1
|
Alejandro-Navarreto X, Freitag NE. Revisiting old friends: updates on the role of two-component signaling systems in Listeria monocytogenes survival and pathogenesis. Infect Immun 2024; 92:e0034523. [PMID: 38591895 PMCID: PMC11003226 DOI: 10.1128/iai.00345-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
Listeria monocytogenes is well recognized for both its broad resistance to stress conditions and its ability to transition from a soil bacterium to an intracellular pathogen of mammalian hosts. The bacterium's impressive ability to adapt to changing environments and conditions requires the rapid sensing of environmental cues and the coordinated response of gene products that enable bacterial growth and survival. Two-component signaling systems (TCSs) have been long recognized for their ability to detect environmental stimuli and transmit those signals into transcriptional responses; however, often the precise nature of the stimulus triggering TCS responses can be challenging to define. L. monocytogenes has up to 16 TCSs that have been recognized based on homology and included in this list are several whose functions remain poorly described. This review highlights the current understanding of the breadth and scope of L. monocytogenes TCS as relates to stress resistance and pathogenesis. Precise signals still often remain elusive, but the gene networks associated with TCSs are providing clues into possible functions.
Collapse
Affiliation(s)
| | - Nancy E. Freitag
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| |
Collapse
|
2
|
Meireles D, Pombinho R, Cabanes D. Signals behind Listeria monocytogenes virulence mechanisms. Gut Microbes 2024; 16:2369564. [PMID: 38979800 PMCID: PMC11236296 DOI: 10.1080/19490976.2024.2369564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/13/2024] [Indexed: 07/10/2024] Open
Abstract
The tight and coordinated regulation of virulence gene expression is crucial to ensure the survival and persistence of bacterial pathogens in different contexts within their hosts. Considering this, bacteria do not express virulence factors homogenously in time and space, either due to their associated fitness cost or to their detrimental effect at specific infection stages. To efficiently infect and persist into their hosts, bacteria have thus to monitor environmental cues or chemical cell-to-cell signaling mechanisms that allow their transition from the external environment to the host, and therefore adjust gene expression levels, intrinsic biological activities, and appropriate behaviors. Listeria monocytogenes (Lm), a major Gram-positive facultative intracellular pathogen, stands out for its adaptability and capacity to thrive in a wide range of environments. Because of that, Lm presents itself as a significant concern in food safety and public health, that can lead to potentially life-threatening infections in humans. A deeper understanding of the intricate bacterial virulence mechanisms and the signals that control them provide valuable insights into the dynamic interplay between Lm and the host. Therefore, this review addresses the role of some crucial signals behind Lm pathogenic virulence mechanisms and explores how the ability to assimilate and interpret these signals is fundamental for pathogenesis, identifying potential targets for innovative antimicrobial strategies.
Collapse
Affiliation(s)
- Diana Meireles
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar – ICBAS, Porto, Portugal
| | - Rita Pombinho
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
| | - Didier Cabanes
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
| |
Collapse
|
3
|
De Gaetano GV, Lentini G, Famà A, Coppolino F, Beninati C. Antimicrobial Resistance: Two-Component Regulatory Systems and Multidrug Efflux Pumps. Antibiotics (Basel) 2023; 12:965. [PMID: 37370284 DOI: 10.3390/antibiotics12060965] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
The number of multidrug-resistant bacteria is rapidly spreading worldwide. Among the various mechanisms determining resistance to antimicrobial agents, multidrug efflux pumps play a noteworthy role because they export extraneous and noxious substrates from the inside to the outside environment of the bacterial cell contributing to multidrug resistance (MDR) and, consequently, to the failure of anti-infective therapies. The expression of multidrug efflux pumps can be under the control of transcriptional regulators and two-component systems (TCS). TCS are a major mechanism by which microorganisms sense and reply to external and/or intramembrane stimuli by coordinating the expression of genes involved not only in pathogenic pathways but also in antibiotic resistance. In this review, we describe the influence of TCS on multidrug efflux pump expression and activity in some Gram-negative and Gram-positive bacteria. Taking into account the strict correlation between TCS and multidrug efflux pumps, the development of drugs targeting TCS, alone or together with already discovered efflux pump inhibitors, may represent a beneficial strategy to contribute to the fight against growing antibiotic resistance.
Collapse
Affiliation(s)
| | - Germana Lentini
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
| | - Agata Famà
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
| | - Francesco Coppolino
- Department of Biomedical, Dental and Imaging Sciences, University of Messina, 98124 Messina, Italy
| | - Concetta Beninati
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
- Scylla Biotech Srl, 98124 Messina, Italy
| |
Collapse
|
4
|
Cahoon LA, Alejandro‐Navarreto X, Gururaja AN, Light SH, Alonzo F, Anderson WF, Freitag NE. Listeria monocytogenes two component system PieRS regulates secretion chaperones PrsA1 and PrsA2 and enhances bacterial translocation across the intestine. Mol Microbiol 2022; 118:278-293. [PMID: 35943959 PMCID: PMC9545042 DOI: 10.1111/mmi.14967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/30/2022]
Abstract
Listeria monocytogenes (Lm) is a widespread environmental Gram-positive bacterium that can transition into a pathogen following ingestion by a susceptible host. To cross host barriers and establish infection, Lm is dependent upon the regulated secretion and activity of many proteins including PrsA2, a peptidyl-prolyl cis-trans isomerase with foldase activity. PrsA2 contributes to the stability and activity of a number of secreted virulence factors that are required for Lm invasion, replication, and cell-to-cell spread within the infected host. In contrast, a second related secretion chaperone, PrsA1, has thus far no identified contributions to Lm pathogenesis. Here we describe the characterization of a two-component signal transduction system PieRS that regulates the expression of a regulon that includes the secretion chaperones PrsA1 and PrsA2. PieRS regulated gene products are required for bacterial resistance to ethanol exposure and are important for bacterial survival during transit through the gastrointestinal tract. PrsA1 was also found to make a unique contribution to Lm survival in the GI tract, revealing for the first time a non-overlapping requirement for both secretion chaperones PrsA1 and PrsA2 during the process of intra-gastric infection.
