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PloS One 2018Bacillus cereus is the 2nd most frequent bacterial agent responsible for food-borne outbreaks in France and the 3rd in Europe. In addition, local and systemic infections...
Bacillus cereus is the 2nd most frequent bacterial agent responsible for food-borne outbreaks in France and the 3rd in Europe. In addition, local and systemic infections have been reported, mainly describing individual cases or single hospital setting. The real incidence of such infection is unknown and information on genetic and phenotypic characteristics of the incriminated strains is generally scarce. We performed an extensive study of B. cereus strains isolated from patients and hospital environments from nine hospitals during a 5-year study, giving an overview of the consequences, sources and pathogenic patterns of B. cereus clinical infections. We demonstrated the occurrence of several hospital-cross-contaminations. Identical B. cereus strains were recovered from different patients and hospital environments for up to 2 years. We also clearly revealed the occurrence of inter hospital contaminations by the same strain. These cases represent the first documented events of nosocomial epidemy by B. cereus responsible for intra and inter hospitals contaminations. Indeed, contamination of different patients with the same strain of B. cereus was so far never shown. In addition, we propose a scheme for the characterization of B. cereus based on biochemical properties and genetic identification and highlight that main genetic signatures may carry a high pathogenic potential. Moreover, the characterization of antibiotic resistance shows an acquired resistance phenotype for rifampicin. This may provide indication to adjust the antibiotic treatment and care of patients.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacillus cereus; Child; Child, Preschool; Cross Infection; Female; Genetic Variation; Genomics; Humans; Infant; Infant, Newborn; Male; Middle Aged; Phenotype; Surveys and Questionnaires; Young Adult
PubMed: 29791442
DOI: 10.1371/journal.pone.0194346 -
Microbes and Infection Feb 2000Bacillus cereus is a causative agent in both gastrointestinal and in nongastrointestinal infections. Enterotoxins, emetic toxin (cereulide), hemolysins, and... (Review)
Review
Bacillus cereus is a causative agent in both gastrointestinal and in nongastrointestinal infections. Enterotoxins, emetic toxin (cereulide), hemolysins, and phoshpolipase C as well as many enzymes such as beta-lactamases, proteases and collagenases are known as potential virulence factors of B. cereus. A special surface structure of B. cereus cells, the S-layer, has a significant role in the adhesion to host cells, in phagocytosis and in increased radiation resistance. Interest in B. cereus has been growing lately because it seems that B. cereus-related diseases, in particular food poisonings, are growing in number.
Topics: Animals; Bacillaceae Infections; Bacillus cereus; Bacterial Adhesion; Bacterial Proteins; Gastrointestinal Diseases; Humans; Membrane Glycoproteins; Phagocytosis; Virulence
PubMed: 10742691
DOI: 10.1016/s1286-4579(00)00269-0 -
FEMS Microbiology Ecology Jun 2013Bacillus cereus comprises a highly versatile group of bacteria, which are of particular interest because of their capacity to cause disease. Emetic food poisoning is... (Review)
Review
Bacillus cereus comprises a highly versatile group of bacteria, which are of particular interest because of their capacity to cause disease. Emetic food poisoning is caused by the toxin cereulide produced during the growth of emetic B. cereus in food, while diarrhoeal food poisoning is the result of enterotoxin production by viable vegetative B. cereus cells in the small intestine, probably in the mucus layer and/or attached to the host's intestinal epithelium. The numbers of B. cereus causing disease are highly variable, depending on diverse factors linked to the host (age, diet, physiology and immunology), bacteria (cellular form, toxin genes and expression) and food (nutritional composition and meal characteristics). Bacillus cereus group strains show impressive ecological diversity, ranging from their saprophytic life cycle in soil to symbiotic (commensal and mutualistic) lifestyles near plant roots and in guts of insects and mammals to various pathogenic ones in diverse insect and mammalian hosts. During all these different ecological lifestyles, their toxins play important roles ranging from providing competitive advantages within microbial communities to inhibition of specific pathogenic organisms for their host and accomplishment of infections by damaging their host's tissues.
