Sample records for bacillus cereus formation
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Kronish, Donald P.; Mohan, Raam R.; Schwartz, Benjamin S.
1964-01-01
Kronish, Donald P. (Warner-Lambert Research Institute, Morris Plains, N.J.), Raam R. Mohan, and Benjamin S. Schwartz. Distribution of radioactivity in autolyzed cell wall of Bacillus cereus during spheroplast formation. J. Bacteriol. 87:581–587. 1964.—Spheroplasts of Bacillus cereus strain T were produced from cells grown in the presence of uniformly labeled C14-glucose. At regular intervals during spheroplast formation, enzymatically degraded cell wall was isolated by a new procedure. Radioactivity of solubilized cell wall in cell-free material increased from 2.5 to 42% of the total incorporated label during spheroplast formation. The rate of cell-wall degradation as measured by increase in radioactivity was biphasic with relative slopes of 2.0 and 5.0. During autolytic depolymerization of B. cereus cell wall, two major components were solubilized at different rates. Chemical fractionation revealed these to be a peptide and a mucopeptide. The possibility of two enzymes being involved in spheroplast formation and cell-wall degradation is discussed. Images PMID:14127573
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Bacillus cereus Biofilms—Same, Only Different
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
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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.
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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
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Isolation and expression of a Bacillus cereus gene encoding benzil reductase.
Maruyama, R; Nishizawa, M; Itoi, Y; Ito, S; Inoue, M
2001-12-20
Benzil was reduced stereospecifically to (S)-benzoin by Bacillus cereus strain Tim-r01. To isolate the gene responsible for asymmetric reduction, we constructed a library consisting of Escherichia coli clones that harbored plasmids expressing Bacillus cereus genes. The library was screened using the halo formation assay, and one clone showed benzil reduction to (S)-benzoin. Thus, this clone seemed to carry a plasmid encoding a Bacillus cereus benzil reductase. The deduced amino acid sequence had marked homologies to the Bacillus subtilis yueD protein (41% identity), the yeast open reading frame YIR036C protein (31%), and the mammalian sepiapterin reductases (28% to 30%), suggesting that benzil reductase is a novel short-chain de-hydrogenases/ reductase. Copyright 2001 John Wiley & Sons, Inc.
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Bacillus cereus and related species.
Drobniewski, F A
1993-10-01
Bacillus cereus is a gram-positive aerobic or facultatively anaerobic spore-forming rod. It is a cause of food poisoning, which is frequently associated with the consumption of rice-based dishes. The organism produces an emetic or diarrheal syndrome induced by an emetic toxin and enterotoxin, respectively. Other toxins are produced during growth, including phospholipases, proteases, and hemolysins, one of which, cereolysin, is a thiol-activated hemolysin. These toxins may contribute to the pathogenicity of B. cereus in nongastrointestinal disease. B. cereus isolated from clinical material other than feces or vomitus was commonly dismissed as a contaminant, but increasingly it is being recognized as a species with pathogenic potential. It is now recognized as an infrequent cause of serious nongastrointestinal infection, particularly in drug addicts, the immunosuppressed, neonates, and postsurgical patients, especially when prosthetic implants such as ventricular shunts are inserted. Ocular infections are the commonest types of severe infection, including endophthalmitis, panophthalmitis, and keratitis, usually with the characteristic formation of corneal ring abscesses. Even with prompt surgical and antimicrobial agent treatment, enucleation of the eye and blindness are common sequelae. Septicemia, meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections are other manifestations of severe disease. B. cereus produces beta-lactamases, unlike Bacillus anthracis, and so is resistant to beta-lactam antibiotics; it is usually susceptible to treatment with clindamycin, vancomycin, gentamicin, chloramphenicol, and erythromycin. Simultaneous therapy via multiple routes may be required.
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Gillis, Annika; Mahillon, Jacques
2014-01-01
Many bacteriophages (phages) have been widely studied due to their major role in virulence evolution of bacterial pathogens. However, less attention has been paid to phages preying on bacteria from the Bacillus cereus group and their contribution to the bacterial genetic pool has been disregarded. Therefore, this review brings together the main information for the B. cereus group phages, from their discovery to their modern biotechnological applications. A special focus is given to phages infecting Bacillus anthracis, B. cereus and Bacillus thuringiensis. These phages belong to the Myoviridae, Siphoviridae, Podoviridae and Tectiviridae families. For the sake of clarity, several phage categories have been made according to significant characteristics such as lifestyles and lysogenic states. The main categories comprise the transducing phages, phages with a chromosomal or plasmidial prophage state, γ-like phages and jumbo-phages. The current genomic characterization of some of these phages is also addressed throughout this work and some promising applications are discussed here. PMID:25010767
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Differentiation of strains from the Bacillus cereus group by RFLP-PFGE genomic fingerprinting.
Otlewska, Anna; Oltuszak-Walczak, Elzbieta; Walczak, Piotr
2013-11-01
Bacillus mycoides, Bacillus pseudomycoides, Bacillus weihenstephanensis, Bacillus anthracis, Bacillus thuringiensis, and Bacillus cereus belong to the B. cereus group. The last three species are characterized by different phenotype features and pathogenicity spectrum, but it has been shown that these species are genetically closely related. The macrorestriction analysis of the genomic DNA with the NotI enzyme was used to generate polymorphism of restriction profiles for 39 food-borne isolates (B. cereus, B. mycoides) and seven reference strains (B. mycoides, B. thuringiensis, B. weihenstephanensis, and B. cereus). The PFGE method was applied to differentiate the examined strains of the B. cereus group. On the basis of the unweighted pair group method with the arithmetic mean method and Dice coefficient, the strains were divided into five clusters (types A-E), and the most numerous group was group A (25 strains). A total of 21 distinct pulsotypes were observed. The RFLP-PFGE analysis was successfully used for the differentiation and characterization of B. cereus and B. mycoides strains isolated from different food products. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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A four-gene operon in Bacillus cereus produces two rare spore-decorating sugars
Li, Zi; Mukherjee, Thiya; Bowler, Kyle; Namdari, Sholeh; Snow, Zachary; Prestridge, Sarah; Carlton, Alexandra; Bar-Peled, Maor
2017-01-01
Bacterial glycan structures on cell surfaces are critical for cell-cell recognition and adhesion and in host-pathogen interactions. Accordingly, unraveling the sugar composition of bacterial cell surfaces can shed light on bacterial growth and pathogenesis. Here, we found that two rare sugars with a 3-C-methyl-6-deoxyhexose structure were linked to spore glycans in Bacillus cereus ATCC 14579 and ATCC 10876. Moreover, we identified a four-gene operon in B. cereus ATCC 14579 that encodes proteins with the following sequential enzyme activities as determined by mass spectrometry and one- and two-dimensional NMR methods: CTP:glucose-1-phosphate cytidylyltransferase, CDP-Glc 4,6-dehydratase, NADH-dependent SAM:C-methyltransferase, and NADPH-dependent CDP-3-C-methyl-6-deoxyhexose 4-reductase. The last enzyme predominantly yielded CDP-3-C-methyl-6-deoxygulose (CDP-cereose) and likely generated a 4-epimer CDP-3-C-methyl-6-deoxyallose (CDP-cillose). Some members of the B. cereus sensu lato group produce CDP-3-C-methyl-6-deoxy sugars for the formation of cereose-containing glycans on spores, whereas others such as Bacillus anthracis do not. Gene knockouts of the Bacillus C-methyltransferase and the 4-reductase confirmed their involvement in the formation of cereose-containing glycan on B. cereus spores. We also found that cereose represented 0.2–1% spore dry weight. Moreover, mutants lacking cereose germinated faster than the wild type, yet the mutants exhibited no changes in sporulation or spore resistance to heat. The findings reported here may provide new insights into the roles of the uncommon 3-C-methyl-6-deoxy sugars in cell-surface recognition and host-pathogen interactions of the genus Bacillus. PMID:28298443
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A four-gene operon in Bacillus cereus produces two rare spore-decorating sugars.
Li, Zi; Mukherjee, Thiya; Bowler, Kyle; Namdari, Sholeh; Snow, Zachary; Prestridge, Sarah; Carlton, Alexandra; Bar-Peled, Maor
2017-05-05
Bacterial glycan structures on cell surfaces are critical for cell-cell recognition and adhesion and in host-pathogen interactions. Accordingly, unraveling the sugar composition of bacterial cell surfaces can shed light on bacterial growth and pathogenesis. Here, we found that two rare sugars with a 3- C -methyl-6-deoxyhexose structure were linked to spore glycans in Bacillus cereus ATCC 14579 and ATCC 10876. Moreover, we identified a four-gene operon in B. cereus ATCC 14579 that encodes proteins with the following sequential enzyme activities as determined by mass spectrometry and one- and two-dimensional NMR methods: CTP:glucose-1-phosphate cytidylyltransferase, CDP-Glc 4,6-dehydratase, NADH-dependent SAM: C -methyltransferase, and NADPH-dependent CDP-3- C -methyl-6-deoxyhexose 4-reductase. The last enzyme predominantly yielded CDP-3- C -methyl-6-deoxygulose (CDP-cereose) and likely generated a 4-epimer CDP-3- C -methyl-6-deoxyallose (CDP-cillose). Some members of the B. cereus sensu lato group produce CDP-3- C -methyl-6-deoxy sugars for the formation of cereose-containing glycans on spores, whereas others such as Bacillus anthracis do not. Gene knockouts of the Bacillus C -methyltransferase and the 4-reductase confirmed their involvement in the formation of cereose-containing glycan on B. cereus spores. We also found that cereose represented 0.2-1% spore dry weight. Moreover, mutants lacking cereose germinated faster than the wild type, yet the mutants exhibited no changes in sporulation or spore resistance to heat. The findings reported here may provide new insights into the roles of the uncommon 3- C -methyl-6-deoxy sugars in cell-surface recognition and host-pathogen interactions of the genus Bacillus . © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
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Okshevsky, Mira; Louw, Matilde Greve; Lamela, Elena Otero; Nilsson, Martin; Tolker-Nielsen, Tim; Meyer, Rikke Louise
2018-04-01
Bacillus cereus is one of the most common opportunistic pathogens causing foodborne illness, as well as a common source of contamination in the dairy industry. B. cereus can form robust biofilms on food processing surfaces, resulting in food contamination due to shedding of cells and spores. Despite the medical and industrial relevance of this species, the genetic basis of biofilm formation in B. cereus is not well studied. In order to identify genes required for biofilm formation in this bacterium, we created a library of 5000 + transposon mutants of the biofilm-forming strain B. cereusATCC 10987, using an unbiased mariner transposon approach. The mutant library was screened for the ability to form a pellicle biofilm at the air-media interface, as well as a submerged biofilm at the solid-media interface. A total of 91 genes were identified as essential for biofilm formation. These genes encode functions such as chemotaxis, amino acid metabolism and cellular repair mechanisms, and include numerous genes not previously known to be required for biofilm formation. Although the majority of disrupted genes are not directly responsible for motility, further investigations revealed that the vast majority of the biofilm-deficient mutants were also motility impaired. This observation implicates motility as a pivotal factor in the formation of a biofilm by B. cereus. These results expand our knowledge of the fundamental molecular mechanisms of biofilm formation by B. cereus. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
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Concerted Action of Sphingomyelinase and Non-Hemolytic Enterotoxin in Pathogenic Bacillus cereus
Doll, Viktoria M.
2013-01-01
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. PMID:23613846
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Bräunlich, Marie; Økstad, Ole A; Slimestad, Rune; Wangensteen, Helle; Malterud, Karl E; Barsett, Hilde
2013-12-05
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.
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Bacillus cereus causing fulminant sepsis and hemolysis in two patients with acute leukemia.
Arnaout, M K; Tamburro, R F; Bodner, S M; Sandlund, J T; Rivera, G K; Pui, C H; Ribeiro, R C
1999-01-01
Hemolysis is so rarely associated with Bacillus cereus sepsis that only two very well documented cases have been reported. This article reports two unusual cases of Bacillus cereus sepsis with massive intravascular hemolysis in patients who had acute lymphoblastic leukemia (ALL). A 20-year-old woman who was 9 weeks pregnant experienced a relapse of ALL. A therapeutic abortion was performed. During week 4 of reinduction the patient had abdominal pain, nausea, and vomiting, with severe neutropenia but no fever. Her condition deteriorated rapidly with cardiovascular collapse, acute massive intravascular hemolysis, and death within hours of the onset of symptoms. Blood cultures were positive for Bacillus cereus. Postmortem histologic examination and cultures revealed Bacillus cereus and Candida albicans in multiple organs. The second patient, a 10-year-old girl, presented with relapsed T-cell ALL. In the second week of reinduction, she had abdominal pain followed by hypotension. Again, no fever was noted. Laboratory studies showed intravascular hemolysis 12 hours after admission. Aggressive support was promptly initiated. Despite disseminated intravascular coagulation; cardiovascular, hepatic, and renal failure; and multiple intracerebral hypodense lesions believed to be infarcts, the patient recovered fully and resumed reinduction therapy. Bacillus cereus infection can have a fulminant clinical course that may be complicated by massive intravascular hemolysis. This pathogen should be suspected in immunosuppressed patients who experience gastrointestinal symptoms and should not be precluded by the absence of fever, especially if steroids such as dexamethasone are being given. Exchange transfusion may be lifesaving in Bacillus cereus septicemia associated with massive hemolysis.
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Cleaning and Disinfection of Bacillus cereus Biofilm.
Deal, Amanda; Klein, Dan; Lopolito, Paul; Schwarz, John Spencer
2016-01-01
Methodology has been evolving for the testing of disinfectants against bacterial single-species biofilms, as the difficulty of biofilm remediation continues to gain much-needed attention. Bacterial single-species biofilm contamination presents a real risk to good manufacturing practice-regulated industries. However, mixed-species biofilms and biofilms containing bacterial spores remain an even greater challenge for cleaning and disinfection. Among spore-forming microorganisms frequently encountered in pharmaceutical manufacturing areas, the spores of Bacillus cereus are often determined to be the hardest to disinfect and eradicate. One of the reasons for the low degree of susceptibility to disinfection is the ability of these spores to be encapsulated within an exopolysachharide biofilm matrix. In this series of experiments, we evaluated the disinfectant susceptibility of B. cereus biofilms relative to disassociated B. cereus spores and biofilm from a non-spore-forming species. Further, we assessed the impact that pre-cleaning has on increasing that susceptibility. Methodology has been evolving for the testing of disinfectants against bacterial single-species biofilms, as the difficulty of biofilm remediation continues to gain much-needed attention. Bacterial single-species biofilm contamination presents a real risk to good manufacturing practice-regulated industries. However, mixed-species biofilms and biofilms containing bacterial spores remain an even greater challenge for cleaning and disinfection. Among spore-forming microorganisms frequently encountered in pharmaceutical manufacturing areas, the spores of Bacillus cereus are often determined to be the hardest to disinfect and eradicate. One of the reasons for the low degree of susceptibility to disinfection is the ability of these spores to be encapsulated within an exopolysachharide biofilm matrix. In this series of experiments, we evaluated the disinfectant susceptibility of B. cereus biofilms relative to
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Growth of enterotoxigenic Bacillus cereus on salmon (Oncorhynchus nerka).
Labbé, Ronald; Rahmati, Talat
2012-06-01
We previously demonstrated the widespread presence of enterotoxigenic Bacillus cereus in marine foods. In view of the widespread consumption of raw fish, we sought to determine the ability of this organism to grow on the surface of wild Alaskan salmon at abusive temperatures (12, 16, and 20°C), using an isolate able to produce elevated levels of hemolysin BL enterotoxin and nonhemolytic enterotoxin. An incubation temperature of 37°C for colony formation was found to be selective for B. cereus grown on salmon held for up to 24 h at each temperature. A fivefold increase in log CFU per gram was observed after 26 and 22 h at 16 and 20°C, respectively, while a >4-log CFU/g increase occurred on salmon held at 12°C for 48 h. Generation times of 169.7, 53.5, and 45.6 min were observed at 12, 16, and 20°C. Nonhemolytic enterotoxin was detected when levels of B. cereus were in excess of 10(8) CFU/g. Nisin, at concentrations of 1 and 15 m g/g of salmon, reduced levels of B. cereus 2.5- and 25-fold, respectively. Our results indicate that fresh salmon can serve as an excellent substrate for enterotoxigenic B. cereus and that this organism can reach levels associated with foodborne illness following moderate temperature abuse.
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Hayrapetyan, Hasmik; Muller, Lisette; Tempelaars, Marcel; Abee, Tjakko; Nierop Groot, Masja
2015-05-04
Biofilm formation of Bacillus cereus reference strains ATCC 14579 and ATCC 10987 and 21 undomesticated food isolates was studied on polystyrene and stainless steel as contact surfaces. For all strains, the biofilm forming capacity was significantly enhanced when in contact with stainless steel (SS) as a surface as compared to polystyrene (PS). For a selection of strains, the total CFU and spore counts in biofilms were determined and showed a good correlation between CFU counts and total biomass of these biofilms. Sporulation was favoured in the biofilm over the planktonic state. To substantiate whether iron availability could affect B. cereus biofilm formation, the free iron availability was varied in BHI by either the addition of FeCl3 or by depletion of iron with the scavenger 2,2-Bipyridine. Addition of iron resulted in increased air-liquid interface biofilm on polystyrene but not on SS for strain ATCC 10987, while the presence of Bipyridine reduced biofilm formation for both materials. Biofilm formation was restored when excess FeCl3 was added in combination with the scavenger. Further validation of the iron effect for all 23 strains in microtiter plate showed that fourteen strains (including ATCC10987) formed a biofilm on PS. For eight of these strains biofilm formation was enhanced in the presence of added iron and for eleven strains it was reduced when free iron was scavenged. Our results show that stainless steel as a contact material provides more favourable conditions for B. cereus biofilm formation and maturation compared to polystyrene. This effect could possibly be linked to iron availability as we show that free iron availability affects B. cereus biofilm formation. Copyright © 2015 Elsevier B.V. All rights reserved.
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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.
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A Case Series and Review of Bacillus Cereus Endocarditis from India.
Gopinathan, Anusha; Kumar, Anil; Sen, Amitabh C; Sudha, Srisruthy; Varma, Praveen; Gs, Sunil; Eapen, Malini; Dinesh, Kavitha R
2018-01-01
Bacillus cereus is a gram positive bacilli found commonly in the soil and environment. It is a bacteria rarely associated with endocarditis. Intravenous drug abuse, presence of valvular defects, pacemakers, immunodeficiency are some of the known risk factors for B.cereus endocarditis. We present here a case series of two patients with B.cereus endocarditis along with a review of the literature. This is the first report of B.cereus endocarditis from India to the best of our knowledge.
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Eom, Jeong Seon; Lee, Sun Young; Choi, Hye Sun
2014-11-01
Bacillus subtilis HJ18-4 isolated from buckwheat sokseongjang, a traditional Korean fermented soybean food, exhibits broad-spectrum antimicrobial activity against foodborne pathogens, including Bacillus cereus. In this study, we investigated the antibacterial efficacy and regulation of toxin gene expression in B. cereus by B. subtilis HJ18-4. Expression of B. cereus toxin-related genes (groEL, nheA, nheC, and entFM) was downregulated by B. subtilis HJ18-4, which also exhibited strong antibacterial activity against B. cereus. We also found that water extracts of soy product fermented with B. subtilis HJ18-4 significantly inhibited the growth of B. cereus and toxin expression. These results indicate that B. subtilis HJ18-4 could be used as an antimicrobial agent to control B. cereus in the fermented soybean food industry. Our findings also provide an opportunity to develop an efficient biological control agent against B. cereus. © 2014 The Authors. Journal of Food Science published by Wiley Periodicals, Inc. on behalf of Institute of Food Technologists®
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Probiotic Bacillus cereus Strains, a Potential Risk for Public Health in China
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
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Bacillus cereus in free-stall bedding.
Magnusson, M; Svensson, B; Kolstrup, C; Christiansson, A
2007-12-01
To increase the understanding of how different factors affect the bacterial growth in deep sawdust beds for dairy cattle, the microbiological status of Bacillus cereus and coliforms in deep sawdust-bedded free stalls was investigated over two 14-d periods on one farm. High counts of B. cereus and coliforms were found in the entire beds. On average, 4.1 log(10) B. cereus spores, 5.5 log(10) B. cereus, and 6.7 log(10) coliforms per gram of bedding could be found in the upper layers of the sawdust likely to be in contact with the cows' udders. The highest counts of B. cereus spores, B. cereus, and coliforms were found in the bedding before fresh bedding was added, and the lowest immediately afterwards. Different factors of importance for the growth of B. cereus in the bedding material were explored in laboratory tests. These were found to be the type of bedding, pH, and the type and availability of nutrients. Alternative bedding material such as peat and mixtures of peat and sawdust inhibited the bacterial growth of B. cereus. The extent of growth of B. cereus in the sawdust was increased in a dose-dependent manner by the availability of feces. Urine added to different bedding material raised the pH and also led to bacterial growth of B. cereus in the peat. In sawdust, a dry matter content greater than 70% was needed to lower the water activity to 0.95, which is needed to inhibit the growth of B. cereus. In an attempt to reduce the bacterial growth of B. cereus and coliforms in deep sawdust beds on the farm, the effect of giving bedding daily or a full replacement of the beds was studied. The spore count of B. cereus in the back part of the free stalls before fresh bedding was added was 0.9 log units lower in stalls given daily bedding than in stalls given bedding twice weekly. No effect on coliform counts was found. Replacement of the entire sawdust bedding had an effect for a short period, but by 1 to 2 mo after replacement, the counts of B. cereus spores in the
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Bacillus cereus bacteremia outbreak due to contaminated hospital linens.
Sasahara, T; Hayashi, S; Morisawa, Y; Sakihama, T; Yoshimura, A; Hirai, Y
2011-02-01
We describe an outbreak of Bacillus cereus bacteremia that occurred at Jichi Medical University Hospital in 2006. This study aimed to identify the source of this outbreak and to implement appropriate control measures. We reviewed the charts of patients with blood cultures positive for B. cereus, and investigated B. cereus contamination within the hospital environment. Genetic relationships among B. cereus isolates were analyzed. Eleven patients developed B. cereus bacteremia between January and August 2006. The hospital linens and the washing machine were highly contaminated with B. cereus, which was also isolated from the intravenous fluid. All of the contaminated linens were autoclaved, the washing machine was cleaned with a detergent, and hand hygiene was promoted among the hospital staff. The number of patients per month that developed new B. cereus bacteremia rapidly decreased after implementing these measures. The source of this outbreak was B. cereus contamination of hospital linens, and B. cereus was transmitted from the linens to patients via catheter infection. Our findings demonstrated that bacterial contamination of hospital linens can cause nosocomial bacteremia. Thus, blood cultures that are positive for B. cereus should not be regarded as false positives in the clinical setting.
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Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity.
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.
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Delvecchio, Vito G; Connolly, Joseph P; Alefantis, Timothy G; Walz, Alexander; Quan, Marian A; Patra, Guy; Ashton, John M; Whittington, Jessica T; Chafin, Ryan D; Liang, Xudong; Grewal, Paul; Khan, Akbar S; Mujer, Cesar V
2006-09-01
Differentially expressed and immunogenic spore proteins of the Bacillus cereus group of bacteria, which includes Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis, were identified. Comparative proteomic profiling of their spore proteins distinguished the three species from each other as well as the virulent from the avirulent strains. A total of 458 proteins encoded by 232 open reading frames were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis for all the species. A number of highly expressed proteins, including elongation factor Tu (EF-Tu), elongation factor G, 60-kDa chaperonin, enolase, pyruvate dehydrogenase complex, and others exist as charge variants on two-dimensional gels. These charge variants have similar masses but different isoelectric points. The majority of identified proteins have cellular roles associated with energy production, carbohydrate transport and metabolism, amino acid transport and metabolism, posttranslational modifications, and translation. Novel vaccine candidate proteins were identified using B. anthracis polyclonal antisera from humans postinfected with cutaneous anthrax. Fifteen immunoreactive proteins were identified in B. anthracis spores, whereas 7, 14, and 7 immunoreactive proteins were identified for B. cereus and in the virulent and avirulent strains of B. thuringiensis spores, respectively. Some of the immunodominant antigens include charge variants of EF-Tu, glyceraldehyde-3-phosphate dehydrogenase, dihydrolipoamide acetyltransferase, Delta-1-pyrroline-5-carboxylate dehydrogenase, and a dihydrolipoamide dehydrogenase. Alanine racemase and neutral protease were uniquely immunogenic to B. anthracis. Comparative analysis of the spore immunome will be of significance for further nucleic acid- and immuno-based detection systems as well as next-generation vaccine development.
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DelVecchio, Vito G.; Connolly, Joseph P.; Alefantis, Timothy G.; Walz, Alexander; Quan, Marian A.; Patra, Guy; Ashton, John M.; Whittington, Jessica T.; Chafin, Ryan D.; Liang, Xudong; Grewal, Paul; Khan, Akbar S.; Mujer, Cesar V.
2006-01-01
Differentially expressed and immunogenic spore proteins of the Bacillus cereus group of bacteria, which includes Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis, were identified. Comparative proteomic profiling of their spore proteins distinguished the three species from each other as well as the virulent from the avirulent strains. A total of 458 proteins encoded by 232 open reading frames were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis for all the species. A number of highly expressed proteins, including elongation factor Tu (EF-Tu), elongation factor G, 60-kDa chaperonin, enolase, pyruvate dehydrogenase complex, and others exist as charge variants on two-dimensional gels. These charge variants have similar masses but different isoelectric points. The majority of identified proteins have cellular roles associated with energy production, carbohydrate transport and metabolism, amino acid transport and metabolism, posttranslational modifications, and translation. Novel vaccine candidate proteins were identified using B. anthracis polyclonal antisera from humans postinfected with cutaneous anthrax. Fifteen immunoreactive proteins were identified in B. anthracis spores, whereas 7, 14, and 7 immunoreactive proteins were identified for B. cereus and in the virulent and avirulent strains of B. thuringiensis spores, respectively. Some of the immunodominant antigens include charge variants of EF-Tu, glyceraldehyde-3-phosphate dehydrogenase, dihydrolipoamide acetyltransferase, Δ-1-pyrroline-5-carboxylate dehydrogenase, and a dihydrolipoamide dehydrogenase. Alanine racemase and neutral protease were uniquely immunogenic to B. anthracis. Comparative analysis of the spore immunome will be of significance for further nucleic acid- and immuno-based detection systems as well as next-generation vaccine development. PMID:16957262
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The Hemolytic Enterotoxin HBL Is Broadly Distributed among Species of the Bacillus cereus Group
Prüß, Birgit M.; Dietrich, Richard; Nibler, Birgit; Märtlbauer, Erwin; Scherer, Siegfried
1999-01-01
The prevalence of the hemolytic enterotoxin complex HBL was determined in all species of the Bacillus cereus group with the exception of Bacillus anthracis. hblA, encoding the binding subunit B, was detected by PCR and Southern analysis and was confirmed by partial sequencing of 18 strains. The sequences formed two clusters, one including B. cereus and Bacillus thuringiensis strains and the other one consisting of Bacillus mycoides, Bacillus pseudomycoides, and Bacillus weihenstephanensis strains. From eight B. thuringiensis strains, the enterotoxin gene hblA could be amplified. Seven of them also expressed the complete HBL complex as determined with specific antibodies against the L1, L2, and B components. Eleven of 16 B. mycoides strains, all 3 B. pseudomyoides strains, 9 of 15 B. weihenstephanensis strains, and 10 of 23 B. cereus strains carried hblA. While HBL was not expressed in the B. pseudomycoides strains, the molecular assays were in accordance with the immunological assays for the majority of the remaining strains. In summary, the hemolytic enterotoxin HBL seems to be broadly distributed among strains of the B. cereus group and relates neither to a certain species nor to a specific environment. The consequences of this finding for food safety considerations need to be evaluated. PMID:10584001
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Swiecicka, Izabela; Mahillon, Jacques
2006-04-01
Although Bacillus cereus sensu lato are important both from an ecological and an economical point of view, little is known about their population structure, ecology, and relationships with other organisms. In the present work, the genotypic similarity of arthropod-borne B. cereus s.l. isolates, and their symbiotic relationship with the host are assessed. Bacilli of this group were recovered from the digestive tracts of sow bugs (Porcellio scaber) collected in three closely located sites. Their genotypic diversity was investigated using pulse-field gel electrophoresis (PFGE) following the whole-genome DNA digestions with NotI and AscI, and PCR amplification of virulence genes. The majority of the sow-bug Bacillus cereus sensu stricto isolates originating from the same but also from different sites displayed identical PFGE patterns, virulence gene content and enterotoxicity, indicating strong genetic and genomic relationships. The sow-bug Bacillus mycoides/Bacillus pseudomycoides strains displayed a higher diversity. The isopod-B. cereus s.l. relationship was also evaluated using antibiotic-resistant derivatives of B. cereus s.s., B. mycoides/B. pseudomycoides and Bacillus thuringiensis reintroduced into sow bugs. Both spores and vegetative cells of B. cereus s.l. were recovered from sow bugs over a 30-day period, strongly suggesting that these bacteria are natural residents of terrestrial isopods.
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Comparison of 3 selective media for enumeration of Bacillus cereus in several food matrixes.
Chon, Jung-Whan; Song, Kwang-Young; Kim, Hyunsook; Seo, Kun-Ho
2014-12-01
In this study, we compared the inclusivity, exclusivity, recoverability, and selectivity of the 3 selective agars (mannitol yolk polymyxin B agar [MYPA], polymyxin pyruvate egg yolk mannitol bromothymol blue agar [PEMBA], and Brillance Bacillus cereus agar [BBC agar]) for Bacillus cereus (B. cereus) from pure culture and several food samples. BBC agar showed greater exclusivity and selectivity in pure culture and in foods with high background flora, respectively; however, all the tested media showed similar recoverability (P > 0.05) of B. cereus in pure culture and in most foods. Our results suggest that BBC agar could be useful to enumerate B. cereus from, in particular, food matrixes with high background competing micro flora. © 2014 Institute of Food Technologists®
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Whole-Genome Sequences of 94 Environmental Isolates of Bacillus cereus Sensu Lato
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. PMID:24092776
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Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity
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
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Yeo, In-Cheol; Lee, Nam Keun; Yang, Byung Wook; Hahm, Young Tae
2014-01-01
Bacillus subtilis SC-8 produces an antibiotic that has narrow antagonistic activity against bacteria in the Bacillus cereus group. In B. cereus group bacteria, peptide-activating PlcR (PapR) plays a significant role in regulating the transcription of virulence factors. When B. subtilis SC-8 and B. cereus are co-cultured, PapR is assumed to stimulate antibiotic production by B. subtilis SC-8. To better understand the effect of PapR on this interspecies interaction, the global transcriptome profile of B. subtilis SC-8 was analyzed in the presence of PapR. Significant changes were detected in 12.8 % of the total transcripts. Genes related to amino acid transport and metabolism (16.5 %) and transcription (15 %) were mainly upregulated, whereas genes involved in carbohydrate transport and metabolism (12.7 %) were markedly downregulated. The expression of genes related to transcription, including several transcriptional regulators and proteins involved in tRNA biosynthesis, was increased. The expression levels of genes associated with several transport systems, such as antibiotic, cobalt, and iron complex transporters, was also significantly altered. Among the downregulated genes were transcripts associated with spore formation, the subtilosin A gene cluster, and nitrogen metabolism.
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Anthrax Toxin-Expressing Bacillus cereus Isolated from an Anthrax-Like Eschar.
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.
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Weathering of phlogopite by Bacillus cereus and Acidithiobacillus ferrooxidans.
Styriaková, Iveta; Bhatti, Tariq M; Bigham, Jerry M; Styriak, Igor; Vuorinen, Antti; Tuovinen, Olli H
2004-03-01
The purpose of this study was to assess the weathering of finely ground phlogopite, a trioctahedral mica, by placing it in contact with heterotrophic (Bacillus cereus) and acidophilic (Acidithiobacillus ferrooxidans) cultures. X-ray diffraction analyses of the phlogopite sample before and after 24 weeks of contact in B. cereus cultures revealed a decrease in the characteristic peak intensities of phlogopite, indicating destruction of individual structural planes of the mica. No new solid phase products or interlayer structures were detected in B. cereus cultures. Acidithiobacillus ferrooxidans cultures enhanced the chemical dissolution of the mineral and formed partially weathered interlayer structures, where interlayer K was expelled and coupled with the precipitation of K-jarosite [KFe3(SO4)2(OH)6].
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Comparison of hand hygiene procedures for removing Bacillus cereus spores.
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.
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[Characteristics of Bacillus cereus dissociants].
Doroshenko, E V; Loĭko, N G; Il'inskaia, O N; Kolpakov, A I; Gornova, I B; Klimanova, E V; El'-Registan, G I
2001-01-01
The autoregulation of the phenotypic (populational) variability of the Bacillus cereus strain 504 was studied. The isolated colonial morphotypes of this bacterium were found to differ in their growth characteristics and the synthesis of extracellular proteases. The phenotypic variabilities of vegetative proliferating cells and those germinated from endospores and cystlike refractory cells were different. Bacterial variants also differed in the production of the d1 and d2 factors (the autoinducers of dormancy and autolysis, respectively) and sensitivity to them. The possible role of these factors in the dissociation of microorganisms is discussed.
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Plant compounds enhance assay sensitivity for detection of active bacillus cereus toxin
USDA-ARS?s Scientific Manuscript database
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...
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Kefiran antagonizes cytopathic effects of Bacillus cereus extracellular factors.
Medrano, Micaela; Pérez, Pablo Fernando; Abraham, Analía Graciela
2008-02-29
Kefiran, the polysaccharide produced by microorganisms present in kefir grains, is a water-soluble branched glucogalactan containing equal amounts of D-glucose and D-galactose. In this study, the effect of kefiran on the biological activity of Bacillus cereus strain B10502 extracellular factors was assessed by using cultured human enterocytes (Caco-2 cells) and human erythrocytes. In the presence of kefiran concentrations ranging from 300 to 1000 mg/L, the ability of B. cereus B10502 spent culture supernatants to detach and damage cultured human enterocytes was significantly abrogated. In addition, mitochondrial dehydrogenase activity was higher when kefiran was present during the cell toxicity assays. Protection was also demonstrated in hemolysis and apoptosis/necrosis assays. Scanning electron microscopy showed the protective effect of kefiran against structural cell damages produced by factors synthesized by B. cereus strain B10502. Protective effect of kefiran depended on strain of B. cereus. Our findings demonstrate the ability of kefiran to antagonize key events of B. cereus B10502 virulence. This property, although strain-specific, gives new perspectives for the role of bacterial exopolysaccharides in functional foods.
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Bacillus cereus in personal care products: risk to consumers.
Pitt, T L; McClure, J; Parker, M D; Amézquita, A; McClure, P J
2015-04-01
Bacillus cereus is ubiquitous in nature and thus occurs naturally in a wide range of raw materials and foodstuffs. B. cereus spores are resistant to desiccation and heat and able to survive dry storage and cooking. Vegetative cells produce several toxins which on ingestion in sufficient numbers can cause vomiting and/or diarrhoea depending on the toxins produced. Gastrointestinal disease is commonly associated with reheated or inadequately cooked foods. In addition to being a rare cause of several acute infections (e.g. pneumonia and septicaemia), B. cereus can also cause localized infection of post-surgical or trauma wounds and is a rare but significant pathogen of the eye where it may result in severe endophthalmitis often leading to loss of vision. Key risk factors in such cases are trauma to the eye and retained contaminated intraocular foreign bodies. In addition, rare cases of B. cereus-associated keratitis (inflammation of the cornea) have been linked to contact lens use. Bacillus cereus is therefore a microbial contaminant that could adversely affect product safety of cosmetic and facial toiletries and pose a threat to the user if other key risk factors are also present. The infective dose in the human eye is unknown, but as few as 100 cfu has been reported to initiate infection in a susceptible animal model. However, we are not aware of any reports in the literature of B. cereus infections in any body site linked with use of personal care products. Low levels of B. cereus spores may on occasion be present in near-eye cosmetics, and these products have been used by consumers for many years. In addition, exposure to B. cereus is more likely to occur through other routes (e.g. dustborne contamination) due to its ubiquity and resistance properties of spores. The organism has been recovered from the eyes of healthy individuals. Therefore, although there may be a perceived hazard, the risk of severe eye infections as a consequence of exposure through
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[Can industrial laundry remove Bacillus cereus from hospital linen?].
Yoh, Myonsun; Matsuyama, Junko; Shime, Akiko; Okayama, Kana; Sakamoto, Rei; Honda, Takeshi
2010-09-01
Contaminated hospital linen has caused some cases of Bacillus cereus bacteremia in Japan. We analyzed the disinfection efficacy of industrial washing of hospital towels and sheets by counting the number of B. cereus on linen before and after washing. That before washing averaged 7.6 cells/cm2 on unwashed sheets, decreasing to 1.2 cells/cm2 after washing. That on unwashed towels, however, averaged 10(6) cells/cm2 before washing and 1096 cells/cm2 after washing, which was very high and suggested the possibility of causing nosocomial infection.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Plomp, M; Leighton, T; Wheeler, K
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. cereusmore » 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.« less
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Carroll, Laura M.; Miller, Rachel A.; Wiedmann, Martin
2017-01-01
ABSTRACT The Bacillus cereus group comprises nine species, several of which are pathogenic. Differentiating between isolates that may cause disease and those that do not is a matter of public health and economic importance, but it can be particularly challenging due to the high genomic similarity within the group. To this end, we have developed BTyper, a computational tool that employs a combination of (i) virulence gene-based typing, (ii) multilocus sequence typing (MLST), (iii) panC clade typing, and (iv) rpoB allelic typing to rapidly classify B. cereus group isolates using nucleotide sequencing data. BTyper was applied to a set of 662 B. cereus group genome assemblies to (i) identify anthrax-associated genes in non-B. anthracis members of the B. cereus group, and (ii) identify assemblies from B. cereus group strains with emetic potential. With BTyper, the anthrax toxin genes cya, lef, and pagA were detected in 8 genomes classified by the NCBI as B. cereus that clustered into two distinct groups using k-medoids clustering, while either the B. anthracis poly-γ-d-glutamate capsule biosynthesis genes capABCDE or the hyaluronic acid capsule hasA gene was detected in an additional 16 assemblies classified as either B. cereus or Bacillus thuringiensis isolated from clinical, environmental, and food sources. The emetic toxin genes cesABCD were detected in 24 assemblies belonging to panC clades III and VI that had been isolated from food, clinical, and environmental settings. The command line version of BTyper is available at https://github.com/lmc297/BTyper. In addition, BMiner, a companion application for analyzing multiple BTyper output files in aggregate, can be found at https://github.com/lmc297/BMiner. IMPORTANCE Bacillus cereus is a foodborne pathogen that is estimated to cause tens of thousands of illnesses each year in the United States alone. Even with molecular methods, it can be difficult to distinguish nonpathogenic B. cereus group isolates from their
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Miller, Rachel A.; Beno, Sarah M.; Kent, David J.; Carroll, Laura M.; Martin, Nicole H.; Boor, Kathryn J.
2016-01-01
A facultatively anaerobic, spore-forming Bacillus strain, FSL W8-0169T, collected from raw milk stored in a silo at a dairy powder processing plant in the north-eastern USA was initially identified as a Bacillus cereus group species based on a partial sequence of the rpoB gene and 16S rRNA gene sequence. Analysis of core genome single nucleotide polymorphisms clustered this strain separately from known B. cereus group species. Pairwise average nucleotide identity blast values obtained for FSL W8-0169T compared to the type strains of existing B. cereus group species were <95 % and predicted DNA–DNA hybridization values were <70 %, suggesting that this strain represents a novel B. cereus group species. We characterized 10 additional strains with the same or closely related rpoB allelic type, by whole genome sequencing and phenotypic analyses. Phenotypic characterization identified a higher content of iso-C16 : 0 fatty acid and the combined inability to ferment sucrose or to hydrolyse arginine as the key characteristics differentiating FSL W8-0169T from other B. cereus group species. FSL W8-0169T is psychrotolerant, produces haemolysin BL and non-haemolytic enterotoxin, and is cytotoxic in a HeLa cell model. The name Bacillus wiedmannii sp. nov. is proposed for the novel species represented by the type strain FSL W8-0169T (=DSM 102050T=LMG 29269T). PMID:27520992
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Eijlander, Robyn T.; Holsappel, Siger; de Jong, Anne; Ghosh, Abhinaba; Christie, Graham; Kuipers, Oscar P.
2016-01-01
Sporulation is a highly sophisticated developmental process adopted by most Bacilli as a survival strategy to withstand extreme conditions that normally do not support microbial growth. A complicated regulatory cascade, divided into various stages and taking place in two different compartments of the cell, involves a number of primary and secondary regulator proteins that drive gene expression directed toward the formation and maturation of an endospore. Such regulator proteins are highly conserved among various spore formers. Despite this conservation, both regulatory and phenotypic differences are observed between different species of spore forming bacteria. In this study, we demonstrate that deletion of the regulatory sporulation protein SpoVT results in a severe sporulation defect in Bacillus cereus, whereas this is not observed in Bacillus subtilis. Although spores are initially formed, the process is stalled at a later stage in development, followed by lysis of the forespore and the mother cell. A transcriptomic investigation of B. cereus ΔspoVT shows upregulation of genes involved in germination, potentially leading to premature lysis of prespores formed. Additionally, extreme variation in the expression of species-specific genes of unknown function was observed. Introduction of the B. subtilis SpoVT protein could partly restore the sporulation defect in the B. cereus spoVT mutant strain. The difference in phenotype is thus more than likely explained by differences in promoter targets rather than differences in mode of action of the conserved SpoVT regulator protein. This study stresses that evolutionary variances in regulon members of sporulation regulators can have profound effects on the spore developmental process and that mere protein homology is not a foolproof predictor of similar phenotypes. PMID:27790204
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Eijlander, Robyn T; Holsappel, Siger; de Jong, Anne; Ghosh, Abhinaba; Christie, Graham; Kuipers, Oscar P
2016-01-01
Sporulation is a highly sophisticated developmental process adopted by most Bacilli as a survival strategy to withstand extreme conditions that normally do not support microbial growth. A complicated regulatory cascade, divided into various stages and taking place in two different compartments of the cell, involves a number of primary and secondary regulator proteins that drive gene expression directed toward the formation and maturation of an endospore. Such regulator proteins are highly conserved among various spore formers. Despite this conservation, both regulatory and phenotypic differences are observed between different species of spore forming bacteria. In this study, we demonstrate that deletion of the regulatory sporulation protein SpoVT results in a severe sporulation defect in Bacillus cereus , whereas this is not observed in Bacillus subtilis . Although spores are initially formed, the process is stalled at a later stage in development, followed by lysis of the forespore and the mother cell. A transcriptomic investigation of B. cereus Δ spoVT shows upregulation of genes involved in germination, potentially leading to premature lysis of prespores formed. Additionally, extreme variation in the expression of species-specific genes of unknown function was observed. Introduction of the B. subtilis SpoVT protein could partly restore the sporulation defect in the B. cereus spoVT mutant strain. The difference in phenotype is thus more than likely explained by differences in promoter targets rather than differences in mode of action of the conserved SpoVT regulator protein. This study stresses that evolutionary variances in regulon members of sporulation regulators can have profound effects on the spore developmental process and that mere protein homology is not a foolproof predictor of similar phenotypes.
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Dynamic predictive model for growth of Bacillus cereus from spores in cooked beans
USDA-ARS?s Scientific Manuscript database
Kinetic growth data of Bacillus cereus from spores in cooked beans at several isothermal conditions (between 10 to 49C) were collected. Samples were inoculated with approximately 2 log CFU/g of heat-shocked (80C/10 min) spores and stored at isothermal temperatures. B. cereus populations were deter...
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Wang, Pengxia; Zhu, Yiguang; Zhang, Yuyang; Zhang, Chunyi; Xu, Jianyi; Deng, Yun; Peng, Donghai; Ruan, Lifang; Sun, Ming
2016-06-10
Bacillus thuringiensis and Bacillus cereus are two important species in B. cereus group. The intensive study of these strains at the molecular level and construction of genetically modified bacteria requires the development of efficient genetic tools. To insert genes into or delete genes from bacterial chromosomes, marker-less manipulation methods were employed. We present a novel genetic manipulation method for B. thuringiensis and B. cereus strains that does not leave selection markers. Our approach takes advantage of the relaxase Mob02281 encoded by plasmid pBMB0228 from Bacillus thuringiensis. In addition to its mobilization function, this Mob protein can mediate recombination between oriT sites. The Mob02281 mobilization module was associated with a spectinomycin-resistance gene to form a Mob-Spc cassette, which was flanked by the core 24-bp oriT sequences from pBMB0228. A strain in which the wild-type chromosome was replaced with the modified copy containing the Mob-Spc cassette at the target locus was obtained via homologous recombination. Thus, the spectinomycin-resistance gene can be used to screen for Mob-Spc cassette integration mutants. Recombination between the two oriT sequences mediated by Mob02281, encoded by the Mob-Spc cassette, resulted in the excision of the Mob-Spc cassette, producing the desired chromosomal alteration without introducing unwanted selection markers. We used this system to generate an in-frame deletion of a target gene in B. thuringiensis as well as a gene located in an operon of B. cereus. Moreover, we demonstrated that this system can be used to introduce a single gene or an expression cassette of interest in B. thuringiensis. The Mob/oriT recombination system provides an efficient method for unmarked genetic manipulation and for constructing genetically modified bacteria of B. thuringiensis and B. cereus. Our method extends the available genetic tools for B. thuringiensis and B. cereus strains.
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Effects of Mn2+ Levels on the Resistance Properties of Bacillus cereus Spores
2013-01-01
In contrast, Bacillus subtilis spores with over a 200-fold range of protoplast Mn levels exhibited no significant differences in resistance to... Bacillus subtilis . J. Bacteriol. 189:8458-8466. Coleman WH, Zhang P, Li YQ, Setlow P (2010). Mechanism of killing of spores of Bacillus cereus and...Gaidamakova EK, Matrosova VY, Daly MJ, Setlow P (2011). Effects of levels of Mn and Fe on Bacillus subtilis spore resistance, and effects of Mn 2
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[Bacillus cereus endocarditis and a probable cutaneous gateway].
Soudet, S; Becquart, C; Dezoteux, F; Faure, K; Staumont-Salle, D; Delaporte, E
2017-01-01
Bacillus cereus is a ubiquitous telluric organism. B. cereus endocarditis is a rare condition seen mostly in prosthetic heart valves and among intravenous drug users. We report a new case of a patient without risk factors and with a good clinical outcome not requiring valve replacement. In October 2014, a 50-year-old woman was referred to the dermatology department of Lille University Hospital for lower-limb wounds developing 6 months earlier. She presented fever without clinical signs of infection, except for the lower-limbs wounds. Blood cultures revealed the presence of B. cereus. Transesophageal echocardiography was performed and revealed two foci of aortic valve vegetation with a diameter of 5mm. After bacterial sensitivity testing, rifampicin and levofloxacin treatment was given for six weeks, with complete remission. A skin graft was performed and good improvement was seen. Nineteen cases of B. cereus endocarditis have been described previously, only one of which was without risk factors. We described a case of complete remission after a 6-week course of antibiotics. Our case demonstrates that BC should not be considered as a blood culture contamination, and that treatment may be complex due to antibiotic resistance. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
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NASA Technical Reports Server (NTRS)
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.
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Prevalence of emetic Bacillus cereus in different ice creams in Bavaria.
Messelhäusser, U; Kämpf, P; Fricker, M; Ehling-Schulz, M; Zucker, R; Wagner, B; Busch, U; Höller, C
2010-02-01
In this study, 809 samples of ice cream from different sources were investigated by using cultural methods for the presence of presumptive Bacillus cereus. Isolates from culture-positive samples were examined with a real-time PCR assay targeting a region of the cereulide synthetase gene (ces) that is highly specific for emetic B. cereus strains. The samples were collected from ice cream parlors and restaurants that produced their own ice cream and from international commercial ice cream companies in different regions of Bavaria during the summer of 2008. Presumptive B. cereus was found in 508 (62.7%) ice cream samples investigated, and 24 (4.7%) of the isolates had the genetic background for cereulide toxin production. The level of emetic B. cereus in the positive samples ranged from 0.1 to 20 CFU/g of ice cream.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, C S; Xie, G; Challacombe, J F
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 genomesmore » 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.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, Cliff S.; Xie, Gary; Challacombe, Jean F.
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 othermore » 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.« less
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Bacillus cereus Induces Permeability of an In Vitro Blood-Retina Barrier▿
Moyer, A. L.; Ramadan, R. T.; Thurman, J.; Burroughs, A.; Callegan, M. C.
2008-01-01
Most Bacillus cereus toxin production is controlled by the quorum-sensing-dependent, pleiotropic global regulator plcR, which contributes to the organism's virulence in the eye. The purpose of this study was to analyze the effects of B. cereus infection and plcR-regulated toxins on the barrier function of retinal pigment epithelium (RPE) cells, the primary cells of the blood-retina barrier. Human ARPE-19 cells were apically inoculated with wild-type or quorum-sensing-deficient B. cereus, and cytotoxicity was analyzed. plcR-regulated toxins were not required for B. cereus-induced RPE cytotoxicity, but these toxins did increase the rate of cell death, primarily by necrosis. B. cereus infection of polarized RPE cell monolayers resulted in increased barrier permeability, independent of plcR-regulated toxins. Loss of both occludin and ZO-1 expression occurred by 8 h postinfection, but alterations in tight junctions appeared to precede cytotoxicity. Of the several proinflammatory cytokines analyzed, only interleukin-6 was produced in response to B. cereus infection. These results demonstrate the deleterious effects of B. cereus infection on RPE barrier function and suggest that plcR-regulated toxins may not contribute significantly to RPE barrier permeability during infection. PMID:18268029
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Barrie, D; Wilson, J A; Hoffman, P N; Kramer, J M
1992-11-01
Two patients developed Bacillus cereus meningitis following neurosurgery. During the subsequent investigation into the source of the organism, linen was discovered to be heavily contaminated with B. cereus. No other prolific source of the organism was found. It seems probable that lint from contaminated fabric was the vehicle of transmission of the organism during extended surgery. Linen should be considered as a possible source of B. cereus infection.
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The Water Cycle, a Potential Source of the Bacterial Pathogen Bacillus cereus.
Brillard, Julien; Dupont, Christian M S; Berge, Odile; Dargaignaratz, Claire; Oriol-Gagnier, Stéphanie; Doussan, Claude; Broussolle, Véronique; Gillon, Marina; Clavel, Thierry; Bérard, Annette
2015-01-01
The behaviour of the sporulating soil-dwelling Bacillus cereus sensu lato (B. cereus sl) which includes foodborne pathogenic strains has been extensively studied in relation to its various animal hosts. The aim of this environmental study was to investigate the water compartments (rain and soil water, as well as groundwater) closely linked to the primary B. cereus sl reservoir, for which available data are limited. B. cereus sl was present, primarily as spores, in all of the tested compartments of an agricultural site, including water from rain to groundwater through soil. During rain events, leachates collected after transfer through the soil eventually reached the groundwater and were loaded with B. cereus sl. In groundwater samples, newly introduced spores of a B. cereus model strain were able to germinate, and vegetative cells arising from this event were detected for up to 50 days. This first B. cereus sl investigation in the various types of interrelated environments suggests that the consideration of the aquatic compartment linked to soil and to climatic events should provide a better understanding of B. cereus sl ecology and thus be relevant for a more accurate risk assessment of food poisoning caused by B. cereus sl pathogenic strains.
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The Water Cycle, a Potential Source of the Bacterial Pathogen Bacillus cereus
Brillard, Julien; Dupont, Christian M. S.; Berge, Odile; Dargaignaratz, Claire; Oriol-Gagnier, Stéphanie; Doussan, Claude; Broussolle, Véronique; Gillon, Marina; Clavel, Thierry; Bérard, Annette
2015-01-01
The behaviour of the sporulating soil-dwelling Bacillus cereus sensu lato (B. cereus sl) which includes foodborne pathogenic strains has been extensively studied in relation to its various animal hosts. The aim of this environmental study was to investigate the water compartments (rain and soil water, as well as groundwater) closely linked to the primary B. cereus sl reservoir, for which available data are limited. B. cereus sl was present, primarily as spores, in all of the tested compartments of an agricultural site, including water from rain to groundwater through soil. During rain events, leachates collected after transfer through the soil eventually reached the groundwater and were loaded with B. cereus sl. In groundwater samples, newly introduced spores of a B. cereus model strain were able to germinate, and vegetative cells arising from this event were detected for up to 50 days. This first B. cereus sl investigation in the various types of interrelated environments suggests that the consideration of the aquatic compartment linked to soil and to climatic events should provide a better understanding of B. cereus sl ecology and thus be relevant for a more accurate risk assessment of food poisoning caused by B. cereus sl pathogenic strains. PMID:25918712
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Environmental and Biofilm-dependent Changes in a Bacillus cereus Secondary Cell Wall Polysaccharide*
Candela, Thomas; Maes, Emmanuel; Garénaux, Estelle; Rombouts, Yoann; Krzewinski, Frédéric; Gohar, Michel; Guérardel, Yann
2011-01-01
Bacterial species from the Bacillus genus, including Bacillus cereus and Bacillus anthracis, synthesize secondary cell wall polymers (SCWP) covalently associated to the peptidoglycan through a phospho-diester linkage. Although such components were observed in a wide panel of B. cereus and B. anthracis strains, the effect of culture conditions or of bacterial growth state on their synthesis has never been addressed. Herein we show that B. cereus ATCC 14579 can synthesize not only one, as previously reported, but two structurally unrelated secondary cell wall polymers (SCWP) polysaccharides. The first of these SCWP, →4)[GlcNAc(β1–3)]GlcNAc(β1–6)[Glc(β1-3)][ManNAc(α1–4)]GalNAc(α1–4)ManNAc(β1→, although presenting an original sequence, fits to the already described the canonical sequence motif of SCWP. In contrast, the second polysaccharide was made up by a totally original sequence, →6)Gal(α1–2)(2-R-hydroxyglutar-5-ylamido)Fuc2NAc4N(α1-6)GlcNAc(β1→, which no equivalent has ever been identified in the Bacillus genus. In addition, we established that the syntheses of these two polysaccharides were differently regulated. The first one is constantly expressed at the surface of the bacteria, whereas the expression of the second is tightly regulated by culture conditions and growth states, planktonic, or biofilm. PMID:21784857
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Pan-genome and phylogeny of Bacillus cereus sensu lato.
Bazinet, Adam L
2017-08-02
Bacillus cereus sensu lato (s. l.) is an ecologically diverse bacterial group of medical and agricultural significance. In this study, I use publicly available genomes and novel bioinformatic workflows to characterize the B. cereus s. l. pan-genome and perform the largest phylogenetic and population genetic analyses of this group to date in terms of the number of genes and taxa included. With these fundamental data in hand, I identify genes associated with particular phenotypic traits (i.e., "pan-GWAS" analysis), and quantify the degree to which taxa sharing common attributes are phylogenetically clustered. A rapid k-mer based approach (Mash) was used to create reduced representations of selected Bacillus genomes, and a fast distance-based phylogenetic analysis of this data (FastME) was performed to determine which species should be included in B. cereus s. l. The complete genomes of eight B. cereus s. l. species were annotated de novo with Prokka, and these annotations were used by Roary to produce the B. cereus s. l. pan-genome. Scoary was used to associate gene presence and absence patterns with various phenotypes. The orthologous protein sequence clusters produced by Roary were filtered and used to build HaMStR databases of gene models that were used in turn to construct phylogenetic data matrices. Phylogenetic analyses used RAxML, DendroPy, ClonalFrameML, PAUP*, and SplitsTree. Bayesian model-based population genetic analysis assigned taxa to clusters using hierBAPS. The genealogical sorting index was used to quantify the phylogenetic clustering of taxa sharing common attributes. The B. cereus s. l. pan-genome currently consists of ≈60,000 genes, ≈600 of which are "core" (common to at least 99% of taxa sampled). Pan-GWAS analysis revealed genes associated with phenotypes such as isolation source, oxygen requirement, and ability to cause diseases such as anthrax or food poisoning. Extensive phylogenetic analyses using an unprecedented amount of data
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Antimicrobial Effect of Nisin against Bacillus cereus in Beef Jerky during Storage
Lee, Na-Kyoung; Kim, Hyoun Wook; Lee, Joo Yeon; Ahn, Dong Uk; Kim, Cheon-Jei; Paik, Hyun-Dong
2015-01-01
The microbial distribution of raw materials and beef jerky, and the effect of nisin on the growth of Bacillus cereus inoculated in beef jerky during storage, were studied. Five strains of pathogenic B. cereus were detected in beef jerky, and identified with 99.8% agreement using API CHB 50 kit. To evaluate the effect of nisin, beef jerky was inoculated with approximately 3 Log CFU/g of B. cereus mixed culture and nisin (100 IU/g and 500 IU/g). During the storage of beef jerky without nisin, the number of mesophilic bacteria and B. cereus increased unlikely for beef jerky with nisin. B. cereus started to grow after 3 d in 100 IU nisin/g treatment, and after 21 d in 500 IU nisin/g treatment. The results suggest that nisin could be an effective approach to extend the shelf-life, and improve the microbial safety of beef jerky, during storage. PMID:26761838
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Pavan, Casey; Tarasenko, Olga
Stainless steel is ubiquitous in our modern world, however it can become contaminated. This can endanger our health. The aim of our study is to disinfect stainless steel using Bacillus cereus as a model organism. Bacillus cereus is a microbe that is ubiquitous in nature, specifically soil. B. cereus is known to cause illness in humans. To prevent this, we propose to use a glycoconjugate solution (GS) for disinfection of stainless steel after it is contamination by B. cereus spores. In this study, two GS (9, 10) were tested for disinfection effectiveness on B. cereus spores on the surface ofmore » stainless steel foil (AISI-Series 200/300/400, THERMA-FOIL, Dayville, CT 0241). The disinfection rate of each GS was assessed by exposing the steel surface to B. cereus spores first and allowing them to settle for 24 hours. GS was used to treat the contaminated surface. The steel is washed and the resulting solution is plated on tryptic soy agar (TSA) plates. The GS with the fewest colony forming unit (CFU) formed on TSA is determined to be the most efficient during disinfection. Results show that both GS demonstrate a strong ability to disinfect B. cereus spores. Between the two, GS 9 shows the highest disinfection efficacy by killing approximately 99.5% of spores. This is a drastic improvement over the 0-20% disinfection of the control. Based on this we find that studied GS do have the capacity to act as a disinfectant on stainless steel.« less
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Du, Hechao; Yang, Jie; Lu, Xiaohong; Lu, Zhaoxin; Bie, Xiaomei; Zhao, Haizhen; Zhang, Chong; Lu, Fengxia
2018-05-09
Bacillus cereus is an opportunistic pathogen that causes foodborne diseases. We isolated a novel bacteriocin, designated plantaricin GZ1-27, and elucidated its mode of action against B. cereus. Plantaricin GZ1-27 was purified using ammonium sulfate precipitation, gel-filtration chromatography, and RP-HPLC. MALDI-TOF/MS revealed that its molecular mass was 975 Da, and Q-TOF-MS/MS analysis predicted the amino acid sequence as VSGPAGPPGTH. Plantaricin GZ1-27 showed thermostability and pH stability. The antibacterial mechanism was investigated using flow cytometry, confocal laser-scanning microscopy, scanning and transmission electron microscopy, and RT-PCR, which revealed that GZ1-27 increased cell membrane permeability, triggered K + leakage and pore formation, damaged cell membrane integrity, altered cell morphology and intracellular organization, and reduced the expression of genes related to cytotoxin production, peptidoglycan synthesis, and cell division. These results suggest that plantaricin GZ1-27 effectively inhibits B. cereus at both the cellular and the molecular levels and is a potential natural food preservative targeting B. cereus.
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Tomaso, Herbert; Bartling, Carsten; Al Dahouk, Sascha; Hagen, Ralf M; Scholz, Holger C; Beyer, Wolfgang; Neubauer, Heinrich
2006-01-01
Anthrax Blood Agar (ABA) and Cereus Ident Agar (CEI) were evaluated as selective growth media for the isolation of Bacillus anthracis using 92 B. anthracis and 132 other Bacillus strains from 30 species. The positive predictive values for the identification of B. anthracis on ABA, CEI, and the combination of both were 72%, 71%, and 90%, respectively. Thus, less than 10% of all species were misidentified using both nutrient media. Species which might be misidentified as B. anthracis were B. cereus, B. mycoides, and B. thuringiensis. Particularly, 30% of B. weihenstephanensis strains were misidentified as B. anthracis.
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Combined action of nisin and carvacrol on Bacillus cereus and Listeria monocytogenes.
Pol, I E; Smid, E J
1999-09-01
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 in the last part of the exposure period. Bacillus cereus was more sensitive towards nisin than L. monocytogenes and the inhibitory effect of nisin was stronger towards cells cultivated and exposed at 8 degrees C than towards cells cultivated and exposed at 20 degrees C. Combining nisin with sublethal doses of carvacrol resulted in an increased reduction in the viable count of both organisms, indicating synergy between nisin and carvacrol. Addition of lysozyme as a third preservative factor increased the synergistic effect between nisin and carvone, especially in the last part of the exposure period.
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Mietke, Henriette; Beer, W; Schleif, Julia; Schabert, G; Reissbrodt, R
2010-05-30
Animal feed often contains probiotic Bacillus strains used as feed additives. Spores of the non-pathogenic B. cereus var. toyoi (product name Toyocerin) are used. Distinguishing between toxic wild-type Bacillus cereus strains and this probiotic strain is essential for evaluating the quality and risk of feed. Bacillus cereus CIP 5832 (product name Paciflor was used as probiotic strain until 2001. The properties of the two probiotic strains are quite similar. Differentiating between probiotic strains and wild-type B. cereus strains is not easy. ss-lactam antibiotics such as penicillin and cefamandole exhibit an inhibition zone in the agar diffusion test of probiotic B. cereus strains which are not seen for wild-type strains. Therefore, performing the agar diffusion test first may make sense before FT-IR testing. When randomly checking these strains by Fourier transform infrared spectroscopy (FT-IR), the probiotic B. cereus strains were separated from wild-type B. cereus/B. thuringiensis/B. mycoides/B. weihenstephanensis strains by means of hierarchical cluster analysis. The discriminatory information was contained in the spectral windows 3000-2800 cm(-1) ("fatty acid region"), 1200-900 cm(-1) ("carbohydrate region") and 900-700 cm(-1) ("fingerprint region"). It is concluded that FT-IR spectroscopy can be used for the rapid quality control and risk analysis of animal feed containing probiotic B. cereus strains. (c) 2010 Elsevier B.V. All rights reserved.
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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 (< 200 to 8.3 × 10(7) CFU/g), with 19.1% of samples at levels above 10(5) CFU/g. For examples, paprika, allspice, peppercorns, and mixed 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 <3 to 1,600 MPN/g. Eighty-eight percent of B. cereus isolates and 91% of B. thuringiensis isolates possessed at least one type of enterotoxin gene: HBL (hemolysin BL) or nonhemolytic enterotoxin (NHE). None of the 88 isolates obtained in this study possessed the emetic toxin gene (ces). Using commercially available immunological toxin detection kits, the toxigenicity of the isolates was confirmed. The NHE enterotoxin was expressed in 98% of B. cereus and 91% of B. thuringiensis isolates that possessed the responsible gene. HBL enterotoxin was detected in 87% of B. cereus and 100% of B. thuringiensis PCR-positive isolates. Fifty-two percent of B. cereus and 54% of B. thuringiensis isolates produced both enterotoxins. Ninety-seven percent of B. cereus isolates grew at 12°C, although only two isolates grew well at 9°C. The ability of these spice isolates to form spores, produce diarrheal toxins, and grow at moderately abusive temperatures makes retail spices an important potential vehicle for foodborne illness caused by B. cereus strains, in particular those that produce diarrheal toxins.
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The putative drug efflux systems of the Bacillus cereus group
Elbourne, Liam D. H.; Vörös, Aniko; Kroeger, Jasmin K.; Simm, Roger; Tourasse, Nicolas J.; Finke, Sarah; Henderson, Peter J. F.; Økstad, Ole Andreas; Paulsen, Ian T.; Kolstø, Anne-Brit
2017-01-01
The Bacillus cereus group of bacteria includes seven closely related species, three of which, B. anthracis, B. cereus and B. thuringiensis, are pathogens of humans, animals and/or insects. Preliminary investigations into the transport capabilities of different bacterial lineages suggested that genes encoding putative efflux systems were unusually abundant in the B. cereus group compared to other bacteria. To explore the drug efflux potential of the B. cereus group all putative efflux systems were identified in the genomes of prototypical strains of B. cereus, B. anthracis and B. thuringiensis using our Transporter Automated Annotation Pipeline. More than 90 putative drug efflux systems were found within each of these strains, accounting for up to 2.7% of their protein coding potential. Comparative analyses demonstrated that the efflux systems are highly conserved between these species; 70–80% of the putative efflux pumps were shared between all three strains studied. Furthermore, 82% of the putative efflux system proteins encoded by the prototypical B. cereus strain ATCC 14579 (type strain) were found to be conserved in at least 80% of 169 B. cereus group strains that have high quality genome sequences available. However, only a handful of these efflux pumps have been functionally characterized. Deletion of individual efflux pump genes from B. cereus typically had little impact to drug resistance phenotypes or the general fitness of the strains, possibly because of the large numbers of alternative efflux systems that may have overlapping substrate specificities. Therefore, to gain insight into the possible transport functions of efflux systems in B. cereus, we undertook large-scale qRT-PCR analyses of efflux pump gene expression following drug shocks and other stress treatments. Clustering of gene expression changes identified several groups of similarly regulated systems that may have overlapping drug resistance functions. In this article we review current
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Development of a double-antibody sandwich ELISA for rapid detection of Bacillus Cereus in food
Zhu, Longjiao; He, Jing; Cao, Xiaohan; Huang, Kunlun; Luo, Yunbo; Xu, Wentao
2016-01-01
Bacillus cereus is increasingly recognized as one of the major causes of food poisoning in the industrialized world. In this paper, we describe a sensitive double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) that was developed for rapid detection of B. cereus in food to minimize the risk of contamination. The polyclonal antibody (pAb) and monoclonal antibodies (mAbs) specific to B. cereus were generated from rabbit antiserum and mouse ascites, respectively, using the octanoic acid/saturated ammonium sulfate precipitation method and protein A-sepharose columns. IgG-isotype mAbs were specially developed to undergo a novel peripheral multiple sites immunization for rapid gain of hybridomas and a subtractive screen was used to eliminate cross reactivity with closely related species such as Bacillus thuringiensis, B. subtilis, B. licheniformis and B. perfringens. The linear detection range of the method was approximately 1 × 104–2.8 × 106 cells/mL with a detection limit (LOD) of 0.9 × 103 cells/mL. The assay was able to detect B. cereus when the samples were prepared in meat with various pathogens. The newly developed analytical method provides a rapid method to sensitively detect B. cereus in food specimens. PMID:26976753
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Corrosion effect of Bacillus cereus on X80 pipeline steel in a Beijing soil environment.
Wan, Hongxia; Song, Dongdong; Zhang, Dawei; Du, Cuiwei; Xu, Dake; Liu, Zhiyong; Ding, De; Li, Xiaogang
2018-06-01
The corrosion of X80 pipeline steel in the presence of Bacillus cereus (B. cereus) was studied through electrochemical and surface analyses and live/dead staining. Scanning electron microscopy and live/dead straining results showed that a number of B. cereus adhered to the X80 steel. Electrochemical impedance spectroscopy showed that B. cereus could accelerate the corrosion of X80 steel. In addition, surface morphology observations indicated that B. cereus could accelerate pitting corrosion in X80 steel. The depth of the largest pits due to B. cereus was approximately 11.23μm. Many pits were found on the U-shaped bents and cracks formed under stress after 60days of immersion in the presence of B. cereus. These indicate that pitting corrosion can be accelerated by B. cereus. X-ray photoelectron spectroscopy results revealed that NH 4 + existed on the surface of X80 steel. B. cereus is a type of nitrate-reducing bacteria and hence the corrosion mechanism of B. cereus may involve nitrate reduction on the X80 steel. Copyright © 2018 Elsevier B.V. All rights reserved.
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Leski, Tomasz A.; Caswell, Clayton C.; Pawlowski, Marcin; Klinke, David J.; Bujnicki, Janusz M.; Hart, Sean J.; Lukomski, Slawomir
2009-01-01
The Bacillus cereus group includes three closely related species, B. anthracis, B. cereus, and B. thuringiensis, which form a highly homogeneous subdivision of the genus Bacillus. One of these species, B. anthracis, has been identified as one of the most probable bacterial biowarfare agents. Here, we evaluate the sequence and length polymorphisms of the Bacillus collagen-like protein bcl genes as a basis for B. anthracis detection and fingerprinting. Five genes, designated bclA to bclE, are present in B. anthracis strains. Examination of bclABCDE sequences identified polymorphisms in bclB alleles of the B. cereus group organisms. These sequence polymorphisms allowed specific detection of B. anthracis strains by PCR using both genomic DNA and purified Bacillus spores in reactions. By exploiting the length variation of the bcl alleles it was demonstrated that the combined bclABCDE PCR products generate markedly different fingerprints for the B. anthracis Ames and Sterne strains. Moreover, we predict that bclABCDE length polymorphism creates unique signatures for B. anthracis strains, which facilitates identification of strains with specificity and confidence. Thus, we present a new diagnostic concept for B. anthracis detection and fingerprinting, which can be used alone or in combination with previously established typing platforms. PMID:19767469
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The role of pili in Bacillus cereus intraocular infection.
Callegan, Michelle C; Parkunan, Salai Madhumathi; Randall, C Blake; Coburn, Phillip S; Miller, Frederick C; LaGrow, Austin L; Astley, Roger A; Land, Craig; Oh, So-Young; Schneewind, Olaf
2017-06-01
Bacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity
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Kihara, Takahiro; Hiroe, Ayaka; Ishii-Hyakutake, Manami; Mizuno, Kouhei; Tsuge, Takeharu
2017-08-01
Bacillus cereus and Bacillus megaterium both accumulate polyhydroxyalkanoate (PHA) but their PHA biosynthetic gene (pha) clusters that code for proteins involved in PHA biosynthesis are different. Namely, a gene encoding MaoC-like protein exists in the B. cereus-type pha cluster but not in the B. megaterium-type pha cluster. MaoC-like protein has an R-specific enoyl-CoA hydratase (R-hydratase) activity and is referred to as PhaJ when involved in PHA metabolism. In this study, the pha cluster of B. cereus YB-4 was characterized in terms of PhaJ's function. In an in vitro assay, PhaJ from B. cereus YB-4 (PhaJ YB4 ) exhibited hydration activity toward crotonyl-CoA. In an in vivo assay using Escherichia coli as a host for PHA accumulation, the recombinant strain expressing PhaJ YB4 and PHA synthase led to increased PHA accumulation, suggesting that PhaJ YB4 functioned as a monomer supplier. The monomer composition of the accumulated PHA reflected the substrate specificity of PhaJ YB4 , which appeared to prefer short chain-length substrates. The pha cluster from B. cereus YB-4 functioned to accumulate PHA in E. coli; however, it did not function when the phaJ YB4 gene was deleted. The B. cereus-type pha cluster represents a new example of a pha cluster that contains the gene encoding PhaJ.
