201
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Fagerlund A, Smith V, Røhr ÅK, Lindbäck T, Parmer MP, Andersson KK, Reubsaet L, Økstad OA. Cyclic diguanylate regulation of Bacillus cereus group biofilm formation. Mol Microbiol 2016; 101:471-94. [PMID: 27116468 DOI: 10.1111/mmi.13405] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2016] [Indexed: 12/30/2022]
Abstract
Biofilm formation can be considered a bacterial virulence mechanism. In a range of Gram-negatives, increased levels of the second messenger cyclic diguanylate (c-di-GMP) promotes biofilm formation and reduces motility. Other bacterial processes known to be regulated by c-di-GMP include cell division, differentiation and virulence. Among Gram-positive bacteria, where the function of c-di-GMP signalling is less well characterized, c-di-GMP was reported to regulate swarming motility in Bacillus subtilis while having very limited or no effect on biofilm formation. In contrast, we show that in the Bacillus cereus group c-di-GMP signalling is linked to biofilm formation, and to several other phenotypes important to the lifestyle of these bacteria. The Bacillus thuringiensis 407 genome encodes eleven predicted proteins containing domains (GGDEF/EAL) related to c-di-GMP synthesis or breakdown, ten of which are conserved through the majority of clades of the B. cereus group, including Bacillus anthracis. Several of the genes were shown to affect biofilm formation, motility, enterotoxin synthesis and/or sporulation. Among these, cdgF appeared to encode a master diguanylate cyclase essential for biofilm formation in an oxygenated environment. Only two cdg genes (cdgA, cdgJ) had orthologs in B. subtilis, highlighting differences in c-di-GMP signalling between B. subtilis and B. cereus group bacteria.
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Affiliation(s)
- Annette Fagerlund
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PB1068, Oslo, 0316, Norway
| | - Veronika Smith
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PB1068, Oslo, 0316, Norway.,Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, 0316, Norway
| | - Åsmund K Røhr
- Department of Biosciences, University of Oslo, PB1066, Oslo, 0316, Norway
| | - Toril Lindbäck
- Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, PB8146 Dep, Oslo, 0033, Norway
| | - Marthe P Parmer
- Bioanalytics, Section for Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, PB1068, Oslo, 0316, Norway
| | | | - Leon Reubsaet
- Bioanalytics, Section for Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, PB1068, Oslo, 0316, Norway
| | - Ole Andreas Økstad
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PB1068, Oslo, 0316, Norway.,Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, 0316, Norway
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202
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Lan Y, Rosen G, Hershberg R. Marker genes that are less conserved in their sequences are useful for predicting genome-wide similarity levels between closely related prokaryotic strains. MICROBIOME 2016; 4:18. [PMID: 27138046 PMCID: PMC4853863 DOI: 10.1186/s40168-016-0162-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 03/22/2016] [Indexed: 05/27/2023]
Abstract
BACKGROUND The 16s rRNA gene is so far the most widely used marker for taxonomical classification and separation of prokaryotes. Since it is universally conserved among prokaryotes, it is possible to use this gene to classify a broad range of prokaryotic organisms. At the same time, it has often been noted that the 16s rRNA gene is too conserved to separate between prokaryotes at finer taxonomic levels. RESULTS In this paper, we examine how well levels of similarity of 16s rRNA and 73 additional universal or nearly universal marker genes correlate with genome-wide levels of gene sequence similarity. We demonstrate that the percent identity of 16s rRNA predicts genome-wide levels of similarity very well for distantly related prokaryotes, but not for closely related ones. In closely related prokaryotes, we find that there are many other marker genes for which levels of similarity are much more predictive of genome-wide levels of gene sequence similarity. Finally, we show that the identities of the markers that are most useful for predicting genome-wide levels of similarity within closely related prokaryotic lineages vary greatly between lineages. However, the most useful markers are always those that are least conserved in their sequences within each lineage. CONCLUSIONS Our results show that by choosing markers that are less conserved in their sequences within a lineage of interest, it is possible to better predict genome-wide gene sequence similarity between closely related prokaryotes than is possible using the 16s rRNA gene. We point readers towards a database we have created (POGO-DB) that can be used to easily establish which markers show lowest levels of sequence conservation within different prokaryotic lineages.
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Affiliation(s)
- Yemin Lan
- />School of Biomedical Engineering, Science and Health Systems, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 USA
| | - Gail Rosen
- />Ecological and Evolutionary Signal-processing and Informatics Laboratory, Electrical & Computer Engineering Department, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 USA
| | - Ruth Hershberg
- />Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 31096 Haifa, Israel
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203
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Transcriptome analysis of Bacillus thuringiensis spore life, germination and cell outgrowth in a vegetable-based food model. Food Microbiol 2016; 55:73-85. [DOI: 10.1016/j.fm.2015.11.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 11/03/2015] [Accepted: 11/10/2015] [Indexed: 11/19/2022]
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204
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Verplaetse E, Slamti L, Gohar M, Lereclus D. Two distinct pathways lead Bacillus thuringiensis to commit to sporulation in biofilm. Res Microbiol 2016; 168:388-393. [PMID: 27106256 DOI: 10.1016/j.resmic.2016.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/21/2016] [Accepted: 03/30/2016] [Indexed: 10/21/2022]
Abstract
The spore-forming bacterium Bacillus thuringiensis is an efficient biofilm producer, responsible for persistent contamination of industrial food processing systems. B. thuringiensis biofilms are highly heterogeneous bacterial structures in which three distinct cell types controlled by quorum sensing regulators were identified: PlcR-controlled virulent cells, NprR-dependent necrotrophic cells and cells committed to sporulation, a differentiation process controlled by Rap phosphatases and Spo0A-P. Interestingly, a cell lineage study revealed that, in LB medium or in insect larvae, only necrotrophic cells became spores. Here we analyzed cellular differentiation undertaken by cells growing in biofilm in a medium optimized for sporulation. No virulent cells were identified; surprisingly, two distinct routes could lead to differentiation as a spore in this growth condition: the NprR-dependent route, followed by the majority of cells, and the newly identified NprR-independent route, which is followed by 20% of sporulating cells.
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Affiliation(s)
- Emilie Verplaetse
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
| | - Leyla Slamti
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
| | - Michel Gohar
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
| | - Didier Lereclus
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France.
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205
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Deng Y, Wu J, Yin W, Li P, Zhou J, Chen S, He F, Cai J, Zhang LH. Diffusible signal factor family signals provide a fitness advantage to Xanthomonas campestris pv. campestris in interspecies competition. Environ Microbiol 2016; 18:1534-45. [PMID: 26913592 DOI: 10.1111/1462-2920.13244] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 01/22/2016] [Indexed: 11/29/2022]
Abstract
Diffusible signal factor (DSF) represents a new class of widely conserved quorum sensing signals, which regulates various biological functions through intra- or interspecies signaling. The previous studies identified that there is an antagonistic interaction between Xanthomonas and Bacillus species bacteria in natural ecosystem, but the detailed molecular mechanism of interspecies competition is not clear. This study showed that Xanthomonas campestris pv. campestris (Xcc) interfered with morphological transition and sporulation of Bacillus thuringiensis in mixed cultures, whereas abrogation of the DSF synthase RpfF reduced the interference. DSF inhibited B. thuringiensis cell division and sporulation through modulation of ftsZ, which encodes an important cell division protein in bacterial cells. In addition, RpfF is essential for production of six DSF-family signals in Xcc, which employ the same signaling pathways to regulate biological functions in Xcc and play similar effects on reduction of cell division, sporulation and antibiotic resistance of B. thuringiensis. Furthermore, abrogation of RpfF decreased the competitive capability of Xcc against B. thuringiensis on the surface of Chinese cabbage leaves. Our findings provide new insights into the role of DSF-family signals in interspecies competition and depict molecular mechanisms with which Xcc competes with B. thuringiensis.
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Affiliation(s)
- Yinyue Deng
- Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, 510642, China.,Institute of Molecular and Cell Biology, Proteos, 61 Biopolis Drive, Singapore, 138673, Singapore
| | - Jien Wu
- Institute of Molecular and Cell Biology, Proteos, 61 Biopolis Drive, Singapore, 138673, Singapore
| | - Wenfang Yin
- Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, 510642, China
| | - Peng Li
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China
| | - Jianuan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China
| | - Shaohua Chen
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China
| | - Fei He
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China
| | - Jun Cai
- Department of Microbiology, Nankai University, Tianjin, 300071, China
| | - Lian-Hui Zhang
- Institute of Molecular and Cell Biology, Proteos, 61 Biopolis Drive, Singapore, 138673, Singapore.,Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China
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206
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Abstract
Members of the family Bacillaceae are among the most robust bacteria on Earth, which is mainly due to their ability to form resistant endospores. This trait is believed to be the key factor determining the ecology of these bacteria. However, they also perform fundamental roles in soil ecology (i.e., the cycling of organic matter) and in plant health and growth stimulation (e.g., via suppression of plant pathogens and phosphate solubilization). In this review, we describe the high functional and genetic diversity that is found within the Bacillaceae (a family of low-G+C% Gram-positive spore-forming bacteria), their roles in ecology and in applied sciences related to agriculture. We then pose questions with respect to their ecological behavior, zooming in on the intricate social behavior that is becoming increasingly well characterized for some members of Bacillaceae. Such social behavior, which includes cell-to-cell signaling via quorum sensing or other mechanisms (e.g., the production of extracellular hydrolytic enzymes, toxins, antibiotics and/or surfactants) is a key determinant of their lifestyle and is also believed to drive diversification processes. It is only with a deeper understanding of cell-to-cell interactions that we will be able to understand the ecological and diversification processes of natural populations within the family Bacillaceae. Ultimately, the resulting improvements in understanding will benefit practical efforts to apply representatives of these bacteria in promoting plant growth as well as biological control of plant pathogens.