Topics: Animals; Bacillaceae Infections; Bacillus; Bacillus cereus; Bacterial Toxins; Diarrhea; Ecosystem; Emetics; Enterotoxins; Food Microbiology; Foodborne Diseases; Humans; Microbial Interactions; Phylogeny
PubMed: 23488744
DOI: 10.1111/1574-6941.12110 -
Toxins Oct 2020Cellular proteomes and exoproteomes are dynamic, allowing pathogens to respond to environmental conditions to sustain growth and virulence. is an important food-borne... (Comparative Study)
Comparative Study
Cellular proteomes and exoproteomes are dynamic, allowing pathogens to respond to environmental conditions to sustain growth and virulence. is an important food-borne pathogen causing intoxication via emetic toxin and/or multiple protein exotoxins. Here, we compared the dynamics of the cellular proteome and exoproteome of emetic cells grown at low (16 °C) and high (30 °C) temperature. Tandem mass spectrometry (MS/MS)-based shotgun proteomics analysis identified 2063 cellular proteins and 900 extracellular proteins. Hierarchical clustering following principal component analysis indicated that in the abundance of a subset of these proteins-including cold-stress responders, and exotoxins non-hemolytic enterotoxin (NHE) and hemolysin I (cereolysin O (CLO))-decreased at low temperature, and that this subset governs the dynamics of the cellular proteome. NHE, and to a lesser extent CLO, also contributed significantly to exoproteome dynamics; with decreased abundances in the low-temperature exoproteome, especially in late growth stages. Our data therefore indicate that may reduce its production of secreted protein toxins to maintain appropriate proteome dynamics, perhaps using catabolite repression to conserve energy for growth in cold-stress conditions, at the expense of virulence.
Topics: Bacillus cereus; Bacterial Proteins; Catabolite Repression; Chromatography, Liquid; Cold Temperature; Enterotoxins; Hemolysin Proteins; Proteome; Proteomics; Tandem Mass Spectrometry; Time Factors; Virulence
PubMed: 33036317
DOI: 10.3390/toxins12100645 -
Research in Microbiology Nov 2010When propagated on solid surfaces, Bacillus cereus can produce differentiated swarm cells under a wide range of growth conditions. This behavioural versatility is... (Review)
Review
When propagated on solid surfaces, Bacillus cereus can produce differentiated swarm cells under a wide range of growth conditions. This behavioural versatility is ecologically relevant, since it allows this bacterium to adapt swarming to environmental changes. Swarming by B. cereus is medically important: swarm cells are more virulent and particularly prone to invade host tissues. Characterisation of swarming-deficient mutants highlights that flagellar genes as well as genes governing different metabolic pathways are involved in swarm-cell differentiation. In this review, the environmental and genetic requirements for swarming and the role played by swarm cells in the virulence this pathogen exerts will be outlined.
Topics: Animals; Bacillus cereus; Gram-Positive Bacterial Infections; Humans; Virulence
PubMed: 21035546
DOI: 10.1016/j.resmic.2010.10.007 -
International Journal of Environmental... Mar 2020Chromium contamination has been an increasing threat to the environment and to human health. Cr(VI) and Cr(III) are the most common states of chromium. However, compared...
Chromium contamination has been an increasing threat to the environment and to human health. Cr(VI) and Cr(III) are the most common states of chromium. However, compared with Cr(III), Cr(VI) is more toxic and more easily absorbed, therefore, it is more harmful to human beings. Thus, the conversion of toxic Cr(VI) into Cr(III) is an accepted strategy for chromium detoxification. Here, we isolated two strains with a high chromium tolerance and reduction ability, named D and 332, respectively. Both strains demonstrated a strong pH and temperature adaptability and survival under 8 mM Cr(VI). D achieved 87.8% Cr(VI) removal in 24 h with an initial 2 mM Cr(VI). Cu(II) was found to increase the removal rate of Cr(VI) significantly. With the addition of 0.4 mM Cu(II), 99.9% of Cr(VI) in the culture was removed by 332 in 24 h. This is the highest removal efficiency in the literature that we have seen to date. The immobilization experiments found that sodium alginate with diatomite was the better method for immobilization and was more efficient in immobilized cells. Our research provided valuable information and new, highly effective strains for the bioremediation of chromium pollution.
Topics: Bacillus cereus; Biodegradation, Environmental; Chromium; Soil; Soil Pollutants
PubMed: 32209989
DOI: 10.3390/ijerph17062118 -
Journal of Dairy Science May 2020This study was conducted to reveal the prevalence, molecular characterization, and antibiotic susceptibility of Bacillus cereus isolated from dairy products including...
This study was conducted to reveal the prevalence, molecular characterization, and antibiotic susceptibility of Bacillus cereus isolated from dairy products including powdered infant formula, raw milk, pasteurized milk, ultra-high-temperature milk, and cheese. Five hundred samples collected from 5 provinces in China were analyzed in overall experiments. Multilocus sequence typing, distribution of toxin genes, and antibiotic susceptibility of the isolates were analyzed. Fifty-four B. cereus strains were detected; of these, 13 isolates (26%) were from raw milk, 12 isolates (12%) from pasteurized milk, 10 isolates (10%) from cheese, 12 isolates (8%) from ultra-high-temperature milk, and 7 isolates (7%) from powdered infant formula. These isolates were divided into 24 sequence types (ST); among them, ST24, ST26, ST82, ST142, ST377, ST857, and ST1046 were the main dominant ST. The results of detection of toxin genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, bceT, hlyII, and cesB) showed that 94.4% isolates carried nheABC genes, whereas only 11.1% of the isolates contained the hblACD gene cluster. In addition, detection rates of cytK, bceT, entFM, hlyII, and cesB genes were 75.9, 77.8, 85.2, 53.7, and 11.1%, respectively. The antibiotic susceptibility test indicated that most of B. cereus isolates were resistant to ampicillin, penicillin, cefepime, cephalothin, and oxacillin, and were susceptible to gentamicin, chloramphenicol, imipenem, tetracycline, ciprofloxacin, trimethoprim-sulfamethoxazole, erythromycin, kanamycin, and cefotetan. Therefore, this study revealed the prevalence and characteristics of B. cereus isolated from dairy products in China, indicating the potential risk and contributing to the effective prevention and control of this pathogen.