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Asymmetric reduction of benzil to (S)-benzoin with whole cells of Bacillus cereus.
Saito, Tomoya; Maruyama, Reiji; Ono, Shin; Yasukawa, Nobuo; Kodaira, Ken-ichi; Nishizawa, Mikio; Ito, Seiji; Inoue, Masami
2003-12-01
Benzil (1) was selectively reduced to (S)-benzoin (2) in the presence of a wild-type Bacillus cereus Tim-r01. A 92% yield of 2 with 94% enantiomeric excess ratio was attained in phosphate-buffered saline (PBS) (pH 7.5) by using glucose as a nutrient at 37 degrees C for 12 h. Compound 2 was not reduced further to hydrobenzoin (3) at all. The reduction activity differed greatly depending on the strain of B. cereus. Under these conditions the B. cereus strains IFO3001, IFO15305, IAM1110, IAM1229, IAM1656, and IAM1729 gave 2 in yields ranging from 23 to 46% and the configuration of 2 was (S)-form (7 to 86% ee).
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An outbreak of Bacillus cereus implicating a part-time banquet caterer.
Gaulin, Colette; Viger, Yv Bonnier; Fillion, Lise
2002-01-01
In the aftermath of a party, 70% (25 of 36) of attendees had gastroenteritis. The objectives of this study were to identify a risk factor associated with the food during the banquet and to identify measures of control for avoiding this kind of outbreak in the future. A retrospective cohort study was used. We tried to reach by telephone all guests who had attended this banquet. A standardized questionnaire was used to provide information about identification of a risk factor, especially in relation to food. The cohort study has shown that potato salad served at the party was significantly associated with the disease. The mayonnaise used to prepare the salad was analyzed and Bacillus cereus was isolated (10(3) bacteria per gram). Bacillus microorganisms are usually found in decaying organic matter, dust, soil, vegetables and water. The bacteria has a remarkable ability to survive strong environmental stresses. There are strains of B. cereus that can cause food poisoning episodes with infective doses as low as 10(3) to 10(4) bacteria per gram. B. cereus is an infrequently reported cause of foodborne illnesses in Quebec and in North America but this may be due to underreporting of episodes. In this outbreak, bacterial multiplication was facilitated at several points in the interval between the preparation of the meal and the consumption of the banquet by the guests. Because the spores are ubiquitous and resistant to inactivation with most food grade disinfectants, temperature control should be the main focus of B. cereus outbreak prevention. The meal was prepared by a restaurateur who was inexperienced in catering services and temperature control in particular when food is served outside the restaurant. This outbreak underscores the importance of maintaining meticulous hygienic procedures in food processing. Restaurateurs who offer catering services should be familiar with the constraints that are specific to this sector of the food industry.
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Extending the Bacillus cereus group genomics to putative food-borne pathogens of different toxicity.
Lapidus, Alla; Goltsman, Eugene; Auger, Sandrine; Galleron, Nathalie; Ségurens, Béatrice; Dossat, Carole; Land, Miriam L; Broussolle, Veronique; Brillard, Julien; Guinebretiere, Marie-Helene; Sanchis, Vincent; Nguen-The, Christophe; Lereclus, Didier; Richardson, Paul; Wincker, Patrick; Weissenbach, Jean; Ehrlich, S Dusko; Sorokin, Alexei
2008-01-30
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 530kb) 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
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An outbreak of Bacillus cereus food poisoning--are caterers supervised sufficiently.
Slaten, D D; Oropeza, R I; Werner, S B
1992-01-01
Bacillus cereus is an uncommonly reported cause of foodborne illness in the United States. In May 1989, an outbreak of B. cereus gastroenteritis occurred among 140 guests who had attended a catered wedding reception in Napa, CA. Investigation established Cornish game hens served at the event as the vehicle for disease transmission (OR = 29, P = 0.0001). Although the spores of B. cereus are ubiquitous, large numbers of toxin-producing organisms (more than 10(5) per gram of food) are required for illness to occur. In the Napa outbreak, bacterial multiplication was facilitated at several points during the preparation and transportation of the food. While a licensed restaurant kitchen was used, the facilities were clearly inadequate for the event. At present, the California Health and Safety Code does not address the scope of catering operations. As caterers increase in number, there will be a growing need for governmental oversight to ensure that food production on a large scale is conducted safely. PMID:1641447
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Isolation of Bacillus cereus Group from the Fecal Material of Endangered Wood Turtles.
Nfor, Nancy Ngvumbo; Lapin, Carly N; McLaughlin, Richard William
2015-10-01
Members of the Bacillus cereus group are opportunistic human pathogens. They can be found in a broad range of foods. Diarrheal food poisoning and/or emetic type syndromes can result from eating contaminated food. In this study, seven B. cereus group members were isolated from the fecal material of Wood Turtles (Glyptemys insculpta). The isolates were then assessed for the presence of enterotoxin genes (nheA, entFM, hblC, and cytK) using PCR. The most prevalent is the nonhemolytic enterotoxin gene which was found in all seven isolates.
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Bacillus cereus, a serious cause of nosocomial infections: Epidemiologic and genetic survey.
Glasset, Benjamin; Herbin, Sabine; Granier, Sophie A; Cavalié, Laurent; Lafeuille, Emilie; Guérin, Cyprien; Ruimy, Raymond; Casagrande-Magne, Florence; Levast, Marion; Chautemps, Nathalie; Decousser, Jean-Winoc; Belotti, Laure; Pelloux, Isabelle; Robert, Jerôme; Brisabois, Anne; Ramarao, Nalini
2018-01-01
Bacillus cereus is the 2nd most frequent bacterial agent responsible for food-borne outbreaks in France and the 3rd in Europe. In addition, local and systemic infections have been reported, mainly describing individual cases or single hospital setting. The real incidence of such infection is unknown and information on genetic and phenotypic characteristics of the incriminated strains is generally scarce. We performed an extensive study of B. cereus strains isolated from patients and hospital environments from nine hospitals during a 5-year study, giving an overview of the consequences, sources and pathogenic patterns of B. cereus clinical infections. We demonstrated the occurrence of several hospital-cross-contaminations. Identical B. cereus strains were recovered from different patients and hospital environments for up to 2 years. We also clearly revealed the occurrence of inter hospital contaminations by the same strain. These cases represent the first documented events of nosocomial epidemy by B. cereus responsible for intra and inter hospitals contaminations. Indeed, contamination of different patients with the same strain of B. cereus was so far never shown. In addition, we propose a scheme for the characterization of B. cereus based on biochemical properties and genetic identification and highlight that main genetic signatures may carry a high pathogenic potential. Moreover, the characterization of antibiotic resistance shows an acquired resistance phenotype for rifampicin. This may provide indication to adjust the antibiotic treatment and care of patients.
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Callahan, Courtney; Fox, Karen; Fox, Alvin
2009-01-01
The Bacillus cereus group includes Bacillus anthracis, Bacillus cereus, Bacillus thuringiensis, Bacillus mycoides and Bacillus weihenstephanensis. The small acid-soluble spore protein (SASP) β has been previously demonstrated to be among the biomarkers differentiating B. anthracis and B. cereus; SASP β of B. cereus most commonly exhibits one or two amino acid substitutions when compared to B. anthracis. SASP α is conserved in sequence among these two species. Neither SASP α nor β for B. thuringiensis, B. mycoides and B. weihenstephanensis have been previously characterized as taxonomic discriminators. In the current work molecular weight (MW) variation of these SASPs were determined by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) for representative strains of the 5 species within the B. cereus group. The measured MWs also correlate with calculated MWs of translated amino acid sequences generated from whole genome sequencing projects. SASP α and β demonstrated consistent MW among B. cereus, B. thuringiensis, and B. mycoides strains (group 1). However B. mycoides (group 2) and B. weihenstephanensis SASP α and β were quite distinct making them unique among the B. cereus group. Limited sequence changes were observed in SASP α (at most 3 substitutions and 2 deletions) indicating it is a more conserved protein than SASP β (up to 6 substitutions and a deletion). Another even more conserved SASP, SASP α-β type, was described here for the first time. PMID:19616612
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Omardien, Soraya; Ter Beek, Alexander; Vischer, Norbert; Montijn, Roy; Schuren, Frank; Brul, Stanley
2018-06-14
An empirical approach was taken to screen a novel synthetic compound library designed to be active against Gram-positive bacteria. We obtained five compounds that were active against spores from the model organism Bacillus subtilis and the food-borne pathogen Bacillus cereus during our population based experiments. Using single cell live imaging we were able to observe effects of the compounds on spore germination and outgrowth. Difference in sensitivity to the compounds could be observed between B. subtilis and B. cereus using live imaging, with minor difference in the minimal inhibitory and bactericidal concentrations of the compounds against the spores. The compounds all delayed the bursting time of germinated spores and affected the generation time of vegetative cells at sub-inhibitory concentrations. At inhibitory concentrations spore outgrowth was prevented. One compound showed an unexpected potential for preventing spore germination at inhibitory concentrations, which merits further investigation. Our study shows the valuable role single cell live imaging can play in the final selection process of antimicrobial compounds.
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Kaboré, Donatien; Nielsen, Dennis Sandris; Sawadogo-Lingani, Hagrétou; Diawara, Bréhima; Dicko, Mamoudou Hama; Jakobsen, Mogens; Thorsen, Line
2013-03-01
Maari is a spontaneously alkaline fermented food condiment made from baobab tree seeds. Due to the spontaneous nature of maari fermentations growth of the opportunistic human pathogen Bacillus cereus is occasionally observed. Bacillus subtilis strains are important for alkaline seed fermentations because of their enzymatic activities contributing to desirable texture, flavor and pH development. Some B. subtilis strains have antimicrobial properties against B. cereus. In the present work, three bacteriocin producing B. subtilis strains (B3, B122 and B222) isolated from maari were tested. The production of antimicrobial activity by the three strains was found to be greatly influenced by the substrate. All three B. subtilis strains produced antimicrobial activity against B. cereus NVH391-98 in BHI broth as determined by the agar well diffusion assay, whereas no antimicrobial activity was detected in whole cooked baobab seeds and in 10% (w/v) grinded baobab seeds. Incorporation of BHI with up to 5% (w/w) grinded baobab seeds enhanced the antimicrobial activity of B. subtilis compared with pure BHI in a strain dependent manner. Incorporation of BHI with 50% (w/w) baobab grinded seeds decreased the antimicrobial activity. Addition of the inorganic salts FeCl₃, MgSO₄ and MnSO₄ has previously been reported to increase bacteriocin production of B. subtilis, but the addition of these salts to 10% (w/v) grinded baobab seed broth did not cause antimicrobial activity. Survival of B. cereus NVH391-98 in co-culture with B. subtilis was tested in BHI broth, 10% (w/v) grinded baobab seed based broth and during baobab seed fermentation to produce maari. B. cereus NVH391-98 grew well in all three substrates in mono-culture. All the 3 B. subtilis strains were able to decrease B. cereus NVH391-98 to levels below the detection limit (<10 CFU/ml) in BHI, but not in baobab seed based substrates, even though the outgrowth of B. cereus NVH391-98 was delayed by up to 40 h. In
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USDA-ARS?s Scientific Manuscript database
In previous work, we reported on the isolation and genome sequence analysis of Bacillus cereus strain tsu1 NCBI accession number JPYN00000000. The 36 scaffolds in the assembled tsu1 genome were all aligned with B. cereus B4264 genome with variations. Genes encoding for xylanase and cellulase and the...
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Production and characterization of poly-3-hydroxybutyrate from Bacillus cereus PS 10.
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. Copyright © 2015 Elsevier B.V. All rights reserved.
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NASA Astrophysics Data System (ADS)
Hong, Yun-Hee; Park, Ji-Yong; Park, Jong-Hyun; Chung, Myong-Soo; Kwon, Ki-Sung; Chung, Kyungsook; Won, Misun; Song, Kyung-Bin
2008-09-01
Inactivation of Enterobacter sakazakii, Bacillus cereus, and Salmonella typhimurium were evaluated in powdered weaning food using electron-beam irradiation. E. sakazakii, B. cereus, and S. typhimurium were eliminated by irradiation at 16, 8, and 8 kGy, respectively. The D10-vlaues of E. sakazakii, B. cereus, and S. typhimurium inoculated on powdered weaning food were 4.83, 1.22, and 0.98 kGy, respectively. The results suggest that electron-beam irradiation should inhibit the growth of pathogenic bacteria on baby food without impairing qualities.
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The Arthromitus stage of Bacillus cereus: Intestinal symbionts of animals
Margulis, Lynn; Jorgensen, Jeremy Z.; Dolan, Sona; Kolchinsky, Rita; Rainey, Frederick A.; Lo, Shyh-Ching
1998-01-01
In the guts of more than 25 species of arthropods we observed filaments containing refractile inclusions previously discovered and named “Arthromitus” in 1849 by Joseph Leidy [Leidy, J. (1849) Proc. Acad. Nat. Sci. Philadelphia 4, 225–233]. We cultivated these microbes from boiled intestines of 10 different species of surface-cleaned soil insects and isopod crustaceans. Literature review and these observations lead us to conclude that Arthromitus are spore-forming, variably motile, cultivable bacilli. As long rod-shaped bacteria, they lose their flagella, attach by fibers or fuzz to the intestinal epithelium, grow filamentously, and sporulate from their distal ends. When these organisms are incubated in culture, their life history stages are accelerated by light and inhibited by anoxia. Characterization of new Arthromitus isolates from digestive tracts of common sow bugs (Porcellio scaber), roaches (Gromphodorhina portentosa, Blaberus giganteus) and termites (Cryptotermes brevis, Kalotermes flavicollis) identifies these flagellated, spore-forming symbionts as a Bacillus sp. Complete sequencing of the 16S rRNA gene from four isolates (two sow bug, one hissing roach, one death’s head roach) confirms these as the low-G+C Gram-positive eubacterium Bacillus cereus. We suggest that B. cereus and its close relatives, easily isolated from soil and grown on nutrient agar, enjoy filamentous growth in moist nutrient-rich intestines of healthy arthropods and similar habitats. PMID:9448315
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The Arthromitus stage of Bacillus cereus: intestinal symbionts of animals.
Margulis, L; Jorgensen, J Z; Dolan, S; Kolchinsky, R; Rainey, F A; Lo, S C
1998-02-03
In the guts of more than 25 species of arthropods we observed filaments containing refractile inclusions previously discovered and named "Arthromitus" in 1849 by Joseph Leidy [Leidy, J. (1849) Proc. Acad. Nat. Sci. Philadelphia 4, 225-233]. We cultivated these microbes from boiled intestines of 10 different species of surface-cleaned soil insects and isopod crustaceans. Literature review and these observations lead us to conclude that Arthromitus are spore-forming, variably motile, cultivable bacilli. As long rod-shaped bacteria, they lose their flagella, attach by fibers or fuzz to the intestinal epithelium, grow filamentously, and sporulate from their distal ends. When these organisms are incubated in culture, their life history stages are accelerated by light and inhibited by anoxia. Characterization of new Arthromitus isolates from digestive tracts of common sow bugs (Porcellio scaber), roaches (Gromphodorhina portentosa, Blaberus giganteus) and termites (Cryptotermes brevis, Kalotermes flavicollis) identifies these flagellated, spore-forming symbionts as a Bacillus sp. Complete sequencing of the 16S rRNA gene from four isolates (two sow bug, one hissing roach, one death's head roach) confirms these as the low-G+C Gram-positive eubacterium Bacillus cereus. We suggest that B. cereus and its close relatives, easily isolated from soil and grown on nutrient agar, enjoy filamentous growth in moist nutrient-rich intestines of healthy arthropods and similar habitats.
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The Arthromitus stage of Bacillus cereus: intestinal symbionts of animals
NASA Technical Reports Server (NTRS)
Margulis, L.; Jorgensen, J. Z.; Dolan, S.; Kolchinsky, R.; Rainey, F. A.; Lo, S. C.
1998-01-01
In the guts of more than 25 species of arthropods we observed filaments containing refractile inclusions previously discovered and named "Arthromitus" in 1849 by Joseph Leidy [Leidy, J. (1849) Proc. Acad. Nat. Sci. Philadelphia 4, 225-233]. We cultivated these microbes from boiled intestines of 10 different species of surface-cleaned soil insects and isopod crustaceans. Literature review and these observations lead us to conclude that Arthromitus are spore-forming, variably motile, cultivable bacilli. As long rod-shaped bacteria, they lose their flagella, attach by fibers or fuzz to the intestinal epithelium, grow filamentously, and sporulate from their distal ends. When these organisms are incubated in culture, their life history stages are accelerated by light and inhibited by anoxia. Characterization of new Arthromitus isolates from digestive tracts of common sow bugs (Porcellio scaber), roaches (Gromphodorhina portentosa, Blaberus giganteus) and termites (Cryptotermes brevis, Kalotermes flavicollis) identifies these flagellated, spore-forming symbionts as a Bacillus sp. Complete sequencing of the 16S rRNA gene from four isolates (two sow bug, one hissing roach, one death's head roach) confirms these as the low-G+C Gram-positive eubacterium Bacillus cereus. We suggest that B. cereus and its close relatives, easily isolated from soil and grown on nutrient agar, enjoy filamentous growth in moist nutrient-rich intestines of healthy arthropods and similar habitats.
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Yang, Kai; Zhang, Jing; Yang, Tao; Wang, Hongyu
2016-01-01
In this study, response surface methodology (RSM) based on three-variable-five-level central composite rotatable design was used to analyze the effects of combined and individual operating parameters (biomass dose, initial concentration of Cr(VI) and pH) on the Cr(VI) adsorption capacity of dried Bacillus cereus. A quadratic polynomial equation was obtained to predict the adsorbed Cr(VI) amount. Analysis of variance showed that the effect of biomass dose was the key factor in the removal of Cr(VI). The maximum adsorbed Cr(VI) amount (30.93 mg g(-1)) was found at 165.30 mg L(-1), 2.96, and 3.01 g L(-1) for initial Cr(VI) concentration, pH, and biosorbent dosage, respectively. The surface chemical functional groups and microstructure of unloaded and Cr(VI)-loaded dried Bacillus cereus were identified by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Besides, the results gained from these studies indicated that Langmuir isotherm and the second-order rate expression were suitable for the removal of Cr(VI) from wastewater. The results revealed RSM was an effective method for optimizing biosorption process, and dried Bacillus cereus had a remarkable performance on the removal of Cr(VI) from wastewater.
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40 CFR 180.1181 - Bacillus cereus strain BPO1; exemption from the requirement of a tolerance.
Code of Federal Regulations, 2010 CFR
2010-07-01
... FOOD Exemptions From Tolerances § 180.1181 Bacillus cereus strain BPO1; exemption from the requirement... strain BPO1 in or on all raw agricultural commodities when applied/used in accordance with label...
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40 CFR 180.1181 - Bacillus cereus strain BPO1; exemption from the requirement of a tolerance.
Code of Federal Regulations, 2011 CFR
2011-07-01
... FOOD Exemptions From Tolerances § 180.1181 Bacillus cereus strain BPO1; exemption from the requirement... strain BPO1 in or on all raw agricultural commodities when applied/used in accordance with label...
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The relationship between the structures of four beta-lactamases obtained from Bacillus cereus.
Cid, H; Carrillo, O; Bunster, M; Martínez, J; Vargas, V
1988-06-01
Bacillus cereus has proved to be one of the most interesting microorganisms in the study of beta-lactamases. It secrets these enzymes very efficiently and, frequently, in multiple forms. Three different forms are produced by strain 569/H; mutant 5/B of the same microorganism is constitutive for the secretion of beta-lactamases I and II. The present study, based on secondary structure prediction by two independent methods, states the relationship among the structures of beta-lactamases I, II and III produced by B. cereus 569/H and beta-lactamase I from the strain 5/B of this microorganism. A strong similarity is also established for the enzyme type III of B. cereus and the enzyme type I produced by B. licheniformis which could have an evolutionary explanation. A structural analysis of the leader peptide regions of these enzymes by the method of Mohana and Argos is also reported.
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Wu, Pengfei; Wang, Genyu; Wang, Gehua; Børresen, Børre Tore; Liu, Hongjuan; Zhang, Jianan
2016-01-14
One major problem of ABE (acetone, butanol and ethanol) fermentation is high oxygen sensitivity of Clostridium acetobutylicum. Currently, no single strain has been isolated or genetically engineered to produce butanol effectively under aerobic conditions. In our previous work, a symbiotic system TSH06 has been developed successfully by our group, and two strains, C. acetobutylicum TSH1 and Bacillus cereus TSH2, were isolated from TSH06. Compared with single culture, TSH06 showed promotion on cell growth and solvent accumulation under microaerobic conditions. To simulate TSH06, a new symbiotic system was successfully re-constructed by adding living cells of B. cereus TSH2 into C. acetobutylicum TSH1 cultures. During the fermentation process, the function of B. cereus TSH2 was found to deplete oxygen and provide anaerobic environment for C. acetobutylicum TSH1. Furthermore, inoculation ratio of C. acetobutylicum TSH1 and B. cereus TSH2 affected butanol production. In a batch fermentation with optimized inoculation ratio of 5 % C. acetobutylicum TSH1 and 0.5 % B. cereus TSH2, 11.0 g/L butanol and 18.1 g/L ABE were produced under microaerobic static condition. In contrast to the single culture of C. acetobutylicum TSH1, the symbiotic system became more aerotolerant and was able to produce 11.2 g/L butanol in a 5 L bioreactor even with continuous 0.15 L/min air sparging. In addition, qPCR assay demonstrated that the abundance of B. cereus TSH2 increased quickly at first and then decreased sharply to lower than 1 %, whereas C. acetobutylicum TSH1 accounted for more than 99 % of the whole population in solventogenic phase. The characterization of a novel symbiotic system on butanol fermentation was studied. The new symbiotic system re-constructed by co-culture of C. acetobutylicum TSH1 and B. cereus TSH2 showed excellent performance on butanol production under microaerobic conditions. B. cereus TSH2 was a good partner for C. acetobutylicum TSH1 by providing an anaerobic
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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.
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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
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Detection of toxigenic Bacillus cereus strains isolated from vegetables in Mexico City.
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.
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Purification and characterization of two polyhydroxyalcanoates from Bacillus cereus.
Zribi-Maaloul, Emna; Trabelsi, Imen; Elleuch, Lobna; Chouayekh, Hichem; Ben Salah, Riadh
2013-10-01
This work aimed to study the potential of 155 strains of Bacillus sp., isolated from a collection of Tunisian microorganisms, for polyhydroxyalcanoates production. The strains were submitted to a battery of standard tests commonly used for determining bioplastic properties. The findings revealed that two of the isolates, namely Bacillus US 163 and US 177, provided red excitations at a wavelength of approximately 543 nm. The polyhydroxyalcanoates produced by the two strains were purified. Gas chromatography-mass spectroscopy (GC-MS), Fourier transformed infrared spectroscopy (FTIR), and gel permeation chromatography (GPC) were used to characterize the two biopolymers. Bacillus US 163 was noted to produce a poly methyl-3-hydroxy tetradecanoic acid (P-3HTD) with an average molecular weight of 455 kDa, a completely amorphous homopolymer without crystallinity. The US 177 strain produced a homopolymer of methyl-3-hydroxy octadecanoic acid (P3-HOD) with an average molecular weight of 555 kDa. Exhibiting the highest performance, US 163 and US 177 were submitted to 16S rRNA gene sequencing, and the results revealed that they belonged to the Bacillus cereus species. Overall, the findings indicated that the Bacilli from petroleum soil have a number of promising properties that make them promising candidates for bioplastic production. Copyright © 2013 Elsevier B.V. All rights reserved.
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A hospital cafeteria-related food-borne outbreak due to Bacillus cereus: unique features.
Baddour, L M; Gaia, S M; Griffin, R; Hudson, R
1986-09-01
Although Bacillus cereus is a well-known cause of food-borne illness, hospital-related outbreaks of food-borne disease due to B. cereus have rarely been documented. We report a hospital employee cafeteria outbreak due to foods contaminated with B. cereus in which an outside caterer was employed to prepare the suspect meals. Data were collected from 249 of 291 employees who had eaten either of the two meals. With a mean incubation period of 12.5 hours, 64% (160 of 249) of employees manifested illness. Symptoms, which averaged 24.3 hours in duration, included diarrhea (96.3%), abdominal cramps (90%), nausea (50.6%), weakness (24.7%), and vomiting (13.8%). Eighty-seven employees sought medical attention, 84 of whom were seen in an emergency room. Although a significant difference was not demonstrated in food-specific attack rates, B. cereus was cultured from both rice and chicken items that were served at both meals. Sixty-three employees submitted stools for culture that grew no enteric pathogens, but none were examined for B. cereus. This food-borne outbreak demonstrates: the need for hospital kitchen supervisors to ensure proper handling of food when outside caterers are employed; that significant differences in food-specific attack rates may not be demonstrated in outbreaks, which may be related to several factors; and the importance of notifying microbiology laboratory personnel when B. cereus is a suspect enteric pathogen, since many laboratories do not routinely attempt to identify this organism in stool specimens.
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Summers, R. J.; Boudreaux, D. P.; Srinivasan, V. R.
1979-01-01
Steady-state continuous culture was used to optimize lean chemically defined media for a Cellulomonas sp. and Bacillus cereus strain T. Both organisms were extremely sensitive to variations in trace-metal concentrations. However, medium optimization by this technique proved rapid, and multifactor screening was easily conducted by using a minimum of instrumentation. The optimized media supported critical dilution rates of 0.571 and 0.467 h−1 for Cellulomonas and Bacillus, respectively. These values approximated maximum growth rate values observed in batch culture. PMID:16345417
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Certhrax Toxin, an Anthrax-related ADP-ribosyltransferase from Bacillus cereus*
Visschedyk, Danielle; Rochon, Amanda; Tempel, Wolfram; Dimov, Svetoslav; Park, Hee-Won; Merrill, A. Rod
2012-01-01
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 (KD = 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 (KD = 1.7 ± 0.2 μm, Ki = 1.8 ± 0.4 μm) and PJ34 (KD = 5.8 ± 2.6 μm, Ki = 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. PMID:22992735
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Antimicrobial potential of flavoring ingredients against Bacillus cereus in a milk-based beverage.
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 (p<0.05) reduced bacterial growth when supplementing the LWE-SM beverage. B. cereus behavior was mathematically described for each substrate by means of a modified Gompertz equation. Kinetic parameters, lag time, and maximum specific growth rate were obtained. Cinnamon 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.
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Lessons learnt from a birthday party: a Bacillus cereus outbreak, Bari, Italy, January 2012.
Martinelli, Domenico; Fortunato, Francesca; Tafuri, Silvio; Cozza, Vanessa; Chironna, Maria; Germinario, Cinzia; Pedalino, Biagio; Prato, Rosa
2013-01-01
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. 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. 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. 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.
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Butyric acid released during milk lipolysis triggers biofilm formation of Bacillus species.
Pasvolsky, Ronit; Zakin, Varda; Ostrova, Ievgeniia; Shemesh, Moshe
2014-07-02
Bacillus species form biofilms within milking pipelines and on surfaces of equipment in the dairy industry which represent a continuous hygiene problem and can lead to serious economic losses due to food spoilage and equipment impairment. Although much is known about the mechanism by which the model organism Bacillus subtilis forms biofilms in laboratory mediums in vitro, little is known of how these biofilms are formed in natural environments such as milk. Besides, little is known of the signaling pathways leading to biofilm formation in other Bacillus species, such as Bacillus cereus and Bacillus licheniformis, both of which are known to contaminate milk. In this study, we report that milk triggers the formation of biofilm-related structures, termed bundles. We show this to be a conserved phenomenon among all Bacillus members tested. Moreover, we demonstrate that the tasA gene, which encodes a major portion of the matrix which holds the biofilm together, is vital for this process. Furthermore, we show that the free fatty acid (FFA) - butyric acid (BA), which is released during lipolysis of milk fat and demonstrates antimicrobial activity, is the potent trigger for biofilm bundle formation. We finally show that BA-triggered biofilm bundle formation is mediated by the histidine kinase, KinD. Taken together, these observations indicate that BA, which is a major FFA within milk triggers biofilm formation in a conserved mechanism among members of the Bacillus genus. Copyright © 2014 Elsevier B.V. All rights reserved.
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Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel.
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.
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Hussain, Mohammad Shakhawat; Kwon, Minyeong; Tango, Charles Nkufi; Oh, Deog Hwan
2018-05-01
This study examined the disinfection efficacy and mechanism of electrolyzed water (EW) on Bacillus cereus biofilms. B. cereus strains, ATCC 14579 and Korean Collection for Type Cultures (KCTC) 13153 biofilms, were formed on stainless steel (SS) and plastic slide (PS) coupons. Mature biofilms were treated with slightly acidic EW (SAEW), acidic EW (AEW), and basic EW (BEW). SAEW (available chlorine concentration, 25 ± 1.31 mg L -1 ; pH 5.71 ± 0.16; and oxidation reduction potential, 818 to 855 mV) reduced ATCC 14579 biofilms on plastic slides to below the detection limit within 30 s. However, biofilms on SS coupons showed a higher resistance to the SAEW treatment. When the disinfection activities of three types of EW on biofilms were compared, AEW showed a higher bactericidal activity, followed by SAEW and BEW. In contrast, BEW showed a significantly ( P < 0.05) higher biofilm dispersal activity than AEW and SAEW. SAEW disinfection of the B. cereus biofilms was due to the disruption of the B. cereus plasma membrane. The higher resistance of biofilms formed on the SS coupon might be due to the higher number of attached cells and extracellular polymeric substances formation that reacts with the active chlorine ions, such as hypochlorous acid and hypochlorite ion of SAEW, which decreased the disinfection efficacy of SAEW. This study showed that the EW treatment effectively disinfected B. cereus biofilms, providing insight into the potential use of EW in the food processing industry to control the biofilm formation of B. cereus.
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Proteome data to explore the impact of pBClin15 on Bacillus cereus ATCC 14579.
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.
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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.
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Soya bean tempe extracts show antibacterial activity against Bacillus cereus cells and spores.
Roubos-van den Hil, P J; Dalmas, E; Nout, M J R; Abee, T
2010-07-01
Tempe, a Rhizopus ssp.-fermented soya bean food product, was investigated for bacteriostatic and/or bactericidal effects against cells and spores of the food-borne pathogen Bacillus cereus. Tempe extract showed a high antibacterial activity against B. cereus ATCC 14579 based on optical density and viable count measurements. This growth inhibition was manifested by a 4 log CFU ml(-1) reduction, within the first 15 min of exposure. Tempe extracts also rapidly inactivated B. cereus spores upon germination. Viability and membrane permeability assessments using fluorescence probes showed rapid inactivation and permeabilization of the cytoplasmic membrane confirming the bactericidal mode of action. Cooked beans and Rhizopus grown on different media did not show antibacterial activity, indicating the unique association of the antibacterial activity with tempe. Subsequent characterization of the antibacterial activity revealed that heat treatment and protease addition nullified the bactericidal effect, indicating the proteinaceous nature of the bioactive compound. During fermentation of soya beans with Rhizopus, compounds are released with extensive antibacterial activity against B. cereus cells and spores. The results show the potential of producing natural antibacterial compounds that could be used as ingredients in food preservation and pathogen control. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.
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Plant compounds enhance the assay sensitivity for detection of active Bacillus cereus toxin.
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.
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PATHWAYS OF GLUCOSE CATABOLISM IN BACILLUS CEREUS1
Goldman, Manuel; Blumenthal, Harold J.
1964-01-01
Goldman, Manuel (The University of Michigan, Ann Arbor), and Harold J. Blumenthal. Pathways of glucose catabolism in Bacillus cereus. J. Bacteriol. 87:377–386. 1964.—Estimates by a radiorespirometric method of the pathways of glucose catabolism of resting-cell suspensions of Bacillus cereus strain terminalis indicate that the Embden-Meyerhof pathway predominates at every stage of development, including the sporogenic and germinative phases. At the filamentous, granular, forespore, and transitional stages, 98% of the glucose was catabolized by the Embden-Meyerhof pathway, and the remainder by the hexose monophosphate oxidative pathway. Estimates of the pathways in resting spore-suspensions arrested at defined stages of development indicate that 20% of the glucose was catabolized through the hexose monophosphate pathway in germinated spores, and 10% in the swollen and elongated stages of postgermination. In cells which had completed the first cell division, the figure fell to about 2%, a level similar to that found for vegetative cells at later stages of development. The key Embden-Meyerhof enzymes, hexokinase, phosphohexoisomerase, phosphofructokinase, and aldolase, as well as several other enzymes, were present at all stages of germination and postgerminative development, supporting the radioisotopic data obtained with whole cells. As indicated by the release of C14O2 from glucose-6-C14, terminal respiration of resting-cell suspensions operates maximally in vegetative cells at the granular, fore-spore, and transitional stages. There was marked inhibition of terminal respiration during the development of spores into vegetative cells. Only slight activity occurred in the earliest vegetative stages, and maximal operation developed after about ten cell divisions. Fumarase was absent in spores until sometime late in the elongation stage. At this point, a weak but definite activity appeared which increased during later stages of development so that, by the end of
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Gao, Huijuan; Qi, Gaofu; Yin, Rong; Zhang, Hongchun; Li, Chenggang; Zhao, Xiuyun
2016-01-01
Plant-parasitic nematodes cause serious crop losses worldwidely. This study intended to discover the antagonistic mechanism of Bacillus cereus strain S2 against Meloidogyne incognita. Treatment with B. cereus strain S2 resulted in a mortality of 77.89% to Caenorhabditis elegans (a model organism) and 90.96% to M. incognita. In pot experiment, control efficiency of B. cereus S2 culture or supernatants were 81.36% and 67.42% towards M. incognita, respectively. In field experiment, control efficiency was 58.97% towards M. incognita. Nematicidal substances were isolated from culture supernatant of B. cereus S2 by polarity gradient extraction, silica gel column chromatography and HPLC. Two nematicidal compounds were identified as C16 sphingosine and phytosphingosine by LC-MS. The median lethal concentration of sphingosine was determined as 0.64 μg/ml. Sphingosine could obviously inhibit reproduction of C. elegans, with an inhibition rate of 42.72% for 24 h. After treatment with sphingosine, ROS was induced in intestinal tract, and genital area disappeared in nematode. Furthermore, B. cereus S2 could induce systemic resistance in tomato, and enhance activity of defense-related enzymes for biocontrol of M. incognita. This study demonstrates the nematicidal activity of B. cereus and its product sphingosine, as well provides a possibility for biocontrol of M. incognita. PMID:27338781
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Recent research progress with phospholipase C from Bacillus cereus.
Lyu, Yan; Ye, Lidan; Xu, Jun; Yang, Xiaohong; Chen, Weiwei; Yu, Hongwei
2016-01-01
Phospholipase C (PLC) catalyzes the hydrolysis of phospholipids to produce phosphate monoesters and diacylglycerol. It has many applications in the enzymatic degumming of plant oils. PLC Bc , a bacterial PLC from Bacillus cereus, is an optimal choice for this activity in terms of its wide substrate spectrum, high activity, and approved safety. Unfortunately, its large-scale production and reliable high-throughput screening of PLC Bc remain challenging. Herein, we summarize the research progress regarding PLC Bc with emphasis on the screening methods, expression systems, catalytic mechanisms and inhibitor of PLC Bc . This review hopefully will inspire new achievements in related areas, to promote the sustainable development of PLC Bc and its application.
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Jian, Jiahui; Beno, Sarah M.; Wiedmann, Martin
2018-01-01
ABSTRACT While some species in the Bacillus cereus group are well-characterized human pathogens (e.g., B. anthracis and B. cereus sensu stricto), the pathogenicity of other species (e.g., B. pseudomycoides) either has not been characterized or is presently not well understood. To provide an updated characterization of the pathogenic potential of species in the B. cereus group, we classified a set of 52 isolates, including 8 type strains and 44 isolates from dairy-associated sources, into 7 phylogenetic clades and characterized them for (i) the presence of toxin genes, (ii) phenotypic characteristics used for identification, and (iii) cytotoxicity to human epithelial cells. Overall, we found that B. cereus toxin genes are broadly distributed but are not consistently present within individual species and/or clades. After growth at 37°C, isolates within a clade did not typically show a consistent cytotoxicity phenotype, except for isolates in clade VI (B. weihenstephanensis/B. mycoides), where none of the isolates were cytotoxic, and isolates in clade I (B. pseudomycoides), which consistently displayed cytotoxic activity. Importantly, our study highlights that B. pseudomycoides is cytotoxic toward human cells. Our results indicate that the detection of toxin genes does not provide a reliable approach to predict the pathogenic potential of B. cereus group isolates, as the presence of toxin genes is not always consistent with cytotoxicity phenotype. Overall, our results suggest that isolates from multiple B. cereus group clades have the potential to cause foodborne illness, although cytotoxicity is not always consistently found among isolates within each clade. IMPORTANCE Despite the importance of the Bacillus cereus group as a foodborne pathogen, characterizations of the pathogenic potential of all B. cereus group species were lacking. We show here that B. pseudomycoides (clade I), which has been considered a harmless environmental microorganism, produces toxins and
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Xu Zhou, K; Wisnivesky, F; Wilson, D I; Christie, G
2017-07-01
The influence of variable culture conditions on the size and wet density of spores of Bacillus cereus and Bacillus megaterium were examined in this work. Culture temperature and initial pH was shown to have a significant impact on the size of both species, with increasingly alkaline culture media and elevated culture temperatures resulting in spores that were, on average, up to 25% reduced in volume. Increasing concentrations of inorganic salts in sporulation media exerted differing effects on each species; whereas a fivefold increase in the concentration of all salts resulted in only minor differences to the dimensions of B. cereus spores, B. megaterium spores became more elongated, displaying an average increase in volume of almost 30%. Similarly, as the spore elongated to yield aspect ratios larger than 1·4, their shape changed from typical prolate spheroids to cylinders with hemispherical ends. In contrast with previous studies, culture conditions employed in this study exerted no discernible impact on the wet density of B. cereus or B. megaterium spores. Bacterial spores of the genera Bacillus and Clostridium represent nature's most durable cells in terms of their extreme resistance to a variety of deleterious environments. As a result, they are of concern in the food processing, healthcare and other sectors, and are of increasing biotechnological interest. Improved understanding of variance in spore size, morphology and density may aid the development of certain spore-associated applications (e.g. spore surface display) while contributing to active areas of research such as spore adhesion and resistance to heat. © 2017 The Authors. Letters in Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.
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Zheng, Jinshui; Peng, Donghai; Ruan, Lifang; Sun, Ming
2013-12-02
Plasmids play a crucial role in the evolution of bacterial genomes by mediating horizontal gene transfer. However, the origin and evolution of most plasmids remains unclear, especially for megaplasmids. Strains of the Bacillus cereus group contain up to 13 plasmids with genome sizes ranging from 2 kb to 600 kb, and thus can be used to study plasmid dynamics and evolution. This work studied the origin and evolution of 31 B. cereus group megaplasmids (>100 kb) focusing on the most conserved regions on plasmids, minireplicons. Sixty-five putative minireplicons were identified and classified to six types on the basis of proteins that are essential for replication. Twenty-nine of the 31 megaplasmids contained two or more minireplicons. Phylogenetic analysis of the protein sequences showed that different minireplicons on the same megaplasmid have different evolutionary histories. Therefore, we speculated that these megaplasmids are the results of fusion of smaller plasmids. All plasmids of a bacterial strain must be compatible. In megaplasmids of the B. cereus group, individual minireplicons of different megaplasmids in the same strain belong to different types or subtypes. Thus, the subtypes of each minireplicon they contain may determine the incompatibilities of megaplasmids. A broader analysis of all 1285 bacterial plasmids with putative known minireplicons whose complete genome sequences were available from GenBank revealed that 34% (443 plasmids) of the plasmids have two or more minireplicons. This indicates that plasmid fusion events are general among bacterial plasmids. Megaplasmids of B. cereus group are fusion of smaller plasmids, and the fusion of plasmids likely occurs frequently in the B. cereus group and in other bacterial taxa. Plasmid fusion may be one of the major mechanisms for formation of novel megaplasmids in the evolution of bacteria.
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Arslan, Seza; Eyi, Ayla; Küçüksarı, Rümeysa
2014-02-01
Bacillus spp. can be recovered from almost every environment. It is also found readily in foods, where it may cause food spoilage and/or food poisoning due to its toxigenic and pathogenic nature, and extracellular enzymes. In this study, 29 Bacillus cereus group strains from ice cream were examined for the presence of following virulence genes hblC, nheA, cytK and ces genes, and tested for a range of the extracellular enzymes, and antimicrobial susceptibility. The strains were found to produce extracellular enzymes: proteolytic and lipolytic activity, gelatin hydrolysis and lecithinase production (100%), DNase production (93.1%) and amylase activity (93.1%). Of 29 strains examined, 24 (82.8%) showed hemolytic activity on blood agar. Beta-lactamase enzyme was only produced by 20.7% of B. cereus group. Among 29 B. cereus group from ice cream, nheA was the most common virulence gene detected in 44.8% of the strains, followed by hblC gene with 17.2%. Four (13.8%) of the 29 strains were positive for both hblC gene and nheA gene. Contrarily, cytK and ces genes were not detected in any of the strains. Antimicrobial susceptibility of ice cream isolates was tested to 14 different antimicrobial agents using the disc diffusion method. We detected resistance to penicillin and ampicillin with the same rate of 89.7%. Thirty-one percent of the strains were multiresistant to three or more antibiotics. This study emphasizes that the presence of natural isolates of Bacillus spp. harboring one or more enterotoxin genes, producing extracellular enzymes which may cause spoilage and acquiring antibiotic resistance might hold crucial importance in the food safety and quality. Copyright © 2013 Elsevier Ltd. All rights reserved.
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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.
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Chauhan, Ankit Kumar; Maheshwari, Dinesh Kumar; Kim, Kangmin; Bajpai, Vivek K
2016-10-01
Bacillus strains were isolated from termitarium soil and screened for their antifungal activity through the production of diffusible and volatile metabolites. Further, the bacterial strains that showed antifungal activity were evaluated for their biocontrol potential on the basis of their plant-growth-promoting attributes. Termitarium-inhabiting Bacillus strains TSH42 and TSH77 significantly reduced the growth of pathogenic fungus Fusarium solani, controlled the symptoms of rhizome rot in turmeric (Curcuma longa L.), and demonstrated various plant-growth-promoting traits in different in vitro assays. On the basis of morphological, physiological, biochemical, and 16S rDNA characteristics, isolates TSH42 and TSH77 were identified as Bacillus endophyticus (KT379993) and Bacillus cereus (KT379994), respectively. Through liquid chromatography - mass spectrometry analysis, acidified cell-free culture filtrate (CFCF) of B. cereus TSH77 was shown to contain surfactin and fengycin, while CFCF of B. endophyticus TSH42 contained iturin in addition to surfactin and fengycin. Treatment of the turmeric (C. longa L.) plants with TSH42 and TSH77 significantly reduced the percentage incidence of rhizome rot disease caused by F. solani. The same treatment also increased the fresh rhizome biomass and plant growth in greenhouse conditions.
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Chaves, Jeane Q; de Paiva, Eislaine P; Rabinovitch, Leon; Vivoni, Adriana M
2017-07-01
The presence of Bacillus cereus in milk is a major concern in the dairy industry. In this study 27 Bacillus cereus sensu lato isolates from pasteurized and ultrahigh-temperature (UHT) milk (24 whole UHT and 4 pasteurized samples) collected at supermarket chains in Rio de Janeiro, Brazil, were evaluated to assess the potential risk for food poisoning. Toxigenic and virulence profiles were defined by gene-specific PCR. Affiliation to phylogenetic groups was assigned by panC sequencing. Microbiological analysis revealed the presence of B. cereus s.l. in eight (33.3%) brands (six brands of UHT and two brands of pasteurized milk). Twenty-seven isolates were recovered (13 B. cereus and 14 Bacillus thuringiensis ). Predominant toxigenic patterns were type I (contains all toxin genes except ces) and type II (does not contain cytK and ces), with seven (25.9%) isolates each. Predominant virulence patterns were type 2 (does not contain hlyII or shp) and type 3 (contains all virulence genes), with five (18.5%) isolates each. All isolates belonged to phylogenetic groups III and IV. Presence of hbl, piplc, and sph was associated with group IV isolates. Our results suggest that B. thuringiensis and B. cereus sensu stricto should be considered potential foodborne pathogens. Because the majority of the milk isolates studied have the potential to cause food poisoning because of the high prevalence of toxin and virulence genes and the specific phylogenetic group affiliations, these milk products can be potentially hazardous for human consumption.
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Luksiene, Z; Buchovec, I; Paskeviciute, E
2010-11-01
This study was focused on the possibility to inactivate food-borne pathogen Bacillus cereus by Na-chlorophyllin (Na-Chl)-based photosensitization in vitro and after attachment to the surface of packaging material. Bacillus cereus in vitro or attached to the packaging was incubated with Na-Chl (7·5×10(-8) to 7·5×10(-5) mol l(-1) ) for 2-60min in phosphate buffer saline. Photosensitization was performed by illuminating cells under a light with a λ of 400nm and an energy density of 20mW cm(-2) . The illumination time varied 0-5min and subsequently the total energy dose was 0-6J cm(-2) . The results show that B. cereus vegetative cells in vitro or attached to the surface of packaging after incubation with 7·5×10(-7) mol l(-1) Na-Chl and following illumination were inactivated by 7log. The photoinactivation of B. cereus spores in vitro by 4log required higher (7·5×10(-6) mol l(-1) ) Na-Chl concentration. Decontamination of packaging material from attached spores by photosensitization reached 5log at 7·5×10(-5) mol l(-1) Na-Chl concentration. Comparative analysis of different packaging decontamination treatments indicates that washing with water can diminish pathogen population on the surface by <1log, 100ppm Na-hypochlorite reduces the pathogens about 1·7log and 200ppm Na-hypochlorite by 2·2log. Meanwhile, Na-Chl-based photosensitization reduces bacteria on the surface by 4·2 orders of magnitude. Food-borne pathogen B. cereus could be effectively inactivated (7log) by Na-Chl-based photosensitization in vitro and on the surface of packaging material. Spores are more resistant than vegetative cells to photosensitization-based inactivation. Comparison of different surface decontamination treatments indicates that Na-Chl-based photosensitization is much more effective antibacterial tool than washing with water or 200ppm Na-hypochlorite. Our data support the idea that Na-Chl-based photosensitization has great potential for future application as an environment
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Feinberg, L; Jorgensen, J; Haselton, A; Pitt, A; Rudner, R; Margulis, L
1999-01-01
The filamentous spore-forming bacterium Arthromitus, discovered in termites, millipedes, sow bugs and other soil-dwelling arthropods by Leidy (1850), is the intestinal stage of Bacillus cereus. We extend the range of Arthromitus habitats to include the hindgut of Blaberus giganteus, the large tropical American cockroach. The occurrence and morphology of the intestinal form of the bacillus were compared in individual cockroaches (n=24) placed on four different diet regimes: diurnally maintained insects fed (1) dog food, (2) soy protein only, (3)purified cellulose only, and (4) a dog food-fed group maintained in continuous darkness. Food quality exerted strong influence on population densities and developmental stages of the filamentous bacterium and on fecal pellet composition. The most dramatic rise in Arthromitus populations, defined as the spore-forming filament intestinal stage, occurred in adult cockroaches kept in the dark on a dog food diet. Limited intake of cellulose or protein alone reduced both the frequency of Arthromitus filaments and the rate of weight gain of the insects. Spores isolated from termites, sow bugs, cockroaches and moths, grown on various hard surfaces display a branching mobility and resistance to antibiotics characteristic to group I Bacilli whose members include B. cereus, B. circulans, B. alvei and B. macerans. DNA isolated from pure cultures of these bacilli taken from the guts of Blaberus giganteus (cockroach), Junonia coenia (moth), Porcellio scaber (sow bug) and Cryptotermes brevis (termite) and subjected to Southern hybridization with a 23S-5S B. subtilis ribosomal sequence probe verified that they are indistinguishable from laboratory strains of Bacillus cereus.
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NASA Technical Reports Server (NTRS)
Feinberg, L.; Jorgensen, J.; Haselton, A.; Pitt, A.; Rudner, R.; Margulis, L.
1999-01-01
The filamentous spore-forming bacterium Arthromitus, discovered in termites, millipedes, sow bugs and other soil-dwelling arthropods by Leidy (1850), is the intestinal stage of Bacillus cereus. We extend the range of Arthromitus habitats to include the hindgut of Blaberus giganteus, the large tropical American cockroach. The occurrence and morphology of the intestinal form of the bacillus were compared in individual cockroaches (n=24) placed on four different diet regimes: diurnally maintained insects fed (1) dog food, (2) soy protein only, (3)purified cellulose only, and (4) a dog food-fed group maintained in continuous darkness. Food quality exerted strong influence on population densities and developmental stages of the filamentous bacterium and on fecal pellet composition. The most dramatic rise in Arthromitus populations, defined as the spore-forming filament intestinal stage, occurred in adult cockroaches kept in the dark on a dog food diet. Limited intake of cellulose or protein alone reduced both the frequency of Arthromitus filaments and the rate of weight gain of the insects. Spores isolated from termites, sow bugs, cockroaches and moths, grown on various hard surfaces display a branching mobility and resistance to antibiotics characteristic to group I Bacilli whose members include B. cereus, B. circulans, B. alvei and B. macerans. DNA isolated from pure cultures of these bacilli taken from the guts of Blaberus giganteus (cockroach), Junonia coenia (moth), Porcellio scaber (sow bug) and Cryptotermes brevis (termite) and subjected to Southern hybridization with a 23S-5S B. subtilis ribosomal sequence probe verified that they are indistinguishable from laboratory strains of Bacillus cereus.
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Lee, Nam Keun; Yeo, In-Cheol; Park, Joung Whan; Kang, Byung-Sun; Hahm, Young Tae
2010-09-01
In this study, an effective substance was isolated from Bacillus subtilis SC-8, which was obtained from traditionally fermented soybean paste, cheonggukjang. The substance was purified by HPLC, and its properties were analyzed. It had an adequate antagonistic effect on Bacilluscereus, and its spectrum of activity was narrow. When tested on several gram-negative and gram-positive foodborne pathogenic bacteria such as Salmonella enterica, Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogenes, no antagonistic effect was observed. Applying the derivative from B. subtilis SC-8 within the same genus did not inhibit the growth of major soybean-fermenting bacteria such as Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloquefaciens. The range of pH stability of the purified antagonistic substance was wide (from 4.0 to >10.0), and the substance was thermally stable up to 60 degrees C. In the various enzyme treatments, the antagonistic activity of the purified substance was reduced with proteinase K, protease, and lipase; its activity was partially destroyed with esterase. Spores of B. cereus did not grow at all in the presence of 5mug/mL of the purified antagonistic substance. The isolated antagonistic substance was thought to be an antibiotic-like lipopeptidal compound and was tentatively named BSAP-254 because it absorbed to UV radiation at 254nm. Copyright 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
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Effective Thermal Inactivation of the Spores of Bacillus cereus Biofilms Using Microwave.
Park, Hyong Seok; Yang, Jungwoo; Choi, Hee Jung; Kim, Kyoung Heon
2017-07-28
Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, 108°C of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.
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Morris, Angela D; McCombs, Gayle B; Akan, Tamer; Hynes, Wayne; Laroussi, Mounir; Tolle, Susan L
2009-01-01
Cold plasma, also known as Low Temperature Atmospheric Pressure Plasma (LTAPP) is a novel technology consisting of neutral and charged particles, including free radicals, which can be used to destroy or inactivate microorganisms. Research has been conducted regarding the effect of cold plasma on gram-positive bacteria; however, there is limited research regarding its ability to inactivate the spore-formers Geobacillus stearothermophilus and Bacillus cereus. The purpose of this study was to determine if cold plasma inactivates G. stearothermophilus and B. cereus vegetative cells and spores. Nine hundred eighty-one samples were included in this study (762 experimental and 219 controls). Experimental samples were exposed indirectly or directly to cold plasma, before plating and incubating for 16 hours. Control samples were not exposed to cold plasma. The percentage-kill and cell number reductions were calculated from Colony Forming Units (CFU). Data were statistically analyzed at the .05 level using one-way ANOVA, Kruskal Wallis and Tukey's tests. There was a statistically significant difference in the inactivation of G. stearothermophilus vegetative cells receiving indirect and direct exposure (p=0.0001 and p=0.0013, respectively), as well as for B. cereus vegetative cells and spores (p=0.0001 for direct and indirect). There was no statistically significant difference in the inactivation of G. stearothermophilus spores receiving indirect exposure (p=0.7208) or direct exposure (p=0.0835). Results demonstrate that cold plasma exposure effectively kills G. stearothermophilus vegetative cells and B. cereus vegetative cells and spores; however, G. stearothermophilus spores were not significantly inactivated.
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USDA-ARS?s Scientific Manuscript database
Bacillus cereus is frequently isolated from a variety of foods including vegetables, dairy products, meat, and other raw and processed foods. The bacterium is capable of producing enterotoxin and emetic toxin that can cause severe nausea, vomiting and diarrhea. The objectives of this study were to a...
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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
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Kim, Young-Ji; Kim, Hong-Seok; Kim, Kwang-Yeop; Chon, Jung-Whan; Kim, Dong-Hyeon; Seo, Kun-Ho
2016-12-01
Organic foods have risen in popularity recently. However, the increased risk of bacterial contamination of organic foods has not been fully evaluated. In this study, 100 samples each of organic and conventional fresh vegetables (55 lettuce samples and 45 sprout samples) sold in South Korea were analyzed for aerobic bacteria, coliforms, Escherichia coli, and Bacillus cereus. Although the aerobic bacteria and coliform counts were not significantly different between the two farming types (p > 0.05), the occurrence rate of B. cereus was higher in organically cultivated vegetables compared with those grown conventionally (70% vs. 30%, respectively). The mean contamination level of B. cereus-positive organic samples was also significantly higher (1.86 log colony-forming unit [CFU]/g vs. 0.69 log CFU/g, respectively) (p < 0.05). In addition, six samples of organic vegetables were found to be contaminated with B. cereus at over 4 log CFU/g categorized as unsatisfactory according to Health Protection Agency guideline. The relatively higher occurrence rate of B. cereus in organic vegetables emphasizes the importance of implementing control measures in organic vegetable production and postharvest processing to reduce the risk of food poisoning.
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Venkateswaran, Kasthuri; Checinska Sielaff, Aleksandra; Ratnayake, Shashikala; Pope, Robert K; Blank, Thomas E; Stepanov, Victor G; Fox, George E; van Tongeren, Sandra P; Torres, Clinton; Allen, Jonathan; Jaing, Crystal; Pierson, Duane; Perry, Jay; Koren, Sergey; Phillippy, Adam; Klubnik, Joy; Treangen, Todd J; Rosovitz, M J; Bergman, Nicholas H
2017-08-10
The draft genome sequences of six Bacillus strains, isolated from the International Space Station and belonging to the Bacillus anthracis - B. cereus - B. thuringiensis group, are presented here. These strains were isolated from the Japanese Experiment Module (one strain), U.S. Harmony Node 2 (three strains), and Russian Segment Zvezda Module (two strains). Copyright © 2017 Venkateswaran et al.
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Simon, Nathan C.; Barbieri, Joseph T.
2014-01-01
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. PMID:24573681
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Beuchat, Larry R; Pettigrew, Charles A; Tremblay, Mario E; Roselle, Brian J; Scouten, Alan J
2004-08-01
Chlorine, ClO2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis. The ultimate goal was to use one or both species as a potential surrogate(s) for Bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. Treatment with alkaline (pH 10.5 to 11.0) ClO2 (200 microg/ml) produced by electrochemical technologies reduced populations of a five-strain mixture of vegetative cells and a five-strain mixture of spores of B. cereus by more than 5.4 and more than 6.4 log CFU/ml respectively, within 5 min. This finding compares with respective reductions of 4.5 and 1.8 log CFU/ml resulting from treatment with 200 microg/ml of chlorine. Treatment with a 1.5% acidified (pH 3.0) solution of Fit powder product was less effective, causing 2.5- and 0.4-log CFU/ml reductions in the number of B. cereus cells and spores, respectively. Treatment with alkaline ClO2 (85 microg/ml), acidified (pH 3.4) ClO2 (85 microg/ml), and a mixture of ClO2 (85 microg/ml) and Fit powder product (0.5%) (pH 3.5) caused reductions in vegetative cell/spore populations of more than 5.3/5.6, 5.3/5.7, and 5.3/6.0 log CFU/ml, respectively. Treatment of B. cereus and B. thuringiensis spores in a medium (3.4 mg/ml of organic and inorganic solids) in which cells had grown and produced spores with an equal volume of alkaline (pH 12.1) ClO2 (400 microg/ml) for 30 min reduced populations by 4.6 and 5.2 log CFU/ml, respectively, indicating high lethality in the presence of materials other than spores that would potentially react with and neutralize the sporicidal activity of ClO2.
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Nattermann, Herbert; Brüggemann, Holger; Dupke, Susann; Wollherr, Antje; Franz, Tatjana; Pauli, Georg; Appel, Bernd; Liebl, Wolfgang; Couacy-Hymann, Emmanuel; Boesch, Christophe; Meyer, Frauke-Dorothee; Leendertz, Fabian H.; Ellerbrok, Heinz; Gottschalk, Gerhard; Grunow, Roland; Liesegang, Heiko
2010-01-01
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”. PMID:20634886
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Mani, Chinnasamy; Selvakumari, Jeyaperumal; Han, YeonSoo; Jo, YongHun; Thirugnanasambantham, Krishnaraj; Sundarapandian, Somaiah; Poopathi, Subbiah
2018-04-01
A marine Bacillus cereus (VCRC B540) with mosquitocidal effect was recently reported from red snapper fish (Lutjanus sanguineous) gut and surface layer protein (S-layer protein, SLP) was reported to be mosquito larvicidal factor. In this present study, the gene encoding the surface layer protein was amplified from the genomic DNA and functionally characterized. Amplification of SLP-encoding gene revealed 1,518 bp PCR product, and analysis of the sequence revealed the presence of 1482 bp open reading frame with coding capacity for a polypeptide of 493 amino acids. Phylogenetic analysis revealed with homology among closely related Bacillus cereus groups of organisms as well as Bacillus strains. Removal of nucleotides encoding signaling peptide revealed the functional cloning fragment of length 1398 bp. Theoretical molecular weight (51.7 kDa) and isoelectric point (5.99) of the deduced functional SLP protein were predicted using ProtParam. The amplified PCR product was cloned into a plasmid vector (pGEM-T), and the open reading frame free off signaling peptide was subsequently cloned inpET-28a(+) and expressed in Escherichia coli BL21 (DE3). The isopropyl-β-D-thiogalactopyranoside (IPTG)-induced recombinant SLP was confirmed using western blotting, and functional SLP revealed mosquito larvicidal property. Therefore, the major findings revealed that SLP is a factor responsible for mosquitocidal activity, and the molecular characterization of this toxin was extensively studied.
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Jääskeläinen, E L; Häggblom, M M; Andersson, M A; Salkinoja-Salonen, M S
2004-10-01
Factors influencing the production of cereulide, the emetic toxin of Bacillus cereus in food and laboratory media were investigated, using liquid chromatography-ion trap mass spectrometry and sperm motility inhibition bioassay for detection and quantitation. Oxygen was essential for production of the emetic toxin by B. cereus. When beans, rice or tryptic soy broth were inoculated with cereulide producing strains B203, B116 (recent food isolates) or the strain F-4810/72, high amounts (2 to 7 microg ml(-1) or g(-1) wet wt) of cereulide accumulated during 4-day storage at room temperature. In parallel cultures and foods, stored under nitrogen atmosphere (> 99.5% N2), less than 0.05 microg of cereulide ml(-1) or g(-1) wet wt accumulated. The outcome of the bioassay matched that of the chemical assay, with no indication of interference by substances in the rice or beans. Boiling for 20 to 30 min did not inactivate cereulide or cereulide producing strains in rice or the beans. Adding l-leucine and l-valine (0.3 g l(-1)) stimulated cereulide production 10- to 20-fold in R2A and in rice water agar. When the B. cereus strains were grown on agar media under permissive conditions (air, room temperature), cereulide was produced overnight with little or no increase when the incubation was extended to 4 days. In broth culture, the production of cereulide started later than 16-24 h. Anoxic storage prevented cereulide production also when the amino acids had been supplied. Packaging with modified atmosphere low in oxygen may thus be used to reduce the risk of cereulide formation during storage of food. Copyright 2004 Elsevier B.V.
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Kim, Dong-Hyeon; Kim, Hyunsook; Chon, Jung-Whan; Moon, Jin-San; Song, Kwang-Young; Seo, Kun-Ho
2013-07-15
Blood-yolk-polymyxin B-trimethoprim agar (BYPTA) was developed by the addition of egg yolk, laked horse blood, sodium pyruvate, polymyxin B, and trimethoprim, and compared with mannitol-yolk-polymyxin B agar (MYPA) for the isolation and enumeration of Bacillus cereus (B. cereus) in pure culture and various food samples. In pure culture, there was no statistical difference (p>0.05) between the recoverability and sensitivity of MYPA and BYPTA, whereas BYPTA exhibited higher specificity (p<0.05). To evaluate BYPTA agar with food samples, B. cereus was experimentally spiked into six types of foods, triangle kimbab, sandwich, misugaru, Saengsik, red pepper powder, and soybean paste. No statistical difference was observed in recoverability (p>0.05) between MYPA and BYPTA in all tested foods, whereas BYPTA exhibited higher selectivity than MYPA, especially in foods with high background microflora, such as Saengsik, red pepper powder, and soybean paste. The newly developed selective medium BYPTA could be a useful enumeration tool to assess the level of B. cereus in foods, particularly with high background microflora. Copyright © 2013 Elsevier B.V. All rights reserved.
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A novel bicomponent hemolysin from Bacillus cereus.
Beecher, D J; MacMillan, J D
1990-01-01
A procedure combining isoelectric focusing (Sephadex IEF) and fast protein liquid chromatography (Superose 12; Mono-Q) removed hemolytic activity (presumably a contaminant) from partially purified preparations of the multicomponent diarrheal enterotoxin produced by Bacillus cereus. However, when the separated fractions were recombined, hemolytic activity was restored, suggesting that hemolysis is a property of the enterotoxin components. Combined fractions exhibited a unique ring pattern in gel diffusion assays in blood agar. During diffusion of the hemolysin from an agar well, the erythrocytes closest to the well were not lysed initially. After diffusion, hemolysis was observed as a sharp ring beginning several millimeters away from the edge of the well. With time the cells closer to the well were also lysed. This novel hemolysin consists of a protein (component B) which binds to or alters cells, allowing subsequent lysis by a second protein (component L). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing, and Western blot analysis showed that hemolysin BL has properties similar to those described previously for the enterotoxin and that both components are distinct from cereolysin and cereolysin AB. Images PMID:2114359
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Beecher, D J; Wong, A C
1994-01-01
Bacillus cereus causes distinct exotoxin-mediated diarrheal and emetic food poisoning syndromes and a variety of nongastrointestinal infections. Evidence is accumulating that hemolysin BL is a major B. cereus virulence factor. We describe two methods for detection of hemolysin BL in crude samples and on primary culture media. In the first method, the highly unusual discontinuous hemolysis pattern that is characteristic of pure hemolysin BL was produced in sheep and calf blood agar around wells filled with crude culture supernatant from hemolysin BL-producing strains. In the second method, the pattern was formed surrounding colonies of hemolysin BL-producing strains grown on media consisting of nutrient agar, 0.15 M NaCl, 2% calf serum, and sheep or calf blood. Hemolysin BL production was detected with these methods in 41 of 62 (66%) previously identified B. cereus isolates and in 46 of 136 (34%) presumptive B. cereus isolates from soil. All nine isolates tested that were associated with diarrhea or nongastrointestinal illness were positive for hemolysin BL. The methods presented here are specific, simple, inexpensive, and applicable to the screening of large numbers of samples or isolates. Images PMID:8017944
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Zhao, Dan; Liu, Pengfei; Pan, Chao; Du, Renpeng; Ping, Wenxiang; Ge, Jingping
2016-09-02
High-throughput sequencing and GC-MS (gas chromatography-mass spectrometry) were jointly used to reveal the bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting. The inoculation of Bacillus cereus HDYM-02 decreased bacterial richness and diversity. This inoculum led to the replacement of Enterobacteriaceae by Bacillaceae. The level of aerobic Pseudomonadaceae (mainly Azotobacter) and anaerobic Clostridiaceae_1 gradually increased and decreased, respectively. Following the addition of B. cereus HDYM-02, the dominant groups were all degumming enzyme producers or have been proven to be involved in microbial retting throughout the entire retting period. These results could be verified by the metabolite changes, either degumming enzymes or their catalytic products galacturonic acid and reducing sugars. The GC-MS data showed a clear separation between flax retting with and without B. cereus HDYM-02, particularly within the first 72 h. These findings reveal the important bacterial groups that are involved in fiber retting and will facilitate improvements in the retting process.
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Felici, A; Amicosante, G
1995-01-01
Twenty beta-lactam molecules, including penicillins, cephalosporins, penems, carbapenems, and monobactams, were investigated as potential substrates for Xanthomonas maltophilia ULA-511, Aeromonas hydrophila AE036, and Bacillus cereus 5/B/6 metallo-beta-lactamases. A detailed analysis of the kinetic parameters examined confirmed these enzymes to be broad-spectrum beta-lactamases with different ranges of catalytic efficiency. Cefoxitin and moxalactam, substrates for the beta-lactamases from X. maltophilia ULA-511 and B. cereus 5/B/6, behaved as inactivators of the A. hydrophila AE036 metallo-beta-lactamase, which appeared to be unique among the enzymes tested in this study. In addition, we report a new, faster, and reliable purification procedure for the B. cereus 5/B/6 metallo-beta-lactamase, cloned in Escherichia coli HB101. PMID:7695305
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Bandara, Nadeeka; Jo, Junhee; Ryu, Sangryeol; Kim, Kwang-Pyo
2012-08-01
Bacillus cereus is a foodborne bacterial pathogen that causes diarrhea and vomiting. In this study, the usefulness of bacteriophages to eradicate B. cereus from fermented foods was investigated. A total of 13 phages were isolated from Korean fermented food products, and 2 (BCP1-1 and BCP8-2) were further characterized. Transmission electron microscopy (TEM), restriction enzyme digestion pattern analysis, and SDS-PAGE of the structural proteins suggest that both phages belong to the family Myoviridae, containing approximately 150 kbp-long genomes. The host ranges of both phages were limited to B. cereus group species (12/13), as they were not able to lyse other Gram-positive or negative strains including Bacillus subtilis. Purified phages were used to inhibit B. cereus growth in a model fermented food system, cheonggukjang, a fast-fermented soybean paste product. BCP1-1 and BCP8-2 were able to effectively eradicate B. cereus from the food only if divalent cations (Ca²⁺, Mg²⁺, or Mn²⁺) were added to the medium. Further studies reveal that divalent cations are essential for phage adsorption, while a monovalent cation (Na⁺) is required for the post-adsorption phase of phage infection. Taken together, our findings imply that a phage could be an ideal anti-bacterial agent for use in fermented food products that require the presence of beneficial microflora and, during phage application, optimization of phage reaction conditions is critical for the successful utilization of phage biocontrol. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Yusuf, Umar; Kotwal, S. K.; Gupta, Sanjolly; Ahmed, Touqeer
2018-01-01
Aim: The aims of the present study were to assess the prevalence, identification, and antibiogram pattern of Bacillus cereus from 215 samples of different milk and milk products in and around Jammu region. Materials and Methods: In the present study, 215 samples of milk, rasgulla, burfi, rasmalai, kalaari, paneer, ice cream, and pastry were collected and analyzed for the isolation of the B. cereus using PEMBA, and antibiogram pattern was observed for all the milk and milk products. Results: B. cereus was detected in 61/215 samples with an overall prevalence of 28.37%. Biotyping revealed predominantly 5, 7, and 2 biotypes in raw milk. Burfi and ice cream revealed 2, 3, 5, and 7 biotypes. Rasgulla had 2, 3, and 5 biotypes; paneer and rasmalai had biotypes 2 and 5, while kalaari revealed biotype 5. Antibiogram pattern revealed that isolates were highly sensitive to gentamicin (100%), intermediate to ampicillin (40.98%), tetracycline (31.14%), erythromycin (29.50%), and amoxicillin (26.22%), and high resistance against penicillin G (100%). Adulteration of starch was detected in 16.66 % raw milk samples. All starch positive samples were positive for B. cereus. However, 12 starch negative samples also yielded B. cereus. Conclusion: From this study, it was concluded that highest prevalence of B. cereus was found in ice cream. Several isolates of B. cereus showed toxigenic activity, so the presence of B. cereus in milk and milk products may be of public health hazard. The antibiogram pattern of B. cereus isolates showed sensitivity to gentamicin, ciprofloxacin, chloramphenicol, streptomycin, and resistance to penicillin-G and cephalexin. The presence of B. cereus in milk and milk products showed a strong association besides establishing the fact that starch adulteration can be indicative of the presence of B. cereus. PMID:29657402
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Multilocus sequence type profiles of Bacillus cereus isolates from infant formula in China.
Yang, Yong; Yu, Xiaofeng; Zhan, Li; Chen, Jiancai; Zhang, Yunyi; Zhang, Junyan; Chen, Honghu; Zhang, Zheng; Zhang, Yanjun; Lu, Yiyu; Mei, Lingling
2017-04-01
Bacillus cereus sensu stricto is an opportunistic foodborne pathogen. The multilocus sequence type (MLST) of 74 B. cereus isolated from 513 non-random infant formula in China was analyzed. Of 64 sequence types (STs) detected, 50 STs and 6 alleles were newly found in PubMLST database. All isolates except for one singleton (ST-1049), were classified into 7 clonal complexes (CC) by BURST (n-4), in which CC1 with core ancestral clone ST-26 was the largest group including 86% isolates, and CC2, 3, 9, 10 and 13 were first reported in China. MLST profiles of the isolates from 8 infant formula brands were compared. It was found the brands might be potentially tracked by the variety of STs, such as ST-1049 of singleton and ST-1062 of isolate from goat milk source, though they could not be easily tracked just by clonal complex types of the isolates. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Kefiran protects Caco-2 cells from cytopathic effects induced by Bacillus cereus infection.
Medrano, Micaela; Hamet, Maria F; Abraham, Analía G; Pérez, Pablo F
2009-11-01
The aim of this work was to evaluate the ability of kefiran to antagonize cytopathic effects triggered by Bacillus cereus strain B10502 on cultured human enterocytes (Caco-2 cells). Cell damage was evaluated by F-actin labelling, scanning electron microscopy and determination of ratios of necrotic and detached cells. To assess the interaction between kefiran and bacteria or eukaryotic cells, flow cytometric analysis was conducted with FITC-labelled kefiran. Kefiran significantly protected infected cells from cytopathic effects induced by B. cereus such as cell necrosis, F-actin disorganisation and microvilli effacement, although presence of kefiran did not modify the adhesion of microorganisms to cultured human enterocytes. Results could be ascribed to the ability of kefiran to interact with both bacteria and eukaryotic cells thus antagonizing interactions necessary for maximal biological effects. Our findings encourage further research on the use of bacterial exopolysaccharides to antagonize virulence factors associated to direct bacteria-cell interactions.
