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Belova AM, Basmanov DV, Babenko VV, Podgorny OV, Mitko TV, Prusakov KA, Klinov DV, Lazarev VN. Two novel transcriptional reporter systems for monitoring Helicobacter pylori stress responses. Plasmid 2019; 106:102442. [PMID: 31669286 DOI: 10.1016/j.plasmid.2019.102442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/09/2019] [Accepted: 09/17/2019] [Indexed: 11/27/2022]
Abstract
Helicobacter pylori, a human pathogen linked to many stomach diseases, is well adapted to colonize aggressive gastric environments, and its virulence factors contribute this adaptation. Here, we report the construction of two novel H. pylori vectors, pSv2 and pSv4, carrying a reporter gene fused to the promoters of virulence factor genes for monitoring the response of single H. pylori cells to various stresses. H. pylori cryptic plasmids were modified by the introduction of the Escherichia coli origin of replication, chloramphenicol resistance cassette, and promoterless gfp gene to produce E. coli/H. pylori shuttle vectors. The promoter regions of vacA and ureA genes encoding well-characterized H. pylori virulence factors were fused to the promoterless gfp gene. Recording the GFP fluorescence signal from the genetically modified H. pylori cells immobilized in specifically designed microfluidic devices revealed the response of transcriptional reporter systems to osmotic stress, acidic stress, elevated Ni2+ concentration or iron chelation. Our observations validate the utility of the pSv2 and pSv4 vectors to monitor the regulation of virulence factor genes in diverse strains and clinical isolates of H. pylori.
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Affiliation(s)
- A M Belova
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia.
| | - D V Basmanov
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia
| | - V V Babenko
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia
| | - O V Podgorny
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia; Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, Moscow 119334, Russia
| | - T V Mitko
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia
| | - K A Prusakov
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia
| | - D V Klinov
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia
| | - V N Lazarev
- Federal Research Clinical Center of Physical-Chemical Medicine, Federal Medical and Biological Agency of Russia, Moscow 119435, Russia
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Kang HL, Jo JS, Kwon SU, Song JY, Seo JH, Cho MJ, Baik SC, Youn HS, Rhee KH, Lee WK. An easy way for the rapid purification of recombinant proteins from Helicobacter pylori using a newly designed expression vector. J Microbiol 2014; 52:604-8. [PMID: 24972810 DOI: 10.1007/s12275-014-3679-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 05/08/2014] [Accepted: 05/15/2014] [Indexed: 12/20/2022]
Abstract
We constructed a H. pylori expression vector which consisted of both a His-tag and a GST tag as purification tools for recombinant protein and a chloramphenicol resistant cat gene as a reporter. The backbone of the vector pBK contained an ColEI origin of replication and a kanamycin resistant gene. A set of oligos for the His-tag and the PCR product of gst (glutathione S-transferase) gene were inserted sequentially in frame in the multi-cloning site of pBK. The orf of cat was inserted downstream of the gst to generate pBKHGC. The 3' part of H. pylori clpB and flaA were cloned into the vector which was introduced into H. pylori. Recombinant proteins were purified by GSH affinity column, digested with thrombin and were analyzed by western blotting. The final recombinant proteins were successfully purified.
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Affiliation(s)
- Hyung-Lyun Kang
- Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, 660-751, Republic of Korea
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3
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Fernandez-Gonzalez E, Backert S. DNA transfer in the gastric pathogen Helicobacter pylori. J Gastroenterol 2014; 49:594-604. [PMID: 24515309 DOI: 10.1007/s00535-014-0938-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/16/2014] [Indexed: 02/08/2023]
Abstract
The gastric pathogen Helicobacter pylori is one of the most genetically diverse bacteria. Recombination and DNA transfer contribute to its genetic variability and enhance host adaptation. Among the strategies described to increase genetic diversity in bacteria, DNA transfer by conjugation is one of the best characterized. Using this mechanism, a fragment of DNA from a donor cell can be transferred to a recipient, always mediated by a conjugative nucleoprotein complex, which is evolutionarily related to type IV secretion systems (T4SSs). Interestingly, the H. pylori chromosomes can encode up to four T4SSs, including the cagPAI, comB, tfs3, and tfs4 genes, some of which are known to promote chronic H. pylori infection. The T4SS encoded by the cagPAI mediates the injection of the effector protein CagA and proinflammatory signaling, and the comB system is involved in DNA uptake from the environment. However, the role of tfs3 and tfs4 is not yet clear. The presence of a functional XerD tyrosine recombinase and 5'AAAGAATG-3' border sequences as well as two putative conjugative relaxases (Rlx1 and Rlx2), a coupling protein (TraG), and a chromosomal region carrying a putative origin of transfer (oriT) suggest the existence of a DNA transfer apparatus in tfs4. Moreover, a conjugation-like DNA transfer mechanism in H. pylori has already been described in vitro, but whether this occurs in vivo is still unknown. Some extrachromosomal plasmids and phages are also present in various H. pylori strains. Genetic exchange among plasmids and chromosomes, and involved DNA mobilization events, could explain part of H. pylori's genetic diversity. Here, we review our knowledge about the possible DNA transfer mechanisms in H. pylori and its implications in bacterial adaptation to the host environment.
