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Sample records for enterotoxic bacillus cereus

  1. Bacillus Cereus

    African Journals Online (AJOL)

    Mannitol Egg Yolk Polymyxin B sulfate agar (MEYP) is widely used in Europe and the United States to isolate B. cereus from food products. MEYP is based on lecithin hydrolysis and ... typing, gas-liquid chromatography of ..... Passive Latex Agglutination kit (RPLA) and an Enzyme-Linked lmmunoSorbent Assay. (ELISA).

  2. Germinant receptor diversity and germination responses of four strains of the Bacillus cereus group

    NARCIS (Netherlands)

    Voort, van der M.; Garcia, D.; Moezelaar, R.; Abee, T.

    2010-01-01

    Four strains of the Bacillus cereus group were compared for their germinant receptor composition and spore germination capacity. Phylogenetic analysis of the germinant receptor encoding operons of the enterotoxic strains B. cereus ATCC 14579 and ATCC 10987, the emetic strain AH187, and the

  3. Characterization of Bacillus cereus

    NARCIS (Netherlands)

    Wijnands LM; Dufrenne JB; Leusden FM; MGB

    2002-01-01

    Bacillus cereus is a ubiquitary microorganism that may cause food borne disease. Pathogenicity, however, depends on various characteristics such as the ability to form (entero)-toxin(s) that can not be detected by microbiological methods. Further characterization of pathogenic properties is not only

  4. Siderophores of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis.

    Science.gov (United States)

    Wilson, Melissa K; Abergel, Rebecca J; Raymond, Kenneth N; Arceneaux, Jean E L; Byers, B Rowe

    2006-09-15

    Three Bacillus anthracis Sterne strains (USAMRIID, 7702, and 34F2) and Bacillus cereus ATCC 14579 excrete two catecholate siderophores, petrobactin (which contains 3,4-dihydroxybenzoyl moieties) and bacillibactin (which contains 2,3-dihydroxybenzoyl moieties). However, the insecticidal organism Bacillus thuringiensis ATCC 33679 makes only bacillibactin. Analyses of siderophore production by previously isolated [Cendrowski et al., Mol. Microbiol. 52 (2004) 407-417] B. anthracis mutant strains revealed that the B. anthracis bacACEBF operon codes for bacillibactin production and the asbAB gene region is required for petrobactin assembly. The two catecholate moieties also were synthesized by separate routes. PCR amplification identified both asbA and asbB genes in the petrobactin producing strains whereas B. thuringiensis ATCC 33679 retained only asbA. Petrobactin synthesis is not limited to the cluster of B. anthracis strains within the B. cereus sensu lato group (in which B. cereus, B. anthracis, and B. thuringiensis are classified), although petrobactin might be prevalent in strains with pathogenic potential for vertebrates.

  5. strains of pseudomonas aeruginosa and bacillus cereus

    African Journals Online (AJOL)

    DR. AMINU

    DETERMINATION OF THE GENETIC MARKER OF THE MUTAGENIZED. STRAINS OF PSEUDOMONAS AERUGINOSA AND BACILLUS CEREUS. ISOLATED FROM EFFLUENT OF PETROLEUM REFINERY. Idise, O. E.1, Ameh, J.B.2 Yakubu, S.E. 2, Okuofu, C.A. 3 and Ado, S.A.2. 1 Department of Microbiology, Delta ...

  6. CASE REPORT Uncommon Pathogen Bacillus Cereus Causing ...

    African Journals Online (AJOL)

    2018-01-01

    Jan 1, 2018 ... Uncommon Pathogen Bacillus Cereus Causing Subdural Empyema in a Child. Prastiya Indra Gunawan1*, Leny Kartina1, Dwiyanti Puspitasari1, Erny Erny2. OPEN ACCESS ... secondary to middle ear infection, meningitis, brain surgery, ... classic clinical syndrome is an acute febrile illness punctuated by.

  7. CASE REPORT Uncommon Pathogen Bacillus Cereus Causing ...

    African Journals Online (AJOL)

    2018-01-01

    Jan 1, 2018 ... A complete blood count showed white blood cell count of 13.800/mm3 and the CRP level was 8.3 mg/L. Craniotomy following burr hole drainage procedure was performed to decrease intracranial pressure. The liquor culture indicated Bacillus cereus. A meropenem injection and metronidazole infusion ...

  8. Emetic food poisoning caused by Bacillus cereus.

    Science.gov (United States)

    Holmes, J R; Plunkett, T; Pate, P; Roper, W L; Alexander, W J

    1981-05-01

    Symptoms of acute food poisoning developed in eight members of a group who ate lunch at a cafeteria. After brief incubation periods, all affected individuals complained of nausea and abdominal cramps. Four persons promptly experienced vomiting. None of those affected was found to have fever and all recovered with 48 hours. Epidemiologic investigation incriminated macaroni and cheese as a cause of the illness and samples of this food contained large numbers of Bacillus cereus. Previous outbreaks of B cereus emetic food poisoning have been associated with consumption of contaminated fried rice and may occur after ingestion of other foods.

  9. Bacillus cereus infection in burns.

    Science.gov (United States)

    Attwood, A I; Evans, D M

    1983-05-01

    Two patients are reported in whom severe toxicity developed about 4 days after relatively minor burn injuries and in whom the burn areas then appeared to enlarge. In both patients, B. cereus and Staph. aureus were isolated and the affected burn areas had subcutaneous thrombosis and necrosis. The management is outlined and the dramatic rapidity of onset of toxicity emphasized, with special reference to increasing pain, lividity and extension of the burns.

  10. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity

    NARCIS (Netherlands)

    Warda, Alicja K.; Siezen, Roland J.; Boekhorst, Jos; Wells-Bennik, Marjon H.J.; Jong, de Anne; Kuipers, Oscar P.; Nierop Groot, Masja N.; Abee, Tjakko

    2016-01-01

    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. Linking Bacillus cereus genotypes and carbohydrate utilization capacity

    NARCIS (Netherlands)

    Warda, Alicja K.; Siezen, Roland J.; Boekhorst, Jos; Wells-Bennik, Marjon H.J.; Jong, de Anne; Kuipers, Oscar P.; Nierop Groot, Masja N.; Abee, Tjakko

    2016-01-01

    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

  12. Prevalence of enterotoxigenic Bacillus Cereus and Its enterotoxins ...

    African Journals Online (AJOL)

    Subjects: Ninety six milk samples including 36 raw milk, 42 pasteurised milk, 10 yogurt and eight fermented milk samples. Forty seven Bacillus cereus isolated from milk and milk products. Main outcome measures: Isolation of enterotoxigenic B. cereus from milk and milk products and detection of B. cereus hemolytic ...

  13. Bacillus cereus infection outbreak in captive psittacines.

    Science.gov (United States)

    Godoy, S N; Matushima, E R; Chaves, J Q; Cavados, C F G; Rabinovitch, L; Teixeira, R H F; Nunes, A L V; Melville, P; Gattamorta, M A; Vivoni, A M

    2012-12-28

    This study reports an uncommon epizootic outbreak of Bacillus cereus that caused the sudden death of 12 psittacines belonging to the species Anodorhynchus hyacinthinus (1 individual), Diopsittaca nobilis (1 individual), Ara severa (1 individual) and Ara ararauna (9 individuals) in a Brazilian zoo. Post-mortem examination of the animals reveled extensive areas of lung hemorrhage, hepatic congestion, hemorrhagic enteritis and cardiac congestion. Histopathological examination of the organs showed the presence of multiple foci of vegetative cells of Gram-positive bacilli associated with discrete and moderate mononuclear inflammatory cell infiltrate. Seventeen B. cereus strains isolated from blood and sterile organs of nine A. ararauna were analyzed in order to investigate the genetic diversity (assessed by Rep-PCR) and toxigenic profiles (presence of hblA, hblC and hblD; nheA, nheB and nheC as well as cytK, ces and entFM genes) of such strains. Amplification of genomic DNA by Rep-PCR of B. cereus strains generated two closely related profiles (Rep-PCR types A and B) with three bands of difference. All strains were classified as belonging to the toxigenic profile I which contained HBL and NHE gene complexes, entFM and cytK genes. Altogether, microbiological and histopathological findings and the evidence provided by the success of the antibiotic prophylaxis, corroborate that B. cereus was the causative agent of the infection that killed the birds. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Pathogenomic sequence analysis of Bacillus cereus and Bacillus thuringiensis isolates closely related to Bacillus anthracis.

    Science.gov (United States)

    Han, Cliff S; Xie, Gary; Challacombe, Jean F; Altherr, Michael R; Bhotika, Smriti S; Brown, Nancy; Bruce, David; Campbell, Connie S; Campbell, Mary L; Chen, Jin; Chertkov, Olga; Cleland, Cathy; Dimitrijevic, Mira; Doggett, Norman A; Fawcett, John J; Glavina, Tijana; Goodwin, Lynne A; Green, Lance D; Hill, Karen K; Hitchcock, Penny; Jackson, Paul J; Keim, Paul; Kewalramani, Avinash Ramesh; Longmire, Jon; Lucas, Susan; Malfatti, Stephanie; McMurry, Kim; Meincke, Linda J; Misra, Monica; Moseman, Bernice L; Mundt, Mark; Munk, A Christine; Okinaka, Richard T; Parson-Quintana, B; Reilly, Lee Philip; Richardson, Paul; Robinson, Donna L; Rubin, Eddy; Saunders, Elizabeth; Tapia, Roxanne; Tesmer, Judith G; Thayer, Nina; Thompson, Linda S; Tice, Hope; Ticknor, Lawrence O; Wills, Patti L; Brettin, Thomas S; Gilna, Paul

    2006-05-01

    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.

  15. Induction of natural competence in Bacillus cereus ATCC14579

    OpenAIRE

    Mirończuk, Aleksandra M.; Kovács, Ákos T.; Kuipers, Oscar P.

    2008-01-01

    Summary Natural competence is the ability of certain microbes to take up exogenous DNA from the environment and integrate it in their genome. Competence development has been described for a variety of bacteria, but has so far not been shown to occur in Bacillus cereus. However, orthologues of most proteins involved in natural DNA uptake in Bacillus subtiliscould be identified in B. cereus. Here, we report that B. cereus ATCC14579 can become naturally competent. When expressing the B. subtilis...

  16. Germination of Bacillus cereus spores : the role of germination receptors

    NARCIS (Netherlands)

    Hornstra, L.M.

    2007-01-01

    The Bacillus cereus sensu lato group forms a highly homogeneous subdivision of the genus Bacillus and comprises several species that are relevant for humans. Notorious is Bacillus anthracis, the cause of the often-lethal disease anthrax, while the insect pathogen Bacillus

  17. Identification of Fatty Acids in Bacillus cereus.

    Science.gov (United States)

    Ginies, Christian; Brillard, Julien; Nguyen-The, Christophe

    2016-12-05

    The Bacillus species contain branched chain and unsaturated fatty acids (FAs) with diverse positions of the methyl branch (iso or anteiso) and of the double bond. Changes in FA composition play a crucial role in the adaptation of bacteria to their environment. These modifications entail a change in the ratio of iso versus anteiso branched FAs, and in the proportion of unsaturated FAs relative to saturated FAs, with double bonds created at specific positions. Precise identification of the FA profile is necessary to understand the adaptation mechanisms of Bacillus species. Many of the FAs from Bacillus are not commercially available. The strategy proposed herein identifies FAs by combining information on the retention time (by calculation of the equivalent chain length (ECL)) with the mass spectra of three types of FA derivatives: fatty acid methyl esters (FAMEs), 4,4-dimethyl oxazoline derivatives (DMOX), and 3-pyridylcarbinyl ester (picolinyl). This method can identify the FAs without the need to purify the unknown FAs. Comparing chromatographic profiles of FAME prepared from Bacillus cereus with a commercial mixture of standards allows for the identification of straight-chain saturated FAs, the calculation of the ECL, and hypotheses on the identity of the other FAs. FAMEs of branched saturated FAs, iso or anteiso, display a constant negative shift in the ECL, compared to linear saturated FAs with the same number of carbons. FAMEs of unsaturated FAs can be detected by the mass of their molecular ions, and result in a positive shift in the ECL compared to the corresponding saturated FAs. The branching position of FAs and the double bond position of unsaturated FAs can be identified by the electron ionization mass spectra of picolinyl and DMOX derivatives, respectively. This approach identifies all the unknown saturated branched FAs, unsaturated straight-chain FAs and unsaturated branched FAs from the B. cereus extract.

  18. Necrotizing gastritis due to Bacillus cereus in an immunocompromised patient.

    Science.gov (United States)

    Le Scanff, J; Mohammedi, I; Thiebaut, A; Martin, O; Argaud, L; Robert, D

    2006-04-01

    Bacillus cereus is increasingly being acknowledged as a serious bacterial pathogen in immunocompromised patients. We present a case of acute necrotizing gastritis caused by B. cereus in a 37-year-old woman with acute myeloblastic leukemia, who recovered following total parenteral nutrition and treatment with imipenem and vancomycin. B. cereus was isolated from gastric mucosa and blood cultures. Up to now, no case of acute necrotizing gastritis due to this organism has been reported.

  19. Virulence of Bacillus cereus as natural facultative pathogen of ...

    African Journals Online (AJOL)

    Out of 4407 Anopheles subpictus larvae collected from submerged rice-fields and shallow ponds, 1412 were found to be unhealthy and 2.8% of unhealthy larvae were naturally infected by Bacillus cereus. B. cereus formed circular, white and flat colonies. Bacteria were gram positive, ellipsoidal/oval spore forming aerobic ...

  20. Genetic and functional analysis of the cytK family of genes in Bacillus cereus.

    Science.gov (United States)

    Fagerlund, Annette; Ween, Ola; Lund, Terje; Hardy, Simon P; Granum, Per E

    2004-08-01

    CytK is a pore-forming toxin of Bacillus cereus that has been linked to a case of necrotic enteritis. PCR products of the expected size were generated with cytK primers in 13 of 29 strains. Six strains were PCR-positive for the related gene hly-II, which encodes haemolysin II, a protein that is 37 % identical to the original CytK. Five of the strains were positive for both genes. The DNA sequences of putative cytK genes from three positive strains were determined, and the deduced amino acid sequences were 89 % identical to that of the original CytK. The authors have designated this new cytK variant cytK-2, and refer to the original cytK as cytK-1. The CytK-2 proteins from these three strains were isolated, and their identity was verified by N-terminal sequencing. blast analysis using the cytK-2 gene sequences revealed very high homology with two cytK-2 sequences in the genomes of B. cereus strains ATCC 14579 and ATCC 10987. The differences between CytK-1 and the CytK-2 proteins were clustered to certain regions of the proteins. The isolated CytK-2 proteins were haemolytic and toxic towards human intestinal Caco-2 cells and Vero cells, although their toxicity was about 20 % of that of CytK-1. Both native and recombinant CytK-2 proteins from B. cereus 1230-88 were able to form pores in planar lipid bilayers, but the majority of the channels observed were of lower conductance than those created by CytK-1. It is likely that CytK-2 toxins contribute to the enterotoxicity of several strains of B. cereus, although not all of the CytK-2 toxins may be as harmful as the CytK-1 originally isolated.

  1. Germinant receptor diversity and germination responses of four strains of the Bacillus cereus group.

    Science.gov (United States)

    van der Voort, Menno; García, Diego; Moezelaar, Roy; Abee, Tjakko

    2010-04-30

    Four strains of the Bacillus cereus group were compared for their germinant receptor composition and spore germination capacity. Phylogenetic analysis of the germinant receptor encoding operons of the enterotoxic strains B. cereus ATCC 14579 and ATCC 10987, the emetic strain AH187, and the psychrotolerant strain Bacillus weihenstephanensis KBAB4, indicated a core group of five germinant receptor operons to be present in the four strains, with each strain containing one to three additional receptors. Using quantitative PCR, induction of expression during sporulation was confirmed for all identified germinant receptor operons in these strains. Despite the large overlap in receptors, diversity in amino acid-induced germination capacity was observed, with six out of 20 amino acids, serving as germinants for spores of all four strains. Each strain showed unique features: efficient germination of strain KBAB4 spores required non-inducing amounts of inosine as the co-germinant, strain ATCC 10987 spores germinated only efficiently after heat activation. Furthermore, strain ATCC 14579 and AH187 spores germinated without heat activation or inosine, with strain ATCC 14579 spores being triggered by all amino acids except phenylalanine and strain AH187 spores being specifically triggered efficiently only by phenylalanine. Analysis of all germination data did not reveal strict linkages between specific germinants and germinant receptors. Finally, the diversity in nutrient-induced germination capacity was also reflected in the diverse germination responses of heat-activated spores of the four B. cereus strains in food matrices, such as milk, rice water and meat bouillon, indicating that amino acid composition and/or availability of inosine are important germination determinants in foods. Copyright 2010 Elsevier B.V. All rights reserved.

  2. Toxin production in a rare and genetically remote cluster of strains of the Bacillus cereus group

    Directory of Open Access Journals (Sweden)

    Granum Per

    2007-05-01

    Full Text Available Abstract Background Three enterotoxins are implicated in diarrhoeal food poisoning due to Bacillus cereus: Haemolysin BL (Hbl, Non-haemolytic enterotoxin (Nhe, and Cytotoxin K (CytK. Toxin gene profiling and assays for detection of toxin-producing stains have been used in attempts to evaluate the enterotoxic potential of B. cereus group strains. B. cereus strain NVH 391/98, isolated from a case of fatal enteritis, was genetically remote from other B. cereus group strains. This strain lacked the genes encoding Hbl and Nhe, but contains CytK-1. The high virulence of this strain is thought to be due to the greater cytotoxic activity of CytK-1 compared to CytK-2, and to a high level of cytK expression. To date, only three strains containing cytK-1 have been identified; B. cereus strains NVH 391/98, NVH 883/00, and INRA AF2. Results A novel gene variant encoding Nhe was identified in these three strains, which had an average of 80% identity in protein sequence with previously identified Nhe toxins. While culture supernatants containing CytK and Nhe from NVH 391/98 and INRA AF2 were highly cytotoxic, NVH 883/00 expressed little or no CytK and Nhe and was non-cytotoxic. Comparative sequence and expression studies indicated that neither the PlcR/PapR quorum sensing system, nor theYvrGH and YvfTU two-component systems, were responsible for the observed difference in toxin production. Additionally, phylogenetic analysis of 13 genes showed that NVH 391/98, NVH 883/00, and INRA AF2 comprise a novel cluster of strains genetically distant from other B. cereus group strains. Conclusion Due to its divergent sequence, the novel nhe operon had previously not been detected in NVH 391/98 using PCR and several monoclonal antibodies. Thus, toxigenic profiling based on the original nhe sequence will fail to detect the toxin in this group of strains. The observation that strain NVH 883/00 carries cytK-1 but is non-cytotoxic indicates that the detection of this gene

  3. Phages Preying on Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis: Past, Present and Future

    Science.gov (United States)

    Gillis, Annika; Mahillon, Jacques

    2014-01-01

    Many bacteriophages (phages) have been widely studied due to their major role in virulence evolution of bacterial pathogens. However, less attention has been paid to phages preying on bacteria from the Bacillus cereus group and their contribution to the bacterial genetic pool has been disregarded. Therefore, this review brings together the main information for the B. cereus group phages, from their discovery to their modern biotechnological applications. A special focus is given to phages infecting Bacillus anthracis, B. cereus and Bacillus thuringiensis. These phages belong to the Myoviridae, Siphoviridae, Podoviridae and Tectiviridae families. For the sake of clarity, several phage categories have been made according to significant characteristics such as lifestyles and lysogenic states. The main categories comprise the transducing phages, phages with a chromosomal or plasmidial prophage state, γ-like phages and jumbo-phages. The current genomic characterization of some of these phages is also addressed throughout this work and some promising applications are discussed here. PMID:25010767

  4. Phages Preying on Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis: Past, Present and Future

    Directory of Open Access Journals (Sweden)

    Annika Gillis

    2014-07-01

    Full Text Available Many bacteriophages (phages have been widely studied due to their major role in virulence evolution of bacterial pathogens. However, less attention has been paid to phages preying on bacteria from the Bacillus cereus group and their contribution to the bacterial genetic pool has been disregarded. Therefore, this review brings together the main information for the B. cereus group phages, from their discovery to their modern biotechnological applications. A special focus is given to phages infecting Bacillus anthracis, B. cereus and Bacillus thuringiensis. These phages belong to the Myoviridae, Siphoviridae, Podoviridae and Tectiviridae families. For the sake of clarity, several phage categories have been made according to significant characteristics such as lifestyles and lysogenic states. The main categories comprise the transducing phages, phages with a chromosomal or plasmidial prophage state, γ-like phages and jumbo-phages. The current genomic characterization of some of these phages is also addressed throughout this work and some promising applications are discussed here.

  5. Pan-genome and phylogeny of Bacillus cereus sensu lato

    OpenAIRE

    Bazinet, Adam

    2017-01-01

    Background: Bacillus cereus sensu lato ( s . l .) is an ecologically diverse bacterial group of medical and agricultural significance. In this study, I use publicly available genomes to characterize the B. cereus s. l. pan-genome and perform the largest phylogenetic and population genetic analyses of this group to date in terms of the number of genes and taxa included. With these fundamental data in hand, I identify genes associated with particular phenotypic traits (i.e., "pan-GWAS" analysis...

  6. Pan-genome and phylogeny of Bacillus cereus sensu lato

    OpenAIRE

    Bazinet, Adam L.

    2017-01-01

    Background Bacillus cereus sensu lato (s. l.) is an ecologically diverse bacterial group of medical and agricultural significance. In this study, I use publicly available genomes and novel bioinformatic workflows to characterize the B. cereus s. l. pan-genome and perform the largest phylogenetic and population genetic analyses of this group to date in terms of the number of genes and taxa included. With these fundamental data in hand, I identify genes associated with particular phenotypic tra...

  7. Bacillus cereus in Brazilian Ultra High Temperature milk Bacillus cereus em leite UHT brasileiro

    Directory of Open Access Journals (Sweden)

    Cristiana de Paula Pacheco-Sanchez

    2007-01-01

    Full Text Available Brazilian Ultra High Temperature (UHT milk consumption has increased during the last decade from 187 to 4,200 million liters. In the continuous UHT process, milk is submitted for 2-4 s to 130-150ºC, in a continuous flow system with immediate refrigeration and aseptical packing in hermetic packages. This research had the purpose to verify the incidence of B. cereus species from the B. cereus group, in UHT milk. In 1998 high indexes of these organisms were reported, reaching 34.14% of the analyzed samples. Beyond this fact, there was the need to establish methods and processes adjusted for correct identification of B. cereus. Thus, commercial sterility tests of 6,500 UHT milk packages were investigated in two assays, after ten days incubation at 37ºC and 7ºC to germinate all possible spores and/or to recuperate injured vegetative cells followed by pH measurement. Samples (1,300 packages each from five Brazilian UHT plants of whole UHT milk processed by direct steam injection, packaged in carton were investigated for the presence of Bacillus cereus through phenotypic and genetic (PCR tests. Values of pH were different for the samples, ranging between 6.57 and 6.73. After storage of the samples, only four packages with pH measurement below the lower limit of 6.5 were found and analyzed for the presence of B. cereus. This organism was not detected in any of the samples indicating that the five Brazilian UHT milk processors control pathogenic microorganisms and it can be said that the consumption of UHT milk does not present safety problems to consumers. Fourier Transform Infrared Spectroscopy (FTIR and PCR tests were efficient and must be adopted to confirm the biochemical series for B. cereus.O consumo de leite ultra-alta temperatura (UHT brasileiro aumentou, durante a última década, de 187 milhões de litros para 4,200 milhões de litros. No processo contínuo de leite UHT o leite é submetido por 2-4 seg a 130-150ºC, em sistemas de

  8. The putative drug efflux systems of the Bacillus cereus group.

    Science.gov (United States)

    Hassan, Karl A; Fagerlund, Annette; Elbourne, Liam D H; Vörös, Aniko; Kroeger, Jasmin K; Simm, Roger; Tourasse, Nicolas J; Finke, Sarah; Henderson, Peter J F; Økstad, Ole Andreas; Paulsen, Ian T; Kolstø, Anne-Brit

    2017-01-01

    The Bacillus cereus group of bacteria includes seven closely related species, three of which, B. anthracis, B. cereus and B. thuringiensis, are pathogens of humans, animals and/or insects. Preliminary investigations into the transport capabilities of different bacterial lineages suggested that genes encoding putative efflux systems were unusually abundant in the B. cereus group compared to other bacteria. To explore the drug efflux potential of the B. cereus group all putative efflux systems were identified in the genomes of prototypical strains of B. cereus, B. anthracis and B. thuringiensis using our Transporter Automated Annotation Pipeline. More than 90 putative drug efflux systems were found within each of these strains, accounting for up to 2.7% of their protein coding potential. Comparative analyses demonstrated that the efflux systems are highly conserved between these species; 70-80% of the putative efflux pumps were shared between all three strains studied. Furthermore, 82% of the putative efflux system proteins encoded by the prototypical B. cereus strain ATCC 14579 (type strain) were found to be conserved in at least 80% of 169 B. cereus group strains that have high quality genome sequences available. However, only a handful of these efflux pumps have been functionally characterized. Deletion of individual efflux pump genes from B. cereus typically had little impact to drug resistance phenotypes or the general fitness of the strains, possibly because of the large numbers of alternative efflux systems that may have overlapping substrate specificities. Therefore, to gain insight into the possible transport functions of efflux systems in B. cereus, we undertook large-scale qRT-PCR analyses of efflux pump gene expression following drug shocks and other stress treatments. Clustering of gene expression changes identified several groups of similarly regulated systems that may have overlapping drug resistance functions. In this article we review current

  9. Inhibition of Bacillus cereus in milk fermented with kefir grains.

    Science.gov (United States)

    Kakisu, Emiliano J; Abraham, Analía G; Pérez, Pablo F; De Antoni, Graciela L

    2007-11-01

    The effects of kefir-fermented milk were tested against a toxigenic strain of Bacillus cereus. The incubation of milk with B. cereus spores plus 5% kefir grains prevented spore germination and growth of vegetative forms. In contrast, when 1% kefir grains was used, no effects were observed. The presence of metabolically active kefir grains diminished titers of nonhemolytic enterotoxin A, as assessed by enzyme-linked immunosorbent assay. During fermentation, kefir microorganisms produce extracellular metabolites such as organic acids, which could play a role in the inhibition of spore germination and growth of B. cereus, although the effect of other factors cannot be ruled out. Results of the present study show that kefir-fermented milk is able to antagonize key mechanisms involved in the growth of B. cereus as well as interfere with the biological activity of this microorganism.

  10. Purification and characterization of protease from Bacillus cereus ...

    African Journals Online (AJOL)

    chitti

    2013-09-16

    Sep 16, 2013 ... Purification and characterization of protease from. Bacillus cereus SU12 isolated from oyster. Saccostrea cucullata. S. Umayaparvathi*, S. Meenakshi, M. Arumugam and T. Balasubramanian. Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai - 608.

  11. Germination of Bacillus cereus spores adhered to stainless steel

    NARCIS (Netherlands)

    Hornstra, L.M.; Leeuw, de P.P.L.A.; Moezelaar, R.; Wolbert, E.J.H.; Vries, de Y.P.; Vos, de W.M.; Abee, T.

    2007-01-01

    Adhered spores of Bacillus cereus represent a significant part of the surface-derived contamination in processing equipment used in the dairy industry. As germinated spores lose their resistance capacities instantaneously, efficient germination prior to a cleaning in place treatment could aid to the

  12. effluent by bacillus cereus and clostridium butyricum using

    African Journals Online (AJOL)

    user

    use of pure culture Bacillus cereus and Clostridium butyricum as inoculums in MFCs for simultaneous bioelectricity generation and ... to be used as inoculums for simultaneous bioelectricity generation and treatment of petroleum refinery effluent in MFCs. Keywords: ...... [10] Feng, Y., Wang, X., Logan, B. E., Lee, H. Brewery.

  13. Toxigenic Bacillus cereus isolated from Nunu and Wara, two ...

    African Journals Online (AJOL)

    Traditional fermented dairy foods are produced by small scale processors in different parts of West Africa without adequate attention to good manufacturing practices (GMPs), microbial contamination and ... Further enrichment using chromogenic selective agar medium detected Bacillus cereus in 95% of the tested samples.

  14. Characterization of germination receptors of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Hornstra, L.M.; Vries, de Y.P.; Wells-Bennik, M.H.J.; Vos, de W.M.; Abee, T.

    2006-01-01

    Specific amino acids, purine ribonucleosides, or a combination of the two is required for efficient germination of endospores of Bacillus cereus ATCC 14579. A survey including 20 different amino acids showed that L-alanine, L-cysteine, L-threonine, and L-glutamine are capable of initiating the

  15. Bioenergetic consequences of nisin combined with carvacrol towards Bacillus cereus

    NARCIS (Netherlands)

    Pol, I.E.; Krommer, J.; Smid, E.J.

    2002-01-01

    This paper describes the influence of a combination of nisin and carvacrol on the membrane potential, the pH gradient and the intracellular ATP pools of vegetative cells of Bacillus cereus. Both the membrane potential and the pH gradient were dissipated by nisin and carvacrol. The intracellular ATP

  16. Antimicrobial activity of carvacrol toward Bacillus cereus on rice

    NARCIS (Netherlands)

    Ultee, A.; Slump, R.A.; Steging, G.; Smid, E.J.

    2000-01-01

    The antimicrobial activity of carvacrol, a compound present in the essential oil fraction of oreganum and thyme, toward the foodborne pathogen Bacillus cereus on rice was studied. Carvacrol showed a dose-related inhibition of growth of the pathogen. Concentrations of 0.15 mg/g and higher inhibited

  17. Occurrence and significance of Bacillus cereus and Bacillus thuringiensis in ready-to-eat food

    DEFF Research Database (Denmark)

    Rosenquist, Hanne; Ørum-Smidt, Lasse; Andersen, Sigrid R

    2005-01-01

    Among 48,901 samples of ready-to-eat food products at the Danish retail market, 0.5% had counts of Bacillus cereus-like bacteria above 10(4) cfu g(-1). The high counts were most frequently found in starchy, cooked products, but also in fresh cucumbers and tomatoes. Forty randomly selected strains...... had at least one gene or component involved in human diarrhoeal disease, while emetic toxin was related to only one B. cereus strain. A new observation was that 31 out of the 40 randomly selected B. cereus-like strains could be classified as Bacillus thuringiensis due to crystal production and...

  18. Production of Alpha Amylase by Bacillus cereus in Submerged Fermentation

    Directory of Open Access Journals (Sweden)

    Helen H. Raplong

    2014-09-01

    Full Text Available Microorganisms have the ability to secrete enzymes when they are grown in the presence of certain substrates. Amylases are among the most important industrial enzymes and are of great significance in biotechnological studies. Bacteria belonging to the genus Bacillus were isolated using mannitol egg yolk polymyxin B (MYP agar a highly selective media for Bacillus cereus isolation. The isolates were tested for α-amylase production on nutrient agar supplemented with starch and in submerged fermentation. The bacteria isolated and identified (using the Microgen Bacillus identification kit were all Bacillus cereus and SB2 had the largest zone of hydrolysis of 12mm on nutrient agar supplemented with starch as well as the highest enzyme activity of 1.62U/ml. Amylase activity of 2.56U/ml was obtained after 24 hours incubation in submerged fermentation. When amylase enzyme production parameters where optimized, maximum amylase activity was obtained at a pH of 6.5, temperature of 350C, incubation time of 24 hours and 4% inoculums concentration. Bacillus cereus SB2 is a potential isolate for alpha-amylase production with soluble starch as the sole carbon source in submerged fermentation.

  19. Bacillus cereus food poisoning: international and Indian perspective.

    Science.gov (United States)

    Tewari, Anita; Abdullah, Swaid

    2015-05-01

    Food borne illnesses result from eating food or drinking beverages that are contaminated with chemical matter, heavy metals, parasites, fungi, viruses and Bacteria. Bacillus cereus is one of the food-borne disease causing Bacteria. Species of Bacillus and related genera have long been troublesome to food producers on account of their resistant endospores. Their spores may be present on various types of raw and cooked foods, and their ability to survive high cooking temperatures requires that cooked foods be served hot or cooled rapidly to prevent the growth of this bacteria. Bacillus cereus is well known as a cause of food poisoning, and much more is now known about the toxins produced by various strains of this species, so that its significance in such episodes are clearer. However, it is still unclear why such cases are so rarely reported worldwide.

  20. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity.

    Science.gov (United States)

    Warda, Alicja K; Siezen, Roland J; Boekhorst, Jos; Wells-Bennik, Marjon H J; de Jong, Anne; Kuipers, Oscar P; Nierop Groot, Masja N; Abee, Tjakko

    2016-01-01

    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.

  1. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity.

    Directory of Open Access Journals (Sweden)

    Alicja K Warda

    Full Text Available 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.

  2. Bacillus cereus panophthalmitis associated with intraocular gas bubble.

    Science.gov (United States)

    al-Hemidan, A; Byrne-Rhodes, K A; Tabbara, K F

    1989-01-01

    It has become increasingly apparent that Bacillus cereus can cause a severe and devastating form of endophthalmitis following penetrating trauma by a metallic object. B. cereus is an uncommon aetiological agent in non-clostridial gas-forming infections. The patient studied in this single case report showed evidence of intraocular gas mimicking gas gangrene infection. The physiology of non-clostridial bacteria producing gas from anaerobic metabolic conditions is reviewed. Further intraocular and systemic complications which may be avoided by accurate and early diagnosis and the use of recommended treatment with antibiotics such as clindamycin. Images PMID:2493262

  3. [Can industrial laundry remove Bacillus cereus from hospital linen?].

    Science.gov (United States)

    Yoh, Myonsun; Matsuyama, Junko; Shime, Akiko; Okayama, Kana; Sakamoto, Rei; Honda, Takeshi

    2010-09-01

    Contaminated hospital linen has caused some cases of Bacillus cereus bacteremia in Japan. We analyzed the disinfection efficacy of industrial washing of hospital towels and sheets by counting the number of B. cereus on linen before and after washing. That before washing averaged 7.6 cells/cm2 on unwashed sheets, decreasing to 1.2 cells/cm2 after washing. That on unwashed towels, however, averaged 10(6) cells/cm2 before washing and 1096 cells/cm2 after washing, which was very high and suggested the possibility of causing nosocomial infection.

  4. Invasive Bacillus cereus Infection in a Renal Transplant Patient: A Case Report and Review

    Directory of Open Access Journals (Sweden)

    Susan John

    2012-01-01

    Full Text Available Bacillus cereus is a common cause of gastrointestinal diseases. The majority of individuals with B cereus-related food poisoning recover without any specific treatment. It can, however, rarely cause invasive disease in immunocompromised patients.

  5. Comparative genome analysis of Bacillus cereus group genomes withBacillus subtilis

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain; Sorokin, Alexei; Kapatral, Vinayak; Reznik, Gary; Bhattacharya, Anamitra; Mikhailova, Natalia; Burd, Henry; Joukov, Victor; Kaznadzey, Denis; Walunas, Theresa; D' Souza, Mark; Larsen, Niels; Pusch,Gordon; Liolios, Konstantinos; Grechkin, Yuri; Lapidus, Alla; Goltsman,Eugene; Chu, Lien; Fonstein, Michael; Ehrlich, S. Dusko; Overbeek, Ross; Kyrpides, Nikos; Ivanova, Natalia

    2005-09-14

    Genome features of the Bacillus cereus group genomes (representative strains of Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis sub spp israelensis) were analyzed and compared with the Bacillus subtilis genome. A core set of 1,381 protein families among the four Bacillus genomes, with an additional set of 933 families common to the B. cereus group, was identified. Differences in signal transduction pathways, membrane transporters, cell surface structures, cell wall, and S-layer proteins suggesting differences in their phenotype were identified. The B. cereus group has signal transduction systems including a tyrosine kinase related to two-component system histidine kinases from B. subtilis. A model for regulation of the stress responsive sigma factor sigmaB in the B. cereus group different from the well studied regulation in B. subtilis has been proposed. Despite a high degree of chromosomal synteny among these genomes, significant differences in cell wall and spore coat proteins that contribute to the survival and adaptation in specific hosts has been identified.

  6. Genome sequence of Bacillus cereus and comparative analysis with Bacillus anthracis.

    Science.gov (United States)

    Ivanova, Natalia; Sorokin, Alexei; Anderson, Iain; Galleron, Nathalie; Candelon, Benjamin; Kapatral, Vinayak; Bhattacharyya, Anamitra; Reznik, Gary; Mikhailova, Natalia; Lapidus, Alla; Chu, Lien; Mazur, Michael; Goltsman, Eugene; Larsen, Niels; D'Souza, Mark; Walunas, Theresa; Grechkin, Yuri; Pusch, Gordon; Haselkorn, Robert; Fonstein, Michael; Ehrlich, S Dusko; Overbeek, Ross; Kyrpides, Nikos

    2003-05-01

    Bacillus cereus is an opportunistic pathogen causing food poisoning manifested by diarrhoeal or emetic syndromes. It is closely related to the animal and human pathogen Bacillus anthracis and the insect pathogen Bacillus thuringiensis, the former being used as a biological weapon and the latter as a pesticide. B. anthracis and B. thuringiensis are readily distinguished from B. cereus by the presence of plasmid-borne specific toxins (B. anthracis and B. thuringiensis) and capsule (B. anthracis). But phylogenetic studies based on the analysis of chromosomal genes bring controversial results, and it is unclear whether B. cereus, B. anthracis and B. thuringiensis are varieties of the same species or different species. Here we report the sequencing and analysis of the type strain B. cereus ATCC 14579. The complete genome sequence of B. cereus ATCC 14579 together with the gapped genome of B. anthracis A2012 enables us to perform comparative analysis, and hence to identify the genes that are conserved between B. cereus and B. anthracis, and the genes that are unique for each species. We use the former to clarify the phylogeny of the cereus group, and the latter to determine plasmid-independent species-specific markers.

  7. Bacillus cereus in personal care products: risk to consumers.

    Science.gov (United States)

    Pitt, T L; McClure, J; Parker, M D; Amézquita, A; McClure, P J

    2015-04-01

    Bacillus cereus is ubiquitous in nature and thus occurs naturally in a wide range of raw materials and foodstuffs. B. cereus spores are resistant to desiccation and heat and able to survive dry storage and cooking. Vegetative cells produce several toxins which on ingestion in sufficient numbers can cause vomiting and/or diarrhoea depending on the toxins produced. Gastrointestinal disease is commonly associated with reheated or inadequately cooked foods. In addition to being a rare cause of several acute infections (e.g. pneumonia and septicaemia), B. cereus can also cause localized infection of post-surgical or trauma wounds and is a rare but significant pathogen of the eye where it may result in severe endophthalmitis often leading to loss of vision. Key risk factors in such cases are trauma to the eye and retained contaminated intraocular foreign bodies. In addition, rare cases of B. cereus-associated keratitis (inflammation of the cornea) have been linked to contact lens use. Bacillus cereus is therefore a microbial contaminant that could adversely affect product safety of cosmetic and facial toiletries and pose a threat to the user if other key risk factors are also present. The infective dose in the human eye is unknown, but as few as 100 cfu has been reported to initiate infection in a susceptible animal model. However, we are not aware of any reports in the literature of B. cereus infections in any body site linked with use of personal care products. Low levels of B. cereus spores may on occasion be present in near-eye cosmetics, and these products have been used by consumers for many years. In addition, exposure to B. cereus is more likely to occur through other routes (e.g. dustborne contamination) due to its ubiquity and resistance properties of spores. The organism has been recovered from the eyes of healthy individuals. Therefore, although there may be a perceived hazard, the risk of severe eye infections as a consequence of exposure through

  8. Dissemination of Bacillus cereus in an intensive care unit.

    Science.gov (United States)

    Bryce, E A; Smith, J A; Tweeddale, M; Andruschak, B J; Maxwell, M R

    1993-08-01

    To report the contamination of ventilator equipment with Bacillus cereus and to outline the measures taken to trace the source of the organism. A prospective survey of all intensive care unit patients who were culture-positive for B cereus and obtaining of environmental cultures of the cleaning and assembly area of the respiratory services division between October 1991 and September 1992. Ventilated patients from a 16-bed medical and surgical intensive care unit (ICU) in a 1,000-bed adult tertiary care hospital. From October 1991 to April 1992, B cereus colonized the ventilator circuitry of patients in the ICU. One of two washer/decontaminators in the cleaning and assembly area of the respiratory services division was found to yield the microorganism consistently from the water intake port. The design of the machine precluded easy decontamination of the port with 2% glutaraldehyde and a second outbreak occurred. Following the second outbreak, aqueous chlorhexidine in a final concentration of 0.05% was added to the first of two pasteurization cycles in an attempt to achieve sporicidal activity. This ended the outbreak. Sixty-two patients became colonized with the organism including two with nonfatal Bacillus sepsis and one death due to pneumonia associated with the organism. This experience emphasizes the importance of obtaining cultures of machine parts to identify the source of contamination and thereby direct control measures. Use of chlorhexidine gluconate at high temperatures effectively eradicated B cereus from ventilator circuitry in a practical and cost-effective manner.

  9. Global gene expression profile for swarming Bacillus cereus bacteria.

    Science.gov (United States)

    Salvetti, Sara; Faegri, Karoline; Ghelardi, Emilia; Kolstø, Anne-Brit; Senesi, Sonia

    2011-08-01

    Bacillus cereus can 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 of B. cereus ATCC 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 entire hbl operon during swarming. Finally, BC1435 and BC1436, orthologs of liaI-liaH that are known to be involved in the resistance of Bacillus subtilis to daptomycin, were upregulated under swarming conditions. Accordingly, phenotypic assays showed reduced susceptibility of swarming B. cereus cells to daptomycin, and P(spac)-induced hyper-expression of these genes in liquid medium highlighted the role of BC1435 and BC1436 in the response of B. cereus to daptomycin.

  10. Characterization of a broad range antimicrobial substance from Bacillus cereus.

    Science.gov (United States)

    Risøen, P A; Rønning, P; Hegna, I K; Kolstø, A-B

    2004-01-01

    The aim of this research was to isolate and characterize an antimicrobial substance from the Bacillus cereus type strain ATCC 14579. A substance with antimicrobial activity was isolated from B. cereus ATCC 14579. The substance was produced during late exponential growth and well into the stationary phase with a maximum 9 h after inoculation. The inhibitory substance was purified by reverse-phase HPLC and shown to be highly active against closely related Bacillus spp. Clinically relevant species such as Staphylococcus aureus and Micrococcus luteus were also inhibited. The substance was characterized as a bacteriocin-like inhibitory substance (BLIS) with a molecular mass of ca 3.4 kDa. The BLIS was very heat stable, and sensitive only to pronase E and proteinase K. Antimicrobial activity was stable and high in the pH range of 2.0-9.0, and relatively unaffected by organic chemicals. An antimicrobial substance produced by the B. cereus type strain ATCC 14579 was characterized, with a wide spectrum of activity and the potential to be applied as a control agent against pathogenic bacteria. The present study is the first report of a substance with antimicrobial activity from the B. cereus type strain.

  11. Naphthalene degradation and biosurfactant activity by Bacillus cereus 28BN

    Energy Technology Data Exchange (ETDEWEB)

    Tuleva, B.; Christova, N. [Inst. of Microbiology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Jordanov, B.; Nikolova-Damyanova, B. [Inst. of Organic Chemistry, Sofia (Bulgaria); Petrov, P. [National Center of Infectious and Parasitic Diseases, Sofia (Bulgaria)

    2005-08-01

    Biosurfactant activity and naphthalene degradation by a new strain identified as Bacillus cereus 28BN were studied. The strain grew well and produced effective biosurfactants in the presence of n-alkanes, naphthalene, crude oil and vegetable oils. The biosurfactants were detected by the surface tension lowering of the medium, thin layer chromatography and infrared spectra analysis. With (2%) naphthalene as the sole carbon source, high levels of rhamnolipids at a concentration of 2.3 g l{sup -1} were determined in the stationary growth. After 20 d of incubation 72 {+-} 4% of the initial naphthalene was degraded. This is the first report for a Bacillus cereus rhamnolipid producing strain that utilized naphthalene under aerobic conditions. The strain looks promising for application in environmental technologies. (orig.)

  12. Effect of Ultrasonic Waves on the Heat Resistance of Bacillus cereus and Bacillus licheniformis Spores

    Science.gov (United States)

    Burgos, J.; Ordóñez, J. A.; Sala, F.

    1972-01-01

    Heat resistance of Bacillus cereus and Bacillus licheniformis spores in quarter-strength Ringer solution decreases markedly after ultrasonic treatments which are unable to kill a significant proportion of the spore population. This effect does not seem to be caused by a loss of Ca2+ or dipicolinic acid. The use of ultrasonics to eliminate vegetative cells or to break aggregates in Bacillus spore suspensions to be used subsequently in heat resistance experiments appears to be unadvisable. PMID:4627969

  13. The role of pili in Bacillus cereus intraocular infection.

    Science.gov (United States)

    Callegan, Michelle C; Parkunan, Salai Madhumathi; Randall, C Blake; Coburn, Phillip S; Miller, Frederick C; LaGrow, Austin L; Astley, Roger A; Land, Craig; Oh, So-Young; Schneewind, Olaf

    2017-06-01

    Bacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity

  14. Biological Characterization of the Biocontrol Agent Bacillus amyloliquefaciens CPA-8: The Effect of Temperature, pH and Water Activity on Growth, Susceptibility to Antibiotics and Detection of Enterotoxic Genes.

    Science.gov (United States)

    Gotor-Vila, Amparo; Teixidó, Neus; Sisquella, María; Torres, Rosario; Usall, Josep

    2017-09-01

    This work focuses on the biological understanding of the biocontrol agent Bacillus amyloliquefaciens CPA-8 in order to accomplish the characterization required in the registration process for the development of a microorganism-based product. The tolerance of CPA-8 to grow under different pH-temperature and water activity (a w )-temperature conditions was widely demonstrated. Regarding the pH results, optimum growth at the evaluated conditions was observed at 37 °C and pH between 7 and 5. On the contrary, the slowest growth was recorded at 20 °C and pH 4.5. Moreover, the type of solute used to reduce a w had a great influence on the minimum a w at which the bacterium was able to grow. The lowest a w values for CPA-8 growth in media modified with glycerol and glucose were 0.950 and 0.960, respectively. Besides, the lowest a w for CPA-8 growth increased when the temperature decreased to 20 °C, at which CPA-8 was not able to grow at less than 0.990 a w , regardless of the type of solute. Antibiotic susceptibility tests were carried out to determine which antibiotic could affect the behavior of the bacteria and revealed that CPA-8 was clearly resistant to hygromycin. Finally, a PCR amplification assay to detect the presence of enterotoxic genes from Bacillus cereus in CPA-8 was also performed. CPA-8 gave negative results for all the genes tested except for nheA gene, which is not enough for the toxicity expression, suggesting that fruit treated with this antagonist will not be a potential vehicle for foodborne illnesses.

  15. Occurrence of Toxigenic Bacillus cereus and Bacillus thuringiensis in Doenjang, a Korean Fermented Soybean Paste.

    Science.gov (United States)

    Park, Kyung Min; Kim, Hyun Jung; Jeong, Moon Cheol; Koo, Minseon

    2016-04-01

    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.

  16. Comparative transcriptome and phenotype analysis of acid-stressed Bacillus cereus strain ATCC 14579

    NARCIS (Netherlands)

    Mols, J.M.; Kranenburg, van Richard; Melis, van Clint; Moezelaar, Roy; Abee, Tjakko

    2009-01-01

    The food-borne human pathogen Bacillus cereus is found in environments that often have a low pH, such as food and soil. The physiological response upon exposure to several levels of acidity were investigated of B. cereus model strain ATCC 14579, to elucidate the response of B. cereus to acid stress.

  17. [Bacillus cereus endocarditis and a probable cutaneous gateway].

    Science.gov (United States)

    Soudet, S; Becquart, C; Dezoteux, F; Faure, K; Staumont-Salle, D; Delaporte, E

    2017-01-01

    Bacillus cereus is a ubiquitous telluric organism. B. cereus endocarditis is a rare condition seen mostly in prosthetic heart valves and among intravenous drug users. We report a new case of a patient without risk factors and with a good clinical outcome not requiring valve replacement. In October 2014, a 50-year-old woman was referred to the dermatology department of Lille University Hospital for lower-limb wounds developing 6 months earlier. She presented fever without clinical signs of infection, except for the lower-limbs wounds. Blood cultures revealed the presence of B. cereus. Transesophageal echocardiography was performed and revealed two foci of aortic valve vegetation with a diameter of 5mm. After bacterial sensitivity testing, rifampicin and levofloxacin treatment was given for six weeks, with complete remission. A skin graft was performed and good improvement was seen. Nineteen cases of B. cereus endocarditis have been described previously, only one of which was without risk factors. We described a case of complete remission after a 6-week course of antibiotics. Our case demonstrates that BC should not be considered as a blood culture contamination, and that treatment may be complex due to antibiotic resistance. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Germination of Bacillus cereus spores adhered to stainless steel.

    Science.gov (United States)

    Hornstra, L M; de Leeuw, P L A; Moezelaar, R; Wolbert, E J; de Vries, Y P; de Vos, W M; Abee, T

    2007-05-30

    Adhered spores of Bacillus cereus represent a significant part of the surface-derived contamination in processing equipment used in the dairy industry. As germinated spores lose their resistance capacities instantaneously, efficient germination prior to a cleaning in place treatment could aid to the disinfecting effect of such a treatment. Therefore, spores of B. cereus ATCC 14579 and that of the environmental isolate B. cereus CMCC 3328 were assessed for their germination behaviour when adhered to a stainless steel surface. A mixture of l-alanine and inosine initiated germination of adhered spores efficiently, resulting in 3.2 decimal logarithms of germination. Notably, implementation of a germination-inducing step prior to a representative cleaning in place procedure reduced the number of survivors with over 3 decimal log units, while an alkali treatment alone, as part of the cleaning in place procedure, did not show any effect on B. cereus spore viability. These results show that implementation of a germination step enhances the disinfection effect of currently used cleaning in place procedures.

  19. Proposal of nine novel species of the Bacillus cereus group.

    Science.gov (United States)

    Liu, Yang; Du, Juan; Lai, Qiliang; Zeng, Runying; Ye, Dezan; Xu, Jun; Shao, Zongze

    2017-08-01

    Nine novel Gram-stain-positive bacteria were investigated by a polyphasic taxonomic approach. Based on the analysis of 16S rRNA gene sequences, these strains belonged to the Bacillus cereus group, sharing over 97 % similarity with the known species of this group, and less than 95 % similarity with other species of the genus Bacillus. Multilocus sequence typing analysis showed that they formed nine robust and well-separated branches from the known species. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the nine strains were, respectively, below the 70 and 96 % threshold values for species definition, and between each strain and the known type strains of this group were also below the two threshold values. On the basis of the phenotypic and phylogenetic data, along with low dDDH and ANI values among these strains, these bacteria are assigned to the following nine novel species of the B. cereus group: Bacillus paranthracis sp. nov., type strain Mn5T (=MCCC 1A00395T=KCTC 33714T=LMG 28873T); Bacillus pacificus sp. nov., type strain EB422T (=MCCC 1A06182T=KCTC 33858T); Bacillus tropicus sp. nov., type strain N24T (=MCCC 1A01406T=KCTC 33711T=LMG 28874T); Bacillus albus sp. nov., type strain N35-10-2T (=MCCC 1A02146T=KCTC 33710T=LMG 28875T); Bacillus mobilis sp. nov., type strain 0711P9-1T (=MCCC 1A05942T=KCTC 33717T=LMG 28877T); Bacillus luti sp. nov., type strain TD41T (=MCCC 1A00359T=KCTC 33716T=LMG 28872T); Bacillus proteolyticus sp. nov., type strain TD42T (=MCCC 1A00365T=KCTC 33715T=LMG 28870T); Bacillus nitratireducens sp. nov., type strain 4049T (=MCCC 1A00732T=KCTC 33713T=LMG 28871T); and Bacillus paramycoides sp. nov., type strain NH24A2T (=MCCC 1A04098T=KCTC 33709T=LMG 28876T).

  20. Pan-genome and phylogeny of Bacillus cereus sensu lato.

    Science.gov (United States)

    Bazinet, Adam L

    2017-08-02

    Bacillus cereus sensu lato (s. l.) is an ecologically diverse bacterial group of medical and agricultural significance. In this study, I use publicly available genomes and novel bioinformatic workflows to characterize the B. cereus s. l. pan-genome and perform the largest phylogenetic and population genetic analyses of this group to date in terms of the number of genes and taxa included. With these fundamental data in hand, I identify genes associated with particular phenotypic traits (i.e., "pan-GWAS" analysis), and quantify the degree to which taxa sharing common attributes are phylogenetically clustered. A rapid k-mer based approach (Mash) was used to create reduced representations of selected Bacillus genomes, and a fast distance-based phylogenetic analysis of this data (FastME) was performed to determine which species should be included in B. cereus s. l. The complete genomes of eight B. cereus s. l. species were annotated de novo with Prokka, and these annotations were used by Roary to produce the B. cereus s. l. pan-genome. Scoary was used to associate gene presence and absence patterns with various phenotypes. The orthologous protein sequence clusters produced by Roary were filtered and used to build HaMStR databases of gene models that were used in turn to construct phylogenetic data matrices. Phylogenetic analyses used RAxML, DendroPy, ClonalFrameML, PAUP*, and SplitsTree. Bayesian model-based population genetic analysis assigned taxa to clusters using hierBAPS. The genealogical sorting index was used to quantify the phylogenetic clustering of taxa sharing common attributes. The B. cereus s. l. pan-genome currently consists of ≈60,000 genes, ≈600 of which are "core" (common to at least 99% of taxa sampled). Pan-GWAS analysis revealed genes associated with phenotypes such as isolation source, oxygen requirement, and ability to cause diseases such as anthrax or food poisoning. Extensive phylogenetic analyses using an unprecedented amount of data

  1. 40 CFR 180.1181 - Bacillus cereus strain BPO1; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus cereus strain BPO1; exemption... FOOD Exemptions From Tolerances § 180.1181 Bacillus cereus strain BPO1; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance for residues of the Bacillus cereus...

  2. Enterotoxin production by Bacillus cereus under gastrointestinal conditions and their immunological detection by commercially available kits

    OpenAIRE

    Ceuppens, Siele; Rajkovic, Andreja; Hamelink, Stefanie; Van de Wiele, Tom; Boon, Nico; Uyttendaele, Mieke

    2012-01-01

    Currently, three commercial kits for Bacillus cereus enterotoxins Nhe and/or Hbl detection are available, namely, the Bacillus diarrheal enterotoxin visual immunoassay (BDE VIA (TM)) kit (3M Tecra), B. cereus enterotoxin reversed passive latex agglutination (BCET-RPLA) kit (Oxoid), and the Duopath (R) Cereus Enterotoxins (Merck). The performance of the kits and their applicability to gastrointestinal simulation samples were evaluated. Then, the stability and production of enterotoxins Hbl and...

  3. Elaboration of an electroporation protocol for Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Turgeon, Nathalie; Laflamme, Christian; Ho, Jim; Duchaine, Caroline

    2006-12-01

    An electro-transformation procedure was established for Bacillus cereus ATCC 14579. Using early growth-stage culture and high electric field, the ectroporation efficiency was up to 2 x 10(9) cfu microg(-1) ml(-1) with pC194 plasmid DNA. The procedure was tested with three other plasmids, of various sizes, replication mechanisms and selection markers, and the transformation efficiencies ranged between 2 x 10(6) and 1 x 10(8) cfu microg(-1) ml(-)(1). The effects of two wall-weakening agents on electroporation rates were also evaluated. The transformation rate that was reached with our procedure is 10(3) times higher than that previously obtained with members of the Bacillus genus with similar plasmids, and 10(6) times superior than that achieved with available protocols for B. cereus. The proposed method is quick, simple, efficient with small rolling circle plasmids and large theta replicating plasmids with low copy number per cell, and suitable for many genetic manipulations that are not possible without high-efficiency transformation protocols.

  4. Characterisation and profiling of Bacillus subtilis, Bacillus cereus and Bacillus licheniformis by MALDI-TOF mass fingerprinting.

    Science.gov (United States)

    Fernández-No, I C; Böhme, K; Díaz-Bao, M; Cepeda, A; Barros-Velázquez, J; Calo-Mata, P

    2013-04-01

    The Bacillus genus includes species such as Bacillus cereus, Bacillus licheniformis and Bacillus subtilis, some of which may be pathogenic or causative agents in the spoilage of food products. The main goal of this work was to apply matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) mass fingerprinting to the classification of these Bacillus species. Genetic analyses were also compared to phyloproteomic analyses. A collection of 57 Bacillus strains isolated from fresh and processed food and from culture collections were studied and their mass spectra compiled. The resulting mass fingerprints were compared and characteristic peaks at the strain and species levels were assigned. The results showed that MALDI-TOF was a good complementary approach to 16S rRNA sequencing and even a more powerful tool in the accurate classification of Bacillus species, especially for differentiating B. subtilis and B. cereus from Bacillus amyloliquefaciens and Bacillus thuringiensis, respectively. MALDI-TOF was also found to provide valuable information at both intra- and interspecies levels in the Bacillus species studied. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Purification and characterization of two polyhydroxyalcanoates from Bacillus cereus.

    Science.gov (United States)

    Zribi-Maaloul, Emna; Trabelsi, Imen; Elleuch, Lobna; Chouayekh, Hichem; Ben Salah, Riadh

    2013-10-01

    This work aimed to study the potential of 155 strains of Bacillus sp., isolated from a collection of Tunisian microorganisms, for polyhydroxyalcanoates production. The strains were submitted to a battery of standard tests commonly used for determining bioplastic properties. The findings revealed that two of the isolates, namely Bacillus US 163 and US 177, provided red excitations at a wavelength of approximately 543 nm. The polyhydroxyalcanoates produced by the two strains were purified. Gas chromatography-mass spectroscopy (GC-MS), Fourier transformed infrared spectroscopy (FTIR), and gel permeation chromatography (GPC) were used to characterize the two biopolymers. Bacillus US 163 was noted to produce a poly methyl-3-hydroxy tetradecanoic acid (P-3HTD) with an average molecular weight of 455 kDa, a completely amorphous homopolymer without crystallinity. The US 177 strain produced a homopolymer of methyl-3-hydroxy octadecanoic acid (P3-HOD) with an average molecular weight of 555 kDa. Exhibiting the highest performance, US 163 and US 177 were submitted to 16S rRNA gene sequencing, and the results revealed that they belonged to the Bacillus cereus species. Overall, the findings indicated that the Bacilli from petroleum soil have a number of promising properties that make them promising candidates for bioplastic production. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Population Structure and Evolution of the Bacillus cereus Group

    Science.gov (United States)

    2004-12-01

    B . cereus , in- cluding the type strain ATCC 14579 , were included in...M21 Finland 1998 B . cereus 40 ST-32 ATCC 10987 Canada 1930 B . cereus ATCC Cereus II (emetic) ST-26 F4810/72 United States 1972 B . cereus 55 ST-26...thuringiensis serovar galleriae IP ST-25 T05144 France 1985 B . thuringiensis serovar galleriae IP ST-33 ATCC 10876 1945 B . cereus ATCC ST-39 SPS 2 1999 B

  7. Global transcriptome analysis of Bacillus cereus ATCC 14579 in response to silver nitrate stress

    OpenAIRE

    Ganesh Babu, Malli Mohan; Sridhar, Jayavel; Gunasekaran, Paramasamy

    2011-01-01

    Abstract Silver nanoparticles (AgNPs) were synthesized using Bacillus cereus strains. Earlier, we had synthesized monodispersive crystalline silver nanoparticles using B. cereus PGN1 and ATCC14579 strains. These strains have showed high level of resistance to silver nitrate (1 mM) but their global transcriptomic response has not been studied earlier. In this study, we investigated the cellular and metabolic response of B. cereus ATCC14579 treated with 1 mM silver nitrate for 30 & 60 min. Glob...

  8. Comparative transcriptome and phenotype analysis of Bacillus cereus in response to disinfectant treatments

    OpenAIRE

    Ceragioli, Mara; Mols, J.M.; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko

    2010-01-01

    Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria, such as Bacillus cereus, to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of B. cereus ATCC 14579 exposed to four different disinfectants (i.e., benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. The physiological response of B. cereus to different co...

  9. A new chemically defined medium for the growth and sporulation of Bacillus cereus strains in anaerobiosis.

    Science.gov (United States)

    Abbas, Amina Aicha; Planchon, Stella; Jobin, Michel; Schmitt, Philippe

    2014-10-01

    A new chemically defined liquid medium, MODS, was developed for the aerobic growth and anaerobic growth and sporulation of Bacillus cereus strains. The comparison of sporulation capacity of 18 strains of B. cereus has shown effective growth and spore production in anaerobiosis.. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Polymerase chain reaction assay for the detection of Bacillus cereus group cells

    DEFF Research Database (Denmark)

    Hansen, Bjarne Munk; Leser, Thomas D.; Hendriksen, Niels Bohse

    2001-01-01

    Recent investigations have shown that members of the Bacillus cereus group carry genes which have the potential to cause gastrointestinal and somatic diseases. Although most cases of diseases caused by the B. cereus group bacteria are relatively mild, it is desirable to be able to detect members ...

  11. Modelling the number of viable vegetative cells of Bacillus cereus passing through the stomach

    NARCIS (Netherlands)

    Wijnands, L.M.; Pielaat, A.; Dufrenne, J.B.; Zwietering, M.H.; Leusden, van F.M.

    2009-01-01

    Aims: Model the number of viable vegetative cells of B. cereus surviving the gastric passage after experiments in simulated gastric conditions. Materials and Methods: The inactivation of stationary and exponential phase vegetative cells of twelve different strains of Bacillus cereus, both mesophilic

  12. The impact of oxygen availability on stress survival and radical formation of Bacillus cereus

    NARCIS (Netherlands)

    Mols, J.M.; Pier, I.; Zwietering, M.H.; Abee, T.

    2009-01-01

    Both the growth and stress survival of two model Bacillus cereus strains, ATCC 14579 and ATCC 10987, were tested in three different conditions varying in oxygen availability, i.e., aerobic, microaerobic and anaerobic conditions. Both B. cereus strains displayed highest growth rates and yields under

  13. Metabolic capacity of Bacillus cereus strains ATCC 14579 and ATCC 10987 interlinked with comparative genomics.

    NARCIS (Netherlands)

    Mols, M.; Been, M.W.H.J. de; Zwietering, M.H.; Moezelaar, R.; Abee, T.

    2007-01-01

    Bacillus cereus is an important food-borne pathogen and spoilage organism. In this study, numerous phenotypes and the genomes of B.?cereus strains ATCC 14579 and ATCC 10987 were analysed to compare their metabolic capacity and stress resistance potential. The growth performance of the two strains

  14. Metabolic capacity of Bacillus cereus strains ATCC 14579 and ATCC 10987 interlinked with comparative genomics

    NARCIS (Netherlands)

    Mols, J.M.; Been, de M.W.H.J.; Zwietering, M.H.; Moezelaar, R.; Abee, T.

    2007-01-01

    Bacillus cereus is an important food-borne pathogen and spoilage organism. In this study, numerous phenotypes and the genomes of B. cereus strains ATCC 14579 and ATCC 10987 were analysed to compare their metabolic capacity and stress resistance potential. The growth performance of the two strains

  15. Identification of proteins involved in the heat stress response of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Periago, P.M.; Schaik, van W.; Abee, T.; Wouters, J.A.

    2002-01-01

    To monitor the ability of the food-borne opportunistic pathogen Bacillus cereus to survive during minimal processing of food products, we determined its heat-adaptive response. During pre-exposure to 42°C, B. cereus ATCC 14579 adapts to heat exposure at the lethal temperature of 50°C (maximum

  16. Physiological and transcriptional response of Bacillus cereus treated with low-temperature nitrogen gas plasma

    NARCIS (Netherlands)

    Mols, J.M.; Mastwijk, H.C.; Nierop Groot, M.N.; Abee, T.

    2013-01-01

    Aims - This study was conducted to investigate the inactivation kinetics of Bacillus cereus vegetative cells upon exposure to low-temperature nitrogen gas plasma and to reveal the mode of inactivation by transcriptome profiling. Methods and Results - Exponentially growing B. cereus cells were

  17. Comparative transcriptome and phenotype analysis of Bacillus cereus in response to disinfectant treatments

    NARCIS (Netherlands)

    Ceragioli, Mara; Mols, J.M.; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko

    2010-01-01

    Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria, such as Bacillus cereus, to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of B. cereus ATCC 14579

  18. Soya bean tempe extracts show antibacterial activity against Bacillus cereus cells and spores

    NARCIS (Netherlands)

    Roubos-van den Hil, P.J.; Dalmas, E.; Nout, M.J.R.; Abee, T.

    2010-01-01

    Aims: Tempe, a Rhizopus ssp.-fermented soya bean food product, was investigated for bacteriostatic and/or bactericidal effects against cells and spores of the food-borne pathogen Bacillus cereus. Methods and results: Tempe extract showed a high antibacterial activity against B. cereus ATCC 14579

  19. Adaptation of the food-borne pathogen Bacillus cereus to carvacrol

    NARCIS (Netherlands)

    Ultee, A.; Kets, E.P.W.; Alberda, M.; Hoekstra, F.A.; Smid, E.J.

    2000-01-01

    Carvacrol, a natural antimicrobial compound present in the essential oil fraction of oregano and thyme, is bactericidal towards Bacillus cereus. A decrease of the sensitivity of B. cereus towards carvacrol was observed after growth in the presence of non-lethal carvacrol concentrations. A decrease

  20. Comparative analysis of antimicrobial activities of valinomycin and cereulide, the Bacillus cereus emetic toxin

    NARCIS (Netherlands)

    Tempelaars, M.H.; Rodrigues, S.; Abee, T.

    2011-01-01

    Cereulide and valinomycin are highly similar cyclic dodecadepsipeptides with potassium ionophoric properties. Cereulide, produced by members of the Bacillus cereus group, is known mostly as emetic toxin, and no ecological function has been assigned. A comparative analysis of the antimicrobial

  1. Genes of Bacillus cereus and Bacillus anthracis encoding proteins of the exosporium.

    Science.gov (United States)

    Todd, Sarah J; Moir, Arthur J G; Johnson, Matt J; Moir, Anne

    2003-06-01

    The exosporium is the outermost layer of spores of Bacillus cereus and its close relatives Bacillus anthracis and Bacillus thuringiensis. For these pathogens, it represents the surface layer that makes initial contact with the host. To date, only the BclA glycoprotein has been described as a component of the exosporium; this paper defines 10 more tightly associated proteins from the exosporium of B. cereus ATCC 10876, identified by N-terminal sequencing of proteins from purified, washed exosporium. Likely coding sequences were identified from the incomplete genome sequence of B. anthracis or B. cereus ATCC 14579, and the precise corresponding sequence from B. cereus ATCC 10876 was defined by PCR and sequencing. Eight genes encode likely structural components (exsB, exsC, exsD, exsE, exsF, exsG, exsJ, and cotE). Several proteins of the exosporium are related to morphogenetic and outer spore coat proteins of B. subtilis, but most do not have homologues in B. subtilis. ExsE is processed from a larger precursor, and the CotE homologue appears to have been C-terminally truncated. ExsJ contains a domain of GXX collagen-like repeats, like the BclA exosporium protein of B. anthracis. Although most of the exosporium genes are scattered on the genome, bclA and exsF are clustered in a region flanking the rhamnose biosynthesis operon; rhamnose is part of the sugar moiety of spore glycoproteins. Two enzymes, alanine racemase and nucleoside hydrolase, are tightly adsorbed to the exosporium layer; they could metabolize small molecule germinants and may reduce the sensitivity of spores to these, limiting premature germination.

  2. Extended genetic analysis of Brazilian isolates of Bacillus cereus and Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Viviane Zahner

    2013-02-01

    Full Text Available Multiple locus sequence typing (MLST was undertaken to extend the genetic characterization of 29 isolates of Bacillus cereus and Bacillus thuringiensis previously characterized in terms of presence/absence of sequences encoding virulence factors and via variable number tandem repeat (VNTR. Additional analysis involved polymerase chain reaction for the presence of sequences (be, cytK, inA, pag, lef, cya and cap, encoding putative virulence factors, not investigated in the earlier study. MLST analysis ascribed novel and unique sequence types to each of the isolates. A phylogenetic tree was constructed from a single sequence of 2,838 bp of concatenated loci sequences. The strains were not monophyletic by analysis of any specific housekeeping gene or virulence characteristic. No clear association in relation to source of isolation or to genotypic profile based on the presence or absence of putative virulence genes could be identified. Comparison of VNTR profiling with MLST data suggested a correlation between these two methods of genetic analysis. In common with the majority of previous studies, MLST was unable to provide clarification of the basis for pathogenicity among members of the B. cereus complex. Nevertheless, our application of MLST served to reinforce the notion that B. cereus and B. thuringiensis should be considered as the same species.

  3. Bacteriophage PBC1 and its endolysin as an antimicrobial agent against Bacillus cereus.

    Science.gov (United States)

    Kong, Minsuk; Ryu, Sangryeol

    2015-04-01

    Bacillus cereus is an opportunistic human pathogen responsible for food poisoning and other, nongastrointestinal infections. Due to the emergence of multidrug-resistant B. cereus strains, the demand for alternative therapeutic options is increasing. To address these problems, we isolated and characterized a Siphoviridae virulent phage, PBC1, and its lytic enzymes. PBC1 showed a very narrow host range, infecting only 1 of 22 B. cereus strains. Phylogenetic analysis based on the major capsid protein revealed that PBC1 is more closely related to the Bacillus clarkii phage BCJA1c and phages of lactic acid bacteria than to the phages infecting B. cereus. Whole-genome comparison showed that the late-gene region, including the terminase gene, structural genes, and holin gene of PBC1, is similar to that from B. cereus temperate phage 250, whereas their endolysins are different. Compared to the extreme host specificity of PBC1, its endolysin, LysPBC1, showed a much broader lytic spectrum, albeit limited to the genus Bacillus. The catalytic domain of LysPBC1 when expressed alone also showed Bacillus-specific lytic activity, which was lower against the B. cereus group but higher against the Bacillus subtilis group than the full-length protein. Taken together, these results suggest that the virulent phage PBC1 is a useful component of a phage cocktail to control B. cereus, even with its exceptionally narrow host range, as it can kill a strain of B. cereus that is not killed by other phages, and that LysPBC1 is an alternative biocontrol agent against B. cereus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Characterization of germination receptors of Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Hornstra, Luc M; de Vries, Ynte P; Wells-Bennik, Marjon H J; de Vos, Willem M; Abee, Tjakko

    2006-01-01

    Specific amino acids, purine ribonucleosides, or a combination of the two is required for efficient germination of endospores of Bacillus cereus ATCC 14579. A survey including 20 different amino acids showed that l-alanine, l-cysteine, l-threonine, and l-glutamine are capable of initiating the germination of endospores of B. cereus ATCC 14579. In addition, the purine ribonucleosides inosine and adenosine can trigger germination of the spores. Advanced annotation of the B. cereus ATCC 14579 genome revealed the presence of seven putative germination (ger) operons, termed gerG, gerI, gerK, gerL, gerQ, gerR, and gerS. To determine the role of the encoded putative receptors in nutrient-induced germination, disruption mutants were constructed by the insertion of pMUTIN4 into each of the seven operons. Four of the seven mutants were affected in the germination response to amino acids or purine ribonucleosides, whereas no phenotype could be attributed to the mutants with disrupted gerK, gerL, and gerS loci. The strain with a disrupted gerR operon was severely hampered in the ability to germinate: germination occurred in response to l-glutamine but not in the presence of any of the other amino acids tested. The gerG mutant showed significantly reduced l-glutamine-induced germination, which points to a role of this receptor in the l-glutamine germination signaling pathway. gerR, gerI, and gerQ mutants showed reduced germination rates in the presence of inosine, suggesting a role for these operons in ribonucleoside signaling. Efficient germination by the combination of l-glutamine and inosine was shown to involve the gerG and gerI operons, since the germination of mutants lacking either one of these receptors was significantly reduced. Germination triggered by the combination of l-phenylalanine and inosine was lost in the gerI mutant, indicating that both molecules are effective at the GerI receptor.

  5. A novel and highly specific phage endolysin cell wall binding domain for detection of Bacillus cereus.

    Science.gov (United States)

    Kong, Minsuk; Sim, Jieun; Kang, Taejoon; Nguyen, Hoang Hiep; Park, Hyun Kyu; Chung, Bong Hyun; Ryu, Sangryeol

    2015-09-01

    Rapid, specific and sensitive detection of pathogenic bacteria is crucial for public health and safety. Bacillus cereus is harmful as it causes foodborne illness and a number of systemic and local infections. We report a novel phage endolysin cell wall-binding domain (CBD) for B. cereus and the development of a highly specific and sensitive surface plasmon resonance (SPR)-based B. cereus detection method using the CBD. The newly discovered CBD from endolysin of PBC1, a B. cereus-specific bacteriophage, provides high specificity and binding capacity to B. cereus. By using the CBD-modified SPR chips, B. cereus can be detected at the range of 10(5)-10(8) CFU/ml. More importantly, the detection limit can be improved to 10(2) CFU/ml by using a subtractive inhibition assay based on the pre-incubation of B. cereus and CBDs, removal of CBD-bound B. cereus, and SPR detection of the unbound CBDs. The present study suggests that the small and genetically engineered CBDs can be promising biological probes for B. cereus. We anticipate that the CBD-based SPR-sensing methods will be useful for the sensitive, selective, and rapid detection of B. cereus.