Collapse
Affiliation(s)
- Laty A. Cahoon
- Department of Microbiology and ImmunologyUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | | | - Avinash N. Gururaja
- Department of Microbiology and ImmunologyUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Sam H. Light
- Department of MicrobiologyUniversity of ChicagoChicagoIllinoisUSA
| | - Francis Alonzo
- Department of Microbiology and ImmunologyLoyola UniversityChicagoIllinoisUSA
| | - Wayne F. Anderson
- Center for Genomics and Infectious Diseases, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Nancy E. Freitag
- Department of Microbiology and ImmunologyUniversity of Illinois at ChicagoChicagoIllinoisUSA
| |
Collapse
|
5
|
Nowak J, Visnovsky SB, Pitman AR, Cruz CD, Palmer J, Fletcher GC, Flint S. Biofilm Formation by Listeria monocytogenes 15G01, a Persistent Isolate from a Seafood-Processing Plant, Is Influenced by Inactivation of Multiple Genes Belonging to Different Functional Groups. Appl Environ Microbiol 2021; 87:e02349-20. [PMID: 33741610 PMCID: PMC8117777 DOI: 10.1128/aem.02349-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/25/2021] [Indexed: 01/13/2023] Open
Abstract
Listeria monocytogenes is a ubiquitous foodborne pathogen that results in a high rate of mortality in sensitive and immunocompromised people. Contamination of food with L. monocytogenes is thought to occur during food processing, most often as a result of the pathogen producing a biofilm that persists in the environment and acting as the source for subsequent dispersal of cells onto food. A survey of seafood-processing plants in New Zealand identified the persistent strain 15G01, which has a high capacity to form biofilms. In this study, a transposon library of L. monocytogenes 15G01 was screened for mutants with altered biofilm formation, assessed by a crystal violet assay, to identify genes involved in biofilm formation. This screen identified 36 transposants that showed a significant change in biofilm formation compared to the wild type. The insertion sites were in 27 genes, 20 of which led to decreased biofilm formation and seven to an increase. Two insertions were in intergenic regions. Annotation of the genes suggested that they are involved in diverse cellular processes, including stress response, autolysis, transporter systems, and cell wall/membrane synthesis. Analysis of the biofilms produced by the transposants using scanning electron microscopy and fluorescence microscopy showed notable differences in the structure of the biofilms compared to the wild type. In particular, inactivation of uvrB and mltD produced coccoid-shaped cells and elongated cells in long chains, respectively, and the mgtB mutant produced a unique biofilm with a sandwich structure which was reversed to the wild-type level upon magnesium addition. The mltD transposant was successfully complemented with the wild-type gene, whereas the phenotypes were not or only partially restored for the remaining mutants.IMPORTANCE The major source of contamination of food with Listeria monocytogenes is thought to be due to biofilm formation and/or persistence in food-processing plants. By establishing as a biofilm, L. monocytogenes cells become harder to eradicate due to their increased resistance to environmental threats. Understanding the genes involved in biofilm formation and their influence on biofilm structure will help identify new ways to eliminate harmful biofilms in food processing environments. To date, multiple genes have been identified as being involved in biofilm formation by L. monocytogenes; however, the exact mechanism remains unclear. This study identified four genes associated with biofilm formation by a persistent strain. Extensive microscopic analysis illustrated the effect of the disruption of mgtB, clsA, uvrB, and mltD and the influence of magnesium on the biofilm structure. The results strongly suggest an involvement in biofilm formation for the four genes and provide a basis for further studies to analyze gene regulation to assess the specific role of these biofilm-associated genes.
Collapse
Affiliation(s)
- Jessika Nowak
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| | - Sandra B Visnovsky
- The New Zealand Institute for Plant and Food Research Limited, Lincoln, New Zealand
| | - Andrew R Pitman
- The Foundation for Arable Research, Christchurch, New Zealand
| | - Cristina D Cruz
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Jon Palmer
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| | - Graham C Fletcher
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Steve Flint
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| |
Collapse
|
6
|
Aslan H, Petersen ME, De Berardinis A, Zacho Brunhede M, Khan N, Vergara A, Kallipolitis B, Meyer RL. Activation of the Two-Component System LisRK Promotes Cell Adhesion and High Ampicillin Tolerance in Listeria monocytogenes. Front Microbiol 2021; 12:618174. [PMID: 33584621 PMCID: PMC7873292 DOI: 10.3389/fmicb.2021.618174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/06/2021] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is a foodborne pathogen which can survive in harsh environmental conditions. It responds to external stimuli through an array of two-component systems (TCS) that sense external cues. Several TCS, including LisRK, have been linked to Listeria’s ability to grow at slightly elevated antibiotic levels. The aim of this study was to determine if the TCS LisRK is also involved in acquiring the high antibiotic tolerance that is characteristic of persister cells. LisRK activates a response that leads to remodeling of the cell envelope, and we therefore hypothesized that activation of LisRK could also increase in the cells’ adhesiveness and initiate the first step in biofilm formation. We used a ΔlisR mutant to study antibiotic tolerance in the presence and absence of LisRK, and a GFP reporter strain to visualize the activation of LisRK in L. monocytogenes LO28 at a single-cell level. LisRK was activated in most cells in stationary phase cultures. Antimicrobial susceptibility tests showed that LisRK was required for the generation of ampicillin tolerance under these conditions. The wildtype strain tolerated exposure to ampicillin at 1,000 × inhibitory levels for 24 h, and the fraction of surviving cells was 20,000-fold higher in the wildtype strain compared to the ΔlisR mutant. The same protection was not offered to other antibiotics (vancomycin, gentamicin, tetracycline), and the mechanism for antibiotic tolerance is thus highly specific. Furthermore, quantification of bacterial attachment rates and attachment force also revealed that the absence of a functional LisRK rendered the cells less adhesive. Hence, LisRK TCS promotes multiple protective mechanisms simultaneously.
Collapse
Affiliation(s)
- Hüsnü Aslan
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | | | | | - Maja Zacho Brunhede
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Nasar Khan
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Alberto Vergara
- Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Birgitte Kallipolitis
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Rikke Louise Meyer
- Faculty of Natural Sciences, Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark.,Department of Biology, Faculty of Natural Sciences, Aarhus University, Aarhus, Denmark
| |
Collapse
|
7
|
Brunhede MZ, Santos PTD, Gal L, Garmyn D, Kallipolitis BH, Piveteau P. LisRK is required for optimal fitness of Listeria monocytogenes in soil. FEMS Microbiol Lett 2020; 367:5986613. [PMID: 33202028 DOI: 10.1093/femsle/fnaa188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/13/2020] [Indexed: 01/10/2023] Open
Abstract
Listeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. It is ubiquitously found in the environment and soil is one of its natural habitats. Listeria monocytogenes is highly capable of coping with various stressful conditions. We hypothesized that stress-responsive two-component systems such as LisRK might contribute to the adaptation of L. monocytogenes to the soil environment. Indeed, investigations of the population dynamics of wild-type and mutant strains suggest an important role of LisRK for optimal fitness of L. monocytogenes in sterile soil. Results from non-sterile soil showed that the parental strain was capable of surviving longer than mutant strains lacking lisRK or genes encoding the LisRK-regulated LhrC small RNAs (sRNAs), suggesting that LisRK as well as the LhrC sRNAs were important for survival. Transcription of five LisRK-regulated genes was assessed after 1 h incubation in sterile soil. We observed that LisRK and the LhrC sRNAs contribute to the upregulation of lmo2522 in the soil environment. Notably, lmo2522 encodes an equivalent of the resuscitation promoting factors, Rpfs, in actinobacteria. Collectively, our study demonstrates that LisRK is important for growth and survival in sterile and non-sterile soil and suggests a role for LisRK-regulation of Lmo2522 in resuscitation from dormancy in the soil environment.