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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.
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2013-01-01
Background Comparatively little information is available on members of the Myoviridae infecting low G+C content, Gram-positive host bacteria of the family Firmicutes. While numerous Bacillus phages have been isolated up till now only very few Bacillus cereus phages have been characterized in detail. Results Here we present data on the large, virulent, broad-host-range B. cereus phage vB_BceM_Bc431v3 (Bc431v3). Bc431v3 features a 158,618 bp dsDNA genome, encompassing 239 putative open reading frames (ORFs) and, 20 tRNA genes encoding 17 different amino acids. Since pulsed-field gel electrophoresis indicated that the genome of this phage has a mass of 155-158 kb Bc431v3 DNA appears not to contain long terminal repeats that are found in the genome of Bacillus phage SPO1. Conclusions Bc431v3 displays significant sequence similarity, at the protein level, to B. cereus phage BCP78, Listeria phage A511 and Enterococcus phage ØEF24C and other morphologically related phages infecting Firmicutes such as Staphylococcus phage K and Lactobacillus phage LP65. Based on these data we suggest that Bc431v3 should be included as a member of the Spounavirinae; however, because of all the diverse taxonomical information has been addressed recently, it is difficult to determine the genus. The Bc431v3 phage contains some highly unusual genes such as gp143 encoding putative tRNAHis guanylyltransferase. In addition, it carries some genes that appear to be related to the host sporulation regulators. These are: gp098, which encodes a putative segregation protein related to FstK/SpoIIIE DNA transporters; gp105, a putative segregation protein; gp108, RNA polymerase sigma factor F/B; and, gp109 encoding RNA polymerase sigma factor G. PMID:23388049
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Ji, Xiuling; Zhang, Chunjing; Fang, Yuan; Zhang, Qi; Lin, Lianbing; Tang, Bing; Wei, Yunlin
2015-02-01
As a unique ecological system with low temperature and low nutrient levels, glaciers are considered a "living fossil" for the research of evolution. In this work, a lytic cold-active bacteriophage designated VMY22 against Bacillus cereus MYB41-22 was isolated from Mingyong Glacier in China, and its characteristics were studied. Electron microscopy revealed that VMY22 has an icosahedral head (59.2 nm in length, 31.9 nm in width) and a tail (43.2 nm in length). Bacteriophage VMY22 was classified as a Podoviridae with an approximate genome size of 18 to 20 kb. A one-step growth curve revealed that the latent and the burst periods were 70 and 70 min, respectively, with an average burst size of 78 bacteriophage particles per infected cell. The pH and thermal stability of bacteriophage VMY22 were also investigated. The maximum stability of the bacteriophage was observed to be at pH 8.0 and it was comparatively stable at pH 5.0-9.0. As VMY22 is a cold-active bacteriophage with low production temperature, its characterization and the relationship between MYB41-22 and Bacillus cereus bacteriophage deserve further study.
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Slock, J. A.; Stahly, D. P.
1974-01-01
An intracellular, glucose-containing polysaccharide accumulates in Bacillus cereus early in sporulation and is degraded at the time of spore maturation. This pattern of accumulation and degradation occurred when growth was limited by glucose or a component of yeast extract. These data suggest that the polysaccharide may be serving as a carbon and energy storage compound for sporulation. A somewhat similar pattern of accumulation and degradation of poly-β-hydroxybutyric acid (PHB) was shown earlier by Kominek and Halvorson (1965) to occur in Bacillus cereus. When cells were grown in a medium buffered strongly at pH 7.4, however, very little accumulation of PHB occurred. We have found that polysaccharide accumulates in cells grown in both the strong and weakly buffered media. Perhaps polysaccharide is the major carbon and energy storage compound when cells are grown under conditions preventing significant accumulation of PHB. The lack of polysaccharide accumulation during the exponential phase of growth may be an indication that the needed biosynthetic enzymes are controlled by catabolite repression during growth. The polysaccharide was purified and found to consist of glucose. The iodine absorption spectrum suggests a degree of branching between that of glycogen and amylopectin. PMID:4214355
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Soria, M Cecilia; Audisio, M Carina
2014-12-01
Bacillus cereus is an endospore-forming, Gram-positive bacterium able to cause foodborne diseases. Lactic acid bacteria (LAB) are known for their ability to synthesize organic acids and bacteriocins, but the potential of these compounds against B. cereus has been scarcely documented in food models. The present study has examined the effect of the metabolites produced by Lactobacillus johnsonii CRL1647 and Enterococcus faecium SM21 on the viability of select B. cereus strains. Furthermore, the effect of E. faecium SM21 metabolites against B. cereus strains has also been investigated on a rice food model. L. johnsonii CRL1647 produced 128 mmol/L of lactic acid, 38 mmol/L of acetic acid and 0.3 mmol/L of phenyl-lactic acid. These organic acids reduced the number of vegetative cells and spores of the B. cereus strains tested. However, the antagonistic effect disappeared at pH 6.5. On the other hand, E. faecium SM21 produced only lactic and acetic acid (24.5 and 12.2 mmol/L, respectively) and was able to inhibit both vegetative cells and spores of the B. cereus strains, at a final fermentation pH of 5.0 and at pH 6.5. This would indicate the action of other metabolites, different from organic acids, present in the cell-free supernatant. On cooked rice grains, the E. faecium SM21 bacteriocin(s) were tested against two B. cereus strains. Both of them were significantly affected within the first 4 h of contact; whereas B. cereus BAC1 cells recovered after 24 h, the effect on B. cereus 1 remained up to the end of the assay. The LAB studied may thus be considered to define future strategies for biological control of B. cereus.
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Ogawa, Hirohito; Fujikura, Daisuke; Ohnuma, Miyuki; Ohnishi, Naomi; Hang'ombe, Bernard M.; Mimuro, Hitomi; Ezaki, Takayuki; Mweene, Aaron S.; Higashi, Hideaki
2015-01-01
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. PMID:25774512
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Venkateswaran, Kasthuri; Singh, Nitin K; Checinska Sielaff, Aleksandra; Pope, Robert K; Bergman, Nicholas H; van Tongeren, Sandra P; Patel, Nisha B; Lawson, Paul A; Satomi, Masataka; Williamson, Charles H D; Sahl, Jason W; Keim, Paul; Pierson, Duane; Perry, Jay
2017-01-01
In an ongoing Microbial Observatory investigation of the International Space Station (ISS), 11 Bacillus strains (2 from the Kibo Japanese experimental module, 4 from the U.S. segment, and 5 from the Russian module) were isolated and their whole genomes were sequenced. A comparative analysis of the 16S rRNA gene sequences of these isolates showed the highest similarity (>99%) to the Bacillus anthracis - B. cereus - B. thuringiensis group. The fatty acid composition, polar lipid profile, peptidoglycan type, and matrix-assisted laser desorption ionization-time of flight profiles were consistent with the B. cereus sensu lato group. The phenotypic traits such as motile rods, enterotoxin production, lack of capsule, and resistance to gamma phage/penicillin observed in ISS isolates were not characteristics of B. anthracis . Whole-genome sequence characterizations showed that ISS strains had the plcR non- B. anthracis ancestral "C" allele and lacked anthrax toxin-encoding plasmids pXO1 and pXO2, excluding their identification as B. anthracis . The genetic identities of all 11 ISS isolates characterized via gyrB analyses arbitrarily identified them as members of the B. cereus group, but traditional DNA-DNA hybridization (DDH) showed that the ISS isolates are similar to B. anthracis (88% to 90%) but distant from the B. cereus (42%) and B. thuringiensis (48%) type strains. The DDH results were supported by average nucleotide identity (>98.5%) and digital DDH (>86%) analyses. However, the collective phenotypic traits and genomic evidence were the reasons to exclude the ISS isolates from B. anthracis . Nevertheless, multilocus sequence typing and whole-genome single nucleotide polymorphism analyses placed these isolates in a clade that is distinct from previously described members of the B. cereus sensu lato group but closely related to B. anthracis . IMPORTANCE The International Space Station Microbial Observatory (Microbial Tracking-1) study is generating a
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Singh, Nitin K.; Checinska Sielaff, Aleksandra; Pope, Robert K.; Bergman, Nicholas H.; van Tongeren, Sandra P.; Patel, Nisha B.; Lawson, Paul A.; Satomi, Masataka; Williamson, Charles H. D.; Sahl, Jason W.; Pierson, Duane; Perry, Jay
2017-01-01
ABSTRACT In an ongoing Microbial Observatory investigation of the International Space Station (ISS), 11 Bacillus strains (2 from the Kibo Japanese experimental module, 4 from the U.S. segment, and 5 from the Russian module) were isolated and their whole genomes were sequenced. A comparative analysis of the 16S rRNA gene sequences of these isolates showed the highest similarity (>99%) to the Bacillus anthracis-B. cereus-B. thuringiensis group. The fatty acid composition, polar lipid profile, peptidoglycan type, and matrix-assisted laser desorption ionization–time of flight profiles were consistent with the B. cereus sensu lato group. The phenotypic traits such as motile rods, enterotoxin production, lack of capsule, and resistance to gamma phage/penicillin observed in ISS isolates were not characteristics of B. anthracis. Whole-genome sequence characterizations showed that ISS strains had the plcR non-B. anthracis ancestral “C” allele and lacked anthrax toxin-encoding plasmids pXO1 and pXO2, excluding their identification as B. anthracis. The genetic identities of all 11 ISS isolates characterized via gyrB analyses arbitrarily identified them as members of the B. cereus group, but traditional DNA-DNA hybridization (DDH) showed that the ISS isolates are similar to B. anthracis (88% to 90%) but distant from the B. cereus (42%) and B. thuringiensis (48%) type strains. The DDH results were supported by average nucleotide identity (>98.5%) and digital DDH (>86%) analyses. However, the collective phenotypic traits and genomic evidence were the reasons to exclude the ISS isolates from B. anthracis. Nevertheless, multilocus sequence typing and whole-genome single nucleotide polymorphism analyses placed these isolates in a clade that is distinct from previously described members of the B. cereus sensu lato group but closely related to B. anthracis. IMPORTANCE The International Space Station Microbial Observatory (Microbial Tracking-1) study is generating a
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Caballero, Javier; Peralta, Cecilia; Molla, Antonella; Del Valle, Eleodoro E; Caballero, Primitivo; Berry, Colin; Felipe, Verónica; Yaryura, Pablo; Palma, Leopoldo
2018-01-01
Bacillus cereus is a gram-positive, spore-forming bacterium possessing an important and historical record as a human-pathogenic bacterium. However, several strains of this species exhibit interesting potential to be used as plant growth-promoting rhizobacteria. Here, we report the draft genome sequence of B. cereus strain CITVM-11.1, which consists of 37 contig sequences, accounting for 5,746,486 bp (with a GC content of 34.8%) and 5,752 predicted protein-coding sequences. Several of them could potentially be involved in plant-bacterium interactions and may contribute to the strong antagonistic activity shown by this strain against the charcoal root rot fungus, Macrophomina phaseolina. This genomic sequence also showed a number of genes that may confer this strain resistance against several polluting heavy metals and for the bioconversion of mycotoxins. © 2018 S. Karger AG, Basel.
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Surface characteristics of Bacillus cereus and its adhesion to stainless steel.
Peng, J S; Tsai, W C; Chou, C C
2001-04-11
The ability of a Bacillus cereus strain, isolated from spoiled milk, to adhere to the surface of stainless steel chips was evaluated during its growth in diluted tryptic soy broth (DTSB). The number of cells that adhered to the surface increased markedly as the culture reached the end of the log phase and entered stationary phase, and continued to increase with further incubation. The surface properties of cells from the log, stationary, and late stationary phases were measured by hydrophobic interaction chromatography (HIC) and electrostatic interaction chromatography (ESIC). It was found that surface hydrophobicity of B. cereus vegetative cells from the late stationary phase was the highest followed by those from the stationary phase and the log phase cultures. While the vegetative cells prepared from stationary phase and log phase cultures, respectively, had the highest and the lowest surface charges. Adhesion of B. cereus vegetative cells to stainless steel was positively correlated with the cell surface hydrophobicity (R = 0.979). Surface hydrophobicity and surface positive charge noted on the spores harvested from diluted tryptic soy agar (DTSA) and Mn2+-tryptone glucose extract agar were higher than those harvested from the sucrose or lactose-added DTSA. A wide variation in the surface charge values was noted on the surface of various spores prepared from cultures grown on the four different media tested, while their ability to adhere to stainless steel chips in phosphate buffered saline (PBS) showed no significant difference (p > 0.05). Similarly, the number of spores or vegetative cells adhering to stainless steel suspended in PBS, milk or diluted milk (1000 x) did not differ significantly (p > 0.05).
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Genomic insights into the taxonomic status of the Bacillus cereus group
Liu, Yang; Lai, Qiliang; Göker, Markus; Meier-Kolthoff, Jan P.; Wang, Meng; Sun, Yamin; Wang, Lei; Shao, Zongze
2015-01-01
The identification and phylogenetic relationships of bacteria within the Bacillus cereus group are controversial. This study aimed at determining the taxonomic affiliations of these strains using the whole-genome sequence-based Genome BLAST Distance Phylogeny (GBDP) approach. The GBDP analysis clearly separated 224 strains into 30 clusters, representing eleven known, partially merged species and accordingly 19–20 putative novel species. Additionally, 16S rRNA gene analysis, a novel variant of multi-locus sequence analysis (nMLSA) and screening of virulence genes were performed. The 16S rRNA gene sequence was not sufficient to differentiate the bacteria within this group due to its high conservation. The nMLSA results were consistent with GBDP. Moreover, a fast typing method was proposed using the pycA gene, and where necessary, the ccpA gene. The pXO plasmids and cry genes were widely distributed, suggesting little correlation with the phylogenetic positions of the host bacteria. This might explain why classifications based on virulence characteristics proved unsatisfactory in the past. In summary, this is the first large-scale and systematic study of the taxonomic status of the bacteria within the B. cereus group using whole-genome sequences, and is likely to contribute to further insights into their pathogenicity, phylogeny and adaptation to diverse environments. PMID:26373441
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Cobo Molinos, Antonio; Abriouel, Hikmate; Lucas López, Rosario; Ben Omar, Nabil; Valdivia, Eva; Gálvez, Antonio
2008-09-01
Enterocin AS-48 is a broad-spectrum cyclic antimicrobial peptide produced by Enterococcus faecalis. In the present study, the bacteriocin was tested alone and in combination with other antimicrobials for decontamination of Bacillus inoculated on alfalfa, soybean sprouts and green asparagus. Washing with enterocin AS-48 solutions reduced viable cell counts of Bacillus cereus and Bacillus weihenstephanensis by 1.0-1.5 and by 1.5-2.38 log units right after application of treatment, respectively. In both cases, the bacteriocin was effective in reducing the remaining viable population below detection levels during further storage of the samples at 6 degrees C, but failed to prevent regrowth in samples stored at 15 or 22 degrees C. Application of washing treatments containing enterocin AS-48 in combination with several other antimicrobials and sanitizers (cinnamic and hydrocinnamic acids, carvacrol, polyphosphoric acid, peracetic acid, hexadecylpyridinium chloride and sodium hypochlorite) greatly enhanced the bactericidal effects. The combinations of AS-48 and sodium hypochlorite, peracetic acid or hexadecylpyridinium chloride provided the best results. After application of the combined treatments on alfalfa sprouts contaminated with B. cereus or with B. weihenstephanensis, viable bacilli were not detected or remained at very low concentrations in the treated samples during a 1-week storage period at 15 degrees C. Inhibition of B. cereus by in situ produced bacteriocin was tested by cocultivation with the AS-48 producer strain E. faecalis A-48-32 inoculated on soybean sprouts. Strain A-48-32 was able to grow and produce bacteriocin on sprouts both at 15 and 22 degrees C. At 15 degrees C, growth of B. cereus was completely inhibited in the cocultures, while a much more limited effect was observed at 22 degrees C. The results obtained for washing treatments are very encouraging for the application of enterocin AS-48 in the decontamination of sprouts. Application of washing
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Kang, Il-Byeong; Chon, Jung-Whan; Kim, Dong-Hyeon; Jeong, Dana; Kim, Hong-Seok; Kim, Hyunsook; Seo, Kun-Ho
2017-03-01
A modified polymyxin-egg yolk-mannitol-bromothymol blue agar (mPEMBA) was developed by supplementing polymyxin-egg yolk-mannitol-bromothymol blue agar (PEMBA) with trimethoprim to improve the selectivity for and recoverability of Bacillus cereus from naturally and artificially contaminated food samples. The number of B. cereus in mPEMBA was significantly higher than in PEMBA, indicating better recoverability (P < 0.05) in red pepper powder (PEMBA 0.80 ± 0.22 log CFU/g versus mPEMBA 1.95 ± 0.17 log CFU/g) and soybean paste (PEMBA 2.19 ± 0.18 log CFU/g versus mPEMBA 3.09 ± 0.13 log CFU/g). In addition, mPEMBA provided better visual differentiation of B. cereus colonies than PEMBA, which is attributable to the reduced number of competing microflora. We conclude that the addition of trimethoprim to PEMBA could generate a synergistic effect to improve selectivity for B. cereus .
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Iron regulates expression of Bacillus cereus hemolysin II via global regulator Fur.
Sineva, Elena; Shadrin, Andrey; Rodikova, Ekaterina A; Andreeva-Kovalevskaya, Zhanna I; Protsenko, Alexey S; Mayorov, Sergey G; Galaktionova, Darya Yu; Magelky, Erica; Solonin, Alexander S
2012-07-01
The capacity of pathogens to respond to environmental signals, such as iron concentration, is key to bacterial survival and establishment of a successful infection. Bacillus cereus is a widely distributed bacterium with distinct pathogenic properties. Hemolysin II (HlyII) is one of its pore-forming cytotoxins and has been shown to be involved in bacterial pathogenicity in a number of cell and animal models. Unlike many other B. cereus pathogenicity factors, HlyII is not regulated by pleiotropic transcriptional regulator PlcR but is controlled by its own regulator, HlyIIR. Using a combination of in vivo and in vitro techniques, we show that hlyII expression is also negatively regulated by iron by the global regulator Fur via direct interaction with the hlyII promoter. DNase I footprinting and in vitro transcription experiments indicate that Fur prevents RNA polymerase binding to the hlyII promoter. HlyII expression profiles demonstrate that both HlyIIR and Fur regulate HlyII expression in a concerted fashion, with the effect of Fur being maximal in the early stages of bacterial growth. In sum, these results show that Fur serves as a transcriptional repressor for hlyII expression.
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NASA Astrophysics Data System (ADS)
Jawad, Nisreen; Ahemd, Asmat; Abdullah, Aminah
2018-04-01
The aim of this study was to investigate the presence of Bacillus cereus and detection of enterotoxigenic genes in food samples by utilizing a Polymerase Chain Reaction technique (PCR). In this study the providence of B. cereus was carried out to food samples. The B. cereus isolates were investigated for enterotoxigenic gene. The cooked seafood, and raw milk samples were purchased from several restaurants and market in the area of (Bangi, Kajang, Serdang and UKM) Selangor, Malaysia. A total of 60 samples have been analyzed. B. cereus contamination has been formed between 1.4×105 - 3×105 cfu/mL of cooked seafood and raw milk samples. Five colonies have been detected as B. cereus using biochemical test. All B. cereus isolates named BC1 to BC27, were characterized for haemolytic enterotoxin (HBL) complex encoding genes (hblA), non-haemolytic enterotoxin encoding gene (NheA). 10 isolates have been reported to be positive towards hblA and 12 isolates were positive towards NheA. The presence of B. cereus and their enterotoxigenic genes in cooked seafood and raw milk from to food samples obtained may pose a potential risk for public health.
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Ryang, J H; Kim, N H; Lee, B S; Kim, C T; Rhee, M S
2016-07-01
This study selected spores from Bacillus cereus FSP-2 strain (the isolate from a commercial doenjang processing line) as the test strain which showed significantly higher thermal resistance (P < 0·05) than B. cereus reference strain (ATCC 27348). The spores in doenjang were subjected to ohmic heating (OH) at 95, 105, 115 and 125°C for 30, 60 or 90 s using a five sequential electrode system (electrical field: 26·7 V cm(-1) ; alternating current frequency: 25 kHz). OH at 105°C for 30-90 s reduced the B. cereus spore count in doenjang samples to <4 log CFU g(-1) . Since OH treatment at 115 and 125°C caused a perceivable colour change in the product (>1·5 National Bureau of Standards units), treatment at 105°C for 60 s was selected and applied on a large scale (500 kg of product). Reliable and reproducible destruction of B. cereus spores occurred; the reductions achieved (to < 4 log CFU g(-1) ) met the Korean national standards. Scanning electron microscopy revealed microstructural alterations in the spores (shrinkage and a distorted outer spore coat). OH is an effective method for destroying B. cereus spores to ensure the microbiological quality and safety of a thick, highly viscous sauce. This study shows that an ohmic heating (OH) using a five sequential electrode system can effectively destroy highly heat-resistant Bacillus cereus spores which have been frequently found in a commercial doenjang processing line without perceivable quality change in the product. In addition, it may demonstrate high potential of the unique OH system used in this study that will further contribute to ensure microbiological quality and safety of crude sauces containing high levels of electrolyte other than doenjang as well. © 2016 The Society for Applied Microbiology.
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Johnson, Shannon L.; Minogue, Timothy D.; Teshima, Hazuki; ...
2015-01-15
Bacillus cereus strain 03BB87, a blood culture isolate, originated in a 56-year-old male muller operator with a fatal case of pneumonia in 2003. Here we present the finished genome sequence of that pathogen, including a 5.46-Mb chromosome and two plasmids (209 and 52 Kb, respectively).
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Wang, Xiaoli; Wang, Lei; Wang, Jing; Jin, Peng; Liu, Hongxia; Zheng, Yonghua
2014-01-01
The effectiveness of a biocontrol agent Bacillus cereus AR156 for control of anthracnose rot caused by Colletotrichum acutatum in harvested loquat fruit and the possible mechanisms of its action have been investigated. Treatment of fruit with B. cereus AR156 resulted in lower disease incidence and smaller lesion diameters compared with that of untreated fruit. The treatment enhanced activities of defense-related enzymes including chitinase, β-1, 3-glucanase, phenylalanine ammonia-lyase, peroxidase and polyphenoloxidase, and promoted accumulation of H2O2. Total phenolic content and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity were also increased by treatment. Transcripts of three defense-related genes were enhanced only in fruit undergoing both B. cereus AR156 treatment and C. acutatum inoculation compared with those receiving either intervention alone. These results suggest that the disease resistance against C. acutatum in loquat fruit is enhanced by B. cereus AR156 and that the induced resistance is associated with induction and priming of defense responses in the fruit. PMID:25386680
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Dielectric Study of the Physical State of Electrolytes and Water Within Bacillus cereus Spores
Carstensen, Edwin L.; Marquis, Robert E.; Gerhardt, Philipp
1971-01-01
Dielectric measurements revealed that dormant spores of Bacillus cereus have extremely low conductivities at high frequencies (50 MHz) and so must contain remarkably low concentrations of mobile ions both within the core and in the surrounding integuments. Activation, germination, and outgrowth were all accompanied by increases in conductivity of the cells and their suspending medium, and this result indicated that intracellular electrolytes had become ionized and leaked from the spores. High-frequency dielectric constants of spores were consistent with normal states for cell water. These values increased during successive stages of development from dormant spore to vegetative bacillus, and they could be directly related to increases in cell water content. In all, the results refuted a model of the dormant spore involving freely mobile, ionized electrolytes and supported a model involving electrostatically bound electrolytes. PMID:4998245
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Izadi, Zahra; Sheikh-Zeinoddin, Mahmoud; Ensafi, Ali A; Soleimanian-Zad, Sabihe
2016-06-15
This paper describes fabrication of a DNA-based Au-nanoparticle modified pencil graphite electrode (PGE) biosensor for detection of Bacillus cereus, causative agent of two types of food-borne disease, i.e., emetic and diarrheal syndrome. The sensing element of the biosensor was comprised of gold nanoparticles (GNPs) self-assembled with single-stranded DNA (ssDNA) of nheA gene immobilized with thiol linker on the GNPs modified PGE. The size, shape and dispersion of the GNPs were characterized by field emission scanning electron microscope (FESEM). Detection of B. cereus was carried out based on an increase in the charge transfer resistance (Rct) of the biosensor due to hybridization of the ss-DNA with target DNA. An Atomic force microscope (AFM) was used to confirm the hybridization. The biosensor sensitivity in pure cultures of B. cereus was found to be 10(0) colony forming units per milliliter (CFU/mL) with a detection limit of 9.4 × 10(-12) mol L(-1). The biosensor could distinguish complementary from mismatch DNA sequence. The proposed biosensor exhibited a rapid detection, low cost, high sensitivity to bacterial contamination and could exclusively and specifically detect the target DNA sequence of B. cereus from other bacteria that can be found in dairy products. Moreover, the DNA biosensor exhibited high reproducibility and stability, thus it may be used as a suitable biosensor to detect B. cereus and to become a portable system for food quality control. Copyright © 2016 Elsevier B.V. All rights reserved.
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Diomandé, Sara Esther; Chamot, Stéphanie; Antolinos, Vera; Vasai, Florian; Guinebretière, Marie-Hélène; Bornard, Isabelle; Nguyen-the, Christophe; Broussolle, Véronique
2014-01-01
The different strains of Bacillus cereus can grow at temperatures covering a very diverse range. Some B. cereus strains can grow in chilled food and consequently cause food poisoning. We have identified a new sensor/regulator mechanism involved in low-temperature B. cereus growth. Construction of a mutant of this two-component system enabled us to show that this system, called CasKR, is required for growth at the minimal temperature (Tmin). CasKR was also involved in optimal cold growth above Tmin and in cell survival below Tmin. Microscopic observation showed that CasKR plays a key role in cell shape during cold growth. Introducing the casKR genes in a ΔcasKR mutant restored its ability to grow at Tmin. Although it was first identified in the ATCC 14579 model strain, this mechanism has been conserved in most strains of the B. cereus group. We show that the role of CasKR in cold growth is similar in other B. cereus sensu lato strains with different growth temperature ranges, including psychrotolerant strains. PMID:24509924
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Owusu-Kwarteng, James; Wuni, Alhassan; Akabanda, Fortune; Tano-Debrah, Kwaku; Jespersen, Lene
2017-03-14
B. cereus are of particular interest in food safety and public health because of their capacity to cause food spoilage and disease through the production of various toxins. The aim of this study was to determine the prevalence, virulence factor genes and antibiotic resistance profile of B. cereus sensu lato isolated from cattle grazing soils and dairy products in Ghana. A total of 114 samples made up of 25 soil collected from cattle grazing farm land, 30 raw milk, 28 nunu (yoghurt-like product) and 31 woagashie (West African soft cheese). Ninety-six B. cereus sensu lato isolates from 54 positive samples were screened by PCR for the presence of 8 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK and entFM), and one emetic gene (ces). Phenotypic resistance to 15 antibiotics were also determined for 96 B. cereus sensu lato isolates. About 72% (18 of 25 soil), 47% (14 of 30 raw milk), 35% (10 of 28 nunu) and 39% (12 of 31 woagashi) were positive for B. cereus sensu lato with mean counts (log 10 cfu/g) of 4.2 ± 1.8, 3.3 ± 2.0, 1.8 ± 1.4 and 2.6 ± 1.8 respectively. The distribution of enterotoxigenic genes revealed that 13% (12/96 isolates) harboured all three gene encoding for haemolytic enterotoxin HBL complex genes (hblA, hblC and hblD), 25% (24/96 isolates) possessed no HBL gene, whereas 63% (60/96 isolates) possessed at least one of the three HBL genes. All three genes encoding for non-haemolytic enterotoxin (nheA, nheB and nheC) were detected in 60% (57/96) isolates, 14% (13/96) harboured only one gene, 19% (18/96) whereas 8% possessed none of the NHE genes. The detection rates of cytk, entFM, and ces genes were 75, 67 and 9% respectively. Bacillus cereus s. l. isolates were generally resistant to β-lactam antibiotics such as ampicillin (98%), oxacillin (92%), penicillin (100%), amoxicillin (100%), and cefepime (100%) but susceptible to other antibiotics tested. Bacillus cereus s. l. is prevalent in soil, raw milk and dairy
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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. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
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Gdoura-Ben Amor, Maroua; Siala, Mariam; Zayani, Mariem; Grosset, Noël; Smaoui, Salma; Messadi-Akrout, Feriele; Baron, Florence; Jan, Sophie; Gautier, Michel; Gdoura, Radhouane
2018-01-01
Bacillus cereus group is widespread in nature and foods. Several members of this group are recognized as causing food spoilage and/or health issues. This study was designed to determine the prevalence and genetic diversity of the B. cereus group strains isolated in Tunisia from different foods (cereals, spices, cooked food, fresh-cut vegetables, raw and cooked poultry meats, seafood, canned, pastry, and dairy products). In total, 687 different samples were collected and searched for the presence of the B. cereus group after selective plating on MYP agar and enumeration of each sample. The typical pink-orange uniform colonies surrounded by a zone of precipitate were assumed to belong to the B. cereus group. One typical colony from each sample was subcultured and preserved as cryoculture. Overall, 191 (27.8%) food samples were found positive, giving rise to a collection of 191 B. cereus -like isolates. The concentration of B. cereus -like bacteria were below 10 3 cfu/g or ml in 77.5% of the tested samples. Higher counts (>10 4 cfu/g or ml) were found in 6.8% of samples including fresh-cut vegetables, cooked foods, cereals, and pastry products. To verify whether B. cereus -like isolates belonged to the B. cereus group, a PCR test targeting the sspE gene sequence specific of the group was carried out. Therefore, 174 isolates were found to be positive. Food samples were contaminated as follows: cereals (67.6%), pastry products (46.2%), cooked food (40.8%), cooked poultry meat (32.7%), seafood products (32.3%), spices (28.8%), canned products (16.7%), raw poultry meat (9.4%), fresh-cut vegetables (5.0%), and dairy products (4.8%). The 174 B. cereus isolates were characterized by partial sequencing of the panC gene, using a Sym'Previous software tool to assign them to different phylogenetic groups. Strains were distributed as follows: 61.3, 29.5, 7.5, and 1.7% in the group III, IV, II, and V, respectively. The genetic diversity was further assessed by ERIC-PCR and PFGE
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Gdoura-Ben Amor, Maroua; Siala, Mariam; Zayani, Mariem; Grosset, Noël; Smaoui, Salma; Messadi-Akrout, Feriele; Baron, Florence; Jan, Sophie; Gautier, Michel; Gdoura, Radhouane
2018-01-01
Bacillus cereus group is widespread in nature and foods. Several members of this group are recognized as causing food spoilage and/or health issues. This study was designed to determine the prevalence and genetic diversity of the B. cereus group strains isolated in Tunisia from different foods (cereals, spices, cooked food, fresh-cut vegetables, raw and cooked poultry meats, seafood, canned, pastry, and dairy products). In total, 687 different samples were collected and searched for the presence of the B. cereus group after selective plating on MYP agar and enumeration of each sample. The typical pink-orange uniform colonies surrounded by a zone of precipitate were assumed to belong to the B. cereus group. One typical colony from each sample was subcultured and preserved as cryoculture. Overall, 191 (27.8%) food samples were found positive, giving rise to a collection of 191 B. cereus-like isolates. The concentration of B. cereus-like bacteria were below 103 cfu/g or ml in 77.5% of the tested samples. Higher counts (>104 cfu/g or ml) were found in 6.8% of samples including fresh-cut vegetables, cooked foods, cereals, and pastry products. To verify whether B. cereus-like isolates belonged to the B. cereus group, a PCR test targeting the sspE gene sequence specific of the group was carried out. Therefore, 174 isolates were found to be positive. Food samples were contaminated as follows: cereals (67.6%), pastry products (46.2%), cooked food (40.8%), cooked poultry meat (32.7%), seafood products (32.3%), spices (28.8%), canned products (16.7%), raw poultry meat (9.4%), fresh-cut vegetables (5.0%), and dairy products (4.8%). The 174 B. cereus isolates were characterized by partial sequencing of the panC gene, using a Sym'Previous software tool to assign them to different phylogenetic groups. Strains were distributed as follows: 61.3, 29.5, 7.5, and 1.7% in the group III, IV, II, and V, respectively. The genetic diversity was further assessed by ERIC-PCR and PFGE typing
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USDA-ARS?s Scientific Manuscript database
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...
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Glasset, Benjamin; Herbin, Sabine; Guillier, Laurent; Cadel-Six, Sabrina; Vignaud, Marie-Léone; Grout, Joel; Pairaud, Sylvie; Michel, Valérie; Hennekinne, Jacques-Antoine; Ramarao, Nalini; Brisabois, Anne
2016-01-01
The aim of this study was to identify and characterise Bacillus cereus from a unique national collection of 564 strains associated with 140 strong-evidence food-borne outbreaks (FBOs) occurring in France during 2007 to 2014. Starchy food and vegetables were the most frequent food vehicles identified; 747 of 911 human cases occurred in institutional catering contexts. Incubation period was significantly shorter for emetic strains compared with diarrhoeal strains A sub-panel of 149 strains strictly associated to 74 FBOs and selected on Coliphage M13-PCR pattern, was studied for detection of the genes encoding cereulide, diarrhoeic toxins (Nhe, Hbl, CytK1 and CytK2) and haemolysin (HlyII), as well as panC phylogenetic classification. This clustered the strains into 12 genetic signatures (GSs) highlighting the virulence potential of each strain. GS1 (nhe genes only) and GS2 (nhe, hbl and cytK2), were the most prevalent GS and may have a large impact on human health as they were present in 28% and 31% of FBOs, respectively. Our study provides a convenient molecular scheme for characterisation of B. cereus strains responsible for FBOs in order to improve the monitoring and investigation of B. cereus-induced FBOs, assess emerging clusters and diversity of strains. PMID:27934583
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Xu, Zhenbo; Xie, Jinhong; Liu, Junyan; Ji, Lili; Soteyome, Thanapop; Peters, Brian M; Chen, Dingqiang; Li, Bing; Li, Lin; Shirtliff, Mark E
2017-03-01
Bacillus cereus is one of the most common opportunistic pathogens responsible for various foodborn diseases. To investigate the regulatory mechanism of B. cereus under high osmotic pressure, two B. cereus strains B25 and B26 were isolated from the industrial soy sauce residue containing high-salt concentration. Resequencing was performed by Illumina/Solexa platform and 13,646 SNPs and 434 InDels were identified as common variants between B25 and B26 against reference genome, followed by COG, GO, and KEGG enrichment analysis. Furthermore, 49 key genes involving in Na + /H + ,K + transporter, dipeptide or tripeptide transporter, stress response were selected and classified into 27 groups. Further validation was performed by qRT-PCR, and 4 candidate genes were found most associated with osmotic response. Gene expression of the 4 candidate genes was then analyzed accordingly, and down regulation was obtained for gene BC0669 and BC0754 associated with K + transport system. However, dramatic up regulation was detected for gene BC2114 involving in glutathione peroxidase, indicating the activation of antioxidant responses by osmotic stress via genetic regulation. As concluded, bioinformatic analysis and gene expression profile represented the basis of further investigation on the genetic and regulatory mechanism of bacterial salt tolerance. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Desriac, Noémie; Broussolle, Véronique; Postollec, Florence; Mathot, Anne-Gabrielle; Sohier, Danièle; Coroller, Louis; Leguerinel, Ivan
2013-01-01
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 toward 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 behavior. These biomarkers could be furthermore used to develop new microbial behavior prediction tools which can provide insights into underlying molecular physiological states which govern the behavior of microorganisms and thus opening the avenue toward the detection of stress adaptive behavior at an early stage and the control of stress-induced resistance throughout the food chain. PMID:24106490
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Balm, M N D; Jureen, R; Teo, C; Yeoh, A E J; Lin, R T P; Dancer, S J; Fisher, D A
2012-08-01
A sudden increase in invasive infections caused by Bacillus cereus group organisms prompted an investigation at the National University Hospital in Singapore. To describe the investigation and management and subsequent difficulties controlling the outbreak. Clinical case reviews were performed on all patients with B. cereus group recovered from clinical samples. Widespread environmental sampling was performed followed by review of hospital ventilation systems, domestic cleaning and laundry practices. B. cereus was recovered from 171 patients during a six-month period coinciding with large-scale construction work beside the hospital. Most patients presented with bacteraemia (146/171; 85.4%) with 46/171 (26.9%) requiring extended treatment courses with vancomycin or other interventions. Sampling confirmed extensive airborne dispersal inside the hospital, including isolation rooms and air-conditioned wards. Hospital linen was heavily contaminated [7403 cfu/cm(2); 95% confidence interval (CI): 6349-8457; for 30 towels sampled], encouraged by inappropriate storage in airtight plastic bags (4437 cfu/cm(2); CI: 3125-5750) compared with storage in porous canvas bags (166 cfu/cm(2); CI: 76-256; P < 0.001). Interventions introduced included revision of laundry practices, transport and storage of hospital linen and towels; bleach-based environmental cleaning; and upgrading of ventilation systems throughout the hospital. Clinical case numbers returned to baseline levels within three months, only to rise again following relaxation of laundry practices. Construction work beside this Singapore hospital encouraged heavy contamination of air and environment with Bacillus spp., assumed to be responsible for the outbreak described. Failure to maintain revised laundry practices allowed resurgence of clinical cases, particularly among immunocompromised patients. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
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Identification and Pathogenic Potential of Clinical Bacillus and Paenibacillus Isolates
Celandroni, Francesco; Salvetti, Sara; Gueye, Sokhna Aissatou; Mazzantini, Diletta; Lupetti, Antonella; Senesi, Sonia; Ghelardi, Emilia
2016-01-01
The soil-related Bacillus and Paenibacillus species have increasingly been implicated in various human diseases. Nevertheless, their identification still poses problems in the clinical microbiology laboratory and, with the exception of Bacillus anthracis and Bacillus cereus, little is known on their pathogenicity for humans. In this study, we evaluated the use of matrix-assisted laser desorption—ionization time of flight mass spectrometry (MALDI-TOF MS) in the identification of clinical isolates of these genera and conducted genotypic and phenotypic analyses to highlight specific virulence properties. Seventy-five clinical isolates were subjected to biochemical and MALDI-TOF MS identification. 16S rDNA sequencing and supplemental tests were used to solve any discrepancies or failures in the identification results. MALDI-TOF MS significantly outperformed classical biochemical testing for correct species identification and no misidentification was obtained. One third of the collected strains belonged to the B. cereus species, but also Bacillus pumilus and Bacillus subtilis were isolated at high rate. Antimicrobial susceptibility testing showed that all the B. cereus, B. licheniformis, B. simplex, B. mycoides, Paenibacillus glucanolyticus and Paenibacillus lautus isolates are resistant to penicillin. The evaluation of toxin/enzyme secretion, toxin-encoding genes, motility, and biofilm formation revealed that B. cereus displays the highest virulence potential. However, although generally considered nonpathogenic, most of the other species were shown to swim, swarm, produce biofilms, and secrete proteases that can have a role in bacterial virulence. In conclusion, MALDI-TOF MS appears useful for fast and accurate identification of Bacillus and Paenibacillus strains whose virulence properties make them of increasing clinical relevance. PMID:27031639
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Dwivedi, Naveen; Balomajumder, Chandrajit; Mondal, Prasenji
2016-07-01
The present study aimed to investigate the removal efficiency of cyanide from contaminated water by adsorption, biodegradation and simultaneous adsorption and biodegradation (SAB) process individually in a batch reactor. Adsorption was achieved by using almond shell granules and biodegradation was conducted with suspended cultures of Bacillus cereus, whereas SAB process was carried out using Bacillus cereus and almond shell in a batch reactor. The effect of agitation time, pH, and initial cyanide concentration on the % removal of cyanide has been discussed. Under experimental conditions, optimum removal was obtained at pH 7 with agitation time of 48 hrs and temperature of 35 degrees C. Cyanide was utilized by bacteria as sole source of nitrogen for growth. The removal efficiencies of cyanide by adsorption, biodegradation, and SAB were found to be 91.38%, 95.87%, and 99.63%, respectively, at initial cyanide concentration of 100 mg l(-1). The removal efficiency of SAB was found to be better as compared to that of biodegradation and adsorption alone.
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NASA Astrophysics Data System (ADS)
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.
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Deshmukh, Yogita; Khare, Puja; Patra, D D; Nadaf, Altafhusain B
2014-01-01
A rapid micro-scale solid-phase micro-extraction (SPME) procedure coupled with gas-chromatography with flame ionized detector (GC-FID) was used to extract parts per billion levels of a principle basmati aroma compound "2-acetyl-1-pyrroline" (2-AP) from bacterial samples. In present investigation, optimization parameters of bacterial incubation period, sample weight, pre-incubation time, adsorption time, and temperature, precursors and their concentrations has been studied. In the optimized conditions, detection of 2-AP produced by Bacillus cereus ATCC10702 using only 0.5 g of sample volume was 85 μg/kg. Along with 2-AP, 15 other compounds produced by B. cereus were also reported out of which 14 were reported for the first time consisting mainly of (E)-2-hexenal, pentadecanal, 4-hydroxy-2-butanone, n-hexanal, 2-6-nonadienal, 3-methoxy-2(5H) furanone and 2-acetyl-1-pyridine and octanal. High recovery of 2-AP (87 %) from very less amount of B. cereus samples was observed. The method is reproducible fast and can be used for detection of 2-AP production by B. cereus. © 2014 American Institute of Chemical Engineers.
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Rondon, Michelle R.; Raffel, Sandra J.; Goodman, Robert M.; Handelsman, Jo
1999-01-01
As the study of microbes moves into the era of functional genomics, there is an increasing need for molecular tools for analysis of a wide diversity of microorganisms. Currently, biological study of many prokaryotes of agricultural, medical, and fundamental scientific interest is limited by the lack of adequate genetic tools. We report the application of the bacterial artificial chromosome (BAC) vector to prokaryotic biology as a powerful approach to address this need. We constructed a BAC library in Escherichia coli from genomic DNA of the Gram-positive bacterium Bacillus cereus. This library provides 5.75-fold coverage of the B. cereus genome, with an average insert size of 98 kb. To determine the extent of heterologous expression of B. cereus genes in the library, we screened it for expression of several B. cereus activities in the E. coli host. Clones expressing 6 of 10 activities tested were identified in the library, namely, ampicillin resistance, zwittermicin A resistance, esculin hydrolysis, hemolysis, orange pigment production, and lecithinase activity. We analyzed selected BAC clones genetically to identify rapidly specific B. cereus loci. These results suggest that BAC libraries will provide a powerful approach for studying gene expression from diverse prokaryotes. PMID:10339608
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Haydar, Abbass; Tran, Seav-Ly; Guillemet, Elisabeth; Darrigo, Claire; Perchat, Stéphane; Lereclus, Didier; Coquet, Laurent; Jouenne, Thierry; Ramarao, Nalini
2018-01-01
Bacillus cereus is a Gram-positive spore-forming bacterium causing food poisoning and serious opportunistic infections. These infections are characterized by bacterial accumulation in the host despite the induction of inflammation. To circumvent inflammation, bacteria must resist the bactericidal activity of professional phagocytes, which constitute a first line of host defense against pathogens. Interactions between phagocytic cells and B. cereus are still poorly characterized and the mechanism of resistance to the host immune system is not known yet. We have previously shown that the spores are phagocytosed by macrophages but survive and escape from these cells. The metalloprotease InhA1 is a key effector involved in these processes. inhA1 -deficient spores are retained intracellularly, in contrast to the wild type strain spores. NprA is also a B. cereus metalloprotease able to cleave tissue components such as fibronectin, laminin, and collagen. Here, we show that NprA, concomitantly secreted with InhA1 in the B. cereus secretome, is essential to promote bacterial escape from macrophages. We show that InhA1 cleaves NprA at specific sites. This cleavage allows liberation of the mature form of the NprA protein in the supernatant of the wild type strain. This mature form of NprA is actually the principal effector allowing bacterial escape from host macrophages.
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Van Der Zwet, W C; Parlevliet, G A; Savelkoul, P H; Stoof, J; Kaiser, A M; Van Furth, A M; Vandenbroucke-Grauls, C M
2000-11-01
In 1998, an outbreak of systemic infections caused by Bacillus cereus occurred in the Neonatal Intensive Care Unit of the University Hospital Vrije Universiteit, Amsterdam, The Netherlands. Three neonates developed sepsis with positive blood cultures. One neonate died, and the other two neonates recovered. An environmental survey, a prospective surveillance study of neonates, and a case control study were performed, in combination with molecular typing, in order to identify potential sources and transmission routes of infection. Genotypic fingerprinting by amplified-fragment length polymorphism (AFLP) showed that the three infections were caused by a single clonal type of B. cereus. The same strain was found in trachea aspirate specimens of 35 other neonates. The case control study showed mechanical ventilation with a Sensormedics ventilation machine to be a risk factor for colonization and/or infection (odds ratio, 9.8; 95% confidence interval, 1.1 to 88.2). Prospective surveillance showed that colonization with B. cereus occurred exclusively in the respiratory tract of mechanically ventilated neonates. The epidemic strain of B. cereus was found on the hands of nursing staff and in balloons used for manual ventilation. Sterilization of these balloons ended the outbreak. We conclude that B. cereus can cause outbreaks of severe opportunistic infection in neonates. Typing by AFLP proved very useful in the identification of the outbreak and in the analysis of strains recovered from the environment to trace the cause of the epidemic.
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Van Der Zwet, Wil C.; Parlevliet, Gerard A.; Savelkoul, Paul H.; Stoof, Jeroen; Kaiser, Annie M.; Van Furth, A. Marceline; Vandenbroucke-Grauls, Christina M.
2000-01-01
In 1998, an outbreak of systemic infections caused by Bacillus cereus occurred in the Neonatal Intensive Care Unit of the University Hospital Vrije Universiteit, Amsterdam, The Netherlands. Three neonates developed sepsis with positive blood cultures. One neonate died, and the other two neonates recovered. An environmental survey, a prospective surveillance study of neonates, and a case control study were performed, in combination with molecular typing, in order to identify potential sources and transmission routes of infection. Genotypic fingerprinting by amplified-fragment length polymorphism (AFLP) showed that the three infections were caused by a single clonal type of B. cereus. The same strain was found in trachea aspirate specimens of 35 other neonates. The case control study showed mechanical ventilation with a Sensormedics ventilation machine to be a risk factor for colonization and/or infection (odds ratio, 9.8; 95% confidence interval, 1.1 to 88.2). Prospective surveillance showed that colonization with B. cereus occurred exclusively in the respiratory tract of mechanically ventilated neonates. The epidemic strain of B. cereus was found on the hands of nursing staff and in balloons used for manual ventilation. Sterilization of these balloons ended the outbreak. We conclude that B. cereus can cause outbreaks of severe opportunistic infection in neonates. Typing by AFLP proved very useful in the identification of the outbreak and in the analysis of strains recovered from the environment to trace the cause of the epidemic. PMID:11060080
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Klein, Günter
2011-07-01
Bacillus cereus var. toyoi strain NCIMB 40112 (Toyocerin), a probiotic authorized in the European Union as feed additive for swine, bovines, poultry, and rabbits, was characterized by DNA fingerprinting applying pulsed-field gel electrophoresis and multilocus sequence typing and was compared with reference strains (of clinical and environmental origins). The probiotic strain was clearly characterized by pulsed-field gel electrophoresis using the restriction enzymes Apa I and Sma I resulting in unique DNA patterns. The comparison to the clinical reference strain B. cereus DSM 4312 was done with the same restriction enzymes, and again a clear differentiation of the two strains was possible by the resulting DNA patterns. The use of the restriction enzymes Apa I and Sma I is recommended for further studies. Furthermore, multilocus sequence typing analysis revealed a sequence type (ST 111) that was different from all known STs of B. cereus strains from food poisoning incidents. Thus, a strain characterization and differentiation from food poisoning strains for the probiotic strain was possible. Copyright ©, International Association for Food Protection
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Conducting polymer based DNA biosensor for the detection of the Bacillus cereus group species
NASA Astrophysics Data System (ADS)
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.
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Rolny, I S; Tiscornia, I; Racedo, S M; Pérez, P F; Bollati-Fogolín, M
2016-11-30
It is known that probiotic microorganisms are able to modulate pathogen virulence. This ability is strain dependent and involves multiple interactions between microorganisms and relevant host's cell populations. In the present work we focus on the effect of a potentially probiotic lactobacillus strain (Lactobacillus delbrueckii subsp. lactis CIDCA 133) in an in vitro model of Bacillus cereus infection. Our results showed that infection of intestinal epithelial HT-29 cells by B. cereus induces nuclear factor kappa B (NF-κB) pathway. Noteworthy, the presence of strain L. delbrueckii subsp.lactis CIDCA 133 increases stimulation. However, B. cereus-induced interleukin (IL)-8 production by epithelial cells is partially abrogated by L. delbrueckii subsp. lactis CIDCA 133. These findings suggest that signalling pathways other than that of NF-κB are involved. In a co-culture system (HT-29 and monocyte-derived dendritic cells), B. cereus was able to translocate from the epithelial (upper) to the dendritic cell compartment (lower). This translocation was partially abrogated by the presence of lactobacilli in the upper compartment. In addition, infection of epithelial cells in the co-culture model, led to an increase in the expression of CD86 by dendritic cells. This effect could not be modified in the presence of lactobacilli. Interestingly, infection of enterocytes with B. cereus triggers production of proinflammatory cytokines by dendritic cells (IL-8, IL-6 and tumour necrosis factor alpha (TNF-α)). The production of TNF-α (a protective cytokine in B. cereus infections) by dendritic cells was increased in the presence of lactobacilli. The present work demonstrates for the first time the effect of L. delbrueckii subsp. lactis CIDCA 133, a potentially probiotic strain, in an in vitro model of B. cereus infection. The presence of the probiotic strain modulates cell response both in infected epithelial and dendritic cells thus suggesting a possible beneficial effect of
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Santos-Gandelman, Juliana F; Cruz, Kimberly; Crane, Sharron; Muricy, Guilherme; Giambiagi-deMarval, Marcia; Barkay, Tamar; Laport, Marinella S
2014-09-01
Sponges are sessile marine invertebrates that can live for many years in the same location, and therefore, they have the capability to accumulate anthropogenic pollutants such as metals over a long period. Almost all marine sponges harbor a large number of microorganisms within their tissues. The Bacillus cereus strain Pj1 was isolated from a marine sponge, Polymastia janeirensis, and was found to be resistant to 100 μM HgCl(2) and to 10 μM methylmercury (MeHg). Pj1 was also highly resistant to other metals, including CdCl(2) and Pb(NO(3))(2), alone or in combination. The mer operon was located on the bacterial chromosome, and the volatilization test indicated that the B. cereus Pj1 was able to reduce Hg(2+)-Hg(0). Cold vapor atomic absorption spectrometry demonstrated that Pj1 volatilized 80 % of the total MeHg that it was exposed to and produced elemental Hg when incubated with 1.5 μM MeHg. Pj1 also demonstrated sensitivity to all antibiotics tested. In addition, Pj1 demonstrated a potential for biosurfactant production, presenting an emulsification activity better than synthetic surfactants. The results of this study indicate that B. cereus Pj1 is a strain that can potentially be applied in the bioremediation of HgCl(2) and MeHg contamination in aquatic environments.
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Thenmozhi, C; Sankar, R; Karuppiah, V; Sampathkumar, P
2011-06-01
To isolate marine bacteria, statistically optimize them for maximum asparaginase production. 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. Plackett-Barman design was used to identify the interactive effect of the eight variables viz. yeast extract, soyabean meal, glucose, magnesium sulphate, KH(2)PO(4), 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). 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. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.
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2018-01-01
ABSTRACT The complete genome sequence of Bacillus cereus strain TG1-6, which is a highly salt-tolerant rhizobacterium that enhances plant tolerance to drought stress, is reported here. The sequencing process was performed based on a combination of pyrosequencing and single-molecule sequencing. The complete genome is estimated to be approximately 5.42 Mb, containing a total of 5,610 predicted protein-coding DNA sequences (CDSs). PMID:29748401
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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. Published 2014. This article is a US Government work and is in the public domain in the USA.
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Real-Time PCR Assay for a Unique Chromosomal Sequence of Bacillus anthracis
2004-12-01
13061 Neisseria lactamica .............................................................. 23970 Bacillus coagulans ...NEG Bacillus coagulane 7050 NEG NEG Bacillus cereus 13472 NEG NEG Bacillus licheniforms 12759 NEG NEG Bacillus cereus 13824 NEG NEG Bacillus ...Assay for a Unique Chromosomal Sequence of Bacillus anthracis Elizabeth Bode,1 William Hurtle,2† and David Norwood1* United States Army Medical
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Madeira, Jean-Paul; Alpha-Bazin, Béatrice; Armengaud, Jean; Duport, Catherine
2018-06-01
Aerobic respiratory growth generates endogenous reactive oxygen species (ROS). ROS oxidize protein-bound methionine residues into methionine sulfoxide. Methionine sulfoxide reductases catalyze the reduction of methionine sulfoxide to methionine in proteins. Here, we use high-throughput nanoLC-MS/MS methodology to establish detailed maps of oxidized proteins from Bacillus cereus ATCC 14579 ΔpBClin15 and its mutant for which the methionine sulfoxide reductase AB gene ( msrAB ) has been inactivated (Madeira et al., 2017) [1]. Lists of oxidized peptides and proteins identified at early exponential, late exponential and stationary growth phases are supplied in this article as data files. Raw data are deposited at the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers, PXD006169 and PDX006205 (http://www.ebi.ac/uk). Given the importance of methionine oxidation in several key cellular processes and its impact in the field of medical and food microbiology, this paper should be useful for further insightful redox studies in B. cereus and its numerous relatives.
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Savić, Dejana; Miljković-Selimović, Biljana; Lepšanović, Zorica; Tambur, Zoran; Konstantinović, Sonja; Stanković, Nemanja; Ristanović, Elizabeta
2016-10-01
Bacillus cereus (B. cereus) usually ingested by food can cause two types of diseases: vomiting due to the presence of emetic toxin and diarrheal syndrome, due to the presence of diarrheal toxins. Systemic manifestations can also occur. The severe forms of disease demand antibiotic treatmant. The aim of this study was to determine the differences in antibiotic susceptibility and β-lactamase activity of B. cereus isolates from stools of humans, food and environment. Identification of B. cereus was performed with selective medium, classical biochemical test and polymerase chain reaction (PCR) with primers specific for bal gene. Thirty isolates from each group were analysed for antibiotic susceptibility using the disk-diffusion assay. Production of β-lactamase was determined by cefinase test, and double-disc method. All strains identified as B. cereus using classical biochemical test, yielded 533 bp fragment with PCR. Isolates from all the three groups were susceptible to imipenem, vancomycin, and erythromycin. All isolates were susceptible to ciprofloxacin but one from the environment. A statistically significant difference between the groups was confirmed to tetracycline and trimethoprim-sulphamethoxazole sensitivity. A total of 28/30 (93.33%) samples from the foods and 25/30 (83.33%) samples from environment were approved sensitive to tetracycline, while 10/30 (33.33%) isolates from stools were sensitive. Opposite to this result, high susceptibility to trimethoprim-sulphamethoxazole was shown in samples from stools (100%), while isolates from foods (63.33%) and from environment (70%) had low susceptibility. All samples produced β-lactamases. The strains of B. cereus from all the three groups showed high rate of sensitivity to most tested antibiotics, except to tetracycline in samples from human stool and to trimethoprim-sulphamethoxazole in samples from food and environment. The production of β-lactamases was confirmed in all the strains.
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Purification of chitinase/chitosanase from Bacillus cereus and discovery of an enzyme inhibitor.
Liang, Tzu-Wen; Chen, Yue-Yin; Pan, Po-Shen; Wang, San-Lang
2014-02-01
A chitinase and a chitosanase were induced from a squid pen powder (SPP)-containing medium of Bacillus cereus TKU030 and purified by precipitation with ammonium sulphate and combined column chromatography. The purified chitinase and chitosanase exhibited optimum activity at 60 °C, pH 5-6 and 40 °C, pH 4, respectively. The chitinase and chitosanase were stable at 25-60 °C, pH 4-7 and 25-50 °C, pH 3-7, respectively. The chitinase and chitosanase showed the highest activity toward β-chitin and 60% DD chitosan, respectively. The chitinase was significantly inhibited by Mn(2+) and EDTA but activated by Cu(2+), Fe(2+) and Ca(2+). The chitosanase was significantly inhibited by Cu(2+), Fe(2+), Zn(2+), Mn(2+) and EDTA. The chitinase showed high stability in the presence of various surfactants, such as SDS, Tween 20, Tween 40 and Triton X-100. In contrast, these surfactants were inhibitors of the chitosanase. The chitinase and chitosanase were also inhibited by TKUPSP017, a small synthetic boron-containing molecule with a BF3K side-chain. However, TKUPSP017 enhanced the growth of B. cereus TKU030 in SPP-containing medium. Copyright © 2013 Elsevier B.V. All rights reserved.
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Chheda, Anuj H; Vernekar, Madhavi R
2015-10-01
Epsilon poly-L-lysine (ε-PL) is a homo-biopolymer with approximately 25-30 L-lysine residues. It is a promising natural biopolymer widely used in food and pharmaceutical industry. The present work reports enhanced production of ε-PL with a novel producer Bacillus cereus using amino acids and TCA cycle intermediates in the fermentation medium. Among the various amino acids and TCA cycle intermediates tested 2 mM L-aspartic acid and 5 mM citric acid gave ε-PL yield of 145.5 and 230 mg/L, respectively. A combination of citric acid after 24 h and L-aspartic acid after 36 h improved ε-PL yield from 85 mg/L (control) to 335 mg/L. Glucose feeding strategy along with metabolic precursors was employed which further enhanced ε-PL yield to 565 mg/L. Thus, more than sixfold increase in ε-PL yield was achieved suggesting the potential of Bacillus cereus as a novel ε-PL producer.
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Vasiee, Alireza; Behbahani, Behrooz Alizadeh; Yazdi, Farideh Tabatabaei; Moradi, Samira
2016-12-01
In this study, the screening of lipase positive bacteria from rice flour was carried out by Rhodamin B agar plate method. Bacillus cereus was identified by 16S rDNA method. Screening of the appropriate variables and optimization of the lipase production was performed using Plackett-Burman design (PBD) and response surface methodology (RSM). Among the isolated bacteria, an aerobic Bacillus cereus strain was recognized as the best lipase-producing bacteria (177.3 ± 20 U/ml). Given the results, the optimal enzyme production conditions were achieved with coriander seed extract (CSE)/yeast extract ratio of 16.9 w/w, olive oil (OO) and MgCl 2 concentration of 2.37 g/L and 24.23 mM, respectively. In these conditions, the lipase activity (LA) was predicted 343 U/mL that was approximately close to the predicted value (324 U/mL), which was increased 1.83 fold LA compared with the non-optimized lipase. The kinetic parameters of V max and K m for the lipase were measured 0.367 μM/min.mL and 5.3 mM, respectively. The lipase producing Bacillus cereus was isolated and RSM was used for the optimization of enzyme production. The CSE/yeast extract ratio of 16.9 w/w, OO concentration of 2.37 g/L and MgCl 2 concentration of 24.23 mM, were found to be the optimal conditions of the enzyme production process. LA at optimal enzyme production conditions was observed 1.83 times more than the non-optimal conditions. Ultimately, it can be concluded that the isolated B. cereus from rice flour is a proper source of lipase. Copyright © 2016 Elsevier Ltd. All rights reserved.
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USDA-ARS?s Scientific Manuscript database
The inhibition of Bacillus cereus spore germination and outgrowth in cooked rice by nine fruit and vegetable peel powders prepared from store-bought conventional (nonorganic) and organic apples, oranges, and potatoes was investigated. The powders were mixed into rice at 10% (wt/wt) along with heat ...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Doyle, J.J.; Marshall, R.T.; Pfander, W.H.
1975-01-01
Six species of microorganisms, Escherichia coli, Bacillus cereus, Lactobacillus acidophilus, Staphylococcus aureus, Streptococcus faecalis and Actinomyces niger, were grown under suitable conditions in appropriate media. Cadmium chloride was added to provide 0, 5, 10, 20, 40, and 80 ..mu..g of Cd per ml. At 40 and 80 ..mu..g of Cd per ml, E. coli and B. cereus grew well and the other species were repressed. Cd uptake patterns differed significantly among the species tested. The significance of these data with respect to Cd in food chains is discussed. 14 references, 3 tables.
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Gómez-Guzmán, Abril; Jiménez-Magaña, Sergio; Guerra-Rentería, A Suggey; Gómez-Hermosillo, César; Parra-Rodríguez, F Javier; Velázquez, Sergio; Aguilar-Uscanga, Blanca Rosa; Solis-Pacheco, Josue; González-Reynoso, Orfil
2017-07-01
In this research removal of NH 3 -N, NO 3 -N and PO 4 -P nutrients from municipal wastewater was studied, using Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and an artificial consortium of them. The objective is to analyze the performance of these microorganisms and their consortium, which has not been previously studied for nutrient removal in municipal wastewater. A model wastewater was prepared simulating the physicochemical characteristics found at the wastewater plant in Chapala, Mexico. Experiments were carried out without adding an external carbon source. Results indicate that nutrient removal with Chlorella vulgaris was the most efficient with a removal of 24.03% of NO 3 -N, 80.62% of NH 3 -N and 4.30% of PO 4 -P. With Bacillus cereus the results were 8.40% of NO 3 -N, 28.80% of NH 3 -N and 3.80% of PO 4 -P. The removals with Pseudomonas putida were 2.50% of NO 3 -N, 41.80 of NH 3 -N and 4.30% of PO 4 -P. The consortium of Chlorella vulgaris-Bacillus cereus-Pseudomonas putida removed 29.40% of NO 3 -N, 4.2% of NH 3 -N and 8.4% of PO 4 -P. The highest biomass production was with Bacillus cereus (450 mg/l) followed by Pseudomonas putida (444 mg/l), the consortium (205 mg/l) and Chlorella vulgaris (88.9 mg/l). This study highlights the utility of these microorganisms for nutrient removal in wastewater treatments.
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Endotrophic Calcium, Strontium, and Barium Spores of Bacillus megaterium and Bacillus cereus1
Foerster, Harold F.; Foster, J. W.
1966-01-01
Foerster, Harold F. (The University of Texas, Austin), and J. W. Foster. Endotrophic calcium, strontium, and barium spores of Bacillus megaterium and Bacillus cereus. J. Bacteriol. 91:1333–1345. 1966.—Spores were produced by washed vegetative cells suspended in deionized water supplemented with CaCl2, SrCl2, or BaCl2. Normal, refractile spores were produced in each case; a portion of the barium spores lost refractility and darkened. Thin-section electron micrographs revealed no apparent anatomical differences among the three types of spores. Analyses revealed that the different spore types were enriched specifically in the metal to which they were exposed during sporogenesis. The calcium content of the strontium and the barium spores was very small. From binary equimolar mixtures of the metal salts, endotrophic spores accumulated both metals to nearly the same extent. Viability of the barium spores was considerably less than that of the other two types. Strontium and barium spores were heat-resistant; however, calcium was essential for maximal heat resistance. Significant differences existed in the rates of germination; calcium spores germinated fastest, strontium spores were slower, and barium spores were slowest. Calcium-barium and calcium-strontium spores germinated readily. Endotrophic calcium and strontium spores germinated without the prior heat activation essential for growth spores. Chemical germination of the different metal-type spores with n-dodecylamine took place at the same relative rates as physiological germination. Heat-induced release of dipicolinic acid occurred much faster with barium and strontium spores than with calcium spores. The washed “coat fraction” from disrupted spores contained little of the spore calcium but most of the spore barium. The metal in this fraction was released by dilute acid. The demineralized coats reabsorbed calcium and barium at neutral pH. Images PMID:4956334
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NASA Astrophysics Data System (ADS)
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.
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Jun, Hyejung; Kim, Jinsol; Bang, Jihyun; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon
2013-01-01
A study was done to determine the potential use of plant extracts to inhibit the growth of Bacillus cereus in reconstituted infant rice cereal. A total of 2116 extracts were screened for inhibitory activity against B. cereus using an agar well diffusion assay. The minimal inhibitory concentrations (MIC) and minimal lethal concentrations (MLC) of 14 promising extracts in tryptic soy broth (TSB) were determined. Dryopteris erythrosora (autumn fern) root extract showed the lowest MIC (0.0156 mg/ml), followed by Siegesbeckia glabrescens (Siegesbeckia herb) leaf (0.0313 mg/ml), Morus alba (white mulberry) cortex (0.0313 mg/ml), Carex pumila (sand sedge) root (0.0625 mg/ml), and Citrus paradisi (grapefruit) seed (0.0625 mg/ml) extracts. The order of MLCs of extracts was D. erythrosora root (0.0156 mg/ml)
cereus in TSB were determined using a checkerboard assay. A combination of D. erythrosora and C. pumila extracts showed a partial synergistic inhibition, with a fractional inhibitory concentration index (FICI) of 0.75. Single and combined inhibitory activities of selected plant extracts against B. cereus in reconstituted infant rice cereal were investigated. The MICs of S. glabrescens, M. alba, D. erythrosora, and C. pumila extracts against B. cereus were 1.0, 2.0, 2.0, and 8.0mg/ml, respectively. A combination of D. erythrosora (1.00 mg/ml) and C. pumila (1.00 mg/ml) extracts showed a partial synergistic effect (FICI 0.63) in inhibiting the growth of B. cereus. Results indicate that by combining extracts, the amounts of D. erythrosora and C. pumila extracts can be reduced by 50% and 87.5%, respectively, compared with individual extracts, and give similar inhibitory activity in reconstituted infant rice cereal. Sensory evaluation showed that supplementing reconstituted -
Basit, Madiha; Rasool, Muhammad Hidayat; Naqvi, Syed Ali Raza; Waseem, Muhammad; Aslam, Bilal
2018-01-01
Present study was designed to evaluate the biosurfactant production potential by native strains of Bacillus cereus as well as determine their antimicrobial and antioxidant activities. The strains isolated from garden soil were characterized as B. cereus MMIC 1, MMIC 2 and MMIC 3. Biosurfactants were extracted as grey white precipitates. Optimum conditions for biosurfactant production were 37°C, the 7th day of incubation, 0.5% NaCl, pH 7.0. Moreover, corn steep liquor was the best carbon source. Biuret test, Thin Layer Chromatography (TLC), agar double diffusion and Fourier Transform Infrared Spectroscopy (FTIR) characterized the biosurfactants as cationic lipopeptides. Biosurfactants exhibited significant antibacterial and antifungal activity against S. aureus, E. coli, P. aeruginosa, K. pneumoniae, A. niger and C. albicans at 30 mg/ml. Moreover, they also possessed antiviral activity against NDV at 10 mg/ml. Cytotoxicity assay in BHK-21 cell lines revealed 63% cell survival at 10 mg/ml of biosurfactants and thus considered as safe. They also showed very good antioxidant activity by ferric-reducing activity and DPPH scavenging activity at 2 mg/ml. Consequently, the study offers an insight for the exploration of new bioactive molecules from the soil. It was concluded that lipopeptide biosurfactants produced from native strains of B. cereus may be recommended as safe antimicrobial, emulsifier and antioxidant agent.
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Vacuum distillation residue upgrading by an indigenous bacillus cereus
2013-01-01
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. PMID:24499629
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Vacuum distillation residue upgrading by an indigenous Bacillus cereus.
Tabatabaee, Mitra Sadat; Mazaheri Assadi, Mahnaz
2013-07-16
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. 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. Remarkable abilities of this microorganism propose its application in an ecofriendly technology to upgrade heavy crude oils.
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Friedman, Mendel; Henika, P R; Levin, C E; Mandrell, R E
2007-08-01
We have evaluated bactericidal activities against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica of several antimicrobial wine recipes, each consisting of red or white wine extracts of oregano leaves with added garlic juice and oregano oil. Dose-response plots were used to determine the percentage of the recipes that resulted in a 50% decrease in colony-forming units (CFU) at 60 min (BA(50)). Studies designed to optimize antibacterial activities of the recipes demonstrated that several combinations of the naturally occurring plant-derived ingredients rapidly inactivated the above mentioned 4 foodborne pathogens. We also showed that (a) incubation temperature affected activities in the following order: 37 degrees C > 21 degrees C > 4 degrees C; (b) varying the initial bacterial concentrations from 10(3) to 10(4) to 10(5) CFU/well did not significantly affect BA(50) values; (c) storage of 3 marinades up to 2 mo did not change their effectiveness against Salmonella enterica; and (d) polyphenolic compounds isolated by chromatography from red wine exhibited exceptional activity at nanogram levels against 2 strains of Bacillus cereus. These observations suggest that antimicrobial wine formulations have the potential to improve the microbiological safety of foods.
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Sudhaus, Nadine; Pina-Pérez, Maria Consuelo; Martínez, Antonio; Klein, Günter
2012-05-01
The purpose of this study was to assess the effect of a commercial peracetic acid-based disinfectant against spores of Bacillus cereus, to identify the most influential factor for the final number of microorganisms after different disinfection procedures, and to evaluate the nature of the inactivation kinetics. The spores of four different strains of B. cereus (DSM 318, 4312, 4313, and 4384) were treated with five different disinfectant concentrations (0.25%, 0.5%, 1.0%, 1.5%, and 2.0% [w/v]) at three different temperatures (10°C, 15°C, and 20°C) with or without protein load. A higher temperature and PES 15/23 concentration resulted in a higher inactivation. Inactivation of B. cereus strain 4312 was around 2 log₁₀ cycles at 10°C and around 7 log₁₀ at 20°C (conc=1% [w/v] PAA; t=60 min; without protein). The protein load at higher concentrations did not significantly reduce the efficacy of the disinfectant (p>0.05). This article indicates the applicability of the Weibull model to fit the B. cereus disinfectant survival curves. A Monte Carlo simulation was used to carry out a sensitivity analysis, which revealed the most influential factors affecting the final number of microorganisms after the disinfection process.