  6. PCR detection of cytK gene in Bacillus cereus group strains isolated from food samples.

    Science.gov (United States)

    Oltuszak-Walczak, Elzbieta; Walczak, Piotr

    2013-11-01

    A method for detection of the cytotoxin K cytK structural gene and its active promoter preceded by the PlcR-binding box, controlling the expression level of this enterotoxin, was developed. The method was applied for the purpose of the analysis of 47 bacterial strains belonging to the Bacillus cereus group isolated from different food products. It was found that the majority of the analyzed strains carried the fully functional cytK gene with its PlcR regulated promoter. The cytK gene was not detected in four emetic strains of Bacillus cereus carrying the cesB gene and potentially producing an emetic toxin - cereulide. The cytotoxin K gene was detected in 4 isolates classified as Bacillus mycoides and one reference strain B. mycoides PCM 2024. The promoter region and the N-terminal part of the cytK gene from two strains of B. mycoides (5D and 19E) showed similarities to the corresponding sequences of Bacillus cereus W23 and Bacillus thuringiensis HD-789, respectively. It was shown for the first time that the cytK gene promoter region from strains 5D and 19E of Bacillus mycoides had a similar arrangement to the corresponding sequence of Bacillus cereus ATCC 14579. The presence of the cytK gene in Bacillus mycoides shows that this species, widely recognized as nonpathogenic, may pose potential biohazard to human beings. © 2013.

  7. Bacillus cereus un patógeno importante en el control microbiológico de los alimentos / Bacillus cereus an important pathogen the microbiological control of food

    Directory of Open Access Journals (Sweden)

    Jennifer Sánchez

    2016-05-01

    Full Text Available Resumen Bacillus cereus es una bacteria genéticamente diversa que se encuentra comúnmente en el ambiente. Contamina los alimentos afectando la salud humana, al ingerir el microorganismo y/o sus toxinas, la emética o las enterotoxinas. En Colombia son escasos los reportes de intoxicación por B. cereus y se estima que hay un gran subregistro. Por lo anterior, se recomienda aumentar la vigilancia de este patógeno y realizar estudios sobre aspectos relevantes que permitan aplicar medidas de control para disminuir las intoxicaciones por B. cereus. El objetivo de esta revisión bibliográfica es presentar información actualizada sobre B. cereus, que incluye aspectos de su biología, taxonomía, toxinas, alimentos que contamina y metodologías para detectar, prevenir y controlar este microorganismo. La información presentada es de utilidad para el público en general, especialmente personas vinculadas al sector de alimentos, inocuidad alimentaria y control de procesos. / Abstract Bacillus cereus is a genetically diverse bacterium commonly found in the environment. It contaminates food, thus affecting human health upon ingestion of the microorganism and/or its toxins, the emetic or enterotoxins. In Colombia, reports of intoxication by B. cereus are scarce and under-registration is presumed. Because of this, it is recommended to increase surveillance of this pathogen and to develop studies on relevant aspects that allow the application of control measures to reduce intoxications by B. cereus. The aim of this review is to present current information on B. cereus, including aspects of its biology, taxonomy, toxins, food that it contaminates and methodologies for the detection, prevention and control of this microorganism. This information is useful for the general public, especially people involved with the food sector, food safety and process control.

  8. Deletion of the sigB gene in Bacillus cereus ATCC 14579 leads to hydrogen peroxide hyperresistance

    NARCIS (Netherlands)

    Schaik, van W.; Zwietering, M.H.; Vos, de W.M.; Abee, T.

    2005-01-01

    The sigB gene of Bacillus cereus ATCC 14579 encodes the alternative sigma factor B. Deletion of sigB in B. cereus leads to hyperresistance to hydrogen peroxide. The expression of katA, which encodes one of the catalases of B. cereus, is upregulated in the sigB deletion mutant, and this may

  9. Heat and salt stress in the food pathogen Bacillus cereus.

    Science.gov (United States)

    Browne, N; Dowds, B C

    2001-12-01

    The effects of stresses imposed on bacterial contaminants during food processing and treatment of packaging material were evaluated on the food pathogen Bacillus cereus. Conditions were established which allowed the cells to adapt to heat, ethanol and hydrogen peroxide stresses, but not to osmotic shock. Cross protection between stresses indicated a clear hierarchy of resistance with salt protecting against hydrogen peroxide, which protected against ethanol, which protected against heat shock. The cultures were shown to be most sensitive to heat, ethanol and oxidative stress at mid-exponential phase and to become resistant at stationary phase. Adaptive levels of stressor were found to induce synthesis of general stress and stress-specific proteins and differential accumulation of proteins was demonstrated between heat- or salt-stressed and unstressed cells. Sequencing revealed that a number of glycolytic enzymes were regulated by heat and osmotic shocks and that the chaperone GroEL was induced by heat shock. The implications of the physiological data in designing storage and processing conditions for food are discussed. The identification of stress-regulated proteins reveals a clear role for glycolysis in adaptation to heat shock and osmotic stress.

  10. Vacuum Distillation Residue Upgrading by an Indigenous Bacillus Cereus

    Directory of Open Access Journals (Sweden)

    Mitra Sadat Tabatabaee

    2013-07-01

    Full Text Available Background:Biological processing of heavy fractions of crude oils offers less severe process conditions and higher selectivity for refining. Biochemical Processes are expected to be low demand energy processes and certainly ecofriendly.Results:A strain of biosurfactant producing bacterium was isolated from an oil contaminated soil at Tehran refinery distillation unit. Based on selected phenotypic and genotypic characteristic including morphology, biochemical proprety, and 16 SrRNA sequencing identified as a novel strain of Bacillus cereus (JQ178332. This bacterium endures a wide range of pH, salinity and temperature. This specific strain utilizes both paraffin and anthracene as samples of aliphatic and polycyclic aromatic hydrocarbons. The ability of this bacterium to acquire all its energy and chemical requirements from Vacuum Distillation Residue (VR, as a net sample of problematic hydrocarbons in refineries, was studied. SARA test ASTM D4124-01 revealed 65.5% decrease in asphaltenic, 22.1% in aliphatics and 30.3% in Aromatics content of the VR in MSM medium. Further results with 0.9% saline showed 55% decrease in asphaltene content and 2.1% Aromatics respectively.Conclusion:Remarkable abilities of this microorganism propose its application in an ecofriendly technology to upgrade heavy crude oils.

  11. Production, characterization and purification of chitosanase from Bacillus cereus

    Directory of Open Access Journals (Sweden)

    F. A. T. PIZA

    1999-06-01

    Full Text Available A culture medium for a wild strain of Bacillus cereus was developed for chitosanase production by using an experimental design. The factors having the strongest influence on chitosanase production were ammonium sulfate concentration, aeration, pH and the interaction between the first two parameters. Optimal conditions for chitosan hydrolysis were pH 5.8 and 54 oC; however, hydrolysis activity drastically decreased at pH 7.0. The enzyme was purified (single-electrophoretic band by partitioning in an aqueous two-phase system (ATPS, followed by cation-exchange chromatography with a 66% yield. Chitosanase was mainly collected in the top phase (K = 129 of a 22% PEG 1,500, 13% phosphate (pH = 5.8 and 12% NaCl (w/w solution, and the main protein contaminants were evenly distributed between the phases (K = 1.07. The apparent molecular weight and the isoelectric point of the chitosanase, determined by SDS-PAGE electrophoresis and by isoelectric focalization, were 47 kDa and 8.8, respectively.

  12. Bacillus subtilis HJ18-4 from traditional fermented soybean food inhibits Bacillus cereus growth and toxin-related genes.

    Science.gov (United States)

    Eom, Jeong Seon; Lee, Sun Young; Choi, Hye Sun

    2014-11-01

    Bacillus subtilis HJ18-4 isolated from buckwheat sokseongjang, a traditional Korean fermented soybean food, exhibits broad-spectrum antimicrobial activity against foodborne pathogens, including Bacillus cereus. In this study, we investigated the antibacterial efficacy and regulation of toxin gene expression in B. cereus by B. subtilis HJ18-4. Expression of B. cereus toxin-related genes (groEL, nheA, nheC, and entFM) was downregulated by B. subtilis HJ18-4, which also exhibited strong antibacterial activity against B. cereus. We also found that water extracts of soy product fermented with B. subtilis HJ18-4 significantly inhibited the growth of B. cereus and toxin expression. These results indicate that B. subtilis HJ18-4 could be used as an antimicrobial agent to control B. cereus in the fermented soybean food industry. Our findings also provide an opportunity to develop an efficient biological control agent against B. cereus. © 2014 The Authors. Journal of Food Science published by Wiley Periodicals, Inc. on behalf of Institute of Food Technologists®

  13. Inhibition of Bacillus cereus ATCC 14579 by plantaricin UG1 in vitro and in food.

    Science.gov (United States)

    Enan, G

    2000-10-01

    The inhibition of Bacillus cereus ATCC 14579 viable growth by Lactobacillus plantarum UG1 bacteriocin (plantaricin UG1) in vitro and in food (pasteurized milk and minced meat) was studied. The inhibitory effect against B. cereus food-borne pathogen noticed in this study was due to plantaricin UG1, but not due to lactic acid produced by the L. plantarum UG1 culture. Plataricin UG1 negative clone did not affect viable growth of B. cereus in both broth and meat or pasteurized milk. The inhibitory effect of L. plantarum UG1 and its bacteriocion was apparently more in liquid systems (BHI broth & pasteurized milk) than in minced meat. The inhibitory effect of plantaricin UG1 against B. cereus was dependent on its concentration. The 22880 AU/ml concentration appeared to be an ideal preservative against B. cereus ATCC 14579 in liquid systems.

  14. Antimicrobial Effect of Nisin against Bacillus cereus in Beef Jerky during Storage.

    Science.gov (United States)

    Lee, Na-Kyoung; Kim, Hyoun Wook; Lee, Joo Yeon; Ahn, Dong Uk; Kim, Cheon-Jei; Paik, Hyun-Dong

    2015-01-01

    The microbial distribution of raw materials and beef jerky, and the effect of nisin on the growth of Bacillus cereus inoculated in beef jerky during storage, were studied. Five strains of pathogenic B. cereus were detected in beef jerky, and identified with 99.8% agreement using API CHB 50 kit. To evaluate the effect of nisin, beef jerky was inoculated with approximately 3 Log CFU/g of B. cereus mixed culture and nisin (100 IU/g and 500 IU/g). During the storage of beef jerky without nisin, the number of mesophilic bacteria and B. cereus increased unlikely for beef jerky with nisin. B. cereus started to grow after 3 d in 100 IU nisin/g treatment, and after 21 d in 500 IU nisin/g treatment. The results suggest that nisin could be an effective approach to extend the shelf-life, and improve the microbial safety of beef jerky, during storage.

  15. Inhibition of Bacillus cereus Growth and Toxin Production by Bacillus amyloliquefaciens RD7-7 in Fermented Soybean Products.

    Science.gov (United States)

    Eom, Jeong Seon; Choi, Hye Sun

    2016-01-01

    Bacillus cereus is a gram-positive, rod-shaped, spore-forming bacterium that has been isolated from contaminated fermented soybean food products and from the environment. B. cereus produces diarrheal and emetic toxins and has caused many outbreaks of foodborne diseases. In this study, we investigated whether B. amyloliquefaciens RD7-7, isolated from rice doenjang (Korean fermented soybean paste), a traditional Korean fermented soybean food, shows antimicrobial activity against B. cereus and regulates its toxin gene expression. B. amyloliquefaciens RD7-7 exhibited strong antibacterial activity against B. cereus and inhibited the expression of B. cereus toxin-related genes (groEL, nheA, nheC, and entFM). We also found that addition of water extracts of soybean and buckwheat soksungjang (Korean fermented soybean paste made in a short time) fermented with B. amyloliquefaciens RD7-7 significantly reduced the growth and toxin expression of B. cereus. These results indicate that B. amyloliquefaciens RD7-7 could be used to control B. cereus growth and toxin production in the fermented soybean food industry. Our findings also provide a basis for the development of candidate biological control agents against B. cereus to improve the safety of fermented soybean food products.

  16. Direct detection of toxigenic Bacillus cereus in dietary complement for children and cassava starch

    OpenAIRE

    Jnnifer A. Sánchez; Margarita M. Correa; Ángel E. Aceves Dies; Laura M. Castañeda Sandoval

    2014-01-01

    Bacillus cereus is a food contaminant and a known human pathogen that can cause emetic and diarrheal syndromes. In this study we evaluated the presence of toxigenic B. cereus by multiplex PCR directly in dietary complement for children and cassava starch samples collected on Medellin, Colombia. Of 75 dietary complement for children samples evaluated, 70.7% were contaminated with toxigenic B. cereus and four different toxigenic consortia were detected: I: nheA, hblC, cytK (9.8%), II: nheA, hbl...

  17. Antimicrobial Effect of Nisin against Bacillus cereus in Beef Jerky during Storage

    OpenAIRE

    Lee, Na-Kyoung; Kim, Hyoun Wook; Lee, Joo Yeon; Ahn, Dong Uk; Kim, Cheon-Jei; Paik, Hyun-Dong

    2015-01-01

    The microbial distribution of raw materials and beef jerky, and the effect of nisin on the growth of Bacillus cereus inoculated in beef jerky during storage, were studied. Five strains of pathogenic B. cereus were detected in beef jerky, and identified with 99.8% agreement using API CHB 50 kit. To evaluate the effect of nisin, beef jerky was inoculated with approximately 3 Log CFU/g of B. cereus mixed culture and nisin (100 IU/g and 500 IU/g). During the storage of beef jerky without nisin, t...

  18. Data on genome sequencing, analysis and annotation of a pathogenic Bacillus cereus 062011msu

    Directory of Open Access Journals (Sweden)

    Rashmi Rathy

    2018-04-01

    Full Text Available Bacillus species 062011 msu is a harmful pathogenic strain responsible for causing abscessation in sheep and goat population studied by Mariappan et al. (2012 [1]. The organism specifically targets the female sheep and goat population and results in the reduction of milk and meat production. In the present study, we have performed the whole genome sequencing of the pathogenic isolate using the Ion Torrent sequencing platform and generated 458,944 raw reads with an average length of 198.2 bp. The genome sequence was assembled, annotated and analysed for the genetic islands, metabolic pathways, orthologous groups, virulence factors and antibiotic resistance genes associated with the pathogen. Simultaneously the 16S rRNA sequencing study and genome sequence comparison data confirmed that the strain belongs to the species Bacillus cereus and exhibits 99% sequence homo;logy with the genomes of B. cereus ATCC 10987 and B. cereus FRI-35. Hence, we have renamed the organism as Bacillus cereus 062011msu. The Whole Genome Shotgun (WGS project has been deposited at DDBJ/ENA/GenBank under the accession NTMF00000000 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA404036(SAMN07629099. Keywords: Bacillus cereus, Genome sequencing, Abscessation, Virulence factors

  19. Bacillus Cereus catheter related bloodstream infection in a patient in a patient with acute lymphblastic leukemia

    Directory of Open Access Journals (Sweden)

    Lütfiye Öksüz

    2012-01-01

    Full Text Available Bacillus cereus infection is rarely associated with actual infection and for this reason single positive blood culture is usually regarded as contamination . However it may cause a number of infections, such catheter-related blood stream infections. Significant catheter-related bloodstream infections (CRBSI caused by Bacillus spp. are mainly due to B.cereus and have been predominantly reported in immunocompromised hosts1 . Catheter removal is generally advised for management of infection. In this report, catheter-related bacteremia caused by B.cereus in a patient with acute lymphoblastıc leukemia (ALL in Istanbul Medical Faculty was presented.A 44-year old man presented with fatigue, weight loss, epistaxis and high fever. A double-lumen Hickman–catheter (Bard 12.0 Fr, Round Dual Lumen was inserted by surgical cut-down to access the right subclavian vein which would be necessary for allogeneic stem cell transplantation. Three weeks later the patient presented with high fever and headache. Bacillus spp. was isolated from the cathether while blood culture obtained from the peripheral vein remained negative. The bacterial identification was confirmed as B.cereus using VITEK identification system It has been reported Bacillus cereus septicemia may be fatal in immunocompromised hosts despite broad-spectrum appropriate treatment10. Catheter removal is essential for prevention of recurrent bacteremia. Long-term cathater salvage should be reserved for appropriate patient group.

  20. Identification of multidrug-resistant bacteria and Bacillus cereus from ...

    African Journals Online (AJOL)

    However, B. cereus was isolated from the hands of three. HCWs. Table 1 shows species of bacteria isolated from. HCWs and ES in Elkhomes hospital. B. cereus is a Gram-positive spore-forming facultative- anaerobic rod-shaped organism that can be found in different types of soils and widely distributed in the environment.

  1. Concerted action of sphingomyelinase and non-hemolytic enterotoxin in pathogenic Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Viktoria M Doll

    Full Text Available Bacillus cereus causes food poisoning and serious non-gastrointestinal-tract infections. Non-hemolytic enterotoxin (Nhe, which is present in most B. cereus strains, is considered to be one of the main virulence factors. However, a B. cereus ΔnheBC mutant strain lacking Nhe is still cytotoxic to intestinal epithelial cells. In a screen for additional cytotoxic factors using an in vitro model for polarized colon epithelial cells we identified B. cereus sphingomyelinase (SMase as a strong inducer of epithelial cell death. Using single and double deletion mutants of sph, the gene encoding for SMase, and nheBC in B. cereus we demonstrated that SMase is an important factor for B. cereus cytotoxicity in vitro and pathogenicity in vivo. SMase substantially complemented Nhe induced cytotoxicity in vitro. In addition, SMase but not Nhe contributed significantly to the mortality rate of larvae in vivo in the insect model Galleria mellonella. Our study suggests that the role of B. cereus SMase as a secreted virulence factor for in vivo pathogenesis has been underestimated and that Nhe and SMase complement each other significantly to cause full B. cereus virulence hence disease formation.

  2. Cloning, Purification and Characterization of the Collagenase ColA Expressed by Bacillus cereus ATCC 14579.

    Directory of Open Access Journals (Sweden)

    Carmen M Abfalter

    Full Text Available Bacterial collagenases differ considerably in their structure and functions. The collagenases ColH and ColG from Clostridium histolyticum and ColA expressed by Clostridium perfringens are well-characterized collagenases that cleave triple-helical collagen, which were therefore termed as ´true´ collagenases. ColA from Bacillus cereus (B. cereus has been added to the collection of true collagenases. However, the molecular characteristics of B. cereus ColA are less understood. In this study, we identified ColA as a secreted true collagenase from B. cereus ATCC 14579, which is transcriptionally controlled by the regulon phospholipase C regulator (PlcR. B. cereus ATCC 14579 ColA was cloned to express recombinant wildtype ColA (ColAwt and mutated to a proteolytically inactive (ColAE501A version. Recombinant ColAwt was tested for gelatinolytic and collagenolytic activities and ColAE501A was used for the production of a polyclonal anti-ColA antibody. Comparison of ColAwt activity with homologous proteases in additional strains of B. cereus sensu lato (B. cereus s.l. and related clostridial collagenases revealed that B. cereus ATCC 14579 ColA is a highly active peptidolytic and collagenolytic protease. These findings could lead to a deeper insight into the function and mechanism of bacterial collagenases which are used in medical and biotechnological applications.

  3. Cloning, Purification and Characterization of the Collagenase ColA Expressed by Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Abfalter, Carmen M; Schönauer, Esther; Ponnuraj, Karthe; Huemer, Markus; Gadermaier, Gabriele; Regl, Christof; Briza, Peter; Ferreira, Fatima; Huber, Christian G; Brandstetter, Hans; Posselt, Gernot; Wessler, Silja

    2016-01-01

    Bacterial collagenases differ considerably in their structure and functions. The collagenases ColH and ColG from Clostridium histolyticum and ColA expressed by Clostridium perfringens are well-characterized collagenases that cleave triple-helical collagen, which were therefore termed as ´true´ collagenases. ColA from Bacillus cereus (B. cereus) has been added to the collection of true collagenases. However, the molecular characteristics of B. cereus ColA are less understood. In this study, we identified ColA as a secreted true collagenase from B. cereus ATCC 14579, which is transcriptionally controlled by the regulon phospholipase C regulator (PlcR). B. cereus ATCC 14579 ColA was cloned to express recombinant wildtype ColA (ColAwt) and mutated to a proteolytically inactive (ColAE501A) version. Recombinant ColAwt was tested for gelatinolytic and collagenolytic activities and ColAE501A was used for the production of a polyclonal anti-ColA antibody. Comparison of ColAwt activity with homologous proteases in additional strains of B. cereus sensu lato (B. cereus s.l.) and related clostridial collagenases revealed that B. cereus ATCC 14579 ColA is a highly active peptidolytic and collagenolytic protease. These findings could lead to a deeper insight into the function and mechanism of bacterial collagenases which are used in medical and biotechnological applications.

  4. PENGARUH EKSTRAK ANDALIMAN (Zanthoxyium acanthopodium DC TERHADAP PERMEABILITAS DAN HIDROFOBISITAS Bacillus cereus [Effect of Andaliman (Zanthoxylum acanthopodium DC Extracts upon Permeability and Hidrophobicity of Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Sedarnawati Yasni2

    2005-04-01

    Full Text Available Andaliman spice is usually added as one of main spices in cooked fish and meat. Andaliman seeds were extracted using maceration method with nonpolar, semipolar and polar solvents. The result showed that the three kinds of andaliman extract had antibacterial activity on Bacillus cereus, especially during exponential phase (8 hour incubation period. Ethyl-acetate extract of Andaliman showed the highest antibacterial activity toward B. cereus with MIC and MBC values being 0.2% and 0.8% respectively. The permeability of B. cereus was observed at the dose of 2.5 MIC and 60.30% hydrophobicity leakage was obtained at 6% andaliman extracted by ethyl-acetate.

  5. Successful Treatment of Bacillus cereus Bacteremia in a Patient with Propionic Acidemia.

    Science.gov (United States)

    Aygun, Fatma Deniz; Aygun, Fatih; Cam, Halit

    2016-01-01

    Bacillus cereus can cause serious, life-threatening, systemic infections in immunocompromised patients. The ability of microorganism to form biofilm on biomedical devices can be responsible for catheter-related bloodstream infections. Other manifestations of severe disease are meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections. The most common feature in true bacteremia caused by Bacillus is the presence of an intravascular catheter. Herein, we report a case of catheter-related bacteremia caused by B. cereus in a patient with propionic acidemia.

  6. Successful Treatment of Bacillus cereus Bacteremia in a Patient with Propionic Acidemia

    Directory of Open Access Journals (Sweden)

    Fatma Deniz Aygun

    2016-01-01

    Full Text Available Bacillus cereus can cause serious, life-threatening, systemic infections in immunocompromised patients. The ability of microorganism to form biofilm on biomedical devices can be responsible for catheter-related bloodstream infections. Other manifestations of severe disease are meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections. The most common feature in true bacteremia caused by Bacillus is the presence of an intravascular catheter. Herein, we report a case of catheter-related bacteremia caused by B. cereus in a patient with propionic acidemia.

  7. [Meningitis due to Bacillus cereus in an infant with Reye syndrome].

    Science.gov (United States)

    Ferroni, A; Odièvre, M H; Abachin, E; Révy, P; Casanova, J L; Saudubray, J M; Berche, P; Nassif, X

    1998-10-01

    We report the case of a 2.5-month-old infant with Bacillus cereus meningitis who was initially admitted for Reye syndrome. Gram positive bacteria was isolated in CSF and shown to be located inside the polymorphonuclears. This pathogen was further identified by sequencing of the 16S RNA. Early administration of imipenem in association with amikacin resulted in a rapid recovery. No obvious immune defect or invasive procedure could be assessed. Although Bacillus cereus is mainly associated with contamination, repeated isolations of this bacteria may be due to true infection.

  8. Draft Genome Sequences of Bacillus cereus E41 and Bacillus anthracis F34 Isolated from Algerian Salt Lakes

    OpenAIRE

    Daas, Mohamed Seghir; Rosana, Albert Remus R.; Acedo, Jeella Z.; Nateche, Farida; Kebbouche-Gana, Salima; Vederas, John C.; Case, Rebecca J.

    2017-01-01

    ABSTRACT Two strains of Bacillus, B.?cereus E41 and B.?anthracis F34, were isolated from a salt lake in A?n M?lila-Oum El Bouaghi, eastern Algeria, and Ain Baida-Ouargla, southern Algeria, respectively. Their genomes display genes for the production of several bioactive secondary metabolites, including polyhydroxyalkanoate, iron siderophores, lipopeptides, and bacteriocins.

  9. Proteomic evidences for rex regulation of metabolism in toxin-producing Bacillus cereus ATCC 14579.

    Directory of Open Access Journals (Sweden)

    Sabrina Laouami

    Full Text Available The facultative anaerobe, Bacillus cereus, causes diarrheal diseases in humans. Its ability to deal with oxygen availability is recognized to be critical for pathogenesis. The B. cereus genome comprises a gene encoding a protein with high similarities to the redox regulator, Rex, which is a central regulator of anaerobic metabolism in Bacillus subtilis and other Gram-positive bacteria. Here, we showed that B. cereus rex is monocistronic and down-regulated in the absence of oxygen. The protein encoded by rex is an authentic Rex transcriptional factor since its DNA binding activity depends on the NADH/NAD+ ratio. Rex deletion compromised the ability of B. cereus to cope with external oxidative stress under anaerobiosis while increasing B. cereus resistance against such stress under aerobiosis. The deletion of rex affects anaerobic fermentative and aerobic respiratory metabolism of B. cereus by decreasing and increasing, respectively, the carbon flux through the NADH-recycling lactate pathway. We compared both the cellular proteome and exoproteome of the wild-type and Δrex cells using a high throughput shotgun label-free quantitation approach and identified proteins that are under control of Rex-mediated regulation. Proteomics data have been deposited to the ProteomeXchange with identifier PXD000886. The data suggest that Rex regulates both the cross-talk between metabolic pathways that produce NADH and NADPH and toxinogenesis, especially in oxic conditions.

  10. Proteomic evidences for rex regulation of metabolism in toxin-producing Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Laouami, Sabrina; Clair, Géremy; Armengaud, Jean; Duport, Catherine

    2014-01-01

    The facultative anaerobe, Bacillus cereus, causes diarrheal diseases in humans. Its ability to deal with oxygen availability is recognized to be critical for pathogenesis. The B. cereus genome comprises a gene encoding a protein with high similarities to the redox regulator, Rex, which is a central regulator of anaerobic metabolism in Bacillus subtilis and other Gram-positive bacteria. Here, we showed that B. cereus rex is monocistronic and down-regulated in the absence of oxygen. The protein encoded by rex is an authentic Rex transcriptional factor since its DNA binding activity depends on the NADH/NAD+ ratio. Rex deletion compromised the ability of B. cereus to cope with external oxidative stress under anaerobiosis while increasing B. cereus resistance against such stress under aerobiosis. The deletion of rex affects anaerobic fermentative and aerobic respiratory metabolism of B. cereus by decreasing and increasing, respectively, the carbon flux through the NADH-recycling lactate pathway. We compared both the cellular proteome and exoproteome of the wild-type and Δrex cells using a high throughput shotgun label-free quantitation approach and identified proteins that are under control of Rex-mediated regulation. Proteomics data have been deposited to the ProteomeXchange with identifier PXD000886. The data suggest that Rex regulates both the cross-talk between metabolic pathways that produce NADH and NADPH and toxinogenesis, especially in oxic conditions.

  11. Detection of presumptive Bacillus cereus in the Irish dairy farm environment

    Directory of Open Access Journals (Sweden)

    O’Connell A.

    2016-12-01

    Full Text Available The objective of the study was to isolate potential Bacillus cereus sensu lato (B. cereus s.l. from a range of farm environments. Samples of tap water, milking equipment rinse water, milk sediment filter, grass, soil and bulk tank milk were collected from 63 farms. In addition, milk liners were swabbed at the start and the end of milking, and swabs were taken from cows’ teats prior to milking. The samples were plated on mannitol egg yolk polymyxin agar (MYP and presumptive B. cereus s.l. colonies were isolated and stored in nutrient broth with 20% glycerol and frozen at -80 °C. These isolates were then plated on chromogenic medium (BACARA and colonies identified as presumptive B. cereus s.l. on this medium were subjected to 16S ribosomal RNA (rRNA sequencing. Of the 507 isolates presumed to be B. cereus s.l. on the basis of growth on MYP, only 177 showed growth typical of B. cereus s.l. on BACARA agar. The use of 16S rRNA sequencing to identify isolates that grew on BACARA confirmed that the majority of isolates belonged to B. cereus s.l. A total of 81 of the 98 isolates sequenced were tentatively identified as presumptive B. cereus s.l. Pulsed-field gel electrophoresis was carried out on milk and soil isolates from seven farms that were identified as having presumptive B. cereus s.l. No pulsotype was shared by isolates from soil and milk on the same farm. Presumptive B. cereus s.l. was widely distributed within the dairy farm environment.

  12. [Septicaemia of chironomid larvae (Diptera: Chironomidae) promoted by Bacillus cereus and B. thuringiensis].

    Science.gov (United States)

    Khodyrev, V P

    2012-01-01

    Natural factors regulating the population of chironomids were studied. The bacteria Bacillus cereus were isolated from chironomids sampled from Kuyalnitskii Firth after epizooty of Chironomus sp., and bacteria Bacillus thuringiensis spp. israelensis (Bti) were isolated from dead larva of Chironomus plumosus sampled in the Sea of Azov (3-m depth). Bti were characterized by high insecticide activity on midges Anopheles messeae Fall., Aedes cireneus Mg., and Culex pipiens pipiens f. pipiens L.

  13. Biodegradation and corrosion behavior of manganese oxidizer Bacillus cereus ACE4 in diesel transporting pipeline

    International Nuclear Information System (INIS)

    Rajasekar, A.; Ganesh Babu, T.; Karutha Pandian, S.; Maruthamuthu, S.; Palaniswamy, N.; Rajendran, A.

    2007-01-01

    The degradation problem of petroleum products arises since hydrocarbon acts as an excellent food source for a wide variety of microorganisms. Microbial activity leads to unacceptable level of turbidity, corrosion of pipeline and souring of stored product. The present study emphasizes the role of Bacillus cereus ACE4 on degradation of diesel and its influence on corrosion of API 5LX steel. A demonstrating bacterial strain ACE4 was isolated from corrosion products and 16S rRNA gene sequence analysis showed that it has more than 99% similarity with B. cereus. The biodegradation and corrosion studies revealed that B. cereus degraded the aliphatic protons and aromatic protons in diesel and is capable of oxidizing ferrous/manganese into oxides. This is the first report that discloses the involvement of manganese oxidizer B. cereus ACE4 on biodegradation of diesel and its influence on corrosion in a tropical country pipeline

  14. Involvement of alanine racemase in germination of Bacillus cereus spores lacking an intact exosporium.

    Science.gov (United States)

    Venir, Elena; Del Torre, Manuela; Cunsolo, Vincenzo; Saletti, Rosaria; Musetti, Rita; Stecchini, Mara Lucia

    2014-02-01

    The L-alanine mediated germination of food isolated Bacillus cereus DSA 1 spores, which lacked an intact exosporium, increased in the presence of D-cycloserine (DCS), which is an alanine racemase (Alr) inhibitor, reflecting the activity of the Alr enzyme, capable of converting L-alanine to the germination inhibitor D-alanine. Proteomic analysis of the alkaline extracts of the spore proteins, which include exosporium and coat proteins, confirmed that Alr was present in the B. cereus DSA 1 spores and matched to that encoded by B. cereus ATCC 14579, whose spore germination was strongly affected by the block of conversion of L- to D-alanine. Unlike ATCC 14579 spores, L-alanine germination of B. cereus DSA 1 spores was not affected by the preincubation with DCS, suggesting a lack of restriction in the reactant accessibility.

  15. Incidence and characterization of Bacillus cereus isolated from traditional fermented meals in Nigeria.

    Science.gov (United States)

    Oguntoyinbo, Folarin Anthony; Oni, Oluwajenyo Mathew

    2004-12-01

    The aim of this study was to examine the presence of Bacillus cereus in fermented meals used in food seasoning in Nigeria. The microbial profiles of iru and ogiri, two Nigerian fermented vegetable proteins, were examined for presence of B. cereus. In the 50 samples tested, B. cereus was detected in all the samples, with the level of detection ranging from log 6.3 to log 8.3 g(-1) sample. Phenotypic characteristics of the B. cereus isolates showed that all of them could not ferment many sugars, most especially mannitol, but they utilized propionate citrate as a source of carbon and grew anaerobically. The isolates do not produce gas from glucose but hydrolyzed starch, casein, and gelatin. API-50CHB combined with API-20E identified the isolates as B. cereus. The diarrheal enterotoxin was detected by a reversed passive latex agglutination test kit. Results showed no significant difference in toxin production between ogiri and iru B. cereus isolated from different sources; all the isolates also demonstrated positive hemolytic activity. The API-ZYM enzyme profile showed that the strains have poor hydrolytic enzyme potential; hence, their possible contributions to the fermentation of vegetable protein is doubtful. This study established the proliferation of B. cereus in fermented protein meal and determined the diarrheal toxin production potential of the organism.

  16. Spore prevalence and toxigenicity of Bacillus cereus and Bacillus thuringiensis isolates from U.S. retail spices.

    Science.gov (United States)

    Hariram, Upasana; Labbé, Ronald

    2015-03-01

    Recent incidents of foodborne illness associated with spices as the vehicle of transmission prompted this examination of U.S. retail spices with regard to Bacillus cereus. This study focused on the levels of aerobic-mesophilic spore-forming bacteria and B cereus spores associated with 247 retail spices purchased from five states in the United States. Samples contained a wide range of aerobic-mesophilic bacterial spore counts ( 10(7) CFU/g). Using a novel chromogenic agar, B. cereus and B. thuringiensis spores were isolated from 77 (31%) and 11 (4%) samples, respectively. Levels of B. cereus were thuringiensis isolates possessed at least one type of enterotoxin gene: HBL (hemolysin BL) or nonhemolytic enterotoxin (NHE). None of the 88 isolates obtained in this study possessed the emetic toxin gene (ces). Using commercially available immunological toxin detection kits, the toxigenicity of the isolates was confirmed. The NHE enterotoxin was expressed in 98% of B. cereus and 91% of B. thuringiensis isolates that possessed the responsible gene. HBL enterotoxin was detected in 87% of B. cereus and 100% of B. thuringiensis PCR-positive isolates. Fifty-two percent of B. cereus and 54% of B. thuringiensis isolates produced both enterotoxins. Ninety-seven percent of B. cereus isolates grew at 12°C, although only two isolates grew well at 9°C. The ability of these spice isolates to form spores, produce diarrheal toxins, and grow at moderately abusive temperatures makes retail spices an important potential vehicle for foodborne illness caused by B. cereus strains, in particular those that produce diarrheal toxins.

  17. Production of nanodrug for Bacillus cereus isolated from HIV positive patient using Mallotus philippensis

    Directory of Open Access Journals (Sweden)

    R. Bhuvaneswari

    2016-04-01

    Full Text Available The present investigation was aimed to synthesis of silver nanoparticles (AgNPs using Mallotus philippensis leaf extract and their antibacterial potential against Bacillus cereus isolated from HIV positive patient. In this, UV- Visible spectroscopy showed the high peak of absorption band at 450 nm. Based on XRD analysis, face centered cubic structure and average size of the AgNPs was around 16 nm. FTIR spectroscopy study revealed the seventeen functional groups of the AgNPs was observed. The morphology of AgNPs was spherical, oval shapes and diameter of the particle size ranges between 9 and 24 nm was measured using transmission electron microscopy (TEM. In addition to these green synthesized AgNPs were found to express the higher efficacy in inhibiting the growth of Bacillus cereus (B. cereus isolated from the HIV-positive patient.

  18. The identification of a tetracycline resistance gene tet(M), on a Tn916-like transposon, in the Bacillus cereus group

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Jensen, Lars Bogø; Givskov, Michael Christian

    2002-01-01

    In order to investigate whether resistance genes present in bacteria in manure could transfer to indigenous soil bacteria, resistant isolates belonging to the Bacillus cereus group (Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis) were isolated from farm soil (72 isolates) and manure...

  19. Genomic study of the cereolysin A and B genes in Bacillus cereus ...

    African Journals Online (AJOL)

    Hence study about existence of Bacillus cereus in pasteurized milk is very important due to probability of causing illness by Cereolysin gene products. Therefore, Different milk samples were collected from raw milk to pasteurized milk after various stages of producing pasteurized milk. Cultivation of milk samples in Mannitol ...

  20. Predictive modeling of Bacillus cereus spores in farm tank milk during grazing and housing periods

    NARCIS (Netherlands)

    Vissers, M.M.M.; Giffel, M.C.T.; Driehuis, F.; Jong, de P.; Lankveld, J.M.G.

    2007-01-01

    The shelf life of pasteurized dairy products depends partly on the concentration of Bacillus cereus spores in raw milk. Based on a translation of contamination pathways into chains of unit-operations, 2 simulation models were developed to quantitatively identify factors that have the greatest effect

  1. Genomic study of the cereolysin A and B genes in Bacillus cereus ...

    African Journals Online (AJOL)

    AMAJU

    2011-01-17

    Jan 17, 2011 ... Infect. 2(2): 189-. 198. Miller SA, Dykes DD, Polesky HF (1988). A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res. 16 (3): p. 1215. Nduhiu J, Jackson NO, Dorcas WN, Michael MG (2009). Genetic characterization of food borne Bacillus cereus strains from milk,.

  2. Isolation, identification and characterization of Bacillus cereus from the dairy environment

    NARCIS (Netherlands)

    Giffel, te M.

    1997-01-01

    In this thesis the occurrence of Bacillus cereus in the milk production and processing environment was investigated. Isolates were identified biochemically and by DNA probes based on the variable regions of 16S rRNA. Further characterization was carried out using

  3. Comparative transcriptomic and phenotypic analysis of the responses of Bacillus cereus to various disinfectant treatments

    NARCIS (Netherlands)

    Ceragioli, M.; Mols, J.M.; Moezelaar, R.; Ghelardi, E.; Senesi, S.; Abee, T.

    2010-01-01

    Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four

  4. Comparative transcriptome analysis of biofilm and planktonic cells of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Wijman, Janneke; Mols, M.; Tempelaars, Marcel; Abee, Tjakko

    2015-01-01

    Planktonic and biofilm cells of Bacillus cereus ATCC 14579 and ATCC 10987 were studied using microscopy and transcriptome analysis. By microscopy, clear differences could be observed between biofilm and planktonic cells as well as between the two strains. By using hierarchical clustering of the

  5. Assessment of CcpA-mediated carbolite control of gene expression in Bacillus Cereus ATCC 14579

    NARCIS (Netherlands)

    Voort, van der M.; Kuipers, O.P.; Buist, G.; Vos, de W.M.; Abee, T.

    2008-01-01

    Background - The catabolite control protein CcpA is a transcriptional regulator conserved in many Gram-positives, controlling the efficiency of glucose metabolism. Here we studied the role of Bacillus cereus ATCC 14579 CcpA in regulation of metabolic pathways and expression of enterotoxin genes by

  6. Comparative transcriptome analysis of biofilm and planktonic cells of Bacillus cereus ATCC 10987

    NARCIS (Netherlands)

    Wijman, Janneke; Mols, M.; Tempelaars, Marcel; Abee, Tjakko

    2015-01-01

    Planktonic and biofilm cells of Bacillus cereus ATCC 14579 and ATCC 10987 were studied using microscopy and transcriptome analysis. By microscopy, clear differences could be observed between biofilm and planktonic cells as well as between the two strains. By using hierarchical clustering of the

  7. Assessment of CcpA-mediated catabolite control of gene expression in Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    van der Voort, Menno; Kuipers, Oscar P.; Buist, Girbe; de Vos, Willem M.; Abee, Tjakko

    2008-01-01

    Background: The catabolite control protein CcpA is a transcriptional regulator conserved in many Gram-positives, controlling the efficiency of glucose metabolism. Here we studied the role of Bacillus cereus ATCC 14579 CcpA in regulation of metabolic pathways and expression of enterotoxin genes by

  8. Prevalence of potentially pathogenic Bacillus cereus in food commodities in The Netherlands

    NARCIS (Netherlands)

    Wijnands, L.M.; Dufrenne, J.B.; Rombouts, F.M.; Veld, in 't P.H.; Leusden, van F.M.

    2006-01-01

    Randomly selected food commodities, categorized in product groups, were investigated for the presence and number of Bacillus cereus bacteria. If positive, and when possible, five separate colonies were isolated and investigated for the presence of four virulence factors: presence of genes encoding

  9. A probabilistic modeling approach in thermal inactivation: estimation of postprocess Bacillus cereus spore prevalence and concentration

    NARCIS (Netherlands)

    Membre, J.M.; Amezquita, A.; Bassett, J.; Giavedoni, P.; Blackburn, W.; Gorris, L.G.M.

    2006-01-01

    The survival of spore-forming bacteria is linked to the safety and stability of refrigerated processed foods of extended durability (REPFEDs). A probabilistic modeling approach was used to assess the prevalence and concentration of Bacillus cereus spores surviving heat treatment for a semiliquid

  10. Sporulation dynamics and spore heat resistance in wet and dry biofilms of Bacillus cereus

    NARCIS (Netherlands)

    Hayrapetyan, Hasmik; Abee, Tjakko; Nierop Groot, Masja

    2016-01-01

    Environmental conditions and growth history can affect the sporulation process as well as subsequent properties of formed spores. The sporulation dynamics was studied in wet and air-dried biofilms formed on stainless steel (SS) and polystyrene (PS) for Bacillus cereus ATCC 10987 and the

  11. The effect of selected factors on the survival of Bacillus cereus in the human gastrointestinal tract.

    Science.gov (United States)

    Berthold-Pluta, Anna; Pluta, Antoni; Garbowska, Monika

    2015-05-01

    Bacillus cereus is a Gram-positive bacterium widely distributed in soil and vegetation. This bacterial species can also contaminate raw or processed foods. Pathogenic B. cereus strains can cause a range of infections in humans, as well as food poisoning of an emetic (intoxication) or diarrheal type (toxico-infection). Toxico-infections are due to the action of the Hbl toxin, Nhe toxin, and cytotoxin K produced by the microorganism in the gastrointestinal tract. This occurs once the spores or vegetative B. cereus cells survive the pH barrier of the stomach and reach the small intestine where they produce toxins in sufficient amounts. This article discusses the effect of various factors on the survival of B. cereus in the gastrointestinal tract, including low pH and the presence of digestive enzymes in the stomach, bile salts in the small intestine, and indigenous microflora in the lower parts of the gastrointestinal tract. Additional aspects also reported to affect B. cereus survival and virulence in the gastrointestinal tract include the interaction of the spores and vegetative cells with enterocytes. In vitro studies revealed that both vegetative B. cereus and spores can survive in the gastrointestinal tract suggesting that the biological form of the microorganism may have less influence on the occurrence of the symptoms of infection than was once believed. It is most likely the interaction between the pathogen and enterocytes that is necessary for the diarrheal form of B. cereus food poisoning to develop. The adhesion of B. cereus to the intestinal epithelium allows the bacterium to grow and produce enterotoxins in the proximity of the epithelium. Recent studies suggest that the human intestinal microbiota inhibits the growth of vegetative B. cereus cells considerably. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Bioaccumulation of copper, zinc, cadmium and lead by Bacillus sp., Bacillus cereus, Bacillus sphaericus and Bacillus subtilis Bioacumulação de cobre, zinco, cádmio e chumbo por Bacillus sp., Bacillus cereus, Bacillus sphaericus e Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Augusto da Costa

    2001-03-01

    Full Text Available This work presents some results on the use of microbes from the genus Bacillus for uptake of cadmium, zinc, copper and lead ions. Maximum copper bioaccumulations were 5.6 mol/g biomass for B. sphaericus, 5.9 mol/g biomass for B. cereus and B. subtilis, and 6.4 mol/g biomass for Bacillus sp. Maximum zinc bioaccumulations were 4.3 mol/g biomass for B. sphaericus, 4.6 mol/g biomass for B. cereus, 4.8 mol/g biomass for Bacillus sp. and 5.0 mol/g biomass for B. subtilis. Maximum cadmium bioaccumulations were 8.0 mol/g biomass for B. cereus, 9.5 mol/g biomass for B. subtilis, 10.8 mol/g biomass for Bacillus sp. and 11.8 mol/g biomass for B. sphaericus. Maximum lead biomaccumulations were 0.7 mol/g biomass for B. sphaericus, 1.1 mol/g biomass for B. cereus, 1.4 mol/g biomass for Bacillus sp. and 1.8 mol/g biomass for B. subtilis. The different Bacillus strains tested presented distinct uptake capacities, and the best results were obtained for B. subtilis and B. cereus.Este trabalho apresenta resultados de acumulação dos íons metálicos cádmio, zinco, cobre e chumbo por bactérias do gênero Bacillus. A bioacumulação máxima de cobre foi 5,6 mol/g biomassa para B. sphaericus, 5,9 mol/g biomassa para B. cereus e B. subtilis, e 6,4 mol/g biomassa para Bacillus sp.. A bioacumulação máxima de zinco foi 4,3 mol/g biomassa para B. sphaericus, 4,6 mol/g biomassa para B. cereus, 4,8 mol/g biomassa para Bacillus sp. e 5,0 mol/g biomassa para B. subtilis. A bioacumulação máxima de cádmio foi 8,0 mol/g biomassa para B. cereus, 9,5 mol/g biomassa para B. subtilis, 10,8 mol/g biomassa para Bacillus sp. e 11,8 mol/g biomassa para B. sphaericus. A bioacumulação máxima de chumbo foi 0,7 mol/g biomassa para B. sphaericus, 1,1 mol/g biomassa para B. cereus, 1,4 mol/g biomassa para Bacillus sp. e 1,8 mol/g biomassa para B. subtilis. As distintas linhagens de Bacillus testadas apresentaram variáveis capacidades de carregamento de íons metálicos, sendo os

  13. Deletion of the sigB gene in Bacillus cereus ATCC 14579 leads to hydrogen peroxide hyperresistance.

    Science.gov (United States)

    van Schaik, Willem; Zwietering, Marcel H; de Vos, Willem M; Abee, Tjakko

    2005-10-01

    The sigB gene of Bacillus cereus ATCC 14579 encodes the alternative sigma factor sigma(B). Deletion of sigB in B. cereus leads to hyperresistance to hydrogen peroxide. The expression of katA, which encodes one of the catalases of B. cereus, is upregulated in the sigB deletion mutant, and this may contribute to the hydrogen peroxide-resistant phenotype.

  14. Deletion of the sigB gene in Bacillus cereus ATCC 14579 leads to hydrogen peroxide hyperresistance

    OpenAIRE

    Schaik, van, W.; Zwietering, M.H.; Vos, de, W.M.; Abee, T.

    2005-01-01

    The sigB gene of Bacillus cereus ATCC 14579 encodes the alternative sigma factor σB. Deletion of sigB in B. cereus leads to hyperresistance to hydrogen peroxide. The expression of katA, which encodes one of the catalases of B. cereus, is upregulated in the sigB deletion mutant, and this may contribute to the hydrogen peroxide-resistant phenotype.

  15. Growth and enterotoxin production of Bacillus cereus in cow, goat, and sheep milk

    Directory of Open Access Journals (Sweden)

    Lenka Necidová

    2014-01-01

    Full Text Available The aim of this study was to compare Bacillus cereus growth rates and diarrhoeal enterotoxin production in raw and pasteurized goat, sheep, and cow milk in terms of storage conditions. Milk samples were inoculated with B. cereus (CCM 2010, which produces diarrhoeal enterotoxins. Enterotoxin production was tested by ELISA (Enzyme-Linked Immunosorbent Assay, and the count of B. cereus was determined by the plate method. With raw cow milk, B. cereus growth and enterotoxin production can be completely suppressed; in raw goat and sheep milk, enterotoxin was produced at 22 °C. In pasteurized cow, goat, and sheep milk, the B. cereus count increased under all storage conditions, with more rapid growth being observed at 15 °C (sheep milk and 22 °C (cow and goat milk. Enterotoxin presence was detected at 15 °C and 22 °C, and with pasteurized cow milk also at 8 °C. Our model experiments have determined that B. cereus multiplication and subsequent enterotoxin production depend on storage temperature and milk type.

  16. Direct detection of toxigenic Bacillus cereus in dietary complement for children and cassava starch

    Directory of Open Access Journals (Sweden)

    Jnnifer A. Sánchez

    2014-05-01

    Full Text Available Bacillus cereus is a food contaminant and a known human pathogen that can cause emetic and diarrheal syndromes. In this study we evaluated the presence of toxigenic B. cereus by multiplex PCR directly in dietary complement for children and cassava starch samples collected on Medellin, Colombia. Of 75 dietary complement for children samples evaluated, 70.7% were contaminated with toxigenic B. cereus and four different toxigenic consortia were detected: I: nheA, hblC, cytK (9.8%, II: nheA, hblC (2%, III: hblC, cytK (41.2%, IV: hblC (47%. Of 75 cassava starch samples, 44% were contaminated with toxigenic B. cereus and four different toxigenic consortia were determined: I: nheA, hblC, cytK (48.5%, II: nheA, hblC, cytK, cesB (3%, III: hblC, cytK (30.3%, IV: hblC (18.2%. In general, in dietary complement for children only enterotoxigenic consortia were detected while in cassava starch the enterotoxigenic consortia predominated over the emetic. Multiplex PCR was useful to detect toxigenic B. cereus contamination allowing direct and imultaneous detection of all toxin genes in foods. This study is the first in Colombia to evaluate toxigenic B. cereus, providing information of importance for microbiological risk evaluation in dried foods.

  17. Food poisoning associated with emetic-type of Bacillus cereus in Korea.

    Science.gov (United States)

    Kim, Jung-Beom; Jeong, Hong-Rae; Park, Yong-Bae; Kim, Jae-Moung; Oh, Deog-Hwan

    2010-05-01

    Bacillus cereus can cause diarrheal and emetic types of food poisoning but little study has been done on emetic type of food poisoning in Korea. The objective of this study was to report on the emetic type of food poisoning associated with B. cereus in Korea. The toxin gene profile, toxin production, and antibiotic resistance of B. cereus isolates were investigated in this study. B. cereus was detected in three out of four samples, while the other food poisoning bacteria were not detected. All isolates (KUGH 10, 11, and 12) presented nhe A, B, and C diarrheal toxin genes (755, 743, and 683 bp), detected using NHA, NHB, and NHC primers, and ces emetic toxin gene (1271 bp), detected using CES primer, and produced nonhemolytic enterotoxin and emetic toxin (cereulide), detected using immunochemical assay and high performance liquid chromotography/mass spectrometry (HPLC/MS) analysis. All emetic-associated isolates were resistant to beta-lactam antibiotics. Most important finding in this study was that the risk of emetic-type B. cereus food poisoning has existed in Korea. This suggested that the food poisoning caused by B. cereus producing emetic and diarrheal toxins should be constantly evaluated to prevent misdiagnosis between emetic and diarrheal types of food poisoning.

  18. Modeling of Bacillus cereus distribution in pasteurized milk at the time of consumption

    Directory of Open Access Journals (Sweden)

    Ľubomír Valík

    2013-02-01

    Full Text Available Normal 0 21 false false false SK X-NONE X-NONE Modelling of Bacillus cereus distribution, using data from pasteurized milk produced in Slovakia, at the time of consumption was performed in this study. The Modular Process Risk Model (MPRM methodology was applied to over all the consecutive steps in the food chain. The main factors involved in the risk of being exposed to unacceptable levels of B. cereus (model output were the initial density of B. cereus after milk pasteurization, storage temperatures and times (model input. Monte Carlo simulations were used for probability calculation of B. cereus density. By applying the sensitivity analysis influence of the input factors and their threshold values on the final count of B. cereus were determined. The results of the general case exposure assessment indicated that almost 14 % of Tetra Brik cartons can contain > 104 cfu/ml of B. cereus at the temperature distribution taken into account and time of pasteurized milk consumption. doi:10.5219/264

  19. Prevalence and antimicrobial resistance of Bacillus cereus isolated from beef products in Egypt

    Directory of Open Access Journals (Sweden)

    Reyad Shawish

    2017-12-01

    Full Text Available Foodborne pathogens have the main concern in public health and food safety. Bacillus cereus food poisoning is one of the most important foodborne pathogens worldwide. In the present study, a total of 200 random beef product samples were collected from different supermarkets located at Menofia and Cairo governorates were examined for the presence of B. cereus. In addition, the presence of some virulence encoding genes was evaluated using Multiplex PCR. Finally, the antibiogram testing was conveyed to illustrate the resistance pattern of the confirmed B. cereus. The data showed that B. cereus was recovered from 22.5%, 30%, 25%, 37.5% and 15% of the minced meat, burger, sausage, kofta, and luncheon respectively. Among the 20 examined isolates 18/20 (90% were harbor hblC enterotoxin encoding gene compared with 20/20 (100 were have cytK enterotoxin encoding gene. The isolated strains of B. cereus were resistant to penicillin G and sensitive to oxacillin, clindamycin, vancomycin, erythromycin, gentamicin, ciprofloxacin, and ceftriaxone. In all, the obtained data showed the importance of emerging B. cereus in disease control and prevention programs, and in regular clinical and food quality control laboratories in Egypt.

  20. Growth of Bacillus cereus isolated from some traditional condiments ...

    African Journals Online (AJOL)

    USER

    2010-04-05

    Apr 5, 2010 ... cheese and ice cream have been reported to be frequently contaminated with B. cereus (Ahmed et al.,. 1983; Wong et al., 1988). The factors that make B. ce- reus a potential threat to food processing are ability to form thermoduric endospore, ability to grow and survive at refrigeration temperature and toxin ...

  1. Secondary cell wall polysaccharides of Bacillus anthracis are antigens that contain specific epitopes which cross-react with three pathogenic Bacillus cereus strains that caused severe disease, and other epitopes common to all the Bacillus cereus strains tested.

    Science.gov (United States)

    Leoff, Christine; Saile, Elke; Rauvolfova, Jana; Quinn, Conrad P; Hoffmaster, Alex R; Zhong, Wei; Mehta, Alok S; Boons, Geert-Jan; Carlson, Russell W; Kannenberg, Elmar L

    2009-06-01

    The immunoreactivities of hydrogen fluoride (HF)-released cell wall polysaccharides (HF-PSs) from selected Bacillus anthracis and Bacillus cereus strains were compared using antisera against live and killed B. anthracis spores. These antisera bound to the HF-PSs from B. anthracis and from three clinical B. cereus isolates (G9241, 03BB87, and 03BB102) obtained from cases of severe or fatal human pneumonia but did not bind to the HF-PSs from the closely related B. cereus ATCC 10987 or from B. cereus type strain ATCC 14579. Antiserum against a keyhole limpet hemocyanin conjugate of the B. anthracis HF-PS (HF-PS-KLH) also bound to HF-PSs and cell walls from B. anthracis and the three clinical B. cereus isolates, and B. anthracis spores. These results indicate that the B. anthracis HF-PS is an antigen in both B. anthracis cell walls and spores, and that it shares cross-reactive, and possibly pathogenicity-related, epitopes with three clinical B. cereus isolates that caused severe disease. The anti-HF-PS-KLH antiserum cross-reacted with the bovine serum albumin (BSA)-conjugates of all B. anthracis and all B. cereus HF-PSs tested, including those from nonclinical B. cereus ATCC 10987 and ATCC 14579 strains. Finally, the serum of vaccinated (anthrax vaccine adsorbed (AVA)) Rhesus macaques that survived inhalation anthrax contained IgG antibodies that bound the B. anthracis HF-PS-KLH conjugate. These data indicate that HF-PSs from the cell walls of the bacilli tested here are (i) antigens that contain (ii) a potentially virulence-associated carbohydrate antigen motif, and (iii) another antigenic determinant that is common to B. cereus strains.

  2. The YvfTU Two-component System is involved in plcR expression in Bacillus cereus

    NARCIS (Netherlands)

    Brillard, Julien; Susanna, Kim; Michaud, Caroline; Dargaignaratz, Claire; Gohar, Michel; Nielsen-Leroux, Christina; Ramarao, Nalini; Kolsto, Anne-Brit; Nguyen-The, Christophe; Lereclus, Didier; Broussolle, Veronique

    2008-01-01

    Background: Most extracellular virulence factors produced by Bacillus cereus are regulated by the pleiotropic transcriptional activator PlcR. Among strains belonging to the B. cereus group, the plcR gene is always located in the vicinity of genes encoding the YvfTU two-component system. The putative

  3. Characterization and exposure assessment of emetic bacillus cereus and cereulide production in food products on the Dutch market

    NARCIS (Netherlands)

    Biesta-Peters, Elisabeth G.; Dissel, Serge; Reij, Martine W.; Zwietering, Marcel H.; In't Veld, Paul H.

    2016-01-01

    The emetic toxin cereulide, which can be produced by Bacillus cereus, can be the cause of food poisoning upon ingestion by the consumer. The toxin causes vomiting and is mainly produced in farinaceous food products. This article includes the prevalence of B. cereus and of cereulide in food

  4. Analysis of acid-stressed Bacillus cereus reveals a major oxidative response and inactivation-associated radical formation

    NARCIS (Netherlands)

    Mols, J.M.; Kranenburg, van R.; Melis, van C.C.J.; Moezelaar, R.; Abee, T.

    2010-01-01

    Acid stress resistance of the food-borne human pathogen Bacillus cereus may contribute to its survival in acidic environments, such as encountered in soil, food and the human gastrointestinal tract. The acid stress responses of B. cereus strains ATCC 14579 and ATCC 10987 were analysed in aerobically

  5. Identification of sigmaB-dependent genes in Bacillus cereus by proteome and in vitro transcription analysis

    NARCIS (Netherlands)

    Schaik, van W.; Zwietering, M.H.; Vos, de W.M.; Abee, T.

    2004-01-01

    The alternative sigma factor sigma(B) of the food pathogen Bacillus cereus is activated upon stress exposure and plays a role in the adaptive response of vegetative cells. This study describes the identification of sigma(B)-dependent genes in B. cereus. Two-dimensional gel electrophoresis was

  6. The possibility of discriminating within the Bacillus cereus group using gyrB sequencing and PCR-RFLP

    DEFF Research Database (Denmark)

    Jensen, Gert B; Fisker, Niels; Sparsø, Thomas

    2005-01-01

    Based on a combination of PCR and restriction endonuclease (RE) digestion (PCR-RE digestion), we have examined the possibility of differentiating members of the Bacillus cereus group. Fragments of the gyrB gene (362 bp) from pure cultures of 12 B. cereus, 25 B. thuringiensis, 25 B. mycoides and t...

  7. Determining the source of Bacillus cereus and Bacillus licheniformis isolated from raw milk, pasteurized milk and yoghurt.

    Science.gov (United States)

    Banykó, J; Vyletelová, M

    2009-03-01

    Strain-specific detection of Bacillus cereus and Bacillus licheniformis in raw and pasteurized milk, and yoghurt during processing. Randomly selected isolates of Bacillus spp. were subjected to PCR analysis, where single primer targeting to the repetitive sequence Box elements was used to fingerprint the species. The isolates were separated into six different fingerprint patterns. The results show that isolates clustered together at about the 57% similarity level with two main groups at the 82% and 83% similarity levels, respectively. Contamination with identical strains both of B. cereus and B. licheniformis in raw and pasteurized milk was found as well as contaminated with different strains (in the case of raw milk and yoghurt/pasteurized milk and yoghurt). Several BOX types traced in processed milk samples were not discovered in the original raw milk. BOX-PCR fingerprinting is useful for characterizing Bacillus populations in a dairy environment. It can be used to confirm environmental contamination, eventually clonal transfer of Bacillus strains during the technological processing of milk. Despite the limited number of strains analysed, the two Bacillus species yielded adequately detectable banding profiles, permitting differentiation of bacteria at the strain level and showing their diversity throughout dairy processing.

  8. Sensitivity of Spores of Eight Bacillus Cereus Strains to Pressure-Induced Germination by Moderate Hydrostatic Pressure, Time and Temperature

    National Research Council Canada - National Science Library

    Kalchayanand, Norasak; Ray, Bibek; Dunne, C. P; Sikes, Anthony

    2005-01-01

    The spores of eight Bacillus cereus strains were pressurized at 138 to 483 MPa for 5 to 20 min at 25 to 70 C in order to determine the sensitive and the resistant strains to pressure-induced germination...

  9. Deciphering the interactions between the Bacillus cereus linear plasmid, pBClin15, and its host by high-throughput comparative proteomics

    OpenAIRE

    Madeira, Jean-Paul; Omer, Hélène; Alpha-Bazin, Béatrice; Armengaud, Jean

    2016-01-01

    The pathogen, Bacillus cereus, is able to adapt itsmetabolismto various environmental conditions. The reference strain, Bacillus cereus ATCC 14579, harbors a linear plasmid, pBClin15, which displays a cryptic prophage behavior. Here, we studied the impact of pBClin15 on the aerobic respiratory metabolism of B. cereus by curing its host strain. We compared, by means of a high-throughput shotgun proteomic approach, both the cellular proteome and the exoproteome of B. cereus ATCC 14579 in the pr...

  10. Environmental and Biofilm-dependent Changes in a Bacillus cereus Secondary Cell Wall Polysaccharide*

    Science.gov (United States)

    Candela, Thomas; Maes, Emmanuel; Garénaux, Estelle; Rombouts, Yoann; Krzewinski, Frédéric; Gohar, Michel; Guérardel, Yann

    2011-01-01

    Bacterial species from the Bacillus genus, including Bacillus cereus and Bacillus anthracis, synthesize secondary cell wall polymers (SCWP) covalently associated to the peptidoglycan through a phospho-diester linkage. Although such components were observed in a wide panel of B. cereus and B. anthracis strains, the effect of culture conditions or of bacterial growth state on their synthesis has never been addressed. Herein we show that B. cereus ATCC 14579 can synthesize not only one, as previously reported, but two structurally unrelated secondary cell wall polymers (SCWP) polysaccharides. The first of these SCWP, →4)[GlcNAc(β1–3)]GlcNAc(β1–6)[Glc(β1-3)][ManNAc(α1–4)]GalNAc(α1–4)ManNAc(β1→, although presenting an original sequence, fits to the already described the canonical sequence motif of SCWP. In contrast, the second polysaccharide was made up by a totally original sequence, →6)Gal(α1–2)(2-R-hydroxyglutar-5-ylamido)Fuc2NAc4N(α1-6)GlcNAc(β1→, which no equivalent has ever been identified in the Bacillus genus. In addition, we established that the syntheses of these two polysaccharides were differently regulated. The first one is constantly expressed at the surface of the bacteria, whereas the expression of the second is tightly regulated by culture conditions and growth states, planktonic, or biofilm. PMID:21784857

  11. Environmental and biofilm-dependent changes in a Bacillus cereus secondary cell wall polysaccharide.

    Science.gov (United States)

    Candela, Thomas; Maes, Emmanuel; Garénaux, Estelle; Rombouts, Yoann; Krzewinski, Frédéric; Gohar, Michel; Guérardel, Yann

    2011-09-09

    Bacterial species from the Bacillus genus, including Bacillus cereus and Bacillus anthracis, synthesize secondary cell wall polymers (SCWP) covalently associated to the peptidoglycan through a phospho-diester linkage. Although such components were observed in a wide panel of B. cereus and B. anthracis strains, the effect of culture conditions or of bacterial growth state on their synthesis has never been addressed. Herein we show that B. cereus ATCC 14579 can synthesize not only one, as previously reported, but two structurally unrelated secondary cell wall polymers (SCWP) polysaccharides. The first of these SCWP, →4)[GlcNAc(β1-3)]GlcNAc(β1-6)[Glc(β1-3)][ManNAc(α1-4)]GalNAc(α1-4)ManNAc(β1→, although presenting an original sequence, fits to the already described the canonical sequence motif of SCWP. In contrast, the second polysaccharide was made up by a totally original sequence, →6)Gal(α1-2)(2-R-hydroxyglutar-5-ylamido)Fuc2NAc4N(α1-6)GlcNAc(β1→, which no equivalent has ever been identified in the Bacillus genus. In addition, we established that the syntheses of these two polysaccharides were differently regulated. The first one is constantly expressed at the surface of the bacteria, whereas the expression of the second is tightly regulated by culture conditions and growth states, planktonic, or biofilm.

  12. Milk-originated Bacillus cereus sensu lato strains harbouring Bacillus anthracis-like plasmids are genetically and phenotypically diverse.

    Science.gov (United States)

    Bartoszewicz, Marek; Marjańska, Paulina Sylwia

    2017-10-01

    Bacillus cereus sensu lato is widely distributed in food products, including raw and processed milk. Plasmids often determine bacterial virulence and toxicity, but their role in the evolution of B. cereus sensu lato is only partly known. Here, we observed that nearly 8% of B. cereus sensu lato isolates were positive for pXO1-like plasmids and 12% for pXO2-like plasmids in raw and ultra-heat-treated (UHT) milk from one dairy plant. However, pXO1-like plasmids were significantly more frequent in raw milk, while pXO2-like plasmids were more frequent in processed milk. Strains from raw and UHT milk were enterotoxigenic, with up to one-fifth of the isolates being psychrotolerant. Phylogenetic assessment using multi-locus sequence typing revealed a polyphyletic structure for these bacilli, with distinct groups of cold-adapted isolates and pathogenic strains (including emetic B. cereus). Populations corresponding to both sampling sites exhibited significant linkage disequilibrium and the presence of purifying selection. The far-from-clonal population structure indicated the presence of sequence types or ecotypes adapted to specific conditions in the dairy industry. A high recombination-to-mutation ratio suggested an important role for horizontal gene transfer among B. cereus sensu lato isolates in milk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Draft Genome Sequences of Bacillus cereus E41 and Bacillus anthracis F34 Isolated from Algerian Salt Lakes

    Science.gov (United States)

    Daas, Mohamed Seghir; Rosana, Albert Remus R.; Acedo, Jeella Z.; Nateche, Farida; Kebbouche-Gana, Salima; Vederas, John C.

    2017-01-01

    ABSTRACT Two strains of Bacillus, B. cereus E41 and B. anthracis F34, were isolated from a salt lake in Aïn M’lila-Oum El Bouaghi, eastern Algeria, and Ain Baida-Ouargla, southern Algeria, respectively. Their genomes display genes for the production of several bioactive secondary metabolites, including polyhydroxyalkanoate, iron siderophores, lipopeptides, and bacteriocins. PMID:28522726

  14. Identification and genomic comparison of temperate bacteriophages derived from emetic Bacillus cereus.

    Science.gov (United States)

    Geng, Peiling; Tian, Shen; Yuan, Zhiming; Hu, Xiaomin

    2017-01-01

    Cereulide-producing Bacillus cereus isolates can cause serious emetic (vomiting) syndrome and even acute lethality. As mobile genetic elements, the exploration of prophages derived from emetic B. cereus isolates will help in our understanding of the genetic diversity and evolution of these pathogens. In this study, five temperate phages derived from cereulide-producing B. cereus strains were induced, with four of them undergoing genomic sequencing. Sequencing revealed that they all belong to the Siphoviridae family, but presented in different forms in their hosts. PfNC7401 and PfIS075 have typical icosahedral heads, probably existing alone as phagemids in the host with self-replicating capability in the lysogenic state. PfEFR-4, PfEFR-5, and PfATCC7953 have elongated heads, with the genomes of the former two identified as linear dsDNA, which could be integrated into the host genome during the lysogenic state. Genomic comparison of the four phages with others also derived from emetic B. cereus isolates showed similar genome structures and core genes, thus displaying host spectrum specificity. In addition, phylogenic analysis based on the complete genome and conserved tail fiber proteins of 36 Bacillus species-derived phages confirmed that the phages derived from emetic B. cereus strains were highly similar. Furthermore, one endolysin LysPfEFR-4 was cloned and showed lytic activity against all tested emetic B. cereus strains and cross-lytic activity against some other pathogenic bacteria, implying a potential to control bacterial contamination in the food supply.

  15. Identification and genomic comparison of temperate bacteriophages derived from emetic Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Peiling Geng

    Full Text Available Cereulide-producing Bacillus cereus isolates can cause serious emetic (vomiting syndrome and even acute lethality. As mobile genetic elements, the exploration of prophages derived from emetic B. cereus isolates will help in our understanding of the genetic diversity and evolution of these pathogens. In this study, five temperate phages derived from cereulide-producing B. cereus strains were induced, with four of them undergoing genomic sequencing. Sequencing revealed that they all belong to the Siphoviridae family, but presented in different forms in their hosts. PfNC7401 and PfIS075 have typical icosahedral heads, probably existing alone as phagemids in the host with self-replicating capability in the lysogenic state. PfEFR-4, PfEFR-5, and PfATCC7953 have elongated heads, with the genomes of the former two identified as linear dsDNA, which could be integrated into the host genome during the lysogenic state. Genomic comparison of the four phages with others also derived from emetic B. cereus isolates showed similar genome structures and core genes, thus displaying host spectrum specificity. In addition, phylogenic analysis based on the complete genome and conserved tail fiber proteins of 36 Bacillus species-derived phages confirmed that the phages derived from emetic B. cereus strains were highly similar. Furthermore, one endolysin LysPfEFR-4 was cloned and showed lytic activity against all tested emetic B. cereus strains and cross-lytic activity against some other pathogenic bacteria, implying a potential to control bacterial contamination in the food supply.

  16. Comparative analysis of antimicrobial activities of valinomycin and cereulide, the Bacillus cereus emetic toxin.

    Science.gov (United States)

    Tempelaars, Marcel H; Rodrigues, Susana; Abee, Tjakko

    2011-04-01

    Cereulide and valinomycin are highly similar cyclic dodecadepsipeptides with potassium ionophoric properties. Cereulide, produced by members of the Bacillus cereus group, is known mostly as emetic toxin, and no ecological function has been assigned. A comparative analysis of the antimicrobial activity of valinomycin produced by Streptomyces spp. and cereulide was performed at a pH range of pH 5.5 to pH 9.5, under anaerobic and aerobic conditions. Both compounds display pH-dependent activity against selected Gram-positive bacteria, including Staphylococcus aureus, Listeria innocua, Listeria monocytogenes, Bacillus subtilis, and Bacillus cereus ATCC 10987. Notably, B. cereus strain ATCC 14579 and the emetic B. cereus strains F4810/72 and A529 showed reduced sensitivity to both compounds, with the latter two strains displaying full resistance to cereulide. Both compounds showed no activity against the selected Gram-negative bacteria. Antimicrobial activity against Gram-positive bacteria was highest at alkaline pH values, where the membrane potential (ΔΨ) is the main component of the proton motive force (PMF). Furthermore, inhibition of growth was observed in both aerobic and anaerobic conditions. Determination of the ΔΨ, using the membrane potential probe DiOC(2)(3) (in the presence of 50 mM KCl) in combination with flow cytometry, demonstrated for the first time the ability of cereulide to dissipate the ΔΨ in sensitive Gram-positive bacteria. The putative role of cereulide production in the ecology of emetic B. cereus is discussed.

  17. Comparative Analysis of Antimicrobial Activities of Valinomycin and Cereulide, the Bacillus cereus Emetic Toxin▿

    Science.gov (United States)

    Tempelaars, Marcel H.; Rodrigues, Susana; Abee, Tjakko

    2011-01-01

    Cereulide and valinomycin are highly similar cyclic dodecadepsipeptides with potassium ionophoric properties. Cereulide, produced by members of the Bacillus cereus group, is known mostly as emetic toxin, and no ecological function has been assigned. A comparative analysis of the antimicrobial activity of valinomycin produced by Streptomyces spp. and cereulide was performed at a pH range of pH 5.5 to pH 9.5, under anaerobic and aerobic conditions. Both compounds display pH-dependent activity against selected Gram-positive bacteria, including Staphylococcus aureus, Listeria innocua, Listeria monocytogenes, Bacillus subtilis, and Bacillus cereus ATCC 10987. Notably, B. cereus strain ATCC 14579 and the emetic B. cereus strains F4810/72 and A529 showed reduced sensitivity to both compounds, with the latter two strains displaying full resistance to cereulide. Both compounds showed no activity against the selected Gram-negative bacteria. Antimicrobial activity against Gram-positive bacteria was highest at alkaline pH values, where the membrane potential (ΔΨ) is the main component of the proton motive force (PMF). Furthermore, inhibition of growth was observed in both aerobic and anaerobic conditions. Determination of the ΔΨ, using the membrane potential probe DiOC2(3) (in the presence of 50 mM KCl) in combination with flow cytometry, demonstrated for the first time the ability of cereulide to dissipate the ΔΨ in sensitive Gram-positive bacteria. The putative role of cereulide production in the ecology of emetic B. cereus is discussed. PMID:21357430

  18. The Pathogenomic Sequence Analysis of B. cereus and B.thuringiensis Isolates Closely Related to Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Han, Cliff S.; Xie, Gary; Challacombe, Jean F.; Altherr, MichaelR.; Smriti, B.; Bruce, David; Campbell, Connie S.; Campbell, Mary L.; Chen, Jin; Chertkov, Olga; Cleland, Cathy; Dimitrijevic-Bussod, M.; Doggett, Norman A.; Fawcett, John J.; Glavina, Tijana; Goodwin, Lynne A.; Hill, Karen K.; Hitchcock, Penny; Jackson, Paul J.; Keim, Paul; Kewalramani, Avinash Ramesh; Longmire, Jon; Lucas, Susan; Malfatti,Stephanie; McMurry, Kim; Meincke, Linda J.; Misra, Monica; Moseman,Bernice L.; Mundt, Mark; Munk, A. Christine; Okinaka, Richard T.; Parson-Quintana, B.; Reilly, Lee P.; Richardson, Paul; Robinson, DonnaL.; Rubin, Eddy; Saunders, Elizabeth; Tapia, Roxanne; Tesmer, Judith G.; Thayer, Nina; Thompson, Linda S.; Tice, Hope; Ticknor, Lawrence O.; Wills, Patti L.; Gilna, Payl; Brettin, Thomas S.

    2005-08-18

    The sequencing and analysis of two close relatives of Bacillus anthracis are reported. AFLP analysis of over 300 isolates of B.cereus, B. thuringiensis and B. anthracis identified two isolates as being very closely related to B. anthracis. One, a B. cereus, BcE33L, was isolated from a zebra carcass in Nambia; the second, a B. thuringiensis, 97-27, was isolated from a necrotic human wound. The B. cereus appears to be the closest anthracis relative sequenced to date. A core genome of over 3,900 genes was compiled for the Bacillus cereus group, including Banthracis. Comparative analysis of these two genomes with other members of the B. cereus group provides insight into the evolutionary relationships among these organisms. Evidence is presented that differential regulation modulates virulence, rather than simple acquisition of virulence factors. These genome sequences provide insight into the molecular mechanisms contributing to the host range and virulence of this group of organisms.

