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Migration Rates on Swim Plates Vary between Escherichia coli Soil Isolates: Differences Are Associated with Variants in Metabolic Genes. Appl Environ Microbiol 2023; 89:e0172722. [PMID: 36695629 PMCID: PMC9972950 DOI: 10.1128/aem.01727-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This study investigates migration phenotypes of 265 Escherichia coli soil isolates from the Buffalo River basin in Minnesota, USA. Migration rates on semisolid tryptone swim plates ranged from nonmotile to 190% of the migration rate of a highly motile E. coli K-12 strain. The nonmotile isolate, LGE0550, had mutations in flagellar and chemotaxis genes, including two IS3 elements in the flagellin-encoding gene fliC. A genome-wide association study (GWAS), associating the migration rates with genetic variants in specific genes, yielded two metabolic variants (rygD-serA and metR-metE) with previous implications in chemotaxis. As a novel way of confirming GWAS results, we used minimal medium swim plates to confirm the associations. Other variants in metabolic genes and genes that are associated with biofilm were positively or negatively associated with migration rates. A determination of growth phenotypes on Biolog EcoPlates yielded differential growth for the 10 tested isolates on d-malic acid, putrescine, and d-xylose, all of which are important in the soil environment. IMPORTANCE E. coli is a Gram-negative, facultative anaerobic bacterium whose life cycle includes extra host environments in addition to human, animal, and plant hosts. The bacterium has the genomic capability of being motile. In this context, the significance of this study is severalfold: (i) the great diversity of migration phenotypes that we observed within our isolate collection supports previous (G. NandaKafle, A. A. Christie, S. Vilain, and V. S. Brözel, Front Microbiol 9:762, 2018, https://doi.org/10.3389/fmicb.2018.00762; Y. Somorin, F. Abram, F. Brennan, and C. O'Byrne, Appl Environ Microbiol 82:4628-4640, 2016, https://doi.org/10.1128/AEM.01175-16) ideas of soil promoting phenotypic heterogeneity, (ii) such heterogeneity may facilitate bacterial growth in the many different soil niches, and (iii) such heterogeneity may enable the bacteria to interact with human, animal, and plant hosts.
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Gwisai T, Mirkhani N, Christiansen MG, Nguyen TT, Ling V, Schuerle S. Magnetic torque–driven living microrobots for increased tumor infiltration. Sci Robot 2022; 7:eabo0665. [DOI: 10.1126/scirobotics.abo0665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Biohybrid bacteria–based microrobots are increasingly recognized as promising externally controllable vehicles for targeted cancer therapy. Magnetic fields in particular have been used as a safe means to transfer energy and direct their motion. Thus far, the magnetic control strategies used in this context rely on poorly scalable magnetic field gradients, require active position feedback, or are ill-suited to diffuse distributions within the body. Here, we present a magnetic torque–driven control scheme for enhanced transport through biological barriers that complements the innate taxis toward tumor cores exhibited by a range of bacteria, shown for
Magnetospirillum magneticum
as a magnetically responsive model organism. This hybrid control strategy is readily scalable, independent of position feedback, and applicable to bacterial microrobots dispersed by the circulatory system. We observed a fourfold increase in translocation of magnetically responsive bacteria across a model of the vascular endothelium and found that the primary mechanism driving increased transport is torque-driven surface exploration at the cell interface. Using spheroids as a three-dimensional tumor model, fluorescently labeled bacteria colonized their core regions with up to 21-fold higher signal in samples exposed to rotating magnetic fields. In addition to enhanced transport, we demonstrated that our control scheme offers further advantages, including the possibility for closed-loop optimization based on inductive detection, as well as spatially selective actuation to reduce off-target effects. Last, after systemic intravenous injection in mice, we showed significantly increased bacterial tumor accumulation, supporting the feasibility of deploying this control scheme clinically for magnetically responsive biohybrid microrobots.
