Genetic Analysis of Transfer-Related Regions of the Vancomycin Resistance
            <i>Enterococcus</i>
            Conjugative Plasmid pHTβ: Identification of
            <i>oriT</i>
            and a Putative Relaxase Gene

Tomita, Haruyoshi; Ike, Yasuyoshi

doi:10.1128/jb.187.22.7727-7737.2005

Cited by 39 publications

(45 citation statements)

References 46 publications

(43 reference statements)

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“…pMG1-like plasmids were widely disseminated in vancomycin-resistant E. faecium clinical isolates obtained from a hospital in the United States (27). Recently, we also isolated pMG1-like plasmids carrying Tn1546-like transposons that encode vancomycin resistance in E. faecium clinical isolates in Japan (26,28). All of the pMG1-like plasmids carry a conserved traA gene which is involved in the tra gene system for conjugation and is pMG1 specific (24).…”

Section: Resultsmentioning

confidence: 99%

Molecular Characterization of Vancomycin-Resistant Enterococcus faecium Isolates from Mainland China

Zheng

Tomita²,

Xiao

et al. 2007

J Clin Microbiol

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Little is known about vancomycin-resistant enterococci in China. Thirteen pulsed-field gel electrophoresisconfirmed heterogeneous VanA-type vancomycin-resistant Enterococcus faecium (VRE) isolates were obtained from five Chinese hospitals from 2001 to 2005. The isolates were typed by multilocus sequence typing into nine different sequence types (STs), including five new STs (ST18, ST25, ST78, ST203, ST320, ST321, ST322, ST323, and ST335). Vancomycin resistance in each isolate was encoded on conjugative plasmids; two of the plasmids, pZB18 (67 kbp) and pZB22 (200 kbp), were highly conjugative and were able to transfer at high frequencies of around 10 ؊4 and 10 ؊7 per donor cell in broth mating, respectively. None of the plasmids identified in these isolates carried traA, which is usually conserved in the pMG1-like highly conjugative plasmid for E. faecium, implying that pZB18 and pZB22 were novel types of a highly conjugative plasmid in enterococci. Thirteen Tn1546-like elements encoding VanA-type VRE on the conjugative plasmids were classified into six types (types I to VI), and most of them contained both IS1216V and IS1542 insertions. The isolates carrying the type II element were predominant. The six type elements were different from that of a VanA-type Enterococcus faecalis strain isolated from Chinese chicken meat. The results suggested that the disseminations of VRE in these areas were by Tn1546-like elements being acquired by the conjugative plasmids and transferred among E. faecium strains.

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Section: Resultsmentioning

confidence: 99%

Molecular Characterization of Vancomycin-Resistant Enterococcus faecium Isolates from Mainland China

Zheng

Tomita²,

Xiao

et al. 2007

J Clin Microbiol

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“…Broth mating and solid-surface mating were performed as previously described (48,49), with a donor/recipient ratio of 1:10. Broth matings (in THB) were carried out for 4 h, and solid-surface matings (on THB agar plates) were carried out overnight (16 h) at 37°C.…”

Section: Methodsmentioning

confidence: 99%

Cloning and Genetic Analyses of the Bacteriocin 41 Determinant Encoded on the Enterococcus faecalis Pheromone-Responsive Conjugative Plasmid pYI14: a Novel Bacteriocin Complemented by Two Extracellular Components (Lysin and Activator)

