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

NARCIS (Netherlands)

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

2007-01-01

Biofilm formation by Bacillus cereus was assessed using 56 strains of B. cereus, including the two sequenced strains, ATCC 14579 and ATCC 10987. Biofilm production in microtiter plates was found to be strongly dependent on incubation time, temperature, and medium, as well as the strain used, with

Sequence Analysis of Inducible Prophage phIS3501 Integrated into the Haemolysin II Gene of Bacillus thuringiensis var israelensis ATCC35646

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Bouziane Moumen

2012-01-01

Full Text Available Diarrheic food poisoning by bacteria of the Bacillus cereus group is mostly due to several toxins encoded in the genomes. One of them, cytotoxin K, was recently identified as responsible for severe necrotic syndromes. Cytotoxin K is similar to a class of proteins encoded by genes usually annotated as haemolysin II (hlyII in the majority of genomes of the B. cereus group. The partially sequenced genome of Bacillus thuringiensis var israelensis ATCC35646 contains several potentially induced prophages, one of them integrated into the hlyII gene. We determined the complete sequence and established the genomic organization of this prophage-designated phIS3501. During induction of excision of this prophage with mitomycin C, intact hlyII gene is formed, thus providing to cells a genetic ability to synthesize the active toxin. Therefore, this prophage, upon its excision, can be implicated in the regulation of synthesis of the active toxin and thus in the virulence of bacterial host. A generality of selection for such systems in bacterial pathogens is indicated by the similarity of this genetic arrangement to that of Staphylococcus aureus  β-haemolysin.

Preliminary investigations reveal that Bacillus thuringiensis δ ...

African Journals Online (AJOL)

The imminent introduction of transgenic crops into Kenya requires a rigorous assessment of the potential risks involved. This study focused on the possible effect of Bacillus thuringiensisδ-endotoxin [CryIA(c)] on arbuscular mycorrhizal fungi (AMF) associated with sorghum. In green house experiments, sorghum seedlings ...

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

Science.gov (United States)

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

Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity.

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Alicja K Warda

Full Text Available We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed.

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

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Rashmi Rathy

2018-04-01

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

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

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Gálvez Antonio

2009-10-01

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

Minimizing the level of Bacillus cereus spores in farm tank milk

NARCIS (Netherlands)

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

2007-01-01

In a year-long survey on 24 Dutch farms, Bacillus cereus spore concentrations were measured in farm tank milk (FTM), feces, bedding material, mixed grass and corn silage, and soil from the pasture. The aim of this study was to determine, in practice, factors affecting the concentration of B. cereus

Purification and characterization of protease from Bacillus cereus ...

African Journals Online (AJOL)

chitti

2013-09-16

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

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

NARCIS (Netherlands)

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

2009-01-01

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

Comparative transcriptome and phenotype analysis of acid-stressed Bacillus cereus strain ATCC 10987

NARCIS (Netherlands)

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

2009-01-01

The food-borne human pathogen Bacillus cereus is found in environments that often have a low pH, such as food and soil. The physiological response upon exposure to several levels of acidity were investigated of B. cereus model strain ATCC 10987, to elucidate the response of B. cereus to acid stress.

Pan-genome and phylogeny of Bacillus cereus sensu lato

OpenAIRE

Bazinet, Adam

2017-01-01

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

Pan-genome and phylogeny of Bacillus cereus sensu lato

OpenAIRE

Bazinet, Adam L.

2017-01-01

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

Survival and conjugal transfer between Bacillus thuringiensis strains in aquatic environment Sobrevivência e conjugação de Bacillus thuringiensis em ambiente aquático

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Luciana Furlaneto

2000-10-01

Full Text Available Field and laboratory studies were conducted to assess the survival of cells and spores and plasmid transfer between Bacillus thuringienis strains in aquatic environment. Results indicated that cells and spores of B. thuringiensis can survive for 10 days in water, without altering their number. The sporulation process began after 12-15 hours of inoculation of water. B. thuringiensis was able to transfer conjugative plasmids in the aquatic environment.O presente trabalho é um estudo sobre a sobrevivência e a conjugação de linhagens de Bacillus thuringiensis em água. Os experimentos conduzidos no laboratório mostram que as células e os esporos de B. thuringiensis podem persistir pelo menos 10 dias na água. A esporulação inicia-se 12-15 horas após a inoculação. O processo de conjugação foi demonstrado em diferentes ambientes aquáticos, tanto em condições de laboratório quanto no meio ambiente.

Systematic characterization of Bacillus Genetic Stock Center Bacillus thuringiensis strains using Multi-Locus Sequence Typing.

Science.gov (United States)

Wang, Kui; Shu, Changlong; Soberón, Mario; Bravo, Alejandra; Zhang, Jie

2018-04-30

The goal of this work was to perform a systematic characterization of Bacillus thuringiensis (Bt) strains from the Bacillus Genetic Stock Center (BGSC) collection using Multi-Locus Sequence Typing (MLST). Different genetic markers of 158 Bacillus thuringiensis (Bt) strains from 73 different serovars stored in the BGSC, that represented 92% of the different Bt serovars of the BGSC were analyzed, the 8% that were not analyzed were not available. In addition, we analyzed 72 Bt strains from 18 serovars available at the pubMLST bcereus database, and Bt strains G03, HBF18 and Bt185, with no H serovars provided by our laboratory. We performed a systematic MLST analysis using seven housekeeping genes (glpF, gmK, ilvD, pta, pur, pycA and tpi) and analyzed correlation of the results of this analysis with strain serovars. The 233 Bt strains analyzed were assigned to 119 STs from which 19 STs were new. Genetic relationships were established by phylogenetic analysis and showed that STs could be grouped in two major Clusters containing 21 sub-groups. We found that a significant number of STs (101 in total) correlated with specific serovars, such as ST13 that corresponded to nine Bt isolates from B. thuringiensis serovar kenyae. However, other serovars showed high genetic variability and correlated with multiple STs; for example, B. thuringiensis serovar morrisoni correlated with 11 different STs. In addition, we found that 16 different STs correlated with multiple serovars (2-4 different serovars); for example, ST12 correlated with B. thuringiensis serovar alesti, dakota, palmanyolensis and sotto/dendrolimus. These data indicated that only partial correspondence between MLST and serotyping can be established. Copyright © 2018 Elsevier Inc. All rights reserved.

Gamma radiation effect on Bacillus cereus spores inoculated in black pepper

International Nuclear Information System (INIS)

Froehlich, Angela; Axeredo, Raquel M.C.; Vanetti, Maria Cristina D.

2000-01-01

It had been analyzed 37 samples of worn out black pepper and in 85% of these samples was observed the presence of Bacillus cereus in numbers of up to 4,6 x 10 4 UFC/g. The population of aerobic mesofilis bacteria varied of 2,8 x 10 5 the 1,9 x 10 8 UFC/g. The black pepper used during the experiment was evaluated, evidencing the aerobic presence of one aerobic mesofilis microbiota of, approximately, 2,6 x 10 6 UFC/g, consisting, mainly, for species of the Bacillus sort. It was observed that the absence of B. cereus, coliforms, filamentous fungus and leavenings. The evaluation of the irradiation of the black pepper inoculated with 10 6 UFC/g of B. cereus spores of with doses of gamma radiation varying between 2 and 10 kGy evidenced that doses up to 5 kGy had been enough to reduce the counting of, approximately, 10 6 UFC/g of aerobic mesofilis organisms and 10 4 UFC/g of B. cereus spores the not detectable numbers by the used methodology. The dose of reduction decimal (D 10 ) for the inoculated B. cereus spores in black pepper was of 1,78 kGy

Bacillus cereus panophthalmitis associated with intraocular gas bubble.

Science.gov (United States)

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

1989-01-01

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

Comparison of hand hygiene procedures for removing Bacillus cereus spores.

Science.gov (United States)

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

2014-01-01

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

[Characteristics of Bacillus cereus dissociants].

Science.gov (United States)

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.

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

Science.gov (United States)

Burgos, J.; Ordóñez, J. A.; Sala, F.

1972-01-01

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

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

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Jennifer Sánchez

2016-05-01

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

Naphthalene degradation and biosurfactant activity by Bacillus cereus 28BN

Energy Technology Data Exchange (ETDEWEB)

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

2005-08-01

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

A parasporin from Bacillus thuringiensis native to Peninsular India ...

Indian Academy of Sciences (India)

Thomas Chubicka

2018-05-03

May 3, 2018 ... Apoptosis; Bacillus thuringiensis; crystal protein; cytotoxicity; ... It acts by creating pores in the intestinal duct ... however diverse types of mechanisms of action have been ... parasporins that can be utilized in the cancer drug.

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

NARCIS (Netherlands)

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

2010-01-01

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

Kefiran antagonizes cytopathic effects of Bacillus cereus extracellular factors.

Science.gov (United States)

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.

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

Science.gov (United States)

Banykó, J; Vyletelová, M

2009-03-01

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

Bacillus cereus in personal care products: risk to consumers.

Science.gov (United States)

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

2015-04-01

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

Investigation of Cytocidal Activity of Bacillus Thuringiensis Parasporal Toxin on CCRF-CEM Cell Line

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Elham Moazamian

2013-03-01

Full Text Available Background & Objective: Parasporin is a parasporal protein of Bacillus thuringiensis and exhibits special cytocidal activity against human cancer cells. Similar to other insecticidal Bacillus thuringiensis crystal toxins, parasporin shows target specificity and damages the cellular membrane. In this study, different strains of Bacillus thuringiensis isolated from various regions of Iran and their cytocidal activity against CCRF-CEM cell line and human erythrocyte were investigated.   Materials & Methods: Fifty soil samples were collected from different Iranian provinces, and characterization was performed based on protein crystal morphology by phase-contrast microscope and variations of Cry protein toxin using SDS-PAGE. After parasporin was processed with proteinase K, the active form was produced and protein activity on the cell line was evaluated. Results: Parasporal inclusion proteins showed different cytotoxicity against acute lymphoblastic leukemia cells (ALL, but not against normal lymphocyte. Isolated parasporin demonstrated no hemolytic activity against human erythrocyte. It appears that these proteins have the ability to differentiate between normal lymphocytes and leukemia cells and have specific receptors on specific cancer cell lines. Conclusion: Our results provide evidence that the parasporin-producing organism is a common member in Bacillus thuringiensis populations occurring in the natural environments of Iran.

BACILLUS THURINGIENSIS ELASTASES WITH INSECTICIDE ACTIVITY

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E. V. Matseliukh

2015-10-01

Full Text Available The purpose of the research was a screening of proteases with elastase activity among Bacillus thuringiensis strains, their isolation, partially purification, study of physicochemical properties and insecticide activity in relation to the larvae of the Colorado beetle. The objects of the investigation were 18 strains of B. thuringiensis, isolated from different sources: sea water, dry biological product "Bitoksibatsillin" and also from natural populations of Colorado beetles of the Crimea, Kherson, Odesa, Mykolaiv and Zaporizhiia regions of Ukraine. Purification of enzymes with elastase activity isolated from above mentioned strains was performed by gel-chromatography and insecticide activity was studied on the 3–4 larvae instar of Colorado beetle. The ability of a number of B. thuringiensis strains to synthesize the proteases with elastase activity has been established. The most active were enzymes obtained from strains IMV B-7465, IMV B-7324 isolated from sea water, and strains 9, 902, Bt-H and 0-239 isolated from Colorado beetles. The study of the physicochemical properties of the partially purified proteases of these strains showed that they belonged to enzymes of the serine type. Peptidases of a number of B. thuringiensis strains (IMV B-7324, IMV B-7465, 902, 0-239, 9 are metal-dependent enzymes. Optimal conditions of action of all tested enzymes are the neutral and alkaline рН values and the temperatures of 30–40 °С. The studies of influence of the complex enzyme preparations and partially purified ones of B. thuringiensis strains on the larvae instar of Colorado beetles indicated that enzymes with elastase activity could be responsible for insecticide action of the tested strains.

Dynamic predictive model for growth of Bacillus cereus from spores in cooked beans

Science.gov (United States)

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...

Characterization of germination receptors of Bacillus cereus ATCC 14579

NARCIS (Netherlands)

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

2006-01-01

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

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

LENUS (Irish Health Repository)

Foy, Niall

2010-07-22

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

Enhancement of virulence of bacillus thuringiensis and serratia marcescens by chemicals

International Nuclear Information System (INIS)

Khan, K. A.

2006-01-01

Studies were conducted on the enhancement of pathogenicity of Bacillus thuringiensis by 1% boric acid against various species of termites. The increase in virulence of Serratia marcescens by 1% potassium chloride or 1% Sodium citrate against the workers of M. championi has also been established. The increase in virulence is confirmed by the enhancement ratio, which are ranging from about 1.5 to 1.8 for Bacillus thuringiensis and 1.3 to 1.6 for Serratia marcescens. It was also noted that 1% boric acid alone was found toxic to various species of termites. However, Potassium chloride and Sodium citrate in a concentration of 1% were non-toxic to the workers of M. championi. (author)

An anionic defensin from Plutella xylostella with potential activity against Bacillus thuringiensis.

Science.gov (United States)

Xu, X-X; Zhang, Y-Q; Freed, S; Yu, J; Gao, Y-F; Wang, S; Ouyang, L-N; Ju, W-Y; Jin, F-L

2016-12-01

Insect defensins, are cationic peptides that play an important role in immunity against microbial infection. In the present study, an anionic defensin from Plutella xylostella, (designated as PxDef) was first cloned and characterized. Amino acid sequence analysis showed that the mature peptide owned characteristic six-cysteine motifs with predicted isoelectric point of 5.57, indicating an anionic defensin. Quantitative real-time polymerase chain reaction analysis showed that PxDef was significantly induced in epidermis, fat body, midgut and hemocytes after injection of heat-inactivated Bacillus thuringiensis, while such an induction was delayed by the injection of live B. thuringiensis in the 4th instar larvae of P. xylostella. Knocking down the expression of nuclear transcription factor Dorsal in P. xylostella by RNA interference significantly decreased the mRNA level of PxDef, and increased the sensitivity of P. xylostella larvae to the infection by live B. thuringiensis. The purified recombinant mature peptide (PxDef) showed higher activity against Gram-positive bacteria, with the minimum inhibition concentrations of 1.6 and 2.6 µM against B. thuringiensis and Bacillus subtilis, respectively. To our knowledge, this is the first report about an anionic PxDef, which may play an important role in the immune system of P. xylostella against B. thuringiensis.

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

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Sedarnawati Yasni2

2005-04-01

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

The alternative sigma factor sigmaB and the stress response of Bacillus cereus

NARCIS (Netherlands)

Schaik, van W.

2005-01-01

cum laude graduation (with distinction) The bacterium Bacillus cereus is responsible for a large number of cases of foodborne illness across the world. It is also an important cause of spoilage of food, in particular of milk and dairy-products. The growth and survival of B. cereus in food or during

Bacillus thuringiensis and its application in agriculture | Ali | African ...

African Journals Online (AJOL)

Presently, a number of approaches to pest control via genetic engineering have been developed and genetically engineered crops expressing insecticidal characteristics are under cultivation for the last 15 years. Use of Bacillus thuringiensis genes encoding o̅ endotoxins with insecticidal characteristics is the major ...

The colonization of Bacillus thuringiensis strains in bryophytes

Czech Academy of Sciences Publication Activity Database

Lin, Q.; Zhu, P.; Carballar-Lejarazú, R.; Gelbič, Ivan; Guan, X.; Xu, L.; Zhang, L.

2017-01-01

Roč. 41, č. 1 (2017), s. 41-48 ISSN 1300-0152 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * GFP * plant colonization Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.038, year: 2016 http://journals.tubitak.gov.tr/biology/issues/biy-17-41-1/biy-41-1-5-1510-16.pdf

Diversity of Protease-Producing Bacillus spp. From Fresh Indonesian Tempeh Based on 16S rRNA Gene Sequence

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Tati Barus

2017-01-01

Full Text Available Tempeh is a type of traditional fermented food in Indonesia. The fermentation can be performed by Rhizopus microsporus as a main microorganism. However, Bacillus spp. is found in abundance in tempeh production. Nevertheless, information regarding the diversity of Bacillus spp. in tempeh production has not been reported yet. Therefore, the aim of this investigation was to study the genetic diversity of Bacillus spp. in tempeh production based on the 16S ribosomal RNA sequence. In this study, about 22 of 24 fresh tempeh from Jakarta, Bogor, and Tangerang were used. A total of 52 protease-producing Bacillus spp. isolates were obtained. Based on 16S ribosomal RNA results, all 52 isolates were identified to be similar to B. pumilus, B. subtilis, B. megaterium, B. licheniformis, B. cereus, B. thuringiensis, B. amyloliquefaciens, Brevibacillus brevis, and Bacillus sp. All the identified isolates were divided into two large clusters: 1 a cluster of B. cereus, B. thuringiensis, Bacillus sp., and B. brevis and 2 a cluster of B. pumilus, B. subtilis, B. megaterium, B. licheniformis, and B. amyloliquefaciens. Information about the Bacillus spp. role in determining the quality of tempeh has not been reported and this is a preliminary study of Bacillus spp. from tempeh.

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

NARCIS (Netherlands)

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

2009-01-01

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

[Susceptibility of Aedes aegypti (L.) strains from Havana to a Bacillus thuringiensis var. israelensis].

Science.gov (United States)

Menéndez Díaz, Zulema; Rodríguez Rodríguez, Jinnay; Gato Armas, René; Companioni Ibañez, Ariamys; Díaz Pérez, Manuel; Bruzón Aguila, Rosa Yirian

2012-01-01

the integration of chemical and biological methods is one of the strategies for the vector control, due to the existing environmental problems and the concerns of the community as a result of the synthetic organic insecticide actions. The bacterium called Bacillus thuringiensis var. israelensis in liquid formulation has been widely used in the vector control programs in several countries and has shown high efficacy at lab in Cuba. to determine the susceptibility of Aedes aegypti collected in the municipalities of La Habana province to Bacillus thuringiensis var. israelensis. fifteen Aedes aegypti strains, one from each municipality, were used including larvae and pupas collected in 2010 and one reference strain known as Rockefeller. The aqueous formulation of Bacillus thuringiensis var. israelensis (Bactivec, Labiofam, Cuba) was used. The bioassays complied with the World Health Organization guidelines for use of bacterial larvicides in the public health sector. The larval mortality was read after 24 hours and the results were processed by the statistical system SPSS (11.0) through Probit analysis. the evaluated mosquito strains showed high susceptibility to biolarvicide, there were no significant differences in LC50 values of Ae. aegypti strains, neither in the comparison of these values with those of the reference strain. the presented results indicate that the use of Bacillus thuringiensis var. israelensis continues to be a choice for the control of Aedes aegypti larval populations in La Habana province.

Synergistic effect of certain insecticides combined with Bacillus thuringiensis on mosquito larvae

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C.P. Narkhede

2017-04-01

Full Text Available For effective vector control it is essential to formulate new preparations having multiple action against the vector pest. Developing combined formulation of biopesticide and chemical pesticide is one of the novel concept to fight against the vectors with new weapons; however, compatibility of biopesticide i.e. Bacillus thuringiensis (Bt and chemical pesticide is a real hurdle. In this investigation, local isolate Bacillus thuringiensis SV2 (BtSV2 was tested for its compatibility with various available mosquito larvicides. Temephos was most compatible with BtSV2 than with other tested pesticides. These two compatible agents were tested for larvicidal potential. Our study revealed that the synergistic effect of both agents reduces LC50 value by 30.68 and 22.36% against the Ae. aegypti and An. stephensi, respectively. The larvicidal potential increased when compared to individual pesticides. It was also observed a biochemical change in larvae after the TBT (Temephos + Bacillus thuringiensis combination treatment; it involves decreased level of alpha esterase, acetylcholine esterase and protein while level of beta esterase and acid phosphatase was unchanged and alkaline phosphatase activity was increased. Increased potential of combined formulation may be due to altered physiological condition.

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

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Lütfiye Öksüz

2012-01-01

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

Profile of cry from native Bacillus thuringiensis isolates and ...

African Journals Online (AJOL)

The characterization of 255 Bacillus thuringiensis isolates of Coorg, Sharavatti and BR hills, containing genes known to be active against coleopteran and lepidopteran insect species was done through PCR amplification using the specific and degenerate primers. The isolates were also tested for their insecticidal activity ...

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

NARCIS (Netherlands)

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

2009-01-01

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

Methodology for fast evaluation of Bacillus thuringiensis crystal protein content

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Alves Lúcia M. Carareto

2000-01-01

Full Text Available The development of the production and use of Bacillus thuringiensis in Brazil at a commercial scale faces certain difficulties, among them the establishment of efficient methodologies for the quantitation of toxic products to be commercialized. Presently, the amount of toxin is given in percentage by analyzing the samples total protein content. Such methodology however, does not measure the actual amount of active protein present in the product, since most strains express different endotoxin genes and might even produce b-toxin. Since the various types of toxins exhibit different antigenic characteristics, this work has as objective the utilization of fast immunological techniques to quantify the level of crystal protein. Crystal protein produced by a subspecies of Bacillus thuringiensis var. israelensis was purified by ultracentrifugation and utilized to immunize rabbits and to produce hiperimmune sera. Such sera were latter used to evaluate the level of proteins on commercial bioinsecticide and on laboratory cultures of B. thuringiensis through the immunodot technique. The results were obtained by comparison of data obtained from reactions with known concentrations of crystal protein permitting to evaluate the level of such protein on various materials.

Expression of Bacillus thuringiensis serovar. israelensis toxins in Asticcacaulis excentricus to control dipteran larvae of vectors of diseases

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Óscar Enrique Guevara

2004-01-01

Full Text Available Bacillus thuringiensis cry genes encode for a diverse group of crystal-forming proteins that exhibit insecticidal activity towards dipteran, lepidopteran and coleopteran larvae. The effectiveness of insecticides based on mosquito larvicidal B. thuringiensis strains can be enhanced by using aquatic prosthecated bacteria as alternative hosts, since they do not sink, cytoplasmic located toxins are protected f rom UV radiation and, most importantly, mosquito larvae feed on them. An Asticcacaulis excentricus reference strain was transformed with the cry1 1Aa gene from Bacillus thuringiensis serovar. israelensis. Western blot and electrophoresis were used to test recombinant protein expression; Western blot revealed a 72 kDa protein corresponding to B. thuringiensis serovar. israelensis Cry1 1 Aa. These aquatic bacte­rias toxicity achieved 50% mortality at 23 ng/mL concentration in f irst instar Culex quinquefasciatus larvae. Other bioassays indicated that recombinant A. excentricus is toxic against Aedes aegyptiand Anopheles albimanus first instar larvae. Buoyancy tests demonstrated the advantage of A. excentricus over B. thuringiensis. Key words: Asticcacaulis excentricus, Bacillus thuringiensis, prosthecated bacteria, dengue, malaria.

Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua

NARCIS (Netherlands)

Hernandez-Martinez, P.; Navarro-Cerrillo, G.; Caccia, S.; Maagd, de R.A.; Moar, W.J.; Ferre, J.; Escriche, B.; Herrero, S.

2010-01-01

Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes

Interactions of transgenic Bacillus thuringiensis insecticidal crops with spiders (Araneae)

Science.gov (United States)

Genetically modified crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) have dramatically increased in acreage since their introduction in the mid-1990’s. Although the insecticidal mechanisms of Bt target specific pests, concerns persist regarding direct and indirect effects on...

[Bacillus cereus endocarditis and a probable cutaneous gateway].

Science.gov (United States)

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

2017-01-01

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

40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

Science.gov (United States)

2010-07-01

... thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens is exempt from the...

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

Directory of Open Access Journals (Sweden)

Lütfiye Öksüz

2012-01-01

Full Text Available

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

It has been reported Bacillus cereus septicemia may be fatal in immunocompromised hosts despite broad-spectrum appropriate treatment¹⁰. Catheter removal is essential for prevention of recurrent bacteremia. Long-term cathater salvage should be reserved for appropriate patient group.

[Potential of Bacillus thuringiensis israelensis Berliner for controlling Aedes aegypti].

Science.gov (United States)

Polanczyk, Ricardo Antonio; Garcia, Marcelo de Oliveira; Alves, Sérgio Batista

2003-12-01

The importance of the entomopathogenic bacterium Bacillus thuringiensis israelensis in the control of Aedes aegypti is presented. The use and potential of B. thuringiensis israelensis against the mosquito vector of dengue fever is described. Other aspects such as insect's resistance development against chemicals and advantages and constraints of using microbial control are discussed. Emphasis is given to the importance of the use of this bacterium in Brazil, which could contribute significantly to solving the mosquito problem without affecting the environment, humans and others invertebrate organisms in critical regions.

Bacillus cereus: a competent plant growth promoting bacterium of saline sodic field

International Nuclear Information System (INIS)

Hassan, T.; Naz, I.; Hussain, M.

2018-01-01

The effects of Bacillus cereus were investigated on wheat in the presence or absence of L-tryptophan, in a saline sodic field. An aqueous solution of L-tryptophan was added to the rhizosphere soil at 1 µg/L, after 8d of seeds germination with irrigated water. The survival efficiency measured as colony forming unit revealed that B. cereus was salt tolerant to rhizosphere soil filtrate and in NaCl. Bio-inoculation of B. cereus significantly decreased Electrical conductivity (EC), Na and Cl contents by 35%, and increased K, NO3-N, P, and organic matter by (25%) over control. Tryptophan addition assisted B. cereus to further decrease Na, Cl, sodium absorption ratio (SAR) and Na/K by 80%. Inoculation of B. cereus alone and with tryptophan significantly increased proline, antioxidant enzymes, phytohormones and yield attributes. The results revealed that tryptophan addition augmented the potential of B. cereus in improving crop growth and productivity which was mediated by the salinity alleviation. (author)

The occurrence of Photorhabdus-like toxin complexes in Bacillus thuringiensis

Science.gov (United States)

Recently, genomic sequencing of a Bacillus thuringiensis (Bt) isolate from our collection revealed the presence of an apparent operon encoding an insecticidal toxin complex (Tca) similar to that first described from the entomopathogen Photorhabdus luminescens. To determine whether these genes are w...

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

NARCIS (Netherlands)

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

2002-01-01

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

Long lasting persistence of Bacillus thuringiensis Subsp. israelensis (Bti in mosquito natural habitats.

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Mathieu Tilquin

Full Text Available BACKGROUND: The detrimental effects of chemical insecticides on the environment and human health have lead to the call for biological alternatives. Today, one of the most promising solutions is the use of spray formulations based on Bacillus thuringiensis subsp. israelensis (Bti in insect control programs. As a result, the amounts of Bti spread in the environment are expected to increase worldwide, whilst the common belief that commercial Bti is easily cleared from the ecosystem has not yet been clearly established. METHODOLOGY/MAIN FINDINGS: In this study, we aimed to determine the nature and origin of the high toxicity toward mosquito larvae found in decaying leaf litter collected in several natural mosquito breeding sites in the Rhône-Alpes region. From the toxic fraction of the leaf litter, we isolated B. cereus-like bacteria that were further characterized as B. thuringiensis subsp. israelensis using PCR amplification of specific toxin genes. Immunological analysis of these Bti strains showed that they belong to the H14 group. We finally used amplified length polymorphism (AFLP markers to show that the strains isolated from the leaf litter were closely related to those present in the commercial insecticide used for field application, and differed from natural worldwide genotypes. CONCLUSIONS/SIGNIFICANCE: Our results raise the issue of the persistence, potential proliferation and environmental accumulation of human-spread Bti in natural mosquito habitats. Such Bti environmental persistence may lengthen the exposure time of insects to this bio-insecticide, thereby increasing the risk of resistance acquisition in target insects, and of a negative impact on non-target insects.

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

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Viktoria M Doll

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

In vitro effect of Bacillus thuringiensis strains and Cry proteins in phytopathogenic fungi of paddy rice-field Efeito in vitro de cepas e proteínas Cry de Bacillus thuringiensis em fungos fitopatogênicos da cultura do arroz irrigado

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Neiva Knaak

2007-09-01

Full Text Available Cry1Ab and Cry1Ac strains and proteins synthesized by Bacillus thuringiensis thuringiensis and B. thuringiensis kurstaki were assessed in the following phytopathogens: Rhizoctonia solani,Pyricularia grisea,Fusarium oxysporum and F. solani, which had their micelial growth decreased after incubation in the presence of the bacterial strains. As to Cry proteins, there were no inhibition halo development in the assessed concentrations.As cepas e proteínas Cry1Ab e Cry1Ac sintetizadas por Bacillus thuringiensis thuringiensis e B. thuringiensis kurstaki, foram avaliadas nos fitopatógenos: Rhizoctonia solani,Pyricularia grisea,Fusarium oxysporum e F. solani, os quais tiveram seu crescimento micelial reduzido após a incubação na presença das cepas bacterianas. Em relação às proteínas Cry, não houve formação de halo de inibição nas concentrações avaliadas.

Screening of Local Bacillus thuringiensis Isolates for Toxicity to ...

African Journals Online (AJOL)

Stem borers are a major source of pre-harvest maize crop losses in Kenya and many Sub- Saharan African countries. This menace needs to be addressed if food security is to be realized in this region. Seven local isolates of Bacillus thuringiensis (Bt) strains were isolated from soils collected from Kakamega and Machakos ...

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

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R. Bhuvaneswari

2016-04-01

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

Bacillus thuringiensis: the legacy to the XXI century

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M. Realpe

1998-01-01

Full Text Available Bacillus thuringiensis-based insecticides are the main production line of the biopesticides world market. The research devoted to this area, promoted by the necessity to solve problems in agriculture and public health has resulted in an exhaustive knowledge of its biology. The diversity of the B. thuringiensis strains has permitted to develop several products mainly, but not exclusively, for insect control. With the new developments in the field of molecular biology, it has been possible to understand the molecular basis of the mode of action and to increase the range of activity as well. As a result of the broad use in several countries, resistant strains of some of the susceptible insects have appeared. The aim of this review is to elaborate a theoretical framework of the current state of research on B. thuringiensis, describing briefly the knowledge on this bacterium, with emphasis on biological phenomena that underlie its toxic activity and the problems that will be faced during the XXI century with the increasingly common resistance, all this analyzed from a biotechnological perspective.

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

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Sabrina Laouami

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

The Water Cycle, a Potential Source of the Bacterial Pathogen Bacillus cereus

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Julien Brillard

2015-01-01

Full Text Available 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.

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

NARCIS (Netherlands)

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

2008-01-01

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

A four-gene operon in Bacillus cereus produces two rare spore-decorating sugars.

Science.gov (United States)

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.

Isolation and identification of some Bacillus thuringiensis strains with insecticidal activity against Ceratitis capitata

International Nuclear Information System (INIS)

Majdoub, Nihed

2010-01-01

The aims of the present work is to study the effect of toxins (delta-endotoxins), extracted from different strains of Bacillus thuringiensis on Ceratitis capitata, a devastating of citrus and fruit trees. Strains of B. thuringiensis were isolated from the mud of Sebket Sejoumi. Among 70 isolates tested, 15 showed a significant identicalness activity in which 5 isolates led to mortality rates ≥ 90 pour cent . These mortality rates are caused by endotoxins of B. thuringiensis. Analysis of proteins profiles of different isolates of B. thuringiensis revealed variability between them. The preliminary results of this study encourage us towards the characterization of the insecticidal activity produced by B. thuringiensis strains for large scale application.