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Zhang, Zhihong; Tao, Xueying; Shah, Nagendra P; Wei, Hua
2016-04-01
Lactobacillus plantarum ZDY2013 is a potential probiotic isolated from fermented bean acid. In this study, we aimed to evaluate the in vitro antimicrobial activity of this organism against Bacillus cereus in milk fermentation, the antiadhesion ability on intestinal epithelial cells, as well as its ability to abrogate the cytotoxic effect and expression levels of genes. We found no antimicrobial activity produced by L. plantarum once the pH was adjusted to 6.0 and 7.0. The pH decreased continuously when L. plantarum and B. cereus were co-incubated during milk fermentation, which caused a decrease in the B. cereus counts. Antiadhesion assays showed that L. plantarum can significantly inhibit the adhesion of enterotoxin-producing B. cereus ATCC14579 and pathogenic B. cereus HN001 by inhibition, competition, and displacement. The supernatants of B. cereus, either alone or in conjunction with L. plantarum, caused damage to the membrane integrity of Caco-2 cells to release lactate dehydrogenase. In addition, L. plantarum tended to attenuate proinflammatory cytokine and oxidative stress gene expression on Caco-2 cells, inducing with B. cereus HN001 supernatants. This study provided systematic insights into the antagonistic effect of L. plantarum ZDY2013, and the information may be helpful to explore potential control measures for preventing food poisoning by lactic acid bacteria. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
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Rigourd, V; Barnier, J P; Ferroni, A; Nicloux, M; Hachem, T; Magny, J F; Lapillonne, A; Frange, P; Nassif, X; Bille, E
2018-05-03
Three cases of Bacillus cereus infection or colonization occurred in the same region in France, and milk from the milk bank was suspected as a possible common source of contamination. All Batches delivered to the three cases complied with the requirements of the bacteriological reference method recommended by good practices guidelines. Still, a retrospective analysis with a more sensitive method showed one batch to contain B. cereus, however straincomparison revealed no epidemiological link betweenisolates from patients and those from the milk. Consequently, in accordance with the precautionary principle, we developed a new sensitive method for the screening of pasteurized milk for pathogenic bacteria. From January 1 to August 31, 2017, 2526 samples of pasteurized milk were prospectively included in the study. We showed that a 20 mL sample of pasteurized milk incubated for 18 h at 37 °C under aerobic conditions was favoring the detection of B. Cereus. The nonconformity rate was 6.3% for the reference method and 12.6% for the improved method (p < 0.0001). Nonconformity was due to the presence of B. cereus in 88.5% of cases for the improved method and 53% of cases for the reference method (p < 0.0001). Thus our new method is improves the microbiological safety of the product distributed and only moderately increases the rate of bacteriological nonconformity .
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Fajardo, C; Saccà, M L; Martinez-Gomariz, M; Costa, G; Nande, M; Martin, M
2013-10-01
Nanosized zero valent iron (nZVI) is emerging as an option for treating contaminated soil and groundwater even though the potentially toxic impact exerted by nZVI on soil microorganisms remains uncertain. In this work, we focus on nanotoxicological studies performed in vitro using commercial nZVI and one common soil bacterium (Bacillus cereus). Results showed a negative impact of nZVI on B. cereus growth capability, consistent with the entrance of cells in an early sporulation stage, observed by TEM. Despite no changes at the transcriptional level are detected in genes of particular relevance in cellular activity (narG, nirS, pykA, gyrA and katB), the proteomic approach used highlights differentially expressed proteins in B. cereus under nZVI exposure. We demonstrate that proteins involved in oxidative stress-response and tricarboxilic acid cycle (TCA) modulation are overexpressed; moreover proteins involved in motility and wall biosynthesis are repressed. Our results enable to detect a molecular-level response as early warning signal, providing new insight into first line defense response of a soil bacterium after nZVI exposure. Copyright © 2013 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Sawei, Jelin; Sani, Norrakiah Abdullah
2016-11-01
Bacillus cereus is a spore-forming, facultative anaerobic, motile microorganism that has been identified as a causative agent of two types of gastrointestinal diseases such as emetic and diarrhea. This foodborne pathogen is found in both vegetative cells and endospores form in foods such as rice either raw or cooked. The aim of this study is to investigate and determine the prevalence, characterize and identify the isolation of vegetative cells and endospores of B. cereus in thirty varieties (n=3) of raw rice from Sabah, Sarawak and Peninsular Malaysia. A total of 90 (n=90) raw rice were examined and 84 (93.33%) samples were positive to vegetative cells of B. cereus. However, only 32 (35.56%) samples were positive for endospore cells that able to germinate after samples were heated at 75°C for 15 mins. The mean log cfu/g for vegetative cells were higher range (0.00 - 4.1533) than visible endospores (0.00 - 3.7533 mean log cfu/g). Sample of raw red rice (UKMRC9) had significantly higher contamination by both vegetative cells and endospores at p<0.05, than the other raw rice samples.
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Thiopeptide antibiotics stimulate biofilm formation in Bacillus subtilis.
Bleich, Rachel; Watrous, Jeramie D; Dorrestein, Pieter C; Bowers, Albert A; Shank, Elizabeth A
2015-03-10
Bacteria have evolved the ability to produce a wide range of structurally complex natural products historically called "secondary" metabolites. Although some of these compounds have been identified as bacterial communication cues, more frequently natural products are scrutinized for antibiotic activities that are relevant to human health. However, there has been little regard for how these compounds might otherwise impact the physiology of neighboring microbes present in complex communities. Bacillus cereus secretes molecules that activate expression of biofilm genes in Bacillus subtilis. Here, we use imaging mass spectrometry to identify the thiocillins, a group of thiazolyl peptide antibiotics, as biofilm matrix-inducing compounds produced by B. cereus. We found that thiocillin increased the population of matrix-producing B. subtilis cells and that this activity could be abolished by multiple structural alterations. Importantly, a mutation that eliminated thiocillin's antibiotic activity did not affect its ability to induce biofilm gene expression in B. subtilis. We go on to show that biofilm induction appears to be a general phenomenon of multiple structurally diverse thiazolyl peptides and use this activity to confirm the presence of thiazolyl peptide gene clusters in other bacterial species. Our results indicate that the roles of secondary metabolites initially identified as antibiotics may have more complex effects--acting not only as killing agents, but also as specific modulators of microbial cellular phenotypes.
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Thiopeptide antibiotics stimulate biofilm formation in Bacillus subtilis
Bleich, Rachel; Watrous, Jeramie D.; Dorrestein, Pieter C.; Bowers, Albert A.; Shank, Elizabeth A.
2015-01-01
Bacteria have evolved the ability to produce a wide range of structurally complex natural products historically called “secondary” metabolites. Although some of these compounds have been identified as bacterial communication cues, more frequently natural products are scrutinized for antibiotic activities that are relevant to human health. However, there has been little regard for how these compounds might otherwise impact the physiology of neighboring microbes present in complex communities. Bacillus cereus secretes molecules that activate expression of biofilm genes in Bacillus subtilis. Here, we use imaging mass spectrometry to identify the thiocillins, a group of thiazolyl peptide antibiotics, as biofilm matrix-inducing compounds produced by B. cereus. We found that thiocillin increased the population of matrix-producing B. subtilis cells and that this activity could be abolished by multiple structural alterations. Importantly, a mutation that eliminated thiocillin’s antibiotic activity did not affect its ability to induce biofilm gene expression in B. subtilis. We go on to show that biofilm induction appears to be a general phenomenon of multiple structurally diverse thiazolyl peptides and use this activity to confirm the presence of thiazolyl peptide gene clusters in other bacterial species. Our results indicate that the roles of secondary metabolites initially identified as antibiotics may have more complex effects—acting not only as killing agents, but also as specific modulators of microbial cellular phenotypes. PMID:25713360
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Prakash, S; Rajeswari, K; Divya, P; Ferlin, M; Rajeshwari, C T; Vanavil, B
2018-05-28
Curdlan gum is a neutral water-insoluble bacterial exopolysaccharide composed primarily of linear β-(1,3) glycosidic linkages. Recently, there has been increasing interest in the applications of curdlan and its derivatives. Curdlan is found to inhibit tumors and its sulfated derivative possess anti-HIV activity. Curdlan is biodegradable, non-toxic towards human, environment and edible which makes it suitable as drug-delivery vehicles for sustained drug release. The increasing demand for the growing applications of curdlan requires an efficient high yield fermentation production process so as to satisfy the industrial needs. In this perspective, the present work is aimed to screen and isolate an efficient curdlan gum producing bacteria from rhizosphere of ground nut plant using aniline-blue agar. High yielding isolate was selected based on curdlan yield and identified as Bacillus cereus using gas-chromatography fatty acid methyl ester analysis. B. cereus PR3 curdlan gum was characterized using FT-IR spectroscopy, SEM, XRD and TGA. Fermentation time for curdlan production using B. cereus PR3 was optimized. Media constituents like carbon, nitrogen and mineral sources were screened using Plackett-Burman design. Subsequent statistical analysis revealed that Starch, NH 4 NO 3 , K 2 HPO 4 , Na 2 SO 4 , KH 2 SO 4 and CaCl 2 were significant media constituents and these concentrations were optimized for enhancement of curdlan production up to 20.88 g/l.
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Buisson, Christophe; Daou, Nadine; Kallassy, Mireille; Lereclus, Didier; Arosio, Paolo; Bou-Abdallah, Fadi; Nielsen Le Roux, Christina
2014-01-01
In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis. PMID:24550730
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Binding Affinity of Glycoconjugates to BACILLUS Spores and Toxins
NASA Astrophysics Data System (ADS)
Rasol, Aveen; Eassa, Souzan; Tarasenko, Olga
2010-04-01
Early recognition of Bacillus cereus group species is important since they can cause food-borne illnesses and deadly diseases in humans. Glycoconjugates (GCs) are carbohydrates covalently linked to non-sugar moieties including lipids, proteins or other entities. GCs are involved in recognition and signaling processes intrinsic to biochemical functions in cells. They also stimulate cell-cell adhesion and subsequent recognition and activation of receptors. We have demonstrated that GCs are involved in Bacillus cereus spore recognition. In the present study, we have investigated whether GCs possess the ability to bind and recognize B. cereus spores and Bacillus anthracis recombinant single toxins (sTX) and complex toxins (cTX). The affinity of GCs to spores + sTX and spores + cTX toxins was studied in the binding essay. Our results demonstrated that GC9 and GC10 were able to selectively bind to B. cereus spores and B. anthracis toxins. Different binding affinities for GCs were found toward Bacillus cereus spores + sTX and spores + cTX. Dilution of GCs does not impede the recognition and binding. Developed method provides a tool for simultaneous recognition and targeting of spores, bacteria toxins, and/or other entities.
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Diomandé, Sara Esther; Nguyen-the, Christophe; Abee, Tjakko; Tempelaars, Marcel H; Broussolle, Véronique; Brillard, Julien
2015-11-20
Bacillus cereus sensu lato is composed of a set of ubiquitous strains including human pathogens that can survive a range of food processing conditions, grow in refrigerated food, and sometimes cause food poisoning. We previously identified the two-component system CasK/R that plays a key role in cold adaptation. To better understand the CasK/R-controlled mechanisms that support low-temperature adaptation, we performed a transcriptomic analysis on the ATCC 14579 strain and its isogenic ∆casK/R mutant grown at 12°C. Several genes involved in fatty acid (FA) metabolism were downregulated in the mutant, including desA and desB encoding FA acyl-lipid desaturases that catalyze the formation of a double-bond on the FA chain in positions ∆5 and ∆10, respectively. A lower proportion of FAs presumably unsaturated by DesA was observed in the ΔcasK/R strain compared to the parental strain while no difference was found for FAs presumably unsaturated by DesB. Addition of phospholipids from egg yolk lecithin rich in unsaturated FAs, to growth medium, abolished the cold-growth impairment of ΔcasK/R suggesting that exogenous unsaturated FAs can support membrane-level modifications and thus compensate for the decreased production of these FAs in the B. cereus ∆casK/R mutant during growth at low temperature. Our findings indicate that CasK/R is involved in the regulation of FA metabolism, and is necessary for cold adaptation of B. cereus unless an exogenous source of unsaturated FAs is available. Copyright © 2015 Elsevier B.V. All rights reserved.
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Influence of Structural Properties and Kinetic Constraints on Bacillus cereus Growth
Stecchini, Mara Lucia; Del Torre, Manuela; Sarais, Ileana; Saro, Onorio; Messina, Mariella; Maltini, Enrico
1998-01-01
The influence of structural properties and kinetic constraints on the behavior of Bacillus cereus was investigated on agar media. Dimensional criteria were used to study the growth in bacterial colonies. The architecture of the agar gel as modified by the agar content was found to influence the colony size, and smaller colonies were observed on media containing 50 to 70 g of agar liter−1. Except at low nutrient levels, colonies responded to nutrient gradients by decreasing in size the farther away they were from the nutrient source, and the decrease in colony size was influenced by the agar content. The diffusivities of glucose and a protein (insulin-like growth factor) were not affected by the gel architecture, suggesting that other factors, such as mechanical factors, could influence microbial growth in the agar systems used. Increasing the viscosity of the liquid phase of the agar media by adding polyvinylpyrrolidone resulted in a reduction in colony size. When the agar concentration was increased, the colony areas were not influenced by the viscosity of the system. PMID:9501447
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Dynamic Predictive Model for Growth of Bacillus cereus from Spores in Cooked Beans.
Juneja, Vijay K; Mishra, Abhinav; Pradhan, Abani K
2018-02-01
Kinetic growth data for Bacillus cereus grown from spores were collected in cooked beans under several isothermal conditions (10 to 49°C). Samples were inoculated with approximately 2 log CFU/g heat-shocked (80°C for 10 min) spores and stored at isothermal temperatures. B. cereus populations were determined at appropriate intervals by plating on mannitol-egg yolk-polymyxin agar and incubating at 30°C for 24 h. Data were fitted into Baranyi, Huang, modified Gompertz, and three-phase linear primary growth models. All four models were fitted to the experimental growth data collected at 13 to 46°C. Performances of these models were evaluated based on accuracy and bias factors, the coefficient of determination ( R 2 ), and the root mean square error. Based on these criteria, the Baranyi model best described the growth data, followed by the Huang, modified Gompertz, and three-phase linear models. The maximum growth rates of each primary model were fitted as a function of temperature using the modified Ratkowsky model. The high R 2 values (0.95 to 0.98) indicate that the modified Ratkowsky model can be used to describe the effect of temperature on the growth rates for all four primary models. The acceptable prediction zone (APZ) approach also was used for validation of the model with observed data collected during single and two-step dynamic cooling temperature protocols. When the predictions using the Baranyi model were compared with the observed data using the APZ analysis, all 24 observations for the exponential single rate cooling were within the APZ, which was set between -0.5 and 1 log CFU/g; 26 of 28 predictions for the two-step cooling profiles also were within the APZ limits. The developed dynamic model can be used to predict potential B. cereus growth from spores in beans under various temperature conditions or during extended chilling of cooked beans.
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Pajohi, Mohamad Reza; Tajik, Hossein; Farshid, Amir Abbas; Basti, Afshin Akhondzadeh; Hadian, Mojtaba
2011-02-01
In the face of emerging new pathogens and ever-growing health-conscious customers, food preservation technology remains on the top agenda of food industry. This study was aimed at determining the effects of the essential oil of Mentha longifolia L., alone and in combination with nisin, on Bacillus cereus and Bacillus subtilis at 8°C and 25°C in a food model (commercial barley soup) during 15 days. The essential oil alone at 8°C inhibited bacterial growth significantly compared with the control (p < 0.05). However, at 25°C, none of the concentrations of the essential oil alone showed inhibitory effect on bacterial growth. At 8°C, the combination effect of the essential oil and nisin on bacteria was noted at 0.25 μg mL(-1) for nisin and 0.05 μL mL(-1) for the essential oil (p < 0.05). The combination of nisin and the essential oil demonstrated significant inhibitory effects on the vegetative forms of bacteria at 25°C, although it was comparable to that of nisin alone at the same concentrations. Electron microscopy studies revealed a great deal of damage to B. cereus treated with a combination of nisin and the essential oil. However, the combination of nisin with the essential oil led to a complete destruction of cell wall and cytoplasm of vegetative cells of B. subtilis.
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Zhao, Yancui; Yuan, Lei; Wan, Junli; Sun, Zhenxing; Wang, Yiyan; Sun, Hushan
2016-02-01
This study was conducted to determine effects of potential probiotic Bacillus cereus EN25 (isolated from mud of sea cucumber culturing water bodies) on growth, immunity and disease resistance against Vibrio splendidus infection in juvenile sea cucumbers Apostichopus japonicus. Animals were respectively fed diets with B. cereus EN25 at 0 (control), 10(5), 10(7) and 10(9) CFU/g for 30 days. Results showed that dietary B. cereus EN25 had no significant effects on growth, total coelomocytes counts and acid phosphatase activity of A. japonicus (P > 0.05). Dietary EN25 at 10(7) CFU/g had significantly improved the phagocytosis, respiratory burst activity and total nitric oxide synthase activity of animals (P < 0.05). Compared to control, dietary EN25 at 10(5) or 10(7) CFU/g had no significant effects on superoxide dismutase activity of A. japonicus (P > 0.05), whereas dietary EN25 at 10(9) CFU/g had significantly decreased its activity (P < 0.05). The cumulative mortality after V. splendidus challenge decreased significantly in sea cucumbers fed with EN25 at 10(7) CFU/g (P < 0.05). The present study confirmed dietary B. cereus EN25 at 10(7) CFU/g could significantly improve immunity and disease resistance in juvenile A. japonicus. Copyright © 2015 Elsevier Ltd. All rights reserved.
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In vitro susceptibility of Bacillus spp. to selected antimicrobial agents.
Weber, D J; Saviteer, S M; Rutala, W A; Thomann, C A
1988-01-01
Although often dismissed as contaminants when isolated from blood cultures, Bacillus spp. are increasingly recognized as capable of causing serious systemic infections. As part of a clinical-microbiological study, 89 strains of Bacillus spp. isolated from clinical blood cultures between 1981 and 1985 had their species determined and were tested for antimicrobial agent susceptibility to 18 antibiotics. Species of isolates were determined by the API 50CH and API 20E systems. Bacillus cereus (54 strains) was the most common species isolated, followed by B. megaterium (13 strains), B. polymyxa (5 strains), B. pumilus (4 strains), B. subtilis (4 strains), B. circulans (3 strains), B. amyloliquefaciens (2 strains), B. licheniformis (1 strain), and Bacillus spp. (3 strains). Microdilution MIC susceptibility tests revealed all B. cereus strains to be susceptible to imipenem, vancomycin, chloramphenicol, gentamicin, and ciprofloxacin. Non-B. cereus strains were most susceptible to imipenem, vancomycin, LY146032, and ciprofloxacin. Disk susceptibility testing suggested that B. cereus was rarely susceptible to penicillins, semisynthetic penicillins, or cephalosporins with the exception of mezlocillin. In contrast, many non-B. cereus strains were susceptible to penicillins, semisynthetic penicillins, and cephalosporins, but marked variability was noted among species. PMID:3395100
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Prüß, Birgit M.; Francis, Kevin P.; von Stetten, Felix; Scherer, Siegfried
1999-01-01
Sequences of the 16S ribosomal DNA (rDNA) from psychrotolerant and mesophilic strains of the Bacillus cereus group revealed signatures which were specific for these two thermal groups of bacteria. Further analysis of the genomic DNA from a wide range of food and soil isolates showed that B. cereus group strains have between 6 and 10 copies of 16S rDNA. Moreover, a number of these environmental strains have both rDNA operons with psychrotolerant signatures and rDNA operons with mesophilic signatures. The ability of these isolates to grow at low temperatures correlates with the prevalence of rDNA operons with psychrotolerant signatures, indicating specific nucleotides within the 16S rRNA to play a role in psychrotolerance. PMID:10198030
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Compensatory Evolution of Intrinsic Transcription Terminators in Bacillus Cereus
Safina, Ksenia R.; Mironov, Andrey A.
2017-01-01
Many RNA molecules possess complicated secondary structure critical to their function. Mutations in double-helical regions of RNA may disrupt Watson–Crick (WC) interactions causing structure destabilization or even complete loss of function. Such disruption can be compensated by another mutation restoring base pairing, as has been shown for mRNA, rRNA and tRNA. Here, we investigate the evolution of intrinsic transcription terminators between closely related strains of Bacillus cereus. While the terminator structure is maintained by strong natural selection, as evidenced by the low frequency of disrupting mutations, we observe multiple instances of pairs of disrupting-compensating mutations in RNA structure stems. Such two-step switches between different WC pairs occur very fast, consistent with the low fitness conferred by the intermediate non-WC variant. Still, they are not instantaneous, and probably involve transient fixation of the intermediate variant. The GU wobble pair is the most frequent intermediate, and remains fixed longer than other intermediates, consistent with its less disruptive effect on the RNA structure. Double switches involving non-GU intermediates are more frequent at the ends of RNA stems, probably because they are associated with smaller fitness loss. Together, these results show that the fitness landscape of bacterial transcription terminators is rather rugged, but that the fitness valleys associated with unpaired stem nucleotides are rather shallow, facilitating evolution. PMID:28201729
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Stanford, K; Reuter, T; Gilroyed, B H; McAllister, T A
2015-04-01
To investigate impact of sporulation and compost temperatures on feasibility of composting for disposal of carcasses contaminated with Bacillus anthracis. Two strains of B. cereus, 805 and 1391, were sporulated at either 20 or 37°C (Sporulation temperature, ST) and 7 Log10 CFU g(-1) spores added to autoclaved manure in nylon bags (pore size 50 μm) or in sealed vials. Vials and nylon bags were embedded into compost in either a sawdust or manure matrix each containing 16 bovine mortalities (average weight 617 ± 33 kg), retrieved from compost at intervals over 217 days and survival of B. cereus spores assessed. A ST of 20°C decreased spore survival by 1·4 log10 CFU g(-1) (P < 0·05) compared to a 37°C ST. Spore survival was strain dependent. Compost temperatures >55°C reduced spore survival (P < 0·05) and more frequently occurred in the sawdust matrix. Sporulation and compost temperatures were key factors influencing survival of B. cereus spores in mortality compost. Composting may be most appropriate for the disposal of carcasses infected with B. anthracis at ambient temperatures ≤20°C under thermophillic composting conditions (>55°C). © 2015 The Society for Applied Microbiology.
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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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Han, Jinzhi; Gao, Peng; Zhao, Shengming; Bie, Xiaomei; Lu, Zhaoxin; Zhang, Chong; Lv, Fengxia
2017-01-06
LI-F type peptides (AMP-jsa9) produced by Paenibacillus polymyxa JSa-9 are a group of cyclic lipodepsipeptide antibiotics that exhibit a broad antimicrobial spectrum against Gram-positive bacteria and filamentous fungi, especially Bacillus cereus and Fusarium moniliforme. In this study, to better understand the antibacterial mechanism of AMP-jsa9 against B. cereus, the ultrastructure of AMP-jsa9-treated B. cereus cells was observed by both atomic force microscopy and transmission electron microscopy, and quantitative proteomic analysis was performed on proteins extracted from treated and untreated bacterial cells by using isobaric tag for relative and absolute quantitation (iTRAQ) labeling and LC-MS/MS analysis to access differentially expressed proteins. Furthermore, multiple experiments were conducted to validate the results of the proteomic analysis, including determinations of ATP, NAD (+) H, NADP (+) H, reactive oxygen species (ROS), the activities of catalase (CAT) and superoxide dismutase (SOD), and the relative expression of target genes by quantitative real-time PCR. Bacterial cells exposed to AMP-jsa9 showed irregular surfaces with bleb projections and concaves; we hypothesize that AMP-jsa9 penetrated the cell wall and was anchored on the cytoplasmic membrane and that ROS accumulated in the cell membrane after treatment with AMP-jsa9, modulating the bacterial membrane properties and increasing membrane permeability. Consequently, the blebs were formed on the cell wall by the impulsive force of the leakage of intercellular contents. iTRAQ-based proteomic analysis detected a total of 1317 proteins, including 176 differentially expressed proteins (75 upregulated (fold >2) and 101 downregulated (fold <0.5)). Based on proteome analysis, the putative pathways of AMP-jsa9 action against B. cereus can be summarized as: (i) inhibition of bacterial sporulation, thiamine biosynthesis, energy metabolism, DNA transcription and translation, and cell wall biosynthesis
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Bressuire-Isoard, Christelle; Bornard, Isabelle; Henriques, Adriano O; Carlin, Frédéric; Broussolle, Véronique
2016-01-01
The Bacillus cereus spore surface layers consist of a coat surrounded by an exosporium. We investigated the interplay between the sporulation temperature and the CotE morphogenetic protein in the assembly of the surface layers of B. cereus ATCC 14579 spores and on the resulting spore properties. The cotE deletion affects the coat and exosporium composition of the spores formed both at the suboptimal temperature of 20°C and at the optimal growth temperature of 37°C. Transmission electron microscopy revealed that ΔcotE spores had a fragmented and detached exosporium when formed at 37°C. However, when produced at 20°C, ΔcotE spores showed defects in both coat and exosporium attachment and were susceptible to lysozyme and mutanolysin. Thus, CotE has a role in the assembly of both the coat and exosporium, which is more important during sporulation at 20°C. CotE was more represented in extracts from spores formed at 20°C than at 37°C, suggesting that increased synthesis of the protein is required to maintain proper assembly of spore surface layers at the former temperature. ΔcotE spores formed at either sporulation temperature were impaired in inosine-triggered germination and resistance to UV-C and H2O2 and were less hydrophobic than wild-type (WT) spores but had a higher resistance to wet heat. While underscoring the role of CotE in the assembly of B. cereus spore surface layers, our study also suggests a contribution of the protein to functional properties of additional spore structures. Moreover, it also suggests a complex relationship between the function of a spore morphogenetic protein and environmental factors such as the temperature during spore formation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
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Senouci-Rezkallah, Khadidja; Jobin, Michel P; Schmitt, Philippe
2015-01-01
This study examined the involvement of ATPase activity in the acid tolerance response (ATR) of Bacillus cereus ATCC14579 strain. In the current work, B. cereus cells were grown in anaerobic chemostat culture at external pH (pHe) 7.0 or 5.5 and at a growth rate of 0.2 h−1. Population reduction and internal pH (pHi) after acid shock at pH 4.0 was examined either with or without ATPase inhibitor N,N’-dicyclohexylcarbodiimide (DCCD) and ionophores valinomycin and nigericin. Population reduction after acid shock at pH 4.0 was strongly limited in cells grown at pH 5.5 (acid-adapted cells) compared with cells grown at pH 7.0 (unadapted cells), indicating that B. cereus cells grown at low pHe were able to induce a significant ATR and Exercise-induced increase in ATPase activity. However, DCCD and ionophores had a negative effect on the ability of B. cereus cells to survive and maintain their pHi during acid shock. When acid shock was achieved after DCCD treatment, pHi was markedly dropped in unadapted and acid-adapted cells. The ATPase activity was also significantly inhibited by DCCD and ionophores in acid-adapted cells. Furthermore, transcriptional analysis revealed that atpB (ATP beta chain) transcripts was increased in acid-adapted cells compared to unadapted cells before and after acid shock. Our data demonstrate that B. cereus is able to induce an ATR during growth at low pH. These adaptations depend on the ATPase activity induction and pHi homeostasis. Our data demonstrate that the ATPase enzyme can be implicated in the cytoplasmic pH regulation and in acid tolerance of B. cereus acid-adapted cells. PMID:25740257
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Beuchat, L R; Clavero, M R; Jaquette, C B
1997-05-01
The presence of psychrotrophic enterotoxigenic Bacillus cereus in ready-to-serve meats and meat products that have not been subjected to sterilization treatment is a public health concern. A study was undertaken to determine the survival, growth, and diarrheal enterotoxin production characteristics of four strains of psychrotrophic B. cereus in brain heart infusion (BHI) broth and beef gravy as affected by temperature and supplementation with nisin. A portion of unheated vegetative cells from 24-h BHI broth cultures was sensitive to nisin as evidenced by an inability to form colonies on BHI agar containing 10 micrograms of nisin/ml. Heat-stressed cells exhibited increased sensitivity to nisin. At concentrations as low as 1 microgram/ml, nisin was lethal to B. cereus, the effect being more pronounced in BHI broth than in beef gravy. The inhibitory effect of nisin (1 microgram/ml) was greater on vegetative cells than on spores inoculated into beef gravy and was more pronounced at 8 degrees C than at 15 degrees C. Nisin, at a concentration of 5 or 50 micrograms/ml, inhibited growth in gravy inoculated with vegetative cells and stored at 8 or 15 degrees C, respectively, for 14 days. Growth of vegetative cells and spores of B. cereus after an initial period of inhibition is attributed to loss of activity of nisin. One of two test strains produced diarrheal enterotoxin in gravy stored at 8 or 15 degrees C within 9 or 3 days, respectively. Enterotoxin production was inhibited in gravy supplemented with 1 microgram of nisin/ml and stored at 8 degrees C for 14 days; 5 micrograms of nisin/ml was required for inhibition at 15 degrees C. Enterotoxin was not detected in gravy in which less than 5.85 log10 CFU of B. cereus/ml had grown. Results indicate that as little as 1 microgram of nisin/ml may be effective in inhibiting or retarding growth of and diarrheal enterotoxin production by vegetative cells and spores of psychrotrophic B. cereus in beef gravy at 8 degrees C, a
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Beuchat, L R; Clavero, M R; Jaquette, C B
1997-01-01
The presence of psychrotrophic enterotoxigenic Bacillus cereus in ready-to-serve meats and meat products that have not been subjected to sterilization treatment is a public health concern. A study was undertaken to determine the survival, growth, and diarrheal enterotoxin production characteristics of four strains of psychrotrophic B. cereus in brain heart infusion (BHI) broth and beef gravy as affected by temperature and supplementation with nisin. A portion of unheated vegetative cells from 24-h BHI broth cultures was sensitive to nisin as evidenced by an inability to form colonies on BHI agar containing 10 micrograms of nisin/ml. Heat-stressed cells exhibited increased sensitivity to nisin. At concentrations as low as 1 microgram/ml, nisin was lethal to B. cereus, the effect being more pronounced in BHI broth than in beef gravy. The inhibitory effect of nisin (1 microgram/ml) was greater on vegetative cells than on spores inoculated into beef gravy and was more pronounced at 8 degrees C than at 15 degrees C. Nisin, at a concentration of 5 or 50 micrograms/ml, inhibited growth in gravy inoculated with vegetative cells and stored at 8 or 15 degrees C, respectively, for 14 days. Growth of vegetative cells and spores of B. cereus after an initial period of inhibition is attributed to loss of activity of nisin. One of two test strains produced diarrheal enterotoxin in gravy stored at 8 or 15 degrees C within 9 or 3 days, respectively. Enterotoxin production was inhibited in gravy supplemented with 1 microgram of nisin/ml and stored at 8 degrees C for 14 days; 5 micrograms of nisin/ml was required for inhibition at 15 degrees C. Enterotoxin was not detected in gravy in which less than 5.85 log10 CFU of B. cereus/ml had grown. Results indicate that as little as 1 microgram of nisin/ml may be effective in inhibiting or retarding growth of and diarrheal enterotoxin production by vegetative cells and spores of psychrotrophic B. cereus in beef gravy at 8 degrees C, a
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Inhibition of toxicogenic Bacillus cereus in rice-based foods by enterocin AS-48.
Grande, Maria J; Lucas, Rosario; Abriouel, Hikmate; Valdivia, Eva; Omar, Nabil Ben; Maqueda, Mercedes; Martínez-Bueno, Manuel; Martínez-Cañamero, Magdalena; Gálvez, Antonio
2006-02-01
The antimicrobial effect of the broad-spectrum bacteriocin enterocin AS-48 against the toxicogenic psychrotrophic strain Bacillus cereus LWL1 has been investigated in a model food system consisting of boiled rice and in a commercial infant rice-based gruel dissolved in whole milk stored at temperatures of 37 degrees C, 15 degrees C and 6 degrees C. In food samples supplemented with enterocin AS-48 (in a concentration range of 20-35 mug/ml), viable cell counts decreased rapidly over incubation time, depending on the bacteriocin concentration, the temperature of incubation and the food sample. Enterotoxin production at 37 degrees C was also inhibited. Heat sensitivity of endospores increased markedly in food samples supplemented with enterocin AS-48: inactivation of endospores was achieved by heating for 1 min at 90 degrees C in boiled rice or at 95 degrees C in rice-based gruel. Activity of enterocin AS-48 in rice gruel was potentiated by sodium lactate in a concentration-dependent way.
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Ryu, Jee-Hoon; Beuchat, Larry R
2005-12-01
Biofilm formation by Bacillus cereus 038-2 on stainless steel coupons, sporulation in the biofilm as affected by nutrient availability, temperature, and relative humidity, and the resistance of vegetative cells and spores in biofilm to sanitizers were investigated. Total counts in biofilm formed on coupons immersed in tryptic soy broth (TSB) at 12 and 22 degrees C consisted of 99.94% of vegetative cells and 0.06% of spores. Coupons on which biofilm had formed were immersed in TSB or exposed to air with 100, 97, 93, or 85% relative humidity. Biofilm on coupons immersed in TSB at 12 degrees C for an additional 6 days or 22 degrees C for an additional 4 days contained 0.30 and 0.02% of spores, respectively, whereas biofilm exposed to air with 100 or 97% relative humidity at 22 degrees C for 4 days contained 10 and 2.5% of spores, respectively. Sporulation did not occur in biofilm exposed to 93 or 85% relative humidity at 22 degrees C. Treatment of biofilm on coupons that had been immersed in TSB at 22 degrees C with chlorine (50 microg/ml), chlorine dioxide (50 microg/ml), and a peroxyacetic acid-based sanitizer (Tsunami 200, 40 microg/ml) for 5 min reduced total cell counts (vegetative cells plus spores) by 4.7, 3.0, and 3.8 log CFU per coupon, respectively; total cell counts in biofilm exposed to air with 100% relative humidity were reduced by 1.5, 2.4, and 1.1 log CFU per coupon, respectively, reflecting the presence of lower numbers of vegetative cells. Spores that survived treatment with chlorine dioxide had reduced resistance to heat. It is concluded that exposure of biofilm formed by B. cereus exposed to air at high relative humidity (> or =97%) promotes the production of spores. Spores and, to a lesser extent, vegetative cells embedded in biofilm are protected against inactivation by sanitizers. Results provide new insights to developing strategies to achieve more effective sanitation programs to minimize risks associated with B. cereus in biofilm formed on
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Ehrhardt, Christopher J; Chu, Vivian; Brown, TeeCie; Simmons, Terrie L; Swan, Brandon K; Bannan, Jason; Robertson, James M
2010-03-01
The goal of this study was to determine if cellular fatty acid methyl ester (FAME) profiling could be used to distinguish among spore samples from a single species (Bacillus cereus T strain) that were prepared on 10 different medium formulations. To analyze profile differences and identify FAME biomarkers diagnostic for the chemical constituents in each sporulation medium, a variety of statistical techniques were used, including nonmetric multidimensional scaling (nMDS), analysis of similarities (ANOSIM), and discriminant function analysis (DFA). The results showed that one FAME biomarker, oleic acid (18:1 omega9c), was exclusively associated with spores grown on Columbia agar supplemented with sheep blood and was indicative of blood supplements that were present in the sporulation medium. For spores grown in other formulations, multivariate comparisons across several FAME biomarkers were required to discern profile differences. Clustering patterns in nMDS plots and R values from ANOSIM revealed that dissimilarities among FAME profiles were most pronounced when spores grown with disparate sources of complex additives or protein supplements were compared (R > 0.8), although other factors also contributed to FAME differences. DFA indicated that differentiation could be maximized with a targeted subset of FAME variables, and the relative contributions of branched FAME biomarkers to group dissimilarities changed when different media were compared. When taken together, these analyses indicate that B. cereus spore samples grown in different media can be resolved with FAME profiling and that this may be a useful technique for providing intelligence about the production methods of Bacillus organisms in a forensic investigation.
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Ehrhardt, Christopher J.; Chu, Vivian; Brown, TeeCie; Simmons, Terrie L.; Swan, Brandon K.; Bannan, Jason; Robertson, James M.
2010-01-01
The goal of this study was to determine if cellular fatty acid methyl ester (FAME) profiling could be used to distinguish among spore samples from a single species (Bacillus cereus T strain) that were prepared on 10 different medium formulations. To analyze profile differences and identify FAME biomarkers diagnostic for the chemical constituents in each sporulation medium, a variety of statistical techniques were used, including nonmetric multidimensional scaling (nMDS), analysis of similarities (ANOSIM), and discriminant function analysis (DFA). The results showed that one FAME biomarker, oleic acid (18:1 ω9c), was exclusively associated with spores grown on Columbia agar supplemented with sheep blood and was indicative of blood supplements that were present in the sporulation medium. For spores grown in other formulations, multivariate comparisons across several FAME biomarkers were required to discern profile differences. Clustering patterns in nMDS plots and R values from ANOSIM revealed that dissimilarities among FAME profiles were most pronounced when spores grown with disparate sources of complex additives or protein supplements were compared (R > 0.8), although other factors also contributed to FAME differences. DFA indicated that differentiation could be maximized with a targeted subset of FAME variables, and the relative contributions of branched FAME biomarkers to group dissimilarities changed when different media were compared. When taken together, these analyses indicate that B. cereus spore samples grown in different media can be resolved with FAME profiling and that this may be a useful technique for providing intelligence about the production methods of Bacillus organisms in a forensic investigation. PMID:20097814
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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. PMID:25157831
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Saxena, Rajshree
2015-01-01
The ability to predict protein function from structure is becoming increasingly important; hence, elucidation and determination of protein structure become the major steps in proteomics. The present study was undertaken for identification of metalloprotease produced by Bacillus cereus B80 and recognition of characteristics that can be industrially exploited. The enzyme was purified in three steps combining precipitation and chromatographic methods resulting in 33.5% recovery with 13.1-fold purification of enzyme which was detected as a single band with a molecular mass of 26 kDa approximately in SDS-PAGE and zymogram. The MALDI-TOF MS showed that the enzyme exhibited 70–93% similarity with zinc metalloproteases from various strains Bacillus sp. specifically from Bacillus cereus group. The sequence alignment revealed the presence of zinc-binding region VVVHEMCHMV in the most conserved C terminus region. Secondary structure of the enzyme was obtained by CD spectra and I-TASSER. The enzyme kinetics revealed a Michaelis constant (K m) of 0.140 μmol/ml and V max of 2.11 μmol/min. The application studies showed that the enzyme was able to hydrolyze various proteins with highest affinity towards casein followed by BSA and gelatin. The enzyme exhibited strong fibrinolytic, collagenolytic, and gelatinolytic properties and stability in various organic solvents. PMID:25802851
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Sawant, Shailesh S.; Salunke, Bipinchandra K.; Taylor, II, Larry E.
Over reliance on energy or petroleum products has raised concerns both in regards to the depletion of their associated natural resources as well as their increasing costs. Bioplastics derived from microbes are emerging as promising alternatives to fossil fuel derived petroleum plastics. The development of a simple and eco-friendly strategy for bioplastic production with high productivity and yield, which is produced in a cost effective manner utilising abundantly available renewable carbon sources, would have the potential to result in an inexhaustible global energy source. Here we report the biosynthesis of bioplastic polyhydroxyalkanoates (PHAs) in pure cultures of marine bacterium, Saccharophagusmore » degradans 2-40 ( Sde 2-40), its contaminant, Bacillus cereus, and a co-culture of these bacteria ( Sde 2-40 and B. cereus) degrading plant and algae derived complex polysaccharides. Sde 2-40 degraded the complex polysaccharides agarose and xylan as sole carbon sources for biosynthesis of PHAs. The ability of Sde 2-40 to degrade agarose increased after co-culturing with B. cereus. The association of Sde 2-40 with B. cereus resulted in increased cell growth and higher PHA production (34.5% of dry cell weight) from xylan as a carbon source in comparison to Sde 2-40 alone (22.7% of dry cell weight). Lastly, the present study offers an innovative prototype for production of PHA through consolidated bioprocessing of complex carbon sources by pure and co-culture of microorganisms.« less
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Sawant, Shailesh S.; Salunke, Bipinchandra K.; Taylor, II, Larry E.; ...
2017-02-28
Over reliance on energy or petroleum products has raised concerns both in regards to the depletion of their associated natural resources as well as their increasing costs. Bioplastics derived from microbes are emerging as promising alternatives to fossil fuel derived petroleum plastics. The development of a simple and eco-friendly strategy for bioplastic production with high productivity and yield, which is produced in a cost effective manner utilising abundantly available renewable carbon sources, would have the potential to result in an inexhaustible global energy source. Here we report the biosynthesis of bioplastic polyhydroxyalkanoates (PHAs) in pure cultures of marine bacterium, Saccharophagusmore » degradans 2-40 ( Sde 2-40), its contaminant, Bacillus cereus, and a co-culture of these bacteria ( Sde 2-40 and B. cereus) degrading plant and algae derived complex polysaccharides. Sde 2-40 degraded the complex polysaccharides agarose and xylan as sole carbon sources for biosynthesis of PHAs. The ability of Sde 2-40 to degrade agarose increased after co-culturing with B. cereus. The association of Sde 2-40 with B. cereus resulted in increased cell growth and higher PHA production (34.5% of dry cell weight) from xylan as a carbon source in comparison to Sde 2-40 alone (22.7% of dry cell weight). Lastly, the present study offers an innovative prototype for production of PHA through consolidated bioprocessing of complex carbon sources by pure and co-culture of microorganisms.« less
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Walker-York-Moore, Laura; Moore, Sean C.; Fox, Edward M.
2017-01-01
Bacillus cereus sensu lato species, as well as Staphylococcus aureus, are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA, hblA and entFM toxin genes, with lower prevalence of bceT and hlyII. When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log10(CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices. PMID:28714887
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Grant, I R; Nixon, C R; Patterson, M F
1993-03-01
The effect of irradiation (2 kGy) on growth of and toxin production by Staphylococcus aureus and Bacillus cereus in roast beef and gravy during storage at abuse temperatures (15 and 22 degrees C) was assessed by inoculation studies. Irradiation resulted in a 3-4 log10 reduction in numbers of both pathogens. Whenever B. cereus and S. aureus numbers reached 10(6) and 10(7) cfu/g, respectively, during storage their toxins were detectable. As the time taken to attain these levels was longer in irradiated than in unirradiated samples, toxin production by both pathogens was delayed by irradiation. When samples initially containing low levels (10(2)/g) of S. aureus were irradiated no toxin was produced during subsequent storage at 15 or 22 degrees C. Diarrhoeal toxin produced by B. cereus was detected after 2 days at 22 degrees C, but not at 15 degrees C, in samples containing 10(2) cells/g prior to irradiation. When higher numbers (10(6)/g) of either pathogen were present prior to irradiation, toxins were produced by both pathogens at 22 degrees C, but not at 15 degrees C. Microbial competition had an effect on the growth of B. cereus and S. aureus after irradiation when a low initial inoculum was applied. However, when a higher inoculum was used the pathogens outnumbered their competitors and competition effects were less important. It was concluded that low-dose irradiation would improve the microbiological safety of roast beef and gravy.
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Walker-York-Moore, Laura; Moore, Sean C; Fox, Edward M
2017-07-15
Bacillus cereus sensu lato species, as well as Staphylococcus aureus , are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA , hblA and entFM toxin genes, with lower prevalence of bceT and hlyII . When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log 10 (CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices.
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Olmez, Hülya Kaptan; Aran, Necla
2005-02-01
Mathematical models describing the growth kinetic parameters (lag phase duration and growth rate) of Bacillus cereus as a function of temperature, pH, sodium lactate and sodium chloride concentrations were obtained in this study. In order to get a residual distribution closer to a normal distribution, the natural logarithm of the growth kinetic parameters were used in modeling. For reasons of parsimony, the polynomial models were reduced to contain only the coefficients significant at a level of p
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Shashidhar, M.S.; Kuppe, A.; Volwerk, J.J.
1990-09-04
The inositol phosphate products formed during the cleavage of phosphatidylinositol by phosphatidylinositol-specific phospholipase C from Bacillus cereus were analyzed by {sup 31}P NMR. {sup 31}P NMR spectroscopy can distinguish between the inositol phosphate species and phosphatidylinositol. Chemical shift values (with reference to phosphoric acid) observed are {minus}0.41, 3.62, 4.45, and 16.30 ppm for phosphatidylinositol, myo-inositol 1-monophosphate, myo-inositol 2-monophosphate, and myo-inositol 1,2-cyclic monophosphate, respectively. It is shown that under a variety of experimental conditions this phospholipase C cleaves phosphatidylinositol via an intramolecular phosphotransfer reaction producing diacylglycerol and D-myo-inositol 1,2-cyclic monophosphate. The authors also report the new and unexpected observation that themore » phosphatidylinositol-specific phospholipase C from B. cereus is able to hydrolyze the inositol cyclic phosphate to form D-myo-inositol 1-monophosphate. The enzyme, therefore, possesses phosphotransferase and cyclic phosphodiesterase activities. The second reaction requires thousandfold higher enzyme concentrations to be observed by {sup 31}P NMR. This reaction was shown to be regiospecific in that only the 1-phosphate was produced and stereospecific in that only D-myo-inositol 1,2-cyclic monophosphate was hydrolyzed. Inhibition with a monoclonal antibody specific for the B.cereus phospholipase C showed that the cyclic phosphodiesterase activity is intrinsic to the bacterial enzyme. They propose a two-step mechanism for the phosphatidyl-inositol-specific phospholipase C from B. cereus involving sequential phosphotransferase and cyclic phosphodiesterase activities. This mechanism bears a resemblance to the well-known two-step mechanism of pancreatic ribonuclease, RNase A.« less
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Isolation and characterization of a furfural-degrading bacterium Bacillus cereus sp. strain DS1.
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.
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Ceragioli, Mara; Mols, Maarten; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko
2010-01-01
Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growth arrest, and cell death were determined. The transcriptome analysis revealed that B. cereus, upon exposure to the selected concentrations of disinfectants, induced common and specific responses. Notably, the common response included genes involved in the general and oxidative stress responses. Exposure to benzalkonium chloride, a disinfectant known to induce membrane damage, specifically induced genes involved in fatty acid metabolism. Membrane damage induced by benzalkonium chloride was confirmed by fluorescence microscopy, and fatty acid analysis revealed modulation of the fatty acid composition of the cell membrane. Exposure to sodium hypochlorite induced genes involved in metabolism of sulfur and sulfur-containing amino acids, which correlated with the excessive oxidation of sulfhydryl groups observed in sodium hypochlorite-stressed cells. Exposures to hydrogen peroxide and peracetic acid induced highly similar responses, including the upregulation of genes involved in DNA damage repair and SOS response. Notably, hydrogen peroxide- and peracetic acid-treated cells exhibited high mutation rates correlating with the induced SOS response. PMID:20348290
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Cetin-Karaca, Hayriye; Newman, Melissa C
2018-02-01
The objective of this study was to determine the potential use of Trans-cinnamaldehyde (TC), (-)-Epigallocatechin gallate (EGCG) and [10]-Gingerol (GI) to inhibit the growth of B. cereus in infant rice cereal reconstituted with infant formula. Samples were inoculated with either vegetative cells or spores of B. cereus (ATCC 14579), and they were treated with 500 ppm (mg/L) TC, EGCG and GI. They were stored at 7 °C, 23 °C, or 37 °C for 0, 4, 8 and 24 h to simulate advance preparation, handling and temperature abuse. At 23 °C no growth was observed with TC over 24 h. TC also showed the highest antimicrobial activity 37 °C by inhibiting the growth of B. cereus vegetative cells by 0.83 log CFU/g and B. cereus spores by 2.0 log CFU/g after 24 h. B. cereus (ATCC 14579) did not grow at 7 °C over 24 h and TC had no effect on its survival. Significant differences (P < 0.05) were found in color and aroma of rice cereal samples containing EGCG and TC, respectively. Additionally, TC exhibited a cinnamon taste, while EGCG gave a purple color to the reconstituted rice cereal. These results indicate that TC may serve as a potential natural antimicrobial in reconstituted infant rice cereal even when utilized at low concentrations, inhibiting both vegetative cells and spores of B. cereus. Copyright © 2017. Published by Elsevier Ltd.
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den Besten, Heidy M. W.; Mataragas, Marios; Moezelaar, Roy; Abee, Tjakko; Zwietering, Marcel 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 concentrations of sodium chloride for 30 min, after which their thermotolerance was assessed at 50°C. Linear and nonlinear microbial survival models, which cover a wide range of known inactivation curvatures for vegetative cells, were fitted to the inactivation data and evaluated. Based on statistical indices and model characteristics, biphasic models with a shoulder were selected and used for quantification. Each model parameter reflected a survival characteristic, and both models were flexible, allowing a reduction of parameters when certain phenomena were not present. Both strains showed enhanced thermotolerance after preexposure to (non)lethal salt stress conditions in the exponential phase. The maximum adaptive stress response due to salt preexposure demonstrated for exponential-phase cells was comparable to the effect of physiological state on thermotolerance in both strains. However, the adaptive salt stress response was less pronounced for transition- and stationary-phase cells. The distinct tailing of strain ATCC 10987 was attributed to the presence of a subpopulation of spores. The existence of a stable heat-resistant subpopulation of vegetative cells could not be demonstrated for either of the strains. Quantification of the adaptive stress response might be instrumental in understanding adaptation mechanisms and will allow the food industry to develop more accurate and reliable stress-integrated predictive modeling to optimize minimal processing conditions. PMID:16957208
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Kim, Man Suk; Kim, Young Jae
2004-11-30
Membranes prepared from Bacillus cereus KCTC 3674, grown aerobically on a complex medium, oxidized NADH exclusively, whereas deamino-NADH was little oxidized. The respiratory chain-linked NADH oxidase exhibited an apparent K(m) value of approximately 65 microM for NADH. The maximum activity of the NADH oxidase was obtained at about pH 8.5 in the presence of 0.1 M KCl (or NaCl). Respiratory chain inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) inhibited the activity of the NADH oxidase by about 90% at a concentration of 40 microM. Interestingly, rotenone and capsaicin inhibited the activity of the NADH oxidase by about 60% at a concentration of 40 microM and the activity was also highly sensitive to Ag(+).
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Differentiation of Bacillus Anthracis and Other Bacillus Species by Use of Lectins
1983-07-18
TITL9 fAnd Subtfitle) S.TypeO REPORT gi PZRCC rvt 4 DIFFERENTIATION OF BACIL-LUSg’ ANTHRAtgACIS D OTHER BACILLUS , SPECIES BY-USE OYLECTINS" Inter[im...Ricinus communis. Some strains of Bacillus cer-eus var. m-ycoides (B. Mycoides) were strongly reactive with the lectin from Helbi pomtia and weakly reacti...ve with the Glycine max lectin. The differential iCnteractions between Bacillus species and lectins af forded a means of distinguishing B. anthracis
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Frenzel, Elrike; Kranzler, Markus; Stark, Timo D; Hofmann, Thomas; Ehling-Schulz, Monika
2015-12-08
Bacillus cereus is among the microorganisms most often isolated from cases of food spoilage and causes gastrointestinal diseases as well as nongastrointestinal infections elicited by the emetic toxin cereulide, enterotoxins, and a panel of tissue-destructive virulence factors. This opportunistic pathogen is increasingly associated with rapidly fatal clinical infections especially linked to neonates and immunocompromised individuals. Fatality results from either the misdiagnosis of B. cereus as a contaminant of the clinical specimen or from failure of antibiotic therapy. Here we report for the first time that exposure to aminoglycoside antibiotics induces a phenotype switching of emetic B. cereus subpopulations to a slow-growing small colony variant (SCV) state. Along with altered antibiotic resistance, SCVs showed distinct phenotypic and metabolic properties, bearing the risk of antibiotic treatment failure and of clinical misdiagnosis by standard identification tests used in routine diagnostic. The SCV subpopulation is characterized by enhanced production of the toxin cereulide, but it does not secrete tissue-destructive and immune system-affecting enzymes such as sphingomyelinase and phospholipase. SCVs showed significantly prolonged persistence and decreased virulence in the Galleria mellonella model for bacterial infections, indicating diversification concerning their ecological lifestyle. Importantly, diversification into coexisting wild-type and SCV subpopulations also emerged during amikacin pressure during in vivo infection experiments. This study shows for the first time that pathogenic spore-forming B. cereus strains are able to switch to a so far unreported slow-growing lifestyle, which differs substantially in terms of developmental, phenotypic, metabolic, and virulence traits from the wild-type populations. This underpins the necessity of molecular-based differential diagnostics and a well-chosen therapeutic treatment strategy in clinical
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Nano-Mechanical Properties of Heat Inactivated Bacillus anthracis and Bacillus thuringiensis Spores
2008-03-01
Scanner Laser Mirror Cantilever Sample Probe Tip 16 cereus strain 569, and Bacillus globigii var. niger . Zolock determined that there wer...been used to measure the surface elasticities of a variety of microbial organisms including Pseudomonas putida, Bacillus subtilis, Aspergillus ...66:307-311 (2005). Zhao, Liming, David Schaefer, and Mark R. Marten. “Assessment of Elasticity and Topography of Aspergillus nidulans Spores via
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Yossa, N; Arce, G; Smiley, J; Jo Huang, M-C; Yin, L; Bell, R; Tallent, S; Brown, E; Hammack, T
2018-02-01
Pathogenic contamination of cosmetics intended to be applied on or around the eye area, including make-up removers, may lead to severe eye infections. To assess the efficacy of antimicrobial preservatives in these products, we investigated the survival and detection of Bacillus cereus F 4227A spiked into make-up removers, alone and in the presence of other relevant micro-organisms. Four brands of make-up removers, A, B, C and D, were challenged three times (day 0, day 7 and day 14) using B. cereus, in pure and mixed cultures, at a final concentration of 5 log CFU per mL of Bacillus cereus or 6 log CFU per mL for other micro-organisms. Inoculated samples were diluted and spiral-plated after 30 min and 24 h of each challenge onto selective media for recovery of surviving micro-organisms: BACARA (B. cereus), MacConkey (E. coli), ChromID (P. aeruginosa), XLT4 (S. enteritidis), Baird Parker agar (Staph. aureus) and PDA+chlortetracycline HCL (C. albicans). The population of B. cereus spiked as a pure culture increased significantly from the first to the third challenge after 30-min exposure time, going from 0.73 to 2.59 in A, from 0.80 to 2.69 in B and from 0.80 to 1.67 log CFU per mL in C (P < 0.05). Likewise, the B. cereus population from the mixed cultures had a significantly higher survival count at the third challenge: from 0.12 log MPN per mL to 2.16 log CFU per mL in A, 0.57 to 2.27 log CFU per mL in B and from undetected (LOD = 0.48 log MPN) to 0.98 log CFU per mL in C, respectively. After challenges, Staph. aureus, C. albicans and P. aeruginosa increased in B; Staph. aureus and C. albicans in C; and E. coli and Staph. aureus in D. The growth of other bacteria types was unaffected by the number of challenges, but B. cereus population was detected with the third challenge. It is appropriate to assess the antimicrobial efficacy of preservatives using at least three challenges, especially for cosmetics that are subjected to repetitive contamination by users. © 2017
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Park, Hyong Seok; Choi, Hee Jung; Kim, Myoung-Dong; Kim, Kyoung Heon
2013-09-02
Supercritical carbon dioxide (SC-CO2) was used to inactivate Bacillus cereus spores inside biofilms, which were grown on stainless steel. SC-CO2 treatment was tested using various conditions, such as pressure treatment (10-30 MPa), temperature (35-60°C), and time (10-120 min). B. cereus vegetative cells in the biofilm were completely inactivated by treatment with SC-CO2 at 10 MPa and at 35°C for 5 min. However, SC-CO2 alone did not inactivate spores in biofilm even after the treatment time was extended to 120 min. When ethanol was used as a cosolvent with SC-CO2 in the SC-CO2 treatment using only 2-10 ml of ethanol in 100ml of SC-CO2 vessel for 60-90 min of treatment time at 10 MPa and 60°C, B. cereus spores in the biofilm were found to be completely inactivated in the colony-forming test. We also assessed the viability of SC-CO2-treated bacterial spores and vegetative cells in the biofilm by staining with SYTO 9 and propidium iodide. The membrane integrity of the vegetative cells was completely lost, while the integrity of the membrane was still maintained in most spores. However, when SC-CO2 along with ethanol was used, both vegetative cells and spores lost their membrane integrity, indicating that the use of ethanol as a cosolvent with SC-CO2 is efficient in inactivating the bacterial spores in the biofilm. © 2013.
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Aoki, Takanori; Aoki, Yoshinao; Ishiai, Shiho; Otoguro, Misa; Suzuki, Shunji
2017-01-01
Vine growers are faced with the difficult problem of how to control grape ripe rot disease in vineyards because of fear of accumulation of pesticide residues on grape berries near harvest. Biological control is an alternative non-hazardous technique to control the diseases. Application of resveratrol-synthesis-promoting bacterium, Bacillus cereus strain NRKT, reduced the incidence of grape ripe rot disease caused by Colletotrichum gloeosporioides in a vineyard. The application of NRKT to berry bunches upregulated the gene expression of stilbene synthase, a key enzyme for resveratrol synthesis in berry skins, thereby promoting resveratrol synthesis in berry skins. The potential use of NRKT in vineyards is expected to contribute to the increase in resveratrol content in berry skins, thereby protecting grape berries against fungal diseases. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
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Tayabali, A F; Seligy, V L
2000-01-01
Most contemporary bioinsecticides are derived from scaled-up cultures of Bacillus thuringiensis subspecies israelensis (Bti) and kurstaki (Btk), whose particulate fractions contain mostly B. thuringiensis spores (> 10(12)/L) and proteinaceous aggregates, including crystal-like parasporal inclusion bodies (PIB). Based on concerns over relatedness to B. cereus-group pathogens, we conducted extensive testing of B. thuringiensis (BT) products and their subfractions using seven human cell types. The Bti/Btk products generated nonspecific cytotoxicities involving loss in bioreduction, cell rounding, blebbing and detachment, degradation of immunodetectable proteins, and cytolysis. Their threshold dose (Dt approximately equal.5 times 10(-14)% BT product/target cell) equated to a single spore and a target cell half-life (tLD(50)) of approximately 16 hr. At Dts > 10(4), the tLD(50) rapidly shifted to < 4 hr; with antibiotic present, no component, including PIB-related [delta]-endotoxins, was cytolytic up to an equivalent of approximately 10(9 )Dt. The cytolytic agent(s) within the Bti/Btk-vegetative cell exoprotein (VCP) pool is an early spore outgrowth product identical to that of B. cereus and acting possibly by arresting protein synthesis. No cytolytic effects were seen with VCP from B. subtilis and Escherichia coli. These data, including recent epidemiologic work indicate that spore-containing BT products have an inherent capacity to lyse human cells in free and interactive forms and may also act as immune sensitizers. To critically impact at the whole body level, the exposure outcome would have to be an uncontrolled infection arising from intake of Btk/Bti spores. For humans, such a condition would be rare, arising possibly in equally rare exposure scenarios involving large doses of spores and individuals with weak or impaired microbe-clearance capacities and/or immune response systems. PMID:11049810
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Banerjee, D; Mondal, A; Gupta, M; Guha, A K; Ray, L
2014-01-01
Optimal culture conditions for the production of green pigment was investigated. The optimal culture condition for the production of an extracellular green pigment by growing Bacillus cereus M(1) 16 (MTCC 5521) in a complex medium containing (g l(-1) ) Peptone-4.0, Beef Extract-9.0, NaCl-7.0, MgSO4 .7H2 O-1.0 and KH2 PO4 -5.0 was as follows pH-7.0 at 30°C for 72 h in a 5 l fermenter. Aeration rate and agitator speed had no effect on the pigment production. Thin layer chromatogram of the pigment extracted from the fermented broth with chloroform on silica gel GF254 using ethyl acetate and hexane (1 : 1) as solvent showed three fractions. The major fraction (C3 ) was separated out and identified as 9-methyl-1, 4, 5, 8-tetra-azaphenanthrene. Acute toxicity test revealed the nontoxic nature upto a dose of 2000 mg kg(-1) , b.wt., of mice. MTT assay showed the cytotoxic nature in HL60 cells having an IC50 of 2.47 mmol. So, this biopigment may have application in food, textile colorant and pharmaceutical industry. This study demonstrated the optimum production of a biopigment (9-methyl-1, 4, 5, 8-tetra-azaphenanthrene) by fermentation of a complex medium with Bacillus cereus M(1) 16 (MTCC 5521) in submerged fermentation. This is the first investigation of toxicity and cytotoxicity activities of this biopigment. The study showed that the purified pigment had no toxicity to healthy albino mice but a high cytotoxicity activity in HL60 cancer cell line in vitro. The biopigment had further displayed dyeing capability to both solidified agar and cotton cloth. Therefore, it may represent a nontoxic and natural alternative to chemical dyes and pigments. © 2013 The Society for Applied Microbiology.
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Purification and characterization of Bacillus cereus protease suitable for detergent industry.
Prakash, Monika; Banik, Rathindra Mohan; Koch-Brandt, Claudia
2005-12-01
An extracellular alkaline protease from an alkalophilic bacterium, Bacillus cereus, was produced in a large amount by the method of extractive fermentation. The protease is thermostable, pH tolerant, and compatible with commercial laundry detergents. The protease purified and characterized in this study was found to be superior to endogenous protease already present in commercial laundry detergents. The enzyme was purified to homogeneity by ammonium sulfate precipitation, concentration by ultrafiltration, anion-exchange chromatography, and gel filtration. The purified enzyme had a specific activity of 3256.05 U/mg and was found to be a monomeric protein with a molecular mass of 28 and 31 kDa, as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and nondenaturing PAGE, respectively. Its maximum protease activity against casein was found to be at pH 10.5 and 50 degrees C. Proteolytic activity of the enzyme was detected by casein and gelatin zymography, which gave a very clear protease activity zone on gel that corresponded to the band obtained on SDS-PAGE and nondenaturing PAGE with a molecular mass of nearly 31 kDa. The purified enzyme was analyzed through matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and identified as a subtilisin class of protease. Specific serine protease inhibitors, suggesting the presence of serine residues at the active site, inhibited the enzyme significantly.
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Physiology of Growth and Sporulation in Bacillus cereus I. Effect of Glutamic and Other Amino Acids
Buono, F.; Testa, R.; Lundgren, D. G.
1966-01-01
Buono, F. (Syracuse University, Syracuse, N.Y.), R. Testa, and D. G. Lundgren. Physiology of growth and sporulation in Bacillus cereus. I. Effect of glutamic and other amino acids. J. Bacteriol. 91:2291–2299. 1966.—Growth and sporulation were studied in Bacillus cereus by use of an active culture technique and a synthetic medium. A high level of glutamic acid (70 mm) was required for optimal growth and glucose oxidation followed by sporulation even though relatively little glutamic acid was consumed (14 mm). Optimal growth occurred with a combination of 14 mm glutamic acid and 56 mm (NH4)2SO4, aspartic acid, or alanine. Ornithine or arginine at 70 mm could replace glutamic acid in the synthetic medium without affecting the normal growth cycle. Glutamic acid was not replaced by any other amino acid, by (NH4)2SO4, or by a combination of either α-ketoglutarate or pyruvate plus (NH4)2SO4. Enzyme assays of cell-free extracts prepared from cells harvested at different times were used to study the metabolism of glutamic acid. Glutamic-oxaloacetic and glutamic-pyruvate transaminases were completely activated (or derepressed) during early stages of sporulation (period of 6 to 8 hr). Alanine dehydrogenase responded in a similar manner, but the levels of this enzyme were much higher throughout the culture cycle. Neither glutamic dehydrogenase nor α-ketoglutarate dehydrogenase was detected. Sporulation in a replacement salts medium was studied with cells harvested at different times from the synthetic medium. Cultures 2 to 6 hr old were unable to sporulate in the replacement salts medium unless glutamic acid (7.0 mm) was present. By the 6th hr, cells were in the early stages of sporulation, showing spore septa development. Cultures 8 hr old sporulated in the replacement salts medium. Other metabolic intermediates able to replace glutamic acid in the replacement salts medium were alanine, aspartic acid, and glutamine at equimolar concentrations. Also, ammonium ions in
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Engineered Mononuclear Variants in Bacillus cereus Metallo-β-lactamase BcII Are Inactive†
Abriata, Luciano A.; González, Lisandro J.; Llarrull, Leticia I.; Tomatis, Pablo E.; Myers, William K.; Costello, Alison L.; Tierney, David L.; Vila, Alejandro J.
2008-01-01
Metallo-β-lactamases (MβLs) are zinc enzymes able to hydrolyze almost all β-lactam antibiotics, rendering them inactive, at the same time endowing bacteria high levels of resistance. The design of inhibitors active against all classes of MβLs has been hampered by their structural diversity and by the heterogeneity in metal content in enzymes from different sources. BcII is the metallo-β-lactamase from Bacillus cereus, which is found in both the mononuclear and dinuclear forms. Despite extensive studies, there is still controversy about the nature of the active BcII species. Here we have designed two mutant enzymes in which each one of the metal binding sites was selectively removed. Both mutants were almost inactive, despite preserving most of the structural features of each metal site. These results reveal that neither site isolated in the MβL scaffold is sufficient to render a fully active enzyme. This suggests that only the dinuclear species is active or that the mononuclear variants can be active only if aided by other residues that would be metal ligands in the dinuclear species. PMID:18652482
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Blöchinger, Claudia; Zucker, Renate; Kämpf, Peter
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. PMID:24895578
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Huang, Fei; Dang, Zhi; Guo, Chu-Ling; Lu, Gui-Ning; Gu, Roy R; Liu, Hong-Juan; Zhang, Hui
2013-07-01
The present study investigated the biosorption capacity of live and dead cells of Bacillus cereus RC-1 for Cd(II). The biosorption characteristics were investigated as a function of initial pH, contact time, and initial cadmium concentration. Equilibrium biosorption was modeled using Langmuir, Freundlich and Redlich-Peterson isotherm equations. It was found that the maximum biosorption capacities calculated from Langmuir isotherm were 31.95 mg/g and 24.01 mg/g for dead cells and live cells, respectively. The kinetics of the biosorption was better described by pseudo-second order kinetic model. Desorption efficiency of biosorbents was investigated at various pH values. These results indicated that dead cells have higher Cd(II) biosorption capacity than live cells. Furthermore, zeta potential, transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX), and Fourier transform infrared spectroscopy (FTIR) studies were carried out to understand the differences in the Cd(II) biosorption behavior for the both biosorbents. The bioaccumulation of Cd(II) by B. cereus RC-1 was found to depend largely on extracellular biosorption rather than intracellular accumulation. Based on the above studies, dead biomass appears to be a more efficient biosorbent for the removal of Cd(II) from aqueous solution. Copyright © 2013 Elsevier B.V. All rights reserved.
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Vergis, James M.; Cote, Christopher K.; Bozue, Joel; Alem, Farhang; Ventura, Christy L.; Welkos, Susan L.
2013-01-01
Bacillus anthracis spores are the infectious form of the organism for humans and animals. However, the approved human vaccine in the United States is derived from a vegetative culture filtrate of a toxigenic, nonencapsulated B. anthracis strain that primarily contains protective antigen (PA). Immunization of mice with purified spore proteins and formalin-inactivated spores (FIS) from a nonencapsulated, nontoxigenic B. anthracis strain confers protection against B. anthracis challenge when PA is also administered. To investigate the capacity of the spore particle to act as a vaccine without PA, we immunized mice subcutaneously with FIS from nontoxigenic, nonencapsulated B. cereus strain G9241 pBCXO1−/pBC210− (dcG9241), dcG9241 ΔbclA, or 569-UM20 or with exosporium isolated from dcG9241. FIS vaccination provided significant protection of mice from intraperitoneal or intranasal challenge with spores of the virulent B. anthracis Ames or Ames ΔbclA strain. Immunization with dcG9241 ΔbclA FIS, which are devoid of the immunodominant spore protein BclA, provided greater protection from challenge with either Ames strain than did immunization with FIS from BclA-producing strains. In addition, we used prechallenge immune antisera to probe a panel of recombinant B. anthracis Sterne spore proteins to identify novel immunogenic vaccine candidates. The antisera were variably reactive with BclA and with 10 other proteins, four of which were previously tested as vaccine candidates. Overall our data show that immunization with FIS from nontoxigenic, nonencapsulated B. cereus strains provides moderate to high levels of protection of mice from B. anthracis Ames challenge and that neither PA nor BclA is required for this protection. PMID:23114705
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Naik, Umesh Chandra; Srivastava, Shaili; Thakur, Indu Shekhar
2011-08-01
Electroplating industries are the main sources of heavy metals, chromium, nickel, lead, zinc, cadmium and copper. The highest concentrations of chromium (VI) in the effluent cause a direct hazards to human and animals. Therefore, there is a need of an effective and affordable biotechnological solution for removal of chromium from electroplating effluent. Bacterial strains were isolated from electroplating effluent to find out higher tolerant isolate against chromate. The isolate was identified by 16S rDNA sequence analysis. Absorbed chromium level of bacterium was determined by inductively coupled plasma-atomic emission spectrometer (ICP-AES), atomic absorption spectrophotometer (AAS), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray analysis (EDX). Removal of metals by bacterium from the electroplating effluent eventually led to the detoxification of effluent confirmed by MTT assay. Conformational changes of functional groups of bacterial cell surface were studied through Fourier transform infrared spectroscopy. The chromate tolerant isolate was identified as Bacillus cereus. Bacterium has potency to remove more than 75% of chromium as measured by ICP-AES and AAS. The study indicated the accumulation of chromium (VI) on bacterial cell surface which was confirmed by the SEM-EDX and TEM analysis. The biosorption of metals from the electroplating effluent eventually led to the detoxification of effluent. The increased survivability of Huh7 cells cultured with treated effluent also confirmed the detoxification as examined by MTT assay. Isolated strain B. cereus was able to remove and detoxify chromium (VI). It would be an efficient tool of the biotechnological approach in mitigating the heavy metal pollutants.
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Ditu, L M; Chifiriuc, M C; Bezirtzoglou, E; Marutescu, L; Bleotu, C; Pelinescu, D; Mihaescu, G; Lazar, V
2014-01-01
Competition of probiotic bacteria with other species from the intestinal microbiota involves different mechanisms that occur regardless of probiotics' viability. The objective of this paper was to assess the cytokine serum levels in holoxenic mice after oral administration of non-viable components (NVC) of Enterococcus faecium probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus in comparison to NVC of unstimulated E. faecium probiotic culture. Probiotic E. faecium CMGb 16 culture, grown in the presence of heat-inactivated cultures of E. coli and B. cereus CMGB 102, was subsequently separated into supernatant (SN) and heat-inactivated cellular sediment (CS) fractions by centrifugation. Each NVC was orally administered to holoxenic mice (balb C mouse strain), in three doses, given at 24 hours. Blood samples were collected from the retinal artery, at 7, 14, and 21 days after the first administration of the NVC. The serum concentrations of IL-12 and tumor necrosis factor-alpha (TNF-α) interleukins were assessed by ELISA method. After the oral administration of SN component obtained from the probiotic culture stimulated with heat-inactivated cultures of B. cereus CMGB 102 and E. coli O28, the serum concentrations of IL-12 were maintained higher in the samples collected at 7 and 14 days post-administration. No specific TNF-α profile could be established, depending on stimulated or non-stimulated probiotic culture, NVC fraction, or harvesting time. The obtained results demonstrate that non-viable fractions of probiotic bacteria, stimulated by other bacterial species, could induce immunostimulatory effects mediated by cytokines and act, therefore, as immunological adjuvants.