Tomita¹,

Kamei²,

Ike

2008

J Bacteriol

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The conjugative plasmid pYI14 (61 kbp) was isolated from Enterococcus faecalis YI714, a clinical isolate. pYI14 conferred a pheromone response on its host and encoded bacteriocin 41 (bac41). Bacteriocin 41 (Bac41) only showed activity against E. faecalis. Physical mapping of pYI14 showed that it consisted of EcoRI fragments A to P. The clone pHT1100, containing EcoRI fragments A (12.6 kbp) and H (3.5 kbp), conferred the bacteriocin activity on E. faecalis strains. Genetic analysis showed that the determinant was located in a 6.6-kbp region within the EcoRI AH fragments. Six open reading frames (ORFs) were identified in this region and designated ORF7 (bacL 1 ) ORF8 (bacL 2 ), ORF9, ORF10, ORF11 (bacA), and ORF12 (bacI). They were aligned in this order and oriented in the same direction. ORFs bacL 1 , bacL 2 , bacA, and bacI were essential for expression of the bacteriocin in E. faecalis. Extracellular complementation of bacteriocin expression was possible for bacL 1 and -L 2 and bacA mutants. bacL 1 and -L 2 and bacA encoded bacteriocin component L and activator component A, respectively. The products of these genes are secreted into the culture medium and extracellularly complement bacteriocin expression. bacI encoded immunity, providing the host with resistance to its own bacteriocin activity. The bacL 1 -encoded protein had significant homology with lytic enzymes that attack the gram-positive bacterial cell wall. Sequence data for the deduced bacL 1 -encoded protein suggested that it has a domain structure consisting of an N-terminal signal peptide, a second domain with the enzymatic activity, and a third domain with a three-repeat structure directing the proenzyme to its cell surface receptor.Bacteriocins are bacterial proteins or peptides which inhibit the growth of other bacteria that are closely related to the producer strain. They usually exhibit a relatively narrow spectrum of activity and are produced by a wide variety of grampositive and gram-negative bacteria (27). Bacteriocin production is thought to provide the host strain with an ecological or other selective advantage over other strains.Many Enterococcus faecalis clinical isolates produce a bacteriocin (3, 5), and the bacteriocin is frequently encoded on the E. faecalis pheromone-responding conjugative plasmid (6,14,21,46). Several E. faecalis bacteriocins have been genetically and biochemically characterized (15, 35), including the ␤-hemolysin/bacteriocin (cytolysin) (6,7,18,20,22) and the peptide antibiotics AS-48 (33), bacteriocin 21 (47), and bacteriocin 31 (46), which are encoded by the E. faecalis conjugative plasmids pAD1 (58 kbp), pMB2 (58 kbp), pPD1 (59 kbp), and pYI17 (57.5 kbp), respectively. A significant number of E. faecalis clinical isolates produce hemolysin/bacteriocin (10, 26), and more than 50% of the hemolytic clinical isolates carry transferable hemolysin/bacteriocin determinants (21, 26). The hemolysin/bacteriocin of pAD1 is associated with virulence in animal models (4,25,29), and this plasmid is considered to be a typical ...

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“…Conjugative transfer of plasmids encoding the synthesis of several products such as bacteriocins has been well studied by Rauch et al [2]. The investigation of mechanisms and conditions allowing plasmid transfer and expression of plasmid-encoded genes in host cells have been reported [3,4,5]. B. thuringiensis is the most known insecticidal bacterium worldwide for the control of various plant pests.…”

Section: Introductionmentioning

confidence: 99%

Isolation of the Bacillus thuringiensis plasmid carrying Bacthuricin F4 coding genes and evidence of its conjugative transfer

Fguira

Fourati

Kamoun

et al. 2014

J Infect Dev Ctries

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Introduction: Conjugation is an excellent natural mode of DNA transfer in vivo between bacteria, particularly when these conjugative elements carry technological traits such as bacteriocin encoding genes. In the present work, the bacteriocinogenic plasmid pIBF4 from Bacillus thuringiensis responsible of Bacthuricin F4 synthesis was isolated and characterized. Methodology: To isolate pIBF4, the total plasmid DNA from a non-bacteriocin transposant carrying the mini-Tn10 spectinomycin selective marker was extracted and used to transform Escherichia coli strain Top10. PIBF4 was extracted from the obtained transformant and then subjected to restriction enzyme analysis. Plasmid curing experiments were conducted to test the stability of pIBF4 at a stringent temperature of 42°C. Conjugative behavior of pIBF4 was assessed by mating experiments using the non-bacteriocin transposant mutant as a donor strain and several Bacillus thuringiensis strains as recipients. Results: The pIBF4 plasmid was isolated and had a molecular weight of 19.1 kb. Ninety-five percent of cells retained the pIBF4 plasmid after 200 generations, demonstrating its high stability. PIBF4 was successfully transferred to Bacillus thuringiensis HD1CryB strain with a transfer frequency of 110 -8 transconjugants per donor cell. The study of the recipient host range revealed that pIBF4 is specifically transferable to Bacillus thuringiensis strains with variable transfer frequencies depending on the recipient host strain. Conclusion: Our results show that pIBF4 is a 19.1 kb highly stable plasmid transferable by conjugation to Bacillus thuringiensis strains with deferent transfer frequencies.

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Genetic Analysis of Transfer-Related Regions of the Vancomycin Resistance Enterococcus Conjugative Plasmid pHTβ: Identification of oriT and a Putative Relaxase Gene

Cited by 39 publications

References 46 publications

Molecular Characterization of Vancomycin-Resistant Enterococcus faecium Isolates from Mainland China

Molecular Characterization of Vancomycin-Resistant Enterococcus faecium Isolates from Mainland China

Cloning and Genetic Analyses of the Bacteriocin 41 Determinant Encoded on the Enterococcus faecalis Pheromone-Responsive Conjugative Plasmid pYI14: a Novel Bacteriocin Complemented by Two Extracellular Components (Lysin and Activator)

Isolation of the Bacillus thuringiensis plasmid carrying Bacthuricin F4 coding genes and evidence of its conjugative transfer

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