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M, Hemalatha y Subathra Devi C. "OPTIMIZATION OF RIBOFLAVIN PRODUCTION USING BACILLUS CEREUS HDS07: A STRAIN ISOLATED FROM AGARICUS BISPORUS". Journal of microbiology, biotechnology and food sciences 12, n.º 5 (1 de febrero de 2023): e9066. http://dx.doi.org/10.55251/jmbfs.9066.
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The current study focused on the production and optimization of riboflavin from Bacillus cereus, a strain isolated from Agaricus bisporus. Seven different strains were isolated from Agaricus bisporus and screened for riboflavin production. Among the 7 strains, only 4 strains were identified as riboflavin producers by riboflavin assay medium (RAM). To determine the potency of the strains, selected strains were exposed to roseoflavin – an analogue of riboflavin. The potent strain was identified through morphological, biochemical, and molecular characterization and the strain name was designated as HDS07. Estimation of riboflavin was done by UV Spectrophotometry. Riboflavin production was done in Chemically Defined Medium (CDM) and De Man, Rogosa and Sharpe agar (MRS) using a strain Bacillus cereus HDS07. To enhance riboflavin production, the medium was optimized with different parameters like carbon, nitrogen sources, pH, temperature, and inoculum size. The potent strain HDS07 was identified as Bacillus cereus by 16S rDNA sequencing and NCBI-Gen Bank accession number - MK177597 was obtained. Riboflavin production from Bacillus cereus-HDS07 was more in the MRS medium than that of CDM. It was found to be 2.97 mg/L and 1.8 mg/L correspondingly. The maximum riboflavin (3.48 mg/L) was obtained from Bacillus cereus-HDS07 under the culture conditions; glucose, glycine, pH-6, 30℃, and 3% inoculum size. The current study emphasizes that the isolated potent strain Bacillus cereus-HDS07 from Agaricus bisporus could be used as a starter for the industrial production of riboflavin.
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Han, Cliff S., Gary Xie, Jean F. Challacombe, Michael R. Altherr, Smriti S. Bhotika, David Bruce, Connie S. Campbell et al. "Pathogenomic Sequence Analysis of Bacillus cereus and Bacillus thuringiensis Isolates Closely Related to Bacillus anthracis". Journal of Bacteriology 188, n.º 9 (1 de mayo de 2006): 3382–90. http://dx.doi.org/10.1128/jb.188.9.3382-3390.2006.
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ABSTRACT Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis are closely related gram-positive, spore-forming bacteria of the B. cereus sensu lato group. While independently derived strains of B. anthracis reveal conspicuous sequence homogeneity, environmental isolates of B. cereus and B. thuringiensis exhibit extensive genetic diversity. Here we report the sequencing and comparative analysis of the genomes of two members of the B. cereus group, B. thuringiensis 97-27 subsp. konkukian serotype H34, isolated from a necrotic human wound, and B. cereus E33L, which was isolated from a swab of a zebra carcass in Namibia. These two strains, when analyzed by amplified fragment length polymorphism within a collection of over 300 of B. cereus, B. thuringiensis, and B. anthracis isolates, appear closely related to B. anthracis. The B. cereus E33L isolate appears to be the nearest relative to B. anthracis identified thus far. Whole-genome sequencing of B. thuringiensis 97-27and B. cereus E33L was undertaken to identify shared and unique genes among these isolates in comparison to the genomes of pathogenic strains B. anthracis Ames and B. cereus G9241 and nonpathogenic strains B. cereus ATCC 10987 and B. cereus ATCC 14579. Comparison of these genomes revealed differences in terms of virulence, metabolic competence, structural components, and regulatory mechanisms.
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Quagliariello, Andrea, Angela Cirigliano y Teresa Rinaldi. "Bacilli in the International Space Station". Microorganisms 10, n.º 12 (22 de noviembre de 2022): 2309. http://dx.doi.org/10.3390/microorganisms10122309.
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Astronauts remote from Earth, not least those who will inhabit the Moon or Mars, are vulnerable to disease due to their reduced immunity, isolation from clinical support, and the disconnect from any buffering capacity provided by the Earth. Here, we explore potential risks for astronaut health, focusing on key aspects of the biology of Bacillus anthracis and other anthrax-like bacilli. We examine aspects of Bacillus cereus group genetics in relation to their evolutionary biology and pathogenicity; a new clade of the Bacillus cereus group, close related to B. anthracis, has colonized the International Space Station (ISS), is still present, and could in theory at least acquire pathogenic plasmids from the other B. cereus group strains. The main finding is that the genomic sequence alignments of the B. cereus group ISS strains revealed a high sequence identity, indicating they originated from the same strain and that a close look to the genetic variations among the strains suggesting they lived, or they are living, in a vegetative form in the ISS enough time to accumulate genetic variations unique for each single strains.
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Daffonchio, Daniele, Noura Raddadi, Maya Merabishvili, Ameur Cherif, Lorenzo Carmagnola, Lorenzo Brusetti, Aurora Rizzi et al. "Strategy for Identification of Bacillus cereus and Bacillus thuringiensis Strains Closely Related to Bacillus anthracis". Applied and Environmental Microbiology 72, n.º 2 (febrero de 2006): 1295–301. http://dx.doi.org/10.1128/aem.72.2.1295-1301.2006.
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ABSTRACT Bacillus cereus strains that are genetically closely related to B. anthracis can display anthrax-like virulence traits (A. R. Hoffmaster et al., Proc. Natl. Acad. Sci. USA 101:8449-8454, 2004). Hence, approaches that rapidly identify these “near neighbors” are of great interest for the study of B. anthracis virulence mechanisms, as well as to prevent the use of such strains for B. anthracis-based bioweapon development. Here, a strategy is proposed for the identification of near neighbors of B. anthracis based on single nucleotide polymorphisms (SNP) in the 16S-23S rRNA intergenic spacer (ITS) containing tRNA genes, characteristic of B. anthracis. By using restriction site insertion-PCR (RSI-PCR) the presence of two SNP typical of B. anthracis was screened in 126 B. cereus group strains of different origin. Two B. cereus strains and one B. thuringiensis strain showed RSI-PCR profiles identical to that of B. anthracis. The sequencing of the entire ITS containing tRNA genes revealed two of the strains to be identical to B. anthracis. The strict relationship with B. anthracis was confirmed by multilocus sequence typing (MLST) of four other independent loci: cerA, plcR, AC-390, and SG-749. The relationship to B. anthracis of the three strains described by MLST was comparable and even higher to that of four B. cereus strains associated with periodontitis in humans and previously reported as the closest known strains to B. anthracis. SNP in ITS containing tRNA genes combined with RSI-PCR provide a very efficient tool for the identification of strains closely related to B. anthracis.
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CHAVES, JEANE QUINTANILHA, CLARA de FÁTIMA GOMES CAVADOS y ADRIANA MARCOS VIVONI. "Molecular and Toxigenic Characterization of Bacillus cereus and Bacillus thuringiensis Strains Isolated from Commercial Ground Roasted Coffee". Journal of Food Protection 75, n.º 3 (1 de marzo de 2012): 518–22. http://dx.doi.org/10.4315/0362-028x.jfp-11-325.
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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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MOSSO, Mªs ANGELES, Mª LUISA GARCÍA ARRIBAS, JOSÉ A. CUENA y Mª CARMEN DE LA ROSA. "Enumeration of Bacillus and Bacillus cereus Spores in Food from Spain". Journal of Food Protection 52, n.º 3 (1 de marzo de 1989): 184–88. http://dx.doi.org/10.4315/0362-028x-52.3.184.
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The Bacillus and B. cereus spore populations of 102 samples of food (salad dressing, dried soups, sweet desserts, milk and milk products, rice dishes, pasta and flour), 93 collected from retail markets of Madrid and 9 from chinese restaurants have been studied. Bacillus spores were detected in 82.4% of the samples, while the incidence of B. cereus spores was 14.7%. In salad dressing and dried soups the contamination rate by species of Bacillus was 100% and also both showed the highest contamination of B. cereus spores (25% and 50% respectively). No samples of rice dishes and pasta exhibited B. cereus spore contamination although these were contaminated by other Bacillus species. All the samples studies showed less than 104 and 105 c.f.u./g or ml B. cereus and Bacillus spores respectively. Twenty-four strains of B. cereus isolated were characterized by morphology and biochemical properties and showed most of the characteristics of the type strain. Enterotoxin, phospholipase C and hemolysin production were present in 13 of the isolated strains showing different degrees of production. The vascular permeability reaction (VPR) was used for determining enterotoxin activity. The enterotoxigenic strains showed a positive VPR; 6 of them caused necrosis and 12 positive mouse lethal tests.
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DE SIANO, TARA, SALLY PADHI, DONALD W. SCHAFFNER y THOMAS J. MONTVILLE. "Growth Characteristics of Virulent Bacillus anthracis and Potential Surrogate Strains". Journal of Food Protection 69, n.º 7 (1 de julio de 2006): 1720–23. http://dx.doi.org/10.4315/0362-028x-69.7.1720.
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The objectives of this study were to compare generation and lag times of virulent Bacillus anthracis strains with those of other Bacillus strains, to identify possible surrogates for growth studies, and to determine if the B. cereus module of the U.S. Department of Agriculture Pathogen Modeling Program (PMP) had predictive value for B. anthracis. Growth characteristics of B. anthracis, B. cereus, B. mycoides, and B. subtilis strains in brain heart infusion broth at pH 6.5, 6.0, and 5.5 were determined by absorbance measurements. Growth curves of B. anthracis Sterne and B. cereus strains appeared similar, and the generation times for strain Sterne fell within the PMP's 95% confidence interval for B. cereus. However, the virulent B. anthracis strains Vollum and Pasteur had shorter generation times than the avirulent Sterne strain and most other surrogates and were lower than the PMP's 95% confidence interval for B. cereus. Growth curves of B. cereus ATCC 9818 and B. subtilis ATCC 6633 were more similar to those of virulent B. anthracis strains, but all potential surrogates had significantly different generation times and lag times under some conditions.
