Cells of Actinobacillus actinomycetemcomitans, a gram-negative pathogen responsible for an aggressive form of juvenile periodontitis, form tenaciously adherent biofilms on solid surfaces. The bacteria produce long fibrils of bundled pili, which are required for adherence. Mutations in flp-1, which encodes the major subunit of the pili, or any of seven downstream tad genes (tadABCDEFG) cause def...

Viruses have evolved to efficiently direct the resources of their hosts toward their own reproduction. A quantitative understanding of viral growth will help researchers develop antiviral strategies, design metabolic pathways, construct vectors for gene therapy, and engineer molecular systems that self-assemble. As a model system we examine here the growth of bacteriophage T7 in Escherichia col...

BACKGROUND Recently, the use of T7 RNA polymerase instead of other viral and cellular promoters is increasing due to high efficacy of transcription in the cell cytoplasm by this polymerase. In order to translate the transcripts produced by T7 RNA polymerase in mammalian cell lines, it is necessary to include Internal Ribosome Entry Site (IRES) sequences. In addition, if sequence of poly A signa...

Specific fragmentation of T7 DNA at glyoxal-fixed denatured regions by the S1 endonuclease followed by restriction analysis made it possible to localize four low-melting regions in phage T7 DNA. These regions have the following coordinates:0.5-1.2;14.8+/-0.3;46.3+/-0.5; 98.4+/-0.3 (in T7 DNA length units). The location of the low-melting regions was refined by means of electron-microscopic dena...

In vivo, replication of T7 DNA does not occur after infection of Escherchia coli tsnC mutants (CHAMBERLIN, M. (1974) J. Virol. 14, 509-516). In vitro, extracts of tsnC mutant E. coli infected with T7 hage are incapable of replicating duplex T7 DNA, although extracts of wild type E. coli infected with T7 phage support replication of T7 DNA. In addition, extracts of the infected tsnC mutant are d...

After infection of Escherichia coli B with radiolabeled T7 bacteriophage, the parental deoxyribonucleic acid label was found in both polynucleotide chains of the intracellular T7 concatemer.

Bacteriophages are ideal candidates for pathogen biocontrol to mitigate outbreaks of prevalent foodborne pathogens, such as Escherichia coli We identified a bacteriophage (AAPEc6) from wastewater that infects E. coli O45:H10. The AAPEc6 genome sequence shares 93% identity (with 92% coverage) to enterobacterial phage K1E (Sp6likevirus) in the Autographivirinae subfamily (Podoviridae).

Alkylation of T7 bacteriophage considerably delayed phage development and reduced the phage's killing action on host cells. Only a small fraction of infected cells produced phage. For these phages, the latent period was markedly prolonged but the burst was equivalent to or only slightly lower than that of untreated phage. In the progeny of alkylated phage, there was an increase in the fraction ...