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Sample records for bacillus cereus strain

  1. Emetic toxin-producing strains of Bacillus cereus show distinct characteristics within the Bacillus cereus group.

    NARCIS (Netherlands)

    Carlin, Frédéric; Fricker, Martina; Pielaat, Annemarie; Heisterkamp, Simon; Shaheen, Ranad; Salonen, Mirja Salkinoja; Svensson, Birgitta; Nguyen-the, Christophe; Ehling-Schulz, Monika

    2006-01-01

    One hundred representative strains of Bacillus cereus were selected from a total collection of 372 B. cereus strains using two typing methods (RAPD and FT-IR) to investigate if emetic toxin-producing hazardous B. cereus strains possess characteristic growth and heat resistance profiles. The strains

  2. Genotyping of Bacillus cereus strains by microarray-based resequencing.

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    Michael E Zwick

    Full Text Available The ability to distinguish microbial pathogens from closely related but nonpathogenic strains is key to understanding the population biology of these organisms. In this regard, Bacillus anthracis, the bacterium that causes inhalational anthrax, is of interest because it is closely related and often difficult to distinguish from other members of the B. cereus group that can cause diverse diseases. We employed custom-designed resequencing arrays (RAs based on the genome sequence of Bacillus anthracis to generate 422 kb of genomic sequence from a panel of 41 Bacillus cereus sensu lato strains. Here we show that RAs represent a "one reaction" genotyping technology with the ability to discriminate between highly similar B. anthracis isolates and more divergent strains of the B. cereus s.l. Clade 1. Our data show that RAs can be an efficient genotyping technology for pre-screening the genetic diversity of large strain collections to selected the best candidates for whole genome sequencing.

  3. Biodiversity in Bacillus cereus

    NARCIS (Netherlands)

    Pielaat A; Fricker M; Nauta MJ; Leusden FM van; MGB

    2006-01-01

    Experiments have been performed by different partners to identify variability in properties of Bacillus cereus strains that contribute to the extent of their virulence as part of an EU project. To this end, 100 B. cereus strains were selected and screened for biological properties, such as toxin pro

  4. Biodegradation of Eugenol by Bacillus Cereus Strain PN24

    OpenAIRE

    Kadakol, Jagannath C.; Kamanavalli, Chandrappa M.

    2010-01-01

    Bacillus cereus PN24 was isolated from soil by a conventional enrichment culture method using eugenol as a sole source of carbon and energy. The organism also utilized eugenol, 4-vinyl guaiacol, vanillin, vanillic acid and protocatechuic acid as growth substrates. The organism degraded eugenol to protocatechuic acid, which was further metabolized by a β-ketoadipate pathway. On the other hand, the intermediate of the eugenol-degrading pathway, such as ferulic acid was not detected in the cultu...

  5. 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.

  6. Probiotic Bacillus cereus Strains, a Potential Risk for Public Health in China.

    Science.gov (United States)

    Zhu, Kui; Hölzel, Christina S; Cui, Yifang; Mayer, Ricarda; Wang, Yang; Dietrich, Richard; Didier, Andrea; Bassitta, Rupert; Märtlbauer, Erwin; Ding, Shuangyang

    2016-01-01

    Bacillus cereus is an important cause of foodborne infectious disease and food poisoning. However, B. cereus has also been used as a probiotic in human medicine and livestock production, with low standards of safety assessment. In this study, we evaluated the safety of 15 commercial probiotic B. cereus preparations from China in terms of mislabeling, toxin production, and transferable antimicrobial resistance. Most preparations were incorrectly labeled, as they contained additional bacterial species; one product did not contain viable B. cereus at all. In total, 18 B. cereus group strains-specifically B. cereus and Bacillus thuringiensis-were isolated. Enterotoxin genes nhe, hbl, and cytK1, as well as the ces-gene were assessed by PCR. Enterotoxin production and cytotoxicity were confirmed by ELISA and cell culture assays, respectively. All isolated B. cereus group strains produced the enterotoxin Nhe; 15 strains additionally produced Hbl. Antimicrobial resistance was assessed by microdilution; resistance genes were detected by PCR and further characterized by sequencing, transformation and conjugation assays. Nearly half of the strains harbored the antimicrobial resistance gene tet(45). In one strain, tet(45) was situated on a mobile genetic element-encoding a site-specific recombination mechanism-and was transferable to Staphylococcus aureus and Bacillus subtilis by electro-transformation. In view of the wide and uncontrolled use of these products, stricter regulations for safety assessment, including determination of virulence factors and transferable antimicrobial resistance genes, are urgently needed.

  7. Probiotic Bacillus cereus Strains, a Potential Risk for Public Health in China

    Science.gov (United States)

    Zhu, Kui; Hölzel, Christina S.; Cui, Yifang; Mayer, Ricarda; Wang, Yang; Dietrich, Richard; Didier, Andrea; Bassitta, Rupert; Märtlbauer, Erwin; Ding, Shuangyang

    2016-01-01

    Bacillus cereus is an important cause of foodborne infectious disease and food poisoning. However, B. cereus has also been used as a probiotic in human medicine and livestock production, with low standards of safety assessment. In this study, we evaluated the safety of 15 commercial probiotic B. cereus preparations from China in terms of mislabeling, toxin production, and transferable antimicrobial resistance. Most preparations were incorrectly labeled, as they contained additional bacterial species; one product did not contain viable B. cereus at all. In total, 18 B. cereus group strains—specifically B. cereus and Bacillus thuringiensis—were isolated. Enterotoxin genes nhe, hbl, and cytK1, as well as the ces-gene were assessed by PCR. Enterotoxin production and cytotoxicity were confirmed by ELISA and cell culture assays, respectively. All isolated B. cereus group strains produced the enterotoxin Nhe; 15 strains additionally produced Hbl. Antimicrobial resistance was assessed by microdilution; resistance genes were detected by PCR and further characterized by sequencing, transformation and conjugation assays. Nearly half of the strains harbored the antimicrobial resistance gene tet(45). In one strain, tet(45) was situated on a mobile genetic element—encoding a site-specific recombination mechanism—and was transferable to Staphylococcus aureus and Bacillus subtilis by electro-transformation. In view of the wide and uncontrolled use of these products, stricter regulations for safety assessment, including determination of virulence factors and transferable antimicrobial resistance genes, are urgently needed. PMID:27242738

  8. Exoproteome analysis of a novel strain of Bacillus cereus implicated in disease resembling cutaneous anthrax.

    Science.gov (United States)

    Ghosh, Neha; Goel, Ajay Kumar; Alam, Syed Imteyaz

    2014-03-01

    Bacillus cereus belongs to B. cereus sensu lato group, shared by six other related species including Bacillus anthracis. B. anthracis is the causative agent for serious illness affecting a wide range of animals as well as humans and is a category A Biological and Toxin Warfare (BTW) agent. Recent studies indicate that a Bacillus species other than B. anthracis can cause anthrax-like disease and role of anthrax virulence plasmids (pXO1 and pXO2) on the pathogenicity of B. cereus has been documented. B. cereus strain TF5 was isolated from the tissue fluid of cutaneous anthrax-like skin lesions of a human patient from an anthrax endemic area in India. The strain harboured a PA gene, however, presence of pXO1 or pXO2-like plasmids could not be ascertained using reported primers. Abundant exoproteome of the strain in the early stationary phase was elucidated using a 2-DE MS approach and compared with that from a reference B. cereus strain. Analysis of proteins showing qualitative and quantitative differences between the two strains indicated an altered regulatory mechanism and putative role of S-layer protein and sphingomyelinase in the pathogenesis of strain TF5. Phylogenetic analysis of the S-layer protein indicated close affiliation of the strain with anthracis-like B. cereus strains such as B. cereus var. anthracis strain CI; whereas sphingomyelinase exhibited specific relationship with all the strains of B. anthracis apart from that with anthracis-like B. cereus strains.

  9. A case of intoxication due to a highly cytotoxic Bacillus cereus strain isolated from cooked chicken.

    Science.gov (United States)

    López, Ana C; Minnaard, Jessica; Pérez, Pablo F; Alippi, Adriana M

    2015-04-01

    Outbreaks of Bacillus cereus infection/intoxication are not commonly reported because symptoms are often mild, and the disease is self-limiting. However, hypervirulent strains increase health risks. We report a case, which occurred in Argentina, of severe food poisoning illness on a healthy adult woman associated to B. cereus strain MVL2011. The studied strain was highly cytotoxic, showed high ability to detach Caco-2 cells and was positive for the hblA, hblB, and hblC genes of the hbl complex, bceT, entS and ces. As it is considered that B. cereus emetic cluster evolved from a panmictic population of diarrheal strains, B. cereus MVL2011 could constitute an intermediate strain between diarrheal and emetic strains.

  10. Zwittermicin A-producing strains of Bacillus cereus from diverse soils.

    OpenAIRE

    Stabb, E V; Jacobson, L. M.; Handelsman, J

    1994-01-01

    Bacillus cereus UW85 produces a novel aminopolyol antibiotic, zwittermicin A, that contributes to the ability of UW85 to suppress damping-off of alfalfa caused by Phytophthora medicaginis. UW85 produces a second antibiotic, provisionally designated antibiotic B, which also contributes to suppression of damping-off but has not been structurally defined yet and is less potent than zwittermicin A. The purpose of this study was to isolate genetically diverse strains of B. cereus that produce zwit...

  11. Probiotic Bacillus cereus strains, a potential risk for public health in China

    Directory of Open Access Journals (Sweden)

    Kui eZhu

    2016-05-01

    Full Text Available Bacillus cereus is an important cause of foodborne infectious disease and food poisoning. However, B. cereus has also been used as a probiotic in human medicine and livestock production, with low standards of safety assessment. In this study, we evaluated the safety of 15 commercial probiotic B. cereus preparations from China in terms of mislabeling, toxin production, and transferable antimicrobial resistance. Most preparations were incorrectly labeled, as they contained additional bacterial species; one product did not contain viable B. cereus at all. In total, 18 B. cereus group strains – specifically B. cereus and B. thuringiensis – were isolated. Enterotoxin genes nhe, hbl, and cytK1, as well as the ces-gene were assessed by PCR. Enterotoxin production and cytotoxicity were confirmed by ELISA and cell culture assays, respectively. All isolated B. cereus group strains produced the enterotoxin Nhe; 15 strains additionally produced Hbl. Antimicrobial resistance was assessed by microdilution; resistance genes were detected by PCR and further characterized by sequencing, transformation and conjugation assays. Nearly half of the strains harbored the antimicrobial resistance gene tet(45. In one strain, tet(45 was situated on a mobile genetic element – encoding a site specific recombination mechanism – and was transferable to Staphylococcus aureus and B. subtilis by electro-transformation. In view of the wide and uncontrolled use of these products, stricter regulations for safety assessment, including determination of virulence factors and transferable antimicrobial resistance genes, are urgently needed.

  12. Study on Attenuation Characteristics of Biocontrol Strain Anti-8098A, Bacillus cereus, against Ralstoniasolanacearum

    Institute of Scientific and Technical Information of China (English)

    BoLIU; Ying-ZhiLIN; Yu-JingZHU; Ci-BinGE; YiCAO

    2004-01-01

    The present study dealt with the attenuation characteristics of bacterial-wilt-disease biocontrol strain Anti-8098A, Bacillus cereus, againstpathogeny Ralstonia solanacearum (RS). In order to distinguish the pathogenicity of RS, the attenuation index (radius of the center red ring/radius of the whole mycelium ring, on TTC culture medium) was established (Hayward, 1976), companying with the mortality of tomato

  13. Draft Genome Sequence of Bacillus cereus Strain BcFL2013, a Clinical Isolate Similar to G9241

    OpenAIRE

    Gee, Jay E.; Marston, Chung K.; Sammons, Scott A.; Burroughs, Mark A.; Hoffmaster, Alex R.

    2014-01-01

    Bacillus cereus strains, such as G9241, causing anthrax-like illnesses have recently been discovered. We report the genome sequence of a clinical strain, B. cereus BcFL2013, which is similar to G9241, recovered from a patient in Florida.

  14. Comparison of Bacillus thuringiensis and Bacillus cereus

    International Nuclear Information System (INIS)

    Bacillus cereus and Bacillus thuringiensis are closely related, spore forming soil bacteria. B. thuringiensis produces insecticidal crystal proteins during sporulation and these toxins are the most important biopesticides in the world today. Genomes of the B. thuringiensis and B. cereus strains were analysed by pulsed field gel electrophoresis after treatment of the DNA with the restriction enzyme NotI. The NotI fingerprint patterns varied both within the B. thuringiensis and the B. cereus strains. The size of the fragments varied between 15 and 1350 kb. When physical maps of the B. thuringiensis and B. cereus strains were compared, B. thuringiensis appeared to be as closely related to B. cereus as the B. cereus strains were to each other. Nine out of 12 B. thuringiensis strains and 18 out of 25 B. cereus strains produced enterotoxins. The close relationship between B. thuringiensis and B. cereus should be taken into consideration when B. thuringiensis is used as a biopesticide. (author). 10 refs, 4 figs, 1 tab

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yiqiang [Department of Environmental Sciences, University of California, Riverside, Riverside, CA-92521 (United States)]. E-mail: yqzhang@ucr.edu; Lu Jianhang [Department of Environmental Sciences, University of California, Riverside, Riverside, CA-92521 (United States); Wu Laosheng [Department of Environmental Sciences, University of California, Riverside, Riverside, CA-92521 (United States); Chang, Andrew [Department of Environmental Sciences, University of California, Riverside, Riverside, CA-92521 (United States); Frankenberger, William T. [Department of Environmental Sciences, University of California, Riverside, Riverside, CA-92521 (United States)

    2007-09-01

    Elevated NO{sub 3} {sup -} 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{sub 3} {sup -} and degrade CTN in a mineral medium. The results showed that the efficiency of NO{sub 3} {sup -} 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{sub 3} {sup -} (100 mg/L) and 99% of CTN (78 {mu}g/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{sub 3} {sup -} 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{sub 3} {sup -}, and simultaneously degrade CTN. These results suggest that B. cereus strain NS1 may have great potential to remediate NO{sub 3} {sup -} and CTN contaminated water in nursery recycling ponds.

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

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    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.

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

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    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

  18. 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. PMID:24309214

  19. Detection of toxigenic Bacillus cereus strains isolated from vegetables in Mexico City.

    Science.gov (United States)

    Flores-Urbán, Karen A; Natividad-Bonifacio, Iván; Vázquez-Quiñones, Carlos R; Vázquez-Salinas, Carlos; Quiñones-Ramírez, Elsa Irma

    2014-12-01

    Bacillus cereus can cause diarrhea and emetic syndromes after ingestion of food contaminated with it. This ability is due to the production of enterotoxins by this microorganism, these being the hemolysin BL complex, which is involved in the diarrheal syndrome, and cereulide, which is responsible for the emetic syndrome. The detection of genes associated with the production of these toxins can predict the virulence of strains isolated from contaminated food. In this paper, we analyzed 100 samples of vegetables, 25 of each kind (broccoli, coriander, carrot, and lettuce) obtained from different markets in Mexico City and its metropolitan area. B. cereus was isolated in 32, 44, 84, and 68% of the samples of broccoli, carrot, lettuce, and coriander, respectively. The hblA gene (encoding one of the three subunits of hemolysin BL) was amplified in 100% of the B. cereus isolates, and the ces gene (encoding the cereulide) could not be amplified from any of them. This is the first report of B. cereus isolation from the vegetables analyzed in this work and, also, the first report in Mexico of the isolation from vegetables of strains with potential virulence. The results should serve as evidence of the potential risk of consuming these foods without proper treatment.

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

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    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.

  1. Comparative analysis of biofilm formation by Bacillus cereus reference strains and undomesticated food isolates and the effect of free iron

    NARCIS (Netherlands)

    Hayrapetyan, H.; Muller, L.K.; Tempelaars, M.H.; Abee, T.; Nierop Groot, M.N.

    2015-01-01

    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)

  2. 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

  3. Characterization of melanin produced by a wild-type strain of Bacillus cereus

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianping; CAI Jun; DENG Yinyue; CHEN Yuehua; REN Gaixin

    2007-01-01

    Bacillus cereus 58 (Bc58)is a UV-resistant wild type strain that has an ability to produce a sorrel pigment induced by L-tyrosine.The Fourier-transform infrared (FT-IR)spectra and chemical tests of its pigment are similar to that of the standard melanin (Sigma).A bioassay shows that the LC50 of a Bacillus thuringiensis (Bt)formulation added with the melanin of Bc58 and exposed to UV for 5 h is 16.1 μg/ml,which is similar to that of the Bt formulation without UV treatment,however,it is almost double that of the Bt formulation exposed to UV without the melanin of Bc58.The result of SDS-PAGE indicates that the melanin of Bc58 can protect the insecticidal crystal proteins from degradation.This suggests that it is an excellent UV protective agent for the insecticidal crystal proteins of the Bt formulation.

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

    Science.gov (United States)

    Thorsen, Line; Kando, Christine Kere; Sawadogo, Hagrétou; Larsen, Nadja; Diawara, Bréhima; Ouédraogo, Georges Anicet; Hendriksen, Niels Bohse; Jespersen, Lene

    2015-03-01

    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 cereus occasionally occurs in Maari. This study characterizes succession patterns and pathogenic potential of B. cereus isolated from the raw materials (ash, water from a drilled well (DW) and potash), seed mash throughout fermentation (0-96h), after steam cooking and sun drying (final product) from two production sites of Maari. Aerobic mesophilic bacterial (AMB) counts in raw materials were of 10(5)cfu/ml in DW, and ranged between 6.5×10(3) and 1.2×10(4)cfu/g in potash, 10(9)-10(10)cfu/g in seed mash during fermentation and 10(7) - 10(9) after sun drying. Fifty three out of total 290 AMB isolates were 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 analysis of concatenated sequences of glpF, gmk, ilvD, pta, pur, pycA and tpi revealed that the M13-PCR group 1 isolates were related to B. cereus biovar anthracis CI, while the M13-PCR group 2 isolates were identical to cereulide (emetic toxin) producing B. cereus strains. The M13-PCR group 1 isolates harboured poly-γ-D-glutamic acid capsule biosynthesis genes capA, capB and capC showing 99-100% identity with the environmental B. cereus isolate 03BB108. Presence of cesB of the cereulide synthetase gene cluster was confirmed by PCR in M13-PCR group 2 isolates. The B. cereus harbouring the cap genes were 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

  5. COLONIZATION OF VIGNA RADIATA ROOTS BY CHROMIUM RESISTANT BACTERIAL STRAINS OF OCHROBACTRUM INTERMEDIUM, BACILLUS CEREUS AND BREVIBA CTERIUM SP.

    Institute of Scientific and Technical Information of China (English)

    MUHAMMAD Faisal; SHAHIDA Hasnain

    2005-01-01

    The present study deals with colonization potential of plant growth promoting bacterial strains ( Ochrobactrum intermedium, Bacillus cereus and Brevibacterium sp. ) on Vigna radiata roots. The roots were heavily colonized with O. intermedium and B. cereus as compared to Brevibacterium sp. O. intermedium mainly colonized rhizoplane while B. cereus occurred both on the rhizoplane and near root zone. O. intermedium and B. cereus were found to be present both on the rhizoplane and near root zone, while Brevibacterium only in the rhizosphere in the form of groups. The cells of B. cereus were found more in the sites where root exudates were existed. From the above results it was observed that the number of O. intermedium cells were large at root exudate site. Fig 2, Tab 1, Ref 15

  6. Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.

    Science.gov (United States)

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Gao, Chunlei

    2015-02-01

    Furfural was found to be the main organic pollutant in the wastewater coming from the Diosgenin factory. This substance is derived from acidic pentosan in Dioscorea zingiberensis and is also found in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. It is regarded as a toxicant and an inhibitor to the growth of microorganism in both sewage disposal and biological fermentation. A furfural-degrading strain (DS1) was isolated from activated sludge of wastewater treatment plant in a diosgenin factory by continuous enrichment culture. The strain was identified as Bacillus cereus based on morphological, physiological tests, as well as on 16S rDNA sequence and Biolog analyses. The capacity of this strain to grow on a mineral salt medium, utilizing furfural as the sole carbon and energy source to degrade furfural, was investigated in this study. Under the condition of pH 9.0, temperature 35 °C, with rotating speed of 150 rpm, and an inoculum of 6 %, the strain showed that the furfural degradation capacity reaches 35 % in 7 days, as measured by high-performance liquid chromatography. The addition of inorganic carbon sources could bring down the biodegradation efficiency of the furfural. The strain DS1 showed better furfural removal capacity, as compared to other inorganic carbon sources in the media. Furthermore, a furfural concentration of as high as 4,000 mg L(-1) was tolerated by the culture. The capacity to degrade furfural was demonstrated for the first time by using the genus B. cereus. This study suggests the possible application in biodegradation strategies.

  7. 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 BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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

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

    International Nuclear Information System (INIS)

    The local strain Bacillus cereus S3, 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 S3 towards PHB accumulation. At dose level 1.5 kGy the maximum PHB accumulation obtained was 3.2 gl-1

  9. 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.

  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 wi

  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 with

  12. Diversity of Bacillus cereus group strains is reflected in their broad range of pathogenicity and diverse ecological lifestyles.

    Science.gov (United States)

    Ceuppens, Siele; Boon, Nico; Uyttendaele, Mieke

    2013-06-01

    Bacillus cereus comprises a highly versatile group of bacteria, which are of particular interest because of their capacity to cause disease. Emetic food poisoning is caused by the toxin cereulide produced during the growth of emetic B. cereus in food, while diarrhoeal food poisoning is the result of enterotoxin production by viable vegetative B. cereus cells in the small intestine, probably in the mucus layer and/or attached to the host's intestinal epithelium. The numbers of B. cereus causing disease are highly variable, depending on diverse factors linked to the host (age, diet, physiology and immunology), bacteria (cellular form, toxin genes and expression) and food (nutritional composition and meal characteristics). Bacillus cereus group strains show impressive ecological diversity, ranging from their saprophytic life cycle in soil to symbiotic (commensal and mutualistic) lifestyles near plant roots and in guts of insects and mammals to various pathogenic ones in diverse insect and mammalian hosts. During all these different ecological lifestyles, their toxins play important roles ranging from providing competitive advantages within microbial communities to inhibition of specific pathogenic organisms for their host and accomplishment of infections by damaging their host's tissues.

  13. Biodegradation of real petroleum wastewater by immobilized hyper phenol-tolerant strains of Bacillus cereus in a fluidized bed bioreactor

    OpenAIRE

    Banerjee, Aditi; Ghoshal, Aloke K.

    2016-01-01

    Microbial bioremediation of petroleum wastewater by phenol-degrading-bacteria holds promise in circumventing the issue of petroleum-spill related pollution. Herein, biodegradation of petroleum wastewater samples collected from oil refinery site was carried out in a fluidized bed bioreactor by Ca-alginate immobilized biomass of phenol-degrading strains of Bacillus cereus (AKG1 MTCC9817 and AKG2 MTCC9818). Degradation performance of the system was evaluated by measuring the changes in chemical ...

  14. Identification, genetic diversity and cereulide producing ability of Bacillus cereus group strains isolated from Beninese traditional fermented food condiments.

    Science.gov (United States)

    Thorsen, Line; Azokpota, Paulin; Hansen, Bjarne Munk; Hounhouigan, D Joseph; Jakobsen, Mogens

    2010-08-15

    Bacillus cereus sensu lato is often detected in spontaneously fermented African foods but is rarely identified to species level. Only some of the B. cereus group species are reported to be pathogenic to humans and identification to species level is necessary to estimate the safety of these products. In the present study, a total of 19 Bacillus cereus group spp. isolated from afitin, iru and sonru, three spontaneously fermented African locust (Parkia biglobosa) bean based condiments produced in Benin, were investigated. The strains were isolated at 6, 12, 18, 24 and 48 h fermentation time. By using phenotypic and genotypic methods all of the isolates could be identified as B. cereus sensu stricto. The isolates were grouped according to their PM13 PCR (random amplification of polymorphic DNA PCR) fingerprint and formed two major clusters, one of which contained eight strains isolated from afitin (cluster 1). Highly similar PM13 profiles were obtained for seven of the isolates, one from afitin, one from iru and five from sonru (cluster 2). Four of the isolates, one from afitin and three from sonru, did not form any particular cluster. The PM13 profiles of cluster 2 isolates were identical to those which are specific to emetic toxin producers. Cereulide production of these isolates was confirmed by liquid chromatography mass spectrometry/mass spectrometry. This is the first report on cereulide producing B. cereus in African fermented foods. Occurrence of the opportunistic human pathogen B. cereus, which is able to produce emetic toxin in afitin, iru and sonru, could impose a health hazard. Interestingly, no reports on food poisoning from the consumption of the fermented condiments exist.

  15. 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

    2015-05-01

    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.

  16. De-hairing protease production by an isolated Bacillus cereus strain AT under solid-state fermentation using cow dung: Biosynthesis and properties

    OpenAIRE

    Vijayaraghavan, Ponnuswamy; Lazarus, Sophia; Vincent, Samuel Gnana Prakash

    2013-01-01

    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 supplementa...

  17. Biodiversity in Bacillus cereus

    NARCIS (Netherlands)

    Pielaat A; Fricker M; Nauta MJ; van Leusden FM; MGB

    2006-01-01

    In het kader van een EU project zijn door de verschillende partners experimenten uitgevoerd om inzicht te krijgen in de variatie in eigenschappen van B. cereus-stammen welke bijdragen aan de mate van virulentie. Hiertoe zijn 100 B. cereus-stammen geselecteerd en eigenschappen zoals toxine-vorming,

  18. Bacillus cereus Biofilms—Same, Only Different

    Science.gov (United States)

    Majed, Racha; Faille, Christine; Kallassy, Mireille; Gohar, Michel

    2016-01-01

    Bacillus cereus displays a high diversity of lifestyles and ecological niches and include beneficial as well as pathogenic strains. These strains are widespread in the environment, are found on inert as well as on living surfaces and contaminate persistently the production lines of the food industry. Biofilms are suspected to play a key role in this ubiquitous distribution and in this persistency. Indeed, B. cereus produces a variety of biofilms which differ in their architecture and mechanism of formation, possibly reflecting an adaptation to various environments. Depending on the strain, B. cereus has the ability to grow as immersed or floating biofilms, and to secrete within the biofilm a vast array of metabolites, surfactants, bacteriocins, enzymes, and toxins, all compounds susceptible to act on the biofilm itself and/or on its environment. Within the biofilm, B. cereus exists in different physiological states and is able to generate highly resistant and adhesive spores, which themselves will increase the resistance of the bacterium to antimicrobials or to cleaning procedures. Current researches show that, despite similarities with the regulation processes and effector molecules involved in the initiation and maturation of the extensively studied Bacillus subtilis biofilm, important differences exists between the two species. The present review summarizes the up to date knowledge on biofilms produced by B. cereus and by two closely related pathogens, Bacillus thuringiensis and Bacillus anthracis. Economic issues caused by B. cereus biofilms and management strategies implemented to control these biofilms are included in this review, which also discuss the ecological and functional roles of biofilms in the lifecycle of these bacterial species and explore future developments in this important research area. PMID:27458448

  19. Fluorescent Amplified Fragment Length Polymorphism Analysis of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis Isolates

    OpenAIRE

    Hill, Karen K.; Ticknor, Lawrence O.; Okinaka, Richard T.; Asay, Michelle; Blair, Heather; Bliss, Katherine A.; Laker, Mariam; Pardington, Paige E.; Richardson, Amber P.; Tonks, Melinda; Beecher, Douglas J.; Kemp, John D.; Kolstø, Anne-Brit; Wong, Amy C. Lee; Keim, Paul

    2004-01-01

    DNA from over 300 Bacillus thuringiensis, Bacillus cereus, and Bacillus anthracis isolates was analyzed by fluorescent amplified fragment length polymorphism (AFLP). B. thuringiensis and B. cereus isolates were from diverse sources and locations, including soil, clinical isolates and food products causing diarrheal and emetic outbreaks, and type strains from the American Type Culture Collection, and over 200 B. thuringiensis isolates representing 36 serovars or subspecies were from the U.S. D...

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

    Directory of Open Access Journals (Sweden)

    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

  1. Identification, genetic diversity and cereulide producing ability of Bacillus cereus group strains isolated from Beninese traditional fermented food condiments

    DEFF Research Database (Denmark)

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

    2010-01-01

    . In the present study, a total of 19 Bacillus cereus group spp. isolated from afitin, iru and sonru, three spontaneously fermented African locust (Parkia biglobosa) bean based condiments produced in Benin, were investigated. The strains were isolated at 6, 12, 18, 24 and 48 h fermentation time. By using...

  2. Comparative genomics of iron-transporting systems in Bacillus cereus strains and impact of iron sources on growth and biofilm formation

    NARCIS (Netherlands)

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

    2016-01-01

    Iron is an important element for bacterial viability, however it is not readily available in most environments. We studied the ability of 20 undomesticated food isolates of Bacillus cereus and two reference strains for capacity to use different (complex) iron sources for growth and biofilm format

  3. Bacillus Cereus GD 55 Strain Improvement by Physical and Chemical Mutagenesis for Enhanced Production of Fibrinolytic Protease

    Directory of Open Access Journals (Sweden)

    E. VENKATA NAGA RAJU

    2013-05-01

    Full Text Available This work has been undertaken to enhance the production of industrially important fibrinolytic protease by subjecting indigenous fibrinolytic protease producing Bacillus cereus to strain improvement by random mutagenesis using ultra-violet (UV irradiation, ethyl methane sulfonate (EMS and ethidium bromide treatment. Mutants were screened on the basis of enzyme assay by spectrophotometer using folin’s phenol reagent. Ethyl methane sulfonate (EMS and ethidium bromide treated Bacillus cereus GD 55 was proved to be the best for optimum production of fibrinolytic protease. The effect of different production parameters such as carbon source, inoculum sizes, pH, temperature, nitrogen source (inorganic and organic and incubation time on fibrinolytic protease production by the mutated bacterial strain was studied. The enzyme production was assayed in submerged fermentation (SmF condition. The maximum fibrinolytic protease production was observed with fructose 1% (18.60 ± 0.62 U/ml, inoculum size level 2% (22.10 ± 0.80 U/ml, pH 8.0 (28.65 ± 0.41 U/ml, temperature 35°C (28.68 ± 0.19 U/ml, NH4NO3 1% (34.24 ± 0.12 U/ml, peptone 1% (35.68 ± 0.27 U/ml and incubation time 48 hours (38.92 ± 0.56 U/ml in the production medium. EMS&EB-15 mutant strains were found to produce 2-4 fold more enzyme. Thus these findings have more impact on enzyme economy for biotechnological applications of microbial fibrinolytic proteases.

  4. 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

  5. Fatty Acid Profiles for Differentiating Growth Medium Formulations Used to Culture Bacillus cereus T-strain Spores.

    Science.gov (United States)

    Ehrhardt, Christopher J; Murphy, Devonie L; Robertson, James M; Bannan, Jason D

    2015-07-01

    Microbial biomarkers that indicate aspects of an organism's growth conditions are important targets of forensic research. In this study, we examined fatty acid composition as a signature for the types of complex nutrients in the culturing medium. Bacillus cereus T-strain spores were grown in medium formulations supplemented with one of the following: peptone (meat protein), tryptone (casein protein), soy protein, and brain-heart infusion. Cellular biomass was profiled with fatty acid methyl ester (FAME) analysis. Results showed peptone cultures produced spores enriched in straight-chained lipids. Tryptone cultures produced spores enriched in branched-odd lipids when compared with peptone, soy, and brain-heart formulations. The observed FAME variation was used to construct a set of discriminant functions that could help identify the nutrients in a culturing recipe for an unknown spore sample. Blinded classification tests were most successful for spores grown on media containing peptone and tryptone, showing 88% and 100% correct identification, respectively. PMID:25854710

  6. BACILLUS CEREUS: ISOLATION IN JENNET MILK

    Directory of Open Access Journals (Sweden)

    M.L. Scatassa

    2011-01-01

    Full Text Available Jennet milk as human food is hypoallergenic for patients affected by Cow Milk Protein Allergy and multiple food allergies. For these pathologies, jennet milk represents the best alternative to other types of milk. Therefore, jennet milk consumers are very sensible to the effects of pathogens' contaminations, and several hygienic practices during the milk production need to be adopted. During regular monitoring in one Sicilian jennet farm, Bacillus cereus in the milk was detected. In 3 bulk milk samples (maximum concentration: 1.2 x 103 ufc/ml, in 3 individual milk samples (10, 20 e 60 ufc/ml, in the milk filter (5 ufc/cm2, in the soil (maximum concentration: 1.5 x 103 ufc/g, on the hands and the gloves of two milkers, on the animal hide (from 1 to 3 ufc/cm2. No spores were detected. A total of 8 Bacillus cereus s.s. strains were analyzed for diarrhoic toxin, and 6 strains producing enterotoxins resulted. The improvement of environmental and milking hygienic conditions reduced Bacillus cereus concentration.

  7. 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 toxin-producin

  8. 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.

  9. Evaluation of the Toxicity and Toxicokinetics of Cereulide from an Emetic Bacillus cereus Strain of Milk Origin.

    Science.gov (United States)

    Cui, Yifang; Liu, Yuan; Liu, Xiaoye; Xia, Xi; Ding, Shuangyang; Zhu, Kui

    2016-06-06

    Bacillus cereus is an opportunistic foodborne agent causing food poisoning and many infectious diseases. The heat-stable emetic toxin cereulide is one of the most prevalent toxins produced by pathogenic B. cereus, resulting in symptoms such as emesis and liver failure. In the present work, the toxicity and toxicokinetics of cereulide from an emetic B. cereus isolate (CAU45) of raw milk were evaluated. The production of cereulide was tested by a cytotoxicity test and enzyme immunoassay, and confirmed by the presence of the ces (cereulide synthetase) gene and the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. All results showed that the amount and toxicity of cereulide produced by CAU45 was 7 to 15.3 folds higher than the reference emetic B. cereus DSMZ 4312. Cereulide in plasma was collected at different time points after a single intravenous injection to evaluate its toxicokinetics in rabbits. The maximum concentration of cereulide was achieved in 2.6 ± 3.4 h after administration, with the elimination half-life of 10.8 ± 9.1 h, which expands our understanding of the toxic effects of cereulide. Together, it suggests that urgent sanitary practices are needed to eliminate emetic toxins and emetic B. cereus in raw milk.

  10. Evaluation of the Toxicity and Toxicokinetics of Cereulide from an Emetic Bacillus cereus Strain of Milk Origin

    Directory of Open Access Journals (Sweden)

    Yifang Cui

    2016-06-01

    Full Text Available Bacillus cereus is an opportunistic foodborne agent causing food poisoning and many infectious diseases. The heat-stable emetic toxin cereulide is one of the most prevalent toxins produced by pathogenic B. cereus, resulting in symptoms such as emesis and liver failure. In the present work, the toxicity and toxicokinetics of cereulide from an emetic B. cereus isolate (CAU45 of raw milk were evaluated. The production of cereulide was tested by a cytotoxicity test and enzyme immunoassay, and confirmed by the presence of the ces (cereulide synthetase gene and the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS method. All results showed that the amount and toxicity of cereulide produced by CAU45 was 7 to 15.3 folds higher than the reference emetic B. cereus DSMZ 4312. Cereulide in plasma was collected at different time points after a single intravenous injection to evaluate its toxicokinetics in rabbits. The maximum concentration of cereulide was achieved in 2.6 ± 3.4 h after administration, with the elimination half-life of 10.8 ± 9.1 h, which expands our understanding of the toxic effects of cereulide. Together, it suggests that urgent sanitary practices are needed to eliminate emetic toxins and emetic B. cereus in raw milk.

  11. Evaluation of the Toxicity and Toxicokinetics of Cereulide from an Emetic Bacillus cereus Strain of Milk Origin.

    Science.gov (United States)

    Cui, Yifang; Liu, Yuan; Liu, Xiaoye; Xia, Xi; Ding, Shuangyang; Zhu, Kui

    2016-01-01

    Bacillus cereus is an opportunistic foodborne agent causing food poisoning and many infectious diseases. The heat-stable emetic toxin cereulide is one of the most prevalent toxins produced by pathogenic B. cereus, resulting in symptoms such as emesis and liver failure. In the present work, the toxicity and toxicokinetics of cereulide from an emetic B. cereus isolate (CAU45) of raw milk were evaluated. The production of cereulide was tested by a cytotoxicity test and enzyme immunoassay, and confirmed by the presence of the ces (cereulide synthetase) gene and the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. All results showed that the amount and toxicity of cereulide produced by CAU45 was 7 to 15.3 folds higher than the reference emetic B. cereus DSMZ 4312. Cereulide in plasma was collected at different time points after a single intravenous injection to evaluate its toxicokinetics in rabbits. The maximum concentration of cereulide was achieved in 2.6 ± 3.4 h after administration, with the elimination half-life of 10.8 ± 9.1 h, which expands our understanding of the toxic effects of cereulide. Together, it suggests that urgent sanitary practices are needed to eliminate emetic toxins and emetic B. cereus in raw milk. PMID:27275834

  12. [Detection of toxigenic genes nheA, nheB and nheC in Bacillus cereus strains isolated from powdered milk samples in Costa Rica].

    Science.gov (United States)

    Rojas, Jonathan; Rodríguez-Rodríguez, Carlos E; Pérez, Cristian; Chaves, Carolina; Arias, María Laura

    2014-09-01

    Powdered milk is a frequently consumed product that does not need to be kept under cold conditions. Nevertheless, different microorganisms may contaminate it. Powdered milk is a highly consumed product by Costa Rican population, and Bacillus cereus is a potentially pathogenic bacteria associated to it, with the ability to develop toxins depending on the presence of the respective codifying genes. The aim of this study was to determine the presence of the toxigenic genes nheA, nheB and nheC from B. cereus strains, found in powdered milk sold at the Costa Rican national market. Five different lots of ten brands of powdered milk, distributed in the metropolitan area of San José, Costa Rica were analyzed. B cereus load was quantified using the Most Probable Number technique and identified using the Vitek system. The presence of the toxigenic genes was determined using the PCR technique. The isolation frequency of this bacteria in the powdered milk samples analyzed reached 50%, with populations ranging from 3 to > 100 MPN/g. Five out from nineteen strains were found positive for the three toxigenic genes, indicating contamination with potentially toxigenic B. cereus in powdered milk distributed in the national market, and an important risk for public. health.

  13. 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. PMID:27272929

  14. 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. PMID:27272929

  15. 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.

  16. Genetic relationships between sympatric populations of Bacillus cereus and Bacillus thuringiensis, as revealed by rep-PCR genomic fingerprinting

    Directory of Open Access Journals (Sweden)

    Ana Paula S Peruca

    2008-08-01

    Full Text Available The bacterial strain Bacillus cereus is closely related to Bacillus thuringiensis, although any genetic relationship between the two strains is still in debate. Using rep-PCR genomic fingerprinting, we established the genetic relationships between Brazilian sympatric populations of B. cereus and B. thuringiensis simultaneously collected from two geographically separate sites. We observed the formation of both B. thuringiensis and B. cereus clusters, as well as strains of B. cereus that are more closely related to B. thuringiensis than to other B. cereus strains. In addition, lower genetic variability was observed among B. thuringiensis clusters compared to B. cereus clusters, indicating that either the two species should be categorized as separate or that B. thuringiensis may represent a clone from a B. cereus background.

  17. Differentiation of Bacillus anthracis from Bacillus cereus by gas chromatographic whole-cell fatty acid analysis.

    OpenAIRE

    Lawrence, D; Heitefuss, S; Seifert, H S

    1991-01-01

    Three strains of Bacillus anthracis and seven strains of Bacillus cereus were grown on complex medium and on synthetic medium. Gas chromatographic analysis of whole-cell fatty acids of strains grown on complex medium gave nearly identical fatty acid patterns. Fatty acid patterns of strains grown on synthetic medium showed a high content of branched-chain fatty acids. Significant differences between the fatty acid patterns of the two species were found. Odd iso/anteiso fatty acid ratios were a...

  18. 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

    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......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....../or content of cry genes. Thus, a large proportion of the B. cereus-like organisms present in food may belong to B. thuringiensis....

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

    NARCIS (Netherlands)

    Wijman, J.G.E.; Leeuw, de P.P.L.A.; Moezelaar, R.; Zwietering, M.H.; Abee, T.

    2007-01-01

    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 so

  20. Mass spectrometric profiling of Bacillus cereus strains and quantitation of the emetic toxin cereulide by means of stable isotope dilution analysis and HEp-2 bioassay.

    Science.gov (United States)

    Stark, Timo; Marxen, Sandra; Rütschle, Andrea; Lücking, Genia; Scherer, Siegfried; Ehling-Schulz, Monika; Hofmann, Thomas

    2013-01-01

    A fast and robust high-throughput ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC-TOF MS) profiling method was developed and successfully applied to discriminate a total of 78 Bacillus cereus strains into no/low, medium and high producers of the emetic toxin cereulide. The data obtained by UPLC-TOF MS profiling were confirmed by absolute quantitation of cereulide in selected samples by means of high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) and stable isotope dilution assay (SIDA). Interestingly, the B. cereus strains isolated from four vomit samples and five faeces samples from patients showing symptoms of intoxication were among the group of medium or high producers. Comparison of HEp-2 bioassay data with those determined by means of mass spectrometry showed differences, most likely because the HEp-2 bioassay is based on the toxic action of cereulide towards mitochondria of eukaryotic cells rather than on a direct measurement of the toxin. In conclusion, the UPLC-electrospray ionization (ESI)-TOF MS and the HPLC-ESI-MS/MS-SIDA analyses seem to be promising tools for the robust high-throughput analysis of cereulide in B. cereus cultures, foods and other biological samples.

  1. Bacillus cereus as a nongastrointestinal pathogen

    Directory of Open Access Journals (Sweden)

    Pavani G.

    2014-02-01

    Full Text Available The potential of Bacillus cereus to cause systemic infections is of serious concern. Apart from Gastrointestinal infections, it causes respiratory tract infections, nosocomial infections, eye infections, CNS infections, cutaneous infections, endocarditis, osteomyelitis and urinary tract infections. The potential of this bacterium to cause life threatening infections has increased. Trauma is an important predisposing factor for Bacillus cereus infections. The maintenance of skin and mucous membrane integrity limits infection by this micro-organism. [Int J Res Med Sci 2014; 2(1.000: 28-30

  2. 产异甘露聚糖酶菌株的复合诱变%Compound Inducement of Bacillus cereus Strain Producing Isomerous Mannanase

    Institute of Scientific and Technical Information of China (English)

    王永; 田春华; 竹磊; 朱海华

    2011-01-01

    Bacillus cereus strain SKS4 was induced by ultraviolet radiation, DES and 60Co - γ ray, and a strain SKS4360 with high activity of isomerous mannanase was screened out. The enzyme activity of SKS4360 in the fermentation solution was increased from 1004 U/mL to 2026. 6 U/mL, and it was stable in different generations.%利用紫外线照射法、硫酸二乙酯(DES)法、60Co-γ射线辐照法对蜡样芽孢杆菌(Bacillus cereus)SKS4进行复合诱变处理,筛选到了1株产异甘露聚糖酶的蜡样芽孢杆菌SKS4360,使其发酵液酶活从1004U/mL提高到2026.6U/ML,而且其酶活力表现稳定.

  3. 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.

  4. 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.

  5. The Phylogeny of Bacillus cereus sensu lato.

    Science.gov (United States)

    Okinaka, Richard T; Keim, Paul

    2016-02-01

    The three main species of the Bacillus cereus sensu lato, B. cereus, B. thuringiensis, and B. anthracis, were recognized and established by the early 1900s because they each exhibited distinct phenotypic traits. B. thuringiensis isolates and their parasporal crystal proteins have long been established as a natural pesticide and insect pathogen. B. anthracis, the etiological agent for anthrax, was used by Robert Koch in the 19th century as a model to develop the germ theory of disease, and B. cereus, a common soil organism, is also an occasional opportunistic pathogen of humans. In addition to these three historical species designations, are three less-recognized and -understood species: B. mycoides, B. weihenstephanensis, and B. pseudomycoides. All of these "species" combined comprise the Bacillus cereus sensu lato group. Despite these apparently clear phenotypic definitions, early molecular approaches to separate the first three by various DNA hybridization and 16S/23S ribosomal sequence analyses led to some "confusion" because there were limited differences to differentiate between these species. These and other results have led to frequent suggestions that a taxonomic change was warranted to reclassify this group to a single species. But the pathogenic properties of B. anthracis and the biopesticide applications of B. thuringiensis appear to "have outweighed pure taxonomic considerations" and the separate species categories are still being maintained. B. cereus sensu lato represents a classic example of a now common bacterial species taxonomic quandary. PMID:26999390

  6. Genetic Differentiation between Sympatric Populations of Bacillus cereus and Bacillus thuringiensis

    Science.gov (United States)

    Vilas-Boas, Gislayne; Sanchis, Vincent; Lereclus, Didier; Lemos, Manoel Victor F.; Bourguet, Denis

    2002-01-01

    Little is known about genetic exchanges in natural populations of bacteria of the spore-forming Bacillus cereus group, because no population genetics studies have been performed with local sympatric populations. We isolated strains of Bacillus thuringiensis and B. cereus from small samples of soil collected at the same time from two separate geographical sites, one within the forest and the other at the edge of the forest. A total of 100 B. cereus and 98 B. thuringiensis strains were isolated and characterized by electrophoresis to determine allelic composition at nine enzymatic loci. We observed genetic differentiation between populations of B. cereus and B. thuringiensis. Populations of a given Bacillus species—B. thuringiensis or B. cereus—were genetically more similar to each other than to populations of the other Bacillus species. Hemolytic activity provided further evidence of this genetic divergence, which remained evident even if putative clones were removed from the data set. Our results suggest that the rate of gene flow was higher between strains of the same species, but that exchanges between B. cereus and B. thuringiensis were nonetheless possible. Linkage disequilibrium analysis revealed sufficient recombination for B. cereus populations to be considered panmictic units. In B. thuringiensis, the balance between clonal proliferation and recombination seemed to depend on location. Overall, our data indicate that it is not important for risk assessment purposes to determine whether B. cereus and B. thuringiensis belong to a single or two species. Assessment of the biosafety of pest control based on B. thuringiensis requires evaluation of the extent of genetic exchange between strains in realistic natural conditions. PMID:11872495

  7. 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. PMID:24596497

  8. Food – bacteria interplay: Pathometabolism of emetic Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Monika eEhling-Schulz

    2015-07-01

    Full Text Available Bacillus cereus is a gram-positive endospore forming bacterium known for its wide spectrum of phenotypic traits, enabling it to occupy diverse ecological niches. Although the population structure of B. cereus is highly dynamic and rather panmictic, production of the emetic B. cereus toxin cereulide is restricted to strains with specific genotypic traits, associated with distinct environmental habitats. Cereulide is an ionophoric dodecadepsipeptide that is produced non-ribosomally by an enzyme complex with an unusual modular structure, named cereulide synthetase (Ces NRPS. The ces gene locus is encoded on a mega virulence plasmid related to the Bacillus anthracis toxin plasmid pXO1. Cereulide, a highly thermo- and pH- resistant molecule, is preformed in food, evokes vomiting a few hours after ingestion and was shown to be the direct cause of gastroenteritis symptoms; occasionally it is implicated in severe clinical manifestations including acute liver failures. Control of toxin gene expression in emetic Bacillus cereus involves central transcriptional regulators, such as CodY and AbrB, thereby inextricably linking toxin gene expression to life cycle phases and specific conditions, such as the nutrient supply encountered in food matrices. While in recent years considerable progress has been made in the molecular and biochemical characterization of cereulide toxin synthesis, far less is known about the embedment of toxin synthesis in the life cycle of B. cereus. Information about signals acting on toxin production in the food environment is literally lacking. We summarize the data available on the complex regulatory network controlling cereulide toxin synthesis, discuss the role of intrinsic and extrinsic factors acting on toxin biosynthesis in emetic B. cereus and stress how unraveling these processes can lead to the development of novel effective strategies to prevent toxin synthesis in the food production and processing chain.

  9. Antimicrobial Effects of Honey on Bacillus Cereus

    OpenAIRE

    This paper should be cited as: Javadzadeh M, Najafi M, Rezaei M, Dastoor M, Behzadi AS, Amiri A . [ Antimicrobial Effects of Honey on Bacillus Cereus ]. MLJ. 201 4 ; 8 ( 2 ): 55 - 61 [Article in Persian] Javadzadeh, M. (MSc; M Najafi; Rezaei, M. (MSc; Dastoor, M. (BSc; Behzadi, AS. (MSc; Amiri, A. (MSc

    2014-01-01

    Background and Objective: Honey is a healthy and nutritious food that has been used for a long time as a treatment for different diseases. One of the applied properties of honey is its antimicrobial effect, which differs between different types of honey due to variation of phenolic and antioxidant compositions. This study aimed to assess antimicrobial effect of honey on Bacillus cereus, considering its chemical properties. Material and Methods: Three samples of honey (A1 and A2 of Khorasan Ra...

  10. Progress in food-related research focussing on Bacillus cereus

    NARCIS (Netherlands)

    Vries, de Y.P.; Voort, van der M.; Schaik, van W.; Hornstra, L.M.; Vos, de W.M.; Abee, T.

    2004-01-01

    Bacillus cereus is a gram-positive, rod-shaped, endospore-forming bacterium that occurs ubiquitously and is frequently isolated from soil and food products. When B. cereus is present in foods, it can cause spoilage and poisoning. The work of our group is focussed on several properties of B. cereus t

  11. Quantification of the Effects of Salt Stress and Physiological State on Thermotolerance of Bacillus cereus ATCC 10987 and ATCC 14579

    NARCIS (Netherlands)

    Besten, den H.M.W.; Mataragas, M.; Moezelaar, R.; Abee, T.; Zwietering, M.H.

    2006-01-01

    The food-borne pathogen Bacillus cereus can acquire enhanced thermal resistance through multiple mechanisms. Two Bacillus cereus strains, ATCC 10987 and ATCC 14579, were used to quantify the effects of salt stress and physiological state on thermotolerance. Cultures were exposed to increasing concen

  12. Enhanced transformation efficiency of recalcitrant Bacillus cereus and Bacillus weihenstephanensis isolates upon in vitro methylation of plasmid DNA

    NARCIS (Netherlands)

    Nierop Groot, M.N.; Nieboer, F.; Abee, T.

    2008-01-01

    Digestion patterns of chromosomal DNAs of Bacillus cereus and Bacillus weihenstephanensis strains suggest that Sau3AI-type restriction modification systems are widely present among the isolates tested. In vitro methylation of plasmid DNA was used to enhance poor plasmid transfer upon electroporation

  13. Assessment of a new selective chromogenic Bacillus cereus group plating medium and use of enterobacterial autoinducer of growth for cultural identification of Bacillus species.

