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Genetic diversity of Brazilian Bacillus thuringiensis isolates with toxicity against Aedes aegypti (Diptera: Culicidae). Sci Rep 2022; 12:14408. [PMID: 36002607 PMCID: PMC9402949 DOI: 10.1038/s41598-022-18559-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 08/16/2022] [Indexed: 11/08/2022] Open
Abstract
Bacillus thuringiensis (Bt) isolates native to Maranhão (BtMA) that are highly toxic to Aedes aegypti larvae and seven standard subspecies of Bt were analyzed for genetic diversity using the rep-PRC technique with BOX, ERIC, REP, MB1, and GTG5 markers. The rep-PCR technique is considered an extremely reliable, reproducible, fast and highly discriminatory technique that may be used even among populations of the same species. These five markers revealed a total of 38 polymorphic DNA fragments for 30 BtMA isolates. Eight groups were obtained with the dendrogram generated through Pearson's correlation analysis, with four groups formed only with BtMA isolates and four comprised of isolates of BtMA and the standard subspecies toxic to dipterans and lepidopterans. Despite the high genetic diversity of BtMA, a low correlation between the collection site, gene content and mortality against A. aegypti larvae was evidenced. The clustering of the standard subspecies of Bt that were toxic against dipterans with BtMA isolates confirm the mosquitocidal action of the native isolates from Maranhão, and they can be used as an alternative for A. aegypti control and other insects of medical importance and for the control of agricultural pests.
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García-Suárez R, Verduzco-Rosas LA, Ibarra JE. Isolation and characterization of two highly insecticidal, endophytic strains of Bacillus thuringiensis. FEMS Microbiol Ecol 2021; 97:fiab080. [PMID: 34117749 DOI: 10.1093/femsec/fiab080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/10/2021] [Indexed: 11/14/2022] Open
Abstract
Recent discovery of endophytic strains of Bacillus thuringiensis significantly improves the knowledge on its ecology. It also may be a new source for the isolation of insecticidal strains. This report shows the characterization of two endophytic, highly insecticidal strains of B. thuringiensis. Strains LBIT-1250L and LBIT-1251P were isolated from lavender and Poinsettia sap, respectively. Their parasporal crystals were very similar in morphology to those shown by serotypes israelensis and kurstaki, respectively. Bioassays on Aedes aegypti fourth instar larvae and on Manduca sexta first instar larvae, respectively, showed significantly higher levels of toxicity than those of their standard counterparts, IPS-82 (israelensis) and HD-1 (kurstaki) strains, respectively. Characterization of both strains included the sequencing of flagellin (hag) gene, plasmid and Bc Rep-PCR patterns and crystal protein content. All four characterization features indicated that LBIT1250L is highly related to the IPS-82 standard (serotype H-14: israelensis); while the LBIT-1251P was highly related to the HD-1 standard (serotype H-3a3b3c kurstaki). These results indicate that endophytic strains of B. thuringiensis may be a new source of potential insecticidal strains and opens more in-depth studies about the role of this bacterium in such a specialized habitat.
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Affiliation(s)
- Rosalina García-Suárez
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto., Mexico
| | - Luis A Verduzco-Rosas
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto., Mexico
| | - Jorge E Ibarra
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado postal 629, 36500 Irapuato, Gto., Mexico
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Shikov AE, Malovichko YV, Lobov AA, Belousova ME, Nizhnikov AA, Antonets KS. The Distribution of Several Genomic Virulence Determinants Does Not Corroborate the Established Serotyping Classification of Bacillus thuringiensis. Int J Mol Sci 2021; 22:2244. [PMID: 33668147 PMCID: PMC7956386 DOI: 10.3390/ijms22052244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/02/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Bacillus thuringiensis, commonly referred to as Bt, is an object of the lasting interest of microbiologists due to its highly effective insecticidal properties, which make Bt a prominent source of biologicals. To categorize the exuberance of Bt strains discovered, serotyping assays are utilized in which flagellin serves as a primary seroreactive molecule. Despite its convenience, this approach is not indicative of Bt strains' phenotypes, neither it reflects actual phylogenetic relationships within the species. In this respect, comparative genomic and proteomic techniques appear more informative, but their use in Bt strain classification remains limited. In the present work, we used a bottom-up proteomic approach based on fluorescent two-dimensional difference gel electrophoresis (2D-DIGE) coupled with liquid chromatography/tandem mass spectrometry(LC-MS/MS) protein identification to assess which stage of Bt culture, vegetative or spore, would be more informative for strain characterization. To this end, the proteomic differences for the israelensis-attributed strains were assessed to compare sporulating cultures of the virulent derivative to the avirulent one as well as to the vegetative stage virulent bacteria. Using the same approach, virulent spores of the israelensis strain were also compared to the spores of strains belonging to two other major Bt serovars, namely darmstadiensis and thuringiensis. The identified proteins were analyzed regarding the presence of the respective genes in the 104 Bt genome assemblies available at open access with serovar attributions specified. Of 21 proteins identified, 15 were found to be encoded in all the present assemblies at 67% identity threshold, including several virulence factors. Notable, individual phylogenies of these core genes conferred neither the serotyping nor the flagellin-based phylogeny but corroborated the reconstruction based on phylogenomics approaches in terms of tree topology similarity. In its turn, the distribution of accessory protein genes was not confined to the existing serovars. The obtained results indicate that neither gene presence nor the core gene sequence may serve as distinctive bases for the serovar attribution, undermining the notion that the serotyping system reflects strains' phenotypic or genetic similarity. We also provide a set of loci, which fit in with the phylogenomics data plausibly and thus may serve for draft phylogeny estimation of the novel strains.
