-
Applied and Environmental Microbiology Jan 2016The primary goal of this study was to determine the conditions required for the effective inactivation of Bacillus anthracis spores on materials by using methyl bromide...
The primary goal of this study was to determine the conditions required for the effective inactivation of Bacillus anthracis spores on materials by using methyl bromide (MeBr) gas. Another objective was to obtain comparative decontamination efficacy data with three avirulent microorganisms to assess their potential for use as surrogates for B. anthracis Ames. Decontamination tests were conducted with spores of B. anthracis Ames and Geobacillus stearothermophilus, B. anthracis NNR1Δ1, and B. anthracis Sterne inoculated onto six different materials. Experimental variables included temperature, relative humidity (RH), MeBr concentration, and contact time. MeBr was found to be an effective decontaminant under a number of conditions. This study highlights the important role that RH has when fumigation is performed with MeBr. There were no tests in which a ≥6-log10 reduction (LR) of B. anthracis Ames was achieved on all materials when fumigation was done at 45% RH. At 75% RH, an increase in the temperature, the MeBr concentration, or contact time generally improved the efficacy of fumigation with MeBr. This study provides new information for the effective use of MeBr at temperatures and RH levels lower than those that have been recommended previously. The study also provides data to assist with the selection of an avirulent surrogate for B. anthracis Ames spores when additional tests with MeBr are conducted.
Topics: Bacillus anthracis; Construction Materials; Decontamination; Disinfectants; Fumigation; Hydrocarbons, Brominated; Spores, Bacterial
PubMed: 26801580
DOI: 10.1128/AEM.03445-15 -
ACS Omega Feb 2023Apple replant disease (ARD) is common in apple production, which seriously affects the growth and development of apples. In this study, hydrogen peroxide with a...
Apple replant disease (ARD) is common in apple production, which seriously affects the growth and development of apples. In this study, hydrogen peroxide with a bactericidal effect was used to treat the replanted soil, and the effects of different concentrations of hydrogen peroxide on replanted seedlings and soil microbiology were investigated in order to seek a green, clean way to control ARD. Five treatments were set up in this study: replanted soil (CK1), replanted soil with methyl bromide fumigation (CK2), replanted soil + 1.5% hydrogen peroxide (H1), replanted soil + 3.0% hydrogen peroxide (H2), and replanted soil + 4.5% hydrogen peroxide (H3). The results showed that hydrogen peroxide treatment improved replanted seedling growth and also inactivated a certain number of , while the , , and also became more abundant in relative terms. The best results were obtained with replanted soil + 4.5% hydrogen peroxide (H3). Consequently, hydrogen peroxide applied to the soil can effectively prevent and control ARD.
PubMed: 36844530
DOI: 10.1021/acsomega.2c06665 -
Journal of Applied Microbiology Jan 2016To evaluate the field inactivation of Bacillus anthracis Sterne spores with methyl bromide (MB) using commercial fumigation techniques.
AIMS
To evaluate the field inactivation of Bacillus anthracis Sterne spores with methyl bromide (MB) using commercial fumigation techniques.
METHODS AND RESULTS
Eighty-seven wood and 87 glass coupons each containing ca. 1 × 10(6) B. anthracis Sterne spores, were placed in 22 locations inside a 1444 m(3) conference building. Four additional 12-coupon sets (six wood, six glass) were removed from the building at 16, 24, 32 and 40 h during fumigation. The building was sealed under two tarpaulins and fumigated with MB at ≥225 g m(-3) mean concentration for 48 h at 28°C and 83% RH. All B. anthracis spores fumigated for more than 16 h were inactivated. A single wood coupon from the 16-h set yielded ca. 2 × 10(3) CFU. No damage to the building or its contents was observed.
CONCLUSIONS
MB fumigation is a rapid, economical and effective whole-structure decontamination method for B. anthracis spores.
SIGNIFICANCE AND IMPACT OF THE STUDY
MB fumigation offers a method of whole-structure B. anthracis decontamination without removal of materials, damage to sensitive electronics, costly indoor retrofitting.
Topics: Bacillus anthracis; Decontamination; Fumigation; Hydrocarbons, Brominated; Spores, Bacterial
PubMed: 26492200
DOI: 10.1111/jam.12974 -
Insects Sep 2016Research here explored the use of controlled atmospheres (CA) for managing arthropod pests that infest dry-cured hams. Experiments were conducted with low oxygen (O₂)...
Research here explored the use of controlled atmospheres (CA) for managing arthropod pests that infest dry-cured hams. Experiments were conducted with low oxygen (O₂) achieved with low pressure under a vacuum, high carbon dioxide (CO₂), and ozone (O₃). Results showed that both low O₂ and high CO₂ levels required exposures up to 144 h to kill 100% of all stages of red-legged ham beetle, Necrobia rufipes (De Geer) (Coleoptera: Cleridae) and ham mite Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) at 23 °C. In addition, both low O₂ and high CO₂ had no significant mortality against the ham beetle and ham mites at short exposures ranging from 12 to 48 h. Ham beetles were more tolerant than ham mites to an atmosphere of 75.1% CO₂ and low pressure of 25 mm Hg, which imposed an atmosphere estimated at 0.9% O₂. Both low O₂ and high CO₂ trials indicated that the egg stages of both species were more tolerant than other stages tested, but N. rufipes eggs and pupae were more susceptible than larvae and adults to high concentration ozone treatments. The results indicate that O₃ has potential to control ham beetles and ham mites, particularly at ≈166 ppm in just a 24 h exposure period, but O₃ is known from other work to have poor penetration ability, thus it may be more difficult to apply effectively than low O₂ or high CO₂. would be. CA treatment for arthropod pests of dry-cured hams show promise as components of integrated pest management programs after methyl bromide is no longer available for use.
