1
|
Yao H, Li G, Xiong X, Jin F, Li S, Xie X, Zhong D, Zhang R, Meng F, Yin Y, Jiao X. LygA retention on the surface of Listeria monocytogenes via its interaction with wall teichoic acid modulates bacterial homeostasis and virulence. PLoS Pathog 2023; 19:e1011482. [PMID: 37379353 DOI: 10.1371/journal.ppat.1011482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 06/13/2023] [Indexed: 06/30/2023] Open
Abstract
Wall teichoic acid (WTA) is the abundant cell wall-associated glycopolymer in Gram-positive bacteria, playing crucial roles in surface proteins retention, bacterial homeostasis, and virulence. Hypervirulent serovar (SV) 4h Listeria monocytogenes is a newly designated serotype with only galactosylated (Gal) type II WTA. Although the surface association of some proteins relies on the WTA glycosylation, the nature and function of the noncovalent interactions between cell wall-associated proteins and WTA are less known. In this study, we found Gal-WTA plays a key role in modulating the novel glycine-tryptophan (GW) domain-containing autolysin protein LygA through direct interactions. An SV 4h strain deficient in WTA galactosylation (XYSNΔgalT) showed a dramatic reduction of LygA on the cell surface, significantly decreasing the autolytic activity, impairing the bacterial colonization in colon and brain. Notably, we demonstrated LygA binds to Gal-WTA with high affinity through the GW domain and that the extent of binding increases with the number of GW domains. Moreover, we confirmed the direct Gal-dependent binding of the GW protein Auto from the type I WTA strain, which has no interaction with l-rhamnosylated WTA, indicating that the complexity of both WTA and GW proteins can affect the coordination patterns. Altogether, our findings suggest that both the glycosylation patterns of WTA and a fixed numbers of GW domains are closely associated with the retention of LygA on the cell surface, which facilitates L. monocytogenes infection by promoting bacteria colonization in intestine and brain.
Collapse
Affiliation(s)
- Hao Yao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Guo Li
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Xianglian Xiong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Fanxin Jin
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Sirui Li
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Xinyu Xie
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Dan Zhong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Renling Zhang
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Fanzeng Meng
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Yuelan Yin
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Xin'an Jiao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| |
Collapse
|
2
|
Griffin ME, Klupt S, Espinosa J, Hang HC. Peptidoglycan NlpC/P60 peptidases in bacterial physiology and host interactions. Cell Chem Biol 2023; 30:436-456. [PMID: 36417916 PMCID: PMC10192474 DOI: 10.1016/j.chembiol.2022.11.001] [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: 05/18/2022] [Revised: 09/15/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The bacterial cell wall is composed of a highly crosslinked matrix of glycopeptide polymers known as peptidoglycan that dictates bacterial cell morphology and protects against environmental stresses. Regulation of peptidoglycan turnover is therefore crucial for bacterial survival and growth and is mediated by key protein complexes and enzyme families. Here, we review the prevalence, structure, and activity of NlpC/P60 peptidases, a family of peptidoglycan hydrolases that are crucial for cell wall turnover and division as well as interactions with antibiotics and different hosts. Understanding the molecular functions of NlpC/P60 peptidases should provide important insight into bacterial physiology, their interactions with different kingdoms of life, and the development of new therapeutic approaches.
Collapse
Affiliation(s)
- Matthew E Griffin
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Steven Klupt
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Juliel Espinosa
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA; Department of Chemistry, Scripps Research, La Jolla, CA 92037, USA.
| |
Collapse
|
3
|
Yu C, Dong H, Li Q, Wang X, Mao F, Qian M, Niu J, Cheng X, Liao C. Biological Characteristics of Listeria monocytogenes Following Deletion of TatD-like Protein Gene. Curr Microbiol 2023; 80:118. [PMID: 36853439 DOI: 10.1007/s00284-023-03229-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/13/2023] [Indexed: 03/01/2023]
Abstract
TatD is the subunit of the twin-arginine translocation (Tat) pathway. Members of TatD family are multifunctional, conserved and widely presented proteins in most prokaryotes. It has been reported that Tat can affect bacterial motility in some bacteria. This study was conducted to determine the contribution of the TatD protein (herein named LmTatD) to the regulation of flagella in Listeria monocytogenes. We constructed an LmTatD gene mutant in L. monocytogenes strain 10403 s and evaluated its biological characteristics. The results showed no difference in growth or morphology between the wild-type strain and the ΔLmTatD mutant. Intriguingly, the ΔLmTatD mutant showed impaired swimming motility and flagella structure but increased biofilm formation. Comparative proteomic analysis using tandem mass tag (TMT) combined with liquid chromatography-tandem mass spectrometry (LC‒MS/MS) was performed to determine differentially expressed proteins (DEPs). The results revealed that 134 proteins out of 2228 total proteins identified were differentially expressed, among which 18 proteins were upregulated and 116 proteins were downregulated in the ΔLmTatD mutant. Analysis of DEPs indicated that the reduced expression levels of the proteins related to flagellar assembly in the ΔLmTatD mutant correlate with its characteristics. Compared to the wild-type strain, the most downregulated proteins in the ΔLmTatD mutant included FlaA, FliD, FliR, FlgD, FlgL, and FlgG. Collectively, our data suggest that although LmTatD is not required for growth in L. monocytogenes, loss of LmTatD reduces flagellar production and motility by regulating flagellar assembly-related protein expression.
Collapse
Affiliation(s)
- Chuan Yu
- Animal Diseases and Public Health Engineering Research Center of Henan Province, Luoyang Polytechnic, Luoyang, 471023, China
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Hefan Dong
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Qi Li
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Xiaoli Wang
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, 471023, China
| | - Fuchao Mao
- Animal Diseases and Public Health Engineering Research Center of Henan Province, Luoyang Polytechnic, Luoyang, 471023, China
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Man Qian
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Junhui Niu
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Xiangchao Cheng
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China
| | - Chengshui Liao
- College of Animal Science and Technology /Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Technology, 263 Kaiyuan Road, Luoyang, 471023, China.
| |
Collapse
|
4
|
Schulz LM, Rothe P, Halbedel S, Gründling A, Rismondo J. Imbalance of peptidoglycan biosynthesis alters the cell surface charge of Listeria monocytogenes. Cell Surf 2022; 8:100085. [PMID: 36304571 PMCID: PMC9593813 DOI: 10.1016/j.tcsw.2022.100085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 02/09/2023] Open
Abstract
The bacterial cell wall is composed of a thick layer of peptidoglycan and cell wall polymers, which are either embedded in the membrane or linked to the peptidoglycan backbone and referred to as lipoteichoic acid (LTA) and wall teichoic acid (WTA), respectively. Modifications of the peptidoglycan or WTA backbone can alter the susceptibility of the bacterial cell towards cationic antimicrobials and lysozyme. The human pathogen Listeria monocytogenes is intrinsically resistant towards lysozyme, mainly due to deacetylation and O-acetylation of the peptidoglycan backbone via PgdA and OatA. Recent studies identified additional factors, which contribute to the lysozyme resistance of this pathogen. One of these is the predicted ABC transporter, EslABC. An eslB mutant is hyper-sensitive towards lysozyme, likely due to the production of thinner and less O-acetylated peptidoglycan. Using a suppressor screen, we show here that suppression of eslB phenotypes could be achieved by enhancing peptidoglycan biosynthesis, reducing peptidoglycan hydrolysis or alterations in WTA biosynthesis and modification. The lack of EslB also leads to a higher negative surface charge, which likely stimulates the activity of peptidoglycan hydrolases and lysozyme. Based on our results, we hypothesize that the portion of cell surface exposed WTA is increased in the eslB mutant due to the thinner peptidoglycan layer and that latter one could be caused by an impairment in UDP-N-acetylglucosamine (UDP-GlcNAc) production or distribution.
Collapse
Affiliation(s)
- Lisa Maria Schulz
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Patricia Rothe
- FG11, Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Sven Halbedel
- FG11, Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstraße 37, 38855 Wernigerode, Germany
- Institute for Medical Microbiology and Hospital Hygiene, Otto von Guericke University Magdeburg, Leipziger Straße 44, 39120 Magdeburg, Germany
| | - Angelika Gründling
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jeanine Rismondo
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| |
Collapse
|
5
|
SecA2 Associates with Translating Ribosomes and Contributes to the Secretion of Potent IFN-β Inducing RNAs. Int J Mol Sci 2022; 23:ijms232315021. [PMID: 36499346 PMCID: PMC9736482 DOI: 10.3390/ijms232315021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/24/2022] [Accepted: 11/26/2022] [Indexed: 12/05/2022] Open
Abstract
Protein secretion plays a central role in modulating interactions of the human pathogen Listeria monocytogenes with its environment. Recently, secretion of RNA has emerged as an important strategy used by the pathogen to manipulate the host cell response to its advantage. In general, the Sec-dependent translocation pathway is a major route for protein secretion in L. monocytogenes, but mechanistic insights into the secretion of RNA by these pathways are lacking. Apart from the classical SecA1 secretion pathway, L. monocytogenes also encodes for a SecA paralogue (SecA2) which targets the export of a specific subset of proteins, some of which are involved in virulence. Here, we demonstrated that SecA2 co-sediments with translating ribosomes and provided evidence that it associates with a subset of secreted small non-coding RNAs (sRNAs) that induce high levels of IFN-β response in host cells. We found that enolase, which is translocated by a SecA2-dependent mechanism, binds to several sRNAs, suggesting a pathway by which sRNAs are targeted to the supernatant of L. monocytogenes.
Collapse
|
6
|
Astafyeva Y, Gurschke M, Qi M, Bergmann L, Indenbirken D, de Grahl I, Katzowitsch E, Reumann S, Hanelt D, Alawi M, Streit WR, Krohn I. Microalgae and Bacteria Interaction-Evidence for Division of Diligence in the Alga Microbiota. Microbiol Spectr 2022; 10:e0063322. [PMID: 35913168 PMCID: PMC9430724 DOI: 10.1128/spectrum.00633-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 07/07/2022] [Indexed: 11/20/2022] Open
Abstract
Microalgae are one of the most dominant forms of life on earth that is tightly associated with a distinct and specialized microbiota. We have previously shown that the microbiota of Scenedesmus quadricauda harbors less than 10 distinct microbial species. Here, we provide evidence that dominant species are affiliated with the genera of Variovorax, Porphyrobacter, and Dyadobacter. Experimental and transcriptome-based evidence implies that within this multispecies interaction, Dyadobacter is a key to alga growth and fitness and is highly adapted to live in the phycosphere. While presumably under light conditions the alga provides the energy source to the bacteria, Dyadobacter produces and releases mainly a large variety of polysaccharides modifying enzymes. This is coherent with high-level expression of the T9SS in alga cocultures. The transcriptome data further imply that quorum-quenching proteins (QQ) and biosynthesis of vitamins B1, B2, B5, B6, and B9 are expressed by Dyadobacter at high levels in comparison to Variovorax and Porphyrobacter. Notably, Dyadobacter produces a significant number of leucine-rich repeat (LRR) proteins and enzymes involved in bacterial reactive oxygen species (ROS) tolerance. Complementary to this, Variovorax expresses the genes of the biosynthesis of vitamins B2, B5, B6, B7, B9, and B12, and Porphyrobacter is specialized in the production of vitamins B2 and B6. Thus, the shared currency between partners are vitamins, microalgae growth-promoting substances, and dissolved carbon. This work significantly enlarges our knowledge on alga-bacteria interaction and demonstrates physiological investigations of microalgae and associated bacteria, using microscopy observations, photosynthetic activity measurements, and flow cytometry. IMPORTANCE The current study gives a detailed insight into mutualistic collaboration of microalgae and bacteria, including the involvement of competitive interplay between bacteria. We provide experimental evidence that Gram-negative bacteria belonging to the Dyadobacter, Porphyrobacter, and Variovorax are the key players in a Scenedesmus quadricauda alga-bacteria interaction. We impart strong evidence that Dyadobacter produces and releases polysaccharides degradation enzymes and leucine-rich repeat proteins; Variovorax supplies the consortium with auxins and vitamin B12, while Porphyrobacter produces a broad spectrum of B vitamins. We show not only that the microalgae collaborate with the bacteria and vice versa but also that the bacteria interact with each other via quorum-sensing and secretion system mechanisms. The shared currency between partners appears to be vitamins, microalgae growth-promoting substances, and dissolved carbon.