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207
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Ultrasensitive electrochemical immunoassay for surface array protein, a Bacillus anthracis biomarker using Au-Pd nanocrystals loaded on boron-nitride nanosheets as catalytic labels. Biosens Bioelectron 2016; 80:442-449. [PMID: 26874112 DOI: 10.1016/j.bios.2016.02.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 02/02/2016] [Accepted: 02/04/2016] [Indexed: 12/31/2022]
Abstract
Bacillus anthracis, the causative agent of anthrax, is a well known bioterrorism agent. The determination of surface array protein (Sap), a unique biomarker for B. anthracis can offer an opportunity for specific detection of B. anthracis in culture broth. In this study, we designed a new catalytic bionanolabel and fabricated a novel electrochemical immunosensor for ultrasensitive detection of B. anthracis Sap antigen. Bimetallic gold-palladium nanoparticles were in-situ grown on poly (diallyldimethylammonium chloride) functionalized boron nitride nanosheets (Au-Pd NPs@BNNSs) and conjugated with the mouse anti-B. anthracis Sap antibodies (Ab2); named Au-Pd NPs@BNNSs/Ab2. The resulting Au-Pd NPs@BNNSs/Ab2 bionanolabel demonstrated high catalytic activity towards reduction of 4-nitrophenol. The sensitivity of the electrochemical immunosensor along with redox cycling of 4-aminophenol to 4-quinoneimine was improved to a great extent. Under optimal conditions, the proposed immunosensor exhibited a wide working range from 5 pg/mL to 100 ng/mL with a minimum detection limit of 1 pg/mL B. anthracis Sap antigen. The practical applicability of the immunosensor was demonstrated by specific detection of Sap secreted by the B. anthracis in culture broth just after 1h of growth. These labels open a new direction for the ultrasensitive detection of different biological warfare agents and their markers in different matrices.
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208
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Kilcullen K, Teunis A, Popova TG, Popov SG. Cytotoxic Potential of Bacillus cereus Strains ATCC 11778 and 14579 Against Human Lung Epithelial Cells Under Microaerobic Growth Conditions. Front Microbiol 2016; 7:69. [PMID: 26870026 PMCID: PMC4735842 DOI: 10.3389/fmicb.2016.00069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/14/2016] [Indexed: 12/28/2022] Open
Abstract
Bacillus cereus, a food poisoning bacterium closely related to Bacillus anthracis, secretes a multitude of virulence factors including enterotoxins, hemolysins, and phospholipases. However, the majority of the in vitro experiments evaluating the cytotoxic potential of B. cereus were carried out in the conditions of aeration, and the impact of the oxygen limitation in conditions encountered by the microbe in natural environment such as gastrointestinal tract remains poorly understood. This research reports comparative analysis of ATCC strains 11778 (BC1) and 14579 (BC2) in aerobic and microaerobic (static) cultures with regard to their toxicity for human lung epithelial cells. We showed that BC1 increased its toxicity upon oxygen limitation while BC2 was highly cytotoxic in both growth conditions. The combined effect of the pore-forming, cholesterol-dependent hemolysin, cereolysin O (CLO), and metabolic product(s) such as succinate produced in microaerobic conditions provided substantial contribution to the toxicity of BC1 but not BC2 which relied mainly on other toxins. This mechanism is shared between CB1 and B. anthracis. It involves the permeabilization of the cell membrane which facilitates transport of toxic bacterial metabolites into the cell. The toxicity of BC1 was potentiated in the presence of bovine serum albumin which appeared to serve as reservoir for bacteria-derived nitric oxide participating in the downstream production of reactive oxidizing species with the properties of peroxynitrite. In agreement with this the BC1 cultures demonstrated the increased oxidation of the indicator dye Amplex Red catalyzed by peroxidase as well as the increased toxicity in the presence of externally added ascorbic acid.
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Affiliation(s)
| | - Allison Teunis
- School of Systems Biology, George Mason University Manassas, VA, USA
| | - Taissia G Popova
- School of Systems Biology, George Mason University Manassas, VA, USA
| | - Serguei G Popov
- School of Systems Biology, George Mason University Manassas, VA, USA
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209
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A novel pentaplex real time (RT)- PCR high resolution melt curve assay for simultaneous detection of emetic and enterotoxin producing Bacillus cereus in food. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.08.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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210
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Genomic characterization and comparison of seven Myoviridae bacteriophage infecting Bacillus thuringiensis. Virology 2016; 489:243-51. [DOI: 10.1016/j.virol.2015.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 08/02/2015] [Accepted: 12/22/2015] [Indexed: 11/18/2022]
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211
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Abstract
ABSTRACT
The three main species of the
Bacillus cereus sensu lato
,
B. cereus
,
B. thuringiensis
, and
B. anthracis
, were recognized and established by the early 1900s because they each exhibited distinct phenotypic traits.
B. thuringiensis
isolates and their parasporal crystal proteins have long been established as a natural pesticide and insect pathogen.
B. anthracis
, the etiological agent for anthrax, was used by Robert Koch in the 19th century as a model to develop the germ theory of disease, and
B. cereus
, a common soil organism, is also an occasional opportunistic pathogen of humans. In addition to these three historical species designations, are three less-recognized and -understood species:
B. mycoides
,
B. weihenstephanensis
, and
B. pseudomycoides
. All of these “species” combined comprise the
Bacillus cereus sensu lato
group. Despite these apparently clear phenotypic definitions, early molecular approaches to separate the first three by various DNA hybridization and 16S/23S ribosomal sequence analyses led to some “confusion” because there were limited differences to differentiate between these species. These and other results have led to frequent suggestions that a taxonomic change was warranted to reclassify this group to a single species. But the pathogenic properties of
B. anthracis
and the biopesticide applications of
B. thuringiensis
appear to “have outweighed pure taxonomic considerations” and the separate species categories are still being maintained.
B. cereus sensu lato
represents a classic example of a now common bacterial species taxonomic quandary.
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212
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The Regulation of Exosporium-Related Genes in Bacillus thuringiensis. Sci Rep 2016; 6:19005. [PMID: 26805020 PMCID: PMC4750369 DOI: 10.1038/srep19005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 12/02/2015] [Indexed: 11/09/2022] Open
Abstract
Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis (Bt) are spore-forming members of the Bacillus cereus group. Spores of B. cereus group species are encircled by exosporium, which is composed of an external hair-like nap and a paracrystalline basal layer. Despite the extensive studies on the structure of the exosporium-related proteins, little is known about the transcription and regulation of exosporium gene expression in the B. cereus group. Herein, we studied the regulation of several exosporium-related genes in Bt. A SigK consensus sequence is present upstream of genes encoding hair-like nap proteins (bclA and bclB), basal layer proteins (bxpA, bxpB, cotB, and exsY ), and inosine hydrolase (iunH). Mutation of sigK decreased the transcriptional activities of all these genes, indicating that the transcription of these genes is controlled by SigK. Furthermore, mutation of gerE decreased the transcriptional activities of bclB, bxpB, cotB, and iunH but increased the expression of bxpA, and GerE binds to the promoters of bclB, bxpB, cotB, bxpA, and iunH. These results suggest that GerE directly regulates the transcription of these genes, increasing the expression of bclB, bxpB, cotB, and iunH and decreasing that of bxpA. These findings provide insight into the exosporium assembly process at the transcriptional level.
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213
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Sitaraman R. The Role of DNA Restriction-Modification Systems in the Biology of Bacillus anthracis. Front Microbiol 2016; 7:11. [PMID: 26834729 PMCID: PMC4722110 DOI: 10.3389/fmicb.2016.00011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/08/2016] [Indexed: 11/13/2022] Open
Abstract
Restriction-modification (R-M) systems are widespread among prokaryotes and, depending on their type, may be viewed as selfish genetic elements that persist as toxin-antitoxin modules, or as cellular defense systems against phage infection that confer a selective advantage to the host bacterium. Studies in the last decade have made it amply clear that these two options do not exhaust the list of possible biological roles for R-M systems. Their presence in a cell may also have a bearing on other processes such as horizontal gene transfer and gene regulation. From genome sequencing and experimental data, we know that Bacillus anthracis encodes at least three methylation-dependent (typeIV) restriction endonucleases (RE), and an orphan DNA methyltransferase. In this article, we first present an outline of our current knowledge of R-M systems in B. anthracis. Based on available DNA sequence data, and on our current understanding of the functions of similar genes in other systems, we conclude with hypotheses on the possible roles of the three REs and the orphan DNA methyltransferase.