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Affiliation(s)
- Anton E. Shikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (A.E.S.); (Y.V.M.); (M.E.B.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia;
| | - Yury V. Malovichko
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (A.E.S.); (Y.V.M.); (M.E.B.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia;
| | - Arseniy A. Lobov
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia;
- Laboratory of Regenerative Biomedicine, Institute of Cytology of the Russian Academy of Science, 194064 St. Petersburg, Russia
| | - Maria E. Belousova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (A.E.S.); (Y.V.M.); (M.E.B.); (A.A.N.)
| | - Anton A. Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (A.E.S.); (Y.V.M.); (M.E.B.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia;
| | - Kirill S. Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia; (A.E.S.); (Y.V.M.); (M.E.B.); (A.A.N.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia;
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Wang K, Shu C, Soberón M, Bravo A, Zhang J. Systematic characterization of Bacillus Genetic Stock Center Bacillus thuringiensis strains using Multi-Locus Sequence Typing. J Invertebr Pathol 2018; 155:5-13. [PMID: 29723494 DOI: 10.1016/j.jip.2018.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 04/23/2018] [Accepted: 04/26/2018] [Indexed: 11/16/2022]
Abstract
The goal of this work was to perform a systematic characterization of Bacillus thuringiensis (Bt) strains from the Bacillus Genetic Stock Center (BGSC) collection using Multi-Locus Sequence Typing (MLST). Different genetic markers of 158 Bacillus thuringiensis (Bt) strains from 73 different serovars stored in the BGSC, that represented 92% of the different Bt serovars of the BGSC were analyzed, the 8% that were not analyzed were not available. In addition, we analyzed 72 Bt strains from 18 serovars available at the pubMLST bcereus database, and Bt strains G03, HBF18 and Bt185, with no H serovars provided by our laboratory. We performed a systematic MLST analysis using seven housekeeping genes (glpF, gmK, ilvD, pta, pur, pycA and tpi) and analyzed correlation of the results of this analysis with strain serovars. The 233 Bt strains analyzed were assigned to 119 STs from which 19 STs were new. Genetic relationships were established by phylogenetic analysis and showed that STs could be grouped in two major Clusters containing 21 sub-groups. We found that a significant number of STs (101 in total) correlated with specific serovars, such as ST13 that corresponded to nine Bt isolates from B. thuringiensis serovar kenyae. However, other serovars showed high genetic variability and correlated with multiple STs; for example, B. thuringiensis serovar morrisoni correlated with 11 different STs. In addition, we found that 16 different STs correlated with multiple serovars (2-4 different serovars); for example, ST12 correlated with B. thuringiensis serovar alesti, dakota, palmanyolensis and sotto/dendrolimus. These data indicated that only partial correspondence between MLST and serotyping can be established.
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Affiliation(s)
- Kui Wang
- College of Life Sciences, Northeast Agricultural University, Harbin 150030, China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62250, Mexico
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62250, Mexico
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; College of Life Sciences, Northeast Agricultural University, Harbin 150030, China.
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Pereira KS, Cayres CA, Chaves JQ, Brito JTD, Rabinovitch L, Vivoni AM. Salad dressing spoilage by Bacillus amyloliquefaciens with gas formation. BRAZILIAN JOURNAL OF FOOD TECHNOLOGY 2017. [DOI: 10.1590/1981-6723.2517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract B. amyloliquefaciens is a Gram-positive, aerobic, motile rod, often found in soil, which has been described as a plant growth promoter and is used in several industrial processes. This study reports an episode involving the gassy spoilage of salad dressing caused by B. amyloliquefaciens in a production facility located in Rio de Janeiro, Brazil. Nine B. amyloliquefaciens strains were isolated from spoiled salad dressings, the sugar used as a raw material in the manufacture and from the production plant. A genotypic analysis of the isolates by Rep-PCR generated eight band profiles grouped in five Rep-PCR clusters. When re-inoculated into fresh salad dressing three B. amyloliquefaciens isolates belonging to the Rep-PCR clusters A, D and E were able to reproduce the gassy spoilage process, whereas the isolates belonging to the Rep-PCR clusters B and C did not produce any visible spoilage, suggesting that these isolates were not directly involved in the spoilage process. The predominant Rep-PCR cluster, cluster A, included strains isolated from barbecue and passion fruit seed salad dressings and from sugar (raw material), suggesting it is a common source of contamination for such salad dressings.
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Bartoszewicz M, Czyżewska U. Spores and vegetative cells of phenotypically and genetically diverse Bacillus cereus sensu lato are common bacteria in fresh water of northeastern Poland. Can J Microbiol 2017; 63:939-950. [PMID: 28930645 DOI: 10.1139/cjm-2017-0337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Gram-positive rods Bacillus cereus sensu lato (sl) are common in natural habitats and food products. It is believed that they are restricted to spores; however, their ecology in aquatic habitats is still poorly investigated. Thus, the aim of the study was to assess the rain-dependent fluctuations in the concentration of B. cereus sl vegetative cells and spores, with evaluation of their phylogenetic and population structure in relation to the toxicity and psychrotolerance. We proved that vegetative cells of B. cereus sl are widely distributed in fresh water of rivers and lakes, being as common as spores. Moreover, heavy rain has a huge impact on their concentration in undisturbed environments. The diversity of B. cereus sl reflects the multiple sources of bacteria and the differences between their distinct environments. Next, their diverse genetic structure and phenotypes better fit their ecological properties than their taxonomic affiliation.
