scholarly journals Sequential CRISPR-Based Screens Identify LITAF and CDIP1 as the Bacillus cereus Hemolysin BL Toxin Host Receptors

2020 ◽  
Vol 28 (3) ◽  
pp. 402-410.e5 ◽  
Author(s):  
Jie Liu ◽  
Zehua Zuo ◽  
Inka Sastalla ◽  
Chengyu Liu ◽  
Ji Yong Jang ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Hemolysin Bl

scholarly journals Exposure to Bacillus cereus in Water Buffalo Mozzarella Cheese

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1899
Author(s):  
Angela Michela Immacolata Montone ◽  
Federico Capuano ◽  
Andrea Mancusi ◽  
Orlandina Di Maro ◽  
Maria Francesca Peruzy ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Water Buffalo ◽  
Diarrheal Disease ◽  
Food Poisoning ◽  
Mozzarella Cheese ◽  
Food Borne ◽  
Genes Encoding ◽  
Spoilage Bacterium ◽  
Hemolysin Bl

Bacillus cereus is a spoilage bacterium and is recognized as an agent of food poisoning. Two food-borne illnesses are caused by B. cereus: a diarrheal disease, associated with cytotoxin K, hemolysin BL, non-hemolytic enterotoxin and enterotoxin FM, and an emetic syndrome, associated with the cereulide toxin. Owing to the heat resistance of B. cereus and its ability to grow in milk, this organism should be considered potentially hazardous in dairy products. The present study assessed the risk of B. cereus poisoning due to the consumption of water buffalo mozzarella cheese. A total of 340 samples were analyzed to determine B. cereus counts (ISO 7932:2005); isolates underwent molecular characterization to detect the presence of genes encoding toxins. Eighty-nine (26.1%) samples harbored B. cereus strains, with values ranging from 2.2 × 102 to 2.6 × 106 CFU/g. Isolates showed eight different molecular profiles, and some displayed virulence characteristics. Bacterial counts and the toxin profiles of isolates were evaluated both separately and jointly to assess the risk of enteritis due to B. cereus following the consumption of buffalo mozzarella cheese. In conclusion, the results of the present study showed that the risk of poisoning by B. cereus following the consumption of this cheese was moderate.

Growth of Enterotoxigenic Bacillus cereus on Salmon (Oncorhynchus nerka)

2012 ◽  
Vol 75 (6) ◽  
pp. 1153-1156 ◽  
Author(s):  
RONALD LABBÉ ◽  
TALAT RAHMATI
Keyword(s):  
Bacillus Cereus ◽  
Colony Formation ◽  
Incubation Temperature ◽  
Oncorhynchus Nerka ◽  
Foodborne Illness ◽  
Moderate Temperature ◽  
Fivefold Increase ◽  
Generation Times ◽  
Raw Fish ◽  
Hemolysin Bl

We previously demonstrated the widespread presence of enterotoxigenic Bacillus cereus in marine foods. In view of the widespread consumption of raw fish, we sought to determine the ability of this organism to grow on the surface of wild Alaskan salmon at abusive temperatures (12, 16, and 20°C), using an isolate able to produce elevated levels of hemolysin BL enterotoxin and nonhemolytic enterotoxin. An incubation temperature of 37°C for colony formation was found to be selective for B. cereus grown on salmon held for up to 24 h at each temperature. A fivefold increase in log CFU per gram was observed after 26 and 22 h at 16 and 20°C, respectively, while a >4-log CFU/g increase occurred on salmon held at 12°C for 48 h. Generation times of 169.7, 53.5, and 45.6 min were observed at 12, 16, and 20°C. Nonhemolytic enterotoxin was detected when levels of B. cereus were in excess of 108 CFU/g. Nisin, at concentrations of 1 and 15 μg/g of salmon, reduced levels of B. cereus 2.5- and 25-fold, respectively. Our results indicate that fresh salmon can serve as an excellent substrate for enterotoxigenic B. cereus and that this organism can reach levels associated with foodborne illness following moderate temperature abuse.

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.