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Affiliation(s)
- T. Gwisai
- Department of Health Sciences and Technology, Institute for Translational Medicine, ETH Zürich, 8092 Zürich, Switzerland
| | - N. Mirkhani
- Department of Health Sciences and Technology, Institute for Translational Medicine, ETH Zürich, 8092 Zürich, Switzerland
| | - M. G. Christiansen
- Department of Health Sciences and Technology, Institute for Translational Medicine, ETH Zürich, 8092 Zürich, Switzerland
| | - T. T. Nguyen
- Department of Health Sciences and Technology, Institute for Translational Medicine, ETH Zürich, 8092 Zürich, Switzerland
| | - V. Ling
- Takeda Pharmaceuticals, 40 Landsdowne St., Cambridge, MA 02139, USA
| | - S. Schuerle
- Department of Health Sciences and Technology, Institute for Translational Medicine, ETH Zürich, 8092 Zürich, Switzerland
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High-throughput identification of genes influencing the competitive ability to obtain nutrients and performance of biocontrol in Pseudomonas putida JBC17. Sci Rep 2022; 12:872. [PMID: 35042886 PMCID: PMC8766522 DOI: 10.1038/s41598-022-04858-z] [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: 05/28/2021] [Accepted: 10/11/2021] [Indexed: 11/22/2022] Open
Abstract
Elucidating underlying mechanisms of biocontrol agents (BCAs) could aid in selecting potent BCAs and increasing their biocontrol efficacy. Nutrient competition is an important biocontrol mechanism; however, essential nutrient sources, and contributing genes for nutrient competition still remain to be explored. Pseudomonas putida JBC17 (JBC17WT) suppressed green mold in satsuma mandarins by inhibiting conidial germination of Penicillium digitatum via nutrient competition. To analyze genes essential for biocontrol performance of JBC17WT, we generated a transposon (Tn)-mediated mutant library and selected mutants with the ability to suppress conidial germination. Several mutants in the genes of flagella-formation, including fliR, fliH, and flgG, increased biocontrol performance and enhanced inhibition of conidial germination. They lost swimming motility, exhibited increased growth and rapid carbon and nitrogen utilization than the wild type under nutrient-poor conditions. The nutrient competition assay using polytetrafluoroethylene cylinders revealed that conidial germination was inhibited by nutrient absorption under nutrient-poor conditions. In addition, genes, including amidohydrolase (ytcJ), tonB-dependent receptor (cirA), argininosuccinate synthase (argG), D-3-phosphoglycerate dehydrogenase (serA), and chaperone protein (dnaJ), were involved in the inhibition of conidial germination. The results of this study indicate that rapid and continuous absorption of nutrients by JBC17WT restrict nutrient availability for conidial germination on nutrient-limited fruit surfaces, thereby decreasing the chances of fungal spores infecting fruits. The high-throughput analysis of Tn mutants of this study highlighted the importance of nutrient competition and the genes that influence biocontrol ability, which contributes to the development of biocontrol applications.
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Opperman CJ, Moodley C, Lennard K, Smith M, Ncayiyana J, Vulindlu M, Gafoor M, Govender N, Ismail H, Bamford C, McCarthy KM, Nicol MP, Centner CM. A citywide, clonal outbreak of Pseudomonas aeruginosa. Int J Infect Dis 2022; 117:74-86. [DOI: 10.1016/j.ijid.2022.01.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/15/2022] [Accepted: 01/17/2022] [Indexed: 10/19/2022] Open
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A D-2-hydroxyglutarate biosensor based on specific transcriptional regulator DhdR. Nat Commun 2021; 12:7108. [PMID: 34876568 PMCID: PMC8651671 DOI: 10.1038/s41467-021-27357-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 11/16/2021] [Indexed: 12/02/2022] Open
Abstract
D-2-Hydroxyglutarate (D-2-HG) is a metabolite involved in many physiological metabolic processes. When D-2-HG is aberrantly accumulated due to mutations in isocitrate dehydrogenase or D-2-HG dehydrogenase, it functions in a pro-oncogenic manner and is thus considered a therapeutic target and biomarker in many cancers. In this study, DhdR from Achromobacter denitrificans NBRC 15125 is identified as an allosteric transcriptional factor that negatively regulates D-2-HG dehydrogenase expression and responds to the presence of D-2-HG. Based on the allosteric effect of DhdR, a D-2-HG biosensor is developed by combining DhdR with amplified luminescent proximity homogeneous assay (AlphaScreen) technology. The biosensor is able to detect D-2-HG in serum, urine, and cell culture medium with high specificity and sensitivity. Additionally, this biosensor is used to identify the role of D-2-HG metabolism in lipopolysaccharide biosynthesis of Pseudomonas aeruginosa, demonstrating its broad usages.