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Affiliation(s)
- Marek Bartoszewicz
- a Department of Microbiology, Institute of Biology, Faculty of Biology and Chemistry, University of Bialystok, 1J Ciolkowski Street, Bialystok 15-245, Poland
| | - Urszula Czyżewska
- b Department of Cytobiochemistry, Institute of Biology, Faculty of Biology and Chemistry, University of Bialystok, 1J Ciolkowski Street, Bialystok 15-245, Poland
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Characterization of the synergistic interaction between Beauveria bassiana strain GHA and Bacillus thuringiensis morrisoni strain tenebrionis applied against Colorado potato beetle larvae. J Invertebr Pathol 2017; 144:47-57. [DOI: 10.1016/j.jip.2017.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 01/12/2017] [Accepted: 01/14/2017] [Indexed: 11/22/2022]
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8
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de Fátima Gomes Cavados C, Pires ES, Chaves JQ, Alvarez DN, Benites Gil H, Braz Ribeiro de Oliveira I, de Barros Pinto Viviani Cunha A, Pereira da Cunha de Araújo-Coutinho CJ. Isolation and genetic characterization of Lysinibacillus sphaericus strains found in mosquito larvae (Diptera: Culicidae). Res Rep Trop Med 2017; 8:17-20. [PMID: 30050341 PMCID: PMC6038891 DOI: 10.2147/rrtm.s124066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Introduction Lysinibacillus sphaericus is a highly effective and specific bioinsecticide used for the control of Culicidae larvae. Objective This study aimed to identify and characterize L. sphaericus strains isolated from Culex quinquefasciatus larvae in Brazil. Methods C. quinquefasciatus larvae were collected from streams in the urban area of São Paulo state. L. sphaericus strains were identified through cytomorphology, biochemical, and physiological analyses. Qualitative bioassays were performed to evaluate the toxicity of the strains against C. quinquefasciatus. The crystal compound protein pattern of L. sphaericus strains was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Five reference strains were used as standards in all tests performed. Repetitive extragenic palindromic elements-polymerase chain reaction (REP-PCR) was utilized in an attempt to differentiate pathogenic and nonpathogenic isolates. Results Twenty-one strains were isolated. Only one presented toxic activity against C. quinquefasciatus. REP-PCR results identified 23 patterns among the 26 strains used in the study, and the fragment analysis showed low similarity (16%) between L. sphaericus isolates and the five reference strains. Conclusion Comparison of strains isolated in this study using REP-PCR showed a low similarity to other strains, demonstrating the high intraspecific variability for L. sphaericus.
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Affiliation(s)
| | - Eder Soares Pires
- Laboratory of Bacterial Physiology, Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Rio de Janeiro
| | - Jeane Quintanilha Chaves
- Laboratory of Bacterial Physiology, Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Rio de Janeiro
| | - Danielle Nunes Alvarez
- Laboratory of Bacterial Physiology, Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Rio de Janeiro
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9
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Genetic diversity and functional characterization of endophytic Bacillus thuringiensis isolates from the North Western Indian Himalayas. ANN MICROBIOL 2016. [DOI: 10.1007/s13213-016-1244-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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10
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Reinoso-Pozo Y, Del Rincón-Castro MC, Ibarra JE. Characterization of a highly toxic strain of Bacillus thuringiensis serovar kurstaki very similar to the HD-73 strain. FEMS Microbiol Lett 2016; 363:fnw188. [PMID: 27535648 DOI: 10.1093/femsle/fnw188] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2016] [Indexed: 11/14/2022] Open
Abstract
The LBIT-1200 strain of Bacillus thuringiensis was recently isolated from soil, and showed a 6.4 and 9.5 increase in toxicity, against Manduca sexta and Trichoplusia ni, respectively, compared to HD-73. However, LBIT-1200 was still highly similar to HD-73, including the production of bipyramidal crystals containing only one protein of ∼130 000 kDa, its flagellin gene sequence related to the kurstaki serotype, plasmid and RepPCR patterns similar to HD-73, no production of β-exotoxin and no presence of VIP genes. Sequencing of its cry gene showed the presence of a cry1Ac-type gene with four amino acid differences, including two amino acid replacements in domain III, compared to Cry1Ac1, which may explain its higher toxicity. In conclusion, the LBIT-1200 strain is a variant of the HD-73 strain but shows a much higher toxicity, which makes this new strain an important candidate to be developed as a bioinsecticide, once it passes other tests, throughout its biotechnological development.
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Affiliation(s)
- Yaritza Reinoso-Pozo
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, 36500 Irapuato, Guanajuato, Mexico
| | - Ma Cristina Del Rincón-Castro
- Departamento de Alimentos, División de Ciencias de la Vida, Universidad de Guanajuato, 36500 Irapuato, Guanajuato, Mexico
| | - Jorge E Ibarra
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, 36500 Irapuato, Guanajuato, Mexico
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García K, Ibarra JE, Bravo A, Díaz J, Gutiérrez D, Torres PV, Gomez de Leon P. Variability of Bacillus thuringiensis strains by ERIC-PCR and biofilm formation. Curr Microbiol 2014; 70:10-8. [PMID: 25129641 DOI: 10.1007/s00284-014-0675-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 07/07/2014] [Indexed: 10/24/2022]
Abstract
Bacillus thuringiensis (Bt) is a soil-dwelling bacterium of great interest for agronomical research because of its use as biological pesticide. There are some limitations regarding the subspecies classification. Phenotyping and genotyping studies are important to ascertain its variability. The diversity of 40 environmental strains, isolated from different regions in Mexico, was analyzed by ERIC-PCR and the ability of biofilm formation. Thirty-nine different fingerprinting patterns revealed enough data to discriminate among the 40 strains. A total of 24 polymorphic fragments with sizes between 139 and 1,468 bp were amplified. Almost all (95 %) strains showed biofilm formation after 96 h of incubation. At 96 h of incubation the biofilm-forming strains from the CINVESTAV collection showed a more heterogeneous ability as biofilms producers. Results showed a large intra-species genomic variability in Bt. However, some strains could be correlated as they were found within clusters depending on the location of isolation.