Collapse
Affiliation(s)
- Maja Z Brunhede
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne Franche-Comté, Dijon, France
| | - Patrícia T Dos Santos
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Laurent Gal
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne Franche-Comté, Dijon, France
| | - Dominique Garmyn
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne Franche-Comté, Dijon, France
| | - Birgitte H Kallipolitis
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | |
Collapse
|
8
|
Wambui J, Eshwar AK, Aalto-Araneda M, Pöntinen A, Stevens MJA, Njage PMK, Tasara T. The Analysis of Field Strains Isolated From Food, Animal and Clinical Sources Uncovers Natural Mutations in Listeria monocytogenes Nisin Resistance Genes. Front Microbiol 2020; 11:549531. [PMID: 33123101 PMCID: PMC7574537 DOI: 10.3389/fmicb.2020.549531] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/02/2020] [Indexed: 12/19/2022] Open
Abstract
Nisin is a commonly used bacteriocin for controlling spoilage and pathogenic bacteria in food products. Strains possessing high natural nisin resistance that reduce or increase the potency of this bacteriocin against Listeria monocytogenes have been described. Our study sought to gather more insights into nisin resistance mechanisms in natural L. monocytogenes populations by examining a collection of 356 field strains that were isolated from different foods, food production environments, animals and human infections. A growth curve analysis-based approach was used to access nisin inhibition levels and assign the L. monocytogenes strains into three nisin response phenotypic categories; resistant (66%), intermediate (26%), and sensitive (8%). Using this categorization isolation source, serotype, genetic lineage, clonal complex (CC) and strain-dependent natural variation in nisin phenotypic resistance among L. monocytogenes field strains was revealed. Whole genome sequence analysis and comparison of high nisin resistant and sensitive strains led to the identification of new naturally occurring mutations in nisin response genes associated with increased nisin resistance and sensitivity in this bacterium. Increased nisin resistance was detected in strains harboring RsbUG77S and PBPB3V240F amino acid substitution mutations, which also showed increased detergent stress resistance as well as increased virulence in a zebra fish infection model. On the other hand, increased natural nisin sensitivity was detected among strains with mutations in sigB, vir, and dlt operons that also showed increased lysozyme sensitivity and lower virulence. Overall, our study identified naturally selected mutations involving pbpB3 (lm0441) as well as sigB, vir, and dlt operon genes that are associated with intrinsic nisin resistance in L. monocytogenes field strains recovered from various food and human associated sources. Finally, we show that combining growth parameter-based phenotypic analysis and genome sequencing is an effective approach that can be useful for the identification of novel nisin response associated genetic variants among L. monocytogenes field strains.
Collapse
Affiliation(s)
- Joseph Wambui
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Athmanya K Eshwar
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Mariella Aalto-Araneda
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Anna Pöntinen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Marc J A Stevens
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Patrick M K Njage
- Research Group for Genomic Epidemiology, Division for Global Surveillance, National Food Institute, Technical University of Denmark, Kengens Lyngby, Denmark
| | - Taurai Tasara
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| |
Collapse
|
9
|
Rismondo J, Halbedel S, Gründling A. Cell Shape and Antibiotic Resistance Are Maintained by the Activity of Multiple FtsW and RodA Enzymes in Listeria monocytogenes. mBio 2019; 10:e01448-19. [PMID: 31387909 PMCID: PMC6686043 DOI: 10.1128/mbio.01448-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022] Open
Abstract
Rod-shaped bacteria have two modes of peptidoglycan synthesis: lateral synthesis and synthesis at the cell division site. These two processes are controlled by two macromolecular protein complexes, the elongasome and divisome. Recently, it has been shown that the Bacillus subtilis RodA protein, which forms part of the elongasome, has peptidoglycan glycosyltransferase activity. The cell division-specific RodA homolog FtsW fulfils a similar role at the divisome. The human pathogen Listeria monocytogenes carries genes that encode up to six FtsW/RodA homologs; however, their functions have not yet been investigated. Analysis of deletion and depletion strains led to the identification of the essential cell division-specific FtsW protein, FtsW1. Interestingly, L. monocytogenes carries a gene that encodes a second FtsW protein, FtsW2, which can compensate for the lack of FtsW1, when expressed from an inducible promoter. L. monocytogenes also possesses three RodA homologs, RodA1, RodA2, and RodA3, and their combined absence is lethal. Cells of a rodA1 rodA3 double mutant are shorter and have increased antibiotic and lysozyme sensitivity, probably due to a weakened cell wall. Results from promoter activity assays revealed that expression of rodA3 and ftsW2 is induced in the presence of antibiotics targeting penicillin binding proteins. Consistent with this, a rodA3 mutant was more susceptible to the β-lactam antibiotic cefuroxime. Interestingly, overexpression of RodA3 also led to increased cefuroxime sensitivity. Our study highlights that L. monocytogenes genes encode a multitude of functional FtsW and RodA enzymes to produce its rigid cell wall and that their expression needs to be tightly regulated to maintain growth, cell division, and antibiotic resistance.IMPORTANCE The human pathogen Listeria monocytogenes is usually treated with high doses of β-lactam antibiotics, often combined with gentamicin. However, these antibiotics only act bacteriostatically on L. monocytogenes, and the immune system is needed to clear the infection. Therefore, individuals with a compromised immune system are at risk to develop a severe form of Listeria infection, which can be fatal in up to 30% of cases. The development of new strategies to treat Listeria infections is necessary. Here we show that the expression of some of the FtsW and RodA enzymes of L. monocytogenes is induced by the presence of β-lactam antibiotics, and the combined absence of these enzymes makes bacteria more susceptible to this class of antibiotics. The development of antimicrobial agents that inhibit the activity or production of FtsW and RodA enzymes might therefore help to improve the treatment of Listeria infections and thereby lead to a reduction in mortality.
