1
|
Zhang Y, Liang S, Zhang S, Bai Q, Dai L, Wang J, Yao H, Zhang W, Liu G. Streptococcal arginine deiminase system defences macrophage bactericidal effect mediated by XRE family protein XtrSs. Virulence 2024; 15:2306719. [PMID: 38251714 PMCID: PMC10841013 DOI: 10.1080/21505594.2024.2306719] [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] [Received: 07/30/2023] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
The arginine deiminase system (ADS) has been identified in various bacteria and functions to supplement energy production and enhance biological adaptability. The current understanding of the regulatory mechanism of ADS and its effect on bacterial pathogenesis is still limited. Here, we found that the XRE family transcriptional regulator XtrSs negatively affected Streptococcus suis virulence and significantly repressed ADS transcription when the bacteria were incubated in blood. Electrophoretic mobility shift (EMSA) and lacZ fusion assays further showed that XtrSs directly bind to the promoter of ArgR, an acknowledged positive regulator of bacterial ADS, to repress ArgR transcription. Moreover, we provided compelling evidence that S. suis could utilize arginine via ADS to adapt to acid stress, while ΔxtrSs enhanced this acid resistance by upregulating the ADS operon. Moreover, whole ADS-knockout S. suis increased arginine and antimicrobial NO in the infected macrophage cells, decreased intracellular survival, and even caused significant attenuation of bacterial virulence in a mouse infection model, while ΔxtrSs consistently presented the opposite results. Our experiments identified a novel ADS regulatory mechanism in S. suis, whereby XtrSs regulated ADS to modulate NO content in macrophages, promoting S. suis intracellular survival. Meanwhile, our findings provide a new perspective on how Streptococci evade the host's innate immune system.
Collapse
Affiliation(s)
- Yumin Zhang
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Song Liang
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Shidan Zhang
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Qiankun Bai
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Lei Dai
- Hainan Animal Disease Prevention and Control Center, Haikou, China
| | - Jinxiu Wang
- Hainan Animal Disease Prevention and Control Center, Haikou, China
| | - Huochun Yao
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Wei Zhang
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Guangjin Liu
- Sanya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Sanya, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
2
|
Myintzaw P, Pennone V, McAuliffe O, Begley M, Callanan M. Association of Virulence, Biofilm, and Antimicrobial Resistance Genes with Specific Clonal Complex Types of Listeria monocytogenes. Microorganisms 2023; 11:1603. [PMID: 37375105 DOI: 10.3390/microorganisms11061603] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Precise classification of foodborne pathogen Listeria monocytogenes is a necessity in efficient foodborne disease surveillance, outbreak detection, and source tracking throughout the food chain. In this study, a total of 150 L. monocytogenes isolates from various food products, food processing environments, and clinical sources were investigated for variations in virulence, biofilm formation, and the presence of antimicrobial resistance genes based on their Whole-Genome Sequences. Clonal complex (CC) determination based on Multi-Locus Sequence Typing (MLST) revealed twenty-eight CC-types including eight isolates representing novel CC-types. The eight isolates comprising the novel CC-types share the majority of the known (cold and acid) stress tolerance genes and are all genetic lineage II, serogroup 1/2a-3a. Pan-genome-wide association analysis by Scoary using Fisher's exact test identified eleven genes specifically associated with clinical isolates. Screening for the presence of antimicrobial and virulence genes using the ABRicate tool uncovered variations in the presence of Listeria Pathogenicity Islands (LIPIs) and other known virulence genes. Specifically, the distributions of actA, ecbA, inlF, inlJ, lapB, LIPI-3, and vip genes across isolates were found to be significantly CC-dependent while the presence of ami, inlF, inlJ, and LIPI-3 was associated with clinical isolates specifically. In addition, Roary-derived phylogenetic grouping based on Antimicrobial-Resistant Genes (AMRs) revealed that the thiol transferase (FosX) gene was present in all lineage I isolates, and the presence of the lincomycin resistance ABC-F-type ribosomal protection protein (lmo0919_fam) was also genetic-lineage-dependent. More importantly, the genes found to be specific to CC-type were consistent when a validation analysis was performed with fully assembled, high-quality complete L. monocytogenes genome sequences (n = 247) extracted from the National Centre for Biotechnology Information (NCBI) microbial genomes database. This work highlights the usefulness of MLST-based CC typing using the Whole-Genome Sequence as a tool in classifying isolates.
Collapse
Affiliation(s)
- Peter Myintzaw
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
| | - Vincenzo Pennone
- Teagasc Food Research Centre, Moorepark, Fermoy, Co., P61 C996 Cork, Ireland
| | - Olivia McAuliffe
- Teagasc Food Research Centre, Moorepark, Fermoy, Co., P61 C996 Cork, Ireland
| | - Máire Begley
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
| | - Michael Callanan
- Department of Biological Sciences, Munster Technological University, Bishopstown, T12 P928 Cork, Ireland
| |
Collapse
|
3
|
Guerreiro DN, Boyd A, O'Byrne CP. The stressosome is required to transduce low pH signals leading to increased transcription of the amino acid-based acid tolerance mechanisms in Listeria monocytogenes. Access Microbiol 2022; 4:acmi000455. [PMID: 36415544 PMCID: PMC9675040 DOI: 10.1099/acmi.0.000455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 08/02/2022] [Indexed: 10/03/2023] Open
Abstract
Increasing proton concentration in the environment represents a potentially lethal stress for single-celled microorganisms. To survive in an acidifying environment, the foodborne pathogen Listeria monocytogenes quickly activates the alternative sigma factor B (σB), resulting in upregulation of the general stress response (GSR) regulon. Activation of σB is regulated by the stressosome, a multi-protein sensory complex involved in stress detection and signal transduction. In this study, we used L. monocytogenes strains harbouring two stressosome mutants to investigate the role of this complex in triggering expression of known amino acid-based resistance mechanisms in response to low pH. We found that expression of glutamate decarboxylase (gadD3) and arginine and agmatine deiminases (arcA and aguA1, respectively) were upregulated upon acid shock (pH 5 for 15 min) in a stressosome-dependent manner. In contrast, transcription of the arg operons (argGH and argCJBDF), which encode enzymes for the l-arginine biosynthesis pathway, were upregulated upon acid shock in a stressosome-independent manner. Finally, we found that transcription of argR, which encodes a transcriptional regulator of the arc and arg operons, was largely unaffected by acidic shock. Thus, our findings suggest that the stressosome plays a role in activating amino acid-based pH homeostatic mechanisms in L. monocytogenes . Additionally, we show that genes encoding the l-arginine biosynthesis pathway are highly upregulated under acidic conditions, suggesting that intracellular arginine can help withstand environmental acidification in this pathogen.
Collapse
Affiliation(s)
- Duarte N. Guerreiro
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, National University of Ireland, Galway, Ireland
| | - Aoife Boyd
- Pathogenic Mechanisms Research Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Conor P. O'Byrne
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, National University of Ireland, Galway, Ireland
| |
Collapse
|
4
|
Myintzaw P, Pennone V, McAuliffe O, Begley M, Callanan M. Correlation of organic acid tolerance and genotypic characteristics of Listeria monocytogenes food and clinical isolates. Food Microbiol 2022; 104:104004. [DOI: 10.1016/j.fm.2022.104004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 01/05/2022] [Accepted: 02/11/2022] [Indexed: 11/29/2022]
|
5
|
Ceviche-Natural Preservative: Possibility of Microbiota Survival and Effect on L. monocytogenes. Foods 2022; 11:foods11060860. [PMID: 35327282 PMCID: PMC8950590 DOI: 10.3390/foods11060860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 11/23/2022] Open
Abstract
Ceviche is a marinated raw fish dish ready for consumption; it is a part of the cuisine of various countries on the Pacific coast and its preparation may differ among them. Although the process uses the traditional method of food preservation by lowering the pH, the exposure time is very limited, so the aim of the study was to determine the viability of bacteria often isolated from fish after the process of preparing traditional ceviche. For this purpose, the traditional plate method and flow cytometry were used, and for pathogenic L. monocytogenes strains, the influence of stress during the preparation of the dish on the pathogenic potential was determined. The study showed that the highest percentage of viable cells was observed in the case of L. monocytogenes and remained at the level of 98.54%, slightly less for L. innocua, 96.93%. For the remaining species the reduction did not exceed 10%, for E. faecalis it was 92.76%, for S. liqefaciens 91.44%, H. alvei 93.68%. In addition, the study of the antibacterial properties of individual ingredients showed that habanero and coriander did not show any bactericidal effect, while for onions the amount of live cells was 99.11%, and for lime juice 97.26%, Additionally, the study of changes in virulence, antibiotic resistance and gene expression showed that the stress during the preparation of ceviche has different effects depending on the strain and may cause virulence potential increase, levofloxacin and daptomycin minimum inhibiotory concentration increase and some crucial virulence gene expression induction; therefore, it is important to take care of the quality of the products used to prepare the ceviche and accurate pretreatment.
Collapse
|
6
|
Lakicevic BZ, Den Besten HMW, De Biase D. Landscape of Stress Response and Virulence Genes Among Listeria monocytogenes Strains. Front Microbiol 2022; 12:738470. [PMID: 35126322 PMCID: PMC8811131 DOI: 10.3389/fmicb.2021.738470] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/30/2021] [Indexed: 12/23/2022] Open
Abstract
The pathogenic microorganism Listeria monocytogenes is ubiquitous and responsible for listeriosis, a disease with a high mortality rate in susceptible people. It can persist in different habitats, including the farm environment, the food production environments, and in foods. This pathogen can grow under challenging conditions, such as low pH, low temperatures, and high salt concentrations. However, L. monocytogenes has a high degree of strain divergence regarding virulence potential, environmental adaption, and stress response. This review seeks to provide the reader with an up-to-date overview of clonal and serotype-specific differences among L. monocytogenes strains. Emphasis on the genes and genomic islands responsible for virulence and resistance to environmental stresses is given to explain the complex adaptation among L. monocytogenes strains. Moreover, we highlight the use of advanced diagnostic technologies, such as whole-genome sequencing, to fine-tune quantitative microbiological risk assessment for better control of listeriosis.