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

OpenAIRE

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

2014-01-01

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

40 CFR 180.1108 - Delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas...

Science.gov (United States)

2010-07-01

... thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens is...

Pan-genome and phylogeny of Bacillus cereus sensu lato.

Science.gov (United States)

Bazinet, Adam L

2017-08-02

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

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

Directory of Open Access Journals (Sweden)

Albenones José de Mesquita

2007-09-01

Full Text Available

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

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

Purification and Characterization of a Novel Cold Shock Protein-Like Bacteriocin Synthesized by Bacillus thuringiensis.

Science.gov (United States)

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.

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

NARCIS (Netherlands)

Giffel, te M.

1997-01-01

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

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

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Ľubomír Valík

2013-02-01

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

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

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Karla D Passalacqua

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

Detection of presumptive Bacillus cereus in the Irish dairy farm environment

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O’Connell A.

2016-12-01

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

Survival of diverse bacillus thuringiensis strains in gypsy moth (Lepidotera: Lymantriidae) is correlated with urease production

Science.gov (United States)

Bacillus thuringiensis is an entomopathogenic bacterium that can kill a variety of pest insects, but seldom causes epizootics because it replicates poorly in insects. By attempting to repeatedly pass lepidopteran-active B. thuringiensis strains through gypsy moth larvae, we found that only those str...

Detection of Bacillus thuringiensis genes in transgenic maize by the ...

African Journals Online (AJOL)

We optimized the PCR method to detect genetically engineered Bacillus thuringiensis (Bt) maize in open quarantine fields in Kenya. Many factors affect the extraction of the DNA from plants, such as the amount of tissue available, the condition of the plant material, the numbers of steps involved in the extraction procedure, ...

Estirpes de Bacillus thuringiensis efetivas contra insetos das ordens Lepidoptera, Coleoptera e Diptera Bacillus thuringiensis strains effective against insects of Lepidoptera, Coleoptera and Diptera orders

Directory of Open Access Journals (Sweden)

Lílian Botelho Praça

2004-01-01

Full Text Available O objetivo deste trabalho foi selecionar entre 300 estirpes de Bacillus thuringiensis as efetivas simultaneamente contra larvas de Spodoptera frugiperda J.E. Smith e Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae, Anthonomus grandis Boheman (Coleoptera: Curculionidae, Aedes aegypti Linnaeus e Culex quinquefasciatus Say (Diptera: Culicidae. Foram selecionadas duas estirpes de B. thuringiensis, denominadas S234 e S997, que apresentaram atividade contra as três ordens de insetos. As estirpes foram caracterizadas por métodos morfológicos, bioquímicos e moleculares. As mesmas apresentaram duas proteínas principais de 130 e 65 kDa, produtos de reação em cadeia da polimerase de tamanho esperado para a detecção dos genes cry1Aa, cry1Ab, cry1Ac, cry1B e cry2 e cristais bipiramidais, cubóides e esféricos.The aim of this work was to select among 300 strains of Bacillus thuringiensis those which are simultaneously effective against larvae of Spodoptera frugiperda J.E. Smith and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae, Anthonomus grandis Boheman (Coleoptera: Curculionidae, Aedes aegypti Linnaeus and Culex quinquefasciatus Say (Diptera: Culicidae. Two strains of B. thuringiensis were selected, S234 and S997, which presented activity against those three insect orders. Both strains were characterized by morphological, biochemical and molecular methods. They have presented two main proteins with 130 and 65 kDa, polimerase chain reaction products with expected sizes for detection of the genes cry1Aa, cry1Ab, cry1Ac, cry1B and cry2 and bipiramidal, cubical and spherical crystals.

Expression of the sigma35 and cry2AB genes involved in Bacillus thuringiensis virulence Expressão dos genes sigma35 e cry2AB envolvidos na virulência de Bacillus thuringiensis

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Ana Maria Guidelli-Thuler

2009-06-01

Full Text Available There are several genes involved in Bacillus thuringiensis sporulation. The regulation and expression of these genes results in an upregulation in Cry protein production, and this is responsible for the death of insect larvae infected by Bacillus thuringiensis. Gene expression was monitored in Bacillus thuringiensis during three developmental phases. DNA macroarrays were constructed for selected genes whose sequences are available in the GenBank database. These genes were hybridized to cDNA sequences from B. thuringiensis var. kurstaki HD-1. cDNA probes were synthesized by reverse transcription from B. thuringiensis RNA templates extracted during the exponential (log growth, stationary and sporulation phases, and labeled with 33PadCTP. Two genes were differentially expressed levels during the different developmental phases. One of these genes is related to sigma factor (sigma35, and the other is a cry gene (cry2Ab. There were differences between the differential levels of expression of various genes and among the expression detected for different combinations of the sigma factor and cry2Ab genes. The maximum difference in expression was observed for the gene encoding sigma35 factor in the log phase, which was also expressed at a high level during the sporulation phase. The cry2Ab gene was only expressed at a high level in the log phase, but at very low levels in the other phases when compared to the sigma35.Muitos genes estão envolvidos nos mecanismos de esporulação da bactéria Bacillus thuringiensis. A regulação e expressão desses genes resultam em uma produção massiva da proteína Cry, responsável pela morte das larvas de muitos insetos. Neste trabalho monitorou-se a expressão de genes de Bacillus thuringiensis, ao longo de três fases de seu desenvolvimento. Foram construídos macroarrays de DNA dos genes selecionados, cujas seqüências estão disponibilizadas no GenBank. Estes genes foram hibridizados com cDNAs obtidos de B

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

DEFF Research Database (Denmark)

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

2001-01-01

From four Danish pig farms, bacteria of Pseudomonas spp. and the Bacillus cereus group were isolated from soil and susceptibility towards selected antimicrobials was tested. From each farm, soil samples representing soil just before and after spread of animal waste and undisturbed agricultural so...... spp., and for bacitracin, erythromycin, penicillin and streptomycin for the B. cereus group. Variations in resistance levels were observed when soil before and after spread of animal waste was compared, indicating an effect from spread of animal waste.......From four Danish pig farms, bacteria of Pseudomonas spp. and the Bacillus cereus group were isolated from soil and susceptibility towards selected antimicrobials was tested. From each farm, soil samples representing soil just before and after spread of animal waste and undisturbed agricultural soil......, when possible, were collected. Soil from a well-characterized Danish farm soil (Hojbakkegaard) was collected for comparison. The Psudomonas spp. and B. cereus were chosen as representative for Gram-negative and Gram-positive indigenous soil bacteria to test the effect of spread of animal waste...

Large-Scale Purification, Characterization, and Spore Outgrowth Inhibitory Effect of Thurincin H, a Bacteriocin Produced by Bacillus thuringiensis SF361.

Science.gov (United States)

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.

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

OpenAIRE

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

2012-01-01

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

The Impact of Bacillus Thuringiensis Israelensis (Bti) on Adult and ...

African Journals Online (AJOL)

In the year 2007, the Ministry of Health (MoH) initiated a larviciding program using Bacillus thuringiensis israelensis (Bti) to mitigate the effects of black fly bites. This study was aimed at assessing the impact of Bti on adult and larvae black fly populations. Baseline data was collected prior to Bti application and after ...

Corrosion effect of Bacillus cereus on X80 pipeline steel in a Beijing soil environment.

Science.gov (United States)

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.

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

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Lenka Necidová

2014-01-01

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

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

NARCIS (Netherlands)

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

2006-01-01

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

The role of pili in Bacillus cereus intraocular infection.

Science.gov (United States)

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

2017-06-01

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

Environmental Distribution and Diversity of Insecticidal Proteins of Bacillus thuringiensis Berliner

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Xavier, R.

2007-01-01

Full Text Available Bacillus thuringiensis Berliner based biopesticides have been successfully used world over for the control of agricultural pests and vectors of human diseases. Currently there are more than 200 B. thuringiensis strains with differing insecticidal activities are available as biocontrol agents and for developing transgenic plants. However, two major disadvantages are the development of insect resistance and high target specificity (narrow host range. Globally there is a continuous search for new B. thuringiensis strains with novel insecticidal activities. The present study aims to study the environmental distribution of B. thuringiensis and their toxic potential against insect pests. Soil and grain samples were collected from different environments and were processed by a modified acetate selection method. Initially B. thuringiensis isolates were screened on the basis of colony morphology and phase contrast microscopy for the presence of parasporal crystal inclusions. The population dynamics showed that B. thuringiensis is abundant in sericulture environment compared to other niches. Relative abundance of B. thuringiensis strains in sericulture environment shows the persistent association of B. thuringiensis with Bombyx mori (silk worm as insect pathogen. The protein profiles of the selected strains were studied by SDS-PAGE. The protein profiles of majority of B. thuringiensis isolates from grain storage facilities predominantly showing the 130 kDa and 68 kDa proteins, which is characteristics of lepidopteran active B. thuringiensis. However, one isolate BTRX-4 has 80-85 kDa protein, which is novel in that, this strain also exhibits antilepidopteran activity, which is normally presented by B. thuringiensis strains having 130 kDa and 68 kDa proteins. The protein profile of B. thuringiensis isolates from sericulture environment shows two different protein profiles. B. thuringiensis isolates BTRX-16 to BTRX-22 predominantly show 130 kDa protein

Toxin profiles of Bacillus cereus occurring in high numbers in spontaneously fermented African locust beans (Parkia biglobosa)

DEFF Research Database (Denmark)

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

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

Resistance: a threat to the insecticidal crystal proteins of Bacillus thuringiensis

Science.gov (United States)

Leah S. Bauer

1995-01-01

Insecticidal crystal proteins (also known as d-endotoxins) synthesized by the bacterium Bacillus thuringiensis Berliner (Bt) are the active ingredient of various environmentally friendly insecticides that are 1) highly compatible with natural enemies and other nontarget organisms due to narrow host specificity, 2) harmless to vertebrates, 3) biodegradable in the...

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

NARCIS (Netherlands)

Mols, J.M.; Abee, T.

2008-01-01

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

TRANSGENIC PLANTS EXPRESSING BACILLUS THURINGIENSIS DELTA-ENDOTOXINS

Institute of Scientific and Technical Information of China (English)

Hua-rong,Li; BrendaOppert; KunYanZhu; RandallA.Higgins; Fang-nengHuang; LawrentL.Buschman

2003-01-01

Commercial varieties of transgenic Bacillus thuringiensis (Bt) plants have been developed in many countries to control target pests. Initially, the expression of native Bt genes in plants was low due to mRNA instability, improper splicing, and post-translation modifications. Subsequently, modifications of the native Bt genes greatly enhanced expression levels. This is a review of the developments that made modem high-expression transgenic Bt plants possible, with an emphasis on the reasons for the low-level expression of native Bt genes in plant systems, and the techniques that have been used to improve plant expression of Bt toxin genes.

Exploratory analysis for the optimization of culture media for Bacillus thuringiensis fermentation

Directory of Open Access Journals (Sweden)

Jenny M. Escobar

2004-07-01

Full Text Available Agrichemical involve health risks for producers and consumers; they can also affect beneficial insects, birds, fish and mammals. Bacillus thuringiensis-based biopesticides specific for insect plagues are available, which, represent an alternative to traditional chemically-based products. Culture media design is an impor-tant factor in the production of biopesticides based on Bacillus thuringiensis. The media have to be economi-cal and they must contain all the nutrition factors required by the bacteria. The yield of active ingredient, comprising the toxin-containing crystal protein and bacterial spores, must be high and with adequate toxi-city to formulate the biopesticide. In this work we studied different culture media and optimised a promi-sing culture medium for B. thuringiensis fermentation to obtain an active ingredient for use as raw material in manufacturing a biopesticide. The final concentration of active ingredient was 15 to 16 g/L and the raw material cost around US $0,30/kg product. Calculations for the experimental phase were done using the response surface technique in a central composite design (CCD, the optimisation phase used Derringer and Suich (1980 method for dual response. Key words: Biopesticides, culture media, surface response, dual response, contour plots, central composite design.

Simultaneous removal of chlorothalonil and nitrate by Bacillus cereus strain NS1

International Nuclear Information System (INIS)

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

2007-01-01

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

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

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Reyad Shawish

2017-12-01

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

Metabolomic analysis of cooperative adaptation between co-cultured Bacillus cereus and Ketogulonicigenium vulgare.

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Ming-Zhu Ding

Full Text Available The cooperative adaptation of subcultivated Bacillus cereus and Ketogulonicigenium vulgare significantly increased the productivity of 2-keto-L-gulonic acid, the precursor of vitamin C. The mechanism of cooperative adaptation of the serial subcultivated B. cereus and K. vulgare was investigated in this study by culturing the two strains orthogonally on agar plates. It was found that the swarming distance of B. cereus along the trace of K. vulgare on the plate decreased after 150 days' subcultivation. Metabolomic analysis on these co-cultured B. cereus and K. vulgare strains showed that their cooperative adaptation was accomplished by three key events: (i the ability of nutrients (e.g., amino acids and purines searching and intaking, and proteins biosynthesis is increased in the evolved B. cereus; (ii the capability of protein degradation and amino acids transportation is enhanced in evolved K. vulgare; (iii the evolved B. cereus was found to provide more nutrients (mostly amino acids and purines to K. vulgare, thus strengthening the oxidation and energy generation of K. vulgare. Our results provided novel insights into the systems-level understanding of the cooperative adaptation between strains in synergistic consortium.

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

African Journals Online (AJOL)

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

An outbreak of Bacillus cereus implicating a part-time banquet caterer.

Science.gov (United States)

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.

Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

Science.gov (United States)

Caccia, Silvia; Di Lelio, Ilaria; La Storia, Antonietta; Marinelli, Adriana; Varricchio, Paola; Franzetti, Eleonora; Banyuls, Núria; Tettamanti, Gianluca; Casartelli, Morena; Giordana, Barbara; Ferré, Juan; Gigliotti, Silvia; Pennacchio, Francesco

2016-01-01

Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. Here this key issue is addressed by RNAi-mediated silencing of an immune gene in a lepidopteran host Spodoptera littoralis, leaving the midgut microbiota unaltered. The resulting cellular immunosuppression was characterized by a reduced nodulation response, which was associated with a significant enhancement of host larvae mortality triggered by B. thuringiensis and a Cry toxin. This was determined by an uncontrolled proliferation of midgut bacteria, after entering the body cavity through toxin-induced epithelial lesions. Consequently, the hemolymphatic microbiota dramatically changed upon treatment with Cry1Ca toxin, showing a remarkable predominance of Serratia and Clostridium species, which switched from asymptomatic gut symbionts to hemocoelic pathogens. These experimental results demonstrate the important contribution of host enteric flora in B. thuringiensis-killing activity and provide a sound foundation for developing new insect control strategies aimed at enhancing the impact of biocontrol agents by reducing the immunocompetence of the host. PMID:27506800

Characterization of a Chitin-Binding Protein from Bacillus thuringiensis HD-1.

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Naresh Arora

Full Text Available Strains of Bacillus thuringiensis produce insecticidal proteins. These strains have been isolated from diverse ecological niches, such as soil, phylloplane, insect cadavers and grain dust. To effectively propagate, these strains produce a range of molecules that facilitate its multiplication in a competing environment. In this report, we have examined synthesis of a chitin-binding protein and evaluated its effect on fungi encountered in environment and its interaction with insecticidal proteins synthesized by B. thuringiensis. The gene encoding chitin-binding protein has been cloned and expressed. The purified protein has been demonstrated to interact with Cry insecticidal protein, Cry1Ac by Circular Dichrosim spectroscopy (CD and in vitro pull down assays. The chitin-binding protein potentiates insecticidal activity of bacillar insecticidal protein, Cry1Ac. Further, chitin-binding protein was fungistatic against several soil fungi. The chitin binding protein is expressed in spore mother cell and deposited along with insecticidal protein, Cry1Ac. It interacts with Cry1Ac to potentiate its insecticidal activity and facilitate propagation of Bacillus strain in environment by inhibiting growth of certain fungi.

An outbreak of Bacillus cereus food poisoning--are caterers supervised sufficiently.

Science.gov (United States)

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

Experimental design and Bayesian networks for enhancement of delta-endotoxin production by Bacillus thuringiensis.

Science.gov (United States)

Ennouri, Karim; Ayed, Rayda Ben; Hassen, Hanen Ben; Mazzarello, Maura; Ottaviani, Ennio

2015-12-01

Bacillus thuringiensis (Bt) is a Gram-positive bacterium. The entomopathogenic activity of Bt is related to the existence of the crystal consisting of protoxins, also called delta-endotoxins. In order to optimize and explain the production of delta-endotoxins of Bacillus thuringiensis kurstaki, we studied seven medium components: soybean meal, starch, KH₂PO₄, K₂HPO₄, FeSO₄, MnSO₄, and MgSO₄and their relationships with the concentration of delta-endotoxins using an experimental design (Plackett-Burman design) and Bayesian networks modelling. The effects of the ingredients of the culture medium on delta-endotoxins production were estimated. The developed model showed that different medium components are important for the Bacillus thuringiensis fermentation. The most important factors influenced the production of delta-endotoxins are FeSO₄, K2HPO₄, starch and soybean meal. Indeed, it was found that soybean meal, K₂HPO₄, KH₂PO₄and starch also showed positive effect on the delta-endotoxins production. However, FeSO4 and MnSO4 expressed opposite effect. The developed model, based on Bayesian techniques, can automatically learn emerging models in data to serve in the prediction of delta-endotoxins concentrations. The constructed model in the present study implies that experimental design (Plackett-Burman design) joined with Bayesian networks method could be used for identification of effect variables on delta-endotoxins variation.

Characterization of parasporin gene harboring Indian isolates of Bacillus thuringiensis

OpenAIRE

Lenina, N. K.; Naveenkumar, A.; Sozhavendan, A. E.; Balakrishnan, N.; Balasubramani, V.; Udayasuriyan, V.

2013-01-01

Bacillus thuringiensis (Bt) is popularly known as insecticidal bacterium. However, non-insecticidal Bt strains are more extensively available in natural environment than the insecticidal ones. Parasporin (PS) is a collection of genealogically heterogeneous Cry proteins synthesized in non-insecticidal isolates of Bt. An important character generally related with PS proteins is their strong cytocidal activity preferentially on human cancer cells of various origins. Identification and characteri...

Avaliação da eficiência de formulações de Bacillus thuringiensis para o controle de traça-das-crucíferas em repolho no Distrito Federal Efficiency of Bacillus thuringiensis formulations in controlling Diamondback Moth in cabbage in the Federal District

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Marina Castelo Branco

1999-11-01

Full Text Available A traça-das-crucíferas (Plutella xylostella é a praga mais importante do repolho no Distrito Federal. Seu controle é feito basicamente com inseticidas. Novos produtos são constantemente avaliados para o controle da praga e neste trabalho duas novas formulações de Bacillus thuringiensis [Bacillus thuringiensis var. aizawai (350 e 500 g/hae B. thuringiensis var. kurstaki x B. thuringiensis var. aizawai (350 e 500 ml/ha] foram avaliadas no período de maio a outubro de 1995. Os tratamentos B. thuringiensis var. kurstaki (500 ml/ha, deltametrina (240 ml/ha e uma testemunha sem pulverização foram também incluídos no experimento. O delineamento foi blocos ao acaso, com sete tratamentos e quatro repetições. Os resultados mostraram que B. thuringiensis var. aizawai nas duas dosagens avaliadas e B. thuringiensis var. kurstaki x B. thuringiensis var. aizawai (500 ml/ha foram os produtos mais eficientes. Ao final do experimento larvas e pupas de traça-das-crucíferas foram coletadas no campo e a primeira geração foi submetida a um teste de laboratório onde discos de folhas de repolho foram tratados com as dosagens dos inseticidas a base de B. thuringiensis utilizadas no campo. Larvas de segundo estádio foram colocadas sobre os discos tratados e a mortalidade de larvas avaliada após 72 h. Todos os tratamentos causaram mais de 97% de mortalidade de larvas. O resultado do teste de laboratório sugere que a menor eficiência de B. thuringiensis var. kurstaki x B. thuringiensis var. aizawai (350 ml/ha e B. thuringiensis var. kurstaki (500 ml/ha no teste de campo quando comparada aos demais Bacillus, pode ser devido à mais rápida degradação destes produtos no ambiente.The Diamondback Moth (Plutella xylostella is the most important cabbage pest in the Federal District. New insecticides are frequently tested for its control and in this study two new Bacillus thuringiensis formulations [B. thuringiensis var. aizawai (350 and 500 g/ha and B

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

Science.gov (United States)

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

2015-04-01

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

Isolation of Bacillus cereus Group from the Fecal Material of Endangered Wood Turtles.

Science.gov (United States)

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.

The CodY-dependent clhAB2 operon is involved in cell shape, chaining and autolysis in Bacillus cereus ATCC 14579.

Science.gov (United States)

Huillet, Eugénie; Bridoux, Ludovic; Wanapaisan, Pagakrong; Rejasse, Agnès; Peng, Qi; Panbangred, Watanalai; Lereclus, Didier

2017-01-01

The Gram-positive pathogen Bacillus cereus is able to grow in chains of rod-shaped cells, but the regulation of chaining remains largely unknown. Here, we observe that glucose-grown cells of B. cereus ATCC 14579 form longer chains than those grown in the absence of glucose during the late exponential and transition growth phases, and identify that the clhAB2 operon is required for this chain lengthening phenotype. The clhAB2 operon is specific to the B. cereus group (i.e., B. thuringiensis, B. anthracis and B. cereus) and encodes two membrane proteins of unknown function, which are homologous to the Staphylococcus aureus CidA and CidB proteins involved in cell death control within glucose-grown cells. A deletion mutant (ΔclhAB2) was constructed and our quantitative image analyses show that ΔclhAB2 cells formed abnormal short chains regardless of the presence of glucose. We also found that glucose-grown cells of ΔclhAB2 were significantly wider than wild-type cells (1.47 μm ±CI95% 0.04 vs 1.19 μm ±CI95% 0.03, respectively), suggesting an alteration of the bacterial cell wall. Remarkably, ΔclhAB2 cells showed accelerated autolysis under autolysis-inducing conditions, compared to wild-type cells. Overall, our data suggest that the B. cereus clhAB2 operon modulates peptidoglycan hydrolase activity, which is required for proper cell shape and chain length during cell growth, and down-regulates autolysin activity. Lastly, we studied the transcription of clhAB2 using a lacZ transcriptional reporter in wild-type, ccpA and codY deletion-mutant strains. We found that the global transcriptional regulatory protein CodY is required for the basal level of clhAB2 expression under all conditions tested, including the transition growth phase while CcpA, the major global carbon regulator, is needed for the high-level expression of clhAB2 in glucose-grown cells.

RNA-seq analysis of antibiotic-producing Bacillus subtilis SC-8 in response to signal peptide PapR of Bacillus cereus.

Science.gov (United States)

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.

IMPACT OF BT ( BACILLUS THURINGIENSIS ) CROPS ON BAT ACTIVITY IN SOUTH TEXAS AGROECOSYSTEMS

Science.gov (United States)

The widespread adoption of transgenic insecticidal crops raises concerns that nontarget species may be harmed and food webs disrupted. The goal of this research is to determine how transgenic Bt (Bacillus thuringiensis) crops impact the activity of Brazilian freetailed bats (Tada...

Ocorrência de Bacillus cereus em leite integral e capacidade enterotoxigênica das cepas isoladas Occurrence of Bacillus cereus in Whole milk and enterotoxigenic potential of the isolated strains

Directory of Open Access Journals (Sweden)

N.C.M. Rezende-Lago

2007-12-01

Full Text Available Pesquisaram-se a presença de Bacillus cereus e a produção de enterotoxinas produzidas por esses microrganismos em 120 amostras de diversos tipos de leite. Bacillus cereus foi isolado e identificado em 22 (73,3%, 15 (50,0%, 29 (96,7% e quatro (13,3% amostras de leite em pó, cru, pasteurizado e UAT (longa vida, respectivamente. Para a detecção de enterotoxinas pela técnica da alça ligada de coelho, foram positivos, respectivamente, três (13,6%, um (7,1% e 10 (35,7% microrganismos isolados das amostras de leite em pó, leite cru e leite pasteurizado. Pelo teste de aumento de permeabilidade vascular, dois (9,1%, um (7,1%, um (3,6% e um (4,0% microrganismos isolados de leite em pó, cru, pasteurizado e UAT apresentaram-se enterotoxigênicos, respectivamente. O uso da técnica de aglutinação passiva em látex demonstrou a produção da toxina diarréica por três (33,3%, sete (63,6%, quatro (30,8% e oito (80,0% microrganismos isolados, respectivamente, de leite em pó, cru, pasteurizado e UAT. Os resultados indicam um risco potencial, podendo colocar em risco a saúde dos consumidores desses produtos.A hundred and twenty samples of different types of milk were examined to the presence of Bacillus cereus and the enterotoxigenic potential of the isolated strains. Bacillus cereus was isolated and identified in 22 (73.0%, 15 (50.0%, 29 (96.7% and four (13.3% samples of powder, raw, pasteurized and UHT milk, respectively. The enterotoxigenicity detection using the rabbit ileal loop assay showed positive, respectively, three (13.6%, one (7.1% and 10 (35.7% isolated strains from powder, raw and pasteurized milk. Using vascular permeability activity assay two (9.1%, one (7.1%, one (3.6% and one (4.0% isolated strains from powder, raw, pasteurized and UHT milk were positive, respectively. The reversed passive latex agglutination test showed diarrheal toxin production by three (33.3%, seven (63.6%, four (30.8% and eight (80.0% strains isolated from

Effects of ensiling of Bacillus thuringiensis (Bt) maize (MON810) on ...

African Journals Online (AJOL)

The study investigated the degradation of the Bt protein (Cry1Ab) in Bt maize during ensiling and chemical composition of the silage. Two laboratory studies were conducted at the University of Fort Hare. One Bacillus thuringiensis (Bt) maize cultivar (DKC80-12B) and its isoline (DKC80-10) in the 2008/2009 study and two Bt ...

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

NARCIS (Netherlands)

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

2015-01-01

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

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

NARCIS (Netherlands)

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

2015-01-01

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

Bacillus thuringiensis subsp. israelensis and Its Dipteran-Specific Toxins

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Eitan Ben-Dov

2014-03-01

Full Text Available Bacillus thuringiensis subsp. israelensis (Bti is the first Bacillus thuringiensis to be found and used as an effective biological control agent against larvae of many mosquito and black fly species around the world. Its larvicidal activity resides in four major (of 134, 128, 72 and 27 kDa and at least two minor (of 78 and 29 kDa polypeptides encoded respectively by cry4Aa, cry4Ba, cry11Aa, cyt1Aa, cry10Aa and cyt2Ba, all mapped on the 128 kb plasmid known as pBtoxis. These six δ-endotoxins form a complex parasporal crystalline body with remarkably high, specific and different toxicities to Aedes, Culex and Anopheles larvae. Cry toxins are composed of three domains (perforating domain I and receptor binding II and III and create cation-selective channels, whereas Cyts are composed of one domain that acts as well as a detergent-like membrane perforator. Despite the low toxicities of Cyt1Aa and Cyt2Ba alone against exposed larvae, they are highly synergistic with the Cry toxins and hence their combinations prevent emergence of resistance in the targets. The lack of significant levels of resistance in field mosquito populations treated for decades with Bti-bioinsecticide suggests that this bacterium will be an effective biocontrol agent for years to come.

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

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Kym S Antonation

2016-09-01

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

Relapsing peritonitis with Bacillus cereus in a patient on continuous ambulatory peritoneal dialysis

DEFF Research Database (Denmark)

Magnussen, Eyð Tausen; Vang, Amanda Gratton; á Steig, Torkil

2016-01-01

We present a case where Bacillus cereus was determined to be the causative agent of relapsing peritonitis in a patient on continuous ambulatory peritoneal dialysis (CAPD). The patient, a 70-year-old man from the Faroe Islands, was admitted with relapsing peritonitis four times over a 3-month period....... Peritoneal cultures were positive for growth of B. cereus, a rare bacterial cause of peritonitis. The cultures demonstrated susceptibility to vancomycin, and therefore the patient was treated with intraperitoneal vancomycin, intraperitoneal gentamycin and oral ciprofloxacin. As a result of the relapsing B....... cereus peritonitis diagnosis and a CT scan showing contraction of the peritoneum after longstanding inflammation, the peritoneal catheter was removed and the patient converted to haemodialysis. To date, the patient has not been readmitted due to peritonitis. A lack of proper hygiene when changing...

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

Science.gov (United States)

Sharma, Priyanka; Bajaj, Bijender Kumar

2015-11-01

Usage of renewable raw materials for production of fully degradable bioplastics (bacterial poly-3-hydroxybutyrate, PHB) has gained immense research impetus considering recalcitrant nature of petroleum based plastics, dwindling fossil fuel feed stocks, and associated green house gas emissions. However, high production cost of PHB is the major bottleneck for its wide range industrial applications. In current study, Bacillus cereus PS 10, a recent isolate, efficiently utilized molasses, an abundantly available by-product from sugar industries as sole carbon source for growth and PHB production. Most influential bioprocess variables i.e. molasses, pH and NH4Cl were identified based on Plackett-Burman-designed experiments. Design of experiment approach (response surface methodology) was further employed for optimization of these bioprocess variables, and an enhanced PHB yield (57.5%) was obtained. PHB produced by Bacillus cereus PS 10 was investigated using various physico-chemical approaches viz. thermogravimetric analysis, proton and carbon NMR ((1)H and (13)C) spectroscopy, melting point, elemental analysis and polarimetry for its detail characterization, and assessment for industrial application potential. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of Baculovirus Insecticides Expressing Tailored Bacillus thuringiensis CryIA(b) Crystal Proteins

NARCIS (Netherlands)

Martens, John W M; Knoester, Marga; Weijts, Franci; Groffen, Sander J A; Hu, Zhihong; Bosch, Dirk; Vlak, Just M.

1995-01-01

Full-length, truncated, and mature forms of the CryIA(b) insecticidal crystal protein gene of Bacillus thuringiensis were engineered into the p10 locus of Autographa californica nuclear polyhedrosis virus (AcNPV). A signal sequence of Heliothis virescens juvenile hormone esterase was introduced at

Fatores de virulência de Bacillus thuringiensis: o que existe além das proteínas Cry

Directory of Open Access Journals (Sweden)

Gislayne Vilas-Bôas

2012-03-01

Virulence Factors of Bacillus thuringiensis Berliner: Something Beyond of Cry Proteins? Abstract. The Cry proteins produced by the entomopathogenic bacterium Bacillus thuringiensis Berliner are widely known due to its high toxicity against a variety of insects. The mode of action of these proteins is specific and becomes B. thuringiensis-based products the most used in biological control programs of insect pests in agriculture and of important human disease vectors. However, while the Cry proteins are the best-known insect-specific virulence factor, strains of B. thuringiensis show also a wide range of other virulence factors, which allow the bacteria to achieve the hemolymph and colonize efficiently the insect host. Among these factors, we highlight the Vip proteins, Cyt, enterotoxins, hemolysins, phospholipases, proteases and enzymes of degradation, in addition to the recently described parasporin. This review explores the action of these virulence factors, as well as, the characterization and control of expression of their genes. Additionally, we discuss aspects related to the ecological niche of the bacteria with emphasis on the characteristics involved in the biosafety of the use of B. thuringiensis-based products for biological control of target insects.

