Investigating the roles of Listeria monocytogenes peroxidases in growth and virulence

Bacteria have necessarily evolved a protective arsenal of proteins to contend with peroxides and other reactive oxygen species generated in aerobic environments. Listeria monocytogenes encounters an onslaught of peroxide both in the environment and during infection of the mammalian host, where it is the causative agent of the foodborne illness listeriosis. Despite the importance of peroxide for the immune response to bacterial infection, the strategy by which L. monocytogenes protects against peroxide toxicity has yet to be illuminated. Here, we investigated the expression and essentiality of all the peroxidase-encoding genes during L. monocytogenes growth in vitro and during infection of murine cells in tissue culture. We found that chdC and kat were required for aerobic growth in vitro, and fri and ahpA were each required for L. monocytogenes to survive acute peroxide stress. Despite increased expression of fri, ahpA, and kat during infection of macrophages, only fri proved necessary for cytosolic growth and intercellular spread. In contrast, the proteins encoded by lmo0367, lmo0983, tpx, lmo1609, and ohrA were dispensable for aerobic growth, acute peroxide detoxification, and infection. Together, our results provide insight into the multifaceted L. monocytogenes peroxide detoxification strategy and demonstrate that L. monocytogenes encodes a functionally diverse set of peroxidase enzymes.

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Investigating the Roles of Listeria monocytogenes Peroxidases in Growth and Virulence

Microbiology Spectrum ◽

10.1128/spectrum.00440-21 ◽

2021 ◽

Author(s):

Monica R. Cesinger ◽

Nicole H. Schwardt ◽

Cortney R. Halsey ◽

Maureen K. Thomason ◽

Michelle L. Reniere

Keyword(s):

Reactive Oxygen Species ◽

Immune System ◽

Listeria Monocytogenes ◽

Causative Agent ◽

Foodborne Illness ◽

Intracellular Pathogen ◽

Host Immune System ◽

Oxygen Species ◽

Aerobic Growth ◽

Content Type

Listeria monocytogenes is a facultative intracellular pathogen and the causative agent of the foodborne illness listeriosis. L. monocytogenes must contend with reactive oxygen species generated extracellularly during aerobic growth and intracellularly by the host immune system. However, the mechanisms by which L. monocytogenes defends against peroxide toxicity have not yet been defined.

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A Redox-Responsive Transcription Factor Is Critical for Pathogenesis and Aerobic Growth of Listeria monocytogenes

Infection and Immunity ◽

10.1128/iai.00978-16 ◽

2017 ◽

Vol 85 (5) ◽

Cited By ~ 12

Author(s):

Aaron T. Whiteley ◽

Brittany R. Ruhland ◽

Mauna B. Edrozo ◽

Michelle L. Reniere

Keyword(s):

Oxidative Stress ◽

Listeria Monocytogenes ◽

Aerobic Growth ◽

Redox Stress ◽

Content Type ◽

Redox Responsive ◽

Cell Cytosol ◽

Redox Sensing ◽

Anaerobic Environment

ABSTRACT Bacterial pathogens have evolved sophisticated mechanisms to sense and adapt to redox stress in nature and within the host. However, deciphering the redox environment encountered by intracellular pathogens in the mammalian cytosol is challenging, and that environment remains poorly understood. In this study, we assessed the contributions of the two redox-responsive, Spx-family transcriptional regulators to the virulence of Listeria monocytogenes, a Gram-positive facultative intracellular pathogen. Spx-family proteins are highly conserved in Firmicutes, and the L. monocytogenes genome contains two paralogues, spxA1 and spxA2. Here, we demonstrate that spxA1, but not spxA2, is required for the oxidative stress response and pathogenesis. SpxA1 function appeared to be conserved with the Bacillus subtilis homologue, and resistance to oxidative stress required the canonical CXXC redox-sensing motif. Remarkably, spxA1 was essential for aerobic growth, demonstrating that L. monocytogenes SpxA1 likely regulates a distinct set of genes. Although the ΔspxA1 mutant did not grow in the presence of oxygen in the laboratory, it was able to replicate in macrophages and colonize the spleens, but not the livers, of infected mice. These data suggest that the redox state of bacteria during infection differs significantly from that of bacteria growing in vitro. Further, the host cell cytosol may resemble an anaerobic environment, with tissue-specific variations in redox stress and oxygen concentration.

