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.

scholarly journals Divergence in environmental adaptation between terrestrial clades of the Bacillus cereus group

2020 ◽  
Vol 97 (1) ◽  
Author(s):  
C James Manktelow ◽  
Hugh White ◽  
Neil Crickmore ◽  
Ben Raymond
Keyword(s):  
Bacillus Cereus ◽  
Thermal Adaptation ◽  
Optimal Growth ◽  
Relative Fitness ◽  
Ecological Specialization ◽  
Phylogenetic Groups ◽  
Bacillus Cereus Group ◽  
Rich Media ◽  
Group B ◽  
Protein Rich

ABSTRACT The Bacillus cereus group encompasses beneficial and harmful species in diverse niches and has a much debated taxonomy. Investigating whether selection has led to ecological divergence between phylogenetic clades can help understand the basis of speciation, and has implications for predicting biological safety across this group. Using three most terrestrial species in this group (B. cereus, Bacillus thuringiensis and Bacillus mycoides) we charactererized ecological specialization in terms of resource use, thermal adaptation and fitness in different environmental conditions and tested whether taxonomic species or phylogenetic clade best explained phenotypic variation. All isolates grew vigorously in protein rich media and insect cadavers, but exploitation of soil or plant derived nutrients was similarly weak for all. For B. thuringiensis and B. mycoides, clade and taxonomic species were important predictors of relative fitness in insect infections. Fully psychrotolerant isolates could outcompete B. thuringiensis in insects at low temperature, although psychrotolerance predicted growth in artificial media better than clade. In contrast to predictions, isolates in the Bacillus anthracis clade had sub-optimal growth at 37°C. The common ecological niche in these terrestrial B. cereus species is the ability to exploit protein rich resources such as cadavers. However, selection has led to different phylogenetic groups developing different strategies for accessing this resource. Thus, clades, as well as traditional taxonomic phenotypes, predict biologically important traits.

scholarly journals Identification and Classification of bcl Genes and Proteins of Bacillus cereus Group Organisms and Their Application in Bacillus anthracis Detection and Fingerprinting

2009 ◽  
Vol 75 (22) ◽  
pp. 7163-7172 ◽  
Author(s):  
Tomasz A. Leski ◽  
Clayton C. Caswell ◽  
Marcin Pawlowski ◽  
David J. Klinke ◽  
Janusz M. Bujnicki ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Length Polymorphism ◽  
Genomic Dna ◽  
Length Variation ◽  
Specific Detection ◽  
Bacillus Cereus Group ◽  
Closely Related Species ◽  
Length Polymorphisms ◽  
Pcr Products

ABSTRACT The Bacillus cereus group includes three closely related species, B. anthracis, B. cereus, and B. thuringiensis, which form a highly homogeneous subdivision of the genus Bacillus. One of these species, B. anthracis, has been identified as one of the most probable bacterial biowarfare agents. Here, we evaluate the sequence and length polymorphisms of the Bacillus collagen-like protein bcl genes as a basis for B. anthracis detection and fingerprinting. Five genes, designated bclA to bclE, are present in B. anthracis strains. Examination of bclABCDE sequences identified polymorphisms in bclB alleles of the B. cereus group organisms. These sequence polymorphisms allowed specific detection of B. anthracis strains by PCR using both genomic DNA and purified Bacillus spores in reactions. By exploiting the length variation of the bcl alleles it was demonstrated that the combined bclABCDE PCR products generate markedly different fingerprints for the B. anthracis Ames and Sterne strains. Moreover, we predict that bclABCDE length polymorphism creates unique signatures for B. anthracis strains, which facilitates identification of strains with specificity and confidence. Thus, we present a new diagnostic concept for B. anthracis detection and fingerprinting, which can be used alone or in combination with previously established typing platforms.