Collapse
Affiliation(s)
- Yekaterina Astafyeva
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Microbiology and Biotechnology, Hamburg, Germany
| | - Marno Gurschke
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Microbiology and Biotechnology, Hamburg, Germany
| | - Minyue Qi
- University Medical Center Hamburg-Eppendorf, Bioinformatics Core, Hamburg, Germany
| | - Lutgardis Bergmann
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Microbiology and Biotechnology, Hamburg, Germany
| | - Daniela Indenbirken
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, Virus Genomics, Hamburg, Germany
| | - Imke de Grahl
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Plant Biochemistry and Infection Biology, Hamburg, Germany
| | - Elena Katzowitsch
- University of Würzburg, Core Unit Systems Medicine, Würzburg, Germany
| | - Sigrun Reumann
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Plant Biochemistry and Infection Biology, Hamburg, Germany
| | - Dieter Hanelt
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Aquatic Ecophysiology and Phycology, Hamburg, Germany
| | - Malik Alawi
- University Medical Center Hamburg-Eppendorf, Bioinformatics Core, Hamburg, Germany
| | - Wolfgang R. Streit
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Microbiology and Biotechnology, Hamburg, Germany
| | - Ines Krohn
- University of Hamburg, Institute of Plant Science and Microbiology, Department of Microbiology and Biotechnology, Hamburg, Germany
| |
Collapse
|
7
|
Defining the Genes Required for Survival of Mycobacterium bovis in the Bovine Host Offers Novel Insights into the Genetic Basis of Survival of Pathogenic Mycobacteria. mBio 2022; 13:e0067222. [PMID: 35862770 PMCID: PMC9426507 DOI: 10.1128/mbio.00672-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This is the first report of the genetic requirements of an animal-adapted member of the
Mycobacterium tuberculosis
complex (MTBC) in a natural host.
M. bovis
has devastating impacts on cattle, and bovine tuberculosis is a considerable economic, animal welfare, and public health concern. The data highlight the importance of mycobacterial cholesterol catabolism and identify several new virulence factors.
Collapse
|
8
|
Liu Y, Yoo BB, Hwang CA, Martinez MR, Datta AR, Fratamico PM. Involvement of a putative ATP-Binding Cassette (ABC) Involved in manganese transport in virulence of Listeria monocytogenes. PLoS One 2022; 17:e0268924. [PMID: 35617277 PMCID: PMC9135185 DOI: 10.1371/journal.pone.0268924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 05/10/2022] [Indexed: 11/18/2022] Open
Abstract
Listeria monocytogenes is a foodborne pathogen and the causative agent of listeriosis, a disease associated with high fatality (20–30%) and hospitalization rates (>95%). ATP-Binding Cassette (ABC) transporters have been demonstrated to be involved in the general stress response. In previous studies, in-frame deletion mutants of the ABC transporter genes, LMOf2365_1875 and LMOf2365_1877, were constructed and analyzed; however, additional work is needed to investigate the virulence potential of these deletion mutants. In this study, two in vitro methods and one in vivo model were used to investigate the virulence potential of in-frame deletion mutants of ABC transporter genes. First, the invasion efficiency in host cells was measured using the HT-29 human cell line. Second, cell-to-cell spread activity was measured using a plaque forming assay. Lastly, virulence potential of the mutants was tested in the Galleria mellonella wax moth model. Our results demonstrated that the deletion mutant, ⊿LMOf2365_1875, displayed decreased invasion and cell-to-cell spread efficiency in comparison to the wild-type, LMOf2365, indicating that LMOf2365_1875 may be required for virulence. Furthermore, the reduced virulence of these mutants was confirmed using the Galleria mellonella wax moth model. In addition, the expression levels of 15 virulence and stress-related genes were analyzed by RT-PCR assays using stationary phase cells. Our results showed that virulence-related gene expression levels from the deletion mutants were elevated (15/15 genes from ⊿LMOf2365_1877 and 7/15 genes from ⊿LMOf2365_1875) compared to the wild type LMOf2365, suggesting that ABC transporters may negatively regulate virulence gene expression under specific conditions. The expression level of the stress-related gene, clpE, also was increased in both deletion mutants, indicating the involvement of ABC transporters in the stress response. Taken together, our findings suggest that ABC transporters may be used as potential targets to develop new therapeutic strategies to control L. monocytogenes.
Collapse
Affiliation(s)
- Yanhong Liu
- Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, PA, United States of America
- * E-mail:
| | - Brian ByongKwon Yoo
- Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Cheng-An Hwang
- Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, PA, United States of America
| | - Mira Rakic Martinez
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, United States of America
| | - Atin R. Datta
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States of America
| | - Pina M. Fratamico
- Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, PA, United States of America
| |
Collapse
|
9
|
Chafsey I, Ostrowski R, Guilbaud M, Teixeira P, Herry JM, Caccia N, Chambon C, Hébraud M, Azeredo J, Bellon-Fontaine MN, Popowska M, Desvaux M. Deep impact of the inactivation of the SecA2-only protein export pathway on the proteosurfaceome of Listeria monocytogenes. J Proteomics 2022; 250:104388. [PMID: 34601155 DOI: 10.1016/j.jprot.2021.104388] [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: 07/19/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 01/23/2023]
Abstract
Listeria monocytogenes presents a dimorphism associated to the SecA2 activity with cells having a normal rod shape or a dysmorphic elongated filamentous form. Besides variation of the cell and colony morphotype, this cell differentiation has profound ecophysiological and physiopathological implications with collateral effects on virulence and pathogenicity, biotope colonisation, bacterial adhesion and biofilm formation. This suggests the SecA2-only protein export could influence the listerial cell surface, which was investigated first by characterising its properties in L. monocytogenes wt and ΔsecA2. The degree of hydrophilicity and Lewis acid-base properties appeared significantly affected upon SecA2 inactivation. As modification of electrostatic properties would owe to modification in the composition of cell-surface proteins, the proteosurfaceome was further investigated by shotgun label-free proteomic analysis with a comparative relative quantitative approach. Following secretomic analysis, the protein secretion routes of the identified proteins were mapped considering the cognate transport and post-translocational maturation systems, as well as protein categories and subcellular localisation. Differential protein abundance profiles coupled to network analysis revealed the SecA2 dependence of 48 proteins, including some related to cell envelope biogenesis, translation and protein export, which could account for modifications of adhesion and surface properties of L. monocytogenes upon SecA2 inactivation. This investigation unravelled the profound influence of SecA2 activity on the cell surface properties and proteosurfaceome of L. monocytogenes, which provides advanced insights about its ecophysiopathology. SIGNIFICANCE: L. monocytogenes is a foodborne zoonotic pathogen and etiological agent of human listeriosis. This species presents a cellular dimorphism associated to the SecA2 activity that has profound physiopathological and ecophysiological implications with collateral effects on bacterial virulence and colonisation. To explore the influence of the SecA2-only protein export on the listerial cell, the surface properties of L. monocytogenes expressing or depleted of SecA2 was characterised by microelectrophoresis, microbial affinity to solvents and contact angles analyses. As modifications of hydrophilicity and Lewis acid-base electrostatic properties would owe to modification in the composition of cell-surface proteins, the proteinaceous subset of the surfaceome, i.e. the proteosurfaceome, was investigated further by shotgun label-free proteomic analysis. This subproteome appeared quite impacted upon SecA2 inactivation with the identification of proteins accounting for modifications in the cell surface properties. The profound influence of SecA2 activity on the cell surface of L. monocytogenes was unravelled, which provides advanced insights about its ecophysiopathology.
Collapse
Affiliation(s)
- Ingrid Chafsey
- INRAE, Université Clermont Auvergne, UMR454 MEDiS, 63000 Clermont-Ferrand, France
| | - Rafal Ostrowski
- University of Warsaw, Faculty of Biology, Department of Bacterial Physiology, Applied Microbiology, Institute of Microbiology, Warsaw, Poland
| | - Morgan Guilbaud
- Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 91300 Massy, France
| | - Pilar Teixeira
- University of Minho, Centre of Biological Engineering, Campus de Gualtar, Braga 4710-057, Portugal
| | - Jean-Marie Herry
- Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 91300 Massy, France
| | - Nelly Caccia
- INRAE, Université Clermont Auvergne, UMR454 MEDiS, 63000 Clermont-Ferrand, France
| | - Christophe Chambon
- INRAE, Plateforme d'Exploration du Métabolisme, 63122 Saint-Genès Champanelle, France
| | - Michel Hébraud
- INRAE, Université Clermont Auvergne, UMR454 MEDiS, 63000 Clermont-Ferrand, France; INRAE, Plateforme d'Exploration du Métabolisme, 63122 Saint-Genès Champanelle, France
| | - Joana Azeredo
- University of Minho, Centre of Biological Engineering, Campus de Gualtar, Braga 4710-057, Portugal
| | | | - Magdalena Popowska
- University of Warsaw, Faculty of Biology, Department of Bacterial Physiology, Applied Microbiology, Institute of Microbiology, Warsaw, Poland.
| | - Mickaël Desvaux
- INRAE, Université Clermont Auvergne, UMR454 MEDiS, 63000 Clermont-Ferrand, France.
| |
Collapse
|
10
|
Descoeudres N, Jouneau L, Henry C, Gorrichon K, Derré-Bobillot A, Serror P, Gillespie LL, Archambaud C, Pagliuso A, Bierne H. An Immunomodulatory Transcriptional Signature Associated With Persistent Listeria Infection in Hepatocytes. Front Cell Infect Microbiol 2021; 11:761945. [PMID: 34858876 PMCID: PMC8631403 DOI: 10.3389/fcimb.2021.761945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/11/2021] [Indexed: 12/15/2022] Open
Abstract
Listeria monocytogenes causes severe foodborne illness in pregnant women and immunocompromised individuals. After the intestinal phase of infection, the liver plays a central role in the clearance of this pathogen through its important functions in immunity. However, recent evidence suggests that during long-term infection of hepatocytes, a subpopulation of Listeria may escape eradication by entering a persistence phase in intracellular vacuoles. Here, we examine whether this long-term infection alters hepatocyte defense pathways, which may be instrumental for bacterial persistence. We first optimized cell models of persistent infection in human hepatocyte cell lines HepG2 and Huh7 and primary mouse hepatocytes (PMH). In these cells, Listeria efficiently entered the persistence phase after three days of infection, while inducing a potent interferon response, of type I in PMH and type III in HepG2, while Huh7 remained unresponsive. RNA-sequencing analysis identified a common signature of long-term Listeria infection characterized by the overexpression of a set of genes involved in antiviral immunity and the under-expression of many acute phase protein (APP) genes, particularly involved in the complement and coagulation systems. Infection also altered the expression of cholesterol metabolism-associated genes in HepG2 and Huh7 cells. The decrease in APP transcripts was correlated with lower protein abundance in the secretome of infected cells, as shown by proteomics, and also occurred in the presence of APP inducers (IL-6 or IL-1β). Collectively, these results reveal that long-term infection with Listeria profoundly deregulates the innate immune functions of hepatocytes, which could generate an environment favorable to the establishment of persistent infection.