    Science.gov (United States)

    Reissbrodt, R; Rassbach, A; Burghardt, B; Rienäcker, I; Mietke, H; Schleif, J; Tschäpe, H; Lyte, M; Williams, P H

    2004-08-01

    A new chromogenic Bacillus cereus group plating medium permits differentiation of pathogenic Bacillus species by colony morphology and color. Probiotic B. cereus mutants were distinguished from wild-type strains by their susceptibilities to penicillin G or cefazolin. The enterobacterial autoinducer increased the sensitivity and the speed of enrichment of B. cereus and B. anthracis spores in serum-supplemented minimal salts medium (based on the standard American Petroleum Institute medium) and buffered peptone water. PMID:15297532

  14. Development of a powder formulation based on Bacillus cereus sensu lato strain B25 spores for biological control of Fusarium verticillioides in maize plants.

    Science.gov (United States)

    Martínez-Álvarez, Juan C; Castro-Martínez, Claudia; Sánchez-Peña, Pedro; Gutiérrez-Dorado, Roberto; Maldonado-Mendoza, Ignacio E

    2016-05-01

    Maize is an economically important crop in northern Mexico. Different fungi cause ear and root rot in maize, including Fusarium verticillioides (Sacc.) Nirenberg. Crop management of this pathogen with chemical fungicides has been difficult. By contrast, the recent use of novel biocontrol strategies, such as seed bacterization with Bacillus cereus sensu lato strain B25, has been effective in field trials. These approaches are not without their problems, since insufficient formulation technology, between other factors, can limit success of biocontrol agents. In response to these drawbacks, we have developed a powder formulation based on Bacillus B25 spores and evaluated some of its characteristics, including shelf life and efficacy against F. verticillioides, in vitro and in maize plants. A talc-based powder formulation containing 1 × 10(9) c.f.u. g(-1) was obtained and evaluated for seed adherence ability, seed germination effect, shelf life and antagonism against F. verticillioides in in vitro and in planta assays. Seed adherence of viable bacterial spores ranged from 1.0 to 1.41 × 10(7) c.f.u. g(-1). Bacteria did not display negative effects on seed germination. Spore viability for the powder formulation slowly decreased over time, and was 53 % after 360 days of storage at room temperature. This formulation was capable of controlling F. verticillioides in greenhouse assays, as well as eight other maize phytopathogenic fungi in vitro. The results suggest that a talc-based powder formulation of Bacillus B25 spores may be sufficient to produce inoculum for biocontrol of maize ear and root rots caused by F. verticillioides. PMID:27038945

  15. Characterization of cell-free extracts from fenpropathrin-degrading strain Bacillus cereus ZH-3 and its potential for bioremediation of pyrethroid-contaminated soils.

    Science.gov (United States)

    Liu, Jie; Huang, Wenwen; Han, Haitao; She, Changchun; Zhong, Guohua

    2015-08-01

    Synthetic pyrethroid fenpropathrin has received increasing attention because of its environmental contamination and toxic effects on non-target organisms including human beings. Here we report the degradation characteristics of cell-free extracts from fenpropathrin-degrading strain Bacillus cereus ZH-3 and its potential for pyrethroid bioremediation in soils. 50mg·L(-1) of fenpropathrin was decreased to 20.6mg·L(-1) by the enzymatic extracts (869.4mg·L(-1)) within 30min. Kinetic constants Km and Vm were determined to be 1006.7nmol·L(-1) and 56.8nmol·min(-1), respectively. Degradation products were identified as 3-phenoxybenzaldehyde, α-hydroxy-3-phenoxy-benzeneacetonitrile and phenol by gas chromatography-mass spectrometry (GC-MS). In addition to degradation of fenpropathrin, the cell-free extracts could degrade other pyrethroids including beta-cypermethrin, cyfluthrin, deltamethrin and cypermethrin. Additionally, the reaction conditions were optimized. In the sterile and non-sterile soils, 50mg·kg(-1) of fenpropathrin was reduced to 15.3 and 13.9mg·L(-1) in 1d, respectively. Sprayed 100 and 300mg·kg(-1) of fenpropathrin emulsifiable concentrate (EC), up to 84.6% and 92.1% of soil fenpropathrin were removed from soils within 7d, respectively. Taken together, our results depict the biodegradation characteristics of cell-free extracts from B. cereus ZH-3, highlight its promising potential in bioremediation of pyrethroid-contaminated soils and also provide new insights into the utilization of degrading microbes.

  16. Food-bacteria interplay: pathometabolism of emetic Bacillus cereus.

    Science.gov (United States)

    Ehling-Schulz, Monika; Frenzel, Elrike; Gohar, Michel

    2015-01-01

    Bacillus cereus is a Gram-positive endospore forming bacterium known for its wide spectrum of phenotypic traits, enabling it to occupy diverse ecological niches. Although the population structure of B. cereus is highly dynamic and rather panmictic, production of the emetic B. cereus toxin cereulide is restricted to strains with specific genotypic traits, associated with distinct environmental habitats. Cereulide is an ionophoric dodecadepsipeptide that is produced non-ribosomally by an enzyme complex with an unusual modular structure, named cereulide synthetase (Ces non-ribosomal peptide synthetase). The ces gene locus is encoded on a mega virulence plasmid related to the B. anthracis toxin plasmid pXO1. Cereulide, a highly thermo- and pH- resistant molecule, is preformed in food, evokes vomiting a few hours after ingestion, and was shown to be the direct cause of gastroenteritis symptoms; occasionally it is implicated in severe clinical manifestations including acute liver failures. Control of toxin gene expression in emetic B. cereus involves central transcriptional regulators, such as CodY and AbrB, thereby inextricably linking toxin gene expression to life cycle phases and specific conditions, such as the nutrient supply encountered in food matrices. While in recent years considerable progress has been made in the molecular and biochemical characterization of cereulide toxin synthesis, far less is known about the embedment of toxin synthesis in the life cycle of B. cereus. Information about signals acting on toxin production in the food environment is lacking. We summarize the data available on the complex regulatory network controlling cereulide toxin synthesis, discuss the role of intrinsic and extrinsic factors acting on toxin biosynthesis in emetic B. cereus and stress how unraveling these processes can lead to the development of novel effective strategies to prevent toxin synthesis in the food production and processing chain.

  17. 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.

  18. Role of ureolytic activity in Bacillus cereus nitrogen metabolism and acid survival

    NARCIS (Netherlands)

    Mols, J.M.; Abee, T.

    2008-01-01

    The presence and activities of urease genes were investigated in 49 clinical, food, and environmental Bacillus cereus isolates. Ten strains were shown to have urease genes, with eight of these strains showing growth on urea as the sole nitrogen source. Two of the urease-positive strains, including t

  19. Genome Differences That Distinguish Bacillus anthracis from Bacillus cereus and Bacillus thuringiensis

    OpenAIRE

    Radnedge, Lyndsay; Agron, Peter G.; Hill, Karen K.; Jackson, Paul J.; Ticknor, Lawrence O; Keim, Paul; Andersen, Gary L.

    2003-01-01

    The three species of the group 1 bacilli, Bacillus anthracis, B. cereus, and B. thuringiensis, are genetically very closely related. All inhabit soil habitats but exhibit different phenotypes. B. anthracis is the causative agent of anthrax and is phylogenetically monomorphic, while B. cereus and B. thuringiensis are genetically more diverse. An amplified fragment length polymorphism analysis described here demonstrates genetic diversity among a collection of non-anthrax-causing Bacillus speci...

  20. 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.

  1. Stem bark extract and fraction of Persea americana (Mill.) exhibits bactericidal activities against strains of bacillus cereus associated with food poisoning.

    Science.gov (United States)

    Akinpelu, David A; Aiyegoro, Olayinka A; Akinpelu, Oluseun F; Okoh, Anthony I

    2015-01-01

    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. PMID:25558854

  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

    harboured poly-γ-D-glutamic acid capsule biosynthesis genes capA, capB and capC showing 99-100% identity with the environmental B. cereus isolate 03BB108. Presence of cesB of the cereulide synthetase gene cluster was confirmed by PCR in M13-PCR group 2 isolates. The B. cereus harbouring the cap genes were...... production sites of Maari. Aerobic mesophilic bacterial (AMB) counts in raw materials were of 10(5)cfu/ml in DW, and ranged between 6.5×10(3) and 1.2×10(4)cfu/g in potash, 10(9)-10(10)cfu/g in seed mash during fermentation and 10(7) - 10(9) after sun drying. Fifty three out of total 290 AMB isolates were...

  3. Occurrence and characterization of toxigenic Bacillus cereus in food and infant feces

    Institute of Scientific and Technical Information of China (English)

    Sameer; Rushdi; Organji; Hussein; Hasan; Abulreesh; Khaled; Elbanna; Gamal; Ebrahim; Haridy; Osman; Manal; Khider

    2015-01-01

    Objective: To investigate the true incidence of Bacillus cereus(B. cereus) in food and children diarrhea cases. Methods: A total of 110 samples of various dairy products such as raw milk, long life pasteurized milk, yoghurt and infant powdered milk formulas, raw rice, and feces were examined for the presence of B. cereus by selective plating on mannitol-egg-yolk-polymyxin agar. Confirmation of B. cereus was carried out by biochemical tests and PCR. Identification of non-B. cereus isolates was carried out by 16 S r DNA sequencing. Antimicrobial susceptibility was done by disk diffusion method.Results: Overall 35 samples(31.8%, n = 110) yielded Bacillus-like growth. Of which 19 samples(54.28%) were positive for B. cereus. All isolates were positive for enterotoxin production. No psychrotolerant B. cereus strains were detected in all samples. All B. cereus isolates were resistant to penicillin G, but susceptible to vancomycin, erythromycin and clindamycin. Conclusions: The results of this study confirm the importance of including B. cereus in disease control and prevention programs, as well as in routine clinical and food quality control laboratories in both Saudi Arabia and Egypt.

  4. Solid-state fermentation: tool for bioremediation of adsorbed textile dyestuff on distillery industry waste-yeast biomass using isolated Bacillus cereus strain EBT1.

    Science.gov (United States)

    Kadam, Avinash A; Kamatkar, Jeevan D; Khandare, Rahul V; Jadhav, Jyoti P; Govindwar, Sanjay P

    2013-02-01

    Bioremediation of textile dyestuffs under solid-state fermentation (SSF) using industrial wastes as substrate pose an economically feasible, promising, and eco-friendly alternative. The purpose of this study was to adsorb Red M5B dye, a sample of dyes mixture and a real textile effluent on distillery industry waste-yeast biomass (DIW-YB) and its further bioremediation using Bacillus cereus EBT1 under SSF. Textile dyestuffs were allowed to adsorb on DIW-YB. DIW-YB adsorbed dyestuffs were decolorized under SSF by using B. cereus. Enzyme analysis was carried out to ensure decolorization of Red M5B. Metabolites after dye degradation were analyzed using UV-Vis spectroscopy, FTIR, HPLC, and GC-MS. DIW-YB showed adsorption of Red M5B, dyes mixture and a textile wastewater sample up to 87, 70, and 81 %, respectively. DIW-YB adsorbed Red M5B was decolorized up to 98 % by B. cereus in 36 h. Whereas B. cereus could effectively reduce American Dye Manufacture Institute value from DIW-YB adsorbed mixture of textile dyes and textile wastewater up to 70 and 100 %, respectively. Induction of extracellular enzymes such as laccase and azoreductase suggests their involvement in dye degradation. Repeated utilization of DIW-YB showed consistent adsorption and ADMI removal from textile wastewater up to seven cycles. HPLC and FTIR analysis confirms the biodegradation of Red M5B. GC-MS analysis revealed the formation of new metabolites. B. cereus has potential to bioremediate adsorbed textile dyestuffs on DIW-YB. B. cereus along with DIW-YB showed enhanced decolorization performance in tray bioreactor which suggests its potential for large-scale treatment procedures.

  5. Bacillus cereus: emetic toxin production and gamma hypothesis for growth

    NARCIS (Netherlands)

    Biesta-Peters, E.G.

    2011-01-01

    Bacillus cereus is a food spoilage microorganism and a pathogen. Growth of B. cereus can be prevented or delayed by adding growth limiting compounds to the food product or by altered storage conditions. Combinations of growth limiting factors

  6. Draft Genome Sequence of Biocontrol Agent Bacillus cereus UW85.

    Science.gov (United States)

    Lozano, Gabriel L; Holt, Jonathan; Ravel, Jacques; Rasko, David A; Thomas, Michael G; Handelsman, Jo

    2016-01-01

    Bacillus cereus UW85 was isolated from a root of a field-grown alfalfa plant from Arlington, WI, and identified for its ability to suppress damping off, a disease caused by Phytophthora megasperma f. sp. medicaginis on alfalfa. Here, we report the draft genome sequence of B. cereus UW85, obtained by a combination of Sanger and Illumina sequencing. PMID:27587823

  7. 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 (spices had high levels of aerobic spores (> 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 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.

  8. Laundry detergent compatibility of the alkaline protease from Bacillus cereus.

    Science.gov (United States)

    Banik, Rathindra Mohan; Prakash, Monika

    2004-01-01

    The endogenous protease activity in various commercially available laundry detergents of international companies was studied. The maximum protease activity was found at 50 degrees C in pH range 10.5-11.0 in all the tested laundry detergents. The endogenous protease activity in the tested detergents retained up to 70% on incubation at 40 degrees C for 1 h, whereas less than 30% activity was only found on incubation at 50 degrees C for 1 h. The alkaline protease from an alkalophilic strain of Bacillus cereus was studied for its compatibility in commercial detergents. The cell free fermented broth from shake flask culture of the organism showed maximum activity at pH 10.5 and 50 degrees C. The protease from B. cereus showed much higher residual activity (more than 80%) on incubation with laundry detergents at 50 degrees C for 1 h or longer. The protease enzyme from B. cereus was found to be superior over the endogenous proteases present in the tested commercial laundry detergents in comparison to the enzyme stability during the washing at higher temperature, e.g., 40-50 degrees C. PMID:15293947

  9. 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;

    The microbiology of the naturally fermented African condiments Afiitin, iru and sonru produced in Benin from locust beans, has recently been studied showing high Bacillus cereus counts of log7CFU/g (Azokpota, 2005). A total of 19 B. cereus strains isolated from the three condiments showed to be p...

  10. Vaccine Protection against Bacillus cereus-Mediated Respiratory Anthrax-Like Disease in Mice

    OpenAIRE

    Oh, So-Young; Maier, Hannah; Schroeder, Jay; Richter, G. Stefan; Elli, Derek; Musser, James M.; Quenee, Lauriane E.; Missiakas, Dominique M.; Schneewind, Olaf

    2013-01-01

    Bacillus cereus strains harboring a pXO1-like virulence plasmid cause respiratory anthrax-like disease in humans, particularly in welders. We developed mouse models for intraperitoneal as well as aerosol challenge with spores of B. cereus G9241, harboring pBCXO1 and pBC218 virulence plasmids. Compared to wild-type B. cereus G9241, spores with a deletion of the pBCXO1-carried protective antigen gene (pagA1) were severely attenuated, whereas spores with a deletion of the pBC218-carried protecti...

  11. 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.

  12. Phages preying on Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis: past, present and future.

    Science.gov (United States)

    Gillis, Annika; Mahillon, Jacques

    2014-07-01

    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

  13. The PlcR virulence regulon of Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Michel Gohar

    Full Text Available PlcR is a Bacillus cereus transcriptional regulator, which activates gene expression by binding to a nucleotidic sequence called the 'PlcR box'. To build a list of all genes included in the PlcR regulon, a consensus sequence was identified by directed mutagenesis. The reference strain ATCC14579 sequenced genome was searched for occurrences of this consensus sequence to produce a virtual regulon. PlcR control of these genes was confirmed by comparing gene expression in the reference strain and its isogenic Delta-plcR strain using DNA microarrays, lacZ fusions and proteomics methods. The resulting list included 45 genes controlled by 28 PlcR boxes. Forty of the PlcR controlled proteins were exported, of which 22 were secreted in the extracellular medium and 18 were bound or attached to cell wall structures (membrane or peptidoglycan layer. The functions of these proteins were related to food supply (phospholipases, proteases, toxins, cell protection (bacteriocins, toxins, transporters, cell wall biogenesis and environment-sensing (two-component sensors, chemotaxis proteins, GGDEF family regulators. Four genes coded for cytoplasmic regulators. The PlcR regulon appears to integrate a large range of environmental signals, including food deprivation and self cell-density, and regulate the transcription of genes designed to overcome obstacles that hinder B. cereus growth within the host: food supply, host barriers, host immune defenses, and competition with other bacterial species. PlcR appears to be a key component in the efficient adaptation of B. cereus to its host environment.

  14. The T box regulatory element controlling expression of the class I lysyl-tRNA synthetase of Bacillus cereus strain 14579 is functional and can be partially induced by reduced charging of asparaginyl-tRNAAsn

    LENUS (Irish Health Repository)

    Foy, Niall

    2010-07-22

    Abstract Background Lysyl-tRNA synthetase (LysRS) is unique within the aminoacyl-tRNA synthetase family in that both class I (LysRS1) and class II (LysRS2) enzymes exist. LysRS1 enzymes are found in Archaebacteria and some eubacteria while all other organisms have LysRS2 enzymes. All sequenced strains of Bacillus cereus (except AH820) and Bacillus thuringiensis however encode both a class I and a class II LysRS. The lysK gene (encoding LysRS1) of B. cereus strain 14579 has an associated T box element, the first reported instance of potential T box control of LysRS expression. Results A global study of 891 completely sequenced bacterial genomes identified T box elements associated with control of LysRS expression in only four bacterial species: B. cereus, B. thuringiensis, Symbiobacterium thermophilum and Clostridium beijerinckii. Here we investigate the T box element found in the regulatory region of the lysK gene in B. cereus strain 14579. We show that this T box element is functional, responding in a canonical manner to an increased level of uncharged tRNALys but, unusually, also responding to an increased level of uncharged tRNAAsn. We also show that B. subtilis strains with T box regulated expression of the endogenous lysS or the heterologous lysK genes are viable. Conclusions The T box element controlling lysK (encoding LysRS1) expression in B. cereus strain 14579 is functional, but unusually responds to depletion of charged tRNALys and tRNAAsn. This may have the advantage of making LysRS1 expression responsive to a wider range of nutritional stresses. The viability of B. subtilis strains with a single LysRS1 or LysRS2, whose expression is controlled by this T box element, makes the rarity of the occurrence of such control of LysRS expression puzzling.

  15. 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.

  16. An Optical Biosensor for Bacillus Cereus Spore Detection

    Science.gov (United States)

    Li, Chengquan; Tom, Harry W. K.

    2005-03-01

    We demonstrate a new transduction scheme for optical biosensing. Bacillus cereus is a pathogen that may be found in food and dairy products and is able to produce toxins and cause food poisoning. It is related to Bacillus anthracis (anthrax). A CCD array covered with micro-structured glass coverslip is used to detect the optical resonant shift due to the binding of the antigen (bacillus cereus spore) to the antibody (polyclonal antibody). This novel optical biosensor scheme has the potential for detecting 10˜100 bioagents in a single device as well as the potential to test for antigens with multiple antibody tests to avoid ``false positives.''

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

    Science.gov (United States)

    Zahner, Viviane; Silva, Ana Carolina Telles de Carvalho e; de Moraes, Gabriela Pinhel; McIntosh, Douglas; de Filippis, Ivano

    2013-01-01

    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. PMID:23440117

  18. 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.

  19. 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. PMID:27588686

  20. The study of effect bacteriocin producing Lactoco ccus lactis on Listeria monocytogenes and Bacillus cereus

    Directory of Open Access Journals (Sweden)

    M. Mirhossieni, M.Sc

    2007-01-01

    Full Text Available AbstractBackground and purpose: Dairy products often associated with problems such as short shelf life and poor hygiene control. A novel approach is to utilize bacteriocin or bacteriocin producer strains, to control undesirable micro flora as Listeria monocytogenes and Bacillus cereus in foods. Hence, we studied the effect of nisin like producing Lactococcus lactis against Listeria monocytogenes and Bacillus cereus, in order to compare the isolated strain within different countries.Materials and Methods: In this research we studied the effect of nisin like producing Lactococcus lactis, with producer spot test method. We also used supernatant from 24 h culture of Lactoccus lactis. Moreover, we studied the effect of bacteriocin on Listeria monocytogenes and Bacillus cereus growth curves.Results: The growth of both strains was inhibited by the bacteriocin. Conclusion: According to our results, the bacteriocin could be used in liquid food with bacteriocin added directly or as a starter culture in fermentation. This would inhibit the growth of Listeria monocytogenes; furthermore, Bacillus cereus is used to reduce food poisoning for fermented food products.

  1. Production, Secretion and Biological Activity of Bacillus cereus Enterotoxins

    Directory of Open Access Journals (Sweden)

    Sonia Senesi

    2010-06-01

    Full Text Available Bacillus cereus behaves as an opportunistic pathogen frequently causing gastrointestinal diseases, and it is increasingly recognized to be responsible for severe local or systemic infections. Pathogenicity of B. cereus mainly relies on the secretion of a wide array of toxins and enzymes and also on the ability to undergo swarming differentiation in response to surface-sensing. In this report, the pathogenicity exerted by B. cereus toxins is described with particular attention to the regulatory mechanisms of production and secretion of HBL, Nhe and CytK enterotoxins.

  2. 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

  3. Characterization of Bacillus cereus isolates from local dairy farms in China.

    Science.gov (United States)

    Cui, Yifang; Liu, Xiaoye; Dietrich, Richard; Märtlbauer, Erwin; Cao, Jie; Ding, Shuangyang; Zhu, Kui

    2016-06-01

    Bacillus cereus is an important opportunistic foodborne pathogen. In the present work, a total of 306 milk and environmental samples were collected from 10 local dairy farms in Beijing, China. Of the 92 B. cereus-like isolates, 88 and 4 belonged to B. cereus and B. thuringiensis, respectively. The prevalence of B. cereus isolates in bedding, feces, feed, liquid manure and raw milk was 93.3%, 78.9%, 41.2%, 100.0% and 9.8%, respectively. Three main toxin genes nhe, hbl and ces were detected with rates of 100.0%, 78.3% and 1.1%, but no strain harbored cytK1 The production of Nhe, Hbl and cereulide could be confirmed by specific monoclonal antibodies-based enzyme immunoassays in 94.6%, 70.7% and 1.1% of all isolates, respectively. Cytotoxicity tests were used to further corroborate the results of genetic and protein-based assays; 91.3% of the isolates showed cytotoxicity to Vero cells. All isolates were tested for antimicrobial resistance against 17 antibiotics. All isolates were resistant to lincomycin, retapamulin, tiamulin and valnemulin, while two strains were susceptible to ampicillin and ceftiofur. A total of 16 isolated strains were resistant to tetracycline. Since spores of B. cereus are not inactivated during manufacturing of most milk products, contamination of milk with B. cereus on the farm level may represent a potential hazard, particularly with respect to emetic toxin-producing strains.

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

    International Nuclear Information System (INIS)

    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

  5. Isolation and characterisation of Bacillus cereus from pasteurised milk in household refrigerators in The Netherlands.

    Science.gov (United States)

    Te Giffel, M C; Beumer, R R; Granum, P E; Rombouts, F M

    1997-03-01

    The incidence and some characteristics (carbohydrate metabolism, growth profiles, haemolysin production and enterotoxin production) of Bacillus cereus, in pasteurised, low-fat (1.5%) milk, in household refrigerators in the Netherlands was investigated. In 247 (74%) of the 334 milk samples analyzed, the mesophilic aerobic counts were between 50 and 5000 per millilitre. B. cereus could be isolated from 133 (40%) of the samples. In general the B. cereus counts were low; numbers of less than five per millilitre were observed in 258 (77%) of the samples. As expected, both the mesophilic aerobic counts and levels of B. cereus increased with increasing storage temperatures in the refrigerator and prolonged storage times. In total, 143 presumptive B. cereus colonies were isolated. According to the ISO confirmation tests and the carbohydrate patterns (API 50 CHB) 134 (94%) of these isolates were confirmed to be B. cereus. Of these 134 isolates 20% fermented lactose and 53% of the 106 strains tested were able to grow at 7 degrees C. These percentages are much higher than expected for strains isolated from non-dairy products, suggesting that strains can adapt to environmental conditions in milk. All 106 strains tested, produced haemolysin, 27% showed the discontinuous haemolytic pattern characteristic for haemolysin BL, possibly a virulence factor. Of the 37 B. cereus isolates tested for enterotoxin production 27 (73%), 28 (76%) and 26 (70%) were found to be enterotoxigenic (as determined by the Western immunoblot technique, polymerase chain reaction (PCR) and Vero cell assays, respectively). Isolates unable to ferment lactose, produced less enterotoxin in comparison with those able to utilize lactose. Although only a few outbreaks of food poisoning caused by B. cereus in milk (products) have been reported, most strains isolated from these products are able to produce enterotoxins and may represent a health hazard. PMID:9039575

  6. 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

  7. The Bacillus cereus spoIIS programmed cell death system

    Directory of Open Access Journals (Sweden)

    Jana eMelnicakova

    2015-08-01

    Full Text Available Programmed cell death in bacteria is generally associated with two¬ component toxin antitoxin systems. The SpoIIS toxin-antitoxin system, consisting of a membrane bound SpoIISA toxin and a small, cytosolic antitoxin SpoIISB, was originally identified in Bacillus subtilis. In this work we describe the Bacillus cereus SpoIIS system which is a three-component system, harbouring an additional gene spoIISC. Its protein product serves as an antitoxin, and similarly as SpoIISB, is able to bind SpoIISA and abolish its toxic effect. Our results indicate that SpoIISC seems to be present not only in B. cereus but also in other Bacilli containing a SpoIIS toxin antitoxin system. In addition, we show that B. cereus SpoIISA can form higher oligomers and we discuss the possible role of this multimerization for the protein’s toxic function.

  8. The fate of Bacillus cereus in the gastrointestinal tract

    NARCIS (Netherlands)

    Pielaat A; Wijnands LM; Takumi K; Nauta MJ; Leusden FM van; MGB

    2006-01-01

    This report presents a mathematical dynamical model for the behaviour of Bacillus cereus in the gastro-intestinal tract. Biological processes and system dynamics are simultaneously incorporated in this mechanistic model. Variability in growth characteristics and physical traits of different B. cereu

  9. 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 t

  10. Genome Sequence of Bacillus cereus Group Phage SalinJah.

    Science.gov (United States)

    Erill, Ivan; Caruso, Steven M

    2016-01-01

    The double-stranded DNA (dsDNA) Myoviridae Bacillus cereus group bacteriophage SalinJah was isolated from soil collected in Gyeonggi-do, South Korea. SalinJah, a cluster C phage with a broad host range, suggests the need to create a new subcluster with SalinJah and Helga as founding members. PMID:27688335

  11. Complete Genome Sequences of Nine Bacillus cereus Group Phages

    Science.gov (United States)

    Foltz, Samantha

    2016-01-01

    We report the sequences of nine novel Bacillus cereus group bacteriophages: DIGNKC, Juglone, Nemo, Nigalana, NotTheCreek, Phrodo, SageFayge, Vinny, and Zuko. These bacteriophages are double-stranded DNA-containing Myoviridae isolated from soil samples using B. thuringiensis subsp. kurstaki as the host bacterium. PMID:27417827

  12. Induction of natural competence in Bacillus cereus ATCC14579

    NARCIS (Netherlands)

    Mironczuk, Aleksandra M.; Kovács, Ákos T.; Kuipers, O.P.

    2008-01-01

    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

  13. 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.

  14. 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.

  15. Elucidation of enterotoxigenic Bacillus cereus outbreaks in Austria by complementary epidemiological and microbiological investigations, 2013.

    Science.gov (United States)

    Schmid, Daniela; Rademacher, Corinna; Kanitz, Elisabeth Eva; Frenzel, Elrike; Simons, Erica; Allerberger, Franz; Ehling-Schulz, Monika

    2016-09-01

    Identifying Bacillus cereus as the causative agent of a foodborne outbreak still poses a challenge. We report on the epidemiological and microbiological investigation of three outbreaks of food poisoning (A, B, and C) in Austria in 2013. A total of 44% among 32 hotel guests (A), 22% among 63 employees (B) and 29% among 362 residents of a rehab clinic (C) fell sick immediately after meal consumption. B. cereus isolated from left overs or retained samples from related foods were characterized by toxin gene profiling, and molecular typing using panC sequencing and M13-PCR typing (in outbreak A and C). We identified two B. cereus strains in outbreak A, and six B. cereus strains, each in outbreak B and C; we also found Staphylococcus aureus and staphylococcal enterotoxins in outbreak A. The panC sequence based phylogenetic affiliation of the B. cereus strains, together with findings of the retrospective cohort analyses, helped determining their etiological role. Consumption of a mashed potatoes dish in outbreak A (RR: ∞), a pancake strips soup in outbreak B (RR 13.0; 95% CI 1.8-93.0) and for outbreak C of a fruit salad (RR 1.50; 95% CI 1.09-2.00), deer ragout (RR: 1.99; 95% CI 1.23-3.22) and a cranberry/pear (RR 2.46; 95% CI 1.50-4.03)were associated with increased risk of falling sick. An enterotoxigenic strain affiliated to the phylogenetic group with the highest risk of food poisoning was isolated from the crème spinach and the strawberry buttermilk, and also from the stool samples of the one B. cereus positive outbreak case-patient, who ate both. Our investigation of three food poisoning outbreaks illustrates the added value of a combined approach by using epidemiological, microbiological and genotyping methods in identifying the likely outbreak sources and the etiological B. cereus strains.

  16. Elucidation of enterotoxigenic Bacillus cereus outbreaks in Austria by complementary epidemiological and microbiological investigations, 2013.

    Science.gov (United States)

    Schmid, Daniela; Rademacher, Corinna; Kanitz, Elisabeth Eva; Frenzel, Elrike; Simons, Erica; Allerberger, Franz; Ehling-Schulz, Monika

    2016-09-01

    Identifying Bacillus cereus as the causative agent of a foodborne outbreak still poses a challenge. We report on the epidemiological and microbiological investigation of three outbreaks of food poisoning (A, B, and C) in Austria in 2013. A total of 44% among 32 hotel guests (A), 22% among 63 employees (B) and 29% among 362 residents of a rehab clinic (C) fell sick immediately after meal consumption. B. cereus isolated from left overs or retained samples from related foods were characterized by toxin gene profiling, and molecular typing using panC sequencing and M13-PCR typing (in outbreak A and C). We identified two B. cereus strains in outbreak A, and six B. cereus strains, each in outbreak B and C; we also found Staphylococcus aureus and staphylococcal enterotoxins in outbreak A. The panC sequence based phylogenetic affiliation of the B. cereus strains, together with findings of the retrospective cohort analyses, helped determining their etiological role. Consumption of a mashed potatoes dish in outbreak A (RR: ∞), a pancake strips soup in outbreak B (RR 13.0; 95% CI 1.8-93.0) and for outbreak C of a fruit salad (RR 1.50; 95% CI 1.09-2.00), deer ragout (RR: 1.99; 95% CI 1.23-3.22) and a cranberry/pear (RR 2.46; 95% CI 1.50-4.03)were associated with increased risk of falling sick. An enterotoxigenic strain affiliated to the phylogenetic group with the highest risk of food poisoning was isolated from the crème spinach and the strawberry buttermilk, and also from the stool samples of the one B. cereus positive outbreak case-patient, who ate both. Our investigation of three food poisoning outbreaks illustrates the added value of a combined approach by using epidemiological, microbiological and genotyping methods in identifying the likely outbreak sources and the etiological B. cereus strains. PMID:27257745

  17. Genetic diversity of clinical isolates of Bacillus cereus using multilocus sequence typing

    Directory of Open Access Journals (Sweden)

    Pruckler James M

    2008-11-01

    Full Text Available Abstract Background Bacillus cereus is most commonly associated with foodborne illness (diarrheal and emetic but is also an opportunistic pathogen that can cause severe and fatal infections. Several multilocus sequence typing (MLST schemes have recently been developed to genotype B. cereus and analysis has suggested a clonal or weakly clonal population structure for B. cereus and its close relatives B. anthracis and B. thuringiensis. In this study we used MLST to determine if B. cereus isolates associated with illnesses of varying severity (e.g., severe, systemic vs. gastrointestinal (GI illness were clonal or formed clonal complexes. Results A retrospective analysis of 55 clinical B. cereus isolates submitted to the Centers for Disease Control and Prevention between 1954 and 2004 was conducted. Clinical isolates from severe infections (n = 27, gastrointestinal (GI illness (n = 18, and associated isolates from food (n = 10 were selected for analysis using MLST. The 55 isolates were diverse and comprised 38 sequence types (ST in two distinct clades. Of the 27 isolates associated with serious illness, 13 clustered in clade 1 while 14 were in clade 2. Isolates associated with GI illness were also found throughout clades 1 and 2, while no isolates in this study belonged to clade 3. All the isolates from this study belonging to the clade 1/cereus III lineage were associated with severe disease while isolates belonging to clade1/cereus II contained isolates primarily associated with severe disease and emetic illness. Only three STs were observed more than once for epidemiologically distinct isolates. Conclusion STs of clinical B. cereus isolates were phylogenetically diverse and distributed among two of three previously described clades. Greater numbers of strains will need to be analyzed to confirm if specific lineages or clonal complexes are more likely to contain clinical isolates or be associated with specific illness, similar to B. anthracis and

  18. 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.

  19. Comparison of hand hygiene procedures for removing Bacillus cereus spores.

    Science.gov (United States)

    Sasahara, Teppei; Hayashi, Shunji; Hosoda, Kouichi; Morisawa, Yuji; Hirai, Yoshikazu

    2014-01-01

    Bacillus cereus is a spore-forming bacterium. B. cereus occasionally causes nosocomial infections, in which hand contamination with the spores plays an important role. Therefore, hand hygiene is the most important practice for controlling nosocomial B. cereus infections. This study aimed to determine the appropriate hand hygiene procedure for removing B. cereus spores. Thirty volunteers' hands were experimentally contaminated with B. cereus spores, after which they performed 6 different hand hygiene procedures. We compared the efficacy of the procedures in removing the spores from hands. The alcohol-based hand-rubbing procedures scarcely removed them. The soap washing procedures reduced the number of spores by more than 2 log10. Extending the washing time increased the spore-removing efficacy of the washing procedures. There was no significant difference in efficacy between the use of plain soap and antiseptic soap. Handwashing with soap is appropriate for removing B. cereus spores from hands. Alcohol-based hand-rubbing is not effective. PMID:25252644

  20. 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.

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

    Science.gov (United States)

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

    2008-06-10

    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 (BCET-RPLA) and the Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (BDEVIA). Detection of genes encoding cytotoxin K (CytK), haemolysin BL (Hbl A, Hbl C, Hbl D), non-hemolytic enterotoxin (NheA, NheB, NheC) and EM1 specific of emetic toxin producers was 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. Using RPLA, enterotoxin production was detected for three isolates of B. cereus in broth and all B. cereus (9) in fermented seeds. Using BDEVIA, enterotoxin production was detected in broth as well as in fermented seeds for all B. cereus isolates. None of the isolates belonging to the other Bacillus species was able to produce enterotoxins either by RPLA or BDEVIA. Nhe genes were detected in all B. cereus while Hbl and CytK genes were detected respectively in five and six B. cereus strains. A weak presence of Hbl (A, D) and CytK genes was detected in two isolates of B. subtilis and one of B. licheniformis but results were inconsistent, especially for Hbl genes. The emetic specific gene fragment EM1 was not detected in any of the isolates studied.

  2. 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

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

    OpenAIRE

    Hilde Mellegård; Ákos T Kovács; Toril Lindbäck; 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 chemic...

  4. Tracking cereulide producing Bacillus cereus in foods, papermaking and biowaste management

    OpenAIRE

    Hoornstra, Douwe

    2014-01-01

    Bacillus cereus is a ubiquitous food poisoning bacterium, but only producers of the emetic toxin, cereulide can be life threatening. Therefore a fast and reliable method is needed for identifying strains that produce the toxin. In this thesis the previously developed sperm bioassay was refined into a tool for the detection of microbially produced mitochondria toxic substances. This refined tool, Sperm Combi Assay effectively detected not only cereulide, but also other mitochondrial toxic subs...

  5. From genome to toxicity: a combinatory approach highlights the complexity of enterotoxin production in Bacillus cereus.

    Science.gov (United States)

    Jeßberger, Nadja; Krey, Viktoria M; Rademacher, Corinna; Böhm, Maria-Elisabeth; Mohr, Ann-Katrin; Ehling-Schulz, Monika; Scherer, Siegfried; Märtlbauer, Erwin

    2015-01-01

    In recent years Bacillus cereus has gained increasing importance as a food poisoning pathogen. It is the eponymous member of the B. cereus sensu lato group that consists of eight closely related species showing impressive diversity of their pathogenicity. The high variability of cytotoxicity and the complex regulatory network of enterotoxin expression have complicated efforts to predict the toxic potential of new B. cereus isolates. In this study, comprehensive analyses of enterotoxin gene sequences, transcription, toxin secretion and cytotoxicity were performed. For the first time, these parameters were compared in a whole set of B. cereus strains representing isolates of different origin (food or food poisoning outbreaks) and of different toxic potential (enteropathogenic and apathogenic) to elucidate potential starting points of strain-specific differential toxicity. While toxin gene sequences were highly conserved and did not allow for differentiation between high and low toxicity strains, comparison of nheB and hblD enterotoxin gene transcription and Nhe and Hbl protein titers revealed not only strain-specific differences but also incongruence between toxin gene transcripts and toxin protein levels. With one exception all strains showed comparable capability of protein secretion and so far, no secretion patterns specific for high and low toxicity strains were identified. These results indicate that enterotoxin expression is more complex than expected, possibly involving the orchestrated interplay of different transcriptional regulator proteins, as well as posttranscriptional and posttranslational regulatory mechanisms plus additional influences of environmental conditions.

  6. Toxin profile, antibiotic resistance, and phenotypic and molecular characterization of Bacillus cereus in Sunsik.

    Science.gov (United States)

    Chon, Jung-Whan; Kim, Jong-Hyun; Lee, Sun-Jin; Hyeon, Ji-Yeon; Seo, Kun-Ho

    2012-10-01

    Sunsik, a ready-to-eat food in Korea, is comprised of various agricultural and marine products, and has been an important concern in Bacillus cereus food poisoning. The aim of this study was to investigate the toxin profiles, genotypic and phenotypic patterns as well as antibiotic resistance of B. cereus strains isolated from Sunsik. A subtyping method known as automated repetitive sequence-based PCR system (DiversiLab™) was used to assess the intraspecific biodiversity of these isolates. Thirty-five B. cereus strains were isolated from 100 commercial Sunsik samples, all of which harbored at least 1 enterotoxin gene. The detection rates of nheABC, hblCDA, cytK, and entFM enterotoxin gene among all isolates were 97%, 86%, 77%, and 100%, respectively. Most strains also produced corresponding enterotoxins such as HBL (83%) and NHE (94%). One strain (2.9%) carried the emetic toxin genes, including ces and EM1, and was positive for the HEp-2 cell emetic toxin assay. Most strains were positive for various biochemical tests such as salicin hydrolysis (86%), starch fermentation (89%), hemolysis (89%), motility test (100%) and lecithinase hydrolysis (89%). All isolates were susceptible to most antibiotics although they were highly resistant to β-lactam antibiotics. By using the automated rep-PCR system, all isolates were successfully differentiated, indicating the diversity of B. cereus strains present in Sunsik.

  7. From genome to toxicity: A combinatory approach highlights the complexity of enterotoxin production in Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Nadja eJessberger

    2015-06-01

    Full Text Available In recent years Bacillus cereus has gained increasing importance as a food poisoning pathogen. It is the eponymous member of the B. cereus sensu lato group that consists of eight closely related species showing impressive diversity of their pathogenicity. The high variability of cytotoxicity and the complex regulatory network of enterotoxin expression have complicated efforts to predict the toxic potential of new B. cereus isolates. In this study, comprehensive analyses of enterotoxin gene sequences, transcription, toxin secretion and cytotoxicity were performed. For the first time, these parameters were compared in a whole set of B. cereus strains representing isolates of different origin (food or food poisoning outbreaks and of different toxic potential (enteropathogenic and apathogenic to elucidate potential starting points of strain-specific differential toxicity. While toxin gene sequences were highly conserved and did not allow for differentiation between high and low toxicity strains, comparison of nheB and hblD enterotoxin gene transcription and Nhe and Hbl protein titers revealed not only strain-specific differences but also incongruence between toxin gene transcripts and toxin protein levels. With one exception all strains showed comparable capability of protein secretion and so far, no secretion patterns specific for high and low toxicity strains were identified. These results indicate that enterotoxin expression is more complex than expected, possibly involving the orchestrated interplay of different transcriptional regulator proteins, as well as posttranscriptional and posttranslational regulatory mechanisms plus additional influences of environmental conditions.

  8. Biotyping of Bacillus cereus from the street vended Foods in Srinagar area of Kashmir

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    Yasir Hafeez

    Full Text Available Aim: The present study was undertaken to describe the biotyping of Bacillus cereus isolated from different street vended mutton tikka and chutney samples. Materials and Methods: A total of 100 street vended food samples comprising of 60 mutton tikka and 40 chutney samples were tested. Results: The biotype 3 and biotype 4 showed the highest occurrence with, 29.63% and 25.93% isolates falling in these biotypes, respectively. The percentage occurrence of the biotypes 1, 6, 2, 5, and 7 was 14.81%, 11.11%, 7.40%, 7.40% and 3.84%, respectively. The most common found biotypes in Mutton tikka were biotypes 3(29.63%, 4(25.93%, 1(14.81% and 6(11.11%. The Bacillus cereus strains isolated from chutney samples could be divided into 7 of the 9 possible biotypes. The biotypes 6 and 7 showed the highest occurrence with 38.46% and 30.76% falling in these biotypes, respectively. The biotype 5 and 2 were prevalent to the extent of 23.07%, 7.69%, respectively. The biotypes 3, 4 and 1 were absent. The mean bacterial count of 60 mutton tikka and 40 chutney samples was 4.6817 and 5.6575 log cfu/g. 10 Conclusion: The field isolates and the standard strains of Bacillus cereus had similar cultural, morphological and biochemical characteristics. The biotypes recovered from the Mutton tikka samples were biotypes 3, 4, 1 and 6 and in chutneys the biotypes recovered were 6, 7, 5 and 2. The strains of Bacillus cereus were highly resistant to penicillin G (92.59%. [Vet World 2012; 5(10.000: 590-593

  9. Toxin producing Bacillus cereus persist in ready-to-reheat spaghetti Bolognese mainly in vegetative state.

    Science.gov (United States)

    Rajkovic, Andreja; Kljajic, Milica; Smigic, Nada; Devlieghere, Frank; Uyttendaele, Mieke

    2013-10-15

    The potential of Bacillus cereus to cause a diarrheal toxico-infection is related to its ability to perform de novo enterotoxin production in the small intestine. A prerequisite for this is presence of sufficient numbers of B. cereus that have survived gastro-intestinal passage. It is known that the percentage of survival is much smaller for vegetative cells in comparison to spores and it is therefore important to know the state in which B. cereus is ingested. The results of the current study performed on twelve B. cereus strains, comprising both diarrheal and emetic type, indicate that exposure via contaminated foods mainly concerns vegetative cells. Inoculated vegetative cells grew to high counts, with the growth dynamic depending on the storage temperature. At 28 °C growth to high counts resulted in spore formation, in general, after 1 day of storage. One strain was an exception, producing spores only after 16 days. At 12 °C obtained high counts did not result in spore formation for 11 of 12 tested strains after two weeks of storage. The highest counts and time to sporulation were different between strains, but no difference was observed on the group level of diarrheal and emetic strains. The spore counts were always lower than vegetative cell counts and occurred only when food was obviously sensory spoiled (visual and odor evaluation). Similar observations were made with food inoculated with B. cereus spores instead of vegetative cells. Although the prospect of consuming spores was found very weak, the numbers of vegetative B. cereus cells were high enough, without obvious sensory deviation, to survive in sufficient level to cause diarrheal toxico-infection.

  10. Identification and characterization of a novel marine Bacillus cereus for mosquito control.

    Science.gov (United States)

    Poopathi, Subbiah; Mani, C; Thirugnanasambantham, K; Praba, V Lakshmi; Ahangar, Niyaz Ahmad; Balagangadharan, K

    2014-01-01

    Entomopathogenic bacteria to control mosquitoes are a promising environmentally friendly alternative to synthetic pesticides. In the present study, a novel mosquitocidal bacterium was isolated from marine soil collected from east coastal areas at Pondicherry (India). 16S rRNA gene sequence alignment depicted that this isolate belonged to Bacillus cereus VCRC-B520 (NCBI: KC-119192). Biochemical studies on bacterial growth, biomass, and toxin production have revealed that this strain could possibly be helpful in the production of a biopesticide in mosquito control. Toxicity assay with B. cereus against mosquito larvae has shown that the filariasis vector, Culex quinquefasciatus, is more susceptible than the other two species (Anopheles stephensi and Aedes aegypti). The LC50 and LC90 values for C. quinquefasciatus were 0.30 and 2.21 mg/L, respectively. No effect of B. cereus was found on nontargeted organisms. SDS-PAGE analysis and protein purification result from the cell mass of B. cereus have shown that a well-perceptible polypeptide was the dependable factor (85 kDa) for mosquitocidal action. Protein characterization (M/S MALDI-TOF) has shown that it is an endotoxin-specific insecticidal protein, namely "Cry4Aa". Phylogenetic analyses of 16S rDNA gene sequence from this marine isolate have revealed the presence of homology among closely related Bacillus strains. Therefore, considerable interest has been shown on the identification of a potential mosquitocidal bacterium from marine environment (B. cereus), which was not reported earlier in view of the current scenario of the rapid development of resistance to Bacillus sphaericus in mosquito vector control program.

  11. Respiratory systems of the Bacillus cereus mother cell and forespore.

    OpenAIRE

    Escamilla, J E; R. Ramírez; Del-Arenal, P; Aranda, A.

    1986-01-01

    The respiratory systems of the mother cells and forespores of Bacillus cereus were compared throughout the maturation stages (III to VI) of sporulation. The results indicated that both cell compartments contain the same assortment of oxidoreductases and cytochromes. However membrane fractions from young forespores were clearly distinct from those of the mother cell, i.e., lower content of cytochrome aa3, lower cytochrome c oxidase activity, higher concentration of cytochrome o, and a lower se...

  12. The Pore-Forming Haemolysins of Bacillus Cereus: A Review

    OpenAIRE

    Vincent Sanchis; Nalini Ramarao

    2013-01-01

    The Bacillus cereus sensu lato group contains diverse Gram-positive spore-forming bacteria that can cause gastrointestinal diseases and severe eye infections in humans. They have also been incriminated in a multitude of other severe, and frequently fatal, clinical infections, such as osteomyelitis, septicaemia, pneumonia, liver abscess and meningitis, particularly in immuno-compromised patients and preterm neonates. The pathogenic properties of this organism are mediated by the synergistic ef...

  13. Genome characteristics of a novel phage from Bacillus thuringiensis showing high similarity with phage from Bacillus cereus.

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    Yihui Yuan

    Full Text Available Bacillus thuringiensis is an important entomopathogenic bacterium belongs to the Bacillus cereus group, which also includes B. anthracis and B. cereus. Several genomes of phages originating from this group had been sequenced, but no genome of Siphoviridae phage from B. thuringiensis has been reported. We recently sequenced and analyzed the genome of a novel phage, BtCS33, from a B. thuringiensis strain, subsp. kurstaki CS33, and compared the gneome of this phage to other phages of the B. cereus group. BtCS33 was the first Siphoviridae phage among the sequenced B. thuringiensis phages. It produced small, turbid plaques on bacterial plates and had a narrow host range. BtCS33 possessed a linear, double-stranded DNA genome of 41,992 bp with 57 putative open reading frames (ORFs. It had a typical genome structure consisting of three modules: the "late" region, the "lysogeny-lysis" region and the "early" region. BtCS33 exhibited high similarity with several phages, B. cereus phage Wβ and some variants of Wβ, in genome organization and the amino acid sequences of structural proteins. There were two ORFs, ORF22 and ORF35, in the genome of BtCS33 that were also found in the genomes of B. cereus phage Wβ and may be involved in regulating sporulation of the host cell. Based on these observations and analysis of phylogenetic trees, we deduced that B. thuringiensis phage BtCS33 and B. cereus phage Wβ may have a common distant ancestor.

  14. 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.

  15. Use of 16S rRNA, 23S rRNA, and gyrB gene sequence analysis to determine phylogenetic relationships of Bacillus cereus group.

    Energy Technology Data Exchange (ETDEWEB)

    Bayvkin, S. G.; Lysov, Y. P.; Zakhariev, V.; Kelly, J. J.; Jackman, J.; Stahl, D. A.; Cherni, A.; Engelhardt Inst. of Molecular Biology; Loyola Univ.; Johns Hopkins Univ.; Univ. of Washington

    2004-08-01

    In order to determine if variations in rRNA sequence could be used for discrimination of the members of the Bacillus cereus group, we analyzed 183 16S rRNA and 74 23S rRNA sequences for all species in the B. cereus group. We also analyzed 30 gyrB sequences for B. cereus group strains with published 16S rRNA sequences. Our findings indicated that the three most common species of the B. cereus group, B. cereus, Bacillus thuringiensis, and Bacillus mycoides, were each heterogeneous in all three gene sequences, while all analyzed strains of Bacillus anthracis were found to be homogeneous. Based on analysis of 16S and 23S rRNA sequence variations, the microorganisms within the B. cereus group were divided into seven subgroups, Anthracis, Cereus A and B, Thuringiensis A and B, and Mycoides A and B, and these seven subgroups were further organized into two distinct clusters. This classification of the B. cereus group conflicts with current taxonomic groupings, which are based on phenotypic traits. The presence of B. cereus strains in six of the seven subgroups and the presence of B. thuringiensis strains in three of the subgroups do not support the proposed unification of B. cereus and B. thuringiensis into one species. Analysis of the available phenotypic data for the strains included in this study revealed phenotypic traits that may be characteristic of several of the subgroups. Finally, our results demonstrated that rRNA and gyrB sequences may be used for discriminating B. anthracis from other microorganisms in the B. cereus group.

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

    NARCIS (Netherlands)

    From, C.; Voort, van der M.; Abee, T.; Granum, P.E.

    2012-01-01

    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

  17. Toxin Profile, Biofilm Formation, and Molecular Characterization of Emetic Toxin-Producing Bacillus cereus Group Isolates from Human Stools.