Collapse
Affiliation(s)
- Jeanine Rismondo
- Section of Microbiology, Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Sven Halbedel
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Angelika Gründling
- Section of Microbiology, Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| |
Collapse
|
10
|
Tierney AR, Rather PN. Roles of two-component regulatory systems in antibiotic resistance. Future Microbiol 2019; 14:533-552. [PMID: 31066586 DOI: 10.2217/fmb-2019-0002] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Two-component regulatory systems (TCSs) are a major mechanism by which bacteria sense and respond to changes in their environment. TCSs typically consist of two proteins that bring about major regulation of the cell genome through coordinated action mediated by phosphorylation. Environmental conditions that activate TCSs are numerous and diverse and include exposure to antibiotics as well as conditions inside a host. The resulting regulatory action often involves activation of antibiotic defenses and changes to cell physiology that increase antibiotic resistance. Examples of resistance mechanisms enacted by TCSs contained in this review span those found in both Gram-negative and Gram-positive species and include cell surface modifications, changes in cell permeability, increased biofilm formation, and upregulation of antibiotic-degrading enzymes.
Collapse
Affiliation(s)
- Aimee Rp Tierney
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, 30322 USA
| | - Philip N Rather
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, 30322 USA.,Research Service, Department of Veterans' Affairs, Atlanta VA Health Care System, Decatur, GA, 30033 USA
| |
Collapse
|
11
|
Dos Santos PT, Larsen PT, Menendez-Gil P, Lillebæk EMS, Kallipolitis BH. Listeria monocytogenes Relies on the Heme-Regulated Transporter hrtAB to Resist Heme Toxicity and Uses Heme as a Signal to Induce Transcription of lmo1634, Encoding Listeria Adhesion Protein. Front Microbiol 2018; 9:3090. [PMID: 30619169 PMCID: PMC6305404 DOI: 10.3389/fmicb.2018.03090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/29/2018] [Indexed: 01/29/2023] Open
Abstract
For pathogenic bacteria, host-derived heme represents an important metabolic cofactor and a source for iron. However, high levels of heme are toxic to bacteria. We have previously shown that excess heme has a growth-inhibitory effect on the Gram-positive foodborne pathogen Listeria monocytogenes, and we have learned that the LhrC1-5 family of small RNAs, together with the two-component system (TCS) LisRK, play a role in the adaptation of L. monocytogenes to heme stress conditions. However, a broader knowledge on how this pathogen responds to heme toxicity is still lacking. Here, we analyzed the global transcriptomic response of L. monocytogenes to heme stress. We found that the response of L. monocytogenes to excess heme is multifaceted, involving various strategies acting to minimize the toxic effects of heme. For example, heme exposure triggers the SOS response that deals with DNA damage. In parallel, L. monocytogenes shuts down the transcription of genes involved in heme/iron uptake and utilization. Furthermore, heme stress resulted in a massive increase in the transcription of a putative heme detoxification system, hrtAB, which is highly conserved in Gram-positive bacteria. As expected, we found that the TCS HssRS is required for heme-mediated induction of hrtAB and that a functional heme efflux system is essential for L. monocytogenes to resist heme toxicity. Curiously, the most highly up-regulated gene upon heme stress was lmo1634, encoding the Listeria adhesion protein, LAP, which acts to promote the translocation of L. monocytogenes across the intestinal barrier. Additionally, LAP is predicted to act as a bifunctional acetaldehyde-CoA/alcohol dehydrogenase. Surprisingly, a mutant lacking lmo1634 grows well under heme stress conditions, showing that LAP is not required for L. monocytogenes to resist heme toxicity. Likewise, a functional ResDE TCS, which contributes to heme-mediated expression of lmo1634, is not required for the adaptation of L. monocytogenes to heme stress conditions. Collectively, this study provides novel insights into the strategies employed by L. monocytogenes to resist heme toxicity. Our findings indicate that L. monocytogenes is using heme as a host-derived signaling molecule to control the expression of its virulence genes, as exemplified by lmo1634.
Collapse
Affiliation(s)
| | - Pernille Tholund Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Pilar Menendez-Gil
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | | | |
Collapse
|
12
|
Crystal Structures of Penicillin-Binding Protein D2 from Listeria monocytogenes and Structural Basis for Antibiotic Specificity. Antimicrob Agents Chemother 2018; 62:AAC.00796-18. [PMID: 30082290 DOI: 10.1128/aac.00796-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 07/06/2018] [Indexed: 02/05/2023] Open
Abstract
β-Lactam antibiotics that inhibit penicillin-binding proteins (PBPs) have been widely used in the treatment of bacterial infections. However, the molecular basis underlying the different inhibitory potencies of β-lactams against specific PBPs is not fully understood. Here, we present the crystal structures of penicillin-binding protein D2 (PBPD2) from Listeria monocytogenes, a Gram-positive foodborne bacterial pathogen that causes listeriosis in humans. The acylated structures in complex with four antibiotics (penicillin G, ampicillin, cefotaxime, and cefuroxime) revealed that the β-lactam core structures were recognized by a common set of residues; however, the R1 side chains of each antibiotic participate in different interactions with PBPD2. In addition, the structural complementarities between the side chains of β-lactams and the enzyme were found to be highly correlated with the relative reactivities of penam or cephem antibiotics against PBPD2. Our study provides the structural basis for the inhibition of PBPD2 by clinically important β-lactam antibiotics that are commonly used in listeriosis treatment. Our findings imply that the modification of β-lactam side chains based on structural complementarity could be useful for the development of potent inhibitors against β-lactam-resistant PBPs.
Collapse
|
13
|
Cardona ST, Choy M, Hogan AM. Essential Two-Component Systems Regulating Cell Envelope Functions: Opportunities for Novel Antibiotic Therapies. J Membr Biol 2017; 251:75-89. [DOI: 10.1007/s00232-017-9995-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 01/22/2023]
|
14
|
Metabolic determinants in Listeria monocytogenes anaerobic listeriolysin O production. Arch Microbiol 2017; 199:827-837. [PMID: 28289786 PMCID: PMC5504256 DOI: 10.1007/s00203-017-1355-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/21/2017] [Indexed: 11/21/2022]
Abstract
Listeria monocytogenes is a human pathogen and a facultative anaerobe. To better understand how anaerobic growth affects L. monocytogenes pathogenesis, we first showed that anaerobic growth led to decreased growth and changes in surface morphology. Moreover, compared to aerobically grown bacteria, anaerobically grown L. monocytogenes established higher level of invasion but decreased intracellular growth and actin polymerization in cultured cells. The production of listeriolysin O (LLO) was significantly lower in anaerobic cultures—a phenotype observed in wild type and isogenic mutants lacking transcriptional regulators SigB or CodY or harboring a constitutively active PrfA. To explore potential regulatory mechanisms, we established that the addition of central carbon metabolism intermediates, such as acetate, citrate, fumarate, pyruvate, lactate, and succinate, led to an increase in LLO activity in the anaerobic culture supernatant. These results highlight the regulatory role of central carbon metabolism in L. monocytogenes pathogenesis under anaerobic conditions.