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214
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Bacillus thuringiensis Crystal Protein Cry6Aa Triggers Caenorhabditis elegans Necrosis Pathway Mediated by Aspartic Protease (ASP-1). PLoS Pathog 2016; 12:e1005389. [PMID: 26795495 PMCID: PMC4721865 DOI: 10.1371/journal.ppat.1005389] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 12/18/2015] [Indexed: 02/07/2023] Open
Abstract
Cell death plays an important role in host-pathogen interactions. Crystal proteins (toxins) are essential components of Bacillus thuringiensis (Bt) biological pesticides because of their specific toxicity against insects and nematodes. However, the mode of action by which crystal toxins to induce cell death is not completely understood. Here we show that crystal toxin triggers cell death by necrosis signaling pathway using crystal toxin Cry6Aa-Caenorhabditis elegans toxin-host interaction system, which involves an increase in concentrations of cytoplasmic calcium, lysosomal lyses, uptake of propidium iodide, and burst of death fluorescence. We find that a deficiency in the necrosis pathway confers tolerance to Cry6Aa toxin. Intriguingly, the necrosis pathway is specifically triggered by Cry6Aa, not by Cry5Ba, whose amino acid sequence is different from that of Cry6Aa. Furthermore, Cry6Aa-induced necrosis pathway requires aspartic protease (ASP-1). In addition, ASP-1 protects Cry6Aa from over-degradation in C. elegans. This is the first demonstration that deficiency in necrosis pathway confers tolerance to Bt crystal protein, and that Cry6A triggers necrosis represents a newly added necrosis paradigm in the C. elegans. Understanding this model could lead to new strategies for nematode control. Necrosis contributes to many devastating pathological conditions, such as neurodegenerative diseases and microbial pathogenesis. Bacillus thuringiensis crystal proteins are effective biopesticides. Our study reveals that B. thuringiensis Cry6Aa protein triggers the necrosis pathway using Caenorhabditis elegans as a model. We show that aspartic protease ASP-1 is required for Cry6Aa protein-induced necrosis, whereas intrinsic insults induce necrosis mediated by ASP-3 and ASP-4. Our findings contribute to the understanding of the mechanism of Bt crystal protein action and host-pathogen interactions. Because necrosis mechanisms are conserved from nematodes to humans, the fact that necrosis can be induced by Cry6Aa provides a model system for studying necrosis mechanisms in human diseases.
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215
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Castaneda-Alvarez C, Prodan S, Rosales I, Aballay E. Exoenzymes and metabolites related to the nematicidal effect of rhizobacteria on Xiphinema index
Thorne & Allen. J Appl Microbiol 2016; 120:413-24. [DOI: 10.1111/jam.12987] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/09/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
Affiliation(s)
- C. Castaneda-Alvarez
- Departamento de Sanidad Vegetal; Facultad de Ciencias Agronómicas; Universidad de Chile; Santiago Chile
| | - S. Prodan
- Departamento de Sanidad Vegetal; Facultad de Ciencias Agronómicas; Universidad de Chile; Santiago Chile
| | - I.M. Rosales
- Departamento de Ciencias Vegetales; Facultad de Agronomía e Ingeniería Forestal; Pontificia Universidad Católica de Chile; Santiago Chile
| | - E. Aballay
- Departamento de Sanidad Vegetal; Facultad de Ciencias Agronómicas; Universidad de Chile; Santiago Chile
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216
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Dai JK, Dan WJ, Li N, Du HT, Zhang JW, Wang JR. Synthesis, in vitro antibacterial activities of a series of 3- N -substituted canthin-6-ones. Bioorg Med Chem Lett 2016; 26:580-583. [DOI: 10.1016/j.bmcl.2015.11.070] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 11/02/2015] [Accepted: 11/20/2015] [Indexed: 12/17/2022]
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217
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Araújo NKD, Pagnoncelli MGB, Pimentel VC, Xavier MLO, Padilha CEA, Macedo GRD, Santos ESD. Single-step purification of chitosanases from Bacillus cereus using expanded bed chromatography. Int J Biol Macromol 2016; 82:291-8. [DOI: 10.1016/j.ijbiomac.2015.09.063] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 01/19/2023]
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218
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Lo CI, Fall B, Sambe-Ba B, Diawara S, Gueye MW, Mediannikov O, Sokhna C, Faye N, Diemé Y, Wade B, Raoult D, Fenollar F. MALDI-TOF Mass Spectrometry: A Powerful Tool for Clinical Microbiology at Hôpital Principal de Dakar, Senegal (West Africa). PLoS One 2015; 10:e0145889. [PMID: 26716681 PMCID: PMC4696746 DOI: 10.1371/journal.pone.0145889] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 12/09/2015] [Indexed: 12/26/2022] Open
Abstract
Our team in Europe has developed the routine clinical laboratory identification of microorganisms by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). To evaluate the utility of MALDI-TOF MS in tropical Africa in collaboration with local teams, we installed an apparatus in the Hôpital Principal de Dakar (Senegal), performed routine identification of isolates, and confirmed or completed their identification in France. In the case of discordance or a lack of identification, molecular biology was performed. Overall, 153/191 (80.1%) and 174/191 (91.1%) isolates yielded an accurate and concordant identification for the species and genus, respectively, with the 2 different MALDI-TOF MSs in Dakar and Marseille. The 10 most common bacteria, representing 94.2% of all bacteria routinely identified in the laboratory in Dakar (Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus haemolyticus, Enterobacter cloacae, Enterococcus faecalis, and Staphylococcus epidermidis) were accurately identified with the MALDI-TOF MS in Dakar. The most frequent misidentification in Dakar was at the species level for Achromobacter xylosoxidans, which was inaccurately identified as Achromobacter denitrificans, and the bacteria absent from the database, such as Exiguobacterium aurientacum or Kytococcus schroeteri, could not be identified. A few difficulties were observed with MALDI-TOF MS for Bacillus sp. or oral streptococci. 16S rRNA sequencing identified a novel bacterium, “Necropsobacter massiliensis.” The robust identification of microorganisms by MALDI-TOF MS in Dakar and Marseille demonstrates that MALDI-TOF MS can be used as a first-line tool in clinical microbiology laboratories in tropical countries.
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Affiliation(s)
- Cheikh I. Lo
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Marseille, France and Dakar, Senegal
| | | | | | | | | | - Oleg Mediannikov
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Marseille, France and Dakar, Senegal
| | - Cheikh Sokhna
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Marseille, France and Dakar, Senegal
| | - Ngor Faye
- Université Cheikh Anta Diop, Dakar, Senegal
| | - Yaya Diemé
- Hôpital Principal de Dakar, Dakar, Senegal
| | | | - Didier Raoult
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Marseille, France and Dakar, Senegal
| | - Florence Fenollar
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Marseille, France and Dakar, Senegal
- * E-mail:
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Remigi P, Zhu J, Young JPW, Masson-Boivin C. Symbiosis within Symbiosis: Evolving Nitrogen-Fixing Legume Symbionts. Trends Microbiol 2015; 24:63-75. [PMID: 26612499 DOI: 10.1016/j.tim.2015.10.007] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/08/2015] [Accepted: 10/22/2015] [Indexed: 10/22/2022]
Abstract
Bacterial accessory genes are genomic symbionts with an evolutionary history and future that is different from that of their hosts. Packages of accessory genes move from strain to strain and confer important adaptations, such as interaction with eukaryotes. The ability to fix nitrogen with legumes is a remarkable example of a complex trait spread by horizontal transfer of a few key symbiotic genes, converting soil bacteria into legume symbionts. Rhizobia belong to hundreds of species restricted to a dozen genera of the Alphaproteobacteria and Betaproteobacteria, suggesting infrequent successful transfer between genera but frequent successful transfer within genera. Here we review the genetic and environmental conditions and selective forces that have shaped evolution of this complex symbiotic trait.
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Affiliation(s)
- Philippe Remigi
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, Castanet-Tolosan, France; New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand
| | - Jun Zhu
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China; Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - J Peter W Young
- Department of Biology, University of York, York YO10 5DD, UK
| | - Catherine Masson-Boivin
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, Castanet-Tolosan, France; CNRS, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR2594, Castanet-Tolosan, France.
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Massive horizontal gene transfer, strictly vertical inheritance and ancient duplications differentially shape the evolution of Bacillus cereus enterotoxin operons hbl, cytK and nhe. BMC Evol Biol 2015; 15:246. [PMID: 26555390 PMCID: PMC4641410 DOI: 10.1186/s12862-015-0529-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/30/2015] [Indexed: 11/10/2022] Open
Abstract
Background Bacillus cereus sensu lato comprises eight closely related species including the human pathogens Bacillus anthracis and Bacillus cereus. Within B. cereus sensu lato, chromosomally and plasmid-encoded toxins exist. While plasmid-mediated horizontal gene transfer of the emetic toxin, anthrax and insecticidal toxins is known, evolution of enterotoxin genes within the group has not been studied. Results We report draft genome assemblies of 25 strains, a phylogenetic network of 142 strains based on ANI derived from genome sequences and a phylogeny based on whole-genome SNP analysis. The data clearly support subdivision of B. cereus sensu lato into seven phylogenetic groups. While group I, V and VII represent B. pseudomycoides, B. toyonensis and B. cytotoxicus, which are distinguishable at species level (ANI border ≥ 96 %), strains ascribed to the other five species do not match phylogenic groups. The chromosomal enterotoxin operons nheABC and hblCDAB are abundant within B. cereus both isolated from infections and from the environment. While the duplicated hbl variant hbla is present in 22 % of all strains investigated, duplication of nheABC is extremely rare (0.02 %) and appears to be phylogenetically unstable. Distribution of toxin genes was matched to a master tree based on seven concatenated housekeeping genes, which depicts species relationships in B. cereus sensu lato as accurately as whole-genome comparisons. Comparison to the phylogeny of enterotoxin genes uncovered ample evidence for horizontal transfer of hbl, cytK and plcR, as well as frequent deletion of both toxins and duplication of hbl. No evidence for nhe deletion was found and stable horizontal transfer of nhe is rare. Therefore, evolution of B. cereus enterotoxin operons is shaped unexpectedly different for yet unknown reasons. Conclusions Frequent exchange of the pathogenicity factors hbl, cytK and plcR in B. cereus sensu lato appears to be an important mechanism of B. cereus virulence evolution, including so-called probiotic or non-pathogenic species, which might have consequences for risk assessment procedures. In contrast, exclusively vertical inheritance of nhe was observed, and since nhe-negative strains appear to be extremely rare, we suggest that fitness loss may be associated with deletion or horizontal transfer of the nhe operon. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0529-4) contains supplementary material, which is available to authorized users.