    Science.gov (United States)

    Oh, Su Kyung; Chang, Hyun-Joo; Choi, Sung-Wook; Ok, Gyeongsik; Lee, Nari

    2015-11-01

    Emetic toxin-producing Bacillus cereus group species are an important problem, because the staple food for Korean is grains such as rice. In this study, we determined the prevalence (24 of 129 isolates) of emetic B. cereus in 36,745 stool samples from sporadic food-poisoning cases in Korea between 2007 and 2008. The toxin gene profile, toxin production, and biofilm-forming ability of the emetic B. cereus isolates were investigated. Repetitive element sequence polymorphism polymerase chain reaction fingerprints (rep-PCR) were also used to assess the intraspecific biodiversity of these isolates. Emetic B. cereus was present in 0.07% of the sporadic food-poisoning cases. The 24 emetic isolates identified all carried the nheABC and entFM genes and produced NHE enterotoxin. However, they did not have hemolysin BL toxin or related genes. A relationship between biofilm formation and toxin production was not observed in this study. The rep-PCR fingerprints of the B. cereus isolates were not influenced by the presence of toxin genes, or biofilm-forming ability. The rep-PCR assay discriminated emetic B. cereus isolates from nonemetic isolates, even if this assay did not perfectly discriminate these isolates. Further study on emetic isolates possessing a high degree of diversity may be necessary to evaluate the performance of the subtyping assay to discriminate emetic and nonemetic B. cereus isolates and could provide a more accurate indication of the risk from B. cereus strains.

  18. Bacillus cereus Certhrax ADP-ribosylates vinculin to disrupt focal adhesion complexes and cell adhesion.

    Science.gov (United States)

    Simon, Nathan C; Barbieri, Joseph T

    2014-04-11

    Bacillus cereus is often associated with mild to moderate gastroenteritis; however, some recent isolates cause inhalational anthrax-like diseases and death. These potential emerging human pathogens express multiple virulence factors. B. cereus strain G9241 expresses anthrax toxin, several polysaccharide capsules, and the novel ADP-ribosyltransferase, Certhrax. In this study, we show that Certhrax ADP-ribosylates Arg-433 of vinculin, a protein that coordinates actin cytoskeleton and extracellular matrix interactions. ADP-ribosylation of vinculin disrupted focal adhesion complexes and redistributed vinculin to the cytoplasm. Exogenous vinculin rescued these phenotypes. This provides a mechanism for strain G9241 to breach host barrier defenses and promote bacterial growth and spread. Certhrax is the first bacterial toxin to add a post-translational modification to vinculin to disrupt the actin cytoskeleton.

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

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    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.

  20. Phosphatidylcholine-Specific Phospholipase C and Sphingomyelinase Activities in Bacteria of the Bacillus cereus Group

    OpenAIRE

    Pomerantsev, A. P.; Kalnin, K. V.; Osorio, M.; Leppla, S H

    2003-01-01

    Bacillus anthracis is nonhemolytic, even though it is closely related to the highly hemolytic Bacillus cereus. Hemolysis by B. cereus results largely from the action of phosphatidylcholine-specific phospholipase C (PC-PLC) and sphingomyelinase (SPH), encoded by the plc and sph genes, respectively. In B. cereus, these genes are organized in an operon regulated by the global regulator PlcR. B. anthracis contains a highly similar cereolysin operon, but it is transcriptionally silent because the ...

  1. 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.

  2. Diversity of pulsed-field gel electrophoresis patterns of cereulide-producing isolates of Bacillus cereus and Bacillus weihenstephanensis.

    Science.gov (United States)

    Castiaux, Virginie; N'guessan, Elise; Swiecicka, Izabela; Delbrassinne, Laurence; Dierick, Katelijne; Mahillon, Jacques

    2014-04-01

    Bacillus cereus is an important foodborne pathogen causing diarrhoea, emesis and in, rare cases, lethal poisonings. The emetic syndrome is caused by cereulide, a heat-stable toxin. Originally considered as a rather homogenous group, the emetic strains have since been shown to display some diversity, including the existence of two clusters of mesophilic B. cereus and psychrotolerant B. weihenstephanensis. Using pulsed-field gel electrophoresis (PFGE) analysis, this research aimed to better understand the diversity and spatio-temporal occurrence of emetic strains originating from environmental or food niches vs. those isolated from foodborne cases. The diversity was evaluated using a set of 52 B. cereus and B. weihenstephanensis strains isolated between 2000 and 2011 in ten countries. PFGE analysis could discriminate 17 distinct profiles (pulsotypes). The most striking observations were as follows: (1) more than one emetic pulsotype can be observed in a single outbreak; (2) the number of distinct isolates involved in emetic intoxications is limited, and these potentially clonal strains frequently occurred in successive and independent food poisoning cases; (3) isolates from different countries displayed identical profiles; and (4) the cereulide-producing psychrotolerant B. weihenstephanensis were, so far, only isolated from environmental niches.

  3. Short communication: Presence of neutral metallopeptidase (npr) gene and proteolytic activity of Bacillus cereus isolated from dairy products.

    Science.gov (United States)

    Montanhini, M T M; Colombo, M; Nero, L A; Bersot, L S

    2013-09-01

    The control of proteolytic microorganisms is one of the main challenges of the dairy industry, due to their spoilage activity that jeopardizes the quality of their products. Seventy-four Bacillus cereus strains isolated from powdered, UHT, and pasteurized milks were tested for the presence of the neutral metallopeptidase (npr) gene and proteolytic activity at 7, 10, 25, 30, and 37°C. All strains had the npr gene, and proteolytic activity increased with the incubation temperature. The obtained results highlight the relevance of B. cereus as a spoiling agent in the dairy industry in terms of its genetic predisposition for proteolytic capacity, especially at room temperature. PMID:23849645

  4. Isolation of Bacillus Cereus from wounds and burns

    Directory of Open Access Journals (Sweden)

    Behzadiannejhad Gh

    1997-09-01

    Full Text Available The culture results of 203 cases with different wounds were studies; 150 of the latter were burn cases (mainly second and third degree burns, and 53 were of other types (surgical, traumatic, ect. Four subtypes of Bacillus cereus were isolated upon culture, and the different toxins produced in DHT broth with 0.1% glucose were assessed. The lethal toxin was injected intravenously to Syrian rats, none of whom died. VPR factor was assessed in the 4 subtypes. Three subtypes produced VPR in significant amounts.

  5. Architecture and High-Resolution Structure of Bacillus thuringiensis and Bacillus cereus Spore Coat Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Plomp, M; Leighton, T; Wheeler, K; Malkin, A

    2005-02-18

    We have utilized atomic force microscopy (AFM) to visualize the native surface topology and ultrastructure of Bacillus thuringiensis and Bacillus cereus spores in water and in air. AFM was able to resolve the nanostructure of the exosporium and three distinctive classes of appendages. Removal of the exosporium exposed either a hexagonal honeycomb layer (B. thuringiensis) or a rodlet outer spore coat layer (B. cereus). Removal of the rodlet structure from B. cereus spores revealed an underlying honeycomb layer similar to that observed with B. thuringiensis spores. The periodicity of the rodlet structure on the outer spore coat of B. cereus was {approx}8 nm, and the length of the rodlets was limited to the cross-patched domain structure of this layer to {approx}200 nm. The lattice constant of the honeycomb structures was {approx}9 nm for both B. cereus and B. thuringiensis spores. Both honeycomb structures were composed of multiple, disoriented domains with distinct boundaries. Our results demonstrate that variations in storage and preparation procedures result in architectural changes in individual spore surfaces, which establish AFM as a useful tool for evaluation of preparation and processing ''fingerprints'' of bacterial spores. These results establish that high-resolution AFM has the capacity to reveal species-specific assembly and nanometer scale structure of spore surfaces. These species-specific spore surface structural variations are correlated with sequence divergences in a spore core structural protein SspE.

  6. Cloning and expression of vgb gene in Bacillus cereus, improve phenol and p-nitrophenol biodegradation

    Science.gov (United States)

    Vélez-Lee, Angel Eduardo; Cordova-Lozano, Felipe; Bandala, Erick R.; Sanchez-Salas, Jose Luis

    2016-02-01

    In this work, the vgb gene from Vitrocilla stercoraria was used to genetically modify a Bacillus cereus strain isolated from pulp and paper wastewater effluent. The gene was cloned in a multicopy plasmid (pUB110) or uni-copy gene using a chromosome integrative vector (pTrpBG1). B. cereus and its recombinant strains were used for phenol and p-nitrophenol biodegradation using aerobic or micro-aerobic conditions and two different temperatures (i.e. 37 and 25 °C). Complete (100%) phenol degradation was obtained for the strain where the multicopy of vgb gene was present, 98% for the strain where uni-copy gene was present and 45% for wild type strain for the same experimental conditions (i.e. 37 °C and aerobic condition). For p-nitrophenol degradation at the same conditions, the strain with the multi-copy vgb gene was capable to achieve 50% of biodegradation, ˜100% biodegradation was obtained using the uni-copy strain and ˜24% for wild type strain. When the micro-aerobic condition was tested, the biodegradation yield showed a significant decreased. The biodegradation trend observed for aerobic was similar for micro-aerobic assessments: the modified strains showed higher degradation rates when compared with wild type strain. For all experimental conditions, the highest p-nitrophenol degradation was observed using the strain with uni-copy of vgb gene. Besides the increase of biodegradative capability of the strain, insertion of the vgb gene was observed able to modify other morphological characteristics such as avoiding the typical flake formation in the B. cereus culture. In both cases, the modification seems to be related with the enhancement of oxygen supply to the cells generated by the vgb gene insertion. The application of the genetically modified microorganism (GMM) to the biodegradation of pollutants in contaminated water possesses high potential as an environmentally friendly technology to facing this emergent problem.

  7. The Pore-Forming Haemolysins of Bacillus Cereus: A Review

    Directory of Open Access Journals (Sweden)

    Vincent Sanchis

    2013-06-01

    Full Text Available The Bacillus cereus sensu lato group contains diverse Gram-positive spore-forming bacteria that can cause gastrointestinal diseases and severe eye infections in humans. They have also been incriminated in a multitude of other severe, and frequently fatal, clinical infections, such as osteomyelitis, septicaemia, pneumonia, liver abscess and meningitis, particularly in immuno-compromised patients and preterm neonates. The pathogenic properties of this organism are mediated by the synergistic effects of a number of virulence products that promote intestinal cell destruction and/or resistance to the host immune system. This review focuses on the pore-forming haemolysins produced by B. cereus: haemolysin I (cereolysin O, haemolysin II, haemolysin III and haemolysin IV (CytK. Haemolysin I belongs to the cholesterol-dependent cytolysin (CDC family whose best known members are listeriolysin O and perfringolysin O, produced by L. monocytogenes and C. perfringens respectively. HlyII and CytK are oligomeric ß-barrel pore-forming toxins related to the α-toxin of S. aureus or the ß-toxin of C. perfringens. The structure of haemolysin III, the least characterized haemolytic toxin from the B. cereus, group has not yet been determined.

  8. Chemodiversity of cereulide, the emetic toxin of Bacillus cereus.

    Science.gov (United States)

    Marxen, Sandra; Stark, Timo D; Frenzel, Elrike; Rütschle, Andrea; Lücking, Genia; Pürstinger, Gabriel; Pohl, Elena E; Scherer, Siegfried; Ehling-Schulz, Monika; Hofmann, Thomas

    2015-03-01

    Food-borne intoxications are increasingly caused by the dodecadepsipeptide cereulide, the emetic toxin produced by Bacillus cereus. As such intoxications pose a health risk to humans, a more detailed understanding on the chemodiversity of this toxin is mandatory for the reliable risk assessment of B. cereus toxins in foods. Mass spectrometric screening now shows a series of at least 18 cereulide variants, among which the previously unknown isocereulides A-G were determined for the first time by means of UPLC-TOF MS and ion-trap MS(n) sequencing, (13)C-labeling experiments, and post-hydrolytic dipeptide and enantioselective amino acid analysis. The data demonstrate a high microheterogeneity in cereulide and show evidence for a relaxed proof reading function of the non-ribosomal cereulide peptide synthetase complex giving rise to an enhanced cereulide chemodiversity. Most intriguingly, the isocereulides were found to differ widely in their cell toxicity correlating with their ionophoric properties (e.g., purified isocereulide A showed about 8-fold higher cytotoxicity than purified cereulide in the HEp-2 assay and induced an immediate breakdown of bilayer membranes). These findings provide a substantial contribution to the knowledge-based risk assessment of B. cereus toxins in foods, representing a still unsolved challenge in the field of food intoxications.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. DNA as an Adhesin: Bacillus cereus Requires Extracellular DNA To Form Biofilms▿ †

    OpenAIRE

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

    2009-01-01

    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 lik...

  11. Comparative analysis of two-component signal transduction systems of Bacillus cereus, Bacillus thuringiensis and Bacillus anthracis

    NARCIS (Netherlands)

    Been, M.W.H.J. de; Francke, C.; Moezelaar, R.; Abee, T.; Siezen, R.J.

    2006-01-01

    Members of the Bacillus cereus group are ubiquitously present in the environment and can adapt to a wide range of environmental fluctuations. In bacteria, these adaptive responses are generally mediated by two-component signal transduction systems (TCSs), which consist of a histidine kinase (HK) and

  12. 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 two...... B. anthracis strains were amplified and subsequently digested with Sau3A1. Furthermore, a majority of the amplicons were sequenced directly to verify the PCR-RE results. The results obtained suggest that only the B. mycoides generates specific fragments following PCR-RE. Conversely...

  13. Incidence, Antibiotic Susceptibility, and Toxin Profiles of Bacillus cereus sensu lato Isolated from Korean Fermented Soybean Products.

    Science.gov (United States)

    Yim, Jin-Hyeok; Kim, Kwang-Yeop; Chon, Jung-Whan; Kim, Dong-Hyeon; Kim, Hong-Seok; Choi, Da-Som; Choi, In-Soo; Seo, Kun-Ho

    2015-06-01

    Korean fermented soybean products, such as doenjang, kochujang, ssamjang, and cho-kochujang, can harbor foodborne pathogens such as Bacillus cereus sensu lato (B. cereus sensu lato). The aim of this study was to characterize the toxin gene profiles, biochemical characteristics, and antibiotic resistance patterns of B. cereus sensu lato strains isolated from Korean fermented soybean products. Eighty-eight samples of Korean fermented soybean products purchased from retails in Seoul were tested. Thirteen of 26 doenjang samples, 13 of 23 kochujang samples, 16 of 30 ssamjang samples, and 5 of 9 cho-kochujang samples were positive for B. cereus sensu lato strains. The contamination level of all positive samples did not exceed 4 log CFU/g of food (maximum levels of Korea Food Code). Eighty-seven B. cereus sensu lato strains were isolated from 47 positive samples, and all isolates carried at least one enterotoxin gene. The detection rates of hblCDA, nheABC, cytK, and entFM enterotoxin genes among all isolates were 34.5%, 98.9%, 57.5%, and 100%, respectively. Fifteen strains (17.2%) harbored the emetic toxin gene. Most strains tested positive for salicin fermentation (62.1%), starch hydrolysis (66.7%), hemolysis (98.9%), motility test (100%), and lecithinase production (96.6%). The B. cereus sensu lato strains were highly resistant to β-lactam antibiotics such as ampicillin, penicillin, cefepime, imipenem, and oxacillin. Although B. cereus sensu lato levels in Korean fermented soybean products did not exceed the maximum levels permitted in South Korea (<10(4) CFU/g), these results indicate that the bacterial isolates have the potential to cause diarrheal or emetic gastrointestinal diseases.

  14. Growth/no growth models for heat-treated psychrotrophic Bacillus cereus spores under cold storage.

    Science.gov (United States)

    Daelman, Jeff; Vermeulen, An; Willemyns, Tine; Ongenaert, Rebecca; Jacxsens, Liesbeth; Uyttendaele, Mieke; Devlieghere, Frank

    2013-01-15

    The microbiological safety of refrigerated and processed foods of extended durability (REPFED) is linked to spore-forming pathogens, more specifically Clostridium botulinum and Bacillus cereus. In this study two sets of growth/no growth (GNG) models are presented for the spores of two B. cereus strains. The models incorporate both product (water activity (a(w)) and pH) and process parameters (pasteurization value at 90 °C (P(90)) or heating temperature). The first model evaluates the effect of four different P(90)-values (P(90)=0, 4, 7 or 10 min, all applied at 90 °C) on the germination and subsequent growth of B. cereus spores under different conditions of pH and a(w) at 10 °C. These models show that a heat treatment not only increases the time to growth (TTG), but also significantly increases the minimal a(w) and pH necessary for germination and subsequent growth: e.g. at a(w) 0.995 and without heat treatment (P(90)=0), strain FF355 B. cereus spores were predicted to germinate and grow at pH 5.3. With a P(90) of 10 min, the minimal pH increased to 5.7. The second set of models for B. cereus spores compares the effect of three heat treatments with the same P(90)-value (10 min) but applied at different temperatures (85, 87 and 90 °C), on the germination and subsequent growth at 10 °C. The second model shows that lower heating temperatures (85 and 87 °C) had less effect on the TTG and minimal a(w) and pH than a higher temperature (90 °C). Finally, the first set of models was validated in broth using spores of seven psychrotrophic B. cereus strains, to evaluate the effect of strain variability on the model predictions. The results of the validation (% growth) were compared to the predicted growth probability. The results showed that the models were prone to fail-dangerous results (i.e. predicting no growth when growth was observed: 17%-34%). Using a very low threshold for growth (0.1% predicted chance of growth was considered to be complete growth), the models

  15. Fate of pathogenic Bacillus cereus spores after ingestion by protist grazers

    DEFF Research Database (Denmark)

    Winding, Anne; Santos, Susana; Hendriksen, Niels Bohse;

    to the evolution of Bacillus cereus group bacteria (e.g. B. cereus, B. anthracis, B. thuringiensis) as a pathogen. It has been hypothesized that the spore stage protects against digestion by predating protists. Indeed, B. thuringiensis spores have been shown to be readily ingested by ciliated protists but failed...

  16. Persistent Bacillus cereus Bacteremia in 3 Persons Who Inject Drugs, San Diego, California, USA.

    Science.gov (United States)

    Schaefer, Gabrielle; Campbell, Wesley; Jenks, Jeffrey; Beesley, Cari; Katsivas, Theodoros; Hoffmaster, Alex; Mehta, Sanjay R; Reed, Sharon

    2016-09-01

    Bacillus cereus is typically considered a blood culture contaminant; however, its presence in blood cultures can indicate true bacteremia. We report 4 episodes of B. cereus bacteremia in 3 persons who inject drugs. Multilocus sequence typing showed that the temporally associated infections were caused by unrelated clones. PMID:27533890

  17. 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 bas

  18. Plant compounds enhance assay sensitivity for detection of active bacillus cereus toxin

    Science.gov (United States)

    Bacillus cereus is an important food pathogen, producing emetic and diarrheal syndromes, the latter mediated by enterotoxins. It has been estimated that there are 84,000 cases of B. cereus food poisoning in the US each year, with an annual cost of USD 36 million. The ability to sensitively trace and...

  19. Influence of carvacrol on growth and toxin production by Bacillus cereus. International

    NARCIS (Netherlands)

    Ultee, A.; Smid, E.J.

    2001-01-01

    The natural antimicrobial compound carvacrol was investigated for its effect on diarrheal toxin production by Bacillus cereus. Carvacrol (0-0.06 mg/ml) reduced the viable count and the maximal specific growth rate (μmax) of B. cereus in BHI broth. The total amount of protein was not affected by carv

  20. 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 ...

  1. 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 filter

  2. 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 o

  3. Quantitative Prevalence and Toxin Gene Profile of Bacillus cereus from Ready-to-Eat Vegetables in South Korea.

    Science.gov (United States)

    Chon, Jung-Whan; Yim, Jin-Hyeok; Kim, Hong-Seok; Kim, Dong-Hyeon; Kim, Hyunsook; Oh, Deog-Hwan; Kim, Soo-Ki; Seo, Kun-Ho

    2015-09-01

    Ready-to-eat (RTE) foods such as prepared vegetables are becoming an increasingly popular food choice. Since RTE vegetables are not commonly sterilized by heat treatment, contamination with foodborne pathogens such as Bacillus cereus (B. cereus) is a major concern. The objective of this study was to assess the quantitative prevalence and toxin gene profiles of B. cereus strains isolated from RTE vegetables. We found that 70 of the 145 (48%) tested retail vegetable salad and sprout samples were positive for B. cereus. The B. cereus isolates harbored at least one enterotoxin gene. The detection rates of nheABC, hblCDA, cytK, and entFM enterotoxin genes among all isolates were 97.1%, 100%, 81.4%, and 98.6%, respectively. No strain carried the emetic toxin genes. Only 4 strains (5.7%) from the 70 isolates were psychrotrophic and were able to grow at 7°C. All of the psychrotrophic isolates possessed at least 1 enterotoxin gene.

  4. gyrB as a phylogenetic discriminator for members of the Bacillus anthracis-cereus-thuringiensis group

    Science.gov (United States)

    La Duc, Myron T.; Satomi, Masataka; Agata, Norio; Venkateswaran, Kasthuri

    2004-01-01

    Bacillus anthracis, the causative agent of the human disease anthrax, Bacillus cereus, a food-borne pathogen capable of causing human illness, and Bacillus thuringiensis, a well-characterized insecticidal toxin producer, all cluster together within a very tight clade (B. cereus group) phylogenetically and are indistinguishable from one another via 16S rDNA sequence analysis. As new pathogens are continually emerging, it is imperative to devise a system capable of rapidly and accurately differentiating closely related, yet phenotypically distinct species. Although the gyrB gene has proven useful in discriminating closely related species, its sequence analysis has not yet been validated by DNA:DNA hybridization, the taxonomically accepted "gold standard". We phylogenetically characterized the gyrB sequences of various species and serotypes encompassed in the "B. cereus group," including lab strains and environmental isolates. Results were compared to those obtained from analyses of phenotypic characteristics, 16S rDNA sequence, DNA:DNA hybridization, and virulence factors. The gyrB gene proved more highly differential than 16S, while, at the same time, as analytical as costly and laborious DNA:DNA hybridization techniques in differentiating species within the B. cereus group.

  5. A quantitative microbiological exposure assessment model for Bacillus cereus in REPFEDs.

    Science.gov (United States)

    Daelman, Jeff; Membré, Jeanne-Marie; Jacxsens, Liesbeth; Vermeulen, An; Devlieghere, Frank; Uyttendaele, Mieke

    2013-09-16

    One of the pathogens of concern in refrigerated and processed foods of extended durability (REPFED) is psychrotrophic Bacillus cereus, because of its ability to survive pasteurisation and grow at low temperatures. In this study a quantitative microbiological exposure assessment (QMEA) of psychrotrophic B. cereus in REPFEDs is presented. The goal is to quantify (i) the prevalence and concentration of B. cereus during production and shelf life, (ii) the number of packages with potential emetic toxin formation and (iii) the impact of different processing steps and consumer behaviour on the exposure to B. cereus from REPFEDs. The QMEA comprises the entire production and distribution process, from raw materials over pasteurisation and up to the moment it is consumed or discarded. To model this process the modular process risk model (MPRM) was used (Nauta, 2002). The product life was divided into nine modules, each module corresponding to a basic process: (1) raw material contamination, (2) cross contamination during handling, (3) inactivation during preparation, (4) growth during intermediate storage, (5) partitioning of batches in portions, (6) mixing portions to create the product, (7) recontamination during assembly and packaging, (8) inactivation during pasteurisation and (9) growth during shelf life. Each of the modules was modelled and built using a combination of newly gathered and literature data, predictive models and expert opinions. Units (batch/portion/package) with a B. cereus concentration of 10(5)CFU/g or more were considered 'risky' units. Results show that the main drivers of variability and uncertainty are consumer behaviour, strain variability and modelling error. The prevalence of B. cereus in the final products is estimated at 48.6% (±0.01%) and the number of packs with too high B. cereus counts at the moment of consumption is estimated at 4750 packs per million (0.48%). Cold storage at retail and consumer level is vital in limiting the exposure

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

    OpenAIRE

    Vajihe Karbasizade; Arezoo Dabiri

    2014-01-01

    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 spo...

  7. Whole-Genome Sequences of 94 Environmental Isolates of Bacillus cereus Sensu Lato

    OpenAIRE

    Van der Auwera, Géraldine A.; Feldgarden, Michael; Kolter, Roberto; Mahillon, Jacques

    2013-01-01

    Bacillus cereus sensu lato is a species complex that includes the anthrax pathogen Bacillus anthracis and other bacterial species of medical, industrial, and ecological importance. Their phenotypes of interest are typically linked to large plasmids that are closely related to the anthrax plasmids pXO1 and pXO2. Here, we present the draft genome sequences of 94 isolates of B. cereus sensu lato, which were chosen for their plasmid content and environmental origins.

  8. Whole-Genome Sequences of 94 Environmental Isolates of Bacillus cereus Sensu Lato

    OpenAIRE

    Van der Auwera, Géraldine A.; Feldgarden, Michael; Kolter, Roberto; Mahillon, Jacques

    2013-01-01

    Bacillus cereus sensu lato is a species complex that includes the anthrax pathogen Bacillus anthracis and other bacterial species of medical, industrial, and ecological importance. Their phenotypes of interest are typically linked to large plasmids that are closely related to the anthrax plasmids pXO1 and pXO2. Here, we present the draft genome sequences of 94 isolates of B. cereus sensu lato, which were chosen for their plasmid content and environmental origins.

  9. Biodegradation Characteristics of Chlorpyrifos by Mixed Culture of Bacillus cereus Strains%两株降解菌混合对毒死蜱的降解特性研究

    Institute of Scientific and Technical Information of China (English)

    段海明

    2013-01-01

    In the present work,we investigated for the first time the degradation characteristics of chlorpyrifos by the mixed culture of Bacillus cereus strains.The optimal ratio of inoculation volume of the two strains for chlor-pyrifos degradation was established .Further,the effects of the inoculation volume,glucose concentration,initial pH and the initial chlorpyrifos concentration on the degradation efficiency of chlorprifos were determined .Simultaneous-ly,the effect of high salinity on the biodegradation activity of chlorpyrifos was also examined .The results showed that when the ratio(V/V) was 1∶1,the degradation rate to 80 mg/Lof chlorpyrifos reached the highest .The optimal in-oculum amount of the mixed strains was 8%(V/V) of the total volume.Addition of glucose stimulated the growth of the mixed strains but did not enhance the degradation efficiency of chlorpyrifos .The alkaline environment was prone to form the biomass and to achieve a high degradation rate of chlorpyrifos by the mixed strains .When the initial con-centration of chlorpyrifos was 42 mg/L,the residual concentration of chlorpyrifos decreased with the time .However, the degradation curves of chlorpyrifos at high concentrations (108,126 mg/L) followed two peaks.The degradation rate of the mixed strains to 80 mg/L of chlorpyrifos was above 41%while the sodium chloride concentration ranged from 20 g/L to 70 g/L.The results suggest that the mixed strains could be used as a potential and efficient chlor -pyrifos degrader for the bioremediation of contaminated sites ,especially for the cleanup of high salinity wastewater in the chlorpyrifos production enterprises .%  为明确2株蜡状芽孢杆菌(Bacillus cereus)混合对毒死蜱的降解效果,以混合菌对毒死蜱的降解率和菌株的生长量为依据,考察了混合菌不同配比和不同环境因素对混合菌降解毒死蜱的影响。结果表明,两菌株的比例为1∶1(V/V)时,对80 mg/L毒死蜱的降解率最

  10. L-asparaginase production by mangrove derived Bacillus cereus MAB5:optimization by response surface methodology

    Institute of Scientific and Technical Information of China (English)

    ThenmozhiC; SankarR; KaruppiahV; SampathkumarP

    2011-01-01

    Objective:To isolate marine bacteria, statistically optimize them for maximum asparaginase production. Methods:In the present study, statistically based experimental designs were applied to maximize the production of L-asparaginase from bacterial strain of Bacillus cereus (B. cereus) MAB5 (HQ675025) isolated and identified by 16S rDNA sequencing from mangroves rhizosphere sediment. Results:Plackett-Barman design was used to identify the interactive effect of the eight variables viz. yeast extract, soyabean meal, glucose, magnesium sulphate, KH2PO4, wood chips, aspargine and sodium chloride. All the variables are denoted as numerical factors and investigated at two widely spaced intervals designated as-1 (low level) and+1 (high level). The effect of individual parameters on L-asparaginase production was calculated. Soyabean meal, aspargine, wood chips and sodium chloride were found to be the significant among eight variables. The maximum amount of L-asparaginase produced (51.54 IU/mL) from the optimized medium containing soyabean meal (6.282 8 g/L), aspargine (5.5 g/L), wood chips (1.383 8 g/L) and NaCl (4.535 4 g/L). Conclusions:The study revealed that, it is useful to produce the maximum amount of L-asparaginase from B. cereus MAB5 for the treatment of various infections and diseases.

  11. Detection of Anthrax Simulants with Microcalorimetric Spectroscopy: Bacillus subtilis and Bacillus cereus Spores

    Science.gov (United States)

    Arakawa, Edward T.; Lavrik, Nickolay V.; Datskos, Panos G.

    2003-04-01

    Recent advances in the development of ultrasensitive micromechanical thermal detectors have led to the advent of novel subfemtojoule microcalorimetric spectroscopy (CalSpec). On the basis of principles of photothermal IR spectroscopy combined with efficient thermomechanical transduction, CalSpec provides acquisition of vibrational spectra of microscopic samples and absorbates. We use CalSpec as a method of identifying nanogram quantities of biological micro-organisms. Our studies focus on Bacillus subtilis and Bacillus cereus spores as simulants for Bacillus anthracis spores. Using CalSpec, we measured IR spectra of B. subtilis and B. cereus spores present on surfaces in nanogram quantities (approximately 100 -1000 spores). The spectra acquired in the wavelength range of 690 -4000 cm-1 (2.5 -14.5 μm) contain information-rich vibrational signatures that reflect the different ratios of biochemical makeup of the micro-organisms. The distinctive features in the spectra obtained for the two types of micro-organism can be used to distinguish between the spores of the Bacillus family. As compared with conventional IR and Fourier-transform IR microscopic spectroscopy techniques, the advantages of the present technique include significantly improved sensitivity (at least a full order of magnitude), absence of expensive IR detectors, and excellent potential for miniaturization.

  12. The Pathogenomic Sequence Analysis of B. cereus and B. Thuringiensis isolates closely related to Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Han, C S; Xie, G; Challacombe, J F; Altherr, M R; Bhotika, S S; Bruce, D; Campbell, C S; Campbell, M L; Chen, J; Chertkov, O; Cleland, C; Dimitrijevic-Bussod, M; Doggett, N A; Fawcett, J J; Glavina, T; Goodwin, L A; Hill, K K; Hitchcock, P; Jackson, P J; Keim, P; Kewalramani, A R; Longmire, J; Lucas, S; Malfatti, S; McMurry, K; Meincke, L J; Misra, M; Moseman, B L; Mundt, M; Munk, A C; Okinaka, R T; Parson-Quintana, B; Reilly, L P; Richardson, P; Robinson, D L; Rubin, E; Saunders, E; Tapia, R; Tesmer, J G; Thayer, N; Thompson, L S; Tice, H; Ticknor, L O; Wills, P L; Gilna, P; Brettin, T S

    2005-10-12

    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 B anthracis. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Control Efficacy and Antifungal Mechanism of Bacillus Cereus Strain JK14 against Wheat Take-all Disease%蜡样芽孢杆菌JK14 对小麦全蚀病的防治及其抑病机理

    Institute of Scientific and Technical Information of China (English)

    韩艳霞; 胡斌杰; 王宫南

    2008-01-01

    [Objective]Study on control efficacy and inhibitory effect d Bacillus cereus strain JK14,against wheat take-all disease,investigating its antifungal mechanism.[Method]B.cereus JK14 was isolated from soil in the rhizosphere of wheat,inhibitory effects of whose nutrient solution form against Gaeumannomyces graminis var tritici stroins 9862 and 9812 were measured in laboratory and then for its antifungal mechanism.The strain JK14* with rifampicin and wheat take-all disease resistance was screened by increasing concentration of the two substrates,and colonization of JK14* was studied.[Result]In pot experiment,the control effects of JK14* against 9862 and 9812 are 63% and 59%,respectively,which are higher than that of chemical fungicides,with 55% and 51%,respectively.JK14* could deform mycelium and causes degradation of cell wall.And there are also dynamic change of JK14* in root system.JK14* on seed could extend to root along with seed germination and rooting,but per unit tissue mycelium number decreased gradually.[Conclusion]The results indicate some control efficacy of B.cereus strain JK14 against wheat take-all disease.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  17. 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.

  18. A procedure for estimating Bacillus cereus spores in soil and stream-sediment samples - A potential exploration technique

    Science.gov (United States)

    Watterson, J.R.

    1985-01-01

    The presence of bacterial spores of the Bacillus cereus group in soils and stream sediments appears to be a sensitive indicator of several types of concealed mineral deposits, including vein-type gold deposits. The B. cereus assay is rapid, inexpensive, and inherently reproducible. The test, currently under investigation for its potential in mineral exploration, is recommended for use on a research basis. Among the aerobic spore-forming bacilli, only B. cereus and closely related strains produce an opaque zone in egg-yolk emulsion agar. This characteristic, also known as the Nagler of lecitho-vitellin reaction, has long been used to rapidly indentify and estimate presumptive B. cereus. The test is here adapted to permit rapid estimation of B. cereus spores in soil and stream-sediment samples. Relative standard deviation was 10.3% on counts obtained from two 40-replicate pour-plate determinations. As many as 40 samples per day can be processed. Enough procedural detail is included to permit investigation of the test in conventional geochemical laboratories using standard microbiological safety precautions. ?? 1985.

  19. Enterotoxigenic profiling of emetic toxin- and enterotoxin-producing Bacillus cereus, Isolated from food, environmental, and clinical samples by multiplex PCR.

    Science.gov (United States)

    Forghani, Fereidoun; Kim, Jung-Beom; Oh, Deog-Hwan

    2014-11-01

    Bacillus cereus comprises the largest group of endospore-forming bacteria and can cause emetic and diarrheal food poisoning. A total of 496 B. cereus strains isolated from various sources (food, environmental, clinical) were assessed by a multiplex PCR for the presence of enterotoxin genes. The detection rate of nheA, entFM, hblC, and cytK enterotoxin genes among all B. cereus strains was 92.33%, 77.21%, 59.47%, and 47.58%, respectively. Enterotoxigenic profiles were determined in emetic toxin- (8 patterns) and enterotoxin-producing strains (12 patterns). The results provide important information on toxin prevalence and toxigenic profiles of B. cereus from various sources. Our findings revealed that B. cereus must be considered a serious health hazard and Bacillus thuringiensis should be considered of a greater potential concern to food safety among all B. cereus group members. Also, there is need for intensive and continuous monitoring of products embracing both emetic toxin and enterotoxin genes.

  20. A biochemically active MCM-like helicase in Bacillus cereus

    Science.gov (United States)

    Samuels, Martin; Gulati, Gaurav; Shin, Jae-Ho; Opara, Rejoice; McSweeney, Elizabeth; Sekedat, Matt; Long, Stephen; Kelman, Zvi; Jeruzalmi, David

    2009-01-01

    The mini-chromosome maintenance (MCM) proteins serve as the replicative helicases in archaea and eukaryotes. Interestingly, an MCM homolog was identified, by BLAST analysis, within a phage integrated in the bacterium Bacillus cereus (Bc). BcMCM is only related to the AAA region of MCM-helicases; the typical amino-terminus is missing and is replaced by a segment with weak homology to primases. We show that BcMCM displays 3′→5′ helicase and ssDNA-stimulated ATPase activity, properties that arise from its conserved AAA domain. Isolated BcMCM is a monomer in solution but likely forms the functional oligomer in vivo. We found that the BcMCM amino-terminus can bind ssDNA and harbors a zinc atom, both hallmarks of the typical MCM amino-terminus. No BcMCM-catalyzed primase activity could be detected. We propose that the divergent amino-terminus of BcMCM is a paralog of the corresponding region of MCM-helicases. A divergent amino terminus makes BcMCM a useful model for typical MCM-helicases since it accomplishes the same function using an apparently unrelated structure. PMID:19474351

  1. Cereulide synthetase gene cluster from emetic Bacillus cereus: Structure and location on a mega virulence plasmid related to Bacillus anthracis toxin plasmid pXO1

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    Wagner Martin

    2006-03-01

    Full Text Available Abstract Background Cereulide, a depsipeptide structurally related to valinomycin, is responsible for the emetic type of gastrointestinal disease caused by Bacillus cereus. Recently, it has been shown that this toxin is produced by a nonribosomal peptide synthetase (NRPS, but its exact genetic organization and biochemical synthesis is unknown. Results The complete sequence of the cereulide synthetase (ces gene cluster, which encodes the enzymatic machinery required for the biosynthesis of cereulide, was dissected. The 24 kb ces gene cluster comprises 7 CDSs and includes, besides the typical NRPS genes like a phosphopantetheinyl transferase and two CDSs encoding enzyme modules for the activation and incorporation of monomers in the growing peptide chain, a CDS encoding a putative hydrolase in the upstream region and an ABC transporter in the downstream part. The enzyme modules responsible for incorporation of the hydroxyl acids showed an unusual structure while the modules responsible for the activation of the amino acids Ala and Val showed the typical domain organization of NRPS. The ces gene locus is flanked by genetic regions with high homology to virulence plasmids of B. cereus, Bacillus thuringiensis and Bacillus anthracis. PFGE and Southern hybridization showed that the ces genes are restricted to emetic B. cereus and indeed located on a 208 kb megaplasmid, which has high similarities to pXO1-like plasmids. Conclusion The ces gene cluster that is located on a pXO1-like virulence plasmid represents, beside the insecticidal and the anthrax toxins, a third type of B. cereus group toxins encoded on megaplasmids. The ces genes are restricted to emetic toxin producers, but pXO1-like plasmids are also present in emetic-like strains. These data might indicate the presence of an ancient plasmid in B. cereus which has acquired different virulence genes over time. Due to the unusual structure of the hydroxyl acid incorporating enzyme modules of Ces

  2. Characterization and Exposure Assessment of Emetic Bacillus cereus and Cereulide Production in Food Products on the Dutch Market.

    Science.gov (United States)

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

    2016-02-01

    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 products in The Netherlands, a characterization of B. cereus isolates obtained, cereulide production conditions, and a comparison of consumer exposure estimates with those of a previous exposure assessment. Food samples (n = 1,489) were tested for the presence of B. cereus; 5.4% of the samples contained detectable levels (>10(2) CFU/g), and 0.7% contained levels above 10(5) CFU/g. Samples (n = 3,008) also were tested for the presence of cereulide. Two samples (0.067%) contained detectable levels of cereulide at 3.2 and 5.4 μg/kg of food product. Of the 481 tested isolates, 81 produced cereulide and/or contained the ces gene. None of the starch-positive and hbl-containing isolates possessed the ces gene, whereas all strains contained the nhe genes. Culture of emetic B. cereus under nonoptimal conditions revealed a delay in onset of cereulide production compared with culture under optimal conditions, and cereulide was produced in all cases when B. cereus cells had been in the stationary phase for some time. The prevalence of cereulide-contaminated food approached the prevalence of contaminated products estimated in an exposure assessment. The main food safety focus associated with this pathogen should be to prevent germination and growth of any B. cereus present in food products and thus prevent cereulide production in foods.

  3. Characterization and Exposure Assessment of Emetic Bacillus cereus and Cereulide Production in Food Products on the Dutch Market.

    Science.gov (United States)

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

    2016-02-01

    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 products in The Netherlands, a characterization of B. cereus isolates obtained, cereulide production conditions, and a comparison of consumer exposure estimates with those of a previous exposure assessment. Food samples (n = 1,489) were tested for the presence of B. cereus; 5.4% of the samples contained detectable levels (>10(2) CFU/g), and 0.7% contained levels above 10(5) CFU/g. Samples (n = 3,008) also were tested for the presence of cereulide. Two samples (0.067%) contained detectable levels of cereulide at 3.2 and 5.4 μg/kg of food product. Of the 481 tested isolates, 81 produced cereulide and/or contained the ces gene. None of the starch-positive and hbl-containing isolates possessed the ces gene, whereas all strains contained the nhe genes. Culture of emetic B. cereus under nonoptimal conditions revealed a delay in onset of cereulide production compared with culture under optimal conditions, and cereulide was produced in all cases when B. cereus cells had been in the stationary phase for some time. The prevalence of cereulide-contaminated food approached the prevalence of contaminated products estimated in an exposure assessment. The main food safety focus associated with this pathogen should be to prevent germination and growth of any B. cereus present in food products and thus prevent cereulide production in foods. PMID:26818983

  4. Antibacterial activity of 11 essential oils against Bacillus cereus in tyndallized carrot broth.

    Science.gov (United States)

    Valero, M; Salmerón, M C

    2003-08-15

    The antibacterial activity of 11 essential oils from aromatic plants against the strain INRA L2104 of the foodborne pathogen Bacillus cereus grown in carrot broth at 16 degrees C was studied. The quantity needed by the essential oils of nutmeg, mint, clove, oregano, cinnamon, sassafras, sage, thyme or rosemary to produce 14-1110% relative extension of the lag phase was determined. Total growth inhibition of bacterial spores was observed for some of the antimicrobial agents assayed. The addition of 5 microl cinnamon essential oil per 100 ml of broth in combination with refrigeration temperatures of oil. Furthermore, the study of the sensory characteristics of the final product suggests that the use of cinnamon essential oil can be considered as an alternative to "traditional food preservatives". PMID:12810272

  5. Radiosensitization of Bacillus cereus spores in minced meat treated with cinnamaldehyde

    International Nuclear Information System (INIS)

    Minced meat beef inoculated with Bacillus cereus spores was treated with four essential oil constituents. The active compounds were sprayed separately onto the meat in order to determine the concentration needed to reduce by 1 log the population of B. cereus spores. Cinnamaldehyde was the best antimicrobial compound selected. It was mixed with ascorbic acid and/or sodium pyrophosphate decahydrate and tested for its efficiency to increase the relative radiation sensitivity (RRS) of B. cereus spores in minced meat packed under air. Results demonstrated that the radiation treatment in presence of the cinnamaldehyde and sodium phosphate decahydrate increased the RRS of B. cereus spores by two fold. The study revealed also that the irradiation of raw beef meat pre-treated with cinnamaldehyde produced an inhibition of the growth of B. cereus count during refrigerated storage. This technology seems to be compatible with industrial meat processing.

  6. Radiosensitization of Bacillus cereus spores in minced meat treated with cinnamaldehyde

    Science.gov (United States)

    Ayari, S.; Dussault, D.; Jerbi, T.; Hamdi, M.; Lacroix, M.

    2012-08-01

    Minced meat beef inoculated with Bacillus cereus spores was treated with four essential oil constituents. The active compounds were sprayed separately onto the meat in order to determine the concentration needed to reduce by 1 log the population of B. cereus spores. Cinnamaldehyde was the best antimicrobial compound selected. It was mixed with ascorbic acid and/or sodium pyrophosphate decahydrate and tested for its efficiency to increase the relative radiation sensitivity (RRS) of B. cereus spores in minced meat packed under air. Results demonstrated that the radiation treatment in presence of the cinnamaldehyde and sodium phosphate decahydrate increased the RRS of B. cereus spores by two fold. The study revealed also that the irradiation of raw beef meat pre-treated with cinnamaldehyde produced an inhibition of the growth of B. cereus count during refrigerated storage. This technology seems to be compatible with industrial meat processing.

  7. 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.

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

    OpenAIRE

    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 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 inactivate...

  9. Detection and sequencing of plasmid encoded tetracycline resistance determinants (tetA andtetB) from food-borneBacillus cereus isolates

    Institute of Scientific and Technical Information of China (English)

    Mudasir Ali Rather; Rabinder Singh Aulakh; Jatinder Paul Singh Gill; Abdul Qayoom Mir; Mir Nadeem Hassan

    2012-01-01

    Objective:To investigate the detection and sequencing of plasmid encoded tetracycline resistance genes(tetA andtetB) from food-borne and standard strains ofBacillus cereus(B. cereus).Methods:APCR was carried out to detect the tetracycline resistance genes(tetA and tetB) in food-borneB. cereus strains and the amplified products were sequenced.Results:The phenotypic resistance against tetracycline was observed in39 of the118 food-borne isolates and two reference strains(MTCC430 andMTCC1307) ofB. cereus.Among the phenotypically resistant isolates,tetA was detected in36 food-borne isolates and two reference strains(MTCC 430 andMTCC1307), whereas,tetB was detected in12 food-borne isolates andMTCC1307 strain. Conclusions:A close association was therefore found between phenotypic resistance against tetracycline and presence of tetracycline resistance genes.ThetetA andtetB gene fragments were amplified, purified and sequenced.The gene sequences of the isolates studied herein were found similar to tetA andtetB gene sequences of other bacteria available inNCBI.The occurrence oftetA and tetB genes inB. cereus indicate the horizontal transfer of antibiotic resistance determinants from other bacteria intoB. cereus.The transfer of these resistant determinants to other potentially pathogenic bacteria may be a matter of great concern.

  10. Depsipeptide Intermediates Interrogate Proposed Biosynthesis of Cereulide, the Emetic Toxin of Bacillus cereus.

    Science.gov (United States)

    Marxen, Sandra; Stark, Timo D; Rütschle, Andrea; Lücking, Genia; Frenzel, Elrike; Scherer, Siegfried; Ehling-Schulz, Monika; Hofmann, Thomas

    2015-05-27

    Cereulide and isocereulides A-G are biosynthesized as emetic toxins by Bacillus cereus via a non-ribosomal peptide synthetase (NRPS) called Ces. Although a thiotemplate mechanisms involving cyclo-trimerization of ready-made D-O-Leu-D-Ala-L-O-Val-L-Val via a thioesterase (TE) domain is proposed for cereulide biosynthesis, the exact mechanism is far from being understood. UPLC-TOF MS analysis of B. cereus strains in combination with (13)C-labeling experiments now revealed tetra-, octa-, and dodecapeptides of a different sequence, namely (L-O-Val-L-Val-D-O-Leu-D-Ala)1-3, as intermediates of cereulide biosynthesis. Surprisingly, also di-, hexa-, and decadepsipeptides were identified which, together with the structures of the previously reported isocereulides E, F, and G, do not correlate to the currently proposed mechanism for cereulide biosynthesis and violate the canonical NRPS biosynthetic logic. UPLC-TOF MS metabolite analysis and bioinformatic gene cluster analysis highlighted dipeptides rather than single amino or hydroxy acids as the basic modules in tetradepsipeptide assembly and proposed the CesA C-terminal C* domain and the CesB C-terminal TE domain to function as a cooperative esterification and depsipeptide elongation center repeatedly recruiting the action of the C* domain to oligomerize tetradepsipeptides prior to the release of cereulide from the TE domain by macrocyclization.

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

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    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.

  12. Prevalence, genetic diversity, and antibiotic resistance of Bacillus cereus isolated from Korean fermented soybean products.

    Science.gov (United States)

    Kim, Cheol-Woo; Cho, Seung-Hak; Kang, Suk-Ho; Park, Yong-Bae; Yoon, Mi-Hye; Lee, Jong-Bok; No, Wan-Seob; Kim, Jung-Beom

    2015-01-01

    Bacillus cereus contamination is a major food safety problem for Korean fermented soybean products, but few studies have assessed its potential to cause foodborne illness. The objectives of this study were to investigate the prevalence and characteristics of B. cereus isolated from Korean fermented soybean products. B. cereus was detected in 110 of 162 (67.9%) samples. The highest B. cereus frequency was observed in deonjang (68 of 93 samples, 73.1%) and cheonggukjang (18 of 25, 72.0%); however, nonhemolytic enterotoxin was detected only in 22 of 162 samples (13.6%). Although the tested B. cereus isolates showed diverse pulsotypes according to repetitive sequence-PCR banding patterns, they displayed similar antibiotic sensitivity spectra. The low frequency of enterotoxin detection suggests that the potential risk of B. cereus foodborne illness associated with Korean fermented soybean products is lower than generally presumed. However, considering the prevalence of B. cereus and the high content of fermented soybean products in the Korean diet, it is necessary to constantly monitor the level of contamination with B. cereus and its toxins in such Korean food products.

  13. 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.

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

    Science.gov (United States)

    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. PMID:27195164

  15. 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. PMID:27195164

  16. 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.

  17. Detection of viable enterotoxin-producing Bacillus cereus and analysis of toxigenicity from ready-to-eat foods and infant formula milk powder by multiplex PCR.

    Science.gov (United States)

    Zhang, Zhihong; Feng, Lixia; Xu, Hengyi; Liu, Chengwei; Shah, Nagendra P; Wei, Hua

    2016-02-01

    Bacillus cereus is responsible for several outbreaks of foodborne diseases due to its emetic toxin and enterotoxin. Enterotoxins, cytotoxin K (CytK), nonhemolytic enterotoxin (Nhe), and hemolysin BL (Hbl), have been recorded in several diarrheal cases due to food poisoning from B. cereus. The objective of this study was to develop a rapid and accurate method that combines multiplex PCR with propidium monoazide to selectively detect viable cells of enterotoxin-producing B. cereus in milk powder, noodles, and rice, and investigate the distribution of enterotoxins in 62 strains of B. cereus in Jiangxi province, China. The specificity of primers of 3 enterotoxins (i.e., cytK, nheA, and hblD) of B. cereus was verified by inclusivity and exclusivity tests using single PCR. Upon optimization of multiplex PCR conditions, it was found that the detection limit of viable cells was 10(2) cfu/mL of B. cereus in pure culture. By enrichment for 3 or 4 h and propidium monoazide pretreatment, a protocol for detection of viable cells as low as 2.2×10(1) cfu/g in spiked food (e.g., milk powder, noodles, and rice) was established and proved valid even under the interference of non-Bacillus cereus at as high as 10(5) cfu/g. Moreover, the protocol based on multiplex PCR for detection was applied for the analysis of distribution of toxin gene of B. cereus, and the results showed a regional feature for toxin gene distribution, indicating that potential toxigenicity of B. cereus should be evaluated further.

  18. 两株蜡状芽孢杆菌对毒死蜱的降解动力学研究%Kinetics of chlorpyrifos degradation by Bacillus cereus strains

    Institute of Scientific and Technical Information of China (English)

    段海明

    2013-01-01

    Organophosphorus pesticides have been widely used to control insect pests in agriculture. These compounds have been implicated in several nerve and muscular diseases in humans. Large-scale manufacturing and handling of organophosphate insecticides have caused the contamination of soils, air, surface water and groundwater across the globe. Chlorpyrifos degradation has become an increasingly important area of research in recent years. The current focus has been on the development of cost effective and eco-friendly technologies for treating polluted environments. Biodegradation has offered an efficient and cheap option for such decontamination process. Similarly, biodegradation has also been the main mechanism for removed chlorpyrifos residue, especially in the treatment of discharged wastewater from the varied processes of chlorpyrifos production. The study of the degradation kinetics was useful for understanding biodegradation processes as well as estimating pollutant concentrations. The degradation of high concentration pollutants was critical for developing practical applications of degrading bacteria. In this study, two pure Bacillus cereus strains (HY-1 and HY-2) were used in chlorpyrifos biodegradation in a batch of shake-flasks. The rate and extent of biodegradation were quantified at different chlorpyrifos initial concentrations (in the range of 40~200 mg·L-1) by B. cereus through adding chorpyrifos to mineralized medium and analyzing chlorpyrifos residue at a definite time. At the same time, the effects of incubation times and size of inoculum on chlorpyrifos degradation rate were determined. The degradation rate of high chlorpyrifos concentration by B. cereus was also measured. The results showed that the appropriate incubation time of inoculum of HY-1 and HY-2 strains were 10 h and 19 h respectively. The data suggested that inoculum incubation time significantly influenced chlorpyrifos degradation efficiency. Optimum inoculum amount for the two strains

  19. Description of Bacillus toyonensis sp. nov., a novel species of the Bacillus cereus group, and pairwise genome comparisons of the species of the group by means of ANI calculations.