Collapse
|
15
|
Sievers S, Lund A, Menendez-Gil P, Nielsen A, Storm Mollerup M, Lambert Nielsen S, Buch Larsson P, Borch-Jensen J, Johansson J, Kallipolitis BH. The multicopy sRNA LhrC controls expression of the oligopeptide-binding protein OppA in Listeria monocytogenes. RNA Biol 2016; 12:985-97. [PMID: 26176322 DOI: 10.1080/15476286.2015.1071011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Listeria monocytogenes is the causative agent of the foodborne disease listeriosis. During infection, L. monocytogenes produces an array of non-coding RNAs, including the multicopy sRNA LhrC. These five, nearly identical sRNAs are highly induced in response to cell envelope stress and target the virulence adhesin lapB at the post-transcriptional level. Here, we demonstrate that LhrC controls expression of additional genes encoding cell envelope-associated proteins with virulence function. Using transcriptomics and proteomics, we identified a set of genes affected by LhrC in response to cell envelope stress. Three targets were significantly down-regulated by LhrC at both the RNA and protein level: lmo2349, tcsA and oppA. All three genes encode membrane-associated proteins: A putative substrate binding protein of an amino acid ABC transporter (Lmo2349); the CD4+ T cell-stimulating antigen TcsA, and the oligopeptide binding protein OppA, of which the latter 2 are required for full virulence of L. monocytogenes. For OppA, we show that LhrC acts by direct base paring to the ribosome binding site of the oppA mRNA, leading to an impediment of its translation and a decreased mRNA level. The sRNA-mRNA interaction depends on 2 of 3 CU-rich regions in LhrC allowing binding of 2 oppA mRNAs to a single LhrC molecule. Finally, we found that LhrC contributes to infection in macrophage-like cells. These findings demonstrate a central role for LhrC in controlling the level of OppA and other virulence-associated cell envelope proteins in response to cell envelope stress.
Collapse
Affiliation(s)
- Susanne Sievers
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark.,b Institute for Microbiology; Ernst-Moritz-Arndt-University Greifswald ; Greifswald , Germany.,d These authors equally contributed to this work
| | - Anja Lund
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark.,d These authors equally contributed to this work
| | - Pilar Menendez-Gil
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark
| | - Aaraby Nielsen
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark
| | - Maria Storm Mollerup
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark
| | - Stine Lambert Nielsen
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark
| | - Pernille Buch Larsson
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark
| | - Jonas Borch-Jensen
- a Department of Biochemistry and Molecular Biology ; University of Southern Denmark ; Odense , Denmark
| | - Jörgen Johansson
- c Department of Molecular Biology ; Umeå University ; Umeå , Sweden
| | | |
Collapse
|
16
|
Mollerup MS, Ross JA, Helfer AC, Meistrup K, Romby P, Kallipolitis BH. Two novel members of the LhrC family of small RNAs in Listeria monocytogenes with overlapping regulatory functions but distinctive expression profiles. RNA Biol 2016; 13:895-915. [PMID: 27400116 DOI: 10.1080/15476286.2016.1208332] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Multicopy small RNAs (sRNAs) have gained recognition as an important feature of bacterial gene regulation. In the human pathogen Listeria monocytogenes, 5 homologous sRNAs, called LhrC1-5, control gene expression by base pairing to target mRNAs though 3 conserved UCCC motifs common to all 5 LhrCs. We show here that the sRNAs Rli22 and Rli33-1 are structurally and functionally related to LhrC1-5, expanding the LhrC family to 7 members, which makes it the largest multicopy sRNA family reported so far. Rli22 and Rli33-1 both contain 2 UCCC motifs important for post-transcriptional repression of 3 LhrC target genes. One such target, oppA, encodes a virulence-associated oligo-peptide binding protein. Like LhrC1-5, Rli22 and Rli33-1 employ their UCCC motifs to recognize the Shine-Dalgarno region of oppA mRNA and prevent formation of the ribosomal complex, demonstrating that the 7 sRNAs act in a functionally redundant manner. However, differential expression profiles of the sRNAs under infection-relevant conditions suggest that they might also possess non-overlapping functions. Collectively, this makes the LhrC family a unique case for studying the purpose of sRNA multiplicity in the context of bacterial virulence.
Collapse
Affiliation(s)
- Maria Storm Mollerup
- a Department of Biochemistry and Molecular Biology , University of Southern Denmark , Odense , Denmark
| | - Joseph Andrew Ross
- a Department of Biochemistry and Molecular Biology , University of Southern Denmark , Odense , Denmark
| | - Anne-Catherine Helfer
- b Architecture et Réactivité de l´ARN, Université de Strasbourg, CNRS, IBMC , Strasbourg , France
| | - Kristine Meistrup
- a Department of Biochemistry and Molecular Biology , University of Southern Denmark , Odense , Denmark
| | - Pascale Romby
- b Architecture et Réactivité de l´ARN, Université de Strasbourg, CNRS, IBMC , Strasbourg , France
| | | |
Collapse
|
17
|
Listeria monocytogenes – An examination of food chain factors potentially contributing to antimicrobial resistance. Food Microbiol 2016. [DOI: 10.1016/j.fm.2014.08.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
18
|
Krawczyk-Balska A, Markiewicz Z. The intrinsic cephalosporin resistome of Listeria monocytogenes in the context of stress response, gene regulation, pathogenesis and therapeutics. J Appl Microbiol 2015; 120:251-65. [PMID: 26509460 DOI: 10.1111/jam.12989] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/18/2015] [Accepted: 08/28/2015] [Indexed: 12/22/2022]
Abstract
Intrinsic resistance to antibiotics is a serious therapeutic problem in the case of many bacterial species. The Gram-positive human pathogen Listeria monocytogenes is intrinsically resistant to broad spectrum cephalosporin antibiotics, which are commonly used in therapy of bacterial infections. Besides three penicillin-binding proteins the intrinsic cephalosporin resistome of L. monocytogenes includes multidrug resistance transporter transporters, proteins involved in peptidoglycan biosynthesis and modification, cell envelope proteins with structural or general detoxification function, cytoplasmic proteins with unknown function and regulatory proteins. Analysis of the regulation of the expression of genes involved in the intrinsic resistance of L. monocytogenes to cephalosporins highlights the high complexity of control of the intrinsic resistance phenotype. The regulation of the transcription of the intrinsic resistome determinants involves the activity of eight regulators, namely LisR, CesR, LiaR, VirR, σ(B) , σ(H) , σ(L) and PrfA, of which the most prominent role play LisR, CesR and σ(B) . Furthermore, the vast majority of the intrinsic resistome determinants contribute to the tolerance of different stress conditions and virulence. A study indicates that O-acetyltransferase OatA is the most promising candidate for co-drug development since an agent targeting OatA should sensitize L. monocytogenes to certain antibiotics, therefore improving the efficacy of listeriosis treatment as well as food preservation measures.