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The proteolytic activity of Listeria monocytogenes HtrA

BMC Microbiology ◽

10.1186/s12866-019-1633-1 ◽

2019 ◽

Vol 19 (1) ◽

Author(s):

Carmen M. Abfalter ◽

Sabine Bernegger ◽

Miroslaw Jarzab ◽

Gernot Posselt ◽

Karthe Ponnuraj ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Proteolytic Activity ◽

Foodborne Pathogen ◽

Stationary Growth Phase ◽

Bacterial Survival ◽

Highly Active ◽

Molecule Inhibitor ◽

Casein Zymography ◽

Insight Into

Abstract Background High temperature requirement A (HtrA) is a widely expressed chaperone and serine protease in bacteria. HtrA proteases assemble and hydrolyze misfolded proteins to enhance bacterial survival under stress conditions. Listeria monocytogenes (L. monocytogenes) is a foodborne pathogen that induces listeriosis in humans. In previous studies, it was shown that deletion of htrA in the genome of L. monocytogenes increased the susceptibility to cellular stress and attenuated virulence. However, expression and protease activity of listerial HtrA (LmHtrA) were never analyzed in detail. Results In this study, we cloned LmHtrA wildtype (LmHtrAwt) and generated a proteolytic inactive LmHtrASA mutant. Recombinant LmHtrAwt and LmHtrASA were purified and the proteolytic activity was analyzed in casein zymography and in vitro cleavage assays. LmHtrA activity could be efficiently blocked by a small molecule inhibitor targeting bacterial HtrA proteases. The expression of LmHtrA was enhanced in the stationary growth phase of L. monocytogenes and significantly contributed to bacterial survival at high temperatures. Conclusions Our data show that LmHtrA is a highly active caseinolytic protease and provide a deeper insight into the function and mechanism, which could lead to medical and biotechnological applications in the future.

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Role of Copper Efflux in Pneumococcal Pathogenesis and Resistance to Macrophage-Mediated Immune Clearance

Infection and Immunity ◽

10.1128/iai.03015-14 ◽

2015 ◽

Vol 83 (4) ◽

pp. 1684-1694 ◽

Cited By ~ 42

Author(s):

Michael D. L. Johnson ◽

Thomas E. Kehl-Fie ◽

Roger Klein ◽

Jacqueline Kelly ◽

Corinna Burnham ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Copper Stress ◽

Mammalian Host ◽

Bacterial Clearance ◽

Content Type ◽

Immune Clearance ◽

Pulmonary Macrophages ◽

Insight Into

In bacteria, the intracellular levels of metals are mediated by tightly controlled acquisition and efflux systems. This is particularly true of copper, a trace element that is universally toxic in excess. During infection, the toxic properties of copper are exploited by the mammalian host to facilitate bacterial clearance. To better understand the role of copper during infection, we characterized the contribution of thecopoperon to copper homeostasis and virulence inStreptococcus pneumoniae. Deletion of either the exporter, encoded bycopA, or the chaperone, encoded bycupA, led to hypersensitivity to copper stress. We further demonstrated that loss of the copper exporter encoded bycopAled to decreased virulence in pulmonary, intraperitoneal, and intravenous models of infection. Deletion ofcopAresulted in enhanced macrophage-mediated bacterial clearancein vitro. The attenuation phenotype of thecopAmutant in the lung was found to be dependent on pulmonary macrophages, underscoring the importance of copper efflux in evading immune defenses. Overall, these data provide insight into the role of thecopoperon in pneumococcal pathogenesis.

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Regulation of OspE-Related, OspF-Related, and Elp Lipoproteins of Borrelia burgdorferi Strain 297 by Mammalian Host-Specific Signals

Infection and Immunity ◽

10.1128/iai.69.6.3618-3627.2001 ◽

2001 ◽

Vol 69 (6) ◽

pp. 3618-3627 ◽

Cited By ~ 87

Author(s):

P. Scott Hefty ◽

Sarah E. Jolliff ◽

Melissa J. Caimano ◽

Stephen K. Wikel ◽

Justin D. Radolf ◽

...

Keyword(s):