Collapse
Affiliation(s)
- Natalie Descoeudres
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Luc Jouneau
- Université Paris-Saclay, INRAE, Virologie et Immunologie Moléculaires, Jouy-en-Josas, France
| | - Céline Henry
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Kevin Gorrichon
- Université Paris-Saclay, Institut de Biologie Intégrative de la Cellule, CEA, CNRS UMR 9198, Université Paris-Sud, Gif-sur-Yvette, France
| | | | - Pascale Serror
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Laura Lee Gillespie
- Terry Fox Cancer Research Laboratories, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Cristel Archambaud
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Alessandro Pagliuso
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Hélène Bierne
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| |
Collapse
|
11
|
Zhu D, Patabendige HMLW, Tomlinson BR, Wang S, Hussain S, Flores D, He Y, Shaw LN, Sun X. Cwl0971, a novel peptidoglycan hydrolase, plays pleiotropic roles in Clostridioides difficile R20291. Environ Microbiol 2021; 23:5222-5238. [PMID: 33893759 PMCID: PMC11217927 DOI: 10.1111/1462-2920.15529] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 04/12/2021] [Indexed: 02/04/2023]
Abstract
Clostridioides difficile is a Gram-positive, spore-forming, toxin-producing anaerobe that can cause nosocomial antibiotic-associated intestinal disease. Although the production of toxin A (TcdA) and toxin B (TcdB) contribute to the main pathogenesis of C. difficile, the mechanism of TcdA and TcdB release from cell remains unclear. In this study, we identified and characterized a new cell wall hydrolase Cwl0971 (CDR20291_0971) from C. difficile R20291, which is involved in bacterial autolysis. The gene 0971 deletion mutant (R20291Δ0971) generated with CRISPR-AsCpfI exhibited significantly delayed cell autolysis and increased cell viability compared to R20291, and the purified Cwl0971 exhibited hydrolase activity for Bacillus subtilis cell wall. Meanwhile, 0971 gene deletion impaired TcdA and TcdB release due to the decreased cell autolysis in the stationary/late phase of cell growth. Moreover, sporulation of the mutant strain decreased significantly compared to the wild type strain. In vivo, the defect of Cwl0971 decreased fitness over the parent strain in a mouse infection model. Collectively, Cwl0971 is involved in cell wall lysis and cell viability, which affects toxin release, sporulation, germination, and pathogenicity of R20291, indicating that Cwl0971 could be an attractive target for C. difficile infection therapeutics and prophylactics.
Collapse
Affiliation(s)
- Duolong Zhu
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | | | - Brooke Rene Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida
| | - Shaohui Wang
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Syed Hussain
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Domenica Flores
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Yongqun He
- Department of Microbiology and Immunology, and Center for Computational Medicine and Bioinformatics, Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| |
Collapse
|
12
|
EslB Is Required for Cell Wall Biosynthesis and Modification in Listeria monocytogenes. J Bacteriol 2021; 203:JB.00553-20. [PMID: 33229460 PMCID: PMC7847544 DOI: 10.1128/jb.00553-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022] Open
Abstract
The ABC transporter EslABC is associated with the intrinsic lysozyme resistance of Listeria monocytogenes. However, the exact role of the transporter in this process and in the physiology of L. monocytogenes is unknown. Lysozyme is an important component of the innate immune system. It functions by hydrolyzing the peptidoglycan (PG) layer of bacteria. The human pathogen Listeria monocytogenes is intrinsically lysozyme resistant. The peptidoglycan N-deacetylase PgdA and O-acetyltransferase OatA are two known factors contributing to its lysozyme resistance. Furthermore, it was shown that the absence of components of an ABC transporter, referred to here as EslABC, leads to reduced lysozyme resistance. How its activity is linked to lysozyme resistance is still unknown. To investigate this further, a strain with a deletion in eslB, coding for a membrane component of the ABC transporter, was constructed in L. monocytogenes strain 10403S. The eslB mutant showed a 40-fold reduction in the MIC to lysozyme. Analysis of the PG structure revealed that the eslB mutant produced PG with reduced levels of O-acetylation. Using growth and autolysis assays, we showed that the absence of EslB manifests in a growth defect in media containing high concentrations of sugars and increased endogenous cell lysis. A thinner PG layer produced by the eslB mutant under these growth conditions might explain these phenotypes. Furthermore, the eslB mutant had a noticeable cell division defect and formed elongated cells. Microscopy analysis revealed that an early cell division protein still localized in the eslB mutant, indicating that a downstream process is perturbed. Based on our results, we hypothesize that EslB affects the biosynthesis and modification of the cell wall in L. monocytogenes and is thus important for the maintenance of cell wall integrity. IMPORTANCE The ABC transporter EslABC is associated with the intrinsic lysozyme resistance of Listeria monocytogenes. However, the exact role of the transporter in this process and in the physiology of L. monocytogenes is unknown. Using different assays to characterize an eslB deletion strain, we found that the absence of EslB affects not only lysozyme resistance but also endogenous cell lysis, cell wall biosynthesis, cell division, and the ability of the bacterium to grow in media containing high concentrations of sugars. Our results indicate that EslB is, by means of a yet-unknown mechanism, an important determinant for cell wall integrity in L. monocytogenes.
Collapse
|
13
|
Lucas JR, Alía A, Velasco R, Selgas MD, Cabeza MC. Effect of E-beam treatment on expression of virulence and stress-response genes of Listeria monocytogenes in dry-cured ham. Int J Food Microbiol 2021; 340:109057. [PMID: 33460999 DOI: 10.1016/j.ijfoodmicro.2021.109057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 12/05/2020] [Accepted: 01/01/2021] [Indexed: 12/30/2022]
Abstract
Various adverse conditions can trigger defensive mechanisms in Listeria monocytogenes that can increase the virulence of surviving cells. The objective of this study was to evaluate the expression of one stress-response (sigB) and three virulence (plcA, hly, and iap) genes in L. monocytogenes exposed to a sub lethal dose of E-beam irradiation in dry-cured ham. To accomplish this, dry-cured ham slices (10 g) were immersed in a 109 CFU/mL suspension of L. monocytogenes strain S4-2 and subsequently irradiated with 1, 2, or 3 kGy. After irradiation, samples were stored at 7 °C or 15 °C for 30 days. Absolute gene expression levels were determined by RT-qPCR, and numbers of surviving Listeria cells were assessed by microbial counts after different storage times (0, 7, 15, and 30 days). At 7 °C, after E-beam treatment at doses of 2 or 3 kGy, Listeria gene expression significantly increased (p ≤ 0.05) up to day 15. Listeria counts decreased with increasing dosage. The relationship between absolute gene expression and the number of surviving Listeria cells could indicate that sublethal doses of E-beam irradiation can increase expression of the genes studied. We observed no significant influence of storage time or temperature on gene expression (p > 0.05). Listeria that survives E-beam treatment may display increased virulence, constituting a significant potential public health risk.
Collapse
Affiliation(s)
- J R Lucas
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain.
| | - A Alía
- Food Hygiene and Safety, Meat and Meat Products Research Institute, University of Extremadura, Avda. de la Universidad, s/n., 10003 Cáceres, Spain
| | - R Velasco
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - M D Selgas
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - M C Cabeza
- Food Technology Dept. Section, Veterinary Faculty, Complutense University, Avd. Puerta de Hierro s/n, 28040 Madrid, Spain
| |
Collapse
|
14
|
Ramires T, Kleinubing NR, Iglesias MA, Vitola HRS, Núncio ASP, Kroning IS, Moreira GMSG, Fiorentini ÂM, da Silva WP. Genetic diversity, biofilm and virulence characteristics of Listeria monocytogenes in salmon sushi. Food Res Int 2020; 140:109871. [PMID: 33648189 DOI: 10.1016/j.foodres.2020.109871] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 11/18/2022]
Abstract
Sushi is a ready-to-eat (RTE) food prepared from raw or cooked fish that is widely consumed worldwide. Listeria monocytogenes is the foodborne pathogen most commonly associated with RTE and fish products. The aim of the present study was to evaluate the presence of L. monocytogenes in salmon sushi commercialized in Pelotas city, Brazil, and to evaluate the genetic diversity, biofilm-forming ability in stainless steel, and virulence characteristics of the isolates. Four sampling events were carried out in seven specialized sushi establishments totaling 28 sushi pools. Listeria monocytogenes was detected in six samples (21.4%) from two establishments (28.6%). All isolates belonged to serotype 4b and carried the prfA, plcA, plcB, hlyA, mpl, actA, inlA, inlC, inlJ, and iap genes. The inlB gene was not detected in two isolates. The PFGE analysis grouped the isolates into four pulsotypes. All isolates had the ability to form biofilm on stainless steel and the average of biofilm formation counts varied between 6.4 and 7.2 log CFU.cm-2. The isolates harbored the biofilm-related genes agrA, agrB, agrC, agrD, and prfA, with the exception of two isolates that did not harbor the agrD gene. The presence of L. monocytogenes in RTE sushi is a concern, demonstrating that sushi consumption may be a risk of human listeriosis. Furthermore, it was possible to identify the persistence of this pathogen for at least one month (pulsotypes III and IV), in two establishments (A and G), highlighting the need for improving the cleaning and sanitation procedures in establishments that commercialize RTE sushi.
