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Gao B, Cai H, Xu B, Yang F, Dou X, Dong Q, Yan H, Bu X, Li Z. Growth, biofilm formation, and motility of Listeria monocytogenes strains isolated from food and clinical samples located in Shanghai (China). Food Res Int 2024; 184:114232. [PMID: 38609218 DOI: 10.1016/j.foodres.2024.114232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/09/2024] [Accepted: 03/12/2024] [Indexed: 04/14/2024]
Abstract
Listeria monocytogenes is a common foodborne pathogen that frequently causes global outbreaks. In this study, the growth characteristics, biofilm formation ability, motility ability and whole genome of 26 L. monocytogenes strains isolated from food and clinical samples in Shanghai (China) from 2020 to 2022 were analyzed. There are significant differences among isolates in terms of growth, biofilm formation, motility, and gene expression. Compared with other sequence type (ST) types, ST1930 type exhibited a significantly higher maximum growth rate, the ST8 type demonstrated a stronger biofilm formation ability, and the ST121 type displayed greater motility ability. Furthermore, ST121 exhibited significantly high mRNA expression levels compared with other ST types in virulence genes mpl, fbpA and fbpB, the quorum sensing gene luxS, starvation response regulation gene relA, and biofilm adhesion related gene bapL. Whole-genome sequencing (WGS) analyses indicated the isolates of lineage I were mostly derived from clinical, and the isolates of lineage II were mostly derived from food. The motility ability, along with the expression of genes associated with motility (motA and motB), exhibited a significantly higher level in lineage II compared with lineage I. The isolates from food exhibited significantly higher motility ability compared with isolates from clinical. By integrating growth, biofilm formation, motility phenotype with molecular and genotyping information, it is possible to enhance comprehension of the association between genes associated with these characteristics in L. monocytogenes.
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Affiliation(s)
- BinRu Gao
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Hua Cai
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
| | - Biyao Xu
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
| | - Fan Yang
- Department of Pharmacy, Renji Hospital, School of Medicine Shanghai Jiao Tong University, Shanghai 200127, China.
| | - Xin Dou
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Qingli Dong
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Hui Yan
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Xiangfeng Bu
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Zhuosi Li
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
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2
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Alejandro-Navarreto X, Freitag NE. Revisiting old friends: updates on the role of two-component signaling systems in Listeria monocytogenes survival and pathogenesis. Infect Immun 2024; 92:e0034523. [PMID: 38591895 PMCID: PMC11003226 DOI: 10.1128/iai.00345-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
Listeria monocytogenes is well recognized for both its broad resistance to stress conditions and its ability to transition from a soil bacterium to an intracellular pathogen of mammalian hosts. The bacterium's impressive ability to adapt to changing environments and conditions requires the rapid sensing of environmental cues and the coordinated response of gene products that enable bacterial growth and survival. Two-component signaling systems (TCSs) have been long recognized for their ability to detect environmental stimuli and transmit those signals into transcriptional responses; however, often the precise nature of the stimulus triggering TCS responses can be challenging to define. L. monocytogenes has up to 16 TCSs that have been recognized based on homology and included in this list are several whose functions remain poorly described. This review highlights the current understanding of the breadth and scope of L. monocytogenes TCS as relates to stress resistance and pathogenesis. Precise signals still often remain elusive, but the gene networks associated with TCSs are providing clues into possible functions.
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Affiliation(s)
| | - Nancy E. Freitag
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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3
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Chen M, Ren G, Zhang X, Yang L, Ding Q, Sun J, Xia J, Xu J, Jiang L, Fang W, Cheng C, Song H. DegU-mediated suppression of carbohydrate uptake in Listeria monocytogenes increases adaptation to oxidative stress. Appl Environ Microbiol 2023; 89:e0101723. [PMID: 37787570 PMCID: PMC10617591 DOI: 10.1128/aem.01017-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 08/11/2023] [Indexed: 10/04/2023] Open
Abstract
The foodborne bacterial pathogen Listeria monocytogenes exhibits remarkable survival capabilities under challenging conditions, severely threatening food safety and human health. The orphan regulator DegU is a pleiotropic regulator required for bacterial environmental adaptation. However, the specific mechanism of how DegU participates in oxidative stress tolerance remains unknown in L. monocytogenes. In this study, we demonstrate that DegU suppresses carbohydrate uptake under stress conditions by altering global transcriptional profiles, particularly by modulating the transcription of the phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS)-related genes, such as ptsH, ptsI, and hprK. Specifically, in the absence of degU, the transcripts of ptsI are significantly upregulated and those of hprK are significantly downregulated in response to copper ion-induced stress. Overexpression of ptsI significantly increases bacterial growth in vitro, while overexpression of hprK leads to a decrease in growth. We further demonstrate that DegU directly senses oxidative stress, downregulates ptsI transcription, and upregulates hprK transcription. Additionally, through an electrophoretic mobility shift assay, we demonstrate that DegU directly regulates the transcription of ptsI and hprK by binding to specific regions within their respective promoter sequences. Notably, the putative pivotal DegU binding sequence for ptsI is located from 38 to 68 base pairs upstream of the ptsH transcription start site (TSS), whereas for hprK, it is mapped from 36 to 124 base pairs upstream of the hprK TSS. In summary, we elucidate that DegU plays a significant role in suppressing carbohydrate uptake in response to oxidative stress through the direct regulation of ptsI and hprK.ImportanceUnderstanding the adaptive mechanisms employed by Listeria monocytogenes in harsh environments is of great significance. This study focuses on investigating the role of DegU in response to oxidative stress by examining global transcriptional profiles. The results highlight the noteworthy involvement of DegU in this stress response. Specifically, DegU acts as a direct sensor of oxidative stress, leading to the modulation of gene transcription. It downregulates ptsI transcription while it upregulates hprK transcription through direct binding to their promoters. Consequently, these regulatory actions impede bacterial growth, providing a defense mechanism against stress-induced damage. These findings gained from this study may have broader implications, serving as a reference for studying adaptive mechanisms in other pathogenic bacteria and aiding in the development of targeted strategies to control L. monocytogenes and ensure food safety.
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Affiliation(s)
- Mianmian Chen
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Gengjia Ren
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Xian Zhang
- School of Medicine, Zhejiang University, Hangzhou, China
| | - Lifeng Yang
- Ningbo College of Health Sciences, Ningbo, China
| | - Qiang Ding
- Ningbo College of Health Sciences, Ningbo, China
| | - Jing Sun
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Jing Xia
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Jiali Xu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Lingli Jiang
- Ningbo College of Health Sciences, Ningbo, China
| | - Weihuan Fang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Changyong Cheng
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Houhui Song
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
- China-Australia Joint Laboratory for Animal Health Big Data Analytics, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
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4
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Finn L, Onyeaka H, O’Neill S. Listeria monocytogenes Biofilms in Food-Associated Environments: A Persistent Enigma. Foods 2023; 12:3339. [PMID: 37761048 PMCID: PMC10529182 DOI: 10.3390/foods12183339] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
Listeria monocytogenes (LM) is a bacterial pathogen responsible for listeriosis, a foodborne illness associated with high rates of mortality (20-30%) and hospitalisation. It is particularly dangerous among vulnerable groups, such as newborns, pregnant women and the elderly. The persistence of this organism in food-associated environments for months to years has been linked to several devastating listeriosis outbreaks. It may also result in significant costs to food businesses and economies. Currently, the mechanisms that facilitate LM persistence are poorly understood. Unravelling the enigma of what drives listerial persistence will be critical for developing more targeted control and prevention strategies. One prevailing hypothesis is that persistent strains exhibit stronger biofilm production on abiotic surfaces in food-associated environments. This review aims to (i) provide a comprehensive overview of the research on the relationship between listerial persistence and biofilm formation from phenotypic and whole-genome sequencing (WGS) studies; (ii) to highlight the ongoing challenges in determining the role biofilm development plays in persistence, if any; and (iii) to propose future research directions for overcoming these challenges.
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Affiliation(s)
| | - Helen Onyeaka
- School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK
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5
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de Almeida OGG, Pereira MG, Oxaran V, De Martinis ECP, Alves VF. In silico metatranscriptomic approach for tracking biofilm-related effectors in dairies and its importance for improving food safety. Front Microbiol 2022; 13:928480. [PMID: 36147852 PMCID: PMC9487997 DOI: 10.3389/fmicb.2022.928480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Sessile microorganisms are usually recalcitrant to antimicrobial treatments, and it is possible that finding biofilm-related effectors in metatranscriptomics datasets helps to understand mechanisms for bacterial persistence in diverse environments, by revealing protein-encoding genes that are expressed in situ. For this research, selected dairy-associated metatranscriptomics bioprojects were downloaded from the public databases JGI GOLD and NCBI (eight milk and 45 cheese samples), to screen for sequences encoding biofilm-related effectors. Based on the literature, the selected genetic determinants were related to adhesins, BAP, flagellum-related, intraspecific QS (AHL, HK, and RR), interspecific QS (LuxS), and QQ (AHL-acylases, AHL-lactonases). To search for the mRNA sequences encoding for those effector proteins, a custom database was built from UniprotKB, yielding 1,154,446 de-replicated sequences that were indexed in DIAMOND for alignment. The results revealed that in all the dairy-associated metatranscriptomic datasets obtained, there were reads assigned to genes involved with flagella, adhesion, and QS/QQ, but BAP-reads were found only for milk. Significant Pearson correlations (p < 0.05) were observed for transcripts encoding for flagella, RR, histidine kinases, adhesins, and LuxS, although no other significant correlations were found. In conclusion, the rationale used in this study was useful to demonstrate the presence of biofilm-associated effectors in metatranscriptomics datasets, pointing out to possible regulatory mechanisms in action in dairy-related biofilms, which could be targeted in the future to improve food safety.
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Affiliation(s)
| | - Marita Gimenez Pereira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Virginie Oxaran
- Department of Biological Sciences, University of Texas, El Paso, El Paso, TX, United States
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6
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Structural and biochemical analyses of the flagellar expression regulator DegU from Listeria monocytogenes. Sci Rep 2022; 12:10856. [PMID: 35798759 PMCID: PMC9263151 DOI: 10.1038/s41598-022-14459-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 06/07/2022] [Indexed: 11/24/2022] Open
Abstract
Listeria monocytogenes is a pathogenic bacterium that produces flagella, the locomotory organelles, in a temperature-dependent manner. At 37 °C inside humans, L. monocytogenes employs MogR to repress the expression of flagellar proteins, thereby preventing the production of flagella. However, in the low-temperature environment outside of the host, the antirepressor GmaR inactivates MogR, allowing flagellar formation. Additionally, DegU is necessary for flagellar expression at low temperatures. DegU transcriptionally activates the expression of GmaR and flagellar proteins by binding the operator DNA in the fliN-gmaR promoter as a response regulator of a two-component regulatory system. To determine the DegU-mediated regulation mechanism, we performed structural and biochemical analyses on the recognition of operator DNA by DegU. The DegU-DNA interaction is primarily mediated by a C-terminal DNA-binding domain (DBD) and can be fortified by an N-terminal receiver domain (RD). The DegU DBD adopts a tetrahelical helix-turn-helix structure and assembles into a dimer. The DegU DBD dimer recognizes the operator DNA using a positive patch. Unexpectedly, unlike typical response regulators, DegU interacts with operator DNA in both unphosphorylated and phosphorylated states with similar binding affinities. Therefore, we conclude that DegU is a noncanonical response regulator that is constitutively active irrespective of phosphorylation.