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Tang C, Li W, Klosterman SJ, Wang Y. Transcriptome Variations in Verticillium dahliae in Response to Two Different Inorganic Nitrogen Sources. Front Microbiol 2021; 12:712701. [PMID: 34394062 PMCID: PMC8355529 DOI: 10.3389/fmicb.2021.712701] [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: 05/21/2021] [Accepted: 07/01/2021] [Indexed: 11/16/2022] Open
Abstract
The fungus Verticillium dahliae causes vascular wilt disease on hundreds of plant species. The main focus of the research to control this fungus has been aimed at infection processes such as penetration peg formation and effector secretion, but the ability of the fungus to acquire and utilize nutrients are often overlooked and may hold additional potential to formulate new disease control approaches. Little is known about the molecular mechanisms of nitrogen acquisition and assimilation processes in V. dahliae. In this present study, RNA sequencing and gene expression analysis were used to examine differentially expressed genes in response to the different nitrogen sources, nitrate and ammonium, in V. dahliae. A total of 3244 and 2528 differentially expressed genes were identified in response to nitrate and ammonium treatments, respectively. The data indicated nitrate metabolism requires additional energy input while ammonium metabolism is accompanied by reductions in particular cellular processes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses of DEGs during nitrate metabolism revealed that many of the genes encoded those involved in protein biosynthetic and metabolic processes, especially ribosome and RNA polymerase biosynthesis, but also other processes including transport and organonitrogen compound metabolism. Analysis of DEGs in the ammonium treatment indicated that cell cycle, oxidoreductase, and certain metabolic activities were reduced. In addition, DEGs participating in the utilization of both nitrate and ammonium were related to L-serine biosynthesis, energy-dependent multidrug efflux pump activity, and glycerol transport. We further showed that the mutants of three differentially expressed transcription factors (VdMcm1, VdHapX, and VDAG_08640) exhibited abnormal phenotypes under nitrate and ammonium treatment compared with the wild type strain. Deletion of VdMcm1 displayed slower growth when utilizing both nitrogen sources, while deletion of VdHapX and VDAG_08640 only affected nitrate metabolism, inferring that nitrogen assimilation required regulation of bZIP transcription factor family and participation of cell cycle. Taken together, our findings illustrate the convergent and distinctive regulatory mechanisms between preferred (ammonium) and alternative nitrogen (nitrate) metabolism at the transcriptome level, leading to better understanding of inorganic nitrogen metabolism in V. dahliae.
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Affiliation(s)
- Chen Tang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Wenwen Li
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Steven J Klosterman
- Agricultural Research Service, United States Department of Agriculture, Salinas, CA, United States
| | - Yonglin Wang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
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Ismail NS, Subbiah SK, Taib NM. Application of Phenotype Microarray for Profiling Carbon Sources Utilization between Biofilm and Non-Biofilm of Pseudomonas aeruginosa from Clinical Isolates. Curr Pharm Biotechnol 2020; 21:1539-1550. [PMID: 32598252 DOI: 10.2174/1389201021666200629145217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/17/2020] [Accepted: 05/04/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND This is the fastest work in obtaining the metabolic profiles of Pseudomonas aeruginosa in order to combat the infection diseases which leads to high morbidity and mortality rates. Pseudomonas aeruginosa is a high versatility of gram-negative bacteria that can undergo aerobic and anaerobic respiration. Capabilities in deploying different carbon sources, energy metabolism and regulatory system, ensure the survival of this microorganism in the diverse environment condition. Determination of differences in carbon sources utilization among biofilm and non-biofilm of Pseudomonas aeruginosa provides a platform in understanding the metabolic activity of the microorganism. METHODS The study was carried out from September 2017 to February 2019. Four archive isolates forming strong and intermediate biofilm and non-biofilms producer were subcultured from archive isolates. ATCC 27853 P. aeruginosa was used as a negative control or non-biofilm producing microorganism. Biofilm formation was confirmed by Crystal Violet Assay (CVA) and Congo Red Agar (CRA). Metabolic profiles of the biofilm and non-biofilms isolates were determined by phenotype microarrays (Biolog Omnilog). RESULTS AND DISCUSSION In this study, Pseudomonas aeruginosa biofilm isolates utilized uridine, L-threonine and L-serine while non-biofilm utilized adenosine, inosine, monomethyl, sorbic acid and succinamic acid. CONCLUSION The outcome of this result will be used for future studies to improve detection or inhibit the growth of P. aeruginosa biofilm and non-biofilm respectively.