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 Phylogenomic Insights into Distribution and Adaptation of Bdellovibrionota in Marine Waters

2021 ◽  
Vol 9 (4) ◽  
pp. 757
Author(s):  
Qing-Mei Li ◽  
Ying-Li Zhou ◽  
Zhan-Fei Wei ◽  
Yong Wang
Keyword(s):  
Comparative Genomics ◽  
Deep Sea ◽  
Binding Protein ◽  
Glycerol Metabolism ◽  
Metabolic Reconstruction ◽  
Type Ii Secretion ◽  
Phylogenetic Groups ◽  
Genes Encoding ◽  
Epipelagic Zone ◽  
Chitin Binding Protein

Bdellovibrionota is composed of obligate predators that can consume some Gram-negative bacteria inhabiting various environments. However, whether genomic traits influence their distribution and marine adaptation remains to be answered. In this study, we performed phylogenomics and comparative genomics studies using 132 Bdellovibrionota genomes along with five metagenome-assembled genomes (MAGs) from deep sea zones. Four phylogenetic groups, Oligoflexia, Bdello-group1, Bdello-group2 and Bacteriovoracia, were revealed by constructing a phylogenetic tree, of which 53.84% of Bdello-group2 and 48.94% of Bacteriovoracia were derived from the ocean. Bacteriovoracia was more prevalent in deep sea zones, whereas Bdello-group2 was largely distributed in the epipelagic zone. Metabolic reconstruction indicated that genes involved in chemotaxis, flagellar (mobility), type II secretion system, ATP-binding cassette (ABC) transporters and penicillin-binding protein were necessary for the predatory lifestyle of Bdellovibrionota. Genes involved in glycerol metabolism, hydrogen peroxide (H2O2) degradation, cell wall recycling and peptide utilization were ubiquitously present in Bdellovibrionota genomes. Comparative genomics between marine and non-marine Bdellovibrionota demonstrated that betaine as an osmoprotectant is probably widely used by marine Bdellovibrionota, and all the marine genomes have a number of genes for adaptation to marine environments. The genes encoding chitinase and chitin-binding protein were identified for the first time in Oligoflexia, which implied that Oligoflexia may prey on a wider spectrum of microbes. This study expands our knowledge on adaption strategies of Bdellovibrionota inhabiting deep seas and the potential usage of Oligoflexia for biological control.

Phenotypic properties and genotyping analysis of Bacillus cereus group isolates from dairy and potato products

LWT ◽  
2021 ◽  
Vol 140 ◽  
pp. 110853
Author(s):  
Yiying Huang ◽  
Steve H. Flint ◽  
Shubo Yu ◽  
Yu Ding ◽  
Jon S. Palmer
Keyword(s):  
Bacillus Cereus ◽  
Bacillus Cereus Group ◽  
Phenotypic Properties ◽  
Potato Products

Development of Rapid Real-Time PCR and Most-Probable-Number Real-Time PCR Assays To Quantify Enterotoxigenic Strains of the Species in the Bacillus cereus Group

2007 ◽  
Vol 70 (12) ◽  
pp. 2774-2781 ◽  
Author(s):  
I-CHEN YANG ◽  
DANIEL YANG-CHIH SHIH ◽  
JAN-YI WANG ◽  
TZU-MING PAN
Keyword(s):  
Bacillus Cereus ◽  
Real Time ◽  
Real Time Pcr ◽  
Food Samples ◽  
Most Probable Number ◽  
Pcr Assay ◽  
Bacillus Cereus Group ◽  
Probable Number ◽  
Cooked Rice ◽  
Group Detection

Members of the Bacillus cereus group may produce diarrheal enterotoxins and could be potential hazards if they enter the food chain. Therefore, a method capable of detecting all the species in the B. cereus group rather than B. cereus alone is important. We selected nhe as the target and developed a real-time PCR assay to quantify enterotoxigenic strains of the B. cereus group. The real-time PCR assay was evaluated with 60 B. cereus group strains and 28 others. The assay was also used to construct calibration curves for different food matrices and feces. The assay has an excellent quantification capacity, as proved by its linearity (R2 > 0.993), wide dynamic quantification range (102 to 107 CFU/g for cooked rice and chicken, 103 to 107 CFU/ml for milk, and 104 to 107 CFU/g for feces), and adequate relative accuracy (85.5 to 101.1%). For the low-level contaminations, a most-probable-number real-time PCR assay was developed that could detect as low as 100 CFU/ml. Both assays were tested with real food samples and shown to be considerably appropriate for B. cereus group detection and quantification.

