Mutagenesis of Streptococcus equi and Streptococcus suis by transposon Tn917

Slater, Josh; Allen, Andrew G.; May, James P.; Bolitho, Steven; Lindsay, Heather; Maskell, Duncan J.

doi:10.1016/s0378-1135(03)00030-0

Cited by 60 publications

(40 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar discrepancy was found within the closely related Streptococcus equi and Streptococcus suis species. Tn917 insertions did not occur with any obvious bias in the S. suis genome; however, in S. equi, 60% of the Tn917 insertions occurred in a 15-kb region (28). By comparing the genes found in this region of the chromosome with the DNA sequence from S. equi, we can report that Tn917 also targets the terminus region in S. equi (personal observation), a region where dimer chromosomes are likely to be resolved via an unconventional system (dif SL ) found in the Streptococcus and Lactococcus genera (16).…”

Section: Fig 1 Distribution Of Tn917 Insertions Inmentioning

confidence: 82%

“…In E. faecalis and in S. equi, the grouping of Tn917 insertions was surprisingly strong despite the absence of an active replication termination system (23% and 60% of the insertions, respectively, fell in a region around dif that made up about 1% of the chromosome [10,28]); in B. subtilis, insertions were found only to focus tightly in a very small region in the presence of active termination via RTP (30% of the insertions in a region around terI-terII that comprised about 1% of the chromosome) (compare Fig. 1C and D).…”

Section: Fig 1 Distribution Of Tn917 Insertions Inmentioning

confidence: 99%

“…The bacterial transposon Tn917 was originally isolated from Enterococcus faecalis and has been used as an insertion mutagen in this and other gram-positive bacteria (5,28,32). However, Tn917 has been shown to have an extreme regional preference for insertion into the terminus region in E. faecalis, and the molecular mechanism responsible for this bias is unknown (10).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Tn 917 Targets the Region Where DNA Replication Terminates in Bacillus subtilis , Highlighting a Difference in Chromosome Processing in the Firmicutes

2009

View full text Add to dashboard Cite

The bacterial transposon Tn917 inserts preferentially in the terminus region of some members of the Firmicutes. To determine what molecular process was being targeted by the element, we analyzed Tn917 target site selection in Bacillus subtilis. We find that Tn917 insertions accumulate around the central terminators, terI and terII, in wild-type cells with or without the SP␤ lysogen. Highly focused targeting around terI and terII requires the trans-acting termination protein RTP, but it is unaffected in strains compromised in dimer resolution or chromosome translocation. This work indicates that Tn917 is sensitive to differences in DNA replication termination between the Firmicutes.Certain transposons are known to target features associated with DNA metabolism, and these elements have the potential to offer greater insight into these host processes (6). The bacterial transposon Tn917 was originally isolated from Enterococcus faecalis and has been used as an insertion mutagen in this and other gram-positive bacteria (5, 28, 32). However, Tn917 has been shown to have an extreme regional preference for insertion into the terminus region in E. faecalis, and the molecular mechanism responsible for this bias is unknown (10). Multiple processing events associated with chromosome duplication occur in the terminus region, a portion of the chromosome we define here as equidistant from the origin of DNA replication in circular genomes. In some bacteria, a system exists that actively terminates DNA replication forks at specific sites within the terminus region, called ter sites, through the use of a trans-acting protein called Tus in Escherichia coli and RTP in Bacillus subtilis (8,9,18). Another processing event that occurs in the terminus region involves the resolution of dimer chromosomes at a site called dif (2). The resolution of dimer chromosome is usually catalyzed by two tyrosine recombinases called XerC and XerD in E. coli and RipX and CodV in B. subtilis.To better understand processing events in bacterial chromosomes, we investigated Tn917 target site selection in the model low-GϩC gram-positive bacterium, B. subtilis, where replication and recombination are well studied. We were specifically interested in knowing if Tn917 targeted DNA replication termination or dimer resolution as suggested previously (10). There are multiple examples where elements have been suggested to recognize these molecular processes as targets for transposition in E. coli (20,23,29). In the case of Tn917, it is of special interest to understand targeting because this behavior differs even between closely related species; Tn917 transposition preferentially occurs in the terminus region of Enterococcus faecalis and Streptococcus equi, but this behavior is not found in Listeria monocytogenes and Streptococcus suis (see references 10 and 28 and see below).Tn917 insertions were collected in B. subtilis using plasmid pTV1-OK in the strain CU1065 (W168 trpC2 SP␤ Ϫ ) background using a procedure that prevented the isolation and sequencing of the s...

show abstract

Section: Fig 1 Distribution Of Tn917 Insertions Inmentioning

confidence: 82%

Section: Fig 1 Distribution Of Tn917 Insertions Inmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Tn 917 Targets the Region Where DNA Replication Terminates in Bacillus subtilis , Highlighting a Difference in Chromosome Processing in the Firmicutes

2009

View full text Add to dashboard Cite

show abstract

“…pTV408 is a thermo-sensitive plasmid able to replicate at temperatures below 37 uC but not above this temperature (Slater et al, 2003). It harbours the Tn917 transposon conferring erythromycin resistance.…”