Collapse
Affiliation(s)
- Brankica Z. Lakicevic
- Institute of Meat Hygiene and Technology, Belgrade, Serbia
- *Correspondence: Brankica Z. Lakicevic,
| | | | - Daniela De Biase
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| |
Collapse
|
7
|
Quereda JJ, Morón-García A, Palacios-Gorba C, Dessaux C, García-del Portillo F, Pucciarelli MG, Ortega AD. Pathogenicity and virulence of Listeria monocytogenes: A trip from environmental to medical microbiology. Virulence 2021; 12:2509-2545. [PMID: 34612177 PMCID: PMC8496543 DOI: 10.1080/21505594.2021.1975526] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 01/02/2023] Open
Abstract
Listeria monocytogenes is a saprophytic gram-positive bacterium, and an opportunistic foodborne pathogen that can produce listeriosis in humans and animals. It has evolved an exceptional ability to adapt to stress conditions encountered in different environments, resulting in a ubiquitous distribution. Because some food preservation methods and disinfection protocols in food-processing environments cannot efficiently prevent contaminations, L. monocytogenes constitutes a threat to human health and a challenge to food safety. In the host, Listeria colonizes the gastrointestinal tract, crosses the intestinal barrier, and disseminates through the blood to target organs. In immunocompromised individuals, the elderly, and pregnant women, the pathogen can cross the blood-brain and placental barriers, leading to neurolisteriosis and materno-fetal listeriosis. Molecular and cell biology studies of infection have proven L. monocytogenes to be a versatile pathogen that deploys unique strategies to invade different cell types, survive and move inside the eukaryotic host cell, and spread from cell to cell. Here, we present the multifaceted Listeria life cycle from a comprehensive perspective. We discuss genetic features of pathogenic Listeria species, analyze factors involved in food contamination, and review bacterial strategies to tolerate stresses encountered both during food processing and along the host's gastrointestinal tract. Then we dissect host-pathogen interactions underlying listerial pathogenesis in mammals from a cell biology and systemic point of view. Finally, we summarize the epidemiology, pathophysiology, and clinical features of listeriosis in humans and animals. This work aims to gather information from different fields crucial for a comprehensive understanding of the pathogenesis of L. monocytogenes.
Collapse
Affiliation(s)
- Juan J. Quereda
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities. Valencia, Spain
| | - Alvaro Morón-García
- Departamento de Biología Celular. Facultad de Ciencias Biológicas, Universidad Complutense de Madrid. Madrid, Spain
| | - Carla Palacios-Gorba
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities. Valencia, Spain
| | - Charlotte Dessaux
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
| | - Francisco García-del Portillo
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
| | - M. Graciela Pucciarelli
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Biología Molecular ‘Severo Ochoa’. Departamento de Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Madrid. Madrid, Spain
| | - Alvaro D. Ortega
- Departamento de Biología Celular. Facultad de Ciencias Biológicas, Universidad Complutense de Madrid. Madrid, Spain
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB)- Consejo Superior De Investigaciones Científicas (CSIC), Madrid, Spain
| |
Collapse
|
8
|
Hu QQ, Shu JQ, Li WM, Wang GZ. Role of Auxin and Nitrate Signaling in the Development of Root System Architecture. FRONTIERS IN PLANT SCIENCE 2021; 12:690363. [PMID: 34858444 PMCID: PMC8631788 DOI: 10.3389/fpls.2021.690363] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 10/25/2021] [Indexed: 06/12/2023]
Abstract
The plant root is an important storage organ that stores indole-3-acetic acid (IAA) from the apical meristem, as well as nitrogen, which is obtained from the external environment. IAA and nitrogen act as signaling molecules that promote root growth to obtain further resources. Fluctuations in the distribution of nitrogen in the soil environment induce plants to develop a set of strategies that effectively improve nitrogen use efficiency. Auxin integrates the information regarding the nitrate status inside and outside the plant body to reasonably distribute resources and sustainably construct the plant root system. In this review, we focus on the main factors involved in the process of nitrate- and auxin-mediated regulation of root structure to better understand how the root system integrates the internal and external information and how this information is utilized to modify the root system architecture.
Collapse
|
9
|
Hernández VM, Arteaga A, Dunn MF. Diversity, properties and functions of bacterial arginases. FEMS Microbiol Rev 2021; 45:6308370. [PMID: 34160574 DOI: 10.1093/femsre/fuab034] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/17/2021] [Indexed: 02/07/2023] Open
Abstract
The metalloenzyme arginase hydrolyzes L-arginine to produce L-ornithine and urea. In bacteria, arginase has important functions in basic nitrogen metabolism and redistribution, production of the key metabolic precursor L-ornithine, stress resistance and pathogenesis. We describe the regulation and specific functions of the arginase pathway as well as summarize key characteristics of related arginine catabolic pathways. The use of arginase-derived ornithine as a precursor molecule is reviewed. We discuss the biochemical and transcriptional regulation of arginine metabolism, including arginase, with the latter topic focusing on the RocR and AhrC transcriptional regulators in the model organism Bacillus subtilis. Finally, we consider similarities and contrasts in the structure and catalytic mechanism of the arginases from Bacillus caldovelox and Helicobacter pylori. The overall aim of this review is to provide a panorama of the diversity of physiological functions, regulation, and biochemical features of arginases in a variety of bacterial species.
Collapse
Affiliation(s)
- Victor M Hernández
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas-Universidad Nacional Autonoma de México, Cuernavaca, Morelos, C.P. 62210, Mexico
| | - Alejandra Arteaga
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas-Universidad Nacional Autonoma de México, Cuernavaca, Morelos, C.P. 62210, Mexico
| | - Michael F Dunn
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas-Universidad Nacional Autonoma de México, Cuernavaca, Morelos, C.P. 62210, Mexico
| |
Collapse
|
10
|
Transcriptome Analysis of Listeria monocytogenes Exposed to Beef Fat Reveals Antimicrobial and Pathogenicity Attenuation Mechanisms. Appl Environ Microbiol 2021; 87:AEM.03027-20. [PMID: 33608290 DOI: 10.1128/aem.03027-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/09/2021] [Indexed: 12/13/2022] Open
Abstract
Listeria monocytogenes is a deadly intracellular pathogen mostly associated with consumption of ready-to-eat foods. This study investigated the effectiveness of total beef fat (BF-T) from flaxseed-fed cattle and its fractions enriched with monounsaturated fatty acids (BF-MUFA) and polyunsaturated fatty acids (BF-PUFA), along with commercially available long-chain fatty acids (LC-FA), as natural antimicrobials against L. monocytogenes BF-T was ineffective at concentrations up to 6 mg/ml, while L. monocytogenes was susceptible to BF-MUFA and BF-PUFA, with MICs at pH 7 of 0.33 ± 0.21 mg/ml and 0.06 ± 0.03 mg/ml, respectively. The MIC of C14:0 was significantly lower than those of C16:0 and C18:0 (P < 0.05). Fatty acids c9-C16:1, C18:2n-6, and C18:3n-3 showed stronger inhibitory activity than c9-C18:1 and conjugated C18:2, with MICs of <1 mg/ml. Furthermore, global transcriptional analysis by transcriptome sequencing (RNA-seq) was performed to characterize the response of L. monocytogenes to selected fatty acids. Functional analysis indicated that antimicrobial LC-UFA repressed the expression of genes associated with nutrient transmembrane transport, energy generation, and oxidative stress resistance. On the other hand, upregulation of ribosome assembly and translation process is possibly associated with adaptive and repair mechanisms activated in response to LC-UFA. Virulence genes and genes involved in bile, acid, and osmotic stresses were largely downregulated, and more so for c9-C16:1, C18:2n-6, and C18:3n-3, likely through interaction with the master virulence regulator PrfA and the alternative sigma factor σB IMPORTANCE Listeria monocytogenes is a bacterial pathogen known for its ability to survive and thrive under adverse environments and, as such, its control poses a significant challenge, especially with the trend of minimally processed and ready-to-eat foods. This work investigated the effectiveness of fatty acids from various sources as natural antimicrobials against L. monocytogenes and evaluated their potential role in L. monocytogenes pathogenicity modulation, using the strain ATCC 19111. The findings show that long-chain unsaturated fatty acids (LC-UFA), including unsaturated beef fat fractions from flaxseed-fed cattle, could have the potential to be used as effective antimicrobials for L. monocytogenes through controlling growth as well as virulence attenuation. This not only advances our understanding of the mode of action of LC-UFA against L. monocytogenes but also suggests the potential for use of beef fat or its fractions as natural antimicrobials for controlling foodborne pathogens.
Collapse
|
11
|
Arcari T, Feger ML, Guerreiro DN, Wu J, O’Byrne CP. Comparative Review of the Responses of Listeria monocytogenes and Escherichia coli to Low pH Stress. Genes (Basel) 2020; 11:genes11111330. [PMID: 33187233 PMCID: PMC7698193 DOI: 10.3390/genes11111330] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 02/07/2023] Open
Abstract
Acidity is one of the principal physicochemical factors that influence the behavior of microorganisms in any environment, and their response to it often determines their ability to grow and survive. Preventing the growth and survival of pathogenic bacteria or, conversely, promoting the growth of bacteria that are useful (in biotechnology and food production, for example), might be improved considerably by a deeper understanding of the protective responses that these microorganisms deploy in the face of acid stress. In this review, we survey the molecular mechanisms used by two unrelated bacterial species in their response to low pH stress. We chose to focus on two well-studied bacteria, Escherichia coli (phylum Proteobacteria) and Listeria monocytogenes (phylum Firmicutes), that have both evolved to be able to survive in the mammalian gastrointestinal tract. We review the mechanisms that these species use to maintain a functional intracellular pH as well as the protective mechanisms that they deploy to prevent acid damage to macromolecules in the cells. We discuss the mechanisms used to sense acid in the environment and the regulatory processes that are activated when acid is encountered. We also highlight the specific challenges presented by organic acids. Common themes emerge from this comparison as well as unique strategies that each species uses to cope with acid stress. We highlight some of the important research questions that still need to be addressed in this fascinating field.