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

Science.gov (United States)

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

2008-09-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-09-15

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

De-mercurization of wastewater by Bacillus cereus (JUBT1): Growth kinetics, biofilm reactor study and field emission scanning electron microscopic analysis

International Nuclear Information System (INIS)

Ghoshal, Sanjukta; Bhattacharya, Pinaki; Chowdhury, Ranjana

2011-01-01

Graphical abstract: The assembly of biofilm reactor, based on attached growth of Bacillus cereus (JUBT1) on rice husk packing, and an activated carbon filter has been able to ensure the removal of mercury up to near-zero level. Highlights: → A new mercury resistant bacterial strain, Bacillus cereus (JUBT1), has been isolated. → Growth kinetics has been determined. → Biofilm reactor using attached growth of bacteria ensures near-zero level of mercury. → Confinement of mercury is confirmed through energy dispersive spectrometric analysis. - Abstract: Removal of mercuric ions by a mercury resistant bacteria, called Bacillus cereus (JUBT1), isolated from the sludge of a local chlor-alkali industry, has been investigated. Growth kinetics of the bacteria have been determined. A multiplicative, non-competitive relationship between sucrose and mercury ions has been observed with respect to bacterial growth. A combination of biofilm reactor, using attached growth of Bacillus cereus (JUBT1) on rice husk packing, and an activated carbon filter has been able to ensure the removal of mercury up to near-zero level. Energy dispersive spectrometry analysis of biofilm and the activated carbon has proved the transformation of Hg 2+ to Hg 0 and its confinement in the system.

Persistence of Bacillus thuringiensis bioinsecticides in the gut of human-flora-associated rats

DEFF Research Database (Denmark)

Wilcks, Andrea; Hansen, Bjarne Munk; Hendriksen, Niels Bohse

2006-01-01

The capability of two bioinsecticide strains of Bacillus thuringiensis (ssp. israelensis and ssp. kurstaki) to germinate and persist in vivo in the gastrointestinal tract of human-flora-associated rats was studied. Rats were dosed either with vegetative cells or spores of the bacteria for 4 conse...

Biological activity of Bacillus thuringiensis (Bacillales: Bacillaceae) chitinase against Caenorhabditis elegans (Rhabditida: Rhabditidae)

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Yu, J.; Xie, Y.; Lin, H.; Huang, Z.; Xu, L.; Gelbič, Ivan; Guan, X.

2014-01-01

Roč. 107, č. 2 (2014), s. 551-558 ISSN 0022-0493 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * Caenorhabditis elegans * chitinase Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.506, year: 2014 http://www.bioone.org/doi/pdf/10.1603/EC13201

Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

OpenAIRE

Caccia, Silvia; Di Lelio, Ilaria; La Storia, Antonietta; Marinelli, Adriana; Varricchio, Paola; Franzetti, Eleonora; Banyuls, Núria; Tettamanti, Gianluca; Casartelli, Morena; Giordana, Barbara; Ferré, Juan; Gigliotti, Silvia; Ercolini, Danilo; Pennacchio, Francesco

2016-01-01

Bacillus thuringiensis and its toxins are widely used for insect control. Notwithstanding the remarkable importance of this insect pathogen, its killing mechanism has yet to be fully elucidated. Here we show that the microbiota resident in the host midgut triggers a lethal septicemia. The infection process is enhanced by reducing the host immune response and its control on replication of midgut bacteria invading the body cavity through toxin-induced epithelial lesions. The experimental approa...

Growth of hydroxyapatite on the cellular membrane of the bacterium Bacillus thuringiensis for the preparation of hybrid biomaterials

Energy Technology Data Exchange (ETDEWEB)

Cervantes, Eric Reyes, E-mail: onomaeric@hotmail.com [Centro de Investigación en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Prolongación de la 24 Sur y Ave San Claudio, Ciudad Universitaria, Col San Manuel, C.P. 72570 Puebla, Pue (Mexico); Torres, Maykel González, E-mail: mikegcu@fata.unam.mx [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro C.P. 76230 (Mexico); Muñoz, Susana Vargas, E-mail: vmsu@unam.mx [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, Santiago de Querétaro, Querétaro C.P. 76230 (Mexico); Rosas, Efraín Rubio, E-mail: efrainrubio@yahoo.com [Centro de Investigación en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Prolongación de la 24 Sur y Ave San Claudio, Ciudad Universitaria, Col San Manuel, C.P. 72570 Puebla, Pue (Mexico); and others

2016-01-01

This study aimed to grow hydroxyapatite (HAp) crystals on the cellular wall of the Gram-positive bacterium Bacillus thuringiensis using a bio-mimetic method. Several strains were phenotypically and genotypically characterized using multilocus sequence typing (MLST) gene markers to differentiate the strains and confirm the identity of the isolated species to guarantee that the selected species was not harmful to human health or the environment. Three of the analyzed strains were selected because they exhibited the best nucleation and growth of HAp on the bacterial surface. This innovative method to grow HAp crystals on a cellular membrane helps to elucidate the mechanisms by which osseous tissue is formed in nature. The optimum concentration for the simulated physiological fluid (SPF) was 1.5 ×. The hybrid materials were characterized by optical microscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). - Highlights: • HAp crystals are grown on the cellular wall of a GP bacteria Bacillus thuringiensis. • The growing was carried out by using a bio-mimetic method. • Hybrid materials were characterized with morphological and spectroscopic techniques. • The reported method allows understanding the mechanisms to produce osseous tissue. • The membrane of Bacillus thuringiensis can grow more HAp than Bacillus halodurans.

Effects of Bacillus thuringiensis CRY1A(c) d-endotoxin on growth ...

African Journals Online (AJOL)

The recent introduction of Bt maize and Bt cotton transgenic crops into Africa has raised concerns on their potential short and long-term ecological effects on the environment. The effects of Bacillus thuringiensis (Bt) Cry1A(c) d-endotoxin on the growth, nodulation and productivity of two leguminous plants grown in clay soil ...

SpoVT: From Fine-Tuning Regulator in Bacillus subtilis to Essential Sporulation Protein in Bacillus cereus.

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Jean-Paul eMadeira

2015-04-01

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

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

NARCIS (Netherlands)

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

2016-01-01

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

Seleção e caracterização de estirpes de Bacillus thuringiensis efetivas no controle da traça-das-crucíferas Plutella xylostella Selection and characterization of Bacillus thuringiensis strains effective to control the diamondback moth Plutella xylostella

Directory of Open Access Journals (Sweden)

Patrícia Teles Medeiros

2005-11-01

Full Text Available O objetivo deste trabalho foi selecionar e caracterizar, no Banco de Germoplasma de Bacillus spp., da Empresa Brasileira de Pesquisa Agropecuária, as estirpes de Bacillus thuringiensis mais tóxicas à Plutella xylostella, por métodos morfológicos, bioquímicos e moleculares. Das 203 estirpes testadas, sete causaram 100% de mortalidade e foram semelhantes à estirpe padrão utilizada, B. thuringiensis subsp. kurstaki. Elas apresentaram proteínas de 130 kDa e 65 kDa, presença de genes cry1 e cry2 e cristais bipiramidais, cubóides e redondos. As estirpes selecionadas oferecem novas perspectivas de controle de P. xylostella.The aim of this work was to select and characterize the most toxic Bacillus thuringiensis strains, from the Germplasm Bank of Bacillus spp. of Empresa Brasileira de Pesquisa Agropecuária, against Plutella xylostella. Strains were characterized by morphological, biochemical and molecular methods. It was observed that seven out of the 203 strains tested showed high toxicity compared to the standard used B. thuringiensis subsp. kurstaki (HD-1, which showed 100% mortality. Selected strains showed features described for lepidoptera regarding the protein of 130 kDa and 65 kDa; profile and features were obtained through the PCR reactions, making possible to identify the presence of cry1 and cry2 genes. Moreover, the scanning electron microscopy showed the bipiramydal, cubed and round crystal forms. The selected strains offer new perspectives to control P. xylostella.

Microimaging of Bacillus thuringiensis Toxin-binding proteins in gypsy moth larval gut using confocal fluorescence microscopy

Science.gov (United States)

Daniel J. Krofcheck; Algimantas P. Valaitis

2010-01-01

After ingestion by susceptible insect larvae, Bacillus thuringiensis (Bt) insecticidal proteins bind to the brush border membranes of gut epithelial cells and disrupt the integrity of the plasma membrane by forming...

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

Directory of Open Access Journals (Sweden)

Jnnifer A. Sánchez

2014-05-01

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

Investigation of equilibrium and kinetics of Cr(VI) adsorption by dried Bacillus cereus using response surface methodology.

Science.gov (United States)

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.

Butanol production under microaerobic conditions with a symbiotic system of Clostridium acetobutylicum and Bacillus cereus.

Science.gov (United States)

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

A new formulation of Bacillus thuringiensis: UV protection and sustained release mosquito larvae studies

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Zhang, X.; Zhang, Y.; Wu, S.; Gelbič, Ivan; Xu, L.; Guan, X.

2016-01-01

Roč. 6, DEC 22 (2016), č. článku 39425. ISSN 2045-2322 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * pest control * UV protection Subject RIV: EE - Microbiology, Virology Impact factor: 4.259, year: 2016 http://www.nature.com/articles/srep39425

Response of the Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) to Bacillus thuringiensis var. san diego

Science.gov (United States)

Leah S. Bauer

1990-01-01

A standardized laboratory bioassay was used to quantify the lethal and sub-lethal responses of larval and adult cottonwood leaf beetles, Chrysomela scripta F., to Bacillus thuringiensis var. san diego, formulated as M-One standard powder (Mycogen Corporation, San Diego). The median lethal concentration (LC

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

NARCIS (Netherlands)

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

2010-01-01

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

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Activity of wild-type and hybrid Bacillus thuringiensis delta-endotoxins against Agrotis ipsilon

NARCIS (Netherlands)

Maagd, de R.A.; Weemen-Hendriks, M.; Molthoff, J.W.; Naimov, S.

2003-01-01

Twelve Cry1 and two Cry9 ?-endotoxins fromBacillus thuringiensis were tested for their activity against black cutworm (Agrotis ipsilon).A. ipsilon was not susceptible to many toxins, but three toxins had significant activity. Cry9Ca was the most toxic, followed by Cry1Aa and Cry1Fb. Hybrids between

The comER Gene Plays an Important Role in Biofilm Formation and Sporulation in both Bacillus subtilis and Bacillus cereus.

Science.gov (United States)

Yan, Fang; Yu, Yiyang; Wang, Luyao; Luo, Yuming; Guo, Jian-Hua; Chai, Yunrong

2016-01-01

Bacteria adopt alternative cell fates during development. In Bacillus subtilis, the transition from planktonic growth to biofilm formation and sporulation is controlled by a complex regulatory circuit, in which the most important event is activation of Spo0A, a transcription factor and a master regulator for genes involved in both biofilm formation and sporulation. In B. cereus, the regulatory pathway controlling biofilm formation and cell differentiation is much less clear. In this study, we show that a novel gene, comER, plays a significant role in biofilm formation as well as sporulation in both B. subtilis and B. cereus. Mutations in the comER gene result in defects in biofilm formation and a delay in spore formation in the two Bacillus species. Our evidence supports the idea that comER may be part of the regulatory circuit that controls Spo0A activation. comER likely acts upstream of sda, a gene encoding a small checkpoint protein for both sporulation and biofilm formation, by blocking the phosphor-relay and thereby Spo0A activation. In summary, our studies outlined a conserved, positive role for comER, a gene whose function was previously uncharacterized, in the regulation of biofilm formation and sporulation in the two Bacillus species.

The comER Gene Plays an Important Role in Biofilm Formation and Sporulation in both Bacillus subtilis and Bacillus cereus

Science.gov (United States)

Yan, Fang; Yu, Yiyang; Wang, Luyao; Luo, Yuming; Guo, Jian-hua; Chai, Yunrong

2016-01-01

Bacteria adopt alternative cell fates during development. In Bacillus subtilis, the transition from planktonic growth to biofilm formation and sporulation is controlled by a complex regulatory circuit, in which the most important event is activation of Spo0A, a transcription factor and a master regulator for genes involved in both biofilm formation and sporulation. In B. cereus, the regulatory pathway controlling biofilm formation and cell differentiation is much less clear. In this study, we show that a novel gene, comER, plays a significant role in biofilm formation as well as sporulation in both B. subtilis and B. cereus. Mutations in the comER gene result in defects in biofilm formation and a delay in spore formation in the two Bacillus species. Our evidence supports the idea that comER may be part of the regulatory circuit that controls Spo0A activation. comER likely acts upstream of sda, a gene encoding a small checkpoint protein for both sporulation and biofilm formation, by blocking the phosphor-relay and thereby Spo0A activation. In summary, our studies outlined a conserved, positive role for comER, a gene whose function was previously uncharacterized, in the regulation of biofilm formation and sporulation in the two Bacillus species. PMID:27446060

Bacillus cereus as indicator in the sterilization of residual water with high energy electrons; Bacillus cereus como indicador en la desinfeccion de aguas residuales con electrones de alta energia

Energy Technology Data Exchange (ETDEWEB)

Mejia Z, E

2000-07-01

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

A hospital cafeteria-related food-borne outbreak due to Bacillus cereus: unique features.

Science.gov (United States)

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.

EFEKTIVITAS Bacillus thuringiensis H-14 STRAIN LOKAL DALAM BUAH KELAPA TERHADAP LARVA Anopheles sp dan Culex sp di KAMPUNG LAUT KABUPATEN CILACAP

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Blondine Ch. P

2013-07-01

Full Text Available Abstrak Bacillus thuringiensis serotipe H-14 strain lokal adalah bakteri patogen bersifat target spesifiknya larva nyamuk, aman bagi mamalia dan lingkungan. Penelitian bertujuan menentukan efektivitas B. thuringiensis H-14 strain lokal yang dikembangbiakkan dalam buah kelapa untuk pengendalian larva Anopheles sp dan Culex sp. Rancangan eksperimental semu, terdiri dari kelompok perlakuan dan kontrol. Bacillus thuringiensis H-14 strain lokal dikembangbiakan dalam10 buah kelapa umur 6–8 bulan, dengan berat kira-kira 1 kg, telah berisi air kelapa sekitar 400-500 ml/buah kelapa yang diperoleh dari Desa Klaces, Kampung Laut, Kabupaten Cilacap. Diinkubasi selama 14 hari pada temperatur kamar dan ditebarkan di 6 kolam yang menjadi habitat perkembangbiakan larva nyamuk dengan luas berkisar 3–100 m2.Hasil yang diperoleh menunjukkan efektivitas B. thuringiensis H-14 strain lokal terhadap larva Anopheles sp dan Culex sp selama 1 hari sesudah penebaran kematian larva berturut-turut sebesar 80–100% dan 79,31–100%. Sedangkan pada hari ke-14 sebesar 69,30–76,71% dan 67,69–86,04%. Buah kelapa dapat digunakan sebagai media lokal alternatif untuk pengembangbiakan B. thuringiensis H-14 strain lokal Kata kunci: B. thuringiensis H-14,  strain  lokal, buah kelapa, pengendalian larva Abstract Bacillus thuringiensis serotype H-14 local strain is pathogenic bacteria which specific  target to mosquito larvae. It is safe for mammals and enviroment. The aims of this study was to determine the effectivity of B. thuringiensis H-14 local strain which culturing in thecoconut wates against Anopheles sp and Culex sp mosquito larvae. This research is quasi experiment which consist of treated  and control groups. Bacillus thuringiensis H-14 local strain was cultured in 10 coconuts with 6–8 months age with weight around 1 kg that contained were approximately 400-500 ml/coconut were taken from Klaces village, Kampung Laut. After that the coconuts incubated for 14

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

DEFF Research Database (Denmark)

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

2011-01-01

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

Probiotic actions of Bacillus cereus var. toyoi and Saccharomyces boulardii in silver catfish (Rhamdia quelen larvae culture

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Diego Moreira de Souza

2012-03-01

Full Text Available The objective of this study was to evaluate the use of Bacillus cereus var. toyoi and Saccharomyces boulardii as probiotics to improve Rhamdia quelen culture. Six hundred larvaes (0.16±0.07 g were divided in three replicate tanks (25-L recirculation, 20 ºC, photoperiod of 12 h light/12 h darkness per treatment and were randomly assigned to the following treatments: Bacillus cereus var. toyoi; Saccharomyces boulardii; B. toyoi and S. boulardii; and control (without probiotic addition for a period of 30 days. The fish were fed five times daily (56% crude protein - Supra alevino inicial® and the probiotics were applied in water once a day. The doses of probiotics were 5 × 10(8 and 2 × 10(9 CFU (colony forming unit/mL for B. cereus var. toyoi and S. boulardii, respectively. Both probiotics have an inhibitory effect in vitro against Vibrio carchariae and are able to grow in media prepared with fishery water; however, no effect was observed on growth parameters when they were administered to Rhamdia quelen larvae.

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

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Domenico Martinelli

2013-12-01

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

Isolation and Identification of Bacillus Species From Soil and Evaluation of Their Antibacterial Properties

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Amin

2015-02-01

Full Text Available Background Bacillus species are the predominant soil bacteria because of their resistant-endospore formation and production of essential antibiotics such as bacitracin. Objectives The aim of this study was to isolate Bacillus spp. from riverside soil and investigate their antimicrobial characteristics against some pathogenic bacteria. Materials and Methods Fifty soil samples were collected from different sites of Bahmanshir riverside in Abadan city, Iran, and analyzed for the presence of Bacillus species. The media used in this research were nutrient broth and agar. Bacillus species were identified by their phenotypic and biochemical characteristics. The antimicrobial effects of Bacillus extract against the target bacteria including Escherichia coli, Staphylococcus aureus, Salmonella typhi, Shigella dysenteriae and Corynebacterium diphtheriae were examined. Results The identified Bacillus species included B. cereus (86.6%, B. subtilis (6.6%, B. thuringiensis (3.3%, and B. pumilus (3.3%. Evaluation of the antimicrobial activity of the extracted compounds was carried out against five different bacteria. Antibiotic production tests indicated that two Bacillus strains belong to B. cereus, which showed antimicrobial properties. The minimum inhibitory concentrations (MICs of these compounds ranged between 8.34-33.34 mg/mL for the target bacteria. Conclusions This study indicated that some Bacillus species have the potential to produce antimicrobial compounds which can be used to control microbial infections.

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

NARCIS (Netherlands)

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

2007-01-01

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

Effect of inherited sterility and bacillus thuringiensis on mortality and reproduction of phthorimaea opercullela zeller (lepidoptera: gelechidae)

International Nuclear Information System (INIS)

Makee, H.; Tlas, M. D.; Amer, S.; Abdulla, J.

2008-01-01

The effect of a commercial formulation of Bacillus thuringiensis (Dipel 2X) upon F 1 progeny of irradiated and unirradiated phthorimaea operculella male parents was investigated. F 1 progeny of irradiated parents was more susceptible to B. thuringiensis than that of unirradiated parents. A combination of irradiation and B. thuringiensis led to higher mortality in F 1 progeny of P. operculella. The LC 50 was 0.406 g/100ml for F 1 progeny of unirradiated parents, but 0.199 g/100ml for those of irradiated parents. There was a great reduction in the pupal weight, fecundity and egg hatchability of F 1 progeny of irradiated patents compared to those unirradiated parents. Such reduction was increased by applying higher concentration of B. thuringiensis. A combination between inherited sterility technique and B. thuringiensis application could give a good controlling result against P. operculella. (author)

Interactions between Bacillus thuringiensis and parasitoids of late-instar larvae of the spruce budworm (Lepidoptera: Tortricidae)

NARCIS (Netherlands)

Schoenmaker, A.; Cusson, M.; Frankenhuyzen, van K.

2001-01-01

We investigated interactions between Bacillus thuringiensis Berliner var. kurstaki and parasitoids that attack late instars of the eastern spruce budworm, Choristoneura fumiferana (Clemens). In a petri-dish arena, females of Tranosema rostrale rostrale (Brishke) (Hymenoptera: Ichneumonidae) were

Avaliação de produtos à base de Bacillus thuringiensis no controle da traça-das-crucíferas Evaluation of insecticides based on Bacillus thuringiensis in the control of the diamondback moth

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Patrícia T Medeiros

2006-06-01

Full Text Available Avaliou-se em dois experimentos a suscetibilidade da traça-das-crucíferas a inseticidas à base de Bacillus thuringiensis em repolho cv. Itiban. O delineamento do primeiro experimento (de julho a setembro/03, em área de plantio comercial em Brazlândia (DF, foi de blocos casualizados, com seis tratamentos e dez repetições; os bioinseticidas utilizados foram B. thuringiensis kurstaki (S1450CO, B. thuringiensis aizawai comercial (Bta e três produtos formulados com as estirpes S1450BB, S811BB, S845BB de B. thuringiensis pertencentes ao Banco de Bacillus spp. da Embrapa Recursos Genéticos e Biotecnologia. No segundo experimento, realizado no campo experimental da Embrapa (DF, de outubro/03 a janeiro/04, o delineamento foi de blocos casualizados, com seis tratamentos e quatro repetições; os inseticidas utilizados foram os mesmos do primeiro experimento, com a adição de Spinosad, e retirado o tratamento S811BB. Os produtos foram aplicados quando foi atingido o nível de dano de seis furos nas quatro folhas centrais do repolho. O Bta comercial foi o produto mais eficaz no primeiro experimento, tendo sido aplicado cinco vezes e diferiu estaticamente dos demais produtos. Os formulados S845BB e S1450BB não apresentaram diferenças quando comparados ao produto comercial S1450 e foram aplicados seis vezes. O produto S811BB também foi aplicado seis vezes, mas sua eficácia foi inferior aos demais produtos e não diferiu da testemunha. Já no segundo experimento, o S1450 comercial foi aplicado cinco vezes e os demais produtos à base de Bt, seis vezes. Todos os produtos utilizados não diferiram entre si, diferindo apenas no número de aplicações.Two experiments were performed to evaluate the susceptibility of the diamondback moth to insecticides based on Bacillus thuringiensis in cabbage cv. Itiban. The first experiment was carried out from July to September 2003, in a production area in Brazlândia (DF, Brazil. Randomized blocks with six

Effect of chemical additives on Bacillus thuringiensis (Bacillales: Bacillaceae) against Plutella xylostella (Lepidoptera: Pyralidae)

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Qiu, S.; Huang, T.; Huang, Z.; Xu, L.; Wu, C.; Gelbič, Ivan; Guan, X.

2013-01-01

Roč. 106, č. 3 (2013), s. 1075-1080 ISSN 0022-0493 Institutional research plan: CEZ:AV0Z50070508 Keywords : additives * Bacillus thuringiensis * biocontrol Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.605, year: 2013 http://www.bioone.org/doi/pdf/10.1603/EC12288

Use of spent mushroom substrate for production of Bacillus thuringiensis by solid-state fermentation

Czech Academy of Sciences Publication Activity Database

Wu, S.; Lan, Y.; Huang, D.; Peng, Y.; Huang, Z.; Xu, L.; Gelbič, Ivan; Carballar-Lejarazu, R.; Guan, X.; Zhang, L.; Zou, S.

2014-01-01

Roč. 107, č. 1 (2014), s. 137-143 ISSN 0022-0493 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * spent mushroom substrate * solid-state fermentation Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.506, year: 2014 http://www.bioone.org/doi/pdf/10.1603/EC13276

Produccion por tecnologia de fermentacion de bacillus thuringiensis utilizando medios alternativos

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Yaneth Amparo Muñoz-Peñalosa

2000-01-01

Full Text Available In the production by fermentation technology Bacillus thuringiensis of five alternative methods they were studied. The results of cell growth, working-level 100ml in static culture and temperature of 28 ° C, mostraronque the optimal substrate corresponded to the environment in which molasses and rice powder was added (alternative Medium No. 1] The cell development using 100 ml of substrate was studied with reciprocating shaking 110 rpm. in this test was determined filter curve creciemiento medio.The inoculum, allowed tiempode set the process in 6 hours. For the development of fermentations, are counted with the experimental equipment, glass bioreactor in two liters of capacity and aeration devices, mechanical stirring, sampling and output gases.The fermentation in the production of Bacillus thuringiensis is the type discontinuous submerged aerobic process and growth into account .Teniendo bibliographic information and preliminary results of the study, fixed working parameters were determined for production by fermentation of Bacillus thuringiensis, being alternative means No. 1, volume 1 liter temperature 28 ° C and cell concentration of the inoculum. To determine the optimum parameters of fermantacion was used a factorial design of experiments of the type 22, (two variables at two levels, with aeration (3.2-0.5 VVM and agitation (110-210 rpm .The fermentations performed 7, 4 design and 3 the average level of the variables. For monitoring fermentation sample was taken every 12 hours and cell concentration (Chamber of Neuvauer and pH was analyzed. The results of cell concentration measurement for fermentations at 60 hours shows that optimum working conditions and limitations correspond to the values ​​of the variable, 3.2 VVM aeration and agitation 210 Variable rpm.Significant was the aeration of pH in the fermentation media change neutral to acid and ended as a staple. A fermentations I were efectuo controlde microbiological quality, Gram

Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium.

Science.gov (United States)

Ben Khedher, Saoussen; Jaoua, Samir; Zouari, Nabil

2013-01-01

In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L(-1) starch, 30 g L(-1) soya bean and 9 g L(-1) sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch) when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch). Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view.

Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium

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Saoussen Ben Khedher

2013-09-01

Full Text Available In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L-1 starch, 30 g L-1 soya bean and 9g L-1 sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch. Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view.

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

NARCIS (Netherlands)

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

2010-01-01

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

Screening of antibacterial and antifungal activities in green and ...

African Journals Online (AJOL)

... bacteria: Bacillus cereus, Bacillus thuringiensis, Bacillus subtillus, Clostridium sporogenes, Staphylococcus aureus, Mycobacterium smegmatis, Streptococcus faecalis and Bacillus sp, two Gram-negative bacteria: Escherichia coli and Pseudomonas sp and against fungi: Candida tropicalis and Cryptococcus neoformans.

Characterization and selection of Bacillus thuringiensis isolates effective against Sitophilus oryzae Caracterização e seleção de isolados de Bacillus thuringiensis efetivos contra Sitophilus oryzae

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Najara da Silva

2010-08-01

Full Text Available The entomopathogenic bacterium Bacillus thuringiensis is a control agent with toxic and environmental characteristics that allows the control of pest insects according to the Integrate Pest Management (IPM precepts. In order to find new strains, potentially toxic to Sitophilus oryzae L. 1763 (Coleoptera: Curculinidae, 1.073 strains of B. thuringiensis from parts of Brazil were used. Genetic material was extracted with InstaGene Matrix kit, used for the amplification of sequences in Polymerase chain reaction (PCR, and viewed in 1.5% agarose gel. The gene cry35Ba class was represented by 60 B. thuringiensis isolates (5.6%, which were then subjected to bioassays with S. oryzae larvae. Among the isolates studied, four caused more than 50% mortality in pathogenicity tests, and the isolates 544 and 622 were the most virulent, as determined by CL50 estimates. The four toxic isolates had spherical, bi-pyramidal and cuboid crystals, and a 44-kDa protein was found in sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE, which coded for the product of cry35Ba genes. These data demonstrate the potential of B. thuringiensis for the management of S. oryzae larvae.A bactéria entomopatogênica Bacillus thuringiensis (Bt é um agente de controle com características tóxicas e ambientais que permitem o controle de insetos-praga de acordo com as premissas do Manejo integrado de pragas (MIP. Com o objetivo de buscar novas linhagens potencialmente tóxicas para Sitophilus oryzae L. 1763 (Coleoptera: Curculinidae, caracterizaram-se molecularmente 1,073 isolados de B. thuringiensis de regiões do Brasil. O material genético foi extraído através do kit InstaGene Matrix, utilizado para a amplificação das seqüências através da técnica de Polymerase chain reaction PCR, sendo os resultados visualizados em gel de agarose 1,5%. A classe do gene cry35Ba foi representada por 60 isolados (5,6% de Bt, os quais foram submetidos a bioensaio com larvas

To Determine the Frequency of Bacillus cereus in Powdered Milk Infant Formula Consuming in Neonatal Intensive Care Unit (NICU in Tehran Hospitals in 2013-14

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Mohammad Mehdi Soltan Dallal

2017-01-01

Full Text Available Background: In recent years, changing the infant feeding methods and the growing trend of use powdered infant formula (PIF has raised concern about quality and health assessment among them. These products are contaminated with various pathogenic bacteria such as Bacillus cereus which the presence of this bacteria in PIF is important because of consumer age group and virulence of this bacteria in PIF. The aim of this study was to determine the frequency of Bacillus cereus in powdered milk infant formula consuming in neonatal intensive care unit (NICU in Tehran hospitals in 2013-14. Material and Methods: In this cross-sectional study, 125 samples of powdered infant formula milk which were used in Neonatal Intensive Care Unit (NICU were surveyed during 8 month in 2014. Isolation and identification of microorganisms (including Bacillus cereus were carried out according to FDA standard protocol (FDA method on B. cereus selective agar (MYP Agar.   Results: The results of present study showed that of 125 samples from of consumable powdered infant formula milk, 84 (67.2% samples were contaminated with B.cereus and also 18 (14.4% samples were contaminated by more than one B.cereus species. Conclusion: As regards pasteurization process is not effective on the spore of B.cereus., The spores of these bacteria can remain in PIF and can cause food poisoning in infants. For this purpose, more attention to quality control of production units and imported powder milk is recommended in Iranian infant foods.

Smallpox and pan-Orthodox Virus Detection by Real-Time 3’-Minor Groove Binder TaqMan Assays Oil the Roche LightCycler and the Cepheid Smart Cycler Platforms

Science.gov (United States)

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:

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

Science.gov (United States)

Luksiene, Z; Buchovec, I; Paskeviciute, E

2010-11-01

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

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

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Balayogan Sivasankari

2014-01-01

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

RAP-PCR fingerprinting reveals time-dependent expression of development-related genes following differentiation process of Bacillus thuringiensis

Czech Academy of Sciences Publication Activity Database

Huang, T.; Yu, X.; Gelbič, Ivan; Guan, X.

2015-01-01

Roč. 61, č. 9 (2015), s. 683-690 ISSN 0008-4166 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * development * RNA arbitrarily primed PCR Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.335, year: 2015

40 CFR 180.1011 - Viable spores of the microorganism Bacillus thuringiensis Berliner; exemption from the...

Science.gov (United States)

2010-07-01

... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1011 Viable spores of the... characteristics of the parent strain or contamination by other microorganisms. (3) Each lot of spore preparation... production is a Bacillus thuringiensis strain which does not produce β-exotoxin under standard manufacturing...

Chemical modulators of the innate immune response alter gypsy moth larval susceptibility to Bacillus thuringiensis

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Broderick Nichole A

2010-04-01

Full Text Available Abstract Background The gut comprises an essential barrier that protects both invertebrate and vertebrate animals from invasion by microorganisms. Disruption of the balanced relationship between indigenous gut microbiota and their host can result in gut bacteria eliciting host responses similar to those caused by invasive pathogens. For example, ingestion of Bacillus thuringiensis by larvae of some species of susceptible Lepidoptera can result in normally benign enteric bacteria exerting pathogenic effects. Results We explored the potential role of the insect immune response in mortality caused by B. thuringiensis in conjunction with gut bacteria. Two lines of evidence support such a role. First, ingestion of B. thuringiensis by gypsy moth larvae led to the depletion of their hemocytes. Second, pharmacological agents that are known to modulate innate immune responses of invertebrates and vertebrates altered larval mortality induced by B. thuringiensis. Specifically, Gram-negative peptidoglycan pre-treated with lysozyme accelerated B. thuringiensis-induced killing of larvae previously made less susceptible due to treatment with antibiotics. Conversely, several inhibitors of the innate immune response (eicosanoid inhibitors and antioxidants increased the host's survival time following ingestion of B. thuringiensis. Conclusions This study demonstrates that B. thuringiensis infection provokes changes in the cellular immune response of gypsy moth larvae. The effects of chemicals known to modulate the innate immune response of many invertebrates and vertebrates, including Lepidoptera, also indicate a role of this response in B. thuringiensis killing. Interactions among B. thuringiensis toxin, enteric bacteria, and aspects of the gypsy moth immune response may provide a novel model to decipher mechanisms of sepsis associated with bacteria of gut origin.