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Rowan, Neil J.; Deans, Karen; Anderson, John G.; Gemmell, Curtis G.; Hunter, Iain S.; Chaithong, Thararat
2001-01-01
Forty-seven strains representing 14 different Bacillus species isolated from clinical and food samples were grown in reconstituted infant milk formulae (IMF) and subsequently assessed for adherence to, invasion of, and cytotoxicity toward HEp-2 and Caco-2 cells. Cell-free supernatant fluids from 38 strains (81%) were shown to be cytotoxic, 43 strains (91%) adhered to the test cell lines, and 23 strains (49%) demonstrated various levels of invasion. Of the 21 Bacillus cereus strains examined, 5 (24%) were invasive. A larger percentage of clinically derived Bacillus species (20%) than of similar species tested from the food environment were invasive. Increased invasion occurred after growth of selected Bacillus species in reconstituted IMF containing glucose. While PCR primer studies revealed that many different Bacillus species contained DNA sequences encoding the hemolysin BL (HBL) enterotoxin complex and B. cereus enterotoxin T, not all of these isolates expressed these diarrheagenic genes after growth in reconstituted IMF. Of the 47 Bacillus isolates examined, 3 isolates of B. cereus and 1 isolate of B. subtilis produced the HBL enterotoxin after 18 h of growth in brain heart infusion broth. However, eight isolates belonging to the species B. cereus, B. licheniformis, B. circulans, and B. megaterium were found to produce this enterotoxin after growth in reconstituted IMF when assessed with the B. cereus enterotoxin (diarrheal type) reversed passive latex agglutination (RPLA) kit. It is concluded that several Bacillus species occurring occasionally in clinical specimens and food samples are of potential medical significance due to the expression of putative virulence factors. PMID:11525980
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Mercimek, H Aysun; Dincer, Sadık; Guzeldag, Gulcihan; Ozsavli, Aysenur; Matyar, Fatih
2013-10-01
In this study, biological degradation of 2,4,6-trinitrotoluene (TNT) which is very highly toxic environmentally and an explosive in nitroaromatic character was researched in minimal medium by Bacillus cereus isolated from North Atlantic Treaty Organization (NATO) TNT-contaminated soils. In contrast to most previous studies, the capability of this bacteria to transform in liquid medium containing TNT was investigated. During degradation, treatment of TNT was followed by high-performance liquid chromatography (HPLC) and achievement of degradation was calculated as percentage. At an initial concentration of 50 and 75 mg L(-1), TNT was degraded respectively 68 % and 77 % in 96 h. It transformed into 2,4-dinitrotoluene and 4-aminodinitrotoluene derivates, which could be detected as intermediate metabolites by using thin-layer chromatography and gas chromatography-mass spectrometry analyses. Release of nitrite and nitrate ions were searched by spectrophotometric analyses. Depending upon Meisenheimer complex, while nitrite production was observed, nitrate was detected in none of the cultures. Results of our study propose which environmental pollutant can be removed by using microorganisms that are indigenous to the contaminated site.
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Samapundo, S; Heyndrickx, M; Xhaferi, R; de Baenst, I; Devlieghere, F
2014-07-02
The objective of the study was to evaluate the combined effects of pasteurization intensity (no heat treatment and 10 min at 70, 80 and 90 °C), water activity (aw) (0.960-0.990), pH (5.5-7.0) and storage temperature (7 and 10 °C) on the survival and outgrowth of psychrotolerant spores of Bacillus cereus FF119b and Bacillus pumilus FF128a. The experiments were performed in both artificial media and a validation was performed on real food products (cream, béchamel sauce and mixed vegetable soup). It was determined that in general, heat treatments of 10 min at 70 °C or 80 °C activated the spores of both B. cereus FF119b and B. pumilus FF128a, resulting in faster outgrowth compared to native (non-heat treated) spores. A pasteurization treatment of 10 min at 90 °C generally resulted in the longest lag periods before outgrowth of both isolates. Some of the spores were inactivated by this heat treatment, with more inactivation being observed the lower the pH value of the heating medium. Despite this, it was also observed that under some conditions the remaining (surviving) spores were actually activated as their outgrowth took place after a shorter period of time compared to native non-heated spores. While the response of B. cereus FF119b to the pasteurization intensity in cream and béchamel sauce was similar to the trends observed in the artificial media at 10 °C, in difference, outgrowth was only observed at 7 °C in both products when the spores had been heated for 10 min at 80 °C. Moreover, no inactivation was observed in cream or béchamel sauce when the spores were heated for 10 min at 90 °C in these two products. This was attributed to the protective effect of fat in the cream and the ingredients in the béchamel sauce. The study provides some insight into the potential microbial (stability and safety) consequences of the current trend towards milder heat treatments which is being pursued in the food industry. Copyright © 2014. Published by Elsevier B.V.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Hendrickx, Antoni P.A.; Poor, Catherine B.; Jureller, Justin E.
Bacillus cereus strains elaborate pili on their surface using a mechanism of sortase-mediated cross-linking of major and minor pilus components. Here we used a combination of electron microscopy and atomic force microscopy to visualize these structures. Pili occur as single, double or higher order assemblies of filaments formed from monomers of the major pilin, BcpA, capped by the minor pilin, BcpB. Previous studies demonstrated that within assembled pili, four domains of BcpA -- CNA{sub 1}, CNA{sub 2}, XNA and CNA{sub 3} -- each acquire intramolecular lysine-asparagine isopeptide bonds formed via catalytic glutamic acid or aspartic acid residues. Here we showedmore » that mutants unable to form the intramolecular isopeptide bonds in the CNA2 or CNA3 domains retain the ability to form pilus bundles. A mutant lacking the CNA{sub 1} isopeptide bond assembled deformed pilin subunits that failed to associate as bundles. X-ray crystallography revealed that the BcpA variant Asp{sup 312}Ala, lacking an aspartyl catalyst, did not generate the isopeptide bond within the jelly-roll structure of XNA. The Asp{sup 312}Ala mutant was also unable to form bundles and promoted the assembly of deformed pili. Thus, structural integrity of the CNA{sub 1} and XNA domains are determinants for the association of pili into higher order bundle structures and determine native pilus structure.« less
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Chon, Jung-Whan; Hyeon, Ji-Yeon; Park, Jun-Ho; Song, Kwang-Young; Kim, Jong-Hyun; Seo, Kun-Ho
2012-07-01
Mannitol-yolk-polymyxin B agar (MYPA) was modified by supplementation with trimethoprim. The ability of the supplemented medium to select for and recover Bacillus cereus from pure cultures and food samples with high background microflora was compared with MYPA. For evaluation of the modified MYPA (mMYPA) in food samples with high background microflora, B. cereus was experimentally spiked into red pepper powder, fermented soybean paste, vegetable salad, and radish sprouts, and then it was recovered on MYPA and mMYPA for comparison. In all food samples, there was no difference in recoverability (P > 0.05) between mMYPA (red pepper powder, 3.34 ± 0.24 log CFU/g; fermented soybean paste, 3.52 ± 0.47 log CFU/g; vegetable salad, 3.51 ± 0.23 log CFU/g; radish sprouts, 3.32 ± 0.40 log CFU/g) and MYPA (red pepper powder, 3.18 ± 0.20 log CFU/g; fermented soybean paste, 3.33 ± 0.43 log CFU/g; vegetable salad, 3.36 ± 0.19 log CFU/g; radish sprouts, 3.33 ± 0.31 log CFU/g). However, mMYPA exhibited better selectivity than MYPA, because additional trimethoprim made the differentiation of suspected colonies easier by inhibiting competing flora. The addition of trimethoprim to conventional media could be a useful option to improve selectivity in foods with high background microflora.
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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. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Heavy Metal Detoxification by Different Bacillus Species Isolated from Solar Salterns
Syed, Shameer; Chinthala, Paramageetham
2015-01-01
The biosorption mechanism is an alternative for chemical precipitation and ultrafiltration which have been employed to treat heavy metal contamination with a limited success. In the present study, three species of Bacillus which were isolated from solar salterns were screened for their detoxification potential of the heavy metals, lead, chromium, and copper, by biosorption. Biosorption potential of each isolate was determined by Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), and Energy Dispersive Spectroscopy (EDS) as the amount of metal present in the medium after the treatment with the isolates. Bacterial isolates, Bacillus licheniformis NSPA5, Bacillus cereus NSPA8, and Bacillus subtilis NSPA13, showed significant level of lead biosorption with maximum of 87–90% by Bacillus cereus NSPA8. The biosorption of copper and chromium was relatively low in comparison with lead. With the obtained results, we have concluded that the bacterial isolates are potential agents to treat metal contamination in more efficient and ecofriendly manner. PMID:26525498
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NASA Astrophysics Data System (ADS)
Koval'ová, Zuzana; Tarabová, Kataŕna; Hensel, Karol; Machala, Zdenko
2013-02-01
Cold air plasmas of DC and pulsed corona discharges: positive streamers and negative Trichel pulses were used for bio-decontamination of Streptococci biofilm and Bacillus cereus spores on polypropylene plastic surfaces. The reduction of bacterial population (evaluated as log10) in the biofilm on plastic surfaces treated by DC corona reached 2.4 logs with 10 min treatment time and 3.3 logs with 2 min treatment time with water spraying. The enhancement of plasma biocidal effects on the biofilm by electro-spraying of water through a hollow needle high-voltage electrode was investigated. No significant polarity effect was found with DC corona. Pulsed corona was demonstrated slightly more bactericidal for spores, especially in the negative polarity where the bacterial population reduction reached up to 2.2 logs at 10 min exposure time. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.
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Sujatha, V.; Sridhar, Bharat; Krishnamurthy, Srinath; Vinod Kumar, K. S.; Senthil Kumar, K.; Gautam, Pennathur
2010-01-01
The use of tetraammonium tetrakis(4-sulphonato)phenyl porphyrin (TPPS), a water-soluble anionic compound, as a stain to analyse bacterial cells using fluorescent microscopy was investigated. TPPS was effectively used to analyse two different bacteria: Pseudomonas aeruginosa and Bacillus cereus. The variation in brightness with varying concentrations of TPPS was studied. The patterns of variations for these bacteria were found to be the same, but with consistently higher brightness for Bacillus cereus. PMID:20811478
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Pina-Pérez, Maria Consuelo; Silva-Angulo, Angela B; Muguerza-Marquínez, Begoña; Aliaga, D Rodrigo; López, Antonio Martínez
2009-01-01
An in-depth study was conducted in order to extend the storage life of a liquid whole egg-skim milk (LWE-SM) mixed beverage to enhance its safety and the safety of related beverages. Bacillus cereus vegetative cells (1 x 10(8) colony-forming units [CFU]/mL) were inoculated in LWE-SM beverages with or without natural antimicrobial supplements: flavonol rich-cocoa powder (cocoanOX 12%, CCX) (700 ppm), vanillin (700 ppm), anise (700 ppm), and cinnamon (700 ppm). B. cereus cells were maintained at 10 degrees C for 10 days in the different beverages to test the bacteriostatic or inhibitory effect of the aforementioned ingredients. Beverages were treated with high hydrostatic pressure (HHP) technology and stored at 10 degrees C for 15 days after treatment. All natural antimicrobials reduced the micro(max) values and increased the lag phase time of B. cereus, and Gompertz growth curves showed different inhibitory effects depending on the substance. The maximum inhibitory effect (1.330 log cycle reduction) was achieved in LWE-SM-cinnamon-supplemented beverage. The maximum inactivation achieved by HHP in LWE-SM beverage was a reduction of around 3.89 +/- 0.25 log cycles at 300 MPa for 12 minutes. When supplemented beverages were treated under the same conditions, enhanced inactivation levels were achieved. This increased inactivation can be attributed to a synergistic effect when the LWE-SM was supplemented with flavonol-rich cocoa powder, cinnamon, and vanillin. The maximum synergistic effect was observed in LWE-SM-CCX-supplemented beverage. During the refrigerated storage of B. cereus HHP-treated cells in beverages to which antimicrobials had been added, the inhibitory effect was dependent on the previously applied pressure level.
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Influence of food matrix on outgrowth heterogeneity of heat damaged Bacillus cereus spores.
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
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Juneja, Vijay K; Mohr, Tim B; Silverman, Meryl; Snyder, O Peter
2018-02-23
The objective of this study was to assess the ability of Bacillus cereus spores to germinate and grow in order to determine a safe cooling rate for cooked rice, beans, and pasta, rice-chicken (4:1), rice-chicken-vegetables (3:1:1), rice-beef (4:1), and rice-beef-vegetables (3:1:1). Samples were inoculated with a cocktail of four strains of heat-shocked (80°C for 10 min) B. cereus spores (NCTC 11143, 935A/74, Brad 1, and Mac 1) to obtain a final spore concentration of approximately 2 log CFU/g. Thereafter, samples were exponentially cooled through the temperature range of 54.5 to 7.2°C in 6, 9, 12, 15, 18, and 21 h. At the end of the cooling period, samples were removed and plated on mannitol egg yolk polymyxin agar. The plates were incubated at 30°C for 24 h. The net B. cereus growth from spores in beans was <1 log after 9 h of cooling, but the pathogen grew faster in rice and pasta. In combination products, the net growth was as follows: 3.05, 3.89, and 4.91 log CFU/g in rice-chicken; 3.49, 4.28, and 4.96 log CFU/g in rice-beef; 3.50, 4.20, and 5.32 CFU/g in rice-chicken-mixed vegetables; and 3.68, 4.44, and 5.25 CFU/g in rice-beef-mixed vegetables after 15, 18, and 21 h of cooling, respectively. This study suggests safe cooling rates for cooling cooked rice, beans, pasta, rice-chicken, rice-chicken-vegetables, rice-beef, and rice-beef-vegetables to guard against the hazards associated with B. cereus.
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Pina-Pérez, M C; Silva-Angulo, A B; Rodrigo, D; Martínez-López, A
2009-04-15
With a view to extending the shelf-life and enhancing the safety of liquid whole egg/skim milk (LWE-SM) mixed beverages, a study was conducted with Bacillus cereus vegetative cells inoculated in skim milk (SM) and LWE-SM beverages, with or without antimicrobial cocoa powder. The beverages were treated with Pulsed Electric Field (PEF) technology and then stored at 5 degrees C for 15 days. The kinetic results were modeled with the Bigelow model, Weibull distribution function, modified Gompertz equation, and Log-logistic models. Maximum inactivation registered a reduction of around 3 log cycles at 40 kV/cm, 360 micros, 20 degrees C in both the SM and LWE-SM beverages. By contrast, in the beverages supplemented with the aforementioned antimicrobial compound, higher inactivation levels were obtained under the same treatment conditions, reaching a 3.30 log(10) cycle reduction. The model affording the best fit for all four beverages was the four-parameter Log-logistic model. After 15 days of storage, the antimicrobial compound lowered Bacillus cereus survival rates in the samples supplemented with CocoanOX 12% by a 4 log cycle reduction, as compared to the untreated samples without CocoanOX 12%. This could indicate that the PEF-antimicrobial combination has a synergistic effect on the bacterial cells under study, increasing their sensitivity to subsequent refrigerated storage.
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Assembly and Function of the Bacillus anthracis S-Layer.
Missiakas, Dominique; Schneewind, Olaf
2017-09-08
Bacillus anthracis, the anthrax agent, is a member of the Bacillus cereus sensu lato group, which includes invasive pathogens of mammals or insects as well as nonpathogenic environmental strains. The genes for anthrax pathogenesis are located on two large virulence plasmids. Similar virulence plasmids have been acquired by other B. cereus strains and enable the pathogenesis of anthrax-like diseases. Among the virulence factors of B. anthracis is the S-layer-associated protein BslA, which endows bacilli with invasive attributes for mammalian hosts. BslA surface display and function are dependent on the bacterial S-layer, whose constituents assemble by binding to the secondary cell wall polysaccharide (SCWP) via S-layer homology (SLH) domains. B. anthracis and other pathogenic B. cereus isolates harbor genes for the secretion of S-layer proteins, for S-layer assembly, and for synthesis of the SCWP. We review here recent insights into the assembly and function of the S-layer and the SCWP.
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Arul, Dhayalan; Balasubramani, Govindasamy; Balasubramanian, Velramar; Natarajan, Thillainathan; Perumal, Pachiappan
2017-10-01
Bacteria are generally responsible for the prevalence of several diseases and pathogenic bacteria are showing increasing resistance to different antibacterials. During the present study an extremophilic bacterium-A30 isolated from the marine waters was characterized and evaluated against four multi-drug resistant (MDR) pathogens, viz; Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The sensitivity pattern of the selected pathogens was tested with 31 antibiotics. Among the 47 marine microbial extracts tested on 4-MDR pathogens viz: Methicillin-resistant Staphylococcus aureus (MRSA), E. coli, K. pneumoniae and P. aeruginosa, only our strain A30 strain exhibited highest efficacy. This strain was subsequently subjected to 16S rDNA sequencing which confirmed its allocation as Bacillus cereus. Silver nanoparticle (AgNPs) synthesis and ethyl acetate extraction were performed using the supernatant of B. cereus. The synthesized AgNPs were characterized by UV-Visible, Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), Field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Zeta potential analyses. The presence of functional groups and 13 bioactive components in the ethyl acetate extract were analyzed using FT-IR and gas chromatography-mass spectrometry (GC-MS). The synthesized of AgNPs and the ethyl acetate extract showed preponderant activity against P. aeruginosa and MRSA, respectively. The effects of AgNPs were significant when compared to ethyl acetate extract. Therefore, the halophilic bacterium, B. cereus mediated AgNPs could provide antibacterial applications in the biomedical industries.
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Takenaka, Shinji; Cheng, Minyi; Mulyono; Koshiya, Atsushi; Murakami, Shuichiro; Aoki, Kenji
2009-01-01
Bacillus cereus strain 10-L-2 synthesizes two arylamine N-acetyltransferases (Nat-a and Nat-b) with broad substrate specificities toward aniline and its derivatives. In southern blot analysis using probes encoding the NH2-terminus of Nat-b and a conserved region of N-acetyltransferases, digested total DNA of strain 10-L-2 showed one positive band. We cloned and sequenced the gene encoding Nat-b. The NH2-terminal amino acid sequence predicted from the open reading frame (768 base pairs) corresponded to that of purified Nat-b. The cloned Nat-b gene was expressed in Escherichia coli. The expressed enzyme (BcNAT) from the recombinant strain was partially purified and characterized. Nat-b from strain 10-L-2 and BcNAT from the recombinant strain were slightly different from each others in substrate specificity and thermo-stability. We examined the biotransformations of 2-aminophenols and phenylenediamines by the whole cells of the recombinant strain. The cells converted these compounds into their corresponding acetanilides. Only one amino group of phenylenediamines was acetylated. The cells utilized 4-nitroacetanilide as an acetyl donor instead of acetyl-CoA. 4-Aminoacetanilide was produced and 4-nitroaniline was released almost stoichiometrically.
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Expression and characterization of aiiA gene from Bacillus subtilis BS-1.
Pan, Jieru; Huang, Tianpei; Yao, Fan; Huang, Zhipeng; Powell, Charles A; Qiu, Sixin; Guan, Xiong
2008-01-01
AHL-lactonase (AiiA), a metallo-beta-lactamase produced by Bacillus thuringiensis, Bacillus cereus and Bacillus anthracis, specifically hydrolyzes N-acyl-homoserine lactones (AHLs) secreted by Gram-negative bacteria and thereby attenuates the symptoms caused by plant pathogens. In this study, an aiiA gene was cloned from Bacillus subtilis BS-1 by PCR with a pair of degenerate primers. The deduced 250 amino acid sequence contained two small conserved regions, 103SHLHFDH109 and 166TPGHTPGH173, which are characteristic of the metallo-beta-lactamase family. Homology comparison revealed that the deduced amino acid sequence had a high degree of similarity with those of the known AiiA proteins in the B. cereus group. Additionally, the aiiA gene was expressed in Escherichia coli BL21 (DE3) pLysS and the expressed AiiA protein could attenuate the soft rot symptoms caused by Erwinia carotovora var. carotovora.
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Hu, Haijing; Wang, Cong; Li, Xia; Tang, Yunyun; Wang, Yufang; Chen, Shuanglin; Yan, Shuzhen
2018-05-08
The endophytic bacteria Bacillus cereus BCM2 has shown great potential as a defense against the parasitic nematode Meloidogyne incognita. Here, we studied the endophytic bacteria-mediated plant defense against M. incognita and searched for defense-related candidate genes using RNA-Seq. The induced systemic resistance of BCM2 against M. incognita was tested using the split-root method. Pre-inoculated BCM2 on the inducer side was associated with a dramatic reduction in galls and egg masses at the responder side, but inoculated BCM2 alone did not produce the same effect. In order to investigate which plant defense-related genes are specifically activated by BCM2, four RNA samples from tomato roots were sequenced, and four high quality total clean bases were obtained, ranging from 6.64 to 6.75 Gb, with an average of 21558 total genes. The 34 candidate defense-related genes were identified by pair-wise comparison among libraries, representing the targets for BCM2 priming resistance against M. incognita. Functional characterization revealed that the plant-pathogen interaction pathway (ID: ko04626) was significantly enriched for BCM2-mediated M. incognita resistance. This study demonstrates that B. cereus BCM2 maintains a harmonious host-microbe relationship with tomato, but appeared to prime the plant, resulting in more vigorous defense response toward the infection nematode. This article is protected by copyright. All rights reserved.
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Faille, Christine; Jullien, Celine; Fontaine, Francoise; Bellon-Fontaine, Marie-Noelle; Slomianny, Christian; Benezech, Thierry
2002-08-01
The ability of bacterial spores and vegetative cells to adhere to inert surfaces was investigated by means of the number of adherent spores (Bacillus cereus and Bacillus subtilis spores) and Escherichia coli cells and their resistance to cleaning or rinsing procedures (adhesion strength). Six materials (glass, stainless steel, polyethylene high density (PEHD), polyamide-6, polyvinyl chloride, and Teflon) were tested. Slight differences in the number of adherent spores (less than 1 log unit) were observed between materials, but a higher number of adherent E. coli cells was found on the hydrophobic materials PEHD and Teflon. Conversely, the resistance of both B. cereus and B. subtilis spores to a cleaning procedure was significantly affected by the material. Hydrophobic materials were harder to clean. The topography parameter derived from the Abbott-Firestone curve, RVK, and, to a lesser extent, the widely used roughness parameters RA (average roughness) and Rz (maximal roughness), were related to the number of adherent cells. Lastly, the soiling level as well as the adhesion strength were shown to depend largely on the microorganism. The number of adhering B. cereus hydrophobic spores and their resistance to a cleaning procedure were found to be 10 times greater than those of the B. subtilis hydrophilic spores. Escherichia coli was loosely bound to all the materials tested, even after 24 h biofilm formation.
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Mahakarnchanakul, W; Beuchat, L R
1999-03-15
A study was done to determine the influence of temperature on growth and toxin production characteristics of psychrotrophic and mesophilic strains of Bacillus cereus when inoculated into mashed potatoes and chicken gravy containing various concentrations of sodium chloride and held at temperatures different from those at which cells had been cultured. Logarithmic growth phase cells (10 h, 30 degrees C) of psychrotrophic (F3802A/84) and mesophilic (B4ac-1) strains of Bacillus cereus were inoculated into rehydrated commercially processed instant mashed potatoes and chicken gravy supplemented with 0, 2, or 4% sodium chloride. Growth, survival, and diarrheal toxin production in potatoes and gravy held at 30, 37, and 10 degrees C (strain F3802A/84) or 30, 40, and 10 degrees C (strain B4ac-1) were monitored. Both strains grew in both foods containing no added sodium chloride or 2% sodium chloride when held at 30, 37, or 40 degrees C for 2 days. Strain B4ac-1 grew better than strain F3802A/84 in foods containing 4% sodium chloride. Maximum amounts of enterotoxin (1024 ng/g) were produced by strain B4ac-1 in chicken gravy held at 30 and 40 degrees C. Strain F3802A/84 grew to populations of 7 log10 CFU/g in foods containing no added sodium chloride or 2% sodium chloride at 10 degrees C. Strain F3802A/84 produced the highest amount of enterotoxin (1024 ng/g) at 30 degrees C in chicken gravy containing 0.7 or 2% sodium chloride; however, little or low amounts of toxin (4-16 ng/g) were produced in chicken gravy at 10 degrees C. Compared to strain B4ac-1, cells of strain F3802A/84 subjected to a downward shift in incubation temperature (10 degrees C) grew more rapidly in chicken gravy. Strain B4ac-1 produced the highest amount of toxin (1024 ng/g) at 30 degrees C in gravy containing 4% sodium chloride and at 40 degrees C in gravy containing 0.7% sodium chloride. Toxin was not detected in inoculated mashed potatoes. Results of this study indicate that shifts in incubation
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Heat resistance of Bacillus cereus spores: effects of milk constituents and stabilizing additives.
Mazas, M; López, M; Martínez, S; Bernardo, A; Martin, R
1999-04-01
Heat resistance of Bacillus cereus spores (ATCC 7004, 4342, and 9818) heated in different types of milk (skim, whole, and concentrated skim milk), skim milk containing stabilizing additives (sodium citrate, monopotassium phosphate, or disodium phosphate, 0.1%), and cream was investigated. Thermal resistance experiments were performed at temperatures within the range of 92 to 115 degrees C under continuous monitoring of pH. For strain 4342 no significant differences (P < 0.05) in D values were detected in any case. For strains 7004 and 9818 higher D values of about 20% were obtained in whole and concentrated skim milk than those calculated in skim milk. From all stabilizing additives tested, only sodium citrate and sodium phosphate increased the heat resistance for strain 9818. However, when the menstruum pH was measured at the treatment temperature, different pH values were found between the heating media. The differences in heat resistance observed could be due to a pH effect rather than to the difference in the substrates in which spores were heated. In contrast, when cream (fat content 20%) was used, lower D values were obtained, especially for strains 7004 and 9818. z values were not significantly modified by the milk composition, with an average z value of 7.95+/-0.20 degrees C for strain 7004, 7.88+/-0.10 degrees C for strain 4342, and 9.13+/-0.16 degrees C for strain 9818.
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Carvacrol suppresses high pressure high temperature inactivation of Bacillus cereus spores.
Luu-Thi, Hue; Corthouts, Jorinde; Passaris, Ioannis; Grauwet, Tara; Aertsen, Abram; Hendrickx, Marc; Michiels, Chris W
2015-03-16
The inactivation of bacterial spores generally proceeds faster and at lower temperatures when heat treatments are conducted under high pressure, and high pressure high temperature (HPHT) processing is, therefore, receiving an increased interest from food processors. However, the mechanisms of spore inactivation by HPHT treatment are poorly understood, particularly at moderately elevated temperature. In the current work, we studied inactivation of the spores of Bacillus cereus F4430/73 by HPHT treatment for 5 min at 600MPa in the temperature range of 50-100°C, using temperature increments of 5°C. Additionally, we investigated the effect of the natural antimicrobial carvacrol on spore germination and inactivation under these conditions. Spore inactivation by HPHT was less than about 1 log unit at 50 to 70°C, but gradually increased at higher temperatures up to about 5 log units at 100°C. DPA release and loss of spore refractility in the spore population were higher at moderate (≤65°C) than at high (≥70°C) treatment temperatures, and we propose that moderate conditions induced the normal physiological pathway of spore germination resulting in fully hydrated spores, while at higher temperatures this pathway was suppressed and replaced by another mechanism of pressure-induced dipicolinic acid (DPA) release that results only in partial spore rehydration, probably because spore cortex hydrolysis is inhibited. Carvacrol strongly suppressed DPA release and spore rehydration during HPHT treatment at ≤65°C and also partly inhibited DPA release at ≥65°C. Concomitantly, HPHT spore inactivation was reduced by carvacrol at 65-90°C but unaffected at 95-100°C. Copyright © 2014 Elsevier B.V. All rights reserved.
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Faille, C; Bénézech, T; Blel, W; Ronse, A; Ronse, G; Clarisse, M; Slomianny, C
2013-04-01
This study was designed to evaluate the respective roles of mechanical and chemical effects on the removal of Bacillus spores during cleaning-in-place. This analysis was performed on 12 strains belonging to the Bacillus cereus group (B. cereus, Bacillus anthracis, Bacillus thuringiensis) or to less related Bacillus species (Bacillus pumilus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus subtilis). Adherent spores were subjected to rinsing-in-place (mechanical action) and cleaning-in-place (mechanical and chemical actions) procedures, the latter involving NaOH 0.5% at 60°C. Results revealed that mechanical action alone only removed between 53 and 89% of the attached spores at a shear stress of 500 Pa. This resistance to shear was not related to spore surface properties. Conversely, in the presence of NaOH at a shear stress of 4 Pa, spores were readily detached, with between 80 and 99% of the adherent spores detached during CIP and the chemical action greatly depended on the strain. This finding suggests that chemical action plays the major role during CIP, whose efficacy is significantly governed by the spore surface chemistry. Copyright © 2012 Elsevier Ltd. All rights reserved.
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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.
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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
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2011-01-01
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 appears to have preferentially
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Zhan, Tao; Zhang, Kai; Chen, Yangyan; Lin, Yongjun; Wu, Gaobing; Zhang, Lili; Yao, Pei; Shao, Zongze; Liu, Ziduo
2013-01-01
Glyphosate, a broad spectrum herbicide widely used in agriculture all over the world, inhibits 5-enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway, and glycine oxidase (GO) has been reported to be able to catalyze the oxidative deamination of various amines and cleave the C-N bond in glyphosate. Here, in an effort to improve the catalytic activity of the glycine oxidase that was cloned from a glyphosate-degrading marine strain of Bacillus cereus (BceGO), we used a bacteriophage T7 lysis-based method for high-throughput screening of oxidase activity and engineered the gene encoding BceGO by directed evolution. Six mutants exhibiting enhanced activity toward glyphosate were screened from two rounds of error-prone PCR combined with site directed mutagenesis, and the beneficial mutations of the six evolved variants were recombined by DNA shuffling. Four recombinants were generated and, when compared with the wild-type BceGO, the most active mutant B3S1 showed the highest activity, exhibiting a 160-fold increase in substrate affinity, a 326-fold enhancement in catalytic efficiency against glyphosate, with little difference between their pH and temperature stabilities. The role of these mutations was explored through structure modeling and molecular docking, revealing that the Arg51 mutation is near the active site and could be an important residue contributing to the stabilization of glyphosate binding, while the role of the remaining mutations is unclear. These results provide insight into the application of directed evolution in optimizing glycine oxidase function and have laid a foundation for the development of glyphosate-tolerant crops. PMID:24223901
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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
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Mahakarnchanakul, W; Beuchat, L R
1999-01-01
A shift in growth temperature of a psychrotrophic (F3802A/84) strain and a mesophilic strain (B4ac-1) of Bacillus cereus grown at 30 degrees C for 10 h, then at 37 degrees C or 40 degrees C for 14 h, enhanced thermotolerance. Sodium chloride, at concentrations of 2.0 and 4.0% in brain heart infusion (BHI) broth, had no effect on thermotolerance of strain B4ac-1 heated at 50 degrees C, whereas the same concentrations of NaCl caused a decrease in thermotolerance of strain F3802A/84 heated at 48 degrees C. A downshift in growth temperature from 30 degrees C to 10 degrees C followed by incubation for 3 to 9 days increased thermotolerance of strain F3802A/84 but not strain B4ac-1 heated in BHI broth containing 2.0 or 4.0% NaCl compared to thermotolerance in BHI broth containing 0.5% NaCl. Protein analysis using one-dimensional gel electrophoresis revealed an increase in proteins with molecular weights of 54, 50, 44, and 42 kDa in cells of strain F3802A/84 and 83 and 69 kDa in cells of strain B4ac-1 subjected to an upshift in growth temperature from 30 degrees C to 37 degrees C or 40 degrees C, respectively. A downshift in growth temperature from 30 degrees C to 10 degrees C resulted in substantial amounts of proteins with molecular weights of 63, 40, and 29 kDa produced by strain F3802A/84 and 63 kDa to be produced by strain B4ac-1. Proteins produced in response to upshift or downshift in growth temperature are suspected to play an important role in heat resistance of the psychrotrophic and mesophilic strains of B. cereus examined in this study. Changes in resistance to heat or refrigeration temperatures, as well as tolerance to NaCl, as affected by previous exposure of cells to temperature shifts may influence the ability of B. cereus to grow in minimally processed foods during distribution and storage.
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NASA Astrophysics Data System (ADS)
Loukanov, Alexandre; Filipov, Chavdar; Valcheva, Violeta; Lecheva, Marta; Emin, Saim
2015-04-01
The semiconductor zinc oxide nanomaterial (ZnO or ZnO:H) is widely used in advanced biosensor technology for the design of highly-sensitive detector elements for various applications. In the attempt to evaluate its effect on common microorganisms, two types of nanostructured transducer films have been used (average diameter 600-1000 nm). They have been prepared by using both wet sol-gel method and magnetron sputtering. Their polycrystalline structure and specific surface features have been analyzed by X-ray diffraction (XRD), scanning electron microscope, and atomic force microscope. The assessment of growth stimulation of bacteria was determined using epifluorescent microscope by cell staining with Live/Dead BacLight kit. In our experiments, the growth stimulation of Gram-positive and Gram-negative bacteria on nanostructured ZnO film is demonstrated by Bacillus cereus and Pseudomonas putida. These two bacterial species have been selected, because they are well known and studied in biosensor technologies, with structural difference of their cell walls. These pathogens are easy for with common source in the liquid food or some commercial products. Our data has revealed that the method of transducer film preparation influences strongly bacterial inhibition and division. These results present the transforming signal precisely, when ZnO is used in biosensor applications.
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Study of the Bacillus flora of Nigerian spices.
Antai, S P
1988-05-01
Bacteriological examination of 230 samples of five different unprocessed spices (aligator pepper, red pepper, black pepper, thyme and curry powder) collected randomly from Port Harcourt main markets revealed that the spices were highly contaminated, with bacterial counts ranging from 1.8 x 10(4) to 1.1 x 10(8) per gram. Bacillus cereus was isolated in high numbers in the majority of the 230 samples examined. It was also observed that other Bacillus spp. including B. subtilis, B. polymyxa and B. coagulans occurred in significant numbers.
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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. Copyright © 2015. Published by Elsevier B.V.
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Class IV polyhydroxyalkanoate (PHA) synthases and PHA-producing Bacillus.
Tsuge, Takeharu; Hyakutake, Manami; Mizuno, Kouhei
2015-08-01
This review highlights the recent investigations of class IV polyhydroxyalkanoate (PHA) synthases, the newest classification of PHA synthases. Class IV synthases are prevalent in organisms of the Bacillus genus and are composed of a catalytic subunit PhaC (approximately 40 kDa), which has a PhaC box sequence ([GS]-X-C-X-[GA]-G) at the active site, and a second subunit PhaR (approximately 20 kDa). The representative PHA-producing Bacillus strains are Bacillus megaterium and Bacillus cereus; the nucleotide sequence of phaC and the genetic organization of the PHA biosynthesis gene locus are somewhat different between these two strains. It is generally considered that class IV synthases favor short-chain-length monomers such as 3-hydroxybutyrate (C4) and 3-hydroxyvalerate (C5) for polymerization, but can polymerize some unusual monomers as minor components. In Escherichia coli expressing PhaRC from B. cereus YB-4, the biosynthesized PHA undergoes synthase-catalyzed alcoholytic cleavage using endogenous and exogenous alcohols. This alcoholysis is thought to be shared among class IV synthases, and this reaction is useful not only for the regulation of PHA molecular weight but also for the modification of the PHA carboxy terminus. The novel properties of class IV synthases will open up the possibility for the design of new PHA materials.
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Kovács, Ákos T
2016-07-01
The impact of gene mutations on the growth of the cells can be studied using pure cultures. However, the importance of certain proteins and pathways can be also examined via co-culturing wild type and its mutant derivative. Here, the relative fitness of a mutant strain that lacks the global nitrogen regulator, CodY, was examined in Bacillus cereus, a food poisoning Gram-positive bacterium. Fitness measurements revealed that the ΔcodY strain was outcompeted when cocultured with the wild-type ATCC 14579 under various rich laboratory medium, and also when inoculated in certain beverages. In nutrient-poor minimal medium, the ΔcodY mutant had comparable fitness to the wild-type strain. Interestingly, the relative fitness of the ΔcodY strain was antagonistic when it was cultivated in apple or orange juices due to unknown properties of these beverages, highlighting the importance of chemical composition of the test medium during the bacterial fitness measurements. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Shameer, Syed
2016-12-01
Extracellular Polysaccharides (EPS) from both prokaryotes and eukaryotes have a great deal of research interest as they protect the producer from different stresses including antibiotics, ionic stress, desiccation and assist in bio-film formation, pathogenesis, adhesion, etc. In this study haloalkaliphilic Bacillus sp., known to cope with osmophilic stress, was selected and screened for EPS production. The EPS were isolated, partially purified and chemical characteristics were documented using liquid FT-IR followed by assessment of heavy metal biosorption (lead, copper and cadmium) using Atomic Absorption Spectroscopy (AAS). The EPS extracted from three isolates B. licheniformis NSPA5, B. cereus NSPA8 and B. subtilis NSPA13 showed maximum biosorption of Lead followed by Copper and Cadmium. Of the tested isolates, the EPS from isolate B. cereus NSPA8 showed maximum (90 %) biosorption of the lead.
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Kabir, M Shahjahan; Hsieh, Ying-Hsin; Simpson, Steven; Kerdahi, Khalil; Sulaiman, Irshad M
2017-06-01
The genus Bacillus is a group of gram-positive endospore-forming bacteria that can cause food poisoning and diarrheal illness in humans. A wide range of food products have been linked to foodborne outbreaks associated with these opportunistic pathogens. The U.S. Food and Drug Administration recommends (in their Bacteriological Analytical Manual) the use of Bacara or mannitol egg yolk polymyxin (MYP) agar plates and the most-probable-number (MPN) method for enumeration and confirmation of Bacillus cereus and related species isolated from foods, sporadic cases, outbreaks, and routine environmental surveillance samples. We performed a comparative analysis of two chromogenic media (Bacara and Brilliance) and two traditional media (MYP and polymyxin egg yolk mannitol bromothymol blue agar [PEMBA]) for the isolation and enumeration of 16 Bacillus species under modified growth conditions that included pH, temperature, and dilution factor. A total of 50 environmental, food, and American Type Culture Collection reference isolates from 16 distinct Bacillus species were evaluated. A food adulteration experiment also was carried out by artificially adulterating two baby food matrices with two isolates each of B. cereus and Bacillus thuringiensis . Our results clearly indicated that chromogenic plating media (Bacara and Brilliance) are better than conventional standard media (MYP and PEMBA) for the detection and enumeration of B. cereus in foods and other official regulatory samples. The comparison of the two chromogenic media also indicated that Brilliance medium to be more efficient and selective for the isolation of Bacillus.
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β-Lactamase Genes of the Penicillin-Susceptible Bacillus anthracis Sterne Strain
Chen, Yahua; Succi, Janice; Tenover, Fred C.; Koehler, Theresa M.
2003-01-01
Susceptibility to penicillin and other β-lactam-containing compounds is a common trait of Bacillus anthracis. β-lactam agents, particularly penicillin, have been used worldwide to treat anthrax in humans. Nonetheless, surveys of clinical and soil-derived strains reveal penicillin G resistance in 2 to 16% of isolates tested. Bacterial resistance to β-lactam agents is often mediated by production of one or more types of β-lactamases that hydrolyze the β-lactam ring, inactivating the antimicrobial agent. Here, we report the presence of two β-lactamase (bla) genes in the penicillin-susceptible Sterne strain of B. anthracis. We identified bla1 by functional cloning with Escherichia coli. bla1 is a 927-nucleotide (nt) gene predicted to encode a protein with 93.8% identity to the type I β-lactamase gene of Bacillus cereus. A second gene, bla2, was identified by searching the unfinished B. anthracis chromosome sequence database of The Institute for Genome Research for open reading frames (ORFs) predicted to encode β-lactamases. We found a partial ORF predicted to encode a protein with significant similarity to the carboxy-terminal end of the type II β-lactamase of B. cereus. DNA adjacent to the 5′ end of the partial ORF was cloned using inverse PCR. bla2 is a 768-nt gene predicted to encode a protein with 92% identity to the B. cereus type II enzyme. The bla1 and bla2 genes confer ampicillin resistance to E. coli and Bacillus subtilis when cloned individually in these species. The MICs of various antimicrobial agents for the E. coli clones indicate that the two β-lactamase genes confer different susceptibility profiles to E. coli; bla1 is a penicillinase, while bla2 appears to be a cephalosporinase. The β-galactosidase activities of B. cereus group species harboring bla promoter-lacZ transcriptional fusions indicate that bla1 is poorly transcribed in B. anthracis, B. cereus, and B. thuringiensis. The bla2 gene is strongly expressed in B. cereus and B
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Nishanth Kumar, S; Nath, Vishnu Sukumari; Pratap Chandran, R; Nambisan, Bala
2014-02-01
The cell free culture filtrate of Bacillus cereus associated with an entomopathogenic nematode, Rhabditis (Oscheius) sp. exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain four bioactive compounds. The structure and absolute stereochemistry of these compounds were determined based on extensive spectroscopic analyses (FABMS, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, (1)H-(13)C HMBC) and Marfey's method. The compounds were identified as cyclic dipeptides (CDPs): cyclo(L-Pro-L-Trp), cyclo(L-Leu-L-Val), cyclo(D-Pro-D-Met), and cyclo(D-Pro-D-Phe), respectively. Compounds recorded significant antibacterial activity against all the test bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and methicillin-resistant S. aureus) except cyclo(L-Leu-L-Val). Cyclo(L-Leu-L-Val) recorded activity only against Gram positive bacteria. Best antibacterial activity was recorded by cyclo(L-Pro-L-Trp) against S. aureus (4 μg/ml). The four compounds were active against all the five fungi tested (Trichophyton rubrum, Aspergillus flavus, Candida albicans, Candida tropicalis and Cryptococcus neoformans) and the activity was compared with amphotericin B, the standard fungicide. The highest activity of 1 μg/ml by cyclo(L-Pro-L-Trp) was recorded against T. rubrum, a human pathogen responsible for causing athlete's foot, jock itch, and ringworm. The activity of cyclo(L-Pro-L-Trp) against T. rubrum, C. neoformans and C. albicans were better than amphotericin B, the standard antifungal agent. To our knowledge, this is the first report of antifungal activity of CDPs against the human pathogenic fungi T. rubrum and C. neoformans. The four CDPs are nontoxic to healthy human cell line up to 200 μg/ml. We conclude that the bacterium associated with entomopathogenic nematode is promising sources of natural antimicrobial
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1987-07-01
nontransformable Bacillus species such as B. anthracis. Our results suggest that plasmid pLS20 of Bacillus subtilis ( natto ), which promotes transfer of the...mobilizing pBC16, pLS20 mediates transfer of the B. subtills ( natto ) plasmid pLS19 and the Staphylococcus aureus plasmid pUB110. To facilitate direct...and (v) transformation of B. cereus and B. anthracis with plasmid DNA. The 55-kb plasmid, pLS20, of Bacillus subtilis ( natto ) 3335 promotes tr msfer
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Esteban, Maria-Dolores; Conesa, Raquel; Huertas, Juan-Pablo; Palop, Alfredo
2015-06-01
Members of the genus Bacillus include important food-borne pathogen and spoilage microorganisms for food industry. Essential oils are natural products extracted from herbs and spices, which can be used as natural preservatives in many foods because of their antibacterial, antifungal, antioxidant and anti-carcinogenic properties. The aim of this research was to explore the effect of the addition of different concentrations of thymol to the heating and recovery media on the thermal resistance of spores of Bacillus cereus, Bacillus licheniformis and Bacillus subtilis at different temperatures. While the heat resistance was hardly reduced when thymol was present in the heating medium, the effect in the recovery medium was greater, reducing the D100 °C values down to one third for B. subtilis and B. cereus when 0.5 mM thymol was added. This effect was dose dependent and was also observed at other heating temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Ranjan, Preeti; Pandey, Ashok; Binod, Parameswaran
2017-09-01
Chiral intermediates have wide application and high demand in pharmaceutical, agricultural, and other biotechnological industries for the preparation of bulk drug substances or fine chemicals. (S)-1-(1-napthyl) ethanol is an important synthetic intermediate of mevinic acid analog and a potential inhibitor of 3-hydroxy methyl glutaryl coenzyme A reductase enzymes which is rate limiting for cholesterol synthesis. The present study focuses on the resolution of (RS)-1-(1-napthyl) ethanol using whole cell biotransformation approach. The screening of microbial strains for the specific conversion were performed by the enrichment techniques using (RS)-1-(1-napthyl) ethanol. Evaluation of resolution, i.e., the enantioselective conversion of (R)-1-(1-napthyl) ethanol into 1-acetonapthone and production of (S)-1-(1-napthyl) ethanol with high purity were carried out. Among the isolates, a novel strain Bacillus cereus WG3 was found to be potent for the resolution and conversion of (S)-1-(1-napthyl) ethanol. This strain showed 86% conversion of (R)-1-(1-napthyl) ethanol and 95% yield of S-1-(1-napthyl) ethanol with 80% ee after 24 h. Further, the optimization of biotransformation reactions was carried out and the optimal parameters were found to be pH 7.0 and temperature 30 °C. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Decontamination of fluid milk containing Bacillus spores using commercial household products.
Black, D G; Taylor, T M; Kerr, H J; Padhi, S; Montville, T J; Davidson, P M
2008-03-01
Although commercial sanitizers can inactivate bacterial spores in food processing environments, relatively little data exist as to the decontamination of products and surfaces by consumers using commercial household products. Should a large scale bioterrorism incident occur in which consumer food products were contaminated with a pathogenic sporeformer such as Bacillus anthracis, there may be a need to decontaminate these products before disposal as liquid or solid waste. Studies were conducted to test the efficacy of commercial household products for inactivating spores of Bacillus cereus (used as a surrogate for B. anthracis) in vitro and in fluid milk. Validation of the resistance of the B. cereus spores was confirmed with B. anthracis spores. Fifteen commercial products, designed as either disinfectants or sanitizers or as potential sanitizers, were purchased from retail markets. Products selected had one of the following active compounds: NaOCl, HCl, H2O2, acetic acid, quaternary ammonium compounds, ammonium hydroxide, citric acid, isopropanol, NaOH, or pine oil. Compounds were diluted in water (in vitro) or in 2% fat fluid milk, and spores were exposed for up to 6 h. Products containing hypochlorite were most effective against B. cereus spores. Products containing HCl or H2O2 also reduced significant numbers of spores but at a slower rate. The resistance of spores of surrogate B. cereus strains to chlorine-containing compounds was similar to that of B. anthracis spores. Therefore, several household products on the market may be used to decontaminate fluid milk or similar food products contaminated by spores of B. anthracis.
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Food poisoning potential of Bacillus cereus strains from Norwegian dairies.
Stenfors Arnesen, Lotte P; O'sullivan, Kristin; Granum, Per Einar
2007-05-10
Characteristics concerning diarrhoeal potential were investigated in B. cereus dairy strains. The thirty-nine strains, isolated from whipping cream, were tested for cytotoxicity after culturing at human body temperature as well as 25 degrees C and 32 degrees C. At 37 degrees C, none of the strains were highly cytotoxic. This observation suggests that those strains should be considered to pose a minor risk with regard to diarrhoeal food poisoning. However, some strains were moderately or highly cytotoxic when grown at 25 degrees C and 32 degrees C. While the majority of the strains were able to grow at refrigeration temperatures, only four B. weihenstephanensis strains were identified among them when subjected to discriminative PCR assays and growth temperatures which delimit this species.
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Saile, Elke; Klee, Silke R.; Hoffmaster, Alex; Kannenberg, Elmar L.
2017-01-01
Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and Bc 03BB87 have secondary cell wall polysaccharides (SCWPs) comprising an aminoglycosyl trisaccharide repeat: →4)-β-d-ManpNAc-(1→4)-β-d-GlcpNAc-(1→6)-α-d-GlcpNAc-(1→, substituted at GlcNAc residues with both α- and β-Galp. In Bc G9241 and Bc 03BB87, an additional α-Galp is attached to O-3 of ManNAc. Using NMR spectroscopy, mass spectrometry and immunochemical methods, we compared these structures to SCWPs from Bc biovar anthracis strains isolated from great apes displaying “anthrax-like” symptoms in Cameroon (Bc CA) and Côte d’Ivoire (Bc CI). The SCWPs of Bc CA/CI contained the identical HexNAc trisaccharide backbone and Gal modifications found in Ba, together with the α-Gal-(1→3) substitution observed previously at ManNAc residues only in Bc G9241/03BB87. Interestingly, the great ape derived strains displayed a unique α-Gal-(1→3)-α-Gal-(1→3) disaccharide substitution at some ManNAc residues, a modification not found in any previously examined Ba or Bc strain. Immuno-analysis with specific polyclonal anti-Ba SCWP antiserum demonstrated a reactivity hierarchy: high reactivity with SCWPs from Ba 7702 and Ba Sterne 34F2, and Bc G9241 and Bc 03BB87; intermediate reactivity with SCWPs from Bc CI/CA; and low reactivity with the SCWPs from structurally distinct Ba CDC684 (a unique strain producing an SCWP lacking all Gal substitutions) and non-infection-associated Bc ATCC10987 and Bc 14579 SCWPs. Ba-specific monoclonal antibody EAII-6G6-2-3 demonstrated a 10–20 fold reduced reactivity to Bc G9241 and Bc 03BB87 SCWPs compared to Ba 7702/34F2, and low/undetectable reactivity to SCWPs from Bc CI, Bc CA, Ba CDC684, and non-infection-associated Bc strains. Our data indicate that the HexNAc motif is conserved among infection-associated Ba and Bc isolates (regardless of human or great ape origin), and that the number, positions and structures of Gal
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Kamal, Nazia; Ganguly, Jhuma; Saile, Elke; Klee, Silke R; Hoffmaster, Alex; Carlson, Russell W; Forsberg, Lennart S; Kannenberg, Elmar L; Quinn, Conrad P
2017-01-01
Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and Bc 03BB87 have secondary cell wall polysaccharides (SCWPs) comprising an aminoglycosyl trisaccharide repeat: →4)-β-d-ManpNAc-(1→4)-β-d-GlcpNAc-(1→6)-α-d-GlcpNAc-(1→, substituted at GlcNAc residues with both α- and β-Galp. In Bc G9241 and Bc 03BB87, an additional α-Galp is attached to O-3 of ManNAc. Using NMR spectroscopy, mass spectrometry and immunochemical methods, we compared these structures to SCWPs from Bc biovar anthracis strains isolated from great apes displaying "anthrax-like" symptoms in Cameroon (Bc CA) and Côte d'Ivoire (Bc CI). The SCWPs of Bc CA/CI contained the identical HexNAc trisaccharide backbone and Gal modifications found in Ba, together with the α-Gal-(1→3) substitution observed previously at ManNAc residues only in Bc G9241/03BB87. Interestingly, the great ape derived strains displayed a unique α-Gal-(1→3)-α-Gal-(1→3) disaccharide substitution at some ManNAc residues, a modification not found in any previously examined Ba or Bc strain. Immuno-analysis with specific polyclonal anti-Ba SCWP antiserum demonstrated a reactivity hierarchy: high reactivity with SCWPs from Ba 7702 and Ba Sterne 34F2, and Bc G9241 and Bc 03BB87; intermediate reactivity with SCWPs from Bc CI/CA; and low reactivity with the SCWPs from structurally distinct Ba CDC684 (a unique strain producing an SCWP lacking all Gal substitutions) and non-infection-associated Bc ATCC10987 and Bc 14579 SCWPs. Ba-specific monoclonal antibody EAII-6G6-2-3 demonstrated a 10-20 fold reduced reactivity to Bc G9241 and Bc 03BB87 SCWPs compared to Ba 7702/34F2, and low/undetectable reactivity to SCWPs from Bc CI, Bc CA, Ba CDC684, and non-infection-associated Bc strains. Our data indicate that the HexNAc motif is conserved among infection-associated Ba and Bc isolates (regardless of human or great ape origin), and that the number, positions and structures of Gal
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Detection of Bacillus spores within 15 minutes by surface-enhanced Raman spectroscopy
NASA Astrophysics Data System (ADS)
Shende, Chetan; Inscore, Frank; Huang, Hermes; Farquharson, Stuart; Sengupta, Atanu
2012-06-01
Since the distribution of Bacillus anthracis causing spores through the US Postal System, there has been a persistent fear that biological warfare agents (BWAs) will be used by terrorists against our military abroad and our civilians at home. Despite the substantial effort to develop BWA analyzers, they remain either too slow, produce high falsealarm rates, lack sensitivity, or cannot be fielded. Consequently there remains a need for a portable analyzer that can overcome these limitations as expressed at the 2011 Biological Weapons Convention. To meet this need we have been developing a sample system that selectively binds BWAs and produce surface-enhanced Raman (SER) spectra using portable Raman spectrometers. Here we describe the use of a short peptide ligand functionalized on silver nanoparticles to selectively capture Bacillus cereus spores (a surrogate of B. anthracis) and their subsequent detection by SER spectroscopy. This technique was used to specifically detect B. cereus spores over closely related species like B. subtilis belonging to the same genus within 15 minutes. Sensitivity of the method was demonstrated by detecting 104 B. cereus spores/mL of water. The technology, once developed should prove invaluable for rapid monitoring of BWAs, which will immensely help first responders and emergency personnel in implementing appropriate counter measures.
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Hyakutake, Manami; Tomizawa, Satoshi; Mizuno, Kouhei; Hisano, Tamao; Abe, Hideki; Tsuge, Takeharu
2015-06-01
Polyhydroxyalkanoate (PHA) synthase from Bacillus cereus YB-4 (PhaRCYB4) catalyzes not only PHA polymerization but also alcoholytic cleavage of PHA chains. The alcoholysis activity of PhaRCYB4 is expressed when a hydroxyacyl-CoA monomer is absent but an alcohol compound is present. In this study, we performed alanine mutagenesis of the putative catalytic triad (Cys(151), Asp(306), and His(335)) in the PhaCYB4 subunit to identify the active site residues for polymerization and alcoholysis activities. Individual substitution of each triad residue with alanine resulted in loss of both polymerization and alcoholysis activities, suggesting that these residues are commonly shared between polymerization and alcoholysis reactions. The loss of activity was also observed following mutagenesis of the triad to other amino acids, except for one PhaRCYB4 mutant with a C151S substitution, which lost polymerization activity but still possessed cleavage activity towards PHA chains. The low-molecular-weight PHA isolated from the PhaRCYB4(C151S)-expressing strain showed a lower ratio of alcohol capping at the P(3HB) carboxy terminus than did that from the wild-type-expressing strain. This observation implies that hydrolysis activity of PhaRCYB4 might be elicited by the C151S mutation.
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Bag, A; Chattopadhyay, R R
2017-11-01
The aim of the study was to evaluate possible antibacterial and antibiofilm efficacy of a bacteriocin, nisin with two essential oil components linalool and p-coumaric acid in combination against food-borne bacteria Bacillus cereus and Salmonella typhimurium. Their inhibition effects on planktonic cells and preformed biofilms were evaluated using microbroth dilution and checkerboard titration methods. Nisin/p-coumaric acid combination showed synergistic effects against planktonic cells of both the studied bacteria, whereas nisin/linalool combination showed synergistic activity against B. cereus and additive effect against S. typhimurium. In preformed biofilms, nisin by itself failed to show >50% antibiofilm efficacy against both the studied bacteria, but in combination with linalool and p-coumaric acid, it exerted >50% antibiofilm efficacy. On the basis of fractional inhibitory concentration indices values, nisin/p-coumaric acid combination exhibited synergistic antibiofilm activity, whereas nisin/linalool combination showed additive effects against preformed biofilms of studied bacteria. The results provide evidence that p-coumaric acid due to its synergistic interactions with nisin against planktonic cells and biofilms of both Gram-positive and Gram-negative food-borne bacteria enhanced the antibacterial spectrum of nisin, which subsequently may facilitate their use in the food industry. In the present work, synergistic interactions between a bacteriocin, nisin and essential oil component p-coumaric acid on planktonic cells as well as on biofilms of Gram-positive and Gram-negative food-borne bacteria have been reported. The results of this study provide evidence that nisin/p-coumaric acid combination can be considered as a promising source for development of more potent broad spectrum antimicrobial blend for food preservation, which subsequently may facilitate their use in the food industry. To the best of our knowledge, this is the first report of the
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Molecular mechanisms involved in Bacillus subtilis biofilm formation
Mielich-Süss, Benjamin; Lopez, Daniel
2014-01-01
Summary Biofilms are the predominant lifestyle of bacteria in natural environments, and they severely impact our societies in many different fashions. Therefore, biofilm formation is a topic of growing interest in microbiology, and different bacterial models are currently studied to better understand the molecular strategies that bacteria undergo to build biofilms. Among those, biofilms of the soil-dwelling bacterium Bacillus subtilis are commonly used for this purpose. Bacillus subtilis biofilms show remarkable architectural features that are a consequence of sophisticated programs of cellular specialization and cell-cell communication within the community. Many laboratories are trying to unravel the biological role of the morphological features of biofilms, as well as exploring the molecular basis underlying cellular differentiation. In this review, we present a general perspective of the current state of knowledge of biofilm formation in B. subtilis. In particular, a special emphasis is placed on summarizing the most recent discoveries in the field and integrating them into the general view of these truly sophisticated microbial communities. PMID:24909922
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Dash, Hirak R; Basu, Subham; Das, Surajit
2017-04-01
Biofilm-forming mercury-resistant marine bacterium Bacillus cereus BW-201B has been explored to evident that the bacterial biofilm-EPS (exopolymers) trap inorganic mercury but subsequently release EPS-bound mercury for induction of mer operon-mediated volatilization of inorganic mercury. The isolate was able to tolerate 50 ppm of mercury and forms biofilm in presence of mercury. mer operon-mediated volatilization was confirmed, and -SH was found to be the key functional group of bacterial EPS responsible for mercury binding. Biofilm-EPS-bound mercury was found to be internalized to the bacterial system as confirmed by reversible conformational change of -SH group and increased expression level of merA gene in a timescale experiment. Biofilm-EPS trapped Hg after 24 h of incubation, and by 96 h, the volatilization process reaches to its optimum confirming the internalization of EPS-bound mercury to the bacterial cells. Biofilm disintegration at the same time corroborates the results.
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Liang, Tzu-Wen; Hsieh, Jia-Lin; Wang, San-Lang
2012-11-15
A protease- and chitosanase-producing strain was isolated and identified as Bacillus cereus TKU022. The protease and chitosanase were both produced using 1.5% (w/v) shrimp head powder (SHP) as the sole carbon/nitrogen source, and these enzymes were purified from the culture supernatant. The molecular masses of the TKU022 protease and chitosanase determined using SDS-PAGE were approximately 45 and 44kDa, respectively. The high stability of the TKU022 protease toward surfactants, an optimal pH of 10 and an optimal temperature of 50-60°C suggest that this high-alkaline protease has potential applications for various industrial processes. Concomitant with the production of the TKU022 chitosanase, N-acetyl chitooligosaccharides were also observed in the culture supernatant, including (GlcNAc)(2), (GlcNAc)(4), (GlcNAc)(5), and (GlcNAc)(6) at concentrations of 201.5, 12.4, 0.5, and 0.3μg/mL, respectively, as determined using an HPLC analysis. The chitin oligosaccharides products were also characterized using a MALDI-TOF mass spectrometer. A combination of the HPLC and MALDI-TOF MS results showed that the chitin oligosaccharides of the TKU022 culture supernatant comprise oligomers with degree of polymerization (DP) from 2 to 6. Using this method, the production of a protease, a chitosanase, and chitin oligosaccharides may be useful for various industrial and biological applications. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Bacteriocin-like inhibitor substances produced by Mexican strains of Bacillus thuringiensis.
Barboza-Corona, J Eleazar; Vázquez-Acosta, Herminia; Bideshi, Dennis K; Salcedo-Hernández, Rubén
2007-02-01
Bacteriocins are antimicrobial peptides synthesized and secreted by bacteria and could potentially be used as natural food preservatives. Here, we report the production of bacteriocin-like inhibitor substances (Bt-BLIS) by five Mexican strains of Bacillus thuringiensis. Bacillus thuringiensis subsp. morrisoni (LBIT 269), B. thuringiensis subsp. kurstaki (LBIT 287), B. thuringiensis subsp kenyae (LBIT 404), B. thuringiensis subsp. entomocidus (LBIT 420) and B. thuringiensis subsp. tolworthi (LBIT 524) produced proteinaceous Bt-BLIS with high levels of activity against Bacillus cereus and other gram-positive bacteria. Although none was active against the gram-negative bacteria, Escherichia coli, Shigella species and Pseudomonas aeruginosa, the five Bt-BLIS demonstrated antimicrobial activity against Vibrio cholerae, the etiologic agent of cholera. Biochemical and biophysical studies demonstrated that the five Bt-BLIS could be categorized into two groups, those produced by LBIT 269 and 287 (Group A) and LBIT 404, 420, 524 (Group B), based on relative time of peptide synthesis, distinctive bacterial target specificity and stability in a wide range of temperatures and pH. Because of their stability and bactericidal activities against B. cereus and V. cholerae agents of emetic, diarrheal and lethal syndromes in humans, these Bt-BLIS could potentially be used as biodegradable preservatives in the food industry.
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Complete Genome Sequences of Bacillus Phages Janet and OTooleKemple52
2018-01-01
ABSTRACT We report here the genome sequences of two novel Bacillus cereus group-infecting bacteriophages, Janet and OTooleKemple52. These bacteriophages are double-stranded DNA-containing Myoviridae isolated from soil samples. While their genomes share a high degree of sequence identity with one another, their host preferences are unique. PMID:29748396
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Complete Genome Sequences of Bacillus Phages Janet and OTooleKemple52.
Kent, Brenna; Raymond, Thomas; Mosier, Philip D; Johnson, Allison A
2018-05-10
We report here the genome sequences of two novel Bacillus cereus group-infecting bacteriophages, Janet and OTooleKemple52. These bacteriophages are double-stranded DNA-containing Myoviridae isolated from soil samples. While their genomes share a high degree of sequence identity with one another, their host preferences are unique. Copyright © 2018 Kent et al.
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Investigating the Genome Diversity of B. cereus and Evolutionary Aspects of B. anthracis Emergence
Papazisi, Leka; Rasko, David A.; Ratnayake, Shashikala; Bock, Geoff R.; Remortel, Brian G.; Appalla, Lakshmi; Liu, Jia; Dracheva, Tatiana; Braisted, John C.; Shallom, Shamira; Jarrahi, Benham; Snesrud, Erik; Ahn, Susie; Sun, Qiang; Rilstone, Jenifer; Økstad, Ole Andreas; Kolstø, Anne-Brit; Fleischmann, Robert D.; Peterson, Scott N.
2011-01-01
Here we report the use of a multi-genome DNA microarray to investigate the genome diversity of Bacillus cereus group members and elucidate the events associated with the emergence of B. anthracis the causative agent of anthrax–a lethal zoonotic disease. We initially performed directed genome sequencing of seven diverse B. cereus strains to identify novel sequences encoded in those genomes. The novel genes identified, combined with those publicly available, allowed the design of a “species” DNA microarray. Comparative genomic hybridization analyses of 41 strains indicates that substantial heterogeneity exists with respect to the genes comprising functional role categories. While the acquisition of the plasmid-encoded pathogenicity island (pXO1) and capsule genes (pXO2) represent a crucial landmark dictating the emergence of B. anthracis, the evolution of this species and its close relatives was associated with an overall a shift in the fraction of genes devoted to energy metabolism, cellular processes, transport, as well as virulence. PMID:21447378
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Watanabe, K; Hayano, K
1993-07-01
Proteolytic bacteria in paddy field soils under rice cultivation were characterized and enumerated using azocoll agar plates. Bacillus spp. were the proteolytic bacteria that were most frequently present, comprising 59% of the isolates. They were always the numerically dominant proteolytic bacteria isolated from three kinds of fertilizer treatments (yearly application of rice-straw compost and chemical fertilizer, yearly application of chemical fertilizer, and no fertilizer application) and at three different stages of rice development (vegetative growth stage, maximal tillering stage, and harvest stage). Of the 411 proteolytic bacteria isolated, 124 isolates had stronger proteolytic activity than others on the basis of gelatin liquefaction tests and most of them were Bacillus spp. (100% in 1989 and 92.4% in 1991). Bacillus subtilis and Bacillus cereus were the main bacteria of this group and Bacillus mycoides, Bacillus licheniformis, and Bacillus megaterium were also present. We conclude that these Bacillus spp. are the primary source of soil protease in these paddy fields.
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Shu, Lin-Jie; Yang, Yu-Liang
2017-11-14
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a reliable and rapid technique applied widely in the identification and classification of microbes. MALDI-TOF MS has been used to identify many endospore-forming Bacillus species; however, endospores affect the identification accuracy when using MALDI-TOF MS because they change the protein composition of samples. Since culture conditions directly influence endospore formation and Bacillus growth, in this study we clarified how culture conditions influence the classification of Bacillus species by using MALDI-TOF MS. We analyzed members of the Bacillus subtilis group and Bacillus cereus group using different incubation periods, temperatures and media. Incubation period was found to affect mass spectra due to endospores which were observed mixing with vegetative cells after 24 hours. Culture temperature also resulted in different mass spectra profiles depending on the temperature best suited growth and sporulation. Conversely, the four common media for Bacillus incubation, Luria-Bertani agar, nutrient agar, plate count agar and brain-heart infusion agar did not result in any significant differences in mass spectra profiles. Profiles in the range m/z 1000-3000 were found to provide additional data to the standard ribosomal peptide/protein region m/z 3000-15000 profiles to enable easier differentiation of some highly similar species and the identification of new strains under fresh culture conditions. In summary, control of culture conditions is vital for Bacillus identification and classification by MALDI-TOF MS.
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Frederiksen, Kristine; Rosenquist, Hanne; Jørgensen, Kirsten; Wilcks, Andrea
2006-01-01
A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins visualized by microscopy. Random amplified polymorphic DNA analysis and plasmid profiling indicated that 23 of the 50 B. thuringiensis strains were of the same subtype as B. thuringiensis strains used as commercial bioinsecticides. Fourteen isolates were indistinguishable from B. thuringiensis subsp. kurstaki HD1 present in the products Dipel, Biobit, and Foray, and nine isolates grouped with B. thuringiensis subsp. aizawai present in Turex. The commercial strains were primarily isolated from samples of tomatoes, cucumbers, and peppers. A multiplex PCR method was developed to simultaneously detect all three genes in the enterotoxin hemolysin BL (HBL) and the nonhemolytic enterotoxin (NHE), respectively. This revealed that the frequency of these enterotoxin genes was higher among the strains indistinguishable from the commercial strains than among the other B. thuringiensis and B. cereus-like strains isolated from fruits and vegetables. The same was seen for a third enterotoxin, CytK. In conclusion, the present study strongly indicates that residues of B. thuringiensis-based insecticides can be found on fresh fruits and vegetables and that these are potentially enterotoxigenic. PMID:16672488
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Kim, Jung Eun; Choi, Hyeon-Son; Lee, Dong-Un; Min, Sea C
2017-12-18
The efficacy of microwave-combined cold plasma treatment (MCPT) for inactivating Bacillus cereus spores contaminating red pepper (Capsicum annum L.) flakes was investigated. The effects of red pepper drying method, particle size, and water activity (a w ) were also evaluated at two levels of microwave power (1700 and 2500W/cm 2 ). The inactivation effect of MCPT was higher at higher microwave power. Spore reduction was more effective with vacuum-dried red pepper than far-infrared-dried flakes. A significantly higher level of spore reduction was observed with the red pepper sample with a smaller surface to volume ratio when one surface (exterior surface) was inoculated (p<0.05). Spore reduction by MCPT at high microwave power increased from 1.7 to 2.6logspores/cm 2 when the a w of flake increased from 0.4 to 0.9 (p<0.05). MCPT did not change the color of red pepper flakes. MCPT demonstrated potential as a microbial decontaminating technology for red pepper flakes. Copyright © 2017 Elsevier B.V. All rights reserved.
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Inactivation of Bacillus spores by the supercritical carbon dioxide micro-bubble method.
Ishikawa, H; Shimoda, M; Tamaya, K; Yonekura, A; Kawano, T; Osajima, Y
1997-06-01
Bacillus spores were effectively inactivated by the supercritical (SC) CO2 micro-bubble method. The micro-bubble SC CO2 treatment of B. cereus, B. subtilis, B. megaterium, B. polymyxa, and B. coagulans at 40 degrees C and 30 MPa for 30 min produced greater reduction (about 3 log cycles of reduction) than a similar treatment without a filter. The SC CO2 treatment of B. polymyxa, B. cereus, and B. subtilis spores at 45 degrees C, 50 degrees C, respectively, and 30 MPa for 60 min resulted in a 6-log cycle reduction of survival. The SC CO2 treatment under the foregoing conditions should offer higher efficiency than that of heat treatment at 100 degrees C for 60 min. In addition, the SC CO2 treatment (30 MPa, 60 degrees C, 30 min) of B. polymyxa and B. cereus spores also produced a 6-log cycle reduction.
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Posada, Luisa F; Alvarez, Javier C; Hu, Chia-Hui; de-Bashan, Luz E; Bashan, Yoav
2016-09-01
Strains of Bacillus subtilis are plant growth-promoting bacteria (PGPB) of many crops and are used as inoculants. PGPB colonization is an important trait for success of a PGPB on plants. A specific probe, based on the 16 s rRNA of Bacillus subtilis, was designed and evaluated to distinguishing, by fluorescence in situ hybridization (FISH), between this species and the closely related Bacillus amyloliquefaciens. The selected target for the probe was between nucleotides 465 and 483 of the gene, where three different nucleotides can be identified. The designed probe successfully hybridized with several strains of Bacillus subtilis, but failed to hybridize not only with B. amyloliquefaciens, but also with other strains such as Bacillus altitudinis, Bacillus cereus, Bacillus gibsonii, Bacillus megaterium, Bacillus pumilus; and with the external phylogenetic strains Azospirillum brasilense Cd, Micrococcus sp. and Paenibacillus sp. The results showed the specificity of this molecular probe for B. subtilis.
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Chauhan, Ankit Kumar; Maheshwari, Dinesh Kumar; Dheeman, Shrivardhan; Bajpai, Vivek K
2017-02-01
Curcumin (diferuloyl methane) is the main bioactive component of turmeric (Curcuma longa L.) having remarkable multipotent medicinal and therapeutic applications. Two Bacilli isolated from termitarium soil and identified as Bacillus endophyticus TSH42 and Bacillus cereus TSH77 were used for bacterization of rhizome for raising C. longa ver. suguna for growth and enhancement. Both the strains showed remarkable PGP activities and also chemotactic in nature with high chemotactic index. Turmeric plants bacterized with strains B. endophyticus TSH42 and B. cereus TSH77 individually and in combination increased plant growth and turmeric production up to 18% in field trial in comparison to non-bacterized plants. High-performance liquid chromatography analysis was performed to determine the content of curcumin, which showed concentration of curcumin in un-inoculated turmeric as 3.66 g which increased by 13.6% (4.16 g) when combination of TSH42 and TSH77 was used.