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Affiliation(s)
- Esther Fernandez-Gonzalez
- Division of Microbiology, Department of Biology, Friedrich Alexander University Erlangen/Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany
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Joo JS, Song JY, Baik SC, Lee WK, Cho MJ, Lee KH, Cho Y, Youn HS, Seo JH, Rhee KH, Kang HL. Genetic organization and conjugal plasmid DNA transfer of pHP69, a plasmid from a Korean isolate of Helicobacter pylori. J Microbiol 2012; 50:955-61. [PMID: 23274982 DOI: 10.1007/s12275-012-2580-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 11/12/2012] [Indexed: 11/25/2022]
Abstract
We isolated pHP69, a 9,153 bp plasmid from Helicobacter pylori with a 33.98% (G+C) content. We identified 11 open reading frames (ORFs), including replication initiation protein A (repA), fic (cAMP-induced filamentation protein), mccC, mccB, mobA, mobD, mobB, and mobC, as well as four 22 bp tandem repeat sequences. The nucleic acid and predicted amino acid sequences of these ORFs exhibited significant homology to those of other H. pylori plasmids. pHP69 repA encodes a replication initiation protein and its amino acid sequence is similar to those of replicase proteins from theta-type plasmids. pHP69 contains two types of repeat sequences (R1 and R2), a MOBHEN family mobilization region comprising mobC, mobA, mobB, and mobD, and genes encoding microcin B and C. Among the 36 H. pylori strains containing plasmids, mobA or mccBC are present in 12 or 6, respectively and 3 contain both genes. To examine intrinsic capability of H. pylori for conjugative plasmid transfer, a shuttle vector pBHP69KH containing pHP69 and replication origin of pBR322 was constructed. It was shown that this vector could stably replicate and be mobilized among clinical H. pylori strains and demonstrated to gene transfer by natural plasmid.
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Affiliation(s)
- Jung-Soo Joo
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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5
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Multiple pathways of plasmid DNA transfer in Helicobacter pylori. PLoS One 2012; 7:e45623. [PMID: 23029142 PMCID: PMC3447787 DOI: 10.1371/journal.pone.0045623] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Accepted: 08/20/2012] [Indexed: 01/25/2023] Open
Abstract
Many Helicobacter pylori (Hp) strains carry cryptic plasmids of different size and gene content, the function of which is not well understood. A subgroup of these plasmids (e.g. pHel4, pHel12), contain a mobilisation region, but no cognate type IV secretion system (T4SS) for conjugative transfer. Instead, certain H. pylori strains (e.g. strain P12 carrying plasmid pHel12) can harbour up to four T4SSs in their genome (cag-T4SS, comB, tfs3, tfs4). Here, we show that such indigenous plasmids can be efficiently transferred between H. pylori strains, even in the presence of extracellular DNaseI eliminating natural transformation. Knockout of a plasmid-encoded mobA relaxase gene significantly reduced plasmid DNA transfer in the presence of DNaseI, suggesting a DNA conjugation or mobilisation process. To identify the T4SS involved in this conjugative DNA transfer, each individual T4SS was consecutively deleted from the bacterial chromosome. Using a marker-free counterselectable gene deletion procedure (rpsL counterselection method), a P12 mutant strain was finally obtained with no single T4SS (P12ΔT4SS). Mating experiments using these mutants identified the comB T4SS in the recipient strain as the major mediator of plasmid DNA transfer between H. pylori strains, both in a DNaseI-sensitive (natural transformation) as well as a DNaseI-resistant manner (conjugative transfer). However, transfer of a pHel12::cat plasmid from a P12ΔT4SS donor strain into a P12ΔT4SS recipient strain provided evidence for the existence of a third, T4SS-independent mechanism of DNA transfer. This novel type of plasmid DNA transfer, designated as alternate DNaseI-Resistant (ADR) mechanism, is observed at a rather low frequency under in vitro conditions. Taken together, our study describes for the first time the existence of three distinct pathways of plasmid DNA transfer between H. pylori underscoring the importance of horizontal gene transfer for this species.