Collapse
Affiliation(s)
- Tassiana Ramires
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Natalie Rauber Kleinubing
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Mariana Almeida Iglesias
- Center of Technological Development, Biotechnology Department, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Helena Reissig Soares Vitola
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Adriana Souto Pereira Núncio
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Isabela Schneid Kroning
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil
| | | | - Ângela Maria Fiorentini
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Wladimir Padilha da Silva
- Department of Agroindustrial Science and Technology, Faculty of Agronomy, Federal University of Pelotas, Pelotas, RS, Brazil; Center of Technological Development, Biotechnology Department, Federal University of Pelotas, Pelotas, RS, Brazil.
| |
Collapse
|
15
|
First Report on the Finding of Listeria mnocytogenes ST121 Strain in a Dolphin Brain. Pathogens 2020; 9:pathogens9100802. [PMID: 32998344 PMCID: PMC7601084 DOI: 10.3390/pathogens9100802] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 11/18/2022] Open
Abstract
Listeria monocytogenes (Lm) is a ubiquitous bacterium that causes the foodborne illness, listeriosis. Clonal complexes (CC), such as CC121, are overrepresented in the food production industry, and are rarely reported in animals and the environment. Working within a European-wide project, we investigated the routes by which strains are transmitted from environments and animals to food and the food production environment (FPE). In this context, we report, for the first time, the occurrence of a ST121 (CC121) strain isolated from a dolphin brain. The genome was compared with the genomes of 376 CC121 strains. Genomic comparisons showed that 16 strains isolated from food were the closest to the dolphin strain. Like most of the food strains analyzed here, the dolphin strain included genomic features (transposon Tn6188, plasmid pLM6179), both described as being associated with the strain’s adaptation to the FPE. Like all 376 strains, the dolphin strain contained a truncated actA gene and inlA gene, both described as being associated with attenuated virulence. Despite this fact, the strain was able to cross blood-brain barrier in immunosuppressed dolphin exposed polychlorinated biphenyl and invaded by parasites. Our data suggest that the dolphin was infected by a food-related strain released into the Mediterranean Sea.
Collapse
|
16
|
Zhan LZ, Song DF, Gu Q, Yan TT, Ma CC. Reverse transcription – loop-mediated isothermal amplification assay for the rapid detection of pathogenic Listeria monocytogenes in meat products. Can J Microbiol 2019; 65:913-921. [DOI: 10.1139/cjm-2019-0114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This study reports the use of reverse transcription – loop-mediated isothermal amplification (RT–LAMP) to detect Listeria monocytogenes in meat. The assay was designed to target the iap gene of L. monocytogenes, to which four primers, recognizing six distinct iap sites, were designed. We optimized the RT–LAMP conditions and established the following optimal systems: 60 min, 63 °C, 2.0 mmol/L MgSO4, 1.0 mol/L betaine, 2.0 mmol/L dNTPs, 320 U/mL Bst DNA polymerase, 0.4 μmol/L outer primers, and 0.8 μmol/L inner primers. The RT–LAMP amplification products were identified by a visible white Mg2P2O7 precipitate or electrophoresis on a 2% agarose gel. RT–LAMP has a sensitivity of 7.3 × 101 CFU/mL, which is 2-fold higher than that of LAMP. When commercially available raw meat samples (including beef, pork, mutton, and rabbit) were analyzed simultaneously with RT–LAMP and the Chinese National Standard GB 4789.30-2016, their abilities to detect L. monocytogenes were the same. Samples containing L. monocytogenes killed by 15 psi at 121 °C for 15 min were used to confirm the specificity of RT–LAMP for live microorganisms. Thus, we used RT–LAMP to efficiently detect L. monocytogenes in meat products.
Collapse
Affiliation(s)
- Ling-Zhi Zhan
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
| | - Da-Feng Song
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
| | - Qing Gu
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
| | - Ting-Ting Yan
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
| | - Cong-Cong Ma
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
- Key Laboratory for Food Microbial Technology of Zhejiang Province, Zhejiang Gongshang University, No. 18, Xuezheng Street, Hangzhou 310018, China
| |
Collapse
|
17
|
Su X, Cao G, Zhang J, Pan H, Zhang D, Kuang D, Yang X, Xu X, Shi X, Meng J. Characterization of internalin genes in Listeria monocytogenes from food and humans, and their association with the invasion of Caco-2 cells. Gut Pathog 2019; 11:30. [PMID: 31198443 PMCID: PMC6558679 DOI: 10.1186/s13099-019-0307-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/29/2019] [Indexed: 02/07/2023] Open
Abstract
Background Internalins are surface proteins that are utilized by Listeria monocytogenes to facilitate its invasion into human intestinal epithelial cells. The expression of a full-length InlA is one of essential virulence factors for L. monocytogenes to cross the intestinal barrier in order to invade epithelial cells. Results In this study, the gene sequences of inlA in 120 L. monocytogenes isolates from food (n = 107) and humans (n = 13) were analyzed. Premature stop codon (PMSC) mutations in inlA were identified in 51 isolates (50 from food and 1 from human). Six mutation types of PMSCs were identified. Among the 51 isolates with PMSCs in inlA, there were 44 serogroup 1/2c, 3c isolates from food, of which seven belonged to serogroups 1/2a, 3a. A total of 153,382 SNPs in 2247 core genes from 42 genomes were identified and used to construct a phylogenetic tree. Serotype 1/2c isolates with inlA PMSC mutations were grouped together. Cell culture studies on 21 isolates showed that the invasion to Caco-2 cells was significantly reduced among isolates with inlA PMSC mutations compared to those without PMSC mutations (P < 0.01). The PMSC mutations in inlA correlated with the inability of the L. monocytogenes isolates to invade Caco-2 cells (Pearson’s coefficient 0.927, P < 0.01). Conclusion Overall, the study has revealed the reduced ability of L. monocytogenes to invade human intestinal epithelial cells in vitro was linked to the presence of PMSC mutations in inlA. Isolates with PMSC mutations shared the same genomic characteristics indicating the genetic basis on the potential virulence of L. monocytogenes invasion. Electronic supplementary material The online version of this article (10.1186/s13099-019-0307-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xudong Su
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Guojie Cao
- 2Department of Nutrition & Food Science, University of Maryland, College Park, MD 20742 USA
| | - Jianmin Zhang
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Haijian Pan
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Daofeng Zhang
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Dai Kuang
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Xiaowei Yang
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Xuebin Xu
- 3Shanghai Municipal Center for Disease Control and Prevention, Shanghai, 200336 China
| | - Xianming Shi
- 1Department of Food Science and Technology, MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Jianghong Meng
- 2Department of Nutrition & Food Science, University of Maryland, College Park, MD 20742 USA
| |
Collapse
|
18
|
|
19
|
A novel autolysin AtlA SS mediates bacterial cell separation during cell division and contributes to full virulence in Streptococcus suis. Vet Microbiol 2019; 234:92-100. [PMID: 31213278 DOI: 10.1016/j.vetmic.2019.05.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 05/23/2019] [Indexed: 12/19/2022]
Abstract
Streptococcus suis (SS) is a major pathogen in the swine industry, and also an important zoonotic agent for humans. The novel SS cell surface protein, AtlASS, comprising the special GW module and N-acetylmuramidases domain, was designated as a putative autolysin. Indeed, the atlASS deletion mutant almost completely lost its activity in Triton X-100 induced bacterial autolysis, while the wild-type and CΔatlASS strains showed significant decrease, to less than 20% of the initial OD600 values. Unexpectedly, both immunofluorescence and immunogold electron microscopy confirmed that AtlASS is mainly located in the cell division septum, suggesting autolytic activity in peptidoglycan hydrolysis may be required for cell separation, thus modulating and truncating bacterial chain length. The biofilm capacity of the AtlASS mutation was reduced ˜ 40%, as compared to the wild-type strain. The ΔatlASS strain also attenuated bacterial adherence in human brain microvessel endothelial cells (HBMECs). Furthermore, we confirmed that AtlASS has fibrinogen/fibronectin binding capacities. In mouse infection model, the AtlASS inactivation also significantly attenuated bacterial virulence and proliferation in vivo. In conclusion, these results indicate that AtlASS autolysin modulates bacterial chain length, and contributes to the full virulence of SS during infection.
Collapse
|
20
|
Jayeola V, Parsons C, Gorski L, Kathariou S. Validation of an ampicillin selection protocol to enrich for mutants of Listeria monocytogenes unable to replicate on fresh produce. FEMS Microbiol Lett 2019; 366:5449008. [DOI: 10.1093/femsle/fnz076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/10/2019] [Indexed: 12/14/2022] Open
Abstract
ABSTRACT
Several outbreaks of listeriosis have implicated fresh produce but genetic factors required for growth of Listeria monocytogenes on produce remain poorly characterized. Based on the fact that β-lactam antibiotics only kill bacterial cells that are growing, we hypothesized that ampicillin selection can enrich for L. monocytogenes mutants unable to grow on produce. For validation, we examined relative recovery of L. monocytogenes strain 2011L-2858 and its cold-sensitive mutant L1E4 following inoculation of cantaloupe rind fragments with 1:1 mixture of the strains and incubation at 4°C with or without ampicillin. Listeria monocytogenes from rind fragments inoculated with the mixed cultures and incubated in the presence of ampicillin were used to inoculate fresh rind fragments for a second round of enrichment. In the presence of ampicillin, the proportion of L1E4 increased from 55% on day 0 to 78% on day 14, with higher recovery (85% after 14 days) in the second round of enrichment. These data suggested that L1E4 was enriched on cantaloupe rind fragments while growing cells of the wildtype were killed by ampicillin. Application of this protocol to transposon mutant libraries from three L. monocytogenes strains yielded several mutants unable to grow on cantaloupe. Thus, ampicillin selection can facilitate discovery of genes essential for growth of L. monocytogenes on fresh produce.
Collapse
Affiliation(s)
- Victor Jayeola
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - C Parsons
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - L Gorski
- Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA
| | - S Kathariou
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| |
Collapse
|
21
|
Huang Y, Xue C, He W, Zhao X. Inhibition effect of Zedoary turmeric oil on Listeria monocytogenes and Staphylococcus aureus growth and exotoxin proteins production. J Med Microbiol 2019; 68:657-666. [DOI: 10.1099/jmm.0.000949] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Yixuan Huang
- Department of Food Quality and Safety, College of Food Science and Engineering, Tonghua Normal University, 134000 Tonghua, PR China
- Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, 130062 Changchun, PR China
| | - Changsong Xue
- Department of Chinese Medicine, College of Medicine and Pharmacy, Tonghua Normal University, 134000 Tonghua, PR China
| | - Wenbing He
- Changbai Mountain Edible Plant Resources Research and Development Engineering Center, Tonghua Normal University, 134002 Tonghua, PR China
- Department of Food Quality and Safety, College of Food Science and Engineering, Tonghua Normal University, 134000 Tonghua, PR China
| | - Xingchen Zhao
- Department of Food Quality and Safety, College of Food Science and Engineering, Tonghua Normal University, 134000 Tonghua, PR China
- Changbai Mountain Edible Plant Resources Research and Development Engineering Center, Tonghua Normal University, 134002 Tonghua, PR China
| |
Collapse
|
22
|
Vermassen A, Leroy S, Talon R, Provot C, Popowska M, Desvaux M. Cell Wall Hydrolases in Bacteria: Insight on the Diversity of Cell Wall Amidases, Glycosidases and Peptidases Toward Peptidoglycan. Front Microbiol 2019; 10:331. [PMID: 30873139 PMCID: PMC6403190 DOI: 10.3389/fmicb.2019.00331] [Citation(s) in RCA: 179] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/08/2019] [Indexed: 11/13/2022] Open
Abstract
The cell wall (CW) of bacteria is an intricate arrangement of macromolecules, at least constituted of peptidoglycan (PG) but also of (lipo)teichoic acids, various polysaccharides, polyglutamate and/or proteins. During bacterial growth and division, there is a constant balance between CW degradation and biosynthesis. The CW is remodeled by bacterial hydrolases, whose activities are carefully regulated to maintain cell integrity or lead to bacterial death. Each cell wall hydrolase (CWH) has a specific role regarding the PG: (i) cell wall amidase (CWA) cleaves the amide bond between N-acetylmuramic acid and L-alanine residue at the N-terminal of the stem peptide, (ii) cell wall glycosidase (CWG) catalyses the hydrolysis of the glycosidic linkages, whereas (iii) cell wall peptidase (CWP) cleaves amide bonds between amino acids within the PG chain. After an exhaustive overview of all known conserved catalytic domains responsible for CWA, CWG, and CWP activities, this review stresses that the CWHs frequently display a modular architecture combining multiple and/or different catalytic domains, including some lytic transglycosylases as well as CW binding domains. From there, direct physiological and collateral roles of CWHs in bacterial cells are further discussed.