  19. Insertional mutagenesis reveals genes involved in Bacillus cereus ATCC 14579 growth at low temperature.

    Science.gov (United States)

    Broussolle, Véronique; Pandiani, Franck; Haddad, Nabila; Michaud, Caroline; Carlin, Frédéric; Nguyen-the, Christophe; Brillard, Julien

    2010-05-01

    Transposon mutagenesis of Bacillus cereus ATCC 14579 yielded cold-sensitive mutants. Mutants of genes encoding enzymes of the central metabolism were affected by cold, but also by other stresses, such as pH or salt, whereas a mutant with transposon insertion in the promoter region of BC0259 gene, encoding a putative DEAD-box RNA helicase displaying homology with Escherichia coli CsdA and Bacillus subtilis CshA RNA helicases, was only cold-sensitive. Expression of the BC0259 gene at 10 degrees C is reduced in the mutant. Analysis of the 5' untranslated region revealed the transcriptional start and putative cold shock-responsive elements. The role of this RNA helicase in the cold-adaptive response of B. cereus is discussed.

  20. Eco-genetic structure of Bacillus cereus sensu lato populations from different environments in northeastern Poland.

    Science.gov (United States)

    Drewnowska, Justyna M; Swiecicka, Izabela

    2013-01-01

    The Bacillus cereus group, which includes entomopathogens and etiologic agents of foodborne illness or anthrax, persists in various environments. The basis of their ecological diversification remains largely undescribed. Here we present the genetic structure and phylogeny of 273 soil B. cereus s.l. isolates from diverse habitats in northeastern Poland, with samplings acquired from the last European natural forest (Białowieża National Park), the largest marshes in Europe (Biebrza National Park), and a farm. In multi-locus sequence typing (MLST), despite negative selection in seven housekeeping loci, the isolates exhibited high genetic diversity (325 alleles), mostly resulting from mutation events, and represented 148 sequencing types (131 STs new and 17 STs already described) grouped into 19 complexes corresponding with bacterial clones, and 80 singletons. Phylogenetic analyses showed that 74% of the isolates clustered with B. cereus s.l. environmental references (clade III), while only 11 and 15%, respectively, grouped with isolates of clinical origin (clade I), and B. cereus ATCC 14579 and reference B. thuringiensis (clade II). Predominantly within clade III, we found lineages adapted to low temperature (thermal ecotypes), while putative toxigenic isolates (cytK-positive) were scattered in all clades of the marsh and farm samplings. The occurrence of 92% of STs in bacilli originating from one habitat, and the description of new STs for 78% of the isolates, strongly indicate the existence of specific genotypes within the natural B. cereus s.l. populations. In contrast to the human-associated B. cereus s.l. that exhibit a significant level of similarity, the environmental isolates appear more complex. Thus we propose dividing B. cereus s.l. into two groups, the first including environmental isolates, and the second covering those that are of clinical relevance.

  1. Eco-genetic structure of Bacillus cereus sensu lato populations from different environments in northeastern Poland.

    Directory of Open Access Journals (Sweden)

    Justyna M Drewnowska

    Full Text Available The Bacillus cereus group, which includes entomopathogens and etiologic agents of foodborne illness or anthrax, persists in various environments. The basis of their ecological diversification remains largely undescribed. Here we present the genetic structure and phylogeny of 273 soil B. cereus s.l. isolates from diverse habitats in northeastern Poland, with samplings acquired from the last European natural forest (Białowieża National Park, the largest marshes in Europe (Biebrza National Park, and a farm. In multi-locus sequence typing (MLST, despite negative selection in seven housekeeping loci, the isolates exhibited high genetic diversity (325 alleles, mostly resulting from mutation events, and represented 148 sequencing types (131 STs new and 17 STs already described grouped into 19 complexes corresponding with bacterial clones, and 80 singletons. Phylogenetic analyses showed that 74% of the isolates clustered with B. cereus s.l. environmental references (clade III, while only 11 and 15%, respectively, grouped with isolates of clinical origin (clade I, and B. cereus ATCC 14579 and reference B. thuringiensis (clade II. Predominantly within clade III, we found lineages adapted to low temperature (thermal ecotypes, while putative toxigenic isolates (cytK-positive were scattered in all clades of the marsh and farm samplings. The occurrence of 92% of STs in bacilli originating from one habitat, and the description of new STs for 78% of the isolates, strongly indicate the existence of specific genotypes within the natural B. cereus s.l. populations. In contrast to the human-associated B. cereus s.l. that exhibit a significant level of similarity, the environmental isolates appear more complex. Thus we propose dividing B. cereus s.l. into two groups, the first including environmental isolates, and the second covering those that are of clinical relevance.

  2. Prevalence, PFGE typing, and antibiotic resistance of Bacillus cereus group isolated from food in Morocco.

    Science.gov (United States)

    Merzougui, Souad; Lkhider, Mustapha; Grosset, Noel; Gautier, Michel; Cohen, Nozha

    2014-02-01

    This article reports the prevalence and antibiotic resistance of the Bacillus cereus group isolated from different foods (milk and dairy products, spices, and rice salad) in Morocco. In total, 402 different food samples collected from 2008 to 2010 were analyzed by microbiological methods to isolate B. cereus. The strains were subjected to a polymerase chain reaction test in order to verify whether they belonged to the B. cereus group. Sixty-four of all isolates (15.9%) were found to be positive. Among the sources, B. cereus strains from milk and dairy products constituted the largest proportion of isolates (33/64; 51.6%) followed by spices (22/64; 34.4%) and salad with rice (9/64; 14.1%). The genetic diversity of the strains of B. cereus group was examined by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI. The enzyme restriction profiles showed a high degree of polymorphism among the strains. The results showed that PFGE analysis could reveal the genetic differences among B. cereus strains. Investigation of antibiotic-resistance profiles showed that isolates were resistant to ampicillin (98.4%), tetracycline (90.6%), oxacillin (100%), cefepime (100%), and penicillin (100%), and were susceptible to chloramphenicol (67.2%), erythromycin (84.4%), and gentamicin (100%). The results of this study indicated that B. cereus could be a significant etiological agent of food poisoning in Morocco because of its high prevalence. Also, we demonstrated that the majority of strains came from milk and dairy products. However, additional research involving cytotoxicity tests is needed to more evaluate this sanitary risk.

  3. Detection of toxin genes and RAPD analysis of bacillus cereus isolates from different soil types

    Directory of Open Access Journals (Sweden)

    Savic Dejana

    2015-01-01

    Full Text Available The aim of this study was to detect genes for enterotoxins (hbla, entFM and bceT and for emetic toxin (cer, to determine antibiotic resistance, and to estimate intraspecies diversity in B. cereus isolates by RAPD analysis. B. cereus was identified in 12 out of 117 indigenous Bacillus spp. using the classical microbiological methods and PCR. All isolates were resistant to penicillin and ampicillin, two to tetracyclin and four to trimethoprim-sulphamethoxazole. Also, all isolates produced inducible penicillinases and β-lactamase. Toxin genes were detected with PCR. EntFM and cer genes were present in all isolates, hbla in all, but two, and bceT in none. RAPD analysis was performed with four different primers, two of them designed for this study. The intraspecies diversity revealed 10 different patterns at the 90% similarity level. Two separate clusters were formed regardless of a soil type or utilization. The detection of genes encoding toxins in all B. cereus isolates indicated these bacteria as potentially pathogenic and seriously for human health. Regardless of a soil type or utilization, the RAPD analysis showed high intraspecies heterogeneity in B. cereus isolates. To the best of our knowledge, this is the first study to analyse the presence of entero- and emetic toxin genes and genetic heterogeneity in B. cereus isolates from different soil types and different soil utilization in Serbia. [Projekat Ministarstva nauke Republike Srbije, br. TR37006

  4. Simultaneous removal of chlorothalonil and nitrate by Bacillus cereus strain NS1

    International Nuclear Information System (INIS)

    Zhang Yiqiang; Lu Jianhang; Wu Laosheng; Chang, Andrew; Frankenberger, William T.

    2007-01-01

    Elevated NO 3 - and chlorothalonil (CTN) have been found in production nursery recycling ponds. Bacillus cereus strain NS1 isolated from nursery recycling pond sediment was assessed for its ability to reduce NO 3 - and degrade CTN in a mineral medium. The results showed that the efficiency of NO 3 - reduction and CTN degradation by B. cereus strain NS1 were related to the nature of organic carbon sources added to the medium. In the medium amended with 100 mg/L yeast extract, 86% of NO 3 - (100 mg/L) and 99% of CTN (78 μg/L) were simultaneously removed by B. cereus strain NS1 during the first day of the experiment. It took 6 days for the removal of 82-93% of NO 3 - and 87-91% of CTN in the media containing glucose and acetate. B. cereus strain NS1 needed organic carbon as energy sources and electron donors to respire NO 3 - , and simultaneously degrade CTN. These results suggest that B. cereus strain NS1 may have great potential to remediate NO 3 - and CTN contaminated water in nursery recycling ponds

  5. Proteome data to explore the impact of pBClin15 on Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Madeira, Jean-Paul; Alpha-Bazin, Béatrice; Armengaud, Jean; Omer, Hélène; Duport, Catherine

    2016-09-01

    This data article reports changes in the cellular and exoproteome of B. cereus cured from pBClin15.Time-course changes of proteins were assessed by high-throughput nanoLC-MS/MS. We report all the peptides and proteins identified and quantified in B. cereus with and without pBClin15. Proteins were classified into functional groups using the information available in the KEGG classification and we reported their abundance in term of normalized spectral abundance factor. The repertoire of experimentally confirmed proteins of B. cereus presented here is the largest ever reported, and provides new insights into the interplay between pBClin15 and its host B. cereus ATCC 14579. The data reported here is related to a published shotgun proteomics analysis regarding the role of pBClin15, "Deciphering the interactions between the Bacillus cereus linear plasmid, pBClin15, and its host by high-throughput comparative proteomics" Madeira et al. [1]. All the associated mass spectrometry data have been deposited in the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository (http://www.ebi.ac.uk/pride/), with the dataset identifier PRIDE: PXD001568, PRIDE: PXD002788 and PRIDE: PXD002789.

  6. Air-liquid interface biofilms of Bacillus cereus: formation, sporulation, and dispersion.

    Science.gov (United States)

    Wijman, Janneke G E; de Leeuw, Patrick P L A; Moezelaar, Roy; Zwietering, Marcel H; Abee, Tjakko

    2007-03-01

    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.

  7. Proteome data to explore the impact of pBClin15 on Bacillus cereus ATCC 14579

    Directory of Open Access Journals (Sweden)

    Jean-Paul Madeira

    2016-09-01

    Full Text Available This data article reports changes in the cellular and exoproteome of B. cereus cured from pBClin15.Time-course changes of proteins were assessed by high-throughput nanoLC-MS/MS. We report all the peptides and proteins identified and quantified in B. cereus with and without pBClin15. Proteins were classified into functional groups using the information available in the KEGG classification and we reported their abundance in term of normalized spectral abundance factor. The repertoire of experimentally confirmed proteins of B. cereus presented here is the largest ever reported, and provides new insights into the interplay between pBClin15 and its host B. cereus ATCC 14579. The data reported here is related to a published shotgun proteomics analysis regarding the role of pBClin15, “Deciphering the interactions between the Bacillus cereus linear plasmid, pBClin15, and its host by high-throughput comparative proteomics” Madeira et al. [1]. All the associated mass spectrometry data have been deposited in the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org via the PRIDE partner repository (http://www.ebi.ac.uk/pride/, with the dataset identifier PRIDE: PXD001568, PRIDE: PXD002788 and PRIDE: PXD002789.

  8. Infective endocarditis due to Bacillus cereus in a pregnant female: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Mahek Shah

    2015-01-01

    Full Text Available Incidence of infective endocarditis during pregnancy is around 0.006% with high maternal and fetal mortality. Bacillus cereus is an extremely rare cause for endocarditis in intravenous drug abusers (IVDA or those with valvular disease or devices such as pacemakers. We report a case of B. cereus endocarditis, which, to the best of our knowledge, has never been reported in pregnancy. A 30-year-old, 25-week pregnant female presented with right shoulder pain, swelling and erythema on the lateral aspect of deltoid muscle from large abscess over her deltoid muscle. She was found to have a vegetation on the native tricuspid valve. Cultures from abscess fluid and blood cultures grew B. cereus, she was appropriately treated with antimicrobials and had favorable outcomes. There are <20 cases of B. cereus endocarditis reported but none during pregnancy. When cultures grow unusual organisms the case must be thoroughly investigated. This case illustrates a rare situation (endocarditis in pregnancy with an unusual outcome (B. cereus on an uncommon valve (tricuspid valve.

  9. Isolation, Identification, Prevalence, and Genetic Diversity of Bacillus cereus Group Bacteria From Different Foodstuffs in Tunisia.

    Science.gov (United States)

    Gdoura-Ben Amor, Maroua; Siala, Mariam; Zayani, Mariem; Grosset, Noël; Smaoui, Salma; Messadi-Akrout, Feriele; Baron, Florence; Jan, Sophie; Gautier, Michel; Gdoura, Radhouane

    2018-01-01

    Bacillus cereus group is widespread in nature and foods. Several members of this group are recognized as causing food spoilage and/or health issues. This study was designed to determine the prevalence and genetic diversity of the B. cereus group strains isolated in Tunisia from different foods (cereals, spices, cooked food, fresh-cut vegetables, raw and cooked poultry meats, seafood, canned, pastry, and dairy products). In total, 687 different samples were collected and searched for the presence of the B. cereus group after selective plating on MYP agar and enumeration of each sample. The typical pink-orange uniform colonies surrounded by a zone of precipitate were assumed to belong to the B. cereus group. One typical colony from each sample was subcultured and preserved as cryoculture. Overall, 191 (27.8%) food samples were found positive, giving rise to a collection of 191 B. cereus -like isolates. The concentration of B. cereus -like bacteria were below 10 3 cfu/g or ml in 77.5% of the tested samples. Higher counts (>10 4 cfu/g or ml) were found in 6.8% of samples including fresh-cut vegetables, cooked foods, cereals, and pastry products. To verify whether B. cereus -like isolates belonged to the B. cereus group, a PCR test targeting the sspE gene sequence specific of the group was carried out. Therefore, 174 isolates were found to be positive. Food samples were contaminated as follows: cereals (67.6%), pastry products (46.2%), cooked food (40.8%), cooked poultry meat (32.7%), seafood products (32.3%), spices (28.8%), canned products (16.7%), raw poultry meat (9.4%), fresh-cut vegetables (5.0%), and dairy products (4.8%). The 174 B. cereus isolates were characterized by partial sequencing of the panC gene, using a Sym'Previous software tool to assign them to different phylogenetic groups. Strains were distributed as follows: 61.3, 29.5, 7.5, and 1.7% in the group III, IV, II, and V, respectively. The genetic diversity was further assessed by ERIC-PCR and PFGE

  10. Isolation, Identification, Prevalence, and Genetic Diversity of Bacillus cereus Group Bacteria From Different Foodstuffs in Tunisia

    Directory of Open Access Journals (Sweden)

    Maroua Gdoura-Ben Amor

    2018-03-01

    Full Text Available Bacillus cereus group is widespread in nature and foods. Several members of this group are recognized as causing food spoilage and/or health issues. This study was designed to determine the prevalence and genetic diversity of the B. cereus group strains isolated in Tunisia from different foods (cereals, spices, cooked food, fresh-cut vegetables, raw and cooked poultry meats, seafood, canned, pastry, and dairy products. In total, 687 different samples were collected and searched for the presence of the B. cereus group after selective plating on MYP agar and enumeration of each sample. The typical pink-orange uniform colonies surrounded by a zone of precipitate were assumed to belong to the B. cereus group. One typical colony from each sample was subcultured and preserved as cryoculture. Overall, 191 (27.8% food samples were found positive, giving rise to a collection of 191 B. cereus-like isolates. The concentration of B. cereus-like bacteria were below 103 cfu/g or ml in 77.5% of the tested samples. Higher counts (>104 cfu/g or ml were found in 6.8% of samples including fresh-cut vegetables, cooked foods, cereals, and pastry products. To verify whether B. cereus-like isolates belonged to the B. cereus group, a PCR test targeting the sspE gene sequence specific of the group was carried out. Therefore, 174 isolates were found to be positive. Food samples were contaminated as follows: cereals (67.6%, pastry products (46.2%, cooked food (40.8%, cooked poultry meat (32.7%, seafood products (32.3%, spices (28.8%, canned products (16.7%, raw poultry meat (9.4%, fresh-cut vegetables (5.0%, and dairy products (4.8%. The 174 B. cereus isolates were characterized by partial sequencing of the panC gene, using a Sym'Previous software tool to assign them to different phylogenetic groups. Strains were distributed as follows: 61.3, 29.5, 7.5, and 1.7% in the group III, IV, II, and V, respectively. The genetic diversity was further assessed by ERIC-PCR and PFGE

  11. Bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting with Bacillus cereus HDYM-02

    OpenAIRE

    Dan Zhao; Pengfei Liu; Chao Pan; Renpeng Du; Wenxiang Ping; Jingping Ge

    2016-01-01

    High-throughput sequencing and GC-MS (gas chromatography-mass spectrometry) were jointly used to reveal the bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting. The inoculation of Bacillus cereus HDYM-02 decreased bacterial richness and diversity. This inoculum led to the replacement of Enterobacteriaceae by Bacillaceae. The level of aerobic Pseudomonadaceae (mainly Azotobacter) and anaerobic Clostridiaceae_1 gradually increased and decreased, respectively...

  12. Comparative Transcriptomic and Phenotypic Analysis of the Responses of Bacillus cereus to Various Disinfectant Treatments▿ †

    OpenAIRE

    Ceragioli, Mara; Mols, Maarten; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko

    2010-01-01

    Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growt...

  13. Comparative transcriptomic and phenotypic analysis of the responses of Bacillus cereus to various disinfectant treatments

    OpenAIRE

    Ceragioli, M.; Mols, J.M.; Moezelaar, R.; Ghelardi, E.; Senesi, S.; Abee, T.

    2010-01-01

    Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growt...

  14. Isolation of protease producing novel Bacillus cereus and detection ...

    African Journals Online (AJOL)

    user

    2011-02-14

    1991). Industrial enzymes-developments in production and application, Biotechnol. Adv. 9: 643-658. Ferrero MA, Castro GR, Abate CM, Baigori MD, Sineriz F (1996). Thermostable alkaline proteases of Bacillus licheniformis MIR ...

  15. Diagnostic properties of three conventional selective plating media for selection of Bacillus cereus, B. thuringiensis and B. weihenstephanensis

    DEFF Research Database (Denmark)

    Hendriksen, Niels Bohse; Hansen, Bjarne Munk

    2011-01-01

    The aim of this study was to assess the diagnostic properties of the two selective plating media and a chromogenic medium for identification of Bacillus cereus. The 324 isolates were B. cereus (37%), Bacillus weihenstephanensis (45%) or Bacillus thuringiensis (18%), as identified by a new...... combination of techniques. All isolates were growing on mannitol–egg yolk–polymyxin agar (MYP), and they did not form acid from mannitol. However, a significant lower number of B. thuringiensis isolates did not show lecithinase activity. All isolates were also growing on polymyxin–egg yolk...... recommended selective plating media MYP and PEMBA for detection of B. cereus group bacteria both have their limitations for identification of some B. cereus, B. weihenstephanensis or B. thuringiensis. However, MYP is preferable compared to PEMBA. The chromogenic medium has its own advantages and limitations...

  16. Continuous Cultivation for Apparent Optimization of Defined Media for Cellulomonas sp. and Bacillus cereus

    Science.gov (United States)

    Summers, R. J.; Boudreaux, D. P.; Srinivasan, V. R.

    1979-01-01

    Steady-state continuous culture was used to optimize lean chemically defined media for a Cellulomonas sp. and Bacillus cereus strain T. Both organisms were extremely sensitive to variations in trace-metal concentrations. However, medium optimization by this technique proved rapid, and multifactor screening was easily conducted by using a minimum of instrumentation. The optimized media supported critical dilution rates of 0.571 and 0.467 h−1 for Cellulomonas and Bacillus, respectively. These values approximated maximum growth rate values observed in batch culture. PMID:16345417

  17. Enterotoxigenic gene profiles of Bacillus cereus and Bacillus megaterium isolates recovered from honey Búsqueda de factores de virulencia en cepas de Bacillus cereus y de Bacillus megaterium aisladas de miel

    Directory of Open Access Journals (Sweden)

    A. C. López

    2010-09-01

    Full Text Available One hundred and thirty two Bacillus cereus and 52 Bacillus megaterium isolates from honeys were evaluated for the presence of genes encoding enterotoxin HBL, enterotoxin-T, cytotoxin K and the NHE complex, respectively. The relationship between hemolytic and coagulase activity and its correlation with the presence of the four mentioned enterotoxins was determined by principal component analysis (PCA. PCA in B. cereus revealed a positive correlation among free coagulase, hemolysis and the presence of genes hblA, hblB, hblC, hblD (HBL complex and bceT (enterotoxin-T, but no correlation with the clumping factor (bound coagulase and the presence of sequences of the NHE complex. On the other hand, PCA in B. megaterium showed a high positive correlation between coagulase (bound and free and the haemolytic activity but no correlation in relation to the presence of genes of the HBL complex, cytotoxin K, enterotoxin T and the NHE complex. To our knowledge, this is the first report of the detection of cytotoxin K and of the NHE complex genes in B. megaterium. The relationship between the coagulase activity and the presence of virulence factors has not been described before in the genus Bacillus, being this work the first report of this correlation. Interestingly, the presence of the cytK gene was almost independent of the presence of the rest of virulence factors herein analyzed both in B. cereus and B. megaterium populations. Our results suggest that honey could be a possible vehicle for foodborne illness due to the presence of toxigenic B. cereus and B. megaterium strains containing different virulence factors.Se evaluaron 132 aislamientos de Bacillus cereus y 52 de Bacillus megaterium provenientes de mieles de distintos orígenes geográficos para investigar la presencia de secuencias de ADN relacionadas con genes de virulencia y su posible correlación con la actividad hemolítica y coagulasa. Con respecto a los genes de virulencia, se analizaron por

  18. ENUMERATION OF Bacillus cereus IN “FUBÁ” OF CORN (Zea mays. L. ENUMERAÇÃO DE Bacillus cereus EM FUBÁ DE MILHO (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Albenones José de Mesquita

    2007-09-01

    Full Text Available

    A hundred (100 samples of “fubá” were examined, in relation to the incidence of Bacillus cereus, obtained by different technological processes (common “fubá” and previously cooked “fubá” and sold in the retail market in Goiânia - GO. The results of the examination showed that 23% of the samples was contaminated, of this percentual, 39.1% of the contaminations occurred in samples of previously cooked “fubá” and 60.9% in samples of common “fubá”. This in relation of the two products clearly showed the more accurate technological process that the previously cooked “fubá” was brought under. It was also observed that the totality of the analyzed samples showed enumerations below the limit established by the Brazilian microbiologic standard that establishes a limit of 10³ cells of Bacillus cereus for a gram of the food.

    Foram examinadas 100 amostras de fubá de milho, em relação à incidência de Bacillus cereus, obtidas através de processamentos tecnológicos diferentes (fubá comum e fubá pré-cozido e comercializadas no mercado varejista de Goiânia - GO. Os resultados revelaram que 23% das amostras estavam contaminadas, deste percentual, 39,1% das contaminações ocorreram em amostras de fubá pré-cozido e 60,9%, em amostras de fubá comum. Esta considerável diferença, observada em termos percentuais em relação aos dois produtos evidenciou o processamento tecnológico mais rigoroso a que foi submetido o fubá pré-cozido. Observou-se, também, que a totalidade das amostras analisadas apresentou enumerações abaixo do limite estabelecido pelo padrão microbiológico brasileiro que determina um limite de 10³ células de B. cereus por gama do alimento.

  19. Extending the Bacillus cereus group genomics to putative food-borne pathogens of different toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Goltsman, Eugene [U.S. Department of Energy, Joint Genome Institute; Auger, Sandrine [Genetique Microbienne; Galleron, Nathalie [Genetique Microbienne; Segurens, Beatrice [Center National Sequencage, F-91057 Evry, France; Simon, Jorg [Johann Wolfgang Goethe University, Frankfurt am Main, Germany; Dossat, Carole [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Land, Miriam L [ORNL; Broussolle, Veronique [Securite et Qualite des Produits d' Origine Vegetale; Brillard, Julien [Securite et Qualite des Produits d' Origine Vegetale; Guinebretiere, Marie-Helene [Securite et Qualite des Produits d' Origine Vegetale; Sanchis, Vincent [Genetique Microbienne; Nguen-the, Christophe [Securite et Qualite des Produits d' Origine Vegetale; Lereclus, Didier [Genetique Microbienne; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Wincker, Patrick [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Weissenbach, Jean [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Ehrlich, Dusko [Genetique Microbienne; Sorokin, Alexei [Genetique Microbienne

    2008-01-01

    The Bacillus cereus group represents sporulating soil bacteria containing pathogenic strains which may cause diarrheic or emetic food poisoning outbreaks. Multiple locus sequence typing revealed a presence in natural samples of these bacteria of about 30 clonal complexes. Application of genomic methods to this group was however biased due to the major interest for representatives closely related to Bacillus anthracis. Albeit the most important food-borne pathogens were not yet defined, existing data indicate that they are scattered all over the phylogenetic tree. The preliminary analysis of the sequences of three genomes discussed in this paper narrows down the gaps in our knowledge of the B. cereus group. The strain NVH391-98 is a rare but particularly severe food-borne pathogen. Sequencing revealed that the strain should be a representative of a novel bacterial species, for which the name Bacillus cytotoxis or Bacillus cytotoxicus is proposed. This strain has a reduced genome size compared to other B. cereus group strains. Genome analysis revealed absence of sigma B factor and the presence of genes encoding diarrheic Nhe toxin, not detected earlier. The strain B. cereus F837/76 represents a clonal complex close to that of B. anthracis. Including F837/76, three such B. cereus strains had been sequenced. Alignment of genomes suggests that B. anthracis is their common ancestor. Since such strains often emerge from clinical cases, they merit a special attention. The third strain, KBAB4, is a typical facultative psychrophile generally found in soil. Phylogenic studies show that in nature it is the most active group in terms of gene exchange. Genomic sequence revealed high presence of extra-chromosomal genetic material (about 530 kb) that may account for this phenomenon. Genes coding Nhe-like toxin were found on a big plasmid in this strain. This may indicate a potential mechanism of toxicity spread from the psychrophile strain community. The results of this genomic

  20. Small Bacillus cereus ATCC 14579 subpopulations are responsible for cytotoxin K production.

    Science.gov (United States)

    Ceuppens, S; Timmery, S; Mahillon, J; Uyttendaele, M; Boon, N

    2013-03-01

    Bacillus cereus diarrhoeal food poisoning can be caused by several potential enterotoxins, including the nonhaemolytic enterotoxin (Nhe), haemolysin BL (Hbl) and cytotoxin K (CytK). To get more insights into the CytK expression, a fluorescent reporter strain was created for CytK expression. Bacillus cereus ATCC 14579 was used as the reporter strain that contained the cyan fluorescent protein (CFPopt) gene under control of the cytK promoter. Transcription of enterotoxin genes nheB, hblC and cytK was assessed by messenger RNA analysis (RT-qPCR), and their full expression was assessed by immunological protein detection in the case of Nhe and Hbl and fluorescence microscopy in the case of CytK, using the reporter gene CFPopt. Transcription of enterotoxins Nhe, Hbl and CytK showed similar kinetics with a peak during the late exponential growth phase. Toxin expression of the reporter strain was unaltered in comparison with the wild type. However, fluorescence, and thus CytK expression, only occurred in a small (1-2%) portion of the cell population. These results suggest that a small subpopulation of B. cereus ATCC 14579 is responsible for CytK production in a homogeneous monoculture. Future research is warranted to determine whether genetically homogeneous B. cereus populations utilize differential gene expression for other toxins and virulence genes than CytK and whether this also applies to other B. cereus strains. If so, differential expression of toxin genes could be used by these bacteria to increase the fitness and survival chances of their population by diversification and specialization into different subpopulations. © 2012 Ghent University © 2012 The Society for Applied Microbiology.

  1. Enterotoxins and emetic toxins production by Bacillus cereus and other species of Bacillus isolated from Soumbala and Bikalga, African alkaline fermentedfood condiments

    DEFF Research Database (Denmark)

    Ouoba, Labia Irene I.; Thorsen, Line; Varnam, Alan H.

    2008-01-01

    -hemolytic enterotoxin (NheA, NheB, NheC) and EM1 specific of emetic toxin producerswas also investigated using PCR with single pair and multiplex primers. Of 41 isolates, 29 Bacillus belonging to the species of B. cereus, Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus showed haemolysis on blood agar......The ability of various species of Bacillus from fermented seeds of Parkia biglobosa known as African locust bean(Soumbala) and fermented seeds of Hibiscus sabdariffa (Bikalga) was investigated. The study included screening of the isolates by haemolysis on blood agar, detection of toxins in broth...... and during the fermentation of African locust bean using the Bacillus cereus Enterotoxin Reverse Passive Latex Agglutination test kit (BCETRPLA) and the Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (BDEVIA). Detection of genes encoding´cytotoxin K (CytK), haemolysin BL (Hbl A, Hbl C, Hbl D), non...

  2. A genomic region involved in the formation of adhesin fibers in Bacillus cereus biofilms

    Directory of Open Access Journals (Sweden)

    Joaquín eCaro-Astorga

    2015-01-01

    Full Text Available Bacillus cereus is a bacterial pathogen that is responsible for many recurrent disease outbreaks due to food contamination. Spores and biofilms are considered the most important reservoirs of B. cereus in contaminated fresh vegetables and fruits. Biofilms are bacterial communities that are difficult to eradicate from biotic and abiotic surfaces because of their stable and extremely strong extracellular matrix. These extracellular matrixes contain exopolysaccharides, proteins, extracellular DNA, and other minor components. Although B. cereus can form biofilms, the bacterial features governing assembly of the protective extracellular matrix are not known. Using the well-studied bacterium B. subtilis as a model, we identified two genomic loci in B. cereus, which encodes two orthologs of the amyloid-like protein TasA of B. subtilis and a SipW signal peptidase. Deletion of this genomic region in B. cereus inhibited biofilm assembly; notably, mutation of the putative signal peptidase SipW caused the same phenotype. However, mutations in tasA or calY did not completely prevent biofilm formation; strains that were mutated for either of these genes formed phenotypically different surface attached biofilms. Electron microscopy studies revealed that TasA polymerizes to form long and abundant fibers on cell surfaces, whereas CalY does not aggregate similarly. Heterologous expression of this amyloid-like cassette in a B. subtilis strain lacking the factors required for the assembly of TasA amyloid-like fibers revealed i the involvement of this B. cereus genomic region in formation of the air-liquid interphase pellicles and ii the intrinsic ability of TasA to form fibers similar to the amyloid-like fibers produced by its B. subtilis ortholog.

  3. Unusual group II introns in bacteria of the Bacillus cereus group.

    Science.gov (United States)

    Tourasse, Nicolas J; Stabell, Fredrik B; Reiter, Lillian; Kolstø, Anne-Brit

    2005-08-01

    A combination of sequence and structure analysis and reverse transcriptase PCR experiments was used to characterize the group II introns in the complete genomes of two strains of the pathogen Bacillus cereus. While B. cereus ATCC 14579 harbors a single intron element in the chromosome, B. cereus ATCC 10987 contains three introns in the chromosome and four in its 208-kb pBc10987 plasmid. The most striking finding is the presence in B. cereus ATCC 10987 of an intron [B.c.I2(a)] located on the reverse strand of a gene encoding a putative cell surface protein which appears to be correlated to strains of clinical origin. Because of the opposite orientation of B.c.I2(a), the gene is disrupted. Even more striking is that B.c.I2(a) splices out of an RNA transcript corresponding to the opposite DNA strand. All other intragenic introns studied here are inserted in the same orientation as their host genes and splice out of the mRNA in vivo, setting the flanking exons in frame. Noticeably, B.c.I3 in B. cereus ATCC 10987 represents the first example of a group II intron entirely included within a conserved replication gene, namely, the alpha subunit of DNA polymerase III. Another striking finding is that the observed 3' splice site of B.c.I4 occurs 56 bp after the predicted end of the intron. This apparently unusual splicing mechanism may be related to structural irregularities in the 3' terminus. Finally, we also show that the intergenic introns of B. cereus ATCC 10987 are transcribed with their upstream genes and do splice in vivo.

  4. Isolation of protease producing novel Bacillus cereus and detection ...

    African Journals Online (AJOL)

    user

    2011-02-14

    Feb 14, 2011 ... The highest protease activity was determined at 30°C temperature and 6.4 pH conditions and after the 18th hour, it decreased evidently. Key words: Protease, production, optimization, Bacillus sp. INTRODUCTION. Enzymes have been produced in large industrial scale for several decades (Falch, 1991).

  5. Genome Sequencing of Bacillus subtilis SC-8, Antagonistic to the Bacillus cereus Group, Isolated from Traditional Korean Fermented-Soybean Food

    OpenAIRE

    Yeo, In-Cheol; Lee, Nam Keun; Hahm, Young Tae

    2012-01-01

    Bacillus subtilis SC-8 is a Gram-positive bacterium displaying narrow antagonistic activity for the Bacillus cereus group. B. subtilis SC-8 was isolated from Korean traditional fermented-soybean food. Here we report the draft genome sequence of B. subtilis SC-8, including biosynthetic genes for antibiotics that may have beneficial effects for control of food-borne pathogens.

  6. Genome sequencing of Bacillus subtilis SC-8, antagonistic to the Bacillus cereus group, isolated from traditional Korean fermented-soybean food.

    Science.gov (United States)

    Yeo, In-Cheol; Lee, Nam Keun; Hahm, Young Tae

    2012-01-01

    Bacillus subtilis SC-8 is a Gram-positive bacterium displaying narrow antagonistic activity for the Bacillus cereus group. B. subtilis SC-8 was isolated from Korean traditional fermented-soybean food. Here we report the draft genome sequence of B. subtilis SC-8, including biosynthetic genes for antibiotics that may have beneficial effects for control of food-borne pathogens.

  7. Plant Compounds Enhance the Assay Sensitivity for Detection of Active Bacillus cereus Toxin

    Directory of Open Access Journals (Sweden)

    Reuven Rasooly

    2015-03-01

    Full Text Available Bacillus cereus is an important food pathogen, producing emetic and diarrheal syndromes, the latter mediated by enterotoxins. The ability to sensitively trace and identify this active toxin is important for food safety. This study evaluated a nonradioactive, sensitive, in vitro cell-based assay, based on B. cereus toxin inhibition of green fluorescent protein (GFP synthesis in transduced monkey kidney Vero cells, combined with plant extracts or plant compounds that reduce viable count of B. cereus in food. The assay exhibited a dose dependent GFP inhibition response with ~25% inhibition at 50 ng/mL toxin evaluated in culture media or soy milk, rice milk or infant formula, products associated with food poisonings outbreak. The plant extracts of green tea or bitter almond and the plant compounds epicatechin or carvacrol were found to amplify the assay response to ~90% inhibition at the 50 ng/mL toxin concentration greatly increasing the sensitivity of this assay. Additional studies showed that the test formulations also inhibited the growth of the B. cereus bacteria, likely through cell membrane disruption. The results suggest that the improved highly sensitive assay for the toxin and the rapid inactivation of the pathogen producing the toxin have the potential to enhance food safety.

  8. Lessons learnt from a birthday party: a Bacillus cereus outbreak, Bari, Italy, January 2012

    Directory of Open Access Journals (Sweden)

    Domenico Martinelli

    2013-12-01

    Full Text Available INTRODUCTION: Bacillus cereus, a ubiquitous bacterium, can be isolated in various starchy food items, causing both emetic and diarrhoeal disease. The real burden of B. cereus outbreaks is actually poorly known in Italy. We report a B. cereus foodborne outbreak that occurred in a pub in Bari (Italy on January 22nd 2012 during a birthday party, promptly reported by the pub owner. MATERIALS AND METHODS: Between January 22nd and 24th 2012, we performed a retrospective cohort study among the guests of the party to identify risk factors associated with illness. Leftovers of different meals were available for microbiological analysis. Faecal specimens were collected from cases. RESULTS: A total of 12 cases among the 13 customers (attack rate: 92% were reported. All cases had consumed basmati rice and sweet and sour vegetables (aetiological fraction: 100%. B. cereus was isolated from both basmati rice served during the party and faecal specimens. DISCUSSION: The close collaboration between the pub owner and the public health officers and the possibility to test food leftovers and stool samples contributed to prevent further cases.

  9. Partial Characterisation of Bacteriocins Produced by Bacillus cereus Isolates from Milk and Milk Products

    Directory of Open Access Journals (Sweden)

    Bojana Bogović Matijašić

    2003-01-01

    Full Text Available Thirty one (19.2 % out of 161 Bacillus cereus isolates from raw milk and milk products were found to produce proteinaceous substances which inhibit the growth of other B. cereus isolates. The detection of antibacterial activity depended on medium and method used. Bactericidal activity was detected in 23 (14 % or 19 (12 % of the tested strains on the triptic soya agar and brain-heart infusion with glucose, respectively, while 11 (7 % of the strains produced bactericidal substances on both media. Nineteen percent of isolates from raw milk and 20 % of isolates from milk products were found to produce bacteriocins. Four B. cereus isolates inhibited the growth of individual test strains belonging to B. licheniformis, B. subtilis, Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Lactobacillus helveticus and L. casei species. The bacteriocins of four B. cereus isolates were studied in more detail. The production and activity of these substances were detected in stationary- phase of bacterial culture. Two of them were stable after heating at 60 °C, while only one was stable after heating at 75 °C for 15 minutes. All of them were active over a range of pH=3–10. The apparent molecular weights of four bacteriocins detected by SDS-PAGE electrophoresis were in the range of 1 to 8 kDa.

  10. Soya bean tempe extracts show antibacterial activity against Bacillus cereus cells and spores.

    Science.gov (United States)

    Roubos-van den Hil, P J; Dalmas, E; Nout, M J R; Abee, T

    2010-07-01

    Tempe, a Rhizopus ssp.-fermented soya bean food product, was investigated for bacteriostatic and/or bactericidal effects against cells and spores of the food-borne pathogen Bacillus cereus. Tempe extract showed a high antibacterial activity against B. cereus ATCC 14579 based on optical density and viable count measurements. This growth inhibition was manifested by a 4 log CFU ml(-1) reduction, within the first 15 min of exposure. Tempe extracts also rapidly inactivated B. cereus spores upon germination. Viability and membrane permeability assessments using fluorescence probes showed rapid inactivation and permeabilization of the cytoplasmic membrane confirming the bactericidal mode of action. Cooked beans and Rhizopus grown on different media did not show antibacterial activity, indicating the unique association of the antibacterial activity with tempe. Subsequent characterization of the antibacterial activity revealed that heat treatment and protease addition nullified the bactericidal effect, indicating the proteinaceous nature of the bioactive compound. During fermentation of soya beans with Rhizopus, compounds are released with extensive antibacterial activity against B. cereus cells and spores. The results show the potential of producing natural antibacterial compounds that could be used as ingredients in food preservation and pathogen control. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.

  11. Characterization of a spore-specific protein of the Bacillus cereus group.

    Science.gov (United States)

    From, Cecilie; van der Voort, Menno; Abee, Tjakko; Granum, Per Einar

    2012-06-01

    Bc1245 is a monocistronic chromosomal gene of Bacillus cereus ATCC 14579 encoding a putative protein of 143 amino acids identified in this study to have a spore-related function in B. cereus. Bc1245 is highly conserved in the genome of members of the B. cereus group, indicating an important function of the gene in this group of bacteria. Quantitative PCR revealed that bc1245 is transcribed late in sporulation (upon formation of phase-bright spores) and at the same time as the mother cell-specific transcription factor σ(K) . The σ(K) regulon includes structural components of the spore (such as coat proteins), and it is therefore plausible that bc1245 might encode a structural outer spore protein. This was confirmed by detection of BC1245 in exosporium extracts from B. cereus by immunoblotting against BC1245 antiserum. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  12. Metabolic capacity of Bacillus cereus strains ATCC 14579 and ATCC 10987 interlinked with comparative genomics.

    Science.gov (United States)

    Mols, Maarten; de Been, Mark; Zwietering, Marcel H; Moezelaar, Roy; Abee, Tjakko

    2007-12-01

    Bacillus cereus is an important food-borne pathogen and spoilage organism. In this study, numerous phenotypes and the genomes of B. cereus strains ATCC 14579 and ATCC 10987 were analysed to compare their metabolic capacity and stress resistance potential. The growth performance of the two strains was assessed for nearly 2000 phenotypes, including use of nutrient sources, performance in acid and basic environments, osmo-tolerance and antibiotic resistance. Several food-relevant phenotypic differences were found between ATCC 14579 and ATCC 10987, such as differences in utilization of carbohydrates, peptides, amino acids and ammonia. Subsequently, the genomes of both strains were analysed with INPARANOID to search for strain-specific open reading frames (ORFs). B. cereus ATCC 14579 and ATCC 10987 were found to harbour 983 and 1360 strain-specific ORFs respectively. The strain-specific phenotypic features were interlinked with corresponding genetic features and for several phenotypic differences a related strain-specific genetic feature could be identified. In conclusion, the combination of phenotypic data with strain-specific genomic differences has led to detailed insight into the performance of the two B. cereus strains, and may supply indicators for the performance of these bacteria in different environments and ecological niches.

  13. Identification of Bacillus cereus genes specifically expressed during growth at low temperatures.

    Science.gov (United States)

    Brillard, Julien; Jéhanno, Isabelle; Dargaignaratz, Claire; Barbosa, Isabelle; Ginies, Christian; Carlin, Frédéric; Fedhila, Sinda; Nguyen-the, Christophe; Broussolle, Véronique; Sanchis, Vincent

    2010-04-01

    The mechanisms involved in the ability of Bacillus cereus to multiply at low temperatures were investigated. It was assumed that many genes involved in cold acclimation would be upregulated at low temperatures. Recombinase-based in vivo expression technology (IVET) was adapted to the detection of the transient activation of B. cereus promoters during growth at 10 degrees C. Four independent screenings of a promoter library from type strain ATCC 14579 were performed, and 17 clones were isolated. They corresponded to 17 promoter regions that displayed reproducibly elevated expression at 10 degrees C relative to expression at 30 degrees C. This analysis revealed several genes that may be important for B. cereus to grow successfully under the restrictive conditions of cold habitats. Among them, a locus corresponding to open reading frames BC5402 to BC5398, harboring a lipase-encoding gene and a putative transcriptional regulator, was identified three times. While a mutation in the putative regulator-encoding gene did not cause any particular phenotype, a mutant deficient in the lipase-encoding gene showed reduced growth abilities at low temperatures compared with the parental strain. The mutant did not change its fatty acid profiles in the same way as the wild type when grown at 12 degrees C instead of 37 degrees C. This study demonstrates the feasibility of a promoter trap strategy for identifying cold-induced genes. It outlines a first picture of the different processes involved in B. cereus cold acclimation.

  14. Two distinct types of rRNA operons in the Bacillus cereus group.

    Science.gov (United States)

    Candelon, Benjamin; Guilloux, Kévin; Ehrlich, S Dusko; Sorokin, Alexei

    2004-03-01

    The Bacillus cereus group includes insecticidal bacteria (B. thuringiensis), food-borne pathogens (B. cereus and B. weihenstephanensis) and B. anthracis, the causative agent of anthrax. The precise number of rRNA operons in 12 strains of the B. cereus group was determined. Most of the tested strains possess 13 operons and the tested psychrotolerant strains contain 14 operons, the highest number ever found in bacteria. The separate clustering of the tested psychrotolerant strains was confirmed by partial sequencing of several genes distributed over the chromosomes. Analysis of regions downstream of the 23S rRNA genes in the type strain B. cereus ATCC 14579 indicates that the rRNA operons can be divided into two classes, I and II, consisting respectively of eight and five operons. Class II operons exhibit multiple tRNA genes downstream of the 5S rRNA gene and a putative promoter sequence in the 23S-5S intergenic region, suggesting that 5S rRNA and the downstream tRNA genes can be transcribed independently of the 16S and 23S genes. Similar observations were made in the recently sequenced genome of B. anthracis strain Ames. The existence of these distinct types of rRNA operons suggests an unknown mechanism for regulation of rRNA and tRNA synthesis potentially related to the pool of amino acids available for protein synthesis.

  15. Antibacterial Effects of Cissus welwitschii and Triumfetta welwitschii Extracts against Escherichia coli and Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Batanai Moyo

    2015-01-01

    Full Text Available Antibiotic resistance has increased sharply, while the pace for the development of new antimicrobials has slowed down. Plants provide an alternative source for new drugs. This study aimed to screen extracts from Cissus welwitschii and Triumfetta welwitschii for antibacterial activity against Escherichia coli and Bacillus cereus. The tests conducted included a susceptibility determination test, analysis of the effect of T. welwitschii on cell wall integrity, and transport across the membrane. It was found that the T. welwitschii methanol extracts were more effective than the water extracts and had the lowest minimum inhibitory concentration and minimum bactericidal concentration at 0.125 mg/mL and 0.5 mg/mL, respectively, against E. coli and B. cereus. The C. welwitschii extract caused the most drug accumulation in E. coli. In B. cereus, no significant drug accumulation was observed. Nucleic acid leakage in B. cereus and E. coli and protein leakage in E. coli were observed after exposure to the T. welwitschii extract. The extracts from T. welwitschii had greater antibacterial activity than the extracts from C. welwitschii. T. welwitschii may be a potential source of lead compounds for that could be developed into antibacterial agents.

  16. Bacillus cereus and Bacillus thuringiensis spores in Korean rice: prevalence and toxin production as affected by production area and degree of milling.

    Science.gov (United States)

    Kim, Booyoung; Bang, Jihyun; Kim, Hoikyung; Kim, Yoonsook; Kim, Byeong-Sam; Beuchat, Larry R; Ryu, Jee-Hoon

    2014-09-01

    We determined the prevalence of and toxin production by Bacillus cereus and Bacillus thuringiensis in Korean rice as affected by production area and degree of milling. Rough rice was collected from 64 farms in 22 agricultural areas and polished to produce brown and white rice. In total, rice samples were broadly contaminated with B. cereus spores, with no effect of production area. The prevalence and counts of B. cereus spores declined as milling progressed. Frequencies of hemolysin BL (HBL) production by isolates were significantly (P ≤ 0.01) reduced as milling progressed. This pattern corresponded with the presence of genes encoding the diarrheal enterotoxins. The frequency of B. cereus isolates positive for hblC, hblD, or nheB genes decreased as milling progressed. Because most B. cereus isolates from rice samples contained six enterotoxin genes, we concluded that B. cereus in rice produced in Korea is predominantly of the diarrheagenic type. The prevalence of B. thuringiensis in rice was significantly lower than that of B. cereus and not correlated with production area. All B. thuringiensis isolates were of the diarrheagenic type. This study provides information useful for predicting safety risks associated with B. cereus and B. thuringiensis in rough and processed Korean rice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Detection and Characterization of β-Lactam Resistance in Bacillus cereus PTCC 1015

    Directory of Open Access Journals (Sweden)

    Javad Behravan

    2004-01-01

    Full Text Available In the present study, detection, isolation, and characterization of β-lactamases from Bacillus cereus PTCC 1015 were investigated. B. cereus was inoculated in nutrient broth containing ampicillin (50 μg.ml−1 for 24 h (35°C, 200 rpm. Activity measurements were carried out against ampicillin (0.1 mg.ml−1 and cephalexin (0.08 mg.ml−1 by a spectrophotometric method at different conditions (pH 6–10, temperatures 25–45°C.Maximum penicillinase and cephalosporinase activity was observed at pH 7. The optimized temperatures for penicillinase and cephalosporinase activity were 30 and 40°C, respectively. At the above conditions, maximum enzymatic activity was calculated as 0.89 ± 0.014 and 0.037 ± 0.001 units against ampicillin and cephalexin.

  18. Antimicrobial resistance among Pseudomonas spp. and the Bacillus cereus group isolated from Danish agricultural soil

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Baloda, S.; Boye, Mette

    2001-01-01

    From four Danish pig farms, bacteria of Pseudomonas spp. and the Bacillus cereus group were isolated from soil and susceptibility towards selected antimicrobials was tested. From each farm, soil samples representing soil just before and after spread of animal waste and undisturbed agricultural soil...... on selection of resistance among soil bacteria. No variations in resistance levels were observed between farms; but when the four differently treated soils were compared, resistance was seen for carbadox, chloramphenicol, nalidixan (nalidixic acid), nitrofurantoin, streptomycin and tetracycline for Pseudomonas...... spp., and for bacitracin, erythromycin, penicillin and streptomycin for the B. cereus group. Variations in resistance levels were observed when soil before and after spread of animal waste was compared, indicating an effect from spread of animal waste....

  19. Survival and Germination of Bacillus cereus Spores without Outgrowth or Enterotoxin Production during In Vitro Simulation of Gastrointestinal Transit

    OpenAIRE

    Ceuppens, Siele; Uyttendaele, Mieke; Drieskens, Katrien; Heyndrickx, Marc; Rajkovic, Andreja; Boon, Nico; Van de Wiele, Tom

    2012-01-01

    To study the gastrointestinal survival and enterotoxin production of the food-borne pathogen Bacillus cereus, an in vitro simulation experiment was developed to mimic gastrointestinal passage in 5 phases: (i) the mouth, (ii) the stomach, with gradual pH decrease and fractional emptying, (iii) the duodenum, with high concentrations of bile and digestive enzymes, (iv) dialysis to ensure bile reabsorption, and (v) the ileum, with competing human intestinal bacteria. Four different B. cereus stra...

  20. Impact of sorbic acid and other mild preservation stresses on germination and outgrowth of Bacillus cereus spores

    OpenAIRE

    Melis, van, C.C.J.

    2013-01-01

      Weak organic acids such as sorbic acid, lactate, and acetic acid are widely used by the food industry as preservatives to control growth of micro-organisms. With the current trend towards milder processing of food products, opportunities arise for spore-forming spoilage and pathogenic microorganisms such as Bacillus cereus, that may survive the use of milder heating regimes. Dormant spores produced by B. cereus can survive processing conditions and their subsequent outgrowth increases ...

  1. Inactivation of Bacillus cereus by Na-chlorophyllin-based photosensitization on the surface of packaging.

    Science.gov (United States)

    Luksiene, Z; Buchovec, I; Paskeviciute, E

    2010-11-01

    This study was focused on the possibility to inactivate food-borne pathogen Bacillus cereus by Na-chlorophyllin (Na-Chl)-based photosensitization in vitro and after attachment to the surface of packaging material. Bacillus cereus in vitro or attached to the packaging was incubated with Na-Chl (7·5×10(-8) to 7·5×10(-5) mol l(-1) ) for 2-60min in phosphate buffer saline. Photosensitization was performed by illuminating cells under a light with a λ of 400nm and an energy density of 20mW cm(-2) . The illumination time varied 0-5min and subsequently the total energy dose was 0-6J cm(-2) . The results show that B. cereus vegetative cells in vitro or attached to the surface of packaging after incubation with 7·5×10(-7) mol l(-1) Na-Chl and following illumination were inactivated by 7log. The photoinactivation of B. cereus spores in vitro by 4log required higher (7·5×10(-6) mol l(-1) ) Na-Chl concentration. Decontamination of packaging material from attached spores by photosensitization reached 5log at 7·5×10(-5) mol l(-1) Na-Chl concentration. Comparative analysis of different packaging decontamination treatments indicates that washing with water can diminish pathogen population on the surface by packaging material. Spores are more resistant than vegetative cells to photosensitization-based inactivation. Comparison of different surface decontamination treatments indicates that Na-Chl-based photosensitization is much more effective antibacterial tool than washing with water or 200ppm Na-hypochlorite. Our data support the idea that Na-Chl-based photosensitization has great potential for future application as an environment-friendly, nonthermal surface decontamination technique. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  2. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    Science.gov (United States)

    Hong, Yun-Hee; Park, Ji-Yong; Park, Jong-Hyun; Chung, Myong-Soo; Kwon, Ki-Sung; Chung, Kyungsook; Won, Misun; Song, Kyung-Bin

    2008-09-01

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D10-vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities.

  3. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Yun-Hee [Department of Food Science and Technology, College of Agriculture and Life Science, Chungnam National University, Yuseong-Gu, Daejeon 305-764 (Korea, Republic of); Park, Ji-Yong [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Jong-Hyun [Department of Food Science and Biotechnology, Kyungwon University, Sungnam 461-701 (Korea, Republic of); Chung, Myong-Soo [Department of Food Science, Ehwa Women' s University, Seoul 120-750 (Korea, Republic of); Kwon, Ki-Sung [Center for Food safety Evaluation, Korea Food and Drug Administration, Seoul 122-704 (Korea, Republic of); Chung, Kyungsook; Won, Misun [Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333 (Korea, Republic of); Song, Kyung-Bin [Department of Food Science and Technology, College of Agriculture and Life Science, Chungnam National University, Yuseong-Gu, Daejeon 305-764 (Korea, Republic of)], E-mail: kbsong@cnu.ac.kr

    2008-09-15

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D{sub 10}-vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities.

  4. Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium in powdered weaning food by electron-beam irradiation

    International Nuclear Information System (INIS)

    Hong, Yun-Hee; Park, Ji-Yong; Park, Jong-Hyun; Chung, Myong-Soo; Kwon, Ki-Sung; Chung, Kyungsook; Won, Misun; Song, Kyung-Bin

    2008-01-01

    Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D 10 -vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities

  5. One-day pulsed-field gel electrophoresis protocol for rapid determination of emetic Bacillus cereus isolates.

    Science.gov (United States)

    Kaminska, Paulina S; Fiedoruk, Krzysztof; Jankowska, Dominika; Mahillon, Jacques; Nowosad, Karol; Drewicka, Ewa; Zambrzycka, Monika; Swiecicka, Izabela

    2015-04-01

    Bacillus cereus, the Gram-positive and spore-forming ubiquitous bacterium, may cause emesis as the result of food intoxication with cereulide, a heat-stable emetic toxin. Rapid determination of cereulide-positive B. cereus isolates is of highest importance due to consequences of this intoxication for human health and life. Here we present a 1-day pulsed-field gel electrophoresis for emetic B. cereus isolates, which allows rapid and efficient determination of their genomic relatedness and helps determining the source of intoxication in case of outbreaks caused by these bacilli. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Bacillus cereus cell response upon exposure to acid environment: towards the identification of potential biomarkers

    Directory of Open Access Journals (Sweden)

    Noémie eDESRIAC

    2013-10-01

    Full Text Available Microorganisms are able to adapt to different environments and evolve rapidly, allowing them to cope with their new environments. Such adaptive response and associated protections towards other lethal stresses, is a crucial survival strategy for a wide spectrum of microorganisms, including food spoilage bacteria, pathogens and organisms used in functional food applications. The growing demand for minimal processed food yields to an increasing use of combination of hurdles or mild preservation factors in the food industry. A commonly used hurdle is low pH which allows the decrease in bacterial growth rate but also the inactivation of pathogens or spoilage microorganisms. Bacillus cereus is a well-known food-borne pathogen leading to economical and safety issues in food industry. Because survival mechanisms implemented will allow bacteria to cope with environmental changes, it is important to provide understanding of B. cereus stress response. Thus this review deals with the adaptive traits of B. cereus cells facing to acid stress conditions. The acid stress response of B. cereus could be divided into four groups (i general stress response (ii pH homeostasis, (iii metabolic modifications and alkali production and (iv secondary oxidative stress response. This current knowledge may be useful to understand how B. cereus cells may cope to acid environment such as encountered in food products and thus to find some molecular biomarkers of the bacterial behaviour. These biomarkers could be furthermore used to develop new microbial behaviour prediction tools which can provide insights into underlying molecular physiological states which govern the behaviour of microorganisms and thus opening the avenue toward the detection of stress adaptive behaviour at an early stage and the control of stress-induced resistance throughout the food chain.

  7. Inactivation of Bacillus cereus vegetative cells by gastric acid and bile during in vitro gastrointestinal transit

    Directory of Open Access Journals (Sweden)

    Ceuppens Siele

    2012-10-01

    Full Text Available Abstract Background The foodborne pathogen Bacillus cereus can cause diarrhoeal food poisoning by production of enterotoxins in the small intestine. The prerequisite for diarrhoeal disease is thus survival during gastrointestinal passage. Methods Vegetative cells of 3 different B. cereus strains were cultivated in a real composite food matrix, lasagne verde, and their survival during subsequent simulation of gastrointestinal passage was assessed using in vitro experiments simulating transit through the human upper gastrointestinal tract (from mouth to small intestine. Results No survival of vegetative cells was observed, despite the high inoculum levels of 7.0 to 8.0 log CFU/g and the presence of various potentially protective food components. Significant fractions (approx. 10% of the consumed inoculum of B. cereus vegetative cells survived gastric passage, but they were subsequently inactivated by bile exposure in weakly acidic intestinal medium (pH 5.0. In contrast, the low numbers of spores present (up to 4.0 log spores/g showed excellent survival and remained viable spores throughout the gastrointestinal passage simulation. Conclusion Vegetative cells are inactivated by gastric acid and bile during gastrointestinal passage, while spores are resistant and survive. Therefore, the physiological form (vegetative cells or spores of the B. cereus consumed determines the subsequent gastrointestinal survival and thus the infective dose, which is expected to be much lower for spores than vegetative cells. No significant differences in gastrointestinal survival ability was found among the different strains. However, considerable strain variability was observed in sporulation tendency during growth in laboratory medium and food, which has important implications for the gastrointestinal survival potential of the different B. cereus strains.

  8. Triplex PCR-based detection of enterotoxigenic Bacillus cereus ATCC 14579 in nonfat dry milk.

    Science.gov (United States)

    Gracias, Kiev S; McKillip, John L

    2011-04-01

    Although many strains of Bacillaceae are considered nonpathogenic, Bacillus cereus is recognized worldwide as a bacterial pathogen in a variety of foods. The ability of B. cereus to cause gastroenteritis following ingestion of contaminated food is due to the production of enterotoxins. The ubiquity of this genus makes it a persistent problem for quality assurance in food processing environments. The primary objective of this study was to develop and apply a multiplex real-time PCR-based assay for rapid and sensitive detection of enterotoxigenic B. cereus. Template DNA was separately extracted from tryptic soy broth (TSB)-grown and 2.5% Nonfat Dry Milk (NFDM)-grown B. cereus using a commercial system. Three enterotoxin gene fragments (hblC, nheA, and hblA) were simultaneously amplified in real-time followed by melting curve analysis to confirm amplicon identity. Resolution of melting curves (characteristic T(m)) was achieved for each amplicon (hblC = 74.5 °C; nheA = 78 °C; and hblA = 85.5 °C in TSB and 84 °C in NFDM) with an assay sensitivities of 10(1) CFU/ml for both TSB and NFDM-grown B. cereus compared to 10(4) CFU/ml in either matrix using gel electrophoresis. The results demonstrate the potential sensitivity of real-time bacterial detection methods in a heterogenous food matrix using real-time PCR. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Comparative transcriptional profiling of Bacillus cereus sensu lato strains during growth in CO2-bicarbonate and aerobic atmospheres.

    Directory of Open Access Journals (Sweden)

    Karla D Passalacqua

    Full Text Available Bacillus species are spore-forming bacteria that are ubiquitous in the environment and display a range of virulent and avirulent phenotypes. This range is particularly evident in the Bacillus cereus sensu lato group; where closely related strains cause anthrax, food-borne illnesses, and pneumonia, but can also be non-pathogenic. Although much of this phenotypic range can be attributed to the presence or absence of a few key virulence factors, there are other virulence-associated loci that are conserved throughout the B. cereus group, and we hypothesized that these genes may be regulated differently in pathogenic and non-pathogenic strains.Here we report transcriptional profiles of three closely related but phenotypically unique members of the Bacillus cereus group--a pneumonia-causing B. cereus strain (G9241, an attenuated strain of B. anthracis (Sterne 34F(2, and an avirulent B. cereus strain (10987--during exponential growth in two distinct atmospheric environments: 14% CO(2/bicarbonate and ambient air. We show that the disease-causing Bacillus strains undergo more distinctive transcriptional changes between the two environments, and that the expression of plasmid-encoded virulence genes was increased exclusively in the CO(2 environment. We observed a core of conserved metabolic genes that were differentially expressed in all three strains in both conditions. Additionally, the expression profiles of putative virulence genes in G9241 suggest that this strain, unlike Bacillus anthracis, may regulate gene expression with both PlcR and AtxA transcriptional regulators, each acting in a different environment.We have shown that homologous and even identical genes within the genomes of three closely related members of the B. cereus sensu lato group are in some instances regulated very differently, and that these differences can have important implications for virulence. This study provides insights into the evolution of the B. cereus group, and

  10. Bacillus cereus in Infant Foods: Prevalence Study and Distribution of Enterotoxigenic Virulence Factors in Isfahan Province, Iran

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    Ebrahim Rahimi

    2013-01-01

    Full Text Available This study was carried out in order to investigate the presences of Bacillus cereus and its enterotoxigenic genes in infant foods in Isfahan, Iran. Overall 200 infant foods with various based were collected and immediately transferred to the laboratory. All samples were culture and the genomic DNA was extracted from colonies with typical characters of Bacillus cereus. The presences of enterotoxigenic genes were investigated using the PCR technique. Eighty-four of two hundred samples (42% were found to be contaminated with B. cereus with a ranges of 3 × 101–9.3 × 101 spore per gram sample. Totally, entFM had the highest (61.90% incidences of enterotoxigenic genes while hblA had the lowest (13.09% incidences of enterotoxigenic genes. Overall, 6.7% of B. cereus isolates had all studied enetrotoxigenic genes while 25.5% of B. cereus strains had all studied enetrotoxigenic genes expectance bceT gene. Thisstudyisthe first prevalence report of B. cereus and its enterotoxigenic genes in infant foods in Iran. Results showed that the infant food is one of the main sources of enterotoxigenic genes of B. cereus in Iran. Therefore, the accurate food inspection causes to reducing outbreak of diseases.

  11. Comparison of cytotoxin cytK promoters from Bacillus cereus strain ATCC 14579 and from a B. cereus food-poisoning strain.

    Science.gov (United States)

    Brillard, Julien; Lereclus, Didier

    2004-08-01

    The cytotoxin CytK produced by Bacillus cereus is believed to be involved in food-borne diseases. The transcriptional activity of the cytK promoter region in a food-poisoning strain was studied using a reporter gene and compared with that in the reference B. cereus strain ATCC 14579. In the food-poisoning strain, cytK is more strongly transcribed, possibly explaining the pathogenicity. The global regulator PlcR in B. cereus controls several putative virulence factors. It was found that PlcR regulates cytK in this clinical strain despite a mismatch in the PlcR recognition site, as currently defined. This suggests that the PlcR box consensus should be reconsidered and that the PlcR regulon might be larger than suspected. It is also shown that the high level of cytK transcription is not caused by a modification in the PlcR recognition site.

  12. An antibiotic, heavy metal resistant and halotolerant Bacillus cereus SIU1 and its thermoalkaline protease

    Directory of Open Access Journals (Sweden)

    Vikram Surendra

    2010-07-01

    Full Text Available Abstract Background Many workers have reported halotolerant bacteria from saline conditions capable of protease production. However, antibiotic resistance and heavy metal tolerance pattern of such organisms is not documented very well. Similarly, only a few researchers have reported the pattern of pH change of fermentation medium during the course of protease production. In this study, we have isolated a halotolerant Bacillus cereus SIU1 strain from a non-saline environment and studied its antibiotic and heavy metal resistance pattern. The isolate produces a thermoalkaline protease and changes the medium pH during the course of fermentation. Thermostability of protease was also studied for 30 min. Results Seventy bacterial strains isolated from the soils of Eastern Uttar Pradesh, India were screened for protease production. All of them exhibited protease activity. However, 40% bacterial isolates were found good protease producers as observed by caseinolytic zones on milk agar plates. Among them, culture S-4 was adjudged as the best protease producer, and was identified as Bacillus cereus by morphological, biochemical and 16 S rDNA sequence analyses. The isolate was resistant to heavy metals (As2+, Pb2+, Cs1+ and antibiotics (penicillin, lincomycin, cloxacillin, pefloxacin. Its growth behavior and protease production was studied at 45°C and pH 9.0. The protease units of 88 ml-1 were noted in unoptimized modified glucose yeast extract (GYE medium during early stationary phase at 20 h incubation period. The enzyme was stable in the temperature range of 35°-55°C. Conclusions An antibiotic and heavy metal resistant, halotolerant Bacillus cereus isolate is capable of producing thermoalkaline protease, which is active and stable at pH 9.0 and 35°-55°C. This isolate may be useful in several industrial applications owing to its halotolerance and antibiotic and heavy metal resistance characteristics.

  13. Toxigenic genes, spoilage potential, and antimicrobial resistance of Bacillus cereus group strains from ice cream.

    Science.gov (United States)

    Arslan, Seza; Eyi, Ayla; Küçüksarı, Rümeysa

    2014-02-01

    Bacillus spp. can be recovered from almost every environment. It is also found readily in foods, where it may cause food spoilage and/or food poisoning due to its toxigenic and pathogenic nature, and extracellular enzymes. In this study, 29 Bacillus cereus group strains from ice cream were examined for the presence of following virulence genes hblC, nheA, cytK and ces genes, and tested for a range of the extracellular enzymes, and antimicrobial susceptibility. The strains were found to produce extracellular enzymes: proteolytic and lipolytic activity, gelatin hydrolysis and lecithinase production (100%), DNase production (93.1%) and amylase activity (93.1%). Of 29 strains examined, 24 (82.8%) showed hemolytic activity on blood agar. Beta-lactamase enzyme was only produced by 20.7% of B. cereus group. Among 29 B. cereus group from ice cream, nheA was the most common virulence gene detected in 44.8% of the strains, followed by hblC gene with 17.2%. Four (13.8%) of the 29 strains were positive for both hblC gene and nheA gene. Contrarily, cytK and ces genes were not detected in any of the strains. Antimicrobial susceptibility of ice cream isolates was tested to 14 different antimicrobial agents using the disc diffusion method. We detected resistance to penicillin and ampicillin with the same rate of 89.7%. Thirty-one percent of the strains were multiresistant to three or more antibiotics. This study emphasizes that the presence of natural isolates of Bacillus spp. harboring one or more enterotoxin genes, producing extracellular enzymes which may cause spoilage and acquiring antibiotic resistance might hold crucial importance in the food safety and quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Comparative analysis of antimicrobial activities of valinomycin and cereulide, the Bacillus cereus emetic toxin

    OpenAIRE

    Tempelaars, M.H.; Rodrigues, S.; Abee, T.

    2011-01-01

    Cereulide and valinomycin are highly similar cyclic dodecadepsipeptides with potassium ionophoric properties. Cereulide, produced by members of the Bacillus cereus group, is known mostly as emetic toxin, and no ecological function has been assigned. A comparative analysis of the antimicrobial activity of valinomycin produced by Streptomyces spp. and cereulide was performed at a pH range of pH 5.5 to pH 9.5, under anaerobic and aerobic conditions. Both compounds display pH-dependent activity a...

  15. [Biosorption of Ag+ by heavy metals hyperresistant Bacillus cereus strain HQ-1].

    Science.gov (United States)

    Zeng, Jing-Hai; Qi, Hong-Yan; Yang, Jian-Zhou; Hu, Qing; Zhang, Hong-Xun; Zhuang, Guo-Qiang

    2008-01-01

    A newly isolated Bacillus cereus strain HQ-1 was found to possess high capability to absorb silver ions. The study showed that the biosorption process could be described well by pseudo-second-order kinetic model and Freundlich isotherm model. Higher cell concentration was favorable to the biosorption. Temperature's effect on the biosorption was not obvious. The oxygenous and nitrogenous functional groups on the cell wall played a very important role in the process of biosorption. Microdeposits were formed by interaction between silver ions and biopolymers from the cell wall (such as polysaccharides, proteins and some hydrolysis).

  16. Unsaturated fatty acids from food and in the growth medium improve growth of Bacillus cereus under cold and anaerobic conditions.

    Science.gov (United States)

    de Sarrau, Benoît; Clavel, Thierry; Zwickel, Nicolas; Despres, Jordane; Dupont, Sébastien; Beney, Laurent; Tourdot-Maréchal, Raphaëlle; Nguyen-The, Christophe

    2013-12-01

    In a chemically defined medium and in Luria broth, cold strongly reduced maximal population density of Bacillus cereus ATCC 14579 in anaerobiosis and caused formation of filaments. In cooked spinach, maximal population density of B. cereus in anaerobiosis was the same at cold and optimal temperatures, with normal cell divisions. The lipid containing fraction of spinach, but not the hydrophilic fraction, restored growth of B. cereus under cold and anaerobiosis when added to the chemically defined medium. This fraction was rich in unsaturated, low melting point fatty acids. Addition of phosphatidylcholine containing unsaturated, low melting point, fatty acids similarly improved B. cereus anaerobic growth at cold temperature. Addition of hydrogenated phosphatidylcholine containing saturated, high melting point, fatty acids did not modify growth. Fatty acids from phospholipids, from spinach and from hydrogenated phosphatidylcholine, although normally very rare in B. cereus, were inserted in the bacterium membrane. Addition of phospholipids rich in unsaturated fatty acids to cold and anaerobic cultures, increased fluidity of B. cereus membrane lipids, to the same level as those from B. cereus normally cold adapted, i.e. grown aerobically at 15 °C. B. cereus is therefore able to use external fatty acids from foods or from the growth medium to adapt its membrane to cold temperature under anaerobiosis, and to recover the maximal population density achieved at optimal temperature. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Identification and antibiogram pattern of Bacillus cereus from the milk and milk products in and around Jammu region

    Science.gov (United States)

    Yusuf, Umar; Kotwal, S. K.; Gupta, Sanjolly; Ahmed, Touqeer

    2018-01-01

    Aim: The aims of the present study were to assess the prevalence, identification, and antibiogram pattern of Bacillus cereus from 215 samples of different milk and milk products in and around Jammu region. Materials and Methods: In the present study, 215 samples of milk, rasgulla, burfi, rasmalai, kalaari, paneer, ice cream, and pastry were collected and analyzed for the isolation of the B. cereus using PEMBA, and antibiogram pattern was observed for all the milk and milk products. Results: B. cereus was detected in 61/215 samples with an overall prevalence of 28.37%. Biotyping revealed predominantly 5, 7, and 2 biotypes in raw milk. Burfi and ice cream revealed 2, 3, 5, and 7 biotypes. Rasgulla had 2, 3, and 5 biotypes; paneer and rasmalai had biotypes 2 and 5, while kalaari revealed biotype 5. Antibiogram pattern revealed that isolates were highly sensitive to gentamicin (100%), intermediate to ampicillin (40.98%), tetracycline (31.14%), erythromycin (29.50%), and amoxicillin (26.22%), and high resistance against penicillin G (100%). Adulteration of starch was detected in 16.66 % raw milk samples. All starch positive samples were positive for B. cereus. However, 12 starch negative samples also yielded B. cereus. Conclusion: From this study, it was concluded that highest prevalence of B. cereus was found in ice cream. Several isolates of B. cereus showed toxigenic activity, so the presence of B. cereus in milk and milk products may be of public health hazard. The antibiogram pattern of B. cereus isolates showed sensitivity to gentamicin, ciprofloxacin, chloramphenicol, streptomycin, and resistance to penicillin-G and cephalexin. The presence of B. cereus in milk and milk products showed a strong association besides establishing the fact that starch adulteration can be indicative of the presence of B. cereus. PMID:29657402

  18. Growth and sporulation of Bacillus cereus ATCC 14579 under defined conditions: temporal expression of genes for key sigma factors.

    Science.gov (United States)

    de Vries, Ynte P; Hornstra, Luc M; de Vos, Willem M; Abee, Tjakko

    2004-04-01

    An airlift fermentor system allowing precise regulation of pH and aeration combined with a chemically defined medium was used to study growth and sporulation of Bacillus cereus ATCC 14579. Sporulation was complete and synchronous. Expression of sigA, sigB, sigF, and sigG was monitored with real-time reverse transcription-PCR, and the pattern qualitatively resembled that of Bacillus subtilis. This method allows reproducible production of stable spores, while the synchronous growth and defined conditions are excellently suitable for further gene expression studies of cellular differentiation of B. cereus.

  19. A novel multiplex PCR discriminates Bacillus anthracis and its genetically related strains from other Bacillus cereus group species.

    Directory of Open Access Journals (Sweden)

    Hirohito Ogawa

    Full Text Available Anthrax is an important zoonotic disease worldwide that is caused by Bacillus anthracis, a spore-forming pathogenic bacterium. A rapid and sensitive method to detect B. anthracis is important for anthrax risk management and control in animal cases to address public health issues. However, it has recently become difficult to identify B. anthracis by using previously reported molecular-based methods because of the emergence of B. cereus, which causes severe extra-intestinal infection, as well as the human pathogenic B. thuringiensis, both of which are genetically related to B. anthracis. The close genetic relation of chromosomal backgrounds has led to complexity of molecular-based diagnosis. In this study, we established a B. anthracis multiplex PCR that can screen for the presence of B. anthracis virulent plasmids and differentiate B. anthracis and its genetically related strains from other B. cereus group species. Six sets of primers targeting a chromosome of B. anthracis and B. anthracis-like strains, two virulent plasmids, pXO1 and pXO2, a bacterial gene, 16S rRNA gene, and a mammalian gene, actin-beta gene, were designed. The multiplex PCR detected approximately 3.0 CFU of B. anthracis DNA per PCR reaction and was sensitive to B. anthracis. The internal control primers also detected all bacterial and mammalian DNAs examined, indicating the practical applicability of this assay as it enables monitoring of appropriate amplification. The assay was also applied for detection of clinical strains genetically related to B. anthracis, which were B. cereus strains isolated from outbreaks of hospital infections in Japan, and field strains isolated in Zambia, and the assay differentiated B. anthracis and its genetically related strains from other B. cereus group strains. Taken together, the results indicate that the newly developed multiplex PCR is a sensitive and practical method for detecting B. anthracis.