U.v.-induced and N-methyl-N'-nitrosoguanidine-induced mutagenesis in Bacillus thuringiensis

International Nuclear Information System (INIS)

Auffray, Y.; Boutibonnes, P.

1987-01-01

The lethal and mutagenic effects of u.v. light and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on Bacillus thuringiensis were investigated. Lethality studies demonstrated that B. thuringiensis was relatively sensitive to these agents. This bacterium was mutated at the rifampicin resistance marker by u.v. light and to a lesser extent by the direct acting alkylating agent MNNG. One mutant selected for its greater sensitivity to u.v. light expressed a higher frequency of mutagenesis after u.v. light treatment and appeared to be defective in an excision repair pathway. However, this mutant was only slightly mutable by MNNG in comparison with the wild-type strain. This unusual phenotype does not yet have a parallel among the radiation sensitive mutants described in other bacterial species. (author)

Bacillus thuringiensis Cry3Aa toxin increases the susceptibility of Crioceris quatuordecimpunctata to Beauveria bassiana infection

Science.gov (United States)

The spotted asparagus beetle, Crioceris quatuordecimpunctata (Coleoptera: Chrysomelidae), is one of the most devastating pests of asparagus in China and elsewhere. In this study, we investigated the interaction of Bacillus thuringiensis (Bt) Cry3Aa toxin and the entomopathogenic fungus Beauveria bas...

Purification and characterization of the bacteriocin Thuricin Bn1 produced by Bacillus thuringiensis subsp. kurstaki Bn1 isolated from a hazelnut pest.

Science.gov (United States)

Ugras, Serpil; Sezen, Kazim; Kati, Hatice; Demirbag, Zihni

2013-02-01

A novel bioactive molecule produced by Bacillus thuringiensis subsp. kurstaki Bn1 (Bt-Bn1), isolated from a common pest of hazelnut, Balaninus nucum L. (Coleoptera: Curculionidae), was determined, purified, and characterized in this study. The Bt-Bn1 strain was investigated for antibacterial activity with an agar spot assay and well diffusion assay against B. cereus, B. weinhenstephenensis, L. monocytogenes, P. savastanoi, P. syringae, P. lemoignei, and many other B. thuringiensis strains. The production of bioactive molecule was determined at the early logarithmic phase in the growth cycle of strain Bt-Bn1 and its production continued until the beginning of the stationary phase. The mode of action of this molecule displayed bacteriocidal or bacteriolytic effect depending on the concentration. The bioactive molecule was purified 78-fold from the bacteria supernatant with ammonium sulfate precipitation, dialysis, ultrafiltration, gel filtration chromatography, and HPLC, respectively. The molecular mass of this molecule was estimated via SDS-PAGE and confirmed by the ESI-TOFMS as 3,139 Da. The bioactive molecule was also determined to be a heat-stable, pH-stable (range 6-8), and proteinase K sensitive antibacterial peptide, similar to bacteriocins. Based on all characteristics determined in this study, the purified bacteriocin was named as thuricin Bn1 because of the similarities to the previously identified thuricin-like bacteriocin produced by the various B. thuringiensis strains. Plasmid elution studies showed that gene responsible for the production of thuricin Bn1 is located on the chromosome of Bt-Bn1. Therefore, it is a novel bacteriocin and the first recorded one produced by an insect originated bacterium. It has potential usage for the control of many different pathogenic and spoilage bacteria in the food industry, agriculture, and various other areas.

Recent research progress with phospholipase C from Bacillus cereus.

Science.gov (United States)

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.

Selection of optimum conditions of medium acidity and aeration for submerget cultivation of Bacillus thuringiensis and Beauveria bassiana

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O. A. Dregval

2010-06-01

Full Text Available The paper deals with the influence of medium pH and aeration rate on growth and sporulation of Bacillus thuringiensis and Вeauveria bassiana, which are main constituents of the complex microbial insecticide. It was established optimal medium pH for B. thuringiensis – 6.0 and for В. bassiana – 6.0–7.0. The maximum productivity of the studied microorganisms was observed in the same range of aeration – 7– 14 mmol O2/l/h. The selected conditions of cultivation are necessary for the production of complex biological insecticide based on the association of B. thuringiensis and B. bassiana.

Bacillus anthracis: una mirada molecular a un patógeno célebre Bacillus anthracis: a molecular look at a famous pathogen

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María E Pavan

2011-12-01

Full Text Available Bacillus anthracis es un bacilo gram positivo del grupo Bacillus cereus, que posee un genoma extremadamente monomórfco y comparte gran similitud fsiológica y de estructura genética con B. cereus y Bacillus thuringiensis. En este artículo se describen nuevos métodos moleculares para la identifcación y tipifcación de B. anthracis, basados en repeticiones en tándem de número variable o en diferencias genéticas detectadas por secuenciación, desarrollados en los últimos años. Los aspectos moleculares de los factores de virulencia tradicionales, cápsula, antígeno protector, factor letal y factor edema se describen en profundidad, junto con factores de virulencia recientemente propuestos, como los sideróforos, petrobactina y bacilibactina, la adhesina de la capa S y la lipoproteína MntA. También se detalla la organización molecular de los megaplásmidos pXO1 y pXO2, incluyendo la isla de patogenicidad de pXO1. El esqueleto genético de estos plásmidos se ha encontrado en otras especies relacionadas, probablemente debido a eventos de transferencia lateral. Finalmente, se presentan los dos receptores celulares del antígeno protector, ANTXR1/TEM8 y ANTXR2/CMG2, esenciales en la interacción del patógeno con el hospedador. Los estudios moleculares realizados en los últimos años han permitido aumentar enormemente el conocimiento de los diferentes aspectos de este microorganismo y su relación con el hospedador, pero a la vez han abierto nuevos interrogantes sobre este notorio patógeno.Bacillus anthracis, a gram-positive rod belonging to the Bacillus cereus group, has an extremely monomorphic genome, and presents high structural and physiological similarity with B. cereus and Bacillus thuringiensis. In this work, the new molecular methods for the identifcation and typing of B. anthracis developed in the last years, based on variable number tandem repeats or on genetic differences detected through sequencing, are described. The

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

Science.gov (United States)

Arslan, Seza; Eyi, Ayla; Küçüksarı, Rümeysa

2014-02-01

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

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

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Vikram Surendra

2010-07-01

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

Potato expressing beetle-specific Bacillus thuringiensis Cry3Aa toxin reduces performance of a moth

Czech Academy of Sciences Publication Activity Database

Hussein, H. M.; Habuštová, Oxana; Turanli, Ferit; Sehnal, František

2006-01-01

Roč. 32, č. 1 (2006), s. 1-13 ISSN 0098-0331 R&D Projects: GA ČR(CZ) GA522/02/1507 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis * Spodoptera littoralis * Leptinotarsa decemlineata Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.896, year: 2006

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

Science.gov (United States)

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

2014-02-01

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

Effects of nisin and temperature on survival, growth, and enterotoxin production characteristics of psychrotrophic Bacillus cereus in beef gravy.

OpenAIRE

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...

Termitarium-inhabiting Bacillus endophyticus TSH42 and Bacillus cereus TSH77 colonizing Curcuma longa L.: isolation, characterization, and evaluation of their biocontrol and plant-growth-promoting activities.

Science.gov (United States)

Chauhan, Ankit Kumar; Maheshwari, Dinesh Kumar; Kim, Kangmin; Bajpai, Vivek K

2016-10-01

Bacillus strains were isolated from termitarium soil and screened for their antifungal activity through the production of diffusible and volatile metabolites. Further, the bacterial strains that showed antifungal activity were evaluated for their biocontrol potential on the basis of their plant-growth-promoting attributes. Termitarium-inhabiting Bacillus strains TSH42 and TSH77 significantly reduced the growth of pathogenic fungus Fusarium solani, controlled the symptoms of rhizome rot in turmeric (Curcuma longa L.), and demonstrated various plant-growth-promoting traits in different in vitro assays. On the basis of morphological, physiological, biochemical, and 16S rDNA characteristics, isolates TSH42 and TSH77 were identified as Bacillus endophyticus (KT379993) and Bacillus cereus (KT379994), respectively. Through liquid chromatography - mass spectrometry analysis, acidified cell-free culture filtrate (CFCF) of B. cereus TSH77 was shown to contain surfactin and fengycin, while CFCF of B. endophyticus TSH42 contained iturin in addition to surfactin and fengycin. Treatment of the turmeric (C. longa L.) plants with TSH42 and TSH77 significantly reduced the percentage incidence of rhizome rot disease caused by F. solani. The same treatment also increased the fresh rhizome biomass and plant growth in greenhouse conditions.

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

NARCIS (Netherlands)

Voort, van der M.; Abee, T.

2013-01-01

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

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

International Nuclear Information System (INIS)

Mejia Z, E.

2000-01-01

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

Identification of the sigmaB regulon of Bacillus cereus and conservation of sigmaB-regulated genes in low-GC-content gram-positive bacteria

NARCIS (Netherlands)

Schaik, van W.; Voort, van der M.; Molenaar, D.; Moezelaar, R.; Vos, de W.M.; Abee, T.

2007-01-01

The alternative sigma factor B has an important role in the acquisition of stress resistance in many gram-positive bacteria, including the food-borne pathogen Bacillus cereus. Here, we describe the identification of the set of B-regulated genes in B. cereus by DNA microarray analysis of the

Arthromitus (Bacillus cereus) symbionts in the cockroach Blaberus giganteus: dietary influences on bacterial development and population density

Science.gov (United States)

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.

Survival of Bacillus thuringiensis strains in gypsy moth (Lymantria dispar) larvae is correlated with production of urease

Science.gov (United States)

Phyllis A.W. Martin; Robert R. Jr. Farrar; Michael B. Blackburn

2011-01-01

We tested 50 lepidopteran-toxic Bacillus thuringiensis Berliner (Bt) strains with diverse phenotypes for the ability to survive repeated passages through larvae of the gypsy moth, Lymantria dispar (L.), without intervening growth on artificial media. These experiments have revealed a remarkable correlation...

Isolation and characterization of a novel native Bacillus thuringiensis strain BRC-HZM2 capable of degrading chlorpyrifos

Czech Academy of Sciences Publication Activity Database

Wu, S.; Peng, Y.; Huang, Z.; Huang, Z.; Xu, L.; Gelbič, Ivan; Guan, X.; Zhang, L.; Zou, S.

2015-01-01

Roč. 55, č. 3 (2015), s. 389-397 ISSN 0233-111X Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * biopesticide * biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 1.585, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/jobm.201300501/epdf

Bacillus thuringiensis Cry1Ca-resistant Spodoptera exigua lacks expression of one of four Aminopeptidase N genes

NARCIS (Netherlands)

Herrero, S.; Gechev, T.; Bakker, P.L.; Moar, W.; Maagd, de R.A.

2005-01-01

BACKGROUND: Insecticidal toxins from Bacillus thuringiensis bind to receptors on midgut epithelial cells of susceptible insect larvae. Aminopeptidases N (APNs) from several insect species have been shown to be putative receptors for these toxins. Here we report the cloning and expression analysis of

Characterization of cry1Cb3 and cry1Fb7 from Bacillus thuringiensis subsp. galleriae

Czech Academy of Sciences Publication Activity Database

Huang, T.; Xiao, Y.; Pan, J.; Zhang, L.; Gelbič, Ivan; Guan, X.

2015-01-01

Roč. 10, č. 1 (2015), s. 521-528 ISSN 2391-5412 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis subsp. galleriae * PCR-RFLP * cloning Subject RIV: EB - Genetics ; Molecular Biology http://www.degruyter.com/view/j/biol.2015.10.issue-1/biol-2015-0054/biol-2015-0054.xml

Prevalence, virulence factor genes and antibiotic resistance of Bacillus cereus sensu lato isolated from dairy farms and traditional dairy products

DEFF Research Database (Denmark)

Owusu-Kwarteng, James; Wuni, Alhassan; Akabanda, Fortune

2017-01-01

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......%), oxacillin (92%), penicillin (100%), amoxicillin (100%), and cefepime (100%) but susceptible to other antibiotics tested. Conclusions: Bacillus cereus s. l. is prevalent in soil, raw milk and dairy products in Ghana. However, loads are at levels considered to be safe for consumption. Various enterotoxin...

Application of solar treatment for the disinfection of geophagic clays ...

African Journals Online (AJOL)

... in most instances to the reduction of the number (up to 100% inactivation) of microorganisms although in few cases the same conditions have stimulated the growth of some dormant microorganisms including Bacillus subtilis, Paenibacillus, Bacillus cereus, Bacillus thuringiensis, Bacillus humi and Arthrobacterarilaitensis.

Activity of a Brazilian strain of Bacillus thuringiensis israelensis against the cotton Boll Weevil Anthonomus grandis Boheman (Coleoptera: Tenebrionidae).

Science.gov (United States)

Monnerat, R; Martins, E; Praça, L; Dumas, V; Berry, C

2012-02-01

A Brazilian Bacillus thuringiensis subspecies israelensis, toxic to Diptera, including mosquitoes, was found also to show toxicity to the coleopteran boll weevil Anthonomus grandis Boheman at an equivalent level to that of the standard coleopteran-active B. thuringiensis subspecies tenebrionis T08017. Recombinant B. thuringiensis strains expressing the individual Cyt1Aa, Cry4Aa, Cry4Ba and Cry11Aa toxins from this strain were assessed to evaluate their potential contribution to the activity against A. grandis, either alone or in combination. Whilst individual toxins produced mortality, none was sufficiently potent to allow calculation of LC50 values. Combinations of toxins were unable to attain the same potency as the parental B. thuringiensis subsp. israelensis, suggesting a major role for other factors produced by this strain.

Expresión de la toxina Cry11Aa de Bacillus thuringiensis serovar. israelensis en Asticcacaulis excentricus, para el control de larvas acuáticas de dípteros de la familia Culicidae, vectores de enfermedades Expression of Bacillus thuringiensis serovar. israelensis toxins in Asticcacaulis excentricus to control dipteran larvae of vectors of diseases

Directory of Open Access Journals (Sweden)

Orduz Sergio

2004-07-01

Full Text Available Los genes cry de Bacillus thuringiensis codifican para un diverso grupo de proteínas formadoras de cristales que exhiben actividad insecticida contra larvas de dípteros, lepidópteros y coleópteros, entre otros. La efectividad de los insecticidas basados en formulaciones de proteínas de B. thuringiensis puede ser mejorada usando bacterias prostecadas acuáticas como portadoras alternativas de los genes cry, ya que no se sedimentan rápidamente; las proteínas expresadas en el citoplasma están protegidas de los rayos ultra violeta y, lo más importante, las larvas de los mosquitos se alimentan de ellas. Una cepa de referencia de Asticcacaulis excentricus fue transformada con el plásmido pSOD3, el cual contiene el gen que codifica para la proteína Cry1 1 Aa de B. thuringiensis serovar. israelensis. La expresión de la proteína recombinante fue evaluada por electroforesis de proteínas y por Western blot. El Western blot revelado con un anticuerpo policlonal anti-Cry1 1 Aa mostró una banda de 72 kDa correspondiente a la proteína Cry 11 Aa. La toxicidad de las cepas de A. excentricus transformadas fue evaluada en bioensayos con larvas de primer estadío del mosquito Culex quinquefasciatus. Se alcanzó un promedio de mortalidad del 50% de las larvas de primer instar a concentraciones de 23 ng/mL de la toxina. Otros bioensayos indican que A. excentricus recombinante es tóxica para larvas de primer instar de las especies Aedes aegypti y Anopheles albimanus. Los ensayos de flotabilidad indican que A. excentricus no sedimenta hasta pasados 7 días, mientras que B. thuringiensis serovar. israelensis sedimenta al cabo de algunas horas. Palabras clave: Asticcacaulis excentricus, Bacillus thuringiensis, bacterias prostecadas, dengue, malaria.Bacillus thuringiensis cry genes encode for a diverse group of crystal-forming proteins that exhibit insecticidal activity towards dipteran, lepidopteran and coleopteran larvae. The effectiveness of

Isolation and characterization of a novel analyte from Bacillus subtilis SC-8 antagonistic to Bacillus cereus.

Science.gov (United States)

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.

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

Science.gov (United States)

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

2017-07-28

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

Diversity of Bacillus thuringiensis strains in the maize and bean phylloplane and their respective soils in Colombia.

Science.gov (United States)

Jara, S; Maduell, P; Orduz, S

2006-07-01

To evaluate the distribution of Bacillus thuringiensis strains from maize and bean phylloplane and their respective soils. B. thuringiensis was isolated from the phylloplane and soil of maize and bean from three municipalities in Antioquia, Colombia. Ninety six samples of phylloplane and 24 of soil were analyzed. A total of 214 isolates were obtained from 96 phylloplane samples while 59 isolates were recovered from 24 soil samples. Sixty five per cent and 12% of the phylloplane and soil isolates, respectively, showed activity against Spodoptera frugiperda. These isolates contained delta-endotoxin proteins of 57 and 130 kDa. The most toxic isolates against S. frugiperda had the genotype cry1Aa, cry1Ac, cry1B, and cry1D. In contrast, 27% of the phylloplane isolates and 88% of the soil isolates were active against Culex quinquefasciatus and had protein profiles similar to B. thuringiensis serovar. medellin and B. thuringiensis serovar. israelensis. The most active isolates contain cry4 and cry11 genes. The predominant population of B. thuringiensis on the phylloplane harbored the cry1 gene and was active against S. frugiperda, whereas in soil, isolates harboring cry11 gene and active against C. quinquefasciatus were the majority. The predominance of specific B. thuringiensis populations, both on the leaves and in the soil, suggests the presence of selection in B. thuringiensis populations on the studied environment.

Effect of Bacillus thuringiensis parasporal toxin on stimulating of IL-2 and IL-5 cytokines production

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Marzieh Soleimany

2018-03-01

Full Text Available Introduction:Bacillus thuringiensis, is a Gram-positive spore-forming bacterium that produces crystalline parasporal protein (Cry during sporulation. Some of these Cry toxins do not show cytotoxicity against insects but they are capable to kill some human and animal cancer cells. The aim of this study was to verify whether cytocidal parasporal of B thuringiensis strains have immunostimulatory activity on human peripheral blood mononuclear cells (PBMNC and to evaluate the ability of IL-2 and IL-5 production. Materials and methods: B. thuringiensis toxin with cytocidal activity was isolated and treated with proteinase K. PBMNC was cultured and treated with activated crystal proteins. We evaluated the ability of different cytokines production with Flow Cytometry. Results: In this study, immune stimulatory toxins Cry1 were distinguished. This toxin can stimulate production of cytokines IL-2 and stop production of IL-5. Discussion and conclusion: According to anti-cancer effect of B. thuringiensis toxins and also immune stimulatory effect, with more research these toxins can be introduced as immunotherapy drug in cancer treatment.

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

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Joaquín eCaro-Astorga

2015-01-01

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

Recovery of Bacillus thuringiensis and related spore-forming bacteria from soil after application for gypsy moth control

Science.gov (United States)

Phyllis A.W. Martin; Elizabeth A. Mongeon; Michael B. Blackburn; Dawn E. Gundersen-Rindal

2011-01-01

Bacillus thuringiensis Berliner (Bt) has been applied for gypsy moth (Lymantria dispar L.) control in forests in the northeastern U.S. for many years. The subspecies of Bt that is used (urstaki) is not common in U.S. soil. We attempted to recover Bt from...

The introduction of integrated pest management in the Ethiopian horticultural sector : Bacillus thuringiensis strains and its toxicity

NARCIS (Netherlands)

Belder, den E.; Elderson, J.

2012-01-01

1 Introduction As hazards of conventional broad acting pesticides are documented, researchers, poli cymakers and growers look for pesticides that are toxic only to the target pest, have no impact on other such as beneficial species, and have fewer environmental effects. Bacillus thuringiensis (Bt)

Destruction of Bacillus cereus spores in a thick soy bean paste (doenjang) by continuous ohmic heating with five sequential electrodes.

Science.gov (United States)

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 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.

Activity of Bacillus thuringiensis D(delta)-endotoxins against codling moth (Cydia pomonella L.) larvae

NARCIS (Netherlands)

Boncheva, R.; Dukiandjiev, S.; Minkov, I.; Maagd, de R.A.; Naimov, S.

2006-01-01

Solubilized protoxins of nine Cry1 and one hybrid Cry1 ¿-endotoxin from Bacillus thuringiensis were tested for their activity against larvae of the codling moth (Cydia pomonella L). Cry1Da was the most toxic, followed by Cry1Ab, Cry1Ba, and Cry1Ac, while Cry1Aa, Cry1Fa, Cry1Ia, and SN19 were still

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

NARCIS (Netherlands)

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

2005-01-01

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

A probability model for enterotoxin production of Bacillus cereus as a function of pH and temperature

Science.gov (United States)

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...

Isolation and molecular characterization of Bacillus thuringiensis found in soils of the Cerrado region of Brazil, and their toxicity to Aedes aegypti larvae

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Katiane dos Santos Lobo

Full Text Available ABSTRACT This study investigated the potential of Bacillus thuringiensis isolates obtained in the Cerrado region of the Brazilian state of Maranhão for the biological control of Aedes aegypti larvae. The isolates were obtained from soil samples and the identification of the B. thuringiensis colonies was based on morphological characteristics. Bioassays were run to assess the pathogenicity and toxicity of the different strains of the B. thuringiensis against third-instar larvae of A. aegypti. Protein profiles were obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Polymerase chain reaction assays were used to detect the toxin genes found in the bacterial isolates. Overall, 12 (4.0% of the 300 isolates obtained from 45 soil samples were found to present larvicidal activity, with the BtMA-104, BtMA-401 and BtMA-560 isolates causing 100% of mortality. The BtMA-401 isolate was the most virulent, with the lowest median lethal concentration (LC50 (0.004 × 107 spores/mL, followed by the Bacillus thuringiensis var. israelensis standard (0.32 × 107 spores/mL. The protein profiles of BtMA-25 and BtMA-401 isolates indicated the presence of molecular mass consistent with the presence of the proteins Cry4Aa, Cry11Aa and Cyt1, similar to the profile of Bacillus thuringiensis var. israelensis IPS-82. Surprisingly, however, none of the cry and cyt genes analyzed were amplified in the isolate BtMA-401. The results of the present study revealed the larvicidal potential of B. thuringiensis isolates found in the soils of the Cerrado region from Maranhão, although further research will be necessary to better elucidate and describe other genes associated with the production of insecticidal toxins in these isolates.

Bacillus thuringiensis delta-endotoxin Cry1 hybrid proteins with increased activity against the Colorado potato beetle

NARCIS (Netherlands)

Naimov, S.; Weemen-Hendriks, M.; Dukiandjiev, S.; Maagd, de R.A.

2001-01-01

Cry1 delta-endotoxins of Bacillus thuringiensis are generally active against lepidopteran insects, but Cry1Ba and Cry1Ia have additional, though low, levels of activity against coleopterans such as the Colorado potato beetle. Here we report the construction of Cry1Ba/Cry1Ia hybrid toxins which have

Characterization of eight Bacillus thuringiensis isolates originated from fecal samples of Fuzhou Zoo and Fuzhou Panda Center

Czech Academy of Sciences Publication Activity Database

Wu, Ch.; Wu, L.; Zhang, L.; Gelbič, Ivan; Xu, L.; Guan, X.

2014-01-01

Roč. 17, č. 3 (2014), s. 395-397 ISSN 1226-8615 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * faeces * microscophy Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.946, year: 2014 http://www.sciencedirect.com/science/article/pii/S122686151400034X

Eficiência do Bacillus thuringiensis var. kurstaki (Berliner, 1915 no controle da traça da cera Galleria mellonella (Linnaeus, 1758 (Lepidoptera: Pyralidae Efficiency of Bacillus thuringiensis var. kurstaki (Berliner, 1915 for control of the greater wax moth Galleria mellonella (Linnaeus, 1758 (Lepidoptera: Pyralidae

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Deodoro Magno Brighenti

2005-02-01

Full Text Available Objetivou-se avaliar a eficiência do Bacillus thuringiensis var. kurstaki (Berliner no controle de Galleria mellonella (Linnaeus. Os experimentos foram realizados no Laboratório de Biologia de Insetos do Departamento de Entomologia da Universidade Federal de Lavras - UFLA, Lavras, MG, a 28±2ºC, UR 70±10% e fotofase de 12 horas. Aplicou-se formulação comercial de B. thuringiensis var. kurstaki por meio de pulverização, imersão dos favos e também foi incorporada à dieta artificial fornecida às lagartas de terceiro ínstar da traça da cera. A aplicação do produto fitossanitário por meio da pulverização dos favos mostrou-se eficiente no controle de lagartas, atingindo níveis iguais ou superiores a 85% de mortalidade quando foram utilizados 5 g/100 mL de água. Na aplicação por imersão dos favos, todas as dosagens testadas foram eficientes atingindo até 100% de mortalidade. Adicionada à dieta artificial, a concentração com maior porcentagem de mortalidade foi de 10g/60g de dieta. Sintomas de infecção pelo B. thuringiensis foram identificados nas lagartas e o isolamento da bactéria, por meio de uma cultura de Bacillus, comprovou a causa da morte desses insetos em todas as dosagens da formulação comercial do B. thuringiensis var. kurstaki utilizadas.This research aim at evaluating the efficiency of Bacillus thruringiensis var. kurstaki (Berliner in the control of Galleria mellonella (Linnaeus.The experiments were conducted in the Insect Biology Laboratory of the Entomology Department of the Universidade Federal de Lavras - UFLA, Lavras, MG, Brazil, at 28±2ºC, RH 70±10% and 12-hour photophase. Commercial formulation of B. thuringiensis. var. kurstaki was applied through spraying, comb soaking and also incorporated into the artificial diet fed to third instar caterpillars of the greater wax moth. Application of B. thuringiensis var. kurstaki through the spraying of the combs was efficient for control, reaching levels

Characteristics of a broad lytic spectrum endolysin from phage BtCS33 of Bacillus thuringiensis

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Yuan Yihui

2012-12-01

Full Text Available Abstract Background Endolysins produced by bacteriophages lyse bacteria, and are thus considered a novel type of antimicrobial agent. Several endolysins from Bacillus phages or prophages have previously been characterized and used to target Bacillus strains that cause disease in animals and humans. B. thuringiensis phage BtCS33 is a Siphoviridae family phage and its genome has been sequenced and analyzed. In the BtCS33 genome, orf18 was found to encode an endolysin protein (PlyBt33. Results Bioinformatic analyses showed that endolysin PlyBt33 was composed of two functional domains, the N-terminal catalytic domain and the C-terminal cell wall binding domain. In this study, the entire endolysin PlyBt33, and both the N- and C-termini,were expressed in Escherichia coli and then purified. The lytic activities of PlyBt33 and its N-terminus were tested on bacteria. Both regions exhibited lytic activity, although PlyBt33 showed a higher lytic activity than the N-terminus. PlyBt33 exhibited activity against all Bacillus strains tested from five different species, but was not active against Gram-negative bacteria. Optimal conditions for PlyBt33 reactivity were pH 9.0 and 50°C. PlyBt33 showed high thermostability, with 40% of initial activity remaining following 1 h of treatment at 60°C. The C-terminus of PlyBt33 bound to B. thuringiensis strain HD-73 and Bacillus subtilis strain 168. This cell wall binding domain might be novel, as its amino acid sequence showed little similarity to previously reported endolysins. Conclusions PlyBt33 showed potential as a novel antimicrobial agent at a relatively high temperature and had a broad lytic spectrum within the Bacillus genus. The C-terminus of PlyBt33 might be a novel kind of cell wall binding domain.

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

National Research Council Canada - National Science Library

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

2005-01-01

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

Effect of proteolytic and detoxification enzyme inhibitors on Bacillus thuringiensis var. israelensis tolerance in the mosquito Aedes aegypti

Czech Academy of Sciences Publication Activity Database

Hu, X.; Guo, Y.; Wu, S.; Liu, Z.; Fu, T.; Shao, E.; Carballar-Lejarazú, R.; Zhao, G.; Huang, Z.; Gelbič, Ivan; Guan, X.; Zou, S.; Xu, L.; Zhang, L.

2017-01-01

Roč. 27, č. 2 (2017), s. 169-179 ISSN 0958-3157 Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis * Bti * Aedes aegypti Subject RIV: ED - Physiology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 0.919, year: 2016

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

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Bojana Bogović Matijašić

2003-01-01

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

40 CFR 174.509 - Bacillus thuringiensis Cry3A protein; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry3A protein; exemption from the requirement of a tolerance. 174.509 Section 174.509 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance...

A simple identification method for spore-forming bacteria showing high resistance against γ-rays

International Nuclear Information System (INIS)

Koshikawa, Tomihiko; Sone, Koji; Kobayashi, Toshikazu

1993-01-01

A simple identification method was developed for spore-forming bacteria which are highly resistant against γ-rays. Among 23 species of Bacillus studied, the spores of Bacillus megaterium, B. cereus, B. thuringiensis, B. pumilus and B. aneurinolyticus showed high resistance against γ-rays as compared with other spores of Bacillus species. Combination of the seven kinds of biochemical tests, namely, the citrate utilization test, nitrate reduction test, starch hydrolysis test, Voges-Proskauer reaction test, gelatine hydrolysis test, mannitol utilization test and xylose utilization test showed a characteristic pattern for each species of Bacillus. The combination pattern of each the above tests with a few supplementary test, if necessary, was useful to identify Bacillus species showing high radiation resistance against γ-rays. The method is specific for B. megaterium, B. thuringiensis and B. pumilus, and highly selective for B. aneurinolyticus and B. cereus. (author)

Purification, Characterization, and Mode of Action of Plantaricin GZ1-27, a Novel Bacteriocin against Bacillus cereus.

Science.gov (United States)

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.