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Duc, Le H., Huynh A. Hong, Teresa M. Barbosa, Adriano O. Henriques y Simon M. Cutting. "Characterization of Bacillus Probiotics Available for Human Use". Applied and Environmental Microbiology 70, n.º 4 (abril de 2004): 2161–71. http://dx.doi.org/10.1128/aem.70.4.2161-2171.2004.
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ABSTRACT Bacillus species (Bacillus cereus, Bacillus clausii, Bacillus pumilus) carried in five commercial probiotic products consisting of bacterial spores were characterized for potential attributes (colonization, immunostimulation, and antimicrobial activity) that could account for their claimed probiotic properties. Three B. cereus strains were shown to persist in the mouse gastrointestinal tract for up to 18 days postadministration, demonstrating that these organisms have some ability to colonize. Spores of one B. cereus strain were extremely sensitive to simulated gastric conditions and simulated intestinal fluids. Spores of all strains were immunogenic when they were given orally to mice, but the B. pumilus strain was found to generate particularly high anti-spore immunoglobulin G titers. Spores of B. pumilus and of a laboratory strain of B. subtilis were found to induce the proinflammatory cytokine interleukin-6 in a cultured macrophage cell line, and in vivo, spores of B. pumilus and B. subtilis induced the proinflammatory cytokine tumor necrosis factor alpha and the Th1 cytokine gamma interferon. The B. pumilus strain and one B. cereus strain (B. cereus var. vietnami) were found to produce a bacteriocin-like activity against other Bacillus species. The results that provided evidence of colonization, immunostimulation, and antimicrobial activity support the hypothesis that the organisms have a potential probiotic effect. However, the three B. cereus strains were also found to produce the Hbl and Nhe enterotoxins, which makes them unsafe for human use.
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YANTI, YULMIRA, WARNITA WARNITA, REFLIN REFLIN y HASMIANDY HAMID. "Short Communication: Development of selected PGPR consortium to control Ralstonia syzygii subsp. indonesiensis and promote the growth of tomatoYanti Y, Warnita, Reflin. 2018. Short Communication: Development of selected PGPR consortium to control Ralstoni". Biodiversitas Journal of Biological Diversity 19, n.º 6 (9 de octubre de 2018): 2073–78. http://dx.doi.org/10.13057/biodiv/d190612.
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Yanti Y, Warnita, Reflin. 2018. Short Communication: Development of selected PGPR consortium to control Ralstonia syzygii subsp. indonesiensis and promote the growth of tomato. Biodiversitas 19: xxxx. A microbial consortium is a group of different species of microorganisms and acts as a community. Combinations of biocontrol strains are expected to have a better result to suppress multiple plant diseases. Our previous research had selected four plant growth promoting rhizobacteria (PGPR) strains from chili (B. pseudomycoides strain NBRC 101232, B. cereus strain CCM 2010, Bacillus toyonensis strain BCT-7112, Serratia nematodiphila strain DZ0503SBS1) and three strains from tomato (Bacillus pseudomycoides strain NBRC 101232, Bacillus toyonensis strain BCT-7112, Bacillus thuringiensis strain ATCC 10792 ) which had ability to promote growth and control Ralstonia syzygii subsp. indonesiensis indigenously. The strains were used in the development of PGPR consortiums to increase their ability for biocontrol agent of Ralstonia syzigii subsp. indonesiensis and promoting the growth of tomato. Results showed that not all strains had good compatibility to grow together. Ten consortiums were developed based on their compatibilities. All consortiums exhibited the capability to reduce bacterial wilt disease development and also promote the growth of tomato. The consortium consisted of Serratia nematodiphila strain DZ0503SBS1, B. cereus strain CCM 2010, Bacillus aryabhattai strain B8W22 and Bacillus cereus strain IAM 12605 resulted in the best ability to reduce disease development and promote growth and yield of tomato.
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McIntyre, Lorraine, Kathryn Bernard, Daniel Beniac, Judith L. Isaac-Renton y David Craig Naseby. "Identification of Bacillus cereus Group Species Associated with Food Poisoning Outbreaks in British Columbia, Canada". Applied and Environmental Microbiology 74, n.º 23 (10 de octubre de 2008): 7451–53. http://dx.doi.org/10.1128/aem.01284-08.
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ABSTRACT Food poisoning laboratories identify Bacillus cereus using routine methods that may not differentiate all Bacillus cereus group species. We recharacterized Bacillus food-poisoning strains from 39 outbreaks and identified B. cereus in 23 outbreaks, B. thuringiensis in 4, B. mycoides in 1, and mixed strains of Bacillus in 11 outbreaks.
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Xu, Dong y Jean-Charles Côté. "Sequence Diversity of the Bacillus thuringiensis and B. cereus Sensu Lato Flagellin (H Antigen) Protein: Comparison with H Serotype Diversity". Applied and Environmental Microbiology 72, n.º 7 (julio de 2006): 4653–62. http://dx.doi.org/10.1128/aem.00328-06.
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ABSTRACT We set out to analyze the sequence diversity of the Bacillus thuringiensis flagellin (H antigen [Hag]) protein and compare it with H serotype diversity. Some other Bacillus cereus sensu lato species and strains were added for comparison. The internal sequences of the flagellin (hag) alleles from 80 Bacillus thuringiensis strains and 16 strains from the B. cereus sensu lato group were amplified and cloned, and their nucleotide sequences were determined and translated into amino acids. The flagellin allele nucleotide sequences for 10 additional strains were retrieved from GenBank for a total of 106 Bacillus species and strains used in this study. These included 82 B. thuringiensis strains from 67 H serotypes, 5 B. cereus strains, 3 Bacillus anthracis strains, 3 Bacillus mycoides strains, 11 Bacillus weihenstephanensis strains, 1 Bacillus halodurans strain, and 1 Bacillus subtilis strain. The first 111 and the last 66 amino acids were conserved. They were referred to as the C1 and C2 regions, respectively. The central region, however, was highly variable and is referred to as the V region. Two bootstrapped neighbor-joining trees were generated: a first one from the alignment of the translated amino acid sequences of the amplified internal sequences of the hag alleles and a second one from the alignment of the V region amino acid sequences, respectively. Of the eight clusters revealed in the tree inferred from the entire C1-V-C2 region amino acid sequences, seven were present in corresponding clusters in the tree inferred from the V region amino acid sequences. With regard to B. thuringiensis, in most cases, different serovars had different flagellin amino acid sequences, as might have been expected. Surprisingly, however, some different B. thuringiensis serovars shared identical flagellin amino acid sequences. Likewise, serovars from the same H serotypes were most often found clustered together, with exceptions. Indeed, some serovars from the same H serotype carried flagellins with sufficiently different amino acid sequences as to be located on distant clusters. Species-wise, B. halodurans, B. subtilis, and B. anthracis formed specific branches, whereas the other four species, all in the B. cereus sensu lato group, B. mycoides, B. weihenstephanensis, B. cereus, and B. thuringiensis, did not form four specific clusters as might have been expected. Rather, strains from any of these four species were placed side by side with strains from the other species. In the B. cereus sensu lato group, B. anthracis excepted, the distribution of strains was not species specific.
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Fitriyanto, N. A., A. A. Saputri, M. K. Jayamahendra, N. N. A. Prabawati, R. A. Prasetyo, A. Pertiwiningrum, V. Pastawan, M. Z. Abidin y Y. Erwanto. "Characterizing hydrolysate from duck feather degradation by Pseudomonas sp. PK4, Bacillus cereus TD5B, and Bacillus cereus LS2B". IOP Conference Series: Earth and Environmental Science 1241, n.º 1 (1 de septiembre de 2023): 012116. http://dx.doi.org/10.1088/1755-1315/1241/1/012116.
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Abstract Duck feathers are mainly composed of keratin, which is difficult to degrade. We want to know the ability of indigenous strains to produce keratinase and the ability to degrade duck feather’s keratin and observe the hydrolysate’s amino acid profile. All the strains were confirmed to produce keratinase from the formation of clear zones on an agar medium., Bacillus cereus LS2B, Bacillus cereus TD5B, and Pseudomonas sp. PK4 had the maximum enzyme activity on the casein substrate with 10.52 U/mL, 6.24 U/mL, and 16.42 U/mL, respectively. In addition, Strains LS2B, TD5B, and PK4 have activity of 5.23 U/mL, 7.01 U/mL, and 11.3 U/mL, respectively, while growing on the keratin substrate. Pseudomonas sp. PK4, Bacillus cereus LS2B, and Bacillus cereus TD5B degraded 38%, 38%, and 19% of the substrate, respectively. We found 12 amino acids during HPLC analysis. This study concludes that strains Strain PK4, LS2B, and TD5B can produce keratinase and can degrade the keratin of the duck feather substrate into amino acids.
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Phelps, Rebecca J. y John L. McKillip. "Enterotoxin Production in Natural Isolates of Bacillaceae outside the Bacillus cereus Group". Applied and Environmental Microbiology 68, n.º 6 (junio de 2002): 3147–51. http://dx.doi.org/10.1128/aem.68.6.3147-3151.2002.
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ABSTRACT Thirty-nine Bacillus strains obtained from a variety of environmental and food sources were screened by PCR for the presence of five gene targets (hblC, hblD, hblA, nheA, and nheB) in two enterotoxin operons (HBL and NHE) traditionally harbored by Bacillus cereus. Seven isolates exhibited a positive signal for at least three of the five possible targets, including Bacillus amyloliquefaciens, B. cereus, Bacillus circulans, Bacillus lentimorbis, Bacillus pasteurii, and Bacillus thuringiensis subsp. kurstaki. PCR amplicons were confirmed by restriction enzyme digest patterns compared to a positive control strain. Enterotoxin gene expression of each strain grown in a model food system (skim milk) was monitored by gene-specific reverse transcription-PCR and confirmed with the Oxoid RPLA and Tecra BDE commercial kits. Lecithinase production was noted on egg yolk-polymyxin B agar for all strains except B. lentimorbis, whereas discontinuous beta hemolysis was exhibited by all seven isolates grown on 5% sheep blood agar plates. The results of this study confirm the presence of enterotoxin genes in natural isolates of Bacillus spp. outside the B. cereus group and the ability of these strains to produce toxins in a model food system under aerated conditions at 32°C.