Collapse
|
12
|
Rhee KY, Chawla R, Lele PP. Protein expression-independent response of intensity-based pH-sensitive fluorophores in Escherichia coli. PLoS One 2020; 15:e0234849. [PMID: 32555627 PMCID: PMC7302705 DOI: 10.1371/journal.pone.0234849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/02/2020] [Indexed: 12/02/2022] Open
Abstract
Fluorescent proteins that modulate their emission intensities when protonated serve as excellent probes of the cytosolic pH. Since the total fluorescence output fluctuates significantly due to variations in the fluorophore levels in cells, eliminating the dependence of the signal on protein concentration is crucial. This is typically accomplished with the aid of ratiometric fluorescent proteins such as pHluorin. However, pHluorin is excited by blue light, which can complicate pH measurements by adversely impacting bacterial physiology. Here, we characterized the response of intensity-based, pH-sensitive fluorescent proteins that excite at longer wavelengths where the blue light effect is diminished. The pH-response was interpreted in terms of an analytical model that assumed two emission states for each fluorophore: a low intensity protonated state and a high intensity deprotonated state. The model suggested a scaling to eliminate the dependence of the signal on the expression levels as well as on the illumination and photon-detection settings. Experiments successfully confirmed the scaling predictions. Thus, the internal pH can be readily determined with intensity-based fluorophores with appropriate calibrations irrespective of the fluorophore concentration and the signal acquisition setup. The framework developed in this work improves the robustness of intensity-based fluorophores for internal pH measurements in E. coli, potentially extending their applications.
Collapse
Affiliation(s)
- Kathy Y. Rhee
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Ravi Chawla
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Pushkar P. Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, United States of America
| |
Collapse
|
13
|
He K, Xin YP, Shan Y, Zhang X, Song HH, Fang WH. Phosphorylation residue T175 in RsbR protein is required for efficient induction of sigma B factor and survival of Listeria monocytogenes under acidic stress. J Zhejiang Univ Sci B 2020; 20:660-669. [PMID: 31273963 DOI: 10.1631/jzus.b1800551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Listeria monocytogenes is an important zoonotic foodborne pathogen that can tolerate a number of environmental stresses. RsbR, an upstream regulator of the sigma B (SigB) factor, is thought to sense environmental challenges and trigger the SigB pathway. In Bacillus subtilis, two phosphorylation sites in RsbR are involved in activating the SigB pathway and a feedback mechanism, respectively. In this study, the role of RsbR in L. monocytogenes under mild and severe stresses was investigated. Strains with genetic deletion (ΔrsbR), complementation (C-ΔrsbR), and phosphorylation site mutations in the rsbR (RsbR-T175A, RsbR-T209A, and RsbR-T175A-T209A) were constructed to evaluate the roles of these RsbR sequences in listerial growth and survival. SigB was examined at the transcriptional and translational levels. Deletion of rsbR reduced listerial growxth and survival in response to acidic stress. Substitution of the phosphorylation residue RsbR-T175A disabled RsbR complementation, while RsbR-T209A significantly upregulated SigB expression and listerial survival. Our results provide clear evidence that two phosphorylation sites of RsbR are functional in L. monocytogenes under acidic conditions, similar to the situation in B. subtilis.
Collapse
Affiliation(s)
- Ke He
- College of Animal Science and Technology, Zhejiang A&F University, Lin'an 311300, China.,Zhejiang University Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Yong-Ping Xin
- Zhejiang University Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Ying Shan
- Zhejiang University Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Xian Zhang
- College of Animal Science and Technology, Zhejiang A&F University, Lin'an 311300, China
| | - Hou-Hui Song
- College of Animal Science and Technology, Zhejiang A&F University, Lin'an 311300, China
| | - Wei-Huan Fang
- College of Animal Science and Technology, Zhejiang A&F University, Lin'an 311300, China.,Zhejiang University Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| |
Collapse
|
14
|
Validation of Predicted Virulence Factors in Listeria monocytogenes Identified Using Comparative Genomics. Toxins (Basel) 2019; 11:toxins11090508. [PMID: 31480280 PMCID: PMC6783856 DOI: 10.3390/toxins11090508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/14/2019] [Accepted: 08/24/2019] [Indexed: 12/19/2022] Open
Abstract
Listeria monocytogenes is an intracellular facultative pathogen that causes listeriosis, a foodborne zoonotic infection. There are differences in the pathogenic potential of L. monocytogenes subtypes and strains. Comparison of the genome sequences among L. monocytogenes pathogenic strains EGD-e and F2365 with nonpathogenic L. innocua CLIP1182 and L. monocytogenes strain HCC23 revealed a set of proteins that were present in pathogenic strains and had no orthologs among the nonpathogenic strains. Among the candidate virulence factors are five proteins: putrescine carbamoyltransferase; InlH/InlC2 family class 1 internalin; phosphotransferase system (PTS) fructose transporter subunit EIIC; putative transketolase; and transcription antiterminator BglG family. To determine if these proteins have a role in adherence and invasion of intestinal epithelial Caco-2 cells and/or contribute to virulence, five mutant strains were constructed. F2365ΔinlC2, F2365Δeiic, and F2365Δtkt exhibited a significant (p < 0.05) reduction in adhesion to Caco-2 cells compared to parent F2365 strain. The invasion of F2365ΔaguB, F2365ΔinlC2, and F2365ΔbglG decreased significantly (p < 0.05) compared with the parent strain. Bacterial loads in mouse liver and spleen infected by F2365 was significantly (p < 0.05) higher than it was for F2365ΔaguB, F2365ΔinlC2, F2365Δeiic, F2365Δtkt, and F2365ΔbglG strains. This study demonstrates that aguB, inlC2, eiic, tkt, and bglG play a role in L. monocytogenes pathogenicity.
Collapse
|
15
|
Bucur FI, Grigore-Gurgu L, Crauwels P, Riedel CU, Nicolau AI. Resistance of Listeria monocytogenes to Stress Conditions Encountered in Food and Food Processing Environments. Front Microbiol 2018; 9:2700. [PMID: 30555426 PMCID: PMC6282059 DOI: 10.3389/fmicb.2018.02700] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/23/2018] [Indexed: 12/17/2022] Open
Abstract
Listeria monocytogenes is a human food-borne facultative intracellular pathogen that is resistant to a wide range of stress conditions. As a consequence, L. monocytogenes is extremely difficult to control along the entire food chain from production to storage and consumption. Frequent and recent outbreaks of L. monocytogenes infections illustrate that current measures of decontamination and preservation are suboptimal to control L. monocytogenes in food. In order to develop efficient measures to prevent contamination during processing and control growth during storage of food it is crucial to understand the mechanisms utilized by L. monocytogenes to tolerate the stress conditions in food matrices and food processing environments. Food-related stress conditions encountered by L. monocytogenes along the food chain are acidity, oxidative and osmotic stress, low or high temperatures, presence of bacteriocins and other preserving additives, and stresses as a consequence of applying alternative decontamination and preservation technologies such high hydrostatic pressure, pulsed and continuous UV light, pulsed electric fields (PEF). This review is aimed at providing a summary of the current knowledge on the response of L. monocytogenes toward these stresses and the mechanisms of stress resistance employed by this important food-borne bacterium. Circumstances when L. monocytogenes cells become more sensitive or more resistant are mentioned and existence of a cross-resistance when multiple stresses are present is pointed out.
Collapse
Affiliation(s)
- Florentina Ionela Bucur
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Leontina Grigore-Gurgu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Peter Crauwels
- Institute of Microbiology and Biotechnology, Ulm University, Ulm, Germany
| | | | - Anca Ioana Nicolau
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| |
Collapse
|
16
|
Park SB, Steadman CS, Chaudhari AA, Pillai SR, Singh SR, Ryan PL, Willard ST, Feugang JM. Proteomic analysis of antimicrobial effects of pegylated silver coated carbon nanotubes in Salmonella enterica serovar Typhimurium. J Nanobiotechnology 2018; 16:31. [PMID: 29587743 PMCID: PMC5870919 DOI: 10.1186/s12951-018-0355-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/19/2018] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Synthesis of silver nano-compounds with enhanced antimicrobial effects is of great interest for the development of new antibacterial agents. Previous studies have reported the antibacterial properties of pegylated silver-coated carbon nanotubes (pSWCNT-Ag) showing less toxicity in human cell lines. However, the mechanism underlining the pSWCNT-Ag as a bactericidal agent remained unfolded. Here we assessed the pSWCNT-Ag effects against foodborne pathogenic bacteria growth and proteome profile changes. RESULTS Measurements of bioluminescent imaging, optical density, and bacteria colony forming units revealed dose-dependent and stronger bactericidal activity of pSWCNT-Ag than their non-pegylated counterparts (SWCNT-Ag). In ovo administration of pSWCNT-Ag or phosphate-buffered saline resulted in comparable chicken embryo development and growth. The proteomic analysis, using two-dimensional electrophoresis combined with matrix assisted laser desorption/ionization time of flight/time of flight mass spectrometry, was performed on control and surviving Salmonella enterica serovar Typhimurium to pSWCNT-Ag. A total of 15 proteins (ten up-regulated and five down-regulated) differentially expressed proteins were identified. Functional analyses showed significant reduction of proteins associated with biofilm formation, nutrient and energy metabolism, quorum sensing and maintenance of cell structure and cell motility in surviving S. Typhimurium. In contrast, proteins associated with oxygen stress, DNA protection, starvation, membrane rebuilding, and alternative nutrient formation were induced as the compensatory reaction. CONCLUSIONS This study provides further evidence of the antibacterial effects of pSWCNT-Ag nanocomposites and knowledge of their mechanism of action through various protein changes. The findings may lead to the development of more effective and safe antimicrobial agents.