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Affiliation(s)
- Karina García
- Departamento de Salud Pública, Facultad de Medicina UNAM, Circuito escolar s/n Ciudad Universitaria, Col, Copilco Universidad, C.P. 04510, Mexico D. F, Mexico,
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12
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Milutinović B, Stolpe C, Peuβ R, Armitage SAO, Kurtz J. The red flour beetle as a model for bacterial oral infections. PLoS One 2013; 8:e64638. [PMID: 23737991 PMCID: PMC3667772 DOI: 10.1371/journal.pone.0064638] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 04/17/2013] [Indexed: 01/03/2023] Open
Abstract
Experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. The red flour beetle Tribolium castaneum and the spore-forming bacterial insect pathogen Bacillus thuringiensis (Bt) are widely used and tractable model organisms. However, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. We used a high throughput oral infection protocol to infect T. castaneum insects with coleopteran specific B. thuringiensis bv. tenebrionis (Btt) bacteria. We found that larval mortality depends on the dietary spore concentration and on the duration of exposure to the spores. Furthermore, differential susceptibility of larvae from different T. castaneum populations indicates that the host genetic background influences infection success. The recovery of high numbers of infectious spores from the cadavers indicates successful replication of bacteria in the host and suggests that Btt could establish infectious cycles in T. castaneum in nature. We were able to transfer plasmids from Btt to a non-pathogenic but genetically well-characterised Bt strain, which was thereafter able to successfully infect T. castaneum, suggesting that factors residing on the plasmids are important for the virulence of Btt. The availability of a genetically accessible strain will provide an ideal model for more in-depth analyses of pathogenicity factors during oral infections. Combined with the availability of the full genome sequence of T. castaneum, this system will enable analyses of host responses during infection, as well as addressing basic questions concerning host-parasite coevolution.
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Affiliation(s)
- Barbara Milutinović
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Clemens Stolpe
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Robert Peuβ
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | | | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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13
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Germination and proliferation of emetic Bacillus cereus sensu lato strains in milk. Folia Microbiol (Praha) 2013; 58:529-35. [DOI: 10.1007/s12223-013-0237-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 03/05/2013] [Indexed: 10/27/2022]
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14
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Godoy SN, Matushima ER, Chaves JQ, Cavados CFG, Rabinovitch L, Teixeira RHF, Nunes ALV, Melville P, Gattamorta MA, Vivoni AM. Bacillus cereus infection outbreak in captive psittacines. Vet Microbiol 2012; 161:213-7. [PMID: 22902190 DOI: 10.1016/j.vetmic.2012.07.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 07/19/2012] [Accepted: 07/20/2012] [Indexed: 11/27/2022]
Abstract
This study reports an uncommon epizootic outbreak of Bacillus cereus that caused the sudden death of 12 psittacines belonging to the species Anodorhynchus hyacinthinus (1 individual), Diopsittaca nobilis (1 individual), Ara severa (1 individual) and Ara ararauna (9 individuals) in a Brazilian zoo. Post-mortem examination of the animals reveled extensive areas of lung hemorrhage, hepatic congestion, hemorrhagic enteritis and cardiac congestion. Histopathological examination of the organs showed the presence of multiple foci of vegetative cells of Gram-positive bacilli associated with discrete and moderate mononuclear inflammatory cell infiltrate. Seventeen B. cereus strains isolated from blood and sterile organs of nine A. ararauna were analyzed in order to investigate the genetic diversity (assessed by Rep-PCR) and toxigenic profiles (presence of hblA, hblC and hblD; nheA, nheB and nheC as well as cytK, ces and entFM genes) of such strains. Amplification of genomic DNA by Rep-PCR of B. cereus strains generated two closely related profiles (Rep-PCR types A and B) with three bands of difference. All strains were classified as belonging to the toxigenic profile I which contained HBL and NHE gene complexes, entFM and cytK genes. Altogether, microbiological and histopathological findings and the evidence provided by the success of the antibiotic prophylaxis, corroborate that B. cereus was the causative agent of the infection that killed the birds.
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Affiliation(s)
- S N Godoy
- Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Av. Prof. Dr. Orlando Marques Paiva, 87 - Cidade Universitária, São Paulo, SP, Brazil
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15
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Humblot C, Perez-Pulido R, Akaki D, Loiseau G, Guyot JP. Prevalence and fate of Bacillus cereus in African traditional cereal-based foods used as infant foods. J Food Prot 2012; 75:1642-5. [PMID: 22947472 DOI: 10.4315/0362-028x.jfp-11-450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective of the present work was to estimate the prevalence of Bacillus cereus group species in traditional cereal-based lactic acid-fermented slurries and nonfermented flours used to prepare infant foods in an African context. High counts on mannitol-egg yolk-polymixin agar medium were determined for the fermented slurries (median, 4.5 × 10(4) CFU/ml of slurry) compared with the nonfermented flours, most of whose counts were lower than 10(-1) CFU/g. Virulence genes were characterized in 60 isolates from 26 traditional cereal-based foods in Ouagadougou (Burkina Faso). Seventy-two and 38 % of isolates were positive for the complete set of genes coding for hemolysin BL and nonhemolytic enterotoxin, respectively, suggesting a high enterotoxigenic potential for these foodborne isolates. No potentially emetic toxin-producing strains were detected. Because of the high counts found for fermented slurries, survival tests with vegetative cells inoculated in fermented slurries were performed, which showed that growth of B. cereus was inhibited. This result suggests that fermentation in traditional production units is presumably not adequately controlled, enabling growth during any unit operations before fermentation, or even during the fermentation step, when the process was poorly controlled. However, adding nisin (0.1 mg/ml) enabled a 5-log reduction in the B. cereus population in 5 h, suggesting that the use of nisin could be a way to upgrade the hygienic quality of this type of food.