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Ticknor, Lawrence O., Anne-Brit Kolstø, Karen K. Hill, Paul Keim, Miriam T. Laker, Melinda Tonks y Paul J. Jackson. "Fluorescent Amplified Fragment Length Polymorphism Analysis of Norwegian Bacillus cereus and Bacillus thuringiensis Soil Isolates". Applied and Environmental Microbiology 67, n.º 10 (1 de octubre de 2001): 4863–73. http://dx.doi.org/10.1128/aem.67.10.4863-4873.2001.
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ABSTRACT We examined 154 Norwegian B. cereus andB. thuringiensis soil isolates (collected from five different locations), 8 B. cereus and 2B. thuringiensis reference strains, and 2Bacillus anthracis strains by using fluorescent amplified fragment length polymorphism (AFLP). We employed a novel fragment identification approach based on a hierarchical agglomerative clustering routine that identifies fragments in an automated fashion. No method is free of error, and we identified the major sources so that experiments can be designed to minimize its effect. Phylogenetic analysis of the fluorescent AFLP results reveals five genetic groups in these group 1 bacilli. The ATCC reference strains were restricted to two of the genetic groups, clearly not representative of the diversity in these bacteria. Both B. anthracis strains analyzed were closely related and affiliated with a B. cereus milk isolate (ATCC 4342) and a B. cereus human pathogenic strain (periodontitis). Across the entire study, pathogenic strains, including B. anthracis, were more closely related to one another than to the environmental isolates. Eight strains representing the five distinct phylogenetic clusters were further analyzed by comparison of their 16S rRNA gene sequences to confirm the phylogenetic status of these groups. This analysis was consistent with the AFLP analysis, although of much lower resolution. The innovation of automated genotype analysis by using a replicated and statistical approach to fragment identification will allow very large sample analyses in the future.
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NAKANO, SHIGERU, HIDEKI MAESHIMA, ATSUSHI MATSUMURA, KATSUTOSHI OHNO, SHIGEKO UEDA, YOSHIHIRO KUWABARA y TOSHIHIRO YAMADA. "A PCR Assay Based on a Sequence-Characterized Amplified Region Marker for Detection of Emetic Bacillus cereus". Journal of Food Protection 67, n.º 8 (1 de agosto de 2004): 1694–701. http://dx.doi.org/10.4315/0362-028x-67.8.1694.
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A PCR assay for the detection of Bacillus cereus strains able to produce an emetic toxin (cereulide) was developed in this study based on a sequence-characterized amplified region (SCAR) derived from a random amplified polymorphic DNA (RAPD) fragment. One of the RAPD fragments generated was selected, cloned, and sequenced. A set of PCR primers was newly designed from the SCAR obtained (the sequence of the cloned RAPD fragment) and used in this assay. To determine the specificity of the assay, 30 different B. cereus strains, 8 other Bacillus strains (of six species), and 16 other non-Bacillus strains (from 16 genera) were tested. Results were positive for every emetic B. cereus strain and for only one nonemetic B. cereus strain. For all other bacterial strains, results were negative. Bacterial DNA for PCR was prepared by a simple procedure using Chelex 100 resin from the bacterial colony on the agar plate or from culture after growth in brain heart infusion medium. This PCR assay enabled us to detect the bacteria of emetic B. cereus grown on agar plates but not the bacteria of nonemetic B. cereus. To test this PCR assay for the monitoring of the emetic bacteria, 10 to 70 CFU of B. cereus DSM 4312 (emetic) per g of food was inoculated into several foods as an indicator, followed by a 7-h enrichment culture step. Because this PCR assay based on the SCAR derived from the RAPD fragment was able to detect bacterial cells, this assay should be useful for rapid and specific detection of emetic B. cereus.
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Akhter, Kulsoom, Tahseen Ghous, Zain Ul-Abdin, Saiqa Andleeb, Muhammad Naeem Ahmed y Basharat Hussain. "Chromium bioaccumulation potential of Bacillus cereus isolated from rhizospheres of Tagetes minuta L." Bangladesh Journal of Botany 49, n.º 1 (31 de marzo de 2020): 47–54. http://dx.doi.org/10.3329/bjb.v49i1.49091.
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Two metal resistant Bacillus cereus strains (AVP12 and NC7401) isolated from metal polluted and nonpolluted rhizospheres of Tagetes minuta were examined for Cr(VI) bioaccumulation potential. It was found that the strains have potential to survive even at metal concentration of 300 mg/l. The per cent removal capacity of Cr(VI) by AVP12 and NC7401 strains was analyzed as a function of environmental factors including pH, incubation time and biosorbate concentration. The optimum pH was found to be 5 andwas selected for further studies. Both Langmuir and Freundlich isotherm models were found suitable for description of Cr(VI) bioaccumulation. The maximum Cr(VI) bioaccumulation capacity by Bacillus cereus AVP12 and Bacillus cereus NC7401 strains isolated from polluted rhizosphere was 181.0 and 107.5 mg/l, respectively while maximum Cr(VI) bioaccumulation capacity by Bacillus cereus AVP12 and Bacillus cereus NC7401 strains isolated from non-polluted rhizosphere was 92.59 and 62.11 mg/l, respectively. Both types of rhizobacterial strains, especially isolated from metal polluted rhizospheres could serve as economical and ecofriendly bioaccumulating agents for removal of Cr(VI).
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Vilas-Boas, Gislayne, Vincent Sanchis, Didier Lereclus, Manoel Victor F. Lemos y Denis Bourguet. "Genetic Differentiation between Sympatric Populations of Bacillus cereus and Bacillus thuringiensis". Applied and Environmental Microbiology 68, n.º 3 (marzo de 2002): 1414–24. http://dx.doi.org/10.1128/aem.68.3.1414-1424.2002.
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ABSTRACT Little is known about genetic exchanges in natural populations of bacteria of the spore-forming Bacillus cereus group, because no population genetics studies have been performed with local sympatric populations. We isolated strains of Bacillus thuringiensis and B. cereus from small samples of soil collected at the same time from two separate geographical sites, one within the forest and the other at the edge of the forest. A total of 100 B. cereus and 98 B. thuringiensis strains were isolated and characterized by electrophoresis to determine allelic composition at nine enzymatic loci. We observed genetic differentiation between populations of B. cereus and B. thuringiensis. Populations of a given Bacillus species—B. thuringiensis or B. cereus—were genetically more similar to each other than to populations of the other Bacillus species. Hemolytic activity provided further evidence of this genetic divergence, which remained evident even if putative clones were removed from the data set. Our results suggest that the rate of gene flow was higher between strains of the same species, but that exchanges between B. cereus and B. thuringiensis were nonetheless possible. Linkage disequilibrium analysis revealed sufficient recombination for B. cereus populations to be considered panmictic units. In B. thuringiensis, the balance between clonal proliferation and recombination seemed to depend on location. Overall, our data indicate that it is not important for risk assessment purposes to determine whether B. cereus and B. thuringiensis belong to a single or two species. Assessment of the biosafety of pest control based on B. thuringiensis requires evaluation of the extent of genetic exchange between strains in realistic natural conditions.
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Wijman, Janneke G. E., Patrick P. L. A. de Leeuw, Roy Moezelaar, Marcel H. Zwietering y Tjakko Abee. "Air-Liquid Interface Biofilms of Bacillus cereus: Formation, Sporulation, and Dispersion". Applied and Environmental Microbiology 73, n.º 5 (5 de enero de 2007): 1481–88. http://dx.doi.org/10.1128/aem.01781-06.
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ABSTRACT Biofilm formation by Bacillus cereus was assessed using 56 strains of B. cereus, including the two sequenced strains, ATCC 14579 and ATCC 10987. Biofilm production in microtiter plates was found to be strongly dependent on incubation time, temperature, and medium, as well as the strain used, with some strains showing biofilm formation within 24 h and subsequent dispersion within the next 24 h. A selection of strains was used for quantitative analysis of biofilm formation on stainless steel coupons. Thick biofilms of B. cereus developed at the air-liquid interface, while the amount of biofilm formed was much lower in submerged systems. This suggests that B. cereus biofilms may develop particularly in industrial storage and piping systems that are partly filled during operation or where residual liquid has remained after a production cycle. Moreover, depending on the strain and culture conditions, spores constituted up to 90% of the total biofilm counts. This indicates that B. cereus biofilms can act as a nidus for spore formation and subsequently can release their spores into food production environments.
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Aini, Diah Nurul y Tetty Marta Linda. "Efficacy of Cellulolytic Bacteria Consortium for Composting Oil Palm Empty Bunches Containing Phytonutrients". Jurnal Natur Indonesia 18, n.º 1 (8 de mayo de 2020): 12. http://dx.doi.org/10.31258/jnat.18.1.12-19.
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Oil palm empty fruit bunches (OPEFB) are themost solid palm oil waste. OPEFB has often been processed into compost with the addition of certain activators. It is expected that with the addition of a consortium bioactivator composting of OPEFB can be faster and the compost produced has good nutrient content. The study aims was to determine the ability of bioactivator bacteria of cellulolytic consortium in degrading TKKS of incubation laboratory scale for 30 days. A consortium of compost bioactivator used were Bacillus sp. S43, Bacillus cereus strains of IARI-MB-6, Bacillus cereus strains TS11, Alcaligenes faecalis strains ZJUTBX11, Bacillus sp. 13847, Stenotrophomonas sp. S169-III-5, Alcaligenes faecalis strains KH-48 and Bacillus cereus strain Y22 by a comparison of 1:1:1:1:1:1:1:1. The results showed that bioactivator consortium was able to degrade OPEFB which on P4 (OPEFB + chicken manure + consortium isolate) reduced organic C from 50.1 to 34.5, increased total nitrogen from 0.73 to 1.35 and reduced the C/N ratio from 37.11 to 25.56 and produced compost phytonutrients and not phytotoxicity.