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

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Swarnalee Dutta

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

Susceptibilidade de larvas de Cerotoma arcuata Olivier (Coleoptera: Chrysomelidae a Beauveria bassiana (Bals. Vuillemin, Metarhizium anisopliae (Metsch. Sorokin e Bacillus thuringiensis Berliner Susceptibility of Cerotoma arcuata Olivier (Coleoptera: Chrysomelidae larvae to Beauveria bassiana (Bals. Vuillemin, Metarhizium anisopliae (Metsch. Sorokin and Bacillus thuringiensis Berliner

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Maria Lucia França Teixeira

2007-02-01

Full Text Available Larvas de 2° instar de Cerotoma arcuata foram avaliadas em relação à susceptibilidade aos fungos entomopatogênicos Beauveria bassiana, Metarhizium anisopliae e a bactéria Bacillus thuringiensis com as toxinas Cry3. Os insetos adultos foram mantidos em gaiolas e alimentados com plântulas de feijão (Phaseolus vulgaris L. e as larvas em "gerbox" com cotilédones de plântulas de feijão recém-germinadas. Das oito estirpes de B. bassiana avaliadas, CG 156 e CG 213 causaram 100% de mortalidade das larvas, as duas estirpes de M. anisopliae CG 210 e CG 321 foram patogênicas, eliminando 80 e 100% das larvas de C. arcuata, e, das cinco estirpes de B. thuringiensis testadas, o isolado CG 940 causou 70% de mortalidade das larvas.Second instar larvae of Cerotoma arcuata were evaluated concerning the susceptibility to fungi Beauveria bassiana and Metarhizium anisopliae and Bacillus thuringiensis strains containing Cry3 toxin. Adults of C. arcuata were kept in large cages and fed on bean seedlings and the larvae were reared in ‘gearbox’ feeding on germinated Phaseolus bean cotyledons. Strains CG 156 and CG 213 of B. bassiana killed 100% of the insect larvae and strains CG 210 and CG 321 of M. anisopliae killed 80 and 100% of the insect larvae. Strain CG 940 of B. thuringiensis killed 70% of the insect larvae.

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

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Savic Dejana

2015-01-01

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

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

Science.gov (United States)

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

2016-09-02

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

Cloning of the Bacillus thuringiensis serovar sotto chitinase (Schi gene and characterization of its protein

Directory of Open Access Journals (Sweden)

Wan-Fang Zhong

2005-12-01

Full Text Available Chitinase plays a positive role in the pathogenicity of Bacillus thuringiensis to insect pests. We used touchdown PCR to clone the chitinase (Schi gene from Bacillus thuringiensis serovar sotto (Bt sotto chromosomal DNA. Our DNA sequencing analysis revealed that the Bt sotto Schi gene consists of an open reading frame (ORF of 2067 nucleotides with codes for the chitinase precursor. We also found that the putative promoter consensus sequences (the -35 and -10 regions of the Bt soto Schi gene are identical to those of the chiA71 gene from Bt Pakistani, the chiA74 gene from Bt kenyae and the ichi gene from Bt israelensis. The Schi chitinase precursor is 688 amino acids long with an estimated molecular mass of 75.75 kDa and a theoretical isoelectric point of 5.74, and contains four domains, which are, in sequence, a signal peptide, an N-terminal catalytic domain, a fibronectin type III like domain and a C-terminal chitin-binding domain. Sequence comparison and the evolutionary relationship of the Bt sotto Schi chitinase to other chitinase and chitinase-like proteins are also discussed.

Contributions of gut bacteria to Bacillus thuringiensis-induced mortality vary across a range of Lepidoptera

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Holt Jonathan

2009-03-01

Full Text Available Abstract Background Gut microbiota contribute to the health of their hosts, and alterations in the composition of this microbiota can lead to disease. Previously, we demonstrated that indigenous gut bacteria were required for the insecticidal toxin of Bacillus thuringiensis to kill the gypsy moth, Lymantria dispar. B. thuringiensis and its associated insecticidal toxins are commonly used for the control of lepidopteran pests. A variety of factors associated with the insect host, B. thuringiensis strain, and environment affect the wide range of susceptibilities among Lepidoptera, but the interaction of gut bacteria with these factors is not understood. To assess the contribution of gut bacteria to B. thuringiensis susceptibility across a range of Lepidoptera we examined larval mortality of six species in the presence and absence of their indigenous gut bacteria. We then assessed the effect of feeding an enteric bacterium isolated from L. dispar on larval mortality following ingestion of B. thuringiensis toxin. Results Oral administration of antibiotics reduced larval mortality due to B. thuringiensis in five of six species tested. These included Vanessa cardui (L., Manduca sexta (L., Pieris rapae (L. and Heliothis virescens (F. treated with a formulation composed of B. thuringiensis cells and toxins (DiPel, and Lymantria dispar (L. treated with a cell-free formulation of B. thuringiensis toxin (MVPII. Antibiotics eliminated populations of gut bacteria below detectable levels in each of the insects, with the exception of H. virescens, which did not have detectable gut bacteria prior to treatment. Oral administration of the Gram-negative Enterobacter sp. NAB3, an indigenous gut resident of L. dispar, restored larval mortality in all four of the species in which antibiotics both reduced susceptibility to B. thuringiensis and eliminated gut bacteria, but not in H. virescens. In contrast, ingestion of B. thuringiensis toxin (MVPII following antibiotic

Isolation of strains of Bacillus thuringiensis insecticidal biological activity against Ceratitis capitata

International Nuclear Information System (INIS)

Hmaied, Ezzedine; Ben Mbarek, Wael

2010-01-01

The present work is to study the effect of toxins (δ-endotoxins) extracted from strains of Bacillus thuringiensis isolated from the mud on the fly Sabkhat Dejoumi Ceratitis capitata, a pest of citrus and fruit trees. Among 51 isolated tested, 15 showed a very significant insecticidal activity, characterized by mortality rates exceeding 80 pour cent. These mortality rates are caused by endotoxins of Bt revealed variability between them. The preliminary results of this study encourage us towards the characterization of the insecticidal activity produced by strains of Bt for large scale application.

A synthetic cryIC gene, encoding a Bacillus thuringiensis δ-endotoxin, confers Spodoptera resistance in alfalfa and tobacco

NARCIS (Netherlands)

Strizhov, N.; Keller, M.; Mathur, J.; Koncz-Kaiman, Z.; Bosch, D.; Prudovksy, E.; Schell, J.; Sneh, B.; Koncz, C.; Zilberstein, A.

1996-01-01

Spodoptera species, representing widespread polyphagous insect pests, are resistant to Bacillus thuringiensis δ-endotoxins used thus far as insecticides in transgenic plants. Here we describe the chemical synthesis of a cryIC gene by a novel template directed ligation–PCR method. This simple and

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

DEFF Research Database (Denmark)

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

2010-01-01

Bacillus cereus sensu lato is often detected in spontaneously fermented African foods but is rarely identified to species level. Only some of the B. cereus group species are reported to be pathogenic to humans and identification to species level is necessary to estimate the safety of these products...... (cluster 1). Highly similar PM13 profiles were obtained for seven of the isolates, one from afitin, one from iru and five from sonru (cluster 2). Four of the isolates, one from afitin and three from sonru, did not form any particular cluster. The PM13 profiles of cluster 2 isolates were identical to those...... which are specific to emetic toxin producers. Cereulide production of these isolates was confirmed by liquid chromatography mass spectrometry/mass spectrometry. This is the first report on cereulide producing B. cereus in African fermented foods. Occurrence of the opportunistic human pathogen B. cereus...

Elucidation of the mechanisms of CryIIIA overproduction in a mutagenized strain of Bacillus thuringiensis var. tenebrionis

International Nuclear Information System (INIS)

Adams, L.F.; Mathewes, S.; O'Hara, P.; Peterson, A.; Gürtler, H.

1994-01-01

NB176 is a Bacillus thuringiensis mutant derived by λ-irradiation of NB125 Bacillus thuringiensis var. tenebrionis (Krieg). It exhibits two interesting phenotypes: (i) oligosporogeny and (ii) twofold to threefold overproduction of the CryIIIA protein. Southern profiles of the NB176 strain showed an additional copy(s) of the cryIIIA gene located on a 4 kb HindIII fragment, in addition to the expected cryIIIA gene on a 3 kb HindIII fragment. Each cryIIIA gene-bearing HindIII fragment was cloned from NB176. The restriction map of the 3 kb HindIII fragment was identical to that published by Donovan and coworkers. Sequencing of the 4 kb HindIII fragment showed no alterations in the promoter region of the cryIIIA gene but did show replacement of the region immediately following the cryIIIA open reading frame with a sequence encoding a transposase with 50% amino acid homology to that of Tn 1000. These findings suggest that the overproduction phenotype of NB176 results from extra copies of the cryIIIA gene produced from a transposition event(s) induced or stabilized by γ-irradiation. Integration of additional copies of the cryIIIA gene into the native 90MDa plasmid of the wild-type B. thuringiensis var. tenebrionis strain resulted in strains that made enormous crystals, many possessing greatly enhanced insecticidal activity

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

Science.gov (United States)

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

2018-01-01

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

Kefiran protects Caco-2 cells from cytopathic effects induced by Bacillus cereus infection.

Science.gov (United States)

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.

On-line Biomass Estimation in a Batch Biotechnological Process: Bacillus thuringiensis δ - endotoxins production.

OpenAIRE

Amicarelli, Adriana

2010-01-01

In this Chapter it has been addressed the problem of the biomass estimation in a batch biotechnological process: the Bacillus thuringiensis (Bt) δ-endotoxins production process. Different alternatives that can be successfully used in this sense were presented. It has been exposed the design of various biomass estimators, namely: a phenomenological biomass estimator, a standard EKF biomass estimator, a biomass estimator based on ANN, a decentralized Kalman Filter, and a biomass concentration ...

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

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Tiantian Gao

2018-03-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Beetle-specific Bacillus thuringiensis Cry3Aa toxin reduces larval growth and curbs reproduction in Spodoptera littoralis (Boisd.)

Czech Academy of Sciences Publication Activity Database

Hussein, Hany; Habuštová, Oxana; Sehnal, František

2005-01-01

Roč. 61, - (2005), s. 1186-1192 ISSN 1526-498X R&D Projects: GA ČR(CZ) GA522/02/1507 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis * Spodoptera littoralis * Bt applications Subject RIV: ED - Physiology Impact factor: 1.175, year: 2005

Bacillus spp. Isolated from Puba as a Source of Biosurfactants and Antimicrobial Lipopeptides

Science.gov (United States)

Perez, Karla J.; Viana, Jaime dos Santos; Lopes, Fernanda C.; Pereira, Jamile Q.; dos Santos, Daniel M.; Oliveira, Jamil S.; Velho, Renata V.; Crispim, Silvia M.; Nicoli, Jacques R.; Brandelli, Adriano; Nardi, Regina M. D.

2017-01-01

Several products of industrial interest are produced by Bacillus, including enzymes, antibiotics, amino acids, insecticides, biosurfactants and bacteriocins. This study aimed to investigate the potential of two bacterial isolates (P5 and C3) from puba, a regional fermentation product from cassava, to produce multiple substances with antimicrobial and surface active properties. Phylogenetic analyses showed close relation of isolates P5 and C3 with Bacillus amyloliquefaciens and Bacillus thuringiensis, respectively. Notably, Bacillus sp. P5 showed antimicrobial activity against pathogens such as Listeria monocytogenes and Bacillus cereus, in addition to antifungal activity. The presence of genes encoding pre-subtilosin (sboA), malonyl CoA transacylase (ituD), and the putative transcriptional terminator of surfactin (sfp) were detected in Bacillus sp. P5, suggesting the production of the bacteriocin subtilosin A and the lipopeptides iturin A and surfactin by this strain. For Bacillus sp. C3 the presence of sboA and spas (subtilin) genes was observed by the first time in members of B. cereus cluster. Bacillus sp. P5 showed emulsifying capability on mineral oil, soybean biodiesel and toluene, while Bacillus sp. C3 showed emulsifying capability only on mineral oil. The reduction of the surface tension in culture medium was also observed for strain P5, confirming the production of surface-active compounds by this bacterium. Monoprotonated molecular species and adducts of sodium and potassium ions of surfactin, iturin, and fengycin were detected in the P5 culture medium. Comparative MS/MS spectra of the peak m/z 1030 (C14 surfactin A or C15 surfactin B [M+Na]+) and peak m/z 1079 (C15 iturin [M+Na]+) showed the same fragmentation profile of standards, confirming the molecular identification. In conclusion, Bacillus sp. P5 showed the best potential for the production of antifungal, antibacterial, and biosurfactant substances. PMID:28197131

Commercial formulations of Bacillus thuringiensis for control of Indian meal moth.

Science.gov (United States)

Schesser, J H

1976-10-01

Doses of four commercial formulations and one experimental formulation of Bacillus thuringiensis Berliner were mixed with the diet used to rear colonies of the Indian meal moth Plodia interpunctella (Hübner). Indian meal moth eggs were introduced to the treated diet, and the resultant adult emergence was tabulated. The experimental formulations ranked as follows in efficacy in controlling the Indian meal moth: Dipel (50% lethal concentration [LC50], 25 mg/kg) greater than Bactospeine WP (LC50, 100 mg/kg) greater than Thuricide (LC50, 150 mg/kg) greater than IMC 90007 (LC30, 180 mg/kg) greater than Bactospeine Flowable (LC50, 440 mg/kg).

40 CFR 174.502 - Bacillus thuringiensis Cry1A.105 protein; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry1A.105 protein; exemption from the requirement of a tolerance. 174.502 Section 174.502 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and...

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

Science.gov (United States)

Soria, M Cecilia; Audisio, M Carina

2014-12-01

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

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

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Vajihe Karbasizade

2014-10-01

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

A hybrid Bacillus thuringiensis delta-endotoxin gene gives resistance against a coleopteran and a lepidopteran pest in transgenic potato

NARCIS (Netherlands)

Naimov, S.; Dukiandjiev, S.; Maagd, de R.A.

2003-01-01

Expression of Bacillus thuringiensis delta-endotoxins has proven to be a successful strategy for obtaining insect resistance in transgenic plants. Drawbacks of expression of a single resistance gene are the limited target spectrum and the potential for rapid adaptation of the pest. Hybrid toxins

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

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Hélène eOmer

2015-10-01

Full Text Available Bacillus cereus is a gram-positive pathogen that causes a wide variety of diseases in humans. It secretes into the extracellular milieu proteins that may contribute directly or indirectly to its virulence. EntD is a novel exoprotein identified by proteogenomics of B. cereus ATCC 14579. We constructed a ΔentD mutant and analyzed the impact of entD disruption on the cellular proteome and exoproteome isolated from early, late and stationary-phase cultures. We identified 308 and 79 proteins regulated by EntD in the cellular proteome and the exoproteome, respectively. The contribution of these proteins to important virulence-associated functions, including central metabolism, cell structure, antioxidative ability, cell motility and toxin production, are presented. The proteomic data were correlated with the growth defect, cell morphology change, reduced motility and reduced cytotoxicity of the ΔentD mutant strain. We conclude that EntD is an important player in B. cereus virulence. The function of EntD and the putative EntD-dependent regulatory network are discussed. To our knowledge, this study is the first characterization of an Ent family protein in a species of the B. cereus group.

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

DEFF Research Database (Denmark)

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

2018-01-01

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

Tetracycline and oxytetracycline resistance determinants detected in Bacillus cereus strains isolated from honey samples Detección de determinantes de resistencia a tetraciclina y oxitetraciclina en cepas de Bacillus cereus aisladas de muestras de miel

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A. C. López

2008-12-01

Full Text Available The aim of this study was to investigate the presence of tetracycline and oxytetracycline resistance determinants in Bacillus cereus strains isolated from honey samples. Of a total of 77 isolates analyzed, 30 (39% exhibited resistance to tetracyclines according to the results of a disk diffusion method. Resistant strains (n=30 were screened by PCR for the presence of the resistant determinants tetK, tetL, tetM, tetO, tetW, otrA and otrB and their MIC values for tetracycline, oxytetracycline and minocycline were assessed. According to the PCR results, 23 isolates (77% presented at least one tetracycline or oxytetracycline resistance determinant. The tetK genotype was present in 10 isolates while the tetL, tetM, and otrA genotypes were present in 3, 2, and 5 isolates, respectively. In addition, 2 isolates of the tetK plus tetM genotype, 1 of the tetK plus tetL genotype, and 1 of the tetK plus otrA genotype were found. All isolates were tetW, tetO and otrB negatives. On the other hand, 7 isolates (23% showed a tetracycline-resistant and/or minocyclineresistant phenotype (MIC but did not carry any of the tet or otr determinants investigated in this study. This research has shown that B. cereus isolates from honey samples contain a variety of tetracycline and oxytetracycline resistance genes, including the tetK and tetL determinants which encode for efflux proteins, and tetM and otrA, which encode for ribosomal protection proteins. These findings indicate that strains isolated from honeys could represent a reservoir for tetracycline resistance genes. To our knowledge, this is the first report of tetracycline-resistant and oxytetracyclineresistant B. cereus strains carrying the tetK determinant, and also the first report of oxytetracycline-resistant and tetracycline- resistant Bacillus species carrying the otrA determinant.El objetivo del presente estudio ha sido investigar la presencia de diversos determinantes de resistencia a tetraciclina y

Photoproduct formation and repair capacity in a mutant of Bacillus cereus 569 producing UV-sensitive spores

International Nuclear Information System (INIS)

Weinberger, S.; Evenchik, Z.; Hertman, I.; Bar-Ilan Univ., Ramat-Gan

1982-01-01

A mutant of Bacillus cereus 569 UV sensitive in both vegetative and sporal stages was isolated by N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutagenesis followed by selection on mitomycin C. The UV-sensitive mutant designated as B. cereus 2422 exhibited normal content of dipicolinic acid (DPA) and resistance to X-rays and ethyl methanesulphonate. The photoproduct type and amount, induced by a given UV dose, was similar in either cells or spores of both the mutant 2422 and the wild-type ancestor. The mutant 2422 excised cyclobutane thymine dimers only to a limited extent (20%) as compared with 80% removal in the wild type. Removal of a spore-specific photoproduct (TDHT) during germination proceeded to a similar extent in B. cereus 2422 and the wild-type parent. However, under growing conditions, an additional removal of the TDHT was observed only in the wild-type strain. Liquid holding recovery occurred in irradiated wild-type cells, but not in mutant cells. Spontaneous revertants were isolated that regained UV resistance simultaneously in both the vegetative and sporal stage. (orig./AJ)

The potential of the novel mosquitocidal Bacillus thuringiensis strain LLP29 for use in practice

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Wu, S.; Peng, Y.; Li, M.; Sun, L.; Huang, E.; Guan, X.; Gelbič, Ivan

2011-01-01

Roč. 36, č. 2 (2011), s. 458-460 ISSN 1081-1710 R&D Projects: GA MŠk 2B08003 Grant - others:National Natural Science Foundation of China(CN) 31071745; Science Foundation of the Ministry of Education of China(CN) 20093515110010; Science Foundation of the Ministry of Education of China(CN) 20093515120010 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis Subject RIV: ED - Physiology Impact factor: 0.885, year: 2011

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

Directory of Open Access Journals (Sweden)

Haft Daniel H

2009-04-01

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

Inhibition of Bacillus cereus and Bacillus weihenstephanensis in raw vegetables by application of washing solutions containing enterocin AS-48 alone and in combination with other antimicrobials.

Science.gov (United States)

Cobo Molinos, Antonio; Abriouel, Hikmate; Lucas López, Rosario; Ben Omar, Nabil; Valdivia, Eva; Gálvez, Antonio

2008-09-01

Enterocin AS-48 is a broad-spectrum cyclic antimicrobial peptide produced by Enterococcus faecalis. In the present study, the bacteriocin was tested alone and in combination with other antimicrobials for decontamination of Bacillus inoculated on alfalfa, soybean sprouts and green asparagus. Washing with enterocin AS-48 solutions reduced viable cell counts of Bacillus cereus and Bacillus weihenstephanensis by 1.0-1.5 and by 1.5-2.38 log units right after application of treatment, respectively. In both cases, the bacteriocin was effective in reducing the remaining viable population below detection levels during further storage of the samples at 6 degrees C, but failed to prevent regrowth in samples stored at 15 or 22 degrees C. Application of washing treatments containing enterocin AS-48 in combination with several other antimicrobials and sanitizers (cinnamic and hydrocinnamic acids, carvacrol, polyphosphoric acid, peracetic acid, hexadecylpyridinium chloride and sodium hypochlorite) greatly enhanced the bactericidal effects. The combinations of AS-48 and sodium hypochlorite, peracetic acid or hexadecylpyridinium chloride provided the best results. After application of the combined treatments on alfalfa sprouts contaminated with B. cereus or with B. weihenstephanensis, viable bacilli were not detected or remained at very low concentrations in the treated samples during a 1-week storage period at 15 degrees C. Inhibition of B. cereus by in situ produced bacteriocin was tested by cocultivation with the AS-48 producer strain E. faecalis A-48-32 inoculated on soybean sprouts. Strain A-48-32 was able to grow and produce bacteriocin on sprouts both at 15 and 22 degrees C. At 15 degrees C, growth of B. cereus was completely inhibited in the cocultures, while a much more limited effect was observed at 22 degrees C. The results obtained for washing treatments are very encouraging for the application of enterocin AS-48 in the decontamination of sprouts. Application of washing

Isolation of Bacillus thuringiensis from the state of Amazonas, in Brazil, and screening against Aedes aegypti (Diptera, Culicidae

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Joelma Soares-da-Silva

2015-03-01

Full Text Available We investigated the use of Bacillus thuringiensis isolated in the state of Amazonas, in Brazil, for the biological control of the dengue vector Aedes aegypti. From 25 soil samples collected in nine municipalities, 484 bacterial colonies were obtained, 57 (11.78% of which were identified as B. thuringiensis. Six isolates, IBt-03, IBt-06, IBt-07, IBt-28, IBt-30, and BtAM-27 showed insecticidal activity, and only BtAM-27 presents the five genes investigated cry4Aa, cry4Ba, cry10Aa, cry11Aa, and cry11Ba. The IBt-07 and IBt- 28, with lower LC50 values, showed equal toxicity compared to the standards. The isolates of B. thuringiensis from Amazonas constitute potential new means of biological control for A. aegypti, because of their larvicidal activity and the possibility that they may also contain new combinations of toxins.

Fate and effect of ingested Bacillus cereus spores and vegetative cells in the intestinal tract of human-flora-associated rats

DEFF Research Database (Denmark)

Wilcks, Andrea; Hansen, Bjarne Munk; Hendriksen, Niels Bohse

2006-01-01

The fate and effect of Bacillus cereus F4433/73R in the intestine of human-flora-associated rats was studied using bacteriological culturing techniques and PCR-denaturing gradient gel electrophoresis in combination with cell assays and immunoassays for detection of enterotoxins. In faecal samples...

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

NARCIS (Netherlands)

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

2015-01-01

Biofilm formation of Bacillus cereus reference strains ATCC 14579 and ATCC 10987 and 21 undomesticated food isolates was studied on polystyrene and stainless steel as contact surfaces. For all strains, the biofilm forming capacity was significantly enhanced when in contact with stainless steel (SS)

40 CFR 174.530 - Bacillus thuringiensis Cry2Ae protein in cotton; temporary exemption from the requirement of a...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry2Ae protein in cotton; temporary exemption from the requirement of a tolerance. 174.530 Section 174.530 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Determination of haemolytic and non haemolytic genes profiles of Bacillus cereus strains isolated from food samples by polymerase chain reaction (pcr) technique

Science.gov (United States)

Jawad, Nisreen; Ahemd, Asmat; Abdullah, Aminah

2018-04-01

The aim of this study was to investigate the presence of Bacillus cereus and detection of enterotoxigenic genes in food samples by utilizing a Polymerase Chain Reaction technique (PCR). In this study the providence of B. cereus was carried out to food samples. The B. cereus isolates were investigated for enterotoxigenic gene. The cooked seafood, and raw milk samples were purchased from several restaurants and market in the area of (Bangi, Kajang, Serdang and UKM) Selangor, Malaysia. A total of 60 samples have been analyzed. B. cereus contamination has been formed between 1.4×105 - 3×105 cfu/mL of cooked seafood and raw milk samples. Five colonies have been detected as B. cereus using biochemical test. All B. cereus isolates named BC1 to BC27, were characterized for haemolytic enterotoxin (HBL) complex encoding genes (hblA), non-haemolytic enterotoxin encoding gene (NheA). 10 isolates have been reported to be positive towards hblA and 12 isolates were positive towards NheA. The presence of B. cereus and their enterotoxigenic genes in cooked seafood and raw milk from to food samples obtained may pose a potential risk for public health.

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

NARCIS (Netherlands)

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

2004-01-01

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

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

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Nguyen-the Christophe

2008-10-01

Full Text Available Abstract Background Most extracellular virulence factors produced by Bacillus cereus are regulated by the pleiotropic transcriptional activator PlcR. Among strains belonging to the B. cereus group, the plcR gene is always located in the vicinity of genes encoding the YvfTU two-component system. The putative role of YvfTU in the expression of the PlcR regulon was therefore investigated. Results Expression of the plcR gene was monitored using a transcriptional fusion with a lacZ reporter gene in a yvfTU mutant and in its B. cereus ATCC 14579 parental strain. Two hours after the onset of the stationary phase, a stage at which the PlcR regulon is highly expressed, the plcR expression in the yvfTU mutant was only 50% of that of its parental strain. In addition to the reduced plcR expression in the yvfTU mutant, a few members of the PlcR regulon showed a differential expression, as revealed by transcriptomic and proteomic analyses. The virulence of the yvfTU mutant in a Galleria mellonella insect model was slightly lower than that of the parental strain. Conclusion The YvfTU two-component system is not required for the expression of most of the virulence factors belonging to the PlcR regulon. However, YvfTU is involved in expression of plcR, a major regulator of virulence in B. cereus.

Larvicidal activity of Bacillus thuringiensis var. israelensis Cry11Aa toxin against Haemonchus contortus.

Science.gov (United States)

DE Lara, Ana Paula DE Souza Stori; Lorenzon, Lucas Bigolin; Vianna, Ana Muñoz; Santos, Francisco Denis Souza; Pinto, Luciano Silva; Aires Berne, Maria Elisabeth; Leite, Fábio Pereira Leivas

2016-10-01

Effective control of gastrointestinal parasites is necessary in sheep production. The development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. Biological control strategies present an alternative to this problem. In the current study, we tested the larvicidal effects of Bacillus thuringiensis var. israelensis Cry11Aa toxin against Haemonchus contortus larvae. Bacterial suspensions [2 × 108 colony-forming units (CFU) g-1 of the feces] of B. thuringiensis var. israelensis and recombinant Escherichia coli expressing Cry11Aa toxin were added to naturally H. contortus egg-contaminated feces. The larvae were quantified, and significant reductions of 62 and 81% (P var. israelensis and recombinant E. coli expressing Cry11Aa toxin were then orally administered to lambs naturally infected with H. contortus. Twelve hours after administration, feces were collected and submitted to coprocultures. Significant larvae reductions (P var. israelensis is a promising new class of biological anthelmintics for treating sheep against H. contortus.

Localization of Bacillus thuringiensis Cry1A toxin-binding molecules in gypsy moth larval gut sections using fluorescence microscopy

Science.gov (United States)

Algimantas P. Valaitis

2011-01-01

The microbial insecticide Bacillus thuringiensis (Bt) produces Cry toxins, proteins that bind to the brush border membranes of gut epithelial cells of insects that ingest it, disrupting the integrity of the membranes, and leading to cell lysis and insect death. In gypsy moth, Lymantria dispar, two toxin-binding molecules for the...

40 CFR 174.504 - Bacillus thuringiensis Cry1F protein in cotton; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry1F protein in cotton; exemption from the requirement of a tolerance. 174.504 Section 174.504 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and...

40 CFR 174.517 - Bacillus thuringiensis Cry9C protein in corn; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry9C protein in corn; exemption from the requirement of a tolerance. 174.517 Section 174.517 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and...

40 CFR 174.520 - Bacillus thuringiensis Cry1F protein in corn; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry1F protein in corn; exemption from the requirement of a tolerance. 174.520 Section 174.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and...

Purification, crystallization and preliminary X-ray crystallographic analysis of chitinase from Bacillus cereus NCTU2

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Kuo, Chueh-Yuan [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Wu, Yue-Jin [Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010,Taiwan (China); Hsieh, Yin-Cheng; Guan, Hong-Hsiang [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Tsai, Huei-Ju [Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010,Taiwan (China); Lin, Yi-Hung; Huang, Yen-Chieh; Liu, Ming-Yih [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Li, Yaw-Kuen, E-mail: ykl@cc.nctu.edu.tw [Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010,Taiwan (China); Chen, Chun-Jung, E-mail: ykl@cc.nctu.edu.tw [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China)

2006-09-01

The crystallization of B. cereus chitinase is reported. Chitinases (EC 3.2.1.14) are found in a broad range of organisms, including bacteria, fungi and higher plants, and play different roles depending on their origin. A chitinase from Bacillus cereus NCTU2 (ChiNCTU2) capable of hydrolyzing chitin as a carbon and nitrogen nutrient has been identified as a member of the family 18 glycoside hydrolases. ChiNCTU2 of molecular weight 36 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of chitinase crystals at 1.10 Å resolution, the crystal belongs to space group P2{sub 1}, with unit-cell parameters a = 50.79, b = 48.79, c = 66.87 Å, β = 99.31°. Preliminary analysis indicates there is one chitinase molecule in the asymmetric unit, with a solvent content of 43.4%.

Bacillus thuringiensis: generalidades: Un acercamiento a su empleo en el biocontrol de insectos lepidópteros que son plagas agrícolas Bacillus thuringiensis: general aspects: An approach to its use in the biological control of lepidopteran insects behaving as agricultural pests

Directory of Open Access Journals (Sweden)

Diego H. Sauka

2008-06-01

Full Text Available Bacillus thuringiensis es el insecticida biológico más aplicado en el mundo y se utiliza para controlar diversos insectos que afectan la agricultura, la actividad forestal y que transmiten patógenos humanos y animales. B. thuringiensis constituyó durante las últimas décadas un tema de investigación intensiva. Estos esfuerzos brindaron datos importantes sobre las relaciones entre la estructura, el mecanismo de acción y la genética de sus proteínas cristalinas pesticidas, y una visión más clara y coherente sobre estas relaciones ha emergido gracias a ellos. Otros estudios se centraron en el rol ecológico de las proteínas cristalinas de B. thuringiensis, su funcionamiento en sistemas agrícolas y en otros sistemas naturales. Teniendo como base todo el conocimiento generado y las herramientas de la biotecnología, los investigadores están ahora divulgando resultados prometedores sobre el desarrollo de toxinas más útiles, bacterias recombinantes, formulaciones nuevas y plantas transgénicas que expresan actividad pesticida, con el objetivo de asegurar que estos productos sean utilizados con un mayor beneficio y eficacia. Este artículo constituye una tentativa de integrar todos estos progresos recientes sobre el estudio de B. thuringiensis en un contexto de control biológico de plagas de insectos lepidópteros de importancia agrícola.Bacillus thuringiensis is the most widely applied biological pesticide used to control insects that affect agriculture and forestry and which transmit human and animal pathogens. During the past decades B. thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the relationships between the structure, mechanism of action, and genetics of their pesticidal crystal proteins. As a result, a coherent picture of these relationships has emerged. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins and their performance

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

Science.gov (United States)

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

2017-07-01

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

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

Science.gov (United States)

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

2018-01-01

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

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

Directory of Open Access Journals (Sweden)

Maroua Gdoura-Ben Amor

2018-03-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-10-02

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

Recovery of commercially produced Bacillus thuringiensis var. israelensis and Bacillus sphaericus from tires and prevalence of bacilli in artificial and natural containers.