  20. Formation of cereulide and enterotoxins by Bacillus cereus in fermented African locust beans

    DEFF Research Database (Denmark)

    Thorsen, Line; Azokpota, Paulin; Munk Hansen, Bjarne

    2011-01-01

    Afitin, iru and sonru are three spontaneously fermented African locust bean Benin condiments. The fermentation processes are exothermic, with temperatures mostly being above 40 °C. A total of 19 predominant Bacillus cereus isolates from afitin, iru and sonru, were investigated. The enterotoxin...... genes nhe (A, B, C) were present in all 19 isolates, the hbl (A, C, D) in one (afitin), and the cytK gene in three isolates (afitin). Levels of cytotoxicity to Vero cells and NheA production in BHI-broth was within the range of known diarrheal outbreak strains. Autoclaved cooked African locust beans...... inoculated with emetic (cereulide producing) B. cereus Ba18H2/RIF supported growth at 25, 30 and 40 °C with highly different maximum cereulide productions of 6 ± 5, 97 ± 3 and 0.04 ± 0.02 μg/g beans, respectively (48 h). For non-autoclaved cooked beans inoculated with 2, 4 and 6 log10 B. cereus Ba18H2/RIF...

  1. Bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting with Bacillus cereus HDYM-02.

    Science.gov (United States)

    Zhao, Dan; Liu, Pengfei; Pan, Chao; Du, Renpeng; Ping, Wenxiang; Ge, Jingping

    2016-09-02

    High-throughput sequencing and GC-MS (gas chromatography-mass spectrometry) were jointly used to reveal the bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting. The inoculation of Bacillus cereus HDYM-02 decreased bacterial richness and diversity. This inoculum led to the replacement of Enterobacteriaceae by Bacillaceae. The level of aerobic Pseudomonadaceae (mainly Azotobacter) and anaerobic Clostridiaceae_1 gradually increased and decreased, respectively. Following the addition of B. cereus HDYM-02, the dominant groups were all degumming enzyme producers or have been proven to be involved in microbial retting throughout the entire retting period. These results could be verified by the metabolite changes, either degumming enzymes or their catalytic products galacturonic acid and reducing sugars. The GC-MS data showed a clear separation between flax retting with and without B. cereus HDYM-02, particularly within the first 72 h. These findings reveal the important bacterial groups that are involved in fiber retting and will facilitate improvements in the retting process.

  2. Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment

    DEFF Research Database (Denmark)

    Thorsen, Line; Kando, Christine Kere; Sawadogo, Hagrétou

    2015-01-01

    Maari is a spontaneously fermented food condiment made from baobab tree seeds in West African countries. This type of product is considered to be safe, being consumed by millions of people on a daily basis. However, due to the spontaneous nature of the fermentation the human pathogen Bacillus...... identified as B. cereus sensu lato by use of ITS-PCR and grouped into 3 groups using PCR fingerprinting based on Escherichia coli phage-M13 primer (M13-PCR). As determined by panC gene sequencing, the isolates of B. cereus belonged to PanC types III and IV with potential for high cytotoxicity. Phylogenetic...... found in potash, DW, cooking water and at 8h fermentation. The "emetic" type B. cereus were present in DW, the seed mash at 48-72h of fermentation and in the final product, while the remaining isolates (PanC type IV) were detected in ash, at 48-72h fermentation and in the final product. This work sheds...

  3. Time dynamics of the Bacillus cereus exoproteome are shaped by cellular oxidation

    Directory of Open Access Journals (Sweden)

    Jean-Paul eMadeira

    2015-04-01

    Full Text Available At low density, Bacillus cereus cells release a large variety of proteins into the extracellular medium when cultivated in pH-regulated, glucose-containing minimal medium, either in the presence or absence of oxygen. The majority of these exoproteins are putative virulence factors, including toxin-related proteins. Here, B. cereus exoproteome time courses were monitored by nanoLC-MS/MS under low-oxidoreduction potential (ORP anaerobiosis, high-ORP anaerobiosis, and aerobiosis, with a specific focus on oxidative-induced post-translational modifications of methionine residues. Principal component analysis (PCA of the exoproteome dynamics indicated that toxin-related proteins were the most representative of the exoproteome changes, both in terms of protein abundance and their methionine sulfoxide (Met(O content. PCA also revealed an interesting interconnection between toxin-, metabolism-, and oxidative stress–related proteins, suggesting that the abundance level of toxin-related proteins, and their Met(O content in the B. cereus exoproteome, reflected the cellular oxidation under both aerobiosis and anaerobiosis.

  4. Antagonistic effects of Bacillus cereus strain B-02 on morphology, ultrastructure and cytophysiology of Botrytis cinerea.

    Science.gov (United States)

    Li, Feng-Xia; Ma, Hui-Quan; Liu, Jing; Zhang, Chao

    2012-01-01

    The study on antagonistic mechanism of biocontrol strains gives the premise and basis for efficient and stable biological control. This study aimes to overcome of biocontrol agent in aspects of complicated and diversified mode of action, short-lasting and unstable efficacy in the production processes. This study elucidated the antagonistic mechanism of Bacillus cereus strain B-02 on Botrytis cinerea by detecting changes in morphology, ultrastructure and physiology in affected hyphae of Botrytis cinerea. Which provided certain theoretical and practical significance for biological control of gray mould caused by B. cinerea. B. cereus strain B-02 isolated from tomato rhizosphere mightily suppressed gray mold in tomato caused by B. cinerea. Spore germination and hyphal growth of B. cinerea were inhibited by B. cereus strain B-02. Changes of cell morphology such as distortion, shrinking and swelling were observed by SEM. TEM observation further indicated the ultrastructural alterations of hyphae, including mitochondrion reduction, un-membranous inclusion in cytoplasm, considerable thickening of cell walls, and electronic density enhancement. LSCM observation revealed the fluorescence intensity of nucleus DNA, mitochondrion DNA and reactive oxygen radical in treated hyphae were all stronger than control and the difference was significant (P cinerea were likely due to a combination of abnormal synthesis of nucleus DNA and mitochondrion DNA and multifarious ultrastructural alterations in hyphal cell.

  5. Biosurfactants production potential of native strains of Bacillus cereus and their antimicrobial, cytotoxic and antioxidant activities.

    Science.gov (United States)

    Basit, Madiha; Rasool, Muhammad Hidayat; Naqvi, Syed Ali Raza; Waseem, Muhammad; Aslam, Bilal

    2018-01-01

    Present study was designed to evaluate the biosurfactant production potential by native strains of Bacillus cereus as well as determine their antimicrobial and antioxidant activities. The strains isolated from garden soil were characterized as B. cereus MMIC 1, MMIC 2 and MMIC 3. Biosurfactants were extracted as grey white precipitates. Optimum conditions for biosurfactant production were 37°C, the 7th day of incubation, 0.5% NaCl, pH 7.0. Moreover, corn steep liquor was the best carbon source. Biuret test, Thin Layer Chromatography (TLC), agar double diffusion and Fourier Transform Infrared Spectroscopy (FTIR) characterized the biosurfactants as cationic lipopeptides. Biosurfactants exhibited significant antibacterial and antifungal activity against S. aureus, E. coli, P. aeruginosa, K. pneumoniae, A. niger and C. albicans at 30 mg/ml. Moreover, they also possessed antiviral activity against NDV at 10 mg/ml. Cytotoxicity assay in BHK-21 cell lines revealed 63% cell survival at 10 mg/ml of biosurfactants and thus considered as safe. They also showed very good antioxidant activity by ferric-reducing activity and DPPH scavenging activity at 2 mg/ml. Consequently, the study offers an insight for the exploration of new bioactive molecules from the soil. It was concluded that lipopeptide biosurfactants produced from native strains of B. cereus may be recommended as safe antimicrobial, emulsifier and antioxidant agent.

  6. Global transcriptome analysis of Bacillus cereus ATCC 14579 in response to silver nitrate stress

    Directory of Open Access Journals (Sweden)

    Ganesh Babu Malli Mohan

    2011-11-01

    Full Text Available Abstract Silver nanoparticles (AgNPs were synthesized using Bacillus cereus strains. Earlier, we had synthesized monodispersive crystalline silver nanoparticles using B. cereus PGN1 and ATCC14579 strains. These strains have showed high level of resistance to silver nitrate (1 mM but their global transcriptomic response has not been studied earlier. In this study, we investigated the cellular and metabolic response of B. cereus ATCC14579 treated with 1 mM silver nitrate for 30 & 60 min. Global expression profiling using genomic DNA microarray indicated that 10% (n = 524 of the total genes (n = 5234 represented on the microarray were up-regulated in the cells treated with silver nitrate. The majority of genes encoding for chaperones (GroEL, nutrient transporters, DNA replication, membrane proteins, etc. were up-regulated. A substantial number of the genes encoding chemotaxis and flagellar proteins were observed to be down-regulated. Motility assay of the silver nitrate treated cells revealed reduction in their chemotactic activity compared to the control cells. In addition, 14 distinct transcripts overexpressed from the 'empty' intergenic regions were also identified and proposed as stress-responsive non-coding small RNAs.

  7. Bacillus cereus iron uptake protein fishes out an unstable ferric citrate trimer.

    Science.gov (United States)

    Fukushima, Tatsuya; Sia, Allyson K; Allred, Benjamin E; Nichiporuk, Rita; Zhou, Zhongrui; Andersen, Ulla N; Raymond, Kenneth N

    2012-10-16

    Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding protein from the gram-positive pathogenic bacterium Bacillus cereus that binds multinuclear ferric citrate complexes. We have demonstrated that B. cereus ATCC 14579 takes up (55)Fe radiolabeled ferric citrate and that a protein, BC_3466 [renamed FctC (ferric citrate-binding protein C)], binds ferric citrate. The dissociation constant (K(d)) of FctC at pH 7.4 with ferric citrate (molar ratio 1:50) is 2.6 nM. This is the tightest binding observed of any B. cereus siderophore-binding protein. Nano electrospray ionization-mass spectrometry (nano ESI-MS) analysis of FctC and ferric citrate complexes or citrate alone show that FctC binds diferric di-citrate, and triferric tricitrate, but does not bind ferric di-citrate, ferric monocitrate, or citrate alone. Significantly, the protein selectively binds triferric tricitrate even though this species is naturally present at very low equilibrium concentrations.

  8. The impact of oxygen availability on stress survival and radical formation of Bacillus cereus.

    Science.gov (United States)

    Mols, Maarten; Pier, Ilona; Zwietering, Marcel H; Abee, Tjakko

    2009-11-15

    Both the growth and stress survival of two model Bacillus cereus strains, ATCC 14579 and ATCC 10987, were tested in three different conditions varying in oxygen availability, i.e., aerobic, microaerobic and anaerobic conditions. Both B. cereus strains displayed highest growth rates and yields under aerobic conditions, whereas the microaerobic and anaerobic cultures showed similar reduced growth performances. The cells grown and exposed microaerobically and anaerobically were more resistant to heat and acid than cells that were cultured and exposed aerobically. On the other hand, the anaerobically grown cells were more sensitive to hydrogen peroxide compared to the (micro)aerobically grown cells. The increased heat- and acid-induced inactivation in aerobic conditions appeared to be associated with intracellular accumulation of excess hydroxyl and/or peroxynitrite radicals, as determined by flow cytometry in combination with the fluorescent reporter dye 3'-(p-hydroxyphenyl) fluorescein. This suggests that radical formation may contribute to inactivation of bacteria in the presence of oxygen, such as in aerobic and microaerobic conditions. No evidence was found for radical formation upon exposure to salt and hydrogen peroxide. The increased resistance to heat and acid in microaerobic and anaerobic conditions shows that oxygen availability should be taken into account when behavior of bacteria, such as B. cereus, in food industry related conditions is investigated, because oxygen availability may affect the efficiency of food preservation conditions.

  9. Global transcriptome analysis of Bacillus cereus ATCC 14579 in response to silver nitrate stress.

    Science.gov (United States)

    Babu, Malli Mohan Ganesh; Sridhar, Jayavel; Gunasekaran, Paramasamy

    2011-11-10

    Silver nanoparticles (AgNPs) were synthesized using Bacillus cereus strains. Earlier, we had synthesized monodispersive crystalline silver nanoparticles using B. cereus PGN1 and ATCC14579 strains. These strains have showed high level of resistance to silver nitrate (1 mM) but their global transcriptomic response has not been studied earlier. In this study, we investigated the cellular and metabolic response of B. cereus ATCC14579 treated with 1 mM silver nitrate for 30 & 60 min. Global expression profiling using genomic DNA microarray indicated that 10% (n = 524) of the total genes (n = 5234) represented on the microarray were up-regulated in the cells treated with silver nitrate. The majority of genes encoding for chaperones (GroEL), nutrient transporters, DNA replication, membrane proteins, etc. were up-regulated. A substantial number of the genes encoding chemotaxis and flagellar proteins were observed to be down-regulated. Motility assay of the silver nitrate treated cells revealed reduction in their chemotactic activity compared to the control cells. In addition, 14 distinct transcripts overexpressed from the 'empty' intergenic regions were also identified and proposed as stress-responsive non-coding small RNAs.

  10. Prevalence of Bacillus cereus in milk and rice grains collected from great Cairo

    International Nuclear Information System (INIS)

    Abo State, M.A.M.; Youssef, B.M.

    2012-01-01

    Sixty two Samples of heat treated milk, raw rice grains and Cheetos (XO-Snacks) were collected from supermarkets of great Cairo. Seventeen out of 25 milk samples (68%) gave detectable count of B. cereus on MYP medium. These positive samples count was ranging from 1.5 X 10 1 cfu/ml to 11.3X10 2 cfu/ml. Eighteen out of 25 Samples of raw rice grains (72%) gave also detectable count on MYP medium also. The count of positive rice grains was ranging from 2.0X10 1 cfu/g to 11.5X10 3 cfu /ml. However one Sample out of 12 Samples (8%) of Cheetos (Snacks) was positive with count 3.0X10 2 cfu /g. Gamma irradiation reduced the total bacterial count and B. cereus count gradually. Eight kGy reduced total bacterial count and Bacillus cereus count by 3.1 and 2.2 log cycles respectively.

  11. Bacillus cereus as indicator in the sterilization of residual water with high energy electrons

    International Nuclear Information System (INIS)

    Mejia Z, E.

    2000-01-01

    One of the main causes of water pollution is the presence of microorganisms that provoke infections, moreover of chemical substances. The processes of residual water treatment finally require of the disinfection for its use or final disposition. The radiation technology for the residual water treatment by mean of electron beams is an innovator process because as well as decomposing the chemical substance or to degrade them, also it provokes a disinfection by which this is proposed as alternative for disinfection of residual water, with the purpose in reusing the water treated in the agriculture, recreation and industry among others secondary activities, solving environmental or health problems. The objective of this work is to evaluate the use of Bacillus cereus as biological indicator in the disinfection by radiation, using High Energy Electrons. To fulfil with this objective, the work was developed in three stages, the first one consisted in the acquisition, propagation and conservation of the Bacillus cereus stumps, considering Escherichia coli and Salmonella typhimurium as pathogenic germs present in residual water. Moreover, the inocule standardization and the conditions of the Electron accelerator Type Pelletron. In the second stage it was performed the irradiation of aqueous samples of the microorganisms simulating biological pollution and the application to problem samples of a treatment plant sited in the Lerma River zone of mixed residual water. And in the third stage was performed a regression analysis to the reported survival for each kind of microorganisms. The results obtained show that with the use of Electron beams was reduced 6 logarithmic units de E. coli at 129 Gy, for S. typhimurium it was reduced 8 logarithmic units at 383 Gy and the B. cereus at 511 Gy was reduced 6.8 logarithmic units. Of the problem samples irradiated at 500 Gy, the concentration of the total account diminished from 8.70 x 10 7 UFC/ml to 550 UFC/ml, the presence of B. Cereus

  12. Cereulide formation by Bacillus weihenstephanensis and mesophilic emetic Bacillus cereus at temperature abuse depends on pre-incubation conditions

    DEFF Research Database (Denmark)

    Thorsen, Line; Budde, Birgitte Bjørn; Henrichsen, Lars

    2009-01-01

    Emetic toxin (cereulide) formation was recently identified in a psychrotolerant species, Bacillus weihenstephanensis[Thorsen, L., Hansen, B.M., Nielsen, K.F.,Hendriksen, N.B., Phipps, R.K., Budde, B.B., 2006. Characterization ofemetic Bacillus weihenstephanensisis, a new cereulide-producing bacte......Emetic toxin (cereulide) formation was recently identified in a psychrotolerant species, Bacillus weihenstephanensis[Thorsen, L., Hansen, B.M., Nielsen, K.F.,Hendriksen, N.B., Phipps, R.K., Budde, B.B., 2006. Characterization ofemetic Bacillus weihenstephanensisis, a new cereulide......-producing bacterium. Applied and EnvironmentalMicrobiology, 72, 5118-5121.]. Although recent findings indicated B. weihenstephanensis as a cereulide producer only limited information is available regarding environmental conditions affecting cereulide production. In the present study a model agar system was used....... weihenstephanensis MC67 occurred in stationary growth phase, as previously observed for B. cereus, and biomass formation and cereulide formation showed a linear correlation. During incubation at 5 °C for 1, 2 and 3 weeks growth was inhibited and as a consequence no detectable cereulide production occurred for any...

  13. Identification of proteins involved in the heat stress response of Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Periago, Paula M; van Schaik, Willem; Abee, Tjakko; Wouters, Jeroen A

    2002-07-01

    To monitor the ability of the food-borne opportunistic pathogen Bacillus cereus to survive during minimal processing of food products, we determined its heat-adaptive response. During pre-exposure to 42 degrees C, B. cereus ATCC 14579 adapts to heat exposure at the lethal temperature of 50 degrees C (maximum protection occurs after 15 min to 1 h of pre-exposure to 42 degrees C). For this heat-adaptive response, de novo protein synthesis is required. By using two-dimensional gel electrophoresis, we observed 31 heat-induced proteins, and we determined the N-terminal sequences of a subset of these proteins. This revealed induction of stress proteins (CspB, CspE, and SodA), proteins involved in sporulation (SpoVG and AldA), metabolic enzymes (FolD and Dra), identified heat-induced proteins in related organisms (DnaK, GroEL, ClpP, RsbV, HSP16.4, YflT, PpiB, and TrxA), and other proteins (MreB, YloH, and YbbT). The upregulation of several stress proteins was confirmed by using antibodies specific for well-characterized heat shock proteins (HSPs) of B. subtilis. These observations indicate that heat adaptation of B. cereus involves proteins that function in a variety of cellular processes. Notably, a 30-min pre-exposure to 4% ethanol, pH 5, or 2.5% NaCl also results in increased thermotolerance. Also, for these adaptation processes, protein synthesis is required, and indeed, some HSPs are induced under these conditions. Collectively, these data show that during mild processing, cross-protection from heating occurs in pathogenic B. cereus, which may result in increased survival in foods.

  14. Response of Bacillus cereus ATCC 14579 to challenges with sublethal concentrations of enterocin AS-48.

    Science.gov (United States)

    Grande Burgos, María J; Kovács, Akos T; Mirończuk, Aleksandra M; Abriouel, Hikmate; Gálvez, Antonio; Kuipers, Oscar P

    2009-10-28

    Enterocin AS-48 is produced by Enterococcus faecalis S48 to compete with other bacteria in their environment. Due to its activity against various Gram positive and some Gram negative bacteria it has clear potential for use as a food preservative. Here, we studied the effect of enterocin AS-48 challenges on vegetative cells of Bacillus cereus ATCC 14579 by use of transcriptome analysis. Of the 5200 genes analysed, expression of 24 genes was found to change significantly after a 30 min treatment with a subinhibitory bacteriocin concentration of 0.5 microg/ml. Most of up-regulated genes encode membrane-associated or secreted proteins with putative transmembrane segments or signal sequences, respectively. One operon involved in arginine metabolism was significantly downregulated. The BC4206-BC4207 operon was found to be the most upregulated target in our experiments. BC4206 codes for a PadR type transcriptional regulator, while BC4207 codes for a hypothetical membrane protein. The operon structure and genes are conserved in B. cereus and B. thuringiensis species, but are not present in B. anthracis and B. subtilis. Using real-time qPCR, we show that these genes are upregulated when we treated the cells with AS-48, but not upon nisin treatment. Upon overexpression of BC4207 in B. cereus, we observed an increased resistance against AS-48. Expression of BC4207 in B. subtilis 168, which lacks this operon also showed increased resistance against AS-48. BC4207 membrane protein is involved in the resistance mechanism of B. cereus cells against AS-48.

  15. Isolation and characterization of flagellar filaments from Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Tagawa, Yuichi

    2014-12-01

    Isolated flagellar filaments from the type strain of Bacillus cereus, ATCC 14579, were shown to consist of 34, 32 and 31 kDa proteins in similar proportions as judged by band intensities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The N-terminal amino acid sequences of these three proteins of strain ATCC 14579 were identical with the deduced sequences of three flagellin genes BC1657, BC1658 and BC1659 in the whole genome sequence. Strain ATCC 14579 was classified into serotype T2 by a flagellar serotyping scheme for B. cereus strains that are untypeable into known flagellar serotypes H1 to H23. Flagellar filaments from a reference strain of serotype T2 contained two protein bands at 34 and 32 kDa, but a single protein band at 39 kDa was detected in flagellar filaments of a reference strain of serotype H1. Two murine monoclonal antibodies, 1A5 and 2A5, which recognize both the 34 and 32 kDa flagellins and a single flagellin of 32 kDa, respectively, were specifically reactive with B. cereus strains ATCC 14579 and serotype T2 in whole-cell ELISA and bacterial motility inhibition tests. In immunoelectron microscopy with monoclonal antibodies 1A5 and 2A5, colloidal gold spheres were shown to localize almost evenly over the entire part of flagellar filaments. Since strain ATCC 14579, and presumably strain serotype T2, are unusual among B. cereus strains in possessing multiple genes that encode flagellin subunits, a possible unique mechanism may contribute to assembly of multiple flagellin subunits into the filament over its entire length.

  16. Response of Bacillus cereus ATCC 14579 to challenges with sublethal concentrations of enterocin AS-48

    Directory of Open Access Journals (Sweden)

    Gálvez Antonio

    2009-10-01

    Full Text Available Abstract Background Enterocin AS-48 is produced by Enterococcus faecalis S48 to compete with other bacteria in their environment. Due to its activity against various Gram positive and some Gram negative bacteria it has clear potential for use as a food preservative. Here, we studied the effect of enterocin AS-48 challenges on vegetative cells of Bacillus cereus ATCC 14579 by use of transcriptome analysis. Results Of the 5200 genes analysed, expression of 24 genes was found to change significantly after a 30 min treatment with a subinhibitory bacteriocin concentration of 0.5 μg/ml. Most of up-regulated genes encode membrane-associated or secreted proteins with putative transmembrane segments or signal sequences, respectively. One operon involved in arginine metabolism was significantly downregulated. The BC4206-BC4207 operon was found to be the most upregulated target in our experiments. BC4206 codes for a PadR type transcriptional regulator, while BC4207 codes for a hypothetical membrane protein. The operon structure and genes are conserved in B. cereus and B. thuringiensis species, but are not present in B. anthracis and B. subtilis. Using real-time qPCR, we show that these genes are upregulated when we treated the cells with AS-48, but not upon nisin treatment. Upon overexpression of BC4207 in B. cereus, we observed an increased resistance against AS-48. Expression of BC4207 in B. subtilis 168, which lacks this operon also showed increased resistance against AS-48. Conclusion BC4207 membrane protein is involved in the resistance mechanism of B. cereus cells against AS-48.

  17. Evaluation of the Sporicidal Activity of Ethanol Extract of Arctium lappa Root against Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Vajihe Karbasizade

    2014-10-01

    Full Text Available Background: Bacillus cereus is one of the most common causes of food spoilage, keratitis, endophthalmitis, and panophthalmitis. These bacteria produce spores which are resistant to chemical and physical agents. Nowadays, the sporicidal properties of plants have been considered as alternatives to chemical sporicidal agents. Materials and Methods: In this empirical-experimental study the effect of ethanol extract of edible burdock (Arctium lappa root has been studied on Bacillus cereus spores. In this investigation, the suspensions of tested microorganisms were cultured in sporulating agar. Sporulation process was assessed by optical microscopy following the staining of spores. Then the produced spores were exposed to various concentrations (100, 150, 200, 250, 300 mg/mL of ethanol extract of edible burdock (Arctium lappa root and finally the remaining spores were counted. With increasing concentrations of ethanol extract, the number of spores declined. Results: Pearson correlation showed inverse relation between the spores count and concentration of ethanol extract of edible burdock (Arctium lappa root (r=-0.765, p<0.001. The most effective extract concentration was 300 mg /mL. Conclusion: Ethanol extract of edible burdock (Arctium lappa root, has sporicidal activity. Only, the sporicidal nature of ethanol extract has been evaluated by this study; therefore, the assessment of other extracts and essences is necessary.

  18. Simultaneous Detection of Escherichia coli, Salmonella enterica, Listeria monocytegenes and Bacillus cereus by Oligonucleotide Microarray

    Directory of Open Access Journals (Sweden)

    Meysam Sarshar

    2015-11-01

    Full Text Available Background: Traditional laboratory methods to detect pathogenic bacteria are time consuming and laborious. Therefore, it is essential to use powerful and reliable molecular methods for quick and simultaneous detection of microbial pathogens. Objectives: The current study aimed to evaluate the capability and efficiency of 23S rDNA sequence for rapid and simultaneous detection of four important food-borne pathogens by an oligonucleotide microarray technique. Materials and Methods: The 23S rDNA sequences of Escherichia coli, Salmonella enterica, Listeria monocytogenes and Bacillus cereus were obtained from GenBank databases and used to design the oligonucleotide probes and primers by Vector NTI software. Oligonucleotide probes were placed on a nylon membrane and hybridization was performed between probes and 23S rDNA digoxigenin-labeled polymerase chain reaction (PCR products. Hybridization signals were visualized by NBT/BCIP color development. Results: Positive hybridization color was produced for Escherichia coli, Salmonella enterica, Listeria monocytogenes and Bacillus cereus. The oligonucleotide microarray detected all bacterial strains in a single reaction in less than five hours. The sensitivity of the performed microarray assay was 103 cfu/mL for each species of pathogen. No cross reaction was found between the tested bacterial species. Conclusions: The obtained results indicated that amplification of 23S rDNA gene followed by oligonucleotide microarray hybridization is a rapid and reliable method to identify and discriminate foodborne pathogens tested under the study.

  19. Inhibition of Bacillus cereus Strains by Antimicrobial Metabolites from Lactobacillus johnsonii CRL1647 and Enterococcus faecium SM21.

    Science.gov (United States)

    Soria, M Cecilia; Audisio, M Carina

    2014-12-01

    Bacillus cereus is an endospore-forming, Gram-positive bacterium able to cause foodborne diseases. Lactic acid bacteria (LAB) are known for their ability to synthesize organic acids and bacteriocins, but the potential of these compounds against B. cereus has been scarcely documented in food models. The present study has examined the effect of the metabolites produced by Lactobacillus johnsonii CRL1647 and Enterococcus faecium SM21 on the viability of select B. cereus strains. Furthermore, the effect of E. faecium SM21 metabolites against B. cereus strains has also been investigated on a rice food model. L. johnsonii CRL1647 produced 128 mmol/L of lactic acid, 38 mmol/L of acetic acid and 0.3 mmol/L of phenyl-lactic acid. These organic acids reduced the number of vegetative cells and spores of the B. cereus strains tested. However, the antagonistic effect disappeared at pH 6.5. On the other hand, E. faecium SM21 produced only lactic and acetic acid (24.5 and 12.2 mmol/L, respectively) and was able to inhibit both vegetative cells and spores of the B. cereus strains, at a final fermentation pH of 5.0 and at pH 6.5. This would indicate the action of other metabolites, different from organic acids, present in the cell-free supernatant. On cooked rice grains, the E. faecium SM21 bacteriocin(s) were tested against two B. cereus strains. Both of them were significantly affected within the first 4 h of contact; whereas B. cereus BAC1 cells recovered after 24 h, the effect on B. cereus 1 remained up to the end of the assay. The LAB studied may thus be considered to define future strategies for biological control of B. cereus.

  20. Analysis of the life cycle of the soil saprophyte Bacillus cereus in liquid soil extract and in soil.

    Science.gov (United States)

    Vilain, Sébastien; Luo, Yun; Hildreth, Michael B; Brözel, Volker S

    2006-07-01

    Bacillus is commonly isolated from soils, with organisms of Bacillus cereus sensu lato being prevalent. Knowledge of the ecology of B. cereus and other Bacillus species in soil is far from complete. While the older literature favors a model of growth on soil-associated organic matter, the current paradigm is that B. cereus sensu lato germinates and grows in association with animals or plants, resulting in either symbiotic or pathogenic interactions. An in terra approach to study soil-associated bacteria is described, using filter-sterilized soil-extracted soluble organic matter (SESOM) and artificial soil microcosms (ASM) saturated with SESOM. B. cereus ATCC 14579 displayed a life cycle, with the ability to germinate, grow, and subsequently sporulate in both the liquid SESOM extract and in ASM inserted into wells in agar medium. Cells grew in liquid SESOM without separating, forming multicellular structures that coalesced to form clumps and encasing the ensuing spores in an extracellular matrix. Bacillus was able to translocate from the point of inoculation through soil microcosms as shown by the emergence of outgrowths on the surrounding agar surface. Microscopic inspection revealed bundles of parallel chains inside the soil. The motility inhibitor L-ethionine failed to suppress outgrowth, ruling out translocation by a flagellar-mediated mechanism such as swimming or swarming. Bacillus subtilis subsp. subtilis Marburg and four Bacillus isolates taken at random from soils also displayed a life cycle in SESOM and ASM and were all able to translocate through ASM, even in presence of L-ethionine. These data indicate that B. cereus is a saprophytic bacterium that is able to grow in soil and furthermore that it is adapted to translocate by employing a multicellular mode of growth.

  1. Foodborne disease outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus--United States, 1998-2008.

    Science.gov (United States)

    Bennett, Sarah D; Walsh, Kelly A; Gould, L Hannah

    2013-08-01

    From 1998 to 2008, 1229 foodborne outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus were reported in the United States; 39% were reported with a confirmed etiology. Vomiting was commonly reported in B. cereus (median, 75% of cases) and S. aureus outbreaks (median, 87%), but rarely in C. perfringens outbreaks (median, 9%). Meat or poultry dishes were commonly implicated in C. perfringens (63%) and S. aureus (55%) outbreaks, and rice dishes were commonly implicated in B. cereus outbreaks (50%). Errors in food processing and preparation were commonly reported (93%), regardless of etiology; contamination by a food worker was only common in S. aureus outbreaks (55%). Public health interventions should focus on these commonly reported errors to reduce the occurrence of outbreaks caused by B. cereus, C. perfringens, and S. aureus in the United States.

  2. Study of the antibacterial effects of chitosans on Bacillus cereus (and its spores) by atomic force microscopy imaging and nanoindentation

    International Nuclear Information System (INIS)

    Fernandes, Joao C.; Eaton, Peter; Gomes, Ana M.; Pintado, Manuela E.; Xavier Malcata, F.

    2009-01-01

    Bacillus cereus is a Gram-positive, spore-forming bacterium that is widely distributed in nature. Its intrinsic thermal resistance coupled with the extraordinary resistance against common food preservation techniques makes it one of the most frequent food-poisoning microorganisms causing both intoxications and infections. In order to control B. cereus growth/sporulation, and hence minimize the aforementioned hazards, several antimicrobial compounds have been tested. The aim of this work was to assess by atomic force microscopy (AFM) the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon both vegetative and resistance forms of B. cereus. The use of AFM imaging studies helped us to understand how chitosans with different MW act differently upon B. cereus. Higher MW chitosans (628 and 100 kDa) surrounded both forms of B. cereus cells by forming a polymer layer-which eventually led to the death of the vegetative form by preventing the uptake of nutrients yet did not affect the spores since these can survive for extended periods without nutrients. Chitooligosaccharides (COS) (<3 kDa), on the other hand, provoked more visible damages in the B. cereus vegetative form-most probably due to the penetration of the cells by the COS. The use of COS by itself on B. cereus spores was not enough for the destruction of a large number of cells, but it may well weaken the spore structure and its ability to contaminate, by inducing exosporium loss.

  3. Rapid, High-Throughput Identification of Anthrax-Causing and Emetic Bacillus cereus Group Genome Assemblies via BTyper, a Computational Tool for Virulence-Based Classification of Bacillus cereus Group Isolates by Using Nucleotide Sequencing Data

    Science.gov (United States)

    Carroll, Laura M.; Miller, Rachel A.; Wiedmann, Martin

    2017-01-01

    ABSTRACT The Bacillus cereus group comprises nine species, several of which are pathogenic. Differentiating between isolates that may cause disease and those that do not is a matter of public health and economic importance, but it can be particularly challenging due to the high genomic similarity within the group. To this end, we have developed BTyper, a computational tool that employs a combination of (i) virulence gene-based typing, (ii) multilocus sequence typing (MLST), (iii) panC clade typing, and (iv) rpoB allelic typing to rapidly classify B. cereus group isolates using nucleotide sequencing data. BTyper was applied to a set of 662 B. cereus group genome assemblies to (i) identify anthrax-associated genes in non-B. anthracis members of the B. cereus group, and (ii) identify assemblies from B. cereus group strains with emetic potential. With BTyper, the anthrax toxin genes cya, lef, and pagA were detected in 8 genomes classified by the NCBI as B. cereus that clustered into two distinct groups using k-medoids clustering, while either the B. anthracis poly-γ-d-glutamate capsule biosynthesis genes capABCDE or the hyaluronic acid capsule hasA gene was detected in an additional 16 assemblies classified as either B. cereus or Bacillus thuringiensis isolated from clinical, environmental, and food sources. The emetic toxin genes cesABCD were detected in 24 assemblies belonging to panC clades III and VI that had been isolated from food, clinical, and environmental settings. The command line version of BTyper is available at https://github.com/lmc297/BTyper. In addition, BMiner, a companion application for analyzing multiple BTyper output files in aggregate, can be found at https://github.com/lmc297/BMiner. IMPORTANCE Bacillus cereus is a foodborne pathogen that is estimated to cause tens of thousands of illnesses each year in the United States alone. Even with molecular methods, it can be difficult to distinguish nonpathogenic B. cereus group isolates from their

  4. Characterization of LysB4, an endolysin from the Bacillus cereus-infecting bacteriophage B4.

    Science.gov (United States)

    Son, Bokyung; Yun, Jiae; Lim, Jeong-A; Shin, Hakdong; Heu, Sunggi; Ryu, Sangryeol

    2012-03-15

    Bacillus cereus is a foodborne pathogen that causes emetic or diarrheal types of food poisoning. The incidence of B. cereus food poisoning has been gradually increasing over the past few years, therefore, biocontrol agents effective against B. cereus need to be developed. Endolysins are phage-encoded bacterial peptidoglycan hydrolases and have received considerable attention as promising antibacterial agents. The endolysin from B. cereus phage B4, designated LysB4, was identified and characterized. In silico analysis revealed that this endolysin had the VanY domain at the N terminus as the catalytic domain, and the SH3_5 domain at the C terminus that appears to be the cell wall binding domain. Biochemical characterization of LysB4 enzymatic activity showed that it had optimal peptidoglycan hydrolase activity at pH 8.0-10.0 and 50°C. The lytic activity was dependent on divalent metal ions, especially Zn2+. The antimicrobial spectrum was relatively broad because LysB4 lysed Gram-positive bacteria such as B. cereus, Bacillus subtilis and Listeria monocytogenes and some Gram-negative bacteria when treated with EDTA. LC-MS analysis of the cell wall cleavage products showed that LysB4 was an L-alanoyl-D-glutamate endopeptidase, making LysB4 the first characterized endopeptidase of this type to target B. cereus. LysB4 is believed to be the first reported L-alanoyl-D-glutamate endopeptidase from B. cereus-infecting bacteriophages. The properties of LysB4 showed that this endolysin has strong lytic activity against a broad range of pathogenic bacteria, which makes LysB4 a good candidate as a biocontrol agent against B. cereus and other pathogenic bacteria.

  5. Characterization of LysB4, an endolysin from the Bacillus cereus-infecting bacteriophage B4

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    Son Bokyung

    2012-03-01

    Full Text Available Abstract Background Bacillus cereus is a foodborne pathogen that causes emetic or diarrheal types of food poisoning. The incidence of B. cereus food poisoning has been gradually increasing over the past few years, therefore, biocontrol agents effective against B. cereus need to be developed. Endolysins are phage-encoded bacterial peptidoglycan hydrolases and have received considerable attention as promising antibacterial agents. Results The endolysin from B. cereus phage B4, designated LysB4, was identified and characterized. In silico analysis revealed that this endolysin had the VanY domain at the N terminus as the catalytic domain, and the SH3_5 domain at the C terminus that appears to be the cell wall binding domain. Biochemical characterization of LysB4 enzymatic activity showed that it had optimal peptidoglycan hydrolase activity at pH 8.0-10.0 and 50°C. The lytic activity was dependent on divalent metal ions, especially Zn2+. The antimicrobial spectrum was relatively broad because LysB4 lysed Gram-positive bacteria such as B. cereus, Bacillus subtilis and Listeria monocytogenes and some Gram-negative bacteria when treated with EDTA. LC-MS analysis of the cell wall cleavage products showed that LysB4 was an L-alanoyl-D-glutamate endopeptidase, making LysB4 the first characterized endopeptidase of this type to target B. cereus. Conclusions LysB4 is believed to be the first reported L-alanoyl-D-glutamate endopeptidase from B. cereus-infecting bacteriophages. The properties of LysB4 showed that this endolysin has strong lytic activity against a broad range of pathogenic bacteria, which makes LysB4 a good candidate as a biocontrol agent against B. cereus and other pathogenic bacteria.

  6. The bcr1 DNA repeat element is specific to the Bacillus cereus group and exhibits mobile element characteristics.

    Science.gov (United States)

    Økstad, Ole Andreas; Tourasse, Nicolas J; Stabell, Fredrik B; Sundfaer, Cathrine K; Egge-Jacobsen, Wolfgang; Risøen, Per Arne; Read, Timothy D; Kolstø, Anne-Brit

    2004-11-01

    Bacillus cereus strains ATCC 10987 and ATCC 14579 harbor an approximately 155-bp repeated element, bcr1, which is conserved in B. cereus, B. anthracis, B. thuringiensis, and B. mycoides but not in B. subtilis and B. licheniformis. In this study, we show by Southern blot hybridizations that bcr1 is present in all 54 B. cereus group strains tested but absent in 11 Bacillus strains outside the group, suggesting that bcr1 may be specific and ubiquitous to the B. cereus group. By comparative analysis of the complete genome sequences of B. cereus ATCC 10987, B. cereus ATCC 14579, and B. anthracis Ames, we show that bcr1 is exclusively present in the chromosome but absent from large plasmids carried by these strains and that the numbers of full-length bcr1 repeats for these strains are 79, 54, and 12, respectively. Numerous copies of partial bcr1 elements are also present in the three genomes (91, 128, and 53, respectively). Furthermore, the genomic localization of bcr1 is not conserved between strains with respect to chromosomal position or organization of gene neighbors, as only six full-length bcr1 loci are common to at least two of the three strains. However, the intergenic sequence surrounding a specific bcr1 repeat in one of the three strains is generally strongly conserved in the other two, even in loci where bcr1 is found exclusively in one strain. This finding indicates that bcr1 either has evolved by differential deletion from a very high number of repeats in a common ancestor to the B. cereus group or is moving around the chromosome. The identification of bcr1 repeats interrupting genes in B. cereus ATCC 10987 and ATCC 14579 and the presence of a flanking TTTAT motif in each end show that bcr1 exhibits features characteristic of a mobile element.

  7. The genome sequence of Bacillus cereus ATCC 10987 reveals metabolic adaptations and a large plasmid related to Bacillus anthracis pXO1.

    Science.gov (United States)

    Rasko, David A; Ravel, Jacques; Økstad, Ole Andreas; Helgason, Erlendur; Cer, Regina Z; Jiang, Lingxia; Shores, Kelly A; Fouts, Derrick E; Tourasse, Nicolas J; Angiuoli, Samuel V; Kolonay, James; Nelson, William C; Kolstø, Anne-Brit; Fraser, Claire M; Read, Timothy D

    2004-01-01

    We sequenced the complete genome of Bacillus cereus ATCC 10987, a non-lethal dairy isolate in the same genetic subgroup as Bacillus anthracis. Comparison of the chromosomes demonstrated that B.cereus ATCC 10987 was more similar to B.anthracis Ames than B.cereus ATCC 14579, while containing a number of unique metabolic capabilities such as urease and xylose utilization and lacking the ability to utilize nitrate and nitrite. Additionally, genetic mechanisms for variation of capsule carbohydrate and flagella surface structures were identified. Bacillus cereus ATCC 10987 contains a single large plasmid (pBc10987), of approximately 208 kb, that is similar in gene content and organization to B.anthracis pXO1 but is lacking the pathogenicity-associated island containing the anthrax lethal and edema toxin complex genes. The chromosomal similarity of B.cereus ATCC 10987 to B.anthracis Ames, as well as the fact that it contains a large pXO1-like plasmid, may make it a possible model for studying B.anthracis plasmid biology and regulatory cross-talk.

  8. Influence of glutamate on growth, sporulation, and spore properties of Bacillus cereus ATCC 14579 in defined medium

    NARCIS (Netherlands)

    Vries, de Y.P.; Atmadja, R.D.; Hornstra, L.M.; Vos, de W.M.; Abee, T.

    2005-01-01

    A chemically defined medium in combination with an airlift fermentor system was used to study the growth and sporulation of Bacillus cereus ATCC 14579. The medium contained six amino acids and lactate as the main carbon sources. The amino acids were depleted during exponential growth, while lactate

  9. Role of germinant receptors in Caco-2 cell-initiated germination of Bacillus cereus ATCC 14579 endospores

    NARCIS (Netherlands)

    Hornstra, L.M.; Voort, van der M.; Wijnands, L.M.; Roubos-van den Hil, P.J.; Abee, T.

    2009-01-01

    Spores obtained from Bacillus cereus ATCC 14579 and mutant strains lacking each of seven germinant receptor operons were exposed to differentiated Caco-2 cells and monitored for germination. Spores of the gerI and gerL mutants showed a reduced germination response, pointing to a role for these

  10. Sporulation environment of emetic toxin-producing Bacillus cereus strains determines spore size, heat resistance and germination capacity

    NARCIS (Netherlands)

    Voort, van der M.; Abee, T.

    2013-01-01

    Aim Heat resistance, germination and outgrowth capacity of Bacillus cereus spores in processed foods are major factors in causing the emetic type of gastrointestinal disease. In this study, we aim to identify the impact of different sporulation conditions on spore properties of emetic

  11. A novel hybrid kinase is essential for regulating the σB-mediated stress response of Bacillus cereus.

    NARCIS (Netherlands)

    Been, de M.W.H.J.; Tempelaars, Marcel; Schaik, van W.; Moezelaar, Roy; Siezen, R.J.; Abee, Tjakko

    2009-01-01

    A common bacterial strategy for monitoring environmental challenges is to use two-component systems, which consist of a sensor histidine kinase (HK) and a response regulator (RR). In the food-borne pathogen Bacillus cereus, the alternative sigma factor σB is activated by the RR RsbY. Here we present

  12. A novel hybrid kinase is essential for regulating the sigmaB-mediated stress response of Bacillus cereus

    NARCIS (Netherlands)

    Been, de M.W.H.J.; Tempelaars, M.H.; Schaik, van W.; Moezelaar, R.; Siezen, R.J.; Abee, T.

    2010-01-01

    A common bacterial strategy for monitoring environmental challenges is to use two-component systems, which consist of a sensor histidine kinase (HK) and a response regulator (RR). In the food-borne pathogen Bacillus cereus, the alternative sigma factor sB is activated by the RR RsbY. Here we present

  13. Transcriptional regulation of metabolic pathways, alternative respiration and enterotoxin genes in anaerobic growth of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Voort, van der M.; Abee, T.

    2009-01-01

    Aims: To assess genes specifically activated during anaerobic growth that are involved in metabolism and pathogenesis of the foodborne pathogen Bacillus cereus. Methods and Results: Growth under anaerobic conditions in Brain Heart Infusion (BHI) broth revealed a reduced growth rate and lower yield

  14. Characterization of germination and outgrowth of sorbic acid-stressed Bacillus cereus ATCC 14579 spores: Phenotype and transcriptome analysis

    NARCIS (Netherlands)

    Melis, van C.C.J.; Nierop Groot, M.N.; Tempelaars, M.H.; Moezelaar, R.; Abee, T.

    2011-01-01

    Sorbic acid (SA) is widely used as a preservative, but the effect of SA on spore germination and outgrowth has gained limited attention up to now. Therefore, the effect of sorbic acid on germination of spores of Bacillus cereus strain ATCC 14579 was analyzed both at phenotype and transcriptome

  15. Assessment of CcpA-mediated catabolite control of metabolism and enterotoxin production in Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Voort, van der M.; Kuipers, O.P.; Buist, G.; Vos, de Willem; Abee, Tjakko

    2008-01-01

    In Bacillus cereus the catabolite control protein CcpA was shown to be involved in optimizing the efficiency of glucose catabolism by activating genes encoding glycolytic enzymes including a non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase that mediates conversion of D-glyceraldehyde

  16. Growth and sporulation of Bacillus cereus ATCC 14579 under defined conditions: temporal expression of genes for key sigma factors

    NARCIS (Netherlands)

    Vries, de Y.P.; Hornstra, L.M.; Vos, de W.M.; Abee, T.

    2004-01-01

    An airlift fermentor system allowing precise regulation of pH and aeration combined with a chemically defined medium was used to study growth and sporulation of Bacillus cereus ATCC 14579. Sporulation was complete and synchronous. Expression of sigA, sigB, sigF, and sigG was monitored with real-time

  17. Seleção de bacillus spp. para produção de esterases e melhoramento de bacillus cereus (c124 Selection of bacillus spp. For esterase production and genetic improvement of bacillus cereus (c124

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    Analucia Longman Mendonça

    1998-06-01

    Full Text Available Forty-four Bacillus spp. strains obtained from sugar cane derivates and residues, six of them isolated in this work, were tested using Tween 80 as substrate (agar-Tween 80 medium, in order to determine their esterase activity through the enzymatic index averages. After statistic analysis, B. cereus (C124 strain, which presented better results, was submitted to genetic improvement by treatment with ultraviolet light (UV. The survival curve pointed out 28" as the time necessary to obtain 30% of survivors. Fifty survivors and the wild strain C124 were compared in relation to their esterase activity as mentioned previously. The wild strain and the mutant C124UV35, which showed enzymatic index average higher than C124, were characterized in polyacrilamide gel electrophoresis (PAGE. Eletrophoretic patterns for total proteins of wild and mutant strain showed different profiles according to number, position and intensity of bands. For esterase, the bands varied only in intensity.

  18. Characterization and genomic analysis of chromate resistant and reducing Bacillus cereus strain SJ1

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    He Minyan

    2010-08-01

    Full Text Available Abstract Background Chromium is a toxic heavy metal, which primarily exists in two inorganic forms, Cr(VI and Cr(III. Chromate [Cr(VI] is carcinogenic, mutational, and teratogenic due to its strong oxidizing nature. Biotransformation of Cr(VI to less-toxic Cr(III by chromate-resistant and reducing bacteria has offered an ecological and economical option for chromate detoxification and bioremediation. However, knowledge of the genetic determinants for chromate resistance and reduction has been limited so far. Our main aim was to investigate chromate resistance and reduction by Bacillus cereus SJ1, and to further study the underlying mechanisms at the molecular level using the obtained genome sequence. Results Bacillus cereus SJ1 isolated from chromium-contaminated wastewater of a metal electroplating factory displayed high Cr(VI resistance with a minimal inhibitory concentration (MIC of 30 mM when induced with Cr(VI. A complete bacterial reduction of 1 mM Cr(VI was achieved within 57 h. By genome sequence analysis, a putative chromate transport operon, chrIA1, and two additional chrA genes encoding putative chromate transporters that likely confer chromate resistance were identified. Furthermore, we also found an azoreductase gene azoR and four nitroreductase genes nitR possibly involved in chromate reduction. Using reverse transcription PCR (RT-PCR technology, it was shown that expression of adjacent genes chrA1 and chrI was induced in response to Cr(VI but expression of the other two chromate transporter genes chrA2 and chrA3 was constitutive. In contrast, chromate reduction was constitutive in both phenotypic and gene expression analyses. The presence of a resolvase gene upstream of chrIA1, an arsenic resistance operon and a gene encoding Tn7-like transposition proteins ABBCCCD downstream of chrIA1 in B. cereus SJ1 implied the possibility of recent horizontal gene transfer. Conclusion Our results indicate that expression of the chromate

  19. Assessment of CcpA-mediated catabolite control of gene expression in Bacillus cereus ATCC 14579.

    Science.gov (United States)

    van der Voort, Menno; Kuipers, Oscar P; Buist, Girbe; de Vos, Willem M; Abee, Tjakko

    2008-04-16

    The catabolite control protein CcpA is a transcriptional regulator conserved in many Gram-positives, controlling the efficiency of glucose metabolism. Here we studied the role of Bacillus cereus ATCC 14579 CcpA in regulation of metabolic pathways and expression of enterotoxin genes by comparative transcriptome analysis of the wild-type and a ccpA-deletion strain. Comparative analysis revealed the growth performance and glucose consumption rates to be lower in the B. cereus ATCC 14579 ccpA deletion strain than in the wild-type. In exponentially grown cells, the expression of glycolytic genes, including a non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase that mediates conversion of D-glyceraldehyde 3-phosphate to 3-phospho-D-glycerate in one single step, was down-regulated and expression of gluconeogenic genes and genes encoding the citric acid cycle was up-regulated in the B. cereus ccpA deletion strain. Furthermore, putative CRE-sites, that act as binding sites for CcpA, were identified to be present for these genes. These results indicate CcpA to be involved in the regulation of glucose metabolism, thereby optimizing the efficiency of glucose catabolism. Other genes of which the expression was affected by ccpA deletion and for which putative CRE-sites could be identified, included genes with an annotated function in the catabolism of ribose, histidine and possibly fucose/arabinose and aspartate. Notably, expression of the operons encoding non-hemolytic enterotoxin (Nhe) and hemolytic enterotoxin (Hbl) was affected by ccpA deletion, and putative CRE-sites were identified, which suggests catabolite repression of the enterotoxin operons to be CcpA-dependent. The catabolite control protein CcpA in B. cereus ATCC 14579 is involved in optimizing the catabolism of glucose with concomitant repression of gluconeogenesis and alternative metabolic pathways. Furthermore, the results point to metabolic control of enterotoxin gene expression and suggest that Ccp

  20. Assessment of CcpA-mediated catabolite control of gene expression in Bacillus cereus ATCC 14579

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    Buist Girbe

    2008-04-01

    Full Text Available Abstract Background The catabolite control protein CcpA is a transcriptional regulator conserved in many Gram-positives, controlling the efficiency of glucose metabolism. Here we studied the role of Bacillus cereus ATCC 14579 CcpA in regulation of metabolic pathways and expression of enterotoxin genes by comparative transcriptome analysis of the wild-type and a ccpA-deletion strain. Results Comparative analysis revealed the growth performance and glucose consumption rates to be lower in the B. cereus ATCC 14579 ccpA deletion strain than in the wild-type. In exponentially grown cells, the expression of glycolytic genes, including a non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase that mediates conversion of D-glyceraldehyde 3-phosphate to 3-phospho-D-glycerate in one single step, was down-regulated and expression of gluconeogenic genes and genes encoding the citric acid cycle was up-regulated in the B. cereus ccpA deletion strain. Furthermore, putative CRE-sites, that act as binding sites for CcpA, were identified to be present for these genes. These results indicate CcpA to be involved in the regulation of glucose metabolism, thereby optimizing the efficiency of glucose catabolism. Other genes of which the expression was affected by ccpA deletion and for which putative CRE-sites could be identified, included genes with an annotated function in the catabolism of ribose, histidine and possibly fucose/arabinose and aspartate. Notably, expression of the operons encoding non-hemolytic enterotoxin (Nhe and hemolytic enterotoxin (Hbl was affected by ccpA deletion, and putative CRE-sites were identified, which suggests catabolite repression of the enterotoxin operons to be CcpA-dependent. Conclusion The catabolite control protein CcpA in B. cereus ATCC 14579 is involved in optimizing the catabolism of glucose with concomitant repression of gluconeogenesis and alternative metabolic pathways. Furthermore, the results point to metabolic control

  1. Prevalence, Virulence Genes, Antimicrobial Susceptibility, and Genetic Diversity of Bacillus cereus Isolated From Pasteurized Milk in China

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    Tiantian Gao

    2018-03-01

    Full Text Available Bacillus cereus is a common and important food-borne pathogen that can be found in various food products. Due to low-temperature sterilization for a short period of time, pasteurization is not sufficient for complete elimination of B. cereus in milk, thereby cause severe economic loss and food safety problems. It is therefore of paramount importance to perform risk assessment of B. cereus in pasteurized milk. In this study, we isolated B. cereus from pasteurized milk samples in different regions of China, and evaluated the contamination situation, existence of virulence genes, antibiotic resistance profile and genetic polymorphism of B. cereus isolates. Intriguingly, 70 samples (27% were found to be contaminated by B. cereus and the average contamination level was 111 MPN/g. The distribution of virulence genes was assessed toward 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, bceT, and hlyII and one emetic gene (cesB. Forty five percent strains harbored enterotoxigenic genes hblACD and 93% isolates contained nheABC gene cluster. The positive rate of cytK, entFM, bceT, hlyII, and cesB genes were 73, 96, 75, 54, and 5%, respectively. Antibiotic susceptibility assessment showed that most of the isolates were resistant to β-lactam antibiotics and rifampicin, but susceptible to other antibiotics such as ciprofloxacin, gentamicin and chloramphenicol. Total multidrug-resistant population was about 34%. In addition, B. cereus isolates in pasteurized milk showed a high genetic diversity. In conclusion, our findings provide the first reference on the prevalence, contamination level and characteristics of B. cereus isolated from pasteurized milk in China, suggesting a potential high risk of B. cereus to public health and dairy industry.

  2. Intraclade Variability in Toxin Production and Cytotoxicity of Bacillus cereus Group Type Strains and Dairy-Associated Isolates.

    Science.gov (United States)

    Miller, Rachel A; Jian, Jiahui; Beno, Sarah M; Wiedmann, Martin; Kovac, Jasna

    2018-03-15

    While some species in the Bacillus cereus group are well-characterized human pathogens (e.g., B. anthracis and B. cereus sensu stricto ), the pathogenicity of other species (e.g., B. pseudomycoides ) either has not been characterized or is presently not well understood. To provide an updated characterization of the pathogenic potential of species in the B. cereus group, we classified a set of 52 isolates, including 8 type strains and 44 isolates from dairy-associated sources, into 7 phylogenetic clades and characterized them for (i) the presence of toxin genes, (ii) phenotypic characteristics used for identification, and (iii) cytotoxicity to human epithelial cells. Overall, we found that B. cereus toxin genes are broadly distributed but are not consistently present within individual species and/or clades. After growth at 37°C, isolates within a clade did not typically show a consistent cytotoxicity phenotype, except for isolates in clade VI ( B. weihenstephanensis / B. mycoides ), where none of the isolates were cytotoxic, and isolates in clade I ( B. pseudomycoides ), which consistently displayed cytotoxic activity. Importantly, our study highlights that B. pseudomycoides is cytotoxic toward human cells. Our results indicate that the detection of toxin genes does not provide a reliable approach to predict the pathogenic potential of B. cereus group isolates, as the presence of toxin genes is not always consistent with cytotoxicity phenotype. Overall, our results suggest that isolates from multiple B. cereus group clades have the potential to cause foodborne illness, although cytotoxicity is not always consistently found among isolates within each clade. IMPORTANCE Despite the importance of the Bacillus cereus group as a foodborne pathogen, characterizations of the pathogenic potential of all B. cereus group species were lacking. We show here that B. pseudomycoides (clade I), which has been considered a harmless environmental microorganism, produces toxins and

  3. A strain-variable bacteriocin in Bacillus anthracis and Bacillus cereus with repeated Cys-Xaa-Xaa motifs

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    Haft Daniel H

    2009-04-01

    Full Text Available Abstract Bacteriocins are peptide antibiotics from ribosomally translated precursors, produced by bacteria often through extensive post-translational modification. Minimal sequence conservation, short gene lengths, and low complexity sequence can hinder bacteriocin identification, even during gene calling, so they are often discovered by proximity to accessory genes encoding maturation, immunity, and export functions. This work reports a new subfamily of putative thiazole-containing heterocyclic bacteriocins. It appears universal in all strains of Bacillus anthracis and B. cereus, but has gone unrecognized because it is always encoded far from its maturation protein operon. Patterns of insertions and deletions among twenty-four variants suggest a repeating functional unit of Cys-Xaa-Xaa. Reviewers This article was reviewed by Andrei Osterman and Lakshminarayan Iyer.

  4. Bacillus cereus Biovar Anthracis Causing Anthrax in Sub-Saharan Africa-Chromosomal Monophyly and Broad Geographic Distribution.

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    Kym S Antonation

    2016-09-01

    Full Text Available Through full genome analyses of four atypical Bacillus cereus isolates, designated B. cereus biovar anthracis, we describe a distinct clade within the B. cereus group that presents with anthrax-like disease, carrying virulence plasmids similar to those of classic Bacillus anthracis. We have isolated members of this clade from different mammals (wild chimpanzees, gorillas, an elephant and goats in West and Central Africa (Côte d'Ivoire, Cameroon, Central African Republic and Democratic Republic of Congo. The isolates shared several phenotypic features of both B. anthracis and B. cereus, but differed amongst each other in motility and their resistance or sensitivity to penicillin. They all possessed the same mutation in the regulator gene plcR, different from the one found in B. anthracis, and in addition, carry genes which enable them to produce a second capsule composed of hyaluronic acid. Our findings show the existence of a discrete clade of the B. cereus group capable of causing anthrax-like disease, found in areas of high biodiversity, which are possibly also the origin of the worldwide distributed B. anthracis. Establishing the impact of these pathogenic bacteria on threatened wildlife species will require systematic investigation. Furthermore, the consumption of wildlife found dead by the local population and presence in a domestic animal reveal potential sources of exposure to humans.

  5. Dynamic Predictive Model for Growth of Bacillus cereus from Spores in Cooked Beans.

    Science.gov (United States)

    Juneja, Vijay K; Mishra, Abhinav; Pradhan, Abani K

    2018-02-01

    Kinetic growth data for Bacillus cereus grown from spores were collected in cooked beans under several isothermal conditions (10 to 49°C). Samples were inoculated with approximately 2 log CFU/g heat-shocked (80°C for 10 min) spores and stored at isothermal temperatures. B. cereus populations were determined at appropriate intervals by plating on mannitol-egg yolk-polymyxin agar and incubating at 30°C for 24 h. Data were fitted into Baranyi, Huang, modified Gompertz, and three-phase linear primary growth models. All four models were fitted to the experimental growth data collected at 13 to 46°C. Performances of these models were evaluated based on accuracy and bias factors, the coefficient of determination ( R 2 ), and the root mean square error. Based on these criteria, the Baranyi model best described the growth data, followed by the Huang, modified Gompertz, and three-phase linear models. The maximum growth rates of each primary model were fitted as a function of temperature using the modified Ratkowsky model. The high R 2 values (0.95 to 0.98) indicate that the modified Ratkowsky model can be used to describe the effect of temperature on the growth rates for all four primary models. The acceptable prediction zone (APZ) approach also was used for validation of the model with observed data collected during single and two-step dynamic cooling temperature protocols. When the predictions using the Baranyi model were compared with the observed data using the APZ analysis, all 24 observations for the exponential single rate cooling were within the APZ, which was set between -0.5 and 1 log CFU/g; 26 of 28 predictions for the two-step cooling profiles also were within the APZ limits. The developed dynamic model can be used to predict potential B. cereus growth from spores in beans under various temperature conditions or during extended chilling of cooked beans.

  6. Conducting polymer based DNA biosensor for the detection of the Bacillus cereus group species

    Science.gov (United States)

    Velusamy, Vijayalakshmi; Arshak, Khalil; Korostynska, Olga; Oliwa, Kamila; Adley, Catherine

    2009-05-01

    Biosensor designs are emerging at a significant rate and play an increasingly important role in foodborne pathogen detection. Conducting polymers are excellent tools for the fabrication of biosensors and polypyrrole has been used in the detection of biomolecules due to its unique properties. The prime intention of this paper was to pioneer the design and fabrication of a single-strand (ss) DNA biosensor for the detection of the Bacillus cereus (B.cereus) group species. Growth of B. cereus, results in production of several highly active toxins. Therefore, consumption of food containing >106 bacteria/gm may results in emetic and diarrhoeal syndromes. The most common source of this bacterium is found in liquid food products, milk powder, mixed food products and is of particular concern in the baby formula industry. The electrochemical deposition technique, such as cyclic voltammetry, was used to develop and test a model DNA-based biosensor on a gold electrode electropolymerized with polypyrrole. The electrically conducting polymer, polypyrrole is used as a platform for immobilizing DNA (1μg) on the gold electrode surface, since it can be more easily deposited from neutral pH aqueous solutions of pyrrolemonomers. The average current peak during the electrodeposition event is 288μA. There is a clear change in the current after hybridization of the complementary oligonucleotide (6.35μA) and for the noncomplementary oligonucleotide (5.77μA). The drop in current after each event was clearly noticeable and it proved to be effective.

  7. Identification of Cereulide-Producing Bacillus cereus by Nucleic Acid Chromatography and Reverse Transcription Real-Time PCR.

    Science.gov (United States)

    Ueda, Shigeko; Yamaguchi, Manami; Eguchi, Kayoko; Iwase, Miki

    2016-01-01

    RNA extracts were analyzed with a nucleic acid sequence-based amplification (NASBA) - nucleic acid chromatography and a reverse transcription-quantitative PCR assay (RT-qPCR) based on the TaqMan probe for identification of cereulide-producing Bacillus cereus. All 100 emetic B. cereus strains were found to give positive results, but 50 diarrheal B. cereus strains and other bacterial species showed negative results in the NASBA-chromatography. That is, the assay could selectively identify the emetic strains among B. cereus strains. Also, the B. cereus contents of more than 10(7) cfu/ml were required for the identification of the cereulide-producing strains in this assay. In qRT-PCR assays, all 100 emetic type strains of B. cereus produced 10(2) - 10(4) copy numbers per ng of the RNA preparation, and the strains produced 10(4) copies including ones which had the high vacuolation activities of HEp-2 cells.

  8. Characterization of LysPBC4, a novel Bacillus cereus-specific endolysin of bacteriophage PBC4.

    Science.gov (United States)

    Na, Hongjun; Kong, Minsuk; Ryu, Sangryeol

    2016-06-01

    Bacillus cereus is a spore-forming, Gram-positive bacterium and is a major food-borne pathogen. A B. cereus-specific bacteriophage PBC4 was isolated from the soil of a stock farm, and its genome was analyzed. PBC4 belongs to the Siphoviridae family and has a genome consisting of 80 647-bp-long double-stranded DNA, including 123 genes and two tRNAs. LysPBC4, the endolysin of PBC4, has an enzymatically active domain (EAD) on its N-terminal region and a putative cell wall-binding domain (CBD) on its C-terminal region, respectively. Although the phage PBC4 showed a very limited host range, LysPBC4 could lyse all of the B. cereus strains tested. However, LysPBC4 did not kill other bacteria such as B. subtilis or Listeria, indicating that the endolysin has specific lytic activity against the B. cereus group species. Furthermore, LysPBC4_CBD fused with enhanced green fluorescent protein (EGFP) could decorate limited strains of B. cereus group, suggesting that the LysPBC4_CBD may be a promising material for specific detection of B. cereus. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Root exudate-induced alterations in Bacillus cereus cell wall contribute to root colonization and plant growth promotion.

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    Swarnalee Dutta

    Full Text Available The outcome of an interaction between plant growth promoting rhizobacteria and plants may depend on the chemical composition of root exudates (REs. We report the colonization of tobacco, and not groundnut, roots by a non-rhizospheric Bacillus cereus (MTCC 430. There was a differential alteration in the cell wall components of B. cereus in response to the REs from tobacco and groundnut. Attenuated total reflectance infrared spectroscopy revealed a split in amide I region of B. cereus cells exposed to tobacco-root exudates (TRE, compared to those exposed to groundnut-root exudates (GRE. In addition, changes in exopolysaccharides and lipid-packing were observed in B. cereus grown in TRE-amended minimal media that were not detectable in GRE-amended media. Cell-wall proteome analyses revealed upregulation of oxidative stress-related alkyl hydroperoxide reductase, and DNA-protecting protein chain (Dlp-2, in response to GRE and TRE, respectively. Metabolism-related enzymes like 2-amino-3-ketobutyrate coenzyme A ligase and 2-methylcitrate dehydratase and a 60 kDa chaperonin were up-regulated in response to TRE and GRE. In response to B. cereus, the plant roots altered their exudate-chemodiversity with respect to carbohydrates, organic acids, alkanes, and polyols. TRE-induced changes in surface components of B. cereus may contribute to successful root colonization and subsequent plant growth promotion.

  10. Variable responses on early development of shallot (Allium ascalonicum and mustard (Brassica juncea plants to Bacillus cereus inoculation

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    Aziz, Z.F.A

    2012-01-01

    Full Text Available Aim: Auxin, a phytohormone secreted by plant growth-promoting rhizobacteria is one of the direct mechanisms vital for plant growth promotion. A laboratory experiment was conducted to observe the effect of IAA-producing and non-IAA-producing diazotroph Bacillus cereus strains on early growth of shallot (Allium ascalonicum and mustard (Brassica juncea plants.Methodology and Results: Treatments evaluated were as follows: Control = uninoculated, no inoculation, UPMLH1 = IAA-producing B. cereus UPMLH1, and UPMLH24 = non-IAA-producing B. cereus UPMLH24. Inoculation with IAA-producing B. cereus UPMLH1 significantly increased shallot adventitious roots (root number and length and shoot growth (19 to 54% increment. Inoculation of non-IAA-producing B. cereus UPMLH24 did not significantly improve growth of adventitious roots of shallot as compared to uninoculated control, except its shoot (up to 40% increase. However, primary roots and shoot growth of mustard plants significantly increased through inoculation with IAA-producing and non-IAA-producing strains (14 to 73% increment.Conclusion, Significance and Impact of Study: The results indicated that exogenous IAA secreted by B. cereus UPMLH1 might have play an important role in inducing roots of shallot bulbs and it may have a variable promotional effect depending on plant species.

  11. Bacillus cereus AR156 induces resistance against Rhizopus rot through priming of defense responses in peach fruit.

    Science.gov (United States)

    Wang, Xiaoli; Xu, Feng; Wang, Jing; Jin, Peng; Zheng, Yonghua

    2013-01-15

    The biocontrol effects of Bacillus cereus AR156 on Rhizopus rot caused by Rhizopus stolonifer in postharvest peach fruit and the possible mechanisms were investigated. The results showed that fruit treated with B. cereus AR156 had significantly lower disease incidence and smaller lesion diameter than the control fruit did. B. cereus AR156 treatment remarkably enhanced activities of chitinase and β-1,3-glucanase, promoted accumulation of H(2)O(2), and improved total phenolic content and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity. Transcripts of four defense related genes were only significantly enhanced in fruit both treated with B. cereus AR156 and inoculated with R. stolonifer compared with those that were only treated with B. cereus AR156 or inoculated with R. stolonifer. These results suggest that B. cereus AR156 can effectively inhibit Rhizopus rot caused by R. stolonifer and enhance antioxidant activity in peach fruit through the priming of defense responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. YwdL in Bacillus cereus: its role in germination and exosporium structure.

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    Cassandra Terry

    Full Text Available In members of the Bacillus cereus group the outermost layer of the spore is the exosporium, which interacts with hosts and the environment. Efforts have been made to identify proteins of the exosporium but only a few have so far been characterised and their role in determining spore architecture and spore function is still poorly understood. We have characterised the exosporium protein, YwdL. ΔywdL spores have a more fragile exosporium, subject to damage on repeated freeze-thawing, although there is no evidence of altered resistance properties, and coats appear intact. Immunogold labelling and Western blotting with anti-YwdL antibodies identified YwdL to be located exclusively on the inner surface of the exosporium of B. cereus and B. thuringiensis. We conclude that YwdL is important for formation of a robust exosporium but is not required to maintain the crystalline assembly within the basal layer or for attachment of the hairy nap structure. ΔywdL spores are unable to germinate in response to CaDPA, and have altered germination properties, a phenotype that confirms the expected defect in localization of the cortex lytic enzyme CwlJ in the coat.

  13. Effects of Copaifera duckei Dwyer oleoresin on the cell wall and cell division of Bacillus cereus.

    Science.gov (United States)

    Gomes Dos Santos, Elizabeth Cristina; Donnici, Claudio Luis; Camargos, Elizabeth Ribeiro da Silva; Augusto de Rezende, Adriana; Andrade, Eloisa Helena de Aguiar; Soares, Luiz Alberto Lira; Farias, Luiz de Macêdo; Roque de Carvalho, Maria Auxiliadora; Almeida, Maria das Graças

    2013-07-01

    The aim of this work was to evaluate the antibacterial activity of Copaifera duckei oleoresin and to determine its possible mechanism of action against bacteria of clinical and food interest. The antibacterial activity was determined by agar diffusion and dilution methods; the mechanism of action by transmission electron microscopy and by SDS-PAGE; the bioactive compounds by bioautography; and the chemical analysis by GC/MS. Oleoresin showed activity against nine of the 11 strains of bacteria tested. Bacillus cereus was the most sensitive, with a MIC corresponding to 0.03125 mg ml(-1) and with a bactericidal action. Oleoresin acted on the bacterial cell wall, removing proteins and the S-layer, and interfering with the cell-division process. This activity probably can be attributed to the action of terpenic compounds, among them the bisabolene compound. Gram-negative bacteria tested were not inhibited. C. duckei oleoresin is a potential antibacterial, suggesting that this oil could be used as a therapeutic alternative, mainly against B. cereus.

  14. [Lead adsorption by Trametes gallica, Bacillus cereus, and their co-immobilized biomaterial].

    Science.gov (United States)

    Yang, Zhou-Ping; Chen, Ping; Wang, Zhen-Yu; Hu, Rong; Jing, De-Jun; Huang, Qian-Ming

    2012-08-01

    Taking Trametes gallica mycelium pellets, Bacillus cereus, and their co-immobilized biomaterial as bio-adsorbents, this paper studied their Pb2+ adsorption under effects of different contact time, medium initial pH value and Pb2+ concentration, and bio-adsorbent concentration, and compared the infrared spectra of the bio-adsorbents before and after Pb2+ absorption. The Pb2+ adsorption efficiency of the bio-adsorbents was the highest when the bio-adsorbent concentration was 2 g x L(-1), initial pH was 5.0, initial Pb2+ concentration was 50 mg x L(-1), and contact time was 1 h, with the Pb2+ biosorption rate being 71.7% for the mycelium pellets of T. gallica, 91.0% for B. cereus, and 96.9% for the co-immobilized biomaterial. The infrared spectra of the bio-adsorbents were mainly consisted of the absorption zones of protein, carbohydrates, and sulphur- and phosphors-based groups, suggesting that hydroxyl, carboxyl, and sulphur- and phosphate-based groups played important roles in the Pb2+ adsorption by the bio-adsorbents.

  15. Production of Bio polymer (PHB) from Whey by Local Strain of Bacillus cereus

    International Nuclear Information System (INIS)

    Abdel Kareem, H.; Hamed, D.; Omar, S.; Gebreel, H.; Khalaf, M.; El-M-Mahalawy, A.

    2008-01-01

    The local strain Bacillus cereus S 3 , which isolated from the soil attached to the rice root, was employed for PHB production from whey and soya extract as the main carbon and nitrogen sources. Some supplements such as (0.5 g) tryptone and (0.5 g) NaCl were added to 75 ml whey and 25 ml soya extract to optimize the PHB accumulation medium. Different parameters including; initial ph of the medium, working volume, NaCl concentration and inoculum age and size; were carried out under shaking flask conditions (150 rpm) at 30 degree C for 48 h of incubation to enhance the PHB accumulation. The maximum PHB accumulation (2.42 gl -1 ) was achieved at ph 6, 100 ml working volume, (0.5-2%) NaCl, at 60 h and 4 ml inoculum age and size, respectively. An experiment was conducted to investigate the effect of gamma irradiation on the activity of B. cereus S 3 towards PHB accumulation. At dose level 1.5 kGy the maximum PHB accumulation obtained was 3.2 gl -1

  16. Characterization of an endolysin, LysBPS13, from a Bacillus cereus bacteriophage.

    Science.gov (United States)

    Park, Jaeeun; Yun, Jiae; Lim, Jeong-A; Kang, Dong-Hyun; Ryu, Sangryeol

    2012-07-01

    Use of bacteriophages as biocontrol agents is a promising tool for controlling pathogenic bacteria including antibiotic-resistant bacteria. Not only bacteriophages but also endolysins, the peptidoglycan hydrolyzing enzymes encoded by bacteriophages, have high potential for applications as biocontrol agents against food-borne pathogens. In this study, a putative endolysin gene was identified in the genome of the bacteriophage BPS13, which infects Bacillus cereus. In silico analysis of this endolysin, designated LysBPS13, showed that it consists of an N-terminal catalytic domain (PGRP domain) and a C-terminal cell wall binding domain (SH3_5 domain). Further characterization of the purified LysBPS13 revealed that this endolysin is an N-acetylmuramyl-l-alanine amidase, the activity of which was not influenced by addition of EDTA. In addition, LysBPS13 demonstrated remarkable thermostability in the presence of glycerol, and it retained its lytic activity even after incubation at 100 °C for 30 min. Taken together, these results indicate that LysBPS13 can be considered a favorable candidate for a new antimicrobial agent to control B. cereus. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. Comparative transcriptomic and phenotypic analysis of the responses of Bacillus cereus to various disinfectant treatments.