Collapse
Affiliation(s)
- Aurore Vermassen
- Université Clermont Auvergne, INRA, MEDiS, Clermont-Ferrand, France
| | - Sabine Leroy
- Université Clermont Auvergne, INRA, MEDiS, Clermont-Ferrand, France
| | - Régine Talon
- Université Clermont Auvergne, INRA, MEDiS, Clermont-Ferrand, France
| | | | - Magdalena Popowska
- Department of Applied Microbiology, Faculty of Biology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRA, MEDiS, Clermont-Ferrand, France
| |
Collapse
|
23
|
Cwp19 Is a Novel Lytic Transglycosylase Involved in Stationary-Phase Autolysis Resulting in Toxin Release in Clostridium difficile. mBio 2018; 9:mBio.00648-18. [PMID: 29895635 PMCID: PMC6016235 DOI: 10.1128/mbio.00648-18] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Clostridium difficile is the major etiologic agent of antibiotic-associated intestinal disease. Pathogenesis of C. difficile is mainly attributed to the production and secretion of toxins A and B. Unlike most clostridial toxins, toxins A and B have no signal peptide, and they are therefore secreted by unusual mechanisms involving the holin-like TcdE protein and/or autolysis. In this study, we characterized the cell surface protein Cwp19, a newly identified peptidoglycan-degrading enzyme containing a novel catalytic domain. We purified a recombinant His6-tagged Cwp19 protein and showed that it has lytic transglycosylase activity. Moreover, we observed that Cwp19 is involved in cell autolysis and that a C. difficilecwp19 mutant exhibited delayed autolysis in stationary phase compared to the wild type when bacteria were grown in brain heart infusion (BHI) medium. Wild-type cell autolysis is correlated to strong alterations of cell wall thickness and integrity and to release of cytoplasmic material. Furthermore, we demonstrated that toxins were released into the extracellular medium as a result of Cwp19-induced autolysis when cells were grown in BHI medium. In contrast, Cwp19 did not induce autolysis or toxin release when cells were grown in tryptone-yeast extract (TY) medium. These data provide evidence for the first time that TcdE and bacteriolysis are coexisting mechanisms for toxin release, with their relative contributions in vitro depending on growth conditions. Thus, Cwp19 is an important surface protein involved in autolysis of vegetative cells of C. difficile that mediates the release of the toxins from the cell cytosol in response to specific environment conditions.IMPORTANCEClostridium difficile-associated disease is mainly known as a health care-associated infection. It represents the most problematic hospital-acquired infection in North America and Europe and exerts significant economic pressure on health care systems. Virulent strains of C. difficile generally produce two toxins that have been identified as the major virulence factors. The mechanism for release of these toxins from bacterial cells is not yet fully understood but is thought to be partly mediated by bacteriolysis. Here we identify a novel peptidoglycan hydrolase in C. difficile, Cwp19, exhibiting lytic transglycosylase activity. We show that Cwp19 contributes to C. difficile cell autolysis in the stationary phase and, consequently, to toxin release, most probably as a response to environmental conditions such as nutritional signals. These data highlight that Cwp19 constitutes a promising target for the development of new preventive and curative strategies.
Collapse
|
24
|
Pitts MG, D'Orazio SEF. A Comparison of Oral and Intravenous Mouse Models of Listeriosis. Pathogens 2018; 7:pathogens7010013. [PMID: 29361677 PMCID: PMC5874739 DOI: 10.3390/pathogens7010013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 01/11/2018] [Accepted: 01/19/2018] [Indexed: 12/18/2022] Open
Abstract
Listeria monocytogenes is one of several enteric microbes that is acquired orally, invades the gastric mucosa, and then disseminates to peripheral tissues to cause systemic disease in humans. Intravenous (i.v.) inoculation of mice with L. monocytogenes has been the most widely-used small animal model of listeriosis over the past few decades. The infection is highly reproducible and has been invaluable in deciphering mechanisms of adaptive immunity in vivo, particularly CD8+ T cell responses to intracellular pathogens. However, the i.v. model completely bypasses the gut phase of the infection. Recent advances in generating both humanized mice and murinized bacteria, as well as the development of a foodborne route of transmission has reignited interest in studying oral models of listeriosis. In this review, we analyze previously published reports to highlight both the similarities and differences in tissue colonization and host response to infection using either oral or i.v. inoculation.
Collapse
Affiliation(s)
- Michelle G Pitts
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, 800 Rose Street-MS417, Lexington, KY 40536-0298, USA.
| | - Sarah E F D'Orazio
- Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky, 800 Rose Street-MS417, Lexington, KY 40536-0298, USA.
| |
Collapse
|
25
|
Tiong HK, Muriana PM. RT-qPCR Analysis of 15 Genes Encoding Putative Surface Proteins Involved in Adherence of Listeria monocytogenes. Pathogens 2016; 5:E60. [PMID: 27706070 PMCID: PMC5198160 DOI: 10.3390/pathogens5040060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 11/30/2022] Open
Abstract
L. monocytogenes adherence to food-associated abiotic surfaces and the development of biofilms as one of the underlying reasons for the contamination of ready-to-eat products is well known. The over-expression of internalins that improves adherence has been noted in cells growing as attached cells or at elevated incubation temperatures. However, the role of other internalin-independent surface proteins as adhesins has been uncharacterized to date. Using two strains each of weakly- and strongly-adherent L. monocytogenes as platforms for temperature-dependent adherence assays and targeted mRNA analyses, these observations (i.e., sessile- and/or temperature-dependent gene expression) were further investigated. Microplate fluorescence assays of both surface-adherent strains exhibited significant (P < 0.05) adherence at higher incubation temperature (42 °C). Of the 15 genes selected for RT-qPCR, at least ten gene transcripts recovered from cells (weakly-adherent strain CW35, strongly-adherent strain 99-38) subject to various growth conditions were over expressed [planktonic/30 °C (10), sessile/30 °C (12), planktonic/42 °C (10)] compared to their internal control (16SrRNA transcripts). Of four genes overexpressed in all three conditions tested, three and one were implicated as virulence factors and unknown function, respectively. PCR analysis of six unexpressed genes revealed that CW35 possessed an altered genome. The results suggest the presence of other internalin-independent adhesins (induced by growth temperature and/or substratum) and that a group of suspect protein members are worthy of further analysis for their potential role as surface adhesins. Analysis of the molecular basis of adherence properties of isolates of L. monocytogenes from food-associated facilities may help identify sanitation regimens to prevent cell attachment and biofilm formation on abiotic surfaces that could play a role in reducing foodborne illness resulting from Listeria biofilms.
Collapse
Affiliation(s)
- Hung King Tiong
- Department of Animal Science, Monroe Street, Oklahoma State University, Stillwater, OK 74078, USA.
- Robert M. Kerr Food & Agricultural Products Centre, 109 FAPC Building, Monroe Street, Oklahoma State University, Stillwater, OK 74078-6055, USA.
| | - Peter M Muriana
- Department of Animal Science, Monroe Street, Oklahoma State University, Stillwater, OK 74078, USA.
- Robert M. Kerr Food & Agricultural Products Centre, 109 FAPC Building, Monroe Street, Oklahoma State University, Stillwater, OK 74078-6055, USA.
| |
Collapse
|
26
|
Yu M, Yang J, Guo M. Is the LysM domain of L. monocytogenes p60 protein suitable for engineering a protein with high peptidoglycan binding affinity? Bioengineered 2016; 7:406-410. [PMID: 27333274 DOI: 10.1080/21655979.2016.1200772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Lysin motif (LysM) is a highly conserved carbohydrate binding module that is widely present in proteins from both prokaryotes and eukaryotes. LysM domains from many LysM-containing proteins can be taken out of their natural context and retain their ability to bind peptidoglycan. Therefore, LysM has enormous potential for applications in both industry and medicine. This potential has stimulated an intensive search for LysM modules with different evolutionary origins. The p60 protein (Lm-p60) is an NlpC/P60-containing peptidoglycan hydrolase secreted by Listeria monocytogenes. The N-terminus of Lm-p60 contains 2 LysM modules separated by an SH3 module. Our recent study of Lm-p60 demonstrates that the N-terminal half of Lm-p60, comprised of 2 LysM and 1 SH3 module, is able to recognize and bind peptidoglycan. The LysM domain of Lm-p60 contains only 2 LysM modules, which is the minimum number of LysM modules in most NlpC/P60-containing proteins, but it shows strong affinity for peptidoglycan. Moreover, these 2 LysM modules have only 38.64% similarity to each other. These data allowed us to conclude that the 2 LysM modules from Lm-p60 have different evolutionary origins, suggesting that they are suitable candidate peptidoglycan-binding modules for protein engineering in order to create a protein with a high binding affinity to peptidoglycan.
Collapse
Affiliation(s)
- Minfeng Yu
- a College of Bioscience and Biotechnology, Yangzhou University , Yangzhou City, Jiangsu , PR China
| | - Jing Yang
- a College of Bioscience and Biotechnology, Yangzhou University , Yangzhou City, Jiangsu , PR China
| | - Minliang Guo
- a College of Bioscience and Biotechnology, Yangzhou University , Yangzhou City, Jiangsu , PR China
| |
Collapse
|
27
|
Dehbashi S, Pourmand MR, Mashhadi R. Characterization of Afb, a novel bifunctional protein in Streptococcus agalactiae. IRANIAN JOURNAL OF MICROBIOLOGY 2016; 8:73-9. [PMID: 27092228 PMCID: PMC4833744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND AND OBJECTIVES Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in newborns and results in pneumonia and bacteremia in adults. A number of S. agalactiae components are involved in colonization of target cells. Destruction of peptidoglycan and division of covalently linked daughter cells is mediated by autolysins. In this study, autolytic activity and plasma binding ability of AFb novel recombinant protein of S. agalactiae was investigated. MATERIALS AND METHODS The gbs1805 gene was cloned and expressed. E. coli strains DH5α and BL21 were used as cloning and expression hosts, respectively. After purification, antigenicity and binding ability to plasma proteins of the recombinant protein was evaluated. RESULTS AFb, the 18KDa protein was purified successfully. The insoluble mature protein revealed the ability to bind to fibrinogen and fibronectin. This insoluble mature protein revealed that it has the ability to bind to fibrinogen and fibronectin plasma proteins. Furthermore, in silico analysis demonstrated the AFb has an autolytic activity. CONCLUSIONS AFb is a novel protein capable of binding to fibrinogen and fibronectin. This findings lay a ground work for further investigation of the role of the bacteria in adhesion and colonization to the host.
