scholarly journals Enigmatic Pilus-like Endospore Appendages of Bacillus cereus Group Species

2021 ◽  
Vol 22 (22) ◽  
pp. 12367
Author(s):  
Ephrem Debebe Zegeye ◽  
Brajabandhu Pradhan ◽  
Ann-Katrin Llarena ◽  
Marina Aspholm
Keyword(s):  
Bacillus Cereus ◽  
Bacillus Cereus Group ◽  
Functional Roles ◽  
Functional Studies ◽  
Cryo Electron Microscopy ◽  
Abiotic Surfaces ◽  
Genes Encoding ◽  
Group Species ◽  
Bacillus Cereus Sensu Lato

The endospores (spores) of many Bacillus cereus sensu lato species are decorated with multiple hair/pilus-like appendages. Although they have been observed for more than 50 years, all efforts to characterize these fibers in detail have failed until now, largely due to their extraordinary resilience to proteolytic digestion and chemical solubilization. A recent structural analysis of B. cereus endospore appendages (Enas) using cryo-electron microscopy has revealed the structure of two distinct fiber morphologies: the longer and more abundant “Staggered-type” (S-Ena) and the shorter “Ladder-like” type (L-Ena), which further enabled the identification of the genes encoding the S-Ena. Ena homologs are widely and uniquely distributed among B. cereus sensu lato species, suggesting that appendages play important functional roles in these species. The discovery of ena genes is expected to facilitate functional studies involving Ena-depleted mutant spores to explore the role of Enas in the interaction between spores and their environment. Given the importance of B. cereus spores for the food industry and in medicine, there is a need for a better understanding of their biological functions and physicochemical properties. In this review, we discuss the current understanding of the Ena structure and the potential roles these remarkable fibers may play in the adhesion of spores to biotic and abiotic surfaces, aggregation, and biofilm formation.

scholarly journals Identification of Bacillus cereus Group Species Associated with Food Poisoning Outbreaks in British Columbia, Canada

2008 ◽  
Vol 74 (23) ◽  
pp. 7451-7453 ◽  
Author(s):  
Lorraine McIntyre ◽  
Kathryn Bernard ◽  
Daniel Beniac ◽  
Judith L. Isaac-Renton ◽  
David Craig Naseby
Keyword(s):  
British Columbia ◽  
Bacillus Cereus ◽  
Food Poisoning ◽  
Bacillus Cereus Group ◽  
Group Species

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.

scholarly journals Detection and quantification of viable Bacillus cereus group species in milk by propidium monoazide quantitative real-time PCR

2016 ◽  
Vol 99 (4) ◽  
pp. 2617-2624 ◽  
Author(s):  
Fernanda Cattani ◽  
Valdir C. Barth ◽  
Jéssica S.R. Nasário ◽  
Carlos A.S. Ferreira ◽  
Sílvia D. Oliveira
Keyword(s):  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Propidium Monoazide ◽  
Quantitative Real Time Pcr ◽  
Bacillus Cereus Group ◽  
Group Species ◽  
Detection And Quantification

scholarly journals Global Gene Expression Profile for Swarming Bacillus cereus Bacteria

2011 ◽  
Vol 77 (15) ◽  
pp. 5149-5156 ◽  
Author(s):  
Sara Salvetti ◽  
Karoline Faegri ◽  
Emilia Ghelardi ◽  
Anne-Brit Kolstø ◽  
Sonia Senesi
Keyword(s):  
Bacillus Cereus ◽  
Transcriptional Response ◽  
Global Gene Expression ◽  
Solid Surfaces ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
Genome Wide ◽  
Genes Encoding ◽  
Hemolysin Bl

ABSTRACTBacillus cereuscan use swarming to move over and colonize solid surfaces in different environments. This kind of motility is a collective behavior accompanied by the production of long and hyperflagellate swarm cells. In this study, the genome-wide transcriptional response ofB. cereusATCC 14579 during swarming was analyzed. Swarming was shown to trigger the differential expression (>2-fold change) of 118 genes. Downregulated genes included those required for basic cellular metabolism. In accordance with the hyperflagellate phenotype of the swarm cell, genes encoding flagellin were overexpressed. Some genes associated with K+transport, phBC6A51 phage genes, and the binding component of the enterotoxin hemolysin BL (HBL) were also induced. Quantitative reverse transcription-PCR (qRT-PCR) experiments indicated an almost 2-fold upregulation of the entirehbloperon during swarming. Finally, BC1435 and BC1436, orthologs ofliaI-liaHthat are known to be involved in the resistance ofBacillus subtilisto daptomycin, were upregulated under swarming conditions. Accordingly, phenotypic assays showed reduced susceptibility of swarmingB. cereuscells to daptomycin, and Pspac-induced hyper-expression of these genes in liquid medium highlighted the role of BC1435 and BC1436 in the response ofB. cereusto daptomycin.

scholarly journals Distinct Mutations in PlcR Explain Why Some Strains of the Bacillus cereus Group Are Nonhemolytic

2004 ◽  
Vol 186 (11) ◽  
pp. 3531-3538 ◽  
Author(s):  
Leyla Slamti ◽  
Stéphane Perchat ◽  
Myriam Gominet ◽  
Gislayne Vilas-Bôas ◽  
Agnès Fouet ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Nonsense Mutation ◽  
Extracellular Proteins ◽  
Phylogenetic Groups ◽  
Bacillus Cereus Group ◽  
Closely Related Species ◽  
Different Types ◽  
Genes Encoding ◽  
Unusual Phenotype ◽  
Pleiotropic Regulator

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.