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Affiliation(s)
- Christèle Humblot
- Institut de Recherche pour le Développement, UMR Nutripass, Université Montpellier 1-Université Montpellier 2, Montpellier, France
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16
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Katara J, Deshmukh R, K Singh N, Kaur S. Molecular typing of native Bacillus thuringiensis isolates from diverse habitats in India using REP-PCR and ERIC-PCR analysis. J GEN APPL MICROBIOL 2012; 58:83-94. [PMID: 22688239 DOI: 10.2323/jgam.58.83] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Bacillus thuringiensis is a bacterium of great agronomic and scientific interest. The subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. Therefore molecular typing and diversity analysis of B. thuringiensis has enormous importance for discrimination of strains isolated from different sources. In this study, 113 native B. thuringiensis isolates collected from diverse habitats and locations in India and 27 B. thuringiensis type strains obtained from the Bacillus Genetic Stock Centre (BGSC), Ohio State University, USA and used as reference, were analyzed for molecular typing. Genotypic data of 140 B. thuringiensis isolates and type strains was generated by using REP-PCR and ERIC-PCR primers and unweighted pair group method with arithmetic mean (UPGMA) analysis using NTSYSpc2.2 and grouped into 4 main clusters. All the groups have isolates from diverse origins. No group was found to represent any specific origin or location. The observed patterns of REP-PCR and ERIC-PCR pattern were discriminatory enough to reveal differences in the B. thuringiensis isolates and reference strains. The resolution power and marker index of the ERIC-PCR (RP 9.39, MI 6.34) was found to be higher than that of the REP-PCR (RP 6.20, MI 4.48). The REP-PCR and ERIC-PCR markers have been found to be useful for discrimination of B. thuringiensis isolates and reference strains. ERIC-PCR was the more informative of the two techniques. This study showed that the B. thuringiensis isolates collected from diverse habitats in India had a high degree of genetic diversity.
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Affiliation(s)
- Jawahar Katara
- National Research Center on Plant Biotechnology, IARI Campus, New Delhi 110012, India
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17
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Chaves JQ, Cavados CDFG, Vivoni AM. Molecular and toxigenic characterization of Bacillus cereus and Bacillus thuringiensis strains isolated from commercial ground roasted coffee. J Food Prot 2012; 75:518-22. [PMID: 22410226 DOI: 10.4315/0362-028x.jfp-11-325] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Thirty samples of roasted ground coffee beans from 10 different commercial brands were analyzed to investigate the occurrence and levels of Bacillus cereus and Bacillus thuringiensis strains. Strains were evaluated for their genetic diversity by repetitive element sequence polymorphism PCR (Rep-PCR) and for their toxigenic profiles, i.e., the presence of hblA, hblC, hblD, nheA, nheB, nheC, cytK, ces, and entFM. Survival and multiplication of B. cereus sensu lato in the ready-to-drink coffee was determined to evaluate this beverage as a possible vehicle for B. cereus infection. B. cereus was detected in 17 (56.7%) of the 30 samples, and B. thuringiensis was detected in 8 (26.7%) of the 30 samples. Five samples did not produce any characteristic growth. The most common gene, entFM, was detected in 23 strains (92%). The NHE complex (nheA, nheB, and nheC genes) was found in 19 strains (76%). The HBL complex (hblA, hblC, and hblD) was found in 16 strains (64%). All strains were negative for ces. The cytK gene was found in 16 strains (64%). The computer-assisted cluster analysis of Rep-PCR profiles using a clustering criterion of 80% similarity revealed four main clusters. Cluster 1 was the predominant and comprised three B. thuringiensis strains with 100% similarity, cluster 2 comprised two B. cereus strains (100% similarity), cluster 3 comprised two B. thuringiensis strains (90% similarity), and cluster 4 comprised one B. thuringiensis strain and one B. cereus strain (85% similarity). The cluster analysis of fingerprints generated by Rep-PCR revealed a high genetic diversity among the B. cereus strains, suggesting that the contamination could have originated from different sources. In our experiments, when sugar was added and the beverage was kept in thermic bottles there was a significant increase in B. cereus sensu lato levels, which may increase the risk of food poisoning. These results highlight the need for additional studies on this subject to better evaluate coffee as a food poisoning vehicle.
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Affiliation(s)
- Jeane Quintanilha Chaves
- Laboratório de Fisiologia Bacteriana, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Avenida Brasil 4365, Pavilhão Rocha Lima, Sala 312, Manguinhos, CEP 21045-900 Rio de Janeiro, Brasil
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18
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Sauka DH, Basile JI, Benintende G. Evidence of Bacillus thuringiensis intra-serovar diversity revealed by Bacillus cereus group-specific repetitive extragenic palindromic sequence-based PCR genomic fingerprinting. J Mol Microbiol Biotechnol 2012; 21:184-90. [PMID: 22286045 DOI: 10.1159/000335532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Bacillus thuringiensis is classified into serovars on the basis of H-flagellar antigens. Several alternative typing methods have been described. Among them, a B. cereus group-specific repetitive extragenic palindromic (Rep)-PCR fingerprinting technique was shown to be discriminative and able to identify B. thuringiensis serovars. The aim of this study was to investigate the genomic diversity and relationship among B. thuringiensis strains collected from different Argentinean ecosystems. Thirty-seven B. thuringiensis reference strains and 131 Argentinean isolates were analyzed using a B. cereus group-specific Rep-PCR. Fourteen different patterns were identified among the Argentinean isolates. Eight could not be associated to any pattern obtained from a reference strain. The pattern identical to the serovar kurstaki HD-1 strain was the most frequently identified in 68 native isolates. The profiles allowed tracing a single dendrogram with two groups and eight main lineages. Some strains showed distinctive patterns despite belonging to the same serovar. An intraspecific diversity resulted from this analysis that was highlighted by this technique since strains from a given serovar showed distinct profiles. This study may help to establish a system of B. thuringiensis classification with a higher discrimination level than established by the H antigen serotyping.