Collapse
Affiliation(s)
- Sanaz Dehbashi
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Pourmand
- Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran,Corresponding author: Mohammad Reza Pourmand Address: Department of Pathobiology, School of Public Health and Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Tel: +98-21- 88954910, E-mail:
| | - Rahil Mashhadi
- Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
28
|
Meng R, Zhao Z, Guo N, Liu Z, Zhao X, Li W, Li X, Shi C, Nie D, Wang W, Liu T, Ma W, Yu L, Li J. Effect of honokiol on exotoxin proteins listeriolysin O and p60 secreted by Listeria monocytogenes. J Med Microbiol 2015; 64:1474-1480. [DOI: 10.1099/jmm.0.000183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Rizeng Meng
- Public Health College, Jilin University, 130062 Changchun, PR China
- Jilin Enrty-exit Inspection and Quarantine Bureau, Changchun, 130062, PR China
| | - Ziwen Zhao
- Public Health College, Jilin University, 130062 Changchun, PR China
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Na Guo
- Public Health College, Jilin University, 130062 Changchun, PR China
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Zonghui Liu
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Xingchen Zhao
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Wenli Li
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Xiaoxu Li
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Ce Shi
- Department of Food Quality and Safety, Jilin University, 130062 Changchun, PR China
| | - Dandan Nie
- Jilin Enrty-exit Inspection and Quarantine Bureau, Changchun, 130062, PR China
| | - Weilin Wang
- Jilin Enrty-exit Inspection and Quarantine Bureau, Changchun, 130062, PR China
| | - Tao Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, 130062 Changchun, PR China
| | - Wenchen Ma
- Jilin Enrty-exit Inspection and Quarantine Bureau, Changchun, 130062, PR China
| | - Lu Yu
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, 130062 Changchun, PR China
- Public Health College, Jilin University, 130062 Changchun, PR China
| | - Juan Li
- Public Health College, Jilin University, 130062 Changchun, PR China
| |
Collapse
|
29
|
Domain function dissection and catalytic properties of Listeria monocytogenes p60 protein with bacteriolytic activity. Appl Microbiol Biotechnol 2015; 99:10527-37. [PMID: 26363556 DOI: 10.1007/s00253-015-6967-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 08/12/2015] [Accepted: 08/23/2015] [Indexed: 02/07/2023]
Abstract
The major extracellular protein p60 of Listeria monocytogenes (Lm-p60) is an autolysin that can hydrolyze the peptidoglycan of bacterial cell wall and has been shown to be required for L. monocytogenes virulence. The predicted three-dimensional structure of Lm-p60 showed that Lm-p60 could be split into two independent structural domains at the amino acid residue 270. Conserved motif analysis showed that V30, D207, S395, and H444 are the key amino acid residues of the corresponding motifs. However, not only the actual functions of these two domains but also the catalytic properties of Lm-p60 are unclear. We try to express recombinant Lm-p60 and identify the functions of two domains by residue substitution (V30A, D207A, S395A, and H444A) and peptide truncation. The C-terminal domain was identified as catalytic element and N-terminal domain as substrate recognition and binding element. Either N-terminal domain truncation or C-terminal domain truncation presents corresponding biological activity. The catalytic activity of Lm-p60 with a malfunctioned substrate-binding domain was decreased, while the substrate binding was not affected by a mulfunctioned catalytic domain. With turbidimetric method, we determined the optimal conditions for the bacteriolytic activity of Lm-p60 against Micrococcus lysodeikficus. The assay for the effect of Lm-p60 on the bacteriolytic activity of lysozyme revealed that the combined use of Lm-p60 protein with lysozyme showed a strong synergistic effect on the bacteriolytic activity.
Collapse
|
30
|
Siegrist MS, Aditham AK, Espaillat A, Cameron TA, Whiteside SA, Cava F, Portnoy DA, Bertozzi CR. Host actin polymerization tunes the cell division cycle of an intracellular pathogen. Cell Rep 2015; 11:499-507. [PMID: 25892235 DOI: 10.1016/j.celrep.2015.03.046] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 02/23/2015] [Accepted: 03/22/2015] [Indexed: 02/02/2023] Open
Abstract
Growth and division are two of the most fundamental capabilities of a bacterial cell. While they are well described for model organisms growing in broth culture, very little is known about the cell division cycle of bacteria replicating in more complex environments. Using a D-alanine reporter strategy, we found that intracellular Listeria monocytogenes (Lm) spend a smaller proportion of their cell cycle dividing compared to Lm growing in broth culture. This alteration to the cell division cycle is independent of bacterial doubling time. Instead, polymerization of host-derived actin at the bacterial cell surface extends the non-dividing elongation period and compresses the division period. By decreasing the relative proportion of dividing Lm, actin polymerization biases the population toward cells with the highest propensity to form actin tails. Thus, there is a positive-feedback loop between the Lm cell division cycle and a physical interaction with the host cytoskeleton.
Collapse
Affiliation(s)
- M Sloan Siegrist
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Arjun K Aditham
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Akbar Espaillat
- Department of Molecular Biology, Umeå University, Umeå 901 87, Sweden; Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå 901 87, Sweden
| | - Todd A Cameron
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Sarah A Whiteside
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Felipe Cava
- Department of Molecular Biology, Umeå University, Umeå 901 87, Sweden; Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå 901 87, Sweden
| | - Daniel A Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Carolyn R Bertozzi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
| |
Collapse
|
31
|
Pillich H, Chakraborty T, Mraheil MA. Cell-autonomous responses in Listeria monocytogenes infection. Future Microbiol 2015; 10:583-97. [DOI: 10.2217/fmb.15.4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
ABSTRACT Listeria monocytogenes is a facultative intracellular bacterium causing listeriosis, a food-borne infection with a high mortality rate. The mechanisms and the role of cells and tissular components in generating protective adaptive immune responses are well studied, and cell biological studies provide a detailed understanding of the processes targeted by the bacterial products. Much less is known of the cellular responses activated to limit infection in individual cells when confronted with stress or infection. Eukaryotic cellular responses depend on multitiered homeostatic systems that ensure maintenance of proteostatis, organellar integrity, function and turnover, and overall cellular viability (‘the cell-autonomous response’). Here, we review the cell-autonomous responses induced during extracellular and intracellular L. monocytogenes growth and discuss their contribution to limiting infection.
Collapse
Affiliation(s)
- Helena Pillich
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
| | - Trinad Chakraborty
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Center for Infection Giessen-Marburg-Langen Site, Justus Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany
| |
Collapse
|
32
|
Paspaliari DK, Loose JSM, Larsen MH, Vaaje-Kolstad G. Listeria monocytogeneshas a functional chitinolytic system and an active lytic polysaccharide monooxygenase. FEBS J 2015; 282:921-36. [DOI: 10.1111/febs.13191] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 12/19/2014] [Accepted: 01/05/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Dafni K. Paspaliari
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
| | - Jennifer S. M. Loose
- Department of Chemistry; Biotechnology and Food Science; Norwegian University of Life Sciences; Ås Norway
| | - Marianne H. Larsen
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Denmark
| | - Gustav Vaaje-Kolstad
- Department of Chemistry; Biotechnology and Food Science; Norwegian University of Life Sciences; Ås Norway
| |
Collapse
|
33
|
Rismondo J, Möller L, Aldridge C, Gray J, Vollmer W, Halbedel S. Discrete and overlapping functions of peptidoglycan synthases in growth, cell division and virulence of Listeria monocytogenes. Mol Microbiol 2014; 95:332-51. [PMID: 25424554 PMCID: PMC4320753 DOI: 10.1111/mmi.12873] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2014] [Indexed: 12/19/2022]
Abstract
Upon ingestion of contaminated food, Listeria monocytogenes can cause serious infections in humans that are normally treated with β-lactam antibiotics. These target Listeria's five high molecular weight penicillin-binding proteins (HMW PBPs), which are required for peptidoglycan biosynthesis. The two bi-functional class A HMW PBPs PBP A1 and PBP A2 have transglycosylase and transpeptidase domains catalyzing glycan chain polymerization and peptide cross-linking, respectively, whereas the three class B HMW PBPs B1, B2 and B3 are monofunctional transpeptidases. The precise roles of these PBPs in the cell cycle are unknown. Here we show that green fluorescent protein (GFP)-PBP fusions localized either at the septum, the lateral wall or both, suggesting distinct and overlapping functions. Genetic data confirmed this view: PBP A1 and PBP A2 could not be inactivated simultaneously, and a conditional double mutant strain is largely inducer dependent. PBP B1 is required for rod-shape and PBP B2 for cross-wall biosynthesis and viability, whereas PBP B3 is dispensable for growth and cell division. PBP B1 depletion dramatically increased β-lactam susceptibilities and stimulated spontaneous autolysis but had no effect on peptidoglycan cross-linkage. Our in vitro virulence assays indicated that the complete set of all HMW PBPs is required for maximal virulence.
Collapse
Affiliation(s)
- Jeanine Rismondo
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstrasse 37, 38855, Wernigerode, Germany
| | | | | | | | | | | |
Collapse
|
34
|
Lmo0171, a novel internalin-like protein, determines cell morphology of Listeria monocytogenes and its ability to invade human cell lines. Curr Microbiol 2014; 70:267-74. [PMID: 25323012 PMCID: PMC4293459 DOI: 10.1007/s00284-014-0715-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 09/06/2014] [Indexed: 12/19/2022]
Abstract
Internalins comprise a class of Listeria monocytogenes proteins responsible for activation of signalling pathways leading to phagocytic uptake of the bacterium by the host cell. In this paper, a possible role of Lmo0171-a new member of the internalin family was investigated. Disruption of the lmo0171 gene resulted in important cell morphology alterations along with a decrease in the ability to invade three eukaryotic cell lines, that is Int407, Hep-2 and HeLa and diminished adhesion efficiency to int407, thereby suggesting bifunctionality of the newly characterised Lmo0171 internalin.
Collapse
|
35
|
Krawczyk-Balska A, Korsak D, Popowska M. The surface protein Lmo1941 with LysM domain influences cell wall structure and susceptibility of Listeria monocytogenes to cephalosporins. FEMS Microbiol Lett 2014; 357:175-83. [PMID: 24974853 DOI: 10.1111/1574-6968.12518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/04/2014] [Accepted: 06/20/2014] [Indexed: 11/30/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive bacterium causing rare but dangerous cases of disease in humans and animals. The β-lactams penicillin G and ampicillin are the antibiotics of choice in the treatment of listeriosis. Recently, lmo1941, encoding a surface protein of L. monocytogenes with unknown function, was identified as a gene transcriptionally upregulated under penicillin G pressure. In this study, the effect of lmo1941 knockout on the susceptibility of L. monocytogenes to β-lactams was examined. Deletion mutant in lmo1941 was constructed and subjected to studies, which revealed that the deletion of lmo1941 had no effect on susceptibility and tolerance to penicillin G and ampicillin but resulted, however, in increased susceptibility of L. monocytogenes to several cephalosporins. Subsequently, the potential effect of lmo1941 mutation on the cell wall of L. monocytogenes was investigated. The analysis revealed quantitative changes in the muropeptide profile of peptidoglycan and a decrease in density of the high-density zone of cell wall of the mutant strain. Both these changes were observed in cells taken from the stationary phase. These results indicate that the surface protein Lmo1941 affects peptidoglycan composition and cell wall structure of L. monocytogenes in the stationary phase of growth.