    Science.gov (United States)

    Jiménez, Guillermo; Urdiain, Mercedes; Cifuentes, Ana; López-López, Aránzazu; Blanch, Anicet R; Tamames, Javier; Kämpfer, Peter; Kolstø, Anne-Brit; Ramón, Daniel; Martínez, Juan F; Codoñer, Francisco M; Rosselló-Móra, Ramon

    2013-09-01

    Strain BCT-7112(T) was isolated in 1966 in Japan from a survey designed to obtain naturally occurring microorganisms as pure cultures in the laboratory for use as probiotics in animal nutrition. This strain, which was primarily identified as Bacillus cereus var toyoi, has been in use for more than 30 years as the active ingredient of the preparation TOYOCERIN(®), an additive for use in animal nutrition (e.g. swine, poultry, cattle, rabbits and aquaculture). Despite the fact that the strain was initially classified as B. cereus, it showed significant genomic differences from the type strains of the B. cereus group that were large enough (ANI values below 92%) to allow it to be considered as a different species within the group. The polyphasic taxonomic study presented here provides sufficient discriminative parameters to classify BCT-7112(T) as a new species for which the name Bacillus toyonensis sp. nov. is proposed, with BCT-7112(T) (=CECT 876(T); =NCIMB 14858(T)) being designated as the type strain. In addition, a pairwise comparison between the available genomes of the whole B. cereus group by means of average nucleotide identity (ANI) calculations indicated that besides the eight classified species (including B. toyonensis), additional genomospecies could be detected, and most of them also had ANI values below 94%. ANI values were on the borderline of a species definition only in the cases of representatives of B. cereus versus B. thuringiensis, and B. mycoides and B. weihenstephanensis. PMID:23791203

  20. Certhrax toxin, an anthrax-related ADP-ribosyltransferase from Bacillus cereus.

    Science.gov (United States)

    Visschedyk, Danielle; Rochon, Amanda; Tempel, Wolfram; Dimov, Svetoslav; Park, Hee-Won; Merrill, A Rod

    2012-11-30

    We identified Certhrax, the first anthrax-like mART toxin from the pathogenic G9241 strain of Bacillus cereus. Certhrax shares 31% sequence identity with anthrax lethal factor from Bacillus anthracis; however, we have shown that the toxicity of Certhrax resides in the mART domain, whereas anthrax uses a metalloprotease mechanism. Like anthrax lethal factor, Certhrax was found to require protective antigen for host cell entry. This two-domain enzyme was shown to be 60-fold more toxic to mammalian cells than anthrax lethal factor. Certhrax localizes to distinct regions within mouse RAW264.7 cells by 10 min postinfection and is extranuclear in its cellular location. Substitution of catalytic residues shows that the mART function is responsible for the toxicity, and it binds NAD(+) with high affinity (K(D) = 52.3 ± 12.2 μM). We report the 2.2 Å Certhrax structure, highlighting its structural similarities and differences with anthrax lethal factor. We also determined the crystal structures of two good inhibitors (P6 (K(D) = 1.7 ± 0.2 μM, K(i) = 1.8 ± 0.4 μM) and PJ34 (K(D) = 5.8 ± 2.6 μM, K(i) = 9.6 ± 0.3 μM)) in complex with Certhrax. As with other toxins in this family, the phosphate-nicotinamide loop moves toward the NAD(+) binding site with bound inhibitor. These results indicate that Certhrax may be important in the pathogenesis of B. cereus.

  1. Inactivation of Spores of Bacillus anthracis Sterne, Bacillus cereus, and Bacillus thuringiensis subsp. israelensis by Chlorination

    OpenAIRE

    Rice, E W; Adcock, N. J.; Sivaganesan, M; Rose, L. J.

    2005-01-01

    Three species of Bacillus were evaluated as potential surrogates for Bacillus anthracis for determining the sporicidal activity of chlorination as commonly used in drinking water treatment. Spores of Bacillus thuringiensis subsp. israelensis were found to be an appropriate surrogate for spores of B. anthracis for use in chlorine inactivation studies.

  2. Glycosylation of BclA Glycoprotein from Bacillus cereus and Bacillus anthracis Exosporium Is Domain-specific.

    Science.gov (United States)

    Maes, Emmanuel; Krzewinski, Frederic; Garenaux, Estelle; Lequette, Yannick; Coddeville, Bernadette; Trivelli, Xavier; Ronse, Annette; Faille, Christine; Guerardel, Yann

    2016-04-29

    The spores of the Bacillus cereus group (B. cereus, Bacillus anthracis, and Bacillus thuringiensis) are surrounded by a paracrystalline flexible yet resistant layer called exosporium that plays a major role in spore adhesion and virulence. The major constituent of its hairlike surface, the trimerized glycoprotein BclA, is attached to the basal layer through an N-terminal domain. It is then followed by a repetitive collagen-like neck bearing a globular head (C-terminal domain) that promotes glycoprotein trimerization. The collagen-like region of B. anthracis is known to be densely substituted by unusual O-glycans that may be used for developing species-specific diagnostics of B. anthracis spores and thus targeted therapeutic interventions. In the present study, we have explored the species and domain specificity of BclA glycosylation within the B. cereus group. First, we have established that the collagen-like regions of both B. anthracis and B. cereus are similarly substituted by short O-glycans that bear the species-specific deoxyhexose residues anthrose and the newly observed cereose, respectively. Second we have discovered that the C-terminal globular domains of BclA from both species are substituted by polysaccharide-like O-linked glycans whose structures are also species-specific. The presence of large carbohydrate polymers covering the surface of Bacillus spores may have a profound impact on the way that spores regulate their interactions with biotic and abiotic surfaces and represents potential new diagnostic targets. PMID:26921321

  3. 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.

  4. Proteomics identifies Bacillus cereus EntD as a pivotal protein for the production of numerous virulence factors

    Directory of Open Access Journals (Sweden)

    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.

  5. An emetic Bacillus cereus outbreak in a kindergarten: detection and quantification of critical levels of cereulide toxin.

    Science.gov (United States)

    Delbrassinne, Laurence; Botteldoorn, Nadine; Andjelkovic, Mirjana; Dierick, Katelijne; Denayer, Sarah

    2015-01-01

    A Bacillus cereus-related emetic outbreak was reported in a Belgian kindergarten. High levels of emetic B. cereus (>1.5E+07 colony-forming units/g) were detected in the food leftovers, and the presence of an emetic strain was confirmed in feces. Emetic toxin levels ranging up to 4.2 μg/g were also quantified in the leftovers by liquid chromatography coupled to tandem mass spectrometry (LC-MS(2)) analysis. Those levels, although moderate in comparison with earlier published intoxications, provoked profuse-vomiting episodes in 20 toddlers aged between 10 and 18 months. Few studies have focused on the levels of emetic toxin implicated in food intoxications. This publication emphasizes the importance of defining toxic doses of emetic toxin among high-risk population groups.

  6. 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.

  7. 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.

  8. Siderophore-mediated iron acquisition systems in Bacillus cereus: identification of receptors for anthrax virulence-associated petrobactin†a

    OpenAIRE

    Zawadzka, Anna M.; Abergel, Rebecca J.; Nichiporuk, Rita; Andersen, Ulla N.; Raymond, Kenneth N.

    2009-01-01

    During growth under iron limitation, Bacillus cereus and Bacillus anthracis, two human pathogens from the Bacillus cereus group of Gram-positive bacteria, secrete two siderophores, bacillibactin (BB) and petrobactin (PB), for iron acquisition via membrane-associated substrate-binding proteins (SBPs) and other ABC transporter components. Since PB is associated with virulence traits in B. anthracis, the PB-mediated iron uptake system presents a potential target for antimicrobial therapies; its ...

  9. Protein- and DNA-based anthrax toxin vaccines confer protection in guinea pigs against inhalational challenge with Bacillus cereus G9241.

    Science.gov (United States)

    Palmer, John; Bell, Matt; Darko, Christian; Barnewall, Roy; Keane-Myers, Andrea

    2014-11-01

    In the past decade, several Bacillus cereus strains have been isolated from otherwise healthy individuals who succumbed to bacterial pneumonia presenting symptoms resembling inhalational anthrax. One strain was indistinguishable from B. cereus G9241, previously cultured from an individual who survived a similar pneumonia-like illness and which was shown to possess a complete set of plasmid-borne anthrax toxin-encoding homologs. The finding that B. cereus G9241 pathogenesis in mice is dependent on pagA1-derived protective antigen (PA) synthesis suggests that an anthrax toxin-based vaccine may be effective against this toxin-encoding B. cereus strain. Dunkin Hartley guinea pigs were immunized with protein- and DNA-based anthrax toxin-based vaccines, immune responses were evaluated and survival rates were calculated after lethal aerosol exposure with B. cereus G9241 spores. Each vaccine induced seroconversion with the protein immunization regimen eliciting significantly higher serum levels of antigen-specific antibodies at the prechallenge time-point compared with the DNA-protein prime-boost immunization schedule. Complete protection against lethal challenge was observed in all groups with a detectable prechallenge serum titer of toxin neutralizing antibodies. For the first time, we demonstrated that the efficacy of fully defined anthrax toxin-based vaccines was protective against lethal B. cereus G9241 aerosol challenge in the guinea pig animal model.

  10. 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

  11. 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

  12. Combined effect of anaerobiosis, low pH and cold temperatures on the growth capacities of psychrotrophic Bacillus cereus.

    Science.gov (United States)

    Guérin, Alizée; Dargaignaratz, Claire; Broussolle, Véronique; Clavel, Thierry; Nguyen-The, Christophe

    2016-10-01

    Psychrotrophic strains of the foodborne pathogen Bacillus cereus can multiply during the refrigerated storage of food products. The aim of this study was to determine the impact of anaerobiosis on the growth of two psychrotrophic B. cereus strains exposed to acidic pH at a cold temperature in a laboratory medium. At 10 °C, growth occurred at pH values equal to or higher than 5.7 during anaerobiosis, whereas aerobic growth was observed from pH 5.4. Growth rates during aerobiosis were similar at pH 5.4 and pH 7. No growth was observed for the two tested strains at 8 °C without oxygen regardless of the pH; however, both strains grew at this temperature from pH 5.4 in the presence of oxygen. These pH growth limits in aerobiosis are consistent with those reported for different strains and different foods or media, but no other studies have described anaerobic growth at acidic pH values. The maximal B. cereus concentration was approximately 6.0 log10 CFU/ml for cultures in the absence of oxygen and approximately 8.0 log10 CFU/ml for cultures in the presence of oxygen. In conclusion, we found that the combination of anaerobiosis, pH < 5.7 at 10 °C, or anaerobiosis and temperatures ≤8 °C prevent psychrotrophic B. cereus growth. PMID:27375252

  13. 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.

  14. 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.

  15. Deletion in sigB in Bacillus cereus affects spore properties

    NARCIS (Netherlands)

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

    2005-01-01

    In Bacillus cereus and other gram-positive bacteria the alternative sigma factor ¿B is an important regulator of the stress response. Deletion of the sigB gene generally leads to a stress-sensitive phenotype of vegetative cells. In this study, we describe the effect of the deletion of the sigB gene

  16. Phenotypic and Transcriptomic Analyses of Mildly and Severely Salt-Stressed Bacillus cereus ATCC 14579 Cells

    NARCIS (Netherlands)

    Besten, den H.M.W.; Mols, J.M.; Moezelaar, R.; Zwietering, M.H.; Abee, T.

    2009-01-01

    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 condition

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

    NARCIS (Netherlands)

    te Giffel, M.C.

    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 biochemical and molecular typing, in

  18. 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 activi

  19. 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 t

  20. Combined action of nisin and carvacrol on Bacillus cereus and Listeria monocytogenes

    NARCIS (Netherlands)

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

    1999-01-01

    Nisin, a small antimicrobial protein, was tested for its bactericidal action against Listeria monocytogenes and Bacillus cereus and a typical biphasic reduction of the viable count was observed. The reduction was most fast during the first 10 min of exposure, while the viable count remained stable i

  1. 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 ge...

  2. Differentiation Between Bacillus thuringiensis and Bacillus cereus by 16S rDNA-PCR and ERIC-PCR

    Institute of Scientific and Technical Information of China (English)

    LI Haitao; LIU Dongming; GAO Jiguo

    2011-01-01

    16S rDNA and ERIC (Enterobacteia Repetitive Intergenic Consensus Sequences) based on PCR method were tested for the effectiveness of the differentiation of B. thuringiensis and B. cereus. 16S rDNA-PCR primers were designed based on the sequence difference in variable regions of B. cereus 16S rDNA and B. thuringiensis 16S rDNA, 16S rDNA-PCR showed no obvious difference between B. cereus and B. thuringiensis. The only difference was that one 1600-bp amplificon could be obtained from all the three B. Cereus strains, and none amplificon from any B. thuringiensis strains. ERIC was optimized based on previous reports. The genonlic DNA was used for the template of ER1C-PCR, and the following DNA fingerprints were analyzed by the agarose gel electrophoresis. The results showed that DNA fingerprint of three B. thuringiensis strains had a unique amplicon less than 100-bp, while DNA fingerprint of three B. cereus" strains had none. Moreover, DNA fingerprint of B. cereus showed a 700-bp amplicon, but didn't have any DNA fingerprints ofB. thuringiensis genome. Therefore, ERIC-PCR technique should be able to be used for the differentiation of B. thuringiensis and B. cereus.

  3. Bacillus cereus cytotoxins Hbl, Nhe and CytK are secreted via the Sec translocation pathway

    Directory of Open Access Journals (Sweden)

    Lindbäck Toril

    2010-11-01

    Full Text Available Abstract Background Bacillus cereus and the closely related Bacillus thuringiensis are Gram positive opportunistic pathogens that may cause food poisoning, and the three secreted pore-forming cytotoxins Hbl, Nhe and CytK have been implicated as the causative agents of diarrhoeal disease. It has been proposed that the Hbl toxin is secreted using the flagellar export apparatus (FEA despite the presence of Sec-type signal peptides. As protein secretion is of key importance in virulence of a microorganism, the mechanisms by which these toxins are secreted were further investigated. Results Sec-type signal peptides were identified in all toxin components, and secretion of Hbl component B was shown to be dependent on an intact Sec-type signal peptide sequence. Further indication that secretion of Hbl, Nhe and CytK is dependent on the Sec translocation pathway, the main pathway on which bacterial secretion relies, was suggested by the observed intracellular accumulation and reduced secretion of the toxins in cultures supplemented with the SecA inhibitor sodium azide. Although a FEA deficient strain (a flhA mutant showed reduced toxin expression and reduced cytotoxicity, it readily secreted overexpressed Hbl B, showing that the FEA is not required for Hbl secretion. Thus, the concurrent lack of flagella and reduced toxin secretion in the FEA deficient strain may point towards the presence of a regulatory link between motility and virulence genes, rather than FEA-dependent toxin secretion. Conclusions The Hbl, Nhe and CytK toxins appear to be secreted using the Sec pathway, and the reduced Hbl expression of a FEA deficient strain was shown not to be due to a secretion defect.

  4. Control Effect and Mechanism of Strain Bacillus cereus CGMCC4348 to Botrytis cinerea%蜡样芽孢杆菌CGMCC4348菌株防治番茄灰霉病的效果及机理研究

    Institute of Scientific and Technical Information of China (English)

    唐容容; 杨文革; 胡永红; 江心敏; 刘邮洲; 章泳

    2013-01-01

    试验研究蜡样芽孢杆菌(Bacillus cereus)CGMCC4348菌株对番茄灰霉病菌(Botrytis cinerea)的生物防治效果,并初步探讨其抑菌机理,以寻找防治番茄灰霉病的新方法.试验从定量生物测定、室内离体抑菌试验和盆栽试验3个方面考察其抑菌作用效果,并以硫酸铵分级沉淀法提取拮抗蛋白进行检测.结果表明,室内抑菌试验的EC50为6.19 mg/L;盆栽试验中处理3对番茄灰霉病的平均防效达75.80%,与50 mg/L嘧霉胺处理的防效相当.试验证明蜡样芽孢杆菌CGMCC4348对番茄灰霉病菌有较好防治效果.

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

    Directory of Open Access Journals (Sweden)

    Jnnifer A. Sánchez

    2015-09-01

    Full Text Available Bacillus cereus is a food contaminant anda known human pathogen that can causeemetic and diarrheal syndromes. In this studywe evaluated the presence of toxigenic B.cereus by multiplex PCR directly in dietarycomplement for children and cassava starchsamples collected on Medellin, Colombia.Of 75 dietary complement for childrensamples evaluated, 70.7% were contaminatedwith toxigenic B. cereus and four differenttoxigenic 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% werecontaminated with toxigenic B. cereus andfour different toxigenic consortia weredetermined: 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 onlyenterotoxigenic consortia were detectedwhile in cassava starch the enterotoxigenicconsortia predominated over the emetic.Multiplex PCR was useful to detect toxigenicB. cereus contamination allowing directand simultaneous detection of all toxingenes in foods. This study is the first inColombia to evaluate toxigenic B. cereus,providing information of importance formicrobiological risk evaluation in driedfoods.

  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. Two capsular polysaccharides enable Bacillus cereus G9241 to cause anthrax-like disease

    OpenAIRE

    Oh, So-Young; Budzik, Jonathan M.; Garufi, Gabriella; Schneewind, Olaf

    2011-01-01

    Bacillus cereus G9241 causes an anthrax-like respiratory illness in humans, however the molecular mechanisms of disease pathogenesis are not known. Genome sequencing identified two putative virulence plasmids proposed to provide for anthrax toxin (pBCXO1) and/or capsule expression (pBC218). We report here that B. cereus G9241 causes anthrax-like disease in immune-competent mice, which is dependent on each of the two virulence plasmids. pBCXO1 encodes pagA1, the homolog of anthrax protective a...

  8. Mechanisms of sorbate inhibition of Bacillus cereus T and Clostridium botulinum 62A spore germination.

    OpenAIRE

    Smoot, L A; Pierson, M. D.

    1981-01-01

    The mechanism by which potassium sorbate inhibits Bacillus cereus T and Clostridium botulinum 62A spore germination was investigated. Spores of B. cereus T were germinated at 35 degrees C in 0.08 M sodium-potassium phosphate buffers (pH 5.7 and 6.7) containing various germinants (L-alanine, L-alpha-NH2-n-butyric acid, and inosine) and potassium sorbate. Spores of C. botulinum 62A were germinated in the same buffers but with 10 mM L-lactic acid, 20 mM sodium bicarbonate, L-alanine or L-cystein...

  9. Resistance and biosorption mechanism of silver ions by Bacillus cereus biomass

    Institute of Scientific and Technical Information of China (English)

    Li Li; Qing Hu; Jinghai Zeng; Hongyan Qi; Guoqiang Zhuang

    2011-01-01

    Biosorption of silver ions onto Bacillus cereus biomass was investigated.Overall kinetic experiments were performed for the determination of the necessary contact time for the attainment of equilibrium.It was found that the overall biosorption process was best described by pseudo second-order kinetic model.The crystals detected by scanning electron microscope and X-ray photoelectron spectroscopy suggested the precipitation was a possible mechanism of biosorption.The molecular genetics of silver resistance of B.cereus biomass was also detected and illustrated by a whole cell sensor tool.

  10. Heat stress leads to superoxide formation in Bacillus cereus detected using the fluorescent probe MitoSOX

    NARCIS (Netherlands)

    Mols, J.M.; Ceragioli, M.; Abee, T.

    2011-01-01

    Bacillus cereus is a food-borne human pathogen and food spoilage organism. Spores and vegetative cells of B. cereus can be found almost everywhere and therefore often end up in food processing equipment and food products. To remove spores and vegetative cells from food or equipment, harsh treatments

  11. 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 produc

  12. 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;

    Bacillus cereus was reported to occur in high numbers (up to 107 CFU/g) during spontaneous fermentation of three different traditional Benin condiments; afitin, iru and sonru made from African locust beans. A total of nineteen B. cereus isolates from the ferments, were examined for the presence o...

  13. 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 perfor

  14. Environmental factors determining the epidemiology and population genetic structure of the Bacillus cereus group in the field.

    Directory of Open Access Journals (Sweden)

    Ben Raymond

    2010-05-01

    Full Text Available Bacillus thuringiensis (Bt and its insecticidal toxins are widely exploited in microbial biopesticides and genetically modified crops. Its population biology is, however, poorly understood. Important issues for the safe, sustainable exploitation of Bt include understanding how selection maintains expression of insecticidal toxins in nature, whether entomopathogenic Bt is ecologically distinct from related human pathogens in the Bacillus cereus group, and how the use of microbial pesticides alters natural bacterial populations. We addressed these questions with a MLST scheme applied to a field experiment in which we excluded/added insect hosts and microbial pesticides in a factorial design. The presence of insects increased the density of Bt/B. cereus in the soil and the proportion of strains expressing insecticidal toxins. We found a near-epidemic population structure dominated by a single entomopathogenic genotype (ST8 in sprayed and unsprayed enclosures. Biopesticidal ST8 proliferated in hosts after spraying but was also found naturally associated with leaves more than any other genotype. In an independent experiment several ST8 isolates proved better than a range of non-pathogenic STs at endophytic and epiphytic colonization of seedlings from soil. This is the first experimental demonstration of Bt behaving as a specialized insect pathogen in the field. These data provide a basis for understanding both Bt ecology and the influence of anthropogenic factors on Bt populations. This natural population of Bt showed habitat associations and a population structure that differed markedly from previous MLST studies of less ecologically coherent B. cereus sample collections. The host-specific adaptations of ST8, its close association with its toxin plasmid and its high prevalence within its clade are analogous to the biology of Bacillus anthracis. This prevalence also suggests that selection for resistance to the insecticidal toxins of ST8 will have

  15. A novel hybrid kinase is essential for regulating the sigma(B)-mediated stress response of Bacillus cereus.

    Science.gov (United States)

    de Been, Mark; Tempelaars, Marcel H; van Schaik, Willem; Moezelaar, Roy; Siezen, Roland J; Abee, Tjakko

    2010-03-01

    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 sigma(B) is activated by the RR RsbY. Here we present strong indications that the PP2C-type phosphatase RsbY receives its input from the multi-sensor hybrid kinase BC1008 (renamed RsbK). Genome analyses revealed that, across bacilli, rsbY and rsbK are located in a conserved gene cluster. A B. cereus rsbK deletion strain was shown to be incapable of inducing sigma(B) upon stress conditions and was impaired in its heat adaptive response. Comparison of the wild-type and rsbK mutant transcriptomes upon heat shock revealed that RsbK was primarily involved in the activation of the sigma(B)-mediated stress response. Truncation of the RsbK RR receiver domain demonstrated the importance of this domain for sigma(B) induction upon stress. The domain architecture of RsbK suggests that in the B. cereus group and in other bacilli, environmental and intracellular stress signalling routes are combined into one single protein. This strategy is markedly different from the sigma(B) activation pathway in other low-GC Gram-positives.

  16. Surface reaction of Bacillus cereus biomass and its biosorption for lead and copper ions

    Institute of Scientific and Technical Information of China (English)

    PAN Jian-hua; LIU Rui-xia; TANG Hong-xiao

    2007-01-01

    In this study, the Fourier transform infrared (FTIR) analytical technique identified the surface chemical functional groups of Bacillus cereus biomass. B. Cereus cells mainly contained carboxyl, hydroxyl, phosphate, amino, and amide functional groups. In order to explain the surface acid-base properties of aqueous B. Cereus biomass, the potentiometric titration was conducted . The computer program FITEQL 4.0 was used to perform the model calculations. The optimization results indicated that three sites-three pKas model, which assumed the cell surface to have three distinct types of surface organic functional groups based on IR analysis results, simulated the experimental results very well. Moreover, batch adsorption experiments were performed to investigate biosorption behavior of Cu (Ⅱ) and Pb (Ⅱ) ions onto the biomass. Obviously, the adsorption equilibrium data for the two ions were reasonably described by typical Langmuir isotherm.

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

    International Nuclear Information System (INIS)

    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 101 cfu/ml to 11.3X102 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 2.0X101 cfu/g to 11.5X103 cfu /ml. However one Sample out of 12 Samples (8%) of Cheetos (Snacks) was positive with count 3.0X102 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.

  18. Effects of Electrolyzed Oxidizing Water on Inactivation of Bacillus subtilis and Bacillus cereus Spores in Suspension and on Carriers.

    Science.gov (United States)

    Zhang, Chunling; Li, Baoming; Jadeja, Ravirajsinh; Hung, Yen-Con

    2016-01-01

    Spores of some Bacillus species are responsible for food spoilage and foodborne disease. These spores are highly resistant to various interventions and cooking processes. In this study, the sporicidal efficacy of acidic electrolyzed oxidizing (EO) water (AEW) and slightly acidic EO water (SAEW) with available chlorine concentration (ACC) of 40, 60, 80, 100, and 120 mg/L and treatment time for 1, 2, 3, 4, 5, and 6 min were tested on Bacillus subtilis and Bacillus cereus spores in suspension and on carrier with or without organics. The reduction of spore significantly increased with increasing ACC and treatment time (P waters containing 120 mg/L ACC, while only SAEW at 120 mg/L and 2 min treatment achieved >6 log reductions of B. subtilis spore. Both types of EO water with ACC of 60 mg/L and 6 min treatment achieved a reduction of B. subtilis and B. cereus spores to nondetectable level. EO water with ACC of 80 mg/L and treatment time of 3 min on carrier test without organics addition resulted in reductions of B. subtilis spore to nondetectable level. But, addition of 0.3% organics on carrier decreased the inactivation effect of EO water. This study indicated that EO water was highly effective in inactivation of B. subtilis and B. cereus spores in suspension or on carrier, and therefore, rendered it as a promising disinfectant to be applied in food industry.

  19. Erratum to: Seasonal trend and clinical presentation of Bacillus cereus bloodstream infection: association with summer and indwelling catheter.

    Science.gov (United States)

    Kato, K; Matsumura, Y; Yamamoto, M; Nagao, M; Ito, Y; Takakura, S; Ichiyama, S

    2016-05-01

    Bacillus cereus, an opportunistic pathogen, can cause fatal infection. However, B. cereus bloodstream infections (BSIs) have not been well characterised. From 2008 to 2013, B. cereus isolates from all of the specimens and patients with B. cereus BSIs were identified. Environmental samples were collected to detect B. cereus contamination. We also characterised the clinical presentation of B. cereus BSI through analyses of risk factors for BSI and mortality. A total of 143 clinical B. cereus isolates was detected. Fifty-one patients with nosocomial infections were diagnosed as B. cereus BSI, and 37 had contaminated blood cultures. The number of B. cereus isolates and BSI patients was significantly greater from June to September than from January to April (3.4 vs. 1.0 per month and 1.4 vs. 0.2, respectively). All BSIs were nosocomial and related to central or peripheral vascular catheter. Urinary catheter [odds ratio (OR) 6.93, 95 % confidence interval (CI) 2.40-20.0] was the independent risk factor associated with BSI patients when compared to patients regarded as contaminated. In-hospital mortality among BSI patients was 20 % and was associated with urinary catheter (OR 12.3, 95 % CI 0.67-225, p=0.045) and higher Charlson index (OR 1.99, 95 % CI 1.26-3.12). The number of B. cereus isolates and BSI increased during summer. Inpatients with indwelling vascular or urinary catheters should be carefully monitored for potential B. cereus BSIs. PMID:27010814

  20. Anthrax Toxin-Expressing Bacillus cereus Isolated from an Anthrax-Like Eschar.

    Directory of Open Access Journals (Sweden)

    Chung K Marston

    Full Text Available Bacillus cereus isolates have been described harboring Bacillus anthracis toxin genes, most notably B. cereus G9241, and capable of causing severe and fatal pneumonias. This report describes the characterization of a B. cereus isolate, BcFL2013, associated with a naturally occurring cutaneous lesion resembling an anthrax eschar. Similar to G9241, BcFL2013 is positive for the B. anthracis pXO1 toxin genes, has a multi-locus sequence type of 78, and a pagA sequence type of 9. Whole genome sequencing confirms the similarity to G9241. In addition to the chromosome having an average nucleotide identity of 99.98% when compared to G9241, BcFL2013 harbors three plasmids with varying homology to the G9241 plasmids (pBCXO1, pBC210 and pBFH_1. This is also the first report to include serologic testing of patient specimens associated with this type of B. cereus infection which resulted in the detection of anthrax lethal factor toxemia, a quantifiable serum antibody response to protective antigen (PA, and lethal toxin neutralization activity.

  1. Anthrax Toxin-Expressing Bacillus cereus Isolated from an Anthrax-Like Eschar.

    Science.gov (United States)

    Marston, Chung K; Ibrahim, Hisham; Lee, Philip; Churchwell, George; Gumke, Megan; Stanek, Danielle; Gee, Jay E; Boyer, Anne E; Gallegos-Candela, Maribel; Barr, John R; Li, Han; Boulay, Darbi; Cronin, Li; Quinn, Conrad P; Hoffmaster, Alex R

    2016-01-01

    Bacillus cereus isolates have been described harboring Bacillus anthracis toxin genes, most notably B. cereus G9241, and capable of causing severe and fatal pneumonias. This report describes the characterization of a B. cereus isolate, BcFL2013, associated with a naturally occurring cutaneous lesion resembling an anthrax eschar. Similar to G9241, BcFL2013 is positive for the B. anthracis pXO1 toxin genes, has a multi-locus sequence type of 78, and a pagA sequence type of 9. Whole genome sequencing confirms the similarity to G9241. In addition to the chromosome having an average nucleotide identity of 99.98% when compared to G9241, BcFL2013 harbors three plasmids with varying homology to the G9241 plasmids (pBCXO1, pBC210 and pBFH_1). This is also the first report to include serologic testing of patient specimens associated with this type of B. cereus infection which resulted in the detection of anthrax lethal factor toxemia, a quantifiable serum antibody response to protective antigen (PA), and lethal toxin neutralization activity.

  2. Anthrax Toxin-Expressing Bacillus cereus Isolated from an Anthrax-Like Eschar.

    Science.gov (United States)

    Marston, Chung K; Ibrahim, Hisham; Lee, Philip; Churchwell, George; Gumke, Megan; Stanek, Danielle; Gee, Jay E; Boyer, Anne E; Gallegos-Candela, Maribel; Barr, John R; Li, Han; Boulay, Darbi; Cronin, Li; Quinn, Conrad P; Hoffmaster, Alex R

    2016-01-01

    Bacillus cereus isolates have been described harboring Bacillus anthracis toxin genes, most notably B. cereus G9241, and capable of causing severe and fatal pneumonias. This report describes the characterization of a B. cereus isolate, BcFL2013, associated with a naturally occurring cutaneous lesion resembling an anthrax eschar. Similar to G9241, BcFL2013 is positive for the B. anthracis pXO1 toxin genes, has a multi-locus sequence type of 78, and a pagA sequence type of 9. Whole genome sequencing confirms the similarity to G9241. In addition to the chromosome having an average nucleotide identity of 99.98% when compared to G9241, BcFL2013 harbors three plasmids with varying homology to the G9241 plasmids (pBCXO1, pBC210 and pBFH_1). This is also the first report to include serologic testing of patient specimens associated with this type of B. cereus infection which resulted in the detection of anthrax lethal factor toxemia, a quantifiable serum antibody response to protective antigen (PA), and lethal toxin neutralization activity. PMID:27257909

  3. 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.

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

    Science.gov (United States)

    Zheng, Li Ping; Zou, Tin; Ma, Yan Jun; Wang, Jian Wen; Zhang, Yu Qing

    2016-01-01

    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. PMID:26861269

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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

  7. 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. PMID:27547804

  8. 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.

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

    OpenAIRE

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

    2012-01-01

    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 ...

  10. Peptidoglycan from Bacillus cereus Mediates Commensalism with Rhizosphere Bacteria from the Cytophaga-Flavobacterium Group

    OpenAIRE

    Peterson, Snow Brook; Dunn, Anne K.; Klimowicz, Amy K.; Handelsman, Jo

    2006-01-01

    Previous research in our laboratory revealed that the introduction of Bacillus cereus UW85 can increase the populations of bacteria from the Cytophaga-Flavobacterium (CF) group of the Bacteroidetes phylum in the soybean rhizosphere, suggesting that these rhizosphere microorganisms have a beneficial relationship (G. S. Gilbert, J. L. Parke, M. K. Clayton, and J. Handelsman, Ecology 74:840-854, 1993). In the present study, we determined the frequency at which CF bacteria coisolated with B. cere...

  11. 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...

  12. 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.

  13. Emetic Bacillus cereus are more volatile than thought: recent foodborne outbreaks and prevalence studies in Bavaria (2007-2013).

    Science.gov (United States)

    Messelhäusser, Ute; Frenzel, Elrike; Blöchinger, Claudia; Zucker, Renate; Kämpf, Peter; Ehling-Schulz, Monika

    2014-01-01

    Several Bacillus cereus strains possess the genetic fittings to produce two different types of toxins, the heat-stable cereulide or different heat-labile proteins with enterotoxigenic potential. Unlike the diarrheal toxins, cereulide is (pre-)formed in food and can cause foodborne intoxications shortly after ingestion of contaminated food. Based on the widely self-limiting character of cereulide intoxications and rarely performed differential diagnostic in routine laboratories, the real incidence is largely unknown. Therefore, during a 7-year period about 4.300 food samples linked to foodborne illness with a preliminary report of vomiting as well as food analysed in the context of monitoring programs were investigated to determine the prevalence of emetic B. cereus in food environments. In addition, a lux-based real-time monitoring system was employed to assess the significance of the detection of emetic strains in different food matrices and to determine the actual risk of cereulide toxin production in different types of food. This comprehensive study showed that emetic strains are much more volatile than previously thought. Our survey highlights the importance and need of novel strategies to move from the currently taxonomic-driven diagnostic to more risk orientated diagnostics to improve food and consumer safety.

  14. Emetic Bacillus cereus Are More Volatile Than Thought: Recent Foodborne Outbreaks and Prevalence Studies in Bavaria (2007–2013

    Directory of Open Access Journals (Sweden)

    Ute Messelhäusser

    2014-01-01

    Full Text Available Several Bacillus cereus strains possess the genetic fittings to produce two different types of toxins, the heat-stable cereulide or different heat-labile proteins with enterotoxigenic potential. Unlike the diarrheal toxins, cereulide is (pre-formed in food and can cause foodborne intoxications shortly after ingestion of contaminated food. Based on the widely self-limiting character of cereulide intoxications and rarely performed differential diagnostic in routine laboratories, the real incidence is largely unknown. Therefore, during a 7-year period about 4.300 food samples linked to foodborne illness with a preliminary report of vomiting as well as food analysed in the context of monitoring programs were investigated to determine the prevalence of emetic B. cereus in food environments. In addition, a lux-based real-time monitoring system was employed to assess the significance of the detection of emetic strains in different food matrices and to determine the actual risk of cereulide toxin production in different types of food. This comprehensive study showed that emetic strains are much more volatile than previously thought. Our survey highlights the importance and need of novel strategies to move from the currently taxonomic-driven diagnostic to more risk orientated diagnostics to improve food and consumer safety.

  15. BIOSYNTHESIS AND THERMAL PROPERTIES OF POLY(3-HYDROXYBUTYRATE-co-3-HYDROXYVALERATE)WITH LARGE VARIETY OF HYDROXYVALERATE CONTENTS BY BACILLUS CEREUS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Biosynthesis and thermal properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with different HV (hydrovalerate) content produced by a Bacillus cereus strain were investigated. A large variety of HV contents (up to about 90 mol%) of PHBV could be produced by this strain. Combined nitrogen sources containing both yeast extract and ammonium sulphate were better for cell growth and polyhydroxyalkanoates (PHA) production than either yeast extract or ammonium sulphate alone. Propionic acid is more favorable for the production of HV content than that of valeric acid. Finally, thermal properties of PHBV produced by this strain are found close to the results of other groups.

  16. Phospholipase C from Pseudomonas aeruginosa and Bacillus cereus;characterization of catalytic activity

    Institute of Scientific and Technical Information of China (English)

    Nooran Sherif Elleboudy; Mohammad Mabrouk Aboulwafa; Nadia Abdel-Haleem Hassouna

    2014-01-01

    Objective:To study characteristics of phospholipases C (PLCs), their importance for producing microorganisms as well as the potential of their use for industrial purposes. Methods:PLC from Bacillus cereus (B. cereus) D101 was selected as an example of Gram-positive PLCs and PLC from Pseudomonas aeruginosa (P. aeruginosa) D183 of Gram-negative ones. Enzymes were partially purified by ammonium sulfate precipitation followed by membrane dialysis. Partially purified preparations were used to study effect of different factors on activities as well as in substrate specificity tests which were conducted using a turbidimetric assay method. Results: Maximum activity was at pH 7 and 8 and 40℃for P. aeruginosa PLC, and pH 8-10 and 37℃for B. cereus PLC. Both PLCs were inhibited by Pi at 5 mM or higher, whereas, PLC from B. cereus only was inhibited by EDTA. Activity of P. aeruginosa PLC was not affected by removing Zn2+ions from reaction mixture or their replacement with Ca2+, Ba2+, Mg2+or Mn2+ions. Vis-à-vis, activity of B. cereus PLC was found to be metal ion dependent. PLCs from both isolates were relatively thermostable and showed maximum affinity toward phosphatidylcholine. Sphingomyelin and phosphatidylethanolamine were not good substrates and phosphatidylinositol, phosphatidylserine, phosphatidylglycerol and cardiolipin could be considered non-substrates. Conclusions: Human body physiological conditions could favor activity of P. aeruginosa and B. cereus PLCs. These enzymes may participate in phosphate scavenging and virulence of producing isolates but not in autolysis. PLCs from both isolates are potential candidates for industrial use.

  17. Intestinal carriage of Bacillus cereus: faecal isolation studies in three population groups.

    Science.gov (United States)

    Turnbull, P C; Kramer, J M

    1985-12-01

    The results of examinations of stools for Bacillus cereus among three unrelated groups of individuals are presented. The groups consisted of (1) healthy school-children aged 6-11 years in a rural region of South Africa examined during each of the four seasons of the year; (2) 15 healthy volunteers comprising staff of a London microbiology laboratory and their families examined on each of 3 consecutive weeks; (3) 75 unrelated young children, 2 months to 5 years of age, in a second rural region of South Africa examined during a pilot study of 1 week's duration on the aetiology of rural gastroenteritis. The stools of the last group were submitted as being related to present or recent diarrhoea in the respective children. In group 1, B. cereus isolation rates ranged from 24.3% at the autumn visit to 43% at the summer visit with a significantly higher rate of isolation in the summer than at other seasons of the year (P less than 0.05). B. cereus was isolated from 40% of group 2 volunteers on week 1, none on week 2 and 20% on week 3. The organism was detected in the 12 positive specimens at levels of approximately 10(2)/g and constituted 2.5-30% of the total aerobic spore-forming bacillus population in the stools. In group 3, B. cereus was recovered from 18.7% of the stool samples and was isolated consecutively with other pathogens (enteropathogenic Escherichia coli and rotavirus) on only five occasions. In groups 1 and 3, less than 5% of the stools had '3+' levels of B. cereus (greater than 10 colonies per direct plate culture). B. cereus was readily isolated from all of 10 food samples, representative of the typical diet of the group 1 individuals, and was present in substantial numbers (10(4) to 5.5 X 10(6)/g) in half of them. The isolation results, supported by serotyping, indicated that carriage of B. cereus in stools is transient and its presence at any one time reflects solely its intake with foods.

  18. 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.

  19. Plant compounds enhance the assay sensitivity for detection of active Bacillus cereus toxin.

    Science.gov (United States)

    Rasooly, Reuven; Hernlem, Bradley; He, Xiaohua; Friedman, Mendel

    2015-03-11

    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.

  20. 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.

  1. Occurrence and behavior of Bacillus cereus in naturally contaminated ricotta salata cheese during refrigerated storage.

    Science.gov (United States)

    Spanu, Carlo; Scarano, Christian; Spanu, Vincenzo; Pala, Carlo; Casti, Daniele; Lamon, Sonia; Cossu, Francesca; Ibba, Michela; Nieddu, Gavino; De Santis, Enrico P L

    2016-09-01

    The present study shows the fate of Bacillus cereus in refrigerated ricotta salata cheese during shelf-life. 144 ricotta salata cheese belonging to nine naturally contaminated batches were stored refrigerated and analyzed at 24 h, 30, 60 and 90 days of storage. Total bacterial count, B. cereus spores and vegetative forms, intrinsic properties and composition were determined. The presence of spores was sporadic while the prevalence and the level of B. cereus vegetative cells decreased respectively from 83.3 % to 4.65 ± 0.74 cfu g(-1) at the beginning of the observation period to 33.3 % and 1.99 ± 0.55 cfu g(-1) after 90 days. No information is currently available on the fate of B. cereus in ricotta salata. The production process of ricotta salata includes steps such as whey heating followed by slow cooling of clots, which expose to the risk of spore germination and successive growth to levels compatible with toxins production. The prolonged refrigerated storage was not favorable to sporulation, explaining the successive death of vegetative cells. The present study demonstrate the potential risk of food poisoning as consequence of pre-formed emetic toxins in ricotta salata. Food safety of ricotta salata relies on the rapid refrigeration of the product during critical phases for cereulide production. PMID:27217369

  2. 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.

  3. A Spontaneous Translational Fusion of Bacillus cereus PlcR and PapR Activates Transcription of PlcR-Dependent Genes in Bacillus anthracis via Binding with a Specific Palindromic Sequence

    OpenAIRE

    Pomerantsev, Andrei P; Pomerantseva, Olga M.; Stephen H Leppla

    2004-01-01

    Transformation of Bacillus anthracis with plasmid pUTE29-plcR-papR carrying the native Bacillus cereus plcR-papR gene cluster did not activate expression of B. anthracis hemolysin genes, even though these are expected to be responsive to activation by the global regulator PlcR. To further characterize the action of PlcR, we examined approximately 3,000 B. anthracis transformants containing pUTE29-plcR-papR and found a single hemolytic colony. The hemolytic strain contained a plasmid having a ...

  4. Inhibitory and Lethal Effects of Aqueous and Ethanolic Extracts of Kelussia odoratissima on Bacillus cereus , Listeria innocua and Escherichia coli "in vitro"

    Directory of Open Access Journals (Sweden)

    Maryam Heidari Sureshjani

    2014-01-01

    Full Text Available Abstract Background and objectives: Karafs Koohi with the scientific name of Kelussia odoratissima and the local name of Keloss belongs to the Apiaceace family, and is a biannual or perennial plant. The present study aims at investigating the antimicrobial effects of the ethanolic and aqueous extracts of Kelussia odoratissima on Bacillus cereus , Listeria innocua and Escherichia coli Materials and methods: In this study, different concentration levels (20, 40, 60, 80 mg/ml of ethanolic and aqueous extracts of Kelussia odoratissima leaves were prepared. The antibacterial effect of extracts were investigated using spreading of the extract on medium surface (pour plate and disk agar diffusion test. Minimum Inhibitory Concentration (MIC( and Minimum Bactericidal Concentration (MBC were also studied using the dilution method .Statistical analysis was carried out by analysis of variance (ANOVA. Results: In disk agar diffusion Method all concentrations of ethanolic extract have inhibitory effect against Bacillus cereus and Listeria innocua. Minimum Inhibitory Concentration (MIC( of Kelussia odoratissima leaves of aqueous and ethanolic extracts for Bacillus cereus and Listeria innocua was 16 and 8 mg/ml and for Escherichia coli was 32and 16 mg/ml, respectively . Minimum Bactericidal Concentration (MBC of Kelussia odoratissima leaves of aqueous and ethanolic extracts for Bacillus cereus and Listeria innocua was 32 and 16 mg/ml and for Escherichia coli was 64 and 32mg/ml, respectively. Escherichia coli exhibited the most resistance against aqueous and ethanol extracts of Kelussia odoratissima leaves. Conclusions: The results showed that the ethanolic extract of Kelussia odoratissima leaves had greater inhibitory effects on the strains studied compared to aqueous extracts in vitro.

  5. BC4707 is a major facilitator superfamily multidrug resistance transport protein from Bacillus cereus implicated in fluoroquinolone tolerance.

    Directory of Open Access Journals (Sweden)

    Roger Simm

    Full Text Available Transcriptional profiling highlighted a subset of genes encoding putative multidrug transporters in the pathogen Bacillus cereus that were up-regulated during stress produced by bile salts. One of these multidrug transporters (BC4707 was selected for investigation. Functional characterization of the BC4707 protein in Escherichia coli revealed a role in the energized efflux of xenobiotics. Phenotypic analyses after inactivation of the gene bc4707 in Bacillus cereus ATCC14579 suggested a more specific, but modest role in the efflux of norfloxacin. In addition to this, transcriptional analyses showed that BC4707 is also expressed during growth of B. cereus under non-stressful conditions where it may have a role in the normal physiology of the bacteria. Altogether, the results indicate that bc4707, which is part of the core genome of the B. cereus group of bacteria, encodes a multidrug resistance efflux protein that is likely involved in maintaining intracellular homeostasis during growth of the bacteria.

  6. 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......, when possible, were collected. Soil from a well-characterized Danish farm soil (Hojbakkegaard) was collected for comparison. The Psudomonas spp. and B. cereus were chosen as representative for Gram-negative and Gram-positive indigenous soil bacteria to test the effect of spread of animal waste...... 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...

  7. Lifesaving liver transplantation for multi-organ failure caused by Bacillus cereus food poisoning.

    Science.gov (United States)

    Tschiedel, Eva; Rath, Peter-Michael; Steinmann, Jörg; Becker, Heinz; Dietrich, Rudolf; Paul, Andreas; Felderhoff-Müser, Ursula; Dohna-Schwake, Christian

    2015-02-01

    Bacillus cereus is a spore-forming, gram-positive bacterium that causes food poisoning presenting with either emesis or diarrhea. Diarrhea is caused by proteinaceous enterotoxin complexes, mainly hemolysin BL, non-hemolytic enterotoxin (NHE), and cytotoxin K. In contrast, emesis is caused by the ingestion of the depsipeptide toxin cereulide, which is produced in B. cereus contaminated food, particularly in pasta or rice. In general, the illness is mild and self-limiting. However, due to cereulide intoxication, nine severe cases with rhabdomyolysis and/or liver failure, five of them lethal, are reported in literature. Here we report the first case of life-threatening liver failure and severe rhabdomyolysis in this context that could not be survived without emergency hepatectomy and consecutive liver transplantation.

  8. 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.

  9. Antimicrobial potential of flavoring ingredients against Bacillus cereus in a milk-based beverage.

    Science.gov (United States)

    Pina-Pérez, Maria C; Rodrigo, Dolores; Martínez-López, Antonio

    2013-11-01

    Natural ingredients--cinnamon, cocoa, vanilla, and anise--were assessed based on Bacillus cereus vegetative cell growth inhibition in a mixed liquid whole egg and skim milk beverage (LWE-SM), under different conditions: ingredient concentration (1, 2.5, and 5% [wt/vol]) and incubation temperature (5, 10, and 22 °C). According to the results obtained, ingredients significantly (pCinnamon was the most bacteriostatic ingredient and cocoa the most bactericidal one when they were added at 5% (wt/vol) and beverages were incubated at 5 °C. The bactericidal effect of cocoa 5% (wt/vol) reduced final B. cereus log10 counts (log Nf, log10 (colony-forming units/mL)) by 4.10 ± 0.21 log10 cycles at 5 °C. PMID:23909775

  10. gerR, a novel ger operon involved in L-alanine- and inosine-initiated germination of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

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

    2005-01-01

    Bacillus cereus endospores germinate in response to particular nutrients. Spores are able to sense these nutrients in the environment by receptors encoded by the gerA family of operons. Analysis of the Bacillus cereus ATCC 14579 genome revealed seven gerA family homologues. Using a transposon Tn917-

  11. 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.

  12. 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.

  13. 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.

  14. Recovery and purification of chitosanase produced by Bacillus cereus using expanded bed adsorption and central composite design.

    Science.gov (United States)

    de Araújo, Nathália Kelly; Pimentel, Vanessa Carvalho; da Silva, Nayane Macedo Portela; de Araújo Padilha, Carlos Eduardo; de Macedo, Gorete Ribeiro; Dos Santos, Everaldo Silvino

    2016-02-01

    This study presents a system for expanded bed adsorption for the purification of chitosanase from broth extract in a single step. A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01 and used to produce chitosanases. The expanded bed adsorption conditions for chitosanase purification were optimized statistically using STREAMLINE(TM) DEAE and a homemade column (2.6 × 30.0 cm). Dependent variables were defined by the quality criteria purification factor (P) and enzyme yield to optimize the chromatographic process. Statistical analyses showed that the optimum conditions for the maximum P were 150 cm/h load flow velocity, 6.0 cm settled bed height, and 7.36 cm distributor height. Distributor height had a strong influence on the process, considerably affecting both the P and enzyme yield. Optimizing the purification variables resulted in an approximately 3.66-fold increase in the P compared with the value under nonoptimized conditions. This system is promising for the recovery of chitosanase from B. cereus C-01 and is economically viable because it promotes the reduction steps. PMID:26638991

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

    Science.gov (United States)

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

    2015-01-01

    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.

  16. 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.

  17. 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.

  18. Arsenic release by indigenous bacteria Bacillus cereus from aquifer sediments at Datong Basin, northern China

    Science.gov (United States)

    Xie, Zuoming; Wang, Yanxin; Duan, Mengyu; Xie, Xianjun; Su, Chunli

    2011-03-01

    Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus ( B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and then, it declined. Supplemented with bacteria only, the concentration could increase on the second day. By contrast, the arsenic concentration in the treatment supplemented with sodium citrate or glucose was kept very low. These results indicate that bacterial activities promoted the release of arsenic in the sediments. Bacterial activities also influenced other geochemical parameters of the aqueous phase, such as pH, Eh, and the concentrations of dissolved Fe, Mn, and Al that are important controls on arsenic release. The removal of Fe, Mn, and Al from sediment samples was observed with the presence of B. cereus. The effects of microbial activities on Fe, Mn, and Al release were nearly the same as those on As mobilization. The pH values of the treatments inoculated with bacteria were lower than those without bacteria, still at alkaline levels. With the decrease of Eh values in treatments inoculated with bacteria, the microcosms became more reducing and are thus favorable for arsenic release.