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7
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Wang Y, Sun L, Hu L, Wang Z, Wang X, Dong Q. Adhesion and kinetics of biofilm formation and related gene expression of Listeria monocytogenes in response to nutritional stress. Food Res Int 2022; 156:111143. [DOI: 10.1016/j.foodres.2022.111143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/11/2022] [Accepted: 03/13/2022] [Indexed: 01/08/2023]
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8
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Cheng C, Liu F, Jin H, Xu X, Xu J, Deng S, Xia J, Han Y, Lei L, Zhang X, Song H. The DegU Orphan Response Regulator Contributes to Heat Stress Resistance in Listeria monocytogenes. Front Cell Infect Microbiol 2021; 11:761335. [PMID: 34966695 PMCID: PMC8711649 DOI: 10.3389/fcimb.2021.761335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/25/2021] [Indexed: 11/24/2022] Open
Abstract
Listeria monocytogenes is more heat-resistant than most other non-spore-forming foodborne pathogens, posing a severe threat to food safety and human health, particularly during chilled food processing. The DegU orphan response regulator is known to control heat resistance in L. monocytogenes; however, the underlying regulatory mechanism is poorly understood. Here, we show that DegU contributes to L. monocytogenes exponential growth under mild heat-shock stress. We further demonstrate that DegU directly senses heat stress through autoregulation and upregulates the hrcA-grpE-dnaK-dnaJ operon, leading to increased production of heat-shock proteins. We also show that DegU can directly regulate the expression of the hrcA-grpE-dnaK-dnaJ operon. In conclusion, our results shed light on the regulatory mechanisms underlying how DegU directly activates the hrcA-grpE-dnaK-dnaJ operon, thereby regulating heat resistance in L. monocytogenes.
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Affiliation(s)
- Changyong Cheng
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Feng Liu
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Haobo Jin
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Xiangfei Xu
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Jiali Xu
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Simin Deng
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Jing Xia
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Yue Han
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Lei Lei
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Xian Zhang
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
| | - Houhui Song
- College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang Agriculture and Forestry University, Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, Hangzhou, China
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9
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Li Q, Liu L, Guo A, Zhang X, Liu W, Ruan Y. Formation of Multispecies Biofilms and Their Resistance to Disinfectants in Food Processing Environments: A Review. J Food Prot 2021; 84:2071-2083. [PMID: 34324690 DOI: 10.4315/jfp-21-071] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 07/16/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT In food processing environments, various microorganisms can adhere and aggregate on the surface of equipment, resulting in the formation of multispecies biofilms. Complex interactions among microorganisms may affect the formation of multispecies biofilms and resistance to disinfectants, which are food safety and quality concerns. This article reviews the various interactions among microorganisms in multispecies biofilms, including competitive, cooperative, and neutral interactions. Then, the preliminary mechanisms underlying the formation of multispecies biofilms are discussed in relation to factors, such as quorum-sensing signal molecules, extracellular polymeric substances, and biofilm-regulated genes. Finally, the resistance mechanisms of common contaminating microorganisms to disinfectants in food processing environments are also summarized. This review is expected to facilitate a better understanding of interspecies interactions and provide some implications for the control of multispecies biofilms in food processing. HIGHLIGHTS
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Affiliation(s)
- Qun Li
- College of Food Science and Technology, Huazhong Agriculture University, Wuhan, Hubei 430070, People's Republic of China
| | - Ling Liu
- College of Food Science and Technology, Huazhong Agriculture University, Wuhan, Hubei 430070, People's Republic of China
| | - Ailing Guo
- College of Food Science and Technology, Huazhong Agriculture University, Wuhan, Hubei 430070, People's Republic of China.,National Research and Development Center for Egg Processing, Wuhan, Hubei 430070, People's Republic of China
| | - Xinshuai Zhang
- College of Food Science and Technology, Huazhong Agriculture University, Wuhan, Hubei 430070, People's Republic of China
| | - Wukang Liu
- College of Food Science and Technology, Huazhong Agriculture University, Wuhan, Hubei 430070, People's Republic of China
| | - Yao Ruan
- College of Food Science and Technology, Huazhong Agriculture University, Wuhan, Hubei 430070, People's Republic of China
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Unrath N, McCabe E, Macori G, Fanning S. Application of Whole Genome Sequencing to Aid in Deciphering the Persistence Potential of Listeria monocytogenes in Food Production Environments. Microorganisms 2021; 9:1856. [PMID: 34576750 PMCID: PMC8464834 DOI: 10.3390/microorganisms9091856] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 01/26/2023] Open
Abstract
Listeria monocytogenes is the etiological agent of listeriosis, a foodborne illness associated with high hospitalizations and mortality rates. This bacterium can persist in food associated environments for years with isolates being increasingly linked to outbreaks. This review presents a discussion of genomes of Listeria monocytogenes which are commonly regarded as persisters within food production environments, as well as genes which are involved in mechanisms aiding this phenotype. Although criteria for the detection of persistence remain undefined, the advent of whole genome sequencing (WGS) and the development of bioinformatic tools have revolutionized the ability to find closely related strains. These advancements will facilitate the identification of mechanisms responsible for persistence among indistinguishable genomes. In turn, this will lead to improved assessments of the importance of biofilm formation, adaptation to stressful conditions and tolerance to sterilizers in relation to the persistence of this bacterium, all of which have been previously associated with this phenotype. Despite much research being published around the topic of persistence, more insights are required to further elucidate the nature of true persistence and its implications for public health.
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Affiliation(s)
- Natalia Unrath
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
| | - Evonne McCabe
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
- Department of Microbiology, St. Vincent’s University Hospital, D04 T6F4 Dublin, Ireland
| | - Guerrino Macori
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, D04 N2E5 Dublin, Ireland; (N.U.); (E.M.); (G.M.)
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11
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Jiang X, Ren S, Geng Y, Jiang C, Liu G, Wang H, Yu T, Liang Y. Role of the VirSR-VirAB system in biofilm formation of Listeria monocytogenes EGD-e. Food Res Int 2021; 145:110394. [PMID: 34112397 DOI: 10.1016/j.foodres.2021.110394] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/14/2021] [Accepted: 05/05/2021] [Indexed: 01/24/2023]
Abstract
The ability of Listeria monocytogenes, an important foodborne pathogen, to form biofilms in food processing environments leads to increased opportunity for contamination of food products, which is a major concern for food safety. In this study, the role of a complex system composed of the VirSR two-component signal transduction system (TCS) and the ATP-binding cassette (ABC) transporter VirAB in biofilm formation of L. monocytogenes EGD-e was investigated. Biofilm formation was measured using the microplate assay with crystal violet staining, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), and attachment and swarming motility were compared between strain EGD-e and its isogenic deletion mutants. Additionally, the relative expression levels of genes associated with the early steps of biofilm development in the wild-type and mutant strains were also determined by RT-qPCR. Results from microplate assay, CLSM and SEM showed that VirR is not required for biofilm formation in L. monocytogenes EGD-e. A central finding of this study is that both VirAB and VirS are essential for biofilm formation and they could function as a whole in biofilm formation of L. monocytogenes EGD-e. The results also demonstrated that both VirAB and VirS are involved in attachment, but they are not associated with swarming motility. Results from RT-qPCR showed that flaA, motA and motB were downregulated in the mutant strains ΔvirAB and ΔvirS, which could be the possible reason for reduced attachment and biofilm formation in these mutants. This study provides a better understanding of the mechanisms involved in biofilm formation of L. monocytogenes, leading to improved processes to control this biofilm-forming foodborne pathogen.
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Affiliation(s)
- Xiaobing Jiang
- Henan Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Siyu Ren
- Henan Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yimin Geng
- Henan Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Congyi Jiang
- Henan Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Guosheng Liu
- Henan Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Hailei Wang
- Henan Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Tao Yu
- College of Life Sciences and Basic Medicine, Xinxiang University, Xinxiang, China.
| | - Yu Liang
- College of Chemistry and Materials Engineering, Xinxiang University, Xinxiang, China
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12
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Gray J, Chandry PS, Kaur M, Kocharunchitt C, Fanning S, Bowman JP, Fox EM. Colonisation dynamics of Listeria monocytogenes strains isolated from food production environments. Sci Rep 2021; 11:12195. [PMID: 34108547 PMCID: PMC8190317 DOI: 10.1038/s41598-021-91503-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/06/2021] [Indexed: 12/19/2022] Open
Abstract
Listeria monocytogenes is a ubiquitous bacterium capable of colonising and persisting within food production environments (FPEs) for many years, even decades. This ability to colonise, survive and persist within the FPEs can result in food product cross-contamination, including vulnerable products such as ready to eat food items. Various environmental and genetic elements are purported to be involved, with the ability to form biofilms being an important factor. In this study we examined various mechanisms which can influence colonisation in FPEs. The ability of isolates (n = 52) to attach and grow in biofilm was assessed, distinguishing slower biofilm formers from isolates forming biofilm more rapidly. These isolates were further assessed to determine if growth rate, exopolymeric substance production and/or the agr signalling propeptide influenced these dynamics and could promote persistence in conditions reflective of FPE. Despite no strong association with the above factors to a rapid colonisation phenotype, the global transcriptome suggested transport, energy production and metabolism genes were widely upregulated during the initial colonisation stages under nutrient limited conditions. However, the upregulation of the metabolism systems varied between isolates supporting the idea that L. monocytogenes ability to colonise the FPEs is strain-specific.
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Affiliation(s)
- Jessica Gray
- CSIRO Agriculture and Food, Werribee, VIC, Australia. .,Food Safety Centre, Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Hobart, TAS, Australia.
| | | | - Mandeep Kaur
- Biosciences and Food Technology, School of Science, RMIT University, Melbourne, VIC, Australia
| | - Chawalit Kocharunchitt
- Food Safety Centre, Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, D04 N2E5, Ireland.,Institute for Global Food Security, Queen's University Belfast, Chlorine Gardens, Belfast, BT5 6AG, UK
| | - John P Bowman
- Food Safety Centre, Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Edward M Fox
- CSIRO Agriculture and Food, Werribee, VIC, Australia. .,Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.