Science.gov (United States)

Siegel, J P; Smith, A R; Novak, R J

2001-03-01

We conducted surveys to identify the species of spore-forming bacteria present in natural and artificial containers. Most of our samples came from Illinois. Identification was based on the cellular fatty acid composition of the bacterial cell wall. In addition, we utilized a custom database for commercially produced strains of Bacillus thuringiensis var. israelensis (Bti) and B. sphaericus, to differentiate between larvicidal isolates with commercial or native origin. Native Bti was present at low levels in almost all habitats but was not recovered from bromeliads and metal containers. In temporary woodland pools, 27.9% of the colonies recovered were native Bti. We did not recover larvicidal B. sphaericus in untreated habitats. VectoBac and VectoLex were applied to tires containing water and the tires were sampled 3 months and 9 months after treatment. Isolates of Bti and B. sphaericus with commercial origin were recovered as long as 9 months after application. We noticed numerous cadavers of Aedes triseriatus in several tires 9 months after treatment with VectoBac. We could not determine if this mortality resulted from recycling of Bti in these tires or whether insecticidal crystal proteins from the original treatment were resuspended. Bacillus thuringiensis var. israelensis isolates with commercial ancestry were recovered from untreated tires 9 months after application. Isolates of larvicidal B. sphaericus that differed from the bacteria in VectoLex were also recovered from untreated tires.

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

DEFF Research Database (Denmark)

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

2018-01-01

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

In vitro ovicidal and cestocidal effects of toxins from Bacillus thuringiensis on the canine and human parasite Dipylidium caninum.

Science.gov (United States)

Peña, Guadalupe; Aguilar Jiménez, Fortino Agustín; Hallal-Calleros, Claudia; Morales-Montor, Jorge; Hernández-Velázquez, Víctor Manuel; Flores-Pérez, Fernando Iván

2013-01-01

Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 μ g/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 μ g/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis.

In Vitro Ovicidal and Cestocidal Effects of Toxins from Bacillus thuringiensis on the Canine and Human Parasite Dipylidium caninum

Directory of Open Access Journals (Sweden)

Guadalupe Peña

2013-01-01

Full Text Available Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum. Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 μg/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 μg/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis.

Effect of ultraviolet and gamma rays on the activity of delta-endotoxin protein crystals of Bacillus thuringiensis

International Nuclear Information System (INIS)

Burges, H.D.; Hillyer, S.; Chanter, D.O.

1975-01-01

Sensitive bioassays with larvae of Pieris brassicae revealed no reduction of insecticidal activity as a result of severe gamma or ultraviolet irradiation of crystals of Bacillus thuringiensis (serotype V). The measured response was the inhibition of larval feeding by the crystals over exposure periods short enough for the presence of live spores not to influence feeding. The results were analyzed using a logistic model. (U.S.)

Microbiological ecology and association of Bacillus thuringiensis in chicken feces originating from feed

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Peng, Y.; Wu, S.; Sun, L.; Huang, E.; Huang, T.; Xu, L.; Wu, Ch.; Gelbič, Ivan; Guan, X.

2012-01-01

Roč. 65, č. 6 (2012), s. 784-791 ISSN 0343-8651 R&D Projects: GA MŠk 2B08003 Grant - others:National Natural Science Foundation of China(CN) 31071745; Ministry of Education of China(CN) 20093515110010; Ministry of Education of China(CN) 20093515120010; Transformation Fund for Agricultural Science and Technology Achievements(CN) 2010GB2C400212; Education Department Foundation(CN) JA12092 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis Subject RIV: EH - Ecology, Behaviour Impact factor: 1.520, year: 2012 http://link.springer.com/content/pdf/10.1007%2Fs00284-012-0231-3

Decolorization of textile dye RB19 using volcanic rock matrix immobilized Bacillus thuringiensis cells with surface displayed laccase.

Science.gov (United States)

Wan, Juan; Sun, Xiaowen; Liu, Cheng; Tang, Mengjun; Li, Lin; Ni, Hong

2017-06-01

A triplicate volcanic rock matrix-Bacillus thuringiensis-laccase WlacD (VRMs-Bt-WlacD) dye decolorization system was developed. WlacD was displayed on the B. thuringiensis MB174 cell surface to prepare a whole-cell laccase biocatalyst by using two repeat N-terminal domains of autolysin Mbg (Mbgn) 2 as the anchoring motif. Immunofluorescence microscopic assays confirmed that the fusion protein (Mbgn) 2 -WlacD was anchored on the surface of the recombinant B. thuringiensis MB174. After optimization by a single factor test, L 9 (3 4 )-orthogonal test, Plackett-Burman test, steepest ascent method, and Box-Behnken response surface methodology, the whole-cell specific laccase activity of B. thuringiensis MB174 was improved to 555.2 U L -1 , which was 2.25 times than that of the primary culture condition. Optimized B. thuringiensis MB174 cells were further adsorbed by VRMs to prepare VRMs-Bt-WlacD, an immobilized whole-cell laccase biocatalyst. Decolorization capacity of as-prepared VRMs-Bt-WlacD toward an initial concentration of 500 mg L -1 of an textile dye reactive blue 19 (RB19) aqueous solution reached 72.36% at a solid-to-liquid ratio of 10 g-100 mL. Repeated decolorization-activation operations showed the high decolorization capacity of VRMs-Bt-WlacD and have the potential for large-scale or continuous operations.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK KASAR LIPID Ulva fasciata TERHADAP Bacillus cereus

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Riong Seulina Panjaitan

2017-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-15

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Identification of new isolates of Bacillus thuringiensis using rep-PCR products and delta-endotoxin electron microscopy

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A.S.G. Lima

2002-01-01

Full Text Available PCR has been used to analyze the distribution of REP (Repetitive Extragenic Palindromic and ERIC (Enterobacterial Repetitive Intergenic Consensus sequences (rep-PCR found within the genome of the bacterium Bacillus thuringiensis, with the purpose to analyze the genetic similarities among 56 subspecies samples and 95 field isolates. The PCR products were analyzed by EB-AGE (ethidium bromide-agarose electrophoresis and then submitted to banding comparisons, based on the Phyllip software algorithm. When the banding similarities were considered for comparison purposes among all the strains, the phylogenic tree patterns varied according to the rep-PCR primers considered, but, from a broader point of view, the ERIC sequences produced better results, which, together with electron microscopy analysis of the released parasporal bodies and colony morphology characteristics, allowed to detect two possible new subspecies of B. thuringiensis.

Mutation effect of MeV protons on bioflocculant bacteria Bacillus cereus

International Nuclear Information System (INIS)

Yang, Y.N.; Ren, N.; Xue, J.M.; Yang, J.; Rong, B.L.

2007-01-01

A 3.2 MeV proton beam was used to irradiate bioflocculant bacteria (Bacillus cereus) to achieve mutation. The ion fluence ranged from 10 11 to 10 14 /cm 2 . Most of the bacteria were killed when the ion fluence reached 10 12 ions/cm 2 . The survival ratio drops in an exponential way on further increasing the ion fluence. The flocculating activity of 7 samples out of 51 showed a positive change, and a perfect mutant C7-23 with a stable high capacity of bioflocculant production was found. RAPD measurements showed that a new lane appears in this sample. The flocculating activity of the C7-23 bacteria increased by factors of 22%, 54% and 217% under pH values of 4, 7 or 10, respectively

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

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Ceuppens Siele

2012-10-01

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

Presence survival spores of Bacillus thuringiensis varieties in grain warehouse

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Sánchez-Yáñez Juan Manuel

2016-08-01

Full Text Available Genus Bacillus thuringiensis (Bt synthesized spores and crystals toxic to pest-insects in agriculture. Bt is comospolitan then possible to isolate some subspecies or varieties from warehouse. The aims of study were: i to isolate Bt varieties from grain at werehouse ii to evaluate Bt toxicity on Spodoptera frugiperda and Shit-ophilus zeamaisese iii to analyze Bt spores persistence in Zea mays grains at werehouse compared to same Bt on grains exposed to sun radiation. Results showed that at werehouse were recovered more than one variety of Bt spores. According to each isolate Bt1 o Bt2 were toxic to S. frugiperda or S. zeamaisese. One those Bt belong to var morrisoni. At werehouse these spores on Z. mays grains surviving more time, while the same spores exposed to boicide sun radiation they died.

[Bacillus thuringiensis: general aspects. An approach to its use in the biological control of lepidopteran insects behaving as agricultural pests].

Science.gov (United States)

Sauka, Diego H; Benintende, Graciela B

2008-01-01

Bacillus thuringiensis is the most widely applied biological pesticide used to control insects that affect agriculture and forestry and which transmit human and animal pathogens. During the past decades B. thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the relationships between the structure, mechanism of action, and genetics of their pesticidal crystal proteins. As a result, a coherent picture of these relationships has emerged. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins and their performance in agricultural and other natural settings. With this knowledge as background and the help of biotechnological tools, researchers are now reporting promising results in the development of more useful toxins, recombinant bacteria, new formulations and transgenic plants that express pesticidal activity, in order to assure that these products are utilized with the best efficiency and benefit. This article is an attempt to integrate all these recent developments in the study of B. thuringiensis into a context of biological control of lepidopteran insect pest of agricultural importance.

40 CFR 174.501 - Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Vip3Aa protein in corn and cotton; exemption from the requirement of a tolerance. 174.501 Section 174.501 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

40 CFR 174.518 - Bacillus thuringiensis Cry3Bb1 protein in corn; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry3Bb1 protein in corn; exemption from the requirement of a tolerance. 174.518 Section 174.518 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and...

40 CFR 174.510 - Bacillus thuringiensis Cry1Ac protein in all plants; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry1Ac protein in all plants; exemption from the requirement of a tolerance. 174.510 Section 174.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances...

40 CFR 174.511 - Bacillus thuringiensis Cry1Ab protein in all plants; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry1Ab protein in all plants; exemption from the requirement of a tolerance. 174.511 Section 174.511 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances...

Field evaluation of the synergistic effects of neem oil with Beauveria bassiana (Hypocreales: Clavicipitaceae) and Bacillus thuringiensis var. kurstaki (Bacillales: Bacillaceae)

NARCIS (Netherlands)

Togbe, C.E.; Zannou, E.; Gbehounou, G.; Kossou, D.; Huis, van A.

2014-01-01

In the present study, the synergistic effects of Beauveria bassiana (Bals.-Criv. Vuill.) (isolate Bb11) and Bacillus thuringiensis var. kurstaki (Berliner) with neem oil were evaluated in three agroecological zones in Be´nin. Four bioinsecticide treatments (neem oil, neem oil and B. bassiana used

Combined effect of seaweed (Sargassum wightii) and Bacillus thuringiensis var. israelensis on the coastal mosquito,Anopheles sundaicus, in Tamil Nadu, India

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Studies were made of the extract of Sargassum wightii combined with Bacillus thuringiensis var. israelensis (Bti) for control of the malaria vector Anopheles sundaicus. Treatment of mosquito larvae with 0.001% S. wightii extract indicated median lethal concentrations (LC50) of 88, 73, 134, 156, and...

Increased toxicity of Bacillus thuringiensis Cry3Aa against Crioceris quatuordecimpunctata, Phaedon brassicae and Colaphellus bowringi by a Tenebrio molitor cadherin fragment

Science.gov (United States)

BACKGROUND: Biopesticides containing Cry insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are effective against many lepidopteran pests, but there is a lack of Bt-based pesticides to efficiently control important coleopteran pests. Based on the reported increase of Bt toxin olig...

Outbreak of Bacillus cereus infections in a neonatal intensive care unit traced to balloons used in manual ventilation.

Science.gov (United States)

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.

Risk assessment of the biological plant protection product Turex 50 WG, with the organism Bacillus thuringiensis ssp. aizawai CG-91. Opinion of the Panel on Plant Protection Products of the Norwegian Scientific Committee for Food Safety

OpenAIRE

Källqvist, Torsten; Dirven, Hubert; Gjøen, Tor; Tronsmo, Arne; Yazdankhah, Siamak Pour; Rivedal, Edgar; Borgå, Katrine; Eklo, Ole Martin; Grung, Merete; Lyche, Jan Ludvig; Låg, Marit; Nilsen, Asbjørn Magne; Sverdrup, Line Emilie

2016-01-01

Bacillus thuringiensis are anaerobic, gram-positive bacteria that produce parasporal crystalline protein inclusions, δ-endotoxin, which are toxic to certain invertebrates, especially larvae belonging to the insect orders Coleoptera, Diptera and Lepidoptera. Different strains of Bacillus thuringiensis have therefore a long standing history as plant protective insecticides in many countries, but have not been approved for use in Norway. The Norwegian Scientific Committee for Food Safety (Vitens...

Radiosensibilisation of bacteria on beef minced by essential oils with special reference to the spores of Bacillus cereus ATCC 7004

International Nuclear Information System (INIS)

Ayari, Samia

2007-01-01

The radiosensitization of Bacillus Cereus ATCC 7004 spores was evaluated in the presence of thymol, thyme, D-L menthol, trans-cinnamaldehyde and eugenol in ground beef. Meat cattle minced (5 % fat) was inoculated with spores of Bacillus Cereus (10 5 - 10 6 CFU / g), and each compound was added separately at various concentrations. The antimicrobial potential was evaluated in unirradiated meat by determining the MIC in percentage (wt / wt) after 24 h of storage at 4± 1C. Results showed that the best antimicrobial compound was the trans-cinnamaldehyde with MIC of 1.47%, wt/wt. In presence of cinnamaldehyde, the addition of sodium pyrophosphate decahydrate (0.1%, wt/wt) increased significantly (p < 0.05) the relative sensitivity of Bacillus Cereus spores 2 times. However, the presence of ascorbic acid in the media reduced significantly (p < 0.05) the radiosensitivity of bacteria. The combined effect of gamma irradiation in presence of cinnamaldehyde, added with ascorbic acid or sodium pyrophosphate decahydrate, on the microbiological and physico-chemical characteristic of meat samples was evaluated at 2 kGy under air. The use of the active compounds with the irradiation reduced significantly (p < 0.05) the count of total bacteria with a concomitant effect in the extension periods of shelf life. The addition of the cinnamaldehyde induced a significant reduction (p < 0.05) in TVN and free amino acids of irradiated samples. In presence of ascorbic acid the thiobarbituric acid-reactive substances (TBARS) concentration was significantly reduced (P...0.05). A significant reduction (p < 0.05) of a* and C* of color values and a significant increase (p < 0.05 ) of b* value were obtained for the samples treated by the cinnamaldehyde. The application of bioactive films for the immobilization of the essential oils is a good alternate to check their stability during storage time. (Author). 155 refs

Molecular characterization of the probiotic strain Bacillus cereus var. toyoi NCIMB 40112 and differentiation from food poisoning strains.

Science.gov (United States)

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

Extraction and separation of water soluble proteins from Bacillus thuringiensis-transgenic and non-transgenic maize species by CZE

Czech Academy of Sciences Publication Activity Database

Sázelová, Petra; Kašička, Václav; Ibanez, E.; Cifuentes, A.

2009-01-01

Roč. 32, č. 21 (2009), s. 3801-3808 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA203/08/1428 Grant - others:GA ČR(CZ) GA203/09/0675 Program:GA Institutional research plan: CEZ:AV0Z40550506 Keywords : Bacillus thuringiensis -transgenic maize * CZE-UV profiling * Maize proteins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.551, year: 2009

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

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Bandna Chand

2013-02-01

Full Text Available Antibacterial activity of extracts of Allium sativum (garlic and Zingiber officinale (ginger has been evaluated against four different bacteria namely Escherichia coli, Salmonella Typhi, Staphylococcus aureus and Bacillus cereus. Two methods were used to determine the antimicrobial activity of garlic and ginger extracts namely disk diffusion method and agar well diffusion method. Garlic extract exhibited excellent antibacterial activity against all four test organisms while ginger extract showed antibacterial activity against Bacillus cereus and Staphylococcus aureus only. In addition, agar well diffusion method showed higher zone in inhibition when compared with the zone of inhibition produced by the spice of same concentration against the test microorganism by disk diffusion method. Antibiotic sensitivity of the four different bacteria was tested with commercially available antibiotics namely Ciprofloxacin; Oxytetracycline; Vancomycin; Streptomycin; Gentamicin; Tetracycline; Novobiocin; Amikacin and Penicillin G. Penicillin G produced the highest zone of inhibition of 40.00±0.00against Staphylococcus aureus and the lowest zone of inhibition of 0.00±0.00against Escherichia coli.

Use of spent mushroom substrate for production of Bacillus thuringiensis by solid-state fermentation.

Science.gov (United States)

Wu, Songqing; Lan, Yanjiao; Huang, Dongmei; Peng, Yan; Huang, Zhipeng; Xu, Lei; Gelbic, Ivan; Carballar-Lejarazu, Rebeca; Guan, Xiong; Zhang, Lingling; Zou, Shuangquan

2014-02-01

The aim of this study was to explore a cost-effective method for the mass production of Bacillus thuringiensis (Bt) by solid-state fermentation. As a locally available agroindustrial byproduct, spent mushroom substrate (SMS) was used as raw material for Bt cultivation, and four combinations of SMS-based media were designed. Fermentation conditions were optimized on the best medium and the optimal conditions were determined as follows: temperature 32 degrees C, initial pH value 6, moisture content 50%, the ratio of sieved material to initial material 1:3, and inoculum volume 0.5 ml. Large scale production of B. thuringiensis subsp. israelensis (Bti) LLP29 was conducted on the optimal medium at optimal conditions. High toxicity (1,487 international toxic units/milligram) and long larvicidal persistence of the product were observed in the study, which illustrated that SMS-based solid-state fermentation medium was efficient and economical for large scale industrial production of Bt-based biopesticides. The cost of production of 1 kg of Bt was approximately US$0.075.

Combined effects of plant extracts in inhibiting the growth of Bacillus cereus in reconstituted infant rice cereal.

Science.gov (United States)

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)extracts against B. 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 infant rice cereal with plant extracts reduces sensorial quality. These observations will be useful when developing and applying interventions using natural plant extracts to inhibit B

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

Science.gov (United States)

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

2009-05-01

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

Lactobacillus delbrueckii subsp lactis CIDCA 133 modulates response of human epithelial and dendritic cells infected with Bacillus cereus.

Science.gov (United States)

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

The Synergist Effect of The Henna Plant, Lawsonia alba on Bacillus thuringiensis var. kurstaki Against Third Larval Instar of Pistachio Leaf Borer, Ocneria terebinthina Strg. (Lep.: Lymanteriidae

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Zahra Sheibani

2017-12-01

Full Text Available Ocneria terebinthina Strg. (Lep.: Lymanteriidae is a leaf borer pest in pistachio orchard. The toxicity of Bacillus thuringiensis var. kurstaki alone and in combination with henna powder was investigated on third larval instar of O. terebinthina under laboratory conditions. Bioassay was carried out using spray technique on pistachio offshoot. Probit analysis of concentration-mortality data was conducted to estimate the LC50 value. The LC50 value of B. thuringiensis on third instar of larvae was estimated as 2817.30 ppm. The synergist effect of henna powder on efficacy of B. thuringiensis was also evaluated. Three concentrations of henna powder were combined with minimum lethal dose of B. thuringiensis against third larval instar. The results revealed that the henna powder had synergist effect on B. thuringiensis. The combination of B. thuringiensis and henna powder (6000 ppm caused 80.68% mortality, whereas B. thuringiensis alone caused 15.91% mortality. Our results suggested that henna powder can increase the efficacy of B. thuringiensis in controlling O. terebinthina in pest integrated management.

Glucose 6P binds and activates HlyIIR to repress Bacillus cereus haemolysin hlyII gene expression.

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Elisabeth Guillemet

Full Text Available Bacillus cereus is a Gram-positive spore-forming bacterium causing food poisoning and serious opportunistic infections. These infections are characterized by bacterial accumulation despite the recruitment of phagocytic cells. We have previously shown that B. cereus Haemolysin II (HlyII induces macrophage cell death by apoptosis. In this work, we investigated the regulation of the hlyII gene. We show that HlyIIR, the negative regulator of hlyII expression in B. cereus, is especially active during the early bacterial growth phase. We demonstrate that glucose 6P directly binds to HlyIIR and enhances its activity at a post-transcriptional level. Glucose 6P activates HlyIIR, increasing its capacity to bind to its DNA-box located upstream of the hlyII gene, inhibiting its expression. Thus, hlyII expression is modulated by the availability of glucose. As HlyII induces haemocyte and macrophage death, two cell types that play a role in the sequestration of nutrients upon infection, HlyII may induce host cell death to allow the bacteria to gain access to carbon sources that are essential components for bacterial growth.

Bacillus thuringiensis monogenic strains: screening and interactions with insecticides used against rice pests

Science.gov (United States)

Pinto, Laura M.N.; Dörr, Natália C.; Ribeiro, Ana Paula A.; de Salles, Silvia M.; de Oliveira, Jaime V.; Menezes, Valmir G.; Fiuza, Lidia M.

2012-01-01

The screening of Bacillus thuringiensis (Bt) Cry proteins with high potential to control insect pests has been the goal of numerous research groups. In this study, we evaluated six monogenic Bt strains (Bt dendrolimus HD-37, Bt kurstaki HD-1, Bt kurstaki HD-73, Bt thuringiensis 4412, Bt kurstaki NRD-12 and Bt entomocidus 60.5, which codify the cry1Aa, cry1Ab, cry1Ac, cry1Ba, cry1C, cry2A genes respectively) as potential insecticides for the most important insect pests of irrigated rice: Spodoptera frugiperda, Diatraea saccharalis, Oryzophagus oryzae, Oebalus poecilus and Tibraca limbativentris. We also analyzed their compatibility with chemical insecticides (thiamethoxam, labdacyhalothrin, malathion and fipronil), which are extensively used in rice crops. The bioassay results showed that Bt thuringiensis 4412 and Bt entomocidus 60.5 were the most toxic for the lepidopterans, with a 93% and 82% mortality rate for S. frugiperda and D. saccharalis, respectively. For O. oryzae, the Bt kurstaki NRD-12 (64%) and Bt dendrolimus HD-37 (62%) strains were the most toxic. The Bt dendrolimus HD-37 strain also caused high mortality (82%) to O. poecilus, however the strains assessed to T. limbativentris caused a maximum rate of 5%. The assays for the Bt strains interaction with insecticides revealed the compatibility of the six strains with the four insecticides tested. The results from this study showed the high potential of cry1Aa and cry1Ba genes for genetic engineering of rice plants or the strains to biopesticide formulations. PMID:24031872

Toxicity of parasporal crystals of Bacillus thuringiensis to the Indian meal moth, Plodia interpunctella.

Science.gov (United States)

Schesser, J H; Bulla, L A

1979-05-01

Toxicity of Bacillus thuringiensis parasporal crystals to the Indian meal moth, Plodia interpunctella, is described. The numbers of insects killed were in relation to crystal dry weight. Mortality was determined by comparing adult emergence in diets treated with crystals to emergence in untreated diets. There was only a 30% survival at an application of 0.414 microgram/cm2, and the mean 50% lethal concentration value was found to be 0.299 microgram/cm2. The use of emergence data has provided a reliable and reproducible bioassay for comparing relative toxicities of crystals, spores, and other cellular components to this economically important insect.

Outbreak of Bacillus cereus Infections in a Neonatal Intensive Care Unit Traced to Balloons Used in Manual Ventilation

OpenAIRE

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 ...

First report of detection of the putative receptor of Bacillus thuringiensis toxin Vip3Aa from black cutworm (Agrotis ipsilon

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Gamal H. Osman

2018-03-01

Full Text Available Black cutworm (BCW Agrotis ipsilon, an economically important lepidopteran insect, has attracted a great attention. Bacillus thuringiensis (Bt is spore forming soil bacteria and is an excellent environment-friendly approach for the control of phytophagous and disease-transmitting insects. In fact, bio-pesticide formulations and insect resistant transgenic plants based on the bacterium Bt delta-endotoxin have attracted worldwide attention as a safer alternative to harmful chemical pesticides. The major objective of the current study was to understand the mechanism of interaction of Bt toxin with its receptor molecule(s. The investigation involved the isolation, identification, and characterization of a putative receptor – vip3Aa. In addition, the kinetics of vip toxin binding to its receptor molecule was also studied. The present data suggest that Vip3Aa toxin bound specifically with high affinity to a 48-kDa protein present at the brush border membrane vesicles (BBMV prepared from the midgut epithelial cells of BCW larvae. Keywords: Receptor, vip3Aa, Bacillus thuringiensis, BBMV

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

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Marcelo Luiz Lima Brandão

2014-02-01

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

Real-Time PCR Assay for a Unique Chromosomal Sequence of Bacillus anthracis

Science.gov (United States)

2004-12-01

13061 Neisseria lactamica .............................................................. 23970 Bacillus coagulans ...NEG Bacillus coagulane 7050 NEG NEG Bacillus cereus 13472 NEG NEG Bacillus licheniforms 12759 NEG NEG Bacillus cereus 13824 NEG NEG Bacillus ...Assay for a Unique Chromosomal Sequence of Bacillus anthracis Elizabeth Bode,1 William Hurtle,2† and David Norwood1* United States Army Medical

A Novel Tenebrio molitor Cadherin Is a Functional Receptor for Bacillus thuringiensis Cry3Aa Toxin*

OpenAIRE

Fabrick, Jeff; Oppert, Cris; Lorenzen, Marcé D.; Morris, Kaley; Oppert, Brenda; Jurat-Fuentes, Juan Luis

2009-01-01

Cry toxins produced by the bacterium Bacillus thuringiensis are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. Here we present data that demonstrate that a coleopteran cadherin is a functional Cry3Aa toxin receptor. The Cry3Aa receptor cadherin was cloned from Tenebrio molitor larval midgut mRNA, and the predicted protein, TmCad1, has domain structure and a putative toxin binding region similar to those in lepid...

A novel mosquitocidal Bacillus thuringiensis strain LLP29 isolated from the phylloplane of Magnolia denudata

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Huang, E.; Lin, J.; Gelbič, Ivan; Zhang, Q.; Guan, Y.; Huang, T.; Guan, X.

2010-01-01

Roč. 165, č. 2 (2010), s. 133-141 ISSN 0944-5013 R&D Projects: GA MŠk 2B08003 Grant - others:United Fujian Provincial Health and Education Project for Tackling Key Research(CN) WKJ2008-2-44; Talented Youth Project of Fujian Province(CN) 2008F3012; Educational Department of Fujian Province(CN) JA08080; Fujian Agriculture and Forestry University(CN) 08A01 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis * cyt1 * mosquito Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.958, year: 2010

40 CFR 174.519 - Bacillus thuringiensis Cry2Ab2 protein in corn and cotton; exemption from the requirement of a...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry2Ab2 protein in corn and cotton; exemption from the requirement of a tolerance. 174.519 Section 174.519 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

40 CFR 174.532 - Bacillus thuringiensis eCry3.1Ab protein in corn; temporary exemption from the requirement of a...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis eCry3.1Ab protein in corn; temporary exemption from the requirement of a tolerance. 174.532 Section 174.532 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae

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N. Knaak

Full Text Available Among the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797 (Lepidoptera, Noctuidae is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus thuringiensis Berliner demonstrates toxicity due to synthesis of the Cry protein, the present study was undertaken to evaluate this toxic effect of B. thuringiensis thuringiensis 407 (pH 408 and B. thuringiensis kurstaki HD-73 on S. frugiperda. The following method was used. Both bacterial strains were evaluated in vitro in 1st instar S. frugiperda caterpillars, by means of histopathological assays. The Cry1Ab and Cry1Ac proteins, codified by the respective strains of B. thuringiensis, were evaluated in vivo by bioassays of 1st instar S. frugiperda caterpillars in order to determine the Mean Lethal Concentration (LC50. The results of the histopathological analysis of the midget of S. frugiperda caterpillars demonstrate that treatment with the B. thuringiensis thuringiensis strain was more efficient, because the degradations of the microvilosities started 9 hours after treatment application (HAT, while in the B. thuringiensis kurstaki the same effect was noticed only after 12 HAT. Toxicity data of the Cry1Ab and Cry1Ac proteins presented for the target-species LC50 levels of 9.29 and 1.79 μg.cm-2 respectively. The strains and proteins synthesised by B. thuringiensis thuringiensis and B. thuringiensis kurstaki are effective in controlling S. frugiperda, and may be used to produce new biopesticides or the genes may be utilised in the genetic transformation of Oryza sativa L.

Operational Evaluation Of Vectomax® WSP (Bacillus thuringiensis Subsp. israelensis+Bacillus sphaericus) Against Larval Culex pipiens in Septic Tanks (1).

Science.gov (United States)

Cetin, Huseyin; Oz, Emre; Yanikoglu, Atila; Cilek, James E

2015-06-01

The residual effectiveness of VectoMax® WSP (a water-soluble pouch formulation containing a combination of Bacillus thuringiensis subsp. israelensis strain AM65-52 and B. sphaericus strain ABTS 1743) when applied to septic tanks against 3rd- and 4th-stage larvae of Culex pipiens L. was evaluated in this study. This formulation was evaluated at operational application rates of 1 pouch (10 g) and 2 pouches (20 g) per septic tank. Both application rates resulted in >96% control of larvae for 24 days. Operationally, VectoMax WSP has proven to be a useful tool for the nonchemical control of Culex species in septic tank environments.

Evolution of Bacillus thuringiensis Cry toxins insecticidal activity.

Science.gov (United States)

Bravo, Alejandra; Gómez, Isabel; Porta, Helena; García-Gómez, Blanca Ines; Rodriguez-Almazan, Claudia; Pardo, Liliana; Soberón, Mario

2013-01-01

Insecticidal Cry proteins produced by Bacillus thuringiensis are use worldwide in transgenic crops for efficient pest control. Among the family of Cry toxins, the three domain Cry family is the better characterized regarding their natural evolution leading to a large number of Cry proteins with similar structure, mode of action but different insect specificity. Also, this group is the better characterized regarding the study of their mode of action and the molecular basis of insect specificity. In this review we discuss how Cry toxins have evolved insect specificity in nature and analyse several cases of improvement of Cry toxin action by genetic engineering, some of these examples are currently used in transgenic crops. We believe that the success in the improvement of insecticidal activity by genetic evolution of Cry toxins will depend on the knowledge of the rate-limiting steps of Cry toxicity in different insect pests, the mapping of the specificity binding regions in the Cry toxins, as well as the improvement of mutagenesis strategies and selection procedures. © 2012 The Authors. Microbial Biotechnology © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Toxicity and residual control of Plutella xylostella L. (Lepidoptera: Plutellidae with Bacillus thuringiensis Berliner and insecticides Toxicidade e controle residual de Plutella xylostella L. (Lepidoptera: Plutellidae com Bacillus thuringiensis Berliner e inseticidas

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Carla Pedroso de Moraes

2012-08-01

Full Text Available Plutella xylostella L. is the most important worldwide pest of cruciferous plants and indiscriminate use of insecticides has led to the resistance of the species to different groups. This research was conducted to compare the toxicity and persistence of two strains of Bacillus thuringiensis to P. xylostella larvae. Concentrations between 125 and 500g 100L-1 of water of the commercial products were evaluated and compared to the insect growth inhibitor diflubenzuron and to the neurotoxic pyrethroid deltamethrin. The efficacy of the insecticides was compared between treated plants kept indoor greenhouse and outdoor. Third instar larvae were more susceptible to B. thuringiensis than first instar ones. Agree and Dipel showed similar control rates of third instars until 10 days after treatment, but on the 15th day, Agree was significantly more efficient than Dipel. Both B. thuringiensis formulations showed a reduction in mortality after 10 days when the treated plants were exposed to natural weather conditions in comparison to the same treatments kept inside greenhouse. Dimilin (100g 100L-1 of water and deltamethrin (30ml of commercial product 100L-1 of water were not efficient to control third instar larvae of P. xylostella. This inefficiency cannot be attributed to a resistant population of P. xylostella since the larval population used in the experiments was not subjected to insecticide pressure, once the crop was organically cultivated all year round. The results showed that both formulations of B. thuringiensis are sound alternatives for the control of the diamondback moth in organically conducted cruciferous crops, considering the high residual control provided under subtropical weather conditions.Larvas de Plutella xylostella L. são as principais pragas de crucíferas cultivadas e o uso excessivo e indiscriminado de inseticidas tem levado a resistência da espécie para diferentes grupos de inseticidas. Este trabalho foi conduzido para

Slow release formulations of Bacillus thuringiensis israelensis (AM 65-52 and spinosyns: effectiveness against the West Nile vector Culex pipiens in Saudi Arabia

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Alaa Sulaiman Alsobhi

2016-07-01

Full Text Available Objective: To investigate the effectiveness of slow release formulations of Bacillus thuringiensis israelensis (AM 65-52 (B. thuringiensis israelensis and spinosyns against the West Nile vector Culex pipiens (Cx. pipiens in Saudi Arabia. Methods: We tested slow release insecticide formulations of Natular DT, Tap 60 and VectoBac granule against II instars of Cx. pipiens larvae in 50 L laboratory arenas. Results: Slow release formulations of B. thuringiensis israelensis and spinosyns gave continuous control against Cx. pipiens for several weeks. Natular DT was more effective over Tap 60 and VectoBac granule of about 1.3 and 5.8 times, respectively. Variations in the durations of effective control among the tested slow release formulations may reflect differences in their active ingredients and the mode of action. Conclusions: Our results highlighted the effectiveness of B. thuringiensis israelensis and spinosyns against an important West Nile vector, providing baseline data to develop ecofriendly mosquito control programs in Saudi Arabia.