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    Ceragioli, Mara; Mols, Maarten; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko

    2010-05-01

    Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growth arrest, and cell death were determined. The transcriptome analysis revealed that B. cereus, upon exposure to the selected concentrations of disinfectants, induced common and specific responses. Notably, the common response included genes involved in the general and oxidative stress responses. Exposure to benzalkonium chloride, a disinfectant known to induce membrane damage, specifically induced genes involved in fatty acid metabolism. Membrane damage induced by benzalkonium chloride was confirmed by fluorescence microscopy, and fatty acid analysis revealed modulation of the fatty acid composition of the cell membrane. Exposure to sodium hypochlorite induced genes involved in metabolism of sulfur and sulfur-containing amino acids, which correlated with the excessive oxidation of sulfhydryl groups observed in sodium hypochlorite-stressed cells. Exposures to hydrogen peroxide and peracetic acid induced highly similar responses, including the upregulation of genes involved in DNA damage repair and SOS response. Notably, hydrogen peroxide- and peracetic acid-treated cells exhibited high mutation rates correlating with the induced SOS response.

  18. Comparative analysis of transcriptional and physiological responses of Bacillus cereus to organic and inorganic acid shocks.

    Science.gov (United States)

    Mols, Maarten; van Kranenburg, Richard; Tempelaars, Marcel H; van Schaik, Willem; Moezelaar, Roy; Abee, Tjakko

    2010-01-31

    Comparative phenotype and transcriptome analyses were performed with Bacillus cereus ATCC 14579 exposed to pH 5.5 set with different acidulants including hydrochloric acid (HCl), lactic acid (HL) and acetic acid (HAc). Phenotypes observed included a decreased growth rate (with HCl), bacteriostatic and bactericidal conditions, with 2mM undissociated HAc or HL, and 15mM undissociated HAc, respectively. In the latter condition a concomitant decrease in intracellular ATP levels was observed. The transcriptome analyses revealed general and specific responses to the acidulants used. The general acid stress response includes modulation of pyruvate metabolism with activation of the butanediol fermentation pathway, and an oxidative stress response that was, however, more extensive in the bacteriostatic and bactericidal conditions. HL-specific and HAc-specific responses include modulation of metabolic pathways for amino acid metabolism. Activation of lactate, formate, and ethanol fermentation pathways, alternative electron-transport chain components and fatty acid biosynthesis genes was noted in the presence of 15mM undissociated HAc. In conclusion, our study has provided insights in phenotype-associated, and general and acidulant-specific responses in B. cereus. Copyright 2009 Elsevier B.V. All rights reserved.

  19. Effective Thermal Inactivation of the Spores of Bacillus cereus Biofilms Using Microwave.

    Science.gov (United States)

    Park, Hyong Seok; Yang, Jungwoo; Choi, Hee Jung; Kim, Kyoung Heon

    2017-07-28

    Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, 108°C of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.

  20. Effects of Aronia melanocarpa Constituents on Biofilm Formation of Escherichia coli and Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Marie Bräunlich

    2013-12-01

    Full Text Available Many bacteria growing on surfaces form biofilms. Adaptive and genetic changes of the microorganisms in this structure make them resistant to antimicrobial agents. Biofilm-forming organisms on medical devices can pose serious threats to human health. Thus, there is a need for novel prevention and treatment strategies. This study aimed to evaluate the ability of Aronia melanocarpa extracts, subfractions and compounds to prevent biofilm formation and to inhibit bacterial growth of Escherichia coli and Bacillus cereus in vitro. It was found that several aronia substances possessed anti-biofilm activity, however, they were not toxic to the species screened. This non-toxic inhibition may confer a lower potential for resistance development compared to conventional antimicrobials.

  1. Effects of sporulation pH on the heat resistance and the sporulation of Bacillus cereus.

    Science.gov (United States)

    Mazas, M; López, M; González, I; Bernardo, A; Martín, R

    1997-11-01

    Spores of Bacillus cereus ATCC 7004, 4342 and 9818 were obtained in nutrient agar at several pH from 5.9 to 8.3. The optimum pH for sporulation was around 7, but good production of spores was obtained in the range 6.5-8.3. With all three strains, D-values clearly dropped with sporulation pH, decreasing by about 65% per pH unit. z-Values were not significantly modified (P > 0.05) by this factor. Mean z-values of 7.13 degrees C +/- 0.16 for strain 7004, 7.67 degrees C +/- 0.04 for 4342 and 8.80 degrees C +/- 0.64 for 9818 were obtained.

  2. The Genetically Remote Pathogenic Strain NVH391-98 of the Bacillus cereus Group Represents the Cluster of Thermophilic Strains

    Energy Technology Data Exchange (ETDEWEB)

    Auger, Sandrine; Galleron, Nathalie; Bidnenko, Elena; Ehrlich, S. Dusko; Lapidus, Alla; Sorokin, Alexei

    2007-10-02

    Bacteria of the Bacillus cereus group are known to cause food poisoning. A rare phylogenetically remote strain, NVH391-98, was recently characterized to encode a particularly efficient cytotoxin K presumably responsible for food poisoning. This pathogenic strain and its close relatives can be phenotypically distinguished from other strains of the B. cereus group by the inability to grow at temperatures below 17 degrees C and by the ability to grow at temperatures from 48 to 53 degrees C. A temperate phage, phBC391A2, residing in the genome of NVH391-98 allows us to distinguish the three known members of this thermophilic strain cluster.

  3. Influence of multi-year Bacillus thuringiensis subsp. israelensis on the abundance of B. cereus group populations in Swedish riparian wetland soils

    DEFF Research Database (Denmark)

    Hendriksen, Niels Bohse; Schneider, Salome; Tajrin, Tania

    Bacillus thuringiensis subsp. israelensis (Bti) is a soil-born bacterium affiliated to the B. cereus group (Bcg, a group including the pathogens B. cereus, B. thuringiensis, and B. anthracis) and used in biocontrol products against nematoceran larvae. However, knowledge is limited on how long...

  4. A transposon mutant library of Bacillus cereus ATCC 10987 reveals novel genes required for biofilm formation and implicates motility as an important factor for pellicle-biofilm formation

    DEFF Research Database (Denmark)

    Okshevsky, Mira; Louw, Matilde Greve; Lamela, Elena Otero

    2018-01-01

    Bacillus cereus is one of the most common opportunistic pathogens causing foodborne illness, as well as a common source of contamination in the dairy industry. B. cereus can form robust biofilms on food processing surfaces, resulting in food contamination due to shedding of cells and spores. Desp...

  5. A Study To Assess the Numbers and Prevalence of Bacillus cereus and Its Toxins in Pasteurized Fluid Milk.

    Science.gov (United States)

    Saleh-Lakha, Saleema; Leon-Velarde, Carlos G; Chen, Shu; Lee, Susan; Shannon, Kelly; Fabri, Martha; Downing, Gavin; Keown, Bruce

    2017-07-01

    Bacillus cereus is a pathogenic adulterant of raw milk and can persist as spores and grow in pasteurized milk. The objective of this study was to determine the prevalence of B. cereus and its enterotoxins in pasteurized milk at its best-before date when stored at 4, 7, and 10°C. More than 5.5% of moderately temperature-abused products (stored at 7°C) were found to contain >10 5 CFU/mL B. cereus , and about 4% of them contained enterotoxins at a level that may result in foodborne illness; in addition, more than 31% of the products contained >10 5 CFU/mL B. cereus and associated enterotoxins when stored at 10°C. Results from a growth kinetic study demonstrated that enterotoxin production by B. cereus in pasteurized milk can occur in as short as 7 to 8 days of storage at 7°C. The higher B. cereus counts were associated with products containing higher butterfat content or with those produced using the conventional high-temperature, short-time pasteurization process. Traditional indicators, aerobic colony counts and psychrotrophic counts, were found to have no correlation with level of B. cereus in milk. The characterization of 17 representative B. cereus isolates from pasteurized milk revealed five toxigenic gene patterns, with all the strains carrying genes encoding for diarrheal toxins but not for an emetic toxin, and with one strain containing all four diarrheal enterotoxin genes (nheA, entFM, hblC, and cytK). The results of this study demonstrate the risks associated even with moderately temperature-abused pasteurized milk and the necessity of a controlled cold chain throughout the shelf life of fluid milk to enhance product safety and minimize foodborne illness.

  6. Detection of hblA and bal Genes in Bacillus cereus Isolates From Cheese Samples Using the Polymerase Chain Reaction

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    Molayi Kohneshahri

    2016-03-01

    Full Text Available Background Bacillus cereus is a Gram-positive spore-forming bacterium, which causes food poisoning. Spores enable the persistence of B. cereus in the environment, and B. cereus strains can tolerate adverse environmental conditions, such as temperature and insufficient nutrients. B. cereus causes food poisoning via the production of two enterotoxins. Most isolates produce toxins leading to diarrhea (enterotoxins and vomiting (emetic forms. Diarrhea is caused by the production of three different heat-labile enterotoxins: HBL, NHE, and cytotoxin K. A heat-stable toxin, cereulide, is responsible for emesis. Objectives This study aimed to detect enterotoxigenic B. cereus isolates in cheese samples using the polymerase chain reaction (PCR. Materials and Methods Two-hundred pasteurized (n = 100 and nonpasteurized (n = 100 cheese samples were collected. The initial isolation was performed on PEMBA specific medium. Antibiotic susceptibility testing was performed using several antibiotic disks, according to the guidelines of the Clinical Laboratory and Standards Institute. Specific primers amplifying the hblA enterotoxin-encoding gene and bal hemolysin-encoding gene were used for the molecular detection of the toxins. Results Ten samples were positive for the presence of B. cereus, with both Gram staining and biochemical reactions. All the isolates were resistant to penicillin and ampicillin but susceptible to vancomycin, erythromycin, and ciprofloxacin. Six and three isolates were resistant to tetracycline and trimethoprim-sulfamethoxazole, respectively. The hblA and bal genes were amplified in all the B. cereus isolates. Conclusions The prevalence of B. cereus among the cheese samples was low. All the isolates were positive for genes encoding the hblA enterotoxin and bal toxin.

  7. Purification and characterization of a new Bacillus thuringiensis bacteriocin active against Listeria monocytogenes, Bacillus cereus and Agrobacterium tumefaciens.

    Science.gov (United States)

    Kamoun, Fakher; Fguira, Ines Ben; Hassen, Najeh Belguith Ben; Mejdoub, Hafedh; Lereclus, Didier; Jaoua, Samir

    2011-09-01

    This study reports on the identification, characterization and purification of a new bacteriocin, named Bacthuricin F103, from a Bacillus thuringiensis strain BUPM103. Bacthuricin F103 production began in the early exponential phase and reached a maximum in the middle of the same phase. Two chromatographic methods based on high performance liquid chromatography and fast protein liquid chromatography systems were used to purify Bacthuricin F103. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed that this bacteriocin had a molecular weight of approximately 11 kDa. It also showed a wide range of thermostability of up to 80 °C for 60 min and a broad spectrum of antimicrobial activity over a pH range of 3.0-10.0. This bacteriocin was noted, and for the first time, to exhibit potent antimicrobial activity against Agrobacterium subsp. strains, the major causal agents of crown gall disease in tomato and vineyard crops, and against several challenging organisms in food, such as Listeria monocytogenes and Bacillus cereus. Complete killing with immediate impact on cells was observed within a short period of time. The sequence obtained for Bacthuricin F103 by direct N-terminal sequencing shared considerable homology with hemolysin. Bacthuricin F103 was noted to act through the depletion of intracellular ions, which suggest that the cell membrane was a possible target to Bacthuricin F103.

  8. Isolation and Molecular Characterization of Potential Plant Growth Promoting Bacillus cereus GGBSTD1 and Pseudomonas spp. GGBSTD3 from Vermisources

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    Balayogan Sivasankari

    2014-01-01

    Full Text Available Vermicompost was prepared from leaf materials of Gliricidia sepium + Cassia auriculata + Leucaena leucocephala with cow dung (1 : 1 : 2 using Eudrilus eugeniae (Kinberg and Eisenia fetida for 60 days. Nineteen bacterial strains which have the capability to fix nitrogen, solubilize inorganic phosphate, and produce phytohormones were isolated from vermicompost, vermisources, and earthworm (fore, mid, and hind guts and tested for plant growth studies. Among the bacterial strains only five strains had both activities; among the five Bacillus spp. showed more nitrogen fixing activity and Pseudomonas spp. showed more phosphate solubilizing activity. Hence these bacterial strains were selected for further molecular analysis and identified Bacillus cereus GGBSTD1 and Pseudomonas spp. GGBSTD3. Plant growth studies use these two organisms separately and as consortium (Bacillus cereus + Pseudomonas spp. in (1 : 1 ratio at different concentrations using Vigna unguiculata (L. Walp. at different day intervals. The germination percent, shoot length, root length, leaf area, chlorophyll a content of the leaves, chlorophyll b content of the leaves, total chlorophyll content of the leaves, fresh weight of the whole plant, and dry weight of the whole plant were significantly enhanced by the consortium (Bacillus cereus + Pseudomonas spp. of two organisms at 5 mL concentrations on the 15th day compared to others.

  9. Structural elucidation of the nonclassical secondary cell wall polysaccharide from Bacillus cereus ATCC 10987. Comparison with the polysaccharides from Bacillus anthracis and B. cereus type strain ATCC 14579 reveals both unique and common structural features.

    Science.gov (United States)

    Leoff, Christine; Choudhury, Biswa; Saile, Elke; Quinn, Conrad P; Carlson, Russell W; Kannenberg, Elmar L

    2008-10-31

    Nonclassical secondary cell wall polysaccharides constitute a major cell wall structure in the Bacillus cereus group of bacteria. The structure of the secondary cell wall polysaccharide from Bacillus cereus ATCC 10987, a strain that is closely related to Bacillus anthracis, was determined. This polysaccharide was released from the cell wall with aqueous hydrogen fluoride (HF) and purified by gel filtration chromatography. The purified polysaccharide, HF-PS, was characterized by glycosyl composition and linkage analyses, mass spectrometry, and one- and two-dimensional NMR analysis. The results showed that the B. cereus ATCC 10987 HF-PS has a repeating oligosaccharide consisting of a -->6)-alpha-GalNAc-(1-->4)-beta-ManNAc-(1-->4)-beta-GlcNAc-(1--> trisaccharide that is substituted with beta-Gal at O3 of the alpha-GalNAc residue and nonstoichiometrically acetylated at O3 of the N-acetylmannosamine (ManNAc) residue. Comparison of this structure with that of the B. anthracis HF-PS and with structural data obtained for the HF-PS from B. cereus type strain ATCC 14579 revealed that each HF-PS had the same general structural theme consisting of three HexNAc and one Hex residues. A common structural feature in the HF-PSs from B. cereus ATCC 10987 and B. anthracis was the presence of a repeating unit consisting of a HexNAc(3) trisaccharide backbone in which two of the three HexNAc residues are GlcNAc and ManNAc and the third can be either GlcNAc or GalNAc. The implications of these results with regard to the possible functions of the HF-PSs are discussed.

  10. Crystallization and preliminary crystallographic analysis of the NheA component of the Nhe toxin from Bacillus cereus

    International Nuclear Information System (INIS)

    Phung, Danh; Ganash, Magdah; Sedelnikova, Svetlana E.; Lindbäck, Toril; Granum, Per Einar; Artymiuk, Peter J.

    2012-01-01

    The NheA component of the B. cereus Nhe toxin was overexpressed in E. coli, purified and crystallized. Diffraction data were collected and processed to 2.05 Å resolution. The nonhaemolytic enterotoxin (Nhe) of Bacillus cereus plays a key role in cases of B. cereus food poisoning. The toxin is comprised of three different proteins: NheA, NheB and NheC. Here, the expression in Escherichia coli, purification and crystallization of the NheA protein are reported. The protein was crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as a precipitant. The crystals of NheA diffracted to 2.05 Å resolution and belonged to space group C2, with unit-cell parameters a = 308.7, b = 58.2, c = 172.9 Å, β = 110.6°. Calculation of V M values suggests that there are approximately eight protein molecules per asymmetric unit

  11. CodY, a pleiotropic regulator, influences multicellular behaviour and efficient production of virulence factors in Bacillus cereus.

    Science.gov (United States)

    Lindbäck, Toril; Mols, Maarten; Basset, Coraline; Granum, Per Einar; Kuipers, Oscar P; Kovács, Ákos T

    2012-08-01

    In response to nutrient limitation in the environment, the global transcriptional regulator CodY modulates various pathways in low G+C Gram-positive bacteria. In Bacillus subtilis CodY triggers adaptation to starvation by secretion of proteases coupled to the expression of amino acid transporters. Furthermore, it is involved in modulating survival strategies like sporulation, motility, biofilm formation, and CodY is also known to affect virulence factor production in pathogenic bacteria. In this study, the role of CodY in Bacillus cereus ATCC 14579, the enterotoxin-producing type strain, is investigated. A marker-less deletion mutant of codY (ΔcodY) was generated in B.cereus and the transcriptome changes were surveyed using DNA microarrays. Numerous genes involved in biofilm formation and amino acid transport and metabolism were upregulated and genes associated with motility and virulence were repressed upon deletion of codY. Moreover, we found that CodY is important for efficient production of toxins and for adapting from nutrient-rich to nutrient-limited growth conditions of B.cereus. In contrast, biofilm formation is highly induced in the ΔcodY mutant, suggesting that CodY represses biofilm formation. Together, these results indicate that CodY plays a crucial role in the growth and persistence of B.cereus in different environments such as soil, food, insect guts and the human body. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  12. Identification of sigmaB-dependent genes in Bacillus cereus by proteome and in vitro transcription analysis.

    Science.gov (United States)

    van Schaik, Willem; Zwietering, Marcel H; de Vos, Willem M; Abee, Tjakko

    2004-07-01

    The alternative sigma factor sigmaB of the food pathogen Bacillus cereus is activated upon stress exposure and plays a role in the adaptive response of vegetative cells. This study describes the identification of sigmaB-dependent genes in B. cereus. Two-dimensional gel electrophoresis was performed with protein extracts from a sigmaB-overproducing B. cereus strain. Nine protein spots, which were absent from the negative control, were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry or N-terminal sequencing. The sigmaB-dependent expression of the corresponding genes was confirmed by Northern blot analysis with RNA isolated from B. cereus ATCC 14579 and its sigB null mutant. Northern blot analysis also revealed that six other genes were part of sigmaB-dependent operons. The proteins that are predicted to be encoded by the sigmaB-dependent genes include an intracellular protease, a Mg2+ transporter, and a thiamine biosynthesis protein (ThiG). Highly conserved promoter sites were found to precede all sigmaB-dependent genes, with the exception of thiG. By searching the B. cereus genome for this conserved promoter sequence, five more candidate sigmaB-dependent genes were identified. Northern blot analysis and in vitro transcription experiments with a reconstituted B. cereus sigmaB-RNA polymerase holoenzyme confirmed the sigmaB dependency of two of these genes and strongly suggested that two other genes, encoding an oligopeptide-binding OppA-like protein and subunit II of the cytochrome d ubiquinol oxidase, are also sigmaB dependent. In conclusion, sigmaB of B. cereus not only regulates genes directly involved in the stress response but may also control specific metabolic rearrangements.

  13. Bacillus cereus Adhesion to Simulated Intestinal Mucus Is Determined by Its Growth on Mucin, Rather Than Intestinal Environmental Parameters.

    Science.gov (United States)

    Tsilia, Varvara; Uyttendaele, Mieke; Kerckhof, Frederiek-Maarten; Rajkovic, Andreja; Heyndrickx, Marc; Van de Wiele, Tom

    2015-11-01

    Adhesion of pathogenic bacteria to intestinal mucus, the protective layer of the gastrointestinal epithelium, is often considered a virulence factor. The ability of food-poisoning Bacillus cereus strains to attach to mucus and the factors affecting this interaction have not yet been investigated. Therefore, the role of adhesion in pathogenesis of B. cereus still remains unknown. In the present study, an in vitro assay based on mucin agar was used to simulate adhesion of B. cereus to mucus. Bacterial-associated factors (e.g., strain specificity and microbial competition) known to influence adhesion to different surfaces and a variety of environmental conditions (e.g., pH and oxygen) encountered in the gastrointestinal tract were investigated. The effect of these parameters on B. cereus NVH 0500/00 mucin adhesion was generally limited even in the presence of microbial competition. This suggests that B. cereus NVH 0500/00 is a versatile pathogen. Inoculation of 4 to 5 log colony-forming units (CFU) per milliliter. B. cereus NVH 0500/00 resulted in 5-6 log CFU/mL mucin-associated bacteria after a short incubation period. This indicates that this pathogenic strain could grow in the presence of mucin agar. This growth may potentially mask the effect of the studied conditions. Yet, extensive attachment of B. cereus to mucin is not necessarily a prerequisite for virulence, because other pathogenic strains do not adhere with the same efficiency to mucin. Nevertheless, adhesion may contribute to the disease by providing close contact to nutrient sources, such as mucin, which would not only result in bacterial proliferation, but also in disruption of the protective host mucus surface.

  14. Epidemiologic Investigation of a Cluster of Neuroinvasive Bacillus cereus Infections in 5 Patients With Acute Myelogenous Leukemia.

    Science.gov (United States)

    Rhee, Chanu; Klompas, Michael; Tamburini, Fiona B; Fremin, Brayon J; Chea, Nora; Epstein, Lauren; Halpin, Alison Laufer; Guh, Alice; Gallen, Rachel; Coulliette, Angela; Gee, Jay; Hsieh, Candace; Desjardins, Christopher A; Pedamullu, Chandra Sekhar; DeAngelo, Daniel J; Manzo, Veronica E; Folkerth, Rebecca Dunn; Milner, Danny A; Pecora, Nicole; Osborne, Matthew; Chalifoux-Judge, Diane; Bhatt, Ami S; Yokoe, Deborah S

    2015-09-01

    Background.  Five neuroinvasive Bacillus cereus infections (4 fatal) occurred in hospitalized patients with acute myelogenous leukemia (AML) during a 9-month period, prompting an investigation by infection control and public health officials. Methods.  Medical records of case-patients were reviewed and a matched case-control study was performed. Infection control practices were observed. Multiple environmental, food, and medication samples common to AML patients were cultured. Multilocus sequence typing was performed for case and environmental B cereus isolates. Results.  All 5 case-patients received chemotherapy and had early-onset neutropenic fevers that resolved with empiric antibiotics. Fever recurred at a median of 17 days (range, 9-20) with headaches and abrupt neurological deterioration. Case-patients had B cereus identified in central nervous system (CNS) samples by (1) polymerase chain reaction or culture or (2) bacilli seen on CNS pathology stains with high-grade B cereus bacteremia. Two case-patients also had colonic ulcers with abundant bacilli on autopsy. No infection control breaches were observed. On case-control analysis, bananas were the only significant exposure shared by all 5 case-patients (odds ratio, 9.3; P = .04). Five environmental or food isolates tested positive for B cereus, including a homogenized banana peel isolate and the shelf of a kitchen cart where bananas were stored. Multilocus sequence typing confirmed that all case and environmental strains were genetically distinct. Multilocus sequence typing-based phylogenetic analysis revealed that the organisms clustered in 2 separate clades. Conclusions.  The investigation of this neuroinvasive B cereus cluster did not identify a single point source but was suggestive of a possible dietary exposure. Our experience underscores the potential virulence of B cereus in immunocompromised hosts.

  15. A case report with catheter caused Bacillus cereus bacteriemia and investigating the clonal relatedness between the isolates by PFGE

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    Fırat Zafer Mengeloğlu

    2011-09-01

    Full Text Available Bacillus cereus is a motile and spore-forming Gram positive rod and is a microorganism species which cause infections such as food poisoning, endocarditis, bacteremia sepsis.In our case; 57 years old, acute myeloid leukemia diagnosed female patient who had bone narrow transplantation and getting chemotherapy was interned with prediagnosis of neutropenic fever and pneumonia in internal medicine clinics which she admitted with high fever. Since B.cereus growth in peripheral vein blood cultures, catheter blood cultures was performed simultaneously. B.cereus growth repeated in the cultures so catheter caused bacteremia was considered as the diagnosis and antibiotherapy was expanded. After treatment, no growth was observed except catheter blood cultures, general condition of the patient improved and her fever disappeared.Pulsed-field gel electrophoresis was performed in order to investigate the clonal relatedness between B.cereus isolates which were grown in three cultures of separate times and isolates were observed as the same clone.Blood cultures yielded B.cereus are usually considered the possibility of contamination so some clinical laboratories do not perform identification at species level. But the species which is isolated may be the cause of infection, so this approach may be time-consuming for the patient and cause a delay in necessary treatment. In such cases; repeat blood culture should be requested and a decision should be done whether to perform species identification according to the patient’s immune system condition and clinical presentation.

  16. ANTIBACTERIAL EFFECT OF GARLIC (ALLIUM SATIVUM) AND GINGER (ZINGIBER OFFICINALE) AGAINST STAPHYLOCOCCUS AUREUS, SALMONELLA TYPHI, ESCHERICHIA COLI AND BACILLUS CEREUS

    OpenAIRE

    Bandna Chand

    2013-01-01

    Antibacterial activity of extracts of Allium sativum (garlic) and Zingiber officinale (ginger) has been evaluated against four different bacteria namely Escherichia coli, Salmonella Typhi, Staphylococcus aureus and Bacillus cereus. Two methods were used to determine the antimicrobial activity of garlic and ginger extracts namely disk diffusion method and agar well diffusion method. Garlic extract exhibited excellent antibacterial activity against all four test organisms while ginger extract s...

  17. Growth and Sporulation of Bacillus cereus ATCC 14579 under Defined Conditions: Temporal Expression of Genes for Key Sigma Factors

    OpenAIRE

    de Vries, Ynte P.; Hornstra, Luc M.; de Vos, Willem M.; Abee, Tjakko

    2004-01-01

    An airlift fermentor system allowing precise regulation of pH and aeration combined with a chemically defined medium was used to study growth and sporulation of Bacillus cereus ATCC 14579. Sporulation was complete and synchronous. Expression of sigA, sigB, sigF, and sigG was monitored with real-time reverse transcription-PCR, and the pattern qualitatively resembled that of Bacillus subtilis. This method allows reproducible production of stable spores, while the synchronous growth and defined ...

  18. DNA as an adhesin: Bacillus cereus requires extracellular DNA to form biofilms.

    Science.gov (United States)

    Vilain, Sébastien; Pretorius, Jakobus M; Theron, Jacques; Brözel, Volker S

    2009-05-01

    The soil saprophyte Bacillus cereus forms biofilms at solid-liquid interfaces. The composition of the extracellular polymeric matrix is not known, but biofilms of other bacteria are encased in polysaccharides, protein, and also extracellular DNA (eDNA). A Tn917 screen for strains impaired in biofilm formation at a solid-liquid interface yielded several mutants. Three mutants deficient in the purine biosynthesis genes purA, purC, and purL were biofilm impaired, but they grew planktonically like the wild type in Luria-Bertani broth. Biofilm populations had higher purA, purC, and purL transcript ratios than planktonic cultures, as measured by real-time PCR. Laser scanning confocal microscopy (LSCM) of BacLight-stained samples indicated that there were nucleic acids in the cell-associated matrix. This eDNA could be mobilized off the biofilm into an agarose gel matrix through electrophoresis, and it was a substrate for DNase. Glass surfaces exposed to exponentially growing populations acquired a DNA-containing conditioning film, as indicated by LSCM. Planktonic exponential-phase cells released DNA into an agarose gel matrix through electrophoresis, while stationary-phase populations did not do this. DNase treatment of planktonic exponential-phase populations rendered cells more susceptible than control populations to the DNA-interacting antibiotic actinomycin D. Exponential-phase purA cells did not contain detectable eDNA, nor did they convey a DNA-containing conditioning film to the glass surface. These results indicate that exponential-phase cells of B. cereus ATCC 14579 are decorated with eDNA and that biofilm formation requires DNA as part of the extracellular polymeric matrix.

  19. Phenotypic and transcriptomic analyses of mildly and severely salt-stressed Bacillus cereus ATCC 14579 cells.

    Science.gov (United States)

    den Besten, Heidy M W; Mols, Maarten; Moezelaar, Roy; Zwietering, Marcel H; Abee, Tjakko

    2009-06-01

    Bacteria are able to cope with the challenges of a sudden increase in salinity by activating adaptation mechanisms. In this study, exponentially growing cells of the pathogen Bacillus cereus ATCC 14579 were exposed to both mild (2.5% [wt/vol] NaCl) and severe (5% [wt/vol] NaCl) salt stress conditions. B. cereus continued to grow at a slightly reduced growth rate when it was shifted to mild salt stress conditions. Exposure to severe salt stress resulted in a lag period, and after 60 min growth had resumed, with cells displaying a filamentous morphology. Whole-genome expression analyses of cells exposed to 2.5% salt stress revealed that the expression of these cells overlapped with the expression of cells exposed to 5% salt stress, suggesting that the corresponding genes were involved in a general salt stress response. Upregulation of osmoprotectant, Na(+)/H(+), and di- and tripeptide transporters and activation of an oxidative stress response were noticeable aspects of the general salt stress transcriptome response. Activation of this response may confer cross-protection against other stresses, and indeed, increased resistance to heat and hydrogen peroxide could be demonstrated after preexposure to salt. A temporal shift between the transcriptome response and several phenotypic responses of severely salt-stressed cells was observed. After resumption of growth, these cells showed cellular filamentation, reduced chemotaxis, increased catalase activity, and optimal oxidative stress resistance, which corresponded to the transcriptome response displayed in the initial lag period. The linkage of transcriptomes and phenotypic characteristics can contribute to a better understanding of cellular stress adaptation strategies and possible cross-protection mechanisms.

  20. Structural basis of the substrate specificity of Bacillus cereus adenosine phosphorylase

    Energy Technology Data Exchange (ETDEWEB)

    Dessanti, Paola [Cornell University, Ithaca, NY 14853-1301 (United States); Università di Sassari, (Italy); Zhang, Yang [Cornell University, Ithaca, NY 14853-1301 (United States); Allegrini, Simone [Università di Sassari, (Italy); Tozzi, Maria Grazia [Università di Pisa, (Italy); Sgarrella, Francesco [Università di Sassari, (Italy); Ealick, Steven E., E-mail: see3@cornell.edu [Cornell University, Ithaca, NY 14853-1301 (United States)

    2012-03-01

    Adenosine phosphorylase from B. cereus shows a strong preference for adenosine over other 6-oxopurine nucleosides. Mutation of Asp204 to asparagine reduces the efficiency of adenosine cleavage but does not affect inosine cleavage, effectively reversing the substrate specificity. The structures of D204N complexes explain these observations. Purine nucleoside phosphorylases catalyze the phosphorolytic cleavage of the glycosidic bond of purine (2′-deoxy)nucleosides, generating the corresponding free base and (2′-deoxy)ribose 1-phosphate. Two classes of PNPs have been identified: homotrimers specific for 6-oxopurines and homohexamers that accept both 6-oxopurines and 6-aminopurines. Bacillus cereus adenosine phosphorylase (AdoP) is a hexameric PNP; however, it is highly specific for 6-aminopurines. To investigate the structural basis for the unique substrate specificity of AdoP, the active-site mutant D204N was prepared and kinetically characterized and the structures of the wild-type protein and the D204N mutant complexed with adenosine and sulfate or with inosine and sulfate were determined at high resolution (1.2–1.4 Å). AdoP interacts directly with the preferred substrate through a hydrogen-bond donation from the catalytically important residue Asp204 to N7 of the purine base. Comparison with Escherichia coli PNP revealed a more optimal orientation of Asp204 towards N7 of adenosine and a more closed active site. When inosine is bound, two water molecules are interposed between Asp204 and the N7 and O6 atoms of the nucleoside, thus allowing the enzyme to find alternative but less efficient ways to stabilize the transition state. The mutation of Asp204 to asparagine led to a significant decrease in catalytic efficiency for adenosine without affecting the efficiency of inosine cleavage.

  1. Identification and Characterization of Bacillus cereus SW7-1 in Bombyx mori (Lepidoptera: Bombycidae).

    Science.gov (United States)

    Li, Guan-Nan; Xia, Xue-Juan; Zhao, Huan-Huan; Sendegeya, Parfait; Zhu, Yong

    2015-01-01

    The bacterial diseases of silkworms cause significant reductions in sericulture and result in huge economic loss. This study aimed to identify and characterize a pathogen from diseased silkworm. SW7-1, a pathogenic bacterial strain, was isolated from the diseased silkworm. The strain was identified on the basis of its bacteriological properties and 16S rRNA gene sequence. The colony was round, slightly convex, opaque, dry, and milky on a nutrient agar medium, the colony also exhibited jagged edges. SW7-1 was Gram-positive, without parasporal crystal, and 0.8-1.2 by 2.6-3.4 µm in length, resembling long rods with rounded ends. The strain was positive to most of the physiological biochemical tests used in this study. The strain could utilize glucose, sucrose, and maltose. The results of its 16S rRNA gene sequence analysis revealed that SW7-1 shared the highest sequence identity (>99%) with Bacillus cereus strain 14. The bacterial strain was highly susceptible to gentamycin, streptomycin, erythromycin, norfloxacin, and ofloxacin and moderately susceptible to tetracycline and rifampicin. It exhibited resistance to other antibiotics. SW7-1 had hemolytic activity and could produce extracellular casease, lipase, and amylase. SW7-1 could reproduce septicemia-like symptoms with high mortality rate when re-fed to healthy silkworm. .The median lethal concentration (LC50) was 5.45 × 10(4) cfu/ml. Thus, SW7-1 was identified as B. cereus, which is a pathogen for silkworm and human infections are possible. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  2. Identification of novel nitroreductases from Bacillus cereus and their interaction with the CB1954 prodrug.

    Science.gov (United States)

    Gwenin, Vanessa V; Poornima, Paramasivan; Halliwell, Jennifer; Ball, Patrick; Robinson, George; Gwenin, Chris D

    2015-12-01

    Directed enzyme prodrug therapy is a form of cancer chemotherapy in which bacterial prodrug-activating enzymes, or their encoding genes, are directed to the tumour before administration of a prodrug. The prodrug can then be activated into a toxic drug at the tumour site, reducing off-target effects. The bacterial nitroreductases are a class of enzymes used in this therapeutic approach and although very promising, the low turnover rate of prodrug by the most studied nitroreductase enzyme, NfnB from Escherichia coli (NfnB_Ec), is a major limit to this technology. There is a continual search for enzymes with greater efficiency, and as part of the search for more efficient bacterial nitroreductase enzymes, two novel enzymes from Bacillus cereus (strain ATCC 14579) have been identified and shown to reduce the CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) prodrug to its respective 2'-and 4'-hydroxylamine products. Both enzymes shared features characteristic of the nitro-FMN-reductase superfamily including non-covalently associated FMN, requirement for the NAD(P)H cofactor, homodimeric, could be inhibited by Dicoumarol (3,3'-methylenebis(4-hydroxy-2H-chromen-2-one)), and displayed ping pong bi bi kinetics. Based on the biochemical characteristics and nucleotide alignment with other nitroreductase enzymes, one enzyme was named YdgI_Bc and the other YfkO_Bc. Both B. cereus enzymes had greater turnover for the CB1954 prodrug compared with NfnB_Ec, and in the presence of added NADPH cofactor, YfkO_Bc had superior cell killing ability, and produced mainly the 4'-hydroxylamine product at low prodrug concentration. The YfkO_Bc was identified as a promising candidate for future enzyme prodrug therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Transcriptional responses of Bacillus cereus towards challenges with the polysaccharide chitosan.

    Science.gov (United States)

    Mellegård, Hilde; Kovács, Ákos T; Lindbäck, Toril; Christensen, Bjørn E; Kuipers, Oscar P; Granum, Per E

    2011-01-01

    The antibacterial activity of the polysaccharide chitosan towards different bacterial species has been extensively documented. The response mechanisms of bacteria exposed to this biopolymer and the exact molecular mechanism of action, however, have hardly been investigated. This paper reports the transcriptome profiling using DNA microarrays of the type-strain of Bacillus cereus (ATCC 14579) exposed to subinhibitory concentrations of two water-soluble chitosan preparations with defined chemical characteristics (molecular weight and degree of acetylation (F(A))). The expression of 104 genes was significantly altered upon chitosan A (weight average molecular weight (M(w)) 36.0 kDa, F(A) = 0.01) exposure and 55 genes when treated with chitosan B (M(w) 28.4 kDa, F(A) = 0.16). Several of these genes are involved in ion transport, especially potassium influx (BC0753-BC0756). Upregulation of a potassium transporting system coincides with previous studies showing a permeabilizing effect on bacterial cells of this polymer with subsequent loss of potassium. Quantitative PCR confirmed the upregulation of the BC0753 gene encoding the K(+)-transporting ATPase subunit A. A markerless gene replacement method was used to construct a mutant strain deficient of genes encoding an ATP-driven K(+) transport system (Kdp) and the KdpD sensor protein. Growth of this mutant strain in potassium limiting conditions and under salt stress did not affect the growth pattern or growth yield compared to the wild-type strain. The necessity of the Kdp system for potassium acquisition in B. cereus is therefore questionable. Genes involved in the metabolism of arginine, proline and other cellular constituents, in addition to genes involved in the gluconeogenesis, were also significantly affected. BC2798 encoding a chitin binding protein was significantly downregulated due to chitosan exposure. This study provides insight into the response mechanisms of B. cereus to chitosan treatment and the

  4. Transcriptional responses of Bacillus cereus towards challenges with the polysaccharide chitosan.

    Directory of Open Access Journals (Sweden)

    Hilde Mellegård

    Full Text Available The antibacterial activity of the polysaccharide chitosan towards different bacterial species has been extensively documented. The response mechanisms of bacteria exposed to this biopolymer and the exact molecular mechanism of action, however, have hardly been investigated. This paper reports the transcriptome profiling using DNA microarrays of the type-strain of Bacillus cereus (ATCC 14579 exposed to subinhibitory concentrations of two water-soluble chitosan preparations with defined chemical characteristics (molecular weight and degree of acetylation (F(A. The expression of 104 genes was significantly altered upon chitosan A (weight average molecular weight (M(w 36.0 kDa, F(A = 0.01 exposure and 55 genes when treated with chitosan B (M(w 28.4 kDa, F(A = 0.16. Several of these genes are involved in ion transport, especially potassium influx (BC0753-BC0756. Upregulation of a potassium transporting system coincides with previous studies showing a permeabilizing effect on bacterial cells of this polymer with subsequent loss of potassium. Quantitative PCR confirmed the upregulation of the BC0753 gene encoding the K(+-transporting ATPase subunit A. A markerless gene replacement method was used to construct a mutant strain deficient of genes encoding an ATP-driven K(+ transport system (Kdp and the KdpD sensor protein. Growth of this mutant strain in potassium limiting conditions and under salt stress did not affect the growth pattern or growth yield compared to the wild-type strain. The necessity of the Kdp system for potassium acquisition in B. cereus is therefore questionable. Genes involved in the metabolism of arginine, proline and other cellular constituents, in addition to genes involved in the gluconeogenesis, were also significantly affected. BC2798 encoding a chitin binding protein was significantly downregulated due to chitosan exposure. This study provides insight into the response mechanisms of B. cereus to chitosan treatment and

  5. Survival of foodborne pathogenic bacteria (Bacillus cereus, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Listeria monocytogenes) and Bacillus cereus spores in fermented alcoholic beverages (beer and refined rice wine).

    Science.gov (United States)

    Kim, S A; Kim, N H; Lee, S H; Hwang, I G; Rhee, M S

    2014-03-01

    Only limited information is available on the microbiological safety of fermented alcoholic beverages because it is still a common belief that such beverages do not provide a favorable environment for bacterial growth and survival. Thus, in this study, we examined the survival of major foodborne pathogens and spores in fermented alcoholic beverages. Foodborne pathogens (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Typhimurium, and Staphylococcus aureus) and B. cereus spores (initial population, 3 to 4 log CFU/ml) were inoculated separately into three types of beer and refined rice wine, which were then stored at 5 and 22°C. Bacterial counts were assayed periodically for up to 28 days. Vegetative B. cereus counts decreased rapidly, whereas B. cereus spore counts remained constant (P > 0.05) for a long period of time in all beverages. Vegetative B. cereus cells formed spores in beer at 5 and 22°C, and the spores survived for long periods. Among vegetative cells, E. coli O157:H7 had the highest survival (only 1.49 to 1.56 log reduction during 28 days in beer at 5°C). Beer and refined rice wine supported microbial survival from several days to several weeks. Our results appear to contradict the common belief that pathogens cannot survive in alcoholic beverages. Long-term survival of pathogens (especially B. cereus and E. coli O157:H7) in beer and refined rice wine should be taken into consideration by the manufacturers of these beverages. This study provides basic information that should help further research into microbial survival in alcoholic beverages and increase the microbiological safety regulation of fermented alcoholic beverages.

  6. UJI AKTIVITAS ANTIBAKTERI EKSTRAK KASAR LIPID Ulva fasciata TERHADAP Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Riong Seulina Panjaitan

    2017-01-01

    Full Text Available Abstract: The increasing of antimicrobial resistance in medical field has become a serious problem which is have to be solved by exploring raw material on natural product. Seaweed or macroalgae is one of marine natural wealth of Indonesia’s sea. In this research, lipid extraction of seaweed (macroalgae Ulva fasciata has been done according to Folch method by using sochlet and mixure of solvent namely chloroform:methanol (2:1/ (v/v. The result gave two phase namely chloroform phase (0,6% (v/b and methanol phase (7,79% (v/b. Furthermore, both of phase of crude extract lipid Ulva fasciata were tested their antibacterial activities against Bacillus cereus bacterial which is three times. Tetracyclin is used as positive control and the solvent (methanol-chloroform is used as negative control. The results were both of phase gave antibacterial activity namely 0,02 mm/ μg extract for chloroform phase and 0,02 mm/ μg extract for methanol phase.Abstrak: Peningkatan kasus resistensi antimikroba pada dunia medis telah menjadi masalah yang serius sehingga perlu dilakukan pengeksplorasian bahan baku untuk antibiotik khususnya dari bahan alam. Rumput laut (makroalga merupakan salah satu kekayaan alam hayati laut Indonesia yang memiliki kandungan lipid. Pada penelitian ini dilakukan ekstraksi lipid rumput laut (makroalga Ulva fasciata berdasarkan metode Folch dengan menggunakan sokhlet dan campuran pelarut yang digunakan yaitu kloroform:metanol (2:1/ (v/v. Hasil ekstraksi lipid Ulva fasciata menghasilkan dua fasa yaitu fasa kloroform sebanyak 0,6 % (v/b dan fasa metanol sebanyak 7,79 % (v/b. Selanjutnya kedua fasa ekstrak kasar lipid Ulva fasciata tersebut diuji aktivitas antibakterinya terhadap bakteri Bacillus cereus sebanyak tiga kali pengulangan. Kontrol positif yang digunakan adalah tetrasiklin dan kontrol negatifnya adalah pelarut yaitu kloroform dan metanol. Hasil penelitian menunjukkan bahwa kedua fasa tersebut memberikan aktivitas antibakteri

  7. Antimicrobial susceptibility and β-lactamase production in Bacillus cereus isolates from stool of patients, food and environment samples

    Directory of Open Access Journals (Sweden)

    Savić Dejana

    2016-01-01

    Full Text Available Background/Aim. Bacillus cereus (B. cereus usually ingested by food can cause two types of diseases: vomiting due to the presence of emetic toxin and diarrheal syndrome, due to the presence of diarrheal toxins. Systemic manifestations can also occur. The severe forms of disease demand antibiotic treatmant. The aim of this study was to determine the differences in antibiotic susceptibility and β-lactamase activity of B. cereus isolates from stools of humans, food and environment. Methods. Identification of B. cereus was performed with selective medium, classical biochemical test and polymerase chain reaction (PCR with primers specific for bal gene. Thirty isolates from each group were analysed for antibiotic susceptibility using the disk-diffusion assay. Production of β-lactamase was determined by cefinase test, and double-disc method. Results. All strains identified as B. cereus using classical biochemical test, yielded 533 bp fragment with PCR. Isolates from all the three groups were susceptible to imipenem, vancomycin, and erythromycin. All isolates were susceptible to ciprofloxacin but one from the environment. A statistically significant difference between the groups was confirmed to tetracycline and trimethoprim-sulphamethoxazole sensitivity. A total of 28/30 (93.33% samples from the foods and 25/30 (83.33% samples from environment were approved sensitive to tetracycline, while 10/30 (33.33% isolates from stools were sensitive. Opposite to this result, high susceptibility to trimethoprim-sulphamethoxazole was shown in samples from stools (100%, while isolates from foods (63.33% and from environment (70% had low susceptibility. All samples produced β-lactamases. Conclusion. The strains of B. cereus from all the three groups showed high rate of sensitivity to most tested antibiotics, except to tetracycline in samples from human stool and to trimethoprim-sulphamethoxazole in samples from food and environment. The production of

  8. Cell Wall Carbohydrate Compositions of Strains from the Bacillus cereus Group of Species Correlate with Phylogenetic Relatedness▿

    Science.gov (United States)

    Leoff, Christine; Saile, Elke; Sue, David; Wilkins, Patricia; Quinn, Conrad P.; Carlson, Russell W.; Kannenberg, Elmar L.

    2008-01-01

    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. PMID:17981984

  9. Cell wall carbohydrate compositions of strains from the Bacillus cereus group of species correlate with phylogenetic relatedness.

    Science.gov (United States)

    Leoff, Christine; Saile, Elke; Sue, David; Wilkins, Patricia; Quinn, Conrad P; Carlson, Russell W; Kannenberg, Elmar L

    2008-01-01

    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.

  10. Deciphering the interactions between the Bacillus cereus linear plasmid, pBClin15, and its host by high-throughput comparative proteomics.

    Science.gov (United States)

    Madeira, Jean-Paul; Omer, Hélène; Alpha-Bazin, Béatrice; Armengaud, Jean; Duport, Catherine

    2016-09-02

    The pathogen, Bacillus cereus, is able to adapt its metabolism to various environmental conditions. The reference strain, Bacillus cereus ATCC 14579, harbors a linear plasmid, pBClin15, which displays a cryptic prophage behavior. Here, we studied the impact of pBClin15 on the aerobic respiratory metabolism of B. cereus by curing its host strain. We compared, by means of a high-throughput shotgun proteomic approach, both the cellular proteome and the exoproteome of B. cereus ATCC 14579 in the presence and absence of pBClin15 at the early, late and stationary growth phases. The results were visualized through a hierarchical cluster analysis of proteomic data. We found that pBClin15 contributes significantly to the metabolic efficiency of B. cereus by restricting the production of chromosome-encoded phage proteins in the extracellular milieu. The data also revealed intricate regulatory mechanisms between pBClin15 and its host. Finally, we show that pBClin15 provides benefit to its host to adapt to different ecologic niches. Bacteria belonging to the Bacillus cereus group include B. cereus, a notorious food borne pathogen which causes gastroenteritis. The B. cereus type, strain ATCC 14579, harbors a linear plasmid, pBClin15, which displays cryptic prophage behavior. Here, we present data supporting the idea that pBClin15 may have a much greater role in B. cereus metabolism that has hitherto been suspected. Specifically, our comparative proteomic analyses reveal that pBClin15 manages B. cereus central metabolism to optimize energy and carbon utilization through the repression of several chromosome-encoded phage proteins. These results suggest that pBClin15 provides benefit to the host for surviving adverse environmental conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Enzymatic Synthesis of Isopropyl Acetate by Immobilized   Bacillus cereus Lipase in Organic Medium

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    Madan Lal Verma

    2011-01-01

    Full Text Available Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM, concentration of biocatalyst (25–125 mg/mL, reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm using bound lipase (25 mg. Addition of molecular sieves (3 Å  × 1.5 mm resulted in a marked increase in ester synthesis (73.0 mM. Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse.

  12. Antioxidant and DNA Damage Protecting Activity of Exopolysaccharides from the Endophytic Bacterium Bacillus cereus SZ1

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    Li Ping Zheng

    2016-02-01

    Full Text Available An endophytic bacterium was isolated from the Chinese medicinal plant Artemisia annua L. The phylogenetic and physiological characterization indicated that the isolate, strain SZ-1, was Bacillus cereus. The endophyte could produce an exopolysaccharide (EPS at 46 mg/L. The 1,1-diphenyl-2-picrylhydracyl (DPPH radical scavenging activity of the EPS reached more than 50% at 3–5 mg/mL. The EPS was also effective in scavenging superoxide radical in a concentration dependent fashion with an EC50 value of 2.6 mg/mL. The corresponding EC50 for scavenging hydroxyl radical was 3.1 mg/mL. Moreover, phenanthroline-copper complex-mediated chemiluminescent emission of DNA damage was both inhibited and delayed by EPS. The EPS at 0.7–1.7 mg/mL also protected supercoiled DNA strands in plasmid pBR322 against scission induced by Fenton-mediated hydroxyl radical. The preincubation of PC12 cells with the EPS prior to H2O2 exposure increased the cell survival and glutathione (GSH level and catalase (CAT activities, and decreased the level of malondialdehyde (MDA and lactate dehydrogenase (LDH activity in a dose-dependent manner, suggesting a pronounced protective effect against H2O2-induced cytotoxicity. Our study indicated that the EPS could be useful for preventing oxidative DNA damage and cellular oxidation in pharmaceutical and food industries.

  13. Formation of flavone di-O-glucosides using a glycosyltransferase from Bacillus cereus.

    Science.gov (United States)

    Ahn, Byoung Chan; Kim, Bong Gyu; Jeon, Young Min; Lee, Eun Jeong; Lim, Yoongho; Ahn, Joong-Hoon

    2009-04-01

    Microbial UDP-glycosyltransferases can convert many small lipophilic compounds into glycons using uridinediphosphate- activated sugars. The glycosylation of flavonoids affects solubility, stability, and bioavailability. The gene encoding the UDP-glycosyltransferase from Bacillus cereus, BcGT-3, was cloned by PCR and sequenced. BcGT-3 was expressed in Escherichia coli BL21 (DE3) with a glutathione S-transferase tag and purified using a glutathione Stransferase affinity column. BcGT-3 was tested for activity on several substrates including genistein, kaempferol, luteolin, naringenin, and quercetin. Flavonols were the best substrates for BcGT-3. The enzyme dominantly glycosylated the 3-hydroxyl group, but the 7-hydroxyl group was glycosylated when the 3-hydroxyl group was not available. The kaempferol reaction products were identified as kaempferol-3-O-glucoside and kaempferol- 3,7-O-diglucoside. Kaempferol was the most effective substrate tested. Based on HPLC, LC/MS, and NMR analyses of the reaction products, we conclude that BcGT-3 can be used for the synthesis of kaempferol 3,7-O-diglucose.

  14. Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel.

    Science.gov (United States)

    Huang, Kang; McLandsborough, Lynne A; Goddard, Julie M

    2016-01-01

    Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm(-2). Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm(-2) of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment.

  15. Structural basis of the substrate specificity of Bacillus cereus adenosine phosphorylase

    Energy Technology Data Exchange (ETDEWEB)

    Dessanti, Paola; Zhang, Yang; Allegrini, Simone; Tozzi, Maria Grazia; Sgarrella, Francesco; Ealick, Steven E. (Cornell); (Sassari); (Pisa)

    2012-10-08

    Purine nucleoside phosphorylases catalyze the phosphorolytic cleavage of the glycosidic bond of purine (2{prime}-deoxy)nucleosides, generating the corresponding free base and (2{prime}-deoxy)ribose 1-phosphate. Two classes of PNPs have been identified: homotrimers specific for 6-oxopurines and homohexamers that accept both 6-oxopurines and 6-aminopurines. Bacillus cereus adenosine phosphorylase (AdoP) is a hexameric PNP; however, it is highly specific for 6-aminopurines. To investigate the structural basis for the unique substrate specificity of AdoP, the active-site mutant D204N was prepared and kinetically characterized and the structures of the wild-type protein and the D204N mutant complexed with adenosine and sulfate or with inosine and sulfate were determined at high resolution (1.2-1.4 {angstrom}). AdoP interacts directly with the preferred substrate through a hydrogen-bond donation from the catalytically important residue Asp204 to N7 of the purine base. Comparison with Escherichia coli PNP revealed a more optimal orientation of Asp204 towards N7 of adenosine and a more closed active site. When inosine is bound, two water molecules are interposed between Asp204 and the N7 and O6 atoms of the nucleoside, thus allowing the enzyme to find alternative but less efficient ways to stabilize the transition state. The mutation of Asp204 to asparagine led to a significant decrease in catalytic efficiency for adenosine without affecting the efficiency of inosine cleavage.

  16. Heat resistance of Bacillus cereus spores: effects of milk constituents and stabilizing additives.

    Science.gov (United States)

    Mazas, M; López, M; Martínez, S; Bernardo, A; Martin, R

    1999-04-01

    Heat resistance of Bacillus cereus spores (ATCC 7004, 4342, and 9818) heated in different types of milk (skim, whole, and concentrated skim milk), skim milk containing stabilizing additives (sodium citrate, monopotassium phosphate, or disodium phosphate, 0.1%), and cream was investigated. Thermal resistance experiments were performed at temperatures within the range of 92 to 115 degrees C under continuous monitoring of pH. For strain 4342 no significant differences (P < 0.05) in D values were detected in any case. For strains 7004 and 9818 higher D values of about 20% were obtained in whole and concentrated skim milk than those calculated in skim milk. From all stabilizing additives tested, only sodium citrate and sodium phosphate increased the heat resistance for strain 9818. However, when the menstruum pH was measured at the treatment temperature, different pH values were found between the heating media. The differences in heat resistance observed could be due to a pH effect rather than to the difference in the substrates in which spores were heated. In contrast, when cream (fat content 20%) was used, lower D values were obtained, especially for strains 7004 and 9818. z values were not significantly modified by the milk composition, with an average z value of 7.95+/-0.20 degrees C for strain 7004, 7.88+/-0.10 degrees C for strain 4342, and 9.13+/-0.16 degrees C for strain 9818.

  17. The effect of recovery conditions on the apparent heat resistance of Bacillus cereus spores.

    Science.gov (United States)

    Gonzalez, I; Lopez, M; Mazas, M; Gonzalez, J; Bernardo, A

    1995-05-01

    The effect of recovery media and incubation temperature on the apparent heat resistance of three ATCC strains (4342, 7004 and 9818) of Bacillus cereus spores were studied. Nutrient Agar (NA), Tryptic Soy Agar (TSA), Plate Count Agar (PCA) and Milk Agar (MA) as the media and temperatures in the range of 15-40 degrees C were used to recover heated spores. Higher counts of heat injured spores were obtained on PCA and NA. The optimum subculture temperature was about 5 degrees C below the optimum temperature for unheated spores. No significant differences in heat resistance were observed with the different recovery conditions except for strains 4342 and 9818 when MA was used as plating medium. Large differences in D-values were found among the strains (D100 = 0.28 min for 7004; D100 = 0.99 min for 4342; D100 = 4.57 min for 9818). The 7004 strain showed a sub-population with a greater heat resistance. The z values obtained for the three strains studied under the different recovery conditions were similar (7.64 degrees C +/- 0.25).

  18. The YvfTU Two-component System is involved in plcR expression in Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Nguyen-the Christophe

    2008-10-01

    Full Text Available Abstract Background Most extracellular virulence factors produced by Bacillus cereus are regulated by the pleiotropic transcriptional activator PlcR. Among strains belonging to the B. cereus group, the plcR gene is always located in the vicinity of genes encoding the YvfTU two-component system. The putative role of YvfTU in the expression of the PlcR regulon was therefore investigated. Results Expression of the plcR gene was monitored using a transcriptional fusion with a lacZ reporter gene in a yvfTU mutant and in its B. cereus ATCC 14579 parental strain. Two hours after the onset of the stationary phase, a stage at which the PlcR regulon is highly expressed, the plcR expression in the yvfTU mutant was only 50% of that of its parental strain. In addition to the reduced plcR expression in the yvfTU mutant, a few members of the PlcR regulon showed a differential expression, as revealed by transcriptomic and proteomic analyses. The virulence of the yvfTU mutant in a Galleria mellonella insect model was slightly lower than that of the parental strain. Conclusion The YvfTU two-component system is not required for the expression of most of the virulence factors belonging to the PlcR regulon. However, YvfTU is involved in expression of plcR, a major regulator of virulence in B. cereus.

  19. Proteomics identifies Bacillus cereus EntD as a pivotal protein for the production of numerous virulence factors

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    Hélène eOmer

    2015-10-01

    Full Text Available Bacillus cereus is a gram-positive pathogen that causes a wide variety of diseases in humans. It secretes into the extracellular milieu proteins that may contribute directly or indirectly to its virulence. EntD is a novel exoprotein identified by proteogenomics of B. cereus ATCC 14579. We constructed a ΔentD mutant and analyzed the impact of entD disruption on the cellular proteome and exoproteome isolated from early, late and stationary-phase cultures. We identified 308 and 79 proteins regulated by EntD in the cellular proteome and the exoproteome, respectively. The contribution of these proteins to important virulence-associated functions, including central metabolism, cell structure, antioxidative ability, cell motility and toxin production, are presented. The proteomic data were correlated with the growth defect, cell morphology change, reduced motility and reduced cytotoxicity of the ΔentD mutant strain. We conclude that EntD is an important player in B. cereus virulence. The function of EntD and the putative EntD-dependent regulatory network are discussed. To our knowledge, this study is the first characterization of an Ent family protein in a species of the B. cereus group.

  20. Proteomics identifies Bacillus cereus EntD as a pivotal protein for the production of numerous virulence factors.

    Science.gov (United States)

    Omer, Hélène; Alpha-Bazin, Béatrice; Brunet, Jean-Luc; Armengaud, Jean; Duport, Catherine

    2015-01-01

    Bacillus cereus is a Gram-positive pathogen that causes a wide variety of diseases in humans. It secretes into the extracellular milieu proteins that may contribute directly or indirectly to its virulence. EntD is a novel exoprotein identified by proteogenomics of B. cereus ATCC 14579. We constructed a ΔentD mutant and analyzed the impact of entD disruption on the cellular proteome and exoproteome isolated from early, late, and stationary-phase cultures. We identified 308 and 79 proteins regulated by EntD in the cellular proteome and the exoproteome, respectively. The contribution of these proteins to important virulence-associated functions, including central metabolism, cell structure, antioxidative ability, cell motility, and toxin production, are presented. The proteomic data were correlated with the growth defect, cell morphology change, reduced motility, and reduced cytotoxicity of the ΔentD mutant strain. We conclude that EntD is an important player in B. cereus virulence. The function of EntD and the putative EntD-dependent regulatory network are discussed. To our knowledge, this study is the first characterization of an Ent family protein in a species of the B. cereus group.

  1. The YvfTU two-component system is involved in plcR expression in Bacillus cereus.

    Science.gov (United States)

    Brillard, Julien; Susanna, Kim; Michaud, Caroline; Dargaignaratz, Claire; Gohar, Michel; Nielsen-Leroux, Christina; Ramarao, Nalini; Kolstø, Anne-Brit; Nguyen-the, Christophe; Lereclus, Didier; Broussolle, Véronique

    2008-10-16

    Most extracellular virulence factors produced by Bacillus cereus are regulated by the pleiotropic transcriptional activator PlcR. Among strains belonging to the B. cereus group, the plcR gene is always located in the vicinity of genes encoding the YvfTU two-component system. The putative role of YvfTU in the expression of the PlcR regulon was therefore investigated. Expression of the plcR gene was monitored using a transcriptional fusion with a lacZ reporter gene in a yvfTU mutant and in its B. cereus ATCC 14579 parental strain. Two hours after the onset of the stationary phase, a stage at which the PlcR regulon is highly expressed, the plcR expression in the yvfTU mutant was only 50% of that of its parental strain. In addition to the reduced plcR expression in the yvfTU mutant, a few members of the PlcR regulon showed a differential expression, as revealed by transcriptomic and proteomic analyses. The virulence of the yvfTU mutant in a Galleria mellonella insect model was slightly lower than that of the parental strain. The YvfTU two-component system is not required for the expression of most of the virulence factors belonging to the PlcR regulon. However, YvfTU is involved in expression of plcR, a major regulator of virulence in B. cereus.

  2. Transcriptional regulation of metabolic pathways, alternative respiration and enterotoxin genes in anaerobic growth of Bacillus cereus ATCC 14579.

    Science.gov (United States)

    van der Voort, M; Abee, T

    2009-09-01

    To assess genes specifically activated during anaerobic growth that are involved in metabolism and pathogenesis of the foodborne pathogen Bacillus cereus. Growth under anaerobic conditions in Brain Heart Infusion (BHI) broth revealed a reduced growth rate and lower yield as compared to growth under aerobic conditions. Subsequently, comparative transcriptome analysis showed specific genes induced under anaerobic conditions. These included novel genes identified for anaerobic growth of B. cereus, encoding metabolic pathways, such as the arginine deiminase pathway (ArcABDC), formate dehydrogenase (FdhF) and pyruvate formate lyase (Pfl), and alternative respiratory proteins, such as arsenate reductases. Notably, haemolytic enzyme encoding genes were induced during anaerobic growth, and enterotoxin genes were induced in high cell density transition and stationary phases of aerobic cultures. These data point to induction of stress adaptation and pathogenicity factors and rearrangements of expression of metabolic pathways in response to oxygen limitations in B. cereus. The reported changes in gene expression show that the foodborne pathogen B. cereus can adjust to anaerobic conditions, such as encountered in the human GI-tract.

  3. Effects of potential probiotic Bacillus cereus EN25 on growth, immunity and disease resistance of juvenile sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Zhao, Yancui; Yuan, Lei; Wan, Junli; Sun, Zhenxing; Wang, Yiyan; Sun, Hushan

    2016-02-01

    This study was conducted to determine effects of potential probiotic Bacillus cereus EN25 (isolated from mud of sea cucumber culturing water bodies) on growth, immunity and disease resistance against Vibrio splendidus infection in juvenile sea cucumbers Apostichopus japonicus. Animals were respectively fed diets with B. cereus EN25 at 0 (control), 10(5), 10(7) and 10(9) CFU/g for 30 days. Results showed that dietary B. cereus EN25 had no significant effects on growth, total coelomocytes counts and acid phosphatase activity of A. japonicus (P > 0.05). Dietary EN25 at 10(7) CFU/g had significantly improved the phagocytosis, respiratory burst activity and total nitric oxide synthase activity of animals (P  0.05), whereas dietary EN25 at 10(9) CFU/g had significantly decreased its activity (P < 0.05). The cumulative mortality after V. splendidus challenge decreased significantly in sea cucumbers fed with EN25 at 10(7) CFU/g (P < 0.05). The present study confirmed dietary B. cereus EN25 at 10(7) CFU/g could significantly improve immunity and disease resistance in juvenile A. japonicus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Presenting a rapid method for detection of Bacillus cereus, Listeria monocytogenes and Campylobacter jejuni in food samples

    Directory of Open Access Journals (Sweden)

    Ali Razei

    2017-08-01

    Full Text Available Objective(s: Listeria monocytogens, Bacillus cereus and Campylobacter jejuni are three toxin producing bacteria over the world, especially in Iran, and it is essential to find a certain, rapid procedure to identify these microorganisms. In this research, these bacteria were simultaneously detected by multiplex PCR technique in foods. Materials and Methods: The primary approval of bacterial strains was performed by biochemical tests. PCR primers were designed based on the nucleotide sequences of the NHEB/NHEC gene of B. cereus, the hly gene of L. monocytogenes and the C gene of C. jejuni. The specificity of Multiplex PCR method was determined using seven food poisoning bacteria including Salmonella typhi, Shigella dysentery, Yersinia pestis, Staphylococcus aureus, Clostridium perfringens, Clostridium botulinum and Vibrio cholerae. To confirm the reaction, DNA extraction was performed from 30 food samples (milk, and gene amplification was performed by PCR. The length of amplified fragments was 300 bp, 210 bp and 160 bpfor NHEB/NHEC, hly and C genes, respectively. Results: The detection limits of the PCR method were 5, 4 and 3 pg for L. monocytogenes, B. cereus and C. jejuni, respectively. Specifisity test showed that this reaction is spesific to these 3 bacteria. Conclusion: In this study, we  introduced a new multiplex PCR method for simultsnus detection of L. monocytogens, B. cereus and C. jejuni. These results can be used  for detection of other toxin producing bacteria in food.

  5. Presenting a rapid method for detection of Bacillus cereus, Listeria monocytogenes and Campylobacter jejuni in food samples.

    Science.gov (United States)

    Razei, Ali; Sorouri, Rahim; Mousavi, Seyed Latif; Nazarian, Shahram; Amani, Jafar; Aghamollaei, Hosien

    2017-09-01

    Listeria monocytogens, Bacillus cereus and Campylobacter jejuni are three toxin producing bacteria over the world, especially in Iran, and it is essential to find a certain, rapid procedure to identify these microorganisms. In this research, these bacteria were simultaneously detected by multiplex PCR technique in foods. The primary approval of bacterial strains was performed by biochemical tests. PCR primers were designed based on the nucleotide sequences of the NHEB/NHEC gene of B . cereus , the hly gene of L. monocytogenes and the C gene of C. jejuni . The specificity of Multiplex PCR method was determined using seven food poisoning bacteria including Salmonella typhi, Shigella dysentery, Yersinia pestis, Staphylococcus aureus, Clostridium perfringens, Clostridium botulinum and Vibrio cholerae . To confirm the reaction, DNA extraction was performed from 30 food samples (milk), and gene amplification was performed by PCR. The length of amplified fragments was 300 bp, 210 bp and 160 bp for NHEB/NHEC , hly and C genes, respectively. The detection limits of the PCR method were 5, 4 and 3 pg for L. monocytogenes , B. cereus and C. jejuni , respectively. Specifisity test showed that this reaction is spesific to these 3 bacteria. In this study, we introduced a new multiplex PCR method for simultsnus detection of L. monocytogens, B. cereus and C. jejuni . These results can be used for detection of other toxin producing bacteria in food.

  6. Secreted Compounds of the Probiotic Bacillus clausii Strain O/C Inhibit the Cytotoxic Effects Induced by Clostridium difficile and Bacillus cereus Toxins.

    Science.gov (United States)

    Ripert, Gabrielle; Racedo, Silvia M; Elie, Anne-Marie; Jacquot, Claudine; Bressollier, Philippe; Urdaci, Maria C

    2016-06-01

    Although the use of probiotics based on Bacillus strains to fight off intestinal pathogens and antibiotic-associated diarrhea is widespread, the mechanisms involved in producing their beneficial effects remain unclear. Here, we studied the ability of compounds secreted by the probiotic Bacillus clausii strain O/C to counteract the cytotoxic effects induced by toxins of two pathogens, Clostridium difficile and Bacillus cereus, by evaluating eukaryotic cell viability and expression of selected genes. Coincubation of C. difficile and B. cereus toxic culture supernatants with the B. clausii supernatant completely prevented the damage induced by toxins in Vero and Caco-2 cells. The hemolytic effect of B. cereus was also avoided by the probiotic supernatant. Moreover, in these cells, the expression of rhoB, encoding a Rho GTPase target for C. difficile toxins, was normalized when C. difficile supernatant was pretreated using the B. clausii supernatant. All of the beneficial effects observed with the probiotic were abolished by the serine protease inhibitor phenylmethylsulfonyl fluoride (PMSF). Suspecting the involvement of a secreted protease in this protective effect, a protease was purified from the B. clausii supernatant and identified as a serine protease (M-protease; GenBank accession number Q99405). Experiments on Vero cells demonstrated the antitoxic activity of the purified protease against pathogen supernatants. This is the first report showing the capacity of a protease secreted by probiotic bacteria to inhibit the cytotoxic effects of toxinogenic C. difficile and B. cereus strains. This extracellular compound could be responsible, at least in part, for the protective effects observed for this human probiotic in antibiotic-associated diarrhea. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  7. Efecto Antagónico del Kefir sobre Endosporas y Células Vegetativas de Bacillus Cereus y Clostridium Perfringens Antagonistic Effect of the Kefir on Endospores and Vegetative Cells of Bacillus Cereus and Clostridium Perfringens

    OpenAIRE

    Ricardo J Anselmo; Silvia S Viora; Pablo A Ojeda; Lucía I Lausada

    2010-01-01

    Se estudió el efecto bactericida del kéfir sobre endosporas y células vegetativas de Bacillus cereus y Clostridium perfringens inoculados en kéfir durante su almacenamiento. Muestras de kéfir de dos procedencias, uno de origen italiano y otro peruano, fueron inoculadas con una población conocida de B. cereus y Cl. perfringens (10(6) UFC/mL) y conservados a 4ºC durante 30 días. Cada dos días se realizó un recuento de bacterias lácticas, de levaduras, de los patógenos agregados y se determinó e...

  8. Probiotic actions of Bacillus cereus var. toyoi and Saccharomyces boulardii in silver catfish (Rhamdia quelen larvae culture

    Directory of Open Access Journals (Sweden)

    Diego Moreira de Souza

    2012-03-01

    Full Text Available The objective of this study was to evaluate the use of Bacillus cereus var. toyoi and Saccharomyces boulardii as probiotics to improve Rhamdia quelen culture. Six hundred larvaes (0.16±0.07 g were divided in three replicate tanks (25-L recirculation, 20 ºC, photoperiod of 12 h light/12 h darkness per treatment and were randomly assigned to the following treatments: Bacillus cereus var. toyoi; Saccharomyces boulardii; B. toyoi and S. boulardii; and control (without probiotic addition for a period of 30 days. The fish were fed five times daily (56% crude protein - Supra alevino inicial® and the probiotics were applied in water once a day. The doses of probiotics were 5 × 10(8 and 2 × 10(9 CFU (colony forming unit/mL for B. cereus var. toyoi and S. boulardii, respectively. Both probiotics have an inhibitory effect in vitro against Vibrio carchariae and are able to grow in media prepared with fishery water; however, no effect was observed on growth parameters when they were administered to Rhamdia quelen larvae.

  9. Cytochrome c551 and the cytochrome c maturation pathway affect virulence gene expression in Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Han, Hesong; Sullivan, Thomas; Wilson, Adam C

    2015-02-01

    Loss of the cytochrome c maturation system in Bacillus cereus results in increased transcription of the major enterotoxin genes nhe, hbl, and cytK and the virulence regulator plcR. Increased virulence factor production occurs at 37°C under aerobic conditions, similar to previous findings in Bacillus anthracis. Unlike B. anthracis, much of the increased virulence gene expression can be attributed to loss of only c551, one of the two small c-type cytochromes. Additional virulence factor expression occurs with loss of resBC, encoding cytochrome c maturation proteins, independently of the presence of the c-type cytochrome genes. Hemolytic activity of strains missing either cccB or resBC is increased relative to that in the parental strain, while sporulation efficiency is unaffected in the mutants. Increased virulence gene expression in the ΔcccB and ΔresBC mutants occurs only in the presence of an intact plcR gene, indicating that this process is PlcR dependent. These findings suggest a new mode of regulation of B. cereus virulence and reveal intriguing similarities and differences in virulence regulation between B. cereus and B. anthracis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Polymerase chain reaction assay for the detection of Bacillus cereus group cells

    DEFF Research Database (Denmark)

    Hansen, Bjarne Munk; Leser, Thomas D.; Hendriksen, Niels Bohse

    2001-01-01

    of the B. cereus group in food and in the environment. Using 16S rDNA as target, a PCR assay for the detection of B. cereus group cells has been developed. Primers specific for the 16S rDNA of the B. cereus group bacteria were selected and used in combination with consensus primers for 165 rDNA as internal...... PCR procedure control. The PCR procedure was optimized with respect to annealing temperature. When DNA from the B. cereus group bacteria was present, the PCR assay yielded a B. cereus specific fragment, while when non-B. cereus prokaryotic DNA was present, the consensus 165 rDNA primers directed...

  11. Influence of food matrix on outgrowth heterogeneity of heat damaged Bacillus cereus spores.

    Science.gov (United States)

    Warda, Alicja K; den Besten, Heidy M W; Sha, Na; Abee, Tjakko; Nierop Groot, Masja N

    2015-05-18

    Spoilage of heat treated foods can be caused by the presence of surviving spore-formers. It is virtually impossible to prevent contamination at the primary production level as spores are ubiquitous present in the environment and can contaminate raw products. As a result spore inactivation treatments are widely used by food producing industries to reduce the microbial spore loads. However consumers prefer mildly processed products that have less impact on its quality and this trend steers industry towards milder preservation treatments. Such treatments may result in damaged instead of inactivated spores, and these spores may germinate, repair, and grow out, possibly leading to quality and safety issues. The ability to repair and grow out is influenced by the properties of the food matrix. In the current communication we studied the outgrowth from heat damaged Bacillus cereus ATCC 14579 spores on Anopore membrane, which allowed following outgrowth heterogeneity of individual spores on broccoli and rice-based media as well as standard and mildly acidified (pH 5.5) meat-based BHI. Rice, broccoli and BHI pH 5.5 media resulted in delayed outgrowth from untreated spores, and increased heterogeneity compared to BHI pH 7.4, with the most pronounced effect in rice media. Exposure to wet heat for 1 min at 95 °C caused 2 log inactivation and approximately 95% of the spores in the surviving fraction were damaged resulting in substantial delay in outgrowth based on the time required to reach a maximum microcolony size of 256 cells. The delay was most pronounced for heat-treated spores on broccoli medium followed by spores on rice media (both untreated and treated). Interestingly, the increase in outgrowth heterogeneity of heat treated spores on BHI pH 7.4 was more pronounced than on rice, broccoli and BHI pH 5.5 conceivably reflecting that conditions in BHI pH 7.4 better support spore damage repair. This study compares the effects of three main factors, namely heat treatment, p

  12. Inactivation of Bacillus cereus vegetative cells by gastric acid and bile during in vitro gastrointestinal transit

    OpenAIRE

    Ceuppens Siele; Uyttendaele Mieke; Hamelink Stefanie; Boon Nico; Van de Wiele Tom

    2012-01-01

    Abstract Background The foodborne pathogen Bacillus cereus can cause diarrhoeal food poisoning by production of enterotoxins in the small intestine. The prerequisite for diarrhoeal disease is thus survival during gastrointestinal passage. Methods Vegetative cells of 3 different B. cereus strains were cultivated in a real composite food matrix, lasagne verde, and their survival during subsequent simulation of gastrointestinal passage was assessed using in vitro experiments simulating transit t...