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Affiliation(s)
- Diego H Sauka
- Insumos Bacterianos, Instituto de Microbiología y Zoología Agrícola, Instituto Nacional de Tecnología Agropecuaria, Castelar, Argentina.
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19
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Biological characterization of two Bacillus thuringiensis strains toxic against Spodoptera frugiperda. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0701-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Chaves JQ, Pires ES, Vivoni AM. Genetic diversity, antimicrobial resistance and toxigenic profiles of Bacillus cereus isolated from food in Brazil over three decades. Int J Food Microbiol 2011; 147:12-6. [PMID: 21440319 DOI: 10.1016/j.ijfoodmicro.2011.02.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 02/22/2011] [Accepted: 02/23/2011] [Indexed: 10/18/2022]
Abstract
Bacillus cereus is an ever-present problem. It is widely distributed in several environments such as soil and plants and is commonly isolated from food and additives. In this study we analyzed 97 foodborne B. cereus sensu stricto strains isolated in Brazil in the 1980's, 1990's and 2000's in order to investigate the genetic diversity (assessed by Rep-PCR), antimicrobial resistance and toxigenic profiles (presence of hblA, hblC and hblD; nheA, nheB and nheC as well as cytK, ces and entFM genes) of such strains. The majority of the strains (79, 81.4%) were β-hemolytic. The NHE complex was found in 82 strains (84.5%) and HBL complex was found in 61 (62.9%) strains. All strains were negative to ces. The cytK-2 gene was found in 44 (45.4%) strains. The predominant toxigenic pattern was type I (32, 33%) which included strains positive for all toxin genes but ces. Computer assisted cluster analysis of Rep-PCR profiles showed a high genetic diversity. Seven major clusters comprising two or more strains were found and cluster 1 was predominant (ten strains, nine of them showing 100% similarity). This cluster included strains isolated in the 1980's and the 1990's. Cluster analysis of Rep-PCR profiles based on decade of isolation, source, hemolytic pattern, toxigenic and antibiotic resistance patterns revealed a similar clustering pattern as found in the analysis including all strains. The inability to observe a predominant band pattern when Rep-PCR cluster analysis was based on decade of isolation suggests that this diversity has been maintained over time. All strains were susceptible to gentamicin. We detected resistance to tetracycline (11 strains showing intermediate resistance and nine completely resistant strains), clindamycin (ten intermediate strains) and vancomycin (one strain). Clindamycin resistance showed statistical association with strains isolated in 2000's. The predominant resistance pattern was type A (72, 72.2%) which included strains susceptible to all drugs tested. Our results suggest that the majority of the strains present in several types of food in Brazil pose a potential risk to cause food poisoning due to the high prevalence of toxin genes found in these strains. However, additional studies involving cytotoxicity tests and affiliation of these strains to phylogenetic groups based on molecular data would be useful to better evaluate this potential and could provide a more accurate indication of the risk.
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Affiliation(s)
- Jeane Quintanilha Chaves
- Laboratório de Fisiologia Bacteriana, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, FIOCRUZ, RJ, Brazil
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21
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Detection of new cry genes of Bacillus thuringiensis by use of a novel PCR primer system. Appl Environ Microbiol 2010; 76:6150-5. [PMID: 20656876 DOI: 10.1128/aem.00797-10] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
On the basis of the known cry gene sequences of Bacillus thuringiensis, three sets of primers were designed from four conserved blocks found in the delta-endotoxin-coding region. The primer pairs designed amplify the regions between blocks 1 and 5, 2 and 5, and 1 and 4. In silico analyses indicated that 100% of the known three-domain cry gene sequences can be amplified by these sets of primers. To test their ability to amplify known and unknown cry gene sequences, 27 strains from the CINVESTAV (LBIT series) collection showing atypical crystal morphology were selected. Their DNA was used as the template with the new primer system, and after a systematic amplification and sequencing of the amplicons, each strain showed one or more cry-related sequences, totaling 54 different sequences harbored by the 27 strains. Seven sequences were selected on the basis of their low level of identity to the known cry sequences, and once cloning and sequencing of the complete open reading frames were done, three new cry-type genes (primary ranks) were identified and the toxins that they encode were designated Cry57Aa1, Cry58Aa1, and Cry59Aa1 by the B. thuringiensis Toxin Nomenclature Committee. The rest of the seven sequences were classified Cry8Ka2, Cry8-like, Cry20Ba1, and Cry1Ma1 by the committee. The crystal morphology of the selected strains and analysis of the new Cry protein sequences showed interesting peculiarities.
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Ventura-Suárez A, Cruz-Camarillo R, Rampersad J, Ammons DR, López-Villegas EO, Ibarra JE, Rojas-Avelizapa LI. Characterization of a novel Bacillus thuringiensis phenotype possessing multiple appendages attached to a parasporal body. Curr Microbiol 2010; 62:307-12. [PMID: 20640854 DOI: 10.1007/s00284-010-9678-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 05/10/2010] [Indexed: 11/29/2022]
Abstract
Bacillus thuringiensis is a bacterium best known for its production of crystal-like bodies comprised of one or more Cry-proteins, which can be toxic to insects, nematodes or cancer cells. Although strains of B. thuringiensis have occasionally been observed with filamentous appendages attached to their spores, appendages in association with their parasporal bodies are extremely rare. Herein we report the characterization of Bt1-88, a bacterial strain isolated from the Caribbean that produces a spore-crystal complex containing six long appendages, each comprised of numerous thinner filaments approximately 10 nm in diameter and 2.5 μm in length. Each of the multi-filament appendages was attached to a single, small parasporal body located at one end of the bacterial spore. Biochemical tests, 16S rDNA gene sequencing, and the identification of two Cry proteins by partial protein sequencing (putatively Cry1A and Cry2A), unambiguously identified Bt1-88 as a strain of B. thuringiensis. Bt1-88 represents the second reported strain of B. thuringiensis possessing a parasporal body/appendage phenotype characterized by one or more long appendages, comprised of numerous filaments in association with a parasporal body. This finding suggests that Bt1-88 is a member of a new phenotypic class of B. thuringiensis, in which the parasporal body may perform a novel structural role through its association with multi-filament appendages.