  19. Arsenic release by indigenous bacteria Bacillus cereus from aquifer sediments at Datong Basin, northern China

    Institute of Scientific and Technical Information of China (English)

    Zuoming XIE; Yanxin WANG; Mengyu DUAN; Xianjun XIE; Chunli SU

    2011-01-01

    Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus (B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and then, it declined.Supplemented with bacteria only, the concentration could increase on the second day. By contrast, the arsenic concentration in the treatment supplemented with sodium citrate or glucose was kept very low. These results indicate that bacterial activities promoted the release of arsenic in the sediments. Bacterial activities also influenced other geochemical parameters of the aqueous phase, such as pH,Eh, and the concentrations of dissolved Fe, Mn, and Al that are important controls on arsenic release. The removal of Fe, Mn, and Al from sediment samples was observed with the presence of B. cereus. The effects of microbial activities on Fe, Mn, and Al release were nearly the same as those on As mobilization. The pH values of the treatments inoculated with bacteria were lower than those without bacteria, still at alkaline levels. With the decrease of Eh values in treatments inoculated with bacteria, the microcosms became more reducing and are thus favorable for arsenic release.

  20. 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

    2016-01-01

    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. 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. PMID:27585559

  1. Complete genome sequence of the cold-active bacteriophage VMY22 from Bacillus cereus.

    Science.gov (United States)

    Qin, Kunhao; Cheng, Benxu; Zhang, Shengting; Wang, Nan; Fang, Yuan; Zhang, Qi; Kuang, Anxiu; Lin, Lianbing; Ji, Xiuling; Wei, Yunlin

    2016-06-01

    The cold-active bacteriophage VMY22, belonging to the Podoviridae family, was isolated from Mingyong Glacier in China. Sequence analysis revealed that the genome is 18,609 bp long, with an overall G + C content of 36.4 mol%, and 25 open reading frames (ORFs). The sequence contains 46 potential promoters, 6 transcription terminators, and no tRNAs. Most of the ORFs show a high degree of similarity to B103 (NC_004165). Two noteworthy findings were made. First, one of the predicted proteins, ORF 19, shows high sequence similarity to the bacteriocin biosynthesis protein from Bacillus cereus. From this information, we propose that the VMY22 phage is at an intermediate phase in its coevolution with its bacterial host. Second, seven of the hypothetical proteins appear to be unique to this cold-active B. cereus phage (i.e., not found in temperate-active B. cereus phages). These observations add to our current knowledge about the coevolution of bacteriophages and their hosts. The identification of a novel group of gene and protein structures and functions will lead to a better understanding of cold-adaptation mechanisms in bacteria and their bacteriophages.

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

    International Nuclear Information System (INIS)

    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 107 UFC/ml to 550 UFC/ml, the presence of B. Cereus

  3. Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis.

    Science.gov (United States)

    Brézillon, Christophe; Haustant, Michel; Dupke, Susann; Corre, Jean-Philippe; Lander, Angelika; Franz, Tatjana; Monot, Marc; Couture-Tosi, Evelyne; Jouvion, Gregory; Leendertz, Fabian H; Grunow, Roland; Mock, Michèle E; Klee, Silke R; Goossens, Pierre L

    2015-04-01

    Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain) and Côte d'Ivoire (CI strain). These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA) capsule and the B. anthracis polyglutamate (PDGA) capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have emerged.

  4. Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis.

    Directory of Open Access Journals (Sweden)

    Christophe Brézillon

    2015-04-01

    Full Text Available Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain and Côte d'Ivoire (CI strain. These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA capsule and the B. anthracis polyglutamate (PDGA capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have

  5. Effect of temperatures on the growth, toxin production, and heat resistance of Bacillus cereus in cooked rice.

    Science.gov (United States)

    Wang, Jun; Ding, Tian; Oh, Deog-Hwan

    2014-02-01

    Bacillus cereus is capable of producing enterotoxin and emetic toxin, and Bacillus foodborne illnesses occur due to the consumption of food contaminated with endospores. The objectives of this study were to investigate the growth and toxin production of B. cereus in cooked rice and to determine the effect of temperature on toxin destruction. Cooked rice inoculated with B. cereus was stored at 15, 25, 35, and 45°C or treated at 80, 90, and 100°C. The results indicated that emetic toxin was produced faster than enterotoxin (which was not detected below 15°C) at all the storage temperatures (15-45°C) during the first 72 h. Emetic toxin persisted at 100°C for 2 h, although enterotoxin was easily to be destroyed by this treatment within 15 min. In addition, B. cereus in cooked rice stored at a warm temperature for a period was not inactivated due to survival of the thermostable endospores. These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers. Results from this study may help enhance the safety of such food, and provide valuable and reliable information for risk assessment and management, associated with the problem of B. cereus in cooked rice.

  6. Production and characterization of poly-3-hydroxybutyrate from Bacillus cereus PS 10.

    Science.gov (United States)

    Sharma, Priyanka; Bajaj, Bijender Kumar

    2015-11-01

    Usage of renewable raw materials for production of fully degradable bioplastics (bacterial poly-3-hydroxybutyrate, PHB) has gained immense research impetus considering recalcitrant nature of petroleum based plastics, dwindling fossil fuel feed stocks, and associated green house gas emissions. However, high production cost of PHB is the major bottleneck for its wide range industrial applications. In current study, Bacillus cereus PS 10, a recent isolate, efficiently utilized molasses, an abundantly available by-product from sugar industries as sole carbon source for growth and PHB production. Most influential bioprocess variables i.e. molasses, pH and NH4Cl were identified based on Plackett-Burman-designed experiments. Design of experiment approach (response surface methodology) was further employed for optimization of these bioprocess variables, and an enhanced PHB yield (57.5%) was obtained. PHB produced by Bacillus cereus PS 10 was investigated using various physico-chemical approaches viz. thermogravimetric analysis, proton and carbon NMR ((1)H and (13)C) spectroscopy, melting point, elemental analysis and polarimetry for its detail characterization, and assessment for industrial application potential. PMID:26257381

  7. 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.

  8. Biogenesis of antibacterial silver nanoparticles using the endophytic bacterium Bacillus cereus isolated from Garcinia xanthochymus

    Institute of Scientific and Technical Information of China (English)

    Swetha Sunkar; C Valli Nachiyar

    2012-01-01

    Objective:To synthesize the ecofriendly nanoparticles, which is viewed as an alternative to the chemical method which initiated the use of microbes like bacteria and fungi in their synthesis. Methods: The current study uses the endophytic bacterium Bacillus cereus isolated from the Garcinia xanthochymus to synthesize the silver nanoparticles (AgNPs). The AgNPs were synthesized by reduction of silver nitrate solution by the endophytic bacterium after incubation for 3-5 d at room temperature. The synthesis was initially observed by colour change from pale white to brown which was confirmed by UV-Vis spectroscopy. The AgNPs were further characterized using FTIR, SEM-EDX and TEM analyses. Results:The synthesized nanoparticles were found to be spherical with the size in the range of 20-40 nm which showed a slight aggregation. The energy-dispersive spectra of the nanoparticle dispersion confirmed the presence of elemental silver. The AgNPs were found to have antibacterial activity against a few pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Klebsiella pneumoniae. Conclusions:The endophytic bacteria identified as Bacillus cereus was able to synthesize silver nanoparticles with potential antibacterial activity.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Joao C. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Eaton, Peter, E-mail: peter.eaton@fc.up.pt [REQUIMTE, Departamento de Quimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Gomes, Ana M.; Pintado, Manuela E.; Xavier Malcata, F. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

    2009-07-15

    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.

  10. Analysis of the Bacillus cereus SpoIIS antitoxin-toxin system reveals its three-component nature.

    Science.gov (United States)

    Melničáková, Jana; Bečárová, Zuzana; Makroczyová, Jana; Barák, Imrich

    2015-01-01

    Programmed cell death in bacteria is generally associated with two-component toxin-antitoxin systems. The SpoIIS toxin-antitoxin system, consisting of a membrane-bound SpoIISA toxin and a small, cytosolic antitoxin SpoIISB, was originally identified in Bacillus subtilis. In this work we describe the Bacillus cereus SpoIIS system which is a three-component system, harboring an additional gene spoIISC. Its protein product serves as an antitoxin, and similarly as SpoIISB, is able to bind SpoIISA and abolish its toxic effect. Our results indicate that SpoIISC seems to be present not only in B. cereus but also in other Bacilli containing a SpoIIS toxin-antitoxin system. In addition, we show that B. cereus SpoIISA can form higher oligomers and we discuss the possible role of this multimerization for the protein's toxic function.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Quantitative analysis of population heterogeneity of the adaptive salt stress response and growth capacity of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Besten, den H.M.W.; Ingham, C.J.; Hylckama Vlieg, van J.E.T.; Beerthuyzen, M.M.; Zwietering, M.H.; Abee, T.

    2007-01-01

    Bacterial populations can display heterogeneity with respect to both the adaptive stress response and growth capacity of individual cells. The growth dynamics of Bacillus cereus ATCC 14579 during mild and severe salt stress exposure were investigated for the population as a whole in liquid culture.

  13. Direct-Imaging-Based Quantification of Bacillus cereus ATCC 14579 Population Heterogeneity at a Low Incubation Temperature

    NARCIS (Netherlands)

    Besten, den H.M.W.; Garcia, D.; Moezelaar, R.; Zwietering, M.H.; Abee, T.

    2010-01-01

    Bacillus cereus ATCC 14579 was cultured in microcolonies on Anopore strips near its minimum growth temperature to directly image and quantify its population heterogeneity at an abusive refrigeration temperature. Eleven percent of the microcolonies failed to grow during low-temperature incubation, an

  14. 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

    For the first time a consistent catalytic mechanism of phospholipase C from Bacillus cereus is reported based on molecular mechanics calculations. We have identified the position of the nucleophilic water molecule, which is directly involved in the hydrolysis of the natural substrate phosphatidyl...

  15. Distinct Roles of ComK1 and ComK2 in Gene Regulation in Bacillus cereus

    NARCIS (Netherlands)

    Mironczuk, Aleksandra; Maňu, Amagoia; Kuipers, Oscar P.; Kovacs, Akos

    2011-01-01

    The B. subtilis transcriptional factor ComK regulates a set of genes coding for DNA uptake from the environment and for its integration into the genome. In previous work we showed that Bacillus cereus expressing the B. subtilis ComK protein is able to take up DNA and integrate it into its own genome

  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. 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 a

  18. Selection and Molecular Biological Identification of a Strain of Bacillus sp. Inhibiting the Growth of Saprolegnia ferax

    Institute of Scientific and Technical Information of China (English)

    Song; Zengfu; Fan; Bin; She; Linrong; Tang; Lei; Zhao; Shilin; Lv; Liqun; Yang; Xianle

    2014-01-01

    Based on the theory of biological control of Saprolegnia ferax,antagonism test of nine strains of Bacillus sp. to S. ferax JL was carried out. Bacillus sp.BA1 was screened to have significantly inhibitory effects on the growth of S. ferax JL( P < 0. 05). Then,the effects of Bacillus sp. BA1 on different sources of S. ferax were carried out. Results showed that BA1 also had significantly inhibitory effects on S. ferax 6#,10# and S2( P < 0. 05). Sequence of 16 S r DNA of BA1 was analyzed; and homologous alignment analysis showed that BA1 had more than 99% similarity with Bacillus cereus. Therefore,it could be concluded that strain BA1 was B. cereus,which significantly inhibited the growth of S. ferax and could be used as the biological control agent for S. ferax diseases in aquaculture.

  19. 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.

  20. 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.

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

    Science.gov (United States)

    Mabon, Philip; Zimmermann, Fee; Lankester, Felix; Peller, Tianna; Feistner, Anna; Todd, Angelique; Herbinger, Ilka; de Nys, Hélène M.; Muyembe-Tamfun, Jean-Jacques; Karhemere, Stomy; Wittig, Roman M.; Couacy-Hymann, Emmanuel; Grunow, Roland; Calvignac-Spencer, Sébastien; Corbett, Cindi R.; Klee, Silke R.; Leendertz, Fabian H.

    2016-01-01

    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. PMID:27607836

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. Effects of Aronia melanocarpa constituents on biofilm formation of Escherichia coli and Bacillus cereus.

    Science.gov (United States)

    Bräunlich, Marie; Økstad, Ole A; Slimestad, Rune; Wangensteen, Helle; Malterud, Karl E; Barsett, Hilde

    2013-01-01

    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. PMID:24317526

  7. Crystallization and preliminary X-ray analysis of a phosphopentomutase from Bacillus cereus

    Energy Technology Data Exchange (ETDEWEB)

    Panosian, Timothy D.; Nannemann, David P.; Bachmann, Brian O.; Iverson, T.M. (Vanderbilt)

    2013-09-18

    Phosphopentomutases (PPMs) interconvert D-ribose 5-phosphate and {alpha}-D-ribose 1-phosphate to link glucose and nucleotide metabolism. PPM from Bacillus cereus was overexpressed in Escherichia coli, purified to homogeneity and crystallized. Bacterial PPMs are predicted to contain a di-metal reaction center, but the catalytically relevant metal has not previously been identified. Sparse-matrix crystallization screening was performed in the presence or absence of 50 mM MnCl{sub 2}. This strategy resulted in the formation of two crystal forms from two chemically distinct conditions. The crystals that formed with 50 mM MnCl{sub 2} were more easily manipulated and diffracted to higher resolution. These results suggest that even if the catalytically relevant metal is not known, the crystallization of putative metalloproteins may still benefit from supplementation of the crystallization screens with potential catalytic metals.

  8. 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...

  9. Pathogensis Mechanism and Detection Methods of Bacillus cereus%蜡状芽孢杆菌毒株的致病机理及检测方法

    Institute of Scientific and Technical Information of China (English)

    何文艳; 裘娟萍; 赵春田

    2012-01-01

    蜡状芽孢杆菌系无荚膜的革兰氏阳性菌,是最常见的食源性病原菌之一.致病性菌株能产生呕吐毒素和肠毒素,临床上可分为致呕吐型和腹泻型.研究病原件蜡状芽孢杆菌的致病机理,有助于了解其致病途径,从而改进和完善检测方法和诊治途径.通过综述蜡状芽孢杆菌几种毒素的致病机理,整理了一套蜡状芽孢杆菌致病毒株的鉴定检测技术方法:用鉴定平板等传统的鉴定方法将蜡状芽孢杆菌检出,应用先进的PCR和免疫方法检测毒素基因及毒蛋白,通过荧光多重PCR提高灵敏度和准确性等,以期加强食品安全.%Bacillus cereus are Gram-positive, no capsule bacteria, which have been one of the important food-bome pathogens. Some strains can produce emetic toxin and enterotoxins to cause two types of food-bome illness: emetic syn-drome and diarrheal illness. This is closely related with industrial production, food security and medical health. The study on pathogenic mechanism of Bacillus cereus could help us to understand the pathogenic pathway and improve the detection of B. cereus. The pathogenic mechanism of several toxin from Bacillus cereus is reviewed in this article. A rea-sonable protocol is proposed, including the use of conventional detection methods, the molecular biological methods and immunological detection methods, in order to strengthen the research and supervision of B. cereus to guarantee food safety.

  10. Effect of endophytic Bacillus cereus ERBP inoculation into non-native host: Potentials and challenges for airborne formaldehyde removal.

    Science.gov (United States)

    Khaksar, Gholamreza; Treesubsuntorn, Chairat; Thiravetyan, Paitip

    2016-10-01

    Phytoremediation could be a cost-effective, environmentally friendly approach for the treatment of indoor air. However, some drawbacks still dispute the expediency of phytotechnology. Our objectives were to investigate the competency of plant growth-promoting (PGP) endophytic Bacillus cereus ERBP (endophyte root blue pea), isolated from the root of Clitoria ternatea, to colonize and stabilize within Zamioculcas zamiifolia and Euphorbia milii as non-native hosts without causing any disease or stress symptoms. Moreover, the impact of B. cereus ERBP on the natural shoot endophytic community and for the airborne formaldehyde removal capability of non-native hosts was assessed. Non-native Z. zamiifolia was effectively inoculated with B. cereus ERBP through soil as the most efficient method of endophyte inoculation. Denaturing gradient gel electrophoresis profiling of the shoot endophytic community verified the colonization and stability of B. cereus ERBP within its non-native host during a 20-d fumigation period without interfering with the natural shoot endophytic diversity of Z. zamiifolia. B. cereus ERBP conferred full protection to its non-native host against formaldehyde phytotoxicity and enhanced airborne formaldehyde removal of Z. zamiifolia whereas non-inoculated plants suffered from formaldehyde phytotoxicity because their natural shoot endophytic community was detrimentally affected by formaldehyde. In contrast, B. cereus ERBP inoculation into non-native E. milii deteriorated airborne formaldehyde removal of the non-native host (compared to a non-inoculated one) as B. cereus ERBP interfered with natural shoot endophytic community of E. milii, which caused stress symptoms and stimulated ethylene biosynthesis. Non-native host inoculation with PGP B. cereus ERBP could bear potentials and challenges for airborne formaldehyde removal. PMID:27362296

  11. 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

  12. Genome Sequence of Bacillus endophyticus and Analysis of Its Companion Mechanism in the Ketogulonigenium vulgare-Bacillus Strain Consortium.

    Directory of Open Access Journals (Sweden)

    Nan Jia

    Full Text Available Bacillus strains have been widely used as the companion strain of Ketogulonigenium vulgare in the process of vitamin C fermentation. Different Bacillus strains generate different effects on the growth of K. vulgare and ultimately influence the productivity. First, we identified that Bacillus endophyticus Hbe603 was an appropriate strain to cooperate with K. vulgare and the product conversion rate exceeded 90% in industrial vitamin C fermentation. Here, we report the genome sequencing of the B. endophyticus Hbe603 industrial companion strain and speculate its possible advantage in the consortium. The circular chromosome of B. endophyticus Hbe603 has a size of 4.87 Mb with GC content of 36.64% and has the highest similarity with that of Bacillus megaterium among all the bacteria with complete genomes. By comparing the distribution of COGs with that of Bacillus thuringiensis, Bacillus cereus and B. megaterium, B. endophyticus has less genes related to cell envelope biogenesis and signal transduction mechanisms, and more genes related to carbohydrate transport and metabolism, energy production and conversion, as well as lipid transport and metabolism. Genome-based functional studies revealed the specific capability of B. endophyticus in sporulation, transcription regulation, environmental resistance, membrane transportation, extracellular proteins and nutrients synthesis, which would be beneficial for K. vulgare. In particular, B. endophyticus lacks the Rap-Phr signal cascade system and, in part, spore coat related proteins. In addition, it has specific pathways for vitamin B12 synthesis and sorbitol metabolism. The genome analysis of the industrial B. endophyticus will help us understand its cooperative mechanism in the K. vulgare-Bacillus strain consortium to improve the fermentation of vitamin C.

  13. Genome Sequence of Bacillus endophyticus and Analysis of Its Companion Mechanism in the Ketogulonigenium vulgare-Bacillus Strain Consortium.

    Science.gov (United States)

    Jia, Nan; Du, Jin; Ding, Ming-Zhu; Gao, Feng; Yuan, Ying-Jin

    2015-01-01

    Bacillus strains have been widely used as the companion strain of Ketogulonigenium vulgare in the process of vitamin C fermentation. Different Bacillus strains generate different effects on the growth of K. vulgare and ultimately influence the productivity. First, we identified that Bacillus endophyticus Hbe603 was an appropriate strain to cooperate with K. vulgare and the product conversion rate exceeded 90% in industrial vitamin C fermentation. Here, we report the genome sequencing of the B. endophyticus Hbe603 industrial companion strain and speculate its possible advantage in the consortium. The circular chromosome of B. endophyticus Hbe603 has a size of 4.87 Mb with GC content of 36.64% and has the highest similarity with that of Bacillus megaterium among all the bacteria with complete genomes. By comparing the distribution of COGs with that of Bacillus thuringiensis, Bacillus cereus and B. megaterium, B. endophyticus has less genes related to cell envelope biogenesis and signal transduction mechanisms, and more genes related to carbohydrate transport and metabolism, energy production and conversion, as well as lipid transport and metabolism. Genome-based functional studies revealed the specific capability of B. endophyticus in sporulation, transcription regulation, environmental resistance, membrane transportation, extracellular proteins and nutrients synthesis, which would be beneficial for K. vulgare. In particular, B. endophyticus lacks the Rap-Phr signal cascade system and, in part, spore coat related proteins. In addition, it has specific pathways for vitamin B12 synthesis and sorbitol metabolism. The genome analysis of the industrial B. endophyticus will help us understand its cooperative mechanism in the K. vulgare-Bacillus strain consortium to improve the fermentation of vitamin C.

  14. Expression of the genes encoding the CasK/R two-component system and the DesA desaturase during Bacillus cereus cold adaptation.

    Science.gov (United States)

    Diomandé, Sara Esther; Doublet, Bénédicte; Vasaï, Florian; Guinebretière, Marie-Hélène; Broussolle, Véronique; Brillard, Julien

    2016-08-01

    Two-component systems (TCS) allow a cell to elaborate a variety of adaptive responses to environment changes. The recently discovered CasK/R TCS plays a role in the optimal unsaturation of fatty acids necessary for cold adaptation of the foodborne-pathogen Bacillus cereus Here, we showed that the promoter activity of the operon encoding this TCS was repressed during growth at low temperature in the stationary phase in the parental strain when compared to the casK/R mutant, suggesting that CasR negatively regulates the activity of its own promoter in these conditions. The promoter activity of the desA gene encoding the Δ5 fatty acid desaturase, providing unsaturated fatty acids (UFAs) required for low temperature adaptation, was repressed in the casK/R mutant grown at 12°C versus 37°C. This result suggests that CasK/R activates desA expression during B. cereus growth at low temperature, allowing an optimal unsaturation of the fatty acids. In contrast, desA expression was repressed during the lag phase at low temperature in presence of UFAs, in a CasK/R-independent manner. Our findings confirm that the involvement of this major TCS in B. cereus cold adaptation is linked to the upregulation of a fatty acid desaturase. PMID:27435329

  15. 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 japonicus (P > 0.05), whereas dietary EN25 at 10(9) CFU/g had significantly decreased its activity (P japonicus. PMID:26723266

  16. Screening and Genetic Stability of Bacillus cereus SZ-4 Producing Dehairing Protease%脱毛蛋白酶生产菌株Bacillus cereus SZ-4的筛选及遗传稳定性检测

    Institute of Scientific and Technical Information of China (English)

    杨姗

    2010-01-01

    采用平皿菌落分离法、透明圈法及摇瓶发酵法从盐腌皮上分离、筛选得到脱毛蛋白酶生产菌株Bacillus cereus SZ-4,该菌株经发酵后得到的粗酶液酶活力为72/mL;对其遗传稳定性检测结果表明,Bacillus cereus SZ-4遗传稳定性较差,在1~4代菌种之间差异不是很显著,可用于发酵生产接种.

  17. Bacillus cereus X5 Enhanced Bio-Organic Fertilizers Effectively Control Root-Knot Nematodes (Meloidogyne sp.)

    Institute of Scientific and Technical Information of China (English)

    XIAO Tong-Jian; CHEN Fang; GAO Chao; ZHAO Qing-Yun; SHEN Qi-Rong; RAN Wei

    2013-01-01

    The efficacy of Bacillus cereus X5 as a potential biological control agent against root-knot nematodes was evaluated in vitro by examining second-stage juvenile mortality and egg hatching rate under addition of culture filtrate and in planta by application of bio-organic fertilizers enhanced with B.cereus X5,B.thuringiensis BTG,or Trichoderma harzianum SQR-T037 alone or together in greenhouse and field experiments.The biofumigation of the root-knot nematode-infested soil with organic materials (chicken manure,pig manure and rice straw) alone or in combination with B.cereus X5 was also conducted in greenhouse experiments.In laboratory,the filtrate of B.cereus X5 more effectively reduced egg hatching rates during the incubation period for 14 d and more effectively killed the second-stage juvenile during the incubation period of 24 h than that of B.thuringiensis BTG.The highest dry shoot weights for greenhouse tomatoes and field muskmelons were found in both the treatment consisting of the bio-organic fertilizer enhanced with the three biocontrol agents and the treatment consisting of the bio-organic fertilizer enhanced only with B.cereus X5.The two bio-organic fertilizers achieved better nematicidal effects than those enhanced only with B.thuringiensis BTG or T.harzianum SQR-T037.B.cereus X5 also enhanced effect of biofumigation,which resulted in increased plant biomass and reduced nematode counts in the roots and rhizosphere soil.Therefore,these results suggested that biological control of root-knot nematodes both in greenhouses and fields could be effectively achieved by using B.cereus X5 and agricultural wastes.

  18. Quantitative analysis of cereulide toxin from Bacillus cereus in rice and pasta using synthetic cereulide standard and 13C6-cereulide standard - a short validation study.

    Science.gov (United States)

    Zuberovic Muratovic, Aida; Tröger, Rikard; Granelli, Kristina; Hellenäs, Karl-Erik

    2014-12-11

    A single laboratory validation study of a rapid and sensitive quantitative method for the analysis of cereulide toxin produced by Bacillus cereus using ultra high performance liquid chromatography-electrospray-tandem mass spectrometry is presented. The analysis of this cyclic peptide toxin was validated for pasta and rice samples using a newly presented synthetic cereulide peptide standard, together with 13C6-cereulide that previously have not been commercially available. The use of cereulide standard was also compared to the most frequently used surrogate standard, the antibiotic valinomycin. The performance of the method was evaluated by analyzing spiked sample pools from different types of rice and pasta, as well as 21 individual rice and pasta samples from differently prepared meals. Inoculation of samples with three cereulide toxin-producing strains of Bacillus cereus was finally used to mimic naturally contaminated foods. The quantification range of the method was 1-500 ng/g (R2 = 0.999) and the limits of detection and quantification were 0.1 and 1 ng/g, respectively. The precision varied from 3% to 7% relative standard deviation and the trueness from -2% to +6% relative bias at different concentration levels in cooked rice and pasta.

  19. Quantitative Analysis of Cereulide Toxin from Bacillus cereus in Rice and Pasta Using Synthetic Cereulide Standard and 13C6-Cereulide Standard—A Short Validation Study

    Directory of Open Access Journals (Sweden)

    Aida Zuberovic Muratovic

    2014-12-01

    Full Text Available A single laboratory validation study of a rapid and sensitive quantitative method for the analysis of cereulide toxin produced by Bacillus cereus using ultra high performance liquid chromatography-electrospray-tandem mass spectrometry is presented. The analysis of this cyclic peptide toxin was validated for pasta and rice samples using a newly presented synthetic cereulide peptide standard, together with 13C6-cereulide that previously have not been commercially available. The use of cereulide standard was also compared to the most frequently used surrogate standard, the antibiotic valinomycin. The performance of the method was evaluated by analyzing spiked sample pools from different types of rice and pasta, as well as 21 individual rice and pasta samples from differently prepared meals. Inoculation of samples with three cereulide toxin-producing strains of Bacillus cereus was finally used to mimic naturally contaminated foods. The quantification range of the method was 1–500 ng/g (R2 = 0.999 and the limits of detection and quantification were 0.1 and 1 ng/g, respectively. The precision varied from 3% to 7% relative standard deviation and the trueness from −2% to +6% relative bias at different concentration levels in cooked rice and pasta.

  20. Postincision steps of photoproduct removal in a mutant of Bacillus cereus 569 that produces UV-sensitive spores.

    OpenAIRE

    Weinberger, S; Evenchick, Z; Hertman, I

    1983-01-01

    An excision-defective mutant of Bacillus cereus 569 is normal in incision and repair synthesis, but rejoining of incision breaks is defective, resulting in accumulation of low-molecular-weight DNA after UV irradiation. The defect in removal of photoproducts by exonuclease after incision renders both vegetative cells and dormant spores of the mutant sensitive to UV. A similarity is indicated to the uvrD mutation described recently in Escherichia coli.

  1. Bacillus cereus food poisoning associated with fried rice at two child day care centers--Virginia, 1993.

    Science.gov (United States)

    1994-03-18

    Bacillus cereus, an infectious cause of foodborne illness, accounted for 2% of outbreaks with confirmed etiology that were reported to CDC during 1973-1987 (1). On July 21, 1993, the Lord Fairfax (Virginia) Health District received reports of acute gastrointestinal illness that occurred among children and staff at two jointly owned child day care centers following a catered lunch. This report summarizes the investigation of this outbreak. PMID:8121375

  2. Surfactin production by strains of Bacillus mojavensis

    Science.gov (United States)

    Bacillus mojavensis, RRC101 is an endophytic bacterium patented for control of fungal diseases in maize and other plants. DNA fingerprint analysis of the rep-PCR fragments of 35 B. mojavensis and 4 B. subtilis strains using the Diversilab genotyping system revealed genotypic distinctive strains alon...

  3. Multiparametric Quantitation of the Bacillus cereus Toxins Cereulide and Isocereulides A-G in Foods.

    Science.gov (United States)

    Marxen, Sandra; Stark, Timo D; Rütschle, Andrea; Lücking, Genia; Frenzel, Elrike; Scherer, Siegfried; Ehling-Schulz, Monika; Hofmann, Thomas

    2015-09-23

    Consumption of food products contaminated with cereulide (1), a toxin produced by Bacillus cereus, might cause intoxications with symptoms reported to range from indigestion pain and emesis to death. Recently, a series of structural variants, coined isocereulides A-G (2-8), were identified for the first time to be produced along with cereulide (1). The observation that isocereulide A (2) shows an ∼ 8-fold increased cytotoxicity when compared to 1 urges the development of analytical tools enabling an accurate quantitation of these toxins. Therefore, a rapid, sensitive, and robust stable isotope dilution assay (SIDA) was developed for the combined quantitation of 1-8 by means of UPLC-MS/MS. On average, trueness and precision of the method were 112.5 ± 1.8% RSD, repeatability and reproducibility were 2 and 4% for cereulide and isocereulides A-G, and the LOD and LOQ of 0.1 and 0.5 ng/g, respectively, demonstrated a high sensitivity for the developed SIDA method. Application of this method to food samples revealed elevated levels of 1-8 in two suspicious noodle samples, for example, ranging from 0.59 (7) to 189.08 ng/g (1) in sample 1 and from 5.77 (7) to 6198.17 ng/g (1) in sample 2, whereas the analysis of 25 randomly selected food samples, which have not been the subject to any complaints, did not contain detectable amounts of any of these toxins. As a consequence, this SIDA method could add an important contribution to the knowledge-based risk assessment of B. cereus toxins in foods.

  4. Comparative bioinformatics and experimental analysis of the intergenic regulatory regions of Bacillus cereus hbl and nhe enterotoxin operons and the impact of CodY on virulence heterogeneity

    Directory of Open Access Journals (Sweden)

    Maria-Elisabeth eBöhm

    2016-05-01

    Full Text Available Bacillus cereus is a food contaminant with greatly varying enteropathogenic potential. Almost all known strains harbor the genes for at least one of the three enterotoxins Nhe, Hbl and CytK. While some strains show no cytotoxicity, others have caused outbreaks, in rare cases even with lethal outcome. The reason for these differences in cytotoxicity is unknown. To gain insight into the origin of enterotoxin expression heterogeneity in different strains, the architecture and role of 5’ intergenic regions (5’IGRs upstream of the nhe and hbl operons was investigated. In silico comparison of 142 strains of all seven phylogenetic groups of B. cereus sensu lato proved the presence of long 5’IGRs upstream of the nheABC and hblCDAB operons, which harbor recognition sites for several transcriptional regulators, including the virulence regulator PlcR, redox regulators ResD and Fnr, the nutrient-sensitive regulator CodY as well as the master regulator for biofilm formation SinR. By determining transcription start sites, unusually long 5’ untranslated regions (5’UTRs upstream of the nhe and hbl start codons were identified, which are not present upstream of cytK-1 and cytK-2. Promoter fusions lacking various parts of the nhe and hbl 5’UTR in B. cereus INRA C3 showed that the entire 331 bp 5’UTR of nhe is necessary for full promoter activity, while the presence of the complete 606 bp hbl 5’UTR lowers promoter activity. Repression was caused by a 268 bp sequence directly upstream of the hbl transcription start. Luciferase activity of reporter strains containing nhe and hbl 5’IGR lux fusions provided evidence that toxin gene transcription is upregulated by the depletion of free amino acids. Electrophoretic mobility shift assays showed that the branched-chain amino acid sensing regulator CodY binds to both nhe and hbl 5’UTR downstream of the promoter, potentially acting as a nutrient-responsive roadblock repressor of toxin gene transcription

  5. Comparative Bioinformatics and Experimental Analysis of the Intergenic Regulatory Regions of Bacillus cereus hbl and nhe Enterotoxin Operons and the Impact of CodY on Virulence Heterogeneity.

    Science.gov (United States)

    Böhm, Maria-Elisabeth; Krey, Viktoria M; Jeßberger, Nadja; Frenzel, Elrike; Scherer, Siegfried

    2016-01-01

    Bacillus cereus is a food contaminant with greatly varying enteropathogenic potential. Almost all known strains harbor the genes for at least one of the three enterotoxins Nhe, Hbl, and CytK. While some strains show no cytotoxicity, others have caused outbreaks, in rare cases even with lethal outcome. The reason for these differences in cytotoxicity is unknown. To gain insight into the origin of enterotoxin expression heterogeneity in different strains, the architecture and role of 5' intergenic regions (5' IGRs) upstream of the nhe and hbl operons was investigated. In silico comparison of 142 strains of all seven phylogenetic groups of B. cereus sensu lato proved the presence of long 5' IGRs upstream of the nheABC and hblCDAB operons, which harbor recognition sites for several transcriptional regulators, including the virulence regulator PlcR, redox regulators ResD and Fnr, the nutrient-sensitive regulator CodY as well as the master regulator for biofilm formation SinR. By determining transcription start sites, unusually long 5' untranslated regions (5' UTRs) upstream of the nhe and hbl start codons were identified, which are not present upstream of cytK-1 and cytK-2. Promoter fusions lacking various parts of the nhe and hbl 5' UTR in B. cereus INRA C3 showed that the entire 331 bp 5' UTR of nhe is necessary for full promoter activity, while the presence of the complete 606 bp hbl 5' UTR lowers promoter activity. Repression was caused by a 268 bp sequence directly upstream of the hbl transcription start. Luciferase activity of reporter strains containing nhe and hbl 5' IGR lux fusions provided evidence that toxin gene transcription is upregulated by the depletion of free amino acids. Electrophoretic mobility shift assays showed that the branched-chain amino acid sensing regulator CodY binds to both nhe and hbl 5' UTR downstream of the promoter, potentially acting as a nutrient-responsive roadblock repressor of toxin gene transcription. PlcR binding sites are

  6. Comparative Bioinformatics and Experimental Analysis of the Intergenic Regulatory Regions of Bacillus cereus hbl and nhe Enterotoxin Operons and the Impact of CodY on Virulence Heterogeneity.

    Science.gov (United States)

    Böhm, Maria-Elisabeth; Krey, Viktoria M; Jeßberger, Nadja; Frenzel, Elrike; Scherer, Siegfried

    2016-01-01

    Bacillus cereus is a food contaminant with greatly varying enteropathogenic potential. Almost all known strains harbor the genes for at least one of the three enterotoxins Nhe, Hbl, and CytK. While some strains show no cytotoxicity, others have caused outbreaks, in rare cases even with lethal outcome. The reason for these differences in cytotoxicity is unknown. To gain insight into the origin of enterotoxin expression heterogeneity in different strains, the architecture and role of 5' intergenic regions (5' IGRs) upstream of the nhe and hbl operons was investigated. In silico comparison of 142 strains of all seven phylogenetic groups of B. cereus sensu lato proved the presence of long 5' IGRs upstream of the nheABC and hblCDAB operons, which harbor recognition sites for several transcriptional regulators, including the virulence regulator PlcR, redox regulators ResD and Fnr, the nutrient-sensitive regulator CodY as well as the master regulator for biofilm formation SinR. By determining transcription start sites, unusually long 5' untranslated regions (5' UTRs) upstream of the nhe and hbl start codons were identified, which are not present upstream of cytK-1 and cytK-2. Promoter fusions lacking various parts of the nhe and hbl 5' UTR in B. cereus INRA C3 showed that the entire 331 bp 5' UTR of nhe is necessary for full promoter activity, while the presence of the complete 606 bp hbl 5' UTR lowers promoter activity. Repression was caused by a 268 bp sequence directly upstream of the hbl transcription start. Luciferase activity of reporter strains containing nhe and hbl 5' IGR lux fusions provided evidence that toxin gene transcription is upregulated by the depletion of free amino acids. Electrophoretic mobility shift assays showed that the branched-chain amino acid sensing regulator CodY binds to both nhe and hbl 5' UTR downstream of the promoter, potentially acting as a nutrient-responsive roadblock repressor of toxin gene transcription. PlcR binding sites are

  7. 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.

  8. The Biosynthesis of UDP-D-QuiNAc in Bacillus cereus ATCC 14579.

    Directory of Open Access Journals (Sweden)

    Soyoun Hwang

    Full Text Available N-acetylquinovosamine (2-acetamido-2,6-di-deoxy-D-glucose, QuiNAc is a relatively rare amino sugar residue found in glycans of few pathogenic gram-negative bacteria where it can play a role in infection. However, little is known about QuiNAc-related polysaccharides in gram-positive bacteria. In a routine screen for bacillus glycan grown at defined medium, it was surprising to identify a QuiNAc residue in polysaccharides isolated from this gram-positive bacterium. To gain insight into the biosynthesis of these glycans, we report the identification of an operon in Bacillus cereus ATCC 14579 that contains two genes encoding activities not previously described in gram-positive bacteria. One gene encodes a UDP-N-acetylglucosamine C4,6-dehydratase, (abbreviated Pdeg that converts UDP-GlcNAc to UDP-4-keto-4,6-D-deoxy-GlcNAc (UDP-2-acetamido-2,6-dideoxy-α-D-xylo-4-hexulose; and the second encodes a UDP-4-reductase (abbr. Preq that converts UDP-4-keto-4,6-D-deoxy-GlcNAc to UDP-N-acetyl-quinovosamine in the presence of NADPH. Biochemical studies established that the sequential Pdeg and Preq reaction product is UDP-D-QuiNAc as determined by mass spectrometry and one- and two-dimensional NMR experiments. Also, unambiguous evidence for the conversions of the dehydratase product, UDP-α-D-4-keto-4,6-deoxy-GlcNAc, to UDP-α-D-QuiNAc was obtained using real-time 1H-NMR spectroscopy and mass spectrometry. The two genes overlap by 4 nucleotides and similar operon organization and identical gene sequences were also identified in a few other Bacillus species suggesting they may have similar roles in the lifecycle of this class of bacteria important to human health. Our results provide new information about the ability of Bacilli to form UDP-QuiNAc and will provide insight to evaluate their role in the biology of Bacillus.

  9. Siderophore-mediated iron acquisition systems in Bacillus cereus: Identification of receptors for anthrax virulence-associated petrobactin .

    Science.gov (United States)

    Zawadzka, Anna M; Abergel, Rebecca J; Nichiporuk, Rita; Andersen, Ulla N; Raymond, Kenneth N

    2009-04-28

    During growth under iron limitation, Bacillus cereus and Bacillus anthracis, two human pathogens from the Bacillus cereus group of Gram-positive bacteria, secrete two siderophores, bacillibactin (BB) and petrobactin (PB), for iron acquisition via membrane-associated substrate-binding proteins (SBPs) and other ABC transporter components. Since PB is associated with virulence traits in B. anthracis, the PB-mediated iron uptake system presents a potential target for antimicrobial therapies; its characterization in B. cereus is described here. Separate transporters for BB, PB, and several xenosiderophores are suggested by (55)Fe-siderophore uptake studies. The PB precursor, 3,4-dihydroxybenzoic acid (3,4-DHB), and the photoproduct of FePB (FePB(nu)) also mediate iron delivery into iron-deprived cells. Putative SBPs were recombinantly expressed, and their ligand specificity and binding affinity were assessed using fluorescence spectroscopy. The noncovalent complexes of the SBPs with their respective siderophores were characterized using ESI-MS. The differences between solution phase behavior and gas phase measurements are indicative of noncovalent interactions between the siderophores and the binding sites of their respective SBPs. These studies combined with bioinformatics sequence comparison identify SBPs from five putative transporters specific for BB and enterobactin (FeuA), 3,4-DHB and PB (FatB), PB (FpuA), schizokinen (YfiY), and desferrioxamine and ferrichrome (YxeB). The two PB receptors show different substrate ranges: FatB has the highest affinity for ferric 3,4-DHB, iron-free PB, FePB, and FePB(nu), whereas FpuA is specific to only apo- and ferric PB. The biochemical characterization of these SBPs provides the first identification of the transporter candidates that most likely play a role in the B. cereus group pathogenicity.

  10. Siderophore-mediated iron acquisition systems in Bacillus cereus: identification of receptors for anthrax virulence-associated petrobactin†a

    Science.gov (United States)

    Zawadzka, Anna M.; Abergel, Rebecca J.; Nichiporuk, Rita; Andersen, Ulla N.; Raymond, Kenneth N.

    2009-01-01

    During growth under iron limitation, Bacillus cereus and Bacillus anthracis, two human pathogens from the Bacillus cereus group of Gram-positive bacteria, secrete two siderophores, bacillibactin (BB) and petrobactin (PB), for iron acquisition via membrane-associated substrate-binding proteins (SBPs) and other ABC transporter components. Since PB is associated with virulence traits in B. anthracis, the PB-mediated iron uptake system presents a potential target for antimicrobial therapies; its characterization in B. cereus is described here. Separate transporters for BB, PB, and several xenosiderophores are suggested by 55Fe-siderophore uptake studies. The PB precursor, 3,4-dihydroxybenzoic acid (3,4-DHB), and the photoproduct of FePB (FePBν) also mediate iron delivery into iron-deprived cells. Putative SBPs were recombinantly expressed, and their ligand specificity and binding affinity assessed using fluorescence spectroscopy. The noncovalent complexes of the SBPs with their respective siderophores were characterized using ESI-MS. The differences between solution phase behavior and gas phase measurements are indicative of noncovalent interactions between the siderophores and the binding sites of their respective SBPs. These studies combined with bioinformatics sequence comparison identify SBPs from five putative transporters specific for BB and enterobactin (FeuA), 3,4-DHB and PB (FatB), PB (FpuA), schizokinen (YfiY), and desferrioxamine and ferrichrome (YxeB). The two PB receptors show different substrate ranges: FatB has the highest affinity for ferric 3,4-DHB, iron-free PB, FePB, and FePBν, whereas FpuA is specific to only apo- and ferric PB. The biochemical characterization of these SBPs provides the first identification of the transporter candidates that most likely play a role in the B. cereus group pathogenicity. PMID:19254027

  11. Cost-effective-substrates for production of poly-β-hydroxybutyrate by a newly isolated Bacillus cereus PS-10.

    Science.gov (United States)

    Sharma, Priyanka; Bajaj, Bijender Kumar

    2015-11-01

    Poly-β-hydroxybutyrate (PHB) may serve as one of the imperative substitutes for petroleum derived plastics because of their close functional analogy and biodegradation quality. In the present study, PHB producing ability of bacterial isolates was examined on low-cost agro industrial residues. Isolate PS-10 from domestic waste landfills, identified as Bacillus cereus PS-10 produced and accumulated appreciable amount of PHB. Bacillus cereus PS-10 was capable of using a wide variety of agro-based residues viz. maize bran, rice husk, wood waste, molasses, whey etc. as cost-effective carbon sources for PHB production. Molasses at 3% (w/v) supported maximum PHB production (9.5 gl(-1)) and was followed by glycerol (8.9 gl(-1)) at 2% (w/v). Certain carbon sources like almond shell powder and walnut shell powder are being reported for the first time for PHB production and supported reasonable PHB yield i.e. 6.6 and 4.6 gl(-1), respectively. Different cost-effective nitrogen sources like corn steep liquor, chick pea bran, soy bean meal, mustard cake etc. were used for PHB production. Highest PHB production was observed at pH 7 (9.6 gl(-1)) after 48 hrs of fermentation, although B. cereus PS-10 grew and produced PHB over pH range of 5-9. Optimum inoculum level for maximum PHB production was found to be 5% v/v (A600 0.9; approximately 10(8) cfu ml(-1)). Fourier transform infrared spectroscopy (FT-IR) analysis of the extracted PHB showed characteristic peaks (1721.95, 1632.19 and 2926.43 cm(-1)) similar to standard PHB. Melting point of PHB was found to be 185°C. Bacillus cereus PS-10 may be a sound PHB producer, especially by exploiting low cost substrates. PMID:26688964

  12. Sensitivity of Hep G2 cells to Bacillus cereus emetic toxin.

    Science.gov (United States)

    Kamata, Yoichi; Kanno, Shinji; Mizutani, Noriko; Agata, Norio; Kawakami, Hiroshi; Sugiyama, Kei-ichi; Sugita-Konishi, Yoshiko

    2012-11-01

    We herein examined the sensitivity of Hep G2 human hepatoma cells to Bacillus cereus emetic toxin. Hep G2 cells were treated with the emetic toxin, and the cell shape was observed. The same experiments were performed for comparison purposes, using HEp-2 cells, which are currently used by most laboratories for a bioassay of the emetic toxin. Hep G2 cells showed clearer vacuolation in the cytosol within 2 hr and required a shorter incubation period than HEp-2 cells (10 hr). The number of vacuoles in the Hep G2 cells was greater, and the size of the vacuoles was larger than those observed in HEp-2 cells. The minimal concentration of the emetic toxin required to induce the vacuolation of Hep G2 cells was 0.04 ng/ml. The concentration for the HEp-2 cells was 1 ng/ml. These findings indicate that Hep G2 cells show higher sensitivity to the emetic toxin. Hep G2 cells may be superior to the currently used HEp-2 cells for the bioassay of the emetic toxin.

  13. 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. PMID:27020838

  14. Purification and Characterization of a Nonylphenol (NP)-degrading Enzyme from Bacillus cereus.Frankland

    Institute of Scientific and Technical Information of China (English)

    YANG Ge; ZHANG Ying; BAI Yanfen

    2011-01-01

    An extracellular NP-degrading enzyme secreted by Bacillus cereus.Frankland was purified to homogeneity by a combination of ammonium sulfate precipitation,Phenyl-Sepharose hydrophobic-interaction chromatography and DEAE anion-exchange chromatography.On SDS(sodium dodecyl sulfate)-polyacrylamide gel electrophoresis analysis,the purified enzyme showed a relative molecular mass of 58.3 kDa.The depolymerzation of subunits was accompanied with the loss of NP-degrading enzyme activity,and removing denaturing factors by dialysis could restore the dimer structure and enzymatic activity.The enzyme had an isoelectric point of 5.5 and an optimal temperature of 60℃,and was the most active at pH 6.0.The enzymatic activity was stable at pH 4-8 and inhibited by Cu2+.TenN-terminal amino acids were determined to be ASVNSIKIGY,demonstrating that the purified enzyme was a novel one.The hydrolysis pattern of the purified enzyme indicated that the NP-degrading enzyme was an endo NP-degrading enzyme.The extraordinary thermo-stability provided the enzyme with a good prospect to be used as a new tool for clean-production process for textile industry.

  15. Aislamiento e identificación de Bacillus cereus a partir de dos variantes de arroz comercial (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Irasema Pérez-Portuondo

    2011-01-01

    Full Text Available Bacillus cereus es una bacteria habitante común del suelo, de importancia tanto para la salud pública como para la Biotecnología. Con el objetivo de aislar ejemplares de esta bacteria para su utilización en estudios posteriores, así como de evaluar su permanencia en el arroz cocido, se desarrolló el protocolo propuesto por Kramer y cols. (1982. Con este fin, se tomaron muestras de arroz en grano con cáscara y de arroz cocido y se buscaron bacterias con propiedades hemolíticas y lecitinasa positiva. La identificación de los aislados se realizó mediante pruebas morfológicas y bioquímicas. Se obtuvieron 14 aislados, ocho de los cuales reunían las características distintivas de B. cereus, comparados con B. cereus ATCC 11778, incluida la resistencia a antibióticos. No se observó presencia de cuerpos parasporales típica de B. thuringiensis. Se comprobó que en el arroz cocido, transcurridas ocho horas de la cocción, pueden aislarse bacterias hemolíticas y lecitinasa positivas, en mayor número si este es conservado a temperatura ambiente, lo que convierte este alimento en potencialmente peligroso para su consumo. Estos resultados sugieren también la posibilidad de emplear al arroz como fuente para aislamiento de B. cereus.

  16. 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.

  17. 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

    Directory of Open Access Journals (Sweden)

    Ricardo J Anselmo

    2010-01-01

    Full Text Available 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 el pH. La población de células vegetativas de B. cereus se redujo a niveles no detectables en 14 días de almacenamiento y la de sus endosporas en 20 días de almacenamiento. Respecto a Cl. perfringens se redujo la población de células vegetativas y de endosporas a niveles no detectables en 14 y 18 días de almacenamiento, respectivamente. Los resultados confirman los efectos bactericidas de los cultivos iniciadores del kéfir.The bactericide effect of the kefir was studied on endospores and vegetative cells of Bacillus cereus and Clostridium perfringens inoculated in kefir during its storage. Samples of kefir of two different origins, one Italian and the other Peruvian were inoculated with a well-known population of B. cereus and Cl. perfringens (10(6 UFC/mL and conserved at 4ºC during 30 days. Every two days it was carried out a recount of lactic bacteria, of yeasts, of the pathogenic added and the pH was determined. The population of vegetative cells of B. cereus reduced to non detectable levels in 14 days of storage and of its endospores in 20 days of storage. Regarding Cl. perfringens the population of vegetative cells and its endospores reduced to non detectable levels in 14 and 18 days of storage, respectively. The results confirm the bactericide effects of the starter cultures of kefir.

  18. 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

  19. Cooperation and the evolutionary ecology of bacterial virulence: the Bacillus cereus group as a novel study system.

    Science.gov (United States)

    Raymond, Ben; Bonsall, Michael B

    2013-08-01

    How significant is social evolution theory for the maintenance of virulence in natural populations? We assume that secreted, distantly acting virulence factors are highly likely to be cooperative public goods. Using this assumption, we discuss and critically assess the potential importance of social interactions for understanding the evolution, diversity and distribution of virulence in the Bacillus cereus group, a novel study system for microbial social biology. We conclude that dynamic equilibria in Cry toxin production, as well as strong spatial structure and population bottlenecks in hosts are the main ecological factors maintaining the cooperative secretion of virulence factors and argue that collective action has contributed to the evolution of narrow host range. Non-linearities in the benefits associated with public goods, as well as the lack of private secretion systems in the Firmicutes may also explain the prevalence and importance of distantly acting virulence factors in B. cereus and its relatives.

  20. Purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3

    International Nuclear Information System (INIS)

    B. cereus arylamine N-acetyltransferase 3 was expressed, purified and crystallized. X-ray diffraction data were collected to 2.42 Å resolution and the crystals belonged to the monoclinic space group C121. Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes (XMEs) that catalyze the acetylation of arylamines. All functional NATs described to date possess a strictly conserved Cys-His-Asp catalytic triad. Here, the purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3], a putative NAT isoenzyme that possesses a unique catalytic triad containing a glutamate residue, is reported. The crystal diffracted to 2.42 Å resolution and belonged to the monoclinic space group C121, with unit-cell parameters a = 90.44, b = 44.52, c = 132.98 Å, β = 103.8°

  1. Gene detection and toxin production evaluation of hemolysin BL of Bacillus cereus isolated from milk and dairy products marketed in Brazil.