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Affiliation(s)
- Nur S Ismail
- Department of Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Suresh K Subbiah
- Department of Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Niazlin M Taib
- Department of Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
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Affiliation(s)
- Daniel Hollander
- Division of Digestive Diseases, Department of Medicine, UCLA School of Medicine, Los Angeles, CA 90024, USA
| | - Jonathan D. Kaunitz
- Division of Digestive Diseases, Department of Medicine, UCLA School of Medicine, Los Angeles, CA 90024, USA,Department of Surgery, UCLA School of Medicine, Los Angeles, CA 90024, USA,Gastroenterology Section, Medical Service, West Los Angeles VAMC, Los Angeles, CA 90073, USA
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9
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Kriner MA, Subramaniam AR. The serine transporter SdaC prevents cell lysis upon glucose depletion in Escherichia coli. Microbiologyopen 2019; 9:e960. [PMID: 31680488 PMCID: PMC7002108 DOI: 10.1002/mbo3.960] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/25/2019] [Accepted: 10/09/2019] [Indexed: 11/10/2022] Open
Abstract
The amino acid serine plays diverse metabolic roles, yet bacteria actively degrade exogenously provided serine via deamination to pyruvate. Serine deamination is thought to be a detoxification mechanism due to the ability of serine to inhibit several biosynthetic reactions, but this pathway remains highly active even in nutrient-replete conditions. While investigating the physiological roles of serine deamination in different growth conditions, we discovered that Escherichia coli cells lacking the sdaCB operon, which encodes the serine transporter SdaC and the serine deaminase SdaB, lyse upon glucose depletion in a medium containing no exogenous serine but all other amino acids and nucleobases. Unexpectedly, this lysis phenotype can be recapitulated by deleting sdaC alone and can be rescued by heterologous expression of SdaC. Lysis of ΔsdaC cells can be prevented by omitting glycine from the medium, inhibiting the glycine cleavage system, or by increasing alanine availability. Together, our results reveal that the serine transporter SdaC plays a critical role in maintaining amino acid homeostasis during shifts in nutrient availability in E. coli.
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Affiliation(s)
- Michelle A Kriner
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Arvind R Subramaniam
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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Sakata N, Ishiga T, Saito H, Nguyen VT, Ishiga Y. Transposon mutagenesis reveals Pseudomonas cannabina pv. alisalensis optimizes its virulence factors for pathogenicity on different hosts. PeerJ 2019; 7:e7698. [PMID: 31579596 PMCID: PMC6756136 DOI: 10.7717/peerj.7698] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 08/19/2019] [Indexed: 11/30/2022] Open
Abstract
Pseudomonas cannabina pv. alisalensis (Pcal), which causes bacterial blight disease of Brassicaceae, is an economically important pathogen worldwide. To identify Pcal genes involved in pathogenesis, we conducted a screen for 1,040 individual Pcal KB211 Tn5 mutants with reduced virulence on cabbage plants using a dip-inoculation method. We isolated 53 reduced virulence mutants and identified several potential virulence factors involved in Pcal virulence mechanisms such as the type III secretion system, membrane transporters, transcription factors, and amino acid metabolism. Importantly, Pcal is pathogenic on a range of monocotyledonous and dicotyledonous plants. Therefore, we also carried out the inoculation test on oat plants, which are cultivated after cabbage cultivation as green manure crops. Interestingly among the 53 mutants, 31 mutants also exhibited reduced virulence on oat seedlings, indicating that Pcal optimizes its virulence factors for pathogenicity on different host plants. Our results highlight the importance of revealing the virulence factors for each plant host-bacterial interaction, and will provide new insights into Pcal virulence mechanisms.