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Affiliation(s)
- Antonio Ventura-Suárez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del I.P.N, Carpio y Plan de Ayala S/N, Casco de Santo Tomas, Mexico DF, 11340, Mexico
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23
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Schuch R, Fischetti VA. The secret life of the anthrax agent Bacillus anthracis: bacteriophage-mediated ecological adaptations. PLoS One 2009; 4:e6532. [PMID: 19672290 PMCID: PMC2716549 DOI: 10.1371/journal.pone.0006532] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Accepted: 07/01/2009] [Indexed: 12/31/2022] Open
Abstract
Ecological and genetic factors that govern the occurrence and persistence of anthrax reservoirs in the environment are obscure. A central tenet, based on limited and often conflicting studies, has long held that growing or vegetative forms of Bacillus anthracis survive poorly outside the mammalian host and must sporulate to survive in the environment. Here, we present evidence of a more dynamic lifecycle, whereby interactions with bacterial viruses, or bacteriophages, elicit phenotypic alterations in B. anthracis and the emergence of infected derivatives, or lysogens, with dramatically altered survival capabilities. Using both laboratory and environmental B. anthracis strains, we show that lysogeny can block or promote sporulation depending on the phage, induce exopolysaccharide expression and biofilm formation, and enable the long-term colonization of both an artificial soil environment and the intestinal tract of the invertebrate redworm, Eisenia fetida. All of the B. anthracis lysogens existed in a pseudolysogenic-like state in both the soil and worm gut, shedding phages that could in turn infect non-lysogenic B. anthracis recipients and confer survival phenotypes in those environments. Finally, the mechanism behind several phenotypic changes was found to require phage-encoded bacterial sigma factors and the expression of at least one host-encoded protein predicted to be involved in the colonization of invertebrate intestines. The results here demonstrate that during its environmental phase, bacteriophages provide B. anthracis with alternatives to sporulation that involve the activation of soil-survival and endosymbiotic capabilities.
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Bartoszewicz M, Hansen B, Swiecicka I. The members of the Bacillus cereus group are commonly present contaminants of fresh and heat-treated milk. Food Microbiol 2008; 25:588-96. [DOI: 10.1016/j.fm.2008.02.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 02/08/2008] [Accepted: 02/12/2008] [Indexed: 11/26/2022]
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25
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De Jonghe V, Coorevits A, Vandroemme J, Heyrman J, Herman L, De Vos P, Heyndrickx M. Intraspecific genotypic diversity of Bacillus species from raw milk. Int Dairy J 2008. [DOI: 10.1016/j.idairyj.2007.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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26
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Klevan A, Tourasse NJ, Stabell FB, Kolstø AB, Økstad OA. Exploring the evolution of the Bacillus cereus group repeat element bcr1 by comparative genome analysis of closely related strains. MICROBIOLOGY-SGM 2008; 153:3894-3908. [PMID: 17975097 DOI: 10.1099/mic.0.2007/005504-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
bcr1 is a chromosomal approximately 155 bp repeated element found uniquely and ubiquitously in the Bacillus cereus group of Gram-positive bacteria; it exhibits several features characteristic of mobile elements, including a variable distribution pattern between strains. Here, highly similar bcr1 elements in non-conserved genomic loci are identified in a set of closely related B. cereus and Bacillus thuringiensis strains near the Bacillus anthracis phylogenetic cluster. It is also shown that bcr1 may be present on small RNA transcripts in the 100-400 bp size range. In silico folding of bcr1 at the RNA level indicated that transcripts may form a double-hairpin-like structure predicted to have high structural stability. A functional role of bcr1 at the RNA level is supported by multiple cases of G-U base-pairing, and compensatory mutations maintaining structural stability of the RNA fold. In silico folding at the DNA level produced similar predicted structures, with the potential to form a cruciform structure at open DNA complexes. The predicted structural stability was greater for bcr1 elements showing high sequence identities to bcr1 elements in non-conserved chromosomal loci in other strains, relative to other bcr1 copies. bcr1 mobility could thus be dependent on the formation of a stable DNA or RNA intermediate. Furthermore, bcr1 elements potentially encoding structurally stable and less stable transcripts were phylogenetically intermixed, indicating that loss of bcr1 mobility may have occurred multiple times during evolution. Repeated elements with similar features in other bacteria have been shown to provide functions such as mRNA stabilization, transcription termination and/or promoter function. Similarly, bcr1 may constitute a mobile element which occasionally gains a function when it enters an appropriate chromosomal locus.
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Affiliation(s)
- Are Klevan
- Department of Pharmaceutical Biosciences (Microbiology), University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Nicolas J Tourasse
- Department of Pharmaceutical Biosciences (Microbiology), University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Fredrik B Stabell
- Department of Pharmaceutical Biosciences (Microbiology), University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Anne-Brit Kolstø
- Department of Pharmaceutical Biosciences (Microbiology), University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Ole Andreas Økstad
- Department of Pharmaceutical Biosciences (Microbiology), University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
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Multiple-locus sequence typing and analysis of toxin genes in Bacillus cereus food-borne isolates. Appl Environ Microbiol 2007; 74:850-60. [PMID: 18083872 DOI: 10.1128/aem.01495-07] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present study we characterized 47 food-borne isolates of Bacillus cereus using multilocus sequence typing (MLST). Newly determined sequences were combined with sequences available in public data banks in order to produce the largest data set possible. Phylogenetic analysis was performed on a total of 296 strains for which MLST sequence information is available, and three main lineages--I, II, and III--within the B. cereus complex were identified. With few exceptions, all food-borne isolates were in group I. The occurrence of horizontal gene transfer (HGT) among various strains was analyzed by several statistical methods, providing evidence of widespread lateral gene transfer within B. cereus. We also investigated the occurrence of toxin-encoding genes, focusing on their evolutionary history within B. cereus. Several patterns were identified, indicating a pivotal role of HGT in the evolution of toxin-encoding genes. Our results indicate that HGT is an important element in shaping the population structure of the B. cereus complex. The results presented here also provide strong evidence of reticulate evolution within the B. cereus complex.