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From, Cecilie, Rudiger Pukall, Peter Schumann, Víctor Hormazábal y Per Einar Granum. "Toxin-Producing Ability among Bacillus spp. Outside the Bacillus cereus Group". Applied and Environmental Microbiology 71, n.º 3 (marzo de 2005): 1178–83. http://dx.doi.org/10.1128/aem.71.3.1178-1183.2005.
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ABSTRACT A total of 333 Bacillus spp. isolated from foods, water, and food plants were examined for the production of possible enterotoxins and emetic toxins using a cytotoxicity assay on Vero cells, the boar spermatozoa motility assay, and a liquid chromatography-mass spectrometry method. Eight strains produced detectable toxins; six strains were cytotoxic, three strains produced putative emetic toxins (different in size from cereulide), and one strain produced both cytotoxin(s) and putative emetic toxin(s). The toxin-producing strains could be assigned to four different species, B. subtilis, B. mojavensis, B. pumilus, or B. fusiformis, by using a polyphasic approach including biochemical, chemotaxonomic, and DNA-based analyses. Four of the strains produced cytotoxins that were concentrated by ammonium sulfate followed by dialysis, and two strains produced cytotoxins that were not concentrated by such a treatment. Two cultures maintained full cytotoxic activity, two cultures reduced their activity, and two cultures lost their activity after boiling. The two most cytotoxic strains (both B. mojavensis) were tested for toxin production at different temperatures. One of these strains produced cytotoxin at growth temperatures ranging from 25 to 42°C, and no reduction in activity was observed even after 24 h of growth at 42°C. The strains that produced putative emetic toxins were tested for the influence of time and temperature on the toxin production. It was shown that they produced putative emetic toxin faster or just as fast at 30 as at 22°C. None of the cytotoxic strains produced B. cereus-like enterotoxins as tested by PCR or by immunological methods.
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Hill, Karen K., Lawrence O. Ticknor, Richard T. Okinaka, Michelle Asay, Heather Blair, Katherine A. Bliss, Mariam Laker et al. "Fluorescent Amplified Fragment Length Polymorphism Analysis of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis Isolates". Applied and Environmental Microbiology 70, n.º 2 (febrero de 2004): 1068–80. http://dx.doi.org/10.1128/aem.70.2.1068-1080.2004.
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ABSTRACT DNA from over 300 Bacillus thuringiensis, Bacillus cereus, and Bacillus anthracis isolates was analyzed by fluorescent amplified fragment length polymorphism (AFLP). B. thuringiensis and B. cereus isolates were from diverse sources and locations, including soil, clinical isolates and food products causing diarrheal and emetic outbreaks, and type strains from the American Type Culture Collection, and over 200 B. thuringiensis isolates representing 36 serovars or subspecies were from the U.S. Department of Agriculture collection. Twenty-four diverse B. anthracis isolates were also included. Phylogenetic analysis of AFLP data revealed extensive diversity within B. thuringiensis and B. cereus compared to the monomorphic nature of B. anthracis. All of the B. anthracis strains were more closely related to each other than to any other Bacillus isolate, while B. cereus and B. thuringiensis strains populated the entire tree. Ten distinct branches were defined, with many branches containing both B. cereus and B. thuringiensis isolates. A single branch contained all the B. anthracis isolates plus an unusual B. thuringiensis isolate that is pathogenic in mice. In contrast, B. thuringiensis subsp. kurstaki (ATCC 33679) and other isolates used to prepare insecticides mapped distal to the B. anthracis isolates. The interspersion of B. cereus and B. thuringiensis isolates within the phylogenetic tree suggests that phenotypic traits used to distinguish between these two species do not reflect the genomic content of the different isolates and that horizontal gene transfer plays an important role in establishing the phenotype of each of these microbes. B. thuringiensis isolates of a particular subspecies tended to cluster together.
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Guinebretière, Marie-Hélène, Sandrine Auger, Nathalie Galleron, Matthias Contzen, Benoit De Sarrau, Marie-Laure De Buyser, Gilles Lamberet et al. "Bacillus cytotoxicus sp. nov. is a novel thermotolerant species of the Bacillus cereus Group occasionally associated with food poisoning". International Journal of Systematic and Evolutionary Microbiology 63, Pt_1 (1 de enero de 2013): 31–40. http://dx.doi.org/10.1099/ijs.0.030627-0.
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An aerobic endospore-forming bacillus (NVH 391-98T) was isolated during a severe food poisoning outbreak in France in 1998, and four other similar strains have since been isolated, also mostly from food poisoning cases. Based on 16S rRNA gene sequence similarity, these strains were shown to belong to the Bacillus cereus Group (over 97 % similarity with the current Group species) and phylogenetic distance from other validly described species of the genus Bacillus was less than 95 %. Based on 16S rRNA gene sequence similarity and MLST data, these novel strains were shown to form a robust and well-separated cluster in the B. cereus Group, and constituted the most distant cluster from species of this Group. Major fatty acids (iso-C15 : 0, C16 : 0, iso-C17 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C13 : 0) supported the affiliation of these strains to the genus Bacillus , and more specifically to the B. cereus Group. NVH 391-98T taxon was more specifically characterized by an abundance of iso-C15 : 0 and low amounts of iso-C13 : 0 compared with other members of the B. cereus Group. Genome similarity together with DNA–DNA hybridization values and physiological and biochemical tests made it possible to genotypically and phenotypically differentiate NVH 391-98T taxon from the six current B. cereus Group species. NVH 391-98T therefore represents a novel species, for which the name Bacillus cytotoxicus sp. nov. is proposed, with the type strain NVH 391-98T ( = DSM 22905T = CIP 110041T).
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Huang, H. C., E. G. Kokko, L. J. Yanke y R. C. Phillippe. "Bacterial suppression of basal pod rot and end rot of dry peas caused by Sclerotinia sclerotiorum". Canadian Journal of Microbiology 39, n.º 2 (1 de febrero de 1993): 227–33. http://dx.doi.org/10.1139/m93-032.
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Morphological and biochemical characteristics indicate that the two bacterial strains used in this study belong to Bacillus cereus Frankland and Frankland. Tests in vitro revealed that strains of B. cereus differ in their antagonistic activities on Sclerotinia sclerotiorum (Lib.) de Bary. Vegetative growth and ascospore germination of S. sclerotiorum were inhibited by diffusible metabolites induced by B. cereus strain alf-87A, but were unaffected by strain B43. In vivo studies showed that the antagonistic strain alf-87A, when sprayed onto pea plants (Pisum sativum L.) at the pod development stage, reduced the incidence of basal pod rot from infection by airborne ascospores of S. sclerotiorum by 39–55%. This treatment also significantly (P < 0.05) reduced the severity of basal pod rot by decreasing lesion size. Strain alf-87A significantly reduced the incidence of end pod rot. Spraying pea plants with strain B43 of B. cereus was not consistently effective in reducing basal and end pod rots. Scanning electron microscopic studies revealed that both strains of B. cereus could colonize senescing pea stamens but only the antagonistic strain alf-87A was consistently effective in controlling sclerotinia basal and end pod rots of dry peas.Key words: Sclerotinia sclerotiorum, Bacillus cereus, basal pod rot, end pod rot, stamens, ascospores, apothecia.
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Reyes-Ramirez, Arturo y Jorge E. Ibarra. "Fingerprinting of Bacillus thuringiensis Type Strains and Isolates by Using Bacillus cereus Group-Specific Repetitive Extragenic Palindromic Sequence-Based PCR Analysis". Applied and Environmental Microbiology 71, n.º 3 (marzo de 2005): 1346–55. http://dx.doi.org/10.1128/aem.71.3.1346-1355.2005.
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ABSTRACT A total of 119 Bacillus thuringiensis strains (83 type strains and 26 native isolates), as well as five B. cereus group species, were analyzed by repetitive extragenic palindromic sequence-based PCR analysis (Rep-PCR) fingerprinting. Primers Bc-REP-1 and Bc-REP-2 were specifically designed according to an extragenic 26-bp repeated sequence found in the six B. cereus group genomes reported. A total of 47 polymorphic bands were detected, and the patterns varied from 5 to 13 bands in number and from 0.2 to 3.8 kb in size. Virtually each type strain showed a distinctive B. cereus (Bc)-Rep-PCR pattern, except for B. thuringiensis serovars dakota (H serotype 15 [H15]) and sotto (H4a,4b), as well as serovars amagiensis (H29) and seoulensis (H35), which shared the same patterns. As expected, serovar entomocidus (H6) and its biovar subtoxicus showed an identical pattern; similarly, serovars sumiyoshiensis (H3a,3d) and fukuokaensis (H3a,3d,3e), which share two antigenic determinants, also showed identical Bc-Rep-PCR patterns. Interestingly, serovars israelensis (H14) and malaysiensis (H36), which share several phenotypic attributes, also showed identical Bc-Rep-PCR patterns. Native, coleopteran-active strains, including the self-agglutinated LBIT-74 strain, showed Bc-Rep-PCR patterns identical or very similar to that of the tenebrionis strain. Likewise, native mosquitocidal strains (including some self-agglutinated strains) also showed patterns identical or very similar to that of the serovar israelensis IPS-82 strain. Additionally, native β-exotoxin-producing strains from serovar thuringiensis showed patterns identical to that of the B. thuringiensis type strain. The B. cereus group-specific Bc-Rep-PCR fingerprinting technique was shown to be highly discriminative, fast, easy, and able to identify B. thuringiensis serotypes, including nonflagellar and self-agglutinated strains.
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Rossi, Eliandra Mirlei, Suelen Caroline Mahl, Ana Carolina Spaniol, Jéssica Fernanda Barreto Honorato y Tauany Rocha. "Evaluating the thermoresistance of Bacillus cereus strains isolated from wheat flour". Research, Society and Development 10, n.º 6 (19 de mayo de 2021): e2510615268. http://dx.doi.org/10.33448/rsd-v10i6.15268.