Collapse
Affiliation(s)
- Seong B. Park
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762 USA
| | - Christy S. Steadman
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762 USA
| | - Atul A. Chaudhari
- Center for Nanobiotechnology Research, Alabama State University, Montgomery, AL USA
| | - Shreekumar R. Pillai
- Center for Nanobiotechnology Research, Alabama State University, Montgomery, AL USA
| | - Shree R. Singh
- Center for Nanobiotechnology Research, Alabama State University, Montgomery, AL USA
| | - Peter L. Ryan
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762 USA
- Department of Pathobiology and Population Medicine, Mississippi State University, Mississippi State, MS 39762 USA
| | - Scott T. Willard
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762 USA
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762 USA
| | - Jean M. Feugang
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS 39762 USA
| |
Collapse
|
17
|
Vivant AL, Desneux J, Pourcher AM, Piveteau P. Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Lagoon and Soil Matrices Associated with a Piggery Environment: Comparison of Expression Profiles. Front Microbiol 2017; 8:1811. [PMID: 29018416 PMCID: PMC5623016 DOI: 10.3389/fmicb.2017.01811] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 09/05/2017] [Indexed: 12/20/2022] Open
Abstract
Understanding how Listeria monocytogenes, the causative agent of listeriosis, adapts to the environment is crucial. Adaptation to new matrices requires regulation of gene expression. To determine how the pathogen adapts to lagoon effluent and soil, two matrices where L. monocytogenes has been isolated, we compared the transcriptomes of L. monocytogenes CIP 110868 20 min and 24 h after its transfer to effluent and soil extract. Results showed major variations in the transcriptome of L. monocytogenes in the lagoon effluent but only minor modifications in the soil. In both the lagoon effluent and in the soil, genes involved in mobility and chemotaxis and in the transport of carbohydrates were the most frequently represented in the set of genes with higher transcript levels, and genes with phage-related functions were the most represented in the set of genes with lower transcript levels. A modification of the cell envelop was only found in the lagoon environment. Finally, the differential analysis included a large proportion of regulators, regulons, and ncRNAs.
Collapse
Affiliation(s)
- Anne-Laure Vivant
- UR OPAALE, IRSTEA, Rennes, France
- Université Bretagne Loire, Rennes, France
| | - Jeremy Desneux
- UR OPAALE, IRSTEA, Rennes, France
- Université Bretagne Loire, Rennes, France
| | | | - Pascal Piveteau
- Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique, Université Bourgogne Franche-Comté, Dijon, France
| |
Collapse
|
18
|
Cheng C, Dong Z, Han X, Wang H, Jiang L, Sun J, Yang Y, Ma T, Shao C, Wang X, Chen Z, Fang W, Freitag NE, Huang H, Song H. Thioredoxin A Is Essential for Motility and Contributes to Host Infection of Listeria monocytogenes via Redox Interactions. Front Cell Infect Microbiol 2017; 7:287. [PMID: 28702378 PMCID: PMC5487381 DOI: 10.3389/fcimb.2017.00287] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/12/2017] [Indexed: 12/17/2022] Open
Abstract
Microbes employ the thioredoxin system to defend against oxidative stress and ensure correct disulfide bonding to maintain protein function. Listeria monocytogenes has been shown to encode a putative thioredoxin, TrxA, but its biological roles and underlying mechanisms remain unknown. Here, we showed that expression of L. monocytogenes TrxA is significantly induced in bacteria treated with the thiol-specific oxidizing agent, diamide. Deletion of trxA markedly compromised tolerance of the pathogen to diamide, and mainly impaired early stages of infection in human intestinal epithelial Caco-2 cells. In addition, most trxA mutant bacteria were not associated with polymerized actin, and the rare bacteria that were associated with polymerized actin displayed very short tails or clouds during infection. Deletion or constitutive overexpression of TrxA, which was regulated by SigH, severely attenuated the virulence of the pathogen. Transcriptome analysis of L. monocytogenes revealed over 270 genes that were differentially transcribed in the ΔtrxA mutant compared to the wild-type, especially for the virulence-associated genes plcA, mpl, hly, actA, and plcB. Particularly, deletion of TrxA completely reduced LLO expression, and thereby led to a thoroughly impaired hemolytic activity. Expression of these virulence factors are positively regulated by the master regulator PrfA that was found here to use TrxA to maintain its reduced forms for activation. Interestingly, the trxA deletion mutant completely lacked flagella and was non-motile. We further confirmed that this deficiency is attributable to TrxA in maintaining the reduced intracellular monomer status of MogR, the key regulator for flagellar formation, to ensure correct dimerization. In summary, we demonstrated for the first time that L. monocytogenes thioredoxin A as a vital cellular reductase is essential for maintaining a highly reducing environment in the bacterial cytosol, which provides a favorable condition for protein folding and activation, and therefore contributes to bacterial virulence and motility.
Collapse
Affiliation(s)
- Changyong Cheng
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Zhimei Dong
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Xiao Han
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Hang Wang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Li Jiang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Jing Sun
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Yongchun Yang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Tiantian Ma
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Chunyan Shao
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Xiaodu Wang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Zhongwei Chen
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Weihuan Fang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China.,Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary MedicineHangzhou, China
| | - Nancy E Freitag
- Department of Microbiology and Immunology, University of Illinois at ChicagoChicago, IL, United States
| | - Huarong Huang
- Institute of Developmental and Regenerative Biology, College of Biological and Environmental Science, Hangzhou Normal UniversityZhejiang, China
| | - Houhui Song
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| |
Collapse
|
19
|
Cheng C, Dong Z, Han X, Sun J, Wang H, Jiang L, Yang Y, Ma T, Chen Z, Yu J, Fang W, Song H. Listeria monocytogenes 10403S Arginine Repressor ArgR Finely Tunes Arginine Metabolism Regulation under Acidic Conditions. Front Microbiol 2017; 8:145. [PMID: 28217122 PMCID: PMC5291005 DOI: 10.3389/fmicb.2017.00145] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/19/2017] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is able to colonize human and animal intestinal tracts and to subsequently cross the intestinal barrier, causing systemic infection. For successful establishment of infection, L. monocytogenes must survive the low pH environment of the stomach. L. monocytogenes encodes a functional ArgR, a transcriptional regulator belonging to the ArgR/AhrC arginine repressor family. We aimed at clarifying the specific functions of ArgR in arginine metabolism regulation, and more importantly, in acid tolerance of L. monocytogenes. We showed that ArgR in the presence of 10 mM arginine represses transcription and expression of the argGH and argCJBDF operons, indicating that L. monocytogenes ArgR plays the classical role of ArgR/AhrC family proteins in feedback inhibition of the arginine biosynthetic pathway. Notably, transcription and expression of arcA (encoding arginine deiminase) and sigB (encoding an alternative sigma factor B) were also markedly repressed by ArgR when bacteria were exposed to pH 5.5 in the absence of arginine. However, addition of arginine enabled ArgR to derepress the transcription and expression of these two genes. Electrophoretic mobility shift assays showed that ArgR binds to the putative ARG boxes in the promoter regions of argC, argG, arcA, and sigB. Reporter gene analysis with gfp under control of the argG promoter demonstrated that ArgR was able to activate the argG promoter. Unexpectedly, deletion of argR significantly increased bacterial survival in BHI medium adjusted to pH 3.5 with lactic acid. We conclude that this phenomenon is due to activation of arcA and sigB. Collectively, our results show that L. monocytogenes ArgR finely tunes arginine metabolism through negative transcriptional regulation of the arginine biosynthetic operons and of the catabolic arcA gene in an arginine-independent manner during lactic acid-induced acid stress. ArgR also appears to activate catabolism as well as sigB transcription by anti-repression in an arginine-dependent way.
Collapse
Affiliation(s)
- Changyong Cheng
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Zhimei Dong
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Xiao Han
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Jing Sun
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Hang Wang
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Li Jiang
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Yongchun Yang
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Tiantian Ma
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Zhongwei Chen
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Jing Yu
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| | - Weihuan Fang
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F UniversityLin'an, China; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, Zhejiang UniversityHangzhou, China
| | - Houhui Song
- College of Animal Science and Technology, China-Australia Joint-Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Zhejiang A&F University Lin'an, China
| |
Collapse
|
20
|
Lim SY, Yap KP, Thong KL. Comparative genomics analyses revealed two virulent Listeria monocytogenes strains isolated from ready-to-eat food. Gut Pathog 2016; 8:65. [PMID: 27999619 PMCID: PMC5153821 DOI: 10.1186/s13099-016-0147-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/03/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Listeria monocytogenes is an important foodborne pathogen that causes considerable morbidity in humans with high mortality rates. In this study, we have sequenced the genomes and performed comparative genomics analyses on two strains, LM115 and LM41, isolated from ready-to-eat food in Malaysia. RESULTS The genome size of LM115 and LM41 was 2,959,041 and 2,963,111 bp, respectively. These two strains shared approximately 90% homologous genes. Comparative genomics and phylogenomic analyses revealed that LM115 and LM41 were more closely related to the reference strains F2365 and EGD-e, respectively. Our virulence profiling indicated a total of 31 virulence genes shared by both analysed strains. These shared genes included those that encode for internalins and L. monocytogenes pathogenicity island 1 (LIPI-1). Both the Malaysian L. monocytogenes strains also harboured several genes associated with stress tolerance to counter the adverse conditions. Seven antibiotic and efflux pump related genes which may confer resistance against lincomycin, erythromycin, fosfomycin, quinolone, tetracycline, and penicillin, and macrolides were identified in the genomes of both strains. CONCLUSIONS Whole genome sequencing and comparative genomics analyses revealed two virulent L. monocytogenes strains isolated from ready-to-eat foods in Malaysia. The identification of strains with pathogenic, persistent, and antibiotic resistant potentials from minimally processed food warrant close attention from both healthcare and food industry.