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13
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Villoria Recio M, Lee BH, Lillebæk EMS, Kallipolitis BH, Gahan CGM, Ingmer H, Larsen MH. Chitin Attenuates Expression of Listeria monocytogenes Virulence Genes in vitro. Front Microbiol 2020; 11:588906. [PMID: 33343529 PMCID: PMC7744463 DOI: 10.3389/fmicb.2020.588906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/12/2020] [Indexed: 11/13/2022] Open
Abstract
External signals are crucial for bacteria to sense their immediate environment and fine-tune gene expression accordingly. The foodborne pathogen Listeria monocytogenes senses a range of environmental cues in order to activate or deactivate the virulence-inducing transcriptional factor PrfA during transition between infectious and saprophytic lifecycles. Chitin is an abundant biopolymer formed from linked β-(1-4)-N-acetyl-D-glucosamine residues associated with fungi, the exoskeleton of insects and often incorporated into foods as a thickener or stabilizer. L. monocytogenes evolved to hydrolyse chitin, presumably, to facilitate nutrient acquisition from competitive environments such as soil where the polymer is abundant. Since mammals do not produce chitin, we reasoned that the polymer could serve as an environmental signal contributing to repression of L. monocytogenes PrfA-dependent expression. This study shows a significant downregulation of the core PrfA-regulon during virulence-inducing conditions in vitro in the presence of chitin. Our data suggest this phenomenon occurs through a mechanism that differs from PTS-transport of oligosaccharides generated from either degradation or chitinase-mediated hydrolysis of the polymer. Importantly, an indication that chitin can repress virulence expression of a constitutively active PrfA∗ mutant is shown, possibly mediated via a post-translational modification inhibiting PrfA∗ activity. To our knowledge, this is the first time that chitin is reported as a molecule with anti-virulence properties against a pathogenic bacterium. Thus, our findings identify chitin as a signal which may downregulate the virulence potential of the pathogen and may provide an alternative approach toward reducing disease risk.
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Affiliation(s)
- Miguel Villoria Recio
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, Food Safety and Zoonoses-University of Copenhagen, Frederiksberg, Denmark.,Alimentary Pharmabotic Centre Microbiome Ireland, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Bo-Hyung Lee
- Université Paris-Saclay, INRAE, UVSQ, VIM, Jouy-en-Josas, France
| | | | - Birgitte H Kallipolitis
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Cormac G M Gahan
- Alimentary Pharmabotic Centre Microbiome Ireland, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, Food Safety and Zoonoses-University of Copenhagen, Frederiksberg, Denmark
| | - Marianne Halberg Larsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, Food Safety and Zoonoses-University of Copenhagen, Frederiksberg, Denmark
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14
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Assisi C, Forauer E, Oliver HF, Etter AJ. Genomic and Transcriptomic Analysis of Biofilm Formation in Persistent and Transient Listeria monocytogenes Isolates from the Retail Deli Environment Does Not Yield Insight into Persistence Mechanisms. Foodborne Pathog Dis 2020; 18:179-188. [PMID: 33227214 DOI: 10.1089/fpd.2020.2817] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Persistence of Listeria monocytogenes in retail deli environments is a serious food safety issue, potentially leading to cross-contamination of ready-to-eat foods such as deli meats, salads, and cheeses. We previously discovered strong evidence of L. monocytogenes persistence in delis across multiple states. We hypothesized that this was correlated with isolates' innate characteristics, such as biofilm-forming capacity or gene differences. To test this hypothesis, we sequenced the genomes of 21 L. monocytogenes isolates previously collected longitudinally from the retail deli environment. Isolates were chosen to represent varying attachment capacity and sanitizer tolerance as well as persistence or transience. We used single-nucleotide polymorphism analysis to characterize the isolates' genetic relationships and used BLAST to search the isolates' genomes for antibiotic resistance elements, quaternary ammonium tolerance genes, and stress survival islets. We further chose four isolates for RNA-sequencing analysis and compared their global biofilm transcriptome with their global planktonic transcriptome. We did not find genetic content that explained persistence. The presence of stress survival islet-1 correlated to increased attachment capacity (p < 0.05), but not persistence. Further, the presence of sanitizer tolerance elements was not significantly correlated with phenotypic sanitizer tolerance. Analysis of biofilm versus planktonic gene expression did not show the expected differences in gene expression patterns. Overall, L. monocytogenes persistence in the deli environment is likely a matter of poor sanitation and/or facility design, rather than isolates' biofilm-forming capacity, sanitizer tolerance, or genomic content.
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Affiliation(s)
- Clara Assisi
- Department of Food Science, College of Agriculture, Purdue University, West Lafayette, Indiana, USA.,Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, USA
| | - Emily Forauer
- Department of Nutrition and Food Sciences, College of Agriculture and Life Sciences. The University of Vermont, Burlington, Vermont, USA
| | - Haley F Oliver
- Department of Food Science, College of Agriculture, Purdue University, West Lafayette, Indiana, USA
| | - Andrea J Etter
- Department of Food Science, College of Agriculture, Purdue University, West Lafayette, Indiana, USA.,Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, USA.,Department of Nutrition and Food Sciences, College of Agriculture and Life Sciences. The University of Vermont, Burlington, Vermont, USA
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15
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Qian H, Li W, Guo L, Tan L, Liu H, Wang J, Pan Y, Zhao Y. Stress Response of Vibrio parahaemolyticus and Listeria monocytogenes Biofilms to Different Modified Atmospheres. Front Microbiol 2020; 11:23. [PMID: 32153513 PMCID: PMC7044124 DOI: 10.3389/fmicb.2020.00023] [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: 10/20/2019] [Accepted: 01/07/2020] [Indexed: 12/11/2022] Open
Abstract
The sessile biofilms of Vibrio parahaemolyticus and Listeria monocytogenes have increasingly become a critical threat in seafood safety. This study aimed to evaluate the effects of modified atmospheres on the formation ability of V. parahaemolyticus and L. monocytogenes biofilms. The stress responses of bacterial biofilm formation to modified atmospheres including anaerobiosis (20% carbon dioxide, 80% nitrogen), micro-aerobiosis (20% oxygen, 80% nitrogen), and aerobiosis (60% oxygen, 40% nitrogen) were illuminated by determining the live cells, chemical composition analysis, textural parameter changes, expression of regulatory genes, etc. Results showed that the biofilm formation ability of V. parahaemolyticus was efficiently decreased, supported by the fact that the modified atmospheres significantly reduced the key chemical composition [extracellular DNA (eDNA) and extracellular proteins] of the extracellular polymeric substance (EPS) and negatively altered the textural parameters (biovolume, thickness, and bio-roughness) of biofilms during the physiological conversion from anaerobiosis to aerobiosis, while the modified atmosphere treatment increased the key chemical composition of EPS and the textural parameters of L. monocytogenes biofilms from anaerobiosis to aerobiosis. Meanwhile, the expression of biofilm formation genes (luxS, aphA, mshA, oxyR, and opaR), EPS production genes (cpsA, cpsC, and cpsR), and virulence genes (vopS, vopD1, vcrD1, vopP2β, and vcrD2β) of V. parahaemolyticus was downregulated. For the L. monocytogenes cells, the expression of biofilm formation genes (flgA, flgU, and degU), EPS production genes (Imo2554, Imo2504, inlA, rmlB), and virulence genes (vopS, vopD1, vcrD1, vopP2β, and vcrD2β) was upregulated during the physiological conversion. All these results indicated that the modified atmospheres possessed significantly different regulation on the biofilm formation of Gram-negative V. parahaemolyticus and Gram-positive L. monocytogenes, which will provide a novel insight to unlock the efficient control of Gram-negative and Gram-positive bacteria in modified-atmosphere packaged food.
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Affiliation(s)
- Hui Qian
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Wei Li
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Linxia Guo
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Ling Tan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Haiquan Liu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China.,Shanghai Engineering Research Center of Aquatic-Product Processing and Preservation, Shanghai, China.,Engineering Research Center of Food Thermal-Processing Technology, Shanghai Ocean University, Shanghai, China
| | - Jingjing Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China.,Shanghai Engineering Research Center of Aquatic-Product Processing and Preservation, Shanghai, China
| | - Yingjie Pan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China.,Shanghai Engineering Research Center of Aquatic-Product Processing and Preservation, Shanghai, China
| | - Yong Zhao
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China.,Shanghai Engineering Research Center of Aquatic-Product Processing and Preservation, Shanghai, China
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16
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Chen P, Wang JJ, Hong B, Tan L, Yan J, Zhang Z, Liu H, Pan Y, Zhao Y. Characterization of Mixed-Species Biofilm Formed by Vibrio parahaemolyticus and Listeria monocytogenes. Front Microbiol 2019; 10:2543. [PMID: 31787947 PMCID: PMC6856058 DOI: 10.3389/fmicb.2019.02543] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/21/2019] [Indexed: 12/15/2022] Open
Abstract
Mixed-species biofilms are the predominant form of biofilms found in nature. Research on biofilms have typically concentrated on single species biofilms and this study expands the horizon of biofilm research, where the characterization and dynamic changes of mono and mixed-species biofilms formed by the pathogens, Vibrio parahaemolyticus and Listeria monocytogenes were investigated. Compared to mono-species biofilm, the biomass, bio-volume, and thickness of mixed-species biofilms were significantly lower, which were confirmed using crystal violet staining, confocal laser scanning microscopy and scanning electron microscopy. Further experimental analysis showed these variations might result from the reduction of bacterial numbers, the down-regulation of biofilm-regulated genes and loss of metabolic activity in mixed-species biofilm. In addition, V. parahaemolyticus was located primarily on the surface layers of the mixed-species biofilms thus accruing competitive advantage. This competitive advantage was evidenced in a higher V. parahaemolyticus population density in the mixed-species biofilms. The adhesion to surfaces of the mixed-species biofilms were also reduced due to lower concentrations of extracellular polysaccharide and protein when the structure of the mixed-species was examined using Raman spectral analysis, phenol-sulfuric acid method and Lowry method. Furthermore, the minimum biofilm inhibitory concentration to antibiotics obviously decreased when V. parahaemolyticus co-exited with L. monocytogenes. This study firstly elucidated the interactive behavior in biofilm development of two foodborne pathogens, and future studies for biofilm control and antibiotic therapy should take into account interactions in mixed-species biofilms.