Análisis del Klap como parámetro de escalado en fermentaciones de Bacillus thuringiensis subesp. Medellín

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Sergio Ordúz

2000-02-01

Full Text Available

Los biopesticidas basados en Bacillus thuringiensis son los de mayor producción y uso a nivel mundial. B. thuringiensis es una bacteria gram positiva que sintetiza proteínas d-endotoxinas que son tóxicas contra larvas de insectos de los géneros Díptera, Lepidóptera y Coleóptera. Las ventajas que tienen los biopesticidas en comparación a los agroquímicos convencionales son: 1 alta selectividad por los insectos blancos, 2 ningún efecto adverso al medio ambiente y 3 bajo índice de resistencia.

Detection of the mosquitocidal toxin genes encoding Cry11 proteins from Bacillus thuringiensis using a novel PCR-RFLP method Detección de genes que codifican proteínas mosquitocidas Cry11 de Bacillus thuringiensis mediante un método de PCR-RFLP novedoso

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D. H. Sauka

2010-02-01

Full Text Available A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP method for detection of cry11 genes from Bacillus thuringiensis was established. Based on the analysis of conserved regions of the cry11 genes, 2 oligonucleotide primers were designed to amplify a 1459-bp fragment of the cry11Aa gene, and a 1471-bp of the cry11Ba and cry11Bb genes. The amplification products were digested with restriction endonuclease HinfI. Exotic B. thuringiensis strains and native isolates collected from soils, leaves and stored product dust of Argentina were analyzed to study the distribution of cry11 genes. The PCR-RFLP patterns revealed the detection of cry11 genes in 3 of 64 exotic strains and in 10 of 107 native B. thuringiensis isolates tested. Just the cry11Aa gene subclass was detected among these bacteria. Since the methodology was also developed to detect cry11Ba and cry11Bb genes, an experimental future confirmation will be required. Based on the results obtained, the PCR-RFLP method presented may be a valuable tool for specific detection of the mosquitocidal toxin genes encoding Cry11 proteins from B. thuringiensis.En el presente estudio se estableció una estrategia basada en la amplificación génica (PCR y el posterior análisis de restricción (RFLP para detectar todos los genes cry11 de Bacillus thuringiensis informados hasta ahora. De acuerdo con el análisis de las regiones conservadas en los genes cry11, se diseñaron dos cebadores para amplificar un fragmento de 1459 pb de los genes cry11Aa y un fragmento de 1471 pb de los genes cry11Ba y cry11Bb. Los productos de la amplificación fueron digeridos con la enzima de restricción HinfI. Se analizaron cepas exóticas de B. thuringiensis y aislamientos nativos de Argentina obtenidos a partir de muestras de suelos, hojas y polvillo de silos, para estudiar la distribución de los genes cry11. Los patrones de PCR-RFLP revelaron la presencia de genes cry11 en 3 de las 64 cepas ex

Beneficial effects of bio-controlling agent Bacillus cereus IB311 on the agricultural crop production and its biomass optimization through response surface methodology

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GOUTAM BANERJEE

2017-10-01

Full Text Available ABSTRACT Disease in agricultural field is a big problem that causes a massive loss in production. In this present investigation, we have reported a soil-borne bacterium Bacillus cereus IB311 which is antagonistic to plant pathogens (Pseudomonas syringae and Agrobacterium tumefaciens, and could make a substantial contribution to the prevention of plant diseases. To prove the practical application, the strain was directly applied in agricultural field. The results demonstrated that B. cereus IB311 has increased the production (20% and 26% in term of average pod number per plant, average seed number per pod, and seed yield per experimental plot in ground nut (Arachis hypogaea var. Koushal, G201 and sesame (Sesamum indicum var. Kanak, respectively. To reduce the production cost, the biomass production was optimized through response surface methodology (RSM. Interactions of three variables (glucose, beef extract and inoculum were studied using Central Composite Design. According to our analysis, optimum production of Bacillus cereus IB311 (5.383 µg/ mL may be obtained at glucose 1.985%, beef extract 1.615% and inoculums size 0.757%. Therefore, we strongly believe that the application of this strain in agricultural field as bio-controlling agent will definitely enhance the production yield and will reduce the disease risk.

CARACTERIZACIÓN MOLECULAR MEDIANTE rep-PCR DE AISLADOS NATIVOS DE Bacillus thuringiensis, OBTENIDOS DE MUESTRAS DE SUELO

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Fabián Galvis

2014-01-01

Full Text Available Bacillus thuringiensis es una bacteria Gram-positiva formadora de esporas, que produ - ce cristales parasporales de naturaleza proteica, tóxicos contra diferentes órdenes de insectos y biodegradables e inocuos para otras especies. Esta investigación empleó el modelo experimen - tal, que mediante técnicas de observación permi - tió, la identificación microbiológica y bioquímica de B. thuringiensis a partir de muestras de suelo de los municipios de Cúcuta, El Zulia, Los Patios, San Cayetano y Villa del Rosario, Norte de Santander, Colombia, y su posterior caracteri - zación con los marcadores moleculares Bc-Rep y MB1. Se identificaron microbiológica y bioquí - micamente 10 aislados como B. thuringiensis ; los resultados del análisis filogenético mostraron diferencias significativas en los agrupamientos obtenidos con los marcadores Bc-Rep y MB1. Con Bc-Rep se registró un índice de similaridad bajo (18%, mientras que con el marcador MB1 se obtuvo un índice mayor de similitud, 58%. En este trabajo se evidenció una gran variabilidad genética entre los aislados, que mostraron a los marcadores Bc-Rep y MB1 como altamente efectivos para diferenciar cepas estrechamente relacionadas, convirtiéndose en una herramienta genética de gran valor para estudios de identifi-cación y diversidad en B. thuringiensis.

Optimization of the production conditions of the lipase produced by Bacillus cereus from rice flour through Plackett-Burman Design (PBD) and response surface methodology (RSM).

Science.gov (United States)

Vasiee, Alireza; Behbahani, Behrooz Alizadeh; Yazdi, Farideh Tabatabaei; Moradi, Samira

2016-12-01

In this study, the screening of lipase positive bacteria from rice flour was carried out by Rhodamin B agar plate method. Bacillus cereus was identified by 16S rDNA method. Screening of the appropriate variables and optimization of the lipase production was performed using Plackett-Burman design (PBD) and response surface methodology (RSM). Among the isolated bacteria, an aerobic Bacillus cereus strain was recognized as the best lipase-producing bacteria (177.3 ± 20 U/ml). Given the results, the optimal enzyme production conditions were achieved with coriander seed extract (CSE)/yeast extract ratio of 16.9 w/w, olive oil (OO) and MgCl 2 concentration of 2.37 g/L and 24.23 mM, respectively. In these conditions, the lipase activity (LA) was predicted 343 U/mL that was approximately close to the predicted value (324 U/mL), which was increased 1.83 fold LA compared with the non-optimized lipase. The kinetic parameters of V max and K m for the lipase were measured 0.367 μM/min.mL and 5.3 mM, respectively. The lipase producing Bacillus cereus was isolated and RSM was used for the optimization of enzyme production. The CSE/yeast extract ratio of 16.9 w/w, OO concentration of 2.37 g/L and MgCl 2 concentration of 24.23 mM, were found to be the optimal conditions of the enzyme production process. LA at optimal enzyme production conditions was observed 1.83 times more than the non-optimal conditions. Ultimately, it can be concluded that the isolated B. cereus from rice flour is a proper source of lipase. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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Nan Jia

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

Heat and desiccation are the predominant factors affecting inactivation of Bacillus licheniformis and Bacillus thuringiensis spores during simulated composting.

Science.gov (United States)

Stanford, K; Harvey, A; Barbieri, R; Xu, S; Reuter, T; Amoako, K K; Selinger, L B; McAllister, T A

2016-01-01

The suitability of composting for disposal of livestock mortalities due to Bacillus anthracis was assessed by measuring viability of surrogate spores from two strains each of Bacillus licheniformis and Bacillus thuringiensis after a heating cycle modelled on a cattle composting study. Sporulation was attempted from 10 to 37°C, but poor yields at lower temperatures resulted in 25, 30 and 37°C being selected to generate sufficient spores (8 log10  CFU ml(-1) ) for experiments. Spores were inoculated into 3 g autoclaved dried-ground compost rehydrated with 6 ml water or silica beads in a factorial design for each strain, sporulation temperature, matrix and sampling day (0, 25, 50, 100, 150). Maximum incubation temperature was 62°C, but spores were maintained at ≥55°C for 78 of 150 days. Although significant differences existed among Bacillus strains and sporulation temperatures, numbers of viable spores after 150 days averaged 1·3 log10  CFU g(-1) , a 5·2 log10 reduction from day 0. Spore inactivation was likely due to heat and desiccation as matrices were autoclaved prior to incubation, negating impacts of microflora. Results support composting for disposal of anthrax mortalities, provided long-term thermophillic heating is achieved. Due to limited sporulation at 10°C, livestock mortalities from anthrax at this or lower ambient temperatures would likely be of lower risk for disease transmission. © 2015 The Society for Applied Microbiology.

Control of bacillus cereus spore germination and outgrowth in cooked rice during chilling by nonorganic and organic appled, orange, and potato peel powders

Science.gov (United States)

The inhibition of Bacillus cereus spore germination and outgrowth in cooked rice by nine fruit and vegetable peel powders prepared from store-bought conventional (nonorganic) and organic apples, oranges, and potatoes was investigated. The powders were mixed into rice at 10% (wt/wt) along with heat ...

Caracterización de una delta endotoxina mutante de Bacillus thuringiensis con estabilidad y toxicidad aumentadas

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A. Hussain Syed Rehan

2012-06-01

Full Text Available Título en ingles: Characterization of a Mutant Bacillus thuringiensis d-endotoxin With Enhanced Stability and Toxicity SummaryThe centrally located a-helix 5 of Bacillus thuringiensis d-endotoxins is critical for insect toxicity through ion-channel formation. We analyzed the role of the highly conserved residue Histidine 168 (H168 using molecular biology, electrophysiology and biophysical techniques. Toxin H168R was ~3-fold more toxic than the wild type (wt protein whereas H168Q was 3 times less toxic against Manduca sexta. Spectroscopic analysis revealed that the H168Q and H168R mutations did not produce gross structural alterations, and that H168R (Tm= 59 °C was more stable than H168Q (Tm= 57.5 °C or than the wt (Tm= 56 °C toxins. These three toxins had similar binding affinities for larval midgut vesicles (Kcom suggesting that the differences in toxicity did not result from changes in initial receptor binding. Dissociation binding assays and voltage clamping analysis suggest that the reduced toxicity of the H168Q toxin may result from reduced insertion and/or ion channel formation. In contrast, the H168R toxin had a greater inhibition of the short circuit current than the wt toxin and an increased rate of irreversible binding (kobs, consistent with its lower LC50 value.  Molecular modeling analysis suggested that both the H168Q and H168R toxins could form additional hydrogen bonds that could account for their greater thermal stability. In addition to this, it is likely that H168R has an extra positive charge exposed to the surface which could increase its rate of insertion into susceptible membranes. Key words: a-helix 5; Circular dichroism; molecular modeling; site-directed mutagenesis;  thermal stability; Bacillus thuringiensis ResumenLa a-Hélice 5 del domino I de las d-endotoxinas de Bacillus thuringiensis, es crítica para la toxicidad de las toxinas contra insectos al participar en la formación de canales iónicos. La

Eficiência e Persistência de Três Produtos Comerciais à Base de Bacillus thuringiensis israelensis e Bacillus sphaericus no controle de Culicidae (Diptera em Lagoas de Tratamento de Efluentes

Directory of Open Access Journals (Sweden)

Jose Lopes

2010-11-01

Abstract. The hematofagic effect caused by females belonging to some species of Culicidae on humans and animals can be directly related to pathogen transmission, allergic reactions and uneasiness. The emergence of populations resistant to chemical insecticides has fostered the use of alternative methods, mainly biological control. The trials were conducted in three effluent treatment lagoons, on larvae of Culicidae to test the efficiency and persistence of commercial products whose active principles are based on Bacillus thuringiensis israelensis Berliner and Bacillus sphaericus Neide. The products tested were Vectolex (a granulated formulation of B. sphaericus, Sphaericus (a liquid formulation of B. sphaericus and Bt-horus (a liquid formulation of B. thuringiensis. The products were applied biweekly and evaluations were conducted 0, 24, 48, 72, and 120 hours after each application. The lagoons were colonized by Culex nigripalpus Theobald (1.5%, Culex saltanensis Dyar (2.25%, and Culex quinquefasciatus Say (96.25%. Bt-horus reduced larvae by 89.06%, 83.97% and 89.96% at 24, 48 and 72 hours after product application, respectively. The granulated and the liquid formulations containing B. sphaericus reduced larvae by 98.89 % and 98.34% 24 hours after application, and by 99.79% and 99.78% after 48 hours, respectively. The products and the different formulations were effective in controlling larvae of all three Culicidae species in lagoons with high levels of organic matter, but the persistence was recorded in two and three days for products containing respectively B. sphaericus and B. thuringiensis israelensis.

Evaluation of nutrients removal (NO3-N, NH3-N and PO4-P) with Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and a consortium of these microorganisms in the treatment of wastewater effluents.

Science.gov (United States)

Gómez-Guzmán, Abril; Jiménez-Magaña, Sergio; Guerra-Rentería, A Suggey; Gómez-Hermosillo, César; Parra-Rodríguez, F Javier; Velázquez, Sergio; Aguilar-Uscanga, Blanca Rosa; Solis-Pacheco, Josue; González-Reynoso, Orfil

2017-07-01

In this research removal of NH 3 -N, NO 3 -N and PO 4 -P nutrients from municipal wastewater was studied, using Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and an artificial consortium of them. The objective is to analyze the performance of these microorganisms and their consortium, which has not been previously studied for nutrient removal in municipal wastewater. A model wastewater was prepared simulating the physicochemical characteristics found at the wastewater plant in Chapala, Mexico. Experiments were carried out without adding an external carbon source. Results indicate that nutrient removal with Chlorella vulgaris was the most efficient with a removal of 24.03% of NO 3 -N, 80.62% of NH 3 -N and 4.30% of PO 4 -P. With Bacillus cereus the results were 8.40% of NO 3 -N, 28.80% of NH 3 -N and 3.80% of PO 4 -P. The removals with Pseudomonas putida were 2.50% of NO 3 -N, 41.80 of NH 3 -N and 4.30% of PO 4 -P. The consortium of Chlorella vulgaris-Bacillus cereus-Pseudomonas putida removed 29.40% of NO 3 -N, 4.2% of NH 3 -N and 8.4% of PO 4 -P. The highest biomass production was with Bacillus cereus (450 mg/l) followed by Pseudomonas putida (444 mg/l), the consortium (205 mg/l) and Chlorella vulgaris (88.9 mg/l). This study highlights the utility of these microorganisms for nutrient removal in wastewater treatments.

Impact of UV radiation on activity of linear furanocoumarins and Bacillus thuringiensis var. kurstaki against Spodoptera exigua: Implications for tritrophic interactions

Energy Technology Data Exchange (ETDEWEB)

Trumble, J.T.; Moar, W.J.; Brewer, M.J.; Carson, W.G. (Univ. of California, Riverside (United States))

1991-05-01

Acidic fogs with a pH of 2.0 and duration of 2 hr did not reduce the efficacy of Bacillus thuringiensis var. kurstaki. Therefore, the impact of UV radiation was investigated on the interactions between (1) levels of the antibacterial linear furanocoumarins psoralen, bergapten, and xanthotoxin in Apium graveolens (L.) occurring following a 2.0 pH acidic fog episode, (2) the noctuid Spodoptera exigua, and (3) a sublethal dosage of the microbial pathogen B. thuringiensis var. kurstaki. Mean time to pupation in the absence of UV radiation was significantly extended by the addition of either psoralens or B. thuringiensis. Larvae developing on diets containing B. thuringiensis plus psoralens required nearly 40% longer to pupate than controls, but their effects were additive as the interaction was not significant. Mean time to mortality, a weighted average time of death, was not significantly affected by any of the treatments. In a 2 {times} 2 {times} 2 factorial analysis, all main effects reduced survival significantly, as did the three-way interaction. Thus, antagonistic interactions with psoralens that would reduce the effectiveness of B. thuringiensis in the field were not observed. When pairs of main effects were nested within the two levels of the third factor, several two-way interactions were found. Interestingly, the activity of B. thuringiensis and the psoralens, individually or in combination, was enhanced by exposure to UV radiation. Implications of this research are discussed for both natural and agricultural ecosystems.

Impact of UV radiation on activity of linear furanocoumarins and Bacillus thuringiensis var. kurstaki against Spodoptera exigua: Implications for tritrophic interactions

International Nuclear Information System (INIS)

Trumble, J.T.; Moar, W.J.; Brewer, M.J.; Carson, W.G.

1991-01-01

Acidic fogs with a pH of 2.0 and duration of 2 hr did not reduce the efficacy of Bacillus thuringiensis var. kurstaki. Therefore, the impact of UV radiation was investigated on the interactions between (1) levels of the antibacterial linear furanocoumarins psoralen, bergapten, and xanthotoxin in Apium graveolens (L.) occurring following a 2.0 pH acidic fog episode, (2) the noctuid Spodoptera exigua, and (3) a sublethal dosage of the microbial pathogen B. thuringiensis var. kurstaki. Mean time to pupation in the absence of UV radiation was significantly extended by the addition of either psoralens or B. thuringiensis. Larvae developing on diets containing B. thuringiensis plus psoralens required nearly 40% longer to pupate than controls, but their effects were additive as the interaction was not significant. Mean time to mortality, a weighted average time of death, was not significantly affected by any of the treatments. In a 2 x 2 x 2 factorial analysis, all main effects reduced survival significantly, as did the three-way interaction. Thus, antagonistic interactions with psoralens that would reduce the effectiveness of B. thuringiensis in the field were not observed. When pairs of main effects were nested within the two levels of the third factor, several two-way interactions were found. Interestingly, the activity of B. thuringiensis and the psoralens, individually or in combination, was enhanced by exposure to UV radiation. Implications of this research are discussed for both natural and agricultural ecosystems

Two New Secreted Proteases Generate a Casein-Derived Antimicrobial Peptide in Bacillus cereus Food Born Isolate Leading to Bacterial Competition in Milk

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Awatef Ouertani

2018-06-01

Full Text Available Milk and dairy products harbor a wide variety of bacterial species that compete for both limited resources and space. Under these competitive conditions, bacteria develop specialized mechanisms to protect themselves during niche colonization and nutrient acquisition processes. The bacterial antagonism mechanisms include the production of antimicrobial agents or molecules that facilitate competitor dispersal. In the present work, a bacterial strain designated RC6 was isolated from Ricotta and identified as Bacillus cereus. It generates antimicrobial peptide (AMP when grown in the presence of casein. The AMP was active against several species of Bacillus and Listeria monocytogenes. MALDI-TOF analysis of the RP-HPLC purified fractions and amino acid sequencing revealed a molecular mass of 751 Da comprised of a 6-residue sequence, YPVEPF. BLAST analysis showed that the AMP corresponds to the fractions 114–119 of bovine β-casein and represents the product of a specific proteolysis. Analysis of the purified proteolytic fractions from the B. cereus RC6 culture supernatant indicated that the presence of at least two different endoproteases is crucial for the generation of the AMP. Indeed, we were able to identify two new candidate endoproteases by means of genome sequencing and functional assignment using a 3D structural model and molecular docking of misannotated hypothetical proteins. In this light, the capacity of B. cereus RC6 to generate antimicrobial peptides from casein, through the production of extracellular enzymes, presents a new model of antagonistic competition leading to niche colonization. Hence, as a dairy product contaminant, this strategy may enable proteolytic B. cereus RC6 niche specialization in milk matrices.

Structural basis of the phospholipase C activity in neutral sphingomyelinase from Bacillus cereus

International Nuclear Information System (INIS)

Ago, Hideo; Miyano, Masashi

2007-01-01

Degradation of cell membrane and mucosa, of which phospholipids are major components, and production of lipid mediators are roles of phospholipases from pathogenic bacteria to grow, survive and spread in the host organism. The studies on the enzymes the important for the pathobiology of bacterial infectious disease. The crystal structure of Sphingomyelinase from Bacillus cereus revealed the structure basis of the phospholipase C and hemolysis activities in a divalent cation dependent manner. The water-bridged double divalent cations were concluded to be the catalytic architecture to the phospholipase C activity. In addition, the β-hairpin structure with aromatic amino acid residues was shown to be involved in the membrane binding of the enzyme as a part of the hemolysis activity. (author)

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

Science.gov (United States)

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

2018-01-01

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

Decontamination of materials contaminated with Bacillus anthracis and Bacillus thuringiensis Al Hakam spores using PES-Solid, a solid source of peracetic acid.

Science.gov (United States)

Buhr, T L; Wells, C M; Young, A A; Minter, Z A; Johnson, C A; Payne, A N; McPherson, D C

2013-08-01

To develop test methods and evaluate survival of Bacillus anthracis Ames, B. anthracis ∆Sterne and B. thuringiensis Al Hakam spores after exposure to PES-Solid (a solid source of peracetic acid), including PES-Solid formulations with bacteriostatic surfactants. Spores (≥ 7 logs) were dried on seven different test materials and treated with three different PES-Solid formulations (or preneutralized controls) at room temperature for 15 min. There was either no spore survival or less than 1 log (<10 spores) of spore survival in 56 of 63 test combinations (strain, formulation and substrate). Less than 2.7 logs (<180 spores) survived in the remaining seven test combinations. The highest spore survival rates were seen on water-dispersible chemical agent resistant coating (CARC-W) and Naval ship topcoat (NTC). Electron microscopy and Coulter analysis showed that all spore structures were intact after spore inactivation with PES-Solid. Three PES-Solid formulations inactivated Bacillus spores that were dried on seven different materials. A test method was developed to show that PES-Solid formulations effectively inactivate Bacillus spores on different materials. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Vacuum distillation residue upgrading by an indigenous Bacillus cereus.

Science.gov (United States)

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.

40 CFR 174.505 - Bacillus thuringiensis modified Cry3A protein (mCry3A) in corn; exemption from the requirement of...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis modified Cry3A protein (mCry3A) in corn; exemption from the requirement of a tolerance. 174.505 Section 174.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

Spatial and temporal distribution of airborne Bacillus thuringiensis var. kurstaki during an aerial spray program for gypsy moth eradication.

OpenAIRE

Teschke, K; Chow, Y; Bartlett, K; Ross, A; van Netten, C

2001-01-01

We measured airborne exposures to the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) during an aerial spray program to eradicate gypsy moths on the west coast of Canada. We aimed to determine whether staying indoors during spraying reduced exposures, to determine the rate of temporal decay of airborne concentrations, and to determine whether drift occurred outside the spray zone. During spraying, the average culturable airborne Btk concentration measured outdoors within the...

Inactivation kinetics of spores of Bacillus cereus strains treated by a peracetic acid-based disinfectant at different concentrations and temperatures.

Science.gov (United States)

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.

Draft genome sequence of Bacillus thuringiensis strain BrMgv02-JM63, a chitinolytic bacterium isolated from oil-contaminated mangrove soil in Brazil

NARCIS (Netherlands)

Marcon, Joelma; Taketani, Rodrigo Gouvêa; Dini-Andreote, Francisco; Mazzero, Giulia Inocêncio; Soares Junior, Fabio Lino; Melo, Itamar Soares; Azevedo, João Lúcio; Andreote, Fernando Dini

2014-01-01

Here, we report the draft genome sequence and the automatic annotation of Bacillus thuringiensis strain BrMgv02-JM63. This genome comprises a set of genes involved in the metabolism of chitin and N-acetylglucosamine utilization, thus suggesting the possible role of this strain in the cycling of

A differentially displayed mRNA related to restistance to Bacillus thuringiensis israelensis of Aedes albopictus selected in vitro-activated CYT1AA6

Czech Academy of Sciences Publication Activity Database

Zhang, L.; Zhang, Q.; Huang, E.; Li, M.; Huang, T.; Xu, L.; Wu, Ch.; Guan, X.; Gelbič, Ivan

2012-01-01

Roč. 28, č. 4 (2012), s. 327-329 ISSN 8756-971X Institutional support: RVO:60077344 Keywords : Bacillus thuringiensis israelensis * resistence * Aedes albopictus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.755, year: 2012 http://www.bioone.org/doi/pdf/10.2987/12-6263R.1

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

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Marie Bräunlich

2013-12-01

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

Antagonistics against pathogenic Bacillus cereus in milk fermentation by Lactobacillus plantarum ZDY2013 and its anti-adhesion effect on Caco-2 cells against pathogens.

Science.gov (United States)

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.

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

African Journals Online (AJOL)

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

Use of Fatty Acid Methyl Ester Profiles for Discrimination of Bacillus cereus T-Strain Spores Grown on Different Media▿

OpenAIRE

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 similarit...

Impacts of sporulation temperature, exposure to compost matrix and temperature on survival of Bacillus cereus spores during livestock mortality composting.

Science.gov (United States)

Stanford, K; Reuter, T; Gilroyed, B H; McAllister, T A

2015-04-01

To investigate impact of sporulation and compost temperatures on feasibility of composting for disposal of carcasses contaminated with Bacillus anthracis. Two strains of B. cereus, 805 and 1391, were sporulated at either 20 or 37°C (Sporulation temperature, ST) and 7 Log10 CFU g(-1) spores added to autoclaved manure in nylon bags (pore size 50 μm) or in sealed vials. Vials and nylon bags were embedded into compost in either a sawdust or manure matrix each containing 16 bovine mortalities (average weight 617 ± 33 kg), retrieved from compost at intervals over 217 days and survival of B. cereus spores assessed. A ST of 20°C decreased spore survival by 1·4 log10 CFU g(-1) (P Compost temperatures >55°C reduced spore survival (P compost temperatures were key factors influencing survival of B. cereus spores in mortality compost. Composting may be most appropriate for the disposal of carcasses infected with B. anthracis at ambient temperatures ≤20°C under thermophillic composting conditions (>55°C). © 2015 The Society for Applied Microbiology.

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

DEFF Research Database (Denmark)

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

2001-01-01

of the B. cereus group in food and in the environment. Using 16S rDNA as target, a PCR assay for the detection of B. cereus group cells has been developed. Primers specific for the 16S rDNA of the B. cereus group bacteria were selected and used in combination with consensus primers for 165 rDNA as internal...... PCR procedure control. The PCR procedure was optimized with respect to annealing temperature. When DNA from the B. cereus group bacteria was present, the PCR assay yielded a B. cereus specific fragment, while when non-B. cereus prokaryotic DNA was present, the consensus 165 rDNA primers directed...

The mechanism of uranium transformation from U(VI) into nano-uramphite by two indigenous Bacillus thuringiensis strains

Energy Technology Data Exchange (ETDEWEB)

Pan, Xiaohong; Chen, Zhi [Key Lab of Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education & Fujian–Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian 350002 (China); Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chen, Fanbing [Key Lab of Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education & Fujian–Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian 350002 (China); Cheng, Yangjian [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Lin, Zhang, E-mail: zlin@fjirsm.ac.cn [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Guan, Xiong, E-mail: guanxfafu@126.com [Key Lab of Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education & Fujian–Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian 350002 (China)

2015-10-30

Highlights: • Indigenous B. thuringiensis exhibited highly accumulation ability to U(VI) in the absence of additional nutrients. • The amorphous uranium compound would transformed into crystalline nano-uramphite by B. thuringiensis. • The chemical nature of formed U-species were monitored. • The cell-free extracts of B. thuringiensis had better uranium-immobilization ability than its cell debris. • Provided the understanding of the uranium transformation mechanism. - Abstract: The mechanism of uranium transformation from U(VI) into nano-uramphite by two indigenous Bacillus thuringiensis strains was investigated in the present work. Our data showed that the bacteria isolated from uranium mine possessed highly accumulation ability to U(VI), and the maximum accumulation capacity was around 400 mg U/g biomass (dry weight). X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) analyzes indicated that the U(VI) was adsorbed on the bacterial surface firstly through coordinating with phosphate, −CH{sub 2} and amide groups, and then needle-like amorphous uranium compounds were formed. With the extension of time, the extracellular crystalline substances were disappeared, but some particles were appeared in the intracellular region, and these particles were characterized as tetragonal-uramphite. Moreover, the disrupted experiment indicated that the cell-free extracts had better uranium-immobilization ability than cell debris. Our findings provided the understanding of the uranium transformation process from amorphous uranium to crystalline uramphite, which would be useful in the regulation of uranium immobilization process.