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Eppinger M, Baar C, Linz B, Raddatz G, Lanz C, Keller H, Morelli G, Gressmann H, Achtman M, Schuster SC. Who ate whom? Adaptive Helicobacter genomic changes that accompanied a host jump from early humans to large felines. PLoS Genet 2006; 2:e120. [PMID: 16789826 PMCID: PMC1523251 DOI: 10.1371/journal.pgen.0020120] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Accepted: 06/15/2006] [Indexed: 01/10/2023] Open
Abstract
Helicobacter pylori infection of humans is so old that its population genetic structure reflects that of ancient human migrations. A closely related species, Helicobacter acinonychis, is specific for large felines, including cheetahs, lions, and tigers, whereas hosts more closely related to humans harbor more distantly related Helicobacter species. This observation suggests a jump between host species. But who ate whom and when did it happen? In order to resolve this question, we determined the genomic sequence of H. acinonychis strain Sheeba and compared it to genomes from H. pylori. The conserved core genes between the genomes are so similar that the host jump probably occurred within the last 200,000 (range 50,000-400,000) years. However, the Sheeba genome also possesses unique features that indicate the direction of the host jump, namely from early humans to cats. Sheeba possesses an unusually large number of highly fragmented genes, many encoding outer membrane proteins, which may have been destroyed in order to bypass deleterious responses from the feline host immune system. In addition, the few Sheeba-specific genes that were found include a cluster of genes encoding sialylation of the bacterial cell surface carbohydrates, which were imported by horizontal genetic exchange and might also help to evade host immune defenses. These results provide a genomic basis for elucidating molecular events that allow bacteria to adapt to novel animal hosts.
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Affiliation(s)
- Mark Eppinger
- Department of Biochemistry and Molecular Biology, Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Claudia Baar
- Department of Biochemistry and Molecular Biology, Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Bodo Linz
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Günter Raddatz
- Genomics Group, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Christa Lanz
- Genomics Group, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Heike Keller
- Genomics Group, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Giovanna Morelli
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Helga Gressmann
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Mark Achtman
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Stephan C Schuster
- Department of Biochemistry and Molecular Biology, Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania, United States of America
- Genomics Group, Max Planck Institute for Developmental Biology, Tübingen, Germany
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, United States of America
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7
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Eppinger M, Baar C, Linz B, Raddatz G, Lanz C, Keller H, Morelli G, Gressmann H, Achtman M, Schuster SC. Who ate whom? Adaptive Helicobacter genomic changes that accompanied a host jump from early humans to large felines. PLoS Genet 2006. [PMID: 16789826 DOI: 10.1371/journal.pgen.0020120.eor] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Helicobacter pylori infection of humans is so old that its population genetic structure reflects that of ancient human migrations. A closely related species, Helicobacter acinonychis, is specific for large felines, including cheetahs, lions, and tigers, whereas hosts more closely related to humans harbor more distantly related Helicobacter species. This observation suggests a jump between host species. But who ate whom and when did it happen? In order to resolve this question, we determined the genomic sequence of H. acinonychis strain Sheeba and compared it to genomes from H. pylori. The conserved core genes between the genomes are so similar that the host jump probably occurred within the last 200,000 (range 50,000-400,000) years. However, the Sheeba genome also possesses unique features that indicate the direction of the host jump, namely from early humans to cats. Sheeba possesses an unusually large number of highly fragmented genes, many encoding outer membrane proteins, which may have been destroyed in order to bypass deleterious responses from the feline host immune system. In addition, the few Sheeba-specific genes that were found include a cluster of genes encoding sialylation of the bacterial cell surface carbohydrates, which were imported by horizontal genetic exchange and might also help to evade host immune defenses. These results provide a genomic basis for elucidating molecular events that allow bacteria to adapt to novel animal hosts.
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Affiliation(s)
- Mark Eppinger
- Department of Biochemistry and Molecular Biology, Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania, USA
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Höfler C, Fischer W, Hofreuter D, Haas R. Cryptic plasmids in Helicobacter pylori: putative functions in conjugative transfer and microcin production. Int J Med Microbiol 2005; 294:141-8. [PMID: 15493824 DOI: 10.1016/j.ijmm.2004.06.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Claudia Höfler
- Max von Pettenkofer Institut für Hygiene und Mikrobiologie, LMU München, Pettenkoferstr 9a, D-80336 München, Germany
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