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Lee, Nari; Kwon, Kyung Yoon; Oh, Su Kyung; Chang, Hyun-Joo; Chun, Hyang Sook; Choi, Sung-Wook
2014-07-01
A multiplex polymerase chain reaction (PCR) assay was developed for simultaneous detection of Escherichia coli O157:H7, Bacillus cereus, Vibrio parahaemolyticus, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus in various Korean ready-to-eat foods. The six specific primer pairs for multiplex PCR were selected based on the O157 antigen (rfbE) gene of E. coli O157:H7, the DNA gyrase subunit B (gyrB) gene of B. cereus, the toxin regulatory protein (toxR) gene of V. parahaemolyticus, the invasion protein A (invA) gene of Salmonella spp., the hemolysin (hly) gene of L. monocytogenes, and the thermonuclease (nuc) gene of S. aureus. The 16S rRNA gene was targeted as an internal control gene in the presence of bacterial DNA. The specificity and sensitivity assays for multiplex primer pairs were investigated by testing different strains. When this multiplex PCR assay was applied to evaluate the validity of detecting six foodborne pathogens in artificially inoculated several ready-to-eat food samples, the assay was able to specifically simultaneously detect as few as 1 colony-forming unit/mL of each pathogen after enrichment for 12 h. Their presence in naturally contaminated samples also indicates that the developed multiplex PCR assay is an effective and informative supplement for practical use.
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Jetiyanon, Kanchalee; Plianbangchang, Pinyupa
2012-03-30
There is increasing interest in the development of technologies which can reduce the requirement for chemical fertilisers in rice production. The objective of this study was to investigate the efficacy of Bacillus cereus strain RS87 for the partial replacement of chemical fertiliser in rice production. A greenhouse experiment was designed using different fertiliser regimes, with and without strain RS87. Six Thai rice cultivars were tested separately. Maximum rice growth and yield were obtained in rice receiving the full recommended fertiliser rate in combination with the strain RS87. Interestingly, all rice cultivars which were treated with strain RS87 and 50% recommended fertiliser rate provided equivalent plant growth and yield to that receiving the full recommended fertiliser rate only. A paired comparison between rice treated with 50% of the recommended fertiliser rate with the bacterial inoculant and the full fertiliser rate alone was further examined in small experimental rice paddy fields. Growth and yield of all rice cultivars which received the 50% fertiliser rate supplemented with strain RS87 gave a similar yield to that receiving the full fertiliser rate alone. Bacterial strain RS87 showed the potential to replace 50% of the recommended fertiliser rate for yield production. Integration of plant growth-promoting rhizobacterial inoculants with reduced application rates of chemical fertiliser appears promising for future agriculture. Copyright © 2012 Society of Chemical Industry.
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Manni, Laila; Jellouli, Kemel; Ghorbel-Bellaaj, Olfa; Agrebi, Rym; Haddar, Anissa; Sellami-Kamoun, Alya; Nasri, Moncef
2010-04-01
The current increase in amount of shrimp wastes produced by the shrimp industry has led to the need in finding new methods for shrimp wastes disposal. In this study, an extracellular organic solvent- and oxidant-stable metalloprotease was produced by Bacillus cereus SV1. Maximum protease activity (5,900 U/mL) was obtained when the strain was grown in medium containing 40 g/L shrimp wastes powder as a sole carbon source. The optimum pH, optimum temperature, pH stability, and thermal stability of the crude enzyme preparation were pH 8.0, 60 degrees C, pH 6-9.5, and <55 degrees C, respectively. The crude protease was extremely stable toward several organic solvents. No loss of activity was observed even after 60 days of incubation at 30 degrees C in the presence of 50% (v/v) dimethyl sulfoxide and ethyl ether; the enzyme retained more than 70% of its original activity in the presence of ethanol and N,N-dimethylformamide. The protease showed high stability toward anionic (SDS) and non-ionic (Tween 80, Tween 20, and Triton X-100) surfactants. Interestingly, the activity of the enzyme was significantly enhanced by oxidizing agents. In addition, the enzyme showed excellent compatibility with some commercial liquid detergents. The protease of B. cereus SV1, produced under the optimal culture conditions, was tested for shrimp waste deproteinization in the preparation of chitin. The protein removal with a ratio E/S of 20 was about 88%. The novelties of the SV1 protease include its high stability to organic solvents and surfactants. These unique properties make it an ideal choice for application in detergent formulations and enzymatic peptide synthesis. In addition, the enzyme may find potential applications in the deproteinization of shrimp wastes to produce chitin.
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Gustafsson, Tomas N; Osman, Harer; Werngren, Jim; Hoffner, Sven; Engman, Lars; Holmgren, Arne
2016-06-01
Bacillus anthracis is the causative agent of anthrax, a disease associated with a very high mortality rate in its invasive forms. We studied a number of ebselen analogs as inhibitors of B. anthracis thioredoxin reductase and their antibacterial activity on Bacillus subtilis, Staphylococcus aureus, Bacillus cereus and Mycobacterium tuberculosis. The most potent compounds in the series gave IC(50) values down to 70 nM for the pure enzyme and minimal inhibitory concentrations (MICs) down to 0.4 μM (0.12 μg/ml) for B. subtilis, 1.5 μM (0.64 μg/ml) for S. aureus, 2 μM (0.86 μg/ml) for B. cereus and 10 μg/ml for M. tuberculosis. Minimal bactericidal concentrations (MBCs) were found at 1-1.5 times the MIC, indicating a general, class-dependent, bactericidal mode of action. The combined bacteriological and enzymological data were used to construct a preliminary structure-activity-relationship for the benzoisoselenazol class of compounds. When S. aureus and B. subtilis were exposed to ebselen, we were unable to isolate resistant mutants on both solid and in liquid medium suggesting a high resistance barrier. These results suggest that ebselen and analogs thereof could be developed into a novel antibiotic class, useful for the treatment of infections caused by B. anthracis, S. aureus, M. tuberculosis and other clinically important bacteria. Furthermore, the high barrier against resistance development is encouraging for further drug development. We have characterized the thioredoxin system from B. anthracis as a novel drug target and ebselen and analogs thereof as a potential new class of antibiotics targeting several important human pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.
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Zhou, Xuan; Zhang, Nan; Xia, Liming; Li, Qing; Shao, Jiahui; Shen, Qirong; Zhang, Ruifu
2018-04-15
Efficient biofilm formation and root colonization capabilities facilitate the ability of beneficial plant rhizobacteria to promote plant growth and antagonize soilborne pathogens. Biofilm formation by plant-beneficial Bacillus strains is triggered by environmental cues, including oxygen deficiency, but the pathways that sense these environmental signals and regulate biofilm formation have not been thoroughly elucidated. In this study, we showed that the ResDE two-component regulatory system in the plant growth-promoting rhizobacterium Bacillus amyloliquefaciens strain SQR9 senses the oxygen deficiency signal and regulates biofilm formation. ResE is activated by sensing the oxygen limitation-induced reduction of the NAD + /NADH pool through its PAS domain, stimulating its kinase activity, and resulting in the transfer of a phosphoryl group to ResD. The phosphorylated ResD directly binds to the promoter regions of the qoxABCD and ctaCDEF operons to improve the biosynthesis of terminal oxidases, which can interact with KinB to activate biofilm formation. These results not only revealed the novel regulatory function of the ResDE two-component system but also contributed to the understanding of the complicated regulatory network governing Bacillus biofilm formation. This research may help to enhance the root colonization and the plant-beneficial efficiency of SQR9 and other Bacillus rhizobacteria used in agriculture. IMPORTANCE Bacillus spp. are widely used as bioinoculants for plant growth promotion and disease suppression. The exertion of their plant-beneficial functions is largely dependent on their root colonization, which is closely related to their biofilm formation capabilities. On the other hand, Bacillus is the model bacterium for biofilm study, and the process and molecular network of biofilm formation are well characterized (B. Mielich-Süss and D. Lopez, Environ Microbiol 17:555-565, 2015, https://doi.org/10.1111/1462-2920.12527; L. S. Cairns, L. Hobley, and
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Kalenova, L F; Kolyvanova, S S; Bazhin, A S; Besedin, I M; Mel'nikov, V P
2017-06-01
We studied the effects of secondary metabolites of Bacillus sp. isolated from late Neogene permafrost on secretion of proinflammatory (TNF-α, IL-1β, IL-8, IL-2, and IFNγ) and antiinflammatory (IL-4 and IL-10) cytokines by human peripheral blood mononuclear cells. It was found that metabolites of Bacillus sp. produced more potent effect on cytokine secretion than mitogen phytohemagglutinin and metabolites of Bacillus cereus, medicinal strain IP5832. Activity of metabolites depended on the temperature of bacteria incubation. "Cold" metabolites of Bacillus sp. (isolated at -5°C) primarily induced Th1-mediated secretion of IFNγ, while "warm" metabolites (obtained at 37°C) induced Th2-mediated secretion of IL-4. The results suggest that Bacillus sp. metabolites are promising material for the development of immunomodulating drugs.
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Fisher, K; Phillips, C A
2006-12-01
To investigate the effectiveness of oils and vapours of lemon (Citrus limon), sweet orange (Citrus sinensis) and bergamot (Citrus bergamia) and their components against a number of common foodborne pathogens. The disc diffusion method was used to screen the oils and vapours against Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Escherichia coli O157 and Campylobacter jejuni. The survival of each species, demonstrated to be susceptible in the in vitro studies, was tested on cabbage leaf for 60 s by direct contact and on chicken skin for 10 min by direct contact and 24 h by vapour. The results indicate that bergamot was the most inhibitory essential oil (EO) and citral and linalool mimicked its effect (P > 0.001). Citral and linalool vapours produced 6 log reductions in L. monocytogenes, Staph. aureus and B. cereus populations on cabbage leaf after 8-10 h exposure but bergamot vapour exposure, while producing a similar reduction in L. monocytogenes and B. cereus populations, had no effect on Staph. aureus. Bergamot was the most effective of the oils tested and linalool the most effective anti-bacterial component. Gram-positive bacteria were more susceptible than Gram-negative bacteria in vitro, although Camp. jejuni and E. coli O157 were inhibited by bergamot and linalool oils and by linalool vapour. All bacteria tested were less susceptible in food systems than in vitro. Of the Gram-positive bacteria tested Staph. aureus was the least susceptible to both the oils and the components tested. Results suggest the possibility that citrus EOs, particularly bergamot, could be used as a way of combating the growth of common causes of food poisoning.
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Inhibitory effects of spice essential oils on the growth of Bacillus species.
Ozcan, Mehmet Musa; Sağdiç, Osman; Ozkan, Gülcan
2006-01-01
A series of essential oils of 11 Turkish plant spices [black thyme, cumin, fennel (sweet), laurel, marjoram, mint, oregano, pickling herb, sage, savory, and thyme], used in foods mainly for their flavor, aromas, and preservation, in herbal tea, in alternative medicines, and in natural therapies, were screened for antibacterial effects at 1:50, 1:100, 1:250, and 1:500 dilutions by the paper disc diffusion method against six Bacillus species (Bacillus amyloliquefaciens ATCC 3842, Bacillus brevis FMC 3, Bacillus cereus FMC 19, Bacillus megaterium DSM 32, Bacillus subtilis IMG 22, and B. subtilis var. niger ATCC 10). All of the tested essential oils (except for cumin) showed antibacterial activity against one or more of the Bacillus species used in this study. Generally, the essential oils at 1:50 and 1:100 levels were more effective. Only one essential oil (laurel) was not found effective against the tested bacteria. The bacterium most sensitive to all of the spice essential oils was B. amyloliquefaciens ATCC 3842. Based on the results of this study, it is likely that essential oils of some spices may be used as antimicrobial agents to prevent the spoilage of food products.
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2004-01-01
Flagellar genes Presentb Presentc Presentc Tagatose utilization genes Absent Present Partiald Functional PlcR Absente Presente Presente Mobile genetic...closely related and one that is divergent (Supplementary ®g. S3). dThere are similar tagatose utilization genes in B.cereus ATCC 14579; however, they...replacement responsible for the transport and utilization of the carbohydrate tagatose (BCE1896±BCE1912). The corres- ponding 5.0 kb region in
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Bavykin, Sergei G.; Mirzabekov, Andrei D.
2007-10-30
The present invention is directed to a novel method of discriminating a highly infectious bacterium Bacillus anthracis from a group of closely related microorganisms. Sequence variations in the 16S and 23S rRNA of the B. cereus subgroup including B. anthracis are utilized to construct an array that can detect these sequence variations through selective hybridizations. The identification and analysis of these sequence variations enables positive discrimination of isolates of the B. cereus group that includes B. anthracis. Discrimination of single base differences in rRNA was achieved with a microchip during analysis of B. cereus group isolates from both single and in mixed probes, as well as identification of polymorphic sites. Successful use of a microchip to determine the appropriate subgroup classification using eight reference microorganisms from the B. cereus group as a study set, was demonstrated.
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Maheshwari, Neha; Kumar, Madan; Thakur, Indu Shekhar; Srivastava, Shaili
2018-04-01
Carbon dioxide sequestering bacterial strains were previously isolated from free air CO 2 enriched (FACE) soil. In the present study, these strains were screened for PHA accumulation and Bacillus cereus SS105 was found to be the most prominent PHA accumulating strain on sodium bicarbonate and molasses as carbon source. This strain was further characterized by Spectrofluorometric method and Confocal microscopy after staining with Nile red. PHA granules in inclusion bodies were visualized by Transmission Electron Microscopy. The PHA and its monomer composition were characterized by GC-MS followed by FTIR and NMR. The genetic basis of PHA production was confirmed by the amplification, cloning and analysis of PHA biosynthesis genes phaR, phaB and phaC from B. cereus with the degenerate primers. The PHA production was further optimized by Response Surface Methodology and the percent increase observed after optimization was 55.16% (w/v). Copyright © 2018 Elsevier Ltd. All rights reserved.
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Akinpelu, David A; Aiyegoro, Olayinka A; Akinpelu, Oluseun F; Okoh, Anthony I
2014-12-30
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.
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Wu, Huiqing; Wu, Qingping; Wu, Guojie; Gu, Qihui; Wei, Linting
2016-01-01
The goal of this study was to identify Cd-resistant bacterial strains with endurance capacity and to evaluate their ability to remove cadmium ions from cadmium-polluted water. The Bacillus cereusS5 strain identified in this study had the closest genetic relationship with B. cereus sp. Cp1 and performed well in the removal of Cd2+ions from solution. The results showed that both the live and dead biomasses of the Cd2+-tolerant B. cereus S5 strain could absorb Cd2+ ions in solution but that the live biomass of the B. cereus S5 strain outperformed the dead biomass at lower Cd2+concentrations. An analysis of the cadmium tolerance genes of B. cereus S5 identified ATPase genes that were associated with cadmium tolerance and involved in the ATP pumping mechanism. The FTIR spectra revealed the presence of amino, carboxyl and hydroxyl groups on the pristine biomass and indicated that the cadmium ion removal ability was related to the structure of the strain. The maximum absorption capacity of the B. cereus S5 strain in viable spore biomass was 70.16 mg/g (dry weight) based on a pseudo-second-order kinetic model fit to the experimental data. The Langmuir and Langmuir-Freundlich isotherm adsorption models fit the cadmium ion adsorption data well, and the kinetic curves indicated that the adsorption rate was second-order. For Cd2+ concentrations (mg/L) of 1–109 mg/L, good removal efficiency (>80%) was achieved using approximately 3.48–10.3 g/L of active spore biomass of the B. cereus S5 strain. A cadmium-tolerant bacteria-activated carbon-immobilized column could be used for a longer duration and exhibited greater treatment efficacy than the control column in the treatment of cadmium-polluted water. In addition, a toxicity assessment using mice demonstrated that the biomass of the B. cereus S5 strain and its fermentation products were non-toxic. Thus, the isolated B. cereus S5 strain can be considered an alternative biological adsorbent for use in emergency responses to
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Genome Sequence of a Chromium-Reducing Strain, Bacillus cereus S612
Wang, Dongping; Boukhalfa, Hakim; Ware, Doug S.; ...
2015-12-10
We report here the genome sequence of an effective chromium-reducing bacterium,Bacillus cereusstrain S612. We found that the size of the draft genome sequence is approximately 5.4 Mb, with a G+C content of 35%, and it is predicted to contain 5,450 protein-coding genes.
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Douriet-Gámez, Nadia R; Maldonado-Mendoza, Ignacio E; Ibarra-Laclette, Enrique; Blom, Jochen; Calderón-Vázquez, Carlos L
2018-03-01
Bacillus sp. B25 is an effective biocontrol agent against the maize pathogenic fungus Fusarium verticillioides (Fv). Previous in vitro assays have shown that B25 has protease, glucanase, and chitinase activities and siderophores production; however, specific mechanisms by which B25 controls Fv are still unknown. To determine the genetic traits involved in biocontrol, B25 genome was sequenced and analyzed. B25 genome is composed of 5,113,413 bp and 5251 coding genes. A multilocus phylogenetic analysis (MLPA) suggests that B25 is closely related to the Bacillus cereus group and a high percentage (70-75%) of the genetic information is conserved between B25 and related strains, which include most of the genes associated to fungal antagonism. Some of these genes are shared with some biocontrol agents of the Bacillus genus and less with Pseudomonas and Serratia strains. We performed a genomic comparison between B25 and five Bacillus spp., Pseudomonas and Serratia strains. B25 contains genes involved in a wide variety of antagonistic mechanisms including chitinases, glycoside hydrolases, siderophores, antibiotics, and biofilm production that could be implicated in root colonization. Also, 24 genomic islands and 3 CRISPR sequences were identified in the B25 genome. This is the first comparative genome analysis between strains belonging to the B. cereus group and biocontrol agents of phytopathogenic fungi. These results are the starting point for further studies on B25 gene expression during its interaction with Fv.
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Prakash Vincent, Samuel Gnana
2014-01-01
A potent fibrinolytic enzyme-producing Bacillus cereus IND1 was isolated from the Indian food, rice. Solid-state fermentation was carried out using agroresidues for the production of fibrinolytic enzyme. Among the substrates, wheat bran supported more enzyme production and has been used for the optimized enzyme production by statistical approach. Two-level full-factorial design demonstrated that moisture, supplementation of beef extract, and sodium dihydrogen phosphate have significantly influenced enzyme production (P < 0.05). A central composite design resulted in the production of 3699 U/mL of enzyme in the presence of 0.3% (w/w) beef extract and 0.05% (w/w) sodium dihydrogen phosphate, at 100% (v/w) moisture after 72 h of fermentation. The enzyme production increased fourfold compared to the original medium. This enzyme was purified to homogeneity by ammonium sulfate precipitation, diethylaminoethyl-cellulose ion-exchange chromatography, Sephadex G-75 gel filtration chromatography, and casein-agarose affinity chromatography and had an apparent molecular mass of 29.5 kDa. The optimum pH and temperature for the activity of fibrinolytic enzyme were found to be 8.0 and 60°C, respectively. This enzyme was highly stable at wide pH range (7.0–9.0) and showed 27% ± 6% enzyme activity after initial denaturation at 60°C for 1 h. In vitro assays revealed that the enzyme could activate plasminogen and significantly degraded the fibrin net of blood clot, which suggests its potential as an effective thrombolytic agent. PMID:25003130
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Janahiraman, Veeranan; Anandham, Rangasamy; Kwon, Soon W; Sundaram, Subbiah; Karthik Pandi, Veeranan; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Samaddar, Sandipan; Sa, Tongmin
2016-01-01
The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM) bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1, and PPB-1, respectively, identified as Delftia lacustris, Bacillus subtilis , and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B . subtilis PPT-1, and B . cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05, and 1.95 cm), Sclerotium rolfsii (2.14, 2.04, and 1.94 cm), Pythium ultimum (2.12, 2.02, and 1.92 cm), and Rhizoctonia solani (2.18, 2.08, and 1.98 cm) and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D . lacustris PPO-1, B . subtilis PPT-1, and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D . lacustris PPO-1, B . subtilis PPT-1, and B . cereus PPB-1 inoculated tomato plants, when challenged with F . oxysporum f. sp. lycopersici, S . rolfsii, P . ultimum , and R . solani , increased the pathogenesis related proteins (β-1,3-glucanase and chitinase) and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase) on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented D. lacustris, B . subtilis , and B . cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent.
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Janahiraman, Veeranan; Anandham, Rangasamy; Kwon, Soon W.; Sundaram, Subbiah; Karthik Pandi, Veeranan; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Samaddar, Sandipan; Sa, Tongmin
2016-01-01
The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM) bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1, and PPB-1, respectively, identified as Delftia lacustris, Bacillus subtilis, and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05, and 1.95 cm), Sclerotium rolfsii (2.14, 2.04, and 1.94 cm), Pythium ultimum (2.12, 2.02, and 1.92 cm), and Rhizoctonia solani (2.18, 2.08, and 1.98 cm) and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 inoculated tomato plants, when challenged with F. oxysporum f. sp. lycopersici, S. rolfsii, P. ultimum, and R. solani, increased the pathogenesis related proteins (β-1,3-glucanase and chitinase) and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase) on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented D. lacustris, B. subtilis, and B. cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent. PMID:27872630
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Gangrenous mastitis caused by Bacillus species in six goats.
Mavangira, Vengai; Angelos, John A; Samitz, Eileen M; Rowe, Joan D; Byrne, Barbara A
2013-03-15
6 lactating dairy goats were examined because of acute mastitis. Goats were considered to have endotoxemia on the basis of physical examination and clinicopathologic findings. The affected udder halves had gangrenous discolored distal portions with sharp demarcations from grossly normal tissue proximally. Udder secretions from the affected sides were serosanguineous in all cases. A Bacillus sp was isolated in pure cultures in all cases. In 1 case, the Bacillus sp was identified as Bacillus cereus. Goats were treated for mastitis and endotoxemia with polyionic IV fluid therapy, systemic and intramammary antimicrobial administration, anti-inflammatory drug administration, and other supportive treatment. All goats survived to discharge. All except 1 goat had follow-up information available. The affected udder halves sloughed in 1 to 2 months following discharge. In subsequent lactations after the mastitis episodes, milk production in 2 of 5 goats was above the mean, as determined on the basis of Dairy Herd Improvement records, and 3 of 5 goats were voluntarily withdrawn from lactation. All 5 goats had successful kiddings after the Bacillus mastitis episode. Bacillus sp should be considered as a causative agent in goats with gangrenous mastitis, especially when the Bacillus sp is isolated in a pure culture. Antimicrobial sensitivity testing is recommended for selection of an appropriate antimicrobial for treatment. Prognosis for survival appears to be good, although milk production may be decreased.
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Azcón, Rosario; Medina, Almudena; Roldán, Antonio; Biró, Borbála; Vivas, Astrid
2009-04-01
In this study, we analyzed the impact of treatments such as Aspergillus niger-treated sugar beet waste (SB), PO4(3-) fertilization and autochthonous inoculants [arbuscular mycorrhizal (AM) fungi and Bacillus cereus], on the bacterial community structure in a soils contaminated with heavy metals as well as, the effectiveness on plant growth (Trifolium repens). The inoculation with AM fungi in SB amended soil, increased plant growth similarly to PO4(3-) addition, and both treatments matched in P acquisition but bacterial biodiversity estimated by denaturing gradient gel electrophoresis of amplified 16S rDNA sequences, was more stimulated by the presence of the AM fungus than by PO4(3-) fertilization. The SB amendment plus AM inoculation increased the microbial diversity by 233% and also changed (by 215%) the structure of the bacterial community. The microbial inoculants and amendment used favoured plant growth and the phytoextraction process and concomitantly modified bacterial community in the rhizosphere; thus they can be used for remediation. Therefore, the understanding of such microbial ecological aspects is important for phytoremediation and the recovery of contaminated soils.
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2011-08-01
endocarditis , osteomyelitis, endophthalmitis, and urinary tract infections in humans (2). Strains of B. cereus have also been associated with more...C57BU6J mice were comparably susceptible to B. cereus G9241 by both subcutaneous and intranasal routes of infection . However, the LD50s for B...by the presence of vegetative cells in the spleen and blood of animals 48 h after infection . Lastly, B. cereus G9241 derivatives cured of one or
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Kent, R M; Guinane, C M; O'Connor, P M; Fitzgerald, G F; Hill, C; Stanton, C; Ross, R P
2012-08-01
The aim of this study was to identify Bacillus isolates capable of degrading sodium caseinate and subsequently to generate bioactive peptides with antimicrobial activity. Sodium caseinate (2.5% w/v) was inoculated separately with 16 Bacillus isolates and allowed to ferment overnight. Protein breakdown in the fermentates was analysed using gel permeation-HPLC (GP-HPLC) and screened for peptides (<3-kDa) with MALDI-TOF mass spectrometry. Caseicin A (IKHQGLPQE) and caseicin B (VLNENLLR), two previously characterized antimicrobial peptides, were identified in the fermentates of both Bacillus cereus and Bacillus thuringiensis isolates. The caseicin peptides were subsequently purified by RP-HPLC and antimicrobial assays indicated that the peptides maintained the previously identified inhibitory activity against the infant formula pathogen Cronobacter sakazakii. We report a new method using Bacillus sp. to generate two previously characterized antimicrobial peptides from casein. This study highlights the potential to exploit Bacillus sp. or the enzymes they produce for the generation of bioactive antimicrobial peptides from bovine casein. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.
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Yucel, Nihal; Aslim, Belma; Ozdoğan, Hakan
2009-08-01
In this study a total of 30 raw meat samples obtained from Ankara, Turkey were screened for the presence of Bacillus species. Among the meat samples analyzed, the predominant species isolated was Bacillus circulans; other Bacillus species were identified as Bacillus firmus, Bacillus lentus, Bacillus megaterium, Bacillus licheniformis, Bacillus mycoides, Bacillus sphaericus, and Bacillus cereus. Minced meat samples were more contaminated with Bacillus species than sliced beef sample. From these samples, 242 Bacillus species isolates were obtained, which were investigated for proteolytic and lipolytic activity, associated with meat spoilage. Interestingly, some Bacillus strains produced the highest values of proteolytic/lipolytic activities. Nineteen Bacillus strains were selected among the 242 isolates according to their proteolytic/lipolytic activity with a clear zone diameter of > or =6 mm. The essential oil of Satureja wiedemanniana (Lalem) Velen was also tested against these 19 Bacillus species that had proteolytic and lipolytic activity. The essential oil yield obtained from the aerial parts of the plant was 0.35% (vol/wt). The inhibition zones of the essential oil obtained against all the Bacillus species were in the range of 5.0-12.0 mm. The oil showed high antimicrobial activities against B. licheniformis M 6(26), M 11(16), and M 12(1) strains. B. licheniformis 12(1) showed high lipolytic activity (18.0 mm). Also, B. licheniformis M 6(26) and M 11(16) showed high proteolytic activity (16.0 and 14.0 mm). These results may suggest that an essential oil of S. wiedemanniana can be used as a natural preservative in meat against spoilage bacteria.
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Hutchison, Janine R; Erikson, Rebecca L; Sheen, Allison M; Ozanich, Richard M; Kelly, Ryan T
2015-09-21
Bacillus anthracis is the causative agent of anthrax and can be contracted by humans and herbivorous mammals by inhalation, ingestion, or cutaneous exposure to bacterial spores. Due to its stability and disease potential, B. anthracis is a recognized biothreat agent and robust detection and viability methods are needed to identify spores from unknown samples. Here we report the use of smartphone-based microscopy (SPM) in combination with a simple microfluidic incubation device (MID) to detect 50 to 5000 B. anthracis Sterne spores in 3 to 5 hours. This technique relies on optical monitoring of the conversion of the ∼1 μm spores to the filamentous vegetative cells that range from tens to hundreds of micrometers in length. This distinguishing filament formation is unique to B. anthracis as compared to other members of the Bacillus cereus group. A unique feature of this approach is that the sample integrity is maintained, and the vegetative biomass can be removed from the chip for secondary molecular analysis such as PCR. Compared with existing chip-based and rapid viability PCR methods, this new approach reduces assay time by almost half, and is highly sensitive, specific, and cost effective.
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Villéger, Romain; Saad, Naima; Grenier, Karine; Falourd, Xavier; Foucat, Loïc; Urdaci, Maria C; Bressollier, Philippe; Ouk, Tan-Sothea
2014-10-01
Probiotics represent a potential strategy to influence the host's immune system thereby modulating immune response. Lipoteichoic Acid (LTA) is a major immune-stimulating component of Gram-positive cell envelopes. This amphiphilic polymer, anchored in the cytoplasmic membrane by means of its glycolipid component, typically consists of a poly (glycerol-phosphate) chain with D-alanine and/or glycosyl substitutions. LTA is known to stimulate macrophages in vitro, leading to secretion of inflammatory mediators such as Nitric Oxide (NO). This study investigates the structure-activity relationship of purified LTA from three probiotic Bacillus strains (Bacillus cereus CH, Bacillus subtilis CU1 and Bacillus clausii O/C). LTAs were extracted from bacterial cultures and purified. Chemical modification by means of hydrolysis at pH 8.5 was performed to remove D-alanine. The molecular structure of native and modified LTAs was determined by (1)H NMR and GC-MS, and their inflammatory potential investigated by measuring NO production by RAW 264.7 macrophages. Structural analysis revealed several differences between the newly characterized LTAs, mainly relating to their D-alanylation rates and poly (glycerol-phosphate) chain length. We observed induction of NO production by LTAs from B. subtilis and B. clausii, whereas weaker NO production was observed with B. cereus. LTA dealanylation abrogated NO production independently of the glycolipid component, suggesting that immunomodulatory potential depends on D-alanine substitutions. D-alanine may control the spatial configuration of LTAs and their recognition by cell receptors. Knowledge of molecular mechanisms behind the immunomodulatory abilities of probiotics is essential to optimize their use.
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The genome and variation of Bacillus anthracis
Keim, Paul; Gruendike, Jeffrey M.; Klevytska, Alexandra M.; Schupp, James M.; Challacombe, Jean; Okinaka, Richard
2009-01-01
The Bacillus anthracis genome reflects its close genetic ties to B. cereus and B. thuringiensis but has been shaped by its own unique biology and evolutionary forces. The genome is comprised of a chromosome and two large virulence plasmids, pXO1 and pXO2. The chromosome is mostly co-linear among B. anthracis strains and even with the closest near neighbor strains. An exception to this pattern has been observed in a large inversion in an attenuated strain suggesting that chromosome co-linearity is important to the natural biology of this pathogen. In general, there are few polymorphic nucleotides among B. anthracis strains reflecting the short evolutionary time since its derivation from a B. cereus-like ancestor. The exceptions to this lack of diversity are the variable number tandem repeat (VNTR) loci that exist in genic and non genic regions of the chromosome and both plasmids. Their variation is associated with high mutability that is driven by rapid insertion and deletion of the repeats within an array. A notable example is found in the vrrC locus which is homologous to known DNA translocase genes from other bacteria. PMID:19729033
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Myasnik, M; Manasherob, R; Ben-Dov, E; Zaritsky, A; Margalith, Y; Barak, Z
2001-08-01
Susceptibility of Bacillus thuringiensis spores and toxins to the UV-B range (280--330 nm) of the solar spectrum reaching Earth's surface may be responsible for its inactivation and low persistence in nature. Spores of the mosquito larvicidal B. thuringiensis subsp. israelensis were significantly more resistant to UV-B than spores of the lepidopteran-active subsp. kurstaki. Spores of subsp. israelensis were as resistant to UV-B as spores of B. subtilis and more resistant than spores of the closely related B. cereus and another mosquito larvicidal species B. sphaericus. Sensitivity of B. thuringiensis subsp. israelensis spores to UV-B radiation depended upon their culture age; 24-h cultures, approaching maximal larvicidal activity, were still sensitive. Maximal resistance to UV-B was achieved only at 48 h.
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Torres, M J; Petroselli, G; Daz, M; Erra-Balsells, R; Audisio, M C
2015-06-01
In this work a new Bacillus sp. strain, isolated from honey, was characterized phylogenetically. Its antibacterial activity against three relevant foodborne pathogenic bacteria was studied; the main bioactive metabolites were analyzed using ultraviolet matrix assisted laser desorption-ionization mass spectrometry (UV-MALDI MS). Bacillus CBMDC3f was phylogenetically characterized as Bacillus subtilis subsp. subtilis after rRNA analysis of the 16S subunit and the gyrA gene (access codes Genbank JX120508 and JX120516, respectively). Its antibacterial potential was evaluated against Listeria monocytogenes (9 strains), B. cereus (3 strains) and Staphylococcus aureus ATCC29213. Its cell suspension and cell-free supernatant (CFS) exerted significant anti-Listeria and anti-S. aureus activities, while the lipopeptides fraction (LF) also showed anti-B. cereus effect. The UV-MALDI-MS analysis revealed surfactin, iturin and fengycin in the CFS, whereas surfactin predominated in the LF. The CFS from CBMDC3f contained surfactin, iturin and fengycin with four, two and four homologues per family, respectively, whereas four surfactin, one iturin and one fengycin homologues were identified in the LF. For some surfactin homologues, their UV-MALDI-TOF/TOF (MS/MS; Laser Induced Decomposition method, LID) spectra were also obtained. Mass spectrometry analysis contributed with relevant information about the type of lipopeptides that Bacillus strains can synthesize. From our results, surfactin would be the main metabolite responsible for the antibacterial effect.
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Bioremoval of trivalent chromium using Bacillus biofilms through continuous flow reactor.
Sundar, K; Sadiq, I Mohammed; Mukherjee, Amitava; Chandrasekaran, N
2011-11-30
Present study deals with the applicability of bacterial biofilms for the bioremoval of trivalent chromium from tannery effluents. A continuous flow reactor was designed for the development of biofilms on different substrates like glass beads, pebbles and coarse sand. The parameters for the continuous flow reactor were 20 ml/min flow rate at 30°C, pH4. Biofilm biomass on the substrates was in the following sequence: coarse sand>pebbles>glass beads (4.8 × 10(7), 4.5 × 10(7) and 3.5 × 10(5)CFU/cm(2)), which was confirmed by CLSM. Biofilms developed using consortium of Bacillus subtilis and Bacillus cereus on coarse sand had more surface area and was able to remove 98% of Cr(III), SEM-EDX proved 92.60% Cr(III) adsorption on biofilms supported by coarse sand. Utilization of Bacillus biofilms for effective bioremoval of Cr(III) from chrome tanning effluent could be a better option for tannery industry, especially during post chrome tanning operation. Copyright © 2011 Elsevier B.V. All rights reserved.
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Kinetics of Germination of Bacillus Spores1
Vary, J. C.; Halvorson, H. O.
1965-01-01
Vary, J. C. (University of Wisconsin, Madison), and H. O. Halvorson. Kinetics or germination of Bacillus spores. J. Bacteriol. 89:1340–1347. 1965.—The kinetics of germination of Bacillus cereus strain T spores was accurately described by McCormick. To study the mechanism of germination, it is necessary to correlate the characteristic changes in a population of germinating spores with the behavior of the individual spores in the same population. Two microscopic events are apparent during germination: microlag, the time interval between the addition of l-alanine to heat-activated spores and the beginning of loss in refractility, and microgermination time, the time for the actual change in refractility to occur. The frequency distributions of both events are skewed, and appear to be independent. The effects of l-alanine concentration, heat activation, and temperature of germination on three parameters, microlag, microgermination, and per cent germination, were microscopically studied. The data are discussed in relation to the mechanism of germination, and a correlation between microlag and microgermination times with the constants of McCormick's equation has been suggested. Images PMID:14293008
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2006-01-01
the sporangium) contributes the com- plex layers of the spore coats that encase the spore DNA. The mother cell dies and begins to fall apart at the end...spores. Bacillus spores contain a number of coat layers and some species posses an additional outermost layer called the exosporium. BA, B. cereus, and B...exosporium is the outermost layer of the BA spores, it likely contains important protein and carbohydrate markers that are recognized by antibodies
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Time to B. cereus about hot chocolate.
Nelms, P K; Larson, O; Barnes-Josiah, D
1997-01-01
To determine the cause of illnesses experienced by employees of a Minneapolis manufacturing plant after drinking hot chocolate bought from a vending machine and to explore the prevalence of similar vending machine-related illnesses. The authors inspected the vending machines at the manufacturing plant where employees reported illnesses and at other locations in the city where hot chocolate beverages were sold in machines. Tests were performed on dry mix, water, and beverage samples and on machine parts. Laboratory analyses confirmed the presence of B. cereus in dispensed beverages at a concentration capable of causing illness (170,000 count/gm). In citywide testing of vending machines dispensing hot chocolate, 7 of the 39 licensed machines were found to be contaminated, with two contaminated machines having B. cereus levels capable of causing illness. Hot chocolate sold in vending machines may contain organisms capable of producing toxins that under favorable conditions, can induce illness. Such illnesses are likely to be underreported. Even low concentrations of B. cereus may be dangerous for vulnerable populations such as the aged or immunosuppressed. Periodic testing of vending machines is thus warranted. The relationship between cleaning practices and B. cereus contamination is an issue for further study.
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Time to B. cereus about hot chocolate.
Nelms, P K; Larson, O; Barnes-Josiah, D
1997-01-01
OBJECTIVE: To determine the cause of illnesses experienced by employees of a Minneapolis manufacturing plant after drinking hot chocolate bought from a vending machine and to explore the prevalence of similar vending machine-related illnesses. METHODS: The authors inspected the vending machines at the manufacturing plant where employees reported illnesses and at other locations in the city where hot chocolate beverages were sold in machines. Tests were performed on dry mix, water, and beverage samples and on machine parts. RESULTS: Laboratory analyses confirmed the presence of B. cereus in dispensed beverages at a concentration capable of causing illness (170,000 count/gm). In citywide testing of vending machines dispensing hot chocolate, 7 of the 39 licensed machines were found to be contaminated, with two contaminated machines having B. cereus levels capable of causing illness. CONCLUSIONS: Hot chocolate sold in vending machines may contain organisms capable of producing toxins that under favorable conditions, can induce illness. Such illnesses are likely to be underreported. Even low concentrations of B. cereus may be dangerous for vulnerable populations such as the aged or immunosuppressed. Periodic testing of vending machines is thus warranted. The relationship between cleaning practices and B. cereus contamination is an issue for further study. PMID:9160059
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van Bokhorst-van de Veen, Hermien; Xie, Houyu; Esveld, Erik; Abee, Tjakko; Mastwijk, Hennie; Nierop Groot, Masja
2015-02-01
Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity. Copyright © 2014 Elsevier Ltd. All
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Benitez, Lisianne; Correa, AnaPaula; Daroit, Daniel; Brandelli, Adriano
2011-03-01
Increased antimicrobial activity was observed when Bacillus amyloliquefaciens LBM 5006 strain was cultivated in the presence of thermally inactivated cells of Escherichia coli, but not with Staphylococcus aureus, Listeria monocytogenes, or Bacillus cereus. E. coli also enhanced the antimicrobial activity when it was added to the medium in the form of living cells or as cell debris after cellular fractionation. No inducing activity was observed with addition of cell-free supernatant of E. coli cultures, suggesting that inducing factor is associated to the cells. Polyacrylamide gel electrophoresis revealed that additional peptide bands are secreted when B. amyloliquefaciens was cultivated in the presence of cell debris of E. coli. These results suggest that the presence of intact or inactivated E. coli enhanced the synthesis of antimicrobial peptides by B. amyloliquefaciens LBM 5006.
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Ouoba, L I I; Parkouda, C; Diawara, B; Scotti, C; Varnam, A H
2008-01-01
To identify Bacillus spp. responsible of the fermentation of Hibiscus sabdariffa for production of Bikalga, an alkaline fermented food used as a condiment in Burkina Faso. Seventy bacteria were isolated from Bikalga produced in different regions of Burkina Faso and identified by phenotyping and genotyping using PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS-PCR), repetitive sequence-based PCR (rep-PCR) and DNA sequencing. The isolates were characterized as motile, rod-shaped, endospore forming, catalase positive, Gram-positive bacteria. ITS-PCR allowed typing mainly at species level. Rep-PCR was more discriminative and allowed a typing at ssp. level. The DNA sequencing combined with the Blast search program and fermentation profiles using API 50CHB system allowed an identification of the bacteria as Bacillus subtilis, B. licheniformis, B. cereus, B. pumilus, B. badius, Brevibacillus bortelensis, B. sphaericus and B. fusiformis. B. subtilis were the predominant bacterium (42) followed by B. licheniformis (16). Various species and ssp. of Bacillus are involved in fermentation of H. sabdariffa for production of Bikalga. Selection of starter cultures of Bacillus for controlled production of Bikalga, selection of probiotic bacteria.
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Puišo, Judita; Jonkuvienė, Dovilė; Mačionienė, Irena; Šalomskienė, Joana; Jasutienė, Ina; Kondrotas, Rokas
2014-09-01
In this study lingonberry and cranberry juices were used for silver nanoparticle synthesis. The berry juices were characterized by total phenolics, total anthocyanins and benzoic acid content, respectively 1.9-2.7mg/ml, 55.2-83.4mg/l and 590.8-889.2mg/l. The synthesis of silver nanoparticles was performed at room temperature assisting in solutions irradiated by ultraviolet for 30min. Ultraviolet-visible (UV-vis) spectroscopy and microscopy confirmed the formation of nanoparticles as well as the dark red color of colloid of silver samples showed the formation of stable nanoparticles. Broad localized surface plasmon resonance (LSPR) peaks in UV-vis spectra indicated the formation of polydispersive silver nanoparticles and LSPR was observed at 485nm and 520nm for the silver nanoparticles synthesis using lingonberry and cranberry juices, respectively. The antimicrobial activity of silver nanoparticles was determined against the reference strains of microorganisms that could be found in food products: Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 13076, Listeria monocytogenes ATCC 19111, Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and foodborne B. cereus producing and non-producing enterotoxins. Silver nanoparticles showed a broad spectrum of antimicrobial activity and were most active against S. aureus ATCC 25923, B. subtilis ATCC 6633 and B. cereus ATCC 11778 reference cultures, and less active against C. albicans ATCC 10231 and foodborne B. cereus. It can be concluded that lingonberry and cranberry juices could be used as bioreductants for silver ions. Copyright © 2014 Elsevier B.V. All rights reserved.
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Seasonal Outbreak of Bacillus Bacteremia Associated With Contaminated Linen in Hong Kong.
Cheng, Vincent C C; Chen, Jonathan H K; Leung, Sally S M; So, Simon Y C; Wong, Shuk-Ching; Wong, Sally C Y; Tse, Herman; Yuen, Kwok-Yung
2017-05-15
A high seasonal incidence of Bacillus bacteremia was associated with the use of contaminated hospital linens. An outbreak investigation was conducted to study the incidence and source of Bacillus bacteremia during the baseline, outbreak, and postoutbreak period from 1 January 2012 through 31 July 2016 at a university-affiliated teaching hospital in Hong Kong. Replicate organism detection and counting plates were used for microbial screening of linen samples. The Bacillus species isolated from patient and linen samples were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were phylogenetically analyzed. During the study period, a total of 113 207 blood cultures were collected from 43 271 patients, of which 978 (0.86%) specimens from 744 (1.72%) patients were identified as Bacillus species. The incidence of Bacillus bacteremia per 10 000 patient admissions and per 10 000 patient-days was significantly higher during the summer outbreak as compared with baseline and 1 year postoutbreak after cessation of the linen supply from the designated laundry and change of laundry protocol (39.97 vs 18.21 vs 2.27; 13.36 vs 5.61 vs 0.73; P < .001). The mean total aerobic bacterial count per 100 cm2 was significantly higher among the 99 linen samples screened during the outbreak period compared to the 100 screened in the postoutbreak period (916.0 ± 641.6 vs 0.6 ± 1.6; P < .001). Blood culture isolates of Bacillus cereus group in 14 of 87 (16.1%) patients were phylogenetically associated with 9 linen sample isolates. Suboptimal conditions of hospital laundry contributed to the seasonal outbreak of Bacillus bacteremia. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
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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.
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Novel Strategy to Control the Warfighter’s Exposure to Polymicrobial Environments
2015-09-30
RELEASE 13. SUPPLEMENTARY NOTES 14. ABSTRACT Bacteriocins active against clinically-relevant Pseudomonas aeruginosa, Staphylococcus aureus ...SUBJECT TERMS Bacteriocins, Antimicrobials, Pseudomonas aeruginosa, Staphylococcus aureus , Acinetobacter baumanii, Bacillus cereus 16. SECURITY...Pseudomonas aeruginosa, Staphylococcus aureus , Acinetobacter baumanni and Bacillus cereus (target pathogens for the proposed research). Summary
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Kubiak, Xavier; Duval, Romain; Pluvinage, Benjamin; Chaffotte, Alain F; Dupret, Jean-Marie; Rodrigues-Lima, Fernando
2017-07-01
The arylamine N-acetyltransferases (NATs) are xenobiotic-metabolizing enzymes that play an important role in the detoxification and/or bioactivation of arylamine drugs and xenobiotics. In bacteria, NATs may contribute to the resistance against antibiotics such as isoniazid or sulfamides through their acetylation, which makes this enzyme family a possible drug target. Bacillus anthracis, a bacterial species of clinical significance, expresses three NAT isozymes with distinct structural and enzymatic properties, including an inactive isozyme ((BACAN)NAT3). (BACAN)NAT3 features both a non-canonical Glu residue in its catalytic triad and a truncated C-terminus domain. However, the role these unusual characteristics play in the lack of activity of the (BACAN)NAT3 isozyme remains unclear. Protein engineering, recombinant expression, enzymatic analyses with aromatic amine substrates and phylogenetic analysis approaches were conducted. The deletion of guanine 580 (G580) in the nat3 gene was shown to be responsible for the expression of a truncated (BACAN)NAT3 isozyme. Artificial re-introduction of G580 in the nat3 gene led to a functional enzyme able to acetylate several arylamine drugs displaying structural characteristics comparable with its functional Bacillus cereus homologue ((BACCR)NAT3). Phylogenetic analysis of the nat3 gene in the B. cereus group further indicated that nat3 may constitute a pseudogene of the B. anthracis species. The existence of NATs with distinct properties and evolution in Bacillus species may account for their adaptation to their diverse chemical environments. A better understanding of these isozymes is of importance for their possible use as drug targets. This article is part of a themed section on Drug Metabolism and Antibiotic Resistance in Micro-organisms. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.14/issuetoc. © 2016 The British Pharmacological Society.
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Inhibition of biofilm formation in Bacillus subtilis by new halogenated furanones.
Kayumov, Airat R; Khakimullina, Elvina N; Sharafutdinov, Irshad S; Trizna, Elena Y; Latypova, Lilia Z; Thi Lien, Hoang; Margulis, Anna B; Bogachev, Mikhail I; Kurbangalieva, Almira R
2015-05-01
Gram-positive bacteria can cause various infections including hospital-acquired infections. While in the biofilm, the resistance of bacteria to both antibiotics and the human immune system is increased causing difficulties in the treatment. Bacillus subtilis, a non-pathogenic Gram-positive bacterium, is widely used as a model organism for studying biofilm formation. Here we investigated the effect of novel synthesized chloro- and bromo-containing 2(5H)-furanones on biofilm formation by B. subtilis. Mucobromic acid (3,4-dibromo-5-hydroxy-2(5H)-furanone) and the two derivatives of mucochloric acid (3,4-dichloro-5-hydroxy-2(5H)-furanone)-F8 and F12-were found to inhibit the growth and to efficiently prevent biofilm formation by B. subtilis. Along with the low production of polysaccharide matrix and repression of the eps operon, strong repression of biofilm-related yqxM also occurred in the presence of furanones. Therefore, our data confirm that furanones affect significantly the regulatory pathway(s) leading to biofilm formation. We propose that the global regulator, Spo0A, is one of the potential putative cellular targets for these compounds.
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Meissner, Lena; Kauffmann, Kira; Wengeler, Timo; Mitsunaga, Hitoshi; Fukusaki, Eiichiro; Büchs, Jochen
2015-09-01
Bacillus spp. are used for the production of industrial enzymes but are also known to be capable of producing biopolymers such as poly(γ-glutamic acid). Biopolymers increase the viscosity of the fermentation broth, thereby impairing mixing, gas/liquid mass and heat transfer in any bioreactor system. Undesired biopolymer formation has a significant impact on the fermentation and downstream processing performance. This study shows how undesirable poly(γ-glutamic acid) formation of an industrial protease producing Bacillus licheniformis strain was prevented by switching the nitrogen source from ammonium to nitrate. The viscosity was reduced from 32 to 2.5 mPa s. A constant or changing pH value did not influence the poly(γ-glutamic acid) production. Protease production was not affected: protease activities of 38 and 46 U mL(-1) were obtained for ammonium and nitrate, respectively. With the presented results, protease production with industrial Bacillus strains is now possible without the negative impact on fermentation and downstream processing by undesired poly(γ-glutamic acid) formation.
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Pepe, Olimpia; Blaiotta, Giuseppe; Moschetti, Giancarlo; Greco, Teresa; Villani, Francesco
2003-04-01
Two types of white wheat bread (high- and low-type loaves) were investigated for rope spoilage. Thirty of the 56 breads tested developed rope spoilage within 5 days; the high-type loaves were affected by rope spoilage more than the low-type loaves. Sixty-one Bacillus strains were isolated from ropy breads and were characterized on the basis of their phenotypic and genotypic traits. All of the isolates were identified as Bacillus subtilis by biochemical tests, but molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads. In fact, besides strains of B. subtilis, Bacillus licheniformis, Bacillus cereus, and isolates of Bacillus clausii and Bacillus firmus were also identified. All of the ropy Bacillus isolates exhibited amylase activity, whereas only 32.4% of these isolates were able to produce ropiness in bread slices after treatment at 96 degrees C for 10 min. Strains of lactic acid bacteria previously isolated from sourdough were first selected for antirope activity on bread slices and then used as starters for bread-making experiments. Prevention of growth of approximately 10(4) rope-producing B. subtilis G1 spores per cm(2) on bread slices for more than 15 days was observed when heat-treated cultures of Lactobacillus plantarum E5 and Leuconostoc mesenteroides A27 were added. Growth of B. subtilis G1 occurred after 7 days in breads started with Saccharomyces cerevisiae T22, L. plantarum E5, and L. mesenteroides A27.
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Yasin, Ina-salwany Md; Razak, Nabilah Fatin; Natrah, F M I; Harmin, Sharr Azni
2016-07-01
A total of 58 Gram-positive bacteria strains were isolated from the marine environment and screened for potential probiotics for disease prevention and improving the productivity of tiger grouper Epinephelus fuscoguttatus larvae and juveniles. The bacteria were identified as Bacillus licheniformis, B. subtilis, B. circulans, B. sphaericus, B. cereus, Brevibacillus brevis, Corynebacterium propinquum, Leifsonia aquatica and Paenibacillus macerans. Only 24 strains showed antagonistic activities against four pathogenic strains; Vibrio alginolyticus, V. harveyi, V. parahaemolyticus and Aeromonas hydrophila, where two of the Bacillus strains, B12 and B45 demonstrated intermediate to highest level of inhibitory activity against these pathogenic strains, respectively. Further assessment by co-culture assay showed that Bacillus strain B12 exhibited a total inhibition of V. alginolyticus, while B45 strain displayed no inhibitory activity. Mixed culture of Bacillus B12 and B45 strains to outcompete V. alginolyticus was observed at a cell density of 10(7) CFU ml(-1). Molecular identification and phylogenetic tree analysis have categorized Bacillus strain B12 to the reference strains GQ340480 and JX290193 of? B. amyloliquafaciens, and Bacillus strain B45 with a reference strain JF496522 of B. subtilis. Safety tests of probionts by intraperitoneal administration of B12 and B45 strains at cell densities of 103, 105 and 10(7) CFU ml(-1) revealed no abnormalities and cent percent survival for healthy Epinephelus fuscoguttatus juveniles within 15 days of experimental period. Overall, the study revealed that Bacillus B12 strain possesses tremendous probiotic potential that could be used as a feed supplement in tiger grouper diets. ?
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In 't Veld, P H; van der Laak, L F J; van Zon, M; Biesta-Peters, E G
2018-04-12
A method for the quantification of the Bacillus cereus emetic toxin (cereulide) was developed and validated. The method principle is based on LC-MS as this is the most sensitive and specific method for cereulide. Therefore the study design is different from the microbiological methods validated under this mandate. As the method had to be developed a two stage validation study approach was used. The first stage (pre-study) focussed on the method applicability and the experience of the laboratories with the method. Based on the outcome of the pre-study and comments received during voting at CEN and ISO level a final method was agreed to be used for the second stage the (final) validation of the method. In the final (validation) study samples of cooked rice (both artificially contaminated with cereulide or contaminated with B. cereus for production of cereulide in the rice) and 6 other food matrices (fried rice dish, cream pastry with chocolate, hotdog sausage, mini pancakes, vanilla custard and infant formula) were used. All these samples were spiked by the participating laboratories using standard solutions of cereulide supplied by the organising laboratory. The results of the study indicate that the method is fit for purpose. Repeatability values were obtained of 0.6 μg/kg at low level spike (ca. 5 μg/kg) and 7 to 9.6 μg/kg at high level spike (ca. 75 μg/kg). Reproducibility at low spike level ranged from 0.6 to 0.9 μg/kg and from 8.7 to 14.5 μg/kg at high spike level. Recovery from the spiked samples ranged between 96.5% for mini-pancakes to 99.3% for fries rice dish. Copyright © 2018. Published by Elsevier B.V.
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2003-11-08
Bacillus anthracis BA0068 Ames Sterne SPS 97.13.213 Bacillus cereus Bacillus coagulans Bacillus licheniformis Bacillus macerans Bacillus ...megaterium Bacillus polymyxa Bacillus sphaericus Bacillus stearothermophilus Bacillus subtilis subsp. niger Bacillus thuringiensis Bacillus popilliae...varicella- zoster virus, and Bacillus anthracis DNA by LightCycler polymerase chain reaction after autoclaving:
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Inactivation of Bacillus spores inoculated in milk by Ultra High Pressure Homogenization.
Amador Espejo, Genaro Gustavo; Hernández-Herrero, M M; Juan, B; Trujillo, A J
2014-12-01
Ultra High-Pressure Homogenization treatments at 300 MPa with inlet temperatures (Ti) of 55, 65, 75 and 85 °C were applied to commercial Ultra High Temperature treated whole milk inoculated with Bacillus cereus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus coagulans, Geobacillus stearothermophilus and Bacillus subtilis spores in order to evaluate the inactivation level achieved. Ultra High-Pressure Homogenization conditions at 300 MPa with Ti = 75 and 85 °C were capable of a spore inactivation of ∼5 log CFU/mL. Furthermore, under these processing conditions, commercial sterility (evaluated as the complete inactivation of the inoculated spores) was obtained in milk, with the exception of G. stearothermophilus and B. subtilis treated at 300 MPa with Ti = 75 °C. The results showed that G. stearothermophilus and B. subtilis have higher resistance to the Ultra High-Pressure Homogenization treatments applied than the other microorganisms inoculated and that a treatment performed at 300 MPa with Ti = 85 °C was necessary to completely inactivate these microorganisms at the spore level inoculated (∼1 × 10(6) CFU/mL). Besides, a change in the resistance of B. licheniformis, B. sporothermodurans, G. stearothermophilus and B. subtilis spores was observed as the inactivation obtained increased remarkably in treatments performed with Ti between 65 and 75 °C. This study provides important evidence of the suitability of UHPH technology for the inactivation of spores in high numbers, leading to the possibility of obtaining commercially sterile milk. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Kasan, Nor Azman; Ghazali, Nurarina Ayuni; Ikhwanuddin, Mhd; Ibrahim, Zaharah
2017-01-01
A new green technology to reduce environmental damages while optimizing production of Pacific Whiteleg shrimp, Litopenaeus vannamei was developed known as "Biofloc technology". Microbial communities in biofloc aggregates are responsible in eliminating water exchange and producing microbial proteins that can be used as supplemented feed for L. vannamei. This study aimed to isolate and identify potential bioflocculant-producing bacteria to be used as inoculum for rapid formation of biofloc. For the purpose of this study, bacterial communities during 0, 30 and 70 days of culture (DOC) of L. vannamei grow-out ponds were isolated and identified through phenotypic and 16S rDNA sequences analysis. Phylogenetic relationships between isolated bacteria were then evaluated through phylogenetic tree analysis. One-way analysis of variance (ANOVA) was used to compare the differences of microbial communities at each DOC. Out of 125 bacterial isolates, nine species of bacteria from biofloc were identified successfully. Those bacteria species were identified as Halomonas venusta, H. aquamarina, Vibrio parahaemolyticus, Bacillus infantis, B. cereus, B. safensis, Providencia vermicola, Nitratireductor aquimarinus and Pseudoalteromonas sp., respectively. Through phylogenetic analysis, these isolates belong to Proteobacteria and Firmicutes families under the genera of Halomonas sp., Vibrio sp., Bacillus sp., Providencia sp., Nitratireductor sp. and Pseudoalteromonas sp. In this study, bioflocculant-producing bacteria were successfully identified which are perfect candidates in forming biofloc to reduce water pollution towards a sustainable aquaculture industry. Presence of Halomonas sp. and Bacillus sp. in all stages of biofloc formation reinforces the need for new development regarding the ability of these species to be used as inoculum in forming biofloc rapidly.
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Biesta-Peters, Elisabeth G.; Reij, Martine W.; Zwietering, Marcel H.; Gorris, Leon G. M.
2011-01-01
This research aims to test the absence (gamma hypothesis) or occurrence of synergy between two growth-limiting factors, i.e., pH and water activity (aw), using a systematic approach for model selection. In this approach, preset criteria were used to evaluate the performance of models. Such a systematic approach is required to be confident in the correctness of the individual components of the combined (synergy) models. With Bacillus cereus F4810/72 as the test organism, estimated growth boundaries for the aw-lowering solutes NaCl, KCl, and glucose were 1.13 M, 1.13 M, and 1.68 M, respectively. The accompanying aw values were 0.954, 0.956, and 0.961, respectively, indicating that equal aw values result in similar effects on growth. Out of the 12 models evaluated using the preset criteria, the model of J. H. T. Luong (Biotechnol. Bioeng. 27:280–285, 1985) was the best model to describe the effect of aw on growth. This aw model and the previously selected pH model were combined into a gamma model and into two synergy models. None of the three models was able to describe the combined pH and aw conditions sufficiently well to satisfy the preset criteria. The best matches between predicted and experimental data were obtained with the gamma model, followed by the synergy model of Y. Le Marc et al. (Int. J. Food Microbiol. 73:219–237, 2002). No combination of models that was able to predict the impact of both individual and combined hurdles correctly could be found. Consequently, in this case we could not prove the existence of synergy nor falsify the gamma hypothesis. PMID:21705525
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Auta, H S; Emenike, C U; Fauziah, S H
2017-12-01
The continuous accumulation of microplastics in the environment poses ecological threats and has been an increasing problem worldwide. In this study, eight bacterial strains were isolated from mangrove sediment in Peninsular Malaysia to mitigate the environmental impact of microplastics and develop a clean-up option. The bacterial isolates were screened for their potential to degrade UV-treated microplastics from polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS). Only two isolates, namely, Bacillus cereus and Bacillus gottheilii, grew on a synthetic medium containing different microplastic polymers as the sole carbon source. A shake flask experiment was carried out to further evaluate the biodegradability potential of the isolates. Degradation was monitored by recording the weight loss of microplastics and the growth pattern of the isolates in the mineral medium. The biodegradation extent was validated by assessment of the morphological and structural changes through scanning electron microscopy and Fourier transform infrared spectroscopy analyses. The calculated weight loss percentages of the microplastic particles by B. cereus after 40 days were 1.6%, 6.6%, and 7.4% for PE, PET, and PS, respectively. B. gottheilii recorded weight loss percentages of 6.2%, 3.0%, 3.6%, and 5.8% for PE, PET, PP, and PS, respectively. The designated isolates degraded the microplastic material and exhibited potential for remediation of microplastic-contaminated environment. Biodegradation tests must be conducted to characterize the varied responses of microbes toward pollutants, such as microplastics. Hence, a novel approach for biodegradation of microplastics must be developed to help mitigate the environmental impact of plastics and microplastic polymers. Copyright © 2017 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Lahiani, Mohamed; Tarasenko, Olga
2010-04-01
Members of the Bacillus cereus group demonstrate different pathological effects. B. cereus is a spore-forming, gram positive bacterium responsible for most foodborne illnesses. It was shown that susceptibility to infection and response to vaccines or treatments can be attributed to specific immunogenetic factors including gender and ethnicity. Glycoconjugate polymers (GCs) are potentially important in pharmaceutical and biomedical research. Our group has shown that GCs activate murine macrophages and promote killing of Bacillus cereus spores during phagocytosis. We hypothesized that the GCs effects are independent from gender and race. The goal of the present study was two-folds: A) determine whether GCs influence on human PMNC exposure of B. cereus spores and B) analyze whether gender and ethnicity influence of the effect of GCs. GCs were studied during exposure and post-exposure conditions. Phagocytosis was performed during exposure of PMNC to Bacillus spores. Post-exposure analysis involved cytotoxicity, cell viability and activation, and colonies forming unit. GC1 and GC3 enhance Bacillus spore killing. GC1 proved more effective than GC3 in spore killing while activating PMNC. Results demonstrate GCs effect were independent from ethnicity or gender. Findings of this research demonstrated that GC can be used as ligands to stimulate PMNC and kill B. cereus spores.
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USDA-ARS?s Scientific Manuscript database
The objective of this study was to assess the ability of B. cereus spores to germinate and grow in order to determine a safe cooling rate for cooked rice, beans, and pasta, rice/chicken (4:1), rice/chicken/vegetables (3:1:1), rice/beef (4:1), and rice/beef/vegetables (3:1:1). Samples were inoculate...
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Bacteriocins synthesized by Bacillus thuringiensis: generalities and potential applications
Salazar-Marroquín, Elma Laura; Galán-Wong, Luis J.; Moreno-Medina, Víctor Ricardo; Reyes-López, Miguel Ángel; Pereyra-Alférez, Benito
2016-01-01
The members of the Bacillus thuringiensis group, commonly known as Bt, produce a huge number of metabolites, which show biocidal and antagonistic activity. B. thuringiensis is widely known for synthesizing Cry, Vip and Cyt proteins, active against insects and other parasporins with biocidal activity against certain types of cancerous cells. Nevertheless, B. thuringiensis also synthesizes compounds with antimicrobial activity, especially bacteriocins. Some B. thuringiensis bacteriocins resemble lantibiotics and other small linear peptides (class IIa) from the lactic acid bacteria bacteriocins classification system. Although many bacteriocins produced by Bt have been reported, there is no proper classification for them. In this work, we have grouped these based on molecular weight and functionality. Bacteriocins are small peptides synthesized by bacteria, presenting inhibitory activity against Gram-positive and Gram-negative bacteria and to a lesser extent against fungi. These molecules represent a good study model in the search for microbial control alternatives. Lactic acid bacteria produces a huge number of these types of molecules with great potential. Nonetheless, members of the Bacillus, cereus group, especially B. thuringiensis, emerge as an attractive alternative for obtaining bacteriocins showing novel activities. This review describes the potential applications of B. thuringiensis bacteriocins in the control of foodborne pathogens, environment and medical area. PMID:27340340
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Bacteriocins synthesized by Bacillus thuringiensis: generalities and potential applications.
Salazar-Marroquín, Elma Laura; Galán-Wong, Luis J; Moreno-Medina, Víctor Ricardo; Reyes-López, Miguel Ángel; Pereyra-Alférez, Benito
2016-07-01
The members of the Bacillus thuringiensis group, commonly known as Bt, produce a huge number of metabolites, which show biocidal and antagonistic activity. B. thuringiensis is widely known for synthesizing Cry, Vip and Cyt proteins, active against insects and other parasporins with biocidal activity against certain types of cancerous cells. Nevertheless, B. thuringiensis also synthesizes compounds with antimicrobial activity, especially bacteriocins. Some B. thuringiensis bacteriocins resemble lantibiotics and other small linear peptides (class IIa) from the lactic acid bacteria bacteriocins classification system. Although many bacteriocins produced by Bt have been reported, there is no proper classification for them. In this work, we have grouped these based on molecular weight and functionality. Bacteriocins are small peptides synthesized by bacteria, presenting inhibitory activity against Gram-positive and Gram-negative bacteria and to a lesser extent against fungi. These molecules represent a good study model in the search for microbial control alternatives. Lactic acid bacteria produces a huge number of these types of molecules with great potential. Nonetheless, members of the Bacillus, cereus group, especially B. thuringiensis, emerge as an attractive alternative for obtaining bacteriocins showing novel activities. This review describes the potential applications of B. thuringiensis bacteriocins in the control of foodborne pathogens, environment and medical area.
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Corrêa, E K; Ulguim, R R; Corrêa, L B; Castilhos, D D; Bianchi, I; Gil-Turnes, C; Lucia, T
2012-10-01
Thermal and microbiological characteristics of beddings for swine were compared according to their depth and of addition of inoculums. Bedding was added to boxes at 0.25 (25D) and 0.50 m (50D), with three treatments: control (no inoculums); T1, with 250 g of Bacillus cereus var. toyoii at 8.4 × 10(7) CFU; and T2, with 250 g of a pool of B. subtilis, Bacillus licheniformis and Bacillus polymyxa at 8.4 × 10(7) CFU (250 g for 25D and 500 g for 50D). Mean temperatures were 28.5 ± 3.9 at the surface and 35.2 ± 8.9 inside the beddings. The most probable number (MPN) of thermophilic bacteria was higher for T1 and T2 than for the control (P<0.05). The MPN of thermophilic bacteria and fungi was greater for D50 than for D25 (P<0.05). The use of 25D without inoculums is recommended due to the reduction of thermophilic microbiota. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Das, Subhasish; Sen, Ramkrishna
2011-10-01
A logistic kinetic model was derived and validated to characterize the dynamics of a sporogenous bacterium in stationary phase with respect to sporulation and product formation. The kinetic constants as determined using this model are particularly important for describing intrinsic properties of a sporogenous bacterial culture in stationary phase. Non-linear curve fitting of the experimental data into the mathematical model showed very good correlation with the predicted values for sporulation and lipase production by Bacillus coagulans RK-02 culture in minimal media. Model fitting of literature data of sporulation and product (protease and amylase) formation in the stationary phase by some other Bacilli and comparison of the results of model fitting with those of Bacillus coagulans helped validate the significance and robustness of the developed kinetic model. Copyright © 2011 Elsevier Ltd. All rights reserved.
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RAPID IDENTIFICATION OF MICROORGANISMS BY CONTINUOUS PARTICLE ELECTROPHORESIS.
MICROORGANISMS, IDENTIFICATION), (*ELECTROPHORESIS, MICROORGANISMS), MOBILITY, PH FACTOR, OPTICAL SCANNING, ESCHERICHIA COLI, SHIGELLA FLEXNERI, BACILLUS CEREUS, SERRATIA MARCESCENS , BACILLUS SUBTILIS
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Properties of a Bacteriocin Produced by Bacillus subtilis EMD4 Isolated from Ganjang (Soy Sauce).
Liu, Xiaoming; Lee, Jae Yong; Jeong, Seon-Ju; Cho, Kye Man; Kim, Gyoung Min; Shin, Jung-Hye; Kim, Jong-Sang; Kim, Jeong Hwan
2015-09-01
A Bacillus species, EMD4, with strong antibacterial activity was isolated from ganjang (soy sauce) and identified as B. subtilis. B. subtilis EMD4 strongly inhibited the growth of B. cereus ATCC14579 and B. thuringiensis ATCC33679. The antibacterial activity was stable at pH 3-9 but inactive at pH 10 and above. The activity was fully retained after 15 min at 80°C but reduced by 50% after 15 min at 90°C. The activity was completely destroyed by proteinase K and protease treatment, indicating its proteinaceous nature. The bacteriocin (BacEMD4) was partially purified from culture supernatant by ammonium sulfate precipitation, and QSepharose and Sephadex G-50 column chromatographies. The specific activity was increased from 769.2 AU/mg protein to 8,347.8 AU/mg protein and the final yield was 12.6%. The size of BacEMD4 was determined to be 3.5 kDa by Tricine SDS-PAGE. The N-terminal amino acid sequence was similar with that of Subtilosin A. Nucleotide sequencing of the cloned gene confirmed that BacEMD4 was Subtilosin A. BacEMD4 showed bactericidal activity against B. cereus ATCC14579.
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Dobson, Tresha E; Maxwell, Anderson R; Ramsubhag, Adesh
2018-07-01
Six cholic acid derivatives (1-6) were isolated from broth cultures of Bacillus amyloliquefaciens UWI-W23, an isolate from the Trinidad Pitch Lake. The compounds were extracted via solvent extraction and/or XAD resin adsorption and purified using silica gel column chromatography. Their structures were elucidated using 1D, 2D NMR and ESI-MS spectrometry and FT-IR spectrophotometry. One of the compounds, taurodeoxycholate (2) is for the first time being reported from a bacterial source while deoxycholate (4) is for the first time being reported from a Gram-positive bacterium. The other compounds have not been previously isolated from Bacillus spp. viz. cholate (1), taurocholic acid (3); glycodeoxycholic acid (5) and glycocholic acid (6). All six compounds exhibited antimicrobial activity against P. aeruginosa and B. cereus with MICs ranging from 7 to 250 µg/mL. Cholate (1) also showed activity against MRSA (MICs = 125 µg/mL) and glycocholic acid (6) against S. cerevisiae (MICs = 15.6 µg/mL). Copyright © 2018 Elsevier Inc. All rights reserved.