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Li Q, Zou T, Ai P, Pan L, Fu C, Li P, Zheng A. Complete genome sequence of Bacillus thuringiensis HS18-1. J Biotechnol 2015; 214:61-2. [DOI: 10.1016/j.jbiotec.2015.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
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Lin W, Chen H, Chen Q, Liu Y, Jiao N, Zheng Q. Genome sequence of Bacillus sp. CHD6a, isolated from the shallow-sea hydrothermal vent. Mar Genomics 2015; 25:15-16. [PMID: 26508672 DOI: 10.1016/j.margen.2015.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/21/2015] [Accepted: 10/21/2015] [Indexed: 11/25/2022]
Abstract
Bacillus sp. CHD6a, which can produce oval endosperms, isolated from the shallow-sea hydrothermal vent systems off northeast Taiwan's coast. Here, we report the draft genome sequence of Bacillus sp. CHD6a. It comprises ~3.97 Mb in 55 contigs with the G+C content of 39.9%, and a total of 3740 protein-coding genes were obtained.
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Affiliation(s)
- Wenxin Lin
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China
| | - Hong Chen
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China
| | - Qi Chen
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China
| | - Yanting Liu
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China.
| | - Qiang Zheng
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China.
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Kaminska PS, Yernazarova A, Drewnowska JM, Zambrowski G, Swiecicka I. The worldwide distribution of genetically and phylogenetically diverse Bacillus cereus isolates harbouring Bacillus anthracis-like plasmids. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:738-745. [PMID: 26033739 DOI: 10.1111/1758-2229.12305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 05/28/2015] [Indexed: 06/04/2023]
Abstract
Bacillus cereus is a close relative of B. anthracis, the causative agent of anthrax whose pathogenic determinants are located on pXO1 and pXO2 plasmids. Bacillus anthracis-like plasmids have been also noted among B. cereus, however, genetic features of B. cereus harbouring these elements remain largely undescribed, especially from the global perspective. Herein, we present the genetic polymorphism, population structure and phylogeny of B. cereus with pXO1-/pXO2-like plasmids originating from Argentina, Kazakhstan, Kenya and Poland. The plasmids were found in about 17% of the isolates, but their frequencies and expression of replicons differed within and between populations. In the multi-locus sequence typing, the bacteria exhibited high genetic polymorphism reflected by 116 sequencing types, including 84 singletons and 10 clonal complexes, which mainly consisted of isolates of the same origin. The phylogenetic analysis of pXO1-/pXO2-like positive B. cereus isolates revealed six independent clades; in certain clades individual populations predominated. Generally, B. cereus with pXO1-/pXO2-like plasmids did not indicate the genetic relationship with B. anthracis, and cannot be classified into an evolutionary independent anthrax line within the B. cereus group. Our report is of a crucial importance for discovering the genetic specificity and evolution of B. cereus bacilli.
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Affiliation(s)
- Paulina Sylwia Kaminska
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, 1J Konstanty Ciolkowski Street, Bialystok, 15-245, Poland
| | - Aliya Yernazarova
- Department of Biotechnology, al-Farabi Kazakh National University, 71 Al Farabi Ave, Almaty, 050121, Kazakhstan
| | - Justyna Malgorzata Drewnowska
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, 1J Konstanty Ciolkowski Street, Bialystok, 15-245, Poland
| | - Grzegorz Zambrowski
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, 1J Konstanty Ciolkowski Street, Bialystok, 15-245, Poland
| | - Izabela Swiecicka
- Department of Microbiology, Institute of Biology, University of Bialystok, Bialystok, 1J Konstanty Ciolkowski Street, Bialystok, 15-245, Poland
- Laboratory of Applied Microbiology, Institute of Biology, University of Bialystok, Bialystok, 1J Konstanty Ciolkowski Street, Bialystok, 15-245, Poland
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224
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Wang G, Xia Y, Song X, Ai L. Common Non-classically Secreted Bacterial Proteins with Experimental Evidence. Curr Microbiol 2015; 72:102-11. [DOI: 10.1007/s00284-015-0915-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/15/2015] [Indexed: 12/13/2022]
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225
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Gwenin VV, Poornima P, Halliwell J, Ball P, Robinson G, Gwenin CD. Identification of novel nitroreductases from Bacillus cereus and their interaction with the CB1954 prodrug. Biochem Pharmacol 2015; 98:392-402. [PMID: 26415543 DOI: 10.1016/j.bcp.2015.09.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/15/2015] [Indexed: 10/23/2022]
Abstract
Directed enzyme prodrug therapy is a form of cancer chemotherapy in which bacterial prodrug-activating enzymes, or their encoding genes, are directed to the tumour before administration of a prodrug. The prodrug can then be activated into a toxic drug at the tumour site, reducing off-target effects. The bacterial nitroreductases are a class of enzymes used in this therapeutic approach and although very promising, the low turnover rate of prodrug by the most studied nitroreductase enzyme, NfnB from Escherichia coli (NfnB_Ec), is a major limit to this technology. There is a continual search for enzymes with greater efficiency, and as part of the search for more efficient bacterial nitroreductase enzymes, two novel enzymes from Bacillus cereus (strain ATCC 14579) have been identified and shown to reduce the CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) prodrug to its respective 2'-and 4'-hydroxylamine products. Both enzymes shared features characteristic of the nitro-FMN-reductase superfamily including non-covalently associated FMN, requirement for the NAD(P)H cofactor, homodimeric, could be inhibited by Dicoumarol (3,3'-methylenebis(4-hydroxy-2H-chromen-2-one)), and displayed ping pong bi bi kinetics. Based on the biochemical characteristics and nucleotide alignment with other nitroreductase enzymes, one enzyme was named YdgI_Bc and the other YfkO_Bc. Both B. cereus enzymes had greater turnover for the CB1954 prodrug compared with NfnB_Ec, and in the presence of added NADPH cofactor, YfkO_Bc had superior cell killing ability, and produced mainly the 4'-hydroxylamine product at low prodrug concentration. The YfkO_Bc was identified as a promising candidate for future enzyme prodrug therapy.
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Affiliation(s)
- Vanessa V Gwenin
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2DG Wales, UK
| | | | - Jennifer Halliwell
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2DG Wales, UK
| | - Patrick Ball
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2DG Wales, UK
| | - George Robinson
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2DG Wales, UK
| | - Chris D Gwenin
- School of Chemistry, Bangor University, Bangor, Gwynedd, LL57 2DG Wales, UK.
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Fischer C, Hünniger T, Jarck JH, Frohnmeyer E, Kallinich C, Haase I, Hahn U, Fischer M. Food Sensing: Aptamer-Based Trapping of Bacillus cereus Spores with Specific Detection via Real Time PCR in Milk. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8050-7. [PMID: 26306797 DOI: 10.1021/acs.jafc.5b03738] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Aerobic spores pose serious problems for both food product manufacturers and consumers. Milk is particularly at risk and thus an important issue of preventive consumer protection and quality assurance. The spore-former Bacillus cereus is a food poisoning Gram-positive pathogen which mainly produces two different types of toxins, the diarrhea inducing and the emetic toxins. Reliable and rapid analytical assays for the detection of B. cereus spores are required, which could be achieved by combining in vitro generated aptamers with highly specific molecular biological techniques. For the development of routine bioanalytical approaches, already existing aptamers with high affinity to B. cereus spores have been characterized by surface plasmon resonance (SPR) spectroscopy and fluorescence microscopy in terms of their dissociation constants and selectivity. Dissociation constants in the low nanomolar range (from 5.2 to 52.4 nM) were determined. Subsequently, the characterized aptamers were utilized for the establishment and validation of an aptamer-based trapping technique in both milk simulating buffer and milk with fat contents between 0.3 and 3.5%. Thereby, enrichment factors of up to 6-fold could be achieved. It could be observed that trapping protocol and characterized aptamers were fully adaptable to the application in milk. Due to the fact that aptamer selectivity is limited, a highly specific real time PCR assay was utilized following trapping to gain a higher degree of selectivity.
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Affiliation(s)
- Christin Fischer
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
| | - Tim Hünniger
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
| | - Jan-Hinnerk Jarck
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
| | - Esther Frohnmeyer
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
| | - Constanze Kallinich
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
| | - Ilka Haase
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
| | - Ulrich Hahn
- Institute of Biochemistry and Molecular Biology, University of Hamburg , Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Markus Fischer
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany
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227
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Liu Y, Lai Q, Göker M, Meier-Kolthoff JP, Wang M, Sun Y, Wang L, Shao Z. Genomic insights into the taxonomic status of the Bacillus cereus group. Sci Rep 2015; 5:14082. [PMID: 26373441 PMCID: PMC4571650 DOI: 10.1038/srep14082] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 08/17/2015] [Indexed: 02/01/2023] Open
Abstract
The identification and phylogenetic relationships of bacteria within the Bacillus cereus group are controversial. This study aimed at determining the taxonomic affiliations of these strains using the whole-genome sequence-based Genome BLAST Distance Phylogeny (GBDP) approach. The GBDP analysis clearly separated 224 strains into 30 clusters, representing eleven known, partially merged species and accordingly 19–20 putative novel species. Additionally, 16S rRNA gene analysis, a novel variant of multi-locus sequence analysis (nMLSA) and screening of virulence genes were performed. The 16S rRNA gene sequence was not sufficient to differentiate the bacteria within this group due to its high conservation. The nMLSA results were consistent with GBDP. Moreover, a fast typing method was proposed using the pycA gene, and where necessary, the ccpA gene. The pXO plasmids and cry genes were widely distributed, suggesting little correlation with the phylogenetic positions of the host bacteria. This might explain why classifications based on virulence characteristics proved unsatisfactory in the past. In summary, this is the first large-scale and systematic study of the taxonomic status of the bacteria within the B. cereus group using whole-genome sequences, and is likely to contribute to further insights into their pathogenicity, phylogeny and adaptation to diverse environments.