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Wheat flour is often used to prepare confectionery and baked goods, however, it can be contaminated by aporulating microorganisms contaminated during harvest or improper storage. The aim of this study was to isolate Bacillus cereus strains from different wheat flour brands and to evaluate their thermoresistance in different confectionery products. It was done in order to investigate the risks posed by food prepared with flour contaminated with B. cereus to consumers’ health. The investigation of B.cereus was realized in five brands of different wheat flours were collected and named A to E. The isolated strains were subjected to boiling tests in vitro to evaluate their thermoresistance. In addition, confectionery products were prepared with flour contaminated with B. cereus strains. These products were subjected to different cooking and B. cereus strain ATCC®30301™ was used as control. Flour brands were contaminated with B. cereus; and counts ranged from 0.25 to 1.57 log CFU/g. The strains presented higher thermoresistance in the confectionery products than in the test conducted in vitro. Based on our results, it was concluded that B. cereus strains are thermoresistant. Moreover, if the flour is contaminated with this bacterium, food products subjected to thermal treatments may remain contaminated. In addition, it is suggested that there is some mechanism (not observed in our study) that could directly influence the thermoresistance of strains found in food.
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Wang, Kui, Changlong Shu, Alejandra Bravo, Mario Soberón, Hongjun Zhang, Neil Crickmore y Jie Zhang. "Development of an Online Genome Sequence Comparison Resource for Bacillus cereus sensu lato Strains Using the Efficient Composition Vector Method". Toxins 15, n.º 6 (12 de junio de 2023): 393. http://dx.doi.org/10.3390/toxins15060393.
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An automated method was developed for differentiating closely related B. cereus sensu lato (s.l.) species, especially biopesticide Bacillus thuringiensis, from other human pathogens, B. anthracis and B. cereus sensu stricto (s.s.). In the current research, four typing methods were initially compared, including multi-locus sequence typing (MLST), single-copy core genes phylogenetic analysis (SCCGPA), dispensable genes content pattern analysis (DGCPA) and composition vector tree (CVTree), to analyze the genomic variability of 23 B. thuringiensis strains from aizawai, kurstaki, israelensis, thuringiensis and morrisoni serovars. The CVTree method was the best option to be used for typing B. thuringiensis strains since it proved to be the fastest method, whilst giving high-resolution data about the strains. In addition, CVTree agrees well with ANI-based method, revealing the relationship between B. thuringiensis and other B. cereus s.l. species. Based on these data, an online genome sequence comparison resource was built for Bacillus strains called the Bacillus Typing Bioinformatics Database to facilitate strain identification and characterization.
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Daffonchio, Daniele, Sara Borin, Giuseppe Frova, Romina Gallo, Elena Mori, Renato Fani y Claudia Sorlini. "A Randomly Amplified Polymorphic DNA Marker Specific for the Bacillus cereus Group Is Diagnostic forBacillus anthracis". Applied and Environmental Microbiology 65, n.º 3 (1 de marzo de 1999): 1298–303. http://dx.doi.org/10.1128/aem.65.3.1298-1303.1999.
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ABSTRACT Aiming to develop a DNA marker specific for Bacillus anthracis and able to discriminate this species fromBacillus cereus, Bacillus thuringiensis, andBacillus mycoides, we applied the randomly amplified polymorphic DNA (RAPD) fingerprinting technique to a collection of 101 strains of the genus Bacillus, including 61 strains of theB. cereus group. An 838-bp RAPD marker (SG-850) specific for B. cereus, B. thuringiensis, B. anthracis, and B. mycoides was identified. This fragment included a putative (366-nucleotide) open reading frame highly homologous to the ypuA gene of Bacillus subtilis. The restriction analysis of the SG-850 fragment withAluI distinguished B. anthracis from the other species of the B. cereus group.
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OGUNTOYINBO, FOLARIN A., MELANIE HUCH, GYU-SUNG CHO, ULRICH SCHILLINGER, WILHELM H. HOLZAPFEL, ABIODUN I. SANNI y CHARLES M. A. P. FRANZ. "Diversity of Bacillus Species Isolated from Okpehe, a Traditional Fermented Soup Condiment from Nigeria". Journal of Food Protection 73, n.º 5 (1 de mayo de 2010): 870–78. http://dx.doi.org/10.4315/0362-028x-73.5.870.
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The diversity of Bacillus species isolated from the fermented soup condiment okpehe in Nigeria was studied using a combination of phenotypic and genotypic methods. Fifty strains presumptively characterized as Bacillus spp. using the API 50 CHB test were further identified by PCR of randomly amplified polymorphic DNA (RAPD) and by amplified ribosomal DNA restriction analysis (ARDRA) genotyping methods. ARDRA fingerprinting with HhaI, HinfI, and Sau3AI restriction enzymes did not allow successful differentiation between the Bacillus species, except for distinguishing B. cereus from other Bacillus species. This problem was overcome with the combination of RAPD PCR and ARDRA genotypic fingerprinting techniques. Sequencing of 16S rRNA genes of selected strains representative of the major clusters revealed that the Bacillus strains associated with this fermentation were B. subtilis, B. amyloliquefaciens, B. cereus, and B. licheniformis (in decreasing order of incidence). The presence of enterotoxin genes in all B. cereus strains was demonstrated by multiplex PCR. The high incidence of detection (20%) of possibly pathogenic B. cereus strains that contained enterotoxin genes indicated that these fermented foods may constitute a potential health risk.
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Graniak, Grzegorz, Alina Olender y Katarzyna Naylor. "Differentiation of Bacillus anthracis and other Bacillus cereus group bacterial strains using multilocus sequence typing method". Folia Biologica et Oecologica 16 (30 de diciembre de 2020): 12–21. http://dx.doi.org/10.18778/1730-2366.16.02.
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The study describes the preparation of the phylogenetic differentiation of Bacillus cereus strains. The Bacillus cereus group of bacteria is very important for human and animal health. The multilocus sequence typing scheme has been used to present this group of bacteria’s phylogenetic relationship and structure. The MLST system was established using 60 isolates of B. anthracis, B. cereus sensu stricto, B. thuringiensis, and transitional environment strains of Bacillus spp. As a negative control, five strains of B. subtilis and B. megaterium were used. Primers for amplification and sequencing were designed to target highly conserved internal fragment of seven housekeeping genes: glpF, gmk, ilvD, pta, pur, pycA, and tpi. A total of 22 different sequence types (STs) were distinguished. Analysis of the sequence data showed that all of the Bacillus cereus strains are very closely related. The MLST scheme exhibited a high level of resolution that can be used as an excellent tool for studying the phylogenetic relationship, epidemiology, and population structure of the Bacillus cereus group strains. The MLST method additionally allows us to define the phylogenetic relationship between very closely related strains based on a combination of the sequences of all seven alleles fragments and each of them separately. Thus, this genetic investigation tool is very useful in epidemiological investigation of potential military/ bioterrorist use of B. anthracis.
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Park, Kyung-Min, Hyun-Jung Kim, Min-Sun Kim y Minseon Koo. "Morphological Features and Cold-Response Gene Expression in Mesophilic Bacillus cereus Group and Psychrotolerant Bacillus cereus Group under Low Temperature". Microorganisms 9, n.º 6 (9 de junio de 2021): 1255. http://dx.doi.org/10.3390/microorganisms9061255.
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At low temperatures, psychrotolerant B. cereus group strains exhibit a higher growth rate than mesophilic strains do. However, the different survival responses of the psychrotolerant strain (BCG34) and the mesophilic strain (BCGT) at low temperatures are unclear. We investigated the morphological and genomic features of BCGT and BCG34 to characterize their growth strategies at low temperatures. At low temperatures, morphological changes were observed only in BCGT. These morphological changes included the elongation of rod-shaped cells, whereas the cell shape in BCG34 was unchanged at the low temperature. A transcriptomic analysis revealed that both species exhibited different growth-related traits during low-temperature growth. The BCGT strain induces fatty acid biosynthesis, sulfur assimilation, and methionine and cysteine biosynthesis as a survival mechanism in cold systems. Increases in energy metabolism and fatty acid biosynthesis in the mesophilic B. cereus group strain might explain its ability to grow at low temperatures. Several pathways involved in carbohydrate mechanisms were downregulated to conserve the energy required for growth. Peptidoglycan biosynthesis was upregulated, implying that a change of gene expression in both RNA-Seq and RT-qPCR contributed to sustaining its growth and rod shape at low temperatures. These results improve our understanding of the growth response of the B. cereus group, including psychrotolerant B. cereus group strains, at low temperatures and provide information for improving bacterial inhibition strategies in the food industry.
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Yenikeyev, R. R. y L. M. Zakharchuk. "Bacteria of the genus Bacillus on the Russian segment of the International Space Station". Vestnik Moskovskogo universiteta. Seria 16. Biologia 78, n.º 3, 2023 (21 de noviembre de 2023): 178–85. http://dx.doi.org/10.55959/msu0137-0952-16-78-3-5.
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Pure cultures of 19 strains of spore-forming bacteria were obtained from the equipment surfaces of the Russian segment of the International Space Station. The study of morphological, cultural and physiological-biochemical properties of these bacteria allowed us to attribute all strains to the genus Bacillus. As a result of using MALDI-TOF methods and genome-wide sequencing, it was found that out of 19 bacillus strains, six belong to the species B. paralicheniformis, four to B. pumilus, four to B. subtilis, two to B. cereus and one to B. amyloliquefaciens. In accordance with the requirements and norms of EUCAST 2023, the resistance of bacillus strains obtained from the Russian segment of the International Space Station to antibiotics such as imipenem, meropenem, ciprofloxacin, levofloxacin, norfloxacin, vancomycin, erythromycin, clindamycin and linezolid was studied. Resistance to erythromycin was found in 11 strains of bacilli and five strains showed resistance to clindamycin. Only one strain showed resistance to imipenem, levofloxacin and norfloxacin, respectively. Analysis of the complete genome of bacterial strains in which resistance to erythromycin and (or) clindamycin was found made it possible to establish that resistance to these antibiotics in B. paralicheniformis strains SE71, SE131, SE181, SE182, SE183 provides the ermD antibiotic resistance gene. In B. cereus SE43, resistance to erythromycin encodes the mphL gene.