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Affiliation(s)
- Nanami Sakata
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takako Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Haruka Saito
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Viet Tru Nguyen
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yasuhiro Ishiga
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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Okuda J, Nagata S, Yasuda M, Suezawa C. Validating the inhibitory effects of d- and l-serine on the enzyme activity of d-3-phosphoglycerate dehydrogenases that are purified from Pseudomonas aeruginosa, Escherichia coli and human colon. Gut Pathog 2019; 11:35. [PMID: 31303896 PMCID: PMC6600881 DOI: 10.1186/s13099-019-0315-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/21/2019] [Indexed: 11/10/2022] Open
Abstract
Background We previously demonstrated that the serA gene is associated with bacterial pathogenicity, including bacterial penetration through the Caco-2 cell monolayers, bacterial motility, bacterial adherence, and fly mortality. l-Serine is known to inhibit the d-3-phosphoglycerate dehydrogenase (PGDH) activity of the SerA protein, and it significantly reduced the bacterial pathogenicity as described above. We also demonstrated that in a PGDH assay using crude extracts isolated from overnight cultures of E. coli overexpressing the P. aeruginosa serA gene, l-serine inhibited the PGDH activity of the SerA protein. The basal PGDH activity of the negative control strain was high, presumably due to contamination of unknown proteins in the crude extracts. Therefore, to further confirm the direct inhibition of PGDH activity of P. aeruginosa SerA by l-serine, we purified and characterized the PGDH from P. aeruginosa and compared it with the previously characterized PGDHs from E. coli, and the human colon as controls. Results Optimum pH and ionic strength of the purified PGDHs were different depending on the three species; optimal activity of P. aeruginosa PGDH was at pH 7.5 with 50-100 mM Tris-HCl, E. coli PGDH was at pH 8.5 with 100-200 mM Tris-HCl, and human PGDH was at pH 9.0 with 100-200 mM Tris-HCl. The addition of l-serine reduced the activity of PGDH from P. aeruginosa and E. coli, but not the PGDH from human colon. The median inhibitory concentration (IC50) of l-serine was 630 μM for P. aeruginosa and 250 μM for E. coli, while IC50 of d-serine was much higher than that of l-serine; 76 mM in P. aeruginosa PGDH and 45 mM in E. coli PGDH. Conclusions These results suggest that l-serine significantly repressed P. aeruginosa pathogenicity through direct inhibition of the PGDH activity, but was not able to inhibit the human PGDH activity. Oral administration of l-serine to compromised hosts might interfere with bacterial translocation and prevent gut-derived sepsis caused by P. aeruginosa through inhibition of the function of the serA gene product.
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Affiliation(s)
- Jun Okuda
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Syouya Nagata
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Masashi Yasuda
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Chigusa Suezawa
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
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12
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Fitting Pieces into the Puzzle of Pseudomonas aeruginosa Type III Secretion System Gene Expression. J Bacteriol 2019; 201:JB.00209-19. [PMID: 31010903 DOI: 10.1128/jb.00209-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Type III secretion systems (T3SS) are widely distributed in Gram-negative microorganisms and critical for host-pathogen and host-symbiont interactions with plants and animals. Central features of the T3SS are a highly conserved set of secretion and translocation genes and contact dependence wherein host-pathogen interactions trigger effector protein delivery and serve as an inducing signal for T3SS gene expression. In addition to these conserved features, there are pathogen-specific properties that include a unique repertoire of effector genes and mechanisms to control T3SS gene expression. The Pseudomonas aeruginosa T3SS serves as a model system to understand transcriptional and posttranscriptional mechanisms involved in the control of T3SS gene expression. The central regulatory feature is a partner-switching system that controls the DNA-binding activity of ExsA, the primary regulator of T3SS gene expression. Superimposed upon the partner-switching mechanism are cyclic AMP and cyclic di-GMP signaling systems, two-component systems, global regulators, and RNA-binding proteins that have positive and negative effects on ExsA transcription and/or synthesis. In the present review, we discuss advances in our understanding of how these regulatory systems orchestrate the activation of T3SS gene expression in the context of acute infections and repression of the T3SS as P. aeruginosa adapts to and colonizes the cystic fibrosis airways.
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Wei K, Yin H, Peng H, Lu G, Dang Z. Bioremediation of triphenyl phosphate in river water microcosms: Proteome alteration of Brevibacillus brevis and cytotoxicity assessments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 649:563-570. [PMID: 30176467 DOI: 10.1016/j.scitotenv.2018.08.342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/24/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
Triphenyl phosphate (TPHP), an organophosphate flame retardant, was detected in river water samples collected from an electronic waste recycling area in Guiyu, Southern China. The concentrations of TPHP ranged from not detected to 347.2 ng/L, with an average of 138.8 ng/L. The bioaugmentation potential of Brevibacillus brevis on TPHP biodegradation by aerobic microcosms contained in river water from Guiyu was assessed. The results showed that TPHP degradation efficiency was significantly improved to 97.9% by bioaugmentation with B. brevis after 96 h incubation. A total of 182 significantly changed proteins in B. brevis were identified and quantified by isobaric tags for relative and absolute quantification (iTRAQ) in response to TPHP stress. The differentially expressed proteins were mainly associated with energy metabolism, lipid metabolism, cell wall biosynthesis, amino acid transport, and metabolism. The identification that proteins of B. brevis respond to TPHP existence provides novel insights into biodegradation mechanisms of bacteria under environmental stress. Additionally, cytotoxicity assays indicated that the degrading intermediates of TPHP, namely diphenyl phosphate and phenyl phosphate, were less cytotoxic to human HepG2 cells compared with TPHP. Collectively, these findings suggest that aerobic bioaugmentation with degrading microorganisms is a potential strategy for in situ treatment of TPHP-contaminated sites.