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Affiliation(s)
- Yang Liu
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Centre; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
| | - Qiliang Lai
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Centre; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
| | - Markus Göker
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Inhoffenstraβe 7B, 38124, Braunschweig, Germany
| | - Jan P Meier-Kolthoff
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Inhoffenstraβe 7B, 38124, Braunschweig, Germany
| | - Meng Wang
- TEDA School of Biological Sciences and Biotechnology Nankai University, Tianjin, China
| | - Yamin Sun
- TEDA School of Biological Sciences and Biotechnology Nankai University, Tianjin, China
| | - Lei Wang
- TEDA School of Biological Sciences and Biotechnology Nankai University, Tianjin, China
| | - Zongze Shao
- State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Centre; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China
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228
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Li Q, Xu LZ, Zou T, Ai P, Huang GH, Li P, Zheng AP. Complete genome sequence of Bacillus thuringiensis strain HD521. Stand Genomic Sci 2015; 10:62. [PMID: 26380647 PMCID: PMC4572618 DOI: 10.1186/s40793-015-0058-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 08/17/2015] [Indexed: 11/15/2022] Open
Abstract
Bacillus thuringiensis is the most widely used biological pesticide in the world. It belongs to the Bacillus cereus sensu lato group, which contains six species. Among these six species, B. thuringiensis, B. anthracis, and B. cereus have a low genetic diversity. B. thuringiensis strain HD521 shows maroon colony which is different from most of the B. thuringiensis strains. Strain HD521 also displays an ability to inhibit plant sheath blight disease pathogen (Rhizoctonia solani AG1 IB) growth and can form bipyramidal parasporal crystals consisting of three cry7 genes. These crystals have an insecticidal activity against Henosepilachna vigintioctomaculata larva (Coleoptera). Here we report the complete genome sequence of strain HD521, which has one chromosome and six circular plasmids.
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Affiliation(s)
- Qiao Li
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China
| | - Li Z Xu
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China
| | - Ting Zou
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China
| | - Peng Ai
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China
| | - Gang H Huang
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China
| | - Ping Li
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China ; Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Ya'an, 625014 China
| | - Ai P Zheng
- Rice Research Institute of Sichuan Agricultural University, Chengdu, 611130 China ; Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Ya'an, 625014 China
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Abstract
Fifty complete Bacillus genome sequences and associated plasmids were compared using the “feature frequency profile” (FFP) method. The resulting whole-genome phylogeny supports the placement of three Bacillus species (B. thuringiensis, B. anthracis and B. cereus) as a single clade. The monophyletic status of B. anthracis was strongly supported by the analysis. FFP proved to be more effective in inferring the phylogeny of Bacillus than methods based on single gene sequences [16s rRNA gene, GryB (gyrase subunit B) and AroE (shikimate-5-dehydrogenase)] analyses. The findings of FFP analysis were verified using kSNP v2 (alignment-free sequence analysis method) and Harvest suite (core genome sequence alignment method).
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230
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Kumar N, Lad G, Giuntini E, Kaye ME, Udomwong P, Shamsani NJ, Young JPW, Bailly X. Bacterial genospecies that are not ecologically coherent: population genomics of Rhizobium leguminosarum. Open Biol 2015; 5:140133. [PMID: 25589577 PMCID: PMC4313370 DOI: 10.1098/rsob.140133] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Biological species may remain distinct because of genetic isolation or ecological adaptation, but these two aspects do not always coincide. To establish the nature of the species boundary within a local bacterial population, we characterized a sympatric population of the bacterium Rhizobium leguminosarum by genomic sequencing of 72 isolates. Although all strains have 16S rRNA typical of R. leguminosarum, they fall into five genospecies by the criterion of average nucleotide identity (ANI). Many genes, on plasmids as well as the chromosome, support this division: recombination of core genes has been largely within genospecies. Nevertheless, variation in ecological properties, including symbiotic host range and carbon-source utilization, cuts across these genospecies, so that none of these phenotypes is diagnostic of genospecies. This phenotypic variation is conferred by mobile genes. The genospecies meet the Mayr criteria for biological species in respect of their core genes, but do not correspond to coherent ecological groups, so periodic selection may not be effective in purging variation within them. The population structure is incompatible with traditional ‘polyphasic taxonomy′ that requires bacterial species to have both phylogenetic coherence and distinctive phenotypes. More generally, genomics has revealed that many bacterial species share adaptive modules by horizontal gene transfer, and we envisage a more consistent taxonomic framework that explicitly recognizes this. Significant phenotypes should be recognized as ‘biovars' within species that are defined by core gene phylogeny.
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Affiliation(s)
- Nitin Kumar
- Department of Biology, University of York, York YO10 5DD, UK
| | - Ganesh Lad
- Department of Biology, University of York, York YO10 5DD, UK
| | - Elisa Giuntini
- Department of Biology, University of York, York YO10 5DD, UK
| | - Maria E Kaye
- Department of Biology, University of York, York YO10 5DD, UK
| | | | | | - J Peter W Young
- Department of Biology, University of York, York YO10 5DD, UK
| | - Xavier Bailly
- Department of Biology, University of York, York YO10 5DD, UK
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231
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Draft Genome Sequence of Bacillus cytotoxicus CVUAS 2833, a Very Close Relative to Type Strain NVH 391-98 Isolated from a Different Location. GENOME ANNOUNCEMENTS 2015; 3:3/4/e00901-15. [PMID: 26294623 PMCID: PMC4543501 DOI: 10.1128/genomea.00901-15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report the draft genome sequence of Bacillus cytotoxicus CVUAS 2833, isolated from potato puree in Germany (2007), which is—despite its clearly different source—very similar to the type strain B. cytotoxicus NVH 391-98 isolated in France (average nucleotide identity, 99.5%).
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232
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Wang C, Ehrhardt CJ, Yadavalli VK. Single cell profiling of surface carbohydrates on Bacillus cereus. J R Soc Interface 2015; 12:rsif.2014.1109. [PMID: 25505137 DOI: 10.1098/rsif.2014.1109] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cell surface carbohydrates are important to various bacterial activities and functions. It is well known that different types of Bacillus display heterogeneity of surface carbohydrate compositions, but detection of their presence, quantitation and estimation of variation at the single cell level have not been previously solved. Here, using atomic force microscopy (AFM)-based recognition force mapping coupled with lectin probes, the specific carbohydrate distributions of N-acetylglucosamine and mannose/glucose were detected, mapped and quantified on single B. cereus surfaces at the nanoscale across the entire cell. Further, the changes of the surface carbohydrate compositions from the vegetative cell to spore were shown. These results demonstrate AFM-based 'recognition force mapping' as a versatile platform to quantitatively detect and spatially map key bacterial surface biomarkers (such as carbohydrate compositions), and monitor in situ changes in surface biochemical properties during intracellular activities at the single cell level.
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Affiliation(s)
- Congzhou Wang
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Christopher J Ehrhardt
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Vamsi K Yadavalli
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
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233
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Břinda K, Sykulski M, Kucherov G. Spaced seeds improvek-mer-based metagenomic classification. Bioinformatics 2015. [DOI: 10.1093/bioinformatics/btv419] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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234
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Isolation of Bacillus cereus Group from the Fecal Material of Endangered Wood Turtles. Curr Microbiol 2015; 71:524-7. [PMID: 26175111 DOI: 10.1007/s00284-015-0875-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/17/2015] [Indexed: 10/23/2022]
Abstract
Members of the Bacillus cereus group are opportunistic human pathogens. They can be found in a broad range of foods. Diarrheal food poisoning and/or emetic type syndromes can result from eating contaminated food. In this study, seven B. cereus group members were isolated from the fecal material of Wood Turtles (Glyptemys insculpta). The isolates were then assessed for the presence of enterotoxin genes (nheA, entFM, hblC, and cytK) using PCR. The most prevalent is the nonhemolytic enterotoxin gene which was found in all seven isolates.
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235
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Abstract
Anthrax is caused by the spore-forming, gram-positive bacterium Bacillus anthracis. The bacterium's major virulence factors are (a) the anthrax toxins and (b) an antiphagocytic polyglutamic capsule. These are encoded by two large plasmids, the former by pXO1 and the latter by pXO2. The expression of both is controlled by the bicarbonate-responsive transcriptional regulator, AtxA. The anthrax toxins are three polypeptides-protective antigen (PA), lethal factor (LF), and edema factor (EF)-that come together in binary combinations to form lethal toxin and edema toxin. PA binds to cellular receptors to translocate LF (a protease) and EF (an adenylate cyclase) into cells. The toxins alter cell signaling pathways in the host to interfere with innate immune responses in early stages of infection and to induce vascular collapse at late stages. This review focuses on the role of anthrax toxins in pathogenesis. Other virulence determinants, as well as vaccines and therapeutics, are briefly discussed.