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Affiliation(s)
- Ping Chen
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Jing Jing Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Bin Hong
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Ling Tan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Jun Yan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Zhaohuan Zhang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Haiquan Liu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
- Engineering Research Center of Food Thermal-Processing Technology, Shanghai Ocean University, Shanghai, China
| | - Yingjie Pan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Yong Zhao
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
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17
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Tiensuu T, Guerreiro DN, Oliveira AH, O’Byrne C, Johansson J. Flick of a switch: regulatory mechanisms allowing Listeria monocytogenes to transition from a saprophyte to a killer. Microbiology (Reading) 2019; 165:819-833. [DOI: 10.1099/mic.0.000808] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Teresa Tiensuu
- Department of Molecular Biology; Molecular Infection Medicine, Sweden (MIMS); Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Duarte N. Guerreiro
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway H91 TK33, Ireland
| | - Ana H. Oliveira
- Department of Molecular Biology; Molecular Infection Medicine, Sweden (MIMS); Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Conor O’Byrne
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway H91 TK33, Ireland
| | - Jörgen Johansson
- Department of Molecular Biology; Molecular Infection Medicine, Sweden (MIMS); Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
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18
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Johansson J, Freitag NE. Regulation of Listeria monocytogenes Virulence. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0064-2019. [PMID: 31441398 PMCID: PMC10957223 DOI: 10.1128/microbiolspec.gpp3-0064-2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Indexed: 02/07/2023] Open
Abstract
Whereas obligate human and animal bacterial pathogens may be able to depend upon the warmth and relative stability of their chosen replication niche, environmental bacteria such as Listeria monocytogenes that harbor the ability to replicate both within animal cells and in the outside environment must maintain the capability to manage life under a variety of disparate conditions. Bacterial life in the outside environment requires adaptation to wide ranges of temperature, available nutrients, and physical stresses such as changes in pH and osmolarity as well as desiccation. Following ingestion by a susceptible animal host, the bacterium must adapt to similar changes during transit through the gastrointestinal tract and overcome a variety of barriers associated with host innate immune responses. Rapid alteration of patterns of gene expression and protein synthesis represent one strategy for quickly adapting to a dynamic host landscape. Here, we provide an overview of the impressive variety of strategies employed by the soil-dwelling, foodborne, mammalian pathogen L. monocytogenes to straddle diverse environments and optimize bacterial fitness both inside and outside host cells.
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Affiliation(s)
- Jörgen Johansson
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden (MIMS) and Umeå Centre for Microbial Research (UCMR), Umeå University, 90187 Umeå, Sweden
| | - Nancy E Freitag
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago IL
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19
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Wang J, Goh KM, Salem DR, Sani RK. Genome analysis of a thermophilic exopolysaccharide-producing bacterium - Geobacillus sp. WSUCF1. Sci Rep 2019; 9:1608. [PMID: 30733471 PMCID: PMC6367360 DOI: 10.1038/s41598-018-36983-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/16/2018] [Indexed: 11/23/2022] Open
Abstract
Geobacillus sp. WSUCF1 is a Gram-positive, spore-forming, aerobic and thermophilic bacterium, isolated from a soil sample obtained from a compost facility. Strain WSUCF1 demonstrated EPS producing capability using different sugars as the carbon source. The whole-genome analysis of WSUCF1 was performed to disclose the essential genes correlated with nucleotide sugar precursor biosynthesis, assembly of monosaccharide units, export of the polysaccharide chain, and regulation of EPS production. Both the biosynthesis pathway and export mechanism of EPS were proposed based on functional annotation. Additionally, the genome description of strain WSUCF1 suggests sophisticated systems for its adaptation under thermophilic conditions. The presence of genes associated with CRISPR-Cas system, quorum quenching lactonase, polyketide synthesis and arsenic resistance makes this strain a potential candidate for various applications in biotechnology and biomedicine. The present study indicates that strain WSUCF1 has promise as a thermophilic EPS producer for a broad range of industrial applications. To the best of our knowledge, this is the first report on genome analysis of a thermophilic Geobacillus species focusing on its EPS biosynthesis and transportation, which will likely pave the way for both enhanced yield and tailor-made EPS production by thermophilic bacteria.
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Affiliation(s)
- Jia Wang
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, 57701, USA
- BuG ReMeDEE Consortium, South Dakota School of Mines and Technology, Rapid City, SD, 57701, USA
| | - Kian Mau Goh
- Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor, 81300, Malaysia
| | - David R Salem
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, 57701, USA.
- Department of Materials and Metallurgical Engineering, South Dakota School of Mines and Technology, Rapid City, SD, 57701, USA.
- Composite and Nanocomposite Advanced Manufacturing - Biomaterials Center (CNAM-Bio Center), Rapid City, SD, 57701, USA.
| | - Rajesh K Sani
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, 57701, USA.
- Composite and Nanocomposite Advanced Manufacturing - Biomaterials Center (CNAM-Bio Center), Rapid City, SD, 57701, USA.
- BuG ReMeDEE Consortium, South Dakota School of Mines and Technology, Rapid City, SD, 57701, USA.
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20
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Pinheiro J, Lisboa J, Pombinho R, Carvalho F, Carreaux A, Brito C, Pöntinen A, Korkeala H, dos Santos NM, Morais-Cabral JH, Sousa S, Cabanes D. MouR controls the expression of the Listeria monocytogenes Agr system and mediates virulence. Nucleic Acids Res 2018; 46:9338-9352. [PMID: 30011022 PMCID: PMC6182135 DOI: 10.1093/nar/gky624] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/25/2018] [Accepted: 06/28/2018] [Indexed: 12/11/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes (Lm) causes invasive infection in susceptible animals and humans. To survive and proliferate within hosts, this facultative intracellular pathogen tightly coordinates the expression of a complex regulatory network that controls the expression of virulence factors. Here, we identified and characterized MouR, a novel virulence regulator of Lm. Through RNA-seq transcriptomic analysis, we determined the MouR regulon and demonstrated how MouR positively controls the expression of the Agr quorum sensing system (agrBDCA) of Lm. The MouR three-dimensional structure revealed a dimeric DNA-binding transcription factor belonging to the VanR class of the GntR superfamily of regulatory proteins. We also showed that by directly binding to the agr promoter region, MouR ultimately modulates chitinase activity and biofilm formation. Importantly, we demonstrated by in vitro cell invasion assays and in vivo mice infections the role of MouR in Lm virulence.
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Affiliation(s)
- Jorge Pinheiro
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Johnny Lisboa
- Group of Fish Immunology & Vaccinology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - Rita Pombinho
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Filipe Carvalho
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Alexis Carreaux
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- SDV - UFR Sciences Du Vivant: Université Paris Diderot-Paris 7, Paris 75013, France
| | - Cláudia Brito
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4200-135, Portugal
| | - Anna Pöntinen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki 00014, Finland
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki 00014, Finland
| | - Nuno M S dos Santos
- Group of Fish Immunology & Vaccinology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - João H Morais-Cabral
- Group of Structural Biochemistry, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - Sandra Sousa
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
| | - Didier Cabanes
- Group of Molecular Microbiology, IBMC – Institute for Molecular and Cell Biology; i3S – Institute for Research and Innovation in Health, Porto 4200-135, Portugal
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Screening of the two-component-system histidine kinases of Listeria monocytogenes EGD-e. LiaS is needed for growth under heat, acid, alkali, osmotic, ethanol and oxidative stresses. Food Microbiol 2017; 65:36-43. [DOI: 10.1016/j.fm.2017.01.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 12/15/2016] [Accepted: 01/30/2017] [Indexed: 11/23/2022]
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22
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Hingston P, Chen J, Allen K, Truelstrup Hansen L, Wang S. Strand specific RNA-sequencing and membrane lipid profiling reveals growth phase-dependent cold stress response mechanisms in Listeria monocytogenes. PLoS One 2017; 12:e0180123. [PMID: 28662112 PMCID: PMC5491136 DOI: 10.1371/journal.pone.0180123] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 06/11/2017] [Indexed: 11/19/2022] Open
Abstract
The human pathogen Listeria monocytogenes continues to pose a challenge in the food industry, where it is known to contaminate ready-to-eat foods and grow during refrigerated storage. Increased knowledge of the cold-stress response of this pathogen will enhance the ability to control it in the food-supply-chain. This study utilized strand-specific RNA sequencing and whole cell fatty acid (FA) profiling to characterize the bacterium's cold stress response. RNA and FAs were extracted from a cold-tolerant strain at five time points between early lag phase and late stationary-phase, both at 4°C and 20°C. Overall, more genes (1.3×) were suppressed than induced at 4°C. Late stationary-phase cells exhibited the greatest number (n = 1,431) and magnitude (>1,000-fold) of differentially expressed genes (>2-fold, p<0.05) in response to cold. A core set of 22 genes was upregulated at all growth phases, including nine genes required for branched-chain fatty acid (BCFA) synthesis, the osmolyte transporter genes opuCBCD, and the internalin A and D genes. Genes suppressed at 4°C were largely associated with cobalamin (B12) biosynthesis or the production/export of cell wall components. Antisense transcription accounted for up to 1.6% of total mapped reads with higher levels (2.5×) observed at 4°C than 20°C. The greatest number of upregulated antisense transcripts at 4°C occurred in early lag phase, however, at both temperatures, antisense expression levels were highest in late stationary-phase cells. Cold-induced FA membrane changes included a 15% increase in the proportion of BCFAs and a 15% transient increase in unsaturated FAs between lag and exponential phase. These increases probably reduced the membrane phase transition temperature until optimal levels of BCFAs could be produced. Collectively, this research provides new information regarding cold-induced membrane composition changes in L. monocytogenes, the growth-phase dependency of its cold-stress regulon, and the active roles of antisense transcripts in regulating its cold stress response.
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Affiliation(s)
- Patricia Hingston
- Department of Food, Nutrition, and Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jessica Chen
- Department of Food, Nutrition, and Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Kevin Allen
- Department of Food, Nutrition, and Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Siyun Wang
- Department of Food, Nutrition, and Health, The University of British Columbia, Vancouver, British Columbia, Canada
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Oloketuyi SF, Khan F. Inhibition strategies of Listeria monocytogenes biofilms-current knowledge and future outlooks. J Basic Microbiol 2017; 57:728-743. [PMID: 28594071 DOI: 10.1002/jobm.201700071] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/12/2017] [Accepted: 05/12/2017] [Indexed: 12/30/2022]
Abstract
There is an increasing trend in the food industry on the Listeria monocytogenes biofilm formation and inhibition. This is attributed to its easy survival on contact surfaces, resistance to disinfectants or antibiotics and growth under the stringent condition used for food processing and preservation thereby leading to food contamination products by direct or indirect exposure. Though, there is a lack of conclusive evidences about the mechanism of biofilm formation, in this review, the concept of biofilm formation and various chemical, physical, and green technology approaches to prevent or control the biofilm formed is discussed. State-of-the-art approaches ranging from the application of natural to synthetic molecules with high effectiveness and non-toxicity targeted at the different steps of biofilm formation could positively influence the biofilm inhibition in the future.