Collapse
Affiliation(s)
- Agata Krawczyk-Balska
- Faculty of Biology, Department of Applied Microbiology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
| | | | | |
Collapse
|
36
|
|
37
|
Carvalho F, Sousa S, Cabanes D. How Listeria monocytogenes organizes its surface for virulence. Front Cell Infect Microbiol 2014; 4:48. [PMID: 24809022 PMCID: PMC4010754 DOI: 10.3389/fcimb.2014.00048] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 04/02/2014] [Indexed: 02/04/2023] Open
Abstract
Listeria monocytogenes is a Gram-positive pathogen responsible for the manifestation of human listeriosis, an opportunistic foodborne disease with an associated high mortality rate. The key to the pathogenesis of listeriosis is the capacity of this bacterium to trigger its internalization by non-phagocytic cells and to survive and even replicate within phagocytes. The arsenal of virulence proteins deployed by L. monocytogenes to successfully promote the invasion and infection of host cells has been progressively unveiled over the past decades. A large majority of them is located at the cell envelope, which provides an interface for the establishment of close interactions between these bacterial factors and their host targets. Along the multistep pathways carrying these virulence proteins from the inner side of the cytoplasmic membrane to their cell envelope destination, a multiplicity of auxiliary proteins must act on the immature polypeptides to ensure that they not only maturate into fully functional effectors but also are placed or guided to their correct position in the bacterial surface. As the major scaffold for surface proteins, the cell wall and its metabolism are critical elements in listerial virulence. Conversely, the crucial physical support and protection provided by this structure make it an ideal target for the host immune system. Therefore, mechanisms involving fine modifications of cell envelope components are activated by L. monocytogenes to render it less recognizable by the innate immunity sensors or more resistant to the activity of antimicrobial effectors. This review provides a state-of-the-art compilation of the mechanisms used by L. monocytogenes to organize its surface for virulence, with special focus on those proteins that work “behind the frontline”, either supporting virulence effectors or ensuring the survival of the bacterium within its host.
Collapse
Affiliation(s)
- Filipe Carvalho
- Group of Molecular Microbiology, Unit of Infection and Immunity, Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal
| | - Sandra Sousa
- Group of Molecular Microbiology, Unit of Infection and Immunity, Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal
| | - Didier Cabanes
- Group of Molecular Microbiology, Unit of Infection and Immunity, Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal
| |
Collapse
|
38
|
Kyoui D, Takahashi H, Miya S, Kuda T, Kimura B. Comparison of the major virulence-related genes of Listeria monocytogenes in internalin A truncated strain 36-25-1 and a clinical wild-type strain. BMC Microbiol 2014; 14:15. [PMID: 24472083 PMCID: PMC3917698 DOI: 10.1186/1471-2180-14-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/21/2014] [Indexed: 01/12/2023] Open
Abstract
Background Internalin A (InlA) facilitates the invasion of Listeria monocytogenes into a host cell. Some strains of Listeria monocytogenes express truncated forms of InlA, which reduces invasiveness. However, few virulence-related genes other than inlA have been analyzed in InlA-truncated strains. In the present study, we sequenced the draft genome of strain 36-25-1, an InlA-truncated strain, with pyrosequencing and compared 36 major virulence-related genes in this strain and a clinical wild-type strain. Results Strain 36-25-1 possessed all of the virulence-related genes analyzed. Of the analyzed genes, only 4 genes (dltA, gtcA, iap, and inlA) differed when the nucleotide sequences of strain 36-25-1 and the clinical wild-type strain were compared. Analysis of the deduced amino acid sequences found no mutations that significantly influenced virulence in genes other than inlA. Conclusions The virulence-associated genes in strain 36-25-1 differ little from those of the clinical wild-type strain, indicating that a slight mutation in the nucleotide sequence determines the virulence of the InlA-truncated strain. In addition, the results suggest that, aside from InlA-mediated cell invasiveness, there is almost no difference between the virulence of strain 36-25-1 and that of the clinical wild-type strain.
Collapse
Affiliation(s)
| | - Hajime Takahashi
- Department of Food Science and Technology, Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan.
| | | | | | | |
Collapse
|
39
|
Krawczyk-Balska A, Lipiak M. Critical role of a ferritin-like protein in the control of Listeria monocytogenes cell envelope structure and stability under β-lactam pressure. PLoS One 2013; 8:e77808. [PMID: 24204978 PMCID: PMC3812014 DOI: 10.1371/journal.pone.0077808] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 09/05/2013] [Indexed: 02/08/2023] Open
Abstract
The human pathogen Listeria monocytogenes is susceptible to the β-lactam antibiotics penicillin G and ampicillin, and these are the drugs of choice for the treatment of listerial infections. However, these antibiotics exert only a bacteriostatic effect on this bacterium and consequently, L. monocytogenes is regarded as β-lactam tolerant. It is widely accepted that the phenomenon of bacterial tolerance to β-lactams is due to the lack of adequate autolysin activity, but the mechanisms of L. monocytogenes tolerance to this class of antibiotics are poorly characterized. A ferritin-like protein (Fri) was recently identified as a mediator of β-lactam tolerance in L. monocytogenes, but its function in this process remains unknown. The present study was undertaken to improve our understanding of L. monocytogenes tolerance to β-lactams and to characterize the role of Fri in this phenomenon. A comparative physiological analysis of wild-type L. monocytogenes and a fri deletion mutant provided evidence of a multilevel mechanism controlling autolysin activity in cells grown under β-lactam pressure, which leads to a reduction in the level and/or activity of cell wall-associated autolysins. This is accompanied by increases in the amount of teichoic acids, cell wall thickness and cell envelope integrity of L. monocytogenes grown in the presence of penicillin G, and provides the basis for the innate β-lactam tolerance of this bacterium. Furthermore, this study revealed the inability of the L. monocytogenes Δ fri mutant to deplete autolysins from the cell wall, to adjust the content of teichoic acids and to maintain their D-alanylation at the correct level when treated with penicillin G, thus providing further evidence that Fri is involved in the control of L. monocytogenes cell envelope structure and stability under β-lactam pressure.
Collapse
Affiliation(s)
- Agata Krawczyk-Balska
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Magdalena Lipiak
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| |
Collapse
|
40
|
Renier S, Chagnot C, Deschamps J, Caccia N, Szlavik J, Joyce SA, Popowska M, Hill C, Knøchel S, Briandet R, Hébraud M, Desvaux M. Inactivation of the SecA2 protein export pathway in Listeria monocytogenes promotes cell aggregation, impacts biofilm architecture and induces biofilm formation in environmental condition. Environ Microbiol 2013; 16:1176-92. [PMID: 24102749 DOI: 10.1111/1462-2920.12257] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/12/2013] [Accepted: 08/16/2013] [Indexed: 12/21/2022]
Abstract
Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. Besides its capacity to grow in a wide range of environmental and stressful conditions, L. monocytogenes has the ability to adhere to and colonize surfaces. Morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. This cell differentiation is mainly attributed to the reduced secretion of two SecA2-dependent cell-wall hydrolases, CwhA and MurA. SecA2 is a non-essential SecA paralogue forming an alternative translocase with the primary Sec translocon. Following investigation at temperatures relevant to its ecological niches, i.e. infection (37°C) and environmental (20°C) conditions, inactivation of this SecA2-only protein export pathway led, despite reduced adhesion, to the formation of filamentous biofilm with aerial structures. Compared to the wild type strain, inactivation of the SecA2 pathway promoted extensive cell aggregation and sedimentation. At ambient temperature, this effect was combined with the abrogation of cell motility resulting in elongated sedimented cells, which got knotted and entangled together in the course of filamentous-biofilm development. Such a cell differentiation provides a decisive advantage for listerial surface colonization under environmental condition. As further discussed, this morphotypic conversion has strong implication on listerial physiology and is also of potential significance for asymptomatic human/animal carriage.
Collapse
Affiliation(s)
- Sandra Renier
- INRA, UR454 Microbiologie, Saint-Genès-Champanelle, F-63122, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Chao MC, Kieser KJ, Minami S, Mavrici D, Aldridge BB, Fortune SM, Alber T, Rubin EJ. Protein complexes and proteolytic activation of the cell wall hydrolase RipA regulate septal resolution in mycobacteria. PLoS Pathog 2013; 9:e1003197. [PMID: 23468634 PMCID: PMC3585148 DOI: 10.1371/journal.ppat.1003197] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 01/03/2013] [Indexed: 01/08/2023] Open
Abstract
Peptidoglycan hydrolases are a double-edged sword. They are required for normal cell division, but when dysregulated can become autolysins lethal to bacteria. How bacteria ensure that peptidoglycan hydrolases function only in the correct spatial and temporal context remains largely unknown. Here, we demonstrate that dysregulation converts the essential mycobacterial peptidoglycan hydrolase RipA to an autolysin that compromises cellular structural integrity. We find that mycobacteria control RipA activity through two interconnected levels of regulation in vivo—protein interactions coordinate PG hydrolysis, while proteolysis is necessary for RipA enzymatic activity. Dysregulation of RipA protein complexes by treatment with a peptidoglycan synthase inhibitor leads to excessive RipA activity and impairment of correct morphology. Furthermore, expression of a RipA dominant negative mutant or of differentially processed RipA homologues reveals that RipA is produced as a zymogen, requiring proteolytic processing for activity. The amount of RipA processing differs between fast-growing and slow-growing mycobacteria and correlates with the requirement for peptidoglycan hydrolase activity in these species. Together, the complex picture of RipA regulation is a part of a growing paradigm for careful control of cell wall hydrolysis by bacteria during growth, and may represent a novel target for chemotherapy development. Peptidoglycan (PG) is a major component of the bacterial cell wall, which forms a flexible, but strong mesh around the cell to oppose osmotic pressure and prevent lysis. PG is also dynamically modified, continually being disassembled and polymerized as the cell elongates and divides. It remains poorly understood how cells can titrate enough hydrolysis of the PG to allow bacterial growth without leading to excessive digestion and disruption of cellular integrity. In our work, we have identified two methods by which a critical PG hydrolase, RipA, is carefully controlled in Mycobacterium tuberculosis—protein interactions help prevent lethal RipA dysregulation, while proteolytic cleavage is used as a second step to activate the enzyme in order to separate daughter cells. Our work elaborates multiple post-transcriptional mechanisms for preventing PG hydrolases from becoming lethal autolysins. These different levels of regulation may serve as a more general paradigm for PG remodeling in other bacterial species.