Collapse
Affiliation(s)
- Shu Yong Lim
- Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kien-Pong Yap
- Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kwai Lin Thong
- Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
21
|
NicAogáin K, O’Byrne CP. The Role of Stress and Stress Adaptations in Determining the Fate of the Bacterial Pathogen Listeria monocytogenes in the Food Chain. Front Microbiol 2016; 7:1865. [PMID: 27933042 PMCID: PMC5120093 DOI: 10.3389/fmicb.2016.01865] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/04/2016] [Indexed: 12/15/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes is a highly adaptable organism that can persist in a wide range of environmental and food-related niches. The consumption of contaminated ready-to-eat foods can cause infections, termed listeriosis, in vulnerable humans, particularly those with weakened immune systems. Although these infections are comparatively rare they are associated with high mortality rates and therefore this pathogen has a significant impact on food safety. L. monocytogenes can adapt to and survive a wide range of stress conditions including low pH, low water activity, and low temperature, which makes it problematic for food producers who rely on these stresses for preservation. Stress tolerance in L. monocytogenes can be explained partially by the presence of the general stress response (GSR), a transcriptional response under the control of the alternative sigma factor sigma B (σB) that reconfigures gene transcription to provide homeostatic and protective functions to cope with the stress. Within the host σB also plays a key role in surviving the harsh conditions found in the gastrointestinal tract. As the infection progresses beyond the GI tract L. monocytogenes uses an intracellular infectious cycle to propagate, spread and remain protected from the host's humoral immunity. Many of the virulence genes that facilitate this infectious cycle are under the control of a master transcriptional regulator called PrfA. In this review we consider the environmental reservoirs that enable L. monocytogenes to gain access to the food chain and discuss the stresses that the pathogen must overcome to survive and grow in these environments. The overlap that exists between stress tolerance and virulence is described. We review the principal measures that are used to control the pathogen and point to exciting new approaches that might provide improved means of control in the future.
Collapse
Affiliation(s)
| | - Conor P. O’Byrne
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, College of Science, National University of IrelandGalway, Ireland
| |
Collapse
|
22
|
Mechanistic studies of the agmatine deiminase from Listeria monocytogenes. Biochem J 2016; 473:1553-61. [PMID: 27034081 PMCID: PMC4888459 DOI: 10.1042/bcj20160221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 03/30/2016] [Indexed: 11/17/2022]
Abstract
Listeria monocytogenes is a Gram-positive food-borne pathogen that is capable of living within extreme environments (i.e. low temperatures and pH). This ability to survive in such conditions may arise, at least in part, from agmatine catabolism via the agmatine deiminase system (AgDS). This catabolic pathway utilizes an agmatine deiminase (AgD) to hydrolyse agmatine into N-carbamoylputrescine (NCP), with concomitant release of ammonia, which increases the pH, thus mitigating the ill effects of the acidic environment. Given the potential significance of this pathway for cell survival, we set out to study the catalytic mechanism of the AgD encoded by L. monocytogenes In the present paper, we describe the catalytic mechanism employed by this enzyme based on pH profiles, pKa measurements of the active site cysteine and solvent isotope effects (SIE). In addition, we report inhibition of this enzyme by two novel AgD inhibitors, i.e. N-(4-aminobutyl)-2-fluoro-ethanimidamide (ABFA) and N-(4-aminobutyl)-2-chloro-ethanimidamide (ABCA). In contrast with other orthologues, L. monocytogenes AgD does not use the reverse protonation or substrate-assisted mechanism, which requires an active site cysteine with a high pKa and has been commonly seen in other members of the guanidinium-modifying enzyme (GME) superfamily. Instead, the L. monocytogenes AgD has a low pKa cysteine in the active site leading to an alternative mechanism of catalysis. This is the first time that this mechanism has been observed in the GME superfamily and is significant because it explains why previously developed mechanism-based inactivators of AgDs are ineffective against this orthologue.
Collapse
|
23
|
To Modulate Survival under Secondary Stress Conditions, Listeria monocytogenes 10403S Employs RsbX To Downregulate σB Activity in the Poststress Recovery Stage or Stationary Phase. Appl Environ Microbiol 2015; 82:1126-1135. [PMID: 26637594 DOI: 10.1128/aem.03218-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 11/27/2015] [Indexed: 01/12/2023] Open
Abstract
Listeria monocytogenes is a saprophytic bacterium that thrives in diverse environments and causes listeriosis via ingestion of contaminated food. RsbX, a putative sigma B (σ(B)) regulator, is thought to maintain the ready state in the absence of stress and reset the bacterium to the initial state in the poststress stage in Bacillus subtilis. We wondered whether RsbX is functional in L. monocytogenes under different stress scenarios. Genetic deletion and complementation of the rsbX gene were combined with survival tests and transcriptional and translational analyses of σ(B) expression in response to stresses. We found that deletion of rsbX increased survival under secondary stress following recovery of growth after primary stress or following stationary-phase culturing. The ΔrsbX mutant had higher expression of σ(B) than its parent strain in the recovery stage following primary sodium stress and in stationary-phase cultures. Apparently, increased σ(B) expression had contributed to improved survival in the absence of RsbX. There were no significant differences in survival rates or σ(B) expression levels in response to primary stresses between the rsbX mutant and its parent strain during the exponential phase. Therefore, we provide clear evidence that RsbX is a negative regulator of L. monocytogenes σ(B) during the recovery period after a primary stress or in the stationary phase, thus affecting its survival under secondary stress.
Collapse
|
24
|
Tang S, Orsi RH, den Bakker HC, Wiedmann M, Boor KJ, Bergholz TM. Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Growth on Vacuum-Packed Cold Smoked Salmon. Appl Environ Microbiol 2015; 81:6812-24. [PMID: 26209664 PMCID: PMC4561693 DOI: 10.1128/aem.01752-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/16/2015] [Indexed: 01/26/2023] Open
Abstract
The foodborne pathogen Listeria monocytogenes is able to survive and grow in ready-to-eat foods, in which it is likely to experience a number of environmental stresses due to refrigerated storage and the physicochemical properties of the food. Little is known about the specific molecular mechanisms underlying survival and growth of L. monocytogenes under different complex conditions on/in specific food matrices. Transcriptome sequencing (RNA-seq) was used to understand the transcriptional landscape of L. monocytogenes strain H7858 grown on cold smoked salmon (CSS; water phase salt, 4.65%; pH 6.1) relative to that in modified brain heart infusion broth (MBHIB; water phase salt, 4.65%; pH 6.1) at 7°C. Significant differential transcription of 149 genes was observed (false-discovery rate [FDR], <0.05; fold change, ≥2.5), and 88 and 61 genes were up- and downregulated, respectively, in H7858 grown on CSS relative to the genes in H7858 grown in MBHIB. In spite of these differences in transcriptomes under these two conditions, growth parameters for L. monocytogenes were not significantly different between CSS and MBHIB, indicating that the transcriptomic differences reflect how L. monocytogenes is able to facilitate growth under these different conditions. Differential expression analysis and Gene Ontology enrichment analysis indicated that genes encoding proteins involved in cobalamin biosynthesis as well as ethanolamine and 1,2-propanediol utilization have significantly higher transcript levels in H7858 grown on CSS than in that grown in MBHIB. Our data identify specific transcriptional profiles of L. monocytogenes growing on vacuum-packaged CSS, which may provide targets for the development of novel and improved strategies to control L. monocytogenes growth on this ready-to-eat food.
Collapse
Affiliation(s)
- Silin Tang
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Renato H Orsi
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Henk C den Bakker
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Martin Wiedmann
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Kathryn J Boor
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Teresa M Bergholz
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, North Dakota, USA
| |
Collapse
|
25
|
Fang C, Cao T, Cheng C, Xia Y, Shan Y, Xin Y, Guo N, Li X, Song H, Fang W. Activation of PrfA results in overexpression of virulence factors but does not rescue the pathogenicity of Listeria monocytogenes M7. J Med Microbiol 2015; 64:818-827. [PMID: 26055558 DOI: 10.1099/jmm.0.000101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Listeria monocytogenes encodes a transcriptional activator, PrfA, to positively regulate the expression of virulence factors. Several mutations in PrfA (PrfA*) have been found to contribute to increased regulatory activity. Here, we describe a strain, M7, containing a PrfA*(G145S) that activates expression of virulence factors but with low pathogenicity. To study this contradictory relationship, we exchanged the prfA genes between strains EGDe and M7 (designated EGDe-prfA(M7) and M7-prfA(EGDe)). The phospholipase B (PlcB) and listeriolysin O (LLO) activities were significantly upregulated in the strain EGDe-prfA(M7) (PrfA*). Constitutive activation of PrfA potentiated virulence of the pathogenic strain EGDe, shown as increased adhesion and invasion as well as enhanced cell-to-cell spread in cultured cell lines. However, the strain M7, though PrfA-activated, had significant defects in these virulence-related phenotypes and low pathogenicity in the murine infection model, as compared with EGDe or EGDe-PrfA(M7). To further uncover the possible mechanisms, we analysed abundance and distributions of InlA, InlB, LLO and ActA proteins, all regulated by PrfA, in EGDe, M7 and their prfA mutants. Western blotting showed that the PrfA-regulated genes of constitutively activated PrfA strains were overexpressed in vitro, while different distributions were observed. In contrast to the virulent strain EGDe-prfA(M7), the majority of InlB in M7 was detected in the culture supernatant and not on the bacterial surface. We suppose that the low virulence of strain M7 is due to its defects in infecting host cells, possibly as a result of failed anchorage on the bacterial cells of surface proteins like InlB, a major protein involved in adhesion and invasion of pathogenic L. monocytogenes strains. Further research is warranted to address why InlB detaches from the bacterial cells of this particular strain.