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Affiliation(s)
- Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Catherine Vrentas
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Andrei P Pomerantsev
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Shihui Liu
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
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236
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Peng Q, Wang G, Liu G, Zhang J, Song F. Identification of metabolism pathways directly regulated by sigma(54) factor in Bacillus thuringiensis. Front Microbiol 2015; 6:407. [PMID: 26029175 PMCID: PMC4428206 DOI: 10.3389/fmicb.2015.00407] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 04/19/2015] [Indexed: 11/13/2022] Open
Abstract
Sigma(54) (σ(54)) regulates nitrogen and carbon utilization in bacteria. Promoters that are σ(54)-dependent are highly conserved and contain short sequences located at the -24 and -12 positions upstream of the transcription initiation site. σ(54) requires regulatory proteins known as bacterial enhancer-binding proteins (bEBPs) to activate gene transcription. We show that σ(54) regulates the capacity to grow on various nitrogen sources using a Bacillus thuringiensis HD73 mutant lacking the sigL gene encoding σ(54) (ΔsigL). A 2-fold-change cutoff and a false discovery rate cutoff of P < 0.05 were used to analyze the DNA microarray data, which revealed 255 genes that were downregulated and 121 that were upregulated in the ΔsigL mutant relative to the wild-type HD73 strain. The σ(54) regulon (stationary phase) was characterized by DNA microarray, bioinformatics, and functional assay; 16 operons containing 47 genes were identified whose promoter regions contain the conserved -12/-24 element and whose transcriptional activities were abolished or reduced in the ΔsigL mutant. Eight σ(54)-dependent transcriptional bEBPs were found in the Bt HD73 genome, and they regulated nine σ(54)-dependent promoters. The metabolic pathways activated by σ(54) in this process have yet to be identified in Bacillus thuringiensis; nonetheless, the present analysis of the σ(54) regulon provides a better understanding of the physiological roles of σ factors in bacteria.
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Affiliation(s)
- Qi Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing, China
| | - Guannan Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing, China
| | - Guiming Liu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences Beijing, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing, China
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing, China
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237
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Stelder SK, Mahmud SA, Dekker HL, de Koning LJ, Brul S, de Koster CG. Temperature Dependence of the Proteome Profile of the Psychrotolerant Pathogenic Food Spoiler Bacillus weihenstephanensis Type Strain WSBC 10204. J Proteome Res 2015; 14:2169-76. [DOI: 10.1021/pr501307t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sacha K. Stelder
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Siraje A. Mahmud
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Henk L. Dekker
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Leo J. de Koning
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Stanley Brul
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Chris G. de Koster
- Molecular Biology & Microbial Food Safety, ‡Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
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238
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Brillard J, Dupont CMS, Berge O, Dargaignaratz C, Oriol-Gagnier S, Doussan C, Broussolle V, Gillon M, Clavel T, Bérard A. The Water Cycle, a Potential Source of the Bacterial Pathogen Bacillus cereus. BIOMED RESEARCH INTERNATIONAL 2015; 2015:356928. [PMID: 25918712 PMCID: PMC4395999 DOI: 10.1155/2015/356928] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 11/07/2014] [Indexed: 01/31/2023]
Abstract
The behaviour of the sporulating soil-dwelling Bacillus cereus sensu lato (B. cereus sl) which includes foodborne pathogenic strains has been extensively studied in relation to its various animal hosts. The aim of this environmental study was to investigate the water compartments (rain and soil water, as well as groundwater) closely linked to the primary B. cereus sl reservoir, for which available data are limited. B. cereus sl was present, primarily as spores, in all of the tested compartments of an agricultural site, including water from rain to groundwater through soil. During rain events, leachates collected after transfer through the soil eventually reached the groundwater and were loaded with B. cereus sl. In groundwater samples, newly introduced spores of a B. cereus model strain were able to germinate, and vegetative cells arising from this event were detected for up to 50 days. This first B. cereus sl investigation in the various types of interrelated environments suggests that the consideration of the aquatic compartment linked to soil and to climatic events should provide a better understanding of B. cereus sl ecology and thus be relevant for a more accurate risk assessment of food poisoning caused by B. cereus sl pathogenic strains.
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Affiliation(s)
- Julien Brillard
- INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- Université d'Avignon, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- INRA-Université Montpellier II, UMR 1333 DGIMI, 34095 Montpellier, France
| | - Christian M. S. Dupont
- INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- Université d'Avignon, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- CNRS, Université Montpellier II, UMR 5235 DIMNP, 34095 Montpellier, France
- EPIM EA 3647, Université de Versailles St-Quentin-en-Yvelines, 78035 Versailles, France
| | - Odile Berge
- INRA, UR 407 Pathologie Végétale, 84140 Montfavet, France
- CNRS, CEA, Université Aix-Marseille, UMR 7265, 13108 Saint-Paul-lez-Durance, France
| | - Claire Dargaignaratz
- INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- Université d'Avignon, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
| | - Stéphanie Oriol-Gagnier
- INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- Université d'Avignon, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
| | - Claude Doussan
- INRA, UMR 1114 EMMAH, 84914 Avignon, France
- Université d'Avignon, UMR 1114 EMMAH, 84914 Avignon, France
| | - Véronique Broussolle
- INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- Université d'Avignon, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
| | - Marina Gillon
- INRA, UMR 1114 EMMAH, 84914 Avignon, France
- Université d'Avignon, UMR 1114 EMMAH, 84914 Avignon, France
| | - Thierry Clavel
- INRA, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
- Université d'Avignon, UMR 408 Sécurité et Qualité des Produits d'Origine Végétale, 84000 Avignon, France
| | - Annette Bérard
- INRA, UMR 1114 EMMAH, 84914 Avignon, France
- Université d'Avignon, UMR 1114 EMMAH, 84914 Avignon, France
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239
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Ogawa H, Ohnuma M, Squarre D, Mweene AS, Ezaki T, Fujikura D, Ohnishi N, Thomas Y, Hang'ombe BM, Higashi H. Bacillus cereus from the environment is genetically related to the highly pathogenic B. cereus in Zambia. J Vet Med Sci 2015; 77:993-5. [PMID: 25797134 PMCID: PMC4565826 DOI: 10.1292/jvms.15-0059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
To follow-up anthrax in Zambia since the outbreak in 2011, we have collected samples from the environment and the carcasses of anthrax-suspected animals, and have tried to isolate Bacillus anthracis. In the process of identification of B. anthracis, we collected two isolates, of which colonies were similar to B. anthracis; however, from the results of identification using the molecular-based methods, two isolates were genetically related to the highly pathogenic B. cereus, of which clinical manifestation is severe and fatal (e.g., pneumonia). In this study, we showed the existence of bacteria suspected to be highly pathogenic B. cereus in Zambia, indicating the possibility of an outbreak caused by highly pathogenic B. cereus.
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Affiliation(s)
- Hirohito Ogawa
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia
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240
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Ogawa H, Fujikura D, Ohnuma M, Ohnishi N, Hang'ombe BM, Mimuro H, Ezaki T, Mweene AS, Higashi H. A novel multiplex PCR discriminates Bacillus anthracis and its genetically related strains from other Bacillus cereus group species. PLoS One 2015; 10:e0122004. [PMID: 25774512 PMCID: PMC4361551 DOI: 10.1371/journal.pone.0122004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/09/2015] [Indexed: 11/30/2022] Open
Abstract
Anthrax is an important zoonotic disease worldwide that is caused by Bacillus anthracis, a spore-forming pathogenic bacterium. A rapid and sensitive method to detect B. anthracis is important for anthrax risk management and control in animal cases to address public health issues. However, it has recently become difficult to identify B. anthracis by using previously reported molecular-based methods because of the emergence of B. cereus, which causes severe extra-intestinal infection, as well as the human pathogenic B. thuringiensis, both of which are genetically related to B. anthracis. The close genetic relation of chromosomal backgrounds has led to complexity of molecular-based diagnosis. In this study, we established a B. anthracis multiplex PCR that can screen for the presence of B. anthracis virulent plasmids and differentiate B. anthracis and its genetically related strains from other B. cereus group species. Six sets of primers targeting a chromosome of B. anthracis and B. anthracis-like strains, two virulent plasmids, pXO1 and pXO2, a bacterial gene, 16S rRNA gene, and a mammalian gene, actin-beta gene, were designed. The multiplex PCR detected approximately 3.0 CFU of B. anthracis DNA per PCR reaction and was sensitive to B. anthracis. The internal control primers also detected all bacterial and mammalian DNAs examined, indicating the practical applicability of this assay as it enables monitoring of appropriate amplification. The assay was also applied for detection of clinical strains genetically related to B. anthracis, which were B. cereus strains isolated from outbreaks of hospital infections in Japan, and field strains isolated in Zambia, and the assay differentiated B. anthracis and its genetically related strains from other B. cereus group strains. Taken together, the results indicate that the newly developed multiplex PCR is a sensitive and practical method for detecting B. anthracis.