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Cherif A, Ettoumi B, Raddadi N, Daffonchio D, Boudabous A. Genomic diversity and relationship of Bacillus thuringiensis and Bacillus cereus by multi-REP-PCR fingerprinting. Can J Microbiol 2007; 53:343-50. [PMID: 17538643 DOI: 10.1139/w06-129] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The genomic diversity and relationship among 56 Bacillus thuringiensis and Bacillus cereus type strains were investigated by multi-REP-PCR fingerprinting consisting of three PCR reactions targeting the enterobacterial ERIC1 and ERIC2 and the streptococcal BOXA1R consensus sequences. A total of 113 polymorphic bands were generated in the REP-PCR profiles that allowed tracing of a single dendrogram with three major groups. Bacillus cereus strains clustered together in the A and B groups. Most of the B. thuringiensis strains clustered in group C, which included groups of serovars with a within-group similarity higher than 40% as follows: darmstadiensis, israelensis, and morrisoni; aizawai, kenyae, pakistani, and thompsoni; canadensis, entomocidus, galleriae, kurstaki, and tolworthi; alesti, dendrolimus, and kurstaki; and finitimus, sotto, and thuringiensis. Multi-REP-PCR fingerprinting clustered B. thuringiensis serovars in agreement with previously developed multilocus sequence typing schemes, indicating that it represents a rapid shortcut for addressing the genetic relationship of unknown strains with the major known serovars.
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Affiliation(s)
- Ameur Cherif
- Laboratoire miroorganismes et biomolécules actives, Faculté des sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisia.
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29
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Shadrin AM, Shapyrina EV, Siunov AV, Severinov KV, Solonin AS. Bacillus cereus pore-forming toxins hemolysin II and cytotoxin K: Polymorphism and distribution of genes among representatives of the cereus group. Microbiology (Reading) 2007. [DOI: 10.1134/s0026261707040042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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30
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López AC, Alippi AM. Phenotypic and genotypic diversity of Bacillus cereus isolates recovered from honey. Int J Food Microbiol 2007; 117:175-84. [PMID: 17466403 DOI: 10.1016/j.ijfoodmicro.2007.03.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 03/19/2007] [Accepted: 03/19/2007] [Indexed: 10/23/2022]
Abstract
Of 433 honey samples collected in Argentina, 114 (27%) yielded Bacillus cereus isolates (27%) and 60 (14%) yielded other species of Bacillus. The Argentinian B. cereus isolates were compared with isolates recovered from honey from other countries (n=16) and with strain ATCC 11718. The 133 B. cereus isolates and the ATCC strain were characterized using rep-PCR fingerprinting with primers BOX, REP and ERIC, restriction fragment length polymorphism analysis of a 16S rRNA gene fragment (16S rRNA PCR/RFLP), and morphological and biochemical tests. There was a high degree of diversity, both phenotypic and genotypic among the isolates of B. cereus. Our results demonstrate the usefulness of rep-PCR genomic fingerprinting for characterizing populations of B. cereus. According to our knowledge, this is the first report of phenotypic and genotypic characterization of B. cereus isolates from honey.
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Affiliation(s)
- Ana C López
- Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, calle 60 y 118 s/n, 1900 La Plata, Argentina
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31
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Tourasse NJ, Helgason E, Økstad OA, Hegna IK, Kolstø AB. The Bacillus cereus group: novel aspects of population structure and genome dynamics. J Appl Microbiol 2007; 101:579-93. [PMID: 16907808 DOI: 10.1111/j.1365-2672.2006.03087.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
AIMS To provide new insights into the population and genomic structure of the Bacillus cereus group of bacteria. METHODS AND RESULTS The genetic relatedness among B. cereus group strains was assessed by multilocus sequence typing (MLST) using an optimized scheme based on seven chromosomal housekeeping genes. A set of 48 strains from different clinical sources was included, and six clonal complexes containing several genetically similar isolates from unrelated patients were identified. Interestingly, several clonal groups contained strains that were isolated from similar human sources. Furthermore, comparative whole genome sequence analysis of 16 strains led to the discovery of novel ubiquitous genome features of the B. cereus group, such as atypical group II introns, IStrons, and hitherto uncharacterized repeated elements. CONCLUSIONS The B. cereus group constitutes a coherent population unified by the presence of ubiquitous and specific genetic elements which do not show any pattern, either in their sequences or genomic locations, which allows to differentiate between the member species of the group. Nevertheless, the population is very dynamic, as particular lineages of clinical origin can evolve to form clonal complexes. At the genome level, the dynamic behaviour is indicated by the presence of numerous mobile and repeated elements. SIGNIFICANCE AND IMPACT OF THE STUDY The B. cereus group of bacteria comprises species that are of medical and economic importance. The MLST data, along with the primers and protocols used, will be available in a public, web-accessible database (http://mlstoslo.uio.no).
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Affiliation(s)
- N J Tourasse
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway
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32
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Esterase electrophoretic polymorphism ofBacillus thuringiensis andBacillus cereus reference strains. ANN MICROBIOL 2007. [DOI: 10.1007/bf03175045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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