Identification of Sulfur Activation Relevant Protein Genes of Extremely Thermophilic Acidianus manzaensis

2017 ◽  
Vol 262 ◽  
pp. 461-465 ◽  
Author(s):  
Hong Chang Liu ◽  
Jin Lan Xia ◽  
Zhen Yuan Nie ◽  
Ya Long Ma ◽  
Yun Yang ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Elemental Sulfur ◽  
Extracellular Proteins ◽  
Laser Desorption Ionization ◽  
Two Dimensional Gel Electrophoresis ◽  
Ionization Time ◽  
Real Time Quantitative Pcr ◽  
Flight Mass Spectrometry ◽  
Genes Encoding ◽  
Acidianus Manzaensis

The sulfur activation by extracellular proteins is considered as the crucial stage during biooxidation of elemental sulfur (S0). In order to study genes encoding sulfur-activation related extracellular proteins of extremely thermophilic Acidianus manzaensis, the extracellular proteins with higher abundance for the strain grown on S0 allotropes than that on Fe2+ were first screened by two-dimensional gel electrophoresis, and then identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Nine genes amplified with PCR were satisfactory according to their agarose gel electrophoresis. The differential expression of these nine genes when the strain grown on S0 allotropes and Fe2+ were analyzed with real-time quantitative PCR (RT-qPCR). Results showed that seven of them were higher expressed when the strain grown on S0 allotropes than on Fe2+, indicating they may be related with sulfur activation by A. manzaensis.

Genomic analysis of Rhodococcus sp. BH4 reveals two genes encoding different types of AHL-lactonase for quorum quenching

2018 ◽  
Vol 44 ◽  
pp. S77-S78
Author(s):  
D.H. Ryu ◽  
S.W. Lee ◽  
S.J. Lee ◽  
H. Jeong ◽  
C.H. Lee ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Quorum Quenching ◽  
Different Types ◽  
Genes Encoding ◽  
Rhodococcus Sp

A proteomics analysis of adventitious root formation after leaf removal in lotus (Nelumbo nucifera Gaertn.)

2018 ◽  
Vol 73 (9-10) ◽  
pp. 375-389 ◽  
Author(s):  
Libao Cheng ◽  
Huiying Liu ◽  
Runzhi Jiang ◽  
Shuyan Li
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Adventitious Root Formation ◽  
Nelumbo Nucifera ◽  
Leaf Removal ◽  
Proteomics Analysis ◽  
Citrate Cycle ◽  
Different Types ◽  
Genes Encoding ◽  
Polymerase Chain ◽  
Isobaric Tags

AbstractThe formation of adventitious roots (ARs) is an important process for lotus (Nelumbo nucifera), which does not have a well-formed main root. In lotus, the removal of leaves above the waterline significantly promoted AR formation, while the removal of leaves below the waterline inhibited AR formation. Proteins were identified using isobaric tags for relative and absolute quantization technique. The number of proteins decreased with increasing sequencing coverage, and most of the identified proteins had fewer than 10 peptides. In the A1/A0 and A2/A1 stages, 661 and 154 proteins showed increased abundance, respectively, and 498 and 111 proteins showed decreased abundance, respectively. In the B1/B0 and B2/B1 stages, 498 and 436 proteins showed increased abundance, respectively, and 358 and 348 proteins showed decreased abundance, respectively. Among the proteins showing large differences in abundance, 17 were identified as being related to AR formation. Proteins involved in the glycolytic pathway and the citrate cycle showed differences in abundance between the two types of leaf removal. The transcriptional levels of nine genes encoding relevant proteins were assessed by quantitative polymerase chain reaction. The results of this study illustrate the changes in metabolism after different types of leaf removal during AR formation in lotus.

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