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Affiliation(s)
- Sandra F Oloketuyi
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, U.P., India
| | - Fazlurrahman Khan
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, U.P., India
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24
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Listeria monocytogenes DNA Glycosylase AdlP Affects Flagellar Motility, Biofilm Formation, Virulence, and Stress Responses. Appl Environ Microbiol 2016; 82:5144-52. [PMID: 27316964 PMCID: PMC4988193 DOI: 10.1128/aem.00719-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/09/2016] [Indexed: 12/16/2022] Open
Abstract
The temperature-dependent alteration of flagellar motility gene expression is critical for the foodborne pathogen Listeria monocytogenes to respond to a changing environment. In this study, a genetic determinant, L. monocytogenesf2365_0220 (lmof2365_0220), encoding a putative protein that is structurally similar to the Bacillus cereus alkyl base DNA glycosylase (AlkD), was identified. This determinant was involved in the transcriptional repression of flagellar motility genes and was named adlP (encoding an AlkD-like protein [AdlP]). Deletion of adlP activated the expression of flagellar motility genes at 37°C and disrupted the temperature-dependent inhibition of L. monocytogenes motility. The adlP null strains demonstrated decreased survival in murine macrophage-like RAW264.7 cells and less virulence in mice. Furthermore, the deletion of adlP significantly decreased biofilm formation and impaired the survival of bacteria under several stress conditions, including the presence of a DNA alkylation compound (methyl methanesulfonate), an oxidative agent (H2O2), and aminoglycoside antibiotics. Our findings strongly suggest that adlP may encode a bifunctional protein that transcriptionally represses the expression of flagellar motility genes and influences stress responses through its DNA glycosylase activity. IMPORTANCE We discovered a novel protein that we named AlkD-like protein (AdlP). This protein affected flagellar motility, biofilm formation, and virulence. Our data suggest that AdlP may be a bifunctional protein that represses flagellar motility genes and influences stress responses through its DNA glycosylase activity.
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Wu Y, Park KC, Choi BG, Park JH, Yoon KS. The Antibiofilm Effect ofGinkgo bilobaExtract AgainstSalmonellaandListeriaIsolates from Poultry. Foodborne Pathog Dis 2016; 13:229-38. [DOI: 10.1089/fpd.2015.2072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Yan Wu
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Keun Cheol Park
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Beom Geun Choi
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Jin Hwa Park
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Ki Sun Yoon
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
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26
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Cheremin AM, Niamsuren C, Toĭmentseva AA, Sharipova MR. [Expression optimization of Bacillus pumilus subtilisin-like proteinase]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2015; 40:752-7. [PMID: 25895372 DOI: 10.1134/s1068162014060053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The characteristics of Bacillus pumilus subtilisin-like protease expression were investigated. Potential binding sites for the transcription factor DegU~P have been identified in the regulatory region of the enzyme gene, which have been optimized for interaction with the regulatory protein. The expression of the extracellular subtilisin-like protease modified gene has been examined. It was established that the modification of one of the sites has resulted in increased expression of the proteinase in 2 times. It is concluded that the optimization of the promoter led to increased expression of subtilisin-like protease.
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Cairns LS, Martyn JE, Bromley K, Stanley-Wall NR. An alternate route to phosphorylating DegU of Bacillus subtilis using acetyl phosphate. BMC Microbiol 2015; 15:78. [PMID: 25887289 PMCID: PMC4404196 DOI: 10.1186/s12866-015-0410-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/12/2015] [Indexed: 11/21/2022] Open
Abstract
Background Two-component signal transduction pathways allow bacteria to sense and respond to the environment. Typically such pathways comprise a sensor histidine kinase and a response regulator. Phosphorylation of the response regulator commonly results in its activation, allowing the protein to bind to target promoter elements to regulate transcription. Several mechanisms are used to prevent inappropriate phosphorylation of the response regulator, thereby ensuring a specific response. In Bacillus subtilis, the DegS-DegU two-component system controls transcription of target genes in a manner dependent on the level of the phosphorylated response regulator, DegU. Previous work has tentatively indicated that DegU, and DegU H12L, a DegU variant which displays enhanced stability of the phosphoryl moiety, can be phosphorylated in the absence of the kinase, DegS. Results The data presented here reveal that DegU H12L requires aspartic acid 56 (D56), the identified DegU phosphorylation site, for its activity. By indirectly measuring the level of DegU ~ P in the cell by assessment of several well recognised DegU regulated processes it was shown that DegU H12L retains its activity in the absence of DegS, and that mutation of D56 produced an inactive protein. Further experiments designed to raise the level of acetyl phosphate within the cell suggest that DegU can be phosphorylated by acetyl phosphate in the absence of degS. Additionally, the phenotypic and biochemical experiments presented indicate that DegU H12L can reliably mimic high levels of phosphorylated DegU. Conclusions The ability of acetyl phosphate to modify DegU, and indeed DegU H12L, reveal an additional layer of regulation for DegU phosphorylation that will be relevant when the level of DegS is low or in the absence of degS. Given the number of processes that DegU can activate or inhibit, extensive regulation at a number of levels is required to ensure that the system is not inappropriately stimulated. DegS has both kinase and phosphatase activity and our findings demonstrate that the phosphatase activity of DegS is essential to control the level of DegU phosphate. Overall we contribute to our understanding of how the intricate signalling pathway DegS-DegU is regulated in B. subtilis.
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Affiliation(s)
- Lynne S Cairns
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK. .,Current address: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111, USA.
| | - Jessica E Martyn
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK. .,Current address: Sir William Dunn School of Pathology, South Parks Road Oxford, Oxford University, Oxford, OX1 3RE, UK.
| | - Keith Bromley
- James Clerk Maxwell Building, School of Physics, University of Edinburgh, Edinburgh, EH9 3JZ, UK.
| | - Nicola R Stanley-Wall
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
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Listeria monocytogenes is resistant to lysozyme through the regulation, not the acquisition, of cell wall-modifying enzymes. J Bacteriol 2014; 196:3756-67. [PMID: 25157076 DOI: 10.1128/jb.02053-14] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that is highly resistant to lysozyme, a ubiquitous enzyme of the innate immune system that degrades cell wall peptidoglycan. Two peptidoglycan-modifying enzymes, PgdA and OatA, confer lysozyme resistance on L. monocytogenes; however, these enzymes are also conserved among lysozyme-sensitive nonpathogens. We sought to identify additional factors responsible for lysozyme resistance in L. monocytogenes. A forward genetic screen for lysozyme-sensitive mutants led to the identification of 174 transposon insertion mutations that mapped to 13 individual genes. Four mutants were killed exclusively by lysozyme and not other cell wall-targeting molecules, including the peptidoglycan deacetylase encoded by pgdA, the putative carboxypeptidase encoded by pbpX, the orphan response regulator encoded by degU, and the highly abundant noncoding RNA encoded by rli31. Both degU and rli31 mutants had reduced expression of pbpX and pgdA, yet DegU and Rli31 did not regulate each other. Since pbpX and pgdA are also present in lysozyme-sensitive bacteria, this suggested that the acquisition of novel enzymes was not responsible for lysozyme resistance, but rather, the regulation of conserved enzymes by DegU and Rli31 conferred high lysozyme resistance. Each lysozyme-sensitive mutant exhibited attenuated virulence in mice, and a time course of infection revealed that the most lysozyme-sensitive strain was killed within 30 min of intravenous infection, a phenotype that was recapitulated in purified blood. Collectively, these data indicate that the genes required for lysozyme resistance are highly upregulated determinants of L. monocytogenes pathogenesis that are required for avoiding the enzymatic activity of lysozyme in the blood.
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Dare K, Shepherd J, Roy H, Seveau S, Ibba M. LysPGS formation in Listeria monocytogenes has broad roles in maintaining membrane integrity beyond antimicrobial peptide resistance. Virulence 2014; 5:534-46. [PMID: 24603093 DOI: 10.4161/viru.28359] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Listeria monocytogenes is an intracellular, foodborne gastrointestinal pathogen that is primarily responsible for causing listeriosis or food poisoning in otherwise healthy individuals. Infections that arise during pregnancy or within immune compromised individuals are much more serious resulting in the risk of fetal termination or fetal fatality postpartum in the former and septicemia or meningitis with a 20% fatality rate in the latter. While the roles of internalin proteins and listeriolysin-O in the infection process are well characterized, the specific roles of lysine-modified phospholipids in the membrane of L. monocytogenes are not. Investigation into the lipid bilayer composition of L. monocytogenes indicated that the overall proportions of lipids, including lysylcardiolipin and lysylphosphatidylglycerol (LysPG), vary with growth temperature and growth phase. In addition, we demonstrate that LysPG formation is essential for L. monocytogenes survival in the presence of increased osmolytic stress but has no effect on bacterial adherence, invasion or survival in the presence of physiologically relevant concentrations of human neutrophil peptide (HNP-1). In the absence of LysPG synthesis, L. monocytogenes unexpectedly retained flagellum-mediated motility at 37 °C. Taken together, these findings show that LysPG formation in L. monocytogenes has broader functions in virulence and survival beyond its known role in the modification of membrane potential previously observed in other bacteria.
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Affiliation(s)
- Kiley Dare
- Department of Microbiology; The Ohio State University; Columbus, OH USA
| | - Jennifer Shepherd
- Department of Microbiology; The Ohio State University; Columbus, OH USA
| | - Hervé Roy
- Department of Microbiology; The Ohio State University; Columbus, OH USA
| | - Stephanie Seveau
- Department of Microbiology; The Ohio State University; Columbus, OH USA
| | - Michael Ibba
- Department of Microbiology; The Ohio State University; Columbus, OH USA; Ohio State Biochemistry Program; Center for RNA Biology; The Ohio State University; Columbus, OH USA
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30
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Robitaille G, Choinière S, Ells T, Deschènes L, Mafu AA. Attachment of Listeria innocua to polystyrene: effects of ionic strength and conditioning films from culture media and milk proteins. J Food Prot 2014; 77:427-34. [PMID: 24674434 DOI: 10.4315/0362-028x.jfp-13-353] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is recognized that bacterial adhesion usually occurs on conditioning films made of organic macromolecules absorbed to abiotic surfaces. The objectives of this study were to determine the extent to which milk protein-coated polystyrene (PS) pegs interfere with biofilm formation and the synergistic effect of this conditioning and hypertonic growth media on the bacterial adhesion and biofilm formation of Listeria innocua, used as a nonpathogenic surrogate for Listeria monocytogenes. PS pegs were uncoated (bare PS) or individually coated with whey proteins isolate (WPI), β-lactoglobulin, bovine serum albumin, or tryptic soy broth (TSB) and were incubated in bacterial suspensions in modified Welshimer's broth. After 4 h, the number of adherent cells was dependent on the coating, as follows: TSB (10(7) CFU/ml) > bare PS > β-lactoglobulin > bovine serum albumin ∼ WPI (10(4) CFU/ml). The sessile cell counts increased up to 24 h, reaching > 10(7) CFU per peg for all surfaces (P > 0.1), except for WPI-coated PS; this indicates that the inhibitory effects of milk protein conditioning films are transient, slowing down the adhesion process. The 4-h bacterial adhesion on milk protein-coated PS in modified Welshimer's broth supplemented with salt (0 to 10% [wt/vol]) did not vary (P > 0.1), indicating that conditioning with milk proteins was the major determinant for inhibition of bacterial adhesion and that the synergetic effect of salt and milk proteins on adhesion was minimal. Moreover, the presence of 5 to 10% salt significantly inhibited 24-h biofilm formation on the TSB-coated and bare PS, with a decrease of >3 log at 10% (wt/vol) NaCl and almost completely depleted viable sessile bacteria on the milk protein-coated PS.
