous ice formation by Bacterial Ghosts (BGs) from Escherichia coli carrying ice nucleation protein InaZ from Pseudomonas syringae in their outer membrane was investigated by a droplet-freezing assay of ultra-pure water. As determined by the median freezing temperature and cumulative ice nucleation spectra it could be demonstrated that both the living recombinant E. coli and their corresponding BGs functionally display InaZ on their surface.

Brucella vulpis sp. nov., isolated from mandibular lymph nodes of red foxes (Vulpes vulpes).

Two slow-growing, Gram-negative, non-motile, non-spore-forming, coccoid bacteria (strains F60T and F965), isolated in Austria from mandibular lymph nodes of two red foxes (Vulpes vulpes), were subjected to a polyphasic taxonomic analysis. In a recent study, both isolates were assigned to the genus Brucella but could not be attributed to any of the existing species. Hence, we have analysed both strains in further detail to determine their exact taxonomic position and genetic relatedness to other members of the genus Brucella.

Genomic manipulations in alkaliphilic haloarchaea demonstrated by a gene disruption in Natrialba magadii.

Alkaliphilic haloarchaea, a distinct physiological group from the closely related neutrophilic haloarchaea, represent an underutilized resource for basic research and industrial applications. In contrast to the neutrophilic haloarchaea, no reports on genomic manipulations in haloalkaliphiles have been published until now. Genomic manipulations via homologous recombination are useful for basic research.

Genotyping of Burkholderia mallei from an outbreak of glanders in Bahrain suggests multiple introduction events.

Background: Glanders, caused by the gram-negative bacterium Burkholderia mallei, is a highly infectious zoonotic disease of solipeds causing severe disease in animals and men. Although eradicated from many Western countries, it recently emerged in Asia, the Middle-East, Africa, and South America. Due to its rareness, little is known about outbreak dynamics of the disease and its epidemiology.

Antimicrobial activity of a chimeric enzybiotic towards Staphylococcus aureus.

Phage lytic enzymes (enzybiotics) have gained attention as prospective tools to eradicate Gram-positive pathogens resistant to antibiotics. Attempts to purify the P16 endolysin of Staphylococcus aureus phage P68 were unsuccessful owing to the poor solubility of the protein. To overcome this limitation, we constructed a chimeric endolysin (P16-17) comprised of the inferred N-terminal d-alanyl-glycyl endopeptidase domain and the C-terminal cell wall targeting domain of the S.

Genetic diversity and phylogenetic relationships of bacteria belonging to the Ochrobactrum-Brucella group by recA and 16S rRNA gene-based comparative sequence analysis.

The genetic diversity and phylogenetic interrelationships among 106 Ochrobactrum strains (O. anthropi: 72, O. intermedium: 22, O.

Specific detection and differentiation of Ochrobactrum anthropi, Ochrobactrum intermedium and Brucella spp. by a multi-primer PCR that targets the recA gene.

Ochrobactrum anthropi, Ochrobactrum intermedium and Brucella spp. are phenotypically and genetically closely related pathogens that may cause disease with similar clinical presentation. Consequently, difficulties in their identification and differentiation have been reported.

Genotyping of Ochrobactrum anthropi by recA-based comparative sequence, PCR-RFLP, and 16S rRNA gene analysis.

A recA-PCR restriction fragment length polymorphism assay was developed to study intraspecies variation among Ochrobactrum anthropi. Primers deduced from the known recA gene sequence of the genetically closely related genus Brucella allowed the specific amplification of a 1065 bp recA fragment from each of the 38 O. anthropi and the eight Brucella strains investigated.

Detection of the reemerging agent Burkholderia mallei in a recent outbreak of glanders in the United Arab Emirates by a newly developed fliP-based polymerase chain reaction assay.

A polymerase chain reaction (PCR) assay targeting the flagellin P (fliP)-I S407A genomic region of Burkholderia mallei was developed for the specific detection of this organism in pure cultures and clinical samples from a recent outbreak of equine glanders. Primers deduced from the known fliP-IS407A sequence of B. mallei American Type Culture Collection (ATCC) 23344(T) allowed the specific amplification of a 989-bp fragment from each of the 20 B.

Detection of Chromobacterium violaceum by multiplex PCR targeting the prgI, spaO, invG, and sipB genes.

Based on the recently completed genomic sequence of Chromobacterium violaceum American Type Culture Collection (ATCC) 12472 a multiplex PCR assay targeting the prgI, spaO, invG, and sipB genes of the Salmonella SPI-1 homologue type-III secretion system was developed. PCR products of 255bp (prgI), 749bp (spaO), 1685bp (invG), and 1752bp (sipB) were successfully amplified simultaneously in a single reaction with all Chr. violaceum strains investigated whereas other bacteria tested negative.

Functional analysis of the lysis genes of Staphylococcus aureus phage P68 in Escherichia coli.

Double-stranded DNA phages of both Gram-positive and Gram-negative bacteria typically use a holin-endolysin system to achieve lysis of their host. In this study, the lysis genes of Staphylococcus aureus phage P68 were characterized. P68 gene lys16 was shown to encode a cell-wall-degrading enzyme, which causes cell lysis when externally added to clinical isolates of S.

Genotyping of Chromobacterium violaceum isolates by recA PCR-RFLP analysis.

Intraspecies variation of Chromobacterium violaceum was examined by comparative sequence - and by restriction fragment length polymorphism analysis of the recombinase A gene (recA-PCR-RFLP). Primers deduced from the known recA gene sequence of the type strain C. violaceum ATCC 12472(T) allowed the specific amplification of a 1040bp recA fragment from each of the 13 C.

Complete nucleotide sequence and molecular characterization of two lytic Staphylococcus aureus phages: 44AHJD and P68.

The first complete nucleotide sequences of two lytic Staphylococcus aureus double stranded DNA phages, 44AHJD (16784 bp) and P68 (18227 bp), are reported. Both are small isometric phages, with short, non-contractile tails and a pre-neck appendage. Based on their morphology, their genome size, the similarity of the encoded gene products, the type of infection and on the possession of a type B DNA polymerase, 44AHJD and P68 are allocated to the order Caudovirales, family Podoviridae, genus 'phi29-like phages'.