Curing of plasmid pBMB28 fromBacillus thuringiensisYBT-020 using an unstable replication region

The incompatibility properties of IncFII R plasmid NR1 were compared with those of two of its copy number mutants, pRR12 and pRR21. pRR12 produced an altered incompatibility product and also had an altered incompatibility target site. The target site appeared to be located within the incompatibility gene, which is located more than 1,200 base pairs from the plasmid origin of replication. The incompatibility properties of pRR21 were indistinguishable from those of NR1. Lambda phages have been constructed which contain the incompatibility region of NR1 or of one of its copy mutants fused to the lacZ gene. In lysogens constructed with these phages, beta-galactosidase was produced under the control of a promoter located within the plasmid incompatibility region. Lysogens containing prophages with the incompatibility regions from pRR12 and pRR21 produced higher levels of beta-galactosidase than did lysogens containing prophages with the incompatibility region from the wild-type NR1. The introduction into these inc-lac lysogens of pBR322 plasmids carrying the incompatibility regions of the wild-type or mutant plasmids resulted in decreased levels of beta-galactosidase production. For a given lysogen, the decrease was greater when the pBR322 derivative expressed a stronger incompatibility toward the plasmid from which the fragment in the prophage was derived. This suggested that the incompatibility product acts on its target to repress gene expression in the plasmid replication region.

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Insertion sequence IST3091 of Thiobacillus ferrooxidans

Canadian Journal of Microbiology ◽

10.1139/m97-072 ◽

1997 ◽

Vol 43 (6) ◽

pp. 503-508 ◽

Cited By ~ 4

Author(s):

Leena Chakravarty ◽

Joseph D. Kittle Jr. ◽

Olli H. Tuovinen

Keyword(s):

Insertion Sequence ◽

Thiobacillus Ferrooxidans ◽

Insertion Element ◽

Transposase Gene ◽

Integrase Gene ◽

Spiroplasma Citri ◽

E Coli ◽

Putative Origin ◽

Replication Region ◽

Polymerase Chain

An insertion sequence, designated as IST3091, was located adjacent to the putative origin of replication region of plasmid pTFI91 of Thiobacillus ferrooxidans TFI-91. The DNA sequence of the transposase gene of IST3091 revealed similarity with that of IS30, IS1086, IS4351, and the integrase gene of SpV1-R8A2 B (a bacteriophage of Spiroplasma citri). The sequence of IST3091 is 1063 bp long with partially matched 30-bp terminal inverted repeats. Several restriction fragments of plasmid pTFI91 of T. ferrooxidans containing the IST3091 element were cloned into the vector pHSG398. The hybrid plasmids (pBTL) were transformed into Escherichia coli NK7379 containing a miniF plasmid, which was devoid of transposable elements. The transposition function of the IST3091 element was confirmed by mobilizing hybrid plasmids via conjugation from transformed E. coli NK7379 (donor) to E. coli M8820 (recipient). The presence of the transposed element in transconjugants was detected by polymerase chain reaction amplification.Key words: insertion element, Thiobacillus ferrooxidans, transformation, transposase.

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Molecular analysis of the replication region of the pCIZ2 plasmid from the multiple bacteriocin producer strain Enterococcus faecium L50

Plasmid ◽

10.1016/j.plasmid.2008.07.002 ◽

2008 ◽

Vol 60 (3) ◽

pp. 181-189 ◽

Cited By ~ 3

Author(s):

R. Criado ◽

J. Gutiérrez ◽

A. Budin-Verneuil ◽

P.E. Hernández ◽

A. Hartke ◽

...