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Affiliation(s)
- Gilles Robitaille
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Boulevard West, Saint-Hyacinthe, Quebec, Canada J2S 8E3.
| | - Sébastien Choinière
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Boulevard West, Saint-Hyacinthe, Quebec, Canada J2S 8E3
| | - Timothy Ells
- Atlantic Food and Horticulture Research Centre, Agriculture and Agri-Food Canada, 32 Main Street, Kentville, Nova Scotia, Canada B4N 1J5
| | - Louise Deschènes
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Boulevard West, Saint-Hyacinthe, Quebec, Canada J2S 8E3
| | - Akier Assanta Mafu
- Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Boulevard West, Saint-Hyacinthe, Quebec, Canada J2S 8E3
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Transcriptional analysis of genes related to biofilm formation, stress-response, and virulence in Listeria monocytogenes strains grown at different temperatures. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0814-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Yamamoto S, Mitobe J, Ishikawa T, Wai SN, Ohnishi M, Watanabe H, Izumiya H. Regulation of natural competence by the orphan two-component system sensor kinase ChiS involves a non-canonical transmembrane regulator in Vibrio cholerae. Mol Microbiol 2013; 91:326-47. [PMID: 24236404 DOI: 10.1111/mmi.12462] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2013] [Indexed: 11/27/2022]
Abstract
In Vibrio cholerae, 41 chitin-inducible genes, including the genes involved in natural competence for DNA uptake, are governed by the orphan two-component system (TCS) sensor kinase ChiS. However, the mechanism by which ChiS controls the expression of these genes is currently unknown. Here, we report the involvement of a novel transcription factor termed 'TfoS' in this process. TfoS is a transmembrane protein that contains a large periplasmic domain and a cytoplasmic AraC-type DNA-binding domain, but lacks TCS signature domains. Inactivation of tfoS abolished natural competence as well as transcription of the tfoR gene encoding a chitin-induced small RNA essential for competence gene expression. A TfoS fragment containing the DNA-binding domain specifically bound to and activated transcription from the tfoR promoter. Intracellular TfoS levels were unaffected by disruption of chiS and coexpression of TfoS and ChiS in Escherichia coli recovered transcription of the chromosomally integrated tfoR::lacZ gene, suggesting that TfoS is post-translationally modulated by ChiS during transcriptional activation; however, this regulation persisted when the canonical phosphorelay residues of ChiS were mutated. The results presented here suggest that ChiS operates a chitin-induced non-canonical signal transduction cascade through TfoS, leading to transcriptional activation of tfoR.
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Affiliation(s)
- Shouji Yamamoto
- Department of Bacteriology I, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo, 162-8640, Japan
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The CLO3403/CLO3404 two-component system of Clostridium botulinum E1 Beluga is important for cold shock response and growth at low temperatures. Appl Environ Microbiol 2013; 80:399-407. [PMID: 24185852 DOI: 10.1128/aem.03204-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In order to survive a temperature downshift, bacteria have to sense the changing environment and adjust their metabolism and structure. Two-component signal transduction systems (TCSs) play a central role in sensing and responding to many different environmental stimuli. Although the nonproteolytic (group II) Clostridium botulinum represents a major hazard in chilled foods, the cold adaption mechanisms of group II C. botulinum organisms are not known. Here, we show that the CLO3403/CLO3404 TCS of C. botulinum E1 Beluga is involved in the cold shock response and growth at 12°C. Cold shock induced the expression of the genes encoding the histidine kinase (clo3403) and the response regulator (clo3404) by more than 100-fold after 5 h relative to their expression in a nonshocked culture at the corresponding time point. The involvement of CLO3403/CLO3404 in growth at low temperature was demonstrated by impaired growth of the insertional clo3403 and clo3404 knockout mutants at 12°C compared to the growth of the wild-type culture. Additionally, the inactivation of clo3403 had a negative effect on motility. The growth efficiency at 12°C of the TCS mutants and the motility of the kinase mutants were restored by introducing a plasmid harboring the operon of the CLO3403/CLO3404 TCS. The results suggest that the CLO3403/CLO3404 TCS is important for the cold tolerance of C. botulinum E1 Beluga.
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Upadhyay A, Upadhyaya I, Kollanoor-Johny A, Venkitanarayanan K. Antibiofilm effect of plant derived antimicrobials on Listeria monocytogenes. Food Microbiol 2013; 36:79-89. [PMID: 23764223 DOI: 10.1016/j.fm.2013.04.010] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/28/2013] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
Abstract
The present study investigated the efficacy of sub-inhibitory concentrations (SICs, concentrations not inhibiting bacterial growth) and bactericidal concentrations (MBCs) of four, generally recognized as safe (GRAS), plant-derived antimicrobials (PDAs) in inhibiting Listeria monocytogenes (LM) biofilm formation and inactivating mature LM biofilms, at 37, 25 and 4 °C on polystyrene plates and stainless-steel coupons. In addition, the effect of SICs of PDAs on the expression of LM genes critical for biofilm synthesis was determined by real-time quantitative PCR. The PDAs and their SICs used for inhibition of biofilm were trans-cinnamaldehyde (TC 0.50, 0.75 mM), carvacrol (CR 0.50, 0.65 mM), thymol (TY 0.33, 0.50 mM), and eugenol (EG 1.8, 2.5 mM), whereas the PDA concentrations used for inactivating mature biofilms were 5.0 and 10.0 mM (TC, CR), 3.3 and 5.0 mM (TY), 18.5 and 25.0 mM (EG). All PDAs inhibited biofilm synthesis and inactivated fully formed LM biofilms on both matrices at three temperatures tested (P < 0.05). Real-time quantitative PCR data revealed that all PDAs down-regulated critical LM biofilm-associated genes (P < 0.05). Results suggest that TC, CR, TY, and EG could potentially be used to control LM biofilms in food processing environments, although further studies under commercial settings are necessary.
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Affiliation(s)
- Abhinav Upadhyay
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA
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36
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Chang Y, Gu W, Zhang F, McLandsborough L. Disruption of lmo1386, a putative DNA translocase gene, affects biofilm formation of Listeria monocytogenes on abiotic surfaces. Int J Food Microbiol 2012; 161:158-63. [PMID: 23333341 DOI: 10.1016/j.ijfoodmicro.2012.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 12/04/2012] [Accepted: 12/09/2012] [Indexed: 11/16/2022]
Abstract
The distribution and survival of Listeria monocytogenes (L. monocytogenes) in food processing environment is linked to its ability to form biofilms, however the genetic mechanisms remain unclear. In our previous study, a Himar1 mariner-based transposon mutagenesis was performed and 42 mutants were confirmed to have reduced biofilm formation. Among the 42 biofilm deficient mutants, two isolates (s25-10C and s55-1D) harbored single insertion in lmo1386, a gene encoding a putative DNA translocase. The lmo1386 mutants had impaired biofilm formation in both static and flow conditions. The mutant strain s55-1D was complemented by cloning the entire lmo1386 gene into pPL2-gtcAP, a derivative of the integration vector pPL2 with the L. monocytogenes gtcA promoter. The genetically complemented mutant restored its biofilm phenotype, demonstrating the role of lmo1386 in the biofilm formation of L. monocytogenes. The lmo1386 mutant had reduced initial adhesion ability, which could at least partially contribute to the impaired biofilm phenotype. Additionally, the lmo1386 mutant formed elongated cell chains when grown in a nutrient TSBYE media, while no obvious cell morphology changes were observed when grown in the minimal MWB media. Overall, our findings suggest that the disruption of lmo1386, a putative DNA translocase gene affects the biofilm formation of L. monocytogenes on abiotic surfaces, which may further advance the understanding of the complicated process of biofilm formation.
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Affiliation(s)
- Yuhua Chang
- Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA
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A Listeria monocytogenes RNA helicase essential for growth and ribosomal maturation at low temperatures uses its C terminus for appropriate interaction with the ribosome. J Bacteriol 2012; 194:4377-85. [PMID: 22707705 DOI: 10.1128/jb.00348-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Listeria monocytogenes, a Gram-positive food-borne human pathogen, is able to grow at temperatures close to 0°C and is thus of great concern for the food industry. In this work, we investigated the physiological role of one DExD-box RNA helicase in Listeria monocytogenes. The RNA helicase Lmo1722 was required for optimal growth at low temperatures, whereas it was dispensable at 37°C. A Δlmo1722 strain was less motile due to downregulation of the major subunit of the flagellum, FlaA, caused by decreased flaA expression. By ribosomal fractionation experiments, it was observed that Lmo1722 was mainly associated with the 50S subunit of the ribosome. Absence of Lmo1722 decreased the fraction of 50S ribosomal subunits and mature 70S ribosomes and affected the processing of the 23S precursor rRNA. The ribosomal profile could be restored to wild-type levels in a Δlmo1722 strain expressing Lmo1722. Interestingly, the C-terminal part of Lmo1722 was redundant for low-temperature growth, motility, 23S rRNA processing, and appropriate ribosomal maturation. However, Lmo1722 lacking the C terminus showed a reduced affinity for the 50S and 70S fractions, suggesting that the C terminus is important for proper guidance of Lmo1722 to the 50S subunit. Taken together, our results show that the Listeria RNA helicase Lmo1722 is essential for growth at low temperatures, motility, and rRNA processing and is important for ribosomal maturation, being associated mainly with the 50S subunit of the ribosome.