  13. Ocorrência de Bacillus cereus em leite integral e capacidade enterotoxigênica das cepas isoladas Occurrence of Bacillus cereus in Whole milk and enterotoxigenic potential of the isolated strains

    Directory of Open Access Journals (Sweden)

    N.C.M. Rezende-Lago

    2007-12-01

    Full Text Available Pesquisaram-se a presença de Bacillus cereus e a produção de enterotoxinas produzidas por esses microrganismos em 120 amostras de diversos tipos de leite. Bacillus cereus foi isolado e identificado em 22 (73,3%, 15 (50,0%, 29 (96,7% e quatro (13,3% amostras de leite em pó, cru, pasteurizado e UAT (longa vida, respectivamente. Para a detecção de enterotoxinas pela técnica da alça ligada de coelho, foram positivos, respectivamente, três (13,6%, um (7,1% e 10 (35,7% microrganismos isolados das amostras de leite em pó, leite cru e leite pasteurizado. Pelo teste de aumento de permeabilidade vascular, dois (9,1%, um (7,1%, um (3,6% e um (4,0% microrganismos isolados de leite em pó, cru, pasteurizado e UAT apresentaram-se enterotoxigênicos, respectivamente. O uso da técnica de aglutinação passiva em látex demonstrou a produção da toxina diarréica por três (33,3%, sete (63,6%, quatro (30,8% e oito (80,0% microrganismos isolados, respectivamente, de leite em pó, cru, pasteurizado e UAT. Os resultados indicam um risco potencial, podendo colocar em risco a saúde dos consumidores desses produtos.A hundred and twenty samples of different types of milk were examined to the presence of Bacillus cereus and the enterotoxigenic potential of the isolated strains. Bacillus cereus was isolated and identified in 22 (73.0%, 15 (50.0%, 29 (96.7% and four (13.3% samples of powder, raw, pasteurized and UHT milk, respectively. The enterotoxigenicity detection using the rabbit ileal loop assay showed positive, respectively, three (13.6%, one (7.1% and 10 (35.7% isolated strains from powder, raw and pasteurized milk. Using vascular permeability activity assay two (9.1%, one (7.1%, one (3.6% and one (4.0% isolated strains from powder, raw, pasteurized and UHT milk were positive, respectively. The reversed passive latex agglutination test showed diarrheal toxin production by three (33.3%, seven (63.6%, four (30.8% and eight (80.0% strains isolated from

  14. Decontamination of Mesquite Pod Flour Naturally Contaminated with Bacillus cereus and Formation of Furan by Ionizing Irradiation.

    Science.gov (United States)

    Fan, Xuetong; Felker, Peter; Sokorai, Kimberly J

    2015-05-01

    Mesquite pod flour produced from nitrogen-fixing trees of the Prosopis species has a unique aroma and flavor that is preferred by some consumers. Due to the presence of wildlife, grazing domestic animals, and insects, the pods have a high potential of being contaminated with human pathogenic bacteria, such as Bacillus cereus. Nonthermal processing technologies are helpful to reduce the population of microorganisms in the flour because heating deteriorates the characteristic flavor. A study was conducted to investigate the efficacy of ionizing radiation in decontaminating two types of mesquite pod flours (Prosopis alba and Prosopis pallida) naturally contaminated with B. cereus and the effects of irradiation on the formation of furan, a possible human carcinogen. Results showed that the populations of B. cereus were 3.8 and 5.4 log CFU/g in nonirradiated P. alba and P. pallida flours, respectively, and populations of microflora, mesophilic spores, B. cereus, and B. cereus spores decreased with increasing radiation doses. At 6 kGy, the populations fell below 1 log CFU/g. Irradiation at 6 kGy had no significant effect on the fructose, glucose, or sucrose content of the flour. Nonirradiated P. alba and P. pallida flours contained 13.0 and 3.1 ng/g of furan, respectively. Furan levels increased with irradiation doses at rates of 2.3 and 2.4 ng/g/kGy in the two flours. The level of 3-methylbutanal was reduced or not affected by irradiation, while the hexanal level was increased. Our results suggested that irradiation was effective in decontaminating contaminated mesquite flour. The significance of furan formation and possible changes in flavor due to irradiation may need to be further examined.

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

    Science.gov (United States)

    Cattani, Fernanda; Barth, Valdir C; Nasário, Jéssica S R; Ferreira, Carlos A S; Oliveira, Sílvia D

    2016-04-01

    The Bacillus cereus group includes important spore-forming bacteria that present spoilage capability and may cause foodborne diseases. These microorganisms are traditionally evaluated in food using culturing methods, which can be laborious and time-consuming, and may also fail to detect bacteria in a viable but nonculturable state. The purpose of this study was to develop a quantitative real-time PCR (qPCR) combined with a propidium monoazide (PMA) treatment to analyze the contamination of UHT milk by B. cereus group species viable cells. Thirty micrograms per milliliter of PMA was shown to be the most effective concentration for reducing the PCR amplification of extracellular DNA and DNA from dead cells. The quantification limit of the PMA-qPCR assay was 7.5 × 10(2) cfu/mL of milk. One hundred thirty-five UHT milk samples were analyzed to evaluate the association of PMA to qPCR to selectively detect viable cells. The PMA-qPCR was able to detect B. cereus group species in 44 samples (32.6%), whereas qPCR without PMA detected 78 positive samples (57.8%). Therefore, the PMA probably inhibited the amplification of DNA from cells that were killed during UHT processing, which avoided an overestimation of bacterial cells when using qPCR and, thus, did not overvalue potential health risks. A culture-based method was also used to detect and quantify B. cereus sensu stricto in the same samples and showed positive results in 15 (11.1%) samples. The culture method and PMA-qPCR allowed the detection of B. cereus sensu stricto in quantities compatible with the infective dose required to cause foodborne disease in 3 samples, indicating that, depending on the storage conditions, even after UHT treatment, infective doses may be reached in ready-to-consume products. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Bioremediation of Spent Bleaching Earth (SBE Wastes using Lipolitic Bacteria (Bacillus cereus with Variation of Inoculum Volume

    Directory of Open Access Journals (Sweden)

    Maria Lusia

    2018-01-01

    Full Text Available Spent bleaching earth (SBE is a solid waste was generated from the CPO refining step into cooking oil.  SBE that was discharged directly into the environment has the potential to pollute the environment, because in the SBE waste contained oil and acid residues, which are easily to be oxidized and flammable.  Therefore, SBE must be processed first before being discharged into the environment.  One way to manage SBE is by bioremediation.  Bioremediation is a method on cleaning the environment from contaminants by using  biological agents, such as bacteria, fungi etc.  The bacterial isolates used in this study were Bacillus cereus.  This study aims to obtain the best inoculum and to know the ability of Bacillus cereus bacteria in degrading the oil content in SBE waste. This study used Completely Randomized Design with the volume of Bacillus cereus bacteria inoculum as a treatment, consisting of 6 treatment levels of 0 mL kg-1, 25 mL kg-1, 50 mL kg-1, 75 mL kg-1, 100 mL kg-1, 125 mL kg-1.  Each treatment level was repeated 3 times, so taht 18 experimental units were obtained.  Observation was done once a week, in a month.  Parameters observed were bacterial population, percentage of oil degradation, and oil content degradation.  The best treatment result for the bacterial population was obtained at the treatment of 100 mL kg-1, at week 4 which was 7,4 x 108 cfu g-1, and for the oil degradation was obtained at 50 mL kg-1 on the treatment at week 4 as big as 90,43%.

  17. Radiosensibilisation of bacteria on beef minced by essential oils with special reference to the spores of Bacillus cereus ATCC 7004

    International Nuclear Information System (INIS)

    Ayari, Samia

    2007-01-01

    The radiosensitization of Bacillus Cereus ATCC 7004 spores was evaluated in the presence of thymol, thyme, D-L menthol, trans-cinnamaldehyde and eugenol in ground beef. Meat cattle minced (5 % fat) was inoculated with spores of Bacillus Cereus (10 5 - 10 6 CFU / g), and each compound was added separately at various concentrations. The antimicrobial potential was evaluated in unirradiated meat by determining the MIC in percentage (wt / wt) after 24 h of storage at 4± 1C. Results showed that the best antimicrobial compound was the trans-cinnamaldehyde with MIC of 1.47%, wt/wt. In presence of cinnamaldehyde, the addition of sodium pyrophosphate decahydrate (0.1%, wt/wt) increased significantly (p < 0.05) the relative sensitivity of Bacillus Cereus spores 2 times. However, the presence of ascorbic acid in the media reduced significantly (p < 0.05) the radiosensitivity of bacteria. The combined effect of gamma irradiation in presence of cinnamaldehyde, added with ascorbic acid or sodium pyrophosphate decahydrate, on the microbiological and physico-chemical characteristic of meat samples was evaluated at 2 kGy under air. The use of the active compounds with the irradiation reduced significantly (p < 0.05) the count of total bacteria with a concomitant effect in the extension periods of shelf life. The addition of the cinnamaldehyde induced a significant reduction (p < 0.05) in TVN and free amino acids of irradiated samples. In presence of ascorbic acid the thiobarbituric acid-reactive substances (TBARS) concentration was significantly reduced (P...0.05). A significant reduction (p < 0.05) of a* and C* of color values and a significant increase (p < 0.05 ) of b* value were obtained for the samples treated by the cinnamaldehyde. The application of bioactive films for the immobilization of the essential oils is a good alternate to check their stability during storage time. (Author). 155 refs

  18. Improving Glyphosate Oxidation Activity of Glycine Oxidase from Bacillus cereus by Directed Evolution

    Science.gov (United States)

    Zhan, Tao; Zhang, Kai; Chen, Yangyan; Lin, Yongjun; Wu, Gaobing; Zhang, Lili; Yao, Pei; Shao, Zongze; Liu, Ziduo

    2013-01-01

    Glyphosate, a broad spectrum herbicide widely used in agriculture all over the world, inhibits 5-enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway, and glycine oxidase (GO) has been reported to be able to catalyze the oxidative deamination of various amines and cleave the C-N bond in glyphosate. Here, in an effort to improve the catalytic activity of the glycine oxidase that was cloned from a glyphosate-degrading marine strain of Bacillus cereus (BceGO), we used a bacteriophage T7 lysis-based method for high-throughput screening of oxidase activity and engineered the gene encoding BceGO by directed evolution. Six mutants exhibiting enhanced activity toward glyphosate were screened from two rounds of error-prone PCR combined with site directed mutagenesis, and the beneficial mutations of the six evolved variants were recombined by DNA shuffling. Four recombinants were generated and, when compared with the wild-type BceGO, the most active mutant B3S1 showed the highest activity, exhibiting a 160-fold increase in substrate affinity, a 326-fold enhancement in catalytic efficiency against glyphosate, with little difference between their pH and temperature stabilities. The role of these mutations was explored through structure modeling and molecular docking, revealing that the Arg51 mutation is near the active site and could be an important residue contributing to the stabilization of glyphosate binding, while the role of the remaining mutations is unclear. These results provide insight into the application of directed evolution in optimizing glycine oxidase function and have laid a foundation for the development of glyphosate-tolerant crops. PMID:24223901

  19. The effect of nalidixic acid, rifampicin and chloramphenicol on the synthesis of phospholipase C in Bacillus cereus

    International Nuclear Information System (INIS)

    Valle, K.J.; Prydz, H.

    1978-01-01

    The effect of nalidixic acid, rifampicin and chloramphenicol on the synthesis of phospholipase C (EC 3.1.4.3) has been studied in washed Bacillus cereus cells resuspended in nutrient broth. In the absence of inhibitors, the synthesis showed a biphasic pattern. No synthesis or release of enzyme was found in the presence of chloramphenicol. When rifampicin was added, phospholipase C synthesis for 10-15 min. Nalidixic acid, at concentrations which inhibited DNA synthesis completely, permitted the synthesis of phospholipase C at the same rate and for a similar length of time as rifampicin. (author)

  20. Differential Involvement of the Five RNA Helicases in Adaptation of Bacillus cereus ATCC 14579 to Low Growth Temperatures ▿

    OpenAIRE

    Pandiani, Franck; Brillard, Julien; Bornard, Isabelle; Michaud, Caroline; Chamot, Stéphanie; Nguyen-the, Christophe; Broussolle, Véronique

    2010-01-01

    Bacillus cereus ATCC 14579 possesses five RNA helicase-encoding genes overexpressed under cold growth conditions. Out of the five corresponding mutants, only the {Delta}cshA, {Delta}cshB, and {Delta}cshC strains were cold sensitive. Growth of the {Delta}cshA strain was also reduced at 30°C but not at 37°C. The cold phenotype was restored with the cshA gene for the {Delta}cshA strain and partially for the {Delta}cshB strain but not for the {Delta}cshC strain, suggesting different functions at ...

  1. Bioremediation of petroleum wastewater by hyper-phenol tolerant Bacillus cereus: Preliminary studies with laboratory-scale batch process.

    Science.gov (United States)

    Banerjee, Aditi; Ghoshal, Aloke K

    2017-09-03

    Petroleum wastewater samples from oil refinery and oil exploration site were treated by hyper phenol-tolerant Bacillus cereus (AKG1 and AKG2) in laboratory-scale batch process to assess their bioremediation efficacy. Quality of the treated wastewater samples were analyzed in terms of removal of chemical oxygen demand (COD), total organic carbon (TOC) and ammonium nitrogen content, and improvement of biological oxygen demand (BOD). Adaptation of these bacteria to the toxic environment through structural changes in their cell membranes was also highlighted. Among different combinations, the co-culture of AKG1 and AKG2 showed the best performance in degrading the wastewater samples.

  2. Effect of pH of the recovery medium on the apparent heat resistance of three strains of Bacillus cereus.

    Science.gov (United States)

    González, I; López, M; Mazas, M; Bernardo, A; Martín, R

    1996-08-01

    The influence of pH of the recovery medium, in the range 7.6-5.4, on the apparent heat resistance of three strains of Bacillus cereus (ATCC 4342, 7004 and 9818) has been investigated. The highest counts of heat-injured spores were obtained at pH near neutral, decreasing markedly as pH was reduced, especially with longer heating times. When the media were acidified, the apparent D-values tended to decrease, although some exceptions related to the strain and the nature of the medium were observed. z-Values determined were not affected by the pH of the medium.

  3. The comER Gene Plays an Important Role in Biofilm Formation and Sporulation in both Bacillus subtilis and Bacillus cereus.

    Science.gov (United States)

    Yan, Fang; Yu, Yiyang; Wang, Luyao; Luo, Yuming; Guo, Jian-Hua; Chai, Yunrong

    2016-01-01

    Bacteria adopt alternative cell fates during development. In Bacillus subtilis, the transition from planktonic growth to biofilm formation and sporulation is controlled by a complex regulatory circuit, in which the most important event is activation of Spo0A, a transcription factor and a master regulator for genes involved in both biofilm formation and sporulation. In B. cereus, the regulatory pathway controlling biofilm formation and cell differentiation is much less clear. In this study, we show that a novel gene, comER, plays a significant role in biofilm formation as well as sporulation in both B. subtilis and B. cereus. Mutations in the comER gene result in defects in biofilm formation and a delay in spore formation in the two Bacillus species. Our evidence supports the idea that comER may be part of the regulatory circuit that controls Spo0A activation. comER likely acts upstream of sda, a gene encoding a small checkpoint protein for both sporulation and biofilm formation, by blocking the phosphor-relay and thereby Spo0A activation. In summary, our studies outlined a conserved, positive role for comER, a gene whose function was previously uncharacterized, in the regulation of biofilm formation and sporulation in the two Bacillus species.

  4. The comER Gene Plays an Important Role in Biofilm Formation and Sporulation in both Bacillus subtilis and Bacillus cereus

    Science.gov (United States)

    Yan, Fang; Yu, Yiyang; Wang, Luyao; Luo, Yuming; Guo, Jian-hua; Chai, Yunrong

    2016-01-01

    Bacteria adopt alternative cell fates during development. In Bacillus subtilis, the transition from planktonic growth to biofilm formation and sporulation is controlled by a complex regulatory circuit, in which the most important event is activation of Spo0A, a transcription factor and a master regulator for genes involved in both biofilm formation and sporulation. In B. cereus, the regulatory pathway controlling biofilm formation and cell differentiation is much less clear. In this study, we show that a novel gene, comER, plays a significant role in biofilm formation as well as sporulation in both B. subtilis and B. cereus. Mutations in the comER gene result in defects in biofilm formation and a delay in spore formation in the two Bacillus species. Our evidence supports the idea that comER may be part of the regulatory circuit that controls Spo0A activation. comER likely acts upstream of sda, a gene encoding a small checkpoint protein for both sporulation and biofilm formation, by blocking the phosphor-relay and thereby Spo0A activation. In summary, our studies outlined a conserved, positive role for comER, a gene whose function was previously uncharacterized, in the regulation of biofilm formation and sporulation in the two Bacillus species. PMID:27446060

  5. Bacillus cereus as indicator in the sterilization of residual water with high energy electrons; Bacillus cereus como indicador en la desinfeccion de aguas residuales con electrones de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Mejia Z, E

    2000-07-01

    One of the main causes of water pollution is the presence of microorganisms that provoke infections, moreover of chemical substances. The processes of residual water treatment finally require of the disinfection for its use or final disposition. The radiation technology for the residual water treatment by mean of electron beams is an innovator process because as well as decomposing the chemical substance or to degrade them, also it provokes a disinfection by which this is proposed as alternative for disinfection of residual water, with the purpose in reusing the water treated in the agriculture, recreation and industry among others secondary activities, solving environmental or health problems. The objective of this work is to evaluate the use of Bacillus cereus as biological indicator in the disinfection by radiation, using High Energy Electrons. To fulfil with this objective, the work was developed in three stages, the first one consisted in the acquisition, propagation and conservation of the Bacillus cereus stumps, considering Escherichia coli and Salmonella typhimurium as pathogenic germs present in residual water. Moreover, the inocule standardization and the conditions of the Electron accelerator Type Pelletron. In the second stage it was performed the irradiation of aqueous samples of the microorganisms simulating biological pollution and the application to problem samples of a treatment plant sited in the Lerma River zone of mixed residual water. And in the third stage was performed a regression analysis to the reported survival for each kind of microorganisms. The results obtained show that with the use of Electron beams was reduced 6 logarithmic units de E. coli at 129 Gy, for S. typhimurium it was reduced 8 logarithmic units at 383 Gy and the B. cereus at 511 Gy was reduced 6.8 logarithmic units. Of the problem samples irradiated at 500 Gy, the concentration of the total account diminished from 8.70 x 10{sup 7} UFC/ml to 550 UFC/ml, the presence of B

  6. Photoproduct formation and repair capacity in a mutant of Bacillus cereus 569 producing UV-sensitive spores

    International Nuclear Information System (INIS)

    Weinberger, S.; Evenchik, Z.; Hertman, I.; Bar-Ilan Univ., Ramat-Gan

    1982-01-01

    A mutant of Bacillus cereus 569 UV sensitive in both vegetative and sporal stages was isolated by N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutagenesis followed by selection on mitomycin C. The UV-sensitive mutant designated as B. cereus 2422 exhibited normal content of dipicolinic acid (DPA) and resistance to X-rays and ethyl methanesulphonate. The photoproduct type and amount, induced by a given UV dose, was similar in either cells or spores of both the mutant 2422 and the wild-type ancestor. The mutant 2422 excised cyclobutane thymine dimers only to a limited extent (20%) as compared with 80% removal in the wild type. Removal of a spore-specific photoproduct (TDHT) during germination proceeded to a similar extent in B. cereus 2422 and the wild-type parent. However, under growing conditions, an additional removal of the TDHT was observed only in the wild-type strain. Liquid holding recovery occurred in irradiated wild-type cells, but not in mutant cells. Spontaneous revertants were isolated that regained UV resistance simultaneously in both the vegetative and sporal stage. (orig./AJ)

  7. Impacts of sporulation temperature, exposure to compost matrix and temperature on survival of Bacillus cereus spores during livestock mortality composting.

    Science.gov (United States)

    Stanford, K; Reuter, T; Gilroyed, B H; McAllister, T A

    2015-04-01

    To investigate impact of sporulation and compost temperatures on feasibility of composting for disposal of carcasses contaminated with Bacillus anthracis. Two strains of B. cereus, 805 and 1391, were sporulated at either 20 or 37°C (Sporulation temperature, ST) and 7 Log10 CFU g(-1) spores added to autoclaved manure in nylon bags (pore size 50 μm) or in sealed vials. Vials and nylon bags were embedded into compost in either a sawdust or manure matrix each containing 16 bovine mortalities (average weight 617 ± 33 kg), retrieved from compost at intervals over 217 days and survival of B. cereus spores assessed. A ST of 20°C decreased spore survival by 1·4 log10 CFU g(-1) (P Compost temperatures >55°C reduced spore survival (P compost temperatures were key factors influencing survival of B. cereus spores in mortality compost. Composting may be most appropriate for the disposal of carcasses infected with B. anthracis at ambient temperatures ≤20°C under thermophillic composting conditions (>55°C). © 2015 The Society for Applied Microbiology.

  8. Food Sensing: Aptamer-Based Trapping of Bacillus cereus Spores with Specific Detection via Real Time PCR in Milk.

    Science.gov (United States)

    Fischer, Christin; Hünniger, Tim; Jarck, Jan-Hinnerk; Frohnmeyer, Esther; Kallinich, Constanze; Haase, Ilka; Hahn, Ulrich; Fischer, Markus

    2015-09-16

    Aerobic spores pose serious problems for both food product manufacturers and consumers. Milk is particularly at risk and thus an important issue of preventive consumer protection and quality assurance. The spore-former Bacillus cereus is a food poisoning Gram-positive pathogen which mainly produces two different types of toxins, the diarrhea inducing and the emetic toxins. Reliable and rapid analytical assays for the detection of B. cereus spores are required, which could be achieved by combining in vitro generated aptamers with highly specific molecular biological techniques. For the development of routine bioanalytical approaches, already existing aptamers with high affinity to B. cereus spores have been characterized by surface plasmon resonance (SPR) spectroscopy and fluorescence microscopy in terms of their dissociation constants and selectivity. Dissociation constants in the low nanomolar range (from 5.2 to 52.4 nM) were determined. Subsequently, the characterized aptamers were utilized for the establishment and validation of an aptamer-based trapping technique in both milk simulating buffer and milk with fat contents between 0.3 and 3.5%. Thereby, enrichment factors of up to 6-fold could be achieved. It could be observed that trapping protocol and characterized aptamers were fully adaptable to the application in milk. Due to the fact that aptamer selectivity is limited, a highly specific real time PCR assay was utilized following trapping to gain a higher degree of selectivity.

  9. Prevalence, isolation and characterization of Bacillus cereus strains from rice of local cultivators of Sabah, Sarawak, and Peninsular Malaysia

    Science.gov (United States)

    Sawei, Jelin; Sani, Norrakiah Abdullah

    2016-11-01

    Bacillus cereus is a spore-forming, facultative anaerobic, motile microorganism that has been identified as a causative agent of two types of gastrointestinal diseases such as emetic and diarrhea. This foodborne pathogen is found in both vegetative cells and endospores form in foods such as rice either raw or cooked. The aim of this study is to investigate and determine the prevalence, characterize and identify the isolation of vegetative cells and endospores of B. cereus in thirty varieties (n=3) of raw rice from Sabah, Sarawak and Peninsular Malaysia. A total of 90 (n=90) raw rice were examined and 84 (93.33%) samples were positive to vegetative cells of B. cereus. However, only 32 (35.56%) samples were positive for endospore cells that able to germinate after samples were heated at 75°C for 15 mins. The mean log cfu/g for vegetative cells were higher range (0.00 - 4.1533) than visible endospores (0.00 - 3.7533 mean log cfu/g). Sample of raw red rice (UKMRC9) had significantly higher contamination by both vegetative cells and endospores at p<0.05, than the other raw rice samples.

  10. Optimization and production of curdlan gum using Bacillus cereus pr3 isolated from rhizosphere of leguminous plant.

    Science.gov (United States)

    Prakash, S; Rajeswari, K; Divya, P; Ferlin, M; Rajeshwari, C T; Vanavil, B

    2018-03-21

    Curdlan gum is a neutral water-insoluble bacterial exopolysaccharide composed primarily of linear β-(1,3) glycosidic linkages. Recently, there has been increasing interest in the applications of curdlan and its derivatives. Curdlan is found to inhibit tumors and its sulfated derivative possess anti- HIV activity. Curdlan is biodegradable, non-toxic towards human, environment and edible which makes it suitable as drug-delivery vehicles for sustained drug release. The increasing demand for the growing applications of curdlan requires an efficient high yield fermentation production process so as to satisfy the industrial needs. In this perspective, the present work is aimed to screen and isolate an efficient curdlan gum producing bacteria from rhizosphere of ground nut plant using aniline-blue agar. High yielding isolate was selected based on curdlan yield and identified as Bacillus cereus using GC-FAME analysis. B. cereus PR3 curdlan gum was characterized using FT-IR spectroscopy, SEM and XRD. Fermentation time for curdlan production using B. cereus PR3 was optimized. Media constituents like carbon, nitrogen and mineral sources were screened using Plackett- Burman design. Subsequent statistical analysis revealed that Starch, NH 4 NO 3 , K 2 HPO 4 , Na 2 SO 4 , KH 2 SO 4 and CaCl 2 were significant media constituents and these concentrations were optimized for enhancement of curdlan production up to 20.88 g/L.

  11. Analysis of acid-stressed Bacillus cereus reveals a major oxidative response and inactivation-associated radical formation.

    Science.gov (United States)

    Mols, Maarten; van Kranenburg, Richard; van Melis, Clint C J; Moezelaar, Roy; Abee, Tjakko

    2010-04-01

    Acid stress resistance of the food-borne human pathogen Bacillus cereus may contribute to its survival in acidic environments, such as encountered in soil, food and the human gastrointestinal tract. The acid stress responses of B. cereus strains ATCC 14579 and ATCC 10987 were analysed in aerobically grown cultures acidified to pH values ranging from pH 5.4 to pH 4.4 with HCl. Comparative phenotype and transcriptome analyses revealed three acid stress-induced responses in this pH range: growth rate reduction, growth arrest and loss of viability. These physiological responses showed to be associated with metabolic shifts and the induction of general stress response mechanisms with a major oxidative component, including upregulation of catalases and superoxide dismutases. Flow cytometry analysis in combination with the hydroxyl (OH.) and peroxynitrite (ONOO(-))-specific fluorescent probe 3'-(p-hydroxyphenyl) fluorescein (HPF) showed excessive radicals to be formed in both B. cereus strains in bactericidal conditions only. Our study shows that radicals can indicate acid-induced malfunctioning of cellular processes that lead to cell death.

  12. Role played by exosporium glycoproteins in the surface properties of Bacillus cereus spores and in their adhesion to stainless steel.

    Science.gov (United States)

    Lequette, Yannick; Garénaux, Estelle; Tauveron, Grégoire; Dumez, Sylvain; Perchat, Stéphane; Slomianny, Christian; Lereclus, Didier; Guérardel, Yann; Faille, Christine

    2011-07-01

    Bacillus cereus spores are surrounded by a loose-fitting layer called the exosporium, whose distal part is mainly formed from glycoproteins. The role played by the exosporium glycoproteins of B. cereus ATCC 14579 (BclA and ExsH) was investigated by considering hydrophobicity and charge, as well as the properties of spore adhesion to stainless steel. The absence of BclA increased both the isoelectric point (IEP) and hydrophobicity of whole spores while simultaneously reducing the interaction between spores and stainless steel. However, neither the hydrophobicity nor the charge associated with BclA could explain the differences in the adhesion properties. Conversely, ExsH, another exosporium glycoprotein, did not play a significant role in spore surface properties. The monosaccharide analysis of B. cereus ATCC 14579 showed different glycosylation patterns on ExsH and BclA. Moreover, two specific glycosyl residues, namely, 2-O-methyl-rhamnose (2-Me-Rha) and 2,4-O-methyl-rhamnose (2,4-Me-Rha), were attached to BclA, in addition to the glycosyl residues already reported in B. anthracis.

  13. ORF 2 from the Bacillus cereus linear plasmid pBClin15 encodes a DNA binding protein.

    Science.gov (United States)

    Stabell, F B; Egge-Jacobsen, W; Risøen, P A; Kolstø, A-B; Økstad, O A

    2009-01-01

    To isolate and identify DNA-binding protein(s) with affinity for the mobile chromosomal repeat element bcr1 in Bacillus cereus group bacteria. A biotinylated bcr1 element was immobilized to streptavidin-coated magnetic beads and used to pull out a 20 kDa DNA-binding protein from a whole cell protein extract of B. cereus ATCC 14579. The protein was identified as the product of ORF 2 encoded by the bacteriophage-related autonomously replicating linear genetic element pBClin15 carried by the strain. DNA binding was not bcr1-specific. By Northern blotting ORF 2 was co-transcribed with ORF 1, and also in certain instances with ORF 3 by transcriptional readthrough of the terminator located between ORF 2 and ORF 3. ORF 2 from pBClin15 encodes a DNA-binding protein. ORF 2 is co-transcribed with its upstream gene ORF 1, and in a subset of the transcripts also with the downstream gene ORF 3 through alternative transcription termination. The B. cereus group contains bacterial species of medical and economic importance. Bacteriophages or phage-encoded proteins from these bacteria have been suggested as potential therapeutic agents. Understanding the biology of bacteriophage-related genetic elements through functional characterization of their genes is of high relevance.

  14. Low concentrations of bile salts induce stress responses and reduce motility in Bacillus cereus ATCC 14579 [corrected].

    Science.gov (United States)

    Kristoffersen, Simen M; Ravnum, Solveig; Tourasse, Nicolas J; Økstad, Ole Andreas; Kolstø, Anne-Brit; Davies, William

    2007-07-01

    Tolerance to bile salts was investigated in forty Bacillus cereus strains, including 17 environmental isolates, 11 dairy isolates, 3 isolates from food poisoning outbreaks, and 9 other clinical isolates. Growth of all strains was observed at low bile salt concentrations, but no growth was observed on LB agar plates containing more than 0.005% bile salts. Preincubation of the B. cereus type strain, ATCC 14579, in low levels of bile salts did not increase tolerance levels. B. cereus ATCC 14579 was grown to mid-exponential growth phase and shifted to medium containing bile salts (0.005%). Global expression patterns were determined by hybridization of total cDNA to a 70-mer oligonucleotide microarray. A general stress response and a specific response to bile salts were observed. The general response was similar to that observed in cultures grown in the absence of bile salts but at a higher (twofold) cell density. Up-regulation of several putative multidrug exporters and transcriptional regulators and down-regulation of most motility genes were observed as part of the specific response. Motility experiments in soft agar showed that motility decreased following bile salts exposure, in accordance with the transcriptional data. Genes encoding putative virulence factors were either unaffected or down-regulated.

  15. Prevalence, virulence factor genes and antibiotic resistance of Bacillus cereus sensu lato isolated from dairy farms and traditional dairy products

    DEFF Research Database (Denmark)

    Owusu-Kwarteng, James; Wuni, Alhassan; Akabanda, Fortune

    2017-01-01

    Background: B. cereus are of particular interest in food safety and public health because of their capacity to cause food spoilage and disease through the production of various toxins. The aim of this study was to determine the prevalence, virulence factor genes and antibiotic resistance profile...... from 54 positive samples were screened by PCR for the presence of 8 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK and entFM), and one emetic gene (ces). Phenotypic resistance to 15 antibiotics were also determined for 96 B. cereus sensu lato isolates. Results: About 72% (18 of 25 soil...... in 60% (57/96) isolates, 14% (13/96) harboured only one gene, 19% (18/96) whereas 8% possessed none of the NHE genes. The detection rates of cytk, entFM, and ces genes were 75, 67 and 9% respectively. Bacillus cereus s. l. isolates were generally resistant to β-lactam antibiotics such as ampicillin (98...

  16. Prevalence and fate of Bacillus cereus in African traditional cereal-based foods used as infant foods.

    Science.gov (United States)

    Humblot, Christèle; Perez-Pulido, Ruben; Akaki, David; Loiseau, Gérard; Guyot, Jean-Pierre

    2012-09-01

    The objective of the present work was to estimate the prevalence of Bacillus cereus group species in traditional cereal-based lactic acid-fermented slurries and nonfermented flours used to prepare infant foods in an African context. High counts on mannitol-egg yolk-polymixin agar medium were determined for the fermented slurries (median, 4.5 × 10(4) CFU/ml of slurry) compared with the nonfermented flours, most of whose counts were lower than 10(-1) CFU/g. Virulence genes were characterized in 60 isolates from 26 traditional cereal-based foods in Ouagadougou (Burkina Faso). Seventy-two and 38 % of isolates were positive for the complete set of genes coding for hemolysin BL and nonhemolytic enterotoxin, respectively, suggesting a high enterotoxigenic potential for these foodborne isolates. No potentially emetic toxin-producing strains were detected. Because of the high counts found for fermented slurries, survival tests with vegetative cells inoculated in fermented slurries were performed, which showed that growth of B. cereus was inhibited. This result suggests that fermentation in traditional production units is presumably not adequately controlled, enabling growth during any unit operations before fermentation, or even during the fermentation step, when the process was poorly controlled. However, adding nisin (0.1 mg/ml) enabled a 5-log reduction in the B. cereus population in 5 h, suggesting that the use of nisin could be a way to upgrade the hygienic quality of this type of food.

  17. Glucose 6P binds and activates HlyIIR to repress Bacillus cereus haemolysin hlyII gene expression.

    Directory of Open Access Journals (Sweden)

    Elisabeth Guillemet

    Full Text Available Bacillus cereus is a Gram-positive spore-forming bacterium causing food poisoning and serious opportunistic infections. These infections are characterized by bacterial accumulation despite the recruitment of phagocytic cells. We have previously shown that B. cereus Haemolysin II (HlyII induces macrophage cell death by apoptosis. In this work, we investigated the regulation of the hlyII gene. We show that HlyIIR, the negative regulator of hlyII expression in B. cereus, is especially active during the early bacterial growth phase. We demonstrate that glucose 6P directly binds to HlyIIR and enhances its activity at a post-transcriptional level. Glucose 6P activates HlyIIR, increasing its capacity to bind to its DNA-box located upstream of the hlyII gene, inhibiting its expression. Thus, hlyII expression is modulated by the availability of glucose. As HlyII induces haemocyte and macrophage death, two cell types that play a role in the sequestration of nutrients upon infection, HlyII may induce host cell death to allow the bacteria to gain access to carbon sources that are essential components for bacterial growth.

  18. The Roles of AtxA Orthologs in Virulence of Anthrax-like Bacillus cereus G9241

    OpenAIRE

    Scarff, Jennifer M.; Raynor, Malik J.; Seldina, Yuliya I.; Ventura, Christy L.; Koehler, Theresa M.; O’Brien, Alison D.

    2016-01-01

    AtxA is a critical transcriptional regulator of plasmid-encoded virulence genes in Bacillus anthracis. Bacillus cereus G9241, which caused an anthrax-like infection, has two virulence plasmids, pBCXO1 and pBC210, that each harbor toxin genes and a capsule locus. G9241 also produces two orthologs of AtxA: AtxA1, encoded on pBCXO1, and AtxA2, encoded on pBC210. The amino acid sequence of AtxA1 is identical to that of AtxA from B. anthracis, while the sequences of AtxA1 and AtxA2 are 79% identic...

  19. Contaminação ambiental e perfil toxigênico de Bacillus cereus isolados em serviços de alimentação Environmental contamination and enterotoxigenic profile of Bacillus cereus isolated in food services

    Directory of Open Access Journals (Sweden)

    Celina Mara Soares

    2008-04-01

    Full Text Available A avaliação da contaminação ambiental por Bacillus cereus foi realizada em 90 amostras de ar ambiente e em 96 amostras de superfícies de bancadas e de equipamentos, de dois restaurantes institucionais. O microrganismo foi detectado em 84,4% e 44,8% das amostras de ar ambiente e de superfícies, respectivamente. O potencial enterotoxigênico dos isolados foi investigado através da reação da polimerase em cadeia (PCR para os genes hblA, hblD e hblC (que codificam a hemolisina BL e para os genes nheA, nheB e nheC (que codificam a enterotoxina não hemolítica - NHE. De um total de 70 isolados investigados, 14,3% foram positivos para os três genes da HBL e 12,8% foram positivos para os três genes da NHE. A produção de NHE também foi verificada através do Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (kit BDE-VIA; Tecra. Os resultados obtidos com o kit revelaram que 61,4% dos 70 isolados são produtores de NHE.Ninety air samples and ninety six samples from benches and equipments surfaces were collected in two food services for investigation of Bacillus cereus contamination sources and characterization of strains toxin profiles. B. cereus was detected in 84.4% and 44.8% from air samples and samples from benches and equipments surfaces, respectively. The potential of enterotoxin production was investigated using polymerase chain reaction (PCR methods for genes hblA, hblD e hblC (encoding hemolysin BL and for genes nheA, nheB and nheC (encoding non-hemolytic enterotoxin - NHE. From 70 isolates investigated 14.3% were positive for the three HBL encoding genes and 12.8% were positive for the three NHE encoding genes. The Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (BDE-VIA; Tecra also was used for NHE detection. The results obtained with BDE-VIA revealed that 61.4% from the 70 strains are NHE producers.

  20. HIDROFOBICIDADE DE RIBOTIPOS DE BACILLUS CEREUS ISOLADOS DE INDÚSTRIA DE LATICÍNIOS

    Directory of Open Access Journals (Sweden)

    Emiliane Andrade ARAÚJO

    2010-03-01

    Full Text Available

    A contaminação de superfícies por microrganismos deterioradores e patogênicos é causa de preocupação na indústria de alimentos. Desenvolvimento de biofilmes em ambientes de processamento de alimentos resulta na deterioração do produto e em possíveis riscos para a saúde pública, além de criar sérios problemas nas operações de processamento do fl uido. A adesão da bactéria à superfície é um dos primeiros passos para a formação do biofilme e propriedades físico-químicas da interface bacteriana infl uenciam o processo de adesão microbiana e, consequentemente, os procedimentos operacionais de higienização. A estrutura do biofilme e as características fisiológicas do microrganismo podem conferir resistência aos agentes antimicrobianos, como por exemplo, aos sanitizantes usados no procedimento de higienização. Dentre os fatores que infl uenciam o processo de adesão, as características de hidrofobicidade do microrganismo e da superfície apresentam grande importância nos mecanismos de adesão. As técnicas da medição do ângulo de contato e da coluna de interação hidrofóbica, para determinação da hidrofobicidade de superfícies de ribotipos de Bacillus cereus isolados de indústria de laticínios, foram avaliadas. Observou-se que as quatro superfícies dos ribotipos avaliados apresentaram a mesma classificação quanto à hidrofobicidade tanto pela medida do ângulo de contato com a água quanto pela determinação da energia livre de interação hidrofóbica (ΔGsas TOT. Três ribotipos foram considerados hidrofílicos e um hidrofóbico. Já a técnica da coluna de interação hidrofóbica não mostrou diferença (p>0,05 no percentual de células retidas na coluna, sugerindo que as superfícies dos ribotipos apresentam as mesmas características quanto à hidrofobicidade. Os resultados indicam que a técnica da medição do ângulo de contato é a mais indicada para avaliar a

  1. Characterization of aerobic and anaerobic vegetative growth of the food-borne pathogen Bacillus cereus F4430/73 strain.

    Science.gov (United States)

    Rosenfeld, Eric; Duport, Catherine; Zigha, Assia; Schmitt, Philippe

    2005-02-01

    The Gram-positive bacterium Bacillus cereus is a facultative anaerobe that is still poorly characterized metabolically. In this study, the aerobic vegetative growth and anaerobic vegetative growth of the food-borne pathogen B. cereus F4430/73 strain were compared with those of the genome-sequenced ATCC14579 strain using glucose and glycerol as fermentative and nonfermentative carbon sources, respectively. Uncontrolled batch cultures on several defined media showed that B. cereus strains had high amino acid or pyruvate requirements for anaerobic fermentative growth. In addition, growth performance was considerably improved by maintaining the pH of the culture medium near neutrality. Spectra of fermentation by-products were typically (per mole of glucose) 0.2-0.4 acetate, 1.1-1.4 L-lactate, 0.3-0.4 formate, and 0.05-0.2 ethanol with only traces of succinate, pyruvate, and 2,3-butanediol. These spectra were drastically changed in the presence of 20 mmol nitrate x L(-1), which stimulated anaerobic growth. During anaerobic and aerobic respiration, the persistent production of acetate and other by-products indicated overflow metabolisms. This was especially true in glucose-grown cells for which respiratory complex III made only a minor contribution to growth. Surprisingly, oxygen uptake rates linked to the cytochrome c and quinol branches of the respiratory chain were maintained at high levels in anaerobic, respiring, or fermenting cells. Growth and metabolic features of B. cereus F4430/73 are discussed using biochemical and genomic data.

  2. Iron acquisition in Bacillus cereus: the roles of IlsA and bacillibactin in exogenous ferritin iron mobilization.

    Directory of Open Access Journals (Sweden)

    Diego Segond

    2014-02-01

    Full Text Available In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis.

  3. Iron Acquisition in Bacillus cereus: The Roles of IlsA and Bacillibactin in Exogenous Ferritin Iron Mobilization

    Science.gov (United States)

    Buisson, Christophe; Daou, Nadine; Kallassy, Mireille; Lereclus, Didier; Arosio, Paolo; Bou-Abdallah, Fadi; Nielsen Le Roux, Christina

    2014-01-01

    In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis. PMID:24550730

  4. Comparative analysis of biofilm formation by Bacillus cereus reference strains and undomesticated food isolates and the effect of free iron.

    Science.gov (United States)

    Hayrapetyan, Hasmik; Muller, Lisette; Tempelaars, Marcel; Abee, Tjakko; Nierop Groot, Masja

    2015-05-04

    Biofilm formation of Bacillus cereus reference strains ATCC 14579 and ATCC 10987 and 21 undomesticated food isolates was studied on polystyrene and stainless steel as contact surfaces. For all strains, the biofilm forming capacity was significantly enhanced when in contact with stainless steel (SS) as a surface as compared to polystyrene (PS). For a selection of strains, the total CFU and spore counts in biofilms were determined and showed a good correlation between CFU counts and total biomass of these biofilms. Sporulation was favoured in the biofilm over the planktonic state. To substantiate whether iron availability could affect B. cereus biofilm formation, the free iron availability was varied in BHI by either the addition of FeCl3 or by depletion of iron with the scavenger 2,2-Bipyridine. Addition of iron resulted in increased air-liquid interface biofilm on polystyrene but not on SS for strain ATCC 10987, while the presence of Bipyridine reduced biofilm formation for both materials. Biofilm formation was restored when excess FeCl3 was added in combination with the scavenger. Further validation of the iron effect for all 23 strains in microtiter plate showed that fourteen strains (including ATCC10987) formed a biofilm on PS. For eight of these strains biofilm formation was enhanced in the presence of added iron and for eleven strains it was reduced when free iron was scavenged. Our results show that stainless steel as a contact material provides more favourable conditions for B. cereus biofilm formation and maturation compared to polystyrene. This effect could possibly be linked to iron availability as we show that free iron availability affects B. cereus biofilm formation. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Structure of the NheA component of the Nhe toxin from Bacillus cereus: implications for function.

    Directory of Open Access Journals (Sweden)

    Magdah Ganash

    Full Text Available The structure of NheA, a component of the Bacillus cereus Nhe tripartite toxin, has been solved at 2.05 Å resolution using selenomethionine multiple-wavelength anomalous dispersion (MAD. The structure shows it to have a fold that is similar to the Bacillus cereus Hbl-B and E. coli ClyA toxins, and it is therefore a member of the ClyA superfamily of α-helical pore forming toxins (α-PFTs, although its head domain is significantly enlarged compared with those of ClyA or Hbl-B. The hydrophobic β-hairpin structure that is a characteristic of these toxins is replaced by an amphipathic β-hairpin connected to the main structure via a β-latch that is reminiscent of a similar structure in the β-PFT Staphylococcus aureus α-hemolysin. Taken together these results suggest that, although it is a member of an archetypal α-PFT family of toxins, NheA may be capable of forming a β rather than an α pore.

  6. A multicomponent sugar phosphate sensor system specifically induced in Bacillus cereus during infection of the insect gut.

    Science.gov (United States)

    Song, Fuping; Peng, Qi; Brillard, Julien; Buisson, Christophe; de Been, Mark; Abee, Tjakko; Broussolle, Véronique; Huang, Dafang; Zhang, Jie; Lereclus, Didier; Nielsen-LeRoux, Christina

    2012-08-01

    Using a previously developed Bacillus cereus in vivo expression technology (IVET) promoter trap system, we showed that spsA, a gene of unknown function, was specifically expressed in the larval gut during infection. Search for gut-related compounds inducing spsA transcription identified glucose-6-phosphate (G6P) as an activation signal. Analysis of the spsA-related 5-gene cluster indicated that SpsA is part of a new sugar phosphate sensor system composed of a 2-component system (TCS) encoded by spsR and spsK, and 2 additional downstream genes, spsB and spsC. In B. cereus, American Type Culture Collection (ATCC) 14579, spsRK, and spsABC are separate transcriptional units, of which only spsABC was activated by extracellular G6P. lacZ transcriptional fusions tested in mutant and complemented strains showed that SpsRK, SpsA, and SpsB are essential for the transcription of spsABC. Deletion mutant analysis showed that SpsC is essential for the G6P uptake. gfp-transcriptional fusions showed that these genes are required for host-activated expression, as well. This sugar phosphate sensor and transport system is found in pathogenic Bacillus group and Clostridia bacteria and may be important for host adaptation. Our findings provide new insights into the function of 2-component sensor systems in host-pathogen interactions, specifically in the gut.

  7. Isolation and characterization of glacier VMY22, a novel lytic cold-active bacteriophage of Bacillus cereus.

    Science.gov (United States)

    Ji, Xiuling; Zhang, Chunjing; Fang, Yuan; Zhang, Qi; Lin, Lianbing; Tang, Bing; Wei, Yunlin

    2015-02-01

    As a unique ecological system with low temperature and low nutrient levels, glaciers are considered a "living fossil" for the research of evolution. In this work, a lytic cold-active bacteriophage designated VMY22 against Bacillus cereus MYB41-22 was isolated from Mingyong Glacier in China, and its characteristics were studied. Electron microscopy revealed that VMY22 has an icosahedral head (59.2 nm in length, 31.9 nm in width) and a tail (43.2 nm in length). Bacteriophage VMY22 was classified as a Podoviridae with an approximate genome size of 18 to 20 kb. A one-step growth curve revealed that the latent and the burst periods were 70 and 70 min, respectively, with an average burst size of 78 bacteriophage particles per infected cell. The pH and thermal stability of bacteriophage VMY22 were also investigated. The maximum stability of the bacteriophage was observed to be at pH 8.0 and it was comparatively stable at pH 5.0-9.0. As VMY22 is a cold-active bacteriophage with low production temperature, its characterization and the relationship between MYB41-22 and Bacillus cereus bacteriophage deserve further study.

  8. ANTIBACTERIAL EFFECT OF GARLIC (ALLIUM SATIVUM AND GINGER (ZINGIBER OFFICINALE AGAINST STAPHYLOCOCCUS AUREUS, SALMONELLA TYPHI, ESCHERICHIA COLI AND BACILLUS CEREUS

    Directory of Open Access Journals (Sweden)

    Bandna Chand

    2013-02-01

    Full Text Available Antibacterial activity of extracts of Allium sativum (garlic and Zingiber officinale (ginger has been evaluated against four different bacteria namely Escherichia coli, Salmonella Typhi, Staphylococcus aureus and Bacillus cereus. Two methods were used to determine the antimicrobial activity of garlic and ginger extracts namely disk diffusion method and agar well diffusion method. Garlic extract exhibited excellent antibacterial activity against all four test organisms while ginger extract showed antibacterial activity against Bacillus cereus and Staphylococcus aureus only. In addition, agar well diffusion method showed higher zone in inhibition when compared with the zone of inhibition produced by the spice of same concentration against the test microorganism by disk diffusion method. Antibiotic sensitivity of the four different bacteria was tested with commercially available antibiotics namely Ciprofloxacin; Oxytetracycline; Vancomycin; Streptomycin; Gentamicin; Tetracycline; Novobiocin; Amikacin and Penicillin G. Penicillin G produced the highest zone of inhibition of 40.00±0.00against Staphylococcus aureus and the lowest zone of inhibition of 0.00±0.00against Escherichia coli.

  9. Antimicrobial efficacy of phytochemicals against Bacillus cereus in reconstituted infant rice cereal.

    Science.gov (United States)

    Cetin-Karaca, Hayriye; Newman, Melissa C

    2018-02-01

    The objective of this study was to determine the potential use of Trans-cinnamaldehyde (TC), (-)-Epigallocatechin gallate (EGCG) and [10]-Gingerol (GI) to inhibit the growth of B. cereus in infant rice cereal reconstituted with infant formula. Samples were inoculated with either vegetative cells or spores of B. cereus (ATCC 14579), and they were treated with 500 ppm (mg/L) TC, EGCG and GI. They were stored at 7 °C, 23 °C, or 37 °C for 0, 4, 8 and 24 h to simulate advance preparation, handling and temperature abuse. At 23 °C no growth was observed with TC over 24 h. TC also showed the highest antimicrobial activity 37 °C by inhibiting the growth of B. cereus vegetative cells by 0.83 log CFU/g and B. cereus spores by 2.0 log CFU/g after 24 h. B. cereus (ATCC 14579) did not grow at 7 °C over 24 h and TC had no effect on its survival. Significant differences (P B. cereus. Copyright © 2017. Published by Elsevier Ltd.

  10. Determination of haemolytic and non haemolytic genes profiles of Bacillus cereus strains isolated from food samples by polymerase chain reaction (pcr) technique

    Science.gov (United States)

    Jawad, Nisreen; Ahemd, Asmat; Abdullah, Aminah

    2018-04-01

    The aim of this study was to investigate the presence of Bacillus cereus and detection of enterotoxigenic genes in food samples by utilizing a Polymerase Chain Reaction technique (PCR). In this study the providence of B. cereus was carried out to food samples. The B. cereus isolates were investigated for enterotoxigenic gene. The cooked seafood, and raw milk samples were purchased from several restaurants and market in the area of (Bangi, Kajang, Serdang and UKM) Selangor, Malaysia. A total of 60 samples have been analyzed. B. cereus contamination has been formed between 1.4×105 - 3×105 cfu/mL of cooked seafood and raw milk samples. Five colonies have been detected as B. cereus using biochemical test. All B. cereus isolates named BC1 to BC27, were characterized for haemolytic enterotoxin (HBL) complex encoding genes (hblA), non-haemolytic enterotoxin encoding gene (NheA). 10 isolates have been reported to be positive towards hblA and 12 isolates were positive towards NheA. The presence of B. cereus and their enterotoxigenic genes in cooked seafood and raw milk from to food samples obtained may pose a potential risk for public health.

  11. Inhibition of Bacillus cereus and Bacillus weihenstephanensis in raw vegetables by application of washing solutions containing enterocin AS-48 alone and in combination with other antimicrobials.

    Science.gov (United States)

    Cobo Molinos, Antonio; Abriouel, Hikmate; Lucas López, Rosario; Ben Omar, Nabil; Valdivia, Eva; Gálvez, Antonio

    2008-09-01

    Enterocin AS-48 is a broad-spectrum cyclic antimicrobial peptide produced by Enterococcus faecalis. In the present study, the bacteriocin was tested alone and in combination with other antimicrobials for decontamination of Bacillus inoculated on alfalfa, soybean sprouts and green asparagus. Washing with enterocin AS-48 solutions reduced viable cell counts of Bacillus cereus and Bacillus weihenstephanensis by 1.0-1.5 and by 1.5-2.38 log units right after application of treatment, respectively. In both cases, the bacteriocin was effective in reducing the remaining viable population below detection levels during further storage of the samples at 6 degrees C, but failed to prevent regrowth in samples stored at 15 or 22 degrees C. Application of washing treatments containing enterocin AS-48 in combination with several other antimicrobials and sanitizers (cinnamic and hydrocinnamic acids, carvacrol, polyphosphoric acid, peracetic acid, hexadecylpyridinium chloride and sodium hypochlorite) greatly enhanced the bactericidal effects. The combinations of AS-48 and sodium hypochlorite, peracetic acid or hexadecylpyridinium chloride provided the best results. After application of the combined treatments on alfalfa sprouts contaminated with B. cereus or with B. weihenstephanensis, viable bacilli were not detected or remained at very low concentrations in the treated samples during a 1-week storage period at 15 degrees C. Inhibition of B. cereus by in situ produced bacteriocin was tested by cocultivation with the AS-48 producer strain E. faecalis A-48-32 inoculated on soybean sprouts. Strain A-48-32 was able to grow and produce bacteriocin on sprouts both at 15 and 22 degrees C. At 15 degrees C, growth of B. cereus was completely inhibited in the cocultures, while a much more limited effect was observed at 22 degrees C. The results obtained for washing treatments are very encouraging for the application of enterocin AS-48 in the decontamination of sprouts. Application of washing

  12. Enterotoxicity of Staphylococcus aureus isolated from beans pudding

    African Journals Online (AJOL)

    36 samples of beans pudding from selected sources were analysed for Staphylococcus aureus and Bacillus cereus using standard protocols aimed at assessing its bacteriological quality. Samples obtained from restaurant showed slightly lower value for total plate count (1.3 x 104 - 1.6 x 106 cfu/gm) compared to samples ...

  13. Effects of Mentha longifolia L. essential oil and nisin alone and in combination on Bacillus cereus and Bacillus subtilis in a food model and bacterial ultrastructural changes.

    Science.gov (United States)

    Pajohi, Mohamad Reza; Tajik, Hossein; Farshid, Amir Abbas; Basti, Afshin Akhondzadeh; Hadian, Mojtaba

    2011-02-01

    In the face of emerging new pathogens and ever-growing health-conscious customers, food preservation technology remains on the top agenda of food industry. This study was aimed at determining the effects of the essential oil of Mentha longifolia L., alone and in combination with nisin, on Bacillus cereus and Bacillus subtilis at 8°C and 25°C in a food model (commercial barley soup) during 15 days. The essential oil alone at 8°C inhibited bacterial growth significantly compared with the control (p < 0.05). However, at 25°C, none of the concentrations of the essential oil alone showed inhibitory effect on bacterial growth. At 8°C, the combination effect of the essential oil and nisin on bacteria was noted at 0.25 μg mL(-1) for nisin and 0.05 μL mL(-1) for the essential oil (p < 0.05). The combination of nisin and the essential oil demonstrated significant inhibitory effects on the vegetative forms of bacteria at 25°C, although it was comparable to that of nisin alone at the same concentrations. Electron microscopy studies revealed a great deal of damage to B. cereus treated with a combination of nisin and the essential oil. However, the combination of nisin with the essential oil led to a complete destruction of cell wall and cytoplasm of vegetative cells of B. subtilis.

  14. Inactivation of Bacillus cereus and Salmonella enterica serovar Typhimurium by aqueous ozone (O3): Modeling and Uv-Vis spectroscopic analysis

    Science.gov (United States)

    Ozone (O3) is a natural antimicrobial agent with potential applications in food industry. In this study, inactivation of Bacillus cereus and Salmonella enterica Typhimurium by aqueous ozone was evaluated. Ozone gas was generated using a domestic ozone generator with an output of 200 mg/hr (approx. 0...

  15. Control of bacillus cereus spore germination and outgrowth in cooked rice during chilling by nonorganic and organic appled, orange, and potato peel powders

    Science.gov (United States)

    The inhibition of Bacillus cereus spore germination and outgrowth in cooked rice by nine fruit and vegetable peel powders prepared from store-bought conventional (nonorganic) and organic apples, oranges, and potatoes was investigated. The powders were mixed into rice at 10% (wt/wt) along with heat ...

  16. The Identification of Intrinsic Chloramphenicol and Tetracycline Resistance Genes in Members of the Bacillus cereus Group (sensu lato)

    Science.gov (United States)

    Glenwright, Helen; Pohl, Susanne; Navarro, Ferran; Miro, Elisenda; Jiménez, Guillermo; Blanch, Anicet R.; Harwood, Colin R.

    2017-01-01

    Bacillus toyonensis strain BCT-7112T (NCIMB 14858T) has been widely used as an additive in animal nutrition for more than 30 years without reports of adverse toxigenic effects. However, this strain is resistant to chloramphenicol and tetracycline and it is generally considered inadvisable to introduce into the food chain resistance determinants capable of being transferred to other bacterial strains, thereby adding to the pool of such determinants in the gastro-enteric systems of livestock species. We therefore characterized the resistance phenotypes of this strain and its close relatives to determine whether they were of recent origin, and therefore likely to be transmissible. To this end we identified the genes responsible for chloramphenicol (catQ) and tetracycline (tetM) resistance and confirmed the presence of homologs in other members of the B. toyonensis taxonomic unit. Unexpectedly, closely related strains encoding these genes did not exhibit chloramphenicol and tetracycline resistance phenotypes. To understand the differences in the behaviors, we cloned and expressed the genes, together with their upstream regulatory regions, into Bacillus subtilis. The data showed that the genes encoded functional proteins, but were expressed inefficiently from their native promoters. B. toyonensis is a taxonomic unit member of the Bacillus cereus group (sensu lato). We therefore extended the analysis to determine the extent to which homologous chloramphenicol and tetracycline resistance genes were present in other species within this group. This analysis revealed that homologous genes were present in nearly all representative species within the B. cereus group (sensu lato). The absence of known transposition elements and the observations that they are found at the same genomic locations, indicates that these chloramphenicol and tetracycline resistance genes are of ancient origin and intrinsic to this taxonomic group, rather than recent acquisitions. In this context we

  17. Characterization of type II and III restriction-modification systems from Bacillus cereus strains ATCC 10987 and ATCC 14579.

    Science.gov (United States)

    Xu, Shuang-yong; Nugent, Rebecca L; Kasamkattil, Julie; Fomenkov, Alexey; Gupta, Yogesh; Aggarwal, Aneel; Wang, Xiaolong; Li, Zhiru; Zheng, Yu; Morgan, Richard

    2012-01-01

    The genomes of two Bacillus cereus strains (ATCC 10987 and ATCC 14579) have been sequenced. Here, we report the specificities of type II/III restriction (R) and modification (M) enzymes. Found in the ATCC 10987 strain, BceSI is a restriction endonuclease (REase) with the recognition and cut site CGAAG 24-25/27-28. BceSII is an isoschizomer of AvaII (G/GWCC). BceSIII cleaves at ACGGC 12/14. The BceSIII C terminus resembles the catalytic domains of AlwI, MlyI, and Nt.BstNBI. BceSIV is composed of two subunits and cleaves on both sides of GCWGC. BceSIV activity is strongly stimulated by the addition of cofactor ATP or GTP. The large subunit (R1) of BceSIV contains conserved motifs of NTPases and DNA helicases. The R1 subunit has no endonuclease activity by itself; it strongly stimulates REase activity when in complex with the R2 subunit. BceSIV was demonstrated to hydrolyze GTP and ATP in vitro. BceSIV is similar to CglI (GCSGC), and homologs of R1 are found in 11 sequenced bacterial genomes, where they are paired with specificity subunits. In addition, homologs of the BceSIV R1-R2 fusion are found in many sequenced microbial genomes. An orphan methylase, M.BceSV, was found to modify GCNGC, GGCC, CCGG, GGNNCC, and GCGC sites. A ParB-methylase fusion protein appears to nick DNA nonspecifically. The ATCC 14579 genome encodes an active enzyme Bce14579I (GCWGC). BceSIV and Bce14579I belong to the phospholipase D (PLD) family of endonucleases that are widely distributed among Bacteria and Archaea. A survey of type II and III restriction-modification (R-M) system genes is presented from sequenced B. cereus, Bacillus anthracis, and Bacillus thuringiensis strains.

  18. Reference genes for quantitative, reverse-transcription PCR in Bacillus cereus group strains throughout the bacterial life cycle.

    Science.gov (United States)

    Reiter, Lillian; Kolstø, Anne-Brit; Piehler, Armin P

    2011-08-01

    Quantitative reverse-transcription PCR (RT-qPCR) has become a major tool to better understand the biology and pathogenesis of bacteria. One prerequisite of valid RT-qPCR data is their proper normalization to stably expressed reference genes. To identify and evaluate reference genes suitable for normalization of gene expression data in Bacillus cereus group strains, mRNA levels of eleven candidate reference genes (rpsU, nifU, udp (UDP-N-acetylglucosamine 2-epimerase), BT9727_5154/BC_5475, BT9727_4034/BC_4293, BT9727_4549/BC_4813, pspA, gatB_Yqey (gatB_Yqey domain containing protein), helicase (SWF/SNF family protein), adk and pta) and a target gene (BT9727_3305/BC3547+BC3546) were quantified by RT-qPCR at different time points throughout the entire life cycle of the wild-type B. cereus ATCC 14579 and Bacillus thuringiensis subsp. konkukian 97-27, a phylogenetically closely related strain to Bacillus anthracis. The programs geNorm and Normfinder were used to calculate expression stabilities and identified the genes gatB_Yqey, rpsU and udp as the most stably expressed reference genes. Compared to this combination or the sets of reference genes as recommended by geNorm or Normfinder, normalization using a traditional housekeeping gene (adk) alone resulted in significantly different gene expression results and in a significant overestimation of the target gene transcription. Normalization of the data to the reference gene gatB_Yqey alone showed no or only small differences to the reference gene combinations indicating that gatB_Yqey may be used as a single reference gene when investigating rather large changes in mRNA transcription. Otherwise, a combination of the stably expressed reference genes is recommended. In conclusion, the present study underlines the importance of normalization to stably expressed reference genes and presents valid endogenous controls suitable for normalization of transcriptional data throughout the life cycle of B. cereus group strains

  19. Proteome data to explore the impact of pBClin15 on Bacillus cereus ATCC 14579

    OpenAIRE

    Madeira, Jean-Paul; Alpha-Bazin, Béatrice; Armengaud, Jean; Omer, Hélène

    2016-01-01

    This data article reports changes in the cellular and exoproteome of B. cereus cured from pBClin15.Time-course changes of proteins were assessed by high-throughput nanoLC-MS/MS. We report all the peptides and proteins identified and quantified in B. cereus with and without pBClin15. Proteins were classified into functional groups using the information available in the KEGG classification and we reported their abundance in term of normalized spectral abundance factor. The repertoire of experim...

  20. Regulation of toxin production by Bacillus cereus and its food safety implications.

    Science.gov (United States)

    Ceuppens, Siele; Rajkovic, Andreja; Heyndrickx, Marc; Tsilia, Varvara; Van De Wiele, Tom; Boon, Nico; Uyttendaele, Mieke

    2011-08-01

    Toxin expression is of utmost importance for the food-borne pathogen B. cereus, both in food poisoning and non-gastrointestinal host infections as well as in interbacterial competition. Therefore it is no surprise that the toxin gene expression is tightly regulated by various internal and environmental signals. An overview of the current knowledge regarding emetic and diarrheal toxin transcription and expression is presented in this review. The food safety aspects and management tools such as temperature control, food preservatives and modified atmosphere packaging are discussed specifically for B. cereus emetic and diarrheal toxin production.

  1. Rapid detection of vip1-type genes from Bacillus cereus and characterization of a novel vip binary toxin gene.

    Science.gov (United States)

    Yu, Xiumei; Liu, Tao; Liang, Xiaoxing; Tang, Changqing; Zhu, Jun; Wang, Shiquan; Li, Shuangcheng; Deng, Qiming; Wang, Linxia; Zheng, Aiping; Li, Ping

    2011-12-01

    A PCR-restriction fragment length polymorphism (PCR-RFLP) method for identifying vegetative insecticidal protein (vip) 1-type genes from Bacillus cereus was developed by designing specific primers based on the conserved regions of the genes to amplify vip1-type gene fragments. PCR products were digested with endonuclease AciI, and four known vip1-type genes were identified. Vip1Ac and vip1Aa-type genes appeared in 17 of 26 B. cereus strains. A novel vip1-type gene, vip1Ac1, was identified from B. cereus strain HL12. The vip1Ac1 and vip2Ae3 genes were co-expressed in Escherichia coli strain BL21 by vector pCOLADuet-1. The binary toxin showed activity only against Aphis gossypii (Homoptera), but not for Coleptera (Tenebrio molitor, Holotrichia oblita), Lepidoptera (Spodoptera exigua, Helicoverpa armigera, and Chilo suppressalis), Diptera (Culex quinquefasciatus). The LC(50) of this binary toxin for A. gossypii is 87.5 (34.2-145.3) ng mL(-1) . This is probably only the second report that Vip1 and Vip2 binary toxin shows toxicity against homopteran pests. The PCR-RFLP method developed could be very useful for identifying novel Vip1-Vip2-type binary toxins, and the novel binary toxins, Vip1Ac1 and Vip2Ae3, identified in this study may have applications in biological control of insects, thus avoiding potential problems of resistance. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  2. Enhanced extracellular production of recombinant proteins in Escherichia coli by co-expression with Bacillus cereus phospholipase C.

    Science.gov (United States)

    Su, Lingqia; Jiang, Qi; Yu, Lingang; Wu, Jing

    2017-02-08

    Our laboratory has reported a strategy for improving the extracellular production of recombinant proteins through co-expression with Thermobifida fusca cutinase, which increases membrane permeability via its phospholipid hydrolysis activity. However, the foam generated by the lysophospholipid product makes the fermentation process difficult to control in a fermentor. Phospholipase C (PLC) catalyzes the hydrolysis of phospholipids to produce sn1,2-diacylglycerides and organic phosphate, which do not induce foam formation. Therefore, co-expression with Bacillus cereus PLC was investigated as a method to improve the extracellular production of recombinant proteins. When B. cereus PLC was expressed in Escherichia coli without its signal peptide, 95.3% of the total PLC activity was detected in the culture supernatant. PLC expression enhanced membrane permeability without obvious cell lysis. Then, six test enzymes, three secretory and three cytosolic, were co-expressed with B. cereus PLC. The enhancement of extracellular production correlated strongly with the molecular mass of the test enzyme. Extracellular production of Streptomyces sp. FA1 xylanase (43 kDa), which had the lowest molecular mass among the secretory enzymes, was 4.0-fold that of its individual expression control. Extracellular production of glutamate decarboxylase (51 kDa), which had the lowest molecular mass among the cytosolic enzymes, reached 26.7 U/mL; 88.3% of the total activity produced. This strategy was effectively scaled up using a 3-L fermentor. No obvious foam was generated during this fermentation process. This is the first study to detail the enhanced extracellular production of recombinant proteins through co-expression with PLC. This new strategy, which is especially appropriate for lower molecular mass proteins, allows large-scale protein production in an easily controlled fermentation process.

  3. Comparison of alkyl hydroperoxide reductase and two water-forming NADH oxidases from Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Wang, Liang; Chong, Huiqing; Jiang, Rongrong

    2012-12-01

    Bacillus cereus (B. cereus) is an ubiquitous facultative anaerobic bacterium, and its growth in aerobic environment correlates to the functions of its oxygen defense system. Water-forming NADH oxidase (nox-2) can catalyze the conversion of oxygen to water with concomitant NADH oxidation in anaerobic microorganisms. Here, we report the cloning and characterization of two annotated nox-2 s (nox-2(444) and nox-2(554)) from B. cereus ATCC 14579 and their comparison with another oxidative stress defense system alkyl hydroperoxide reductase (AhpR) from this microbe, which composed of two enzymes-hydrogen peroxide-forming NADH oxidase (nox-1) and peroxidase. Both nox-2 and AhpR catalyze the same reaction in the presence of oxygen. With the stimulation of exogenously added FAD, the maximum activity of nox-1, nox-2(444), and nox-2(554) could reach 27.7 U/mg, 22.9 U/mg, and 2.4 U/mg, respectively, at pH 7.0, 30 °C. Different from nox-1, both nox-2 s were thermotolerant enzymes and could maintain above 87% of their optimum activity at 80 °C, which was not found in other nox-2 s. As for operational stability, all are turnover-limited. Exogenously added reductive reagent dithiothreitol could dramatically increase the total turnover number of nox-2(444) and nox-2(554) by twofold and threefold, respectively, but had no effect on AhpR or nox-1.

  4. Growth inhibitory effects of kimchi (Korean traditional fermented vegetable product) against Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus.

    Science.gov (United States)

    Kim, Yong-Suk; Zheng, Zian-Bin; Shin, Dong-Hwa

    2008-02-01

    Kimchi is a unique Korean traditional vegetable product that is fermented by lactic acid bacteria (LAB) and is mainly consumed as a side dish with boiled rice. Its main ingredients are brined Chinese cabbage, red pepper powder, and fermented fish sauce, and these are combined with many spices such as garlic, green onion, ginger, and some seaweed. The relationship between the concentration of LAB or the pH and the growth of three gram-positive foodborne pathogens (Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus) was evaluated. Heat treatment (HT; 85 degrees C for 15 min) or neutralization treatment (NT; pH 7.0) was conducted on day 0 (0-D group) and day 3 (3-D group) of incubation. The pH in the control group and the NT group dropped sharply to 4.12 to 4.30 after 2 days of incubation and slightly decreased thereafter, whereas the pH in the control group and HT group stayed at 7.0 during incubation. LAB were not detected in the HT kimchi during incubation. B. cereus in the NT-0-D, NT-3-D, and HT-3-D groups was reduced by 1.5 to 3.1 log CFU/ml but increased slightly in the HT-0-D group. L. monocytogenes in HT-3-D and NT-3-D groups disappeared after 5 days of incubation, and S. aureus in the NT-0-D group disappeared after 4 days. These findings indicate that growth of all the foodborne pathogens was inhibited by NT-0-D, HT-3-D, and NT-3-D, but B. cereus was not inhibited by HT-0-D. Thus, growth of LAB in kimchi is an important factor in the control of foodborne pathogens.

  5. Antibacterial Effect of Eicosapentaenoic Acid against Bacillus cereus and Staphylococcus aureus: Killing Kinetics, Selection for Resistance, and Potential Cellular Target

    Directory of Open Access Journals (Sweden)

    Phuc Nguyen Thien Le

    2017-11-01

    Full Text Available Polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA; C20:5n-3, are attracting interest as possible new topical antibacterial agents, particularly due to their potency and perceived safety. However, relatively little is known of the underlying mechanism of antibacterial action of EPA or whether bacteria can develop resistance quickly against this or similar compounds. Therefore, the aim of this present study was to determine the mechanism of antibacterial action of EPA and investigate whether bacteria could develop reduced susceptibility to this fatty acid upon repeated exposure. Against two common Gram-positive human pathogens, Bacillus cereus and Staphylococcus aureus, EPA inhibited bacterial growth with a minimum inhibitory concentration of 64 mg/L, while minimum bactericidal concentrations were 64 mg/L and 128 mg/L for B. cereus and S. aureus, respectively. Both species were killed completely in EPA at 128 mg/L within 15 min at 37 °C, while reduced bacterial viability was associated with increased release of 260-nm-absorbing material from the bacterial cells. Taken together, these observations suggest that EPA likely kills B. cereus and S. aureus by disrupting the cell membrane, ultimately leading to cell lysis. Serial passage of the strains in the presence of sub-inhibitory concentrations of EPA did not lead to the emergence or selection of strains with reduced susceptibility to EPA during 13 passages. This present study provides data that may support the development of EPA and other fatty acids as antibacterial agents for cosmetic and pharmaceutical applications.

  6. Reducing activity, glucose metabolism and acid tolerance response of Bacillus cereus grown at various pH and oxydo-reduction potential levels.

    Science.gov (United States)

    Le Lay, Julien; Bahloul, Halim; Sérino, Sylvie; Jobin, Michel; Schmitt, Philippe

    2015-04-01

    Bacillus cereus is a major foodborne bacterial pathogen able to survive a large number of physical-chemical stresses. B. cereus encounters different pH and redox potential (Eh7) levels during its passage through the gastrointestinal tract. Analysis of the combined influence of pH and redox stresses on B. cereus F4430/73 physiology found that B. cereus F4430/73 growth at pH 7.0 at 37 °C had strong reducing capacities, with a total change of 315 mV from an initial redox value of +214 ± 17 mV. The combination of low Eh7 and low pH led to a drastic reduction of growth parameters compared to oxidative Eh7 and neutral pH. Metabolic analysis showed that low pH significantly modifies glucose fermentative metabolism, with changes including decreased production of acid metabolite (acetate, lactate, formate) and increased production of 2,3-butanediol. Low Eh7 slightly enhanced the acid-tolerance response of B. cereus whereas low pH pre-adaptation led to thermal stress cross-protection. These results highlight new mechanisms that bring fresh insight into B. cereus pH and redox stress adaptations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Influence of food matrix on inactivation of Bacillus cereus by combinations of nisin, pulsed electric field treatment, and carvacrol.

    Science.gov (United States)

    Pol, I E; Mastwujk, H C; Slump, R A; Popa, M E; Smid, E J

    2001-07-01

    Carvacrol was used as a third preservative factor to enhance further the synergy between nisin and pulsed electric field (PEF) treatment against vegetative cells of Bacillus cereus. When applied simultaneously with nisin (0.04 microg/ml), carvacrol (0.5 mM) enhanced the synergy found between nisin and PEF treatment (16.7 kV/cm, 30 pulses) in potassium-N-2-hydroxyethylpiperazine-N-ethanesulfonic acid (HEPES) buffer. The influence of food ingredients on bactericidal activity was tested using skimmed milk that was diluted to 20% with sterile demineralized water. The efficacy of PEF treatment was not affected by the presence of proteins, and results found in HEPES buffer correlated well with results in milk (20%). Nisin showed less activity against B. cereus in milk. Carvacrol was not able to enhance the synergy between nisin and PEF treatment in milk, unless used in high concentrations (1.2 mM). This concentration in itself did not influence the viable count. Carvacrol did act synergistically with PEF treatment in milk, however not in HEPES buffer. This synergy was not influenced by proteins in milk, as 5% milk still allows synergy between carvacrol and PEF treatment to the same extent as 20% milk.