Borrelia Burgdorferi ◽

Posttranscriptional Regulation ◽

Expression Profiles ◽

Pcr Analysis ◽

Mammalian Host ◽

Promoter Regions ◽

Tick Feeding ◽

Reverse Transcription Pcr ◽

Encoding Genes

ABSTRACT In previous studies we have characterized the cp32/18 loci inBorrelia burgdorferi 297 which encode OspE and OspF orthologs and a third group of lipoproteins which possess OspE/F-like leader peptides (Elps). To further these studies, we have comprehensively analyzed their patterns of expression throughout the borrelial enzootic cycle. Serial dilution reverse transcription-PCR analysis indicated that although a shift in temperature from 23 to 37°C induced transcription for all nine genes analyzed, this effect was often markedly enhanced in mammalian host-adapted organisms cultivated within dialysis membrane chambers (DMCs) implanted within the peritoneal cavities of rats. Indirect immunofluorescence assays performed on temperature-shifted, in vitro-cultivated spirochetes and organisms in the midguts of unfed and fed ticks revealed distinct expression profiles for many of the OspE-related, OspF-related, and Elp proteins. Other than BbK2.10 and ElpA1, all were expressed by temperature-shifted organisms, while only OspE, ElpB1, OspF, and BbK2.11 were expressed in the midguts of fed ticks. Additionally, although mRNA was detected for all nine lipoprotein-encoding genes, two of these proteins (BbK2.10 and ElpA1) were not expressed by spirochetes cultivated in vitro, within DMCs, or by spirochetes within tick midguts. However, the observation that B. burgdorferi-infected mice generated specific antibodies against BbK2.10 and ElpA1 indicated that these antigens are expressed only in the mammalian host and that a form of posttranscriptional regulation is involved. Analysis of the upstream regions of these genes revealed several differences between their promoter regions, the majority of which were found in the −10 and −35 hexamers and the spacer regions between them. Also, rather than undergoing simultaneous upregulation during tick feeding, these genes and the corresponding lipoproteins appear to be subject to progressive recruitment or enhancement of expression as B. burgdorferi is transmitted from its tick vector to the mammalian host. These findings underscore the potential relevance of these molecules to the pathogenic events of early Lyme disease.

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In Vivo Lysogenic Conversion of Tox−Streptococcus pyogenes to Tox+ with Lysogenic Streptococci or Free Phage

Infection and Immunity ◽

10.1128/iai.71.7.3782-3786.2003 ◽

2003 ◽

Vol 71 (7) ◽

pp. 3782-3786 ◽

Cited By ~ 40

Author(s):

Thomas B. Broudy ◽

Vincent A. Fischetti

Keyword(s):

Streptococcus Pyogenes ◽

Microbial Population ◽

Mammalian Host ◽

Evolution Of Virulence ◽

Subsequent Conversion ◽

Efficient Induction ◽

Free Phage ◽

Encoding Genes

ABSTRACT Temperate bacteriophage can transfer toxin-encoding genes between bacteria, often resulting in acquired pathogenicity. However, little is known regarding the effects of the eukaryotic host on the phage-pathogen interaction. Using Streptococcus pyogenes as a model, we demonstrate, both in vitro and in vivo, that the eukaryote mediates the efficient induction of toxin-encoding temperate phage and the resultant conversion of Tox− flora to Tox+. Furthermore, we show that both phage induction and subsequent conversion need not happen in the same mammalian host, as host-to-host phage transmission can result in toxigenic conversion within the secondary host. Ultimately, our findings demonstrate that the eukaryotic host serves as an essential component in the phage-mediated evolution of virulence within the microbial population.

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Phenolic Compounds Present in Medicinal Mushroom Extracts Generate Reactive Oxygen Species in Human Cells In Vitro

International Journal of Medicinal Mushrooms ◽

10.1615/intjmedmushr.v10.i1.20 ◽

2008 ◽

Vol 10 (1) ◽

pp. 1-13 ◽

Cited By ~ 19

Author(s):

Song Wei ◽

Johannes P. F. G. Helsper ◽

L. J. L. D. Van Griensven

Keyword(s):

Reactive Oxygen Species ◽

Phenolic Compounds ◽

Reactive Oxygen ◽

Human Cells ◽

Oxygen Species ◽

Medicinal Mushroom ◽

Mushroom Extracts

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Copper–oxygen Dynamics in Tyrosinase

10.26434/chemrxiv.9255251 ◽

2019 ◽

Author(s):

Nobutaka Fujieda ◽

Sachiko Yanagisawa ◽

Minoru Kubo ◽

Genji Kurisu ◽

Shinobu Itoh

Keyword(s):

Catalytic Mechanism ◽

Substrate Binding ◽

Active Form ◽

Copper Ion ◽

Atomic Resolution ◽

Oxygen Species ◽

X Ray ◽

Oxygen Dynamics ◽

Insight Into ◽

Copper Centre

To unveil the activation of dioxygen on the copper centre (Cu2O2core) of tyrosinase, we performed X-ray crystallograpy with active-form tyrosinase at near atomic resolution. This study provided a novel insight into the catalytic mechanism of the tyrosinase, including the rearrangement of copper-oxygen species as well as the intramolecular migration of copper ion induced by substrate-binding.

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Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

Current Topics in Medicinal Chemistry ◽

10.2174/1568026618666180427151338 ◽

2018 ◽

Vol 18 (5) ◽

pp. 321-368 ◽

Cited By ~ 2

Author(s):

Juan A. Bisceglia ◽

Maria C. Mollo ◽

Nadia Gruber ◽

Liliana R. Orelli

Keyword(s):

Drug Targets ◽

Redox Homeostasis ◽

Cost Effective ◽

Structural Features ◽

Mammalian Host ◽

Neglected Diseases ◽

Nitrogen Compounds ◽

Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.

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