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Affiliation(s)
- Kun Wei
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem, Restoration in Industry Clusters, Guangdong Provincial Engineering and Technology, Research Center for Environxmental Risk Prevention and Emergency Disposal, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, PR China
| | - Hua Yin
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem, Restoration in Industry Clusters, Guangdong Provincial Engineering and Technology, Research Center for Environxmental Risk Prevention and Emergency Disposal, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, PR China.
| | - Hui Peng
- Department of Chemistry, Jinan University, Guangzhou 510632, Guangdong, PR China
| | - Guining Lu
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem, Restoration in Industry Clusters, Guangdong Provincial Engineering and Technology, Research Center for Environxmental Risk Prevention and Emergency Disposal, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, PR China
| | - Zhi Dang
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem, Restoration in Industry Clusters, Guangdong Provincial Engineering and Technology, Research Center for Environxmental Risk Prevention and Emergency Disposal, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, PR China
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14
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Transcriptomic Profiling of Human Placental Trophoblasts in Response to Infection with Enterococcus faecalis. J FOOD QUALITY 2018. [DOI: 10.1155/2018/5607641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Increasing evidence suggests that Enterococcus faecalis strains can pass through placental barriers and cause adverse outcomes during pregnancy. However, the underlying molecular mechanism of the interaction between E. faecalis and the host placental barrier has yet to be fully elucidated. In this study, we have used DNA microarray analysis to investigate the response of human placental trophoblast-like BeWo cells to infection with E. faecalis OG1RF. These results indicate that a total of 2191 genes in BeWo cells are differentially expressed in the presence of E. faecalis OG1RF, with 1357 genes being upregulated and 834 genes being downregulated. These differentially expressed genes (DEGs) are involved in apoptosis, stress and stimulus response, placental and embryonic development, immune response, and cell adhesion. Therefore, these results provide information on the molecular mechanisms that E. faecalis invasion can trigger to cause adverse pregnancy outcomes.
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Okuda J, Yamane S, Nagata S, Kunikata C, Suezawa C, Yasuda M. The Pseudomonas aeruginosa dnaK gene is involved in bacterial translocation across the intestinal epithelial cell barrier. MICROBIOLOGY-SGM 2017; 163:1208-1216. [PMID: 28758636 DOI: 10.1099/mic.0.000508] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pseudomonas aeruginosa can penetrate through polarized epithelial cell monolayers produced by the human adenocarcinoma cell line Caco-2. We previously identified genes associated with bacterial translocation through Caco-2 cell monolayers by analysing transposon insertion mutants with dramatically reduced penetration activity relative to that of the wild-type P. aeruginosa PAO1 strain. In this study, we focused on the dnaK mutant because the association between this gene and penetration activity is unknown. Inactivation of dnaK caused significant repression of bacterial penetration through Caco-2 cell monolayers, with decreased swimming, swarming and twitching motilities; bacterial adherence; and fly mortality rate; as well as dramatic repression of type III effector secretion and production of elastase and exotoxin A. However, type IV pilus protein PilA expression was not affected. These results suggest that dnaK is associated with bacterial motility and adherence, which are mediated by flagella and pili, and with toxin secretion, which plays a key role in the penetration of P. aeruginosa through Caco-2 cell monolayers. Inactivation of P. aeruginosa dnaK function may interfere with bacterial translocation and prevent septicaemia caused by P. aeruginosa.
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Affiliation(s)
- Jun Okuda
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Satoshi Yamane
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Syouya Nagata
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Chinami Kunikata
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Chigusa Suezawa
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
| | - Masashi Yasuda
- Division of Microbiology, Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan
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