  8. Use of Frequency Distribution Functions to Establish Safe Conditions in Relation to the Foodborne Pathogen Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Begoña Delgado

    2005-01-01

    Full Text Available Minimal processing implementation greatly depends on a detailed knowledge of the effects of preservation factors and their combinations on the spoilage and foodborne pathogenic microorganisms. The effectiveness of mild preservation conditions will become increasingly dependent on a more stochastic approach linking microbial physiological factors with product preservation factors. In this study, the validity of frequency distributions to efficiently describe the inactivation and growth of Bacillus cereus in the presence of natural antimicrobials (essential oils has been studied. For this purpose, vegetative cells were exposed to 0.6 mM of thymol or cymene, obtaining survival curves that were best described by the distribution of Weibull, since a tailing effect was observed. B. cereus was also exposed in a growth medium to a low concentration (0.1 mM of both antimicrobials, separately or combined, and the lag times obtained were fitted to a normal distribution, which allowed a description of dispersion of the start of growth. This allowed a more efficient evaluation of the experimental data to establish safe processing conditions according to accurate parameters and their implementation in risk assessment.

  9. Bacillus cereus efflux protein BC3310 - a multidrug transporter of the unknown major facilitator family, UMF-2.

    Science.gov (United States)

    Kroeger, Jasmin K; Hassan, Karl; Vörös, Aniko; Simm, Roger; Saidijam, Massoud; Bettaney, Kim E; Bechthold, Andreas; Paulsen, Ian T; Henderson, Peter J F; Kolstø, Anne-Brit

    2015-01-01

    Phylogenetic classification divides the major facilitator superfamily (MFS) into 82 families, including 25 families that are comprised of transporters with no characterized functions. This study describes functional data for BC3310 from Bacillus cereus ATCC 14579, a member of the "unknown major facilitator family-2" (UMF-2). BC3310 was shown to be a multidrug efflux pump conferring resistance to ethidium bromide, SDS and silver nitrate when heterologously expressed in Escherichia coli DH5α ΔacrAB. A conserved aspartate residue (D105) in putative transmembrane helix 4 was identified, which was essential for the energy dependent ethidium bromide efflux by BC3310. Transport proteins of the MFS comprise specific sequence motifs. Sequence analysis of UMF-2 proteins revealed that they carry a variant of the MFS motif A, which may be used as a marker to distinguish easily between this family and other MFS proteins. Genes orthologous to bc3310 are highly conserved within the B. cereus group of organisms and thus belong to the core genome, suggesting an important conserved functional role in the normal physiology of these bacteria.

  10. Bacillus cereus efflux protein BC3310 - a multidrug transporter of the unknown major facilitator family, UMF-2

    Directory of Open Access Journals (Sweden)

    Jasmin K Kroeger

    2015-10-01

    Full Text Available Phylogenetic classification divides the major facilitator superfamily (MFS into 82 families, including 25 families that are comprised of transporters with no characterized functions. This study describes functional data for BC3310 from Bacillus cereus ATCC 14579, a member of the unknown major facilitator family 2 (UMF 2. BC3310 was shown to be a multidrug efflux pump conferring resistance to ethidium bromide, SDS and silver nitrate when heterologously expressed in E. coli DH5α ΔacrAB. A conserved aspartate residue (D105 in putative transmembrane helix 4 was identified, which was essential for the energy dependent ethidium bromide efflux by BC3310. Transport proteins of the MFS comprise specific sequence motifs. Sequence analysis of UMF 2 proteins revealed that they carry a variant of the MFS motif A, which may be used as a marker to distinguish easily between this family and other MFS proteins. Genes orthologous to bc3310 are highly conserved within the B. cereus group of organisms and thus belong to the core genome, suggesting an important conserved functional role in the normal physiology of these bacteria.

  11. Bacillus cereus efflux protein BC3310 – a multidrug transporter of the unknown major facilitator family, UMF-2

    Science.gov (United States)

    Kroeger, Jasmin K.; Hassan, Karl; Vörös, Aniko; Simm, Roger; Saidijam, Massoud; Bettaney, Kim E.; Bechthold, Andreas; Paulsen, Ian T.; Henderson, Peter J. F.; Kolstø, Anne-Brit

    2015-01-01

    Phylogenetic classification divides the major facilitator superfamily (MFS) into 82 families, including 25 families that are comprised of transporters with no characterized functions. This study describes functional data for BC3310 from Bacillus cereus ATCC 14579, a member of the “unknown major facilitator family-2” (UMF-2). BC3310 was shown to be a multidrug efflux pump conferring resistance to ethidium bromide, SDS and silver nitrate when heterologously expressed in Escherichia coli DH5α ΔacrAB. A conserved aspartate residue (D105) in putative transmembrane helix 4 was identified, which was essential for the energy dependent ethidium bromide efflux by BC3310. Transport proteins of the MFS comprise specific sequence motifs. Sequence analysis of UMF-2 proteins revealed that they carry a variant of the MFS motif A, which may be used as a marker to distinguish easily between this family and other MFS proteins. Genes orthologous to bc3310 are highly conserved within the B. cereus group of organisms and thus belong to the core genome, suggesting an important conserved functional role in the normal physiology of these bacteria. PMID:26528249

  12. Relapsing peritonitis with Bacillus cereus in a patient on continuous ambulatory peritoneal dialysis

    DEFF Research Database (Denmark)

    Magnussen, Eyð Tausen; Vang, Amanda Gratton; á Steig, Torkil

    2016-01-01

    . Peritoneal cultures were positive for growth of B. cereus, a rare bacterial cause of peritonitis. The cultures demonstrated susceptibility to vancomycin, and therefore the patient was treated with intraperitoneal vancomycin, intraperitoneal gentamycin and oral ciprofloxacin. As a result of the relapsing B...

  13. Analysis of germination and outgrowth of sorbic acid-stressed Bacillus cereus ATCC 14579 spores.

    NARCIS (Netherlands)

    Melis, van Clint; Nierop Groot, Masja; Tempelaars, Marcel; Moezelaar, Roy; Abee, Tjakko

    2010-01-01

    Sorbic acid (SA) is widely used as a preservative, but the effect of SA on spore germination and outgrowth has gained limited attention up to now. Therefore, the effect of sorbic acid on germination of spores of B. cereus strain ATCC 14579 was analyzed both at phenotype and transcriptome level.

  14. Fate of pathogenic Bacillus cereus spores after ingestion by protist grazers

    DEFF Research Database (Denmark)

    Winding, Anne; Santos, Susana; Hendriksen, Niels Bohse

    was initially investigated in microcosms inoculated with pure cultures of the protists Acanthamoeba castellanii, Tetrahymena pyriformis and Cercomonas sp. as grazers. Individual protist cultures were fed with fluorescently labelled (CellTracker™RedCMTPX) B. cereus spores or vegetative cells as the only food...

  15. An antifungal chitinase produced by Bacillus cereus with shrimp and crab shell powder as a carbon source.

    Science.gov (United States)

    Chang, Wen-Teish; Chen, Chin-Shuh; Wang, San-Lang

    2003-08-01

    The production of inexpensive chitinolytic enzymes is an element in the utilization of shellfish processing wastes. In this study, shrimp and crab shell powder prepared by treating shrimp and crab processing wastes with boiling and crushing was used as a substrate for the isolation of an antifungal chitinase-producing microorganism. Bacillus cereus YQ 308, a strain isolated from the soil samples, excreted one chitinase when cultured in a medium containing 2% (wt/vol) shrimp and crab shell powder as major carbon source. The chitinase, purified by sequential chromatography, had an Mr of 48 kDa and pI of 5.2. The purified chitinase (2 mg/ml) inhibited the hyphal extension of the fungi Fusarium oxysporum and Pythium ultimum.

  16. Denitration of glycerol trinitrate by resting cells and cell extracts of Bacillus thuringiensis/cereus and Enterobacter agglomerans.

    Science.gov (United States)

    Meng, M; Sun, W Q; Geelhaar, L A; Kumar, G; Patel, A R; Payne, G F; Speedie, M K; Stacy, J R

    1995-07-01

    A number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants. The two most effective bacteria for transforming glycerol trinitrate (GTN) were identified as Bacillus thuringiensis/cereus and Enterobacter agglomerans. For both isolates, denitration activities were expressed constitutively and GTN was not required for induction. Dialysis of cell extracts from both isolates did not affect denitration, which indicates that dissociable and depletable cofactors are not required for denitration. With thin-layer chromatography and high-performance liquid chromatography, the denitration pathway for both isolates was shown to be a sequential denitration of GTN to glycerol dinitrate isomers, glycerol mononitrate isomers, and ultimately to glycerol. GTN was observed to be completely converted to glycerol during a long-term incubation of cell extracts.

  17. Changes in ultraviolet resistance and photoproduct formation as early events in spore germination of Bacillus cereus T

    International Nuclear Information System (INIS)

    Irie, R.

    1978-01-01

    In order to determine the timing of the change in the state of DNA in bacterial spores during the course of germination, L-alanine-induced germination of Bacillus cereus spores was interrupted by 0.3M CaCl 2 as an inhibitor, and the resulting semi-refractive spores (spores at the end of the first phase of germination) were examined for UV-resistance and photoproduct formation. Upon UV-irradiation, these spores, still having a semi-refractile core as observed under a phase-contrast microscope, gave rise to mainly the cyclobutane-type thymine dimer. It was concluded that change in the stats of the spore DNA occurs early in the process of germination, i.e. before the refractility of the core is lost. It was also found that CaCl 2 markedly prolonged the duration of the transient UV-resistant stage. (author)

  18. Fate and effect of ingested Bacillus cereus spores and vegetative cells in the intestinal tract of human-flora-associated rats

    DEFF Research Database (Denmark)

    Wilcks, Andrea; Hansen, Bjarne Munk; Hendriksen, Niels Bohse

    2006-01-01

    The fate and effect of Bacillus cereus F4433/73R in the intestine of human-flora-associated rats was studied using bacteriological culturing techniques and PCR-denaturing gradient gel electrophoresis in combination with cell assays and immunoassays for detection of enterotoxins. In faecal samples...... gradient gel electrophoresis analysis with universal 16S rRNA gene primers revealed significant changes in the intestinal microbiota of animals dosed with spores. Vero cell assays and a commercial kit (BCET-RPLA) did not reveal any enterotoxin production from B. cereus F4433/73R in the intestinal tract....

  19. Effects of cadmium on the growth and uptake of cadmium by microorganisms. [Esherichia coli; Bacillus cereus; Lactobacillus acidophilus; Staphylococcus aureus; Streptococcus faecalis; Actinomyces niger

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, J.J.; Marshall, R.T.; Pfander, W.H.

    1975-01-01

    Six species of microorganisms, Escherichia coli, Bacillus cereus, Lactobacillus acidophilus, Staphylococcus aureus, Streptococcus faecalis and Actinomyces niger, were grown under suitable conditions in appropriate media. Cadmium chloride was added to provide 0, 5, 10, 20, 40, and 80 ..mu..g of Cd per ml. At 40 and 80 ..mu..g of Cd per ml, E. coli and B. cereus grew well and the other species were repressed. Cd uptake patterns differed significantly among the species tested. The significance of these data with respect to Cd in food chains is discussed. 14 references, 3 tables.

  20. Novel motB as a potential predictive tool for identification of B. cereus, B. thuringiensis and differentiation from other Bacillus species by triplex real-time PCR.

    Science.gov (United States)

    Chelliah, Ramachandran; Wei, Shuai; Park, Byung-Jae; Kim, Se-Hun; Park, Dong-Suk; Kim, Soon Han; Hwan, Kim Seok; Oh, Deog-Hwan

    2017-10-01

    Quantitative triplex real-time PCR (qPCR) offers an alternative method for detection of bacterial contamination. It provides quantitation of the number of gene copies. In our study, we established a qPCR assay to detect and quantify the specificity towards Bacillus cereus and B. thuringiensis. The assay was designed to detect a 280 bp fragment of motB gene encoding the flagellar motor protein, specific for detection of B. cereus and B. thuringiensis, excluding other group species B. pseudomycoides, B. mycoides and B. weihenstephanensis. Specificity of the assay was confirmed with 111 strains belonging to Bacillus cereus group and performed against 58 B. cereus, 50 B. thuringiensis, 3 other Bacillus bacteria and 9 non-Bacillus bacteria. Detection limit was determined for each assay. Direct analysis of samples revealed the specificity towards identification and characterization of B. cereus group cultured in nutrient media. Based on results, it was observed that motB showed 97% specificity towards B. cereus strains, 98% for B. thuringiensis but other B. cereus group showed less sensitivity (0%), thus, provides an efficient tool to identify B. cereus and B. thuringiensis. Further, environmental and food samples do not require band isolation, re-amplification or sequence identification. Thus, reducing the time and cost of analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Cytotoxic Potential of Bacillus cereus Strains ATCC 11778 and 14579 Against Human Lung Epithelial Cells Under Microaerobic Growth Conditions

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    Kathleen eKilcullen

    2016-02-01

    Full Text Available Bacillus cereus, a food poisoning bacterium closely related to Bacillus anthracis, secretes a multitude of virulence factors including enterotoxins, hemolysins, and phospholipases. However, the majority of the in vitro experiments evaluating the cytotoxic potential of B. cereus were carried out in the conditions of aeration, and the impact of the oxygen limitation in conditions encountered by the microbe in natural environment such as gastrointestinal tract remains poorly understood. This research reports comparative analysis of ATCC strains 11778 (BC1 and 14579 (BC2 in aerated and microaerobic (static cultures with regard to their toxicity for human lung epithelial cells. We showed that BC1 increased its toxicity upon oxygen limitation while BC2 was highly cytotoxic in both growth conditions. The combined effect of the pore-forming, cholesterol-dependent hemolysin, cereolysin O (CLO, and metabolic product(s such as succinate produced in microaerobic conditions provided substantial contribution to the toxicity of BC1 but not BC2 which relied mainly on other toxins. This mechanism is shared between CB1 and B. anthracis. It involves the permeabilization of the cell membrane which facilitates transport of toxic bacterial metabolites into the cell. The toxicity of BC1was potentiated in the presence of bovine serum albumin which appeared to serve as reservoir for bacteria-derived nitric oxide participating in the downstream production of reactive oxidizing species with the properties of peroxynitrite. In agreement with this the BC1cultures demonstrated the increased oxidation of the indicator dye Amplex Red catalyzed by peroxidase as well as the increased toxicity in the presence of externally added ascorbic acid.

  2. Cytotoxic Potential of Bacillus cereus Strains ATCC 11778 and 14579 Against Human Lung Epithelial Cells Under Microaerobic Growth Conditions.

    Science.gov (United States)

    Kilcullen, Kathleen; Teunis, Allison; Popova, Taissia G; Popov, Serguei G

    2016-01-01

    Bacillus cereus, a food poisoning bacterium closely related to Bacillus anthracis, secretes a multitude of virulence factors including enterotoxins, hemolysins, and phospholipases. However, the majority of the in vitro experiments evaluating the cytotoxic potential of B. cereus were carried out in the conditions of aeration, and the impact of the oxygen limitation in conditions encountered by the microbe in natural environment such as gastrointestinal tract remains poorly understood. This research reports comparative analysis of ATCC strains 11778 (BC1) and 14579 (BC2) in aerobic and microaerobic (static) cultures with regard to their toxicity for human lung epithelial cells. We showed that BC1 increased its toxicity upon oxygen limitation while BC2 was highly cytotoxic in both growth conditions. The combined effect of the pore-forming, cholesterol-dependent hemolysin, cereolysin O (CLO), and metabolic product(s) such as succinate produced in microaerobic conditions provided substantial contribution to the toxicity of BC1 but not BC2 which relied mainly on other toxins. This mechanism is shared between CB1 and B. anthracis. It involves the permeabilization of the cell membrane which facilitates transport of toxic bacterial metabolites into the cell. The toxicity of BC1 was potentiated in the presence of bovine serum albumin which appeared to serve as reservoir for bacteria-derived nitric oxide participating in the downstream production of reactive oxidizing species with the properties of peroxynitrite. In agreement with this the BC1 cultures demonstrated the increased oxidation of the indicator dye Amplex Red catalyzed by peroxidase as well as the increased toxicity in the presence of externally added ascorbic acid.

  3. Optimization of fermentation conditions for green pigment production from Bacillus cereus M¹ 16 (MTCC 5521) and its pharmacological application.

    Science.gov (United States)

    Banerjee, D; Mondal, A; Gupta, M; Guha, A K; Ray, L

    2014-01-01

    Optimal culture conditions for the production of green pigment was investigated. The optimal culture condition for the production of an extracellular green pigment by growing Bacillus cereus M(1) 16 (MTCC 5521) in a complex medium containing (g l(-1) ) Peptone-4.0, Beef Extract-9.0, NaCl-7.0, MgSO4 .7H2 O-1.0 and KH2 PO4 -5.0 was as follows pH-7.0 at 30°C for 72 h in a 5 l fermenter. Aeration rate and agitator speed had no effect on the pigment production. Thin layer chromatogram of the pigment extracted from the fermented broth with chloroform on silica gel GF254 using ethyl acetate and hexane (1 : 1) as solvent showed three fractions. The major fraction (C3 ) was separated out and identified as 9-methyl-1, 4, 5, 8-tetra-azaphenanthrene. Acute toxicity test revealed the nontoxic nature upto a dose of 2000 mg kg(-1) , b.wt., of mice. MTT assay showed the cytotoxic nature in HL60 cells having an IC50 of 2.47 mmol. So, this biopigment may have application in food, textile colorant and pharmaceutical industry. This study demonstrated the optimum production of a biopigment (9-methyl-1, 4, 5, 8-tetra-azaphenanthrene) by fermentation of a complex medium with Bacillus cereus M(1) 16 (MTCC 5521) in submerged fermentation. This is the first investigation of toxicity and cytotoxicity activities of this biopigment. The study showed that the purified pigment had no toxicity to healthy albino mice but a high cytotoxicity activity in HL60 cancer cell line in vitro. The biopigment had further displayed dyeing capability to both solidified agar and cotton cloth. Therefore, it may represent a nontoxic and natural alternative to chemical dyes and pigments. © 2013 The Society for Applied Microbiology.

  4. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

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    Sasidharan Nishanth Kumar

    Full Text Available The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs [cyclo-(L-Pro-Gly, cyclo(L-Tyr-L-Tyr, cyclo-(L-Phe-Gly and cyclo(4-hydroxy-L-Pro-L-Trp]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp. To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp. The cyclo(4-hydroxy-L-Pro-L-Trp was nontoxic to two normal cell lines [fore skin (FS normal fibroblast and African green monkey kidney (VERO] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species.

  5. The chromosome map of Bacillus thuringiensis subsp. canadensis HD224 is highly similar to that of the Bacillus cereus type strain ATCC 14579.

    Science.gov (United States)

    Carlson, C R; Johansen, T; Kolstø, A B

    1996-08-01

    A physical map of the Bacillus thuringiensis subsp. canadensis HD224 chromosome based on AscI, NotI, and SfiI restriction sites has been established. The chromosome map of 4.3 Mb was similar to a revised map of the chromosome of the B. cereus type strain ATCC 14579, except that the B. thuringiensis subsp. canadensis HD224 chromosome lacked a NotI site and had two additional AscI sites. The positions of 27 probes were identical in the common macromap. A probe for the insecticidal toxin gene, cryIA, hybridized only to the B. thuringiensis subsp. canadensis HD224 chromosome. The BssHII ribotype patterns were almost identical confirming the similarity between the two strains.

  6. Tetracycline and oxytetracycline resistance determinants detected in Bacillus cereus strains isolated from honey samples Detección de determinantes de resistencia a tetraciclina y oxitetraciclina en cepas de Bacillus cereus aisladas de muestras de miel

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    A. C. López

    2008-12-01

    Full Text Available The aim of this study was to investigate the presence of tetracycline and oxytetracycline resistance determinants in Bacillus cereus strains isolated from honey samples. Of a total of 77 isolates analyzed, 30 (39% exhibited resistance to tetracyclines according to the results of a disk diffusion method. Resistant strains (n=30 were screened by PCR for the presence of the resistant determinants tetK, tetL, tetM, tetO, tetW, otrA and otrB and their MIC values for tetracycline, oxytetracycline and minocycline were assessed. According to the PCR results, 23 isolates (77% presented at least one tetracycline or oxytetracycline resistance determinant. The tetK genotype was present in 10 isolates while the tetL, tetM, and otrA genotypes were present in 3, 2, and 5 isolates, respectively. In addition, 2 isolates of the tetK plus tetM genotype, 1 of the tetK plus tetL genotype, and 1 of the tetK plus otrA genotype were found. All isolates were tetW, tetO and otrB negatives. On the other hand, 7 isolates (23% showed a tetracycline-resistant and/or minocyclineresistant phenotype (MIC but did not carry any of the tet or otr determinants investigated in this study. This research has shown that B. cereus isolates from honey samples contain a variety of tetracycline and oxytetracycline resistance genes, including the tetK and tetL determinants which encode for efflux proteins, and tetM and otrA, which encode for ribosomal protection proteins. These findings indicate that strains isolated from honeys could represent a reservoir for tetracycline resistance genes. To our knowledge, this is the first report of tetracycline-resistant and oxytetracyclineresistant B. cereus strains carrying the tetK determinant, and also the first report of oxytetracycline-resistant and tetracycline- resistant Bacillus species carrying the otrA determinant.El objetivo del presente estudio ha sido investigar la presencia de diversos determinantes de resistencia a tetraciclina y

  7. Effects of dietary Bacillus cereus G19, B. cereus BC-01, and Paracoccus marcusii DB11 supplementation on the growth, immune response, and expression of immune-related genes in coelomocytes and intestine of the sea cucumber (Apostichopus japonicus Selenka).

    Science.gov (United States)

    Yang, Gang; Tian, Xiangli; Dong, Shuanglin; Peng, Mo; Wang, Dongdong

    2015-08-01

    Probiotics have positive effects on the nutrient digestibility and absorption, immune responses, and growth of aquatic animals, including the sea cucumber (Apostichopus japonicus Selenka). A 60-day feeding trial was conducted to evaluate the effects of Bacillus cereus G19, B. cereus BC-01 and Paracoccus marcusii DB11 supplementation on the growth, immune response, and expression level of four immune-related genes (Aj-p105, Aj-p50, Aj-rel, and Aj-lys) in coelomocytes and the intestine of juvenile sea cucumbers. One group was fed the basal diet (control group), while three other groups were fed the basal diet supplemented with B. cereus G19 (G19 group), B. cereus BC-01 (BC group), or P. marcusii DB11 (PM group). The growth rate of sea cucumbers fed diets with probiotics supplementation was significantly higher than that of the control group (P marcusii DB11 supplementation could have a positive effect on the growth performance and immune response in coelomocytes and the intestine of sea cucumbers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Identification of the sigmaB regulon of Bacillus cereus and conservation of sigmaB-regulated genes in low-GC-content gram-positive bacteria.

    Science.gov (United States)

    van Schaik, Willem; van der Voort, Menno; Molenaar, Douwe; Moezelaar, Roy; de Vos, Willem M; Abee, Tjakko

    2007-06-01

    The alternative sigma factor sigma(B) has an important role in the acquisition of stress resistance in many gram-positive bacteria, including the food-borne pathogen Bacillus cereus. Here, we describe the identification of the set of sigma(B)-regulated genes in B. cereus by DNA microarray analysis of the transcriptome upon a mild heat shock. Twenty-four genes could be identified as being sigma(B) dependent as witnessed by (i) significantly lower expression levels of these genes in mutants with a deletion of sigB and rsbY (which encode the alternative sigma factor sigma(B) and a crucial positive regulator of sigma(B) activity, respectively) than in the parental strain B. cereus ATCC 14579 and (ii) increased expression of these genes upon a heat shock. Newly identified sigma(B)-dependent genes in B. cereus include a histidine kinase and two genes that have predicted functions in spore germination. This study shows that the sigma(B) regulon of B. cereus is considerably smaller than that of other gram-positive bacteria. This appears to be in line with phylogenetic analyses where sigma(B) of the B. cereus group was placed close to the ancestral form of sigma(B) in gram-positive bacteria. The data described in this study and previous studies in which the complete sigma(B) regulon of the gram-positive bacteria Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus were determined enabled a comparison of the sets of sigma(B)-regulated genes in the different gram-positive bacteria. This showed that only three genes (rsbV, rsbW, and sigB) are conserved in their sigma(B) dependency in all four bacteria, suggesting that the sigma(B) regulon of the different gram-positive bacteria has evolved to perform niche-specific functions.

  9. Bacillus cereus can attack the cell membranes of the alga Chara corallina by means of HlyII.

    Science.gov (United States)

    Kataev, Anatoly A; Andreeva-Kovalevskaya, Zhanna I; Solonin, Alexander S; Ternovsky, Vadim I

    2012-05-01

    We studied the influence of Bacillus cereus bacteria on cells of the freshwater alga Chara corallina. These bacteria and recombinant Bacillus subtilis strains are capable of producing the secreted toxin HlyII, which changes the electrophysiological parameters of the algal electrically excitable plasma membrane by forming pores. Cooperative incubation of bacterial cells, which carry active hlyII gene, and Chara corallina cells caused a decrease in the resting potential (V(m)) and plasma membrane resistance (R(m)) of algal cells. The efficiency of each strain was commensurable with its ability to produce HlyII. Purified hemolysin II caused a similar effect on V(m) and R(m) of intact and perfused cells. This protein changed the kinetics and magnitude of transient voltage-dependent calcium and calcium-activated chloride currents owing to the formation of additional Ca(2+)-permeable pores in algal cell membrane. Occurrence of the cellulose cell wall with pores 2.1 to 4.6nm in diameter suggests that HlyII molecules reach the plasma membrane surface strictly as monomers. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. PENGARUH UMPAN TAMBAHAN PADA AKUMULASI POLIHIDROKSIBUTIRAT (PHB OLEH Bacillus cereus IFO 13690 MENGGUNAKAN SUBSTRAT TAPIOKA The Effects of Feeding on Accumulation of Polyhydroxybutyrate (PHB from Tapioca by Bacillus cereus IFO 13690

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    Margono Margono

    2012-05-01

    Full Text Available Bacillus cereus IFO 13690 is Gram positive bacteria that produces polyhydroxybutyrate (PHB. It has amylolytic characteristic that can be cultured using cassava starch. This research reported the ability of B. cereus IFO 13690 on accumulating PHB and the effects of starch and ammonium feeding on cell and PHB productivity. Batch process was conducted with initial starch of 18 g/l, medium pH of 5.6 and medium temperature of 30 oC. Fed batch process was conducted in the same conditions of the optimum batch process with feeding of 2.1 l/hat 7th ­7.65thhours of exponential growth and 1.86 l/hat 10th­10.8thhours of exponential growth. The feeding compositions were starch of 70 g/l and am­ monium sulfate of 20 g/l. The results of batch process showed that the highest accumulation of PHB was achieved with initial ammonium of 1.20 g/l and dissolved oxygen of 5 % air saturation. The highest PHB accumulation of 0.13 g/l was achieved after 29 hours of fermentation. It was similar to 0.005 g/l.h productivity and the PHB content was 2.42%. The productivity of cell and PHB in fed batch process was double compared to the batch process, i.e. 0.39 g/l.h and0.01 g/l.h, respectively. The PHB content in cell dry weight was relatively higher in the fed batch compared to batch process, i.e. 2.50 %. ABSTRAK Bacillus cereus IFO 13690 adalah bakteri Gram positif penghasil polihidroksibutirat(PHB yang bersifat amilolitik sehingga dapat dikulturkan dalam substrat pati. Penelitian ini dimaksudkan untuk melaporkan kemampuan B. cereus IFO 13690 dalam mengakumulasi PHB pada proses batch dan pengaruh penambahan pati serta amonium terhadap produktivitas sel dan PHB pada proses fed batch. Percobaan proses batch dilaksanakan pada konsentrasi pati awal 18 g/l, pH medium 5,6 dan suhu medium 30 oC. Percobaan proses fedbatch dilaksanakan seperti pada proses batch opti­ mum kemudian ditambahkan medium umpan pada saat pertumbuhan eksponensial, yaitu 2,1 l/jam pada saat pertum­ buhan

  11. Molecular Characterization and Risk Assessment of Bacillus cereus Sensu Lato Isolated from Ultrahigh-Temperature and Pasteurized Milk Marketed in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Chaves, Jeane Q; de Paiva, Eislaine P; Rabinovitch, Leon; Vivoni, Adriana M

    2017-07-01

    The presence of Bacillus cereus in milk is a major concern in the dairy industry. In this study 27 Bacillus cereus sensu lato isolates from pasteurized and ultrahigh-temperature (UHT) milk (24 whole UHT and 4 pasteurized samples) collected at supermarket chains in Rio de Janeiro, Brazil, were evaluated to assess the potential risk for food poisoning. Toxigenic and virulence profiles were defined by gene-specific PCR. Affiliation to phylogenetic groups was assigned by panC sequencing. Microbiological analysis revealed the presence of B. cereus s.l. in eight (33.3%) brands (six brands of UHT and two brands of pasteurized milk). Twenty-seven isolates were recovered (13 B. cereus and 14 Bacillus thuringiensis ). Predominant toxigenic patterns were type I (contains all toxin genes except ces) and type II (does not contain cytK and ces), with seven (25.9%) isolates each. Predominant virulence patterns were type 2 (does not contain hlyII or shp) and type 3 (contains all virulence genes), with five (18.5%) isolates each. All isolates belonged to phylogenetic groups III and IV. Presence of hbl, piplc, and sph was associated with group IV isolates. Our results suggest that B. thuringiensis and B. cereus sensu stricto should be considered potential foodborne pathogens. Because the majority of the milk isolates studied have the potential to cause food poisoning because of the high prevalence of toxin and virulence genes and the specific phylogenetic group affiliations, these milk products can be potentially hazardous for human consumption.

  12. Microrganismos heterotróficos mesófilos e bactérias do grupo do Bacillus cereus em leite integral submetido a ultra alta temperatura Mesophilic heterotrophic microorganisms and spore forming bacteria from Bacillus cereus group in ultra high temperature milk

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    A.M.C. Vidal-Martins

    2005-06-01

    Full Text Available Cento e dez amostras de 11 diferentes marcas de leite ultra alta temperatura (UAT, comercializadas em São José do Rio Preto - SP, foram submetidas à contagem de microrganismos heterotróficos mesófilos viáveis e à pesquisa de bactérias do grupo do Bacillus cereus. A população de microrganismos mesófilos variou de ´10² UFC/ml a >1,0´10(6 UFC/ml. Bactérias do grupo do Bacillus cereus foram verificadas em 13 (11,8% amostras. Os resultados evidenciaram elevada população de microrganismos indicadores mesófilos.One hundred and ten ultra high temperature (UHT milk samples, from 11 different brands retailed in São José do Rio Preto - SP were analysed for mesophilic heterotrophic microorganisms counting, as well as for the presence of Bacillus cereus. Mesophilic heterotrophic microorganisms ranged from ´10² CFU/ml to >1.0´10(6 CFU/ml. Bacillus cereus was detected in 13 (11.8% samples. The results demonstrated high countings of mesophilic microorganisms.

  13. Exploring the biosynthesis of unsaturated fatty acids in Bacillus cereus ATCC 14579 and functional characterization of novel acyl-lipid desaturases.

    Science.gov (United States)

    Chazarreta Cifré, Lorena; Alemany, Mariana; de Mendoza, Diego; Altabe, Silvia

    2013-10-01

    At low temperatures, Bacillus cereus synthesizes large amounts of unsaturated fatty acids (UFAs) with double bonds in positions Δ5 and Δ10, as well as Δ5,10 diunsaturated fatty acids. Through sequence homology searches, we identified two open reading frames (ORFs) encoding a putative Δ5 desaturase and a fatty acid acyl-lipid desaturase in the B. cereus ATCC 14579 genome, and these were named BC2983 and BC0400, respectively. Functional characterization of ORFs BC2983 and BC0400 by means of heterologous expression in Bacillus subtilis confirmed that they both encode acyl-lipid desaturases that use phospholipids as the substrates and have Δ5 and Δ10 desaturase activities. Thus, these ORFs were correspondingly named desA (Δ5 desaturase) and desB (Δ10 desaturase). We established that DesA utilizes ferredoxin and flavodoxins (Flds) as electron donors for the desaturation reaction, while DesB preferably employs Flds. In addition, increased amounts of UFAs were found when B. subtilis expressing B. cereus desaturases was subjected to a cold shock treatment, indicating that the activity or the expression of these enzymes is upregulated in response to a decrease in growth temperature. This represents the first work reporting the functional characterization of fatty acid desaturases from B. cereus.

  14. Possible Use of Bacteriophages Active against Bacillus anthracis and Other B. cereus Group Members in the Face of a Bioterrorism Threat

    Science.gov (United States)

    Weber-Dąbrowska, Beata; Borysowski, Jan; Górski, Andrzej

    2014-01-01

    Anthrax is an infectious fatal disease with epidemic potential. Nowadays, bioterrorism using Bacillus anthracis is a real possibility, and thus society needs an effective weapon to neutralize this threat. The pathogen may be easily transmitted to human populations. It is easy to store, transport, and disseminate and may survive for many decades. Recent data strongly support the effectiveness of bacteriophage in treating bacterial diseases. Moreover, it is clear that bacteriophages should be considered a potential incapacitative agent against bioterrorism using bacteria belonging to B. cereus group, especially B. anthracis. Therefore, we have reviewed the possibility of using bacteriophages active against Bacillus anthracis and other species of the B. cereus group in the face of a bioterrorism threat. PMID:25247187

  15. The phosphotransferase system gene ptsI in the endophytic bacterium Bacillus cereus is required for biofilm formation, colonization, and biocontrol against wheat sharp eyespot.

    Science.gov (United States)

    Xu, Yu-Bin; Chen, Mai; Zhang, Ying; Wang, Miao; Wang, Ying; Huang, Qiu-bin; Wang, Xue; Wang, Gang

    2014-05-01

    Natural resistance of wheat plants to wheat sharp eyespot is inadequate, and new strategies for controlling the disease are required. Biological control is an alternative and attractive way of reducing the use of chemicals in agriculture. In this study, we investigated the biocontrol properties of endophytic bacterium Bacillus cereus strain 0-9, which was isolated from the root systems of healthy wheat varieties. The phosphotransferase system is a major regulator of carbohydrate metabolism in bacteria. Enzyme I is one of the protein components of this system. Specific disruption and complementation of the enzyme I-coding gene ptsI from B. cereus was achieved through homologous recombination. Disruption of ptsI in B. cereus caused a 70% reduction in biofilm formation, a 30.4% decrease in biocontrol efficacy, and a 1000-fold reduction in colonization. The growth of ΔptsI mutant strain on G-tris synthetic medium containing glucose as the exclusive carbon source was also reduced. Wild-type properties could be restored to the ΔptsI mutant strain by ptsI complementation. These results suggested that ptsI may be one of the key genes involved in biofilm formation, colonization, and biocontrol of B. cereus and that B. cereus wild-type strain 0-9 may be an ideal biocontrol agent for controlling wheat sharp eyespot. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  16. The CasKR two-component system is required for the growth of mesophilic and psychrotolerant Bacillus cereus strains at low temperatures.

    Science.gov (United States)

    Diomandé, Sara Esther; Chamot, Stéphanie; Antolinos, Vera; Vasai, Florian; Guinebretière, Marie-Hélène; Bornard, Isabelle; Nguyen-the, Christophe; Broussolle, Véronique; Brillard, Julien

    2014-04-01

    The different strains of Bacillus cereus can grow at temperatures covering a very diverse range. Some B. cereus strains can grow in chilled food and consequently cause food poisoning. We have identified a new sensor/regulator mechanism involved in low-temperature B. cereus growth. Construction of a mutant of this two-component system enabled us to show that this system, called CasKR, is required for growth at the minimal temperature (Tmin). CasKR was also involved in optimal cold growth above Tmin and in cell survival below Tmin. Microscopic observation showed that CasKR plays a key role in cell shape during cold growth. Introducing the casKR genes in a ΔcasKR mutant restored its ability to grow at Tmin. Although it was first identified in the ATCC 14579 model strain, this mechanism has been conserved in most strains of the B. cereus group. We show that the role of CasKR in cold growth is similar in other B. cereus sensu lato strains with different growth temperature ranges, including psychrotolerant strains.

  17. Biorremediation of soil polluted by 75000 ppm of waste motor oil applying biostimulation and phytoremediation with Sorghum vulgare and Bacillus cereus or Burkholderia cepacia

    OpenAIRE

    Balderas-León Iván; Sánchez-Yáñez Juan Manuel

    2015-01-01

    Waste motor oil (WMO) pollutes soil and causing lost soil fertility. An alternative to solve this problem its bioremediation (BR) by double and following biostimulation (BS) with mineral solution (MS) and a legume as green manure (GM) then using phytoremediation (PR) with growth promoting vegetal bacteria (GPVB) like Bacillus cereus and Burkholderia cepacia to minimize remaining WMO. The aims of this research were: a) bioremediation of polluted soil by 75000 ppm of WMO by biostimulation and t...

  18. RE-PCR variability and toxigenic profile of food poisoning, foodborne and soil-associated Bacillus cereus isolates from Brazil.

    Science.gov (United States)

    Santos, C A; Almeida, F S; Guimarães, A G; Abrahão, W M; Arantes, O M N; Vilas-Bôas, G T

    2011-12-15

    Twenty-three Bacillus cereus isolates from food poisoning outbreaks associated with a diarrheal-type syndrome, fourteen foodborne isolates not associated with food poisoning and fifteen isolates from Brazilian soil samples were analyzed for the presence and genetic diversity (by RE-PCR) of the virulence genes ces (emetic toxin, cereulide), plcR-papR (pleiotropic regulator PlcR and peptide PapR), nheA (a component of the NHE complex), bceT (diarrheal enterotoxin bc-D-ENT), gyrB (B subunit of DNA gyrase), cytK-2 (necrotic enterotoxin cytotoxin K-2), and plcA (phosphatidylcholine-specific phospholipase C). Additionally, these isolates were phenotypically characterized for motility, hemolytic and lecithinase activities, as well as HBL enterotoxin production. The group of isolates associated with food poisoning had the highest occurrence of the phenotypically analyzed factors and the most frequent occurrence and highest genetic diversity of the plcR-papR, nheA, bceT, cytK-2, plcA, and gyrB genes. An analysis of molecular variance (AMOVA), in which all loci were analyzed, demonstrated that the genetic variation intragroup of isolates (92%) was significantly higher than that intergroup (8%) (Pfood poisoning outbreaks do not have a specific genetic profile characterized by the presence of a particular gene or allele among the genes assessed. On the contrary, different combinations of genes encoding virulence factors may be present in different isolates of B. cereus that potentially cause food poisoning outbreaks. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Recovery of heat treated Bacillus cereus spores is affected by matrix composition and factors with putative functions in damage repair

    Directory of Open Access Journals (Sweden)

    Alicja Katarzyna Warda

    2016-07-01

    Full Text Available The ability of spores to recover and grow out after food processing is affected by cellular factors and by the outgrowth conditions. In the current communication we studied the recovery and outgrowth of individually sorted spores in BHI and rice broth media and on agar plates using flow cytometry (FCM. We show that recovery of wet heat treated Bacillus cereus ATCC 14579 spores is affected by matrix composition with highest recovery in BHI broth or on rice agar plates, compared to BHI agar plates and rice broth. Data show that not only media composition but also its liquid or solid state affect the recovery of heat treated spores. To determine the impact of factors with putative roles in recovery of heat treated spores, specific genes previously shown to be highly expressed in outgrowing heat-treated spores were selected for mutant construction. Spores of nine B. cereus ATCC 14579 deletion mutants were obtained and their recovery from wet heat treatment was evaluated using BHI and rice broth and agar plates. Deletion mutant spores showed different capacity to recover from heat treatment compared to wild type with the most pronounced effect for a mutant lacking BC5242, a gene encoding a membrane protein with C2C2 zinc finger which resulted in over 95% reduction in recovery compared to the wild type in BHI broth. Notably, similar relative performance of wild type and mutants was observed using the other recovery conditions.We obtained insights on the impact of matrix composition and state on recovery of individually sorted heat treated spores and identified cellular factors with putative roles in this process. These results may provide leads for future developments in design of more efficient combined preservation treatments.

  20. Recovery of Heat Treated Bacillus cereus Spores Is Affected by Matrix Composition and Factors with Putative Functions in Damage Repair.

    Science.gov (United States)

    Warda, Alicja K; Tempelaars, Marcel H; Abee, Tjakko; Nierop Groot, Masja N

    2016-01-01

    The ability of spores to recover and grow out after food processing is affected by cellular factors and by the outgrowth conditions. In the current communication we studied the recovery and outgrowth of individually sorted spores in BHI and rice broth media and on agar plates using flow cytometry. We show that recovery of wet heat treated Bacillus cereus ATCC 14579 spores is affected by matrix composition with highest recovery in BHI broth or on rice agar plates, compared to BHI agar plates and rice broth. Data show that not only media composition but also its liquid or solid state affect the recovery of heat treated spores. To determine the impact of factors with putative roles in recovery of heat treated spores, specific genes previously shown to be highly expressed in outgrowing heat-treated spores were selected for mutant construction. Spores of nine B. cereus ATCC 14579 deletion mutants were obtained and their recovery from wet heat treatment was evaluated using BHI and rice broth and agar plates. Deletion mutant spores showed different capacity to recover from heat treatment compared to wild type with the most pronounced effect for a mutant lacking BC5242, a gene encoding a membrane protein with C2C2 zinc finger which resulted in over 95% reduction in recovery compared to the wild type in BHI broth. Notably, similar relative performance of wild type and mutants was observed using the other recovery conditions. We obtained insights on the impact of matrix composition and state on recovery of individually sorted heat treated spores and identified cellular factors with putative roles in this process. These results may provide leads for future developments in design of more efficient combined preservation treatments.

  1. Downstream process for production of a viable and stable Bacillus cereus aquaculture biological agent

    CSIR Research Space (South Africa)

    Lalloo, R

    2010-03-01

    Full Text Available , rapid mixing providing near 441isothermal conditions and uniform end product (Bayrock 442and Ingledew 1997; Larena et al. 2003; Q1Luna-Solano et al. 4432005; Mille et al. 2004). 444The high recovery of B. cereus spores through our 445agglomeration... Biotechnol JrnlID 253_ArtID 2294_Proof# 1 - 13/10/2009 AUTHOR'S PROOF! UNCORRECTE D PROO F AUTHOR QUERY AUTHOR PLEASE ANSWER QUERY. Q1. Luna-Solano et al. 2005 was cited in the body but not listed in the reference list. Please provide complete...

  2. Competitive exclusion as a mode of action of a novel Bacillus cereus aquaculture biological agent

    CSIR Research Space (South Africa)

    Lalloo, R

    2010-01-01

    Full Text Available -109. 17 18 Brunt, J. and Austin, B. (2005) Use of a probiotic to control Latococcosis and streptococcosis in 19 rainbow trout, Oncorhynchus mykiss (Walbaum). J Fish Dis 28, 693-701. 20 21 Chart, H. and Trust, T.J. (1983) Acquisition of iron... controls Aeromonas infection in rainbow trout (Oncorhynchus mykiss, 22 Walbaum). J Appl Microbiol 103, 1699-706. 23 Mode of action B. cereus 18 1 Park, R.Y., Choi, M.H., Sun, H.Y. and Shin, S.H. (2005) Production of catechol-siderophore and 2...

  3. Effect of Bacillus cereus Enzymes on Milk Quality following Ultra High Temperature Processing

    Directory of Open Access Journals (Sweden)

    B. Janštová

    2006-01-01

    Full Text Available Using a model case of contamination of long-life semi-skimmed milk with the spores of six B. cereus strains, isolated from the farm environment and raw milk, proteolysis was monitored by measuring changes in protein content by infra-red spectroscopy; free tyrosine was measured by the Lowry method according to Juffs, and the reduction in casein fractions by SDS-PAGE. Lipolysis was monitored by the dilution extractive method. At a storage temperature of 4 °C for 4 months no enzyme processes were observed, whereas at a storage temperature of 24 °C a marked enzyme activity was found during maximum 3 weeks as well as sensory changes of UHT milk. After three weeks of storage, a reduction in protein content from 34.55 g l-1 milk to 29.46 ± 2.00 g l-1 milk, and a reduction in the free tyrosine from 0.65 to 2.13 ± 0.28 mg ml-1 was found, as well as increased molar contents of free fatty acids (FFA from 41.97 to 1617.22 ± 68.17 mmol kg-1 milk fat. After six days of storage, α-casein, β-casein and κ-casein dropped to 69 ± 10%, 56 ± 16% and 43 ± 10%, respectively. Majority of changes in UHT milk depended on the B. cereus strain used, initial microbial counts and the method of heat inactivation of spores.

  4. Identification and Analysis of Informative Single Nucleotide Polymorphisms in 16S rRNA Gene Sequences of the Bacillus cereus Group.

    Science.gov (United States)

    Hakovirta, Janetta R; Prezioso, Samantha; Hodge, David; Pillai, Segaran P; Weigel, Linda M

    2016-11-01

    Analysis of 16S rRNA genes is important for phylogenetic classification of known and novel bacterial genera and species and for detection of uncultivable bacteria. PCR amplification of 16S rRNA genes with universal primers produces a mixture of amplicons from all rRNA operons in the genome, and the sequence data generally yield a consensus sequence. Here we describe valuable data that are missing from consensus sequences, variable effects on sequence data generated from nonidentical 16S rRNA amplicons, and the appearance of data displayed by different software programs. These effects are illustrated by analysis of 16S rRNA genes from 50 strains of the Bacillus cereus group, i.e., Bacillus anthracis, Bacillus cereus, Bacillus mycoides, and Bacillus thuringiensis These species have 11 to 14 rRNA operons, and sequence variability occurs among the multiple 16S rRNA genes. A single nucleotide polymorphism (SNP) previously reported to be specific to B. anthracis was detected in some B. cereus strains. However, a different SNP, at position 1139, was identified as being specific to B. anthracis, which is a biothreat agent with high mortality rates. Compared with visual analysis of the electropherograms, basecaller software frequently missed gene sequence variations or could not identify variant bases due to overlapping basecalls. Accurate detection of 16S rRNA gene sequences that include intragenomic variations can improve discrimination among closely related species, improve the utility of 16S rRNA databases, and facilitate rapid bacterial identification by targeted DNA sequence analysis or by whole-genome sequencing performed by clinical or reference laboratories. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  5. Optimization of the production conditions of the lipase produced by Bacillus cereus from rice flour through Plackett-Burman Design (PBD) and response surface methodology (RSM).

    Science.gov (United States)

    Vasiee, Alireza; Behbahani, Behrooz Alizadeh; Yazdi, Farideh Tabatabaei; Moradi, Samira

    2016-12-01

    In this study, the screening of lipase positive bacteria from rice flour was carried out by Rhodamin B agar plate method. Bacillus cereus was identified by 16S rDNA method. Screening of the appropriate variables and optimization of the lipase production was performed using Plackett-Burman design (PBD) and response surface methodology (RSM). Among the isolated bacteria, an aerobic Bacillus cereus strain was recognized as the best lipase-producing bacteria (177.3 ± 20 U/ml). Given the results, the optimal enzyme production conditions were achieved with coriander seed extract (CSE)/yeast extract ratio of 16.9 w/w, olive oil (OO) and MgCl 2 concentration of 2.37 g/L and 24.23 mM, respectively. In these conditions, the lipase activity (LA) was predicted 343 U/mL that was approximately close to the predicted value (324 U/mL), which was increased 1.83 fold LA compared with the non-optimized lipase. The kinetic parameters of V max and K m for the lipase were measured 0.367 μM/min.mL and 5.3 mM, respectively. The lipase producing Bacillus cereus was isolated and RSM was used for the optimization of enzyme production. The CSE/yeast extract ratio of 16.9 w/w, OO concentration of 2.37 g/L and MgCl 2 concentration of 24.23 mM, were found to be the optimal conditions of the enzyme production process. LA at optimal enzyme production conditions was observed 1.83 times more than the non-optimal conditions. Ultimately, it can be concluded that the isolated B. cereus from rice flour is a proper source of lipase. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The genome of a Bacillus isolate causing anthrax in chimpanzees combines chromosomal properties of B. cereus with B. anthracis virulence plasmids.

    Directory of Open Access Journals (Sweden)

    Silke R Klee

    Full Text Available Anthrax is a fatal disease caused by strains of Bacillus anthracis. Members of this monophyletic species are non motile and are all characterized by the presence of four prophages and a nonsense mutation in the plcR regulator gene. Here we report the complete genome sequence of a Bacillus strain isolated from a chimpanzee that had died with clinical symptoms of anthrax. Unlike classic B. anthracis, this strain was motile and lacked the four prohages and the nonsense mutation. Four replicons were identified, a chromosome and three plasmids. Comparative genome analysis revealed that the chromosome resembles those of non-B. anthracis members of the Bacillus cereus group, whereas two plasmids were identical to the anthrax virulence plasmids pXO1 and pXO2. The function of the newly discovered third plasmid with a length of 14 kbp is unknown. A detailed comparison of genomic loci encoding key features confirmed a higher similarity to B. thuringiensis serovar konkukian strain 97-27 and B. cereus E33L than to B. anthracis strains. For the first time we describe the sequence of an anthrax causing bacterium possessing both anthrax plasmids that apparently does not belong to the monophyletic group of all so far known B. anthracis strains and that differs in important diagnostic features. The data suggest that this bacterium has evolved from a B. cereus strain independently from the classic B. anthracis strains and established a B. anthracis lifestyle. Therefore we suggest to designate this isolate as "B. cereus variety (var. anthracis".

  7. Characterization of Exopolysaccharides Produced by Bacillus cereus and Brachybacterium sp. Isolated from Asian Sea Bass (Lates calcarifer

    Directory of Open Access Journals (Sweden)

    Mohamed Orsod

    2012-09-01

    Full Text Available Aims: EPS extracted from marine bacteria, which associated with Asian sea bass has potential antimicrobial activities.Methodology and Results: Two marine Bacteria were isolated from Asian sea bass (Lates calcarifer obtained from aquaculture farm, located at Johor bahru Malaysia. 16S rRNA analysis for bacteria identity revealed that bacteria ors1 had 99 % identity to Bacillus cereus and ors2 had 96 % identity with Brachybacterium sp. All bacteria shared many similarities and variation in terms of biochemical reactions and microscopic observation. Exopolysaccharides (EPSs were extracted and purified from bacteria as they produced mucous colonies. Average analysis of EPS components showed 50 % carbohydrates, 26 % protein and 24 % fatty acids. The FTIR analysis confirmed the functional groups of the EPS. Screening for antimicrobial activities assays using Kirby-Bauer methods against both grams positive and negative had shown presence of inhibition zones.Conclusion, significance and impact of study: This study recommends that bacteria isolated from Asian sea bass are having antimicrobial activities and could be used as a potential source for the development of marine drugs.

  8. Cow dung is an ideal fermentation medium for amylase production in solid-state fermentation by Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Ponnuswamy Vijayaraghavan

    2015-12-01

    Full Text Available Amylase production by Bacillus cereus IND4 was investigated by solid state fermentation (SSF using cow dung substrate. The SSF conditions were optimized by using one-variable-at-a-time approach and two level full factorial design. Two level full factorial design demonstrated that moisture, pH, fructose, yeast extract and ammonium sulphate have significantly influenced enzyme production (p < 0.05. A central composite design was employed to investigate the optimum concentration of these variables affecting amylase production. Maximal amylase production of 464 units/ml of enzyme was observed in the presence of 100% moisture, 0.1% fructose and 0.01% ammonium sulphate. The enzyme production increased three fold compared to the original medium. The optimum pH and temperature for the activity of amylase were found to be 8.0 and 50 °C, respectively. This enzyme was highly stable at wide pH range (7.0–9.0 and showed 32% enzyme activity after initial denaturation at 50 °C for 1 h. This is the first detailed report on the production of amylase by microorganisms using cow dung as the low cost medium.

  9. Silver nanoparticles from Prosopis glandulosa and their potential application as biocontrol of Acinetobacter calcoaceticus and Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Ali Abdelmoteleb

    2017-01-01

    Full Text Available In the present study the characterization and properties of silver nanoparticles from Prosopis glandulosa leaf extract (AgNPs were investigated using UV–Vis spectroscopic techniques, energy dispersive X-ray spectrometers (EDS, zeta potential and dynamic light scattering. The UV–Vis spectroscopic analysis showed the absorbance peaked at 487 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had Z-average diameter of 421 nm with higher stability (−200 mV. The EDS analysis also exhibited presentation of silver element. Additionally, the different concentrations of AgNPs (25, 50, 75 and 100 mg/mL showed antibacterial activity against Acinetobacter calcoaceticus and Bacillus cereus. Finally, AgNPs from leaf extracts of P. glandulosa may be used as an agent of biocontrol of microorganism of importance medical. However, further studies will be needed to fully understand the antimicrobial activity of silver nanoparticles obtain from P. glandulosa.

  10. Growth stimulation of Bacillus cereus and Pseudomonas putida using nanostructured ZnO thin film as transducer element

    Energy Technology Data Exchange (ETDEWEB)

    Loukanov, Alexandre, E-mail: loukanov@mail.saitama-u.ac.jp [Saitama University, Department of Chemistry, Faculty of Science (Japan); Filipov, Chavdar [University of Forestry, Department of Infectious pathology, hygiene, technology and control of food stuffs of animal origin, Faculty of Veterinary Medicine (Bulgaria); Valcheva, Violeta [Bulgarian Academy of Science, Department of Infectious Diseases, Institute of microbiology (Bulgaria); Lecheva, Marta [University of Mining and Geology “St. Ivan Rilski”, Laboratory of Engineering NanoBiotechnology, Department of Engineering Geoecology (Bulgaria); Emin, Saim [University of Nova Gorica, Materials Research Laboratory (Slovenia)

    2015-04-15

    The semiconductor zinc oxide nanomaterial (ZnO or ZnO:H) is widely used in advanced biosensor technology for the design of highly-sensitive detector elements for various applications. In the attempt to evaluate its effect on common microorganisms, two types of nanostructured transducer films have been used (average diameter 600–1000 nm). They have been prepared by using both wet sol–gel method and magnetron sputtering. Their polycrystalline structure and specific surface features have been analyzed by X-ray diffraction (XRD), scanning electron microscope, and atomic force microscope. The assessment of growth stimulation of bacteria was determined using epifluorescent microscope by cell staining with Live/Dead BacLight kit. In our experiments, the growth stimulation of Gram-positive and Gram-negative bacteria on nanostructured ZnO film is demonstrated by Bacillus cereus and Pseudomonas putida. These two bacterial species have been selected, because they are well known and studied in biosensor technologies, with structural difference of their cell walls. These pathogens are easy for with common source in the liquid food or some commercial products. Our data has revealed that the method of transducer film preparation influences strongly bacterial inhibition and division. These results present the transforming signal precisely, when ZnO is used in biosensor applications.

  11. Growth stimulation of Bacillus cereus and Pseudomonas putida using nanostructured ZnO thin film as transducer element

    Science.gov (United States)

    Loukanov, Alexandre; Filipov, Chavdar; Valcheva, Violeta; Lecheva, Marta; Emin, Saim

    2015-04-01

    The semiconductor zinc oxide nanomaterial (ZnO or ZnO:H) is widely used in advanced biosensor technology for the design of highly-sensitive detector elements for various applications. In the attempt to evaluate its effect on common microorganisms, two types of nanostructured transducer films have been used (average diameter 600-1000 nm). They have been prepared by using both wet sol-gel method and magnetron sputtering. Their polycrystalline structure and specific surface features have been analyzed by X-ray diffraction (XRD), scanning electron microscope, and atomic force microscope. The assessment of growth stimulation of bacteria was determined using epifluorescent microscope by cell staining with Live/Dead BacLight kit. In our experiments, the growth stimulation of Gram-positive and Gram-negative bacteria on nanostructured ZnO film is demonstrated by Bacillus cereus and Pseudomonas putida. These two bacterial species have been selected, because they are well known and studied in biosensor technologies, with structural difference of their cell walls. These pathogens are easy for with common source in the liquid food or some commercial products. Our data has revealed that the method of transducer film preparation influences strongly bacterial inhibition and division. These results present the transforming signal precisely, when ZnO is used in biosensor applications.

  12. Enhanced Agarose and Xylan Degradation for Production of Polyhydroxyalkanoates by Co-Culture of Marine Bacterium, Saccharophagus degradans and Its Contaminant, Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Shailesh S. Sawant

    2017-02-01

    Full Text Available Over reliance on energy or petroleum products has raised concerns both in regards to the depletion of their associated natural resources as well as their increasing costs. Bioplastics derived from microbes are emerging as promising alternatives to fossil fuel derived petroleum plastics. The development of a simple and eco-friendly strategy for bioplastic production with high productivity and yield, which is produced in a cost effective manner utilising abundantly available renewable carbon sources, would have the potential to result in an inexhaustible global energy source. Here we report the biosynthesis of bioplastic polyhydroxyalkanoates (PHAs in pure cultures of marine bacterium, Saccharophagus degradans 2-40 (Sde 2-40, its contaminant, Bacillus cereus, and a co-culture of these bacteria (Sde 2-40 and B. cereus degrading plant and algae derived complex polysaccharides. Sde 2-40 degraded the complex polysaccharides agarose and xylan as sole carbon sources for biosynthesis of PHAs. The ability of Sde 2-40 to degrade agarose increased after co-culturing with B. cereus. The association of Sde 2-40 with B. cereus resulted in increased cell growth and higher PHA production (34.5% of dry cell weight from xylan as a carbon source in comparison to Sde 2-40 alone (22.7% of dry cell weight. The present study offers an innovative prototype for production of PHA through consolidated bioprocessing of complex carbon sources by pure and co-culture of microorganisms.

  13. Influence of Cooling Rate on Growth of Bacillus cereus from Spore Inocula in Cooked Rice, Beans, Pasta, and Combination Products Containing Meat or Poultry.

    Science.gov (United States)

    Juneja, Vijay K; Mohr, Tim B; Silverman, Meryl; Snyder, O Peter

    2018-02-23

    The objective of this study was to assess the ability of Bacillus cereus spores to germinate and grow in order to determine a safe cooling rate for cooked rice, beans, and pasta, rice-chicken (4:1), rice-chicken-vegetables (3:1:1), rice-beef (4:1), and rice-beef-vegetables (3:1:1). Samples were inoculated with a cocktail of four strains of heat-shocked (80°C for 10 min) B. cereus spores (NCTC 11143, 935A/74, Brad 1, and Mac 1) to obtain a final spore concentration of approximately 2 log CFU/g. Thereafter, samples were exponentially cooled through the temperature range of 54.5 to 7.2°C in 6, 9, 12, 15, 18, and 21 h. At the end of the cooling period, samples were removed and plated on mannitol egg yolk polymyxin agar. The plates were incubated at 30°C for 24 h. The net B. cereus growth from spores in beans was beans, pasta, rice-chicken, rice-chicken-vegetables, rice-beef, and rice-beef-vegetables to guard against the hazards associated with B. cereus.

  14. A Rapid Multiplex Real-Time PCR High-Resolution Melt Curve Assay for the Simultaneous Detection of Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus in Food.

    Science.gov (United States)

    Forghani, Fereidoun; Wei, Shuai; Oh, Deog-Hwan

    2016-05-01

    Three important foodborne pathogens, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus, are of great concern for food safety. They may also coexist in food matrices and, in the case of B. cereus and S. aureus, the resulting illnesses can resemble each other owing to similar symptoms. Therefore, their simultaneous detection may have advantages in terms of cost savings and rapidity. Given this context, a rapid multiplex real-time PCR high-resolution melt curve assay for the simultaneous detection of these three pathogens in food was developed. The assay successfully detected B. cereus (gyrB), L. monocytogenes (hly), and S. aureus (nuc) in a single reaction, and the average melting temperatures were 76.23, 80.19, and 74.01°C, respectively. The application of SYTO9 dye and a slow melt curve analysis ramp rate (0.1°C/s) enabled the production of sharp, high-resolution melt curve peaks that were easily distinguishable from each other. The detection limit in food (milk, rice, and lettuce) was 3.7 × 10(3) CFU/g without an enrichment step and 3.7 × 10(1) CFU/g following the 10-h enrichment. Hence, the assay developed here is specific and sensitive, providing an efficient tool for implementation in food for the simultaneous detection of B. cereus, L. monocytogenes, and S. aureus .

  15. Characterization of Enterotoxigenic Bacillus cereus sensu lato and Staphylococcus aureus Isolates and Associated Enterotoxin Production Dynamics in Milk or Meat-Based Broth.

    Science.gov (United States)

    Walker-York-Moore, Laura; Moore, Sean C; Fox, Edward M

    2017-07-15

    Bacillus cereus sensu lato species, as well as Staphylococcus aureus , are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA , hblA and entFM toxin genes, with lower prevalence of bceT and hlyII . When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log 10 (CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices.

  16. Beneficial effects of bio-controlling agent Bacillus cereus IB311 on the agricultural crop production and its biomass optimization through response surface methodology

    Directory of Open Access Journals (Sweden)

    GOUTAM BANERJEE

    2017-10-01

    Full Text Available ABSTRACT Disease in agricultural field is a big problem that causes a massive loss in production. In this present investigation, we have reported a soil-borne bacterium Bacillus cereus IB311 which is antagonistic to plant pathogens (Pseudomonas syringae and Agrobacterium tumefaciens, and could make a substantial contribution to the prevention of plant diseases. To prove the practical application, the strain was directly applied in agricultural field. The results demonstrated that B. cereus IB311 has increased the production (20% and 26% in term of average pod number per plant, average seed number per pod, and seed yield per experimental plot in ground nut (Arachis hypogaea var. Koushal, G201 and sesame (Sesamum indicum var. Kanak, respectively. To reduce the production cost, the biomass production was optimized through response surface methodology (RSM. Interactions of three variables (glucose, beef extract and inoculum were studied using Central Composite Design. According to our analysis, optimum production of Bacillus cereus IB311 (5.383 µg/ mL may be obtained at glucose 1.985%, beef extract 1.615% and inoculums size 0.757%. Therefore, we strongly believe that the application of this strain in agricultural field as bio-controlling agent will definitely enhance the production yield and will reduce the disease risk.

  17. The Biosynthesis of UDP-d-FucNAc-4N-(2)-oxoglutarate (UDP-Yelosamine) in Bacillus cereus ATCC 14579

    Science.gov (United States)

    Hwang, Soyoun; Li, Zi; Bar-Peled, Yael; Aronov, Avi; Ericson, Jaime; Bar-Peled, Maor

    2014-01-01

    Surface glycan switching is often observed when micro-organisms transition between different biotic and abiotic niches, including biofilms, although the advantages of this switching to the organism are not well understood. Bacillus cereus grown in a biofilm-inducing medium has been shown to synthesize an unusual cell wall polysaccharide composed of the repeating subunit →6)Gal(α1–2)(2-R-hydroxyglutar-5-ylamido)Fuc2NAc4N(α1–6)GlcNAc(β1→, where galactose is linked to the hydroxyglutarate moiety of FucNAc-4-amido-(2)-hydroxyglutarate. The molecular mechanism involved in attaching 2-hydroxyglutarate to 4-amino-FucNAc has not been determined. Here, we show two genes in B. cereus ATCC 14579 encoding enzymes involved in the synthesis of UDP-FucNAc-4-amido-(2)-oxoglutarate (UDP-Yelosamine), a modified UDP-sugar not previously reported to exist. Using mass spectrometry and real time NMR spectroscopy, we show that Bc5273 encodes a C4″-aminotransferase (herein referred to as Pat) that, in the presence of pyridoxal phosphate, transfers the primary amino group of l-Glu to C-4″ of UDP-4-keto-6-deoxy-d-GlcNAc to form UDP-4-amino-FucNAc and 2-oxoglutarate. Pat also converts 4-keto-xylose, 4-keto-glucose, and 4-keto-2-acetamido-altrose to their corresponding UDP-4-amino-sugars. Bc5272 encodes a carboxylate-amine ligase (herein referred as Pyl) that, in the presence of ATP and Mg(II), adds 2-oxoglutarate to the 4-amino moiety of UDP-4-amino-FucNAc to form UDP-Yelosamine and ADP. Pyl is also able to ligate 2-oxoglutarate to other 4-amino-sugar derivatives to form UDP-Yelose, UDP-Solosamine, and UDP-Aravonose. Characterizing the metabolic pathways involved in the formation of modified nucleotide sugars provides a basis for understanding some of the mechanisms used by bacteria to modify or alter their cell surface polysaccharides in response to changing growth and environmental challenges. PMID:25368324

  18. Identification of a Bacillus anthracis specific indel in the yeaC gene and development of a rapid pyrosequencing assay for distinguishing B. anthracis from the B. cereus group.

    Science.gov (United States)

    Ahmod, Nadia Z; Gupta, Radhey S; Shah, Haroun N

    2011-12-01

    Bacillus anthracis, the causative agent of anthrax, is a potential source of bioterrorism. The existing assays for its identification lack specificity due to the close genetic relationship it exhibits to other members of the B. cereus group. Our comparative analyses of protein sequences from Bacillus species have identified a 24 amino acid deletion in a conserved region of the YeaC protein that is uniquely present in B. anthracis. PCR primers based on conserved regions flanking this indel in the Bacillus cereus group of species (viz. Bacillus cereus, B. anthracis, B. thuringiensis, B. mycoides, B. weihenstephnensis and B. pseudomycoides) specifically amplified a 282 bp fragment from all six reference B. anthracis strains, whereas a 354 bp fragment was amplified from 15 other B. cereus group of species/strains. These fragments, due to large size difference, are readily distinguished by means of agarose gel electrophoresis. In contrast to the B. cereus group, no PCR amplification was observed with any of the non-B. cereus group of species/strains. This indel was also used for developing a rapid pyrosequencing assay for the identification of B. anthracis. Its performance was evaluated by examining the presence or absence of this indel in a panel of 81 B. cereus-like isolates from various sources that included 39 B. anthracis strains. Based upon the sequence data from the pyrograms, the yeaC indel was found to be a distinctive characteristic of various B. anthracis strains tested and not found in any other species/strains from these samples. Therefore, this B. anthracis specific indel provides a robust and highly-specific chromosomal marker for the identification of this high-risk pathogen from other members of the B. cereus group independent of a strain's virulence. The pyrosequencing platform also allows for the rapid and simultaneous screening of multiple samples for the presence of this B. anthracis-specific marker. Copyright © 2011. Published by Elsevier B.V.

  19. Characterization of three Bacillus cereus strains involved in a major outbreak of food poisoning after consumption of fermented black beans (Douchi) in Yunan, China.

    Science.gov (United States)

    Zhou, Guoping; Bester, Kai; Liao, Bin; Yang, Zushun; Jiang, Rongrong; Hendriksen, Niels Bohse

    2014-10-01

    Three Bacillus cereus strains isolated from an outbreak of food poisoning caused by the consumption of fermented black beans (douchi) containing B. cereus is described. The outbreak involved 139 persons who had nausea, vomiting, and diarrhea. The strains were isolated from vomit and the unprepared douchi. Two of the strains produced the emetic toxin cereulide, as evidenced by polymerase chain reaction analysis for the presence of the nonribosomal synthetase cluster responsible for the synthesis of cereulide and by chemical analysis by high-performance liquid chromatography-mass spectrometry. These two strains belong to genetic group III of B. cereus, and multiple locus sequence typing revealed that the type was ST26, as a major part of B. cereus emetic strains. One of these strains produced significantly more cereulide at 37°C than the type cereulide producer (F4810/72), and it was also able to produce the toxin at 40°C and 42°C. The third strain belongs to genetic group IV, and it is a new multiple locus sequence type closely related to strains that are cytotoxic and enterotoxigenic. It possesses genes for hemolysin BL, nonhemolytic enterotoxin, and cytotoxin K2; however, it varies from the majority of strains possessing genes for hemolysin BL by not being hemolytic. Thus, two B. cereus strains producing the emetic toxin cereulide and a strain producing enterotoxins might have been involved in this food-poisoning incident caused by the consumption of a natural fermented food. The ability of one of the strains to produce cereulide at ≥37°C makes it possible that it is produced in the human gut in addition to occurring in the food.

  20. Mechanism and site of inhibition of Bacillus cereus spore outgrowth by nitrosothiols

    International Nuclear Information System (INIS)

    Morris, S.L.

    1982-01-01

    Structure vs. activity studies demonstrate that nitrosothiols inhibit outgrowth of B. cereus spores by reversible covalent bond formation with sensitive spore components. Kinetic studies of the binding of nitrosothiols and iodoacetate, a known sulfhydryl reagent, show that they complete for the same spore sites. Since two other nitrite derivatives, the Perigo factor and the transferrin inhibitor, interfere with iodoacetate label uptake in a kinetically similar fashion, all of these compounds may inhibit spore outgrowth by interacting with the same spore thiol groups. Disruption of spores which have been inhibited by radioactive iodoacetate demonstrates that much of the label is incorporated into a membrane-rich fraction that sediments as a single peak on a sucrose density gradient. SDS gel electrophoresis and autofluorography allows the identification of four intensely labelled proteins with molecular weights of 13,000, 28,000, 29,000, and 30,000. If the iodoacetate labelling is carried out in the presence of nitrosothiol, incorporation is greatly reduced into all components. When germinating spores are labelled with succinate or the lactose analog, o-nitrophenylgalactopyranoside, a significant reduction in the amount of label bound is also observed suggesting that two iodoacetate-reactive sites may be the succinate and lactose permease systems. Severe decreases in the transport of succinate and lactose into iodoacetate and nitrosothiol inhibited spores further implicates a nitrosothiol (iodoacetate) permease interaction. Iodoacetate and nitrosothiols therefore may exert their inhibitory effects by interfering with critical membrane protein sulfhydryl groups, possibly by a a covalent modification mechanism. Some of these sensitive thiols may be involved in active transport processes

  1. Germination inhibition of Bacillus cereus spores: impact of the lipophilic character of inhibiting compounds.

    Science.gov (United States)

    van Melis, C C J; Almeida, C Bravo; Kort, R; Groot, M N Nierop; Abee, T

    2012-11-15

    In this study, the impact of a range of organic acids and structurally similar alcohols with three to six carbon backbones and increasing lipophilic character, were tested on the germination behavior of B. cereus ATCC 14579 spores. This approach allowed substantiating whether the effectivity of the various compounds was largely dictated by membrane interference or a classic weak acid acidification effect. The octanol-water partition coefficient (log P(oct/water)) ranges from 0.25/0.33 to 2.03/1.96 for propanol/undissociated propionic acid and hexanol/undissociated hexanoic acid, respectively. Performance of germination assays at neutral (pH7) and acidic conditions (pH5.5) allowed for a comparative analysis of the action of dissociated versus undissociated acids, and the presumed pH-independent effect of the corresponding alcohols. Germination assays, based on both continuously measured optical density and time-based plating experiments, and microscopic observations demonstrated the correlation between the lipophilic character of the selected compounds and their inhibiting effect on spore germination. Real-time fluorescence based assays showed that membrane integrity in dormant spores was maintained in the presence of the tested inhibitors. Lowering the critical concentration of inhibitors by a one-step washing procedure resulted in the onset of nutrient-induced germination, indicating the reversible nature of the inhibition process. Furthermore, blocking of nutrient-induced germination in the presence of inhibitory concentrations of selected lipophilic acids and corresponding alcohols was by-passed upon addition of Ca-dipicolinic acid, pointing to loss of signaling capacity in germinant receptor-mediated germination activity. These findings show that lipophilicity is an important determinant for the ability of the selected acids and corresponding alcohols to accumulate in the spore inner membrane and their ability to act as a germination-inhibitor. Copyright

  2. Termitarium-inhabiting Bacillus endophyticus TSH42 and Bacillus cereus TSH77 colonizing Curcuma longa L.: isolation, characterization, and evaluation of their biocontrol and plant-growth-promoting activities.

    Science.gov (United States)

    Chauhan, Ankit Kumar; Maheshwari, Dinesh Kumar; Kim, Kangmin; Bajpai, Vivek K

    2016-10-01

    Bacillus strains were isolated from termitarium soil and screened for their antifungal activity through the production of diffusible and volatile metabolites. Further, the bacterial strains that showed antifungal activity were evaluated for their biocontrol potential on the basis of their plant-growth-promoting attributes. Termitarium-inhabiting Bacillus strains TSH42 and TSH77 significantly reduced the growth of pathogenic fungus Fusarium solani, controlled the symptoms of rhizome rot in turmeric (Curcuma longa L.), and demonstrated various plant-growth-promoting traits in different in vitro assays. On the basis of morphological, physiological, biochemical, and 16S rDNA characteristics, isolates TSH42 and TSH77 were identified as Bacillus endophyticus (KT379993) and Bacillus cereus (KT379994), respectively. Through liquid chromatography - mass spectrometry analysis, acidified cell-free culture filtrate (CFCF) of B. cereus TSH77 was shown to contain surfactin and fengycin, while CFCF of B. endophyticus TSH42 contained iturin in addition to surfactin and fengycin. Treatment of the turmeric (C. longa L.) plants with TSH42 and TSH77 significantly reduced the percentage incidence of rhizome rot disease caused by F. solani. The same treatment also increased the fresh rhizome biomass and plant growth in greenhouse conditions.

  3. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Directory of Open Access Journals (Sweden)

    Yi-Ru Lai

    2016-10-01

    Full Text Available Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

  4. Global overview of the risk linked to the Bacillus cereus group in the egg product industry: identification of food safety and food spoilage markers.