Collapse
Affiliation(s)
- A Krawczyk-Balska
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Z Markiewicz
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| |
Collapse
|
19
|
Pöntinen A, Markkula A, Lindström M, Korkeala H. Two-Component-System Histidine Kinases Involved in Growth of Listeria monocytogenes EGD-e at Low Temperatures. Appl Environ Microbiol 2015; 81:3994-4004. [PMID: 25841007 PMCID: PMC4524140 DOI: 10.1128/aem.00626-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 03/28/2015] [Indexed: 01/23/2023] Open
Abstract
Two-component systems (TCSs) aid bacteria in adapting to a wide variety of stress conditions. While the role of TCS response regulators in the cold tolerance of the psychrotrophic foodborne pathogen Listeria monocytogenes has been demonstrated previously, no comprehensive studies showing the role of TCS histidine kinases of L. monocytogenes at low temperature have been performed. We compared the expression levels of each histidine kinase-encoding gene of L. monocytogenes EGD-e in logarithmic growth phase at 3°C and 37°C, as well as the expression levels 30 min, 3 h, and 7 h after cold shock at 5°C and preceding cold shock (at 37°C). We constructed a deletion mutation in each TCS histidine kinase gene, monitored the growth of the EGD-e wild-type and mutant strains at 3°C and 37°C, and measured the minimum growth temperature of each strain. Two genes, yycG and lisK, proved significant in regard to induced relative expression levels under cold conditions and cold-sensitive mutant phenotypes. Moreover, the ΔresE mutant showed a lower growth rate than that of wild-type EGD-e at 3°C. Eleven other genes showed upregulated gene expression but revealed no cold-sensitive phenotypes. The results show that the histidine kinases encoded by yycG and lisK are important for the growth and adaptation of L. monocytogenes EGD-e at low temperature.
Collapse
Affiliation(s)
- Anna Pöntinen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Annukka Markkula
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| |
Collapse
|
20
|
Nguyen UT, Harvey H, Hogan AJ, Afonso ACF, Wright GD, Burrows LL. Role of PBPD1 in stimulation of Listeria monocytogenes biofilm formation by subminimal inhibitory β-lactam concentrations. Antimicrob Agents Chemother 2014; 58:6508-17. [PMID: 25136010 PMCID: PMC4249420 DOI: 10.1128/aac.03671-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 08/10/2014] [Indexed: 12/19/2022] Open
Abstract
Disinfectant-tolerant Listeria monocytogenes biofilms can colonize surfaces that come into contact with food, leading to contamination and, potentially, food-borne illnesses. To better understand the process of L. monocytogenes biofilm formation and dispersal, we screened 1,120 off-patent FDA-approved drugs and identified several that modulate Listeria biofilm development. Among the hits were more than 30 β-lactam antibiotics, with effects ranging from inhibiting (≤50%) to stimulating (≥200%) biofilm formation compared to control. Most β-lactams also dispersed a substantial proportion of established biofilms. This phenotype did not necessarily involve killing, as >50% dispersal could be achieved with concentrations as low as 1/20 of the MIC of some cephalosporins. Penicillin-binding protein (PBP) profiling using a fluorescent penicillin analogue showed similar inhibition patterns for most β-lactams, except that biofilm-stimulatory drugs did not bind PBPD1, a low-molecular-weight d,d-carboxypeptidase. Compared to the wild type, a pbpD1 mutant had an attenuated biofilm response to stimulatory β-lactams. The cephalosporin-responsive CesRK two-component regulatory system, whose regulon includes PBPs, was not required for the response. The requirement for PBPD1 activity for β-lactam stimulation of L. monocytogenes biofilms shows that the specific set of PBPs that are inactivated by a particular drug dictates whether a protective biofilm response is provoked.
Collapse
Affiliation(s)
- Uyen T Nguyen
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario, Canada
| | - Hanjeong Harvey
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario, Canada
| | - Andrew J Hogan
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario, Canada
| | - Alexandria C F Afonso
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario, Canada
| | - Gerard D Wright
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario, Canada
| | - Lori L Burrows
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
21
|
Cabrita P, Trigo MJ, Ferreira RB, Brito L. Is the exoproteome important for bacterial pathogenesis? Lessons learned from interstrain exoprotein diversity in Listeria monocytogenes grown at different temperatures. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2014; 18:553-69. [PMID: 25127015 DOI: 10.1089/omi.2013.0151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial exoproteomes vary in composition and quantity among species and within each species, depending on the environmental conditions to which the cells are exposed. This article critically reviews the literature available on exoproteins synthesized by the foodborne pathogenic bacterium Listeria monocytogenes grown at different temperatures. The main challenges posed for exoproteome analyses and the strategies that are being used to overcome these constraints are discussed. Over thirty exoproteins from L. monocytogenes are considered, and the multifunctionality of some of them is discussed. Thus, at the host temperature of 37°C, good examples are provided by Lmo0443, a potential marker for low virulence, and by the virulence factors internalin C (InlC) and listeriolysin O (LLO). Based on the reported LLO-induced mucin exocytosis, a model is proposed for the involvement of extracellular LLO in optimizing the conditions for InlC intervention in the invasion of intestinal epithelial cells. At lower growth temperatures, exoproteins such as flagellin (FlaA) and oligopeptide permease (OppA) may explain the persistence of particular strains in the food industry environment, eventually allowing the development of new tools to eradicate L. monocytogenes, a major concern for public health.
Collapse
Affiliation(s)
- Paula Cabrita
- 1 CBAA/DRAT-Departamento dos Recursos Naturais, Ambiente e Território, Instituto Superior de Agronomia, University of Lisbon , Lisbon, Portugal
| | | | | | | |
Collapse
|
22
|
Krawczyk-Balska A, Korsak D, Popowska M. The surface protein Lmo1941 with LysM domain influences cell wall structure and susceptibility of Listeria monocytogenes to cephalosporins. FEMS Microbiol Lett 2014; 357:175-83. [PMID: 24974853 DOI: 10.1111/1574-6968.12518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/04/2014] [Accepted: 06/20/2014] [Indexed: 11/30/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive bacterium causing rare but dangerous cases of disease in humans and animals. The β-lactams penicillin G and ampicillin are the antibiotics of choice in the treatment of listeriosis. Recently, lmo1941, encoding a surface protein of L. monocytogenes with unknown function, was identified as a gene transcriptionally upregulated under penicillin G pressure. In this study, the effect of lmo1941 knockout on the susceptibility of L. monocytogenes to β-lactams was examined. Deletion mutant in lmo1941 was constructed and subjected to studies, which revealed that the deletion of lmo1941 had no effect on susceptibility and tolerance to penicillin G and ampicillin but resulted, however, in increased susceptibility of L. monocytogenes to several cephalosporins. Subsequently, the potential effect of lmo1941 mutation on the cell wall of L. monocytogenes was investigated. The analysis revealed quantitative changes in the muropeptide profile of peptidoglycan and a decrease in density of the high-density zone of cell wall of the mutant strain. Both these changes were observed in cells taken from the stationary phase. These results indicate that the surface protein Lmo1941 affects peptidoglycan composition and cell wall structure of L. monocytogenes in the stationary phase of growth.