    Science.gov (United States)

    Reis, Andre L S; Montanhini, Maike T M; Bittencourt, Juliana V M; Destro, Maria T; Bersot, Luciano S

    2013-12-01

    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.

  2. 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.

  3. 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)

    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

  4. The Bacillus cereus Hbl and Nhe tripartite enterotoxin components assemble sequentially on the surface of target cells and are not interchangeable.

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    Inka Sastalla

    Full Text Available Bacillus cereus is a spore-forming, Gram-positive bacterium commonly associated with outbreaks of food poisoning. It is also known as an opportunistic pathogen causing clinical infections such as bacteremia, meningitis, pneumonia, and gas gangrene-like cutaneous infections, mostly in immunocompromised patients. B. cereus secretes a plethora of toxins of which four are associated with the symptoms of food poisoning. Two of these, the non-hemolytic enterotoxin Nhe and the hemolysin BL (Hbl toxin, are predicted to be structurally similar and are unique in that they require the combined action of three toxin proteins to induce cell lysis. Despite their dominant role in disease, the molecular mechanism of their toxic function is still poorly understood. We report here that B. cereus strain ATCC 10876 harbors not only genes encoding Nhe, but also two copies of the hbl genes. We identified Hbl as the major secreted toxin responsible for inducing rapid cell lysis both in cultured cells and in an intraperitoneal mouse toxicity model. Antibody neutralization and deletion of Hbl-encoding genes resulted in significant reductions of cytotoxic activity. Microscopy studies with Chinese Hamster Ovary cells furthermore showed that pore formation by both Hbl and Nhe occurs through a stepwise, sequential binding of toxin components to the cell surface and to each other. This begins with binding of Hbl-B or NheC to the eukaryotic membrane, and is followed by the recruitment of Hbl-L1 or NheB, respectively, followed by the corresponding third protein. Lastly, toxin component complementation studies indicate that although Hbl and Nhe can be expressed simultaneously and are predicted to be structurally similar, they are incompatible and cannot complement each other.

  5. Characterization of Pullulanase Type II from Bacillus cereus H1.5

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    Hii Siew Ling

    2009-01-01

    Full Text Available Problem statement: Pullulanase is one of the important enzymes in starch industry. Search for the pullulanase with distinct features, possibly from easily grown bacterium, is of interest for industrial applications Approach: The extracellular pullulanase produced by Bacillus cereus HI.5 was purified by chromatographic method of DEAE-Sepharose, followed by Superdex gel filtration. The enzyme was characterized in terms of the optimal pH and temperature for activity as well as substrate specificity. Results: The enzyme showed optimal activity at 55°C and pH 6.0. The thermostability and the thermoactivity of the enzyme were increased considerably in the presence of Ca2+. In the present of 2 mM Ca2+, the enzyme had half-life duration of more than 2 h at 50°C. Almost all metal ions had a strong inhibitory effect, except Ca2+ and Mn2+. The Ca2+ had a very strong stimulating effect on the enzyme, increasing its activity by 170%. The enzyme was activated by 2-mercaptoethanol and dithiothreitol, where as N-bromosuccinimide and Schardinger dextrins were inhibitors, suggesting that tryptophan and thiol residues may be important for the activity. The apparent Km and Vmax value for pullulan was 1.1 mg mL-1 and 0.275 µmol min-1, respectively. A relative substrate specificity for hydrolysis of pullulan, amylopectin and soluble starch by this pullulanase was 100, 28.5 and 20.4%, respectively. Conclusion: The enzyme was able to attack specifically the α-1,6 linkages in pullulan to generate maltotriose as the major end product, as well as the α-1,4 linkages in amylopectin and soluble starch leading to the formation of a mixture of maltose and glucose and therefore be classified as a type II pullulanase or an amylopullulanase.

  6. Reconstitution of Bacillus cereus 5/B/6 metallo-[beta]-lactamase activity with copper

    Energy Technology Data Exchange (ETDEWEB)

    Hilliard, N.P.; Shaw, R.W. (Texas Tech Univ., Lubbock (United States))

    1992-01-01

    Pathogenic bacteria become resistant to [beta]-lactam antibiotics such as penicillins and cephalosporins through the production of enzymes called [beta]-lactamases. The authors have successfully reconstituted the enzymatic activity of the metallo-[beta]-lactamase of Bacillus cereus 5/B/6 purified from an E. coli expression vector system by the addition of Cu(II) to the apoenzyme. This is the first report that copper supports catalytic activity in this enzyme. Maximal activity of the copper-reconstituted enzyme was achieved by a careful addition of a stoichiometric amount of CuSO[sub 4] to 200 [mu]M apoenzyme. Using either benzylpenicillin or cephalosporin C as the substrate, reconstitution of the activity by addition of copper to the apoenzyme resulted in the recovery of approximately 35% of the control activity of the native Zn(II) enzyme. In agreement with previous reports, in the presence of excess Cu(II), the preparation did not possess measurable catalytic activity. Electronic spectra of the copper-reconstituted enzyme displayed adsorption maxima at 394, 698 and 1,022 nm with extinction coefficients of 2,656, 55 and < 3 M[sup [minus]1]cm[sup [minus]1] respectively. Circular dichorism spectra in the ultraviolent region (UVCD) of the copper-reconstituted enzyme were identical with those of the native Zn(II) enzyme. Addition of excess cephalosporin C to the copper-reconstituted enzyme caused a decrease of about 50% of the absorbance of the 394 nm band and the formation of a new feature at 350 nm.

  7. 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

  8. 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

  9. 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. PMID:26306797

  10. 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.

  11. 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.

  12. The survival and growth of Bacillus cereus in boiled and fried rice in relation to outbreaks of food poisoning.

    Science.gov (United States)

    Gilbert, R J; Stringer, M F; Peace, T C

    1974-12-01

    A number of outbreaks of food poisoning attributed to Bacillus cereus have been reported recently and all have been associated with cooked rice usually from Chinese restaurants and ;take-away' shops.Tests were made to assess the heat resistance of B. cereus spores in aqueous suspension, the growth of the organism in boiled rice stored at temperatures in the range 4-55 degrees C., and the effect of cooking and storage on the growth of the organism in boiled and fried rice. The spores of B. cereus survived cooking and were capable of germination and outgrowth. The optimum temperature for growth in boiled rice was between 30 degrees and 37 degrees C. and growth also occurred during storage at 15 degrees and 43 degrees C.To prevent further outbreaks it is suggested that rice should be boiled in smaller quantities on several occasions during the day, thereby reducing the storage time before frying. After boiling the rice should either be kept hot (> 63 degrees C.) or cooled quickly and transferred to a refrigerator within 2 hr. of cooking. Boiled or fried rice must not be stored under warm conditions especially in the range 15-50 degrees C. PMID:4216605

  13. Purification of a thermostable chitinase from Bacillus cereus by chitin affinity and its application in microbial community changes in soil.

    Science.gov (United States)

    Liang, Tzu-Wen; Hsieh, Tung-Yen; Wang, San-Lang

    2014-06-01

    A thermostable chitinase was purified by chitin affinity from the culture supernatant of Bacillus cereus TKU028 with shrimp head powder (SHP) as the sole carbon/nitrogen source. TKU028 chitinase was purified using a one-step affinity adsorbent system, and the molecular mass of TKU028 chitinase (approximately 40 kDa) was then determined using SDS-PAGE. The enzyme was stable for 60 min at temperatures below 60 °C and stable over a broad pH range of 4-9 for 60 min. In addition, the temporal changes of a bacterial community in mangrove river sediment of the Tamsui River with added SHP were also analysed by PCR-denaturing gradient gel electrophoresis to investigate the effects of B. cereus TKU028 on the degradation of SHP. The 6-week incubation sample of SHP and B. cereus TKU028-amended mangrove river sediment displayed the highest amount of biomass, reducing sugar and total sugar, and some variance of bacterial community composition existed in the soils. PMID:24342954

  14. Physical chemical and biological characterization of a new bacteriocin produced byBacillus cereusNS02

    Institute of Scientific and Technical Information of China (English)

    Senbagam D; Gurusamy R; Senthilkumar B

    2013-01-01

    Objective:To screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical, chemical and biological aspects for the application in biopreservation.Methods:Bacillus cereus(B. cereus) was isolated and assessed for its baceteriocinogenic activity. Bacteriocin was produced and purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography.Purified bacteriocin was used to check its antimicrobial activity against food borne bacteria.Effect and stability of bacteriocin was determined with the respect to temperature, pH, enzymes, organic solvents and chemicals.Bacteriocin was also subjected toSDSPAGE analysis to determine its molecular weight.In addition, functional groups exist in the bacteriocin was determined byFTIR analysis.Results:B. cereus was identified by16S rRNA sequence analysis.Bacteriocin showed increased activity against all the bacteria used and its activity unit was found to be51,200AU/mL.It was stable to high temperature(100 ℃) and wide range of pH(3-10), sensitive to proteolytic enzymes and resistant to nonproteolytic enzymes.It was low molecular weight(3.5 -6KDa) protein andFTIR study revealed the presence of amide group andNH stretching.Conclusions:Bacteriocin produced in this study possesses the highest antimicrobial activity against both gram positive and gram negative bacteria thereby it has immense application as biopreservative agent.FTIR proved its peptide nature.

  15. Distinct roles of ComK1 and ComK2 in gene regulation in Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Aleksandra M Mirończuk

    Full Text Available The B. subtilis transcriptional factor ComK regulates a set of genes coding for DNA uptake from the environment and for its integration into the genome. In previous work we showed that Bacillus cereus expressing the B. subtilis ComK protein is able to take up DNA and integrate it into its own genome. To extend our knowledge on the effect of B. subtilis ComK overexpression in B. cereus we first determined which genes are significantly altered. Transcriptome analysis showed that only part of the competence gene cluster is significantly upregulated. Two ComK homologues can be identified in B. cereus that differ in their respective homologies to other ComK proteins. ComK1 is most similar, while ComK2 lacks the C-terminal region previously shown to be important for transcription activation by B. subtilis ComK. comK1 and comK2 overexpression and deletion studies using transcriptomics techniques showed that ComK1 enhances and ComK2 decreases expression of the comG operon, when B. subtilis ComK was overexpressed simultaneously.

  16. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

    Science.gov (United States)

    Kumar, Sasidharan Nishanth; Sreekala, Sreerag Ravikumar; Chandrasekaran, Dileep; Nambisan, Bala; Anto, Ruby John

    2014-01-01

    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.

  17. Isolation and characterization of glacier VMY22, a novel lytic cold-active bacteriophage of Bacillus cereus

    Institute of Scientific and Technical Information of China (English)

    Xiuling; Ji; Chunjing; Zhang; Yuan; Fang; Qi; Zhang; Lianbing; Lin; Bing; Tang; Yunlin; Wei

    2015-01-01

    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 p H 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.

  18. Structure of the NheA component of the Nhe toxin from Bacillus cereus: implications for function.

    Science.gov (United States)

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

    2013-01-01

    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.

  19. 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.

  20. 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.......1%) isolates did not contain any of the tested genes. All tet(M) positive isolates carried transposon Tn916 and could transfer this mobile DNA element to other Gram-positive bacteria....... (12 isolates) samples. These isolates were screened for tetracycline resistance genes (tet(K), tet(L), tet(M), tet(O), tet(S) and tet(T)). Of 88 isolates examined, three (3.4%) isolates carried both tet(M) and tet(L) genes, while four (4.5%) isolates carried the tet(L) gene. Eighty-one (92...

  1. 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

    from animals receiving vegetative cells, only few B. cereus cells were detected. Spores survived the gastric barrier well, and were in some cases detected up to 2 weeks after ingestion. Selective growing revealed no major changes in the intestinal flora during passage of B. cereus. However, denaturing......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....

  2. 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 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 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.

  3. Influence of sporulation medium composition on transcription of ger operons and the germination response of spores of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

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

    2006-01-01

    Bacillus cereus ATCC 14579 endospores were produced in Y1 medium, a nutrient-rich, chemically defined sporulation medium, and in modified G medium, containing low amounts of nutrients. The average transcription level of the seven ger operons per cell was 3.5 times higher in Y1 medium, and the spores

  4. Draft Genome Sequence of Bacillus cereus LCR12, a Plant Growth-Promoting Rhizobacterium Isolated from a Heavy Metal-Contaminated Environment.

    Science.gov (United States)

    Egidi, Eleonora; Wood, Jennifer L; Mathews, Elizabeth; Fox, Edward; Liu, Wuxing; Franks, Ashley E

    2016-01-01

    Bacillus cereus LCR12 is a plant growth-promoting rhizobacterium, isolated from a heavy metal-contaminated environment. The 6.01-Mb annotated genome sequence provides the genetic basis for revealing its potential application to remediate contaminated soils in association with plants. PMID:27688340

  5. 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...

  6. Bacillus cereus ATCC 14579 RpoN (Sigma 54) is a Pleiotropic Regulator of Growth, Carbohydrate, Metabolism, Motility, Biofilm Formation and Toxin Production

    NARCIS (Netherlands)

    Hayrapetyan, H.; Tempelaars, M.H.; Nierop Groot, M.N.; Abee, T.

    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. c

  7. Draft Genome Sequence of Bacillus cereus LCR12, a Plant Growth–Promoting Rhizobacterium Isolated from a Heavy Metal–Contaminated Environment

    Science.gov (United States)

    Egidi, Eleonora; Wood, Jennifer L.; Mathews, Elizabeth; Fox, Edward; Liu, Wuxing

    2016-01-01

    Bacillus cereus LCR12 is a plant growth–promoting rhizobacterium, isolated from a heavy metal–contaminated environment. The 6.01-Mb annotated genome sequence provides the genetic basis for revealing its potential application to remediate contaminated soils in association with plants. PMID:27688340

  8. Produção de material de referência para ensaio de proficiência de enumeração de Bacillus cereus em leite / Preparation of reference material for proficiency test for enumeration of Bacillus cereus in milk

    Directory of Open Access Journals (Sweden)

    Marcelo Luiz Lima Brandão

    2014-02-01

    Full Text Available A participação em ensaios de proficiência é essencial para que um laboratório de ensaio possa ter seu desempenho avaliado por meio de uma comparação interlaboratorial. O objetivo deste trabalho foi produzir um material de referência (MR quantitativo para EP contendo Bacillus cereus em leite em pó. Uma solução estéril de leite desnatado a 10% contendo 100 mM de sacarose foi contaminada com uma cepa de B. cereus em uma concentração previamente determinada. A matriz foi homogeneizada, distribuída em frascos e liofilizada. O lote produzido foi considerado suficientemente homogêneo atribuindo-se um desvio-padrão alvo de 0,25 log10 UFC/mL. O MR apresentou-se estável a ≤ -70 ºC e (-20 ± 4 ºC durante 1.058 e 60 dias, respectivamente. Na avaliação da influência de diferentes temperaturas para o transporte deste material, o MR se apresentou estável a 4 ºC, 25 ºC e 35 ºC durante o período de quatro dias de estudo. Conclui-se que o lote produzido apresentou todos os requisitos necessários para ser utilizado como itens de EP. ---------------------------------------------------------------------- The participation in proficiency testing (PT is essential for testing laboratories to prove their technical competence. The aim of this study was to produce a quantitative reference material (RM for PT containing Bacillus cereus in milk powder. A sterile solution of 10% skim milk containing 100 mM sucrose was contaminated with a B. cereus strain in a specific concentration. The homogenized matrix was distributed into vials and freeze- -drying. The batch produced was considered sufficiently homogeneous assigning a target standard deviation of 0.25. The RM was stable at ≤ -70 ºC and (-20 ± 4 ºC for 1,058 and 60 days, respectively. In the evaluation of temperatures for the transport of material, the RM was stable at 4, 25 and 35 ºC during four days. It is concluded that the batch produced had all the necessary requirements to be

  9. Crystal structures of two transcriptional regulators from Bacillus cereus define the conserved structural features of a PadR subfamily.

    Directory of Open Access Journals (Sweden)

    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.

  10. The self-assembly of a cyclic lipopeptides mixture secreted by a B. megaterium strain and its implications on activity against a sensitive Bacillus species.

    Directory of Open Access Journals (Sweden)

    Manuel T Pueyo

    Full Text Available Cyclic lipopeptides are produced by a soil Bacillus megaterium strain and several other Bacillus species. In this work, they are detected both in the Bacillus intact cells and the cells culture medium by MALDI-TOF mass spectrometry. The cyclic lipopeptides self-assemble in water media producing negatively charged and large aggregates (300-800 nm of mean hydrodynamic radius as evaluated by dynamic light scattering and zeta-potential analysis. The aggregate size depends on pH and ionic strength. However, it is not affected by changes in the osmolarity of the outer medium suggesting the absence of an internal aqueous compartment despite the occurrence of low molecular weight phospholipids in their composition as determined from inorganic phosphorus analysis. The activity against a sensitive Bacillus cereus strain was evaluated from inhibition halos and B. cereus lysis. Essential features determining the antibiotic activity on susceptible Bacillus cereus cells are the preserved cyclic moiety conferring cyclic lipopeptides resistance to proteases and the medium pH. The aggregates are inactive per se at the pH of the culture medium which is around 6 or below. The knock out of the sensitive cells only takes place when the aggregates are disassembled due to a high negative charge at pH above 6.

  11. 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.

  12. Trypan blue dye enters viable cells incubated with the pore-forming toxin HlyII of Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Seav-Ly Tran

    Full Text Available Trypan blue is a dye that has been widely used for selective staining of dead tissues or cells. Here, we show that the pore-forming toxin HlyII of Bacillus cereus allows trypan blue staining of macrophage cells, despite the cells remaining viable and metabolically active. These findings suggest that the dye enters viable cells through the pores. To our knowledge, this is the first demonstration that trypan blue may enter viable cells. Consequently, the use of trypan blue staining as a marker of vital status should be interpreted with caution. The blue coloration does not necessarily indicate cell lysis, but may rather indicate pore formation in the cell membranes and more generally increased membrane permeability.

  13. Induction of systemic resistance in tomato by the autochthonous phylloplane resident Bacillus cereus Indução de resistência sistêmica em tomateiro pela bactéria autóctone residente no filoplano Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Bernardo de Almeida Halfeld-Vieira

    2006-08-01

    Full Text Available The objective of this work was to verify if the induced resistance mechanism is responsible for the capacity of a phylloplane resident bacteria (Bacillus cereus, isolated from healthy tomato plants, to control several diseases of this crop. A strain of Pseudomonas syringae pv. tomato was used as the challenging pathogen. The absence of direct antibiosis of the antagonist against the pathogen, the significant increase in peroxidases activity in tomato plants exposed to the antagonist and then inoculated with the challenging pathogen, as well as the character of the protection, are evidences wich suggest that biocontrol efficiency presented by the antagonist in previous works might be due to induced systemic resistance (ISR.O objetivo deste trabalho foi investigar se o mecanismo de indução de resistência é responsável pela capacidade de um isolado bacteriano residente no filoplano (Bacillus cereus, obtido de plantas sadias de tomateiro, em controlar diversas doenças da cultura. A fim de investigar o modo de ação envolvido no controle, foi utilizado um isolado de Pseudomonas syringae pv. tomato como patógeno desafiador. A ausência do mecanismo de antibiose contra o patógeno, o aumento significativo dos níveis de peroxidases em plantas expostas ao antagonista e submetidas à inoculação do patógeno desafiador, assim como a sistemicidade da proteção, são evidências que sugerem que o mecanismo de biocontrole em questão se refere à indução de resistência sistêmica (IRS.

  14. 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.

  15. Process parameters for decolorization and biodegradation of orange II (Acid Orange 7) in dye-simulated minimal salt medium and subsequent textile effluent treatment by Bacillus cereus (MTCC 9777) RMLAU1.

    Science.gov (United States)

    Garg, Satyendra Kumar; Tripathi, Manikant

    2013-11-01

    In this study, Bacillus cereus isolate from tannery effluent was employed for orange II dye decolorization in simulated minimal salt broth and textile effluent. Most of the physicochemical parameters of textile effluent were above the permissible limits. The strain was highly tolerant to dye up to 500 mg l(-1). Increasing dye concentration exerted inhibitory effect on the bacterial growth and decolorization. The maximum decolorization of initial 100 mg dye l(-1) was achieved at optimum pH 8.0 and 33 °C under static culture conditions during 96-h incubation. Supplementation with optimized glucose (0.4%, w/v) and ammonium sulfate (0.1%, w/v) with 3.0% B. cereus inoculum further enhanced dye decolorization to highest 68.5% within 96-h incubation. A direct correlation was evident between bacterial growth and dye decolorization. Under above optimized conditions, 24.3% decolorization of unsterilized real textile effluent by native microflora was achieved. The effluent decolorization enhanced substantially to 37.1% with B. cereus augmentation and to 40.5% when supplemented with glucose and ammonium sulfate without augmentation. The maximum decolorization of 52.5% occurred when textile effluent was supplemented with optimized exogenous carbon and nitrogen sources along with B. cereus augmentation. Gas chromatography-mass spectrometry identified sulfanilic acid as orange II degradation product. Fourier transform infra red spectroscopy of metabolic products indicated the presence of amino and hydroxyl functional groups. This strain may be suitably employed for in situ decolorization of textile industrial effluent under broad environmental conditions.

  16. LmbE proteins from Bacillus cereus are de-N-acetylases with broad substrate specificity and are highly similar to proteins in Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Deli, Alexandra; Koutsioulis, Dimitrios; Fadouloglou, Vasiliki E.; Spiliotopoulou, Panagiota; Balomenou, Stavroula; Arnaouteli, Sofia; Tzanodaskalaki, Maria; Mavromatis, Konstantinos; Kokkinidis, Michalis; Bouriotis, Vassilis

    2010-05-19

    The genomes of Bacillus cereus and its closest relative Bacillus anthracis each contain two LmbE protein family homologs: BC1534 (BA1557) and BC3461 (BA3524). Only a few members of this family have been biochemically characterized including N-acetylglucosaminylphosphatidyl inositol (GlcNAc-PI), 1-D-myo-inosityl-2-acetamido-2-deoxy-α-D-glucopyranoside (GlcNAc-Ins), N,N'-diacetylchitobiose (GlcNAc2) and lipoglycopeptide antibiotic de-N-acetylases. All these enzymes share a common feature in that they de-N-acetylate the N-acetyl-D-glucosamine (GlcNAc) moiety of their substrates. The bc1534 gene has previously been cloned and expressed in Escherichia coli. The recombinant enzyme was purified and its 3D structure determined. In this study, the bc3461 gene from B. cereus ATCC14579 was cloned and expressed in E. coli. The recombinant enzymes BC1534 (EC 3.5.1.-) and BC3461 were biochemically characterized. The enzymes have different molecular masses, pH and temperature optima and broad substrate specificity, de-N-acetylating GlcNAc and N-acetylchito-oligomers (GlcNAc2, GlcNAc3 and GlcNAc4), as well as GlcNAc-1P, N-acetyl-d-glucosamine-1 phosphate; GlcNAc-6P, N-acetyl-d-glucosamine-6 phosphate; GalNAc, N-acetyl-d-galactosamine; ManNAc, N-acetyl-d-mannosamine; UDP-GlcNAc, uridine 5'-diphosphate N-acetyl-d-glucosamine. However, the enzymes were not active on radiolabeled glycol chitin, peptidoglycan from B. cereus, N-acetyl-d-glucosaminyl-(β-1,4)-N-acetylmuramyl-l-alanyl-d-isoglutamine (GMDP) or N-acetyl-d-GlcN-Nα1-6-d-myo-inositol-1-HPO4-octadecyl (GlcNAc-I-P-C18). Kinetic analysis of the activity of BC1534 and BC3461 on GlcNAc and GlcNAc2 revealed that GlcNAc2 is the favored substrate for both native enzymes. Based on the recently determined crystal structure of BC1534, a mutational analysis identified functional key residues, highlighting

  17. 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 alkaline phosphatase (AKP) activity of coelomocytes in sea cucumbers fed diets with probiotics supplementation was significantly higher than the control group (P < 0.05). Comparatively, superoxide dismutase (SOD) activity of coelomocytes for sea cucumber in the PM group was significantly greater (P < 0.05). As for the immune-related genes, B. cereus G19 supplementation significantly increased the expression level of the Aj-rel gene in coelomocytes (P < 0.05), while B. cereus BC-01 supplementation significantly increased that of the Aj-p50 gene as compared to the control group (P < 0.05). In the intestine, the relative expression level of Aj-p105, Aj-p50, and Aj-lys genes in the PM group was significantly higher than that in the control group (P < 0.05). These results suggested that B. cereus G19 and B. cereus BC-01 supplementation could improve the growth performance and the immune response in coelomocytes, while P. marcusii DB11 supplementation could have a positive effect on the growth performance and immune response in coelomocytes and the intestine of sea cucumbers. PMID:26052012

  18. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels.

    Science.gov (United States)

    Lücking, Genia; Frenzel, Elrike; Rütschle, Andrea; Marxen, Sandra; Stark, Timo D; Hofmann, Thomas; Scherer, Siegfried; Ehling-Schulz, Monika

    2015-01-01

    The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like megaplasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the non-ribosomal 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.

  19. Prevalence and levels of Bacillus cereus emetic toxin in rice dishes randomly collected from restaurants and comparison with the levels measured in a recent foodborne outbreak.

    Science.gov (United States)

    Delbrassinne, Laurence; Andjelkovic, Mirjana; Dierick, Katelijne; Denayer, Sarah; Mahillon, Jacques; Van Loco, Joris

    2012-09-01

    Whereas the prevalence of Bacillus cereus emetic strains in the environment has been shown to be very low, there is a lack of information on the prevalence of its toxin, cereulide, in food. Yet, the rice leftovers of a family outbreak which occurred after the consumption of dishes taken away from an Asian restaurant revealed significant amounts of cereulide, reaching up to 13,200 ng/g of food. The occurrence of cereulide in rice dishes collected from various restaurants was therefore evaluated using the liquid chromatography coupled with tandem mass spectrometry method, which allows for the direct quantification of the toxin in food. The cereulide prevalence was found to be 7.4% when samples were analyzed at the day of sampling, but reached 12.9% when exposed to temperature abuse conditions (25°C). The cereulide concentrations observed in cooked rice dishes were low (approximately 4 ng/g of food). However, since little is known yet about the potential chronic toxicity of cereulide, one needs to be very careful and vigilant.

  20. 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.

  1. Simultaneous Detection of Listeria monocytogenes, Escherichia coli O157:H7, Bacillus cereus, Salmonella spp., and Staphylococcus aureus in Low-fatted Milk by Multiplex PCR

    Science.gov (United States)

    Kim, Ji-Hyun; Rhim, Seong-Ryul; Kim, Kee-Tae; Paik, Hyun-Dong

    2014-01-01

    A rapid and specific PCR assay for the simultaneous detection of Listeria monocytogenes, Escherichia coli O157:H7, Bacillus cereus, Salmonella spp., and Staphylococcus aureus in foods was developed to reduce the detection time and to increase sensitivity. Multiplex PCR developed in this study produced only actA, fliC, hbl, invA, ileS amplicons, but did not produce any non-specific amplicon. The primer sets successfully amplified the target genes in the multiplex PCR without any non-specific or additional bands on the other strains. The multiplex PCR assays also amplified some target genes from five pathogens, and multiplex amplification was obtained from as little as 1 pg of DNA. According to the results from the sensitivity evaluation, the multiplex PCR developed in this study detected 10 cells/mL of the pathogens inoculated in milk samples, respectively. The results suggested that multiplex PCR was an effective assay demonstrating high specificity for the simultaneous detection of five target pathogens in food system. PMID:26761507

  2. Characterization of the extracellular biodemulsifiers secreted by Bacillus cereus LH-6 and the enhancement of demulsifying efficiency by optimizing the cultivation conditions.

    Science.gov (United States)

    Hou, Ning; Feng, Fengzhao; Shi, Yan; Cao, Huiming; Li, Chunyan; Cao, Zhi; Cheng, Yi

    2014-09-01

    A highly efficient demulsifying strain, LH-6, was isolated from petroleum-contaminated soil and identified as Bacillus cereus by 16S rDNA gene analysis. It achieved 95.61 and 95.40 % demulsifying ratios within 12 h for water-in-oil (W/O) and oil-in-water (O/W) model emulsions, respectively. Fourier transform infrared spectroscopy (FT-IR) and thin-layer chromatography (TLC) detections indicated that the LH-6's extracellular biodemulsifiers were different types of lipopeptides for the W/O and O/W emulsions. Optimization of the culture medium composition was conducted to improve the biosynthesis and demulsifying efficiency of the biodemulsifier. The optimal carbon source was liquid paraffin, while waste frying oil could also be an alternative carbon source. The optimal nitrogen sources were ammonium sulfate and yeast extract. To further enhance the biodemulsifier efficiency, the optimal cultivation conditions were determined using response surface methodology (RSM) based on central composite rotation design (CCRD). Using the optimized cultivation conditions, the demulsifying ratios increased to 98.23 and 97.65 % for the W/O and O/W model emulsions, respectively. PMID:24777330

  3. Ces locus embedded proteins control the non-ribosomal synthesis of the cereulide toxin in emetic Bacillus cereus on multiple levels

    Science.gov (United States)

    Lücking, Genia; Frenzel, Elrike; Rütschle, Andrea; Marxen, Sandra; Stark, Timo D.; Hofmann, Thomas; Scherer, Siegfried; Ehling-Schulz, Monika

    2015-01-01

    The emetic toxin cereulide produced by Bacillus cereus is synthesized by the modular enzyme complex Ces that is encoded on a pXO1-like megaplasmid. To decipher the role of the genes adjacent to the structural genes cesA/cesB, coding for the non-ribosomal 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. PMID:26528255

  4. 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

  5. Possible Use of Bacteriophages Active against Bacillus anthracis and Other B. cereus Group Members in the Face of a Bioterrorism Threat

    Directory of Open Access Journals (Sweden)

    Ewa Jończyk-Matysiak

    2014-01-01

    Full Text Available 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.

  6. 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)

    Jończyk-Matysiak, Ewa; Kłak, Marlena; 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.

  7. Identification of a new Bacillus licheniformis strain producing a bacteriocin-like substance.

    Science.gov (United States)

    Guo, Yaoqi; Yu, Zhanqiao; Xie, Jianhua; Zhang, Rijun

    2012-06-01

    The emergence of antibiotic resistance has spurred a great number of studies for development of new antimicrobials in the past decade. The purpose of this study was to screen environmental samples for Bacillus strains producing potent antimicrobial agents. A new strain, which showed strong antimicrobial activity against Staphylococcus aureus and Salmonella enterica ser. Pullorum, was isolated from soil and designated as B116. This new isolate was identified as Bacillus licheniformis by morphological, biochemical and genetic analyses. The production of bacteriocin-like substance (BLS) started at early exponential phase and achieved highest level at early stationary phase. The BLS was precipitated by ammonium sulfate and its molecular mass was determined as ∼4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Culture supernatant of the new isolate exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria, including Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Micrococcus luteus, Escherichia coli, and Salmonella spp. The BLS was resistant to heat, acid and alkaline treatment. Activity of the BLS was totally lost after digestion by pronase and partially lost after digestion by papain and lipase. The new isolate and relevant BLS are potentially useful in food and feed applications. PMID:22752909

  8. NIH 3T3 cells stably transfected with the gene encoding phosphatidylcholine-hydrolyzing phospholipase C from Bacillus cereus acquire a transformed phenotype.

    OpenAIRE

    Johansen, T.; Bjørkøy, G; Overvatn, A; Diaz-Meco, M T; Traavik, T; Moscat, J

    1994-01-01

    In order to determine whether chronic elevation of intracellular diacylglycerol levels generated by hydrolysis of phosphatidylcholine (PC) by PC-hydrolyzing phospholipase C (PC-PLC) is oncogenic, we generated stable transfectants of NIH 3T3 cells expressing the gene encoding PC-PLC from Bacillus cereus. We found that constitutive expression of this gene (plc) led to transformation of NIH 3T3 cells as evidenced by anchorage-independent growth in soft agar, formation of transformed foci in tiss...

  9. Application of sonication to release DNA from Bacillus cereus for quantitative detection by real-time PCR.

    Science.gov (United States)

    Fykse, Else Marie; Olsen, Jaran Strand; Skogan, Gunnar

    2003-10-01

    A rapid sonication method for lysis of Gram-positive bacteria was evaluated for use in combination with quantitative real-time polymerase chain reaction (PCR) analyses for detection. Other criteria used for evaluation of lysis were microscopic cell count, colony forming units (cfu), optical density at 600 nm and total yield of DNA measured by PicoGreen fluorescence. The aim of this study was complete disruption of cellular structures and release of DNA without the need for lysing reagents and time-consuming sample preparation. The Gram-positive bacterium Bacillus cereus was used as a model organism for Gram-positive bacteria. It was demonstrated by real-time PCR that maximum yield of DNA was obtained after 3 to 5 min of sonication. The yield of DNA was affected by culture age and the cells from a 4-h-old culture in the exponential phase of growth gave a higher yield of DNA after 5 min of sonication than a 24-h-old culture in the stationary phase of growth. The 4-h-old culture was also more sensitive for lysis caused by heating. The maximum yield of DNA, evaluated by real-time PCR, from a culture of the Gram-negative bacterium Escherichia coli, was obtained after 20 s of sonication. However, the yield of target DNA from E. coli rapidly decreased after 50 s of sonication due to degradation of DNA. Plate counting (cfu), microscopic counting and absorbance at 600 nm showed that the number of viable and structurally intact B. cereus cells decreased rapidly with sonication time, whereas the yield of DNA increased as shown by PicoGreen fluorescence and real-time PCR. The present results indicate that 3-5 min of sonication is sufficient for lysis and release of DNA from samples of Gram-positive bacteria.

  10. 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. PMID:27486443

  11. Genome Sequence of Bacillus thuringiensis subsp. kurstaki Strain HD-1

    OpenAIRE

    Day, Michael; Ibrahim, Mohamed; Dyer, David; Bulla, Lee

    2014-01-01

    We report here the complete genome sequence of Bacillus thuringiensis subsp. kurstaki strain HD-1, which serves as the primary U.S. reference standard for all commercial insecticidal formulations of B. thuringiensis manufactured around the world.

  12. Protein engineering of cyclodextrin glycosyltransferase from Bacillus circulans strain 251

    NARCIS (Netherlands)

    Penninga, Dirk

    1996-01-01

    An enormous diversity of molecular functions in living organisms is carried out by proteins. Our studies have focussed on the functional analysis of a starch-converting enzyme, cyclodextrin glycosyltransferase (CGTase) from Bacillus circulans strain 251. Zie: Summary

  13. Prevalence of Bacillus cereus and associated risk factors in Chinese-style fried rice available in the city of Colombo, Sri Lanka.

    Science.gov (United States)

    Perera, Manosha Lakmali; Ranasinghe, Gerard Ranjan

    2012-02-01

    The present study aimed to assess the prevalence of Bacillus cereus and its associated risk factors in Chinese-style fried rice available in Colombo city. In 200 samples of fried rice the prevalence of B. cereus was 56%. The prevalence by variety of fried rice was chicken (20.0%), vegetable (18.0%), seafood (10.0%), egg (5.0%), mixed (2.0%), and beef (1.0%). Of analyzed samples, 28 (14%) had colony counts >10(6) colony forming units per gram (cfu/g), the infectious dose for B. cereus food borne outbreaks. Occurrence of >10(6) cfu/g of B. cereus were associated with storage of boiled rice at room temperature (p=0.030), >4 hours of storage at room temperature (p=0.042) and cooking frequency of more than once per dining session (p=0.017). The type of rice and the quantity boiled per day were not independent risk factors for high B. cereus counts. Majority of B. cereus isolates (53.7%) in this study were not typable. The serotypes observed included H15 (14.3%), H19 (14.3%), and H20 (10.7%). These serotypes are known to be associated with both emetic and diarrheal syndromes. All isolates were sensitive to ciprofloxacin (100%), erythromycin (100%), gentamicin (100%), chloramphenicol (100%), and amikacin (100%) whereas 100% resistance was observed for penicillin with minimal inhibitory concentration range of 32-256 μg/mL. PMID:22085218

  14. Optimization of Pulsed-field Gel Electrophoresis Procedure for Bacillus cereus.

    Science.gov (United States)

    Zhang, Hui Juan; Pan, Zhuo; Wei, Jian Chun; Zhang, En Min; Cai, Hong; Liang, Xu Dong; Li, Wei

    2016-03-01

    In order to develop a rapid and reliable method for B. cereus genotyping, factors influencing PFGE results, including preparation of bacterial cells embedded in agarose, lysis of embedded cells, enzymatic digestion of intact genomic DNA, and electrophoresis parameters allowing for reproducible and meaningful DNA fragment separation, were controlled. Optimal cellular growth (Luria-Bertani agar plates for 12-18 h) and lysis conditions (4 h incubation with 500 µg/mL lysozyme) produced sharp bands on the gel. Restriction enzyme NotI was chosen as the most suitable. Twenty-two isolates were analyzed by NotI digestion, using three electrophoretic parameters (EPs). The EP-a was optimal for distinguishing between isolates. The optimized protocol could be completed within 40 h which is a significant improvement over the previous methods. PMID:27109136

  15. Production of poly-β-hydroxybutyrate by Bacillus cereus PS 10 using biphasic-acid-pretreated rice straw.

    Science.gov (United States)

    Sharma, Priyanka; Bajaj, Bijender Kumar

    2015-08-01

    Poly-β-hydroxybutyrate (PHB) has attracted a great deal of attention in recent years due to its potential use for production of fully degradable bioplastics, however, high cost of PHB production is the major bottleneck for its wide range industrial applications. In the current study rice straw hydrolysate (RSH) was employed as a cost-effective substrate for PHB production. RSH was prepared based on biphasic acid-pretreatment of rice straw i.e. first phase treatment with 1% sulphuric acid at 121 °C for 45 min, followed by second phase treatment using 5% sulphuric acid at 121 °C for 60 min (solid:liquid ratio, 1:10). RSH turned out be an efficient substrate for PHB production from a recently isolated Bacillus cereus PS 10, and yielded higher PHB amount than that obtained with glucose (8.6g/L in glucose based medium vs 10.61 g/L in RSH based medium) after response surface methodology (RSM) based optimization. Design of experiments based on RSM was used to optimize three process variables i.e. amount of RSH and NH4Cl, and medium pH, and enhanced PHB yield (23.3%) was obtained. PHB produced was investigated by differential scanning calorimetry and X-ray diffraction powder analysis. PMID:26047898

  16. Effects of Dissolved Oxygen Tension and Ammonium Concentration on Polyhydroxybutyrate Synthesis from Cassava Starch by Bacillus cereus IFO 13690

    Directory of Open Access Journals (Sweden)

    Margono .

    2015-11-01

    Full Text Available generated by an Adobe application 11.5606 Attempting to get low price of raw material for producing polyhydroxybutyrate is always studied. Tapioca starch is one of the raw material with low price. The objective of this research was to study the effects of initial ammonium concentration and dissolved oxygen tension (doT on producing PHB by Bacillus cereus IFO 13690 with tapioca starch as the carbon source. This fermentation was carried out in 5 L fementors with a 2 L working volume, temperature of 30 oC, and agitation of 500 rpm. The pH medium was controlled at 5.6 after it came down from the initial pH of 6.8. Meanwhile, the initial doT was 100 % air saturation and also came down to and maintained at doT of experiment, i.e. 1 , 5 , or 10 % air saturation. The best result was obtained when the initial ammonium concentration was 5 g/L and the doT value maintained at 5 % air saturation. By this conditions, the cell growth reached 5,457 g cell dry weight/L containing PHB of 2.42 % cell dry weigh after 29 hours fermentation. Normal 0 36 false false false

  17. Purification, crystallization and X-ray crystallographic studies of a Bacillus cereus MepR-like transcription factor, BC0657.

    Science.gov (United States)

    Cho, Min Uk; Kim, Meong Il; Hong, Minsun

    2015-06-01

    Transcription factors of the MarR family respond to internal and external changes and regulate a variety of biological functions through ligand association with microorganisms. MepR belongs to the MarR family, and its mutations are associated with the development of multidrug resistance in Staphylococcus aureus, which has caused a growing health problem. In this study, a Bacillus cereus MepR-like transcription regulator, BC0657, was crystallized. The BC0657 crystals diffracted to 2.05 Å resolution and belonged to either space group P6(2)22 or P6(4)22, with unit-cell parameters a = 110.57, b = 110.57, c = 67.29 Å. There was one molecule per asymmetric unit. Future comparative structural studies on BC0657 would extend knowledge of ligand-induced transcriptional regulatory mechanisms in the MarR family and would make a significant contribution to the design of antibiotic drugs against multidrug-resistant bacteria.

  18. Cyclo(L-Pro-D-Arg): a new antibacterial and antitumour diketopiperazine from Bacillus cereus associated with a rhabditid entomopathogenic.

    Science.gov (United States)

    Kumar, S Nishanth; Mohandas, C; Nambisan, Bala; Sreerag, R S; Jayaprakas, C A

    2014-05-01

    In continuation of our search for new antimicrobial secondary metabolites from Bacillus cereus associated with rhabditid entomopathogenic nematode, a new microbial diketopiperazine, cyclo(L-Pro-D-Arg), was isolated from the ethyl acetate extract of fermented modified nutrient broth. The chemical structures of the isolated compounds were identified based on their 1D, 2D NMR and high-resolution electrospray ionisation-mass spectroscopy data. Antibacterial activity of the compound was determined by minimum inhibitory concentration and disc diffusion method against medically important bacteria, and the compound was recorded to have significant antibacterial activity against test bacteria. The highest activity was recorded against Klebsiella pneumoniae (1 μg/mL). Cyclo(L-Pro-D-Arg) was recorded to have significant antitumor activity against HeLa cells (IC50 value 50 μg/mL), and this compound was recorded to have no cytotoxicity against normal monkey kidney cells (VERO) up to 100 μg/mL). To the best of our knowledge, this is the first time that cyclo(L-Pro-D-Arg) has been isolated from a microbial natural source.

  19. 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.

  20. Growth stimulation of Bacillus cereus and Pseudomonas putida using nanostructured ZnO thin film as transducer element

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. The effect of calcium and sodium lactates on growth from spores of Bacillus cereus and Clostridium perfringens in a 'sous-vide' beef goulash under temperature abuse.

    Science.gov (United States)

    Aran, N

    2001-01-22

    The effect of calcium and sodium lactates on growth from spores of Bacillus cereus and Clostridium perfringens at three different concentrations (0, 1.5 and 3% w/w) and at different temperatures (10, 15 and 20 degrees C for B. cereus and 15, 20 and 25 degrees C for C. perfringens) was investigated, using beef goulash as a model system for pasteurised vacuum-packaged convenience foods. Calcium lactate at a level of 3% reduced the pH values of the samples from 6.0 to 5.5. No B. cereus growth was observed at 10 degrees C, but after 7 days at an incubation temperature of 15 degrees C, cell number increased by 1 log cfu/g in the control samples. At this temperature, lactates were seen to be effective at inhibiting growth. Calcium lactate was more inhibitory than sodium lactate as the growth of B. cereus was inhibited at 1.5 and 3% concentrations at 20 degrees C, respectively. Growth of C. perfringens was arrested in the presence of 1.5% calcium lactate at all storage temperatures, whereas growth was inhibited by 3% sodium lactate only at 15 degrees C. PMID:11205943

  3. Invertebrate pathogenicity and toxin-producing potential of strains of Bacillus thuringiensis endemic to Antarctica.

    Science.gov (United States)

    Prabhakar, A; Bishop, A H

    2011-06-01

    Several strains of Bacillus thuringiensis were previously isolated from soil in Antarctica and appeared to have physiological adaptations to this cold, nutrient-poor environment. In spite of this they could produce abnormally large, parasporal crystals under laboratory conditions. Here, they have been further characterised for toxin genes and invertebrate pathogenicity. All of the strains were positive in PCR assays for the cry1Aa and cry2 genes. This was confirmed by sequence analysis and the parasporal crystals of all strains contained polypeptides of about 130kDa. This potential for lepidopteran toxicity was borne out in bioassays of purified δ-endotoxins against larvae of Pieris brassicae: the LD(50) values of B2408 (288μg) were comparable to that of the reference strain, HD-12 (201μg). There was no activity against the nematode Caenorhabditis elegans in spite of the fact that all strains appeared to possess the cry6 gene. PCR screening for genes encoding other nematode-toxic classes of toxins (Cry5, 4 and 21) was negative. B. thuringiensis has never previously been shown to be toxic to Collembola (springtails) but the purified δ-endotoxins of one of the Antarctic strains showed some activity against Folsomia candida and Seira domestica (224μg and 238μg, respectively). It seems unlikely that the level of toxicity demonstrated against springtails would support a pathogenic life-style in nature. All of the strains were positive for genes encoding Bacillus cereus-type enterotoxins. In the absence of higher insects and mammals the ecological value of retaining the toxic capability demonstrated here is uncertain. PMID:21457716

  4. The mutation Glu151Asp in the B-component of the Bacillus cereus non-hemolytic enterotoxin (Nhe) leads to a diverging reactivity in antibody-based detection systems.

    Science.gov (United States)

    Didier, Andrea; Jeßberger, Nadja; Krey, Victoria; Dietrich, Richard; Scherer, Siegfried; Märtlbauer, Erwin

    2015-11-09

    The ability of Bacillus cereus to cause foodborne toxicoinfections leads to increasing concerns regarding consumer protection. For the diarrhea-associated enterotoxins, the assessment of the non-hemolytic enterotoxin B (NheB) titer determined by a sandwich enzyme immunoassay (EIA) correlates best with in vitro cytotoxicity. In general, the regulation of enterotoxin expression of B. cereus is a coordinately-regulated process influenced by environmental, and probably also by host factors. As long as these factors are not completely understood, the currently-applied diagnostic procedures are based on indirect approaches to assess the potential virulence of an isolate. To date, sandwich EIA results serve as a surrogate marker to categorize isolates as either potentially low or highly toxic. Here, we report on a single amino acid exchange in the NheB sequence leading to an underestimation of the cytotoxic potential in a limited number of strains. During the screening of a large panel of B. cereus isolates, six showed uncommon features with low sandwich EIA titers despite high cytotoxicity. Sequence analysis revealed the point-mutation (Glu)151(Asp) in the potential binding region of the capture antibody. Application of this antibody also results in low titers in an indirect EIA format and shows variable detection intensities in Western-immunoblots. A commercially-available assay based on a lateral flow device detects all strains correctly as NheB producers in a qualitative manner. In conclusion, isolates showing low NheB titers should additionally be assayed in an indirect EIA or for their in vitro cytotoxicity to ensure a correct classification as either low or highly toxic.

  5. The Mutation Glu151Asp in the B-Component of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe Leads to a Diverging Reactivity in Antibody-Based Detection Systems

    Directory of Open Access Journals (Sweden)

    Andrea Didier

    2015-11-01

    Full Text Available The ability of Bacillus cereus to cause foodborne toxicoinfections leads to increasing concerns regarding consumer protection. For the diarrhea-associated enterotoxins, the assessment of the non-hemolytic enterotoxin B (NheB titer determined by a sandwich enzyme immunoassay (EIA correlates best with in vitro cytotoxicity. In general, the regulation of enterotoxin expression of B. cereus is a coordinately-regulated process influenced by environmental, and probably also by host factors. As long as these factors are not completely understood, the currently-applied diagnostic procedures are based on indirect approaches to assess the potential virulence of an isolate. To date, sandwich EIA results serve as a surrogate marker to categorize isolates as either potentially low or highly toxic. Here, we report on a single amino acid exchange in the NheB sequence leading to an underestimation of the cytotoxic potential in a limited number of strains. During the screening of a large panel of B. cereus isolates, six showed uncommon features with low sandwich EIA titers despite high cytotoxicity. Sequence analysis revealed the point-mutation Glu151Asp in the potential binding region of the capture antibody. Application of this antibody also results in low titers in an indirect EIA format and shows variable detection intensities in Western-immunoblots. A commercially-available assay based on a lateral flow device detects all strains correctly as NheB producers in a qualitative manner. In conclusion, isolates showing low NheB titers should additionally be assayed in an indirect EIA or for their in vitro cytotoxicity to ensure a correct classification as either low or highly toxic.

  6. The Mutation Glu151Asp in the B-Component of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) Leads to a Diverging Reactivity in Antibody-Based Detection Systems

    Science.gov (United States)

    Didier, Andrea; Jeßberger, Nadja; Krey, Victoria; Dietrich, Richard; Scherer, Siegfried; Märtlbauer, Erwin

    2015-01-01

    The ability of Bacillus cereus to cause foodborne toxicoinfections leads to increasing concerns regarding consumer protection. For the diarrhea-associated enterotoxins, the assessment of the non-hemolytic enterotoxin B (NheB) titer determined by a sandwich enzyme immunoassay (EIA) correlates best with in vitro cytotoxicity. In general, the regulation of enterotoxin expression of B. cereus is a coordinately-regulated process influenced by environmental, and probably also by host factors. As long as these factors are not completely understood, the currently-applied diagnostic procedures are based on indirect approaches to assess the potential virulence of an isolate. To date, sandwich EIA results serve as a surrogate marker to categorize isolates as either potentially low or highly toxic. Here, we report on a single amino acid exchange in the NheB sequence leading to an underestimation of the cytotoxic potential in a limited number of strains. During the screening of a large panel of B. cereus isolates, six showed uncommon features with low sandwich EIA titers despite high cytotoxicity. Sequence analysis revealed the point-mutation Glu151Asp in the potential binding region of the capture antibody. Application of this antibody also results in low titers in an indirect EIA format and shows variable detection intensities in Western-immunoblots. A commercially-available assay based on a lateral flow device detects all strains correctly as NheB producers in a qualitative manner. In conclusion, isolates showing low NheB titers should additionally be assayed in an indirect EIA or for their in vitro cytotoxicity to ensure a correct classification as either low or highly toxic. PMID:26569304

  7. Bacillus amyloliquefaciens ssp. plantarum strains as potential protective starter cultures for the production of Bikalga, an alkaline fermented food

    DEFF Research Database (Denmark)

    Compaor, C.S.; Nielsen, D.S.; Sawadogo-Lingani, H.;

    2013-01-01

    and fungi. Antimicrobial activity against Bacillus cereus was produced in H. sabdariffa seed-based medium. PCR results revealed that the isolates have potential for the lipopeptides iturin, fengycin, surfactin, the polyketides difficidin, macrolactin, bacillaene and the dipeptide bacilysin production. Ultra......-highperformance liquid chromatography-time of flight mass spectrometry analysis of antimicrobial substance produced in BHI broth allowed identification of iturin, fengycin and surfactin. Conclusions: The Bacillus amyloliquefaciens ssp. plantarum exhibited broadspectrum antifungal and antibacterial properties....... They produced several lipopeptide antibiotics and showed good potential for biological control of Bikalga. Significance and Impact of the Study: Pathogenic bacteria often occur in spontaneous food fermentations. This is the first report to identify indigenous B. amyloliquefaciens ssp. plantarum strains...