Collapse
Affiliation(s)
- Chun Fang
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Tong Cao
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Changyong Cheng
- College of Animal Science and Technology, Zhejiang A&F University, 88 Huanbei Road, Lin'an, Zhejiang, 311300, PR China
| | - Ye Xia
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Ying Shan
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Yongping Xin
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Ningning Guo
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Xiaoliang Li
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| | - Houhui Song
- College of Animal Science and Technology, Zhejiang A&F University, 88 Huanbei Road, Lin'an, Zhejiang, 311300, PR China
| | - Weihuan Fang
- Zhejiang University Institute of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China., College of Animal Science and Technology, Zhejiang A&F University, 88 Huanbei Road, Lin'an, Zhejiang, 311300, PR China., Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, PR China
| |
Collapse
|
26
|
Saá Ibusquiza P, Nierop Groot M, Debán-Valles A, Abee T, den Besten HM. Impact of growth conditions and role of sigB on Listeria monocytogenes fitness in single and mixed biofilms cultured with Lactobacillus plantarum. Food Res Int 2015. [DOI: 10.1016/j.foodres.2015.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
27
|
Cheng C, Yang Y, Dong Z, Wang X, Fang C, Yang M, Sun J, Xiao L, Fang W, Song H. Listeria monocytogenes varies among strains to maintain intracellular pH homeostasis under stresses by different acids as analyzed by a high-throughput microplate-based fluorometry. Front Microbiol 2015; 6:15. [PMID: 25667585 PMCID: PMC4304241 DOI: 10.3389/fmicb.2015.00015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/07/2015] [Indexed: 11/16/2022] Open
Abstract
Listeria monocytogenes, a food-borne pathogen, has the capacity to maintain intracellular pH (pHi) homeostasis in acidic environments, but the underlying mechanisms remain elusive. Here, we report a simple microplate-based fluorescent method to determine pHi of listerial cells that were prelabeled with the fluorescent dye carboxyfluorescein diacetate N-succinimidyl ester and subjected to acid stress. We found that L. monocytogenes responds differently among strains toward organic and inorganic acids to maintain pHi homeostasis. The capacity of L. monocytogenes to maintain pHi at extracellular pH 4.5 (pHex) was compromised in the presence of acetic acid and lactic acid, but not by hydrochloric acid and citric acid. Organic acids exhibited more inhibitory effects than hydrochloric acid at certain pH conditions. Furthermore, the virulent stains L. monocytogenes EGDe, 850658 and 10403S was more resistant to acidic stress than the avirulent M7 which showed a defect in maintaining pHi homeostasis. Deletion of sigB, a stress-responsive alternative sigma factor from 10403S, markedly altered intracellular pHi homeostasis, and showed a significant growth and survival defect under acidic conditions. Thus, this work provides new insights into bacterial survival mechanism to acidic stresses.
Collapse
Affiliation(s)
- Changyong Cheng
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Yongchun Yang
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Zhimei Dong
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Xiaowen Wang
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Chun Fang
- Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University Institute of Preventive Veterinary Medicine Hangzhou, China
| | - Menghua Yang
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Jing Sun
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Liya Xiao
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| | - Weihuan Fang
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China ; Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University Institute of Preventive Veterinary Medicine Hangzhou, China
| | - Houhui Song
- College of Animal Science and Technology, Zhejiang A&F University Lin'an, China
| |
Collapse
|
28
|
Melo J, Andrew P, Faleiro M. Listeria monocytogenes in cheese and the dairy environment remains a food safety challenge: The role of stress responses. Food Res Int 2015. [DOI: 10.1016/j.foodres.2014.10.031] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
29
|
García-Descalzo L, García-López E, Alcázar A, Baquero F, Cid C. Proteomic analysis of the adaptation to warming in the Antarctic bacteria Shewanella frigidimarina. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:2229-40. [PMID: 25149826 DOI: 10.1016/j.bbapap.2014.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 08/06/2014] [Accepted: 08/11/2014] [Indexed: 12/27/2022]
Abstract
Antarctica is subjected to extremely variable conditions, but the importance of the temperature increase in cold adapted bacteria is still unknown. To study the molecular adaptation to warming of Antarctic bacteria, cultures of Shewanella frigidimarina were incubated at temperatures ranging from 0°C to 30°C, emulating the most extreme conditions that this strain could tolerate. A proteomic approach was developed to identify the soluble proteins obtained from cells growing at 4°C, 20°C and 28°C. The most drastic effect when bacteria were grown at 28°C was the accumulation of heat shock proteins as well as other proteins related to stress, redox homeostasis or protein synthesis and degradation, and the decrease of enzymes and components of the cell envelope. Furthermore, two main responses in the adaptation to warm temperature were detected: the presence of diverse isoforms in some differentially expressed proteins, and the composition of chaperone interaction networks at the limits of growth temperature. The abundance changes of proteins suggest that warming induces a stress situation in S. frigidimarina forcing cells to reorganize their molecular networks as an adaptive response to these environmental conditions.
Collapse
Affiliation(s)
| | - Eva García-López
- Centro de Astrobiologia (CSIC-INTA), 28850 Torrejón de Ardoz, Spain
| | - Alberto Alcázar
- Department of Investigation, Hospital Ramon y Cajal, 28034 Madrid, Spain
| | - Fernando Baquero
- Centro de Astrobiologia (CSIC-INTA), 28850 Torrejón de Ardoz, Spain; Department of Microbiology, Hospital Ramon y Cajal, 28034 Madrid, Spain
| | - Cristina Cid
- Centro de Astrobiologia (CSIC-INTA), 28850 Torrejón de Ardoz, Spain.
| |
Collapse
|
30
|
Wunderlichová L, Buňková L, Koutný M, Jančová P, Buňka F. Formation, Degradation, and Detoxification of Putrescine by Foodborne Bacteria: A Review. Compr Rev Food Sci Food Saf 2014. [DOI: 10.1111/1541-4337.12099] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Leona Wunderlichová
- Dept. of Environmental Protection Engineering; Faculty of Technology; Tomas Bata Univ. in Zlín; nám. T. G. Masaryka 275 76272 Zlín Czech Republic
| | - Leona Buňková
- Dept. of Environmental Protection Engineering; Faculty of Technology; Tomas Bata Univ. in Zlín; nám. T. G. Masaryka 275 76272 Zlín Czech Republic
| | - Marek Koutný
- Dept. of Environmental Protection Engineering; Faculty of Technology; Tomas Bata Univ. in Zlín; nám. T. G. Masaryka 275 76272 Zlín Czech Republic
| | - Petra Jančová
- Dept. of Environmental Protection Engineering; Faculty of Technology; Tomas Bata Univ. in Zlín; nám. T. G. Masaryka 275 76272 Zlín Czech Republic
| | - František Buňka
- Dept. of Food Technology; Faculty of Technology; Tomas Bata Univ. in Zlín; nám. T. G. Masaryka 275 76272 Zlín Czech Republic
| |
Collapse
|
31
|
Lund P, Tramonti A, De Biase D. Coping with low pH: molecular strategies in neutralophilic bacteria. FEMS Microbiol Rev 2014; 38:1091-125. [PMID: 24898062 DOI: 10.1111/1574-6976.12076] [Citation(s) in RCA: 282] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 02/26/2014] [Accepted: 03/14/2014] [Indexed: 12/31/2022] Open
Abstract
As part of their life cycle, neutralophilic bacteria are often exposed to varying environmental stresses, among which fluctuations in pH are the most frequent. In particular, acid environments can be encountered in many situations from fermented food to the gastric compartment of the animal host. Herein, we review the current knowledge of the molecular mechanisms adopted by a range of Gram-positive and Gram-negative bacteria, mostly those affecting human health, for coping with acid stress. Because organic and inorganic acids have deleterious effects on the activity of the biological macromolecules to the point of significantly reducing growth and even threatening their viability, it is not unexpected that neutralophilic bacteria have evolved a number of different protective mechanisms, which provide them with an advantage in otherwise life-threatening conditions. The overall logic of these is to protect the cell from the deleterious effects of a harmful level of protons. Among the most favoured mechanisms are the pumping out of protons, production of ammonia and proton-consuming decarboxylation reactions, as well as modifications of the lipid content in the membrane. Several examples are provided to describe mechanisms adopted to sense the external acidic pH. Particular attention is paid to Escherichia coli extreme acid resistance mechanisms, the activity of which ensure survival and may be directly linked to virulence.
Collapse
Affiliation(s)
- Peter Lund
- School of Biosciences, University of Birmingham, Birmingham, UK
| | | | | |
Collapse
|
32
|
Chen J, Fang C, Zheng T, Zhu N, Bei Y, Fang W. Genomic presence of gadD1 glutamate decarboxylase correlates with the organization of ascB-dapE internalin cluster in Listeria monocytogenes. Foodborne Pathog Dis 2014; 9:175-8. [PMID: 22315955 DOI: 10.1089/fpd.2011.1022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The ability to survive and proliferate in acidic environments is a prerequisite for the infection of Listeria monocytogenes. The glutamate decarboxylase (GAD) system is responsible for acid resistance, and three GAD homologs have been identified in L. monocytogenes: gadD1, gadD2, and gadD3. To examine whether GAD genes are specific to lineage, serovar, or certain subpopulation, we performed a systematic investigation on the prevalence of GAD genes in 164 L. monocytogenes. In contrast to gadD2 and gadD3 conserved in all L. monocytogenes strains, gadD1 was identified in 36.6% (60/164) of L. monocytogenes strains, including all serovar 1/2c and 68.5% (37/54) of serovar 1/2a strains, as well as a small fraction of serovar 1/2b (3.4%, 1/29) and lineage III (13.8%, 4/29) strains. All serovar 4b and lineage IV strains lacked this gene. According to the ascB-dapE structure, L. monocytogenes strains were classified into four subpopulations, carrying inlC2DE, inlGC2DE, inlGHE, or no internalin cluster, respectively. All L. monocytogenes strains with inlGC2DE or inlGHE pattern harbored gadD1, whereas those bearing inlC2DE or no internalin cluster between ascB and dapE lacked gadD1. In addition, other five non-monocytogenes Listeria species lacking ascB-dapE internalin cluster were gadD1-negative. Overall, the presence of gadD1 is not fully dependent on lineages or serovars but correlates with ascB-dapE internalin profiles, suggesting gadD1 might have co-evolved with the ascB-dapE internalin cluster in the primitive L. monocytogenes before divergence of serovars.