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Lim, Eun Seob, Seung-Youb Baek, Taeyoung Oh, Minseon Koo, Joo Young Lee, Hyun Jung Kim y Joo-Sung Kim. "Strain variation in Bacillus cereus biofilms and their susceptibility to extracellular matrix-degrading enzymes". PLOS ONE 16, n.º 6 (16 de junio de 2021): e0245708. http://dx.doi.org/10.1371/journal.pone.0245708.
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Bacillus cereus is a foodborne pathogen and can form biofilms on food contact surfaces, which causes food hygiene problems. While it is necessary to understand strain-dependent variation to effectively control these biofilms, strain-to-strain variation in the structure of B. cereus biofilms is poorly understood. In this study, B. cereus strains from tatsoi (BC4, BC10, and BC72) and the ATCC 10987 reference strain were incubated at 30°C to form biofilms in the presence of the extracellular matrix-degrading enzymes DNase I, proteinase K, dispase II, cellulase, amyloglucosidase, and α-amylase to assess the susceptibility to these enzymes. The four strains exhibited four different patterns in terms of biofilm susceptibility to the enzymes as well as morphology of surface-attached biofilms or suspended cell aggregates. DNase I inhibited the biofilm formation of strains ATCC 10987 and BC4 but not of strains BC10 and BC72. This result suggests that some strains may not have extracellular DNA, or their extracellular DNA may be protected in their biofilms. In addition, the strains exhibited different patterns of susceptibility to protein- and carbohydrate-degrading enzymes. While other strains were resistant, strains ATCC 10987 and BC4 were susceptible to cellulase, suggesting that cellulose or its similar polysaccharides may exist and play an essential role in their biofilm formation. Our compositional and imaging analyses of strains ATCC 10987 and BC4 suggested that the physicochemical properties of their biofilms are distinct, as calculated by the carbohydrate to protein ratio. Taken together, our study suggests that the extracellular matrix of B. cereus biofilms may be highly diverse and provides insight into the diverse mechanisms of biofilm formation among B. cereus strains.
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Bdewe Bdewe, Saddam Abdalhamed, Semih Yılmaz, Büşra Gün y Aysun Çetin. "PARTIAL PURIFICATION AND CHARACTERIZATION OF PROTEASE ENZYMES FROM NATIVE Bacillus Cereus STRAINS". CURRENT TRENDS IN NATURAL SCIENCES 12, n.º 24 (31 de diciembre de 2023): 150–60. http://dx.doi.org/10.47068/ctns.2023.v12i24.016.
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Proteases are the main enzymes responsible for the breakdown of protein molecules into amino acids. These enzymes can easily be obtained from plants, animals and microorganisms. However, the easiest, fastest and cheapest source is microorganisms. Bacillus cereus strains B16, B17, B18, B19 and B20 were selected for use in this study. The optimum conditions and other parameters of the strains in the production process of proteases were investigated. The strains were characterized using biochemical methods. Different culture conditions were analyzed for the production efficiency of protease activity. Based on the proteolytic activity analysis, Bacillus cereus B17 strain was selected for detailed studies. Protease purification was done by dialysis, ion exchange chromatography and gel filtration chromatography. It was determined that the growth and the protease activity of Bacillus cereus B17 was greatly affected by parameters such as pH and temperature of the medium, presence of metal ions and inhibitors, and incubation time.
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Davison, Sophie, Evelyne Couture-Tosi, Thomas Candela, Michèle Mock y Agnès Fouet. "Identification of the Bacillus anthracis γ Phage Receptor". Journal of Bacteriology 187, n.º 19 (1 de octubre de 2005): 6742–49. http://dx.doi.org/10.1128/jb.187.19.6742-6749.2005.
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ABSTRACT Bacillus anthracis, a gram-positive, spore-forming bacterium, is the etiological agent of anthrax. It belongs to the Bacillus cereus group, which also contains Bacillus cereus and Bacillus thuringiensis. Most B. anthracis strains are sensitive to phage γ, but most B. cereus and B. thuringiensis strains are resistant to the lytic action of phage γ. Here, we report the identification of a protein involved in the bacterial receptor for the γ phage, which we term GamR (Gamma phage receptor). It is an LPXTG protein (BA3367, BAS3121) and is anchored by the sortase A. A B. anthracis sortase A mutant is not as sensitive as the parental strain nor as the sortase B and sortase C mutants, whereas the GamR mutant is resistant to the lytic action of the phage. Electron microscopy reveals the binding of the phage to the surface of the parental strain and its absence from the GamR mutant. Spontaneous B. anthracis mutants resistant to the phage harbor mutations in the gene encoding the GamR protein. A B. cereus strain that is sensitive to the phage possesses a protein similar (89% identity) to GamR. B. thuringiensis 97-27, a strain which, by sequence analysis, is predicted to harbor a GamR-like protein, is resistant to the phage but nevertheless displays phage binding.
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Wei, Jianchun, Huijuan Zhang, Huifang Zhang, Enmin Zhang, Binghua Zhang, Fei Zhao y Di Xiao. "Novel Strategy for Rapidly and Safely Distinguishing Bacillus anthracis and Bacillus cereus by Use of Peptide Mass Fingerprints Based on Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry". Journal of Clinical Microbiology 59, n.º 1 (28 de octubre de 2020): e02358-20. http://dx.doi.org/10.1128/jcm.02358-20.
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ABSTRACTThe objective of this study was to construct a rapid, high-throughput, and biosafety-compatible screening method for Bacillus anthracis and Bacillus cereus based on matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). MALDI-TOF MS coupled to ClinProTools was used to discover MALDI-TOF MS biomarker peaks and generate a classification model based on a genetic algorithm (GA) to differentiate between different Bacillus anthracis and Bacillus cereus isolates. Thirty Bacillus anthracis and 19 Bacillus cereus strains were used to construct and analyze the model, and 40 Bacillus strains were used for validation. For the GA screening model, the cross-validation values, which reflect the ability of the model to handle variability among the test spectra, and the recognition capability values, which reflect the model’s ability to correctly identify its component spectra, were all 100%. This model contained 10 biomarker peaks (m/z 3,339.9, 3,396.3, 3,682.4, 5,476.7, 6,610.6, 6,680.1, 7,365.3, 7,792.4, 9,475.8, and 10,934.1) used to correctly identify 28 Bacillus anthracis and 12 Bacillus cereus isolates from 40 Bacillus isolates, with a sensitivity and specificity of 100%. With the obvious advantages of being rapid, highly accurate, and highly sensitive and having a low cost and high throughput, MALDI-TOF MS ClinProTools is a powerful and reliable tool for screening Bacillus anthracis and Bacillus cereus strains.
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Kim, Wonyong, Ji-Yeon Kim, Sung-Lim Cho, Sun-Woo Nam, Jong-Wook Shin, Yang-Soo Kim y Hyoung-Shik Shin. "Glycosyltransferase – a specific marker for the discrimination of Bacillus anthracis from the Bacillus cereus group". Journal of Medical Microbiology 57, n.º 3 (1 de marzo de 2008): 279–86. http://dx.doi.org/10.1099/jmm.0.47642-0.
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Bacillus anthracis, the aetiological agent of anthrax, has been taxonomically classified with the Bacillus cereus group, which comprises B. cereus, Bacillus thuringiensis, Bacillus mycoides, Bacillus pseudomycoides and Bacillus weihenstephanensis. Although the pathogenesis and ecological manifestations may be different, B. anthracis shares a high degree of DNA sequence similarity with its group member species. As a result, the discrimination of B. anthracis from its close relatives in the B. cereus group is still quite difficult. Suppression subtractive hybridization (SSH) was performed to search for genomic differences between a B. anthracis Korean isolate CR and the most closely related B. cereus type strain KCTC 3624T. Two-hundred and five B. anthracis CR clones obtained by SSH underwent Southern hybridization, and comparative sequences were analysed using the blast program from the National Center for Biotechnology Information (NCBI). Subsequently, primer sets based on the glycosyltransferase group 1 family protein gene specific to B. anthracis were designed from the sequences of subtracted clones, and their specificities were evaluated using eight B. anthracis, 33 B. cereus, 10 B. thuringiensis, six B. mycoides, one B. pseudomycoides, one B. weihenstephanensis and 19 strains from 11 other representative Bacillus species. PCR primers specific for the glycosyltransferase group 1 family protein gene did not amplify the desired products from any of the Bacillus strains under examination, except B. anthracis alone. These findings may be useful in the future development of efficient diagnostic tools for the rapid identification of B. anthracis from other members of the B. cereus group.
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Priest, Fergus G., Margaret Barker, Les W. J. Baillie, Edward C. Holmes y Martin C. J. Maiden. "Population Structure and Evolution of the Bacillus cereus Group". Journal of Bacteriology 186, n.º 23 (1 de diciembre de 2004): 7959–70. http://dx.doi.org/10.1128/jb.186.23.7959-7970.2004.