Collapse
Affiliation(s)
- Agata Krawczyk-Balska
- Faculty of Biology, Department of Applied Microbiology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
| | | | | |
Collapse
|
23
|
Laursen MF, Bahl MI, Licht TR, Gram L, Knudsen GM. A single exposure to a sublethal pediocin concentration initiates a resistance-associated temporal cell envelope and general stress response inListeria monocytogenes. Environ Microbiol 2014; 17:1134-51. [DOI: 10.1111/1462-2920.12534] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 06/08/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Martin F. Laursen
- Department of Systems Biology; Technical University of Denmark; DK-2800 Kongens Lyngby Denmark
- National Food Institute; Technical University of Denmark; DK-2860 Søborg Denmark
| | - Martin I. Bahl
- National Food Institute; Technical University of Denmark; DK-2860 Søborg Denmark
| | - Tine R. Licht
- National Food Institute; Technical University of Denmark; DK-2860 Søborg Denmark
| | - Lone Gram
- Department of Systems Biology; Technical University of Denmark; DK-2800 Kongens Lyngby Denmark
| | - Gitte M. Knudsen
- Department of Systems Biology; Technical University of Denmark; DK-2800 Kongens Lyngby Denmark
| |
Collapse
|
24
|
Durack J, Ross T, Bowman JP. Characterisation of the transcriptomes of genetically diverse Listeria monocytogenes exposed to hyperosmotic and low temperature conditions reveal global stress-adaptation mechanisms. PLoS One 2013; 8:e73603. [PMID: 24023890 PMCID: PMC3762727 DOI: 10.1371/journal.pone.0073603] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 07/29/2013] [Indexed: 12/29/2022] Open
Abstract
The ability of Listeria monocytogenes to adapt to various food and food- processing environments has been attributed to its robustness, persistence and prevalence in the food supply chain. To improve the present understanding of molecular mechanisms involved in hyperosmotic and low-temperature stress adaptation of L. monocytogenes, we undertook transcriptomics analysis on three strains adapted to sub-lethal levels of these stress stimuli and assessed functional gene response. Adaptation to hyperosmotic and cold-temperature stress has revealed many parallels in terms of gene expression profiles in strains possessing different levels of stress tolerance. Gene sets associated with ribosomes and translation, transcription, cell division as well as fatty acid biosynthesis and peptide transport showed activation in cells adapted to either cold or hyperosmotic stress. Repression of genes associated with carbohydrate metabolism and transport as well as flagella was evident in stressed cells, likely linked to activation of CodY regulon and consequential cellular energy conservation.
Collapse
Affiliation(s)
- Juliana Durack
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
- Food Safety Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
| | - Tom Ross
- Food Safety Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
| | - John P. Bowman
- Food Safety Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
| |
Collapse
|
25
|
Krawczyk-Balska A, Marchlewicz J, Dudek D, Wasiak K, Samluk A. Identification of a ferritin-like protein of Listeria monocytogenes as a mediator of β-lactam tolerance and innate resistance to cephalosporins. BMC Microbiol 2012; 12:278. [PMID: 23176286 PMCID: PMC3534079 DOI: 10.1186/1471-2180-12-278] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/20/2012] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The food-borne pathogen Listeria monocytogenes is the causative agent of listeriosis. The β-lactam antibiotics penicillin G and ampicillin are the current drugs of choice for the treatment of listerial infections. While isolates of L. monocytogenes are susceptible to these antibiotics, their action is only bacteriostatic and consequently, this bacterium is regarded as tolerant to β-lactams. In addition, L. monocytogenes has a high level of innate resistance to the cephalosporin family of β-lactams frequently used to treat sepsis of unknown etiology. Given the high mortality rate of listeriosis despite rational antibiotic therapy, it is important to identify genes that play a role in the susceptibility and tolerance of L. monocytogenes to β-lactams. RESULTS The hly-based promoter trap system was applied to identify penicillin G-inducible genes of L. monocytogenes. The results of reporter system studies, verified by transcriptional analysis, identified ten penicillin G-inducible genes. The contribution of three of these genes, encoding a ferritin-like protein (fri), a two-component phosphate-response regulator (phoP) and an AraC/XylS family transcriptional regulator (axyR), to the susceptibility and tolerance of L. monocytogenes to β-lactams was examined by analysis of nonpolar deletion mutants. The absence of PhoP or AxyR resulted in more rapid growth of the strains in the presence of sublethal concentration of β-lactams, but had no effect on the MIC values or the ability to survive a lethal dose of these antibiotics. However, the Δfri strain showed impaired growth in the presence of sublethal concentrations of penicillin G and ampicillin and a significantly reduced ability to survive lethal concentrations of these β-lactams. A lack of Fri also caused a 2-fold increase in the sensitivity of L. monocytogenes to cefalotin and cephradine. CONCLUSIONS The present study has identified Fri as an important mediator of β-lactam tolerance and innate resistance to cephalosporins in L. monocytogenes. PhoP and AxyR are probably involved in transmitting signals to adjust the rate of growth of L. monocytogenes under β-lactam pressure, but these regulators do not play a significant role in susceptibility and tolerance to this class of antibiotics.
Collapse
Affiliation(s)
- Agata Krawczyk-Balska
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland.