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Listeria monocytogenes mutants with altered growth phenotypes at refrigeration temperature and high salt concentrations. Appl Environ Microbiol 2011; 78:1265-72. [PMID: 22179239 DOI: 10.1128/aem.06576-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Listeria monocytogenes can survive and grow in refrigerated temperatures and high-salt environments. In an effort to better understand the associated mechanisms, a library of ∼ 5,200 transposon mutants of LS411, a food isolate from the Jalisco cheese outbreak, were screened for their ability to grow in brain heart infusion (BHI) broth at 5°C or in the presence of 7% NaCl and two mutants with altered growth profiles were identified. The LS522 mutant has a transposon insertion between secA2 and iap and showed a significant reduction in growth in BHI broth at 5°C and in the presence of 7% NaCl. Reverse transcriptase quantitative PCR (RT-qPCR) revealed a substantial reduction in the expression of iap. Additionally, a hypothetical gene (met), containing a putative S-adenosylmethionine-dependent methyltransferase domain, downstream of iap had downregulated expression. In-frame deletion mutants of iap and met were created in LS411. The LS560 (LS411 Δiap) mutant showed reduced growth at 5°C and in the presence of 7% salt, confirming its role in cold and salt growth attenuation. Surprisingly, the LS655 (LS411 Δmet) mutant showed slightly increased growth during refrigeration, though no alteration was seen in salt growth relative to the wild-type strain. The LS527 mutant, containing an insertion 36 bp upstream of the gbu operon, showed reduced expression of the gbu transcript by RT-qPCR and also showed growth reduction at 5°C and in the presence of 7% salt. This attenuation was severely exacerbated when the mutant was grown under the combined stresses. Analysis of the gbu operon deletion mutant showed decreased growth in 7% salt and refrigeration, supporting the previously characterized role for this gene in cold and salt adaptation. These studies indicate the potential for an intricate relationship between environmental stress regulation and virulence in L. monocytogenes.
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Identification of genes involved in Listeria monocytogenes biofilm formation by mariner-based transposon mutagenesis. Appl Microbiol Biotechnol 2011; 93:2051-62. [PMID: 22120623 DOI: 10.1007/s00253-011-3719-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 10/26/2011] [Accepted: 11/07/2011] [Indexed: 10/15/2022]
Abstract
Listeria monocytogenes is a ubiquitous food-borne pathogen, whose distribution and survival in food-processing environments are associated with the ability to form biofilms. The process of biofilm formation is complex and its molecular mechanism is relatively poorly understood in L. monocytogenes. To better understand the genetics of this process, a mariner-based transposon mutagenesis strategy was used to identify genes involved in biofilm formation of L. monocytogenes. A library of 6,500 mutant colonies was screened for reduced biofilm formation using a microtiter plate biofilm assay. Forty biofilm-deficient mutants of L. monocytogenes were identified based on DNA sequences of the transposon-flanking regions and Southern hybridization with a transposon-based probe. The insertions harbored by these mutants led to the identification of 24 distinct loci, 18 of which, to our knowledge, have not been previously reported to function in the biofilm formation in L. monocytogenes. Genetic complementation confirmed the importance of lmo1386, a gene encoding a putative DNA translocase, for biofilm formation. Molecular analyses of mutants indicated that the majority of the 24 identified genes are related to flagella motility, gene regulation, and cell surface structures.
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Mattila M, Lindström M, Somervuo P, Markkula A, Korkeala H. Role of flhA and motA in growth of Listeria monocytogenes at low temperatures. Int J Food Microbiol 2011; 148:177-83. [PMID: 21683466 DOI: 10.1016/j.ijfoodmicro.2011.05.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 05/09/2011] [Accepted: 05/26/2011] [Indexed: 11/15/2022]
Abstract
While temperature-dependent induction of flagella is a well-characterized phenomenon in Listeria monocytogenes, the essentiality of increased flagellum production during growth at low temperatures remains unclear. To study this relationship, we compared the relative expression levels of two motility genes, flhA and motA, at 3°C, 25°C and 37°C in L. monocytogenes strain EGD-e by using qRT-PCR, and compared the growth curves, motility, and flagellation between the wild-type and flhA and motA deletion mutants. The relative expression levels of flhA and motA at 3°C were significantly higher than at 37°C (p<0.01). At 3°C, the level of flhA transcripts was also significantly higher than at 25°C (p<0.01). Growth curve analysis showed that at 3°C both the growth rates and maximum optical densities of ΔflhA and ΔmotA strains at 600 nm were significantly lower than those of the wild-type (p<0.001), while no significant differences were observed between the wild-type and the mutants at 37°C, and 25°C. Mutant strains ΔflhA and ΔmotA were nonmotile at all three temperatures. At 25°C, the number of flagellated cells of ΔmotA was notably reduced compared with the wild-type, whereas ΔflhA appeared nonflagellated at all temperatures. The results suggest that flhA and motA play a role in the cold tolerance of L. monocytogenes strain EGD-e, and that motile flagella may be needed for optimal cold stress response of L. monocytogenes.
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Affiliation(s)
- Mirjami Mattila
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
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Verghese B, Lok M, Wen J, Alessandria V, Chen Y, Kathariou S, Knabel S. comK prophage junction fragments as markers for Listeria monocytogenes genotypes unique to individual meat and poultry processing plants and a model for rapid niche-specific adaptation, biofilm formation, and persistence. Appl Environ Microbiol 2011; 77:3279-92. [PMID: 21441318 PMCID: PMC3126449 DOI: 10.1128/aem.00546-11] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 03/14/2011] [Indexed: 12/21/2022] Open
Abstract
Different strains of Listeria monocytogenes are well known to persist in individual food processing plants and to contaminate foods for many years; however, the specific genotypic and phenotypic mechanisms responsible for persistence of these unique strains remain largely unknown. Based on sequences in comK prophage junction fragments, different strains of epidemic clones (ECs), which included ECII, ECIII, and ECV, were identified and shown to be specific to individual meat and poultry processing plants. The comK prophage-containing strains showed significantly higher cell densities after incubation at 30°C for 48 h on meat and poultry food-conditioning films than did strains lacking the comK prophage (P < 0.05). Overall, the type of strain, the type of conditioning film, and the interaction between the two were all highly significant (P < 0.001). Recombination analysis indicated that the comK prophage junction fragments in these strains had evolved due to extensive recombination. Based on the results of the present study, we propose a novel model in which the concept of defective comK prophage was replaced with the rapid adaptation island (RAI). Genes within the RAI were recharacterized as "adaptons," as these genes may allow L. monocytogenes to rapidly adapt to different food processing facilities and foods. If confirmed, the model presented would help explain Listeria's rapid niche adaptation, biofilm formation, persistence, and subsequent transmission to foods. Also, comK prophage junction fragment sequences may permit accurate tracking of persistent strains back to and within individual food processing operations and thus allow the design of more effective intervention strategies to reduce contamination and enhance food safety.
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Affiliation(s)
- Bindhu Verghese
- Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA.
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Henne KL, Wan XF, Wei W, Thompson DK. SO2426 is a positive regulator of siderophore expression in Shewanella oneidensis MR-1. BMC Microbiol 2011; 11:125. [PMID: 21624143 PMCID: PMC3127752 DOI: 10.1186/1471-2180-11-125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 05/31/2011] [Indexed: 11/14/2022] Open
Abstract
Background The Shewanella oneidensis MR-1 genome encodes a predicted orphan DNA-binding response regulator, SO2426. Previous studies with a SO2426-deficient MR-1 strain suggested a putative functional role for SO2426 in the regulation of iron acquisition genes, in particular, the siderophore (hydroxamate) biosynthesis operon so3030-3031-3032. To further investigate the functional role of SO2426 in iron homeostasis, we employed computational strategies to identify putative gene targets of SO2426 regulation and biochemical approaches to validate the participation of SO2426 in the control of siderophore biosynthesis in S. oneidensis MR-1. Results In silico prediction analyses revealed a single 14-bp consensus motif consisting of two tandem conserved pentamers (5'-CAAAA-3') in the upstream regulatory regions of 46 genes, which were shown previously to be significantly down-regulated in a so2426 deletion mutant. These genes included so3030 and so3032, members of an annotated siderophore biosynthetic operon in MR-1. Electrophoretic mobility shift assays demonstrated that the SO2426 protein binds to its motif in the operator region of so3030. A "short" form of SO2426, beginning with a methionine at position 11 (M11) of the originally annotated coding sequence for SO2426, was also functional in binding to its consensus motif, confirming previous 5' RACE results that suggested that amino acid M11 is the actual translation start codon for SO2426. Alignment of SO2426 orthologs from all sequenced Shewanella spp. showed a high degree of sequence conservation beginning at M11, in addition to conservation of a putative aspartyl phosphorylation residue and the helix-turn-helix (HTH) DNA-binding domain. Finally, the so2426 deletion mutant was unable to synthesize siderophores at wild-type rates upon exposure to the iron chelator 2,2'-dipyridyl. Conclusions Collectively, these data support the functional characterization of SO2426 as a positive regulator of siderophore-mediated iron acquisition and provide the first insight into a coordinate program of multiple regulatory schemes controlling iron homeostasis in S. oneidensis MR-1.
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Abee T, Kovács AT, Kuipers OP, van der Veen S. Biofilm formation and dispersal in Gram-positive bacteria. Curr Opin Biotechnol 2010; 22:172-9. [PMID: 21109420 DOI: 10.1016/j.copbio.2010.10.016] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/26/2010] [Accepted: 10/26/2010] [Indexed: 11/25/2022]
Abstract
Biofilms are structured communities of bacteria, which are adhered to a surface and embedded in a self-produced matrix of extracellular polymeric substances. Since biofilms are very resistant to antimicrobial agents, they are at the basis of a range of problems, including quality and safety issues in food industry. Recently, major advances have been made in elucidating the different structural components of the biofilm matrix, the regulatory pathways involved in biofilm formation, and signaling molecules involved in biofilm formation and dispersal, which provide opportunities for prevention and control of these biofilms in the food industry.
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Affiliation(s)
- Tjakko Abee
- Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands.
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Renier S, Hébraud M, Desvaux M. Molecular biology of surface colonization by Listeria monocytogenes: an additional facet of an opportunistic Gram-positive foodborne pathogen. Environ Microbiol 2010; 13:835-50. [PMID: 21087384 DOI: 10.1111/j.1462-2920.2010.02378.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The opportunistic and facultative intracellular pathogenic bacterium Listeria monocytogenes causes a rare but severe foodborne disease called listeriosis, the outcome of which can be fatal. The infection cycle and key virulence factors are now well characterized in this species. Nonetheless, this knowledge has not prevented the re-emergence of listeriosis, as recently reported in several European countries. Listeria monocytogenes is particularly problematic in the food industry since it can survive and multiply under conditions frequently used for food preservation. Moreover, this foodborne pathogen also forms biofilms, which increase its persistence and resistance in industrial production lines, leading to contamination of food products. Significant differences have been reported regarding the ability of different isolates to form biofilms, but no clear correlation can be established with serovars or lineages. The architecture of listerial biofilms varies greatly from one strain to another as it ranges from bacterial monolayers to the most recently described network of knitted chains. While the role of polysaccharides as part of the extracellular matrix contributing to listerial biofilm formation remains elusive, the importance of eDNA has been demonstrated. The involvement of flagella in biofilm formation has also been pointed out, but their exact role in the process remains to be clarified because of conflicting results. Two cell-cell communication systems LuxS and Agr have been shown to take part in the regulation of biofilm formation. Several additional molecular determinants have been identified by functional genetic analyses, such as the (p)ppGpp synthetase RelA and more recently BapL. Future directions and questions about the molecular mechanisms of biofilm formation in L. monocytogenes are further discussed, such as correlation between clonal complexes as revealed by MLST and biofilm formation, the swarming over swimming regulation hypothesis regarding the role of the flagella, and the involvement of microbial surface components recognizing adhesive matrix molecules in the colonization of abiotic and biotic surfaces.