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ABSTRACT Representative strains of the Bacillus cereus group of bacteria, including Bacillus anthracis (11 isolates), B. cereus (38 isolates), Bacillus mycoides (1 isolate), Bacillus thuringiensis (53 isolates from 17 serovars), and Bacillus weihenstephanensis (2 isolates) were assigned to 59 sequence types (STs) derived from the nucleotide sequences of seven alleles, glpF, gmk, ilvD, pta, pur, pycA, and tpi. Comparisons of the maximum likelihood (ML) tree of the concatenated sequences with individual gene trees showed more congruence than expected by chance, indicating a generally clonal structure to the population. The STs followed two major lines of descent. Clade 1 comprised B. anthracis strains, numerous B. cereus strains, and rare B. thuringiensis strains, while clade 2 included the majority of the B. thuringiensis strains together with some B. cereus strains. Other species were allocated to a third, heterogeneous clade. The ML trees and split decomposition analysis were used to assign STs to eight lineages within clades 1 and 2. These lineages were defined by bootstrap analysis and by a preponderance of fixed differences over shared polymorphisms among the STs. Lineages were named with reference to existing designations: Anthracis, Cereus I, Cereus II, Cereus III, Kurstaki, Sotto, Thuringiensis, and Tolworthi. Strains from some B. thuringiensis serovars were wholly or largely assigned to a single ST, for example, serovar aizawai isolates were assigned to ST-15, serovar kenyae isolates were assigned to ST-13, and serovar tolworthi isolates were assigned to ST-23, while other serovars, such as serovar canadensis, were genetically heterogeneous. We suggest a revision of the nomenclature in which the lineage and clone are recognized through name and ST designations in accordance with the clonal structure of the population.
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Slamti, Leyla, Stéphane Perchat, Myriam Gominet, Gislayne Vilas-Bôas, Agnès Fouet, Michèle Mock, Vincent Sanchis, Josette Chaufaux, Michel Gohar y Didier Lereclus. "Distinct Mutations in PlcR Explain Why Some Strains of the Bacillus cereus Group Are Nonhemolytic". Journal of Bacteriology 186, n.º 11 (1 de junio de 2004): 3531–38. http://dx.doi.org/10.1128/jb.186.11.3531-3538.2004.
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ABSTRACT Bacillus thuringiensis, Bacillus cereus, and Bacillus anthracis are closely related species belonging to the Bacillus cereus group. B. thuringiensis and B. cereus generally produce extracellular proteins, including phospholipases and hemolysins. Transcription of the genes encoding these factors is controlled by the pleiotropic regulator PlcR. Disruption of plcR in B. cereus and B. thuringiensis drastically reduces the hemolytic, lecithinase, and cytotoxic properties of these organisms. B. anthracis does not produce these proteins due to a nonsense mutation in the plcR gene. We screened 400 B. thuringiensis and B. cereus strains for their hemolytic and lecithinase properties. Eight Hly− Lec− strains were selected and analyzed to determine whether this unusual phenotype was due to a mutation similar to that found in B. anthracis. Sequence analysis of the DNA region including the plcR and papR genes of these strains and genetic complementation of the strains with functional copies of plcR and papR indicated that different types of mutations were responsible for these phenotypes. We also found that the plcR genes of three B. anthracis strains belonging to different phylogenetic groups contained the same nonsense mutation, suggesting that this mutation is a distinctive trait of this species.
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Leoff, Christine, Elke Saile, David Sue, Patricia Wilkins, Conrad P. Quinn, Russell W. Carlson y Elmar L. Kannenberg. "Cell Wall Carbohydrate Compositions of Strains from the Bacillus cereus Group of Species Correlate with Phylogenetic Relatedness". Journal of Bacteriology 190, n.º 1 (2 de noviembre de 2007): 112–21. http://dx.doi.org/10.1128/jb.01292-07.
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ABSTRACT Members of the Bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl compositions. Recent multilocus sequence typing (MLST) refined the relatedness of B. cereus group members by separating them into clades and lineages. Based on MLST, we selected several B. anthracis, B. cereus, and B. thuringiensis strains and compared their cell wall carbohydrates. The cell walls of different B. anthracis strains (clade 1/Anthracis) were composed of glucose (Glc), galactose (Gal), N-acetyl mannosamine (ManNAc), and N-acetylglucosamine (GlcNAc). In contrast, the cell walls from clade 2 strains (B. cereus type strain ATCC 14579 and B. thuringiensis strains) lacked Gal and contained N-acetylgalactosamine (GalNAc). The B. cereus clade 1 strains had cell walls that were similar in composition to B. anthracis in that they all contained Gal. However, the cell walls from some clade 1 strains also contained GalNAc, which was not present in B. anthracis cell walls. Three recently identified clade 1 strains of B. cereus that caused severe pneumonia, i.e., strains 03BB102, 03BB87, and G9241, had cell wall compositions that closely resembled those of the B. anthracis strains. It was also observed that B. anthracis strains cell wall glycosyl compositions differed from one another in a plasmid-dependent manner. When plasmid pXO2 was absent, the ManNAc/Gal ratio decreased, while the Glc/Gal ratio increased. Also, deletion of atxA, a global regulatory gene, from a pXO2− strain resulted in cell walls with an even greater level of Glc.
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Cherif, Ameur, Sara Borin, Aurora Rizzi, Hadda Ouzari, Abdellatif Boudabous y Daniele Daffonchio. "Bacillus anthracis Diverges from Related Clades of the Bacillus cereus Group in 16S-23S Ribosomal DNA Intergenic Transcribed Spacers Containing tRNA Genes". Applied and Environmental Microbiology 69, n.º 1 (enero de 2003): 33–40. http://dx.doi.org/10.1128/aem.69.1.33-40.2003.
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ABSTRACT Mung bean nuclease treatment of 16S-23S ribosomal DNA intergenic transcribed spacers (ITS) amplified from several strains of the six species of the Bacillus cereus group showed that B. anthracis Davis TE702 and B. mycoides G2 have other intermediate fragments in addition to the 220- and 550-bp homoduplex fragments typical of the B. cereus group. Long and intermediate homoduplex ITS fragments from strains Davis TE702 and G2 and from another 19 strains of the six species were sequenced. Two main types of ITS were found, either with two tRNA genes (tRNAIle and tRNAAla) or without any at all. Strain Davis TE702 harbors an additional ITS with a single tRNA gene, a hybrid between the tRNAIle and tRNAAla genes, suggesting that a recombination event rather than a deletion generated the single tDNA-containing ITS. Strain G2 showed an additional ITS of intermediate length with no tDNA and no similarity to other known sequences. Neighbor-joining analysis of tDNA-containing long ITS indicated that B. cereus and B. thuringiensis represent a single clade. Three signature sequences discriminated B. anthracis from B. cereus and B. thuringiensis, indicating that the anthrax agent started evolving separately from the related clades of the B. cereus group. B. mycoides and B. weienstephanensis were very closely related, while B. pseudomycoides appeared the most distant species.
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GRIFFITHS, M. W. "Toxin Production by Psychrotrophic Bacillus spp. Present in Milk". Journal of Food Protection 53, n.º 9 (1 de septiembre de 1990): 790–92. http://dx.doi.org/10.4315/0362-028x-53.9.790.
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Using a reversed passive latex agglutination assay, about 85% of psychrotrophic Bacillus spp. tested were shown to produce diarrhoegenic toxin during growth on brain heart infusion broth at 25°C. The majority of these strains were identified as Bacillus cereus or cereus-related strains. However, a number of other species was capable of synthesizing the toxin. Further investigation of four psychrotrophic Bacilli showed that the toxin was produced during growth in milk at temperatures ranging from 6 to 21°C. Toxin production increased with increasing temperatures and was not synthesized in appreciable quantities until the bacterial count exceeded 1 × 107 cfu/ml.
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Francis, Kevin P., Ralf Mayr, Felix von Stetten, Gordon S. A. B. Stewart y Siegfried Scherer. "Discrimination of Psychrotrophic and Mesophilic Strains of the Bacillus cereus Group by PCR Targeting of Major Cold Shock Protein Genes". Applied and Environmental Microbiology 64, n.º 9 (1 de septiembre de 1998): 3525–29. http://dx.doi.org/10.1128/aem.64.9.3525-3529.1998.
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ABSTRACT Detection of psychrotrophic strains (those able to grow at or below 7°C) of the Bacillus cereus group (Bacillus cereus, Bacillus thuringiensis, and Bacillus mycoides) in food products is at present extremely slow with conventional microbiology. This is due to an inability to discriminate these cold-adapted strains from their mesophilic counterparts (those able to grow only above 7°C) by means other than growth at low temperature, which takes 5 to 10 days for detection. Here we report the development of a single PCR assay that, using major cold shock protein-specific primers and appropriate annealing temperatures, is capable of both rapidly identifying bacteria of the B. cereus group and discriminating between psychrotrophic and mesophilic strains. It is intended that this development help to more accurately predict the shelf life of refrigerated pasteurized food and dairy products and to reduce the incidence of food poisoning by psychrotrophic strains of the B. cereus group.
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Swift, Etobayeva, Reid, Waters, Oakley, Donovan y Nelson. "Characterization of LysBC17, a Lytic Endopeptidase from Bacillus cereus". Antibiotics 8, n.º 3 (19 de septiembre de 2019): 155. http://dx.doi.org/10.3390/antibiotics8030155.
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Bacillus cereus, a Gram-positive bacterium, is an agent of food poisoning. B. cereus is closely related to Bacillus anthracis, a deadly pathogen for humans, and Bacillus thuringenesis, an insect pathogen. Due to the growing prevalence of antibiotic resistance in bacteria, alternative antimicrobials are needed. One such alternative is peptidoglycan hydrolase enzymes, which can lyse Gram-positive bacteria when exposed externally. A bioinformatic search for bacteriolytic enzymes led to the discovery of a gene encoding an endolysin-like endopeptidase, LysBC17, which was then cloned from the genome of B. cereus strain Bc17. This gene is also present in the B. cereus ATCC 14579 genome. The gene for LysBC17 encodes a protein of 281 amino acids. Recombinant LysBC17 was expressed and purified from E. coli. Optimal lytic activity against B. cereus occurred between pH 7.0 and 8.0, and in the absence of NaCl. The LysBC17 enzyme had lytic activity against strains of B. cereus, B. anthracis, and other Bacillus species.
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Draganic, Veselin, Jelena Lozo, Marjan Biocanin, Ivica Dimkic, Eliana Garalejic, Djordje Fira, Slavisa Stankovic y Tanja Beric. "Genotyping of Bacillus spp. isolate collection from natural samples". Genetika 49, n.º 2 (2017): 445–56. http://dx.doi.org/10.2298/gensr1702445d.