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Affiliation(s)
- Hirohito Ogawa
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
| | - Daisuke Fujikura
- Division of Infection and Immunity, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Miyuki Ohnuma
- Division of Infection and Immunity, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Naomi Ohnishi
- Division of Infection and Immunity, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Bernard M. Hang'ombe
- Department of Paraclinical Studies, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
| | - Hitomi Mimuro
- Division of Bacteriology, Department of Infectious Diseases Control, International Research Center for Infectious Diseases, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Pathogenic Microbes Repository Unit, International Research Center for Infectious Diseases, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Takayuki Ezaki
- Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Aaron S. Mweene
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
| | - Hideaki Higashi
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
- Division of Infection and Immunity, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
- Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
- * E-mail:
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241
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Dréan P, McAuley CM, Moore SC, Fegan N, Fox EM. Characterization of the spore-forming Bacillus cereus sensu lato group and Clostridium perfringens bacteria isolated from the Australian dairy farm environment. BMC Microbiol 2015; 15:38. [PMID: 25881096 PMCID: PMC4336692 DOI: 10.1186/s12866-015-0377-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 02/04/2015] [Indexed: 11/10/2022] Open
Abstract
Background The Bacillus cereus sensu lato group and Clostridium perfringens are spore-forming bacteria often associated with food spoilage and which can cause emetic and diarrheal syndromes in humans and ruminants. This study characterised the phenotypes and genotypes of 50 Bacillus cereus s. l. isolates and 26 Clostridium perfringens isolates from dairy farms environments in Victoria, Australia. Results Five of the seven B. cereus s. l. species were isolated, and analysis of the population diversity using Pulsed-Field Gel Electrophoresis (PFGE) suggested that the populations are largely distinct to each farm. Enterotoxin production by representative isolates of each B. cereus s. l. species identified was typically found to be reduced in milk, compared with broth. Among the C. perfringens isolates, only two different toxin types were identified, type A and D. Bovine and ovine farms harbored only type A whereas both type A and D were found on two of the three caprine farms. Conclusions This study showed that the B. cereus s. l. populations on the sampled farms exhibit a broad diversity in both species and genotypes. The risk of toxin-induced diarrheal illness through consumption of contaminated milk may be limited, in comparison with other food matrices. Type A strains of C. perfringens were the most abundant on dairy farms in Victoria, however type D may be of concern on caprine farms as it can cause enterotoxemia in goats. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0377-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paul Dréan
- CSIRO Food and Nutrition, 671 Sneydes Road, Werribee, VIC, 3030, Australia.
| | | | - Sean C Moore
- CSIRO Food and Nutrition, 671 Sneydes Road, Werribee, VIC, 3030, Australia.
| | - Narelle Fegan
- CSIRO Food and Nutrition, 671 Sneydes Road, Werribee, VIC, 3030, Australia.
| | - Edward M Fox
- CSIRO Food and Nutrition, 671 Sneydes Road, Werribee, VIC, 3030, Australia.
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242
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Goswami A, Roy Chowdhury A, Sarkar M, Saha SK, Paul S, Dutta C. Strand-biased gene distribution, purine assymetry and environmental factors influence protein evolution in Bacillus. FEBS Lett 2015; 589:629-38. [PMID: 25639611 DOI: 10.1016/j.febslet.2015.01.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/16/2015] [Accepted: 01/18/2015] [Indexed: 12/23/2022]
Abstract
A strong purine asymmetry, along with strand-biased gene distribution and the presence of PolC, prevails in Bacillus and some other members of Firmicutes, Fusobacteria and Tenericutes. The analysis of protein features in 21 Bacillus species of diverse metabolic, virulence and ecological traits revealed that purine asymmetry in conjunction with lineage/niche specific constraints significantly influences protein evolution in Bacillus. All Bacillus species, except for Se-respiring Bacillus selenitireducens, display distinct strand-specific biases in amino acid usage, which may affect the isoelectric point or surface charge distribution of proteins with prevalence of acidic and basic residues in the leading and lagging strand proteins, respectively.
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Affiliation(s)
- Aranyak Goswami
- Structural Biology & Bioinformatics Division, CSIR - Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, India.
| | - Anindya Roy Chowdhury
- Structural Biology & Bioinformatics Division, CSIR - Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, India.
| | - Munmun Sarkar
- Structural Biology & Bioinformatics Division, CSIR - Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, India.
| | - Sanjoy Kumar Saha
- Structural Biology & Bioinformatics Division, CSIR - Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, India.
| | - Sandip Paul
- Structural Biology & Bioinformatics Division, CSIR - Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, India.
| | - Chitra Dutta
- Structural Biology & Bioinformatics Division, CSIR - Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700032, India.
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243
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Amoako KK. Application of Pyrosequencing® in Food Biodefense. Methods Mol Biol 2015; 1315:363-375. [PMID: 26103911 DOI: 10.1007/978-1-4939-2715-9_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The perpetration of a bioterrorism attack poses a significant risk for public health with potential socioeconomic consequences. It is imperative that we possess reliable assays for the rapid and accurate identification of biothreat agents to make rapid risk-informed decisions on emergency response. The development of advanced methodologies for the detection of biothreat agents has been evolving rapidly since the release of the anthrax spores in the mail in 2001, and recent advances in detection and identification techniques could prove to be an essential component in the defense against biological attacks. Sequence-based approaches such as Pyrosequencing(®), which has the capability to determine short DNA stretches in real time using biotinylated PCR amplicons, have potential biodefense applications. Using markers from the virulence plasmids and chromosomal regions, my laboratory has demonstrated the power of this technology in the rapid, specific, and sensitive detection of B. anthracis spores and Yersinia pestis in food. These are the first applications for the detection of the two organisms in food. Furthermore, my lab has developed a rapid assay to characterize the antimicrobial resistance (AMR) gene profiles for Y. pestis using Pyrosequencing. Pyrosequencing is completed in about 60 min (following PCR amplification) and yields accurate and reliable results with an added layer of confidence, thus enabling rapid risk-informed decisions to be made. A typical run yields 40-84 bp reads with 94-100 % identity to the expected sequence. It also provides a rapid method for determining the AMR profile as compared to the conventional plate method which takes several days. The method described is proposed as a novel detection system for potential application in food biodefense.
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Affiliation(s)
- Kingsley Kwaku Amoako
- National Centers for Animal Disease, Lethbridge Laboratory, Canadian Food Inspection Agency, P.O. Box 640, Township Road 9-1, Lethbridge, AB, Canada, T1J 3Z4,
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244
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Onunga DO, Kowino IO, Ngigi AN, Osogo A, Orata F, Getenga ZM, Were H. Biodegradation of carbofuran in soils within Nzoia River Basin, Kenya. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2015; 50:387-397. [PMID: 25844859 DOI: 10.1080/03601234.2015.1011965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) has been used within the Nzoia River Basin (NRB), especially in Bunyala Rice Irrigation Schemes, in Kenya for the control of pests. In this study, the capacity of native bacteria to degrade carbofuran in soils from NRB was investigated. A gram positive, rod-shaped bacteria capable of degrading carbofuran was isolated through liquid cultures with carbofuran as the only carbon and nitrogen source. The isolate degraded 98% of 100-μg mL(-1) carbofuran within 10 days with the formation of carbofuran phenol as the only detectable metabolite. The degradation of carbofuran was followed by measuring its residues in liquid cultures using high performance liquid chromatography (HPLC). Physical and morphological characteristics as well as molecular characterization confirmed the bacterial isolate to be a member of Bacillus species. The results indicate that this strain of Bacillus sp. could be considered as Bacillus cereus or Bacillus thuringiensis with a bootstrap value of 100% similar to the 16S rRNA gene sequences. The biodegradation capability of the native strains in this study indicates that they have great potential for application in bioremediation of carbofuran-contaminated soil sites.
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Affiliation(s)
- Daniel O Onunga
- a Department of Pure and Applied Chemistry , Masinde Muliro University of Science and Technology , Kakamega , Kenya
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245
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Thorsen L, Kando CK, Sawadogo H, Larsen N, Diawara B, Ouédraogo GA, Hendriksen NB, Jespersen L. Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment. Int J Food Microbiol 2014; 196:70-8. [PMID: 25528535 DOI: 10.1016/j.ijfoodmicro.2014.11.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 11/10/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022]
Abstract
Maari is a spontaneously fermented food condiment made from baobab tree seeds in West African countries. This type of product is considered to be safe, being consumed by millions of people on a daily basis. However, due to the spontaneous nature of the fermentation the human pathogen Bacillus cereus occasionally occurs in Maari. This study characterizes succession patterns and pathogenic potential of B. cereus isolated from the raw materials (ash, water from a drilled well (DW) and potash), seed mash throughout fermentation (0-96h), after steam cooking and sun drying (final product) from two production sites of Maari. Aerobic mesophilic bacterial (AMB) counts in raw materials were of 10(5)cfu/ml in DW, and ranged between 6.5×10(3) and 1.2×10(4)cfu/g in potash, 10(9)-10(10)cfu/g in seed mash during fermentation and 10(7) - 10(9) after sun drying. Fifty three out of total 290 AMB isolates were identified as B. cereus sensu lato by use of ITS-PCR and grouped into 3 groups using PCR fingerprinting based on Escherichia coli phage-M13 primer (M13-PCR). As determined by panC gene sequencing, the isolates of B. cereus belonged to PanC types III and IV with potential for high cytotoxicity. Phylogenetic analysis of concatenated sequences of glpF, gmk, ilvD, pta, pur, pycA and tpi revealed that the M13-PCR group 1 isolates were related to B. cereus biovar anthracis CI, while the M13-PCR group 2 isolates were identical to cereulide (emetic toxin) producing B. cereus strains. The M13-PCR group 1 isolates harboured poly-γ-D-glutamic acid capsule biosynthesis genes capA, capB and capC showing 99-100% identity with the environmental B. cereus isolate 03BB108. Presence of cesB of the cereulide synthetase gene cluster was confirmed by PCR in M13-PCR group 2 isolates. The B. cereus harbouring the cap genes were found in potash, DW, cooking water and at 8h fermentation. The "emetic" type B. cereus were present in DW, the seed mash at 48-72h of fermentation and in the final product, while the remaining isolates (PanC type IV) were detected in ash, at 48-72h fermentation and in the final product. This work sheds light on the succession and pathogenic potential of B. cereus species in traditional West African food condiment and clarifies their phylogenetic relatedness to B. cereus biovar anthracis. Future implementation of GMP and HACCP and development of starter cultures for controlled Maari fermentations will help to ensure a safe product.