Genetic Diversity, Antimicrobial Resistance, and Toxigenic Profiles of Bacillus cereus Strains Isolated from Sunsik

2012 ◽  
Vol 75 (2) ◽  
pp. 225-230 ◽  
Author(s):  
NARI LEE ◽  
JE MIN SUN ◽  
KYUNG YOON KWON ◽  
HYUN JUNG KIM ◽  
MINSEON KOO ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Fruits And Vegetables ◽  
Food Poisoning ◽  
Pcr Analysis ◽  
Contamination Level ◽  
Detection Rates ◽  
Its Gene ◽  
Hemolysin Bl ◽  
Encoding Genes ◽  
Element Sequence

Bacillus cereus can cause emetic and diarrheal types of food poisoning, but little study has been done on the toxins and toxin-encoding genes of B. cereus strains isolated from Sunsik, a Korean ready-to-eat food prepared from grains, fruits, and vegetables. In this study, 39 unique B. cereus strains were isolated and identified from Sunsik samples, with an average contamination level of 10 to 200 CFU/g. The detection rates of the hblACD, cytK, and bceT genes among all the strains were 48.7, 66.7, and 87.1%, respectively. All 39 B. cereus strains carried nheABC and entFM genes, and 36 strains also had the ces gene, which encodes an emetic toxin. Nonhemolytic enterotoxin and hemolysin BL enterotoxin were produced by 39 and 26 strains, respectively. The strains were separated into 13 profiles based on the presence or absence of toxins and their genes, as determined by antibody tests and PCR analysis. Profile 1 was the largest group, comprising 30.7% (12 of 39) of the B. cereus strains tested; these strains harbored all toxins and their genes. The B. cereus strains were susceptible to most of the antibiotics tested but were highly resistant to β-lactam antibiotics. The repetitive element sequence polymorphism PCR fingerprints of the B. cereus strains were not influenced by the presence of toxin genes or antibiotic resistance profiles. Our results suggest that B. cereus strains from Sunsik could cause either the diarrheal or emetic types of food poisoning because all strains isolated contained at least one toxin and its gene, although the level of B. cereus contamination in Sunsik was low.

scholarly journals Production of hemolysin BL by Bacillus cereus group isolates of dairy origin is associated with whole-genome phylogenetic clade

BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Jasna Kovac ◽  
Rachel A. Miller ◽  
Laura M. Carroll ◽  
David J. Kent ◽  
Jiahui Jian ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Whole Genome ◽  
Bacillus Cereus Group ◽  
Hemolysin Bl

scholarly journals The Pore-Forming Hemolysin BL Enterotoxin from Bacillus cereus: Subunit Interactions in Cell-Free Systems

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 807
Author(s):  
Franziska Ramm ◽  
Marlitt Stech ◽  
Anne Zemella ◽  
Hendrik Frentzel ◽  
Stefan Kubick
Keyword(s):  
Bacillus Cereus ◽  
Chinese Hamster ◽  
Iodide Uptake ◽  
Cytotoxic Effects ◽  
Free System ◽  
Multiple Protein ◽  
Uptake Assay ◽  
Membrane Bound ◽  
Hemolysin Bl ◽  
Cell Free Protein Synthesis

The tripartite enterotoxin Hemolysin BL (Hbl) has been widely characterized as a hemolytic and cytotoxic virulence factor involved in foodborne diarrheal illness caused by Bacillus cereus. Previous studies have described the formation of the Hbl complex and aimed to identify the toxin’s mode of action. In this study, we analyzed the assembly of Hbl out of its three individual subunits L1, L2 and B in a soluble as well as a putative membrane bound composition using a Chinese hamster ovary (CHO) cell-free system. Subunits were either coexpressed or synthesized individually in separate cell-free reactions and mixed together afterwards. Hemolytic activity of cell-free synthesized subunits was demonstrated on 5% sheep blood agar and identified both synthesis procedures, coexpression as well as individual synthesis of each subunit, as functional for the synthesis of an active Hbl complex. Hbl’s ability to perforate cell membranes was evaluated using a propidium iodide uptake assay. These data suggested that coexpressed Hbl subunits augmented cytotoxic activity with increasing concentrations. Further, a pre-pore-complex of L1-L2 showed cytotoxic effects suggesting the possibility of an interaction between the cell membrane and the pre-pore-complex. Overall, this study shows that cell-free protein synthesis is a fast and efficient way to study the assembly of multiple protein subunits in soluble as well as vesicular fractions.

scholarly journals DETECTION OF HBLD TOXIN GENE BY BACILLUS CEREUS ISOLATED FROM MEAT CURRY FOOD SAMPLES IN MALAYSIAN RESTAURANTS