Design of specific DNA primers to detect the Bacillus cereus group species

2009 ◽  
Author(s):  
Catherine Adley ◽  
Khalil Arshak ◽  
Camila Molnar ◽  
Kamila Oliwa ◽  
Vijayalakshmi Velusamy
Keyword(s):  
Bacillus Cereus ◽  
Bacillus Cereus Group ◽  
Dna Primers ◽  
Group Species

scholarly journals New Insights into the Potential Cytotoxic Role of Bacillus cytotoxicus Cytotoxin K-1

Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 698
Author(s):  
Klèma Marcel Koné ◽  
Pauline Hinnekens ◽  
Jelena Jovanovic ◽  
Andreja Rajkovic ◽  
Jacques Mahillon
Keyword(s):  
Bacillus Cereus ◽  
Tetrazolium Salt ◽  
Wild Type ◽  
Foodborne Outbreak ◽  
Pathogenic Role ◽  
Bacillus Cereus Group ◽  
Mtt Method ◽  
High Cytotoxicity ◽  
Type Strains

The thermotolerant representative of the Bacillus cereus group, Bacillus cytotoxicus, reliably harbors the coding gene of cytotoxin K-1 (CytK-1). This protein is a highly cytotoxic variant of CytK toxin, initially recovered from a diarrheal foodborne outbreak that caused the death of three people. In recent years, the cytotoxicity of B. cytotoxicus has become controversial, with some strains displaying a high cytotoxicity while others show no cytotoxicity towards cell lines. In order to better circumscribe the potential pathogenic role of CytK-1, knockout (KO) mutants were constructed in two B. cytotoxicus strains, E8.1 and E28.3. The complementation of the cytK-1 KO mutation was implemented in a mutant strain lacking in the cytK-1 gene. Using the tetrazolium salt (MTT) method, cytotoxicity tests of the cytK-1 KO and complemented mutants, as well as those of their wild-type strains, were carried out on Caco-2 cells. The results showed that cytK-1 KO mutants were significantly less cytotoxic than the parental wild-type strains. However, the complemented mutant was as cytotoxic as the wild-type, suggesting that CytK-1 is the major cytotoxicity factor in B. cytotoxicus.

scholarly journals A Novel Multiplex PCR Discriminates Bacillus anthracis and Its Genetically Related Strains from Other Bacillus cereus Group Species

PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0122004 ◽  
Author(s):  
Hirohito Ogawa ◽  
Daisuke Fujikura ◽  
Miyuki Ohnuma ◽  
Naomi Ohnishi ◽  
Bernard M. Hang'ombe ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Bacillus Anthracis ◽  
Multiplex Pcr ◽  
Bacillus Cereus Group ◽  
Group Species

scholarly journals Phylogenetic Analysis of Bacillus cereus sensu lato Isolates from Commercial Bee Pollen Using tRNACys-PCR

2020 ◽  
Vol 8 (4) ◽  
pp. 524
Author(s):  
José Luis Hernández Flores ◽  
Diana Salinas Landaverde ◽  
Yonuen Pacheco Huerta ◽  
Vania Lizeth Guerra Castillo ◽  
María de los Ángeles Barrios Sánchez ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Bacillus Cereus ◽  
Single Copy ◽  
Foodborne Illnesses ◽  
Regulatory Requirements ◽  
Bee Pollen ◽  
Enterotoxin Genes ◽  
Genes Encoding ◽  
Commercial Source ◽  
Bacillus Cereus Sensu Lato

Endospore-forming bacteria related to the Bacillus cereus group produce toxins that cause illnesses in organisms from invertebrates to mammals, including foodborne illnesses in humans. As commercial bee pollen can be contaminated with these bacteria, a comprehensive microbiological risk assessment of commercial bee pollen must be incorporated into the relevant regulatory requirements, including those that apply in Mexico. To facilitate detection of members of this group of bacteria, we have developed a PCR strategy that is based on the amplification of the single-copy tRNACys gene and specific genes associated with tRNACys to detect Bacillus cereus sensu lato (B. cereus s.l.). This tRNACys-PCR-based approach was used to examine commercial bee pollen for endospore-forming bacteria. Our analysis revealed that 3% of the endospore-forming colonies isolated from a commercial source of bee pollen were related to B. cereus s.l., and this result was corroborated by phylogenetic analysis, bacterial identification via MALDI-TOF MS, and detection of enterotoxin genes encoding the HBL and NHE complexes. The results show that the isolated colonies are closely related phylogenetically to B. cereus, B. thuringiensis, and B. bombysepticus. Our results indicate that the tRNACys-PCR, combined with other molecular tools, will be a useful approach for identifying B. cereus s.l. and will assist in controlling the spread of potential pathogens.

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