Section: Methodsmentioning

confidence: 99%

“…L. garvieae strain UNIUD074 was obtained from Dr L. Gusmani (University of Udine, Italy). Plasmid pTV408 (Slater et al, 2003) was obtained from Dr J. P. May (Department of Clinical Veterinary Medicine, University of Cambridge, UK). L. garvieae strains were routinely cultured in brain heart infusion medium (BHI) (Difco) at 20, 28 or 40 uC.…”

Section: Methodsmentioning

confidence: 99%

Genes required for Lactococcus garvieae survival in a fish host

et al. 2007

View full text Add to dashboard Cite

Lactococcus garvieae is considered an emergent pathogen in aquaculture and it is also associated with mastitis in domestic animals as well as human endocarditis and septicaemia. In spite of this, the pathogenic mechanisms of this bacterium are poorly understood. Signature-tagged mutagenesis was used to identify virulence factors and to establish the basis of pathogen-host interactions. A library of 1250 L. garvieae UNIUD074-tagged Tn917 mutants in 25 pools was screened for the ability to grow in fish. Among them, 29 mutants (approx. 2.4 %) were identified which could not be recovered from rainbow trout following infection. Sequence analysis of the tagged Tn917-interrupted genes in these mutants indicated the participation in pathogenesis of the transcriptional regulatory proteins homologous to GidA and MerR; the metabolic enzymes asparagine synthetase A and a-acetolactate synthase; the ABC transport system of glutamine and a calcium-transporting ATPase; the dltA locus involved in alanylation of teichoic acids; and hypothetical proteins containing EAL and Eis domains, among others.Competence index experiments in several of the selected mutants confirmed the relevance of the Tn917-interrupted genes in the development of the infection process. The results suggested some of the metabolic routes and enzymic systems necessary for the complete virulence of this bacterium. This work is believed to represent the first report of a genome-wide scan for virulence factors in L. garvieae. The identified genes will further our understanding of the pathogenesis of L. garvieae infections and may provide targets for intervention or lead to the development of novel therapies. INTRODUCTIONLactococcus garvieae is the aetiological agent of lactococcosis, an emergent disease, which affects cultured freshwater and marine fish with special incidence in rainbow trout (Onchorhynchus mykiss) (Eldar et al., 1999a) and yellowtail (Seriola quinqueradiata) (Kusuda & Kawai, 1998), particularly during the summer given its association with high water temperatures (for a review see Vendrell et al., 2006). In addition, L. garvieae has been isolated from buffalos with mastitis (Teixeira et al., 1996), from clinical specimens of human blood and urine (Elliott et al., 1991) and from patients with bacterial endocarditis and different tissue infections (Aguirre & Collins, 1993;Fefer et al., 1998;James et al., 2000;Mofredj et al., 2000;Fihman et al., 2006;Vinh et al., 2006;Yiu et al., 2007).In fish farming, outbreaks are treated with antibiotics, although they are often ineffective and do not prevent reinfection. On the other hand, vaccination with inactivated whole cells by intraperitoneal injection is only protective for a limited period of time (Ravelo et al., 2005). In recent years, progress has been made in diagnostic techniques (Endo et al., 1998;Zlotkin et al., 1998;Goh et al., 2000;Wilson & Carson, 2003), strain typing (Eldar et al., 1999b;Vela et al., 2000;Wilson et al., 2002; Ravelo et al., 2003;Barnes & Ellis, 2004;Eyngor et al., 2004;Kawani...

show abstract

A mariner transposon vector adapted for mutagenesis in oral streptococci

et al. 2014

View full text Add to dashboard Cite

This article describes the construction and characterization of a mariner-based transposon vector designed for use in oral streptococci, but with a potential use in other Gram-positive bacteria. The new transposon vector, termed pMN100, contains the temperature-sensitive origin of replication repATs-pWV01, a selectable kanamycin resistance gene, a Himar1 transposase gene regulated by a xylose-inducible promoter, and an erythromycin resistance gene flanked by himar inverted repeats. The pMN100 plasmid was transformed into Streptococcus mutans UA159 and transposon mutagenesis was performed via a protocol established to perform high numbers of separate transpositions despite a low frequency of transposition. The distribution of transposon inserts in 30 randomly picked mutants suggested that mariner transposon mutagenesis is unbiased in S. mutans. A generated transposon mutant library containing 5000 mutants was used in a screen to identify genes involved in the production of sucrose-dependent extracellular matrix components. Mutants with transposon inserts in genes encoding glycosyltransferases and the competence-related secretory locus were predominantly found in this screen.

show abstract

Mutagenesis of Streptococcus equi and Streptococcus suis by transposon Tn917

Cited by 60 publications

References 18 publications

Tn 917 Targets the Region Where DNA Replication Terminates in Bacillus subtilis , Highlighting a Difference in Chromosome Processing in the Firmicutes

Tn 917 Targets the Region Where DNA Replication Terminates in Bacillus subtilis , Highlighting a Difference in Chromosome Processing in the Firmicutes

Genes required for Lactococcus garvieae survival in a fish host

A mariner transposon vector adapted for mutagenesis in oral streptococci

Contact Info

Product

Resources

About