  8. Analyze and compare metabolic pathways of Bacillus cereus group%蜡状芽胞杆菌群代谢途径的分析和比较

    Institute of Scientific and Technical Information of China (English)

    喻婵; 王琰; 徐承晨; 何进; 张青叶; 喻子牛

    2011-01-01

    微生物基因组测序和高通量分析方法获得了大量的数据和信息,利用这些信息研究代谢网络成为当前的一个新热点.文章在比较和分析重构代谢网络不同方法的基础上,利用蜡状芽胞杆菌群中已测序的9株蜡状芽胞杆菌、6株炭疽芽胞杆菌、6株苏云金芽胞杆菌基因组,对它们的碳水化合物代谢途径、氨基酸代谢途径和能量代谢途径进行比较与分析,找出它们的共性和特性.这3种菌都存在必需的糖酵解、三羧酸循环、丙氨酸代谢、组氨酸代谢及能量代谢等途径;同时它们还存在特殊的代谢途径,蜡状芽胞杆菌对单糖的利用率较高;炭疽芽胞杆菌的氨基酸降解和转运途径较丰富;苏云金芽胞杆菌中存在催化谷氨酸转化的代谢旁路等.代谢途径的分析为深入研究它们的食物毒素、炭疽毒素和杀虫毒素提供了新思路.%A large number of data and information was obtained from genome sequencing and high-throughput genomic studies, use of the information to study metabolic networks become a new hoispot in biological research. This article compared different methods to reconstruct metabolic networks and analyzed the advantages and disadvantages of each methods, and then introduced some researches about carbohydrate metabolism pathways, amino acid metabolic pathways, and energy metabolism pathways of 9 strains of Bacillus cereus, 6 strains of B. Anthracis,,6 strain of B. Thuringiensis, and finds out their similarities and characteristics. These three strains have some necessary metabolic pathways, such as glycolysis, tri-carboxylic acid cycle, alanine metabolism, histidine metabolism, and energy metabolism, but they may have some specific pathways. B cereus has higher efficiency in utilizing monosaccharide, B. Anthracis is rich in degradation and transport pathways of amino acids. A glutamate metabolic bypass way exists in B. Thuringiensis. Analysis of metabolic pathways provides

  9. Gamma-phage lysin PlyG sequence-based synthetic peptides coupled with Qdot-nanocrystals are useful for developing detection methods for Bacillus anthracis by using its surrogates, B. anthracis-Sterne and B. cereus-4342

    Directory of Open Access Journals (Sweden)

    Atreya Chintamani

    2009-07-01

    Full Text Available Abstract Background Previous reports of site-directed deletion analysis on gamma (γ-phage lysin protein (PlyG have demonstrated that removal of a short amino acid sequence in the C-terminal region encompassing a 10-amino acid motif (190LKMTADFILQ199 abrogates its binding activity specific to the cell wall of Bacillus anthracis. Whether short synthetic peptides representing the10-amino acid PlyG putative binding motif flanked by surrounding N- and C-terminal residues also selectively bind to the bacterial cell wall has not been evaluated. If such peptides do demonstrate selective binding to the cell wall, they could serve as bio-probes towards developing detection technologies for B. anthracis. Furthermore, by using B. anthracis (Sterne, 34F2, an animal vaccine and B. cereus-4342, a γ-phage susceptible rare strain as surrogates of B. anthracis, development of proof-of-concepts for B. anthracis are feasible. Results Using four different methods, we evaluated six synthetic peptides representing the putative binding motif including flanking sequences (PlyG-P1 through P6 for the bacterial cell wall binding capacity. Our analysis identified PlyG-P1, PlyG-P3 and PlyG-P5 to have binding capability to both B. anthracis (Sterne, 34F2 and B. cereus-4342. The peptides however did not bind to B. cereus-11778, B. thuringiensis, and B. cereus-10876 suggesting their specificity for B. anthracis-Sterne and B. cereus-4342. PlyG-P3 in combination with fluorescent light microscopy detected even a single bacterium in plasma spiked with the bacteria. Conclusion Overall, these studies illustrate that the short 10-amino acid sequence 'LKMTADFILQ' in fact is a stand-alone bacterial cell wall-binding motif of PlyG. In principle, synthetic peptides PlyG-P1, PlyG-P3 and PlyG-P5, especially PlyG-P3 coupled with Qdot-nanocrystals are useful as high-sensitivity bio-probes in developing detection technologies for B. anthracis.

  10. Genetic Characterization of Bacillus anthracis 17 JB strain

    Directory of Open Access Journals (Sweden)

    Sakineh Seyed-Mohamadi

    2015-11-01

    Full Text Available Background and Objectives: Bacillus anthracis is one of the most homogenous bacteria ever described. Bacillus anthracis 17JB is a laboratory strain. It is broadly used as a challenge strain in guinea pigs for potency test of anthrax vaccine.Material and Methods: This work describes genetic characterization of B. anthracis 17 JB strain using the SNPs and MLVA genotyping.Results and Conclusion: In SNPs typing, the originally French 17JB strain represented the A. Br. 008/009 subgroup. In Levy's genotyping method, 843, 451 and 864 bp long fragments were identified at AA03, AJ03 and AA07 loci, respectively. In the vaccine manufacturer perspective these findings are much valuable on their own account, but similar research is required to extend molecular knowledge of B. anthracis epidemiology in Persia.Keywords: Bacillus anthracis 17JB, Genetic characterization, SNPs typing

  11. Draft Genome Sequence of Bacillus subtilis strain KATMIRA1933

    OpenAIRE

    Karlyshev, Andrey V.; Melnikov, Vyacheslav G.; Chikindas, Michael L.

    2014-01-01

    In this report, we present a draft sequence of Bacillus subtilis KATMIRA1933. Previous studies demonstrated probiotic properties of this strain partially attributed to production of an antibacterial compound, subtilosin. Comparative analysis of this strain’s genome with that of a commercial probiotic strain, B. subtilis Natto, is presented.

  12. 2-aminohydroxamic acid derivatives as inhibitors of Bacillus cereus phosphatidylcholine preferred phospholipase C PC-PLC(Bc).

    Science.gov (United States)

    González-Bulnes, Patricia; González-Roura, Albert; Canals, Daniel; Delgado, Antonio; Casas, Josefina; Llebaria, Amadeu

    2010-12-15

    Phosphatidylcholine preferring phospholipase C (PC-PLC) is an important enzyme that plays a key role in a variety of cellular events and lipid homoeostases. Bacillus cereus phospholipase C (PC-PLC(Bc)) has antigenic similarity with the elusive mammalian PC-PLC, which has not thus far been isolated and purified. Therefore the discovery of inhibitors of PC-PLC(Bc) is of current interest. Here, we describe the synthesis and biological evaluation of a new type of compounds inhibiting PC-PLC(Bc). These compounds have been designed by evolution of previously described 2-aminohydroxamic acid PC-PLC(Bc) inhibitors that block the enzyme by coordination of the zinc active site atoms present in PC-PLC(Bc) [Gonzalez-Roura, A.; Navarro, I.; Delgado, A.; Llebaria, A.; Casas, J. Angew. Chem. Int. Ed.2004, 43, 862]. The new compounds maintain the zinc coordinating groups and possess an extra trimethylammonium function, linked to the hydroxyamide nitrogen by an alkyl chain, which is expected to mimic the trimethylammonium group of the phosphatidylcholine PC-PLC(Bc) substrates. Some of the compounds described inhibit the enzyme with IC(50)'s in the low micromolar range. Unexpectedly, the most potent inhibitors found are those that possess a trimethylammonium group but have chemically blocked the zinc coordinating functionalities. The results obtained suggest that PC-PLC(Bc) inhibition is not due to the interaction of compounds with the phospholipase catalytic zinc atoms, but rather results from the inhibitor cationic group recognition by the PC-PLC(Bc) amino acids involved in choline lipid binding.

  13. Identification of Bacillus Strains for Biological Control of Catfish Pathogens

    OpenAIRE

    Ran, Chao; Carrias, Abel; Williams, Malachi A.; Capps, Nancy; Dan, Bui C. T.; Newton, Joseph C.; Joseph W Kloepper; Ooi, Ei L.; Browdy, Craig L.; Terhune, Jeffery S.; Liles, Mark R.

    2012-01-01

    Bacillus strains isolated from soil or channel catfish intestine were screened for their antagonism against Edwardsiella ictaluri and Aeromonas hydrophila, the causative agents of enteric septicemia of catfish (ESC) and motile aeromonad septicaemia (MAS), respectively. Twenty one strains were selected and their antagonistic activity against other aquatic pathogens was also tested. Each of the top 21 strains expressed antagonistic activity against multiple aquatic bacterial pathogens including...

  14. Biodegradation of furfural by Bacillus subtilis strain DS3.

    Science.gov (United States)

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Lv, Quanxi

    2015-07-01

    An aerobic bacterial strain DS3, capable of growing on furfural as sole carbon source, was isolated from actived sludge of wastewater treatment plant in a diosgenin factory after enrichment. Based on morphological physiological tests as well as 16SrDNA sequence and Biolog analyses it was identified as Bacillus subtilis. The study revealed that strain DS3 utilized furfural, as analyzed by high-performance liquid chromatography (HPLC). Under following conditions: pH 8.0, temperature 35 degrees C, 150 rpm and 10% inoculum, strain DS3 showed 31.2% furfural degradation. Furthermore, DS3 strain was found to tolerate furfural concentration as high as 6000 mg(-1). The ability of Bacillus subtilis strain DS3 to degrade furfural has been demonstrated for the first time in the present study.

  15. Occurrence and diversity of mosquitocidal strains of Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    K. Balaraman

    2005-09-01

    Full Text Available Ever since the discovery of the first Bacillus thuringiensis strain capable of killing mosquito larvae,namely, B. thuringiensis var israelensis, there are several reports from different parts of the worldabout the occurrence of mosquitocidal strains belonging to different subspecies/serotypes numberingthirty-six. The main sources of these wild type strains are soils/sediments, plants, animal feces,sick/moribund insects and waters. The toxicity of the strains within a subspecies/serotype variedwidely. Some of the strains exhibited toxicity to mosquitoes as well as lepidopterans and dipterans(including mosquitoes as well as plant parasitic nematodes.

  16. Biomineralization of Pb(II) into Pb-hydroxyapatite induced by Bacillus cereus 12-2 isolated from Lead-Zinc mine tailings.

    Science.gov (United States)

    Chen, Zhi; Pan, Xiaohong; Chen, Hui; Guan, Xiong; Lin, Zhang

    2016-01-15

    The remediation of Pb(II) through biomineralization is rergarded as a promising technique as well as an interesting phenomenon for transforming heavy metals from mobile species into very stable minerals in the environment. Studies are well needed for in-depth understanding the mechanism of Pb(II) immobilized by bacteria. In the present study, we investigated the uptake and biomineralization of Pb(II) using Bacillus cereus 12-2 isolated from lead-zinc mine tailings. The maximum Pb(II) uptake capacity of B. cereus 12-2 was 340 mg/g at pH 3.0. Zeta potential analyses and selective passivation experiments demonstrated that electrostatic attraction was the main force driving the uptake of Pb(II), while the carboxyl, amide and phosphate functional groups of the bacteria provided the binding sites for immobilizing Pb(II). XRD and TEM investigation revealed that the Pb(II) loaded on bacteria could be stepwise transformed into rod-shaped Ca2.5Pb7.5(OH)2(PO4)6 nanocrystal. Combined with protein denaturalization experiments, we proposed that the biomineralization of Pb(II) possibly consisted of two steps: (1) Rapid biosorption of Pb(II) on B. cereus 12-2 through the synergy of electrostatic attraction, ionic exchange and chelating activity of functional groups; (2) enzyme-mediated mineral transformation from amorphous precipitate to rod-shaped crystalline minerals happening gradually inside the bacteria. PMID:26468754

  17. 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.

  18. 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.

  19. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Science.gov (United States)

    Lai, Yi-Ru; Lin, Pei-Yu; Chen, Chao-Ying; Huang, Chien-Jui

    2016-01-01

    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. PMID:27721698

  20. Antibacterial activity and genotypic-phenotypic characteristics of bacteriocin-producing Bacillus subtilis KKU213: potential as a probiotic strain.

    Science.gov (United States)

    Khochamit, Nalisa; Siripornadulsil, Surasak; Sukon, Peerapol; Siripornadulsil, Wilailak

    2015-01-01

    The antimicrobial activity and probiotic properties of Bacillus subtilis strain KKU213, isolated from local soil, were investigated. The cell-free supernatant (CFS) of a KKU213 culture containing crude bacteriocins exhibited inhibitory effects on Gram-positive bacteria, including Bacillus cereus, Listeria monocytogenes, Micrococcus luteus, and Staphylococcus aureus. The antibacterial activity of the CFS precipitated with 40% ammonium sulfate (AS) remained even after treatment at 60 and 100 °C, at pH 4 and 10 and with proteolytic enzymes, detergents and heavy metals. When analyzed by SDS-PAGE and overlaid with the indicator strains B. cereus and S. aureus, the 40% AS precipitate exhibited inhibitory activity on proteins smaller than 10 kDa. However, proteins larger than 25 kDa and smaller than 10 kDa were still observed on a native protein gel. Purified subtilosin A was prepared by Amberlite XAD-16 bead extraction and HPLC and analyzed by Nano-LC-QTOF-MS. Its molecular mass was found to be 3.4 kDa, and it retained its antibacterial activity. These results are consistent with the detection of the anti-listerial subtilosin A gene of the sbo/alb cluster in the KKU213 strain, which is 100% identical to that of B. subtilis subsp. subtilis 168. In addition to stable and cyclic subtilosin A, a mixture of many extracellular antibacterial peptides was also detected in the KKU213 culture. The KKU213 strain produced extracellular amylase, cellulase, lipase and protease, is highly acid-resistant (pH 2) when cultured in inulin and promotes health and reduces infection of intestinally colonized broiler chickens. Therefore, we propose that bacteriocin-producing B. subtilis KKU213 could be used as a potential probiotic strain or protective culture. PMID:25440998

  1. Accurate Localization of the Integration Sites of Two Genomic Islands at Single-Nucleotide Resolution in the Genome of Bacillus cereus ATCC 10987

    Directory of Open Access Journals (Sweden)

    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.

  2. Characterization of Emetic Bacillus weihenstephanensis, a New Cereulide-Producing Bacterium

    DEFF Research Database (Denmark)

    Thorsen, Line; Munk Hansen, Bjarne; Nielsen, Kristian Fog;

    2006-01-01

    Cereulide production has until now been restricted to the species Bacillus cereus. Here we report on two psychrotolerant Bacillus weihenstephanensis strains, MC67 and MC118, that produce cereulide. The strains are atypical with regard to pheno- and genotypic characteristics normally used...

  3. Extraction, Purification and Characterization of Thermostable, Alkaline Tolerant α-Amylase from Bacillus cereus

    OpenAIRE

    Annamalai, N.; Thavasi, R.; Vijayalakshmi, S.; Balasubramanian, T.

    2011-01-01

    Thermostable alkaline α-amylase producing bacterium Bacilluscereus strain isolated from Cuddalore harbour waters grew maximally in both shake flask and fermentor, and produced α-amylase at 35°C, pH 7.5 and 1.0% of substrate concentrations. α-Amylase activity was maximum at 65°C, pH 8.0, 89% of its activity was sustained even at pH 11.0. Added with MnCl2, α-amylase activity showed 4% increase but it was inhibited by EDTA. The molecular weight of the purified α-amylase is 42 kDa.

  4. Transformation of undomesticated strains of Bacillus subtilis by protoplast electroporation

    NARCIS (Netherlands)

    Romero, Diego; Perez-Garcia, Alejandro; Veening, Jan-Willem; de Vicente, Antonio; Kuipers, Oscar P.; de, Vicente A.

    2006-01-01

    A rapid method combining the use of protoplasts and electroporation was developed to transform recalcitrant wild strains of Bacillus subtilis. The method described here allows transformation with both replicative and integrative plasmids, as well as with chromosomal DNA, and provides a valuable tool

  5. Structural and chemical aspects of resistance to the antibiotic fosfomycin conferred by FosB from Bacillus cereus.

    Science.gov (United States)

    Thompson, Matthew K; Keithly, Mary E; Harp, Joel; Cook, Paul D; Jagessar, Kevin L; Sulikowski, Gary A; Armstrong, Richard N

    2013-10-15

    The fosfomycin resistance enzymes, FosB, from Gram-positive organisms, are M(2+)-dependent thiol tranferases that catalyze nucleophilic addition of either L-cysteine (L-Cys) or bacillithiol (BSH) to the antibiotic, resulting in a modified compound with no bacteriacidal properties. Here we report the structural and functional characterization of FosB from Bacillus cereus (FosB(Bc)). The overall structure of FosB(Bc), at 1.27 Å resolution, reveals that the enzyme belongs to the vicinal oxygen chelate (VOC) superfamily. Crystal structures of FosB(Bc) cocrystallized with fosfomycin and a variety of divalent metals, including Ni(2+), Mn(2+), Co(2+), and Zn(2+), indicate that the antibiotic coordinates to the active site metal center in an orientation similar to that found in the structurally homologous manganese-dependent fosfomycin resistance enzyme, FosA. Surface analysis of the FosB(Bc) structures show a well-defined binding pocket and an access channel to C1 of fosfomycin, the carbon to which nucleophilic addition of the thiol occurs. The pocket and access channel are appropriate in size and shape to accommodate L-Cys or BSH. Further investigation of the structures revealed that the fosfomycin molecule, anchored by the metal, is surrounded by a cage of amino acids that hold the antibiotic in an orientation such that C1 is centered at the end of the solvent channel, positioning the compound for direct nucleophilic attack by the thiol substrate. In addition, the structures of FosB(Bc) in complex with the L-Cys-fosfomycin product (1.55 Å resolution) and in complex with the bacillithiol-fosfomycin product (1.77 Å resolution) coordinated to a Mn(2+) metal in the active site have been determined. The L-Cys moiety of either product is located in the solvent channel, where the thiol has added to the backside of fosfomycin C1 located at the end of the channel. Concomitant kinetic analyses of FosB(Bc) indicated that the enzyme has a preference for BSH over L-Cys when

  6. Field evaluation of a bioregulator containing live Bacillus cereus spores on health status and performance of sows and their litters.

    Science.gov (United States)

    Alexopoulos, C; Karagiannidis, A; Kritas, S K; Boscos, C; Georgoulakis, I E; Kyriakis, S C

    2001-04-01

    The efficacy of Paciflor, a bioregulator containing live Bacillus cereus CIP 5832 spores, was assessed in sows during late pregnancy and lactation, as well as in their piglets up to the growing phase. Two groups each of 30 pregnant gilts and sows received normal feed (T1 group), or feed with 85 g Paciflor per ton feed (T2 group), from 15 days prior to farrowing up to the end of the lactation period. Furthermore, 15 litters of the T1 group and 15 litters of the T2 group, were offered normal feed from the 5th to the 70th days of life (T1.1 and T2.1 groups, respectively), while the remaining 15 litters each of the T1 and T2 groups received the same feed but including Paciflor at a dose of 100 g/ton (from day 5 to day 49) and 50 g/ton (from day 50 to day 70). These pig litters were T1.2 and T2.2, respectively. No differences were seen between the T1 and T2 groups with respect to the clinical observations (loss of appetite, fever, mastitis, metritis and returns to oestrus, treatments applied, deaths, or removals to the slaughterhouse), gestation length, bodyweight of sows at farrowing or litter-size at birth. However, during lactation, the fat content of the dam's milk was increased (0.46% more fat), the body weight loss of sows was reduced and the number of weaned pigs per sow was increased (0.6 more pigs per litter) after administration of Paciflor (P pigs originating from Paciflor-treated dams (T2.2 group) (P < 0.05). Despite the fact that no difference was seen between groups with regard to the amount of feed consumed, the feed conversion ratio of Paciflor-treated piglets (T2.2 and T1.2) was significantly improved compared to that of the untreated piglets (T2.1 and T1.1) (P < 0.05). With respect to weight gain, for the Paciflor-treated piglets, those born to Paciflor-treated mothers (T2.2) were 0.56 kg heavier than those born to untreated dams (T1.2) (P < 0.05). It is concluded that administration of Paciflor in dams during the end of pregnancy and during lactation

  7. Aerobic granulation of pure bacterial strain Bacillus thuringiensis

    Institute of Scientific and Technical Information of China (English)

    Sunil S ADAV; Duu-Jong LEE

    2008-01-01

    The objective of this study is to cultivate aer-obic granules by pure bacterial strain, Bacillus thuringien-sis, in a sequencing batch reactor. Stable granules sized 2.0-2.2 mm were formed in the reactor after a five-week cultivation. These granules exhibited excellent settling attributes, and degraded phenol at rates of 1.49 and concentration, respectively. Confocal laser scanning microscopic test results show that Bacillus thuringiensis was distributed over the initial small aggregates, and the outer edge of the granule was away from the core regime in the following stage.

  8. Bacillus cereus Cr2产NiR酶能力及其与除Cr(Ⅵ)效率的相关性%Study on the Production of NiR by Bacillus cereus Cr2 and the Correlation between the Enzyme and Removal Rate of Cr (Ⅵ)

    Institute of Scientific and Technical Information of China (English)

    赵欣欣; 许燕滨; 屈毛毛; 孙浩; 阮晶晶; 侯毛宇; 陈锦良

    2013-01-01

    目的:研究除铬优势菌Bacillus cereus Cr2的亚硝酸还原酶(nitrite reductase,NiR)产生情况,以及在Cr(Ⅵ)去除中的作用.方法:通过液体发酵培养和超声破碎的方法获得NiR粗酶液,采用改良的格里斯染色法比较了不同培养温度、pH值、Cr(Ⅵ)诱导浓度及磁场对NiR酶活性的影响,获得最佳产酶条件,进而研究NiR酶活与除铬优势菌去除Cr(Ⅵ)效率之间的关系.结果:细菌产酶的最佳条件是:温度为37℃,pH为6.5,Cr(Ⅵ)诱导浓度为80 mg/L,外加15 mT磁场,酶活力达到30 U/mL,培养体系中的Cr(Ⅵ)诱导浓度低于120 mg/L时不抑制酶活力,此时,NiR酶对Cr(Ⅵ)的去除率比Bacillus cereus Cr2提高10%以上(P<0.05).结论:NiR酶的存在是Bacillus cereus Cr2除Cr(Ⅵ)的机理.

  9. 蜡状芽胞杆菌群16S rDNA分析%Analysis of 16S rDNA in the Bacillus cereus Group

    Institute of Scientific and Technical Information of China (English)

    邹寰; 喻子牛; 孙明

    2008-01-01

    蜡状芽胞杆菌群主要包括炭疽芽胞杆菌(Bacillus anthracis)、蜡状芽胞杆菌(Bacillus cereus)、苏云金芽胞杆菌(Bacillus thuringiensis).GenBank已有这个群的8个菌株完成了全基因组序列测定.对这8株蜡状芽胞杆菌群菌株中98条16S rDNA的序列进行相互BLAST比较,发现在同一基因组内各个16S rDNA拷贝全局相似度最低为96.47%,在不同基因组间16S rDNA局部片段比对最小相似度达到99.72%,对应片段长度也有1417 bp.这点充分说明,该群的细菌完全共用同一种16S rDNA,根据16S rDNA给细菌分类的特点,它们应该属于同一个种.在亲缘关系上,枯草芽胞杆菌离蜡状芽胞杆菌群最近.

  10. Gram-positive siderophore-shuttle with iron-exchange from Fe-siderophore to apo-siderophore by Bacillus cereus YxeB.

    Science.gov (United States)

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

    2013-08-20

    Small molecule iron-chelators, siderophores, are very important in facilitating the acquisition of Fe(III), an essential element for pathogenic bacteria. Many Gram-negative outer-membrane transporters and Gram-positive lipoprotein siderophore-binding proteins have been characterized, and the binding ability of outer-membrane transporters and siderophore-binding proteins for Fe-siderophores has been determined. However, there is little information regarding the binding ability of these proteins for apo-siderophores, the iron-free chelators. Here we report that Bacillus cereus YxeB facilitates iron-exchange from Fe-siderophore to apo-siderophore bound to the protein, the first Gram-positive siderophore-shuttle system. YxeB binds ferrioxamine B (FO, Fe-siderophore)/desferrioxamine B (DFO, apo-siderophore) in vitro. Disc-diffusion assays and growth assays using the yxeB mutant reveal that YxeB is responsible for importing the FO. Cr-DFO (a FO analog) is bound by YxeB in vitro and B. cereus imports or binds Cr-DFO in vivo. In vivo uptake assays using Cr-DFO and FO and growth assays using DFO and Cr-DFO show that B. cereus selectively imports and uses FO when DFO is present. Moreover, in vitro competition assays using Cr-DFO and FO clearly demonstrate that YxeB binds only FO, not Cr-DFO, when DFO is bound to the protein. Iron-exchange from FO to DFO bound to YxeB must occur when DFO is initially bound by YxeB. Because the metal exchange rate is generally first order in replacement ligand concentration, protein binding of the apo-siderophore acts to dramatically enhance the iron exchange rate, a key component of the Gram-positive siderophore-shuttle mechanism.

  11. Identification of CdnL, a Putative Transcriptional Regulator Involved in Repair and Outgrowth of Heat-Damaged Bacillus cereus Spores.

    Directory of Open Access Journals (Sweden)

    Alicja K Warda

    Full Text Available Spores are widely present in the environment and are common contaminants in the food chain, creating a challenge for food industry. Nowadays, heat treatments conventionally applied in food processing may become milder to comply with consumer desire for products with higher sensory and nutritional values. Consequently subpopulations of spores may emerge that are sublethally damaged rather than inactivated. Such spores may germinate, repair damage, and eventually grow out leading to uncontrolled spoilage and safety issues. To gain insight into both the behaviour of damaged Bacillus cereus spores, and the process of damage repair, we assessed the germination and outgrowth performance using OD595 measurements and microscopy combined with genome-wide transcription analysis of untreated and heat-treated spores. The first two methods showed delayed germination and outgrowth of heat-damaged B. cereus ATCC14579 spores. A subset of genes uniquely expressed in heat-treated spores was identified with putative roles in the outgrowth of damaged spores, including cdnL (BC4714 encoding the putative transcriptional regulator CdnL. Next, a B. cereus ATCC14579 cdnL (BC4714 deletion mutant was constructed and assessment of outgrowth from heat-treated spores under food relevant conditions showed increased damage compared to wild type spores. The approach used in this study allows for identification of candidate genes involved in spore damage repair. Further identification of cellular parameters and characterisation of the molecular processes contributing to spore damage repair may provide leads for better control of spore outgrowth in foods.

  12. Bacillus anthracis-like bacteria and other B. cereus group members in a microbial community within the International Space Station: a challenge for rapid and easy molecular detection of virulent B. anthracis.

    Directory of Open Access Journals (Sweden)

    Sandra P van Tongeren

    Full Text Available For some microbial species, such as Bacillus anthracis, the etiologic agent of the disease anthrax, correct detection and identification by molecular methods can be problematic. The detection of virulent B. anthracis is challenging due to multiple virulence markers that need to be present in order for B. anthracis to be virulent and its close relationship to Bacillus cereus and other members of the B. cereus group. This is especially the case in environments where build-up of Bacillus spores can occur and several representatives of the B. cereus group may be present, which increases the chance for false-positives. In this study we show the presence of B. anthracis-like bacteria and other members of the B. cereus group in a microbial community within the human environment of the International Space Station and their preliminary identification by using conventional culturing as well as molecular techniques including 16S rDNA sequencing, PCR and real-time PCR. Our study shows that when monitoring the microbial hygiene in a given human environment, health risk assessment is troublesome in the case of virulent B. anthracis, especially if this should be done with rapid, easy to apply and on-site molecular methods.

  13. Bacillus anthracis-like bacteria and other B. cereus group members in a microbial community within the International Space Station: a challenge for rapid and easy molecular detection of virulent B. anthracis.

    Science.gov (United States)

    van Tongeren, Sandra P; Roest, Hendrik I J; Degener, John E; Harmsen, Hermie J M

    2014-01-01

    For some microbial species, such as Bacillus anthracis, the etiologic agent of the disease anthrax, correct detection and identification by molecular methods can be problematic. The detection of virulent B. anthracis is challenging due to multiple virulence markers that need to be present in order for B. anthracis to be virulent and its close relationship to Bacillus cereus and other members of the B. cereus group. This is especially the case in environments where build-up of Bacillus spores can occur and several representatives of the B. cereus group may be present, which increases the chance for false-positives. In this study we show the presence of B. anthracis-like bacteria and other members of the B. cereus group in a microbial community within the human environment of the International Space Station and their preliminary identification by using conventional culturing as well as molecular techniques including 16S rDNA sequencing, PCR and real-time PCR. Our study shows that when monitoring the microbial hygiene in a given human environment, health risk assessment is troublesome in the case of virulent B. anthracis, especially if this should be done with rapid, easy to apply and on-site molecular methods.

  14. Bactericidal Mechanism of Bio-oil Obtained from Fast Pyrolysis of Pinus densiflora Against Two Foodborne Pathogens, Bacillus cereus and Listeria monocytogenes.

    Science.gov (United States)

    Patra, Jayanta Kumar; Hwang, Hyewon; Choi, Joon Weon; Baek, Kwang-Hyun

    2015-06-01

    Foodborne bacteria are the leading cause of food spoilage and other related diseases. In the present study, the antibacterial activity of bio-oil (BO) manufactured by fast pyrolysis of pinewood sawdust (Pinus densiflora Siebold and Zucc.) against two disease-causing foodborne pathogens (Bacillus cereus and Listeria monocytogenes) was evaluated. BO at a concentration of 1000 μg/disc was highly active against both B. cereus (10.0-10.6 mm-inhibition zone) and L. monocytogenes (10.6-12.0-mm inhibition zone). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values of BO were 500 and 1000 μg/mL, respectively, for both pathogens. At the MIC concentration, BO exhibited an inhibitory effect on the viability of the bacterial pathogens. The mechanism of action of BO revealed its strong impairing effect on the membrane integrity of bacterial cells, which was confirmed by a marked release of 260-nm absorbing material, leakage of electrolytes and K(+) ions, and reduced capacity for osmoregulation under high salt concentration. Scanning electron microscopy clearly showed morphological alteration of the cell membrane due to the effect of BO. Overall, the results of this study suggest that BO exerts effective antibacterial potential against foodborne pathogens and can therefore potentially be used in food processing and preservation. PMID:25928035

  15. A new method for rapid and quantitative detection of the Bacillus cereus emetic toxin cereulide in food products by liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Yamaguchi, Mizuka; Kawai, Takao; Kitagawa, Mikiya; Kumeda, Yuko

    2013-05-01

    The Bacillus cereus emetic toxin cereulide causes foodborne intoxication, which may occasionally result in severe disease, and even death. To differentially diagnose the emetic-type of foodborne disease caused by B. cereus and assess the safety of commercial food, we developed a rapid method to quantitate cereulide. This method was combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis for the extraction of cereulide from food using a normal-phase silica gel cartridge. The limits of detection and quantification were 0.1 and 0.5 ng of cereulide ml(-1), respectively. Spiked cereulide was reproducibly recovered with over 67% efficiency from nine diverse foods implicated in cereulide food poisoning. The recovery rate, reproducibility, and intermediate precision for this single laboratory validation using boiled rice were 87.1%, 4.4%, and 7.0%, respectively. Further, we detected a wide range of cereulide concentrations in leftover food and vomitus samples from two emetic foodborne outbreaks. LC-MS/MS analysis correlated closely with those acquired using the HEp-2 cell assay, and quantitated cereulide from 10 food samples at least five times faster than the bioassay. This new method will provide clinicians with an improved tool for more rapidly and quantitatively determining the presence of cereulide in food and diagnosing food poisoning caused by cereulide.

  16. 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)

    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 P212121, 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

  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

    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.

  18. Caractérisation, identification et étude de la thermorésistance de souches de Bacillus cereus isolées de semoule de couscous

    OpenAIRE

    Ziane, Mohammed

    2014-01-01

    Bacillus cereus est une bactérie sporulée impliquée dans les toxi-infections alimentaires collectives (TIAC). En Algérie, cette bactérie n’est pas recherchée dans le couscous largement consommé en Algérie et troisième aliment incriminé dans les TIAC. Dans ce cadre, cette thèse vise à rechercher ce pathogène, caractériser sa thermorésistance, vérifier sa capacité à se développer dans le couscous pour la prévision du niveau de contamination. Une contamination moyenne de 20 ufc/g a é...

  19. Application of a molecular beacon based real-time isothermal amplification (MBRTIA) technology for simultaneous detection of Bacillus cereus and Staphylococcus aureus.

    Science.gov (United States)

    Mandappa, I M; Joglekar, Prasanna; Manonmani, H K

    2015-07-01

    A multiplex real-time isothermal amplification assay was developed using molecular beacons for the detection of Bacillus cereus and Staphylococcus aureus by targeting four important virulence genes. A correlation between targeting highly accessible DNA sequences and isothermal amplification based molecular beacon efficiency and sensitivity was demonstrated using phi(Φ)29 DNA polymerase at a constant isothermal temperature of 30 °C. It was very selective and consistently detected down to 10(1) copies of DNA. The specificity and sensitivity of this assay, when tested with pure culture were high, surpassing those of currently used PCR assays for the detection of these organisms. The molecular beacon based real-time isothermal amplification (MBRTIA) assay could be carried out entirely in 96 well plates or well strips, enabling a rapid and high-throughput detection of food borne pathogens.

  20. Bacillus cereus AR156 primes induced systemic resistance by suppressing miR825/825? and activating defense-related genes in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Dongdong Niu; Hongwei Zhao; Jing Xia; Chunhao Jiang; Beibei Qi; Xiaoyu Ling; Siyuan Lin; Weixiong Zhang; Jianhua Guo; Hailing Jin

    2016-01-01

    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.

  1. 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 plate count method (1.89 log CFU/ml). B. cereus populations in the inoculated 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).

  2. Biodegradation of malathion by Bacillus licheniformis strain ML-1

    Directory of Open Access Journals (Sweden)

    Khan Sara

    2016-01-01

    Full Text Available Malathion, a well-known organophosphate pesticide, has been used in agriculture over the last two decades for controlling pests of economically important crops. In the present study, a single bacterium, ML-1, was isolated by soil-enrichment technique and identified as Bacillus licheniformis on the basis of the 16S rRNA technique. The bacterium was grown in carbon-free minimal salt medium (MSM and was found to be very efficient in utilizing malathion as the sole source of carbon. Biodegradation experiments were performed in MSM without carbon source to determine the malathion degradation by the selected strain, and the residues of malathion were determined quantitatively using HPLC techniques. Bacillus licheniformis showed very promising results and efficiently consumed malathion as the sole carbon source via malathion carboxylesterase (MCE, and about 78% malathion was degraded within 5 days. The carboxylesterase activity was determined by using crude extract while using malathion as substrate, and the residues were determined by HPLC. It has been found that the MCE hydrolyzed 87% malathion within 96 h of incubation. Characterization of crude MCE revealed that the enzyme is robust in nature in terms of organic solvents, as it was found to be stable in various concentrations of ethanol and acetonitrile. Similarly, and it can work in a wide pH and temperature range. The results of this study highlighted the potential of Bacillus licheniformis strain ML-1 as a biodegrader that can be used for the bioremediation of malathion-contaminated soil.

  3. In vitro fermentation studies for selection and evaluation of Bacillus strains as starter cultures for the production of okpehe, a traditional African fermented condiment.

    Science.gov (United States)

    Oguntoyinbo, Folarin A; Sanni, Abiodun I; Franz, Charles M A P; Holzapfel, Wilhelm H

    2007-01-25

    Selected Bacillus and Enterococcus strains, isolated from traditional okpehe fermentations, were studied for their suitability as starter cultures in laboratory-scale fermentations of Prosopis africana seeds for the production of okpehe, a traditional fermented vegetable product of Nigeria. The strains were selected on the basis of highest proteolytic activity, as determined with the APIZYM (BioMerieux) test. The choice of starter strains was narrowed to Bacillus subtilis strains BFE 5301 and BFE 5372. These were determined as the best starter combination because of rapid growth, high amylolytic and proteolytic activities, high levels of polyglutamic acid production by strain BFE 5372, as well as bacteriocin production by strain BFE 5301. Other mixed culture fermentations did not yield sensorically acceptable products. Although a monoculture fermentation, using only B. subtilis strain BFE 5372, produced okpehe with very good sensory characteristics, the growth of B. cereus could be detected after 48 h fermentation, indicating that this starter did not sufficiently contribute to product safety. Mixed culture fermentation with the combination of bacteriocin-producing starter B. subtilis BFE 5301 and the non-bacteriocin-producing B. subtilis BFE 5372, produced a product with good sensory characteristics, in which growth of B. cereus was delayed. The bacteriocin produced by B. subtilis strain BFE 5301 was identified as subtilisin, using subtilisin-specific primers and PCR amplification of the subtilisin gene. The bacteriocin was heat-stable at 100 degrees C for 10 min and exhibited highest activity at pH values lower or equal to pH 6.0. The bacteriocin was sensitive to the proteolytic enzymes trypsin and alpha-chymotrypsin at concentrations of 10 mg/ml.

  4. Bacillus amyloliquefaciens SUBSP. plantarum PROBIOTIC STRAINS AS PROTEASE PRODUCERS

    Directory of Open Access Journals (Sweden)

    E. V. Маtseliukh

    2015-04-01

    Full Text Available Proteases from probiotic strains of the genus Bacillus, just like the antibiotics, bacteriocins and other hydrolytic enzymes, are one of the main factors that determine their biological activity. The aim of this work was to study the synthesis and biochemical properties of proteases from two strains Bacillus amyloliquefaciens subsp. plantarum UCM B-5139 and UCM B-5140 that included in the probiotic Endosporin. The cultivation of strains was carried out in flasks under rotating for two days. The influence of physico-chemical parameters of the reaction medium on proteolytic activity was studied on partially purified protease preparations. Lytic activity was determined by turbidimetric method. On the second day of cultivation B. amyloliquefaciens subsp. plantarum UCM В-5139 and UCM В-5140 synthesized the metal-dependent peptidase and serine protease, respectively. The optimum conditions of their action were the following: temperature 37–40 °C and pH 6.5–7.0. Isolated proteases are able to lyse the living cells of Staphylococcus aureus and Candida albicans. Thus we demonstrated that B. amyloliquefaciens subsp. plantarum UCM B-5140 and UCM B-5139, included in the probiotic veterinary preparation Endosporin, produced proteolytic enzymes that hydrolyze the native insoluble proteins (elastin, fibrin and collagen. These enzymes belong to the group of neutral metal-dependent and serine proteases. They are active under physiological conditions against gram-positive bacteria and yeasts. The application of these proteases in biotechnology is considered.

  5. Possession, Use, and Transfer of Select Agents and Toxins-- Addition of Bacillus Cereus Biovar Anthracis to the HHS List of Select Agents and Toxins. Interim final rule and request for comments.

    Science.gov (United States)

    2016-09-14

    The Centers for Disease Control and Prevention (CDC) in the Department of Health and Human Services (HHS) is adding Bacillus cereus Biovar anthracis to the list of HHS select agents and toxins as a Tier 1 select agent. We are taking this action to regulate this agent that is similar to B. anthracis to prevent its misuse, which could cause a biological threat to public health and/or national security.

  6. Physiology of Sporolactobacillus strains isolated from different habitats and the indication of in vitro antagonism against Bacillus species.

    Science.gov (United States)

    Holzapfel, W H; Botha, S J

    1988-10-01

    In an ecological study only low numbers of Sporolactobacillus were found in habitats such as the faeces of herbivores, the rumen of cattle and the final waste water of an abattoir. Their presence in the final waste water of an abattoir indicates their possible association with food, and, more specifically, with meat. Differences were found in some physiological characteristics. One isolate (L2404) differed from the authentic Sporolactobacillus ATCC 15538 by its inability to ferment inulin, its growth in presence of 6.5% NaCl and in 0.2% tellurite, by the isomer(s) of lactic acid produced and the mol% G + G in the DNA. One Sporolactobacillus isolate (L2407) showed antagonism against Bacillus cereus, Bacillus cereus var, mycoides, Bacillus megaterium and Bacillus subtilis. PMID:3275317

  7. Bacillus cereus contamination of rice caused by the investigation and analysis of food poisoning%蜡样芽胞杆菌污染米饭引起食物中毒的调查分析

    Institute of Scientific and Technical Information of China (English)

    周晓红; 严军; 陈秀兰; 姜洁

    2013-01-01

    Objectiveanalysis the reason of poisoning by through the epidemiological investigation and laboratory test results.Methods epidemiological investigation at the scene、Manifestations in clinical and laboratory testing.Results etiology inspection results for bacillus cereus,the number of bacillus cereus in rice 1.8×106cfU/g.Conclusion Bacillus cereus to grow in the appropriate temperature, contaminated food, produce toxins that cause food poisoning.%目的:根据流行病学调查及实验室检验结果分析中毒原因。方法现场流行病学调查、临床表现及实验室检验。结果病原学检验结果为蜡样芽胞杆菌,米饭中的蜡样芽胞杆菌菌数1.8×106cfU/g。结论蜡样芽胞杆菌在适宜的温度下生长繁殖,污染食品,产生毒素,引起食物中毒。

  8. Drosophila melanogaster Selection for Survival after Infection with Bacillus cereus Spores: Evolutionary Genetic and Phenotypic Investigations of Respiration and Movement

    Directory of Open Access Journals (Sweden)

    Junjie Ma

    2013-01-01

    Full Text Available Laboratory populations of D. melanogaster have been subjected to selection for survival after live spores of B. cereus were introduced as a pathogenic agent. The present study was designed to investigate correlated traits: respiration as a metabolic trait and movement as a behavioral trait. An underlying hypothesis was that the evolution of increased survival after B. cereus infection exerts a metabolic cost associated with elevated immunity and this would be detected by increased respiration rates. There was support for this hypothesis in the male response to selection, but not for selected-line females. Two phenotypic effects were also observed in the study. Females especially showed a marked increase in respiration after mating compared to the other assay stages regardless of whether respiration was measured per fly or adjusted by lean mass or dry weight. Given that mating stimulates egg production, it is feasible that elevated metabolism was needed to provision oocytes with yolk. Females also moved less than males, perhaps due to behaviors related to oviposition whereas elevated male activity might be due to behaviors associated with seeking females and courtship. Relatively low movement of females indicated that their elevated respiration after mating was not due to a change in locomotion.

  9. Whole-genome phylogenies of the family Bacillaceae and expansion of the sigma factor gene family in the Bacillus cereus species-group

    Directory of Open Access Journals (Sweden)

    Dyer David W

    2011-08-01

    Full Text Available Abstract Background The Bacillus cereus sensu lato group consists of six species (B. anthracis, B. cereus, B. mycoides, B. pseudomycoides, B. thuringiensis, and B. weihenstephanensis. While classical microbial taxonomy proposed these organisms as distinct species, newer molecular phylogenies and comparative genome sequencing suggests that these organisms should be classified as a single species (thus, we will refer to these organisms collectively as the Bc species-group. How do we account for the underlying similarity of these phenotypically diverse microbes? It has been established for some time that the most rapidly evolving and evolutionarily flexible portions of the bacterial genome are regulatory sequences and transcriptional networks. Other studies have suggested that the sigma factor gene family of these organisms has diverged and expanded significantly relative to their ancestors; sigma factors are those portions of the bacterial transcriptional apparatus that control RNA polymerase recognition for promoter selection. Thus, examining sigma factor divergence in these organisms would concurrently examine both regulatory sequences and transcriptional networks important for divergence. We began this examination by comparison to the sigma factor gene set of B. subtilis. Results Phylogenetic analysis of the Bc species-group utilizing 157 single-copy genes of the family Bacillaceae suggests that several taxonomic revisions of the genus Bacillus should be considered. Within the Bc species-group there is little indication that the currently recognized species form related sub-groupings, suggesting that they are members of the same species. The sigma factor gene family encoded by the Bc species-group appears to be the result of a dynamic gene-duplication and gene-loss process that in previous analyses underestimated the true heterogeneity of the sigma factor content in the Bc species-group. Conclusions Expansion of the sigma factor gene family

  10. Draft Whole-Genome Sequence of the Type Strain Bacillus horikoshii DSM 8719

    Science.gov (United States)

    Hernández-González, Ismael L.

    2016-01-01

    Members of the Bacillus genus have been extensively studied because of their ability to produce enzymes with high biotechnological value. Here, we report the draft of the whole-genome sequence of the type strain Bacillus horikoshii DSM 8719, an alkali-tolerant strain. PMID:27417833

  11. Genome Sequence of the Plant Growth-Promoting Rhizobacterium Bacillus sp. Strain 916

    OpenAIRE

    Wang, Xiaoyu; Luo, Chuping; Chen, Zhiyi

    2012-01-01

    Bacillus sp. strain 916, isolated from the soil, showed strong activity against Rhizoctonia solani. Here, we present the high-quality draft genome sequence of Bacillus sp. strain 916. Its 3.9-Mb genome reveals a number of genes whose products are possibly involved in promotion of plant growth or antibiosis.

  12. Microbial dynamics during shelf-life of industrial Ricotta cheese and identification of a Bacillus strain as a cause of a pink discolouration.

    Science.gov (United States)

    Sattin, E; Andreani, N A; Carraro, L; Fasolato, L; Balzan, S; Novelli, E; Squartini, A; Telatin, A; Simionati, B; Cardazzo, B

    2016-08-01

    Dairy products are perishable and have to be preserved from spoilage during the food chain to achieve the desired shelf-life. Ricotta is a typical Italian soft dairy food produced by heat coagulation of whey proteins and is considered to be a light and healthy product. The shelf-life of Ricotta could be extended, as required by the international food trade market; however, heat resistant microflora causes spoilage and poses issues regarding the safety of the product. Next-generation sequencing (NGS) applied to the Ricotta samples defined the composition of the microbial community in-depth during the shelf-life. The analysis demonstrated the predominance of spore-forming bacteria throughout the shelf-life, mostly belonging to Bacillus, Paenibacillus and Clostridium genera. A strain involved in spoilage and causing a pink discolouration of Ricotta was isolated and characterised as Bacillus mycoides/weihenstephanensis. This is the first report of a food discolouration caused by a toxigenic strain belonging to the Bacillus cereus group that resulted the predominant strain in the community of the defective ricotta. These results suggest that the processing of raw materials to eliminate spores and residual microflora could be essential for improving the quality and the safety of the product and to extend the shelf-life of industrial Ricotta.

  13. Microbial dynamics during shelf-life of industrial Ricotta cheese and identification of a Bacillus strain as a cause of a pink discolouration.

    Science.gov (United States)

    Sattin, E; Andreani, N A; Carraro, L; Fasolato, L; Balzan, S; Novelli, E; Squartini, A; Telatin, A; Simionati, B; Cardazzo, B

    2016-08-01

    Dairy products are perishable and have to be preserved from spoilage during the food chain to achieve the desired shelf-life. Ricotta is a typical Italian soft dairy food produced by heat coagulation of whey proteins and is considered to be a light and healthy product. The shelf-life of Ricotta could be extended, as required by the international food trade market; however, heat resistant microflora causes spoilage and poses issues regarding the safety of the product. Next-generation sequencing (NGS) applied to the Ricotta samples defined the composition of the microbial community in-depth during the shelf-life. The analysis demonstrated the predominance of spore-forming bacteria throughout the shelf-life, mostly belonging to Bacillus, Paenibacillus and Clostridium genera. A strain involved in spoilage and causing a pink discolouration of Ricotta was isolated and characterised as Bacillus mycoides/weihenstephanensis. This is the first report of a food discolouration caused by a toxigenic strain belonging to the Bacillus cereus group that resulted the predominant strain in the community of the defective ricotta. These results suggest that the processing of raw materials to eliminate spores and residual microflora could be essential for improving the quality and the safety of the product and to extend the shelf-life of industrial Ricotta. PMID:27052696

  14. Activation of the latent PlcR regulon in Bacillus anthracis

    OpenAIRE

    Sastalla, Inka; Maltese, Lauren M.; Pomerantseva, Olga M.; Pomerantsev, Andrei P; Keane-Myers, Andrea; Stephen H Leppla

    2010-01-01

    Many genes in Bacillus cereus and Bacillus thuringiensis are under the control of the transcriptional regulator PlcR and its regulatory peptide, PapR. In Bacillus anthracis, the causative agent of anthrax, PlcR is inactivated by truncation, and consequently genes having PlcR binding sites are expressed at very low levels when compared with B. cereus. We found that activation of the PlcR regulon in B. anthracis by expression of a PlcR–PapR fusion protein does not alter sporulation in strains c...

  15. Histopathological studies on the effect of bacteriocin producing Bacillus cereus isolate from ‘wara’ a local soft cheese on the liver, kidney and reproductive organs of Wistar albino rats

    Directory of Open Access Journals (Sweden)

    Anyanwu, C.

    2013-01-01

    Full Text Available Aims: This study was done to generate a baseline data on the effect of Bacillus cereus and its bacteriocin on the liver, kidney and reproductive organs in both sexes at different concentration.Methodology and results: B. cereus and its bacteriocin were injected intramuscularly in male and female Wistar rats at doses equivalent to 102 CFU and 104 CFU dilutions. Body weights were also noted. The liver, kidney and reproductive organs of the animals were examined for histopathological changes. The liver of female rats administered B. cereus at 102 CFU showed portal and cellular infiltration by mononuclear cells, diffuse hydropic degeneration and severe interstitial hemorrhages of the kidney was observed when 104 CFU of B. cereus was given. Male rats administered 102 CFU and 104 CFU of B. cereus showed diffuse hydropic degeneration and portal congestion of the liver while at 104 CFU the kidney showed diffuse, moderate interstitial cellular infiltration. This is more evident in the wistar rats administered with bacilli organism than the groups that received the bacteriocin. The reproductive organs of treated animals showed no pathological lesions. There were no visible tissue pathological changes in the untreated groups. There were no visible tissue pathological changes in the untreated groups.Conclusion, significance and impact study: The absence of observable toxic effects of the bacteriocin of B. cereus on the sex organs, is not sufficient to determine the safety of this bacteriocin since pathological lesions were observed in the liver and kidney. We hereby suggest a further study on characterization and purification of this bacteriocin as a biopreservative in items not meant for human use or consumption.

  16. Antibody Binding Studies Reveal Conformational Flexibility of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) A-Component

    Science.gov (United States)

    Märtlbauer, E.