Collapse
Affiliation(s)
- Michael C. Chao
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Karen J. Kieser
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Shoko Minami
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Daniela Mavrici
- Department of Molecular and Cell Biology, QB3 Institute, University of California-Berkeley, Berkeley, California, United States of America
| | - Bree B. Aldridge
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Sarah M. Fortune
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Tom Alber
- Department of Molecular and Cell Biology, QB3 Institute, University of California-Berkeley, Berkeley, California, United States of America
| | - Eric J. Rubin
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
42
|
Renier S, Chambon C, Viala D, Chagnot C, Hébraud M, Desvaux M. Exoproteomic analysis of the SecA2-dependent secretion in Listeria monocytogenes EGD-e. J Proteomics 2013; 80:183-95. [PMID: 23291529 DOI: 10.1016/j.jprot.2012.11.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Revised: 11/12/2012] [Accepted: 11/29/2012] [Indexed: 12/21/2022]
Abstract
As part of the Sec translocase, the accessory ATPase SecA2 is present in some pathogenic Gram-positive bacteria. In Listeria monocytogenes, deletion of secA2 results in filamentous cells that form rough colonies and have lower virulence. However, only a few proteins have been identified that are secreted by this pathway. This investigation aims to provide the first exoproteomic analysis of the SecA2-dependent secretion in L. monocytogenes EGD-e. By using media and temperatures relevant to bacterial physiology, we demonstrated that the rough colony and elongated bacterial cell morphotypes are highly dependent on growth conditions. Subsequently, comparative exoproteomic analyses of the ΔsecA2 versus wt strains were performed in chemically defined medium at 20°C and 37°C. Analyzing the proteomic data following the secretomics-based method, part of the proteins appeared routed towards the Sec pathway and exhibited an N-terminal signal peptide. For another significant part, they were primarily cytoplasmic proteins, thus lacking signal peptide and with no predictable secretion pathway. In total, 13 proteins were newly identified as secreted via SecA2, which were essentially associated with cell-wall metabolism, adhesion and/or biofilm formation. From this comparative exoproteomic analysis, new insights into the L. monocytogenes physiology are discussed in relation to its saprophytic and pathogenic lifestyle.
Collapse
Affiliation(s)
- Sandra Renier
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Christophe Chambon
- INRA, Plate-forme d'Exploration du Métabolisme, F-63122 Saint-Genès Champanelle, France
| | - Didier Viala
- INRA, Plate-forme d'Exploration du Métabolisme, F-63122 Saint-Genès Champanelle, France
| | - Caroline Chagnot
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Michel Hébraud
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France; INRA, Plate-forme d'Exploration du Métabolisme, F-63122 Saint-Genès Champanelle, France
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France.
| |
Collapse
|
43
|
Arai R, Fukui S, Kobayashi N, Sekiguchi J. Solution structure of IseA, an inhibitor protein of DL-endopeptidases from Bacillus subtilis, reveals a novel fold with a characteristic inhibitory loop. J Biol Chem 2012; 287:44736-48. [PMID: 23091053 DOI: 10.1074/jbc.m112.414763] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Bacillus subtilis, LytE, LytF, CwlS, and CwlO are vegetative autolysins, DL-endopeptidases in the NlpC/P60 family, and play essential roles in cell growth and separation. IseA (YoeB) is a proteinaceous inhibitor against the DL-endopeptidases, peptidoglycan hydrolases. Overexpression of IseA caused significantly long chained cell morphology, because IseA inhibits the cell separation DL-endopeptidases post-translationally. Here, we report the first three-dimensional structure of IseA, determined by NMR spectroscopy. The structure includes a single domain consisting of three α-helices, one 3(10)-helix, and eight β-strands, which is a novel fold like a "hacksaw." Noteworthy is a dynamic loop between β4 and the 3(10)-helix, which resembles a "blade." The electrostatic potential distribution shows that most of the surface is positively charged, but the region around the loop is negatively charged. In contrast, the LytF active-site cleft is expected to be positively charged. NMR chemical shift perturbation of IseA interacting with LytF indicated that potential interaction sites are located around the loop. Furthermore, the IseA mutants D100K/D102K and G99P/G101P at the loop showed dramatic loss of inhibition activity against LytF, compared with wild-type IseA, indicating that the β4-3(10) loop plays an important role in inhibition. Moreover, we built a complex structure model of IseA-LytF by docking simulation, suggesting that the β4-3(10) loop of IseA gets stuck deep in the cleft of LytF, and the active site is occluded. These results suggest a novel inhibition mechanism of the hacksaw-like structure, which is different from known inhibitor proteins, through interactions around the characteristic loop regions with the active-site cleft of enzymes.
Collapse
Affiliation(s)
- Ryoichi Arai
- Division of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan.
| | | | | | | |
Collapse
|
44
|
Parthasarathy G, Lun S, Guo H, Ammerman NC, Geiman DE, Bishai WR. Rv2190c, an NlpC/P60 family protein, is required for full virulence of Mycobacterium tuberculosis. PLoS One 2012; 7:e43429. [PMID: 22952680 PMCID: PMC3432046 DOI: 10.1371/journal.pone.0043429] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/20/2012] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis, the etiologic agent of tuberculosis (TB) possesses at least five genes predicted to encode proteins with NlpC/P60 hydrolase domains, including the relatively uncharacterized Rv2190c. As NlpC/P60 domain-containing proteins are associated with diverse roles in bacterial physiology, our objective was to characterize Rv2190c in M. tuberculosis growth and virulence. Our data indicate that lack of Rv2190c is associated with impaired growth, both in vitro and during an in vivo mouse model of TB. These growth defects are associated with altered colony morphology and phthiocerol dimycocerosate levels, indicating that Rv2190c is involved in cell wall maintenance and composition. In addition, we have demonstrated that Rv2190c is expressed during active growth phase and that its protein product is immunogenic during infection. Our findings have significant implications, both for better understanding the role of Rv2190c in M. tuberculosis biology and also for translational developments.
Collapse
Affiliation(s)
- Geetha Parthasarathy
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Shichun Lun
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Haidan Guo
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Nicole C. Ammerman
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Deborah E. Geiman
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - William R. Bishai
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
| |
Collapse
|
45
|
Doyscher D, Fieseler L, Dons L, Loessner MJ, Schuppler M. Acanthamoebafeature a unique backpacking strategy to trap and feed onListeria monocytogenesand other motile bacteria. Environ Microbiol 2012; 15:433-46. [DOI: 10.1111/j.1462-2920.2012.02858.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 07/05/2012] [Accepted: 07/24/2012] [Indexed: 12/28/2022]
Affiliation(s)
- Dominik Doyscher
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7; 8092; Zurich; Switzerland
| | | | - Lone Dons
- Department of Food Science; University of Copenhagen; Rolighedsvej 30; DK-1958; Frederiksberg C; Denmark
| | - Martin J. Loessner
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7; 8092; Zurich; Switzerland
| | - Markus Schuppler
- Institute of Food, Nutrition and Health; ETH Zurich; Schmelzbergstrasse 7; 8092; Zurich; Switzerland
| |
Collapse
|
46
|
Ronholm J, Wang L, Hayashi I, Sugai M, Zhang Z, Cao X, Lin M. The Listeria monocytogenes serotype 4b autolysin IspC has N-acetylglucosaminidase activity. Glycobiology 2012; 22:1311-20. [DOI: 10.1093/glycob/cws100] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
|
47
|
Studies on the pathogenesis and survival of different culture forms of Listeria monocytogenes to pulsed UV-light irradiation after exposure to mild-food processing stresses. Food Microbiol 2012; 30:330-9. [DOI: 10.1016/j.fm.2011.12.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 12/27/2011] [Accepted: 12/28/2011] [Indexed: 12/22/2022]
|
48
|
Monk IR, Foster TJ. Genetic manipulation of Staphylococci-breaking through the barrier. Front Cell Infect Microbiol 2012; 2:49. [PMID: 22919640 PMCID: PMC3417578 DOI: 10.3389/fcimb.2012.00049] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Accepted: 03/20/2012] [Indexed: 12/29/2022] Open
Abstract
Most strains of Staphylococcus aureus and Staphylococcus epidermidis possess a strong restriction barrier that hinders exchange of DNA. Recently, major advances have been made in identifying and characterizing the restriction-modification (RM) systems involved. In particular a novel type IV restriction enzyme that recognizes cytosine methylated DNA has been shown to be the major barrier to transfer of plasmid DNA from Escherichia coli into S. aureus and S. epidermidis. While the conserved type I RM system provides a further barrier. Here we review the recent advances in understanding of restriction systems in staphylococci and highlight how this has been exploited to improve our ability to manipulate genetically previously untransformable strains.
Collapse
Affiliation(s)
- Ian R Monk
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin Dublin, Ireland.
| | | |
Collapse
|
49
|
Potluri LP, de Pedro MA, Young KD. Escherichia coli low-molecular-weight penicillin-binding proteins help orient septal FtsZ, and their absence leads to asymmetric cell division and branching. Mol Microbiol 2012; 84:203-24. [PMID: 22390731 DOI: 10.1111/j.1365-2958.2012.08023.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Escherichia coli cells lacking low-molecular-weight penicillin-binding proteins (LMW PBPs) exhibit morphological alterations that also appear when the septal protein FtsZ is mislocalized, suggesting that peptidoglycan modification and division may work together to produce cell shape. We found that in strains lacking PBP5 and other LMW PBPs, higher FtsZ concentrations increased the frequency of branched cells and incorrectly oriented Z rings by 10- to 15-fold. Invagination of these rings produced improperly oriented septa, which in turn gave rise to asymmetric cell poles that eventually elongated into branches. Branches always originated from the remnants of abnormal septation events, cementing the relationship between aberrant cell division and branch formation. In the absence of PBP5, PBP6 and DacD localized to nascent septa, suggesting that these PBPs can partially substitute for the loss of PBP5. We propose that branching begins when mislocalized FtsZ triggers the insertion of inert peptidoglycan at unusual positions during cell division. Only later, after normal cell wall elongation separates the patches, do branches become visible. Thus, a relationship between the LMW PBPs and cytoplasmic FtsZ ultimately affects cell division and overall shape.
Collapse
Affiliation(s)
- Lakshmi-Prasad Potluri
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205-7199, USA
| | | | | |
Collapse
|
50
|
Halbedel S, Hahn B, Daniel RA, Flieger A. DivIVA affects secretion of virulence-related autolysins in Listeria monocytogenes. Mol Microbiol 2012; 83:821-39. [PMID: 22353466 DOI: 10.1111/j.1365-2958.2012.07969.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DivIVA is a well-conserved coiled-coil protein present in most Gram-positive bacteria and has been implicated in division site selection, peptidoglycan biosynthesis and sporulation. DivIVA proteins bind lipid membranes and characteristically accumulate at curved membrane areas, i.e. the cell poles and the division site, to which they recruit various interaction partners. We have studied the role of this morphogen in the human pathogen Listeria monocytogenes and our results suggest a novel mechanism by which DivIVA contributes to cell division. Contrary to expectation a ΔdivIVA mutant exhibited a pronounced chaining phenotype rather than a defect in cell division which we attributed to reduced extracellular levels of the autolytic enzymes p60 and MurA. We demonstrate that this is due to a malfunction in secretion of these autolysins and phenotypic comparison of the ΔdivIVA strain with a ΔsecA2 mutant suggests that DivIVA influences the activity of the SecA2 secretion route in L. monocytogenes. Also from the phenotypic analysis it was clear that divIVA affected swarming motility, biofilm formation, invasiveness and cell-to-cell spread in cell culture infection models. Thus, our experiments show that DivIVA is an important factor for various listerial traits that are essential for the pathogenicity of this organism.
Collapse
Affiliation(s)
- Sven Halbedel
- Robert Koch Institute, FG11 - Division of Bacterial Infections, Burgstrasse 37, 38855 Wernigerode, Germany.
| | | | | | | |
Collapse
|