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Affiliation(s)
- Sandra Renier
- INRA, UR454 Microbiology, F-63122 Saint-Genès Champanelle, France
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Fritsch F, Mauder N, Williams T, Weiser J, Oberle M, Beier D. The cell envelope stress response mediated by the LiaFSRLm three-component system of Listeria monocytogenes is controlled via the phosphatase activity of the bifunctional histidine kinase LiaSLm. MICROBIOLOGY-SGM 2010; 157:373-386. [PMID: 21030435 DOI: 10.1099/mic.0.044776-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Most members of the phylum Firmicutes harbour a two-component system (TCS), LiaSR, which is involved in the response to cell envelope stress elicited most notably by inhibitors of the lipid II cycle. In all LiaSR systems studied in detail, LiaSR-mediated signal transduction has been shown to be negatively controlled by a membrane protein, LiaF, encoded upstream of liaSR. In this study we have analysed the LiaSR orthologue of Listeria monocytogenes (LiaSR(Lm)). Whole-genome transcriptional profiling indicated that activation of LiaSR(Lm) results in a remodelling of the cell envelope via the massive upregulation of membrane-associated and extracytoplasmic proteins in the presence of inducing stimuli. As shown for other LiaSR TCSs, LiaSR(Lm) is activated by cell wall-active antibiotics. We demonstrate that the level of phosphorylated LiaR(Lm), which is required for the induction of the LiaSR(Lm) regulon, is controlled by the interplay between the histidine kinase and phosphatase activities of the bifunctional sensor protein LiaS(Lm). Our data suggest that the phosphatase activity of LiaS(Lm) is stimulated by LiaF(Lm) in the absence of cell envelope stress.
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Affiliation(s)
- Frederike Fritsch
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Norman Mauder
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Tatjana Williams
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Julia Weiser
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Markus Oberle
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Dagmar Beier
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Mikrobiologie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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Jamet A, Rousseau C, Monfort JB, Nassif X, Martin P. Identification of a novel transcriptional regulator involved in pilC1 regulation in Neisseria meningitidis. FEMS Microbiol Lett 2010; 304:140-7. [PMID: 20377643 DOI: 10.1111/j.1574-6968.2009.01894.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Type IV pili are crucial for the virulence of Neisseria meningitidis. PilC proteins belong to the complex protein machinery required for pili biosynthesis. The expression of the pilC1 gene is known to be induced during host cell contact and to be tightly controlled through four promoters, two transcription factors and a two-component signal transduction system. By screening of an insertional-mutant library, we identified a novel regulatory protein, i.e. NMA1805, involved in the pilC1 complex regulation. Increased transcription of gene NMA1805 was shown to result in augmented expression of the pilC1 gene, whereas abrogated expression of gene NMA1805 was associated with an absence of pilC1 induction upon contact with host cells. Moreover, we demonstrated that the NMA1805 gene displayed two promoters. The NMA1805 regulatory protein was evidenced to interact with one of them.
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Affiliation(s)
- Anne Jamet
- Institut National de la Santé et de la Recherche Médicale, Paris, France.
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Jamet A, Rousseau C, Monfort JB, Nassif X, Martin P. Identification of a novel transcriptional regulator involved in pilC1regulation in Neisseria meningitidis. FEMS Microbiol Lett 2010. [DOI: 10.1111/j.1574-6968.2010.01894.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Camejo A, Buchrieser C, Couvé E, Carvalho F, Reis O, Ferreira P, Sousa S, Cossart P, Cabanes D. In vivo transcriptional profiling of Listeria monocytogenes and mutagenesis identify new virulence factors involved in infection. PLoS Pathog 2009; 5:e1000449. [PMID: 19478867 PMCID: PMC2679221 DOI: 10.1371/journal.ppat.1000449] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 04/27/2009] [Indexed: 11/18/2022] Open
Abstract
Listeria monocytogenes is a human intracellular pathogen able to colonize host tissues after ingestion of contaminated food, causing severe invasive infections. In order to gain a better understanding of the nature of host-pathogen interactions, we studied the L. monocytogenes genome expression during mouse infection. In the spleen of infected mice, approximately 20% of the Listeria genome is differentially expressed, essentially through gene activation, as compared to exponential growth in rich broth medium. Data presented here show that, during infection, Listeria is in an active multiplication phase, as revealed by the high expression of genes involved in replication, cell division and multiplication. In vivo bacterial growth requires increased expression of genes involved in adaptation of the bacterial metabolism and stress responses, in particular to oxidative stress. Listeria interaction with its host induces cell wall metabolism and surface expression of virulence factors. During infection, L. monocytogenes also activates subversion mechanisms of host defenses, including resistance to cationic peptides, peptidoglycan modifications and release of muramyl peptides. We show that the in vivo differential expression of the Listeria genome is coordinated by a complex regulatory network, with a central role for the PrfA-SigB interplay. In particular, L. monocytogenes up regulates in vivo the two major virulence regulators, PrfA and VirR, and their downstream effectors. Mutagenesis of in vivo induced genes allowed the identification of novel L. monocytogenes virulence factors, including an LPXTG surface protein, suggesting a role for S-layer glycoproteins and for cadmium efflux system in Listeria virulence.
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Affiliation(s)
- Ana Camejo
- IBMC - Instituto de Biologia Molecular e Celular, Group of Molecular Microbiology, Universidade do Porto, Porto, Portugal
| | - Carmen Buchrieser
- Institut Pasteur, UP Biologie des Bactéries Intracellulaires and CNRS URA 2171, Paris, France
| | - Elisabeth Couvé
- Institut Pasteur, Unité Génétique des Génomes Bactériens CNRS URA 2171, Paris, France
| | - Filipe Carvalho
- IBMC - Instituto de Biologia Molecular e Celular, Group of Molecular Microbiology, Universidade do Porto, Porto, Portugal
| | - Olga Reis
- IBMC - Instituto de Biologia Molecular e Celular, Group of Molecular Microbiology, Universidade do Porto, Porto, Portugal
| | - Pierre Ferreira
- IBMC - Instituto de Biologia Molecular e Celular, Group of Molecular Microbiology, Universidade do Porto, Porto, Portugal
| | - Sandra Sousa
- IBMC - Instituto de Biologia Molecular e Celular, Group of Molecular Microbiology, Universidade do Porto, Porto, Portugal
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Paris, France
- Inserm U604, Paris, France
- INRA USC2020, Paris, France
| | - Didier Cabanes
- IBMC - Instituto de Biologia Molecular e Celular, Group of Molecular Microbiology, Universidade do Porto, Porto, Portugal
- * E-mail:
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Murray EJ, Kiley TB, Stanley-Wall NR. A pivotal role for the response regulator DegU in controlling multicellular behaviour. MICROBIOLOGY-SGM 2009; 155:1-8. [PMID: 19118340 DOI: 10.1099/mic.0.023903-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacteria control multicellular behavioural responses, including biofilm formation and swarming motility, by integrating environmental cues through a complex regulatory network. Heterogeneous gene expression within an otherwise isogenic cell population that allows for differentiation of cell fate is an intriguing phenomenon that adds to the complexity of multicellular behaviour. This review focuses on recent data about how DegU, a pleiotropic response regulator, co-ordinates multicellular behaviour in Bacillus subtilis. We review studies that challenge the conventional understanding of the molecular mechanisms underpinning the DegU regulatory system and others that describe novel targets of DegU during activation of biofilm formation by B. subtilis. We also discuss a novel role for DegU in regulating multicellular processes in the food-borne pathogen Listeria monocytogenes.
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Affiliation(s)
- Ewan J Murray
- Division of Molecular and Environmental Microbiology, College of Life Sciences, MSI/WTB/JBC Complex, University of Dundee, Dundee DD1 5EH, UK
| | - Taryn B Kiley
- Division of Molecular and Environmental Microbiology, College of Life Sciences, MSI/WTB/JBC Complex, University of Dundee, Dundee DD1 5EH, UK
| | - Nicola R Stanley-Wall
- Division of Molecular and Environmental Microbiology, College of Life Sciences, MSI/WTB/JBC Complex, University of Dundee, Dundee DD1 5EH, UK
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50
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Gueriri I, Bay S, Dubrac S, Cyncynatus C, Msadek T. The Pta-AckA pathway controlling acetyl phosphate levels and the phosphorylation state of the DegU orphan response regulator both play a role in regulating Listeria monocytogenes motility and chemotaxis. Mol Microbiol 2008; 70:1342-57. [PMID: 19019159 DOI: 10.1111/j.1365-2958.2008.06496.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DegU is considered to be an orphan response regulator in Listeria monocytogenes since the gene encoding the cognate histidine kinase DegS is absent from the genome. We have previously shown that DegU is involved in motility, chemotaxis and biofilm formation and contributes to L. monocytogenes virulence. Here, we have investigated the role of DegU phosphorylation in Listeria and shown that DegS of Bacillus subtilis can phosphorylate DegU of L. monocytogenes in vitro. We introduced the B. subtilis degS gene into L. monocytogenes, and showed that this leads to highly increased expression of motility and chemotaxis genes, in a DegU-dependent fashion. We inactivated the predicted phosphorylation site of DegU by replacing aspartate residue 55 with asparagine and showed that this modified protein (DegU(D55N)) is no longer phosphorylated by DegS in vitro. We show that although the unphosphorylated form of DegU retains much of its activity in vivo, expression of motility and chemotaxis genes is lowered in the degU(D55N) mutant. We also show that the small-molecular-weight metabolite acetyl phosphate is an efficient phosphodonor for DegU in vitro and our evidence suggests this is also true in vivo. Indeed, a L. monocytogenesDeltaptaDeltaackA mutant that can no longer synthesize acetyl phosphate was found to be strongly affected in chemotaxis and motility gene expression and biofilm formation. Our findings suggest that phosphorylation by acetyl phosphate could play an important role in modulating DegU activity in vivo, linking its phosphorylation state to the metabolic status of L. monocytogenes.
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Affiliation(s)
- Ibtissem Gueriri
- Biology of Gram-Positive Pathogens, Department of Microbiology, CNRS URA 2172, Paris, France
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