2020 ◽  
Vol 4 (2) ◽  
pp. 68-72
Author(s):  
Marwan Msarah ◽  
Ahmed Alsier ◽  
Sahilah, A.M.
Keyword(s):  
Bacillus Cereus ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Egg Yolk ◽  
Food Samples ◽  
Blood Agar ◽  
Toxin Gene ◽  
Biochemical Tests ◽  
Isolation Medium ◽  
Hemolysin Bl

Bacillus cereus is a ubiquitous foodborne pathogen, can cause food poisoning, leading to infections, have two major types of food poisoning emetic and diarrheal. Foods rich in protein such as meat are associated with foodborne outbreaks of diarrhea caused by B. cereus. The aim of this study is to isolate and identify B. cereus from ready to eat (RTE) meat curry from restaurants in Malaysia and to detect hblD pathogenic gene of B. cereus isolates. Mannitol egg yolk polymyxin agar was used as a selective isolation medium. Commercially available kits and boiling methods were used for DNA extraction, samples acquired from restaurants were examined for the presence of Hemolysin BL gene by polymerase chain reaction (PCR). Among all isolates, twenty-four of B. cereus isolates detected for HBL enterotoxin production by the discontinuous pattern on HBL sheep blood agar then confirmed by biochemical tests. More than 58.33 % of the isolate showed discontinuous hemolysis pattern on HBl blood agar and 29.16% of the samples were shown positive for hblD gene that can cause diarrhea with the size of 807bp on gel. This study demonstrated that RTE meat curry was a potential source for entero-toxigenic B. cereus and the presence of the hblD toxin genes for the HBL complex in the isolates tested were highly associated. Therefore, these meat curry isolates should be regarded as potential toxin producers.

scholarly journals Enterotoxic activity of hemolysin BL from Bacillus cereus.

1995 ◽  
Vol 63 (11) ◽  
pp. 4423-4428 ◽  
Author(s):  
D J Beecher ◽  
J L Schoeni ◽  
A C Wong
Keyword(s):  
Bacillus Cereus ◽  
Hemolysin Bl

scholarly journals Potential Enterotoxicity of Phylogenetically Diverse Bacillus cereus Sensu Lato Soil Isolates from Different Geographical Locations

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Justyna Malgorzata Drewnowska ◽  
Natalia Stefanska ◽  
Magdalena Czerniecka ◽  
Grzegorz Zambrowski ◽  
Izabela Swiecicka
Keyword(s):  
Bacillus Cereus ◽  
Bacterial Population ◽  
Phylogenetic Groups ◽  
Content Type ◽  
Hot Climate ◽  
Hemolysin Bl ◽  
Spore Forming Bacteria ◽  
Geographical Locations ◽  
Bacillus Cereus Sensu Lato

ABSTRACT Bacillus cereus sensu lato comprises Gram-positive spore-forming bacteria producing toxins associated with foodborne diseases. Three pore-forming enterotoxins, nonhemolytic enterotoxin (Nhe), hemolysin BL (Hbl), and cytotoxin K (CytK), are considered the primary factors in B. cereus sensu lato diarrhea. The aim of this study was to determine the potential risk of enterotoxicity among soil B. cereus sensu lato isolates representing diverse phylogroups and originated from different geographic locations with various climates (Burkina Faso, Kenya, Argentina, Kazakhstan, and Poland). While nheA- and hblA-positive isolates were present among all B. cereus sensu lato populations and distributed across all phylogenetic groups, cytK-2-positive strains predominated in geographic regions with an arid hot climate (Africa) and clustered together on a phylogenetic tree mainly within mesophilic groups III and IV. The highest in vitro cytotoxicity to Caco-2 and HeLa cells was demonstrated by the strains clustered within phylogroups II and IV. Overall, our results suggest that B. cereus sensu lato pathogenicity is a comprehensive process conditioned by many intracellular factors and diverse environmental conditions. IMPORTANCE This research offers a new route for a wider understanding of the dependency between pathogenicity and phylogeny of a natural bacterial population, specifically within Bacillus cereus sensu lato, that is widely distributed around the world and easily transferred into food products. Our study indicates differences in the phylogenetic and geographical distributions of potential enterotoxigenic B. cereus sensu lato strains. Hence, these bacilli possess a risk for human health, and rapid testing methods for their identification are greatly needed. In particular, the detection of the CytK enterotoxin should be a supporting strategy for the identification of pathogenic B. cereus sensu lato.

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