A Plasmid Selection System in
            <i>Lactococcus lactis</i>
            and Its Use for Gene Expression in
            <i>L. lactis</i>
            and Human Kidney Fibroblasts

Glenting, Jacob; Madsen, Søren; Vrang, Astrid; Fomsgaard, Anders; Israelsen, Hans

doi:10.1128/aem.68.10.5051-5056.2002

Cited by 28 publications

(16 citation statements)

References 43 publications

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“…Furthermore, cryptic plasmids in lactococci have received considerable attention because the purpose of constructing cloning vectors to enhance the properties of LAB [4,31]. High level plasmid instability characteristics of L. lactis strains, isolated from traditional fermented milk environments in Türkiye, showed similarities with lactose plasmid stability data in the literature [6,11,12,15,16,28]. Results of this study indicate that the tested strains are more stable in plasmid content at lower incubation temperatures than higher incubation temperatures.…”

Section: Discussionsupporting

confidence: 62%

A kinetic study on the plasmid stability of three Lactococcus lactis strains

Avsaroglu

Buzrul

Şanlibaba

et al. 2007

J Ind Microbiol Biotechnol

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The plasmid stability of three wild type Lactococcus lactis strains and their mutants was investigated at different incubation time and temperatures in two different media [M17 broth and reconstituted skim milk (RSM)]. The results showed that both incubation times and temperature are effective on plasmid loss. The plasmid profiles of wild type strains exhibited 8 to 9 distinct plasmid species with molecular weights from 2.1 to 24.0 kb. Lactose fermentation ability was found to be encoded by 22.2 (strain U70), 23.6 (strain U29) and 24.0 (strain U52) kb plasmids in the wild type strains, respectively. The stabilities of the plasmids were explained by applying a second-order polynomial modeling system. Reasonable fittings were obtained for the model and the adjusted regression coefficients (R ( 2 ) (adj)) were between 0.76 and 0.99 for the overall data. Overall, it was found that incubation time had the most profound effect on plasmid stability, with plasmid loss occurring after 72 h, while temperatures in the range of 15-40 degrees C also induced plasmid instability.

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Section: Discussionsupporting

confidence: 62%

A kinetic study on the plasmid stability of three Lactococcus lactis strains

Avsaroglu

Buzrul

Şanlibaba

et al. 2007

J Ind Microbiol Biotechnol

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“…Among the antibiotic-free selection systems that have been developed, the AC system has drawn much attention and has now been applied in numerous bacterial species, such as Lactococcus lactis, Salmonella spp., Vibrio cholerae, Mycobacterium bovis, and E. coli (5,16,21,22,24). However, all of the AC systems utilize plasmid-borne bacterial-origin genes to comple-ment the auxotrophy.…”

mentioning

confidence: 99%

Novel Antibiotic-Free Plasmid Selection System Based on Complementation of Host Auxotrophy in the NAD De Novo Synthesis Pathway

Dong

Xiang

Shao

2010

Appl Environ Microbiol

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The use of antibiotic resistance genes in plasmids causes potential biosafety and clinical hazards, such as the possibility of horizontal spread of resistance genes or the rapid emergence of multidrug-resistant pathogens. This paper introduces a novel auxotrophy complementation system that allowed plasmids and host cells to be effectively selected and maintained without the use of antibiotics. An Escherichia coli strain carrying a defect in NAD de novo biosynthesis was constructed by knocking out the chromosomal quinolinic acid phosphoribosyltransferase (QAPRTase) gene. The resistance gene in the plasmids was replaced by the QAPRTase gene of E. coli or the mouse. As a result, only expression of the QAPRTase gene from plasmids can complement and rescue E. coli host cells in minimal medium. This is the first time that a vertebrate gene has been used to construct a nonantibiotic selection system, and it can be widely applied in DNA vaccine and gene therapy. As

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“…If a strain is auxotrophic to an essential metabolite due to a chromosomal gene mutation, this otherwise lethal mutation can be complemented with a functional, plasmid-borne copy of the gene. This approach has been applied in numerous bacterial species, such as Lactococcus lactis (15), Salmonella spp. (25,45), Vibrio cholerae (39), and Escherichia coli (8).…”

mentioning

confidence: 99%

Use of mchI Encoding Immunity to the Antimicrobial Peptide Microcin H47 as a Plasmid Selection Marker in Attenuated Bacterial Live Vectors

et al. 2008

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Live attenuated bacterial strains expressing heterologous antigens represent an attractive vaccine development strategy. However, the use of drug resistance genes for the selection of expression plasmids introduced into live vectors poses theoretical health risks. Therefore, we developed a novel approach for plasmid selection based on immunity to the antimicrobial peptide microcin H47 (MccH47). Two expression plasmids encoding the reporter green fluorescent protein (GFPuv) were constructed; selection markers comprised either mchI, conferring immunity to MccH47 (pGEN222I), or bla (encoding ␤-lactamase), conferring conventional resistance to ampicillin (pGEN222). GFPuv-specific serum immunoglobulin G (IgG) antibody responses were analyzed in mice immunized intranasally either with Salmonella enterica serovar Typhi CVD 908-htrA or Shigella flexneri 2a CVD 1208S live vector and were boosted parenterally with purified GFPuv. Similar IgG antibody responses were observed for both pGEN222 and pGEN222I when either CVD 1208S or CVD 908-htrA(pGEN222I) was used as the carrier. Interestingly, CVD 908-htrA(pGEN222I) elicited a significantly higher IgG response than CVD 908-htrA(pGEN222). We also compared the priming potential of homologous priming either with CVD 908-htrA(pGEN222I) or CVD 1208S(pGEN222I) to heterologous priming first with CVD 908-htrA(pGEN222I) and then with CVD 1208S(pGEN222I) and vice versa. Immunization with two unrelated live vectors significantly enhanced the IgG responses compared to responses engendered by homologous CVD 908-htrA(pGEN222I) but not to those of CVD 1208S(pGEN222I). MccH47 offers an alternate system for plasmid selection in bacterial live vectors that greatly improves their clinical acceptability. Furthermore, the success of the heterologous priming strategy supports the feasibility of the future development of multivalent live vector-based immunization strategies against multiple human pathogens.

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A Plasmid Selection System in Lactococcus lactis and Its Use for Gene Expression in L. lactis and Human Kidney Fibroblasts

Cited by 28 publications

References 43 publications

A kinetic study on the plasmid stability of three Lactococcus lactis strains

A kinetic study on the plasmid stability of three Lactococcus lactis strains

Novel Antibiotic-Free Plasmid Selection System Based on Complementation of Host Auxotrophy in the NAD De Novo Synthesis Pathway

Use of mchI Encoding Immunity to the Antimicrobial Peptide Microcin H47 as a Plasmid Selection Marker in Attenuated Bacterial Live Vectors

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