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Murata, Kenji; Kanno, Shunsuke; Nishio, Hisanori; Saito, Mitsumasa; Tanaka, Tamami; Yamamura, Kenichiro; Sakai, Yasunari; Takada, Hidetoshi; Miyamoto, Tomofumi; Mizuno, Yumi; Ouchi, Kazunobu; Waki, Kenji; Hara, Toshiro
2014-01-01
Background Kawasaki disease (KD) is a systemic vasculitis of unknown etiology. The innate immune system is involved in its pathophysiology at the acute phase. We have recently established a novel murine model of KD coronary arteritis by oral administration of a synthetic microbe-associated molecular pattern (MAMP). On the hypothesis that specific MAMPs exist in KD sera, we have searched them to identify KD-specific molecules and to assess the pathogenesis. Methods We performed liquid chromatography-mass spectrometry (LC-MS) analysis of fractionated serum samples from 117 patients with KD and 106 controls. Microbiological and LC-MS evaluation of biofilm samples were also performed. Results KD samples elicited proinflammatory cytokine responses from human coronary artery endothelial cells (HCAECs). By LC-MS analysis of KD serum samples collected at 3 different periods, we detected a variety of KD-specific molecules in the lipophilic fractions that showed distinct m/z and MS/MS fragmentation patterns in each cluster. Serum KD-specific molecules showed m/z and MS/MS fragmentation patterns almost identical to those of MAMPs obtained from the biofilms formed in vitro (common MAMPs from Bacillus cereus, Yersinia pseudotuberculosis and Staphylococcus aureus) at the 1st study period, and from the biofilms formed in vivo (common MAMPs from Bacillus cereus, Bacillus subtilis/Bacillus cereus/Yersinia pseudotuberculosis and Staphylococcus aureus) at the 2nd and 3rd periods. The biofilm extracts from Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis and Staphylococcus aureus also induced proinflammatory cytokines by HCAECs. By the experiments with IgG affinity chromatography, some of these serum KD-specific molecules bound to IgG. Conclusions We herein conclude that serum KD-specific molecules were mostly derived from biofilms and possessed molecular structures common to MAMPs from Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis and Staphylococcus
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Huang, Tzu-Pi; Tzeng, Dean Der-Syh; Wong, Amy C. L.; Chen, Chun-Han; Lu, Kuan-Min; Lee, Ya-Huei; Huang, Wen-Di; Hwang, Bing-Fang; Tzeng, Kuo-Ching
2012-01-01
Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a devastating disease resulting in significant crop losses in various citrus cultivars worldwide. A biocontrol agent has not been recommended for this disease. To explore the potential of bacilli native to Taiwan to control this disease, Bacillus species with a broad spectrum of antagonistic activity against various phytopathogens were isolated from plant potting mixes, organic compost and the rhizosphere soil. Seven strains TKS1-1, OF3-16, SP4-17, HSP1, WG6-14, TLB7-7, and WP8-12 showing superior antagonistic activity were chosen for biopesticide development. The genetic identity based on 16S rDNA sequences indicated that all seven native strains were close relatives of the B. subtilis group and appeared to be discrete from the B. cereus group. DNA polymorphisms in strains WG6-14, SP4-17, TKS1-1, and WP8-12, as revealed by repetitive sequence-based PCR with the BOXA1R primers were similar to each other, but different from those of the respective Bacillus type strains. However, molecular typing of the strains using either tDNA-intergenic spacer regions or 16S–23S intergenic transcribed spacer regions was unable to differentiate the strains at the species level. Strains TKS1-1 and WG6-14 attenuated symptom development of citrus bacterial canker, which was found to be correlated with a reduction in colonization and biofilm formation by X. axonopodis pv. citri on leaf surfaces. The application of a Bacillus strain TKS1-1 endospore formulation to the leaf surfaces of citrus reduced the incidence of citrus bacterial canker and could prevent development of the disease. PMID:22848728
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Ishag, Abd Elaziz S A; Abdelbagi, Azhari O; Hammad, Ahmed M A; Elsheikh, Elsiddig A E; Elsaid, Osama E; Hur, J-H; Laing, Mark D
2016-11-16
This study was done to identify pesticide-biodegrading microorganisms and to characterize degradation rates. Bacillus safensis strain FO-36b T , Bacillus subtilis subsp. inaquosorum strain KCTC13429 T , and Bacillus cereus strain ATCC14579 T were isolated from pesticide-polluted soil in Sudan, separately incubated with each pesticide with periodic samples drawn for GC and GC-MS. Pesticide biodegradation followed a biphasic model. α and β half-lives (days) of chlorpyrifos, malathion, and dimethoate in B. safensis culture were 2.13, 4.76; 2.59, 5.66; and 9.5, 11.0, respectively. Values in B. subtilis and B. cereus cultures were 4.09, 9.45 and 4.33, 9.99 for chlorpyrifos; 2.99, 5.36 and 2.43, 4.71 for malathion; and 9.53, 15.11 and 4.16, 9.27 for dimethoate. No metabolite was detected in B. subtilis cultures, whereas a few were detected from B. safensis and B. cereus cultures. Bacterial efficiency can be ordered as B. safensis > B. subtilis > B. cereus for chlorpyrifos and B. cereus > B. subtilis > B. safensis for malathion and dimethoate.
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Using micro-patterned surfaces to inhibit settlement and biofilm formation by Bacillus subtilis.
Chang, Siyuan; Chen, Xiaodong; Jiang, Shuo; Chen, Jinchun; Shi, Lin
2017-07-01
Biofilm is a biological complex caused by bacteria attachment to the substrates and their subsequent reproduction and secretion. This phenomenon reduces heat transfer efficiency and causes significant losses in treated sewage heat-recovering systems. This paper describes a physical approach to inhibit bacteria settlement and biofilm formation by Bacillus subtilis, which is the dominant species in treated sewage. Here, micro-patterned surfaces with different characteristics (stripe and cube) and dimensions (1-100 μm) were fabricated as surfaces of interest. Model sewage was prepared and a rotating coupon device was used to form the biofilms. Precision balance, scanning electron microscopy, and confocal laser scanning microscopy (CLSM) were employed to investigate the inhibitory effects and the mechanisms of the biofilm-surface interactions. The results have shown that surfaces with small pattern sizes (1 and 2 μm) all reduced biofilm formation significantly. Interestingly, the CLSM images showed that the surfaces do not play a role in "killing" the bacteria. These findings are useful for future development of new process surfaces on which bacteria settlement and biofilm formation can be inhibited or minimized.
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Etobayeva, Irina; Linden, Sara B.; Alem, Farhang; Rizkalla, Lucas; Temple, Louise; Hakami, Ramin M.
2018-01-01
Three Bacillus bacteriophage-derived endolysins, designated PlyP56, PlyN74, and PlyTB40, were identified, cloned, purified, and characterized for their antimicrobial properties. Sequence alignment reveals these endolysins have an N-terminal enzymatically active domain (EAD) linked to a C-terminal cell wall binding domain (CBD). PlyP56 has a Peptidase_M15_4/VanY superfamily EAD with a conserved metal binding motif and displays biological dependence on divalent ions for activity. In contrast, PlyN74 and PlyTB40 have T7 lysozyme-type Amidase_2 and carboxypeptidase T-type Amidase_3 EADs, respectively, which are members of the MurNAc-LAA superfamily, but are not homologs and thus do not have a shared protein fold. All three endolysins contain similar SH3-family CBDs. Although minor host range differences were noted, all three endolysins show relatively broad antimicrobial activity against members of the Bacillus cereus sensu lato group with the highest lytic activity against B. cereus ATCC 4342. Characterization studies determined the optimal lytic activity for these enzymes was at physiological pH (pH 7.0–8.0), over a broad temperature range (4–55 °C), and at low concentrations of NaCl (<50 mM). Direct comparison of lytic activity shows the PlyP56 enzyme to be twice as effective at lysing the cell wall peptidoglycan as PlyN74 or PlyTB40, suggesting PlyP56 is a good candidate for further antimicrobial development as well as bioengineering studies. PMID:29883383
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Bistability and Biofilm Formation in Bacillus subtilis
Chai, Yunrong; Chu, Frances; Kolter, Roberto; Losick, Richard
2008-01-01
Summary Biofilms of Bacillus subtilis consist of long chains of cells that are held together in bundles by an extracellular matrix of exopolysaccharide and the protein TasA. The exopolysaccharide is produced by enzymes encoded by the epsA-O operon and the gene encoding TasA is located in the yqxM-sipW-tasA operon. Both operons are under the control of the repressor SinR. Derepression is mediated by the antirepressor SinI, which binds to SinR with a 1:1 stoichiometry. Paradoxically, in medium promoting derepression of the matrix operons, the overall concentration of SinR in the culture greatly exceeded that of SinI. We show that under biofilm-promoting conditions sinI, which is under the control of the response regulator Spo0A, was expressed only in a small subpopulation of cells, whereas sinR was expressed in almost all cells. Activation of Spo0A is known to be subject to a bistable switch, and we infer that SinI reaches levels sufficient to trigger matrix production only in the subpopulation of cells in which Spo0A is active. Additionally, evidence suggests that sinI is expressed at intermediate, but not low or high, levels of Spo0A activity, which may explain why certain nutritional conditions are more effective in promoting biofilm formation than others. PMID:18047568
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Galactose Metabolism Plays a Crucial Role in Biofilm Formation by Bacillus subtilis
Chai, Yunrong; Beauregard, Pascale B.; Vlamakis, Hera; Losick, Richard; Kolter, Roberto
2012-01-01
ABSTRACT Galactose is a common monosaccharide that can be utilized by all living organisms via the activities of three main enzymes that make up the Leloir pathway: GalK, GalT, and GalE. In Bacillus subtilis, the absence of GalE causes sensitivity to exogenous galactose, leading to rapid cell lysis. This effect can be attributed to the accumulation of toxic galactose metabolites, since the galE mutant is blocked in the final step of galactose catabolism. In a screen for suppressor mutants restoring viability to a galE null mutant in the presence of galactose, we identified mutations in sinR, which is the major biofilm repressor gene. These mutations caused an increase in the production of the exopolysaccharide (EPS) component of the biofilm matrix. We propose that UDP-galactose is the toxic galactose metabolite and that it is used in the synthesis of EPS. Thus, EPS production can function as a shunt mechanism for this toxic molecule. Additionally, we demonstrated that galactose metabolism genes play an essential role in B. subtilis biofilm formation and that the expressions of both the gal and eps genes are interrelated. Finally, we propose that B. subtilis and other members of the Bacillus genus may have evolved to utilize naturally occurring polymers of galactose, such as galactan, as carbon sources. PMID:22893383
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A portable cell-based optical detection device for rapid detection of Listeria and Bacillus toxins
NASA Astrophysics Data System (ADS)
Banerjee, Pratik; Banada, Padmapriya P.; Rickus, Jenna L.; Morgan, Mark T.; Bhunia, Arun K.
2005-11-01
A mammalian cell-based optical biosensor was built to detect pathogenic Listeria and Bacillus species. This sensor measures the ability of the pathogens to infect and induce cytotoxicity on hybrid lymphocyte cell line (Ped-2E9) resulting in the release of alkaline phosphatase (ALP) that can be detected optically using a portable spectrophotometer. The Ped-2E9 cells were encapsulated in collagen gel matrices and grown in 48-well plates or in specially designed filtration tube units. Toxin preparations or bacterial cells were introduced and ALP release was assayed after 3-5 h. Pathogenic L. monocytogenes strains or the listeriolysin toxins preparation showed cytotoxicity ranging from 55% - 92%. Toxin preparations (~20 μg/ml) from B. cereus strains showed 24 - 98% cytotoxicity. In contrast, a non-pathogenic L. innocua (F4247) and a B. substilis induced only 2% and 8% cytotoxicity, respectively. This cell-based detection device demonstrates its ability to detect the presence of pathogenic Listeria and Bacillus species and can potentially be used onsite for food safety or in biosecurity application.
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Swider, Catherine; Maguire, Kelly; Rickenbach, Michael; Montgomery, Madeline; Ducote, Matthew J; Marhefka, Craig A
2012-07-01
Following the September 11, 2001 terrorist attacks, letters containing Bacillus anthracis were distributed through the United States postal system killing five people. A complex forensic investigation commenced to identify the perpetrator of these mailings. A novel liquid chromatography/mass spectrometry protocol for the qualitative detection of trace levels of meglumine and diatrizoate in dried spore preparations of B. anthracis was developed. Meglumine and diatrizoate are components of radiographic imaging products that have been used to purify bacterial spores. Two separate chromatographic assays using multiple mass spectrometric analyses were developed for the detection of meglumine and diatrizoate. The assays achieved limits of detection for meglumine and diatrizoate of 1.00 and 10.0 ng/mL, respectively. Bacillus cereus T strain spores were effectively used as a surrogate for B. anthracis spores during method development and validation. This protocol was successfully applied to limited evidentiary B. anthracis spore material, providing probative information to the investigators. 2012 American Academy of Forensic Sciences. Published 2012. This article is a U.S. Government work and is in the public domain in the U.S.A.
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Polyhydroxyalkanoate Production and Degradation Patterns in Bacillus Species.
Ray, Subhasree; Kalia, Vipin Chandra
2017-12-01
Bacteria under stress conditions of excess of carbon (C) and limitations of nutrients divert its metabolism towards C storage as energy reservoir-polyhydroxyalkanoate (PHA). Different Bacillus species- B. cereus and B. thuringiensis , were monitored to produce PHA from different C sources-glucose, crude glycerol and their combination at 37 °C for period up to 192 h. PHA production and its composition was found to vary with feed and bacterial strains. PHA production on crude glycerol continued to increase up to 120 h, reaching a maximum of 2725 mg/L with an effective yield of 71% of the dry cell mass. Depolymerization of PHA was observe to initiate after 96 h of incubation up to 192 h. PHA degradation products have been envisaged to be applied in medical field: tissue engineering, drug carriers, memory enhancers, antiosteoporosis, biodegradable implants. The PHA production and degradation cycle for 192 h has not been reported previously in literature.
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Wang, Gaoyan; Manns, David C; Guron, Giselle K; Churey, John J; Worobo, Randy W
2014-06-01
Large-scale purification of the highly hydrophobic bacteriocin thurincin H was accomplished via a novel and simple two-step method: ammonia sulfate precipitation and C18 solid-phase extraction. The inhibition spectrum and stability of thurincin H as well as its antagonistic activity against Bacillus cereus F4552 spores were further characterized. In the purification method, secreted proteins contained in the supernatant of a 40 h incubated culture of B. thuringiensis SF361 were precipitated by 68 % ammonia sulfate and purified by reverse-phase chromatography, with a yield of 18.53 mg/l of pure thurincin H. Silver-stained SDS-PAGE, high-performance liquid chromatography, and liquid chromatography-mass spectrometry confirmed the high purity of the prepared sample. Thurincin H exhibited a broad antimicrobial activity against 22 tested bacterial strains among six different genera including Bacillus, Carnobacterium, Geobacillus, Enterococcus, Listeria, and Staphylococcus. There was no detectable activity against any of the selected yeast or fungi. The bacteriocin activity was stable for 30 min at 50 °C and decreased to undetectable levels within 10 min at temperatures above 80 °C. Thurincin H is also stable from pH 2-7 for at least 24 h at room temperature. Thurincin H is germicidal against B. cereus spores in brain heart infusion broth, but not in Tris-NaCl buffer. The efficient purification method enables the large-scale production of pure thurincin H. The broad inhibitory spectrum of this bacteriocin may be of interest as a potential natural biopreservative in the food industry, particularly in post-processed and ready-to-eat food.
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Cheng, J; Zhuang, W; Li, N N; Tang, C L; Ying, H J
2017-01-01
Normally, low d-ribose production was identified as responsible for plenty of acid formation by Bacillus subtilis due to its carbon overflow. An approach of co-feeding glucose and sodium citrate is developed here and had been proved to be useful in d-ribose production. This strategy is critical because it affects the cell concentration, the productivity of d-ribose and, especially, the formation of by-products such as acetoin, lactate and acetate. d-ribose production was increased by 59·6% from 71·06 to 113·41 g l -1 without acid formation by co-feeding 2·22 g l -1 h -1 glucose and 0·036 g l -1 h -1 sodium citrate to a 60 g l -1 glucose reaction system. Actually, the cell density was also enhanced from 11·51 to 13·84 g l -1 . These parameters revealed the importance of optimization and modelling of the d-ribose production process. Not only could zero acid formation was achieved over a wide range of co-feeding rate by reducing glycolytic flux drastically but also the cell density and d-ribose yield were elevated by increasing the hexose monophosphate pathway flux. Bacillus subtilis usually produce d-ribose accompanied by plenty of organic acids when glucose is used as a carbon source, which is considered to be a consequence of mismatched glycolytic and tricarboxylic acid cycle capacities. This is the first study to provide high-efficiency biosynthesis of d-ribose without organic acid formation in B. subtilis, which would be lower than the cost of separation and purification. The strain transketolase-deficient B. subtilis CGMCC 3720 can be potentially applied to the production of d-ribose in industry. © 2016 The Society for Applied Microbiology.
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Chen, Yun; Cao, Shugeng; Chai, Yunrong; Clardy, Jon; Kolter, Roberto; Guo, Jian-hua; Losick, Richard
2012-01-01
SUMMARY The soil bacterium Bacillus subtilis is widely used in agriculture as a biocontrol agent able to protect plants from a variety of pathogens. Protection is thought to involve the formation of bacterial communities - biofilms - on the roots of the plants. Here we used confocal microscopy to visualize biofilms on the surface of the roots of tomato seedlings and demonstrated that biofilm formation requires genes governing the production of the extracellular matrix that holds cells together. We further show that biofilm formation was dependent on the sensor histidine kinase KinD and in particular on an extracellular CACHE domain implicated in small molecule sensing. Finally, we report that exudates of tomato roots strongly stimulated biofilm formation ex planta and that an abundant small molecule in the exudates, l-malic acid, was able to stimulate biofilm formation at high concentrations in a manner that depended on the KinD CACHE domain. We propose that small signaling molecules released by the roots of tomato plants are directly or indirectly recognized by KinD, triggering biofilm formation. PMID:22716461
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Raymond, Ben; Elliot, Simon L; Ellis, Richard J
2008-07-01
The Bacillus cereus group comprises a range of micro-organisms with diverse habits, including gut commensals, opportunistic pathogens and soil saprophytes. Using quantitative microbiological methods we tested whether Bacillus thuringiensis (Bt) could reproduce in cadavers of Plutella xylostella killed by Bt, or in the gut of live insects, or be transmitted vertically from females to their offspring. We also tested whether diverse Bt strains could grow in high nutrient broth at a pH similar to that in the larval midgut. Low levels of reproduction were found in insect cadavers but there was no evidence of vertical transmission, or of significant reproduction in live insects. Four strains of B. thuringiensis var. kurstaki and one of B. thuringiensis var. tenebrionis were found to be capable of growth at high pH. Greater spore recovery rates in frass were found in hosts that were resistant or tolerant of infection. We concluded that that spores recovered in frass represent, in general, an ungerminated fraction of ingested inoculum and that germination rates are reduced in unsuitable hosts.
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Thin-layer chromatographic technique for rapid detection of bacterial phospholipases.
Legakis, N J; Papavassiliou, J
1975-11-01
Silica gel thin-layer chromatography was employed to detect lecithinase activity induced from bacterial resting cell preparations induced from bacterial resting cell preparations incubated at 37 C for 4 h in the presence of purified egg yolk lecithin. Bacillus subtilis, Bacillus cereus, Serratia marcescens, and Pseudomonas aeruginosa hydrolyzed lecithin with the formation of free fatty acids as the sole lipid-soluble product. In none of the Escherichia coli and Citrobacter freundii strains tested could lecithinase activity be detected. Four among eight strains of Enterobacter aerogenes and one among 12 strains of Proteus tested produced negligible amounts of free fatty acid.
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Real-Time PCR Diagnostics for Detecting and Identifying Potential Bioweapons
2003-11-18
pestis Bacillus cereus Salmonella enteritidis Yersinia pestis Bacillus thurigiensis Serratia odorifera Yersinia pestis Bacillus coagulans Shigella...10fg NTC 100pg-opt 10pg-opt 1pg-opt 100fg-opt 10fg-opt NTC-opt USAMRIID Specificity Organism Organism Organism Acineobacter baumanni Bacillus subtilis...var niger Staphylococcus saprophyticus Bacillus anthracis BA0068 Bacillus bronchiseptica Staphylococcus epidermidis Bacillus anthracis Clostridium
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ZnO Nanoparticles Affect Bacillus subtilis Cell Growth and Biofilm Formation.
Hsueh, Yi-Huang; Ke, Wan-Ju; Hsieh, Chien-Te; Lin, Kuen-Song; Tzou, Dong-Ying; Chiang, Chao-Lung
2015-01-01
Zinc oxide nanoparticles (ZnO NPs) are an important antimicrobial additive in many industrial applications. However, mass-produced ZnO NPs are ultimately disposed of in the environment, which can threaten soil-dwelling microorganisms that play important roles in biodegradation, nutrient recycling, plant protection, and ecological balance. This study sought to understand how ZnO NPs affect Bacillus subtilis, a plant-beneficial bacterium ubiquitously found in soil. The impact of ZnO NPs on B. subtilis growth, FtsZ ring formation, cytosolic protein activity, and biofilm formation were assessed, and our results show that B. subtilis growth is inhibited by high concentrations of ZnO NPs (≥ 50 ppm), with cells exhibiting a prolonged lag phase and delayed medial FtsZ ring formation. RedoxSensor and Phag-GFP fluorescence data further show that at ZnO-NP concentrations above 50 ppm, B. subtilis reductase activity, membrane stability, and protein expression all decrease. SDS-PAGE Stains-All staining results and FT-IR data further demonstrate that ZnO NPs negatively affect exopolysaccharide production. Moreover, it was found that B. subtilis biofilm surface structures became smooth under ZnO-NP concentrations of only 5-10 ppm, with concentrations ≤ 25 ppm significantly reducing biofilm formation activity. XANES and EXAFS spectra analysis further confirmed the presence of ZnO in co-cultured B. subtilis cells, which suggests penetration of cell membranes by either ZnO NPs or toxic Zn+ ions from ionized ZnO NPs, the latter of which may be deionized to ZnO within bacterial cells. Together, these results demonstrate that ZnO NPs can affect B. subtilis viability through the inhibition of cell growth, cytosolic protein expression, and biofilm formation, and suggest that future ZnO-NP waste management strategies would do well to mitigate the potential environmental impact engendered by the disposal of these nanoparticles.
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ZnO Nanoparticles Affect Bacillus subtilis Cell Growth and Biofilm Formation
Hsueh, Yi-Huang; Ke, Wan-Ju; Hsieh, Chien-Te; Lin, Kuen-Song; Tzou, Dong-Ying; Chiang, Chao-Lung
2015-01-01
Zinc oxide nanoparticles (ZnO NPs) are an important antimicrobial additive in many industrial applications. However, mass-produced ZnO NPs are ultimately disposed of in the environment, which can threaten soil-dwelling microorganisms that play important roles in biodegradation, nutrient recycling, plant protection, and ecological balance. This study sought to understand how ZnO NPs affect Bacillus subtilis, a plant-beneficial bacterium ubiquitously found in soil. The impact of ZnO NPs on B. subtilis growth, FtsZ ring formation, cytosolic protein activity, and biofilm formation were assessed, and our results show that B. subtilis growth is inhibited by high concentrations of ZnO NPs (≥ 50 ppm), with cells exhibiting a prolonged lag phase and delayed medial FtsZ ring formation. RedoxSensor and Phag-GFP fluorescence data further show that at ZnO-NP concentrations above 50 ppm, B. subtilis reductase activity, membrane stability, and protein expression all decrease. SDS-PAGE Stains-All staining results and FT-IR data further demonstrate that ZnO NPs negatively affect exopolysaccharide production. Moreover, it was found that B. subtilis biofilm surface structures became smooth under ZnO-NP concentrations of only 5–10 ppm, with concentrations ≤ 25 ppm significantly reducing biofilm formation activity. XANES and EXAFS spectra analysis further confirmed the presence of ZnO in co-cultured B. subtilis cells, which suggests penetration of cell membranes by either ZnO NPs or toxic Zn+ ions from ionized ZnO NPs, the latter of which may be deionized to ZnO within bacterial cells. Together, these results demonstrate that ZnO NPs can affect B. subtilis viability through the inhibition of cell growth, cytosolic protein expression, and biofilm formation, and suggest that future ZnO-NP waste management strategies would do well to mitigate the potential environmental impact engendered by the disposal of these nanoparticles. PMID:26039692
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Plaut, Roger D; Beaber, John W; Zemansky, Jason; Kaur, Ajinder P; George, Matroner; Biswas, Biswajit; Henry, Matthew; Bishop-Lilly, Kimberly A; Mokashi, Vishwesh; Hannah, Ryan M; Pope, Robert K; Read, Timothy D; Stibitz, Scott; Calendar, Richard; Sozhamannan, Shanmuga
2014-03-01
In order to better characterize the Bacillus anthracis typing phage AP50c, we designed a genetic screen to identify its bacterial receptor. Insertions of the transposon mariner or targeted deletions of the structural gene for the S-layer protein Sap and the sporulation genes spo0A, spo0B, and spo0F in B. anthracis Sterne resulted in phage resistance with concomitant defects in phage adsorption and infectivity. Electron microscopy of bacteria incubated with AP50c revealed phage particles associated with the surface of bacilli of the Sterne strain but not with the surfaces of Δsap, Δspo0A, Δspo0B, or Δspo0F mutants. The amount of Sap in the S layer of each of the spo0 mutant strains was substantially reduced compared to that of the parent strain, and incubation of AP50c with purified recombinant Sap led to a substantial reduction in phage activity. Phylogenetic analysis based on whole-genome sequences of B. cereus sensu lato strains revealed several closely related B. cereus and B. thuringiensis strains that carry sap genes with very high similarities to the sap gene of B. anthracis. Complementation of the Δsap mutant in trans with the wild-type B. anthracis sap or the sap gene from either of two different B. cereus strains that are sensitive to AP50c infection restored phage sensitivity, and electron microscopy confirmed attachment of phage particles to the surface of each of the complemented strains. Based on these data, we postulate that Sap is involved in AP50c infectivity, most likely acting as the phage receptor, and that the spo0 genes may regulate synthesis of Sap and/or formation of the S layer.
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Beaber, John W.; Zemansky, Jason; Kaur, Ajinder P.; George, Matroner; Biswas, Biswajit; Henry, Matthew; Bishop-Lilly, Kimberly A.; Mokashi, Vishwesh; Hannah, Ryan M.; Pope, Robert K.; Read, Timothy D.; Stibitz, Scott; Calendar, Richard; Sozhamannan, Shanmuga
2014-01-01
In order to better characterize the Bacillus anthracis typing phage AP50c, we designed a genetic screen to identify its bacterial receptor. Insertions of the transposon mariner or targeted deletions of the structural gene for the S-layer protein Sap and the sporulation genes spo0A, spo0B, and spo0F in B. anthracis Sterne resulted in phage resistance with concomitant defects in phage adsorption and infectivity. Electron microscopy of bacteria incubated with AP50c revealed phage particles associated with the surface of bacilli of the Sterne strain but not with the surfaces of Δsap, Δspo0A, Δspo0B, or Δspo0F mutants. The amount of Sap in the S layer of each of the spo0 mutant strains was substantially reduced compared to that of the parent strain, and incubation of AP50c with purified recombinant Sap led to a substantial reduction in phage activity. Phylogenetic analysis based on whole-genome sequences of B. cereus sensu lato strains revealed several closely related B. cereus and B. thuringiensis strains that carry sap genes with very high similarities to the sap gene of B. anthracis. Complementation of the Δsap mutant in trans with the wild-type B. anthracis sap or the sap gene from either of two different B. cereus strains that are sensitive to AP50c infection restored phage sensitivity, and electron microscopy confirmed attachment of phage particles to the surface of each of the complemented strains. Based on these data, we postulate that Sap is involved in AP50c infectivity, most likely acting as the phage receptor, and that the spo0 genes may regulate synthesis of Sap and/or formation of the S layer. PMID:24363347
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Galactose metabolism plays a crucial role in biofilm formation by Bacillus subtilis.
Chai, Yunrong; Beauregard, Pascale B; Vlamakis, Hera; Losick, Richard; Kolter, Roberto
2012-01-01
Galactose is a common monosaccharide that can be utilized by all living organisms via the activities of three main enzymes that make up the Leloir pathway: GalK, GalT, and GalE. In Bacillus subtilis, the absence of GalE causes sensitivity to exogenous galactose, leading to rapid cell lysis. This effect can be attributed to the accumulation of toxic galactose metabolites, since the galE mutant is blocked in the final step of galactose catabolism. In a screen for suppressor mutants restoring viability to a galE null mutant in the presence of galactose, we identified mutations in sinR, which is the major biofilm repressor gene. These mutations caused an increase in the production of the exopolysaccharide (EPS) component of the biofilm matrix. We propose that UDP-galactose is the toxic galactose metabolite and that it is used in the synthesis of EPS. Thus, EPS production can function as a shunt mechanism for this toxic molecule. Additionally, we demonstrated that galactose metabolism genes play an essential role in B. subtilis biofilm formation and that the expressions of both the gal and eps genes are interrelated. Finally, we propose that B. subtilis and other members of the Bacillus genus may have evolved to utilize naturally occurring polymers of galactose, such as galactan, as carbon sources. Bacteria switch from unicellular to multicellular states by producing extracellular matrices that contain exopolysaccharides. In such aggregates, known as biofilms, bacteria are more resistant to antibiotics. This makes biofilms a serious problem in clinical settings. The resilience of biofilms makes them very useful in industrial settings. Thus, understanding the production of biofilm matrices is an important problem in microbiology. In studying the synthesis of the biofilm matrix of Bacillus subtilis, we provide further understanding of a long-standing microbiological observation that certain mutants defective in the utilization of galactose became sensitive to it. In this
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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. Copyright © 2014 Elsevier GmbH. All rights reserved.
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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 < 0.05). Weaning to service interval was also reduced by 1 day (P < 0.05). Moreover, piglets receiving Paciflor with their feed (T1.2 and T2.2 groups) showed less incidence of scours and lower mortality compared to the untreated piglets (T1.1 and T2.1 groups), particularly those 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
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Antibacterial properties of grapefruit seed extract against Paenibacillus larvae subsp. larvae.
Semprini, P; Langella, V; Pasini, B; Falda, M T; Calvarese, S
2004-01-01
Twenty-one samples of grapefruit seed extract (GSE) either from marketed products or provided by an apiculturist were analysed to verify their inhibition activity, in particular against Paenibacillus larvae subsp. larvae, responsible for American foulbrood. The bactericide capacity of GSE has been measured in Bacillus subtilis BGA, Bacillus cereus 11778, Bacillus cereus K250 and Micrococcus luteus 9341a; these bacteria are normally used in the laboratory to study inhibitors. The results showed that not all GSE have the same inhibitory activity and two of those analysed do not inhibit the five bacteria used. Considering that 19 samples inhibited American foulbrood bacillus, the authors conclude that the use of a natural product (such as GSE) to control this important disease of bees, can be used as a substitute for chemotherapeutic products, after appropriate expedients.
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Clostridium and bacillus binary enterotoxins: bad for the bowels, and eukaryotic being.
Stiles, Bradley G; Pradhan, Kisha; Fleming, Jodie M; Samy, Ramar Perumal; Barth, Holger; Popoff, Michel R
2014-09-05
Some pathogenic spore-forming bacilli employ a binary protein mechanism for intoxicating the intestinal tracts of insects, animals, and humans. These Gram-positive bacteria and their toxins include Clostridium botulinum (C2 toxin), Clostridium difficile (C. difficile toxin or CDT), Clostridium perfringens (ι-toxin and binary enterotoxin, or BEC), Clostridium spiroforme (C. spiroforme toxin or CST), as well as Bacillus cereus (vegetative insecticidal protein or VIP). These gut-acting proteins form an AB complex composed of ADP-ribosyl transferase (A) and cell-binding (B) components that intoxicate cells via receptor-mediated endocytosis and endosomal trafficking. Once inside the cytosol, the A components inhibit normal cell functions by mono-ADP-ribosylation of globular actin, which induces cytoskeletal disarray and death. Important aspects of each bacterium and binary enterotoxin will be highlighted in this review, with particular focus upon the disease process involving the biochemistry and modes of action for each toxin.
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Prevalence and Toxin Characteristics of Bacillus thuringiensis Isolated from Organic Vegetables.
Kim, Jung-Beom; Choi, Ok-Kyung; Kwon, Sun-Mok; Cho, Seung-Hak; Park, Byung-Jae; Jin, Na Young; Yu, Yong Man; Oh, Deog-Hwan
2017-08-28
The prevalence and toxin characteristics of Bacillus thuringiensis isolated from 39 organic vegetables were investigated. B. thuringiensis was detected in 30 out of the 39 organic vegetables (76.9%) with a mean value of 2.60 log CFU/g. Twenty-five out of the 30 B. thuringiensis isolates (83.3%) showed insecticidal toxicity against Spodoptera exigua . The hblCDA, nheABC , and entFM genes were found to be the major toxin genes, but the ces gene was not detected in any of the tested B. thuringiensis isolates. The hemolysin BL enterotoxin was detected in all 30 B. thuringiensis isolates (100%). The non-hemolytic enterotoxin complex was found in 27 out of 30 B. thuringiensis isolates (90.0%). The B. thuringiensis tested in this study had similar toxin gene characteristics to B. cereus , which possessed more than one toxin gene. B. thuringiensis could have the potential risk of foodborne illness based on the toxin genes and toxin-producing ability.
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Zhang, Pengfei; Kong, Lingbo; Setlow, Peter; Li, Yong-qing
2010-01-01
Dual-trap laser tweezers Raman spectroscopy (LTRS) and elastic light scattering (ELS) were used to investigate dynamic processes during high-temperature treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis in water. Major conclusions from these studies included the following. (i) After spores of all three species were added to water at 80 to 90°C, the level of the 1:1 complex of Ca2+ and dipicolinic acid (CaDPA; ∼25% of the dry weight of the spore core) in individual spores remained relatively constant during a highly variable lag time (Tlag), and then CaDPA was released within 1 to 2 min. (ii) The Tlag values prior to rapid CaDPA release and thus the times for wet-heat killing of individual spores of all three species were very heterogeneous. (iii) The heterogeneity in kinetics of wet-heat killing of individual spores was not due to differences in the microscopic physical environments during heat treatment. (iv) During the wet-heat treatment of spores of all three species, spore protein denaturation largely but not completely accompanied rapid CaDPA release, as some changes in protein structure preceded rapid CaDPA release. (v) Changes in the ELS from individual spores of all three species were strongly correlated with the release of CaDPA. The ELS intensities of B. cereus and B. megaterium spores decreased gradually and reached minima at T1 when ∼80% of spore CaDPA was released, then increased rapidly until T2 when full CaDPA release was complete, and then remained nearly constant. The ELS intensity of B. subtilis spores showed similar features, although the intensity changed minimally, if at all, prior to T1. (vi) Carotenoids in B. megaterium spores' inner membranes exhibited two changes during heat treatment. First, the carotenoid's two Raman bands at 1,155 and 1,516 cm−1 decreased rapidly to a low value and to zero, respectively, well before Tlag, and then the residual 1,155-cm−1 band disappeared, in parallel
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Clostridium and Bacillus Binary Enterotoxins: Bad for the Bowels, and Eukaryotic Being
Stiles, Bradley G.; Pradhan, Kisha; Fleming, Jodie M.; Samy, Ramar Perumal; Barth, Holger; Popoff, Michel R.
2014-01-01
Some pathogenic spore-forming bacilli employ a binary protein mechanism for intoxicating the intestinal tracts of insects, animals, and humans. These Gram-positive bacteria and their toxins include Clostridium botulinum (C2 toxin), Clostridium difficile (C. difficile toxin or CDT), Clostridium perfringens (ι-toxin and binary enterotoxin, or BEC), Clostridium spiroforme (C. spiroforme toxin or CST), as well as Bacillus cereus (vegetative insecticidal protein or VIP). These gut-acting proteins form an AB complex composed of ADP-ribosyl transferase (A) and cell-binding (B) components that intoxicate cells via receptor-mediated endocytosis and endosomal trafficking. Once inside the cytosol, the A components inhibit normal cell functions by mono-ADP-ribosylation of globular actin, which induces cytoskeletal disarray and death. Important aspects of each bacterium and binary enterotoxin will be highlighted in this review, with particular focus upon the disease process involving the biochemistry and modes of action for each toxin. PMID:25198129
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Phase 1 Testing of Bioflash Technology for White Powder Identification
2012-06-01
limit of detection for the test bed system for powdered spores of Bacillus anthracis and Bacillus subtilis , and (2) to determine if common nonhazardous... Bacillus subtilis ; and (2) if common nonhazardous white powders trigger a false positive response or subsequently interfere with the ability of the...Isolated from Flour and Ropy Bread. Letters in App Microbiol. 2003, 37, 169-173. Te Giffel, M.C. Incidence of Bacillus cereus and Bacillus subtilis in
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Huang, Tianpei; Zhang, Xiaojuan; Pan, Jieru; Su, Xiaoyu; Jin, Xin; Guan, Xiong
2016-01-01
Bacillus thuringiensis (Bt), one of the most successful biopesticides, may expand its potential by producing bacteriocins (thuricins). The aim of this study was to investigate the antimicrobial potential of a novel Bt bacteriocin, thuricin BtCspB, produced by Bt BRC-ZYR2. The results showed that this bacteriocin has a high similarity with cold-shock protein B (CspB). BtCspB lost its activity after proteinase K treatment; however it was active at 60 °C for 30 min and was stable in the pH range 5–7. The partial loss of activity after the treatments of lipase II and catalase were likely due to the change in BtCspB structure and the partial degradation of BtCspB, respectively. The loss of activity at high temperatures and the activity variation at different pHs were not due to degradation or large conformational change. BtCspB did not inhibit four probiotics. It was only active against B. cereus strains 0938 and ATCC 10987 with MIC values of 3.125 μg/mL and 0.781 μg/mL, and MBC values of 12.5 μg/mL and 6.25 μg/mL, respectively. Taken together, these results provide new insights into a novel cold shock protein-like bacteriocin, BtCspB, which displayed promise for its use in food preservation and treatment of B. cereus-associated diseases. PMID:27762322
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Huang, Tianpei; Zhang, Xiaojuan; Pan, Jieru; Su, Xiaoyu; Jin, Xin; Guan, Xiong
2016-10-20
Bacillus thuringiensis (Bt), one of the most successful biopesticides, may expand its potential by producing bacteriocins (thuricins). The aim of this study was to investigate the antimicrobial potential of a novel Bt bacteriocin, thuricin BtCspB, produced by Bt BRC-ZYR2. The results showed that this bacteriocin has a high similarity with cold-shock protein B (CspB). BtCspB lost its activity after proteinase K treatment; however it was active at 60 °C for 30 min and was stable in the pH range 5-7. The partial loss of activity after the treatments of lipase II and catalase were likely due to the change in BtCspB structure and the partial degradation of BtCspB, respectively. The loss of activity at high temperatures and the activity variation at different pHs were not due to degradation or large conformational change. BtCspB did not inhibit four probiotics. It was only active against B. cereus strains 0938 and ATCC 10987 with MIC values of 3.125 μg/mL and 0.781 μg/mL, and MBC values of 12.5 μg/mL and 6.25 μg/mL, respectively. Taken together, these results provide new insights into a novel cold shock protein-like bacteriocin, BtCspB, which displayed promise for its use in food preservation and treatment of B. cereus-associated diseases.
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Mikshis, N I; Kashtanova, T N; Kutyrev, V V
2015-01-01
Nucleotide sequence analysis of several genes responsible for the anthrax pathogen definitive properties--motility and penicillinase activity--determined a chromosomal locus promising for interspecies differentiation. We demonstrated that the gene fliC encoding flagellin synthesis contains extended region, distinguishing B. anthracis strains from the majority of non-pathogenic and opportunistic bacilli. A novel method for the anthrax pathogen indication and identification based on determination of the differences in the chromosomal genes fliC and hom2 structure was suggested. A total of 60 strains of different Bacillus spp. (B. anthracis, B. cereus, B. thuringiensis, B. mycoides, B. megaterium, B. subtilis, etc.) were tested using two chromosomal DNA targets. The algorithm developed in this work permits to detect the pathogenic microorganism and reliably differentiate it from other Bacillus spp. representatives. The introduction of primers complementary to specific sequences of pXO1 and pXQ2 plasmids into the multiplex PCR makes it possible to receive additional information on proposed virulence of the isolate.
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The disease complex of the gypsy moth. II. Aerobic bacterial pathogens
J.D. Podgwaite; R.W. Campbell
1972-01-01
Eighty-six pathogenic aerobic bacterial isolates from diseased gypsy moth larvae collected in both sparse and dense populations were characterized and identified as members of the families Bacillaceae, Enterobacteriaceae, Lactobacillaceae, Pseudomonadaceae, and Achromobacteraceae. The commonest pathogens were Streptococcus faecalis, Bacillus cereus, Bacillus...
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Hobley, Laura; Li, Bin; Wood, Jennifer L; Kim, Sok Ho; Naidoo, Jacinth; Ferreira, Ana Sofia; Khomutov, Maxim; Khomutov, Alexey; Stanley-Wall, Nicola R; Michael, Anthony J
2017-07-21
Ubiquitous polyamine spermidine is not required for normal planktonic growth of Bacillus subtilis but is essential for robust biofilm formation. However, the structural features of spermidine required for B. subtilis biofilm formation are unknown and so are the molecular mechanisms of spermidine-stimulated biofilm development. We report here that in a spermidine-deficient B. subtilis mutant, the structural analogue norspermidine, but not homospermidine, restored biofilm formation. Intracellular biosynthesis of another spermidine analogue, aminopropylcadaverine, from exogenously supplied homoagmatine also restored biofilm formation. The differential ability of C-methylated spermidine analogues to functionally replace spermidine in biofilm formation indicated that the aminopropyl moiety of spermidine is more sensitive to C -methylation, which it is essential for biofilm formation, but that the length and symmetry of the molecule is not critical. Transcriptomic analysis of a spermidine-depleted B. subtilis speD mutant uncovered a nitrogen-, methionine-, and S -adenosylmethionine-sufficiency response, resulting in repression of gene expression related to purine catabolism, methionine and S -adenosylmethionine biosynthesis and methionine salvage, and signs of altered membrane status. Consistent with the spermidine requirement in biofilm formation, single-cell analysis of this mutant indicated reduced expression of the operons for production of the exopolysaccharide and TasA protein biofilm matrix components and SinR antagonist slrR Deletion of sinR or ectopic expression of slrR in the spermidine-deficient Δ speD background restored biofilm formation, indicating that spermidine is required for expression of the biofilm regulator slrR Our results indicate that spermidine functions in biofilm development by activating transcription of the biofilm matrix exopolysaccharide and TasA operons through the regulator slrR . © 2017 by The American Society for Biochemistry and
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Sivasothy, Yasodha; Ibrahim, Halijah; Paliany, Audra Shaleena; Alias, Siti Aisyah; Awang, Khalijah
2013-12-01
The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Moura, M C; Trentin, D S; Napoleão, T H; Primon-Barros, M; Xavier, A S; Carneiro, N P; Paiva, P M G; Macedo, A J; Coelho, L C B B
2017-10-01
To evaluate the antibiofilm potential of water-soluble Moringa oleifera seed lectin (WSMoL) on Serratia marcescens and Bacillus sp. WSMoL inhibited biofilm formation by S. marcescens at concentrations lower than 2·6 μg ml -1 and impaired bacterial growth at higher concentrations, avoiding biofilm formation. For Bacillus sp., the lectin inhibited bacterial growth at all concentrations. The antibiofilm action of WSMoL is associated with damage to bacterial cells. WSMoL did not disrupt preformed S. marcescens biofilms but was able to damage cells inside them. On the other hand, the lectin reduced the number of cells in Bacillus sp. biofilm treated with it. WSMoL was able to control biofilm formation when immobilized on glass surface (116 μg cm -2 ), damaging S. marcescens cells and avoiding adherence of Bacillus sp. cells on glass. The Bacillus sp. isolate is member of Bacillus subtilis species complex and closely related to species of the conspecific 'amyloliquefaciens' group. WSMoL prevented biofilm development by S. marcescens and Bacillus sp. and the antibiofilm effect is also observed when the lectin is immobilized on glass. Taking together, our results provide support to the potential use of WSMoL for controlling biofilm formation by bacteria. © 2017 The Society for Applied Microbiology.
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Toxigenic Strains of Bacillus licheniformis Related to Food Poisoning
Salkinoja-Salonen, M. S.; Vuorio, R.; Andersson, M. A.; Kämpfer, P.; Andersson, M. C.; Honkanen-Buzalski, T.; Scoging, A. C.
1999-01-01
Toxin-producing isolates of Bacillus licheniformis were obtained from foods involved in food poisoning incidents, from raw milk, and from industrially produced baby food. The toxin detection method, based on the inhibition of boar spermatozoan motility, has been shown previously to be a sensitive assay for the emetic toxin of Bacillus cereus, cereulide. Cell extracts of the toxigenic B. licheniformis isolates inhibited sperm motility, damaged cell membrane integrity, depleted cellular ATP, and swelled the acrosome, but no mitochondrial damage was observed. The responsible agent from the B. licheniformis isolates was partially purified. It showed physicochemical properties similar to those of cereulide, despite having very different biological activity. The toxic agent was nonproteinaceous; soluble in 50 and 100% methanol; and insensitive to heat, protease, and acid or alkali and of a molecular mass smaller than 10,000 g mol−1. The toxic B. licheniformis isolates inhibited growth of Corynebacterium renale DSM 20688T, but not all inhibitory isolates were sperm toxic. The food poisoning-related isolates were beta-hemolytic, grew anaerobically and at 55°C but not at 10°C, and were nondistinguishable from the type strain of B. licheniformis, DSM 13T, by a broad spectrum of biochemical tests. Ribotyping revealed more diversity; the toxin producers were divided among four ribotypes when cut with PvuII and among six when cut with EcoRI, but many of the ribotypes also contained nontoxigenic isolates. When ribotyped with PvuII, most toxin-producing isolates shared bands at 2.8 ± 0.2, 4.9 ± 0.3, and 11.7 ± 0.5 or 13.1 ± 0.8 kb. PMID:10508100
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Lee, Mi-Hwa; Lee, Jiyeon; Nam, Young-Do; Lee, Jong Suk; Seo, Myung-Ji; Yi, Sung-Hun
2016-03-16
A wild-type microorganism exhibiting antimicrobial activities was isolated from the Korean traditional fermented soybean food Chungkookjang and identified as Bacillus sp. LM7. During its stationary growth phase, the microorganism secreted an antimicrobial substance, which we partially purified using a simple two-step procedure involving ammonium sulfate precipitation and heat treatment. The partially purified antimicrobial substance, Anti-LM7, was stable over a broad pH range (4.0-9.0) and at temperatures up to 80 °C for 30 min, and was resistant to most proteolytic enzymes and maintained its activity in 30% (v/v) organic solvents. Anti-LM7 inhibited the growth of a broad range of Gram-positive bacteria, including Bacillus cereus and Listeria monocytogenes, but it did not inhibit lactic acid bacteria such as Lactobacillus plantarum and Lactococcus lactis subsp. Lactis. Moreover, unlike commercially available nisin and polymyxin B, Anti-LM7 inhibited certain fungal strains. Lastly, liquid chromatography-mass spectrometry analysis of Anti-LM7 revealed that it contained eight lipopeptides belonging to two families: four bacillomycin D and four surfactin analogs. These Bacillus sp. LM7-produced heterogeneous lipopeptides exhibiting extremely high stability and a broad antimicrobial spectrum are likely to be closely related to the antimicrobial activity of Chungkookjang, and their identification presents an opportunity for application of the peptides in environmental bioremediation, pharmaceutical, cosmetic, and food industries. Copyright © 2015 Elsevier B.V. All rights reserved.
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USDA-ARS?s Scientific Manuscript database
‘Bacillus vanillea’ XY18T (=CGMCC 8629 T =NCCB 100507 T) was isolated from cured vanilla beans and involved in the formation of vanilla aroma compounds. A draft genome of this type strain was assembled and yielded a length of 3.72 Mbp and a GC content of 46.3%. Comparative genomic analysis with its ...
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Laser-induced speckle scatter patterns in Bacillus colonies
Kim, Huisung; Singh, Atul K.; Bhunia, Arun K.; Bae, Euiwon
2014-01-01
Label-free bacterial colony phenotyping technology called BARDOT (Bacterial Rapid Detection using Optical scattering Technology) provided successful classification of several different bacteria at the genus, species, and serovar level. Recent experiments with colonies of Bacillus species provided strikingly different characteristics of elastic light scatter (ELS) patterns, which were comprised of random speckles compared to other bacteria, which are dominated by concentric rings and spokes. Since this laser-based optical sensor interrogates the whole volume of the colony, 3-D information of micro- and macro-structures are all encoded in the far-field scatter patterns. Here, we present a theoretical model explaining the underlying mechanism of the speckle formation by the colonies from Bacillus species. Except for Bacillus polymyxa, all Bacillus spp. produced random bright spots on the imaging plane, which presumably dependent on the cellular and molecular organization and content within the colony. Our scatter model-based analysis revealed that colony spread resulting in variable surface roughness can modify the wavefront of the scatter field. As the center diameter of the Bacillus spp. colony grew from 500 to 900 μm, average speckles area decreased two-fold and the number of small speckles increased seven-fold. In conclusion, as Bacillus colony grows, the average speckle size in the scatter pattern decreases and the number of smaller speckle increases due to the swarming growth characteristics of bacteria within the colony. PMID:25352840
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Electron Microscope Study of Sporulation and Parasporal Crystal Formation in Bacillus thuringiensis
Bechtel, Donald B.; Bulla, Lee A.
1976-01-01
A comprehensive ultrastructural analysis of sporulation and parasporal crystal development is described for Bacillus thuringiensis. The insecticidal crystal of B. thuringiensis is initiated at the start of engulfment and is nearly complete by the time the exosporium forms. The crystal and a heretofore unobserved ovoid inclusion develop without any clear association with the forespore septum, exosporium, or mesosomes. These observations contradict previous hypotheses that the crystal is synthesized on the forespore membrane, exosporium, or mesosomes. Formation of forespore septa involves densely staining, double-membrane-bound, vesicular mesosomes that have a bridged appearance. Forespore engulfment is subpolar and also involves mesosomes. Upon completion of engulfment the following cytoplasmic changes occur: decrease in electron density of the incipient forespore membrane; loss of bridged appearance of incipient forespore membrane; change in stainability of incipient forespore, forespore, and mother cell cytoplasms; and alteration in staining quality of plasma membrane. These changes are involved in the conversion of the incipient forespore into a forespore and reflect “commitment” to sporulation. Images PMID:182671
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Parellada, Eduardo A; Igarza, Mercedes; Isacc, Paula; Bardón, Alicia; Ferrero, Marcela; Ameta, Keshav Lalit; Neske, Adriana
Squamocin belongs to a group of compounds called annonaceous acetogenins. They are secondary products of Annonaceae metabolism and can be isolated from Annona cherimolia seeds. This paper deals with the stimulation of biofilm formation of Bacillus atrophaeus CN4 by employing low squamocin concentrations to increase naphthalene degradation. Bacillus atrophaeus CN4, isolated from contaminated soil, has the ability to degrade naphthalene as the only source of carbon and energy. In the absence of additional carbon sources, the strain removed 69% of the initial concentration of naphthalene (approx. 0.2mmol/l) in the first 12h of incubation. The addition of squamocin in LB medium stimulated Bacillus atrophaeus CN4 biofilm formation and enhanced naphthalene removal. Squamocin (2.5μg/ml) does not affect planktonic growth and therefore, the observed increases are solely due to the stimulation of biofilm formation. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.
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USDA-ARS?s Scientific Manuscript database
The rhizosphere isolated bacteria belonging to the Bacillus amyloliquefaciens subsp. plantarum and Bacillus methylotrophicus clades are an important group of strains that are used as plant growth promoters and antagonists of plant pathogens. These properties have made these strains the focus of comm...
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Detection of Bacillus spores using PCR and FTA filters.
Lampel, Keith A; Dyer, Deanne; Kornegay, Leroy; Orlandi, Palmer A
2004-05-01
Emphasis has been placed on developing and implementing rapid detection systems for microbial pathogens. We have explored the utility of expanding FTA filter technology for the preparation of template DNA for PCR from bacterial spores. Isolated spores from several Bacillus spp., B. subtilis, B. cereus, and B. megaterium, were applied to FTA filters, and specific DNA products were amplified by PCR. Spore preparations were examined microscopically to ensure that the presence of vegetative cells, if any, did not yield misleading results. PCR primers SRM86 and SRM87 targeted a conserved region of bacterial rRNA genes, whereas primers Bsub5F and Bsub3R amplified a product from a conserved sequence of the B. subtilis rRNA gene. With the use of the latter set of primers for nested PCR, the sensitivity of the PCR-based assay was increased. Overall, 53 spores could be detected after the first round of PCR, and the sensitivity was increased to five spores by nested PCR. FTA filters are an excellent platform to remove PCR inhibitors and have universal applications for environmental, clinical, and food samples.
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Gu, Fenglin; Chen, Yonggan; Fang, Yiming; Wu, Guiping; Tan, Lehe
2015-10-09
Colonizing Bacillus in vanilla (Vanilla planifolia Andrews) beans is involved in glucovanillin hydrolysis and vanillin formation during conventional curing. The flavor profiles of vanilla beans under Bacillus-assisted curing were analyzed through gas chromatography-mass spectrometry, electronic nose, and quantitative sensory analysis. The flavor profiles were analytically compared among the vanilla beans under Bacillus-assisted curing, conventional curing, and non-microorganism-assisted curing. Vanilla beans added with Bacillus vanillea XY18 and Bacillus subtilis XY20 contained higher vanillin (3.58%±0.05% and 3.48%±0.10%, respectively) than vanilla beans that underwent non-microorganism-assisted curing and conventional curing (3.09%±0.14% and 3.21%±0.15%, respectively). Forty-two volatiles were identified from endogenous vanilla metabolism. Five other compounds were identified from exogenous Bacillus metabolism. Electronic nose data confirmed that vanilla flavors produced through the different curing processes were easily distinguished. Quantitative sensory analysis confirmed that Bacillus-assisted curing increased vanillin production without generating any unpleasant sensory attribute. Partial least squares regression further provided a correlation model of different measurements. Overall, we comparatively analyzed the flavor profiles of vanilla beans under Bacillus-assisted curing, indirectly demonstrated the mechanism of vanilla flavor formation by microbes.
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Genotypic and phenotypic characterization of aerosolized bacteria collected from African dust events
Wilson, Christina A.; Brigmon, Robin L.; Yeager, Chris; ...
2013-07-31
Twenty-one bacteria were isolated and characterized from air samples collected in Africa and the Caribbean by the United States Geological Survey (USGS). Isolates were selected based on preliminary characterization as possible pathogens. Identification of the bacterial isolates was 25 achieved using 16S rRNA gene sequence analysis, fatty acid methyl esters (FAMEs) profiling, the BIOLOG Microlog® System (carbon substrate assay), and repetitive extragenic palindromic (REP)-PCR analysis. The majority of isolates (18/21) were identified as species of the genus Bacillus. Three isolates were classified within the Bacillus cereus senso lato group, which includes Bacillus anthracis, Bacillus thuringiensis, and Bacillus cereus strains. Onemore » isolate was identified as a Staphylococcus sp., 30 most closely related to species (i.e Staphylococcus kloosii, Staphylococcus warneri) that are commonly associated with human or animal skin, but can also act as opportunistic pathogen. Another isolate was tentatively identified as Tsukamurella inchonensis, a known respiratory pathogen, and was resistant to the ten antibiotics tested including vancomycin.« less
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van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Ákos T
2014-01-01
In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express ‘cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation. PMID:24694715
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van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Akos T
2014-10-01
In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express 'cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation.
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Biofilm inhibitors that target amyloid proteins.
Romero, Diego; Sanabria-Valentín, Edgardo; Vlamakis, Hera; Kolter, Roberto
2013-01-24
Bacteria establish stable communities, known as biofilms, that are resistant to antimicrobials. Biofilm robustness is due to the presence of an extracellular matrix, which for several species-among them Bacillus subtilis-includes amyloid-like protein fibers. In this work, we show that B. subtilis biofilms can be a simple and reliable tool for screening of molecules with antiamyloid activity. We identified two molecules, AA-861 and parthenolide, which efficiently inhibited biofilms by preventing the formation of amyloid-like fibers. Parthenolide also disrupted pre-established biofilms. These molecules also impeded the formation of biofilms of other bacterial species that secrete amyloid proteins, such as Bacillus cereus and Escherichia coli. Furthermore, the identified molecules decreased the conversion of the yeast protein New1 to the prion state in a heterologous host, indicating the broad range of activity of the molecules. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Bacillus subtilis Protects Public Goods by Extending Kin Discrimination to Closely Related Species
2017-01-01
ABSTRACT Kin discrimination systems are found in numerous communal contexts like multicellularity and are theorized to prevent exploitation of cooperative behaviors. The kin discrimination system in Bacillus subtilis differs from most other such systems because it excludes nonkin cells rather than including kin cells. Because nonkin are the target of the system, B. subtilis can potentially distinguish degrees of nonkin relatedness, not just kin versus nonkin. We examined this by testing a large strain collection of diverse Bacillus species against B. subtilis in different multicellular contexts. The effects of kin discrimination extend to nearby species, as the other subtilis clade species were treated with the same antagonism as nonkin. Species in the less-related pumilus clade started to display varied phenotypes but were mostly still discriminated against, while cereus clade members and beyond were no longer subject to kin discrimination. Seeking a reason why other species are perceived as antagonistic nonkin, we tested the ability of B. subtilis to steal communally produced surfactant from these species. We found that the species treated as nonkin were the only ones that made a surfactant that B. subtilis could utilize and that nonkin antagonism prevented such stealing when the two strains were mixed. The nonkin exclusion kin discrimination method thus allows effective protection of the cooperative behaviors prevalent in multicellularity while still permitting interactions with more distant species that are not a threat. PMID:28679746
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ECR Plasma Sterilisation, Argon and Nitrogen Treated Plasma
NASA Astrophysics Data System (ADS)
Helhel, Selcuk; Oksuz, Lutfi; Cerezci, Osman; Rad, Abbas Y.
2004-09-01
ECR type plasma system was built to produce plasma in axial direction. Plasma was initiated in a specially designed Nickel - Chrome cylindrical vacuum tube which is being driven through dielectric window by 2.45GHz commercial magnetron source. Tube is also surrounded by a coil driving 150ADC to generate approximately 875Gauss magnetic field at the center. Langmuir probe and ICCD for optical spectrometry were used to characterize internal parameters like electron density, electron temperature and different characteristics of the plasma. Bacillus Subtilis var nigar, bacillus Stearothermophilus, bacillus pumilus E601, Escherichia coli and staphylococcus aureus type bacteria were selected as a reference. Each is resistant for different actions while the Bacilus cereus is the most resistant bacteria for microwave interaction. This study presents the effect of system on used bacteria. Those are gram positive and gram negative bacteria that refers to structure of cell wall. The sterilization efficacy of Argon type ECR plasma was found to be over 99, 5% in Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis (vegetative cell), Bacillus cereus (vegetative cell), Bacillus pumilus and Escherichia coli. System response type is less than 2 minutes.
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2017-01-01
ABSTRACT Bacteria interact with each other in nature and often compete for limited nutrient and space resources. However, it is largely unknown whether and how bacteria also interact with human fungal pathogens naturally found in the environment. Here, we identified a soil bacterium, Bacillus safensis, which potently blocked several key Cryptococcus neoformans virulence factors, including formation of the antioxidant pigment melanin and production of the antiphagocytic polysaccharide capsule. The bacterium also inhibited de novo cryptococcal biofilm formation but had only modest inhibitory effects on already formed biofilms or planktonic cell growth. The inhibition of fungal melanization was dependent on direct cell contact and live bacteria. B. safensis also had anti-virulence factor activity against another major human-associated fungal pathogen, Candida albicans. Specifically, dual-species interaction studies revealed that the bacterium strongly inhibited C. albicans filamentation and biofilm formation. In particular, B. safensis physically attached to and degraded candidal filaments. Through genetic and phenotypic analyses, we demonstrated that bacterial chitinase activity against fungal cell wall chitin is a factor contributing to the antipathogen effect of B. safensis. PMID:28974618
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Detection of Bacillus anthracis DNA in Complex Soil and Air Samples Using Next-Generation Sequencing
Be, Nicholas A.; Thissen, James B.; Gardner, Shea N.; McLoughlin, Kevin S.; Fofanov, Viacheslav Y.; Koshinsky, Heather; Ellingson, Sally R.; Brettin, Thomas S.; Jackson, Paul J.; Jaing, Crystal J.
2013-01-01
Bacillus anthracis is the potentially lethal etiologic agent of anthrax disease, and is a significant concern in the realm of biodefense. One of the cornerstones of an effective biodefense strategy is the ability to detect infectious agents with a high degree of sensitivity and specificity in the context of a complex sample background. The nature of the B. anthracis genome, however, renders specific detection difficult, due to close homology with B. cereus and B. thuringiensis. We therefore elected to determine the efficacy of next-generation sequencing analysis and microarrays for detection of B. anthracis in an environmental background. We applied next-generation sequencing to titrated genome copy numbers of B. anthracis in the presence of background nucleic acid extracted from aerosol and soil samples. We found next-generation sequencing to be capable of detecting as few as 10 genomic equivalents of B. anthracis DNA per nanogram of background nucleic acid. Detection was accomplished by mapping reads to either a defined subset of reference genomes or to the full GenBank database. Moreover, sequence data obtained from B. anthracis could be reliably distinguished from sequence data mapping to either B. cereus or B. thuringiensis. We also demonstrated the efficacy of a microbial census microarray in detecting B. anthracis in the same samples, representing a cost-effective and high-throughput approach, complementary to next-generation sequencing. Our results, in combination with the capacity of sequencing for providing insights into the genomic characteristics of complex and novel organisms, suggest that these platforms should be considered important components of a biosurveillance strategy. PMID:24039948
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Agbobatinkpo, Pélagie B; Thorsen, Line; Nielsen, Dennis S; Azokpota, Paulin; Akissoe, Noèl; Hounhouigan, Joseph D; Jakobsen, Mogens
2013-05-15
Yanyanku and Ikpiru made by the fermentation of Malcavene bean (Hibiscus sabdariffa) are used as functional additives for Parkia biglobosa seed fermentations in Benin. A total of 355 aerobic endospore-forming bacteria (AEFB) isolated from Yanyanku and Ikpiru produced in northern and southern Benin were identified using phenotypic and genotypic methods, including GTG5-PCR, M13-PCR, 16S rRNA, gyrA and gyrB gene sequencing. Generally, the same 5-6 species of the genus Bacillus predominated: Bacillus subtilis (17-41% of isolates), Bacillus cereus (8-39%), Bacillus amyloliquefaciens (9-22%), Bacillus licheniformis (3-26%), Bacillus safensis (8-19%) and Bacillus altitudinis (0-19%). Bacillus aryabhattai, Bacillus flexus, and Bacillus circulans (0-2%), and species of the genera Lysinibacillus (0-14%), Paenibacillus (0-13%), Brevibacillus (0-4%), and Aneurinibacillus (0-3%) occurred sporadically. The diarrheal toxin encoding genes cytK-1, cytK-2, hblA, hblC, and hblD were present in 0%, 91% 15%, 34% and 35% of B. cereus isolates, respectively. 9% of them harbored the emetic toxin genetic determinant, cesB. This study is the first to identify the AEFB of Yanyanku and Ikpiru to species level and perform a safety evaluation based on toxin gene detections. We further suggest, that the gyrA gene can be used for differentiating the closely related species Bacillus pumilus and B. safensis. Copyright © 2013 Elsevier B.V. All rights reserved.
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Perturbation by UV Light for Rapid Classification of Biological Particles by Fluorescence
2007-01-01
thuringiensis (israeliensis) 47,51 Bacillus cereus (T) 37 Clostridium perfringens 59 Gram Negative (GN) Bacteria Species (all vegetative) Escherichia coli (B...non-biological particles in aerosols.1 2 Almost all strains of species belonging to the bacterial genera Bacillus and Clostridium produce...endospores, the situation should be similar for all spores of Bacillus or Clostridium species. As a matter of fact, the results from other endospores
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A Bacillus subtilis malate dehydrogenase gene.
Jin, S; De Jesús-Berríos, M; Sonenshein, A L
1996-01-01
A Bacillus subtilis gene for malate dehydrogenase (citH) was found downstream of genes for citrate synthase and isocitrate dehydrogenase. Disruption of citH caused partial auxotrophy for aspartate and a requirement for aspartate during sporulation. In the absence of aspartate, citH mutant cells were blocked at a late stage of spore formation. PMID:8550482
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Shakeel, Muhammad; Rais, Afroz; Hassan, Muhammad Nadeem; Hafeez, Fauzia Yusuf
2015-01-01
Plant associated rhizobacteria prevailing in different agro-ecosystems exhibit multiple traits which could be utilized in various aspect of sustainable agriculture. Two hundred thirty four isolates were obtained from the roots of basmati-385 and basmati super rice varieties growing in clay loam and saline soil at different locations of Punjab (Pakistan). Out of 234 isolates, 27 were able to solubilize zinc (Zn) from different Zn ores like zinc phosphate [Zn3 (PO4)2], zinc carbonate (ZnCO3) and zinc oxide (ZnO). The strain SH-10 with maximum Zn solubilization zone of 24 mm on Zn3 (PO4)2ore and strain SH-17 with maximum Zn solubilization zone of 14–15 mm on ZnO and ZnCO3ores were selected for further studies. These two strains solubilized phosphorous (P) and potassium (K) in vitro with a solubilization zone of 38–46 mm and 47–55 mm respectively. The strains also suppressed economically important rice pathogens Pyricularia oryzae and Fusarium moniliforme by 22–29% and produced various biocontrol determinants in vitro. The strains enhanced Zn translocation toward grains and increased yield of basmati-385 and super basmati rice varieties by 22–49% and 18–47% respectively. The Zn solubilizing strains were identified as Bacillus sp. and Bacillus cereus by 16S rRNA gene analysis. PMID:26635754
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Biodegradation of Diesel, Crude Oil and Spent Lubricating Oil by Soil Isolates of Bacillus spp.
Raju, Maddela Naga; Leo, Rodriguez; Herminia, Sanaguano Salguero; Morán, Ricardo Ernesto Burgos; Venkateswarlu, Kadiyala; Laura, Scalvenzi
2017-05-01
Two species of Bacillus, B. thuringiensis B3 and B. cereus B6, isolated from crude oil-contaminated sites in Ecuador, were tested for their capability in degrading polycyclic aromatic hydrocarbons (PAHs) in diesel (shake-flask), and to remove total petroleum hydrocarbons (TPHs) from crude oil- or spent lubricating oil-polluted soils (plot-scale). TPHs and PAHs were analyzed by Gas chromatography-Flame ionization detector (GC-FID) and High performance liquid chromatography (HPLC), respectively. Degradation percentages of PAHs by strain B6 were in the range of 11-83 after 30 days. A mixed culture of both the strains removed 84% and 28% of TPHs from crude oil- and spent lubricating oil-polluted soils, respectively. Reduction in the abundance of total n-alkane fractions (C 8 -C 40 ) of spent lubricating oil was 94%, which was 18% higher than the control. Our results clearly indicate that the selected strains have great potential in degrading petroleum hydrocarbons at both laboratory- and field-scales.
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Reed, Walter; Carroll, James
1900-01-01
1. Bacillus X (Sternberg) belongs to the colon group. 2. Bacillus icteroides (Sanarelli) is a member of the hog-cholera group. 3. The various channels of infection, the duration of the disease and the gross and microscopical lesions in mice, guinea-pigs and rabbits are the same for Bacillus icteroides and the hog-cholera bacillus. 4. The clinical symptoms and the lesions observed in dogs inoculated intravenously with Bacillus icteroides, are reproduced in these animals by infection with the hog-cholera bacillus. 5. Bacillus icteroides when fed to the domestic pig causes fatal infection, accompanied by diphtheritic, necrotic and ulcerative lesions in the digestive tract, such as are seen in hogs when infected with the hog-cholera bacillus. 6. This disease may be acquired by exposing swine in pens already infected with Bacillus icteroides, or by feeding them with the viscera of infected pigs. 7. Guinea-pigs may be immunized with sterilized cultures ofBacillus icteroides from a fatal dose of the hog-cholera bacillus and vice versa. 8. Rabbits may be rendered immune by gradually increasing doses of a living culture of Bacillus icteroides of weak virulence from a fatal dose of a virulent culture of the hog-cholera bacillus 9. The sera of animals immunized with Bacillus icteroides and with the hog-cholera bacillus, respectively, show a marked reciprocal agglutinative reaction. 10. While the blood of yellow fever practically does not exercise an agglutinative reaction upon Bacillus icteroides, the blood of hog-cholera agglutinates this bacillus in a much more marked degree, thus pointing, we think, to the closer etiological relationship of this bacillus to hog-cholera than to yellow fever. PMID:19866945
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Lafarga, Tomas; Gallagher, Eimear; Walsh, Des; Valverde, Juan; Hayes, Maria
2013-09-18
Chitosan is nature's second most abundant polymer after cellulose and forms the structural support in crustacean shell material and Basidomycete mushroom stalks. Chitosan is a known antimicrobial agent but, to date, was not examined as an antimicrobial agent in bread formulations for the prevention of mold or rope formation. The aim of this work was to investigate the effects of chitosan generated from prawn shell byproducts on the color, moisture, and texture and crumb formation of bread. A secondary aim of this work was to determine the antimicrobial effect of chitosan added to bread at a rate of 1% against the rope spoilage pathogen Bacillus cereus along with natural molds. The addition of chitosan to bread with a molecular mass of 124000 ± 10000 g/mol and 19% deacetylated was found to inhibit B. cereus growth and rope formation in bread when monitored over 3-5 days. Natural mold growth was also significantly delayed in bread made using chitosan substitution of flour at 1% compared to the control bread, where mold was observed growing on the bread surface after 72 h when bread was incubated at 30 °C.
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NASA Astrophysics Data System (ADS)
Aryati, P. C.; Pangastuti, A.; Sari, S. L. A.
2017-04-01
Amylase is one of the main enzymes used in industry, such as food, detergent, textile, and pharmaceutical industry. Amylase can be produced by plants, animals, and microorganisms. However, bacterial and fungal amylases have dominated application in industries. This research was aimed to determine amylolytic activity of bacteria isolated from the gut of Oryctes rhinoceros larvae. Based on clear zone formation, 9 from 11 isolates showed amylolytic activity. Isolates with the widest clear zone, i.e Bacillus subtilis GOR1, Bacillus cereus GOR3, and Bacillus pumilus GOR2, were screened for amylolytic activity based on reduction sugar production. The result showed that Bacillus subtilis GOR1 was the most potential as amylase producer, showed by the widest clear zone 5.224 cm2 and highest reduction sugar production 0.0235 mg/ml. Highest amylase specific activity (0.1447 U/mg protein) was obtained at 60°C and pH 7. Amylase activity was stable for 3 hours at 60°C with residual activity respectively was 59.7%.
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ANTIMICROBIAL ACTION OF THE LEAF EXTRACT OF MORINGA OLEIFERA LAM.
Pal, Saroj K.; Mukherjee, Pulok K.; Saha, Kakali; Pal, M.; Saha, B.P.
1995-01-01
The ethnolic extract of the leaves of Moringa oleifera Lam. (Fam. Moringaceae) was tested for antimicrobial activities against Gram Positive – Bacillus cereus, Bacillus subtilis Staphylococcus aureus, Sarcina lutea: Gram negative – Escherichia coli and Acid fast Mycobacterium phlei. Significant antimicrobial activity of the extract was found in this study. PMID:22556699
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Chemical composition and antibacterial activities of seven Eucalyptus species essential oils leaves.