Collapse
Affiliation(s)
- Jianshun Chen
- Zhejiang Fisheries Technical Extension Center, Hangzhou, Zhejiang, PR China
| | | | | | | | | | | |
Collapse
|
33
|
Abstract
Rhizobia are bacteria in the α-proteobacterial genera Rhizobium, Sinorhizobium, Mesorhizobium, Azorhizobium and Bradyrhizobium that reduce (fix) atmospheric nitrogen in symbiotic association with a compatible host plant. In free-living and/or symbiotically associated rhizobia, amino acids may, in addition to their incorporation into proteins, serve as carbon, nitrogen or sulfur sources, signals of cellular nitrogen status and precursors of important metabolites. Depending on the rhizobia-host plant combination, microsymbiont amino acid metabolism (biosynthesis, transport and/or degradation) is often crucial to the establishment and maintenance of an effective nitrogen-fixing symbiosis and is intimately interconnected with the metabolism of the plant. This review summarizes past findings and current research directions in rhizobial amino acid metabolism and evaluates the genetic, biochemical and genome expression studies from which these are derived. Specific sections deal with the regulation of rhizobial amino acid metabolism, amino acid transport, and finally the symbiotic roles of individual amino acids in different plant-rhizobia combinations.
Collapse
|
34
|
Fei YY, Gai JY, Zhao TJ. Identification of regulated genes conferring resistance to high concentrations of glyphosate in a new strain of Enterobacter. FEMS Microbiol Lett 2013; 349:135-43. [PMID: 24237416 DOI: 10.1111/1574-6968.12306] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 10/17/2013] [Indexed: 11/29/2022] Open
Abstract
Glyphosate is a widely used herbicide that inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) activity. Most plants and microbes are sensitive to glyphosate. However, transgenic-resistant crops that contain a modified epsps obtained from the resistant microbes have been commercially successful and therefore, new resistance genes and their adaptive regulatory mechanisms are of great interest. In this study, a soil-borne, glyphosate-resistant bacterium was selected and identified as Enterobacter. The EPSPS in this strain was found to have been altered to a resistant one. A total of 42 differentially expressed genes (DEGs) in the glyphosate were screened using microarray techniques. Under treatment, argF, sdhA, ivbL, rrfA-H were downregulated, whereas the transcripts of speA, osmY, pflB, ahpC, fusA, deoA, uxaC, rpoD and a few ribosomal protein genes were upregulated. Data were verified by quantitative real-time PCR on selected genes. All transcriptional changes appeared to protect the bacteria from glyphosate and associated osmotic, acidic and oxidative stresses. Many DEGs may have the potential to confer resistance to glyphosate alone, and some may be closely related to the shikimate pathway, reflecting the complex gene interaction network for glyphosate resistance.
Collapse
Affiliation(s)
- Yun-Yan Fei
- Soybean Research Institute/National Center for Soybean, Improvement/National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | | | | |
Collapse
|
35
|
Suárez C, Espariz M, Blancato VS, Magni C. Expression of the agmatine deiminase pathway in Enterococcus faecalis is activated by the AguR regulator and repressed by CcpA and PTS(Man) systems. PLoS One 2013; 8:e76170. [PMID: 24155893 PMCID: PMC3796520 DOI: 10.1371/journal.pone.0076170] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 08/21/2013] [Indexed: 11/29/2022] Open
Abstract
Although the agmatine deiminase system (AgDI) has been investigated in Enterococcus faecalis, little information is available with respect to its gene regulation. In this study we demonstrate that the presence of exogenous agmatine induces the expression of agu genes in this bacterium. In contrast to the homologous and extensively characterized AgDI system of S. mutants, the aguBDAC operon in E. faecalis is not induced in response to low pH. In spite of this, agmatine catabolism in this bacterium contributes by neutralizing the external medium while enhancing bacterial growth. Our results indicate that carbon catabolic repression (CCR) operates on the AgDI system via a mechanism that involves interaction of CcpA and P-Ser-HPr with a cre site found in an unusual position considering the aguB promoter (55 nt upstream the +1 position). In addition, we found that components of the mannose phosphotransferase (PTSMan) system also contributed to CCR in E. faecalis since a complete relief of the PTS-sugars repressive effect was observed only in a PTSMan and CcpA double defective strain. Our gene context analysis revealed that aguR is present in oral and gastrointestinal microorganisms. Thus, regulation of the aguBDAC operon in E. faecalis seems to have evolved to obtain energy and resist low pH conditions in order to persist and colonize gastrointestinal niches.
Collapse
Affiliation(s)
- Cristian Suárez
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET), Rosario, Santa Fe, Argentina
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Martín Espariz
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET), Rosario, Santa Fe, Argentina
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Víctor S. Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET), Rosario, Santa Fe, Argentina
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET), Rosario, Santa Fe, Argentina
- Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
- * E-mail:
| |
Collapse
|
36
|
Barba M, Dutoit R, Legrain C, Labedan B. Identifying reaction modules in metabolic pathways: bioinformatic deduction and experimental validation of a new putative route in purine catabolism. BMC SYSTEMS BIOLOGY 2013; 7:99. [PMID: 24093154 PMCID: PMC4016543 DOI: 10.1186/1752-0509-7-99] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/25/2013] [Indexed: 01/18/2023]
Abstract
BACKGROUND Enzymes belonging to mechanistically diverse superfamilies often display similar catalytic mechanisms. We previously observed such an association in the case of the cyclic amidohydrolase superfamily whose members play a role in related steps of purine and pyrimidine metabolic pathways. To establish a possible link between enzyme homology and chemical similarity, we investigated further the neighbouring steps in the respective pathways. RESULTS We identified that successive reactions of the purine and pyrimidine pathways display similar chemistry. These mechanistically-related reactions are often catalyzed by homologous enzymes. Detection of series of similar catalysis made by succeeding enzyme families suggested some modularity in the architecture of the central metabolism. Accordingly, we introduce the concept of a reaction module to define at least two successive steps catalyzed by homologous enzymes in pathways alignable by similar chemical reactions. Applying such a concept allowed us to propose new function for misannotated paralogues. In particular, we discovered a putative ureidoglycine carbamoyltransferase (UGTCase) activity. Finally, we present experimental data supporting the conclusion that this UGTCase is likely to be involved in a new route in purine catabolism. CONCLUSIONS Using the reaction module concept should be of great value. It will help us to trace how the primordial promiscuous enzymes were assembled progressively in functional modules, as the present pathways diverged from ancestral pathways to give birth to the present-day mechanistically diversified superfamilies. In addition, the concept allows the determination of the actual function of misannotated proteins.
Collapse
Affiliation(s)
- Matthieu Barba
- Institut de Génétique et Microbiologie, CNRS UMR 8621, Université Paris Sud, Bâtiment 400, 91405, Orsay Cedex, France
- present address: Laboratoire de Biométrie et Biologie Évolutive, CNRS UMR 5558, Université Claude Bernard Lyon 1, 69622, Villeurbanne Cedex, France
| | - Raphaël Dutoit
- Institut de Recherches Microbiologiques J.-M. Wiame IRMW, Campus CERIA, Av. E. Gryson 1, 1070, Brussels, Belgium
| | - Christianne Legrain
- Institut de Recherches Microbiologiques J.-M. Wiame IRMW, Campus CERIA, Av. E. Gryson 1, 1070, Brussels, Belgium
| | - Bernard Labedan
- Institut de Génétique et Microbiologie, CNRS UMR 8621, Université Paris Sud, Bâtiment 400, 91405, Orsay Cedex, France
- present address: Bioinformatique, Laboratoire de Recherche en Informatique, CNRS UMR 8623, Université Paris Sud, Bâtiment 650, 91405, Orsay Cedex, France
| |
Collapse
|
37
|
Liu G, Zhang W, Lu C. Identification of immunoreactive proteins ofStreptococcus agalactiaeisolated from cultured tilapia in China. Pathog Dis 2013; 69:223-31. [DOI: 10.1111/2049-632x.12084] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 07/18/2013] [Accepted: 07/29/2013] [Indexed: 11/27/2022] Open
Affiliation(s)
- Guangjin Liu
- Key Laboratory of Animal Bacteriology; Ministry of Agriculture; Nanjing Agricultural University; Nanjing China
| | - Wei Zhang
- Key Laboratory of Animal Bacteriology; Ministry of Agriculture; Nanjing Agricultural University; Nanjing China
| | - Chengping Lu
- Key Laboratory of Animal Bacteriology; Ministry of Agriculture; Nanjing Agricultural University; Nanjing China
| |
Collapse
|
38
|
Cheng C, Chen J, Fang C, Xia Y, Shan Y, Liu Y, Wen G, Song H, Fang W. Listeria monocytogenes aguA1, but not aguA2, encodes a functional agmatine deiminase: biochemical characterization of its catalytic properties and roles in acid tolerance. J Biol Chem 2013; 288:26606-15. [PMID: 23918931 DOI: 10.1074/jbc.m113.477380] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Listeria monocytogenes is adaptable to low pH environments and therefore crosses the intestinal barrier to establish systemic infections. L. monocytogenes aguA1 and aguA2 encode putative agmatine deiminases (AgDIs) AguA1 and AguA2. Transcription of aguA1 and aguA2 was significantly induced at pH 5.0. Deletion of aguA1 significantly impaired its survival both in gastric fluid at pH 2.5 and in mouse stomach, whereas aguA2 deletion did not show significant defect of survival in gastric fluid. With agmatine as the sole substrate, AguA1 expressed in Escherichia coli was optimal at 25 °C and over a wide range of pH from 3.5 to 10.5. Recombinant AguA2 showed no deiminase activity. Site-directed mutagenesis revealed that all nine AguA1 mutants completely lost enzymatic activity. AguA2 acquired AgDI activity only when Cys-157 was mutated to glycine. AguA1 mutation at the same site, G157C, also inactivated the enzyme. Thus, we have discovered Gly-157 as a novel residue other than the known catalytic triad (Cys-His-Glu/Asp) in L. monocytogenes that is critical for enzyme activity. Of the two putative AgDIs, we conclude that only AguA1 functionally participates in the AgDI pathway and mediates acid tolerance in L. monocytogenes.