Topics: Animals; Anti-Bacterial Agents; Bacillus cereus; China; Dairy Products; Food Contamination; Food Microbiology; Milk; Prevalence
PubMed: 32113767
DOI: 10.3168/jds.2019-17541 -
PloS One 2016We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory... (Comparative Study)
Comparative Study
We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed.
Topics: Bacillus cereus; Biosynthetic Pathways; Carbohydrates; Food Microbiology; Genome, Bacterial; Genotype; Phylogeny; Sequence Analysis, DNA
PubMed: 27272929
DOI: 10.1371/journal.pone.0156796 -
Journal of Food Protection Apr 2016This study determined the prevalence and toxin profile of Bacillus cereus and Bacillus thuringiensis in doenjang, a fermented soybean food, made using both traditional...
This study determined the prevalence and toxin profile of Bacillus cereus and Bacillus thuringiensis in doenjang, a fermented soybean food, made using both traditional and commercial methods. The 51 doenjang samples tested were broadly contaminated with B. cereus; in contrast, only one sample was positive for B. thuringiensis. All B. cereus isolates from doenjang were positive for diarrheal toxin genes. The frequencies of nheABC and hblACD in traditional samples were 22.7 and 0%, respectively, whereas 5.1 and 5.1% of B. cereus isolates from commercial samples possessed nheABC and hblACD, respectively. The detection rate of ces gene was 10.8%. The predominant toxin profile among isolates from enterotoxigenic B. cereus in doenjang was profile 4 (entFM-bceT-cytK). The major enterotoxin genes in emetic B. cereus were cytK, entFM, and nheA genes. The B. thuringiensis isolate was of the diarrheagenic type. These results provide a better understanding of the epidemiology of the enterotoxigenic and emetic B. cereus groups in Korean fermented soybean products.
Topics: Bacillus cereus; Bacillus thuringiensis; Enterotoxins; Fermentation; Food Contamination; Soy Foods; Glycine max
PubMed: 27052865
DOI: 10.4315/0362-028X.JFP-15-416 -
MSphere Apr 2021The exosporium is the outermost spore layer of some and species and related organisms. It mediates the interactions of spores with their environment, modulates spore...
The exosporium is the outermost spore layer of some and species and related organisms. It mediates the interactions of spores with their environment, modulates spore adhesion and germination, and has been implicated in pathogenesis. In , the exosporium consists of a crystalline basal layer, formed mainly by the two cysteine-rich proteins CotY and ExsY, surrounded by a hairy nap composed of glycoproteins. The morphogenetic protein CotE is necessary for the integrity of the exosporium, but how CotE directs exosporium assembly remains unknown. Here, we used super-resolution fluorescence microscopy to follow the localization of SNAP-tagged CotE, CotY, and ExsY during sporulation and evidenced the interdependencies among these proteins. Complexes of CotE, CotY, and ExsY are present at all sporulation stages, and the three proteins follow similar localization patterns during endospore formation that are reminiscent of the localization pattern of CotE. We show that CotE guides the formation of one cap at both forespore poles by positioning CotY and then guides forespore encasement by ExsY, thereby promoting exosporium elongation. By these two actions, CotE ensures the formation of a complete exosporium. Importantly, we demonstrate that the assembly of the exosporium is not a unidirectional process, as previously proposed, but occurs through the formation of two caps, as observed during coat morphogenesis, suggesting that a general principle governs the assembly of the spore surface layers of Spores of are enveloped in an outermost glycoprotein layer. In the group, encompassing the and pathogens, this layer is easily recognizable by a characteristic balloon-like appearance and separation from the underlying coat by an interspace. In spite of its importance for the environmental interactions of spores, including those with host cells, the mechanism of assembly of the exosporium is poorly understood. We used super-resolution fluorescence microscopy to directly visualize the formation of the exosporium during the sporulation of , and we studied the localization and interdependencies of proteins essential for exosporium morphogenesis. We discovered that these proteins form a morphogenetic scaffold before a complete exosporium or coat is detectable. We describe how the different proteins localize to the scaffold and how they subsequently assemble around the spore, and we present a model for the assembly of the exosporium.
Topics: Bacillus cereus; Bacterial Proteins; Microscopy, Fluorescence; Spores, Bacterial
PubMed: 33883264
DOI: 10.1128/mSphere.00007-21