Sebei, Khaled; Sakouhi, Fawzi; Herchi, Wahid; Khouja, Mohamed Larbi; Boukhchina, Sadok
2015-01-19
In this paper, we have studied the essential oils chemical composition of the leaves of seven Eucalyptus species developed in Tunisia. Eucalyptus leaves were picked from trees growing in different arboretums in Tunisia. Choucha and Mrifeg arboretums located in Sedjnene, region of Bizerte (Choucha: E. maideni, E. astrengens et E. cinerea; Mrifeg : E. leucoxylon), Korbous arboretums located in the region of Nabeul, North East Tunisia with sub-humid bioclimate, (E. lehmani), Souiniet-Ain Drahem arboretum located in region of Jendouba (E. sideroxylon, E. bicostata). Essential oils were individually tested against a large panel of microorganisms including Staphylococcus aureus (ATCC 6539), Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC29212), Listeria ivanovii (RBL 30), Bacillus cereus (ATCC11778). The yield of essential oils ranged from 1.2% to 3% (w/w) for the different Eucalyptus species. All essential oils contain α-pinene, 1,8-cineol and pinocarveol-trans for all Eucalyptus species studied. The 1,8-cineol was the major compound in all species (49.07 to 83.59%). Diameter of inhibition zone of essential oils of Eucalyptus species varied from 10 to 29 mm. The largest zone of inhibition was obtained for Bacillus cereus (E. astrengens) and the lowest for Staphylococcus aureus (E. cinerea). The essential oils from E. maideni, E. astrengens, E. cinerea (arboretum of Bizerte), E. bicostata (arboretum of Aindraham) showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus. The major constituents of Eucalyptus leaves essential oils are 1,8-cineol (49.07 to 83.59%) and α-pinene (1.27 to 26.35%). The essential oils from E. maideni, E. astrengens, E. cinerea, E. bicostata showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus, they may have potential applications in food and pharmaceutical products.
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Literature-Related Discovery: Potential Treatments and Preventives for SARS
2010-01-01
evaluated the immunomodulatory effects of probiotic Bacillus cereus var. toyoi on the systemic immunity of piglets……Blood samples of probiotic ...and IFN-gamma production of polyclonally stimulated PBMCs was on average higher in the probiotic group. Specific proliferative responses of PBMCs...average higher in the probiotic group. In conclusion, B. cereus var. toyoi therefore alters the immune status of piglets as indicated by changes in
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Xu Zhou, Ke; Li, Nan; Christie, Graham
2017-01-01
Abstract The adhesion of spores of 3 Bacillus species with distinctive morphologies to stainless steel and borosilicate glass was studied using the fluid dynamic gauging technique. Marked differences were observed between different species of spores, and also between spores of the same species prepared under different sporulation conditions. Spores of the food‐borne pathogen B. cereus were demonstrated to be capable of withstanding shear stresses greater than 1500 Pa when adhered to stainless steel, in contrast to spores of Bacillus subtilis and Bacillus megaterium, which detached in response to lower shear stress. An extended DLVO model was shown to be capable of predicting the relative differences in spore adhesion between spores of different species and different culture conditions, but did not predict absolute values of force of adhesion well. Applying the model to germinating spores showed a significant reduction in adhesion force shortly after triggering germination, indicating a potential strategy to achieve enhanced removal of spores from surfaces in response to shear stress, such as during cleaning‐in‐place procedures. Practical Application Spore‐forming bacteria are a concern to the food industry because they have the potential to cause food‐borne illness and product spoilage, while being strongly adhesive to processing surfaces and resistant to cleaning‐in‐place procedures. This work is of significance to the food processors and manufacturers because it offers insight to the properties of spore adhesion and identifies a potential strategy to facilitate the removal of spores during cleaning procedures. PMID:29125641
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Baril, Eugénie; Coroller, Louis; Couvert, Olivier; El Jabri, Mohammed; Leguerinel, Ivan; Postollec, Florence; Boulais, Christophe; Carlin, Frédéric; Mafart, Pierre
2012-10-01
Sporulation niches in the food chain are considered as a source of hazard and are not clearly identified. Determining the sporulation environmental boundaries could contribute to identify potential sporulation niches. Spore formation was determined in a Sporulation Mineral Buffer. The effect of incubation temperature, pH and water activity on time to one spore per mL, maximum sporulation rate and final spore concentration was investigated for a Bacillus weihenstephanensis and a Bacillus licheniformis strain. Sporulation boundaries of B. weihenstephanensis and of B. licheniformis were similar to, or included within, the range of temperatures, pH and water activities supporting growth. For instance, sporulation boundaries of B. weihenstephanensis were evaluated at 5°C, 35°C, pH 5.2 and a(w) 0.960 while growth boundaries were observed at 5°C, 37°C, pH 4.9 and a(w) 0.950. Optimum spore formation was determined at 30°C pH 7.2 for B. weihenstephanensis and at 45°C pH 7.2 for B. licheniformis. Lower temperatures and pH delayed the sporulation process. For instance, the time to one spore per mL was tenfold longer when sporulation occurred at 10°C and 20°C, for each strain respectively, than at optimum sporulation temperature. The relative effect of temperature and pH on sporulation rates and on growth rates is similar. This work suggests that the influence of environmental factors on the quantitative changes in sporulation boundaries and rates was similar to their influence on changes in growth rate. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Guérin, Alizée; Rønning, Helene Thorsen; Dargaignaratz, Claire; Clavel, Thierry; Broussolle, Véronique; Mahillon, Jacques; Granum, Per Einar; Nguyen-The, Christophe
2017-08-01
Besides Bacillus cereus, some strains of the psychrotolerant, potentially foodborne pathogen Bacillus weihenstephanensis can produce the emetic toxine (cereulide). This toxin is a heat- and acid-stable cyclic dodecadepsipeptide that causes food intoxication with vomiting. However, some severe clinical cases with lethal outcomes have been described. If cereulide can be produced during refrigerated storage, it will not be inactivated by reheating food, representing an important risk of food intoxication for consumers. In this paper, we determined the capacity of the B. weihenstephanensis strains BtB2-4 and MC67 to grow and produce cereulide on agar media at temperatures from 8 °C to 25 °C and at a pH from 5.4 to 7.0. At 8 °C, strain BtB2-4 produced quantifiable amounts of cereulide, whereas the limit of detection was reached for strain MC67. For BtB2-4, cereulide production increased 5-fold between 8 °C and 10-15 °C and by more than 100-fold between 15 °C and 25 °C. At temperatures of 10 °C and higher, cereulide concentrations were within the range of those reported by previous works in foods implicated in emetic poisoning. At 25 °C, decreasing the pH to 5.4 reduced cereulide production by strain BtB2-4 by at least 20-fold. Copyright © 2017 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Baskar, Sushmitha; Baskar, R.; Lee, Natuschka; Theophilus, P. K.
2009-05-01
The Mawsmai cave and Krem Phyllut caves, East Khasi hills, Meghalaya, India has so far not yet attracted the attention of geomicrobiologists. Observations and hypotheses on the possible influence of identified microorganisms for speleothem formations in Meghalaya are reported for the first time. XRD studies identified calcite in speleothems and gypsum in cave wall deposits as the dominant minerals. SEM-EDAX showed interesting microfabric features showing strong resemblance with fossilised bacteria, calcified filaments, needle calcite and numerous nano scale calcite crystals, highly weathered and disintegrated crystals of calcite, that point towards a significant microbial influence in its genesis. Thin section petrography showed laminated stromatolitic features. The microorganisms identified by conventional isolation and further evaluation of isolates by molecular techniques include Bacillus cereus, Bacillus mycoides, Bacillus licheniformis, Micrococcus luteus, and Actinomycetes. Microscopic observations also showed unidentifiable cocci and four unidentifiable strains of CaSO4 (gypsum) precipitating bacteria. Experimental studies confirmed that these bacteria are able to precipitate calcium minerals (calcite, gypsum, minor amounts of dolomite) in the laboratory. These results allow us to postulate that species like these may contribute to active biogenic influence in the cave formations at Meghalaya.
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USDA-ARS?s Scientific Manuscript database
Cellulose nanowhiskers were extracted from the spines of Mandacaru (Cereus jamacaru DC.) spines, a cactus native to the Caatinga biome of in northeastern Brazil, using sulfuric acid hydrolysis preceeded by mercerization and bleaching. Nanowhisker size decreased from about 400 to 260 nm when extracti...
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Abe, Kimihiro; Shimizu, Shin-Ya; Tsuda, Shuhei; Sato, Tsutomu
2017-09-12
Gene rearrangement is a widely-shared phenomenon in spore forming bacteria, in which prophage(-like) elements interrupting sporulation-specific genes are excised from the host genome to reconstitute the intact gene. Here, we report a novel class of gene-intervening elements, named gin, inserted in the 225 bp gerE-coding region of the B. cereus ATCC10987 genome, which generates a sporulation-specific rearrangement. gin has no phage-related genes and possesses three site-specific recombinase genes; girA, girB, and girC. We demonstrated that the gerE rearrangement occurs at the middle stage of sporulation, in which site-specific DNA recombination took place within the 9 bp consensus sequence flanking the disrupted gerE segments. Deletion analysis of gin uncovered that GirC and an additional factor, GirX, are responsible for gerE reconstitution. Involvement of GirC and GirX in DNA recombination was confirmed by an in vitro recombination assay. These results broaden the definition of the sporulation-specific gene rearrangement phenomenon: gene-intervening elements are not limited to phage DNA but may include non-viral genetic elements that carry a developmentally-regulated site-specific recombination system.
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Zhang, Shengpeng; Liao, Shao-An; Yu, Xiaoyuan; Lu, Hongwu; Xian, Jian-An; Guo, Hui; Wang, Anli; Xie, Jian
2015-06-01
Phytases hydrolyze phytate to release inorganic phosphate, which decreases the requirement for phosphorus in fertilizers for crops and thus reduces environmental pollutants. This study analyzed microbial communities in rhizosphere sediment, collected in September 2012 from Shenzhen Bay, Guangdong, China, using high-throughput pyrosequencing; the results showed that the dominant taxonomic phyla were Chloroflexi, Firmicutes, and Proteobacteria, and the proportion of the beneficial bacteria, Bacillus, was 4.95 %. Twenty-nine culturable, phytase-producing bacteria were isolated, their phosphorus solubilization capacity was analyzed, and they were taxonomically characterized. Their phylogenetic placement was determined using 16S ribosomal RNA (rRNA) gene sequence analysis. The result shows that most of the isolates are members of the order Bacillales, although seven strains of Enterobacteriales, two strains of Pseudomonadales, and one strain of Oceanospirillales were also identified. The phytase gene was cloned from SPC09, Bacillus cereus, which showed the highest phosphorus solubilizing ability among the isolated strains. The gene encoded a primary translation product of 335 amino acids. A construct including the 1005-nt ORF fragment, Bc-phy, was transformed into Escherichia coli. The recombinant phytase was produced and purified, which revealed the temperature optima at 60 °C and pH optima at 6.5. The assessment by quantitative PCR (qPCR) showed an abundance of bacteria containing the Bc-phy gene; the level was generally higher in the mangrove forest than in the tidal flats and in surface soil compared to bottom soil, and the highest value was obtained in June. Herein, we report on the cloning, characterization, and activity of a novel phytase isolated from a mangrove system.
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Emergence of multi drug resistance among soil bacteria exposing to insecticides.
Rangasamy, Kirubakaran; Athiappan, Murugan; Devarajan, Natarajan; Parray, Javid A
2017-04-01
Impacts of pesticide exposure on the soil microbial flora and cross resistance to antibiotics have not been well documented. Development of antibiotic resistance is a common issue among soil bacteria which are exposing to pesticides continuously at sub-lethal concentration. The present study was focused to evaluate the correlation between pesticide exposures and evolution of multi drug resistance among isolates collected from soil applied with insecticides. Twenty five insecticide (Monochrotophos) degrading bacteria were isolated from contaminated agricultural soil. The bacterial isolates Bacillus Sps, Bacillus cereus, Bacillus firmus and Bacillus thuringiensis were found to be resistant against chloramphenical, monochrotophos, ampicillin, cefotaxime, streptomycin and tetracycline antibiotics used. Involvement of plasmid in drug as well as insecticide resistant was confirmed through plasmid curing among selected bacterial strains. Bacillus Sps (MK-07), Bacillus cereus (MK-11), Bacillus firmus (MK-13) and Bacillus thuringiensis (MK-24) lost their resistant against insecticides and antibiotics once after removal of plasmid by exposing to 2% sodium dodecyl sulphate. The plasmid was transformed back to bacteria which produced similar derivatives when cultured in Minimal Salt medium (pH 7.0) supplemented with 0.4% of insecticide. Homology modeling was used to prove that organophosphorus hydrolase and able to metabolize all the antibiotics showed positive interaction with high docking score. The present study revealed that persistent of insecticides in the agricultural soil may lead to increasing development of multidrug resistance among soil bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Heyrman, Jeroen; Logan, Niall A; Rodríguez-Díaz, Marina; Scheldeman, Patsy; Lebbe, Liesbeth; Swings, Jean; Heyndrickx, Marc; De Vos, Paul
2005-01-01
A group of 24 strains was isolated from deteriorated mural paintings situated in Spain (necropolis of Carmona) and Germany (church of Greene-Kreiensen). (GTG)5-PCR genomic fingerprinting was performed on these strains to assess their genomic variability and the strains were delineated into four groups. Representatives were studied by 16S rRNA gene sequencing and were found to be closely related to Bacillus simplex and the species 'Bacillus macroides' (strain NCIMB 8796) and 'Bacillus maroccanus' (names not validly published) according to a fasta search. The close similarity between B. simplex, 'B. macroides' NCIMB 8796, 'B. maroccanus' and the mural painting isolates was confirmed by additional (GTG)5-PCR, ARDRA, FAME and SDS-PAGE analyses. Furthermore, these techniques revealed that strains of 'Bacillus carotarum', another name that has not been validly published, also showed high similarity to this group of organisms. On the other hand, it was shown that the strains labelled 'B. macroides' in different collections do not all belong to the same species. Strain NCIMB 8796 can be allocated to B. simplex, while strain DSM 54 (=ATCC 12905) shares the highest 16S rRNA gene sequence similarity with Bacillus sphaericus and Bacillus fusiformis (both around 98.6 %). On the basis of further DNA-DNA hybridization data and the study of phenotypic characteristics, one group of five mural painting strains was attributed to a novel species in the genus Bacillus, for which the name Bacillus muralis sp. nov. is proposed. Finally, the remaining mural painting strains, one (LMG 18508=NCIMB 8796) of two strains belonging to 'B. macroides' and strains belonging to 'B. maroccanus' and 'B. carotarum' are allocated to the species B. simplex and an emended description of B. simplex is given.
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AhpA is a peroxidase expressed during biofilm formation in Bacillus subtilis.
Zwick, Joelie V; Noble, Sarah; Ellaicy, Yasser K; Coe, Gabrielle Dierker; Hakey, Dylan J; King, Alyssa N; Sadauskas, Alex J; Faulkner, Melinda J
2017-02-01
Organisms growing aerobically generate reactive oxygen species such as hydrogen peroxide. These reactive oxygen molecules damage enzymes and DNA, potentially causing cell death. In response, Bacillus subtilis produces at least nine potential peroxide-scavenging enzymes; two belong to the alkylhydroperoxide reductase (Ahp) class of peroxidases. Here, we explore the role of one of these Ahp homologs, AhpA. While previous studies demonstrated that AhpA can scavenge peroxides and thus defend cells against peroxides, they did not clarify when during growth the cell produces AhpA. The results presented here show that the expression of ahpA is regulated in a manner distinct from that of the other peroxide-scavenging enzymes in B. subtilis. While the primary Ahp, AhpC, is expressed during exponential growth and stationary phase, these studies demonstrate that the expression of ahpA is dependent on the transition-state regulator AbrB and the sporulation and biofilm formation transcription factor Spo0A. Furthermore, these results show that ahpA is specifically expressed during biofilm formation, and not during sporulation or stationary phase, suggesting that derepression of ahpA by AbrB requires a signal other than those present upon entry into stationary phase. Despite this expression pattern, ahpA mutant strains still form and maintain robust biofilms, even in the presence of peroxides. Thus, the role of AhpA with regard to protecting cells within biofilms from environmental stresses is still uncertain. These studies highlight the need to further study the Ahp homologs to better understand how they differ from one another and the unique roles they may play in oxidative stress resistance. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
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Bacillus subtilis Protects Public Goods by Extending Kin Discrimination to Closely Related Species.
Lyons, Nicholas A; Kolter, Roberto
2017-07-05
Kin discrimination systems are found in numerous communal contexts like multicellularity and are theorized to prevent exploitation of cooperative behaviors. The kin discrimination system in Bacillus subtilis differs from most other such systems because it excludes nonkin cells rather than including kin cells. Because nonkin are the target of the system, B. subtilis can potentially distinguish degrees of nonkin relatedness, not just kin versus nonkin. We examined this by testing a large strain collection of diverse Bacillus species against B. subtilis in different multicellular contexts. The effects of kin discrimination extend to nearby species, as the other subtilis clade species were treated with the same antagonism as nonkin. Species in the less-related pumilus clade started to display varied phenotypes but were mostly still discriminated against, while cereus clade members and beyond were no longer subject to kin discrimination. Seeking a reason why other species are perceived as antagonistic nonkin, we tested the ability of B. subtilis to steal communally produced surfactant from these species. We found that the species treated as nonkin were the only ones that made a surfactant that B. subtilis could utilize and that nonkin antagonism prevented such stealing when the two strains were mixed. The nonkin exclusion kin discrimination method thus allows effective protection of the cooperative behaviors prevalent in multicellularity while still permitting interactions with more distant species that are not a threat. IMPORTANCE Multicellular systems like bacterial biofilms and swarms rely on cooperative behaviors that could be undermined by exploitative invaders. Discriminating kin from nonkin is one way to help guard against such exploitation but has thus far been examined only intraspecifically, so the phylogenetic range of this important trait is unknown. We tested whether Bacillus subtilis treats other species as nonkin by testing a single strain against a
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NASA Astrophysics Data System (ADS)
Lahiani, Mohamed; Soderberg, Lee; Tarasenko, Olga
2011-06-01
Phagocytes generate nitric oxide (NO) in large quantities to combat bacteria. The spore-producing Gram-positive organisms of Bacillus cereus family are causative agents from mild to a life threatening infection in humans and domestic animals. Our group have shown that glycoconjugates (GCs) activate macrophages and enhance killing of Bacillus spores. In this investigation, we will explore the effect of different GCs structures on NO production. The objective of this study is to study effects of GCs 2, 4, 6, 8, 10 on NO release upon exposure to B. cereus and Bacillus anthracis spores by macrophages. Our results demonstrated that GCs activated macrophages and increased NO production using studied GCs ligands compared to macrophage only (p<0.001). GC2 and GC8 were able to further increase NO production in macrophages compared to the B. anthracis spores treated macrophages (p<0.001). Our finding suggests that GCs could be used as potential mediators of NO production in macrophages to fight B. anthracis and other pathogens.
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Decolourization of 4-Chloro-2-Nitrophenol by a Soil Bacterium, Bacillus subtilis RKJ 700
Arora, Pankaj Kumar
2012-01-01
A 4-Chloro-2-nitrophenol (4C2NP) decolourizing strain RKJ 700 was isolated from soil collected from a pesticide contaminated site of India and identified as Bacillus subtilis on the basis of the 16S rRNA gene sequence analysis. Bacillus subtilis RKJ 700 decolourized 4C2NP up to concentration of 1.5 mM in the presence of additional carbon source. The degradation pathway of 4C2NP was studied and 4-chloro-2-aminophenol, 4-chloro-2-acetaminophenol and 5-chloro-2-methylbenzoxazole (5C2MBZ) were identified as metabolites by high performance liquid chromatography and gas chromatography-mass spectrometry. Resting cell studies showed that Bacillus subtilis RKJ 700 depleted 4C2NP completely with stoichiometric formation of 5C2MBZ. This is the first report of (i) the degradation of 4C2NP at high concentration (1.5 mM) and, (ii) the formation of 5C2MBZ by a soil bacterium. PMID:23251673
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Decolourization of 4-chloro-2-nitrophenol by a soil bacterium, Bacillus subtilis RKJ 700.
Arora, Pankaj Kumar
2012-01-01
A 4-Chloro-2-nitrophenol (4C2NP) decolourizing strain RKJ 700 was isolated from soil collected from a pesticide contaminated site of India and identified as Bacillus subtilis on the basis of the 16S rRNA gene sequence analysis. Bacillus subtilis RKJ 700 decolourized 4C2NP up to concentration of 1.5 mM in the presence of additional carbon source. The degradation pathway of 4C2NP was studied and 4-chloro-2-aminophenol, 4-chloro-2-acetaminophenol and 5-chloro-2-methylbenzoxazole (5C2MBZ) were identified as metabolites by high performance liquid chromatography and gas chromatography-mass spectrometry. Resting cell studies showed that Bacillus subtilis RKJ 700 depleted 4C2NP completely with stoichiometric formation of 5C2MBZ. This is the first report of (i) the degradation of 4C2NP at high concentration (1.5 mM) and, (ii) the formation of 5C2MBZ by a soil bacterium.
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Wang, Xun; Li, Zhou; Li, Xin; Qian, Hongliang; Cai, Xia; Li, Xinfeng; He, Jin
2016-01-01
Poly-3-hydroxybutyrate (PHB) is a natural polymer synthesized by many bacteria as a carbon-energy storage material. It was accumulated maximally prior to the spore formation but was degraded during the process of sporulation in Bacillus thuringiensis. Intriguingly, B. thuringiensis also accumulates large amounts of insecticidal crystal proteins (ICPs) during sporulation, which requires considerable input of carbon and energy sources. How PHB accumulation affects sporulation and ICP formation remains unclear to date. Intuitively, one would imagine that accumulated PHB provides the energy required for ICP formation. Yet our current data indicate that this is not the case. First, growth curves of the deletion mutants of phaC (encoding the PHB synthase) and phaZ (encoding the PHB depolymerase) were found to be similar to the parent strain BMB171; no difference in growth rate could be observed. In addition we further constructed the cry1Ac10 ICP gene overexpression strains of BMB171 (BMB171-cry), as well as its phaC and phaZ deletion mutants ΔphaC-cry and ΔphaZ-cry to compare their spore and ICP production rates. Again, not much change of ICP production was observed among these strains either. In fact, PHB was still degraded in most ΔphaZ-cry cells as observed by transmission electron microscopy. Together these results indicated that there is no direct association between the PHB accumulation and the sporulation and ICP formation in B. thuringiensis. Some other enzymes for PHB degradation or other energy source may be responsible for the sporulation and/or ICP formation in B. thuringiensis.
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Wu, Hui-Juan; Sun, Ling-Bin; Li, Chuan-Biao; Li, Zhong-Zhen; Zhang, Zhao; Wen, Xiao-Bo; Hu, Zhong; Zhang, Yue-Ling; Li, Sheng-Kang
2014-12-01
In a previous study, bacterial communities of the intestine in three populations of crabs (wild crabs, pond-raised healthy crabs and diseased crabs) were probed by culture-independent methods. In this study, we examined the intestinal communities of the crabs by bacterial cultivation with a variety of media. A total of 135 bacterial strains were isolated from three populations of mud crabs. The strains were screened for antagonistic activity against Vibrio parahaemolyticus using an agar spot assay. Antagonistic strains were then identified by 16S rRNA gene sequence analysis. Three strains (Bacillus subtilis DCU, Bacillus pumilus BP, Bacillus cereus HL7) with the strongest antagonistic activity were further evaluated for their probiotic characteristics. The results showed that two (BP and DCU) of them were able to survive low pH and high bile concentrations, showed good adherence characteristics and a broad spectrum of antibiotic resistance. The probiotic effects were then tested by feeding juvenile mud crabs (Scylla paramamosain) with foods supplemented with 10(5) CFU/g of BP or DCU for 30 days before being subjected to an immersion challenge with V. parahaemolyticus for 48 h. The treated crabs showed significantly higher expression levels of immune related genes (CAT, proPO and SOD) and activities of respiratory burst than that in controlled groups. Crabs treated with BP and DCU supplemented diets exhibited survival rates of 76.67% and 78.33%, respectively, whereas survival rate was 54.88% in crabs not treated with the probiotics. The data showed that indigenous mud-associated microbiota, such as DCU and BP, have potential application in controlling pathogenic Vibriosis in mud crab aquaculture. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Zeriouh, Houda; de Vicente, Antonio; Pérez-García, Alejandro; Romero, Diego
2014-07-01
The biocontrol activity of many Bacillus species has been traditionally related to the direct antagonism of pathogens. In previous works, we reported that B. subtilis strain UMAF6614 was an efficient biocontrol agent that produced bacillomycin, fengycin and surfactin lipopeptides. Bacillomycins and fengycins were shown to have antagonistic activity towards fungal and bacterial pathogens of cucurbits; however, the functionality of surfactin remained unclear. In this study, the role of surfactin in the biocontrol activity of this strain was investigated. We observed that a deficiency in surfactin production led to a partial reduction of disease suppression by this biocontrol agent, which coincided with a defect in biofilm formation and the colonization of the melon phylloplane. These effects were due to a dramatic reduction in the production of exopolysaccharide and the TasA protein, which are the two major components of the extracellular matrix. We propose that the biocontrol activity of this strain is the result of the coordinated action of the three families of lipopeptides. B. subtilis UMAF6614 produces surfactin to trigger biofilm formation on melon phylloplane, which ensures the long-term persistence and the adequate secretion of suppressive lipopeptides, bacillomycins and fengycins, which efficiently target pathogens. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.
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Zhang, Pengfei; Kong, Lingbo; Wang, Guiwen; Setlow, Peter; Li, Yong-qing
2011-01-01
Dynamic processes during wet-heat treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis at 80 to 90°C were investigated using dual-trap Raman spectroscopy, differential interference contrast (DIC) microscopy, and nucleic acid stain (SYTO 16) fluorescence microscopy. During spore wet-heat treatment, while the spores' 1:1 chelate of Ca2+ with dipicolinic acid (CaDPA) was released rapidly at a highly variable time Tlag, the levels of spore nucleic acids remained nearly unchanged, and the Tlag times for individual spores from the same preparation were increased somewhat as spore levels of CaDPA increased. The brightness of the spores' DIC image decreased by ∼50% in parallel with CaDPA release, and there was no spore cortex hydrolysis observed. The lateral diameters of the spores' DIC image and SYTO 16 fluorescence image also decreased in parallel with CaDPA release. The SYTO 16 fluorescence intensity began to increase during wet-heat treatment at a time before Tlag and reached maximum at a time slightly later than Trelease. However, the fluorescence intensities of wet-heat-inactivated spores were ∼15-fold lower than those of nutrient-germinated spores, and this low SYTO 16 fluorescence intensity may be due in part to the low permeability of the dormant spores' inner membranes to SYTO 16 and in part to nucleic acid denaturation during the wet-heat treatment. PMID:21602365
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Novel bacteriophages containing a genome of another bacteriophage within their genomes.
Swanson, Maud M; Reavy, Brian; Makarova, Kira S; Cock, Peter J; Hopkins, David W; Torrance, Lesley; Koonin, Eugene V; Taliansky, Michael
2012-01-01
A novel bacteriophage infecting Staphylococus pasteuri was isolated during a screen for phages in Antarctic soils. The phage named SpaA1 is morphologically similar to phages of the family Siphoviridae. The 42,784 bp genome of SpaA1 is a linear, double-stranded DNA molecule with 3' protruding cohesive ends. The SpaA1 genome encompasses 63 predicted protein-coding genes which cluster within three regions of the genome, each of apparently different origin, in a mosaic pattern. In two of these regions, the gene sets resemble those in prophages of Bacillus thuringiensis kurstaki str. T03a001 (genes involved in DNA replication/transcription, cell entry and exit) and B. cereus AH676 (additional regulatory and recombination genes), respectively. The third region represents an almost complete genome (except for the short terminal segments) of a distinct bacteriophage, MZTP02. Nearly the same gene module was identified in prophages of B. thuringiensis serovar monterrey BGSC 4AJ1 and B. cereus Rock4-2. These findings suggest that MZTP02 can be shuttled between genomes of other bacteriophages and prophages, leading to the formation of chimeric genomes. The presence of a complete phage genome in the genome of other phages apparently has not been described previously and might represent a 'fast track' route of virus evolution and horizontal gene transfer. Another phage (BceA1) nearly identical in sequence to SpaA1, and also including the almost complete MZTP02 genome within its own genome, was isolated from a bacterium of the B. cereus/B. thuringiensis group. Remarkably, both SpaA1 and BceA1 phages can infect B. cereus and B. thuringiensis, but only one of them, SpaA1, can infect S. pasteuri. This finding is best compatible with a scenario in which MZTP02 was originally contained in BceA1 infecting Bacillus spp, the common hosts for these two phages, followed by emergence of SpaA1 infecting S. pasteuri.
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Barth, Holger; Aktories, Klaus; Popoff, Michel R; Stiles, Bradley G
2004-09-01
Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic "A-B" paradigm for protein toxins. The binary toxins produced by B. anthracis, B. cereus, C. botulinum, C. difficile, C. perfringens, and C. spiroforme consist of components not physically associated in solution that are linked to various diseases in humans, animals, or insects. The "B" components are synthesized as precursors that are subsequently activated by serine-type proteases on the targeted cell surface and/or in solution. Following release of a 20-kDa N-terminal peptide, the activated "B" components form homoheptameric rings that subsequently dock with an "A" component(s) on the cell surface. By following an acidified endosomal route and translocation into the cytosol, "A" molecules disable a cell (and host organism) via disruption of the actin cytoskeleton, increasing intracellular levels of cyclic AMP, or inactivation of signaling pathways linked to mitogen-activated protein kinase kinases. Recently, B. anthracis has gleaned much notoriety as a biowarfare/bioterrorism agent, and of primary interest has been the edema and lethal toxins, their role in anthrax, as well as the development of efficacious vaccines and therapeutics targeting these virulence factors and ultimately B. anthracis. This review comprehensively surveys the literature and discusses the similarities, as well as distinct differences, between each Clostridium and Bacillus binary toxin in terms of their biochemistry, biology, genetics, structure, and applications in science and medicine. The information may foster future studies that aid novel vaccine and drug development, as well as a better understanding of a conserved intoxication process utilized by various gram-positive, spore-forming bacteria.
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Barth, Holger; Aktories, Klaus; Popoff, Michel R.; Stiles, Bradley G.
2004-01-01
Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic “A-B” paradigm for protein toxins. The binary toxins produced by B. anthracis, B. cereus, C. botulinum, C. difficile, C. perfringens, and C. spiroforme consist of components not physically associated in solution that are linked to various diseases in humans, animals, or insects. The “B” components are synthesized as precursors that are subsequently activated by serine-type proteases on the targeted cell surface and/or in solution. Following release of a 20-kDa N-terminal peptide, the activated “B” components form homoheptameric rings that subsequently dock with an “A” component(s) on the cell surface. By following an acidified endosomal route and translocation into the cytosol, “A” molecules disable a cell (and host organism) via disruption of the actin cytoskeleton, increasing intracellular levels of cyclic AMP, or inactivation of signaling pathways linked to mitogen-activated protein kinase kinases. Recently, B. anthracis has gleaned much notoriety as a biowarfare/bioterrorism agent, and of primary interest has been the edema and lethal toxins, their role in anthrax, as well as the development of efficacious vaccines and therapeutics targeting these virulence factors and ultimately B. anthracis. This review comprehensively surveys the literature and discusses the similarities, as well as distinct differences, between each Clostridium and Bacillus binary toxin in terms of their biochemistry, biology, genetics, structure, and applications in science and medicine. The information may foster future studies that aid novel vaccine and drug development, as well as a better understanding of a conserved intoxication process utilized by various gram-positive, spore-forming bacteria. PMID:15353562
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Performance of Microbial Concrete Developed Using Bacillus Subtilus JC3
NASA Astrophysics Data System (ADS)
Rao, M. V. Seshagiri; Reddy, V. Srinivasa; Sasikala, Ch.
2017-12-01
Concrete is vulnerable to deterioration, corrosion, and cracks, and the consequent damage and loss of strength requires immensely expensive remediation and repair. So need for special concrete that they would respond to crack formation with an autonomous self-healing action lead to research and development of microbial concrete. The microbial concrete works on the principle of calcite mineral precipitation by a specific group of alkali-resistant spore-forming bacteria related to the genus Bacillus called Bacillus subtilis JC3, this phenomenon is called biomineralization or Microbiologically Induced Calcite Crystal Precipitation. Bacillus subtilis JC3, a common soil bacterium, has inherent ability to precipitate calcite crystals continuously which enhances the strength and durability performance of concrete enormously. This microbial concrete can be called as a "Self healing Bacterial Concrete" because it can remediate its cracks by itself without any human intervention and would make the concrete more durable and sustainable. This paper discuss the incorporation of microorganism Bacillus subtilis JC3 (developed at JNTU, India) into concrete and presents the results of experimental investigations carried out to study the improved durability and sustainability characteristics of microbial concrete.
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Nessner Kavamura, Vanessa; Taketani, Rodrigo Gouvêa; Lançoni, Milena Duarte; Andreote, Fernando Dini; Mendes, Rodrigo; Soares de Melo, Itamar
2013-01-01
We used the T-RFLP technique combined with Ion Torrent (PGM) sequencing of 16S rRNA and multivariate analysis to study the structure of bulk soil and rhizosphere bacterial communities of a cactus, Cereus jamacaru, from the Brazilian Caatinga biome, which is unique to Brazil. The availability of water shapes the rhizosphere communities, resulting in different patterns during the rainy and dry seasons. Taxonomic approaches and statistical analysis revealed that the phylum Actinobacteria strongly correlated with the dry season, while samples from the rainy season exhibited a strong correlation with the phylum Proteobacteria for rhizosphere samples and with the phyla Bacteroidetes, Firmicutes, Lentisphaerae, and Tenericutes for bulk soil samples. The STAMP software also indicated that the phylum Bacteroidetes, as well as two classes in the Proteobacteria phylum (γ and δ), were the most significant ones during the rainy season. The average abundance of the phylum Actinobacteria and the genus Bacillus was significantly greater during the dry season. Some significant genera found during the dry season might reflect their tolerance to the extreme conditions found in the Caatinga biome. They may also indicate the ecological function that microorganisms play in providing plants with some degree of tolerance to water stress or in assisting in their development through mechanisms of growth promotion. Alterations in microbial communities can be due to the different abilities of native microorganisms to resist and adapt to environmental changes.
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Nessner Kavamura, Vanessa; Taketani, Rodrigo Gouvêa; Lançoni, Milena Duarte; Andreote, Fernando Dini; Mendes, Rodrigo; Soares de Melo, Itamar
2013-01-01
We used the T-RFLP technique combined with Ion Torrent (PGM) sequencing of 16S rRNA and multivariate analysis to study the structure of bulk soil and rhizosphere bacterial communities of a cactus, Cereus jamacaru, from the Brazilian Caatinga biome, which is unique to Brazil. The availability of water shapes the rhizosphere communities, resulting in different patterns during the rainy and dry seasons. Taxonomic approaches and statistical analysis revealed that the phylum Actinobacteria strongly correlated with the dry season, while samples from the rainy season exhibited a strong correlation with the phylum Proteobacteria for rhizosphere samples and with the phyla Bacteroidetes, Firmicutes, Lentisphaerae, and Tenericutes for bulk soil samples. The STAMP software also indicated that the phylum Bacteroidetes, as well as two classes in the Proteobacteria phylum (γ and δ), were the most significant ones during the rainy season. The average abundance of the phylum Actinobacteria and the genus Bacillus was significantly greater during the dry season. Some significant genera found during the dry season might reflect their tolerance to the extreme conditions found in the Caatinga biome. They may also indicate the ecological function that microorganisms play in providing plants with some degree of tolerance to water stress or in assisting in their development through mechanisms of growth promotion. Alterations in microbial communities can be due to the different abilities of native microorganisms to resist and adapt to environmental changes. PMID:24069212
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Biodegradation of carbofuran in soils within Nzoia River Basin, Kenya.
Onunga, Daniel O; Kowino, Isaac O; Ngigi, Anastasiah N; Osogo, Aggrey; Orata, Francis; Getenga, Zachary M; Were, Hassan
2015-01-01
Carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) has been used within the Nzoia River Basin (NRB), especially in Bunyala Rice Irrigation Schemes, in Kenya for the control of pests. In this study, the capacity of native bacteria to degrade carbofuran in soils from NRB was investigated. A gram positive, rod-shaped bacteria capable of degrading carbofuran was isolated through liquid cultures with carbofuran as the only carbon and nitrogen source. The isolate degraded 98% of 100-μg mL(-1) carbofuran within 10 days with the formation of carbofuran phenol as the only detectable metabolite. The degradation of carbofuran was followed by measuring its residues in liquid cultures using high performance liquid chromatography (HPLC). Physical and morphological characteristics as well as molecular characterization confirmed the bacterial isolate to be a member of Bacillus species. The results indicate that this strain of Bacillus sp. could be considered as Bacillus cereus or Bacillus thuringiensis with a bootstrap value of 100% similar to the 16S rRNA gene sequences. The biodegradation capability of the native strains in this study indicates that they have great potential for application in bioremediation of carbofuran-contaminated soil sites.
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NASA Astrophysics Data System (ADS)
Shovitri, Maya; Nafi'ah, Risyatun; Antika, Titi Rindi; Alami, Nur Hidayatul; Kuswytasari, N. D.; Zulaikha, Enny
2017-06-01
Lately, plastic bag is becoming the most important pollutant for environment since it is difficult to be naturally degraded due to it consists of long hydrocarbon polymer chains. Our previous study indicated that our pure isolate Pseudomonas PL-01 and Bacillus PL-01 could degrade about 10% plastic bag. This present study was aimed to find out whether Pseudomonas PL01 and Bacillus PL01 put a positive effect to indigenous bacteria from marginal area in doing plastic degradation with a soil burial method. Beach sand was used as a representative marginal area, and mangrove sediment was used as a comparison. Plastics were submerged into unsterile beach sand with 10% of Pseudomonas PL-01 or Bacillus PL-01 containing liquid minimal salt medium (MSM) separately, while other plastics were submerged into unsterile mangrove sediments. After 4, 8, 12 and 16 weeks, their biofilm formation on their plastic surfaces and plastic degradation were measured. Results indicated that those 2 isolates put positive influent on biofilm formation and plastic degradation for indigenous beach sand bacteria. Bacillus PL-01 put higher influent than Pseudomonas PL-01. Plastic transparent was preferable degraded than black and white plastic bag `kresek'. But anyhow, indigenous mangrove soil bacteria showed the best performance in biofilm formation and plastic degradation, even without Pseudomonas PL-01 or Bacillus PL-01 addition. Fourier Transform Infrared (FTIR) analysis complemented the results; there were attenuated peaks with decreasing peaks transmittances. This FTIR peaks indicated chemical functional group changes happened among the plastic compounds after 16 weeks incubation time.
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Porwal, Shalini; Kumar, Tarika; Lal, Sadhana; Rani, Asha; Kumar, Sushil; Cheema, Simrita; Purohit, Hemant J; Sharma, Rakesh; Singh Patel, Sanjay Kumar; Kalia, Vipin Chandra
2008-09-01
Thirty five bacterial isolates from diverse environmental sources such as contaminated food, nitrogen rich soil, activated sludges from pesticide and oil refineries effluent treatment plants were found to belong to Bacillus, Bordetella, Enterobacter, Proteus, and Pseudomonas sp. on the basis of 16S rRNA gene sequence analysis. Under dark fermentative conditions, maximum hydrogen (H(2)) yields (mol/mol of glucose added) were recorded to be 0.68 with Enterobacter aerogenes EGU16 followed by 0.63 with Bacillus cereus EGU43 and Bacillus thuringiensis EGU45. H(2) constituted 63-69% of the total biogas evolved. Out of these 35 microbes, 18 isolates had the ability to produce polyhydroxybutyrate (PHB), which varied up to 500 mg/l of medium, equivalent to a yield of 66.6%. The highest PHB yield was recorded with B. cereus strain EGU3. Nine strains had high hydrolytic activities (zone of hydrolysis): lipase (34-38 mm) -Bacillus sphaericus strains EGU385, EGU399 and EGU542; protease (56-62 mm) -Bacillus sp. strains EGU444, EGU447 and EGU445; amylase (23 mm) -B. thuringiensis EGU378, marine bacterium strain EGU409 and Pseudomonas sp. strain EGU448. These strains with high hydrolytic activities had relatively low H(2) producing abilities in the range of 0.26-0.42 mol/mol of glucose added and only B. thuringiensis strain EGU378 had the ability to produce PHB. This is the first report among the non-photosynthetic microbes, where the same organism(s) -B. cereus strain EGU43 and B. thuringiensis strain EGU45, have been shown to produce H(2) - 0.63 mol/mol of glucose added and PHB - 420-435 mg/l medium.
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Mel'nikova, N N; Bulavenko, L V; Kurdish, I K; Titova, L V; Kots', S Ia
2002-01-01
The effects of bacteria belonging to the genera Azotobacter and Bacillus in a mixed culture with Bradyrhizobium japonicum strains on formation and function of the legume-rhizobium symbiosis of soybean plants were studied. The data showed that the bacterial compositions B. japonicum 634b + B. subtilis 5, B. japonicum 634b + A. chroococcum 20, and B. japonicum 10k + A. vinelandii 56 with a cell ratio of 1:0.1 increased the number and weight of root nodules as well as the height and weight of the aboveground plant parts in almost all the cases by 22-105% compared with the control variants. These binary microbial cultures may be used for development of combined bacterial preparations for soybean.
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Li, Lei; Ma, Mingchuan; Huang, Rong; Qu, Qing; Li, Guohong; Zhou, Jinwei; Zhang, Keqin; Lu, Kaiping; Niu, Xuemei; Luo, Jun
2012-08-01
The culture filtrate of Bacillus subtilis strain C2 showed strong activity against the pathogenic fungus Fusarium solani f. sp. radicicola. A partially purified fraction (PPF) from the extract induced chlamydospore formation in Fusarium. Reverse-phase high performance liquid chromatography yielded 8 different fractions, six of which had chlamydospore-inducing activity. Mass spectrometry and nuclear magnetic resonance analyses identified the main active constituent as C(17) fengycin A (FA17), a cyclic lipopeptide. The effect of FA17 on morphology and physiology of two Fusarium species was dependent on the lipopeptide concentration. When challenged with FA17 at concentrations (0.5, 8, 64 μg ml(-1)) below the minimum inhibitory concentration (MIC) (128 μg ml(-1)), two species of Fusarium formed chlamydospores from hyphae, germ tubes, or inside the conidia within 2 days. At concentrations close to the MIC, FA17 caused Fusarium to form sparse and swollen hyphae or lysed conidia. The other five fractions were identified as fengycin A homologues. The homologues could also induce chlamydospore-like structures in 17 species of filamentous fungi including some specimens that do not normally produce chlamydospores, according to their taxonomic descriptions. Like other chlamydospores, these structures contained nuclei and lipid bodies as revealed by DAPI and Nile Red staining, and could germinate. This is the first study to demonstrate that under laboratory conditions fengycin, an antifungal lipopeptide produced by B. subtilis, can induce chlamydospore formation in Fusarium and chlamydospore-like structures in many filamentous fungi.
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Nair, Nilendra; Raff, Hannah; Islam, Mohammed Tarek; Feen, Melanie; Garofalo, Denise M; Sheppard, Kelly
2016-02-13
Synthesis of asparaginyl-tRNA (Asn-tRNA(Asn)) in bacteria can be formed either by directly ligating Asn to tRNA(Asn) using an asparaginyl-tRNA synthetase (AsnRS) or by synthesizing Asn on the tRNA. In the latter two-step indirect pathway, a non-discriminating aspartyl-tRNA synthetase (ND-AspRS) attaches Asp to tRNA(Asn) and the amidotransferase GatCAB transamidates the Asp to Asn on the tRNA. GatCAB can be similarly used for Gln-tRNA(Gln) formation. Most bacteria are predicted to use only one route for Asn-tRNA(Asn) formation. Given that Bacillus halodurans and Bacillus subtilis encode AsnRS for Asn-tRNA(Asn) formation and Asn synthetases to synthesize Asn and GatCAB for Gln-tRNA(Gln) synthesis, their AspRS enzymes were thought to be specific for tRNA(Asp). However, we demonstrate that the AspRSs are non-discriminating and can be used with GatCAB to synthesize Asn. The results explain why B. subtilis with its Asn synthetase genes knocked out is still an Asn prototroph. Our phylogenetic analysis suggests that this may be common among Firmicutes and 30% of all bacteria. In addition, the phylogeny revealed that discrimination toward tRNA(Asp) by AspRS has evolved independently multiple times. The retention of the indirect pathway in B. subtilis and B. halodurans likely reflects the ancient link between Asn biosynthesis and its use in translation that enabled Asn to be added to the genetic code. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Mohamad, Osama A A; Li, Li; Ma, Jin-Biao; Hatab, Shaimaa; Xu, Lin; Guo, Jian-Wei; Rasulov, Bakhtiyor A; Liu, Yong-Hong; Hedlund, Brian P; Li, Wen-Jun
2018-01-01
Endophytic bacteria associated with medicinal plants possess unique strategies that enhance growth and suvival of host plants, many of which are mediated by distinctive secondary metabolites. These bacteria and their secondary metabolites are important subjects for both basic and applied research aimed at sustainable agriculture. In the present study, 114 endophytic strains isolated from the wild ethnomedicinal plant Glycyrrhiza uralensis (licorice) were screened for their in vitro antimicrobial activities against common fungal pathogens of tomato ( Fusarium oxysporum f. sp., Fulvia fulva , Alternaria solani ), cotton ( Fusarium oxysporum f. sp. Vesinfectum, Verticillium dahliae ), pomegranite ( Ceratocystis fimbriata ), Cymbidinium ( Colletotrichum gloeosporioides ), and Tsao-ko ( Pestalotiopsis microspora and Fusarium graminearum ) and the common bacteria Staphylococcus aureus , Bacillus cereus , Salmonella enteritidis , and Escherichia coli . Several Bacillus strains, particularly Bacillus atrophaeus and Bacillus mojavensis , had a broad spectrum of antifungal and antibacterial activity. A total of 16 strains, selected based on broad antimicrobial activity, were shown to contain at least one putative secondary metabolite-encoding gene (i.e., polyketide synthase or non-ribosomal peptide synthetase) and/or one lytic enzyme (i.e., protease, cellulase, lipase, chitinase), which may be important mediators of antagonistic activity against pathogens. Five strains, representing Bacillus atrophaeus and Bacillus mojavensis , were selected for plant growth chamber experiments based on strong in vitro antifungal activities. All five strains significantly reduced disease severity in Arabidopsis thaliana plants challenged with V. dahlia infection. Gas-chromatography/mass-spectrometry analysis of cell-free extracts of Bacillus atrophaeus strain XEGI50 showed that at least 13 compounds were produced only during co-cultivation with V. dahlia , including putative compounds known
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Wu, Rui; Sanishvili, Ruslan; Belitsky, Boris R.; ...
2017-03-27
Here, the Bacillus subtilis protein regulator of the gabTD operon and its own gene (GabR) is a transcriptional activator that regulates transcription of gamma-aminobutyric acid aminotransferase (GABA-AT; GabT) upon interactions with pyridoxal-5'-phosphate (PLP) and GABA, and thereby promotes the biosynthesis of glutamate from GABA. We show here that the external aldimine formed between PLP and GABA is apparently responsible for triggering the GabR-mediated transcription activation. Details of the "active site" in the structure of the GabR effector-binding/oligomerization (Eb/O) domain suggest that binding a monocarboxylic.-amino acid such as GABA should be preferred over dicarboxylic acid ligands. A reactive GABA analog, (S)-4-amino-5-fluoropentanoicmore » acid (AFPA), was used as a molecular probe to examine the reactivity of PLP in both GabR and a homologous aspartate aminotransferase (Asp-AT) from Escherichia coli as a control. A comparison between the structures of the Eb/O-PLP-AFPA complex and Asp-AT-PLP-AFPA complex revealed that GabR is incapable of facilitating further steps of the transamination reaction after the formation of the external aldimine. Results of in vitro and in vivo assays using full-length GabR support the conclusion that AFPA is an agonistic ligand capable of triggering GabR-mediated transcription activation via formation of an external aldimine with PLP.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Rui; Sanishvili, Ruslan; Belitsky, Boris R.
Here, the Bacillus subtilis protein regulator of the gabTD operon and its own gene (GabR) is a transcriptional activator that regulates transcription of gamma-aminobutyric acid aminotransferase (GABA-AT; GabT) upon interactions with pyridoxal-5'-phosphate (PLP) and GABA, and thereby promotes the biosynthesis of glutamate from GABA. We show here that the external aldimine formed between PLP and GABA is apparently responsible for triggering the GabR-mediated transcription activation. Details of the "active site" in the structure of the GabR effector-binding/oligomerization (Eb/O) domain suggest that binding a monocarboxylic.-amino acid such as GABA should be preferred over dicarboxylic acid ligands. A reactive GABA analog, (S)-4-amino-5-fluoropentanoicmore » acid (AFPA), was used as a molecular probe to examine the reactivity of PLP in both GabR and a homologous aspartate aminotransferase (Asp-AT) from Escherichia coli as a control. A comparison between the structures of the Eb/O-PLP-AFPA complex and Asp-AT-PLP-AFPA complex revealed that GabR is incapable of facilitating further steps of the transamination reaction after the formation of the external aldimine. Results of in vitro and in vivo assays using full-length GabR support the conclusion that AFPA is an agonistic ligand capable of triggering GabR-mediated transcription activation via formation of an external aldimine with PLP.« less
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Onishi, Yohei; Prihanto, Asep A; Yano, Shigekazu; Takagi, Kazuyoshi; Umekawa, Midori; Wakayama, Mamoru
2015-10-01
It has been reported that acrylamide, a potential carcinogen, is formed from the reaction of L-asparagine (L-Asn) and reducing sugars contained in foods during heating processes and free asparagine is a limiting factor for acrylamide formation. It has been reported that potato products such as potato chips, which are made through heating processes, contain high levels of acrylamide. To decrease the amount of L-Asn in potatoes using L-asparaginase, effective treatment conditions of sliced potatoes with the enzyme have been investigated. By treating sliced potatoes with Bacillus subtilis L-asparaginase II (BAsnase; 4 U/g potato), appriximately 40 % of L-Asn in the sliced potatoes was converted into L-aspartic acid (L-Asp). To make this enzyme more effective, prior to enzymatic treatment, sliced potatoes were freeze-thawed, dried at 90 °C for 20 min, and vacuum treated for 10 min under decompressed condition, resulting in the hydrolysis of approximately 90 % of L-Asn to L-Asp. The acrylamide content of BAsnase-treated fried potato chips decreased to below 20 % of that of BAsnase-untreated fried potato chips. Treatment conditions examined in this study were found to be effective to suppress the formation of acrylamide in fried potato chips.
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Mora, Isabel; Cabrefiga, Jordi; Montesinos, Emilio
2015-01-01
The antibacterial activity against bacterial plant pathogens and its relationships with the presence of the cyclic lipopeptide (cLP) biosynthetic genes ituC (iturin), bmyB (bacillomycin), fenD (fengycin) and srfAA (surfactin), and their corresponding antimicrobial peptide products have been studied in a collection of 64 strains of Bacillus spp. isolated from plant environments. The most frequent antimicrobial peptide (AMP) genes were bmyB, srfAA and fenD (34-50% of isolates). Most isolates (98.4%) produced surfactin isoforms, 90.6% iturins and 79.7% fengycins. The antibacterial activity was very frequent and generally intense among the collection of strains because 75% of the isolates were active against at least 6 of the 8 bacterial plant pathogens tested. Hierarchical and correspondence analysis confirmed the presence of two clearly differentiated groups. One group consisted of Bacillus strains that showed a strong antibacterial activity, presented several cLPs genes and produced several isoforms of cLPs simultaneously, mainly composed of B. subtilis and B. amyloliquefaciens, although the last one was exclusive to this group. Another group was characterized by strains with very low or none antibacterial activity, that showed one or none of the cLP genes and produced a few or none of the corresponding cLPs, and was the most heterogenous group including B. subtilis, B. licheniformis, B. megaterium, B. pumilus, B. cereus and B. thuringiensis, although the last two were exclusive to this group. This work demonstrated that the antagonistic capacity of plant-associated Bacillus against plant pathogenic bacteria is related to the presence of cLP genes and to the production of the corresponding cLPs, and it is mainly associated to the species B. subtilis and B. amyloliquefaciens. Our findings would help to increase the yield and efficiency of screening methods to obtain candidate strains to biocontrol agents with a mechanism of action relaying on the production of
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Ganguly, Jhuma; Low, Lieh Y; Kamal, Nazia; Saile, Elke; Forsberg, L Scott; Gutierrez-Sanchez, Gerardo; Hoffmaster, Alex R; Liddington, Robert; Quinn, Conrad P; Carlson, Russell W; Kannenberg, Elmar L
2013-01-01
Endolysins are bacteriophage enzymes that lyse their bacterial host for phage progeny release. They commonly contain an N-terminal catalytic domain that hydrolyzes bacterial peptidoglycan (PG) and a C-terminal cell wall-binding domain (CBD) that confers enzyme localization to the PG substrate. Two endolysins, phage lysin L (PlyL) and phage lysin G (PlyG), are specific for Bacillus anthracis. To date, the cell wall ligands for their C-terminal CBD have not been identified. We recently described structures for a number of secondary cell wall polysaccharides (SCWPs) from B. anthracis and B. cereus strains. They are covalently bound to the PG and are comprised of a -ManNAc-GlcNAc-HexNAc- backbone with various galactosyl or glucosyl substitutions. Surface plasmon resonance (SPR) showed that the endolysins PlyL and PlyG bind to the SCWP from B. anthracis (SCWPBa) with high affinity (i.e. in the μM range with dissociation constants ranging from 0.81 × 10−6 to 7.51 × 10−6 M). In addition, the PlyL and PlyG SCWPBa binding sites reside with their C-terminal domains. The dissociation constants for the interactions of these endolysins and their derived C-terminal domains with the SCWPBa were in the range reported for other protein–carbohydrate interactions. Our findings show that the SCWPBa is the ligand that confers PlyL and PlyG lysin binding and localization to the PG. PlyL and PlyG also bound the SCWP from B. cereus G9241 with comparable affinities to SCWPBa. No detectable binding was found to the SCWPs from B. cereus ATCC (American Type Culture Collection) 10987 and ATCC 14579, thus demonstrating specificity of lysin binding to SCWPs. PMID:23493680
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Complete Genome Sequence of the Poly-γ-Glutamate-Synthesizing Bacterium Bacillus subtilis Bs-115.
Wang, Fengqing; Gong, Lijuan; Zhou, Lihong; Liang, Jinzhong
2018-04-19
Bacillus subtilis Bs-115 was isolated from the soil of a corn field in Yutai County, Jinan City, Shandong Province, People's Republic of China, and is characterized by the efficient synthesis of poly-γ-glutamate (γ-PGA), with corn saccharification liquid as the sole energy and carbon source during the process of γ-PGA formation. Here, we report the complete genome sequence of Bacillus subtilis Bs-115 and the genes associated with poly-γ-glutamate synthesis. Copyright © 2018 Wang et al.
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USDA-ARS?s Scientific Manuscript database
Foodborne antibiotic-resistant pathogenic bacteria such as Campylobacter jejuni, Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella enterica, Staphylococcus aureus, and Vibrio cholerae can adversely affect animal and human health, but a better understanding of the factors involve...
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Ko, Kwan Soo; Oh, Won Sup; Lee, Mi Young; Lee, Jang Ho; Lee, Hyuck; Peck, Kyong Ran; Lee, Nam Yong; Song, Jae-Hoon
2006-11-01
Two Gram-positive bacilli, designated as strains SMC 4352-1T and SMC 4352-2T, were isolated sequentially from the blood of a newborn child with sepsis. They could not be identified by using conventional clinical microbiological methods. 16S rRNA gene sequencing and phylogenetic analysis revealed that both strains belonged to the genus Bacillus but clearly diverged from known Bacillus species. Strain SMC 4352-1T and strain SMC 4352-2T were found to be closely related to Bacillus firmus NCIMB 9366T (98.2% sequence similarity) and Bacillus cibi JG-30T (97.1% sequence similarity), respectively. They also displayed low DNA-DNA reassociation values (less than 40%) with respect to the most closely related Bacillus species. On the basis of their polyphasic characteristics, strain SMC 4352-1T and strain SMC 4352-2T represent two novel species of the genus Bacillus, for which the names Bacillus infantis sp. nov. (type strain SMC 4352-1T=KCCM 90025T=JCM 13438T) and Bacillus idriensis sp. nov. (type strain SMC 4352-2T=KCCM 90024T=JCM 13437T) are proposed.
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2014-03-01
Micrococcus sp., Enterococcus faecalis, Enterococcus faecium, Vancomycin resistant Enterococcus, and Escherichia coli). During the second Quarter of...mm) 803 D10 Rhinoptera bonasus MRSA (9.5) MSSA (4.5) Bacillus cereus (6) Listeria monocytogenes (6) MRSA (2) Micrococcus sp (7) VRE (2) 803...E6 Rhinoptera bonasus MRSA (7.5) MSSA (8.5) VRE (4.5) Bacillus subtilis (10) MRSA (10) MRSA (10) Micrococcus (16) Listeria monocytogenes (13
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NASA Technical Reports Server (NTRS)
Wisotzkey, J. D.; Jurtshuk, P. Jr; Fox, G. E.; Deinhard, G.; Poralla, K.
1992-01-01
Comparative 16S rRNA (rDNA) sequence analyses performed on the thermophilic Bacillus species Bacillus acidocaldarius, Bacillus acidoterrestris, and Bacillus cycloheptanicus revealed that these organisms are sufficiently different from the traditional Bacillus species to warrant reclassification in a new genus, Alicyclobacillus gen. nov. An analysis of 16S rRNA sequences established that these three thermoacidophiles cluster in a group that differs markedly from both the obligately thermophilic organisms Bacillus stearothermophilus and the facultatively thermophilic organism Bacillus coagulans, as well as many other common mesophilic and thermophilic Bacillus species. The thermoacidophilic Bacillus species B. acidocaldarius, B. acidoterrestris, and B. cycloheptanicus also are unique in that they possess omega-alicylic fatty acid as the major natural membranous lipid component, which is a rare phenotype that has not been found in any other Bacillus species characterized to date. This phenotype, along with the 16S rRNA sequence data, suggests that these thermoacidophiles are biochemically and genetically unique and supports the proposal that they should be reclassified in the new genus Alicyclobacillus.
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Zhao, Shengming; Han, Jinzhi; Bie, Xiaomei; Lu, Zhaoxin; Zhang, Chong; Lv, Fengxia
2016-04-06
Bacteriocins are ribosomally synthesized peptides with antimicrobial activity produced by numerous bacteria. A novel bacteriocin-producing strain, Lactobacillus plantarum JLA-9, isolated from Suan-Tsai, a traditional Chinese fermented cabbage, was screened and identified by its physiobiochemical characteristics and 16S rDNA sequence analysis. A new bacteriocin, designated plantaricin JLA-9, was purified using butanol extraction, gel filtration, and reverse-phase high-performance liquid chromatography. The molecular mass of plantaricin JLA-9 was shown to be 1044 Da by MALDI-TOF-MS analyses. The amino acid sequence of plantaricin JLA-9 was predicted to be FWQKMSFA by MALDI-TOF-MS/MS, which was confirmed by Edman degradation. This bacteriocin exhibited broad-spectrum antibacterial activity against Gram-positive and Gram-negative bacteria, especially Bacillus spp., high thermal stability (20 min, 121 °C), and narrow pH stability (pH 2.0-7.0). It was sensitive to α-chymotrypsin, pepsin, alkaline protease, and papain. The mode of action of this bacteriocin responsible for outgrowth inhibition of Bacillus cereus spores was studied. Plantaricin JLA-9 had no detectable effects on germination initiation over 1 h on monitoring the hydration, heat resistance, and 2,6-pyridinedicarboxylic acid (DPA) release of spores. Rather, germination initiation is a prerequisite for the action of plantaricin JLA-9. Plantaricin JLA-9 inhibited growth by preventing the establishment of oxidative metabolism and disrupting membrane integrity in germinating spores within 2 h. The results suggest that plantaricin JLA-9 has potential applications in the control of Bacillus spp. in the food industry.
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García García, Tránsito; Ventroux, Magali; Derouiche, Abderahmane; Bidnenko, Vladimir; Correia Santos, Sara; Henry, Céline; Mijakovic, Ivan; Noirot-Gros, Marie-Françoise; Poncet, Sandrine
2018-01-01
Bacillus subtilis cells can adopt different life-styles in response to various environmental cues, including planktonic cells during vegetative growth, sessile cells during biofilm formation and sporulation. While switching life-styles, bacteria must coordinate the progression of their cell cycle with their physiological status. Our current understanding of the regulatory pathways controlling the decision-making processes and triggering developmental switches highlights a key role of protein phosphorylation. The regulatory mechanisms that integrate the bacterial chromosome replication status with sporulation involve checkpoint proteins that target the replication initiator DnaA or the kinase phosphorelay controlling the master regulator Spo0A. B. subtilis YabA is known to interact with DnaA to prevent over-initiation of replication during vegetative growth. Here, we report that YabA is phosphorylated by YabT, a Ser/Thr kinase expressed during sporulation and biofilm formation. The phosphorylation of YabA has no effect on replication initiation control but hyper-phosphorylation of YabA leads to an increase in sporulation efficiency and a strong inhibition of biofilm formation. We also provide evidence that YabA phosphorylation affects the level of Spo0A-P in cells. These results indicate that YabA is a multifunctional protein with a dual role in regulating replication initiation and life-style switching, thereby providing a potential mechanism for cross-talk and coordination of cellular processes during adaptation to environmental change.
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The role of gravity in the nutrition and formation of Bacillus colonies
NASA Astrophysics Data System (ADS)
Puzyr, A.; Tirranen, L.; Krylova, T.
The soil-like substrate is used to cultivate higher plants in man-made closed ecosystems. It allows increasing the closeness of the systems and decreasing the plant solid residues and human wastes. Unusual funnel-shaped bacterial colonies of Bacillus species have been observed during analysis of microflora of plant nutritional solution. The colonies have the following characteristics: a) the diameter of "funnel socket" (the biomass contacting with nutritional agar) is 10.0-15.0 mm; b) the thickness of "funnel socket" is 0.5-2.5 mm; c) the diameter of the middle part of the "funnel spout" (the biomass contacting with the gas phase) is 1,0-1,5 mm; d) the length of the "funnel spout" is 10.0-15.0 mm. In the socket and the middle part of the "funnel spout" there is a gas cavity which is most probably formed by bacterial gas metabolites. It has been shown that: i) the surface of these funnel-shaped colonies of Bacillus species is hydrophobic, as is the surface of other Bacillus species ( . brevis, B. cellulomonos, B. flavus, B.B formosus, B. subtilis); ii) the forms of colonies can be changed by varying the position of the growing biomass in relation to the gravitation forces. The experiment proved that the form of the "funnel sockets" and the length of the "funnel spouts" of the colonies are determined by hydrophobic air-contacting surface layer, which does not leak and stretches under the weight of accumulated water. A hypothesis has been suggested that the gravity force plays the role of a "pump" supplying and holding water within the colony. Thus, the water that comes under the gravity force contains dissolved nutrients and bacterial cells in the hydrophobic layer. These cells that are situated far away from the nutrient agar have no nutrient deficiency. The water accumulated by the colonies might be free water of agar media or it can be produced by metabolic disruption of medium fat. Hence, when growing a colony in agar media the water-soluble nutrient substances
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Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components
NASA Technical Reports Server (NTRS)
Reyes, A. L.; Campbell, J. E.
1978-01-01
The experiments conducted to determine the heat resistance of Bacillus megaterium ATCC 6458 at 90 and 100 C were completed. Estimates from replicate experiments at eight percent relative humidities (less than 0.001 to 100% RH) for each temperature were computed. A Bacillus cereus strain with high heat resistance was cultured and the resistance determined in phosphate buffer (D sub 121.1 = 2.16 min and z = 8.7 C). The profile of the dry heat resistance of B. megaterium is summarized and the most resistant condition to the three spores (Bacillus subtilis var. niger, ATCC 29669, and Bacillus stearothermophilus, strain 1518) is compared.
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Microbial diversity and activity of an aged soil contaminated by polycyclic aromatic hydrocarbons.
Zhao, Xiaohui; Fan, Fuqiang; Zhou, Huaidong; Zhang, Panwei; Zhao, Gaofeng
2018-06-01
In-depth understanding of indigenous microbial assemblages resulted from aged contamination by polycyclic aromatic hydrocarbons (PAHs) is of vital importance in successful in situ bioremediation treatments. Soil samples of three boreholes were collected at 12 different vertical depths. Overall, the dominating three-ring PAHs (76.2%) were closely related to distribution patterns of soil dehydrogenase activity, microbial cell numbers, and Shannon biodiversity index (H') of indigenous microorganisms. High-molecular-weight PAHs tend to yield more diverse communities. Results from 16S rRNA analysis indicated that possible functional groups of PAH degradation include three species in Bacillus cereus group, Bacillus sp. SA Ant14, Nocardioides sp., and Ralstonia pickettii. Principal component analysis indicates significant positive correlations between the content of high-molecular-weight PAHs and the distribution of Bacillus weihenstephanensis KBAB4 and Nocardioides sp. The species B. cereus 03BB102, Bacillus thuringiensis, B. weihenstephanensis KBAB4, and Nocardioides sp. were recognized as main PAH degraders and thus recommended to be utilized in further bioremediation applications. The vertical distribution characteristics of PAHs in soil profiles (1-12 m) and the internal relationship between the transport mechanisms of PAHs and the response of soil biological properties help further understand the microbial diversity and activity in an aged site.
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Du, Cuiying; Cao, Shiyun; Shi, Xiangyu; Nie, Xiangtao; Zheng, Jinshui; Deng, Yun; Ruan, Lifang; Peng, Donghai; Sun, Ming
2017-02-24
trans -Aconitic acid (TAA) is an isomer of cis -aconitic acid (CAA), an intermediate of the tricarboxylic acid cycle that is synthesized by aconitase. Although TAA production has been detected in bacteria and plants for many years and is known to be a potent inhibitor of aconitase, its biosynthetic origins and the physiological relevance of its activity have remained unclear. We have serendipitously uncovered key information relevant to both of these questions. Specifically, in a search for novel nematicidal factors from Bacillus thuringiensis , a significant nematode pathogen harboring many protein virulence factors, we discovered a high yielding component that showed activity against the plant-parasitic nematode Meloidogyne incognita and surprisingly identified it as TAA. Comparison with CAA, which displayed a much weaker nematicidal effect, suggested that TAA is specifically synthesized by B. thuringiensis as a virulence factor. Analysis of mutants deficient in plasmids that were anticipated to encode virulence factors allowed us to isolate a TAA biosynthesis-related ( tbr ) operon consisting of two genes, tbrA and tbrB We expressed the corresponding proteins, TbrA and TbrB, and characterized them as an aconitate isomerase and TAA transporter, respectively. Bioinformatics analysis of the TAA biosynthetic gene cluster revealed the association of the TAA genes with transposable elements relevant for horizontal gene transfer as well as a distribution across B. cereus bacteria and other B. thuringiensis strains, suggesting a general role for TAA in the interactions of B. cereus group bacteria with nematode hosts in the soil environment. This study reveals new bioactivity for TAA and the TAA biosynthetic pathway, improving our understanding of virulence factors employed by B. thuringiensis pathogenesis and providing potential implications for nematode management applications. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
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Construction of a Cell Based Sensor for the Detection of Autoinducer-2 (Reprint)
2012-09-01
transporting pipelines, the distribution of species was found to be B. cereus ACE4 (30%), S . marcescens ACE2 (10%), and 10% of each species of B. subtilis...AR12, P. aeruginosa AI1, K. oxytoca ACP, P. stutzeri AP2, B. litoralis AN1, and Bacillus sp. AN5 [1]. Of these, B. cereus, S . marcescens , and B...NUMBER 6. AUTHOR( S ) Matthew D. Servinsky, Patrick C. Allen, Chen-Yu Tsao, Christopher M. Byrd, Christian J. Sund, and William E. Bentley 5d
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The enzymes with benzil reductase activity conserved from bacteria to mammals.
Maruyama, Reiji; Nishizawa, Mikio; Itoi, Yasushi; Ito, Seiji; Inoue, Masami
2002-03-28
The diketone compound, benzil is reduced to (S)-benzoin with living Bacillus cereus cells. Recently, we isolated a gene responsible for benzil reduction, and Escherichia coli cells in which this gene was overexpressed transformed benzil to (S)-benzoin. Although this benzil reductase showed high identity to the short-chain dehydrogenase/reductase (SDR) family, enzymological features were unknown. Here, we demonstrated that many B. cereus strains had benzil reductase activity in vivo, and that the benzil reductases shared 94-100% amino acid identities. Recombinant B. cereus benzil reductase produced optically pure (S)-benzoin with NADPH in vitro, and the ketone group distal to a benzene ring was asymmetrically reduced. B. cereus benzil reductase showed 31% amino acid identity to the yeast open reading frame YIR036C protein and 28-30% to mammalian sepiapterin reductases, sharing the seven residues consensus for the SDR family. We isolated the genes encoding yeast YIR036C protein and gerbil sepiapterin reductase, and both recombinant proteins also reduced benzil to (S)-benzoin in vitro. Green fluorescent protein-tagged B. cereus benzil reductase distributed in the bipolar cytoplasm in B. cereus cells. Asymmetric reduction with B. cereus benzil reductase, yeast YIR036C protein and gerbil sepiapterin reductase will be utilized to produce important chiral compounds.
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Evaluation of antibacterial properties of some medicinal plants used in Iran.
Bonjar, Shahidi
2004-10-01
Forty-five species of 29 plant families used in the traditional medicine by Iranian people, showed antibacterial activities against one or more of the bacterial species: Bacillus cereus, Bacillus pumilus, Bordetella bronchiseptica, Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Pseudomonas aeruginosa, Pseudomonas fluorescens, Serratia marcescens, Staphylococcus aureus and Staphylococcus epidermidis. No plant showed activity against Serratia marcescens; Bordetella bronchiseptica being the most susceptible species. All extracts showed the same activity 18 months later.
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Sticking together: building a biofilm the Bacillus subtilis way
Vlamakis, Hera; Chai, Yunrong; Beauregard, Pascale; Losick, Richard; Kolter, Roberto
2014-01-01
Preface Biofilms are ubiquitous communities of tightly associated bacteria encased in an extracellular matrix. Bacillus subtilis has long-served as a robust model organism to examine the molecular mechanisms of biofilm formation and a number of studies have revealed that this process is subject to a number of integrated regulatory pathways. In this Review, we focus on the molecular mechanisms controlling biofilm assembly and briefly summarize the current state of knowledge regarding their disassembly. We also discuss recent progress that has expanded our understanding of biofilm formation on plant roots, which are a natural habitat for this soil bacterium. PMID:23353768
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Sticking together: building a biofilm the Bacillus subtilis way.
Vlamakis, Hera; Chai, Yunrong; Beauregard, Pascale; Losick, Richard; Kolter, Roberto
2013-03-01
Biofilms are ubiquitous communities of tightly associated bacteria encased in an extracellular matrix. Bacillus subtilis has long served as a robust model organism to examine the molecular mechanisms of biofilm formation, and a number of studies have revealed that this process is regulated by several integrated pathways. In this Review, we focus on the molecular mechanisms that control B. subtilis biofilm assembly, and then briefly summarize the current state of knowledge regarding biofilm disassembly. We also discuss recent progress that has expanded our understanding of B. subtilis biofilm formation on plant roots, which are a natural habitat for this soil bacterium.