Collapse
Affiliation(s)
- Changyong Cheng
- From the Zhejiang University Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, and Key Laboratory of Molecular Animal Nutrition of the Ministry of Education, Hangzhou, Zhejiang 310058, China
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Cheng C, Chen J, Shan Y, Fang C, Liu Y, Xia Y, Song H, Fang W. Listeria monocytogenes ArcA contributes to acid tolerance. J Med Microbiol 2013; 62:813-821. [PMID: 23518652 DOI: 10.1099/jmm.0.055145-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes is able to colonize the human and animal intestinal tracts and subsequently crosses the intestinal barrier, causing systemic infection. For successful establishment of infection, L. monocytogenes must survive and adapt to the low pH environment of the stomach. Gene sequence analysis indicates that lmo0043, an orthologue of arcA, encodes a protein containing conserved motifs and critical active amino acids characteristic of arginine deiminase that mediates an arginine deimination reaction. We attempted to characterize the role of ArcA in acid tolerance in vitro and in mice models. Transcription of arcA was significantly increased in L. monocytogenes culture subjected to acid stress at pH 4.8, as compared with that at pH 7.0. Deletion of arcA impaired growth of L. monocytogenes under mild acidic conditions at pH 5.5, and reduced its survival in synthetic human gastric fluid at pH 2.5 and in the murine stomach. Bacterial load in the spleen of mice intraperitoneally inoculated with an arcA deletion mutant was significantly lower than that of the wild-type strain. These phenotypic changes were recoverable by genetic complementation. Thus, we conclude that L. monocytogenes arcA not only mediates acid tolerance in vitro but also participates in gastric survival and virulence in mice.
Collapse
Affiliation(s)
- Changyong Cheng
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Jianshun Chen
- Zhejiang Aquatic Disease Prevention and Quarantine Center, 20 Yile Road, Hangzhou, Zhejiang 310012, PR China
| | - Ying Shan
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Chun Fang
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Yuan Liu
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Ye Xia
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Houhui Song
- Zhejiang A&F University College of Animal Science & Technology, Lin'an, Zhejiang 311300, PR China
| | - Weihuan Fang
- Zhejiang A&F University College of Animal Science & Technology, Lin'an, Zhejiang 311300, PR China.,Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| |
Collapse
|
40
|
Smith JL, Liu Y, Paoli GC. How does Listeria monocytogenes combat acid conditions? Can J Microbiol 2012; 59:141-52. [PMID: 23540331 DOI: 10.1139/cjm-2012-0392] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Listeria monocytogenes, a major foodborne pathogen, possesses a number of mechanisms that enable it to combat the challenges posed by acidic environments, such as that of acidic foods and the gastrointestinal tract. One mechanism employed by L. monocytogenes for survival at low pH is the adaptive acid tolerance response (ATR) in which a short adaptive period at a nonlethal pH induces metabolic changes that allow the organism to survive a lethal pH. Overcoming acid conditions by L. monocytogenes involves a variety of regulatory responses, including the LisRK 2-component regulatory system, the SOS response, components of the σ(B) regulon, changes in membrane fluidity, the F0F1-ATPase proton pump, and at least 2 enzymatic systems that regulate internal hydrogen ion concentration (glutamate decarboxylase and arginine deiminase). It is not clear if these mechanisms exert their protective effects separately or in concert, but it is probable that these mechanisms overlap. Studies using mutants indicate that the glutamate decarboxylase system can protect L. monocytogenes when the organism is present in acidic juices, yogurt, salad dressing, mayonnaise, and modified CO2 atmospheres. The glutamate decarboxylase system also has a role in protecting L. monocytogenes against the acidic environment of the stomach. There is a need to study other acid resistance mechanisms of L. monocytogenes to determine their effectiveness in protecting the organism in acidic foods or during transit through the acid stomach.
Collapse
Affiliation(s)
- James L Smith
- Molecular Characterization of Foodborne Pathogens Research Unit, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038-8598, USA.
| | | | | |
Collapse
|
41
|
Tessema GT, Møretrø T, Snipen L, Heir E, Holck A, Naterstad K, Axelsson L. Microarray-based transcriptome ofListeria monocytogenesadapted to sublethal concentrations of acetic acid, lactic acid, and hydrochloric acid. Can J Microbiol 2012; 58:1112-23. [DOI: 10.1139/w2012-091] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Listeria monocytogenes , an important foodborne pathogen, commonly encounters organic acids in food-related environments. The transcriptome of L. monocytogenes L502 was analyzed after adaptation to pH 5 in the presence of acetic acid, lactic acid, or hydrochloric acid (HCl) at 25 °C, representing a condition encountered in mildly acidic ready-to-eat food kept at room temperature. The acid-treated cells were compared with a reference culture with a pH of 6.7 at the time of RNA harvesting. The number of genes and magnitude of transcriptional responses were higher for the organic acids than for HCl. Protein coding genes described for low pH stress, energy transport and metabolism, virulence determinates, and acid tolerance response were commonly regulated in the 3 acid-stressed cultures. Interestingly, the transcriptional levels of histidine and cell wall biosynthetic operons were upregulated, indicating possible universal response against low pH stress in L. monocytogenes. The opuCABCD operon, coding proteins for compatible solutes transport, and the transcriptional regulator sigL were significantly induced in the organic acids, strongly suggesting key roles during organic acid stress. The present study revealed the complex transcriptional responses of L. monocytogenes towards food-related acidulants and opens the roadmap for more specific and in-depth future studies.
Collapse
Affiliation(s)
- Girum Tadesse Tessema
- Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway
| | - Trond Møretrø
- Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway
| | - Lars Snipen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Even Heir
- Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway
| | - Askild Holck
- Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway
| | - Kristine Naterstad
- Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway
| | - Lars Axelsson
- Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 210, N-1431 Ås, Norway
| |
Collapse
|
42
|
Bowman JP, Hages E, Nilsson RE, Kocharunchitt C, Ross T. Investigation of the Listeria monocytogenes Scott A acid tolerance response and associated physiological and phenotypic features via whole proteome analysis. J Proteome Res 2012; 11:2409-26. [PMID: 22372944 DOI: 10.1021/pr201137c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The global proteomic responses of the foodborne pathogen Listeria monocytogenes strain Scott A, during active growth and transition to the stationary growth phase under progressively more acidic conditions, created by addition of lactic acid and HCl, were investigated using label-free liquid chromatography/tandem mass spectrometry. Approximately 56% of the Scott A proteome was quantitatively assessable, and the data provides insight into its acquired acid tolerance response (ATR) as well as the relation of the ATR to the growth phase transition. Alterations in protein abundance due to acid stress were focused in proteins belonging to the L. monocytogenes common genome, with few strain-dependent proteins involved. However, one of the two complete prophage genomes appeared to enter lysogeny. During progressive acidification, the growth rate and yield were reduced 55% and 98%, respectively, in comparison to nonacidified control cultures. The maintenance of the growth rate was determined to be connected to activation of cytoplasmic pH homeostatic mechanisms while cellular reproductive-related and cell component turnover proteins were markedly more abundant in acid stressed cultures. Cell biomass accumulation was impeded predominantly due to repression of phosphodonor-linked enzymes involved with sugar phosphotransfer, glycolysis, and cell wall polymer biosynthesis. Acidification caused a shift from heterofermentation to an oxidatively stressed state in which ATP appears to be generated mainly through the pyruvate dehydrogenase/pyruvate oxidase/phosphotransacetylase/acetate kinase and branched chain acid dehydrogenase pathways. Analysis of regulons indicated energy conservation occurs due to repression by the GTP/isoleucine sensor CodY and also the RelA mediated stringent response. Whole proteome analysis proved to be an effective way to highlight proteins involved with the acquisition of the ATR.
Collapse
Affiliation(s)
- John P Bowman
- Food Safety Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia.
| | | | | | | | | |
Collapse
|
43
|
Shi D, Yu X, Zhao G, Ho J, Lu S, Allewell NM, Tuchman M. Crystal structure and biochemical properties of putrescine carbamoyltransferase from Enterococcus faecalis: Assembly, active site, and allosteric regulation. Proteins 2012; 80:1436-47. [PMID: 22328207 DOI: 10.1002/prot.24042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 01/03/2012] [Accepted: 01/11/2012] [Indexed: 11/09/2022]
Abstract
Putrescine carbamoyltransferase (PTCase) catalyzes the conversion of carbamoylputrescine to putrescine and carbamoyl phosphate (CP), a substrate of carbamate kinase (CK). The crystal structure of PTCase has been determined and refined at 3.2 Å resolution. The trimeric molecular structure of PTCase is similar to other carbamoyltransferases, including the catalytic subunit of aspartate carbamoyltransferase (ATCase) and ornithine carbamoyltransferase (OTCase). However, in contrast to other trimeric carbamoyltransferases, PTCase binds both CP and putrescine with Hill coefficients at saturating concentrations of the other substrate of 1.53 ± 0.03 and 1.80 ± 0.06, respectively. PTCase also has a unique structural feature: a long C-terminal helix that interacts with the adjacent subunit to enhance intersubunit interactions in the molecular trimer. The C-terminal helix appears to be essential for both formation of the functional trimer and catalytic activity, since truncated PTCase without the C-terminal helix aggregates and has only 3% of native catalytic activity. The active sites of PTCase and OTCase are similar, with the exception of the 240's loop. PTCase lacks the proline-rich sequence found in knotted carbamoyltransferases and is unknotted. A Blast search of all available genomes indicates that 35 bacteria, most of which are Gram-positive, have an agcB gene encoding PTCase located near the genes that encode agmatine deiminase and CK, consistent with the catabolic role of PTCase in the agmatine degradation pathway. Sequence comparisons indicate that the C-terminal helix identified in this PTCase structure will be found in all other PTCases identified, suggesting that it is the signature feature of the PTCase family of enzymes.
Collapse
Affiliation(s)
- Dashuang Shi
- Center for Genetic Medicine Research and Department of Integrative Systems Biology, Children's National Medical Center, The George Washington University, Washington, District of Columbia 20010, USA.
| | | | | | | | | | | | | |
Collapse
|