    Science.gov (United States)

    Techer, C; Baron, F; Delbrassinne, L; Belaïd, R; Brunet, N; Gillard, A; Gonnet, F; Cochet, M-F; Grosset, N; Gautier, M; Andjelkovic, M; Lechevalier, V; Jan, S

    2014-05-01

    To evaluate the food safety and spoilage risks associated with psychrotrophic Bacillus cereus group bacteria for the egg product industry and to search for relevant risk markers. A collection of 68 psychrotrophic B. cereus group isolates, coming from pasteurized liquid whole egg products, was analysed through a principal component analysis (PCA) regarding their spoilage and food safety risk potentials. The principal component analysis showed a clear differentiation between two groups within the collection, one half of the isolates representing a safety risk and the other half a spoilage risk. Relevant risk markers were highlighted by PCA, that is (i) for the food safety risk, the presence of the specific 16S rDNA-1m genetic signature and the ability to grow at 43°C on solid medium and (ii) for the spoilage risk, the presence of the cspA genetic signature. This work represents a first step in the development of new diagnostic technologies for the assessment of the microbiological quality of foods likely to be contaminated with psychrotrophic B. cereus group bacteria. © 2014 The Society for Applied Microbiology.

  5. SecDF as part of the Sec-translocase facilitates efficient secretion of Bacillus cereus toxins and cell wall-associated proteins.

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    Aniko Vörös

    Full Text Available The aim of this study was to explore the role of SecDF in protein secretion in Bacillus cereus ATCC 14579 by in-depth characterization of a markerless secDF knock out mutant. Deletion of secDF resulted in pleiotropic effects characterized by a moderately slower growth rate, aberrant cell morphology, enhanced susceptibility to xenobiotics, reduced virulence and motility. Most toxins, including food poisoning-associated enterotoxins Nhe, Hbl, and cytotoxin K, as well as phospholipase C were less abundant in the secretome of the ΔsecDF mutant as determined by label-free mass spectrometry. Global transcriptome studies revealed profound transcriptional changes upon deletion of secDF indicating cell envelope stress. Interestingly, the addition of glucose enhanced the described phenotypes. This study shows that SecDF is an important part of the Sec-translocase mediating efficient secretion of virulence factors in the Gram-positive opportunistic pathogen B. cereus, and further supports the notion that B. cereus enterotoxins are secreted by the Sec-system.

  6. Genome Sequence ofBacillus cereusFORC_021, a Food-Borne Pathogen Isolated from a Knife at a Sashimi Restaurant.

    Science.gov (United States)

    Chung, Han Young; Lee, Kyu-Ho; Ryu, Sangryeol; Yoon, Hyunjin; Lee, Ju-Hoon; Kim, Hyeun Bum; Kim, Heebal; Jeong, Hee Gon; Choi, Sang Ho; Kim, Bong-Soo

    2016-12-28

    Bacillus cereus causes food-borne illness through contaminated foods; therefore, its pathogenicity and genome sequences have been analyzed in several studies. We sequenced and analyzed B. cereus strain FORC_021 isolated from a sashimi restaurant. The genome sequence consists of 5,373,294 bp with 35.36% GC contents, 5,350 predicted CDSs, 42 rRNA genes, and 107 tRNA genes. Based on in silico DNA-DNA hybridization values, B. cereus ATCC 14579 T was closest to FORC_021 among the complete genome-sequenced strains. Three major enterotoxins were detected in FORC_021. Comparative genomic analysis of FORC_021 with ATCC 14579 T revealed that FORC_021 harbored an additional genomic region encoding virulence factors, such as putative ADP-ribosylating toxin, spore germination protein, internalin, and sortase. Furthermore, in vitro cytotoxicity testing showed that FORC_021 exhibited a high level of cytotoxicity toward INT-407 human epithelial cells. This genomic information of FORC_021 will help us to understand its pathogenesis and assist in managing food contamination.

  7. Bacillus cereus ATCC 14579 RpoN (Sigma 54) Is a Pleiotropic Regulator of Growth, Carbohydrate Metabolism, Motility, Biofilm Formation and Toxin Production.

    Science.gov (United States)

    Hayrapetyan, Hasmik; Tempelaars, Marcel; Nierop Groot, Masja; Abee, Tjakko

    2015-01-01

    Sigma 54 is a transcriptional regulator predicted to play a role in physical interaction of bacteria with their environment, including virulence and biofilm formation. In order to study the role of Sigma 54 in Bacillus cereus, a comparative transcriptome and phenotypic study was performed using B. cereus ATCC 14579 WT, a markerless rpoN deletion mutant, and its complemented strain. The mutant was impaired in many different cellular functions including low temperature and anaerobic growth, carbohydrate metabolism, sporulation and toxin production. Additionally, the mutant showed lack of motility and biofilm formation at air-liquid interphase, and this correlated with absence of flagella, as flagella staining showed only WT and complemented strain to be highly flagellated. Comparative transcriptome analysis of cells harvested at selected time points during growth in aerated and static conditions in BHI revealed large differences in gene expression associated with loss of phenotypes, including significant down regulation of genes in the mutant encoding enzymes involved in degradation of branched chain amino acids, carbohydrate transport and metabolism, flagella synthesis and virulence factors. Our study provides evidence for a pleiotropic role of Sigma 54 in B. cereus supporting its adaptive response and survival in a range of conditions and environments.

  8. Role Played by Exosporium Glycoproteins in the Surface Properties of Bacillus cereus Spores and in Their Adhesion to Stainless Steel ▿

    Science.gov (United States)

    Lequette, Yannick; Garénaux, Estelle; Tauveron, Grégoire; Dumez, Sylvain; Perchat, Stéphane; Slomianny, Christian; Lereclus, Didier; Guérardel, Yann; Faille, Christine

    2011-01-01

    Bacillus cereus spores are surrounded by a loose-fitting layer called the exosporium, whose distal part is mainly formed from glycoproteins. The role played by the exosporium glycoproteins of B. cereus ATCC 14579 (BclA and ExsH) was investigated by considering hydrophobicity and charge, as well as the properties of spore adhesion to stainless steel. The absence of BclA increased both the isoelectric point (IEP) and hydrophobicity of whole spores while simultaneously reducing the interaction between spores and stainless steel. However, neither the hydrophobicity nor the charge associated with BclA could explain the differences in the adhesion properties. Conversely, ExsH, another exosporium glycoprotein, did not play a significant role in spore surface properties. The monosaccharide analysis of B. cereus ATCC 14579 showed different glycosylation patterns on ExsH and BclA. Moreover, two specific glycosyl residues, namely, 2-O-methyl-rhamnose (2-Me-Rha) and 2,4-O-methyl-rhamnose (2,4-Me-Rha), were attached to BclA, in addition to the glycosyl residues already reported in B. anthracis. PMID:21622795

  9. SecDF as part of the Sec-translocase facilitates efficient secretion of Bacillus cereus toxins and cell wall-associated proteins.

    Science.gov (United States)

    Vörös, Aniko; Simm, Roger; Slamti, Leyla; McKay, Matthew J; Hegna, Ida K; Nielsen-LeRoux, Christina; Hassan, Karl A; Paulsen, Ian T; Lereclus, Didier; Økstad, Ole Andreas; Molloy, Mark P; Kolstø, Anne-Brit

    2014-01-01

    The aim of this study was to explore the role of SecDF in protein secretion in Bacillus cereus ATCC 14579 by in-depth characterization of a markerless secDF knock out mutant. Deletion of secDF resulted in pleiotropic effects characterized by a moderately slower growth rate, aberrant cell morphology, enhanced susceptibility to xenobiotics, reduced virulence and motility. Most toxins, including food poisoning-associated enterotoxins Nhe, Hbl, and cytotoxin K, as well as phospholipase C were less abundant in the secretome of the ΔsecDF mutant as determined by label-free mass spectrometry. Global transcriptome studies revealed profound transcriptional changes upon deletion of secDF indicating cell envelope stress. Interestingly, the addition of glucose enhanced the described phenotypes. This study shows that SecDF is an important part of the Sec-translocase mediating efficient secretion of virulence factors in the Gram-positive opportunistic pathogen B. cereus, and further supports the notion that B. cereus enterotoxins are secreted by the Sec-system.

  10. Bacillus cereus ATCC 14579 RpoN (Sigma 54 Is a Pleiotropic Regulator of Growth, Carbohydrate Metabolism, Motility, Biofilm Formation and Toxin Production.

    Directory of Open Access Journals (Sweden)

    Hasmik Hayrapetyan

    Full Text Available Sigma 54 is a transcriptional regulator predicted to play a role in physical interaction of bacteria with their environment, including virulence and biofilm formation. In order to study the role of Sigma 54 in Bacillus cereus, a comparative transcriptome and phenotypic study was performed using B. cereus ATCC 14579 WT, a markerless rpoN deletion mutant, and its complemented strain. The mutant was impaired in many different cellular functions including low temperature and anaerobic growth, carbohydrate metabolism, sporulation and toxin production. Additionally, the mutant showed lack of motility and biofilm formation at air-liquid interphase, and this correlated with absence of flagella, as flagella staining showed only WT and complemented strain to be highly flagellated. Comparative transcriptome analysis of cells harvested at selected time points during growth in aerated and static conditions in BHI revealed large differences in gene expression associated with loss of phenotypes, including significant down regulation of genes in the mutant encoding enzymes involved in degradation of branched chain amino acids, carbohydrate transport and metabolism, flagella synthesis and virulence factors. Our study provides evidence for a pleiotropic role of Sigma 54 in B. cereus supporting its adaptive response and survival in a range of conditions and environments.

  11. Screening of freeze-dried protective agents for the formulation of biocontrol strains, Bacillus cereus AR156, Burkholderia vietnamiensis B418 and Pantoea agglomerans 2Re40.

    Science.gov (United States)

    Zhan, Y; Xu, Q; Yang, M-M; Yang, H-T; Liu, H-X; Wang, Y-P; Guo, J-H

    2012-01-01

    The effects of different freeze-drying protective agents on the viabilities of biocontrol strains Bacillus cereus AR156, Burkholderia vietnamiensis B418 and Pantoea agglomerans 2Re40 were investigated. Several concentrations of protective and rehydration media were tested to improve the survival of biocontrol agents after freeze-drying. The subsequent survival rates during storage and rehydration media of freeze-dried biocontrol strains were also examined. The results indicated that cellobiose (5%) and d-galactose (5%) gave maximum viability of strains Bu. vietnamiensis B418 and P. agglomerans 2Re40 (98 and 54·3% respectively) while the perfect one (100%) of strain B. cereus AR156 was obtained with sucrose (5%) during freeze-drying, and the highest survival of the three strains was reached when they were rehydrated with 10% nonfat skim milk. In the following storage, the survival rates showed that B. cereus AR156 could still reach 50% after 12 months. This study showed that freeze-drying could be used to stabilize cells of these three biocontrol strains. Further studies should focus on the scale-up possibilities and formulation development. © Nanjing Agricultural University. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  12. Analysis of Germination Capacity and Germinant Receptor (Sub)clusters of Genome-Sequenced Bacillus cereus Environmental Isolates and Model Strains.

    Science.gov (United States)

    Warda, Alicja K; Xiao, Yinghua; Boekhorst, Jos; Wells-Bennik, Marjon H J; Nierop Groot, Masja N; Abee, Tjakko

    2017-02-15

    Spore germination of 17 Bacillus cereus food isolates and reference strains was evaluated using flow cytometry analysis in combination with fluorescent staining at a single-spore level. This approach allowed for rapid collection of germination data under more than 20 conditions, including heat activation of spores, germination in complex media (brain heart infusion [BHI] and tryptone soy broth [TSB]), and exposure to saturating concentrations of single amino acids and the combination of alanine and inosine. Whole-genome sequence comparison revealed a total of 11 clusters of operons encoding germinant receptors (GRs): GerK, GerI, and GerL were present in all strains, whereas GerR, GerS, GerG, GerQ, GerX, GerF, GerW, and GerZ (sub)clusters showed a more diverse presence/absence in different strains. The spores of tested strains displayed high diversity with regard to their sensitivity and responsiveness to selected germinants and heat activation. The two laboratory strains, B. cereus ATCC 14579 and ATCC 10987, and 11 food isolates showed a good germination response under a range of conditions, whereas four other strains (B. cereus B4085, B4086, B4116, and B4153) belonging to phylogenetic group IIIA showed a very weak germination response even in BHI and TSB media. Germination responses could not be linked to specific (combinations of) GRs, but it was noted that the four group IIIA strains contained pseudogenes or variants of subunit C in their gerL cluster. Additionally, two of those strains (B4086 and B4153) carried pseudogenes in the gerK and gerR I (sub)clusters that possibly affected the functionality of these GRs. Germination of bacterial spores is a critical step before vegetative growth can resume. Food products may contain nutrient germinants that trigger germination and outgrowth of Bacillus species spores, possibly leading to food spoilage or foodborne illness. Prediction of spore germination behavior is, however, very challenging, especially for spores of

  13. Accurate localization of the integration sites of two genomic islands at single-nucleotide resolution in the genome of Bacillus cereus ATCC 10987.

    Science.gov (United States)

    Zhang, Ren; Zhang, Chun-Ting

    2008-01-01

    We have identified two genomic islands, that is, BCEGI-1 and BCEGI-2, in the genome of Bacillus cereus ATCC 10987, based on comparative analysis with Bacillus cereus ATCC 14579. Furthermore, by using the cumulative GC profile and performing homology searches between the two genomes, the integration sites of the two genomic islands were determined at single-nucleotide resolution. BCEGI-1 is integrated between 159705 bp and 198000 bp, whereas BCEGI-2 is integrated between the end of ORF BCE4594 and the start of the intergenic sequence immediately following BCE4626, that is, from 4256803 bp to 4285534 bp. BCEGI-1 harbors two bacterial Tn7 transposons, which have two sets of genes encoding TnsA, B, C, and D. It is generally believed that unlike the TnsABC+E pathway, the TnsABC+D pathway would only promote vertical transmission to daughter cells. The evidence presented in this paper, however, suggests a role of the TnsABC+D pathway in the horizontal transfer of some genomic islands.

  14. Accurate Localization of the Integration Sites of Two Genomic Islands at Single-Nucleotide Resolution in the Genome of Bacillus cereus ATCC 10987

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    Ren Zhang

    2008-01-01

    Full Text Available We have identified two genomic islands, that is, BCEGI-1 and BCEGI-2, in the genome of Bacillus cereus ATCC 10987, based on comparative analysis with Bacillus cereus ATCC 14579. Furthermore, by using the cumulative GC profile and performing homology searches between the two genomes, the integration sites of the two genomic islands were determined at single-nucleotide resolution. BCEGI-1 is integrated between 159705 bp and 198000 bp, whereas BCEGI-2 is integrated between the end of ORF BCE4594 and the start of the intergenic sequence immediately following BCE4626, that is, from 4256803 bp to 4285534 bp. BCEGI-1 harbors two bacterial Tn7 transposons, which have two sets of genes encoding TnsA, B, C, and D. It is generally believed that unlike the TnsABC+E pathway, the TnsABC+D pathway would only promote vertical transmission to daughter cells. The evidence presented in this paper, however, suggests a role of the TnsABC+D pathway in the horizontal transfer of some genomic islands.

  15. Partial characterization of bacteriocin-like compounds from two strains of Bacillus cereus with biological activity against Paenibacillus larvae, the causal agent of American Foulbrood disease.

    Science.gov (United States)

    Minnaard, J; Alippi, A M

    2016-12-01

    American Foulbrood (AFB), caused by the spore-forming Gram-positive bacterium Paenibacillus larvae, is the most severe bacterial disease affecting honeybees worldwide. Two bacterial isolates showing specific inhibitory activity against P. larvae were identified as Bacillus cereus by 16S rDNA sequencing. Antagonistic compounds were obtained from cell-free supernatants of strains m6c and m387 growing on Trypticase Soy Broth and concentrated by NH 4 SO 4 precipitation, ultrafiltration and butanol extraction. Both compounds were characterized as bacteriocin-like inhibitory substances (BLIS). BLISm6c and BLISm387 were stable at 70°C for 30 min and active in the pH range from 3 to 7. The antibacterial activity was completely lost at pH values higher than 8 or temperatures >80°C. Both BLIS have a narrow activity range and highly inhibit the growth of P. larvae. BLISm6c and BLISm387 differ from each other and other BLIS reportedly produced by B. cereus with regard to their molecular weights, antibacterial activity, minimal inhibitory concentration values and sensitivity to degradative enzymes. The findings of this study suggest that BLISm6c and BLISm387 can potentially be used to control AFB. An Integrated Pest Management (IPM) approach is needed to ensure the sustainability of the beekeeping industry due to the increasing demand for organic honey and the reduction of dependence on antibiotics. Biocontrol agents produced by bacteria isolated from apiarian sources seem promising and able to combine with an IPM strategy. The most significant findings of this study are the characterization of bacteriocin-like compounds (BLIS) obtained from two strains of Bacillus cereus isolated from honey. Both BLIS have a narrow activity range and highly inhibit the growth of Paenibacillus larvae, the causal agent of American Foulbrood disease of honey bees. © 2016 The Society for Applied Microbiology.

  16. Insertional inactivation of hblC encoding the L2 component of Bacillus cereus ATCC 14579 haemolysin BL strongly reduces enterotoxigenic activity, but not the haemolytic activity against human erythrocytes.

    Science.gov (United States)

    Lindbäck, T; Okstad, O A; Rishovd, A L; Kolstø, A B

    1999-11-01

    Haemolysin BL (HBL) is a Bacillus cereus toxin composed of a binding component, B, and two lytic components, L1 and L2. HBL is also the enterotoxin responsible for the diarrhoeal food poisoning syndrome caused by several strains of B. cereus. The three genes encoding the HBL components constitute an operon and are transcribed from a promoter 608 bp upstream of the hblC translational start site. The first gene of the hbl operon, hblC, in the B. cereus type strain, ATCC 14579, was inactivated in this study. Inactivation of hblC strongly reduced both the enterotoxigenic activity of B. cereus ATCC 14579 and the haemolytic activity against sheep erythrocytes, while maintaining full haemolytic activity against human erythrocytes.

  17. Crystal structures of two transcriptional regulators from Bacillus cereus define the conserved structural features of a PadR subfamily.

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    Guntur Fibriansah

    Full Text Available PadR-like transcriptional regulators form a structurally-related family of proteins that control the expression of genes associated with detoxification, virulence and multi-drug resistance in bacteria. Only a few members of this family have been studied by genetic, biochemical and biophysical methods, and their structure/function relationships are still largely undefined. Here, we report the crystal structures of two PadR-like proteins from Bacillus cereus, which we named bcPadR1 and bcPadR2 (products of gene loci BC4206 and BCE3449 in strains ATCC 14579 and ATCC 10987, respectively. BC4206, together with its neighboring gene BC4207, was previously shown to become significantly upregulated in presence of the bacteriocin AS-48. DNA mobility shift assays reveal that bcPadR1 binds to a 250 bp intergenic region containing the putative BC4206-BC4207 promoter sequence, while in-situ expression of bcPadR1 decreases bacteriocin tolerance, together suggesting a role for bcPadR1 as repressor of BC4206-BC4207 transcription. The function of bcPadR2 (48% identical in sequence to bcPadR1 is unknown, but the location of its gene just upstream from genes encoding a putative antibiotic ABC efflux pump, suggests a role in regulating antibiotic resistance. The bcPadR proteins are structurally similar to LmrR, a PadR-like transcription regulator in Lactococcus lactis that controls expression of a multidrug ABC transporter via a mechanism of multidrug binding and induction. Together these proteins define a subfamily of conserved, relatively small PadR proteins characterized by a single C-terminal helix for dimerization. Unlike LmrR, bcPadR1 and bcPadR2 lack a central pore for ligand binding, making it unclear whether the transcriptional regulatory roles of bcPadR1 and bcPadR2 involve direct ligand recognition and induction.

  18. The CodY-dependent clhAB2 operon is involved in cell shape, chaining and autolysis in Bacillus cereus ATCC 14579.

    Science.gov (United States)

    Huillet, Eugénie; Bridoux, Ludovic; Wanapaisan, Pagakrong; Rejasse, Agnès; Peng, Qi; Panbangred, Watanalai; Lereclus, Didier

    2017-01-01

    The Gram-positive pathogen Bacillus cereus is able to grow in chains of rod-shaped cells, but the regulation of chaining remains largely unknown. Here, we observe that glucose-grown cells of B. cereus ATCC 14579 form longer chains than those grown in the absence of glucose during the late exponential and transition growth phases, and identify that the clhAB2 operon is required for this chain lengthening phenotype. The clhAB2 operon is specific to the B. cereus group (i.e., B. thuringiensis, B. anthracis and B. cereus) and encodes two membrane proteins of unknown function, which are homologous to the Staphylococcus aureus CidA and CidB proteins involved in cell death control within glucose-grown cells. A deletion mutant (ΔclhAB2) was constructed and our quantitative image analyses show that ΔclhAB2 cells formed abnormal short chains regardless of the presence of glucose. We also found that glucose-grown cells of ΔclhAB2 were significantly wider than wild-type cells (1.47 μm ±CI95% 0.04 vs 1.19 μm ±CI95% 0.03, respectively), suggesting an alteration of the bacterial cell wall. Remarkably, ΔclhAB2 cells showed accelerated autolysis under autolysis-inducing conditions, compared to wild-type cells. Overall, our data suggest that the B. cereus clhAB2 operon modulates peptidoglycan hydrolase activity, which is required for proper cell shape and chain length during cell growth, and down-regulates autolysin activity. Lastly, we studied the transcription of clhAB2 using a lacZ transcriptional reporter in wild-type, ccpA and codY deletion-mutant strains. We found that the global transcriptional regulatory protein CodY is required for the basal level of clhAB2 expression under all conditions tested, including the transition growth phase while CcpA, the major global carbon regulator, is needed for the high-level expression of clhAB2 in glucose-grown cells.

  19. Characteristics of enterotoxin distribution, hemolysis, lecithinase, and starch hydrolysis of Bacillus cereus isolated from infant formulas and ready-to-eat foods.

    Science.gov (United States)

    Hwang, Ji-Yeon; Park, Jong-Hyun

    2015-03-01

    Bacillus cereus is a ubiquitous environmental microbe implicated as a main cause of food poisoning with various symptoms, depending on the strain type and the isolation source. In this study, the potential virulence factors and biochemical properties of B. cereus isolated from infant formulas and ready-to-eat (RTE) foods were analyzed and compared. A total of 347 B. cereus strains were isolated and identified from 687 infant food formulas and RTE food samples. All the isolates had one or more enterotoxin genes, and one-half of the strains had all 3 enterotoxin genes (hbl, nhe, and cytK) that are involved in food poisoning in humans. Here, all the 3 genes were detected in 50% of the B. cereus isolates from RTE foods and only 14% of the isolates were identified from infant formulas. The latter harbored low cytK and bceT, and very low hbl genes. Most B. cereus isolates possessed the hemolysis gene, but not the ces gene. The infant formula isolates showed stronger hemolysis activity than the other isolates. In addition, 26% of the total isolates showed low lecithinase activities and 10% showed high lecithinase activities. A greater number of isolates from the infant formula showed high lecithinase activity than those from the RTE foods. Approximately 83% of the isolates were positive and 17% were negative for starch hydrolysis. Over 90% of the RTE food isolates and only 35% of the infant formula isolates were positive for starch hydrolysis. However, all the strains possessed nhe, but their harboring patterns of hbl and cytK were significantly different. Most starch-hydrolyzing strains possessed hbl, but only 23% nonstarch-hydrolyzing isolates possessed this gene. Moreover, very low nonstarch hydrolyzing strains harbored cytK. Most nonstarch-hydrolyzing isolates showed high lecithinase and strong hemolysis activities, and very low hbl and cytK harboring. In summary, most infant formula isolates showed stronger hemolysis and higher lecithinase activities with lower

  20. Immunomodulatory effect of non-viable components of probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus on holoxenic mice

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    L. M. Ditu

    2014-09-01

    Full Text Available Background: Competition of probiotic bacteria with other species from the intestinal microbiota involves different mechanisms that occur regardless of probiotics’ viability. The objective of this paper was to assess the cytokine serum levels in holoxenic mice after oral administration of non-viable components (NVC of Enterococcus faecium probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus in comparison to NVC of unstimulated E. faecium probiotic culture. Methods: Probiotic E. faecium CMGb 16 culture, grown in the presence of heat-inactivated cultures of E. coli and B. cereus CMGB 102, was subsequently separated into supernatant (SN and heat-inactivated cellular sediment (CS fractions by centrifugation. Each NVC was orally administered to holoxenic mice (balb C mouse strain, in three doses, given at 24 hours. Blood samples were collected from the retinal artery, at 7, 14, and 21 days after the first administration of the NVC. The serum concentrations of IL-12 and tumor necrosis factor-alpha (TNF-α interleukins were assessed by ELISA method. Results: After the oral administration of SN component obtained from the probiotic culture stimulated with heat-inactivated cultures of B. cereus CMGB 102 and E. coli O28, the serum concentrations of IL-12 were maintained higher in the samples collected at 7 and 14 days post-administration. No specific TNF-α profile could be established, depending on stimulated or non-stimulated probiotic culture, NVC fraction, or harvesting time. Conclusion: The obtained results demonstrate that non-viable fractions of probiotic bacteria, stimulated by other bacterial species, could induce immunostimulatory effects mediated by cytokines and act, therefore, as immunological adjuvants.

  1. Implementation of the Bacillus cereus microbiological plate used for the screening of tetracyclines in raw milk samples with STAR protocol - the problem with false-negative results solved.

    Science.gov (United States)

    Raspor Lainšček, P; Biasizzo, M; Henigman, U; Dolenc, J; Kirbiš, A

    2014-01-01

    In antibiotic residue analyses the first step of screening is just as important as the following steps. Screening methods need to be quick and inexpensive, but above all sensitive enough to detect the antibiotic residue at or below the maximum residue limit (MRL). In the case of a positive result, the next step is conducted and further methods are used for confirmation. MRLs stated in European Union Regulation 37/2010 for tetracyclines in raw milk are: 100 µg kg(-1) for tetracycline, 100 µg kg(-1) for oxytetracycline, 100 µg kg(-1) for chlortetracycline and no limit for doxycycline because it is prohibited for use in animals from which milk is produced for human consumption. The current five-plate microbiological screening method for the detection of antibiotic residues in raw milk was found to be simple and inexpensive, but not specific, sensitive and reliable enough to detect tetracycline at MRL in routine raw milk screening procedures. Spiking samples with tetracycline at the MRL level and applying them on Bacillus cereus ATCC 11778 microbiological plates often gave false-negative results, indicating that tetracyclines may have to be inactivated or masked. Tetracyclines seem to bind to a certain component in milk. Consequently, when applying samples to the B. cereus microbiological plate the antibiotic cannot inhibit the growth of B. cereus which disables the formation of inhibition zones on the test plate. After adding the appropriate amount of citric acid into the milk samples, we solved the problem of false-negative results. During the validation 79 samples of milk were spiked with tetracyclines at different concentrations: 100 µg kg(-1) for tetracycline, 100 µg kg(-1) for oxytetracycline, 80 µg kg(-1) for chlortetracycline and 30 µg kg(-1) for doxycycline. Concentrations used in the validation matched the requirements for MRLs (they were either at or below the MRLs) stated in European Union Regulation 37/2010. The sensitivity of the validation was 100%.

  2. Involvement of the CasK/R two-component system in optimal unsaturation of the Bacillus cereus fatty acids during low-temperature growth.

    Science.gov (United States)

    Diomandé, Sara Esther; Nguyen-the, Christophe; Abee, Tjakko; Tempelaars, Marcel H; Broussolle, Véronique; Brillard, Julien

    2015-11-20

    Bacillus cereus sensu lato is composed of a set of ubiquitous strains including human pathogens that can survive a range of food processing conditions, grow in refrigerated food, and sometimes cause food poisoning. We previously identified the two-component system CasK/R that plays a key role in cold adaptation. To better understand the CasK/R-controlled mechanisms that support low-temperature adaptation, we performed a transcriptomic analysis on the ATCC 14579 strain and its isogenic ∆casK/R mutant grown at 12°C. Several genes involved in fatty acid (FA) metabolism were downregulated in the mutant, including desA and desB encoding FA acyl-lipid desaturases that catalyze the formation of a double-bond on the FA chain in positions ∆5 and ∆10, respectively. A lower proportion of FAs presumably unsaturated by DesA was observed in the ΔcasK/R strain compared to the parental strain while no difference was found for FAs presumably unsaturated by DesB. Addition of phospholipids from egg yolk lecithin rich in unsaturated FAs, to growth medium, abolished the cold-growth impairment of ΔcasK/R suggesting that exogenous unsaturated FAs can support membrane-level modifications and thus compensate for the decreased production of these FAs in the B. cereus ∆casK/R mutant during growth at low temperature. Our findings indicate that CasK/R is involved in the regulation of FA metabolism, and is necessary for cold adaptation of B. cereus unless an exogenous source of unsaturated FAs is available. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Sporulation Temperature Reveals a Requirement for CotE in the Assembly of both the Coat and Exosporium Layers of Bacillus cereus Spores.

    Science.gov (United States)

    Bressuire-Isoard, Christelle; Bornard, Isabelle; Henriques, Adriano O; Carlin, Frédéric; Broussolle, Véronique

    2016-01-01

    The Bacillus cereus spore surface layers consist of a coat surrounded by an exosporium. We investigated the interplay between the sporulation temperature and the CotE morphogenetic protein in the assembly of the surface layers of B. cereus ATCC 14579 spores and on the resulting spore properties. The cotE deletion affects the coat and exosporium composition of the spores formed both at the suboptimal temperature of 20°C and at the optimal growth temperature of 37°C. Transmission electron microscopy revealed that ΔcotE spores had a fragmented and detached exosporium when formed at 37°C. However, when produced at 20°C, ΔcotE spores showed defects in both coat and exosporium attachment and were susceptible to lysozyme and mutanolysin. Thus, CotE has a role in the assembly of both the coat and exosporium, which is more important during sporulation at 20°C. CotE was more represented in extracts from spores formed at 20°C than at 37°C, suggesting that increased synthesis of the protein is required to maintain proper assembly of spore surface layers at the former temperature. ΔcotE spores formed at either sporulation temperature were impaired in inosine-triggered germination and resistance to UV-C and H2O2 and were less hydrophobic than wild-type (WT) spores but had a higher resistance to wet heat. While underscoring the role of CotE in the assembly of B. cereus spore surface layers, our study also suggests a contribution of the protein to functional properties of additional spore structures. Moreover, it also suggests a complex relationship between the function of a spore morphogenetic protein and environmental factors such as the temperature during spore formation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. glucanase from Bacillus cereus

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2011-11-16

    Nov 16, 2011 ... to 8.0), borax-NaOH (pH 9.0), NaHCO3-NaOH (pH 10.0) and Na2HPO4-NaOH solution (pH. 11.0 to 12.0). The highest enzyme activity in various pH buffers was taken as 100%. Figure 4. Effect of pH on the stability of purified CMCase. The enzyme was incubated in 0.02. M buffer for 1 h at 30°C prior to ...

  5. Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase (PDF) from Bacillus cereus in ligand-free and actinonin-bound forms

    International Nuclear Information System (INIS)

    Park, Joon Kyu; Moon, Jin Ho; Kim, Jae-Hong; Kim, Eunice EunKyeong

    2004-01-01

    Peptide deformylase (PDF) from B. cereus has been overexpressed, purified and crystallized in ligand-free and actinonin-bound forms. Diffraction data have been collected from these crystals to 1.7 and 2.0 Å resolution, respectively. In bacteria, protein expression initiates with an N-formyl group and this needs to be removed in order to ensure proper bacterial growth. These formylation and deformylation processes are unique to eubacteria; therefore, inhibition of these would provide a novel antibacterial therapy. Deformylation is carried out by peptide deformylase (PDF). PDF from Bacillus cereus, one of the major pathogenic bacteria, was cloned into expression plasmid pET-28a (Novagen), overexpressed in Escherichia coli BL21 (DE3) and purified to high quality. Crystals have been obtained of both ligand-free PDF and PDF to which actinonin, a highly potent naturally occurring inhibitor, is bound. Both crystals belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 42.72, b = 44.04, c = 85.19 Å and a = 41.31, b = 44.56, c = 84.47 Å, respectively. Diffraction data were collected to 1.7 Å resolution for the inhibitor-free crystals and to 2.0 Å resolution for the actinonin-bound crystals

  6. Degradation of acephate by Enterobacter asburiae, Bacillus cereus and Pantoea agglomerans isolated from diamondback moth Plutella xylostella (L), a pest of cruciferous crops.

    Science.gov (United States)

    Ramya, Shanivarsanthe Leelesh; Venkatesan, Thiruvengadam; Murthy, Kottilingam Srinivasa; Jalali, Sushil Kumar; Varghese, Abraham

    2016-07-01

    Acephate-degrading bacterial isolates were isolated from the larval gut of diamondback moth Plutella xylostella, a notorious pest of cruciferous crops worldwide that has developed resistance to insecticides. Partial 16S rRNA gene sequencing identified the isolates as Bacillus cereus (PX-B.C.Or), Enterobacter asburiae (PXE), and Pantoae agglomerans (PX-Pt.ag.Jor). All isolates grew on minimal media (MM) in the presence of acephate at 100 and 200 ppm, with maximum growth at 200 ppm. LC-MS analyses of spent medium showed that E. asburiae degraded acephate to methamidophos and O, O-dimethyl phosporamidate and B. cereus O,S-dimethyl to phosphorothioate but P. agglomerans to an unnamed compound. All three isolates used acephate as a source of carbon and energy for growth; however, P. agglomerans used it also as source of sulphur. Strong evidence revealed that the bacterial communities present in the gut of diamondback moth might aid in acephate degradation and play a role in the development of insecticide resistance.

  7. Crystallization and preliminary X-ray crystallographic studies of a PduO-type ATP:cob(I)alamin adenosyltransferase from Bacillus cereus

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ae Kyung [Division of Biotechnology, College of Life Sciences, Korea University, Seoul 136-713 (Korea, Republic of); Moon, Jin Ho [Insititute of Life Sciences and Natural Resources, Korea University, Seoul 136-713 (Korea, Republic of); Lee, Sung Haeng [Department of Medicine, Medical Research Center (MRC), College of Medicine, Chosun University, Gwangju 501-759 (Korea, Republic of); Chi, Young Min, E-mail: ezeg@korea.ac.kr [Division of Biotechnology, College of Life Sciences, Korea University, Seoul 136-713 (Korea, Republic of)

    2008-07-01

    Orthorhombic crystals of a PduO-type ATP:cob(I)alamin adenosyltransferase from B. cereus were obtained both as an apoenzyme and in the presence of Mg{sup 2+} and ATP. Cobalamin adenosyltransferases transfer a 5′-deoxyadenosyl moiety from ATP and covalently attach it to the cobalt(I) ion of the corrin ring of cobalamin to generate adenosylcobalamin. The PduO-type adenosyltransferase from Bacillus cereus was overexpressed in Escherichia coli, purified and crystallized as the apoenzyme as well as in complex with Mg{sup 2+} and ATP (MgATP). Diffraction data were collected to 1.9 Å resolution for the native crystals and 2.0 Å resolution for the complexed crystals. Both crystals belonged to the orthorhombic space group C222{sub 1}; the native crystals have unit-cell parameters a = 64.93, b = 137.08, c = 158.55 Å. The asymmetric unit contained one trimer, with a corresponding V{sub M} of 2.69 Å{sup 3} Da{sup −1}.

  8. Gene detection and toxin production evaluation of hemolysin BL of Bacillus cereus isolated from milk and dairy products marketed in Brazil

    Directory of Open Access Journals (Sweden)

    Andre L.S. Reis

    2013-12-01

    Full Text Available Bacillus cereusis an ubiquitous, spore-forming bacteria that can survive pasteurization and the majority of the heating processes used in the dairy industry. Besides, it is a pathogen responsible for different types of food poisoning. One type of foodborne disease caused by B.cereusis the diarrheal syndrome, which is caused by the ingestion of vegetative cells producing toxins in the small intestine. One virulence factor for the diarrheal syndrome is the toxin hemolysin BL (HBL, a three-component protein formed by the L1, L2 and B components. In order to evaluate the presence of diarrheal strains isolated from milk and dairy products, 63 B. cereus isolates were obtained from 260 samples of UHT milk, pasteurized milk and powdered milk, sold in commercial establishments and from different brands. The isolates were subjected to the Polymerase Chain Reaction (PCR for the detection of the encoding genes for the L1, L2 and B components and the toxin production capacity were evaluated with an immunoassay. A total of 23 [36.5%] isolates were identified carrying simultaneously the three tested genes, from which, 20 [86.9%] showed toxigenic capacity. 26 [41.3%] isolates did not carry any of genes tested and the other 14 [22.2%] were positive for one or two of them. The results showed a high toxigenic capacity among the B. cereus isolates able to produce the HBL, indicating a potential risk for consumers.

  9. Biorremediation of soil polluted by 75000 ppm of waste motor oil applying biostimulation and phytoremediation with Sorghum vulgare and Bacillus cereus or Burkholderia cepacia

    Directory of Open Access Journals (Sweden)

    Balderas-León Iván

    2015-02-01

    Full Text Available Waste motor oil (WMO pollutes soil and causing lost soil fertility. An alternative to solve this problem its bioremediation (BR by double and following biostimulation (BS with mineral solution (MS and a legume as green manure (GM then using phytoremediation (PR with growth promoting vegetal bacteria (GPVB like Bacillus cereus and Burkholderia cepacia to minimize remaining WMO. The aims of this research were: a bioremediation of polluted soil by 75000 ppm of WMO by biostimulation and then b Its phytoremediation for remaining WMO by Sorghum vulgare inoculated with B. cereus and B. cepacia. Soil polluted by high concentration WMO was biostimulated with MS, and then Phaseolus vulgaris treated by GPVB was incorporated as GM, finally to apply PR to eliminate WMO with S. vulgare with GPVB. Results indicate that soil bioremediated by biostimulation with MS, WMO decreased at 32500 ppm/30 days, and then with GM, WMO was reduced at 10100 ppm after/90 days. Finally, to apply phytoremediation using S. vulgare and GPVB at flowering, WMO was reduced from 2500 ppm to 800 ppm. For recovering soil impacted by high concentration WMO to apply both techniques double and following BS and PR are the best option than each technique separately.

  10. Toxin profiles of Bacillus cereus occurring in high numbers in spontaneously fermented African locust beans (Parkia biglobosa)

    DEFF Research Database (Denmark)

    Thorsen, Line; Azokpota, Paulin; Hansen, Bjarne Munk

    to be potentially pathogenic by harboring and expressing enterotoxin and emetic genes. Isolates from afiitin were the most cytotoxic as detected by a Vero-cell assay, while an isolate from sonru was a potent cereulide producer. Interestingly B. cereus food poisoning frm the consumption of the fermented condiments...

  11. Complete genome sequence analysis and identification of putative metallo-beta-lactamase and SpoIIIE homologs in Bacillus cereus group phage BCP8-2, a new member of the proposed Bastille-like group.

    Science.gov (United States)

    Asare, Paul Tetteh; Bandara, Nadeeka; Jeong, Tae-Yong; Ryu, Sangryeol; Klumpp, Jochen; Kim, Kwang-Pyo

    2015-10-01

    Bacillus cereus group-specific bacteriophage BCP8-2 exhibits a broad lysis spectrum among food and human isolates (330/364) of B. cereus while not infecting B. subtilis (50) or B. licheniformis (12) strains. Its genome is 159,071 bp long with 220 open reading frames, including genes for putative methyltransferases, metallo-beta-lactamase, and a sporulation-related SpoIIIE homolog, as wells as 18 tRNAs. Comparative genome analysis showed that BCP8-2 is related to the recently proposed Bastille-like phages, but not with either SPO1-like or Twort-like phages of the subfamily Spounavirinae.

  12. Bacillus cereus AR156 primes induced systemic resistance by suppressing miR825/825* and activating defense-related genes in Arabidopsis.

    Science.gov (United States)

    Niu, Dongdong; Xia, Jing; Jiang, Chunhao; Qi, Beibei; Ling, Xiaoyu; Lin, Siyuan; Zhang, Weixiong; Guo, Jianhua; Jin, Hailing; Zhao, Hongwei

    2016-04-01

    Small RNAs play an important role in plant immune responses. However, their regulatory function in induced systemic resistance (ISR) is nascent. Bacillus cereus AR156 is a plant growth-promoting rhizobacterium that induces ISR in Arabidopsis against bacterial infection. Here, by comparing small RNA profiles of Pseudomonas syringae pv. tomato (Pst) DC3000-infected Arabidopsis with and without AR156 pretreatment, we identified a group of Arabidopsis microRNAs (miRNAs) that are differentially regulated by AR156 pretreatment. miR825 and miR825* are two miRNA generated from a single miRNA gene. Northern blot analysis indicated that they were significantly downregulated in Pst DC3000-infected plants pretreated with AR156, in contrast to the plants without AR156 pretreatment. miR825 targets two ubiquitin-protein ligases, while miR825* targets toll-interleukin-like receptor (TIR)-nucleotide binding site (NBS) and leucine-rich repeat (LRR) type resistance (R) genes. The expression of these target genes negatively correlated with the expression of miR825 and miR825*. Moreover, transgenic plants showing reduced expression of miR825 and miR825* displayed enhanced resistance to Pst DC3000 infection, whereas transgenic plants overexpressing miR825 and miR825* were more susceptible. Taken together, our data indicates that Bacillus cereus AR156 pretreatment primes ISR to Pst infection by suppressing miR825 and miR825* and activating the defense related genes they targeted. © 2015 Institute of Botany, Chinese Academy of Sciences.

  13. Biosurfactant Production and Surface Translocation Are Regulated by PlcR in Bacillus cereus ATCC 14579 under Low-Nutrient Conditions▿ †

    Science.gov (United States)

    Hsueh, Yi-Huang; Somers, Eileen B.; Lereclus, Didier; Ghelardi, Emilia; Wong, Amy C. Lee

    2007-01-01

    Bacillus cereus ATCC 14579 can respond to nutrient changes by adopting different forms of surface translocation. The B. cereus ATCC 14579 ΔplcR mutant, but not the wild type, formed dendritic (branched) patterns on EPS [a low-nutrient medium that contains 7.0 g K2HPO4, 3.0 g KH2PO4, 0.1 g MgSO4·7H2O, 0.1 g (NH4)2SO4, 0.01 g CaCl2, 0.001 g FeSO4, 0.1 g NaCl, 1.0 g glucose, and 125 mg yeast extract per liter] containing 0.7% agar. The dendritic patterns formed by sliding translocation of nonflagellated cells are enhanced under low-nutrient conditions and require sufficient production of a biosurfactant, which appears to be repressed by PlcR. The wild-type and complemented strains failed to slide on the surface of EPS agar because of the production of low levels of biosurfactant. Precoating EPS agar surfaces with surfactin (a biosurfactant produced by Bacillus subtilis) or biosurfactant purified from the ΔplcR mutant rescued the ability of the wild-type and complemented strains to slide. When grown on a nutrient-rich medium like Luria-Bertani agar, both the wild-type and ΔplcR mutant strains produced flagella. The wild type was hyperflagellated and elongated and exhibited swarming behavior, while the ΔplcR mutant was multiflagellated and the cells often formed long chains but did not swarm. Thin-layer chromatography and mass spectrometry analyses suggested that the biosurfactant purified from the ΔplcR mutant was a lipopeptide and had a mass of 1,278.1722 (m/z). This biosurfactant has hemolytic activity and inhibited the growth of several gram-positive bacteria. PMID:17921286

  14. Biosurfactant production and surface translocation are regulated by PlcR in Bacillus cereus ATCC 14579 under low-nutrient conditions.

    Science.gov (United States)

    Hsueh, Yi-Huang; Somers, Eileen B; Lereclus, Didier; Ghelardi, Emilia; Wong, Amy C Lee

    2007-11-01

    Bacillus cereus ATCC 14579 can respond to nutrient changes by adopting different forms of surface translocation. The B. cereus ATCC 14579 DeltaplcR mutant, but not the wild type, formed dendritic (branched) patterns on EPS [a low-nutrient medium that contains 7.0 g K(2)HPO(4), 3.0 g KH(2)PO(4), 0.1 g MgSO(4).7H(2)O, 0.1 g (NH(4))(2)SO(4), 0.01 g CaCl(2), 0.001 g FeSO(4), 0.1 g NaCl, 1.0 g glucose, and 125 mg yeast extract per liter] containing 0.7% agar. The dendritic patterns formed by sliding translocation of nonflagellated cells are enhanced under low-nutrient conditions and require sufficient production of a biosurfactant, which appears to be repressed by PlcR. The wild-type and complemented strains failed to slide on the surface of EPS agar because of the production of low levels of biosurfactant. Precoating EPS agar surfaces with surfactin (a biosurfactant produced by Bacillus subtilis) or biosurfactant purified from the DeltaplcR mutant rescued the ability of the wild-type and complemented strains to slide. When grown on a nutrient-rich medium like Luria-Bertani agar, both the wild-type and DeltaplcR mutant strains produced flagella. The wild type was hyperflagellated and elongated and exhibited swarming behavior, while the DeltaplcR mutant was multiflagellated and the cells often formed long chains but did not swarm. Thin-layer chromatography and mass spectrometry analyses suggested that the biosurfactant purified from the DeltaplcR mutant was a lipopeptide and had a mass of 1,278.1722 (m/z). This biosurfactant has hemolytic activity and inhibited the growth of several gram-positive bacteria.

  15. De-hairing protease production by an isolated Bacillus cereus strain AT under solid-state fermentation using cow dung: Biosynthesis and properties.

    Science.gov (United States)

    Vijayaraghavan, Ponnuswamy; Lazarus, Sophia; Vincent, Samuel Gnana Prakash

    2014-01-01

    Agro-industrial residues and cow dung were used as the substrate for the production of alkaline protease by Bacillus cereus strain AT. The bacterial strain Bacillus cereus strain AT produced a high level of protease using cow dung substrate (4813 ± 62 U g(-1)). Physiological fermentation factors such as the incubation time (72 h), the pH (9), the moisture content (120%), and the inoculum level (6%) played a vital role in the enzyme bioprocess. The enzyme production improved with the supplementation of maltose and yeast extract as carbon and nitrogen sources, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram analysis of the purified protease indicated an estimated molecular mass of 46 kDa. The protease enzyme was stable over a temperature range of 40-50 °C and pH 6-9, with maximum activity at 50 °C and pH 8. Among the divalent ions tested, Ca(2+), Na(+) and Mg(2+) showed activities of 107 ± 0.7%, 103.5 ± 1.3%, and 104.6 ± 0.9, respectively. The enzyme showed stability in the presence of surfactants such as sodium dodecyl sulfate and on various commercially available detergents. The crude enzyme effectively de-haired goat hides within 18 h of incubation at 30 °C. The enzymatic properties of this protease suggest its suitable application as an additive in detergent formulation and also in leather processing. Based on the laboratory results, the use of cow dung for producing and extracting enzyme is not cumbersome and is easy to scale up. Considering its cheap cost and availability, cow dung is an ideal substrate for enzyme bioprocess in an industrial point of view.

  16. ??????????? ???????????? ???? ?? ???? ?????????? ?????????

    OpenAIRE

    ??????, ?????; ???????????, ?????

    2011-01-01

    ?????????? ????????? ??? ???? ?? ?????????? ????????? ?? ?????? ?????????? ???? ???????? ???? Bacillus cereus ? ????????????? ????????? ?? ?????????? ? ????????? ????? ???? ??????????????? ???????????? ????? ??????. ??????????? ????????? ????????? ????????? ?????????? ???????? ?? ??????????? ????????? ?????? ?????????????????? ?????????? ?????????? ????? ??????????????? ?? ???????? ?? ?????????.

  17. Spectroscopic Studies of the Iron and Manganese Reconstituted Tyrosyl Radical in Bacillus Cereus Ribonucleotide Reductase R2 Protein

    OpenAIRE

    Tomter, Ane B.; Zoppellaro, Giorgio; Bell, Caleb B., III; Barra, Anne-Laure; Andersen, Niels H.; Solomon, Edward I.; Andersson, K. Kristoffer

    2012-01-01

    Ribonucleotide reductase (RNR) catalyzes the rate limiting step in DNA synthesis where ribonucleotides are reduced to the corresponding deoxyribonucleotides. Class Ib RNRs consist of two homodimeric subunits: R1E, which houses the ribonucleotide reduction active site; and R2F, which contains a metallo cofactor and a tyrosyl radical that initiates the ribonucleotide reduction reaction. WIn this work, we studied the R2F subunit of B. cereus reconstituted with both iron and or alternatively with...

  18. Comparing the mannitol-egg yolk-polymyxin agar plating method with the three-tube most-probable-number method for enumeration of Bacillus cereus spores in raw and high-temperature, short-time pasteurized milk.

    Science.gov (United States)

    Harper, Nigel M; Getty, Kelly J K; Schmidt, Karen A; Nutsch, Abbey L; Linton, Richard H

    2011-03-01

    The U.S. Food and Drug Administration's Bacteriological Analytical Manual recommends two enumeration methods for Bacillus cereus: (i) standard plate count method with mannitol-egg yolk-polymyxin (MYP) agar and (ii) a most-probable-number (MPN) method with tryptic soy broth (TSB) supplemented with 0.1% polymyxin sulfate. This study compared the effectiveness of MYP and MPN methods for detecting and enumerating B. cereus in raw and high-temperature, short-time pasteurized skim (0.5%), 2%, and whole (3.5%) bovine milk stored at 4°C for 96 h. Each milk sample was inoculated with B. cereus EZ-Spores and sampled at 0, 48, and 96 h after inoculation. There were no differences (P > 0.05) in B. cereus populations among sampling times for all milk types, so data were pooled to obtain overall mean values for each treatment. The overall B. cereus population mean of pooled sampling times for the MPN method (2.59 log CFU/ml) was greater (P milk samples ranged from 2.36 to 3.46 and 2.66 to 3.58 log CFU/ml for inoculated milk treatments for the MYP plate count and MPN methods, respectively, which is below the level necessary for toxin production. The MPN method recovered more B. cereus, which makes it useful for validation research. However, the MYP plate count method for enumeration of B. cereus also had advantages, including its ease of use and faster time to results (2 versus 5 days for MPN).

  19. Evaluation of nutrients removal (NO3-N, NH3-N and PO4-P) with Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and a consortium of these microorganisms in the treatment of wastewater effluents.

    Science.gov (United States)

    Gómez-Guzmán, Abril; Jiménez-Magaña, Sergio; Guerra-Rentería, A Suggey; Gómez-Hermosillo, César; Parra-Rodríguez, F Javier; Velázquez, Sergio; Aguilar-Uscanga, Blanca Rosa; Solis-Pacheco, Josue; González-Reynoso, Orfil

    2017-07-01

    In this research removal of NH 3 -N, NO 3 -N and PO 4 -P nutrients from municipal wastewater was studied, using Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and an artificial consortium of them. The objective is to analyze the performance of these microorganisms and their consortium, which has not been previously studied for nutrient removal in municipal wastewater. A model wastewater was prepared simulating the physicochemical characteristics found at the wastewater plant in Chapala, Mexico. Experiments were carried out without adding an external carbon source. Results indicate that nutrient removal with Chlorella vulgaris was the most efficient with a removal of 24.03% of NO 3 -N, 80.62% of NH 3 -N and 4.30% of PO 4 -P. With Bacillus cereus the results were 8.40% of NO 3 -N, 28.80% of NH 3 -N and 3.80% of PO 4 -P. The removals with Pseudomonas putida were 2.50% of NO 3 -N, 41.80 of NH 3 -N and 4.30% of PO 4 -P. The consortium of Chlorella vulgaris-Bacillus cereus-Pseudomonas putida removed 29.40% of NO 3 -N, 4.2% of NH 3 -N and 8.4% of PO 4 -P. The highest biomass production was with Bacillus cereus (450 mg/l) followed by Pseudomonas putida (444 mg/l), the consortium (205 mg/l) and Chlorella vulgaris (88.9 mg/l). This study highlights the utility of these microorganisms for nutrient removal in wastewater treatments.

  20. Functionality of a bacillus cereus biological agent in response to physiological variables encountered in cyprinus carpio aquaculture

    CSIR Research Space (South Africa)

    Lalloo, R

    2008-05-01

    Full Text Available Modern aquaculture utilises intensive reticulated systems resulting in waste accumulation and proliferation of disease. Conventional chemical treatments cause resistance in pathogens and negative environmental impact. The potential of a Bacillus...

  1. orf4 of the Bacillus cereus sigB gene cluster encodes a general stress-inducible Dps-like bacterioferritin.

    Science.gov (United States)

    Wang, Shin-Wei; Chen, Chien-Yen; Tseng, Joseph T; Liang, Shih-Hsiung; Chen, Ssu-Ching; Hsieh, Chienyan; Chen, Yen-hsu; Chen, Chien-Cheng

    2009-07-01

    The function of orf4 in the sigB cluster in Bacillus cereus ATCC 14579 remains to be explored. Amino-acid sequence analysis has revealed that Orf4 is homologous with bacterioferritins and Dps. In this study, we generated an orf4-null mutant and produced recombinant protein rOrf4 to establish the role of orf4. In vitro, the purified rOrf4 was found to exist in two distinct forms, a dimeric form and a polymer form, through size exclusion analysis. The latter form exhibited a unique filament structure, in contrast to the typical spherical tetracosamer structure of bacterioferritins; the former can be induced to form rOrf4 polymers immediately after the addition of FeCl(2). Catalysis of the oxidation of ferrous irons by ferroxidase activity was detected with rOrf4, and the mineralized irons were subsequently sequestered only in the rOrf4 polymer. Moreover, rOrf4 exerted DNA-protective activity against oxidative damage via DNA binding in a nonspecific manner, as is seen with Dps. In vivo, deletion of orf4 had no effect on activation of the alternative sigma factor sigma(B), and therefore, orf4 is not associated with sigma(B) regulation; however, orf4 can be significantly upregulated upon environmental stress but not H(2)O(2) treatment. B. cereus strains with constitutive Orf4 expression exhibited a viability higher than that of the orf4-null mutant, under specific oxidative stress or heat shock. Taken together, these results suggest that Orf4 functions as a Dps-like bacterioferritin in response to environmental stress and can provide cell protection from oxidative damage through iron sequestration and DNA binding.

  2. Thermal inactivation of Bacillus cereus spores affected by the solutes used to control water activity of the heating medium.

    Science.gov (United States)

    Mazas, M; Martínez, S; López, M; Alvarez, A B; Martin, R

    1999-12-01

    The heat resistance of B. cereus spores (ATCC 7004, 4342 and 9818) over a wide temperature range (92-125 degrees C) in aqueous solutions of NaCl, LiCl, sucrose and glycerol at different water activities (1.00-0.71) was investigated. Sodium chloride in the heating medium tended to protect the spores of B. cereus against heat. The z-values increased significantly (P 0.87 M), the D-values showed an increase, although only those obtained for strain 4342 in sucrose solutions 2.22 M were higher than those found in pure water. The z-values were significantly higher (P < 0.05) when sucrose was added at concentrations above 1.42 M, except for strain 4342. When a(w) was lowered from 0.96 to 0.71 with glycerol, D-values obtained gradually increased, about 30, 50 and 60 fold for 4342, 7004 and 9818 strains, respectively. No significant effect on z-values were detected.

  3. Presensitization of microorganisms by essential oils treatments to low dose gamma irradiation with special reference to Bacillus cereus ATCC 7004

    International Nuclear Information System (INIS)

    Ayari, Samia; Jerbi, Taieb; Hamdi, M.; Lacroix, M.

    2008-01-01

    The radiosensitization of B.cereus ATCC 7004 spores was evaluated in the presence of thymol, thyme, D-L menthol, trans-cinnamaldehyde and eugenol in ground beef. Cattle minced meat (5% fat) was inoculated with spores of B.cereus (10 5 - 10 6 CFU/g), and each compound was added separately at various concentrations. The antimicrobial potential was evaluated in unirradiated meat by determining the MIC in percentage (wt/wt) after 24 h of storage at 4 ± 1 C. Results showed that the best antimicrobial compound was the trans-cinnamaldehyde with MIC of 1.47%, wt/wt. In presence of cinnamaldehyde, the addition of sodium pyrophosphate decahydrate (0.1% wt/wt) increased significantly (P < 0.05) the relative sensitivity of B.cereus spores 2 times. However, the presence of ascorbic acid in the media reduced significantly (p<0.05) the radiosensitivity of bacteria. The combined effect of gamma irradiation in presence of cinnamaldehyde, added with ascorbic acid or sodium pyrophosphate decahydrate, on the microbiological and physicochemical characteristic of meat samples was evaluated at 2kGy under air. The use of the active compounds with the irradiation reduced significantly (p<0.05) the count of total bacteria with a concomitant effect in the extension periods of shelf life. The addition of the cinnamaldehyde induced a significant reduction (p<0.05) in TVN and free amino acids of irradiated samples. In presence of ascorbic acid the thiobarbituric acid-reactive amino acids of irradiated samples. In presence of ascorbic acid the thiobarbiturate acid-reactive substances (TBARS) concentration was significantly reduced (p<0.05). A significant reduction (p<0.05) of a* and c* of color values and a significant increase (p<0.05) of b* value were obtained for the samples treated by the cinnamaldehyde. The application of bioactive films for the immobilization of the essential oils is a good alternate to check their stability during storage time

  4. Substrate binding and catalytic mechanism in phospholipase C from Bacillus cereus. a molecular mechanics and molecular dynamics study

    DEFF Research Database (Denmark)

    da Graça Thrige, D; Buur, J R; Jørgensen, Flemming Steen

    1997-01-01

    phosphatidylcholine, in phospholipase C. This catalytically essential water molecule, after being activated by an acidic residue (Asp55), performs the nucleophilic attack on the phosphorus atom in the substrate, leading to a trigonal bipyramidal pentacoordinated intermediate (and structurally similar transition state...... cereus including a docked substrate molecule was subjected to a stepwise molecular mechanics energy minimization. Second, the location of the nucleophilic water molecule in the active site of the fully relaxed enzyme-substrate complex was determined by evaluation of nonbonded interaction energies between...... the complex and a water molecule. The nucleophilic water molecule is positioned at a distance (3.8 A) from the phosphorus atom in the substrate, which is in good agreement with experimentally observed distances. Finally, the stability of the complex between phospholipase C, the substrate, and the nucleophilic...

  5. Detection of Bacillus cereus isolated during ultra high temperature milk production flowchart through random amplified polymorphic DNA polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Ana Maria Centola Vidal

    2015-01-01

    Full Text Available ABSTRACT:The present study focused on isolation Bacillus cereusduring the UHT milk production and shelf life, to assess the enterotoxigenic production capacity of isolates and to evaluate the use of the RAPD-PCR technique to verify whether Bacillus cereusisolated at different phases of UHT milk processing belongs to the same strain. For this, six groups of milk samples composed of raw, pasteurized and UHT milk were collected from a processing plant. The results revealed that bacteria belonging to the Bacillus cereusgroup were isolated from 51.6%, 81.6% and from 13.8% of raw, pasteurized and UHT milk samples, respectively. About 50.0% of isolates from raw milk, 19.2% isolates from pasteurized milk and 70.7% isolates from UHT milk were capable of producing enterotoxins. It was confirmed the genetic similarity amongBacillus cereusisolates from raw, pasteurized and UHT milk, therefore demonstrating that the microorganism is able to withstand UHT treatment. These results should serve as a warning to health authorities, given that 13.8% of samples were not in accordance with standards established by the Department of Health for containing a potentially pathogen agent, therefore indicating that contamination of milk by sporulating bacteria should be avoided.

  6. Non-Toxin-Producing Bacillus cereus Strains Belonging to the B. anthracis Clade Isolated from the International Space Station

    NARCIS (Netherlands)

    Venkateswaran, Kasthuri; Singh, Nitin K.; Sielaff, Aleksandra Checinska; Pope, Robert K.; Bergman, Nicholas H.; van Tongeren, Sandra P.; Patel, Nisha B.; Lawson, Paul A.; Satomi, Masataka; Williamson, Charles H. D.; Sahl, Jason W.; Keim, Paul; Pierson, Duane; Perry, Jay

    2017-01-01

    ABSTRACT: In an ongoing Microbial Observatory investigation of the International Space Station (ISS), 11 Bacillus strains (2 from the Kibo Japanese experimental module, 4 from the U.S. segment, and 5 from the Russian module) were isolated and their whole genomes were sequenced. A comparative

  7. CodY, a pleiotropic regulator, influences multicellular behaviour and efficient production of virulence factors in Bacillus cereus

    NARCIS (Netherlands)

    Lindback, Toril; Mols, Maarten; Basset, Coraline; Granum, Per Einar; Kuipers, Oscar P.; Kovacs, Akos T.; Lindbäck, Toril

    In response to nutrient limitation in the environment, the global transcriptional regulator CodY modulates various pathways in low G+C Gram-positive bacteria. In Bacillus subtilis CodY triggers adaptation to starvation by secretion of proteases coupled to the expression of amino acid transporters.

  8. Toxicity of Tolyltriazole to Bacillus Microorganisms.

    Science.gov (United States)

    2000-03-01

    Bacillus coagulans Microbacterium lacticum Jupiter Bacillus thuringiensis Bacillus thuringiensis Bacillus cereus Bacillus Bacillus thuringiensis...TOXICITY OF TOLYLTRIAZOLE TO BACILLUS MICROORGANISMS THESIS Christopher J. Leonard, First Lieutenant, USAF AFIT/GEE/ENV/OOM-12 Approved for...AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE TOXICITY OF TOLYLTRIAZOLE TO BACILLUS MICROORGANISMS 6. AUTHOR(S) Christopher J

  9. Detection of coding genes for enterotoxins in Bacillus cereus by PCR and their products by BCET-RPLA and ELISA Assay

    Directory of Open Access Journals (Sweden)

    Marcela Vyletělová

    2010-01-01

    Full Text Available Determination of enterotoxin production, diarrhoeal and emetic gene identification was studied in 41 Bacillus cereus strains isolated from raw cows’ and raw goats’ milk, pasteurized milk, dairy products during technological processing and from dairy plant equipment. Presence of enterotoxins was detected by BCET-RPLA (HBL and ELISA immunoassay (NHE. Gene identification (nheA, nheB, nheC, hblA, hblC, hblD, bceT, cytK-1, cytK-2, entFM and ces was achieved by means of PCR. Enterotoxin HBL was detected in 32 strains, enterotoxin NHE in all 41 strains. Presence of all three genes nheA, nheB and nheC was confirmed in 40 strains and genes hblA, hblC and hblD in 29 strains. Comparison of used methods was as follow: 1 BCET-RPLA (which detects L2 component and PCR (positive or negative all three hblA, hblC and hblD gene detection were identical in 30 (73%; 2 ELISA (NheA and PCR (all three nheC, nheB and nheA gene expression were identical in 40 (98% cases isolated strains.

  10. Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase (PDF) from Bacillus cereus in ligand-free and actinonin-bound forms.

    Science.gov (United States)

    Park, Joon Kyu; Moon, Jin Ho; Kim, Jae-Hong; Kim, Eunice EunKyeong

    2005-01-01

    In bacteria, protein expression initiates with an N-formyl group and this needs to be removed in order to ensure proper bacterial growth. These formylation and deformylation processes are unique to eubacteria; therefore, inhibition of these would provide a novel antibacterial therapy. Deformylation is carried out by peptide deformylase (PDF). PDF from Bacillus cereus, one of the major pathogenic bacteria, was cloned into expression plasmid pET-28a (Novagen), overexpressed in Escherichia coli BL21 (DE3) and purified to high quality. Crystals have been obtained of both ligand-free PDF and PDF to which actinonin, a highly potent naturally occurring inhibitor, is bound. Both crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 42.72, b = 44.04, c = 85.19 A and a = 41.31, b = 44.56, c = 84.47 A, respectively. Diffraction data were collected to 1.7 A resolution for the inhibitor-free crystals and to 2.0 A resolution for the actinonin-bound crystals.

  11. Biostimulation of soil polluted 10000 ppm of waste motor oil and phytoremediation with Cicer arietinum improved by Bacillus cereus/Rhizobium etli

    Directory of Open Access Journals (Sweden)

    Juárez-Cisneros Gladys

    2016-08-01

    Full Text Available Soil pollution by waste motor oil (WMO is reducing its productivity. An alternative for removing WMO from soil is by biostimulation (BIS applying animal manure and then phytoremediation (PR by legume improving with plant growth promoting bacteria (PGPB to reduce WMO concentration at level below 4400 ppm limit permit for the NOM-138-SEMARNAT/SSA1-2012 (NOM-138. The aims of this re-search were: i to analyze soil biostimulation polluted by 10000 ppm of WMO applying vermicompost, then subsequent soil phytoremediation with Cicer arietinum inoculated by Bacillus cereus and/or Rhizo-bium etli. In soil after applying BS by VC was measured WMO soil concentration and ii for PR was regarded phenology and biomass of C. arietinum and WMO concentration remaining at the end of this step. The results showed that soil biostimulated by VC, WMO was reduced at 1370 ppm, subsequent PR sowing C. arietinum with R. etli, WMR was reduced at 30 ppm concentration both values below to maxi-mum value accepted by NOM-138. Those data indicate that in soil polluted by WMO the best way to biorecovery soil was to integrate strategy BS/PR the last one improved by genus of PGPB.

  12. Evidence of mercury trapping in biofilm-EPS and mer operon-based volatilization of inorganic mercury in a marine bacterium Bacillus cereus BW-201B.

    Science.gov (United States)

    Dash, Hirak R; Basu, Subham; Das, Surajit

    2017-04-01

    Biofilm-forming mercury-resistant marine bacterium Bacillus cereus BW-201B has been explored to evident that the bacterial biofilm-EPS (exopolymers) trap inorganic mercury but subsequently release EPS-bound mercury for induction of mer operon-mediated volatilization of inorganic mercury. The isolate was able to tolerate 50 ppm of mercury and forms biofilm in presence of mercury. mer operon-mediated volatilization was confirmed, and -SH was found to be the key functional group of bacterial EPS responsible for mercury binding. Biofilm-EPS-bound mercury was found to be internalized to the bacterial system as confirmed by reversible conformational change of -SH group and increased expression level of merA gene in a timescale experiment. Biofilm-EPS trapped Hg after 24 h of incubation, and by 96 h, the volatilization process reaches to its optimum confirming the internalization of EPS-bound mercury to the bacterial cells. Biofilm disintegration at the same time corroborates the results.

  13. Isopeptide bonds of the major pilin protein BcpA influence pilus structure and bundle formation on the surface of Bacillus cereus

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, Antoni P.A.; Poor, Catherine B.; Jureller, Justin E.; Budzik, Jonathan M.; He, Chuan; Schneewind, Olaf (UC)

    2012-09-05

    Bacillus cereus strains elaborate pili on their surface using a mechanism of sortase-mediated cross-linking of major and minor pilus components. Here we used a combination of electron microscopy and atomic force microscopy to visualize these structures. Pili occur as single, double or higher order assemblies of filaments formed from monomers of the major pilin, BcpA, capped by the minor pilin, BcpB. Previous studies demonstrated that within assembled pili, four domains of BcpA -- CNA{sub 1}, CNA{sub 2}, XNA and CNA{sub 3} -- each acquire intramolecular lysine-asparagine isopeptide bonds formed via catalytic glutamic acid or aspartic acid residues. Here we showed that mutants unable to form the intramolecular isopeptide bonds in the CNA2 or CNA3 domains retain the ability to form pilus bundles. A mutant lacking the CNA{sub 1} isopeptide bond assembled deformed pilin subunits that failed to associate as bundles. X-ray crystallography revealed that the BcpA variant Asp{sup 312}Ala, lacking an aspartyl catalyst, did not generate the isopeptide bond within the jelly-roll structure of XNA. The Asp{sup 312}Ala mutant was also unable to form bundles and promoted the assembly of deformed pili. Thus, structural integrity of the CNA{sub 1} and XNA domains are determinants for the association of pili into higher order bundle structures and determine native pilus structure.

  14. Stem Bark Extract and Fraction of Persea americana (Mill. Exhibits Bactericidal Activities against Strains of Bacillus cereus Associated with Food Poisoning

    Directory of Open Access Journals (Sweden)

    David A. Akinpelu

    2014-12-01

    Full Text Available The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged between 0.78 and 5.00 mg/mL. The minimum bactericidal concentrations ranged between 3.12 mg/mL–12.5 mg/mL and 1.25–10 mg/mL for the extract and the fraction, respectively. The butanolic fraction killed 91.49% of the test isolates at a concentration of 2× MIC after 60 min of contact time, while a 100% killing was achieved after the test bacterial cells were exposed to the butanolic fraction at a concentration of 3× MIC after 90 min contact time. Intracellular protein and potassium ion leaked out of the test bacterial cells when exposed to certain concentrations of the fraction; this is an indication of bacterial cell wall disruptions by the extract’s butanolic fraction and, thus, caused a biocidal effect on the cells, as evident in the killing rate test results.

  15. Bio-prospecting of cuttle fish waste and cow dung for the production of fibrinolytic enzyme from Bacillus cereus IND5 in solid state fermentation.

    Science.gov (United States)

    Biji, Gurupatham Devadhasan; Arun, Arumugaperumal; Muthulakshmi, Eswaran; Vijayaraghavan, Ponnuswamy; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah

    2016-12-01

    The process parameters governing the production of fibrinolytic enzyme in solid state fermentation employing Bacillus cereus IND5 and using cuttle fish waste and cow dung substrate were optimized. The pH value of the medium, moisture content, sucrose, casein and magnesium sulfate were considered for two-level full factorial design and pH, casein and magnesium sulfate were identified as the important factors for fibrinolytic enzyme production. Central composite design was applied to investigate the interactive effect among variables (pH, casein and magnesium sulfate) and response surface plots were created to find the pinnacle of process response. The optimized levels of factors were pH 7.8, 1.1% casein and 0.1% magnesium sulfate. Enzyme production was increased 2.5-fold after statistical approach. The enzyme was purified up to a specific activity of 364.5 U/g proteins and its molecular weight was 47 kDa. It was stable at pH 8.0 and was highly active at 50 °C. The mixture of cuttle fish waste and cow dung could find great application as solid substrate for the production of fibrinolytic enzyme.

  16. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels

    Directory of Open Access Journals (Sweden)

    Genia eLücking

    2015-10-01

    Full Text Available The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like mega-plasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the nonribosomal peptide synthetase (NRPS, gene inactivation- and overexpression mutants of the emetic strain F4810/72 were constructed and their impact on cereulide biosynthesis was assessed. The hydrolase CesH turned out to be a part of the complex regulatory network controlling cereulide synthesis on a transcriptional Level, while the ABC transporter CesCD was found to be essential for post-translational control of cereulide synthesis. Using a gene inactivation approach, we show that the NRPS activating function of the phosphopantetheinyl transferase (PPtase embedded in the ces locus was complemented by a chromosomally encoded Sfp-like PPtase, representing an interesting example for the functional interaction between a plasmid encoded NRPS and a chromosomally encoded activation enzyme. In summary, our results highlight the complexity of cereulide biosynthesis and reveal multiple levels of toxin formation control. ces operon internal genes were shown to play a pivotal role by acting at different levels of toxin production, thus complementing the action of the chromosomal key transcriptional regulators AbrB and CodY.

  17. Feces derived allergens of Tyrophagus putrescentiae reared on dried dog food and evidence of the strong nutritional interaction between the mite and Bacillus cereus producing protease bacillolysins and exo-chitinases

    Directory of Open Access Journals (Sweden)

    Tomas eErban

    2016-02-01

    Full Text Available Tyrophagus putrescentiae (Schrank, 1781 is an emerging source of allergens in stored products and homes. Feces proteases are the major allergens of astigmatid mites (Acari: Acaridida. In addition, the mites are carriers of microorganisms and microbial adjuvant compounds that stimulate innate signaling pathways. We sought to analyze the mite feces proteome, proteolytic activities and mite-bacterial interaction in dry dog food. Proteomic methods comprising enzymatic and zymographic analysis of proteases and 2D-E-MS/MS were performed. The highest protease activity was assigned to trypsin-like proteases; lower activity was assigned to chymotrypsin-like proteases, and the cysteine protease cathepsin B-like had very low activity. The 2D-E-MS/MS proteomic analysis identified mite trypsin allergen Tyr p3, fatty acid-binding protein Tyr p13 and putative mite allergens ferritin (Grp 30 and (polyubiquitins. Tyr p3 was detected at different positions of the 2D-E. It indicates presence of zymogen at basic pI, and mature-enzyme form and enzyme fragment at acidic pI. Bacillolysins (neutral and alkaline proteases of Bacillus cereus symbiont can contribute to the protease activity of the mite extract. The bacterial exo-chitinases likely contribute to degradation of mite exuviae, mite bodies or food boluses consisting of chitin, including the peritrophic membrane. Thus, the chitinases disrupt the feces and facilitate release of the allergens. B. cereus was isolated and identified based on amplification and sequencing of 16S rRNA and motB genes. B. cereus was added into high-fat, high-protein (dry dog food and low-fat, low-protein (flour diets to 1% and 5% (w/w, and the diets palatability was evaluated in 21-day population growth test. The supplementation of diet with B. cereus significantly suppressed population growth and the suppressive effect was higher in the high-fat, high-protein diet than in the low-fat, low-protein food. Thus, B. cereus has to coexist

  18. Real-Time PCR Assay for a Unique Chromosomal Sequence of Bacillus anthracis

    Science.gov (United States)

    2004-12-01

    13061 Neisseria lactamica .............................................................. 23970 Bacillus coagulans ...NEG Bacillus coagulane 7050 NEG NEG Bacillus cereus 13472 NEG NEG Bacillus licheniforms 12759 NEG NEG Bacillus cereus 13824 NEG NEG Bacillus ...Assay for a Unique Chromosomal Sequence of Bacillus anthracis Elizabeth Bode,1 William Hurtle,2† and David Norwood1* United States Army Medical

  19. Custo adaptativo da indução de resistência em feijoeiro mediada pela rizobactéria Bacillus