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Affiliation(s)
- Line Thorsen
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Christine Kere Kando
- Food Technology Department (DTA/IRSAT/CNRST), Ouagadougou 03 BP 7047, Burkina Faso; Université Polytechnique de Bobo-Dioulasso, 01 BP 1091 Bobo-Dioulasso, Burkina Faso
| | - Hagrétou Sawadogo
- Food Technology Department (DTA/IRSAT/CNRST), Ouagadougou 03 BP 7047, Burkina Faso
| | - Nadja Larsen
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Bréhima Diawara
- Food Technology Department (DTA/IRSAT/CNRST), Ouagadougou 03 BP 7047, Burkina Faso
| | | | - Niels Bohse Hendriksen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Lene Jespersen
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark.
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246
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Cytochrome c551 and the cytochrome c maturation pathway affect virulence gene expression in Bacillus cereus ATCC 14579. J Bacteriol 2014; 197:626-35. [PMID: 25422307 DOI: 10.1128/jb.02125-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Loss of the cytochrome c maturation system in Bacillus cereus results in increased transcription of the major enterotoxin genes nhe, hbl, and cytK and the virulence regulator plcR. Increased virulence factor production occurs at 37°C under aerobic conditions, similar to previous findings in Bacillus anthracis. Unlike B. anthracis, much of the increased virulence gene expression can be attributed to loss of only c551, one of the two small c-type cytochromes. Additional virulence factor expression occurs with loss of resBC, encoding cytochrome c maturation proteins, independently of the presence of the c-type cytochrome genes. Hemolytic activity of strains missing either cccB or resBC is increased relative to that in the parental strain, while sporulation efficiency is unaffected in the mutants. Increased virulence gene expression in the ΔcccB and ΔresBC mutants occurs only in the presence of an intact plcR gene, indicating that this process is PlcR dependent. These findings suggest a new mode of regulation of B. cereus virulence and reveal intriguing similarities and differences in virulence regulation between B. cereus and B. anthracis.
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247
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Celandroni F, Salvetti S, Senesi S, Ghelardi E. Bacillus thuringiensis membrane-damaging toxins acting on mammalian cells. FEMS Microbiol Lett 2014; 361:95-103. [PMID: 25283838 DOI: 10.1111/1574-6968.12615] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/26/2014] [Accepted: 09/29/2014] [Indexed: 01/20/2023] Open
Abstract
Bacillus thuringiensis is widely used as a biopesticide in forestry and agriculture, being able to produce potent species-specific insecticidal toxins and considered nonpathogenic to other animals. More recently, however, repeated observations are documenting the association of this microorganism with various infectious diseases in humans, such as food-poisoning-associated diarrheas, periodontitis, bacteremia, as well as ocular, burn, and wound infections. Similar to B. cereus, B. thuringiensis produces an array of virulence factors acting against mammalian cells, such as phosphatidylcholine- and phosphatidylinositol-specific phospholipase C (PC-PLC and PI-PLC), hemolysins, in particular hemolysin BL (HBL), and various enterotoxins. The contribution of some of these toxins to B. thuringiensis pathogenicity has been studied in animal models of infection, following intravitreous, intranasal, or intratracheal inoculation. These studies lead to the speculation that the activities of PC-PLC, PI-PLC, and HBL are responsible for most of the pathogenic properties of B. thuringiensis in nongastrointestinal infections in mammals. This review summarizes data regarding the biological activity, the genetic basis, and the structural features of these membrane-damaging toxins.
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Affiliation(s)
- Francesco Celandroni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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248
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Toby IT, Widmer J, Dyer DW. Divergence of protein-coding capacity and regulation in the Bacillus cereus sensu lato group. BMC Bioinformatics 2014; 15 Suppl 11:S8. [PMID: 25350501 PMCID: PMC4251056 DOI: 10.1186/1471-2105-15-s11-s8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The Bacillus cereus sensu lato group contains ubiquitous facultative anaerobic soil-borne Gram-positive spore-forming bacilli. Molecular phylogeny and comparative genome sequencing have suggested that these organisms should be classified as a single species. While clonal in nature, there do not appear to be species-specific clonal lineages, excepting B. anthracis, in spite of the wide array of phenotypes displayed by these organisms. RESULTS We compared the protein-coding content of 201 B. cereus sensu lato genomes to characterize differences and understand the consequences of these differences on biological function. From this larger group we selected a subset consisting of 25 whole genomes for deeper analysis. Cluster analysis of orthologous proteins grouped these genomes into five distinct clades. Each clade could be characterized by unique genes shared among the group, with consequences for the phenotype of each clade. Surprisingly, this population structure recapitulates our recent observations on the divergence of the generalized stress response (SigB) regulons in these organisms. Divergence of the SigB regulon among these organisms is primarily due to the placement of SigB-dependent promoters that bring genes from a common gene pool into/out of the SigB regulon. CONCLUSIONS Collectively, our observations suggest the hypothesis that the evolution of these closely related bacteria is a consequence of two distinct processes. Horizontal gene transfer, gene duplication/divergence and deletion dictate the underlying coding capacity in these genomes. Regulatory divergence overlays this protein coding reservoir and shapes the expression of both the unique and shared coding capacity of these organisms, resulting in phenotypic divergence. Data from other organisms suggests that this is likely a common pattern in prokaryotic evolution.
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Affiliation(s)
- Inimary T Toby
- University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC-1106, Oklahoma City, OK 73104, USA
| | - Jonah Widmer
- University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC-1106, Oklahoma City, OK 73104, USA
| | - David W Dyer
- University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC-1106, Oklahoma City, OK 73104, USA
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249
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Omotade TO, Bernhards RC, Klimko CP, Matthews ME, Hill AJ, Hunter MS, Webster WM, Bozue JA, Welkos SL, Cote CK. The impact of inducing germination of Bacillus anthracis and Bacillus thuringiensis spores on potential secondary decontamination strategies. J Appl Microbiol 2014; 117:1614-33. [PMID: 25196092 DOI: 10.1111/jam.12644] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 12/22/2022]
Abstract
AIMS Decontamination and remediation of a site contaminated by the accidental or intentional release of fully virulent Bacillus anthracis spores are difficult, costly and potentially damaging to the environment. Development of novel decontamination strategies that have minimal environmental impacts remains a high priority. Although ungerminated spores are amongst the most resilient organisms known, once exposed to germinants, the germinating spores, in some cases, become susceptible to antimicrobial environments. We evaluated the concept that once germinated, B. anthracis spores would be less hazardous and significantly easier to remediate than ungerminated dormant spores. METHODS AND RESULTS Through in vitro germination and sensitivity assays, we demonstrated that upon germination, B. anthracis Ames spores and Bacillus thuringiensis Al Hakam spores (serving as a surrogate for B. anthracis) become susceptible to environmental stressors. The majority of these germinated B. anthracis and B. thuringiensis spores were nonviable after exposure to a defined minimal germination-inducing solution for prolonged periods of time. Additionally, we examined the impact of potential secondary disinfectant strategies including bleach, hydrogen peroxide, formaldehyde and artificial UV-A, UV-B and UV-C radiation, employed after a 60-min germination-induction step. Each secondary disinfectant employs a unique mechanism of killing; as a result, germination-induction strategies are better suited for some secondary disinfectants than others. CONCLUSIONS These results provide evidence that the deployment of an optimal combination strategy of germination-induction/secondary disinfection may be a promising aspect of wide-area decontamination following a B. anthracis contamination event. SIGNIFICANCE AND IMPACT OF THE STUDY By inducing spores to germinate, our data confirm that the resulting cells exhibit sensitivities that can be leveraged when paired with certain decontamination measures. This increased susceptibility could be exploited to devise more efficient and safe decontamination measures and may obviate the need for more stringent methods that are currently in place.
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Affiliation(s)
- T O Omotade
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, USA
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Forghani F, Kim JB, Oh DH. Enterotoxigenic Profiling of Emetic Toxin- and Enterotoxin-ProducingBacillus cereus, Isolated from Food, Environmental, and Clinical Samples by Multiplex PCR. J Food Sci 2014; 79:M2288-93. [DOI: 10.1111/1750-3841.12666] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 08/21/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Fereidoun Forghani
- Dept. of Food Science and Biotechnology; School of Bio-convergence Science and Technology, Kangwon National Univ., Chuncheon, Gangwon 200-701, Republic of Korea. Author Kim is with Div. of Health Research and Planning, Gyeonggi-do Research Inst. of Health and Environment, Suwon, Gyeonggi 440-290, Korea
| | - Jung-Beom Kim
- Dept. of Food Science and Biotechnology; School of Bio-convergence Science and Technology, Kangwon National Univ., Chuncheon, Gangwon 200-701, Republic of Korea. Author Kim is with Div. of Health Research and Planning, Gyeonggi-do Research Inst. of Health and Environment, Suwon, Gyeonggi 440-290, Korea
| | - Deog-Hwan Oh
- Dept. of Food Science and Biotechnology; School of Bio-convergence Science and Technology, Kangwon National Univ., Chuncheon, Gangwon 200-701, Republic of Korea. Author Kim is with Div. of Health Research and Planning, Gyeonggi-do Research Inst. of Health and Environment, Suwon, Gyeonggi 440-290, Korea
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