| | | | | | | | | |
Collapse
|
26
|
Knudsen G, Holch A, Gram L. Subinhibitory concentrations of antibiotics affect stress and virulence gene expression inListeria monocytogenesand cause enhanced stress sensitivity but do not affect Caco-2 cell invasion. J Appl Microbiol 2012; 113:1273-86. [DOI: 10.1111/j.1365-2672.2012.05435.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 08/14/2012] [Accepted: 08/15/2012] [Indexed: 11/29/2022]
Affiliation(s)
- G.M. Knudsen
- National Food Institute; Technical University of Denmark; Kongens Lyngby; Denmark
| | - A. Holch
- National Food Institute; Technical University of Denmark; Kongens Lyngby; Denmark
| | - L. Gram
- National Food Institute; Technical University of Denmark; Kongens Lyngby; Denmark
| |
Collapse
|
27
|
Genome-wide transcriptional profiling of the cell envelope stress response and the role of LisRK and CesRK in Listeria monocytogenes. Microbiology (Reading) 2012; 158:963-974. [DOI: 10.1099/mic.0.055467-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
28
|
Collins B, Guinane CM, Cotter PD, Hill C, Ross RP. Assessing the contributions of the LiaS histidine kinase to the innate resistance of Listeria monocytogenes to nisin, cephalosporins, and disinfectants. Appl Environ Microbiol 2012; 78:2923-9. [PMID: 22327581 PMCID: PMC3318795 DOI: 10.1128/aem.07402-11] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 02/02/2012] [Indexed: 12/23/2022] Open
Abstract
The Listeria monocytogenes LiaSR two-component system (2CS) encoded by lmo1021 and lmo1022 plays an important role in resistance to the food preservative nisin. A nonpolar deletion in the histidine kinase-encoding component (ΔliaS) resulted in a 4-fold increase in nisin resistance. In contrast, the ΔliaS strain exhibited increased sensitivity to a number of cephalosporin antibiotics (and was also altered with respect to its response to a variety of other antimicrobials, including the active agents of a number of disinfectants). This pattern of increased nisin resistance and reduced cephalosporin resistance in L. monocytogenes has previously been associated with mutation of a second histidine kinase, LisK, which is a predicted regulator of liaS and a penicillin binding protein encoded by lmo2229. We noted that lmo2229 transcription is increased in the ΔliaS mutant and in a ΔliaS ΔlisK double mutant and that disruption of lmo2229 in the ΔliaS ΔlisK mutant resulted in a dramatic sensitization to nisin but had a relatively minor impact on cephalosporin resistance. We anticipate that further efforts to unravel the complex mechanisms by which LiaSR impacts on the antimicrobial resistance of L. monocytogenes could facilitate the development of strategies to increase the susceptibility of the pathogen to these agents.
Collapse
Affiliation(s)
- Barry Collins
- Department of Microbiology, University College Cork, Cork, Ireland
| | - Caitriona M. Guinane
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
- Alimentary Pharmabiotic Centre, Cork, Ireland
| | - Paul D. Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
- Alimentary Pharmabiotic Centre, Cork, Ireland
| | - Colin Hill
- Department of Microbiology, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, Cork, Ireland
| | - R. Paul Ross
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
- Alimentary Pharmabiotic Centre, Cork, Ireland
| |
Collapse
|
29
|
Collins B, Cotter PD, Hill C, Ross RP. The impact of nisin on sensitive and resistant mutants of Listeria monocytogenes in cottage cheese. J Appl Microbiol 2011; 110:1509-14. [PMID: 21435121 DOI: 10.1111/j.1365-2672.2011.05005.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AIMS Listeria monocytogenes ΔgadD1 and ΔlisK mutants display enhanced and reduced sensitivity, respectively, to the food preservative nisin in laboratory media. However, the behaviour of these strains in a nisin-containing food has not been assessed. Here we use cottage cheese as a model food to address this issue. MATERIALS AND RESULTS Antibiotic-resistant forms of the wild-type and mutant strains were employed to investigate the behaviour of multiple strains in a single food sample, thereby eliminating the problem of intersample variation. Using this approach, it was established that percentage survival of the ΔlisK mutant was greater than the parent strain in the absence of nisin and that this relative difference became even more dramatic in cottage cheese supplemented with nisin. The numbers of the ΔgadD1 mutant decreased more rapidly than the parent in cottage cheese without nisin, but surprisingly this trend was reversed in nisin-supplemented cheese. Upon the addition of 10 mmol l(-1) monosodium glutamate, a substrate for the glutamate decarboxylase (GAD) system, the wild-type LO28 strain regained its relative advantage over ΔgadD1. CONCLUSIONS Care needs to be taken when predicting the behaviour of mutants of L. monocytogenes with altered resistance to nisin in food as experiments in laboratory media are not always a good indicator of how the strains will behave in such food environments. SIGNIFICANCE AND IMPACT OF THE STUDY This study further emphasizes the importance of utilizing food matrices to confirm observations made using laboratory media.
Collapse
Affiliation(s)
- B Collins
- Department of Microbiology, University College Cork, Cork, Ireland
| | | | | | | |
Collapse
|
30
|
Korsak D, Markiewicz Z, Gutkind GO, Ayala JA. Identification of the full set of Listeria monocytogenes penicillin-binding proteins and characterization of PBPD2 (Lmo2812). BMC Microbiol 2010; 10:239. [PMID: 20843347 PMCID: PMC2949700 DOI: 10.1186/1471-2180-10-239] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Accepted: 09/15/2010] [Indexed: 11/24/2022] Open
Abstract
Background Bacterial penicillin-binding proteins (PBPs) can be visualized by their ability to bind radiolabeled or fluorescent β-lactam derivatives both whole cells and membrane/cell enriched fractions. Analysis of the Listeria monocytogenes genome sequence predicted ten genes coding for putative PBPs, but not all of their products have been detected in studies using radiolabeled antibiotics, thus hindering their characterization. Here we report the positive identification of the full set of L. monocytogenes PBPs and the characteristics of the hitherto undescribed PBPD2 (Lmo2812). Results Eight L. monocytogenes PBPs were identified by the binding of fluorescent β-lactam antibiotic derivatives Boc-FL, Boc-650 and Amp-Alexa430 to proteins in whole cells or membrane/cell wall extracts. The gene encoding a ninth PBP (Lmo2812) was cloned and expressed in Escherichia coli as a His-tagged protein. The affinity purified recombinant protein had DD-carboxypeptidase activity and preferentially degraded low-molecular-weight substrates. L. monocytogenes mutants lacking the functional Lmo2812 enzyme were constructed and, compared to the wild-type, the cells were longer and slightly curved with bent ends. Protein Lmo1855, previously designated PBPD3, did not bind any of the antibiotic derivatives tested, similarly to the homologous enterococcal protein VanY. Conclusions Nine out of the ten putative L. monocytogenes PBP genes were shown to encode proteins that bind derivatives of β-lactam antibiotics, thus enabling their positive identification. PBPD2 (Lmo2812) was not visualized in whole cell extracts, most probably due to its low abundance, but it was shown to bind Boc-FL after recombinant overexpression and purification. Mutants lacking Lmo2812 and another low molecular mass (LMM) PBP, PBP5 (PBPD1) - both with DD-carboxypeptidase activity - displayed only slight morphological alterations, demonstrating that they are dispensable for cell survival and probably participate in the latter stages of peptidoglycan synthesis. Since Lmo2812 preferentially degrades low-molecular- mass substrates, this may indicate a role in cell wall turnover.
Collapse
Affiliation(s)
- Dorota Korsak
- Institute of Microbiology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland.
| | | | | | | |
Collapse
|