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The aim of this study was genotyping and identification of collection of 164 Bacillus spp. isolates, from samples of soil, manure, and straw gathered from across Serbia, using Pulse field gel electrophoresis (PFGE) combined with sequencing of tuf gene, one of the housekeeping genes. The PFGE analysis with NotI enzyme was used to determine phylogenetic relationships of isolates and referent strains. Four large groups of Bacillus spp. were distinguishable: cereus, subtilis, pumilus and megaterium and within enormous genetic diversity. Bacillus subtilis Marburg referent strain did not group with rest of the strains from the subtilis group (Bacillus subtilis ATCC6633 and Bacillus atrophaeus ATCC9372). Strains from the cereus group were distinguished and closely grouped together. One representative isolate from each of 21 distinct PFGE groups was identified by sequencing of tuf gene. Eight different species were identified among chosen isolates: B. amyloliquefaciens, B. subtilis, B. pumilus, B. safensis, B. megaterium, B. cereus, B. anthracis and B. thuringiensis. Our results showed that PFGE analysis combined with sequencing of one of the housekeeping genes could be used for characterization of large collections of Bacillus isolates. The determination of tuf gene recommended itself to be an adequate and sufficient analysis for obtaining very clear and unambiguous results, with high resolution of separation of Bacillus species.
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YANTI, YULMIRA, WARNITA WARNITA, REFLIN REFLIN y CHAINUR RAHMAN NASUTION. "Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum". Biodiversitas Journal of Biological Diversity 19, n.º 3 (1 de mayo de 2018): 906–11. http://dx.doi.org/10.13057/biodiv/d190320.
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Yanti Y, Warnita, Reflin, Nasution CR. 2018. Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum. Biodiversitas 19: 906-911. Bacterial wilt caused by Ralstonia solanacearum is the most damaging vascular pathogens in tomato and many other crops in tropical, subtropical and warm temperate areas of the world limiting its production. Biological agents such as Plant growth Promoting Rhizobacteria (PGPR) is considered as a potential biological control agent for the suppression of plant diseases such as bacterial wilt. Bacillus spp. are one of the most potential genera of PGPR group used for controlling pathogens and promoting plant growth because of their spore-forming ability which increases their adaptation to the environment. The aims of the research were to isolate Endophytic Bacillus isolates, to characterize its ability as plant growth promoter and pathogen controller, and to identify its molecular genetic using 16S rRNA. Bacillus strains were isolated from healthy tomato roots. All Bacillus spp. strains acquired from isolation were then screened directly on plants in completely randomized design experiments with 3 replications. All potential strains were screened and identified using 16S rRNA with 27F and 1492R primers. Results showed that out of 15 obtained isolates, 6 of them showed a good ability to both promote growth and control R. solanacearum. All isolates were identified as B. Pseudomycoides strain NBRC 101232, B. cereus strain CCM 2010, B. toyonensis strain BCT-7112, B. anthracis strain ATCC 14578, B. cereus strain JCM 2152 and B. cereus ATCC 14579.
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Shen, Cheng, Shouya Feng y Si Ming Man. "Inflammasome activation by members of the Bacillus genus". Journal of Immunology 204, n.º 1_Supplement (1 de mayo de 2020): 68.21. http://dx.doi.org/10.4049/jimmunol.204.supp.68.21.
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Abstract Inflammasome activation induced by microbial components leads to an effective innate immune response. Bacillus anthracis is able to induce activation of the NLRP1b inflammasome, whereas B. cereus can induce activation of the NLRP3 inflammasome. However, whether different strains of B. cereus have differential ability to induce activation of the inflammasome has not been investigated. Further, whether other members of the Bacillus genus can induce activation of the inflammasome has remained unknown. Here, we screened 46 B. cereus strains from environmental and clinical sources to determine whether novel inflammasomes are activated. We infected primary mouse bone marrow-derived macrophages with bacteria or bacteria-free supernatant and observed for pyroptosis and other classical features of inflammasome activation. Strikingly, over 90% (42/46) of the B. cereus strains induced inflammasome activation as measured by caspase-1 cleavage and robust secretion of IL-1b, IL-18 and LDH. We identified that the inflammasome sensor NLRP3 was necessary to drive this response. Further, we confirmed that HBL and/or NHE toxins were expressed in all 42 B. cereus strains, suggesting a conserved inflammasome activation pattern amongst B. cereus strains. We also identified that four pathogenic Bacillus species induced inflammasome activation in an NLRP3-dependent manner, including B. idriensis, B. mycoides, B. pseudomycoides and B. thurigiensis. These findings highlight that the NLRP3 inflammasome sensor is important for immune recognition of several Bacillus species and suggest that therapeutic modulation of NLRP3 may enhance host protection against these Bacillus infections.
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Sizentsov, Alexey y Lyudmila Galaktionova. "The influence of iron salts on the growth characteristics and antagonistic activity of soil isolates of Bacillus cereus". АгроЭкоИнфо 6, n.º 60 (21 de diciembre de 2023): 20. http://dx.doi.org/10.51419/202136620.
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The research is devoted to study of the effect of iron salts on the growth characteristics and antagonistic activity against Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium bacteria Bacillus cereus. 9 strains of B. cereus bacteria, previously isolated from soils, were used as objects of research, which showed different resistance to solutions of iron salts in the concentration range from 1 M/l to 0.031 M/l. In the course of the work, the following methods were used: serial breeding, seeding and cultivation of bacteria on nutrient media, MALDI ToF MS, agar wells and nephelometric. The maximum values of tolerance and growth were recorded in the B. cereus strain OCT2022.6, which was slightly inferior to OCT2022.2 and OCT2022.9, showing relative resistance to both nitrate and iron sulfate. The pronounced antagonistic properties of the strains were manifested against the background of pre-incubation with iron nitrate in relation to E. coli and P. aeruginosa, and in the sulfate variant, suppression was noted only for 3 strains against P. aeruginosa. Iron sulfate has a more pronounced toxic effect on the growth of the tested B. cereus isolates. The OCT2022.6 strain had the highest resistance to iron nitrate and the ability to suppress opportunistic microorganisms. Keywords: BACILLUS CEREUS, IRON, TOLERANCE, ANTAGONISTIC ACTIVITY, SUPPRESSIVENESS
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Mols, Maarten y Tjakko Abee. "Role of Ureolytic Activity in Bacillus cereus Nitrogen Metabolism and Acid Survival". Applied and Environmental Microbiology 74, n.º 8 (22 de febrero de 2008): 2370–78. http://dx.doi.org/10.1128/aem.02737-07.
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ABSTRACT The presence and activities of urease genes were investigated in 49 clinical, food, and environmental Bacillus cereus isolates. Ten strains were shown to have urease genes, with eight of these strains showing growth on urea as the sole nitrogen source. Two of the urease-positive strains, including the sequenced strain ATCC 10987, could not use urea for growth, despite their capacities to produce active urease. These observations can be explained by the inability of the two strains to use ammonium as a nitrogen source. The impact of urea hydrolysis on acid stress resistance was subsequently assessed among the ureolytic B. cereus strains. However, none of the strains displayed increased fitness under acidic conditions or showed enhanced acid shock survival in the presence of urea. Expression analysis of urease genes in B. cereus ATCC 10987 revealed a low level of expression of these genes and a lack of pH-, nitrogen-, urea-, oxygen-, and growth phase-dependent modulation of mRNA transcription. This is in agreement with the low urease activity observed in strain ATCC 10987 and the other nine strains tested. Although a role for B. cereus ureolytic activity in acid survival cannot be excluded, its main role appears to be in nitrogen metabolism, where ammonium may be provided to the cells in nitrogen-limited, urea-containing environments.
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Němečková, I., K. Solichová, P. Roubal, B. Uhrová y E. Šviráková. "Methods for detection of Bacillus sp., B. cereus, and B. licheniformis in raw milk". Czech Journal of Food Sciences 29, Special Issue (4 de enero de 2012): S55—S60. http://dx.doi.org/10.17221/313/2011-cjfs.
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Totally 75 raw milk samples were analysed with the methods employing the media compared – MYPA, PEMBA, Brilliance<sup>TM</sup> Bacillus cereus agar, and HiCrome Bacillus agar. The reference method with MYPA seems to be the most suitable for dairy plants laboratories because there is only low risk of mistaken identity. However, the samples containing miscellaneous micro-flora should be heat-inactivated before plating. Both positive and negative strains (totally 132) were isolated. Twelve strains, which could cause problems in the evaluation of the plates, were selected and identified by phenotyping and by PCR methods for Bacillus sp., B. cereus, and B. licheniformis. The PCR methods differed in their selectivity within particular bacilli group, within genera Bacillus, and within raw milk microflora.
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Bursová, Š., D. Nečasová, K. Dorotíková, L. Necidová y L. Vorlová. "Goat Colostrum—Source of Toxigenic Bacillus Cereus". Folia Veterinaria 63, n.º 3 (1 de septiembre de 2019): 27–33. http://dx.doi.org/10.2478/fv-2019-0024.
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Abstract The aim of this study was to evaluate the toxigenic potential of Bacillus cereus strains isolated from frozen goat colostrum. Of the 50 phenotypically suspected B. cereus isolates, 39 (78.0 %) were confirmed as B. cereus by the polymerase chain reaction (PCR) method based on the gyrB gene detection. In these isolates, genes encoding the production of haemolysin BL (Hbl), a complex of non-haemolytic enterotoxins (Nhe) and emetic toxin were detected by the PCR method. In 36 (92.3 %) confirmed B. cereus isolates, genes encoding at least one type of toxins of interest were detected. In all toxigenic isolates, we found the presence of genes for Nhe production, and in 16 (41.0 %) of the isolates, genes encoding both Nhe and haemolysin BL were shown. Eight (20.5 %) of the emetic strains of B. cereus were identified. The emetic toxin production gene was always detected simultaneously with genes encoding non-haemolytic enterotoxin production. The ability to produce BL haemolysin and non-haemolytic enterotoxins were confirmed by the immunochromatographic method. In summary, goat colostrum can be a significant source of toxigenic strains of B. cereus.