    2016-01-01

    The non-hemolytic enterotoxin complex (Nhe) is supposed to be the main virulence factor of B. cereus causing a diarrheal outcome of food poisoning. This tripartite toxin consists of the single components NheA, -B and -C all of them being necessary for maximum toxicity. In the past, research activities aiming to elucidate the mode-of-action of Nhe were mostly focused on the B- and C-component. In this study the generation of novel monoclonal antibodies (mAb) and their thorough characterization enabled the determination of key features for NheA. By the means of immunoaffinity chromatography it could be shown that NheA does not interact with -B and -C in solution. Additionally, the establishment of a highly sensitive sandwich-EIA now enables the detection of NheA in B. cereus supernatants down to 20 pg ml-1.Peptide-based epitope mapping in combination with partially deleted recombinant NheA fragments allowed the allocation of the binding regions for the three mAbs under study. Furthermore, by different EIA set-ups the conformational flexibility of NheA could be shown. For two of the antibodies under study different mechanisms of NheA neutralization were proven. Due to prevention of complete pore formation by one of the antibodies, NheA could be detected in an intermediate stage of the tripartite complex on the cell surface. Taken together, the results obtained in the present study allow a refinement of the mode-of-action for the Nhe toxin-complex. PMID:27768742

  17. 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

    2012-01-01

    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. F

  18. Determination and quantification of the emetic toxin cereulide from Bacillus cereus in pasta, rice and cream with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rønning, Helene Thorsen; Asp, Tone Normann; Granum, Per Einar

    2015-01-01

    A rapid and sensitive method has been developed for determination and quantification of cereulide in cream, rice and pasta. Samples are homogenised after addition of amylase to cooked rice and pasta, and cereulide is extracted with methanol. After the removal of water with methyl-tert butyl ether/hexane and evaporation until dryness, no further purification was required before analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Recently, both cereulide and (13)C6-cereulide has become commercially available at high purities; hence, this method offers a more reliable quantification of positive samples than previous methods using valinomycin or in-house produced and purified cereulide as calibration standard. The introduction of amylase in the sample preparation improves both the extraction yield of cereulide from positive samples of starch-rich matrices such as pasta and rice, and the within-laboratory reproducibility of the analytical method. The LoQ of the method is 1.1 ng/g cereulide with RSDs ranging from 2.6% to 10%. The method is fully validated based on Commission Decision 2002/657/EC, suitable for routine analysis, and has been used to analyse samples from a cereulide food poisoning outbreak in a kindergarten in Norway. Cereulide production in different rice and pasta samples was investigated, showing that cereulide was unexpectedly produced by emetic Bacillus cereus in all eight pasta and rice samples.

  19. Structural and computational analysis of peptide recognition mechanism of class-C type penicillin binding protein, alkaline D-peptidase from Bacillus cereus DF4-B.

    Science.gov (United States)

    Nakano, Shogo; Okazaki, Seiji; Ishitsubo, Erika; Kawahara, Nobuhiro; Komeda, Hidenobu; Tokiwa, Hiroaki; Asano, Yasuhisa

    2015-01-01

    Alkaline D-peptidase from Bacillus cereus DF4-B, called ADP, is a D-stereospecific endopeptidase reacting with oligopeptides containing D-phenylalanine (D-Phe) at N-terminal penultimate residue. ADP has attracted increasing attention because it is useful as a catalyst for synthesis of D-Phe oligopeptides or, with the help of substrate mimetics, L-amino acid peptides and proteins. Structure and functional analysis of ADP is expected to elucidate molecular mechanism of ADP. In this study, the crystal structure of ADP (apo) form was determined at 2.1 Å resolution. The fold of ADP is similar to that of the class C penicillin-binding proteins of type-AmpH. Docking simulations and fragment molecular orbital analyses of two peptides, (D-Phe)4 and (D-Phe)2-(L-Phe)2, with the putative substrate binding sites of ADP indicated that the P1 residue of the peptide interacts with hydrophobic residues at the S1 site of ADP. Furthermore, molecular dynamics simulation of ADP for 50 nsec suggested that the ADP forms large cavity at the active site. Formation of the cavity suggested that the ADP has open state in the solution. For the ADP, having the open state is convenient to bind the peptides having bulky side chain, such as (D-Phe)4. Taken together, we predicted peptide recognition mechanism of ADP. PMID:26370172

  20. The Role of Active Site Flexible Loops in Catalysis and of Zinc in Conformational Stability of Bacillus cereus 569/H/9 β-Lactamase.

    Science.gov (United States)

    Montagner, Caroline; Nigen, Michaël; Jacquin, Olivier; Willet, Nicolas; Dumoulin, Mireille; Karsisiotis, Andreas Ioannis; Roberts, Gordon C K; Damblon, Christian; Redfield, Christina; Matagne, André

    2016-07-29

    Metallo-β-lactamases catalyze the hydrolysis of most β-lactam antibiotics and hence represent a major clinical concern. The development of inhibitors for these enzymes is complicated by the diversity and flexibility of their substrate-binding sites, motivating research into their structure and function. In this study, we examined the conformational properties of the Bacillus cereus β-lactamase II in the presence of chemical denaturants using a variety of biochemical and biophysical techniques. The apoenzyme was found to unfold cooperatively, with a Gibbs free energy of stabilization (ΔG(0)) of 32 ± 2 kJ·mol(-1) For holoBcII, a first non-cooperative transition leads to multiple interconverting native-like states, in which both zinc atoms remain bound in an apparently unaltered active site, and the protein displays a well organized compact hydrophobic core with structural changes confined to the enzyme surface, but with no catalytic activity. Two-dimensional NMR data revealed that the loss of activity occurs concomitantly with perturbations in two loops that border the enzyme active site. A second cooperative transition, corresponding to global unfolding, is observed at higher denaturant concentrations, with ΔG(0) value of 65 ± 1.4 kJ·mol(-1) These combined data highlight the importance of the two zinc ions in maintaining structure as well as a relatively well defined conformation for both active site loops to maintain enzymatic activity. PMID:27235401

  1. rpoB作为蜡样芽胞杆菌群快速检测的标志基因的实验研究%Using real-time quantitative PCR for the detection of rpoB gene of Bacillus cereus group

    Institute of Scientific and Technical Information of China (English)

    朱诗应; 何胜菲; 王文博; 赵平; 任浩; 戚中田

    2012-01-01

    Objective To develop a routine PCR and a real-time quantitative PCR(Q-PCR) assay for the detection of Bacillus cereus. Methods Genomic DNAs of various groups of Bacillus cereus were extracted. Specific primers for rpoB gene of Bacillus cereus were designed. The target rpoB gene fragment was amplified by a routine PCR and a SYBR green Q-PCR. The PCR products were cloned into pMD18-T plasmid vector and then sequenced. Results The rpoB gene fragment with a length of 174 bp was amplified from 4 species of Bacillus cereus. There was no non-specific amplification from the control bacterial strains by routine PCR or Q-PCR. Results from the sequencing of the amplified DNA fragment showed that there was 5 nucleotides diversity, and the sequence diversity was 2.88%. The sensitivity of routine PCR assay was 3.42 pg, while the sensitivity of the Q-PCR was 171 fg corresponding to (3.32×10±7.45×100) rpoB gene copies. Conclusions The developed Q-PCR method showed a good specificity and sensitivity for the detection of target rpoB gene. It may be used for rapid diagnosis of Bacillus cereus spp.%目的 探讨常规PCR和实时荧光定量PCR(Q-PCR)方法检测蜡样芽胞杆菌群rpoB基因的特异性和敏感性.方法 提取蜡样芽胞杆菌群和其他各种对照细菌的基因组DNA,合成蜡样芽胞杆菌群rpoB基因扩增引物,采用常规PCR和SYBR green实时定量PCR两种方法扩增rpoB基因片段,并将PCR产物克隆到pMD18-T载体后进行DNA测序.结果 常规PCR和Q-PCR均能扩增出蜡样芽胞杆菌群rpoB基因的174 bp DNA片段,而各种对照菌株均未见扩增.序列比对发现蜡样芽胞杆菌群细菌在该片段中存在5处核苷酸的不同,差异率为2.88%.以炭疽芽胞杆菌基因组DNA系列稀释作为扩增模板显示常规PCR最小检出量为3.42 pg,Q-PCR的敏感性达到171 fg,3次重复实验显示Q-PCR检测rpoB基因的灵敏度为(3.32×101±7.45×100)拷贝.结论 以rpoB基因为检测靶基因的Q-PCR方法具有

  2. 空间诱导蜡状芽孢杆菌LCT-BC25和LCT-BC235的蛋白质组学研究%Proteomics of space Bacillus cereus mutant starains LCT-BC25 and LCT-BC235

    Institute of Scientific and Technical Information of China (English)

    苏龙翔; 刘进文; 方向群; 李天志; 王俊峰; 郭英华; 常德; 徐国纲; 刘长庭

    2013-01-01

    Objective To study the proteomics of Bacillus cereus mutant strains LCT-BC25 and LCT-BC235 by detecting the effect of space environment on them. Methods Space Bacillus cereus mutant strains LCT-BC25 and LCT-BC235 and ground control strain LCT-BC244 were identified with isobaric tags for relative and absolute quantitation(iTRAQ) by mass spectrometry. The detected peptides were reassembled and their functions were analyzed. The proteins with a significantly different expression were selected. Results The majority of the 1 269 possible proteins identified in this study were related with the bacterial metabolism according to the cluster of orthologous groups (COG), gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG). The proteomic analysis showed that the protein levels were up-regulated in space 57 and 8 mutant strains and down-regulated in 77 and 73 ground control LCT-BC244 strain. Conclusion The effect of space environment on Bacillus cereus mutant trains is not directional. Bacillus cereus can adapt to the space environment by adjusting its own metablism. The highly expressed hemolytic enterotoxin protein can influence the health of astronauts.%  目的探索空间环境对蜡状芽孢杆菌的影响。方法采用同重同位素相对与绝对定量(isobaric tags for relativeand absolute quantitation,iTRAQ)技术对经空间诱变蜡状芽孢杆菌LCT-BC25和LCT-BC235以及地面对照株LCT-BC244进行蛋白质组质谱检测,对测得的肽段重新组装,对组装的蛋白进行功能注释分析,最终筛选具有明显表达差异的蛋白质。结果本研究共鉴定到1269个可能蛋白质,根据蛋白相邻类的聚簇(cluster of orthologous groups of proteins,COG)、基因本体论(gene ontology,GO)、京都基因与基因组百科全书(kyoto encyclopedia of genes and genomes,KEGG)对这些蛋白质进行分类分析发现,大多数鉴定到的蛋白与细菌代谢相关。比较蛋白质组学结果表明,空间诱变株LCT-BC25

  3. The respiratory arsenate reductase from Bacillus selenitireducens strain MLS10

    Science.gov (United States)

    Afkar, E.; Lisak, J.; Saltikov, C.; Basu, P.; Oremland, R.S.; Stolz, J.F.

    2003-01-01

    The respiratory arsenate reductase from the Gram-positive, haloalkaliphile, Bacillus selenitireducens strain MLS10 was purified and characterized. It is a membrane bound heterodimer (150 kDa) composed of two subunits ArrA (110 kDa) and ArrB (34 kDa), with an apparent Km for arsenate of 34 ??M and Vmax of 2.5 ??mol min-1 mg-1. Optimal activity occurred at pH 9.5 and 150 g l-1 of NaCl. Metal analysis (inductively coupled plasma mass spectrometry) of the holoenzyme and sequence analysis of the catalytic subunit (ArrA; the gene for which was cloned and sequenced) indicate it is a member of the DMSO reductase family of molybdoproteins. ?? 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

  4. Effect of oral administration of Bacillus coagulans B37 and Bacillus pumilus B9 strains on fecal coliforms, Lactobacillus and Bacillus spp. in rat animal model

    OpenAIRE

    Lopamudra Haldar; Gandhi, D.N.

    2016-01-01

    Aim: To investigate the effect of oral administration of two Bacillus strains on fecal coliforms, Lactobacillus and Bacillus spp. in rat animal model. Materials and Methods: An in vivo experiment was conducted for 49-day period on 36 adult male albino Wister rats divided equally into to four groups. After 7-day adaptation period, one group (T1) was fed on sterile skim milk along with basal diet for the next 28 days. Second (T2) and (T3) groups received spore biomass of Bacillus coagulans B...

  5. 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.

    Science.gov (United States)

    Erban, Tomas; Rybanska, Dagmar; Harant, Karel; Hortova, Bronislava; Hubert, Jan

    2016-01-01

    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 (DDF). 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 (poly)ubiquitins. 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 (DDF) 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 with the mite in

  6. 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

  7. 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.

    Science.gov (United States)

    Erban, Tomas; Rybanska, Dagmar; Harant, Karel; Hortova, Bronislava; Hubert, Jan

    2016-01-01

    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 (DDF). 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 (poly)ubiquitins. 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 (DDF) 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 with the mite in

  8. 蜡状芽孢杆菌群中规律成簇间隔短回文重复序列的生物信息学分析%Bioinformatics Analysis of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in the Genomes of Bacillus cereus Group

    Institute of Scientific and Technical Information of China (English)

    王琰; 喻婵; 王阶平; 邱宁; 何进; 孙明; 张青叶

    2011-01-01

    CRISPR is a novel type of microbial defense system, which is unique in that it is invaderspecific, adaptive and heritable. It is a recent breakthrough in understanding host-virus interactions.Bioinformatics methods including BLAST, multiple sequence alignment, and RNA structure prediction was used to analyze the CRISPR structures of 24 Bacillus cereus group genomes. CRISPR existed in 42% strains. Two types of RNA secondary structures derived from the repeat sequences were predicted, and demonstrated that stemloop secondary structure might function in mediating the interaction between foreign genetic elements and CASencoded proteins. The sequence homologous among 31% spacer, phage, plasmid and the genomes of Bacillus cereus group further verified that spacer was likely to come from the exogenous mobile genetic factor. As most of the Bacillus cereus group strains contain multiple plasmids and prophages, the CRISPR research in Bacillus cereus group by this study would be help to reveal relationship between host strains with plasmid or host strains with phage.%规律成簇间隔短回文重复序列(clustered regularly interspaced short palindromic repeats,CRISPR)是最近发现针对噬菌体等外源遗传物质的获得性和可遗传性的新型原核生物防御系统.通过BLAST、多序列比对、RNA二级结构预测等生物信息学方法对已经完成全基因组测序的蜡状芽孢杆菌群24个菌株进行CRISPR的系统分析,结果表明:42%的菌株含有该结构;8个CRISPR座位的正向重复序列可以形成RNA二级结构,提示正向重复序列可能介导外源DNA或RNA与CAS编码蛋白的相互作用;31%的间区序列与噬菌体、质粒、蜡状芽孢杆菌群基因组序列具有同源性,进一步验证间区序列很可能来源于外源可移动遗传因子.由于大部分蜡状芽孢杆菌群菌株含有多个前噬菌体和质粒,通过对蜡状芽孢杆菌群CRISPR的分析,为揭示其对宿主菌与噬菌体,以及宿主

  9. Quantification of the effect of culturing temperature on salt-induced heat resistance of Bacillus species

    NARCIS (Netherlands)

    Besten, den H.M.W.; Mark, E.J.; Hensen, L.; Abee, T.; Zwietering, M.H.

    2010-01-01

    Short- and long-term exposure to mild stress conditions can activate stress adaptation mechanisms in pathogens, resulting in a protective effect toward otherwise lethal stresses. The mesophilic strains Bacillus cereus ATCC 14579 and ATCC 10987 and the psychrotolerant strain B. weihenstephanensis KBA

  10. Draft Genome Sequence of Bacillus subtilis Strain NKYL29, an Antimicrobial-Peptide-Producing Strain from Soil

    OpenAIRE

    Jiang, Yanbin; Xu, Haijin; Ying LI; Liu, Hongbin; Yu, Lei; Qiao, Mingqiang; Liu, Gang

    2014-01-01

    Bacillus subtilis strain NKYL29 is an antimicrobial-peptide-producing strain isolated from the soil of Ranzhuang Tunnel in Hebei Province, China. Here, we present the draft genome of this strain, which provides the genetic basis for application of the antimicrobial peptide.

  11. The effects of citrus extract (Citrox©) on the naturally occurring microflora and inoculated pathogens, Bacillus cereus and Salmonella enterica, in a model food system and the traditional Greek yogurt-based salad Tzatziki.

    Science.gov (United States)

    Tsiraki, Maria I; Savvaidis, Ioannis N

    2016-02-01

    The antimicrobial effect of citrus extract (at 1 mL/kg [TC1] and 2 mL/kg [TC2]) on the naturally occurring microflora and inoculated pathogens (Bacillus cereus and Salmonella enterica, at ca. 6 log cfu/g) in the traditional Greek yogurt-based salad Tzatziki during storage under vacuum at 4 or 10 °C was examined. We also examined the effect of citrus extract (Citrox(©)) against the two aforementioned pathogens in tryptic soy broth (TSB). Of the two treatments, TC2 yielded the lowest yeast counts, irrespective of temperature, resulting in approximately 2 (4 °C) and 3 (10 °C) log reductions on the final day of storage (70 and 30 days, respectively). Although panelists preferred the TC1-treated salad, the TC2-treated product was sensorily acceptable. Therefore, at the concentrations used, Citrox had no negative sensorial effect on the Tzatziki. During storage, the Bacillus populations in the Citrox-treated Tzatziki samples progressively decreased, showing major declines from days 12 and 28 (at 10 and 4 °C, respectively). Citrox, especially at 2 mL/kg, had a significant effect on the survival of B. cereus. S. enterica showed major declines in all untreated Tzatziki samples from day 0-70 (4 °C) and from day 0-30 (10 °C), with averages of 2.5 and 2.8 log cfu/g, respectively. The results indicate that Citrox (at 1 and 2 mL/kg) is effective, from a safety standpoint, for reducing Bacillus and Salmonella spp. in Tzatziki. In addition, 2% citrus extract also showed a higher inhibitory effect against B. cereus and S. enterica grown in TSB than 1% citrus extract.

  12. Formation of small transmembrane pores: An intermediate stage on the way to Bacillus cereus non-hemolytic enterotoxin (Nhe) full pores in the absence of NheA.

    Science.gov (United States)

    Zhu, Kui; Didier, Andrea; Dietrich, Richard; Heilkenbrinker, Uta; Waltenberger, Eva; Jessberger, Nadja; Märtlbauer, Erwin; Benz, Roland

    2016-01-15

    The non-hemolytic enterotoxin (Nhe) of Bacillus cereus is a three-partite toxin formed of the components NheA, -B and -C. Pore formation and subsequent lysis of target cells caused by Nhe is an orchestrated process comprising three steps: (i) formation of NheB/C oligomers in solution, (ii) attachment of the oligomers to the cell membrane, (iii) binding of NheA to the oligomers. The present study aimed to characterize the properties of the NheB/C complex and the fate of the target cell upon binding. An enzyme immunoassay allowing kinetic measurements and surface plasmon resonance revealed the fast and high affinity formation of the NheB/C oligomers. The benefit of these complexes is a more stable cell binding as well as stronger and earlier cytotoxic effect. High molecular mass hetero-oligomers (620 kDa) probably consisting of one NheC and up to 15 NheB were detected by size-exclusion chromatography and on native PAGE immunoblots. Due to the NheBC application the morphology and membrane permeability of Vero cells is partly disturbed. Formation of stable transmembrane channels with a conductance of about 870 pS and a diameter of about 2 nm due to the application of NheBC could be demonstrated in lipid bilayer experiments. Thus, the NheBC complex itself has a tendency to increase the membrane permeability prior to the emergence of full pores containing also NheA.

  13. A computational module assembled from different protease family motifs identifies PI PLC from Bacillus cereus as a putative prolyl peptidase with a serine protease scaffold.

    Science.gov (United States)

    Rendón-Ramírez, Adela; Shukla, Manish; Oda, Masataka; Chakraborty, Sandeep; Minda, Renu; Dandekar, Abhaya M; Ásgeirsson, Bjarni; Goñi, Félix M; Rao, Basuthkar J

    2013-01-01

    Proteolytic enzymes have evolved several mechanisms to cleave peptide bonds. These distinct types have been systematically categorized in the MEROPS database. While a BLAST search on these proteases identifies homologous proteins, sequence alignment methods often fail to identify relationships arising from convergent evolution, exon shuffling, and modular reuse of catalytic units. We have previously established a computational method to detect functions in proteins based on the spatial and electrostatic properties of the catalytic residues (CLASP). CLASP identified a promiscuous serine protease scaffold in alkaline phosphatases (AP) and a scaffold recognizing a β-lactam (imipenem) in a cold-active Vibrio AP. Subsequently, we defined a methodology to quantify promiscuous activities in a wide range of proteins. Here, we assemble a module which encapsulates the multifarious motifs used by protease families listed in the MEROPS database. Since APs and proteases are an integral component of outer membrane vesicles (OMV), we sought to query other OMV proteins, like phospholipase C (PLC), using this search module. Our analysis indicated that phosphoinositide-specific PLC from Bacillus cereus is a serine protease. This was validated by protease assays, mass spectrometry and by inhibition of the native phospholipase activity of PI-PLC by the well-known serine protease inhibitor AEBSF (IC50 = 0.018 mM). Edman degradation analysis linked the specificity of the protease activity to a proline in the amino terminal, suggesting that the PI-PLC is a prolyl peptidase. Thus, we propose a computational method of extending protein families based on the spatial and electrostatic congruence of active site residues.

  14. 蜡样杆菌(Bacillus cereus)M22 Mn-SOD cDNA片断的克隆%Cloning and Analysis of cDNA Fragment of Mn-SOD (Manganese Superoxide Dismutase) from Bacillus cereus M22

    Institute of Scientific and Technical Information of China (English)

    陈惠芳; 尚玉磊; 王琦; 王慧敏; 梅汝鸿

    2004-01-01

    分析不同种细菌Mn-SOD氨基酸序列的保守区域,设计一对简并引物进行RT-PCR扩增,产物经T-A载体连接转化大肠杆菌JM109,筛选阳性克隆、测序并进行同源性分析,得到 436 bp Mn-SOD cDNA片段.根据此片段设计 5′端特异性引物,然后进行5′RACE扩增,获得Mn-SOD 5′端 387 bp cDNA片断.将 2 段序列进行拼接获得 594 bp cDNA片断,编码 172 个氨基酸.对推定氨基酸序列进行BLAST分析,结果表明其与炭疽芽孢杆菌(Bacillus anthracis)同源性为 95 %,且Gly77,Aly78,Phe86,Gln150和Asp151在已报道的Mn-SOD中均存在,构成Mn-SOD的活性中心.表明该序列为蜡样芽孢杆菌Mn-SOD的cDNA序列.

  15. Spectroscopic studies of the iron and manganese reconstituted tyrosyl radical in Bacillus cereus ribonucleotide reductase R2 protein.

    Directory of Open Access Journals (Sweden)

    Ane B Tomter

    Full Text Available 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 active site; and R2F, which contains a metallo cofactor and a tyrosyl radical that initiates the ribonucleotide reduction reaction. We studied the R2F subunit of B. cereus reconstituted with iron or alternatively with manganese ions, then subsequently reacted with molecular oxygen to generate two tyrosyl-radicals. The two similar X-band EPR spectra did not change significantly over 4 to 50 K. From the 285 GHz EPR spectrum of the iron form, a g(1-value of 2.0090 for the tyrosyl radical was extracted. This g(1-value is similar to that observed in class Ia E. coli R2 and class Ib R2Fs with iron-oxygen cluster, suggesting the absence of hydrogen bond to the phenoxyl group. This was confirmed by resonance Raman spectroscopy, where the stretching vibration associated to the radical (C-O, ν(7a = 1500 cm(-1 was found to be insensitive to deuterium-oxide exchange. Additionally, the (18O-sensitive Fe-O-Fe symmetric stretching (483 cm(-1 of the metallo-cofactor was also insensitive to deuterium-oxide exchange indicating no hydrogen bonding to the di-iron-oxygen cluster, and thus, different from mouse R2 with a hydrogen bonded cluster. The HF-EPR spectrum of the manganese reconstituted RNR R2F gave a g(1-value of ∼2.0094. The tyrosyl radical microwave power saturation behavior of the iron-oxygen cluster form was as observed in class Ia R2, with diamagnetic di-ferric cluster ground state, while the properties of the manganese reconstituted form indicated a magnetic ground state of the manganese-cluster. The recent activity measurements (Crona et al., (2011 J Biol Chem 286: 33053-33060 indicates that both the manganese and iron reconstituted RNR R2F could be functional. The manganese form might be very important, as it has 8

  16. Genome Sequence of Bacillus anthracis Strain Stendal, Isolated from an Anthrax Outbreak in Cattle in Germany

    OpenAIRE

    Antwerpen, Markus; Elschner, Mandy; Gaede, Wolfgang; Schliephake, Annette; Grass, Gregor; Tomaso, Herbert

    2016-01-01

    In July 2012, an anthrax outbreak occurred among cattle in northern Germany resulting in ten losses. Here, we report the draft genome sequence of Bacillus anthracis strain Stendal, isolated from one of the diseased cows.

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

    OpenAIRE

    Balayogan Sivasankari; Marimuthu Anandharaj

    2014-01-01

    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 str...

  18. Genome Sequence of the Endophytic Bacterium Bacillus thuringiensis Strain KB1, a Potential Biocontrol Agent against Phytopathogens

    OpenAIRE

    Jeong, Haeyoung; Jo, Sung Hee; Hong, Chi Eun; Park, Jeong Mee

    2016-01-01

    Bacillus thuringiensis is the most widely known microbial pesticide used in agricultural applications. Herein, we report a draft genome sequence of the endophytic bacterium Bacillus thuringiensis strain KB1, which exhibits antagonism against phytopathogens.

  19. Comparison of Growth and Toxin Production in Two Vaccine Strains of Bacillus anthracis

    OpenAIRE

    Johnson, Anna D; Spero, Leonard

    1981-01-01

    Two vaccine strains of Bacillus anthracis were monitored in a 10-liter fermentor to compare growth patterns and toxin production. Under identical conditions, the Sterne strain produced all three components of anthrax toxin, whereas strain V770 produced only the protective antigen.

  20. Genome Sequence of Bacillus subtilis Strain HUK15, Isolated from Hexachlorocyclohexane-Contaminated Soil

    OpenAIRE

    Gasc , Cyrielle; Richard, Jean-Yves; Peyret, Pierre

    2016-01-01

    Bacillus subtilis strain HUK15 has been isolated from hexachlorocyclohexane (HCH)-long-term-contaminated soil. The genome of strain HUK15 was sequenced to investigate its adaptation toward HCH and its potential capability to degrade the pesticide. Here, we report the annotated draft genome sequence (~4.3 Mbp) of this strain.

  1. Isolation and characterization of antagonistic Bacillus strains capable to degrade ethylenethiourea.

    Science.gov (United States)

    Vágvölgyi, Csaba; Sajben-Nagy, Enikő; Bóka, Bettina; Vörös, Mónika; Berki, Adrienn; Palágyi, Andrea; Krisch, Judit; Skrbić, Biljana; Durišić-Mladenović, N; Manczinger, László

    2013-03-01

    In this study, more than 150 bacteria showing antagonistic properties against bacterial and fungal pathogens of the tomato plant were isolated and characterized. The most efficient agents against these phytopathogenic microorganisms belong to the genus Bacillus: the best biocontrol isolates were representatives of Bacillus subtilis, B. mojavensis and B. amyloliquefaciens species. They intensively produced fengycin or/and surfactin depsipeptide antibiotics and also proved to be excellent protease secretors. It was proved, that the selected strains were able to use ethylenethiourea (ETU) as sole nitrogen source. These antagonistic and ETU-degrading Bacillus strains can be applied as biocontrol and also as bioremediation agents. PMID:23143288

  2. The inhibition effect of extracts from Allium sativum on Bacillus cereus%大蒜提取物对蜡样芽孢杆菌抑制效果的研究

    Institute of Scientific and Technical Information of China (English)

    穆可云; 李理

    2011-01-01

    By measuring the diameter of inhibition zone, effects of aqueous extracts, ethanol extracts and acidic aqueous extracts from Allium sativum on Bacillus cereus were discussed. The results showed thai the bacteriostatic effect of ethanol extracts was better than that of aqueous extracts. The bacteriostatic effect of acidic aqueous extracts from Allium sativum was the best, which could restrain Bacillus cereus growth and had good perspective and practicability.%该文采用抑菌圈法研究了大蒜的水提取物、乙醇提取物和酸性水溶液的提取物对蜡样芽孢杆菌的抑制作用.结果表明大蒜的乙醇提取物的抑菌效果好过水提取物,酸性的水溶液提取物效果最好,可以较好地控制蜡样芽孢杆菌的生长,有较好的应用前景.

  3. Genotype Analysis of Bacillus anthracis Strains Circulating in Bangladesh.

    Science.gov (United States)

    Rume, Farzana Islam; Affuso, Alessia; Serrecchia, Luigina; Rondinone, Valeria; Manzulli, Viviana; Campese, Emanuele; Di Taranto, Pietro; Biswas, Paritosh Kumar; Ahsan, Chowdhury Rafiqul; Yasmin, Mahmuda; Fasanella, Antonio; Hugh-Jones, Martin

    2016-01-01

    In Bangladesh, anthrax, caused by the bacterium Bacillus anthracis, is considered an endemic disease affecting ruminants with sporadic zoonotic occurrences in humans. Due to the lack of knowledge about risks from an incorrect removal of infected carcasses, the disease is not properly monitored, and because of the socio-economic conditions, the situation is under-reported and under-diagnosed. For sensitive species, anthrax represents a fatal outcome with sudden death and sometimes bleeding from natural orifices. The most common source of infection for ruminants is ingestion of spores during grazing in contaminated pastures or through grass and water contaminated with anthrax spores. Domestic cattle, sheep and goats can also become infected through contaminated bone meal (used as feed) originating from anthrax-infected carcasses. The present investigation was conducted to isolate B. anthracis organisms from 169 samples (73 soil, 1 tissue, 4 bone and 91 bone meal samples) collected from 12 different districts of Bangladesh. The sampling was carried out from 2012 to 2015. Twelve samples resulted positive for B. anthracis. Biomolecular analyses were conducted starting from the Canonical Single Nucleotide Polymorphism (CanSNP) to analyze the phylogenetic origin of strains. The analysis of genotype, obtained through the Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) with the analysis of 15 Variable Number Tandem Repeats (VNTR), demonstrated four different genotypes: two of them were previously identified in the district of Sirajganj. The sub-genotyping, conducted with Single Nucleotide Repeats analysis, revealed the presence of eight subgenotypes. The data of the present study concluded that there was no observed correlation between imported cattle feed and anthrax occurrence in Bangladesh and that the remarkable genetic variations of B. anthracis were found in the soil of numerous outbreaks in this country. PMID:27082248

  4. Novel giant siphovirus from Bacillus anthracis features unusual genome characteristics.

    Directory of Open Access Journals (Sweden)

    Holly H Ganz

    Full Text Available Here we present vB_BanS-Tsamsa, a novel temperate phage isolated from Bacillus anthracis, the agent responsible for anthrax infections in wildlife, livestock and humans. Tsamsa phage is a giant siphovirus (order Caudovirales, featuring a long, flexible and non-contractile tail of 440 nm (not including baseplate structure and an isometric head of 82 nm in diameter. We induced Tsamsa phage in samples from two different carcass sites in Etosha National Park, Namibia. The Tsamsa phage genome is the largest sequenced Bacillus siphovirus, containing 168,876 bp and 272 ORFs. The genome features an integrase/recombinase enzyme, indicative of a temperate lifestyle. Among bacterial strains tested, the phage infected only certain members of the Bacillus cereus sensu lato group (B. anthracis, B. cereus and B. thuringiensis and exhibited moderate specificity for B. anthracis. Tsamsa lysed seven out of 25 B. cereus strains, two out of five B. thuringiensis strains and six out of seven B. anthracis strains tested. It did not lyse B. anthracis PAK-1, an atypical strain that is also resistant to both gamma phage and cherry phage. The Tsamsa endolysin features a broader lytic spectrum than the phage host range, indicating possible use of the enzyme in Bacillus biocontrol.

  5. In vitro evaluation of the antioxidant, 3,5-dihydroxy-4-ethyl-trans-stilbene (DETS isolated from Bacillus cereus as a potent candidate against malignant melanoma

    Directory of Open Access Journals (Sweden)

    Mohandas eC

    2016-04-01

    Full Text Available 3,5-dihydroxy-4-ethyl-trans-stilbene (DETS is a natural stilbene, which was first identified as bioactive bacterial secondary metabolite isolated from Bacillus cereus associated with a rhabditid entomopathogenic nematode. The present study was intended to investigate the antioxidant and anticancer activity of this compound in vitro. Antioxidant activity was investigated by assaying DPPH free radical scavenging, superoxide radical-(O2− scavenging, hydroxyl radical scavenging and metal chelating activity, which proved that the compound is a powerful antioxidant. The metal chelating activity of DETS was higher than butylated hydroxyanisol (BHA and gallic acid, two well-known antioxidants. As the molecule exhibited strong antioxidant potential, it was further evaluated for cytotoxic activity towards five cancer cells of various origins. Since the compound has a strong structural similarity with resveratrol (trans-3,4,5-trihydroxystilbene, a well-studied chemopreventive polyphenolic antioxidant, its anticancer activity was compared with that of resveratrol. Among the five cancer cells studied, the compound showed maximum cytotoxicity towards the human melanoma cell line, A375 (IC50: 24.01 μM followed by cervical [HeLa- 46.17 μM], colon [SW480- 47.28 μM], liver [HepG2- 69.56 μM] and breast [MCF-7- 84.31 μM] cancer cells. A375 was much more sensitive to DETS compared to the non-melanoma cell line, A431, in which the IC50 of the compound was more than double (49.60 μM. In the present study, the anticancer activity of DETS against melanoma was confirmed by various apoptosis assays. We also observed that DETS, like resveratrol, down-regulates the expression status of major molecules contributing to melanoma progression, such as BRAF, β-catenin and Brn-2, all of which converge in MITF-M, the master regulator of melanoma signaling. The regulatory role of MITF-M DETS-induced cytotoxicity in melanoma cells was confirmed by comparing the cytotoxicity

  6. Draft Genome Sequence of Bacillus thuringiensis Strain DAR 81934, Which Exhibits Molluscicidal Activity

    OpenAIRE

    Wang, Aisuo; Pattemore, Julie; Ash, Gavin; Williams, Angela; Hane, James

    2013-01-01

    Bacillus thuringiensis has been widely used as a biopesticide for a long time. Its molluscicidal activity, however, is rarely realized. Here, we report the genome sequence of B. thuringiensis strain DAR 81934, a strain with molluscicidal activity against the pest snail Cernuella virgata.

  7. Screening Bacillus thuringiensis strains for toxicity against Manduca sexta and Plutella xylostella

    Science.gov (United States)

    Screening Bacillus thuringiensis (Bt) isolates or strains for toxicity has traditionally been performed with one bacterial isolate at time versus a specific insect. By testing of Bt strains in groups, we identified 28 of 147 Bt isolates as toxic to either diamondback moth, Plutella xylostella (L.),...

  8. Characterization of a new Bacillus stearothermophilus isolate : a highly thermostable α-amylase-producing strain

    NARCIS (Netherlands)

    Wind, R.D.; Buitelaar, R.M.; Eggink, G.; Huizing, H.J.; Dijkhuizen, L.

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known α-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable α-amylase. The half-time of inactivation of this α-amylase was 5.1 h

  9. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this alpha-amylas

  10. Complete Genome Sequence of the Endophytic Biocontrol Strain Bacillus velezensis CC09

    Science.gov (United States)

    Cai, Xunchao; Kang, Xingxing; Xi, Huan

    2016-01-01

    Bacillus velezensis is a heterotypic synonym of B. methylotrophicus, B. amyloliquefaciens subsp. plantarum, and Bacillus oryzicola, and has been used to control plant fungal diseases. In order to fully understand the genetic basis of antimicrobial capacities, we did a complete genome sequencing of the endophytic B. velezensis strain CC09. Genes tightly associated with biocontrol ability, including nonribosomal peptide synthetases, polyketide synthetases, iron acquisition, colonization, and volatile organic compound synthesis were identified in the genome. PMID:27688342

  11. Complete Genome Sequence of the Endophytic Biocontrol Strain Bacillus velezensis CC09.

    Science.gov (United States)

    Cai, Xunchao; Kang, Xingxing; Xi, Huan; Liu, Changhong; Xue, Yarong

    2016-01-01

    Bacillus velezensis is a heterotypic synonym of B. methylotrophicus, B. amyloliquefaciens subsp. plantarum, and Bacillus oryzicola, and has been used to control plant fungal diseases. In order to fully understand the genetic basis of antimicrobial capacities, we did a complete genome sequencing of the endophytic B. velezensis strain CC09. Genes tightly associated with biocontrol ability, including nonribosomal peptide synthetases, polyketide synthetases, iron acquisition, colonization, and volatile organic compound synthesis were identified in the genome. PMID:27688342

  12. Bacillus 'next generation' diagnostics: Moving from detection towards sub-typing and risk related strain profiling

    Directory of Open Access Journals (Sweden)

    Monika eEhling-Schulz

    2013-02-01

    Full Text Available The highly heterogeneous genus Bacillus comprises the largest species group of endospore forming bacteria. Because of their ubiquitous nature, Bacillus spores can enter food production at several stages resulting in significant economic losses and posing a potential risk to consumers due the capacity of certain Bacillus strains for toxin production. In the past, food microbiological diagnostics was focused on the determination of species using conventional culture based methods, which are still widely used. However, due to the extreme intraspecies diversity found in the genus Bacillus, DNA based identification and typing methods are gaining increasing importance in routine diagnostics. Several studies showed that certain characteristics are rather strain dependent than species specific. Therefore, the challenge for current and future Bacillus diagnostics is not only the efficient and accurate identification on species level but also the development of rapid methods to identify strains with specific characteristics (such as stress resistance or spoilage potential, trace contamination sources, and last but not least discriminate potential hazardous strains from non-toxic strains.

  13. Plasmid Mediated Antibiotic and Heavy Metal Resistance in Bacillus Strains Isolated From Soils in Rize, Turkey

    Directory of Open Access Journals (Sweden)

    Elif SEVİM

    2015-09-01

    Full Text Available Fifteen Bacillus strains which were isolated from soil samples were examined for resistance to 17 different antibiotics (ampicillin, methicillin, erythromycin, norfloxacin, cephalotine, gentamycin, ciprofloxacin, streptomycin, tobramycin, chloramphenicol, trimethoprim-sulfamethoxazole, tetracycline, vancomycin, oxacilin, neomycin, kanamycin and, novabiocin and to 10 different heavy metals (copper, lead, cobalt, chrome, iron, mercury, zinc, nickel, manganese and, cadmium and for the presence of plasmid DNA. A total of eleven strains (67% were resistant to at least one antibiotic. The most common resistance was observed against methicillin and oxacillin. The most resistance strains were found as Bacillus sp. B3 and Bacillus sp. B11. High heavy metal resistance against copper, chromium, zinc, iron and nickel was detected, but mercury and cobalt resistance was not detected, except for 3 strains (B3, B11, and B12 which showed mercury resistance. It has been determined that seven Bacillus strains have plasmids. The isolated plasmids were transformed into the Bacillus subtilis W168 and it was shown that heavy metal and antibiotic resistance determinants were carried on these plasmids. These results showed that there was a correlation between plasmid content and resistance for both antibiotic and heavy metal resistance

  14. Optimization of polyphosphate production by Bacillus megaterium strain G11

    Directory of Open Access Journals (Sweden)

    Giti Emtiazi

    2013-01-01

    Full Text Available Introduction: Polyphosphates, also called volutin granules, are linear polymers from orthophosphates linked by energy-rich phosphoanhydride bands that have been seen in bacteria, yeasts, fungi, plants and animals. These polymers are completely safe and nontoxic, and have numerous applications in food and drug industries.Materials and methods: Due to the great importance and wide range of the utilization of these polymers in various industries, several factors such as various carbon sources, carbon source concentration and phosphorus concentration were studied and optimized. In order to increase polyphosphate production in Bacillus megaterium strain G11. The optimization process was carried out with determination of the amount of polyphosphate accumulated in cell and phosphorus removed from the medium. One-way ANOVA and Tukey tests were used in order to determine whether there was a significant difference between data obtained in this research.Results: Growth of B. megaterium in the presence of sucrose (OD=3.026 was better than glucose (OD=2.616 whereas polyphosphate production and phosphorus removal from medium were higher in the presence of glucose (0.033 g g-1 dry cell weight and 1.61 g l-1, respectively. On the other hand, polyphosphate production and phosphorus removal from medium coordinately were decreased with increasing glucose concentration. Furthermore, in studying the effects of phosphorus, we faced two phases of rising and falling. Actually, the increase of phosphorus concentration (0.25-1 g l-1 in medium caused an increase in polyphosphate production and phosphorus removal from medium whereas both of them were decreased with a more increase in amount of phosphorus (1-4 g l-1. One-way ANOVA and Tukey tests showed that there was a significant difference (P<0.01 between data obtained at each optimization step and the best glucose and dipotassium phosphate concentrations for polyphosphate production were 5 and 0.5 g l-1 respectively

  15. Draft Genome Sequences of Two Bacillus thuringiensis Strains and Characterization of a Putative 41.9-kDa Insecticidal Toxin

    Directory of Open Access Journals (Sweden)

    Leopoldo Palma

    2014-04-01

    Full Text Available In this work, we report the genome sequencing of two Bacillus thuringiensis strains using Illumina next-generation sequencing technology (NGS. Strain Hu4-2, toxic to many lepidopteran pest species and to some mosquitoes, encoded genes for two insecticidal crystal (Cry proteins, cry1Ia and cry9Ea, and a vegetative insecticidal protein (Vip gene, vip3Ca2. Strain Leapi01 contained genes coding for seven Cry proteins (cry1Aa, cry1Ca, cry1Da, cry2Ab, cry9Ea and two cry1Ia gene variants and a vip3 gene (vip3Aa10. A putative novel insecticidal protein gene 1143 bp long was found in both strains, whose sequences exhibited 100% nucleotide identity. The predicted protein showed 57 and 100% pairwise identity to protein sequence 72 from a patented Bt strain (US8318900 and to a putative 41.9-kDa insecticidal toxin from Bacillus cereus, respectively. The 41.9-kDa protein, containing a C-terminal 6× HisTag fusion, was expressed in Escherichia coli and tested for the first time against four lepidopteran species (Mamestra brassicae, Ostrinia nubilalis, Spodoptera frugiperda and S. littoralis and the green-peach aphid Myzus persicae at doses as high as 4.8 µg/cm2 and 1.5 mg/mL, respectively. At these protein concentrations, the recombinant 41.9-kDa protein caused no mortality or symptoms of impaired growth against any of the insects tested, suggesting that these species are outside the protein’s target range or that the protein may not, in fact, be toxic. While the use of the polymerase chain reaction has allowed a significant increase in the number of Bt insecticidal genes characterized to date, novel NGS technologies promise a much faster, cheaper and efficient screening of Bt pesticidal proteins.

  16. Draft genome sequences of two Bacillus thuringiensis strains and characterization of a putative 41.9-kDa insecticidal toxin.

    Science.gov (United States)

    Palma, Leopoldo; Muñoz, Delia; Berry, Colin; Murillo, Jesús; Caballero, Primitivo

    2014-04-30

    In this work, we report the genome sequencing of two Bacillus thuringiensis strains using Illumina next-generation sequencing technology (NGS). Strain Hu4-2, toxic to many lepidopteran pest species and to some mosquitoes, encoded genes for two insecticidal crystal (Cry) proteins, cry1Ia and cry9Ea, and a vegetative insecticidal protein (Vip) gene, vip3Ca2. Strain Leapi01 contained genes coding for seven Cry proteins (cry1Aa, cry1Ca, cry1Da, cry2Ab, cry9Ea and two cry1Ia gene variants) and a vip3 gene (vip3Aa10). A putative novel insecticidal protein gene 1143 bp long was found in both strains, whose sequences exhibited 100% nucleotide identity. The predicted protein showed 57 and 100% pairwise identity to protein sequence 72 from a patented Bt strain (US8318900) and to a putative 41.9-kDa insecticidal toxin from Bacillus cereus, respectively. The 41.9-kDa protein, containing a C-terminal 6× HisTag fusion, was expressed in Escherichia coli and tested for the first time against four lepidopteran species (Mamestra brassicae, Ostrinia nubilalis, Spodoptera frugiperda and S. littoralis) and the green-peach aphid Myzus persicae at doses as high as 4.8 µg/cm2 and 1.5 mg/mL, respectively. At these protein concentrations, the recombinant 41.9-kDa protein caused no mortality or symptoms of impaired growth against any of the insects tested, suggesting that these species are outside the protein's target range or that the protein may not, in fact, be toxic. While the use of the polymerase chain reaction has allowed a significant increase in the number of Bt insecticidal genes characterized to date, novel NGS technologies promise a much faster, cheaper and efficient screening of Bt pesticidal proteins.

  17. Effect of oral administration of Bacillus coagulans B37 and Bacillus pumilus B9 strains on fecal coliforms, Lactobacillus and Bacillus spp. in rat animal model

    Directory of Open Access Journals (Sweden)

    Lopamudra Haldar

    2016-07-01

    Full Text Available Aim: To investigate the effect of oral administration of two Bacillus strains on fecal coliforms, Lactobacillus and Bacillus spp. in rat animal model. Materials and Methods: An in vivo experiment was conducted for 49-day period on 36 adult male albino Wister rats divided equally into to four groups. After 7-day adaptation period, one group (T1 was fed on sterile skim milk along with basal diet for the next 28 days. Second (T2 and (T3 groups received spore biomass of Bacillus coagulans B37 and Bacillus pumilus B9, respectively, suspended in sterilized skim milk at 8-9 log colony-forming units/ml plus basal diet for 28 days, while control group (T4 was supplied with clean water along with basal diet. There was a 14-day post-treatment period. A total of 288 fecal samples (8 fecal collections per rat were collected at every 7-day interval starting from 0 to 49 days and subjected to the enumeration of the counts of coliforms and lactobacilli and Bacillus spores using respective agar media. In vitro acid and bile tolerance tests on both the strains were performed. Results: The rats those (T2 and T3 received either B. coagulans B37 or B. pumilus B9 spore along with non-fermented skim milk showed decrease (p<0.01 in fecal coliform counts and increase (p<0.05 in both fecal lactobacilli and Bacillus spore counts as compared to the control group (T4 and the group fed only skim milk (T1. In vitro study indicated that both the strains were found to survive at pH 2.0 and 3.0 even up to 3 h and tolerate bile up to 2.0% concentration even after 12 h of exposure. Conclusions: This study revealed that oral administration of either B. coagulans B37 or B. pumilus B9 strains might be useful in reducing coliform counts accompanied by concurrent increase in lactobacilli counts in the intestinal flora in rats.

  18. A recombinant Bacillus anthracis strain producing the Clostridium perfringens Ib component induces protection against iota toxins.

    OpenAIRE

    Sirard, J C; Weber, M.; Duflot, E; Popoff, M R; Mock, M

    1997-01-01

    The Bacillus anthracis toxinogenic Sterne strain is currently used as a live veterinary vaccine against anthrax. The capacity of a toxin-deficient derivative strain to produce a heterologous antigen by using the strong inducible promoter of the B. anthracis pag gene was investigated. The expression of the foreign gene ibp, encoding the Ib component of iota toxin from Clostridium perfringens, was analyzed. A pag-ibp fusion was introduced by allelic exchange into a toxin-deficient Sterne strain...

  19. Preliminary Research of Mechanisms underlying Bacillus cereus AR156-mediated Resistance to Rhizoctonia solani in Rice%蜡质芽孢杆菌AR156防治水稻纹枯病机理初探

    Institute of Scientific and Technical Information of China (English)

    陈刘军; 俞仪阳; 王超; 柯红娇; 刘红霞; 郭坚华

    2014-01-01

    Bacillus cereus AR156, a biocontrol agent against a variety of soil-borne pathogens, could effectively control rice sheath blight in field. Here, the biocontrol efficacy and growth-promoting role of strain AR156 on rice was tested under greenhouse conditions, and the primary mechanism of strain AR156 in controlling rice sheath blight was also studied on both cellular and gene levels. The results revealed that AR156 could control Rhizoctonia solani with an efficiancy of 73.06%, and there was a 14.45% biomass increase in AR156-treated rice plants compared with those non-treated ones. Strain AR156 increased the activities of defensive enzymes SOD, PAL, POD and CAT, and the expression of defense related genes OsPR1b、OsPR10、OsNPR1 and ZB8. In rice plants pretreated with strain AR156 before inoculated with R. solani HNW-21, SOD or PAL activity peak reached in advance by four and two days, respectively, and the accumulation of defense related genes transcripts was rapid and extended. As a result, the resistance of those plants to rice sheath blight was strengthened.%蜡质芽孢杆菌AR156是一种防治多种土传病害的生物制剂,对水稻纹枯病具有较好的防治效果。本研究通过温室试验方面验证菌株 AR156的防病效果和促生作用,从细胞水平和基因水平初步揭示了菌株AR156防治水稻纹枯病的机理。结果表明,菌株AR156对水稻纹枯病的温室防效达73.06%,同时促进水稻生物量增加14.45%。菌株AR156处理提高了水稻植株SOD、PAL、POD和CAT等防御酶活性,增强了OsPR1b、OsPR10、OsNPR1和ZB8等防卫相关基因的表达。接种立枯丝核菌Rhizoctonia solani HNW-21之前用菌株AR156预处理的水稻植株,SOD和PAL分别提前4、2 d出现活性峰;防卫相关基因均提前表达,且表达时间延长,从而提高水稻对纹枯病的抗性。

  20. Production and stability of chlorine dioxide in organic acid solutions as affected by pH, type of acid, and concentration of sodium chlorite, and its effectiveness in inactivating Bacillus cereus spores.

    Science.gov (United States)

    Kim, Hoikyung; Kang, Youngjee; Beuchat, Larry R; Ryu, Jee-Hoon

    2008-12-01

    We studied the production and stability of chlorine dioxide (ClO(2)) in organic acid solutions and its effectiveness in killing Bacillus cereus spores. Sodium chlorite (5000, 10,000, or 50,000 microg/ml) was added to 5% acetic, citric, or lactic acid solution, adjusted to pH 3.0, 4.0, 5.0, or 6.0, and held at 21 degrees C for up to 14 days. The amount of ClO(2) produced was higher as the concentration of sodium chlorite was increased and as the pH of the acid solutions was decreased. However, the stability in production of ClO(2) was enhanced by increasing the pH of the organic acid solutions. To evaluate the lethal activity of ClO(2) produced in various acid solutions as affected by acidulant and pH, suspensions of B. cereus spores were treated at 21 degrees C for 1, 3, 5, or 10 min in hydrochloric acid or organic acid solutions (pH 3.0, 4.0, 5.0, or 6.0) containing ClO(2) at concentrations of 100, 50, or 25 microg/ml. Populations of viable spores treated with ClO(2) at concentrations of 100 or 50 microg/ml in organic acid solutions decreased more rapidly than populations treated with the same concentrations of ClO(2) in HCl. Rates of inactivation tended to increase with higher pH of ClO(2) solutions. Results show that ClO(2) formed in organic acid solutions has higher stability and is more lethal to B. cereus spores than ClO(2) formed at the same concentration in HCl solution. This finding emphasizes the benefits of using organic acid solutions to prepare ClO(2) intended for use as an antimicrobial.