Keyword(s):

Molecular Analysis ◽

Enterococcus Faecium ◽

Producer Strain ◽

Bacteriocin Producer ◽

Replication Region

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Replication Region Analysis Reveals Non-lambdoid Shiga Toxin Converting Bacteriophages

Frontiers in Microbiology ◽

10.3389/fmicb.2021.640945 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ann-Katrin Llarena ◽

Marina Aspholm ◽

Kristin O’Sullivan ◽

Grzegorz Wêgrzyn ◽

Toril Lindbäck

Keyword(s):

Shiga Toxin ◽

Gene Arrangement ◽

Gene Encoding ◽

Lambdoid Phage ◽

Virulence Potential ◽

Genes Encoding ◽

Large Outbreak ◽

Replication Region ◽

Family Based ◽

Novel Strategy

Shiga toxin is the major virulence factor of enterohemorrhagic Escherichia coli (EHEC), and the gene encoding it is carried within the genome of Shiga toxin-converting phages (Stx phages). Numerous Stx phages have been sequenced to gain a better understanding of their contribution to the virulence potential of EHEC. The Stx phages are classified into the lambdoid phage family based on similarities in lifestyle, gene arrangement, and nucleotide sequence to the lambda phages. This study explores the replication regions of non-lambdoid Stx phages that completely lack the O and P genes encoding the proteins involved in initiating replication in the lambdoid phage genome. Instead, they carry sequences encoding replication proteins that have not been described earlier, here referred to as eru genes (after EHEC phage replication unit genes). This study identified three different types of Eru-phages, where the Eru1-type is carried by the highly pathogenic EHEC strains that caused the Norwegian O103:H25 outbreak in 2006 and the O104:H4 strain that caused the large outbreak in Europe in 2011. We show that Eru1-phages exhibit a less stable lysogenic state than the classical lambdoid Stx phages. As production of phage particles is accompanied by production of Stx toxin, the Eru1-phage could be associated with a high-virulence phenotype of the host EHEC strain. This finding emphasizes the importance of classifying Stx phages according to their replication regions in addition to their Stx-type and could be used to develop a novel strategy to identify highly virulent EHEC strains for improved risk assessment and management.

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Functional relationship between parts of the replication region of plasmid ColE1.

Journal of Bacteriology ◽

10.1128/jb.143.2.1073-1076.1980 ◽

1980 ◽

Vol 143 (2) ◽

pp. 1073-1076

Author(s):

J Inselburg

Keyword(s):

Functional Relationship ◽

Replication Region

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High diversity in the regulatory region of Stx-converting bacteriophage genomes

10.1101/2021.11.24.469858 ◽

2021 ◽

Author(s):

Toril Lindback ◽

Annette Fagerlund ◽

Marina Elisabeth Aspholm ◽

Grzegorz Wegrzyn

Keyword(s):

Life Cycle ◽

Western Europe ◽

Regulatory Region ◽

Enterohemorrhagic Escherichia Coli ◽

Replication Proteins ◽

E Coli ◽

Virulence Potential ◽

Replication Region ◽

Severity Of The Disease

Shiga toxin (Stx) is the major virulence factor of enterohemorrhagic Escherichia coli (EHEC), and the stx genes are carried by temperate bacteriophages (Stx phages). The switch between lysogenic and lytic life cycle of the phage, which is crucial for Stx production and for severity of the disease, is regulated by the CI repressor. CI maintain latency by preventing transcription of the replication proteins. Three EHEC phage replication units (Eru1-3) in addition to the classical lambdoid replication region have been described previously, and Stx phages carrying the Eru1 replication region were associated with highly virulent EHEC strains. In this study, we have classified the Eru replication region of 419 Stx phages. In addition to the lambdoid replication region and the three already described Erus, ten novel Erus (named Eru4 to Eru13) were detected. The lambdoid type, Eru1, Eru4 and Eru7 seem to be widely distributed in Western Europe. Notably, EHEC strains involved in severe outbreaks in England and Norway carry Stx phages with Eru1, Eru2, Eru5 and Eru7 replication regions. Phylogenetic analysis of CI repressors from Stx phages revealed eight major clades that largely separate according to Eru type. The classification of replication regions and CI proteins of Stx phages provides an important platform for further studies aimed to assess how characteristics of the replication region influence the regulation of phage life cycle and, consequently, the virulence potential of the host EHEC strain. IMPORTANCE: EHEC is an emerging health challenge worldwide and outbreaks caused by this pathogen tend to be more frequent and severe. Increased knowledge on how characteristics of the replication region influence the virulence of E. coli may be used for more precise identification of high-risk EHEC strains.

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