The mechanism of uranium transformation from U(VI) into nano-uramphite by two indigenous Bacillus thuringiensis strains

International Nuclear Information System (INIS)

Pan, Xiaohong; Chen, Zhi; Chen, Fanbing; Cheng, Yangjian; Lin, Zhang; Guan, Xiong

2015-01-01

Highlights: • Indigenous B. thuringiensis exhibited highly accumulation ability to U(VI) in the absence of additional nutrients. • The amorphous uranium compound would transformed into crystalline nano-uramphite by B. thuringiensis. • The chemical nature of formed U-species were monitored. • The cell-free extracts of B. thuringiensis had better uranium-immobilization ability than its cell debris. • Provided the understanding of the uranium transformation mechanism. - Abstract: The mechanism of uranium transformation from U(VI) into nano-uramphite by two indigenous Bacillus thuringiensis strains was investigated in the present work. Our data showed that the bacteria isolated from uranium mine possessed highly accumulation ability to U(VI), and the maximum accumulation capacity was around 400 mg U/g biomass (dry weight). X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) analyzes indicated that the U(VI) was adsorbed on the bacterial surface firstly through coordinating with phosphate, −CH 2 and amide groups, and then needle-like amorphous uranium compounds were formed. With the extension of time, the extracellular crystalline substances were disappeared, but some particles were appeared in the intracellular region, and these particles were characterized as tetragonal-uramphite. Moreover, the disrupted experiment indicated that the cell-free extracts had better uranium-immobilization ability than cell debris. Our findings provided the understanding of the uranium transformation process from amorphous uranium to crystalline uramphite, which would be useful in the regulation of uranium immobilization process

Comparative analysis of Bacillus thuringiensis toxin binding to gypsy moth, browntail moth, and douglas-fir tussock moth midgut tissue sections using fluorescence microscopy

Science.gov (United States)

Algimantas P. Valaitis; John D. Podgwaite

2011-01-01

Many strains of Bacillus thuringiensis (Bt) produce insecticidal proteins, also referred to as Cry toxins, in crystal inclusions during sporulation. When ingested by insects, the Cry toxins bind to receptors on the brush border midgut epithelial cells and create pores in the epithelial gut membranes resulting in the death of...

Changes in protease activity and Cry3Aa toxin binding in the Colorado potato beetle: implications for insect resistance to Bacillus thuringiensis toxins

Science.gov (United States)

Olga Loseva; Mohamed Ibrahim; Mehmet Candas; C. Noah Koller; Leah S. Bauer; Lee A. Jr. Bulla

2002-01-01

Widespread commercial use of Bacillus thuringiensis Cry toxins to control pest insects has increased the likelihood for development of insect resistance to this entomopathogen. In this study, we investigated protease activity profiles and toxin-binding capacities in the midgut of a strain of Colorado potato beetle (CPB) that has developed resistance...

Uso de productos derivados de Bacillus thuringiensis como alternativa de control en nematodos de importancia veterinaria. Revisión

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Alejandro Vázquez-Pineda

2012-01-01

Full Text Available La bacteria entomopatógena Bacillus thuringiensis produce cristales proteicos con actividad citotóxica en contra de insectos y nematodos. La toxicidad de B. thuringiensis en plagas agrícolas es ampliamente conocida, pero poco se conoce acerca de su actividad en contra de nematodos parásitos. Recientemente, la actividad nematicida de las proteínas derivadas de B. thuringiensis se demostró en parásitos de mamíferos como Haemonchus, Teladorsagia, Nippostrongylus, y Ancylostoma, y en nematodos de plantas, Globodera y Meloidogyne. Entre el grupo de B. thuringiensis con efecto nematicida, las proteínas de la cepa IB-16 han mostrado actividad letal de 50 a 100 % en contra de diferentes estadios del principal género de rumiantes, Haemonchus contortus. Asimismo, los géneros de nematodos de vida libre, Panagrellus redivivus y Caenorhabditis elegans han sido blanco de estudios de la acción nematicida de B. thuringiensis. Por ejemplo, el efecto tóxico de la proteína Cry5B de B. thuringiensis se observó en las células intestinales de C. elegans, además esta acción parece involucrar receptores celulares específicos, similares a los que se han notificado en contra de plagas agrícolas. Asimismo, la unión de la proteína Cry5B ocurre en receptores específicos, como moléculas de carbohidratos, las cuales están presentes en la membrana de las células de intestino de los nematodos, ocasionando daño y muerte. A través de este tipo de estudios, los derivados de B. thuringiensis podrían considerarse una alternativa de control en nematodos que afectan a los animales domésticos, como rumiantes, así como en contra de otros nematodos patógenos de mamíferos e incluso de plantas agrícolas.

Correspondence of High Levels of Beta-Exotoxin I and the Presence of cry1B in Bacillus thuringiensis

Science.gov (United States)

Espinasse, Sylvain; Gohar, Michel; Chaufaux, Josette; Buisson, Christophe; Perchat, Stéphane; Sanchis, Vincent

2002-01-01

Examination of 640 natural isolates of Bacillus thuringiensis showed that the 58 strains (9%) whose supernatants were toxic to Anthonomus grandis (Coleoptera: Curculionidae) produced between 10 and 175 μg of β-exotoxin I per ml. We also found that 55 (46%) of a sample of 118 strains whose culture supernatants were not toxic to A. grandis nevertheless produced between 2 and 5 μg/ml. However, these amounts of β-exotoxin I were below the threshold for detectable toxicity against this insect species. Secretion of large amounts of β-exotoxin I was strongly associated with the presence of cry1B and vip2 genes in the 640 natural B. thuringiensis isolates studied. We concluded that strains carrying cry1B and vip2 genes also possess, on the same plasmid, genetic determinants necessary to promote high levels of production of β-exotoxin I. PMID:12200263

Prevalence, isolation and characterization of Bacillus cereus strains from rice of local cultivators of Sabah, Sarawak, and Peninsular Malaysia

Science.gov (United States)

Sawei, Jelin; Sani, Norrakiah Abdullah

2016-11-01

Bacillus cereus is a spore-forming, facultative anaerobic, motile microorganism that has been identified as a causative agent of two types of gastrointestinal diseases such as emetic and diarrhea. This foodborne pathogen is found in both vegetative cells and endospores form in foods such as rice either raw or cooked. The aim of this study is to investigate and determine the prevalence, characterize and identify the isolation of vegetative cells and endospores of B. cereus in thirty varieties (n=3) of raw rice from Sabah, Sarawak and Peninsular Malaysia. A total of 90 (n=90) raw rice were examined and 84 (93.33%) samples were positive to vegetative cells of B. cereus. However, only 32 (35.56%) samples were positive for endospore cells that able to germinate after samples were heated at 75°C for 15 mins. The mean log cfu/g for vegetative cells were higher range (0.00 - 4.1533) than visible endospores (0.00 - 3.7533 mean log cfu/g). Sample of raw red rice (UKMRC9) had significantly higher contamination by both vegetative cells and endospores at p<0.05, than the other raw rice samples.

In silico and in vitro evaluation of PCR-based assays for the detection of Bacillus anthracis chromosomal signature sequences

DEFF Research Database (Denmark)

Ågren, Joakim; Hamidjaja, Raditijo A.; Hansen, Trine

2013-01-01

Bacillus anthracis, the causative agent of anthrax, is a zoonotic pathogen that is relatively common throughout the world and may cause life threatening diseases in animals and humans. There are many PCR-based assays in use for the detection of B. anthracis. While most of the developed assays rely...... on unique markers present on virulence plasmids pXO1 and pXO2, relatively few assays incorporate chromosomal DNA markers due to the close relatedness of B. anthracis to the B. cereus group strains. For the detection of chromosomal DNA, different genes have been used, such as BA813, rpoB, gyrA, plcR, S...... targets evaluated are claimed to be specific to B. anthracis, cross-reactions with closely related B. cereus and B. thuringiensis strains were often observed. Of the 35 investigated PCR assays, only 4 were 100% specific for the B. anthracis chromosome. An interlaboratory ring trial among five European...

Potency of Bacillus thuringiensis isolates from bareng Tenes-Malang City as a biological control agent for suppressing third instar of Aedes aegypti larvae

Science.gov (United States)

Lutfiana, Nihayatul; Gama, Zulfaidah Penata

2017-11-01

Dengue is a mosquito-borne viral disease that is transmitted by the female Aedes species. The number of dengue fever cases has increased in many geographic regions including Indonesia and one of them occurred in Bareng Tenes, Malang City, East Java Province. The objective of this research was to identify the potency of B. thuringeinsis isolates from Bareng Tenes, Malang, as the biological agent to control third instar Ae. aegypti larvae and to identify the potential B. thuringiensis isolates based on 16S rDNA sequence. B. thuringiensis was isolated from water and soil from 12 sites in the Bareng Tenes area. Bacterial isolation was performed using B. thuringiensis selective media. Several isolates had similar phenotypic characters with B. thuringiensis used to toxicity test against third instar Ae. aegypti larvae. The LC50-96h value was determined using probit regression. The most effective isolate was identified based on the 16S rDNA sequence, then aligned to the reference isolate using the BLAST program. A phylogeny tree was constructed using the Maximum Likelihood method. This study showed that among 22 isolates of B. thuringiensis, only BA02b, BS04a, and BA03a isolates have similar phenotypic characters with B. thuringiensis. Based on the toxicity test of B. thuringiensis against the third instar of Ae. aegypti larvae, it was indicated that BA02b and BA03a isolates were the potential agents to control Ae. aegypti larvae. BA02b isolate was the most effective B. thuringiensis (LC50-96h = 2,75 x 107 cell/mL). Based on 16S rDNA sequence, BA02b was identified as Bacillus thuringiensis var. Israelensis BGSC4Q2 (99 % similarities).

Persistence of Toxic Activity of Fermentation Extracts from Bacillus thuringiensis var. israelensis after More Than Three Decades of Storage

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Luis Jesús Galán-Wong

2017-01-01

Full Text Available This study was carried out to determine the persistence of toxicity of fermentation extracts of Bacillus thuringiensis var. israelensis after more than three decades of storage. For this purpose, a population of Aedes aegypti was established. The mortality rate of 20 spore-crystal extracts purified using the acetone-lactose coprecipitation method was measured and evaluated by bioassays according to a modified WHO protocol. The extracts with the highest mortality rate were determined in triplicate by their LD50 and LD98. All extracts showed toxicity at the highest tested dose (1000 ppm and some, such as strains 3260 and 3501, still killed larvae at doses as low as 0.01 ppm. These data are surprising because no study on the activity of B. thuringiensis toxic proteins after such a long storage time has been reported.

c-di-GMP Regulates Various Phenotypes and Insecticidal Activity of Gram-Positive Bacillus thuringiensis

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Yang Fu

2018-02-01

Full Text Available C-di-GMP has been well investigated to play significant roles in the physiology of many Gram-negative bacteria. However, its effect on Gram-positive bacteria is less known. In order to more understand the c-di-GMP functions in Gram-positive bacteria, we have carried out a detailed study on the c-di-GMP-metabolizing enzymes and their physiological functions in Bacillus thuringiensis, a Gram-positive entomopathogenic bacterium that has been applied as an insecticide successfully. We performed a systematic study on the ten putative c-di-GMP-synthesizing enzyme diguanylate cyclases (DGCs and c-di-GMP-degrading enzyme phosphodiesterases (PDEs in B. thuringiensis BMB171, and artificially elevated the intracellular c-di-GMP level in BMB171 by deleting one or more pde genes. We found increasing level of intracellular c-di-GMP exhibits similar activities as those in Gram-negative bacteria, including altered activities in cell motility, biofilm formation, and cell-cell aggregation. Unexpectedly, we additionally found a novel function exhibited by the increasing level of c-di-GMP to promote the insecticidal activity of this bacterium against Helicoverpa armigera. Through whole-genome transcriptome profile analyses, we found that 4.3% of the B. thuringiensis genes were differentially transcribed when c-di-GMP level was increased, and 77.3% of such gene products are involved in some regulatory pathways not reported in other bacteria to date. In summary, our study represents the first comprehensive report on the c-di-GMP-metabolizing enzymes, their effects on phenotypes, and the transcriptome mediated by c-di-GMP in an important Gram-positive bacterium.

A method for the determination of bacterial spore DNA content based on isotopic labelling, spore germination and diphenylamine assay; ploidy of spores of several Bacillus species

International Nuclear Information System (INIS)

Hauser, P.M.; Karamata, D.

1992-01-01

A reliable method for measuring the spore DNA content, based on radioactive DNA labelling, spore germination in absence of DNA replication and diphenylamine assay, was developed. The accuracy of the method, within 10 - 15%, is adequate for determining the number of chromosomes per spore, provided that the genome size is known. B subtilis spores were shown to be invariably monogenomic, while those of larger bacilli Bacillus megaterium, Bacillus cereus and Bacillus thuringiensis, often, if not invariably, contain two genomes. Attempts to modify the spore DNA content of B subtilis by altering the richness of the sporulation medium, the sporulation conditions (liquid or solid medium), or by mutation, were apparently unsuccessful. An increase of spore size with medium richness, not accompanied by an increase in DNA content, was observed. The implication of the apparently species-specific spore ploidy and the influence of the sporulation conditions on spore size and shape are discussed

Mannose Phosphate Isomerase Isoenzymes in Plutella xylostella Support Common Genetic Bases of Resistance to Bacillus thuringiensis Toxins in Lepidopteran Species

OpenAIRE

Herrero, Salvador; Ferré, Juan; Escriche, Baltasar

2001-01-01

A strong correlation between two mannose phosphate isomerase (MPI) isoenzymes and resistance to Cry1A toxins from Bacillus thuringiensis has been found in a Plutella xylostella population. MPI linkage to Cry1A resistance had previously been reported for a Heliothis virescens population. The fact that the two populations share similar biochemical, genetic, and cross-resistance profiles of resistance suggests the occurrence of homologous resistance loci in both species.

How Quorum Sensing Connects Sporulation to Necrotrophism in Bacillus thuringiensis.

Science.gov (United States)

Perchat, Stéphane; Talagas, Antoine; Poncet, Sandrine; Lazar, Noureddine; Li de la Sierra-Gallay, Inès; Gohar, Michel; Lereclus, Didier; Nessler, Sylvie

2016-08-01

Bacteria use quorum sensing to coordinate adaptation properties, cell fate or commitment to sporulation. The infectious cycle of Bacillus thuringiensis in the insect host is a powerful model to investigate the role of quorum sensing in natural conditions. It is tuned by communication systems regulators belonging to the RNPP family and directly regulated by re-internalized signaling peptides. One such RNPP regulator, NprR, acts in the presence of its cognate signaling peptide NprX as a transcription factor, regulating a set of genes involved in the survival of these bacteria in the insect cadaver. Here, we demonstrate that, in the absence of NprX and independently of its transcriptional activator function, NprR negatively controls sporulation. NprR inhibits expression of Spo0A-regulated genes by preventing the KinA-dependent phosphorylation of the phosphotransferase Spo0F, thus delaying initiation of the sporulation process. This NprR function displays striking similarities with the Rap proteins, which also belong to the RNPP family, but are devoid of DNA-binding domain and indirectly control gene expression via protein-protein interactions in Bacilli. Conservation of the Rap residues directly interacting with Spo0F further suggests a common inhibition of the sporulation phosphorelay. The crystal structure of apo NprR confirms that NprR displays a highly flexible Rap-like structure. We propose a molecular regulatory mechanism in which key residues of the bifunctional regulator NprR are directly and alternatively involved in its two functions. NprX binding switches NprR from a dimeric inhibitor of sporulation to a tetrameric transcriptional activator involved in the necrotrophic lifestyle of B. thuringiensis. NprR thus tightly coordinates sporulation and necrotrophism, ensuring survival and dissemination of the bacteria during host infection.

Iron Acquisition in Bacillus cereus: The Roles of IlsA and Bacillibactin in Exogenous Ferritin Iron Mobilization

Science.gov (United States)

Buisson, Christophe; Daou, Nadine; Kallassy, Mireille; Lereclus, Didier; Arosio, Paolo; Bou-Abdallah, Fadi; Nielsen Le Roux, Christina

2014-01-01

In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis. PMID:24550730

Iron acquisition in Bacillus cereus: the roles of IlsA and bacillibactin in exogenous ferritin iron mobilization.

Directory of Open Access Journals (Sweden)

Diego Segond

2014-02-01

Full Text Available In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis.

Effect of diet supplementation with Toyocerin (R) (Bacillus cereus var. toyoi) on performance and health of growing rabbits.

OpenAIRE

Trocino, A.; Xiccato, G.; Carraro, L.; Jimenez, G.

2005-01-01

Two trials were performed to evaluate the effect of a dietary supplementation with Bacillus cereus var. toyoi on performance and health of growing rabbits. The studies were conducted in two commercial farms using the same experimental diets. In the first trial, 216 rabbits were controlled from 35 d (weaning) until 70 d of age. In the second trial, 180 rabbits were controlled from 37 until 79 d of age. At weaning, rabbits were put into bicellular cages, divided into three groups and fed the ex...

Draft Genome Sequence of Bacillus thuringiensis Strain BrMgv02-JM63, a Chitinolytic Bacterium Isolated from Oil-Contaminated Mangrove Soil in Brazil.

Science.gov (United States)

Marcon, Joelma; Taketani, Rodrigo Gouvêa; Dini-Andreote, Francisco; Mazzero, Giulia Inocêncio; Soares, Fabio Lino; Melo, Itamar Soares; Azevedo, João Lúcio; Andreote, Fernando Dini

2014-01-30

Here, we report the draft genome sequence and the automatic annotation of Bacillus thuringiensis strain BrMgv02-JM63. This genome comprises a set of genes involved in the metabolism of chitin and N-acetylglucosamine utilization, thus suggesting the possible role of this strain in the cycling of organic matter in mangrove soils.

40 CFR 174.506 - Bacillus thuringiensis Cry34Ab1 and Cry35Ab1 proteins in corn; exemption from the requirement of...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry34Ab1 and Cry35Ab1 proteins in corn; exemption from the requirement of a tolerance. 174.506 Section 174.506 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS PROCEDURES AND REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS...

PENGARUH UMPAN TAMBAHAN PADA AKUMULASI POLIHIDROKSIBUTIRAT (PHB OLEH Bacillus cereus IFO 13690 MENGGUNAKAN SUBSTRAT TAPIOKA The Effects of Feeding on Accumulation of Polyhydroxybutyrate (PHB from Tapioca by Bacillus cereus IFO 13690

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Margono Margono

2012-05-01

Full Text Available Bacillus cereus IFO 13690 is Gram positive bacteria that produces polyhydroxybutyrate (PHB. It has amylolytic characteristic that can be cultured using cassava starch. This research reported the ability of B. cereus IFO 13690 on accumulating PHB and the effects of starch and ammonium feeding on cell and PHB productivity. Batch process was conducted with initial starch of 18 g/l, medium pH of 5.6 and medium temperature of 30 oC. Fed batch process was conducted in the same conditions of the optimum batch process with feeding of 2.1 l/hat 7th ­7.65thhours of exponential growth and 1.86 l/hat 10th­10.8thhours of exponential growth. The feeding compositions were starch of 70 g/l and am­ monium sulfate of 20 g/l. The results of batch process showed that the highest accumulation of PHB was achieved with initial ammonium of 1.20 g/l and dissolved oxygen of 5 % air saturation. The highest PHB accumulation of 0.13 g/l was achieved after 29 hours of fermentation. It was similar to 0.005 g/l.h productivity and the PHB content was 2.42%. The productivity of cell and PHB in fed batch process was double compared to the batch process, i.e. 0.39 g/l.h and0.01 g/l.h, respectively. The PHB content in cell dry weight was relatively higher in the fed batch compared to batch process, i.e. 2.50 %. ABSTRAK Bacillus cereus IFO 13690 adalah bakteri Gram positif penghasil polihidroksibutirat(PHB yang bersifat amilolitik sehingga dapat dikulturkan dalam substrat pati. Penelitian ini dimaksudkan untuk melaporkan kemampuan B. cereus IFO 13690 dalam mengakumulasi PHB pada proses batch dan pengaruh penambahan pati serta amonium terhadap produktivitas sel dan PHB pada proses fed batch. Percobaan proses batch dilaksanakan pada konsentrasi pati awal 18 g/l, pH medium 5,6 dan suhu medium 30 oC. Percobaan proses fedbatch dilaksanakan seperti pada proses batch opti­ mum kemudian ditambahkan medium umpan pada saat pertumbuhan eksponensial, yaitu 2,1 l/jam pada saat pertum­ buhan

Influence of Cooling Rate on Growth of Bacillus cereus from Spore Inocula in Cooked Rice, Beans, Pasta, and Combination Products Containing Meat or Poultry.

Science.gov (United States)

Juneja, Vijay K; Mohr, Tim B; Silverman, Meryl; Snyder, O Peter

2018-02-23

The objective of this study was to assess the ability of Bacillus cereus spores to germinate and grow in order to determine a safe cooling rate for cooked rice, beans, and pasta, rice-chicken (4:1), rice-chicken-vegetables (3:1:1), rice-beef (4:1), and rice-beef-vegetables (3:1:1). Samples were inoculated with a cocktail of four strains of heat-shocked (80°C for 10 min) B. cereus spores (NCTC 11143, 935A/74, Brad 1, and Mac 1) to obtain a final spore concentration of approximately 2 log CFU/g. Thereafter, samples were exponentially cooled through the temperature range of 54.5 to 7.2°C in 6, 9, 12, 15, 18, and 21 h. At the end of the cooling period, samples were removed and plated on mannitol egg yolk polymyxin agar. The plates were incubated at 30°C for 24 h. The net B. cereus growth from spores in beans was beans, pasta, rice-chicken, rice-chicken-vegetables, rice-beef, and rice-beef-vegetables to guard against the hazards associated with B. cereus.

Vacuum Distillation Residue Upgrading by an Indigenous Bacillus Cereus

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Mitra Sadat Tabatabaee

2013-07-01

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

Bacillus thuringiensis var. tenebrionis’in Leptinotarsa decemlineata (Say.) (Coleoptera:Chrysomelidae) larvalarının ortabarsağina etik sürecinin histolojik yöntemlerle belirlenmesi

Czech Academy of Sciences Publication Activity Database

Turanli, F.; Cabuk, M.; Kismali, S.; Gelbič, Ivan

2006-01-01

Roč. 30, č. 2 (2006), s. 137-150 ISSN 1010-6960 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis var. tenebrionis * Leptinotarsa decemlineata * mode of action Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection

Exploration of Bacillus thuringiensis Berl. from soil and screening test its toxicity on insects of Lepidoptera order

Science.gov (United States)

Astuti, DT; Pujiastuti, Y.; Suparman, SHK; Damiri, N.; Nugraha, S.; Sembiring, ER; Mulawarman

2018-01-01

Bacillus thuringiensis is a gram-positive bacterium that produces crystal proteins toxic (ᴕ-endotoxin) specific to the target insect, but is not toxic to humans and non-target organisms. This study aims to explore the origin of the soil bacterium B. thuringiensis sub-district Sekayu, Banyuasin, South Sumatra and toxicity to larvae of lepidoptera. Fifty soil samples were taken from Musi Banyuasin District, namely 15 from Kayuare strip 2, 20 from Kayuare and 15 from Lumpatan. Isolation, characterization, identification and screening test were conducted in the laboratorium of Pest and Disease, Agricultural Faculty, Sriwijaya University. Isolat codes were given based on the area origin of the samples. Results of the study showed that from 50 isolates of bacteria that had been isolated, there were 15 bacterial isolates, characterized by morphology and physiology the same as B. thuringiensis, which has round colonies, white, wrinkled edges, slippery, elevation arise, aerobic and gram-positive. Of the 15 codes that contain positive isolates of B. thuringiensis, we have obtained several isolates of the following codes: KJ2D5, KJ2N1, KJ2N4, KJ2B3, KJ3R1, KJ3R2, KJ3R3, KJ3R5, KJ3J3, KJ3J4, KJ3P1, DLM5, DLKK12, and DLKK23. Results of screening tests on insects of the Lepidoptera Order showed that there were six isolates that had toxic to Plutella xylostella and Spodoptera litura insects, ie bacterial isolate codes DLM5, KJ3R3, KJ3R5, KJ3J4, KJ3P1, and DLKK23.

Poly-β-hydroxybutyrate Metabolism Is Unrelated to the Sporulation and Parasporal Crystal Protein Formation in Bacillus thuringiensis.

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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.

Isolation and characterization of bacterial endophytes of Curcuma longa L.

OpenAIRE

Kumar, Ajay; Singh, Ritu; Yadav, Akhilesh; Giri, D. D.; Singh, P. K.; Pandey, Kapil D.

2016-01-01

Fourteen endophytic bacterial isolates were isolated from the rhizome of Curcuma longa L. were characterized on the basis of morphology, biochemical characteristics and 16S rRNA gene sequence analysis. The isolates were identified to six strains namely Bacillus cereus (ECL1), Bacillus thuringiensis (ECL2), Bacillus sp. (ECL3), Bacillus pumilis (ECL4), Pseudomonas putida (ECL5), and Clavibacter michiganensis (ECL6). All the strains produced IAA and solubilized phosphate and only two strains pr...

Cry1A(b)16 toxin from Bacillus thuringiensis: Theoretical refinement of three-dimensional structure and prediction of peptides as molecular markers for detection of genetically modified organisms.

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Plácido, Alexandra; Coelho, Andreia; Abreu Nascimento, Lucas; Gomes Vasconcelos, Andreanne; Fátima Barroso, Maria; Ramos-Jesus, Joilson; Costa, Vladimir; das Chagas Alves Lima, Francisco; Delerue-Matos, Cristina; Martins Ramos, Ricardo; Marani, Mariela M; Roberto de Souza de Almeida Leite, José

2017-07-01

Transgenic maize produced by the insertion of the Cry transgene into its genome became the second most cultivated crop worldwide. Cry gene from Bacillus thuringiensis kurstaki expresses protein derivatives of crystalline endotoxins which confer insect resistance onto the maize crop. Mandatory labeling of processed food containing or made by genetically modified organisms is in force in many countries, so, it is very urgent to develop fast and practical methods for GMO identification, for example, biosensors. In the absence of an available empirical structure of Cry1A(b)16 protein, a theoretical model was effectively generated, in this work, by homology modeling and molecular dynamics simulations based on two available homologous protein structures. Molecular dynamics simulations were carried out to refine the selected model, and an analysis of its global structure was performed. The refined models of Cry1A(b)16 showed a standard fold and structural characteristics similar to those seen in Bacillus thuringiensis Cry1A(a) insecticidal toxin and Bacillus thuringiensis serovar kurstaki Cry1A(c) toxin. After in silico analysis of Cry1A(b)16, two immunoreactive candidate peptides were selected and specific polyclonal antibodies were produced resulting in antibody-peptide interaction. Biosensing devices are expected to be developed for detection of the Cry1A(b) protein as a marker of transgenic maize in food. Proteins 2017; 85:1248-1257. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Sequence and expression of two cry8 genes from Bacillus thuringiensis INTA Fr7-4, a native strain from Argentina.

Science.gov (United States)

Navas, Laura E; Berretta, Marcelo F; Pérez, Melisa P; Amadio, Ariel F; Ortiz, Elio M; Sauka, Diego H; Benintende, Graciela B; Zandomeni, Rubén O

2014-01-01

We found and characterized two cry8 genes from the Bacillus thuringiensis strain INTA Fr7-4 isolated in Argentina. These genes, cry8Kb3 and cry8Pa3, are located in a tandem array within a 13,200-bp DNA segment sequenced from a preparation of total DNA. They encode 1,169- and 1,176-amino-acid proteins, respectively. Both genes were cloned with their promoter sequences and the proteins were expressed separately in an acrystalliferous strain of B. thuringiensis leading to the formation of ovoid crystals in the recombinant strains. The toxicity against larvae of Anthonomus grandis Bh. (Coleoptera: Curculionidae) of a spore-crystal suspension from the recombinant strain containing cry8Pa3 was similar to that of the parent strain INTA Fr7-4. © 2014 S. Karger AG, Basel.

Field trials with tank mixtures of Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus formulations against Culex pipiens larvae in septic tanks in Antalya, Turkey.

Science.gov (United States)

Cetin, Huseyin; Dechant, Peter; Yanikoglu, Atila

2007-06-01

Efficacy of tank mixtures of commercial Bacillus thuringiensis subsp. israelensis (Bti) and Bacillus sphaericus (Bs) water-dispersable granule (WDG) formulations was evaluated in septic tanks, against Culex pipiens L. (Diptera: Culicidae) larvae. VectoLex WDG (Bs) + VectoBac WDG (Bti) were evaluated at various ratios from 488 g/ha VectoLex + 250 g/ha VectoBac up to 3,000 g/ha of each. All applications and ratios delivering VectoLex WDG at a rate equal to or greater than 988 g/ha provided more than 90% control for 28 days after treatment. The lowest dose provided this level of control for at least 7 days after treatment, with greater than 80% control after 2 wk. These results suggest that a retreatment interval of 2 wk is recommended with the lowest dose and retreatment intervals of 4 or more wk are recommended with the doses equal to or higher than 988 g/ha VectoLex + 250 g/ha VectoBac.

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

Science.gov (United States)

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

2018-02-01

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

Native plant growth promoting bacteria Bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in Lavandula dentata plants.

Science.gov (United States)

Armada, E; Probanza, A; Roldán, A; Azcón, R

2016-03-15

This study evaluates the responses of Lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (AM) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native Bacillus thuringiensis (endophytic bacteria). These microorganisms were drought tolerant and in general, increased plant growth and nutrition. Particularly, the AM fungal mixture and B. thuringiensis maximized plant biomass and compensated drought stress as values of antioxidant activities [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase APX)] shown. The AMF-bacteria interactions highly reduced the plant oxidative damage of lipids [malondialdehyde (MDA)] and increased the mycorrhizal development (mainly arbuscular formation representative of symbiotic functionality). These microbial interactions explain the highest potential of dually inoculated plants to tolerate drought stress. B. thuringiensis "in vitro" under osmotic stress does not reduce its PGPB (plant growth promoting bacteria) abilities as indole acetic acid (IAA) and ACC deaminase production and phosphate solubilization indicating its capacity to improve plant growth under stress conditions. Each one of the autochthonous fungal strains maintained their particular interaction with B. thuringiensis reflecting the diversity, intrinsic abilities and inherent compatibility of these microorganisms. In general, autochthonous AM fungal species and particularly their mixture with B. thuringiensis demonstrated their potential for protecting plants against drought and helping plants to thrive in semiarid ecosystems. Copyright © 2015 Elsevier GmbH. All rights reserved.

Structural basis of the substrate specificity of Bacillus cereus adenosine phosphorylase

Energy Technology Data Exchange (ETDEWEB)

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

2012-03-01

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

Effects of Mentha longifolia L. essential oil and nisin alone and in combination on Bacillus cereus and Bacillus subtilis in a food model and bacterial ultrastructural changes.

Science.gov (United States)

Pajohi, Mohamad Reza; Tajik, Hossein; Farshid, Amir Abbas; Basti, Afshin Akhondzadeh; Hadian, Mojtaba

2011-02-01

In the face of emerging new pathogens and ever-growing health-conscious customers, food preservation technology remains on the top agenda of food industry. This study was aimed at determining the effects of the essential oil of Mentha longifolia L., alone and in combination with nisin, on Bacillus cereus and Bacillus subtilis at 8°C and 25°C in a food model (commercial barley soup) during 15 days. The essential oil alone at 8°C inhibited bacterial growth significantly compared with the control (p < 0.05). However, at 25°C, none of the concentrations of the essential oil alone showed inhibitory effect on bacterial growth. At 8°C, the combination effect of the essential oil and nisin on bacteria was noted at 0.25 μg mL(-1) for nisin and 0.05 μL mL(-1) for the essential oil (p < 0.05). The combination of nisin and the essential oil demonstrated significant inhibitory effects on the vegetative forms of bacteria at 25°C, although it was comparable to that of nisin alone at the same concentrations. Electron microscopy studies revealed a great deal of damage to B. cereus treated with a combination of nisin and the essential oil. However, the combination of nisin with the essential oil led to a complete destruction of cell wall and cytoplasm of vegetative cells of B. subtilis.

Larvicidal Activities of Indigenous Bacillus thuringiensis Isolates and Nematode Symbiotic Bacterial Toxins against the Mosquito Vector, Culex pipiens (Diptera: Culicidae

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Ashraf M Ahmed