PubMed: 27598209
DOI: 10.3390/insects7030044 -
Pathogens (Basel, Switzerland) Sep 2022The soil-borne pathogens, particularly f. sp. (FON) and southern root-knot nematode (RKN, ) are the major threats to watermelon production in the southeastern United...
The soil-borne pathogens, particularly f. sp. (FON) and southern root-knot nematode (RKN, ) are the major threats to watermelon production in the southeastern United States. The role of soil micronutrients on induced resistance (IR) to plant diseases is well-documented in soil-based media. However, soil-based media do not allow us to determine the contribution of individual micronutrients in the induction of IR. In this manuscript, we utilized hydroponics-medium to assess the effect of controlled application of micronutrients, including iron (Fe), manganese (Mn), and zinc (Zn) on the expression of important IR genes (, , and from salicylic acid (SA) pathway, and , , and genes from jasmonic acid (JA) pathway) in watermelon seedlings upon inoculation with either FON or RKN or both. A subset of micronutrient-treated plants was inoculated (on the eighth day of micronutrient application) with FON and RKN (single or mixed inoculation). The expression of the IR genes in treated and control samples was evaluated using qRT-PCR. Although, significant phenotypic differences were not observed with respect to the severity of wilt symptoms or RKN galling with any of the micronutrient treatments within the 30-day experimental period, differences in the induction of IR genes were considerably noticeable. However, the level of gene expression varied with sampling period, type and concentration of micronutrients applied, and pathogen inoculation. In the absence of pathogens, micronutrient applications on the seventh day, in general, downregulated the expression of the majority of the IR genes. However, pathogen inoculation preferentially either up- or down-regulated the expression levels of the IR genes at three days post-inoculation depending on the type and concentration of micronutrients. The results demonstrated here indicate that micronutrients in watermelon may potentially make watermelon plants susceptible to infection by FON and RKN. However, upon infection the IR genes are significantly up-regulated that they may potentially aid the prevention of further infection via SA- and JA-pathways. This is the first demonstration of the impact of micronutrients affecting IR in watermelon against FON and RKN infection.
PubMed: 36297194
DOI: 10.3390/pathogens11101136 -
Proceedings of the National Academy of... Sep 2015Adult tissue stem cells can serve two broad functions: to participate actively in the maintenance and regeneration of a tissue or to wait in reserve and participate only...
Adult tissue stem cells can serve two broad functions: to participate actively in the maintenance and regeneration of a tissue or to wait in reserve and participate only when activated from a dormant state. The adult olfactory epithelium, a site for ongoing, life-long, robust neurogenesis, contains both of these functional stem cell types. Globose basal cells (GBCs) act as the active stem cell population and can give rise to all the differentiated cells found in the normal tissue. Horizontal basal cells (HBCs) act as reserve stem cells and remain dormant unless activated by tissue injury. Here we show that HBC activation following injury by the olfactotoxic gas methyl bromide is coincident with the down-regulation of protein 63 (p63) but anticipates HBC proliferation. Gain- and loss-of-function studies show that this down-regulation of p63 is necessary and sufficient for HBC activation. Moreover, activated HBCs give rise to GBCs that persist for months and continue to act as bona fide stem cells by participating in tissue maintenance and regeneration over the long term. Our analysis provides mechanistic insight into the dynamics between tissue stem cell subtypes and demonstrates that p63 regulates the reserve state but not the stem cell status of HBCs.
Topics: Animals; Blotting, Western; Cell Differentiation; Cell Proliferation; Male; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Microscopy, Confocal; Neurogenesis; Olfactory Mucosa; Olfactory Receptor Neurons; Phosphoproteins; Reverse Transcriptase Polymerase Chain Reaction; Stem Cells; Trans-Activators
PubMed: 26305958
DOI: 10.1073/pnas.1512272112 -
NeuroImage. Clinical 2016Enlarged cortical components of somatosensory evoked potentials (giant SEPs) recorded by electroencephalography (EEG) and abnormal somatosensory evoked magnetic fields...
Enlarged cortical components of somatosensory evoked potentials (giant SEPs) recorded by electroencephalography (EEG) and abnormal somatosensory evoked magnetic fields (SEFs) recorded by magnetoencephalography (MEG) are observed in the majority of patients with cortical myoclonus (CM). Studies on simultaneous recordings of SEPs and SEFs showed that generator mechanism of giant SEPs involves both primary sensory and motor cortices. However the generator sources of giant SEPs have not been fully understood as only one report describes clearly giant SEPs following lower limb stimulation. In our study we performed a combined EEG-MEG recording on responses elicited by electric median and tibial nerve stimulation in a patient who developed consequently to methyl bromide intoxication CM with giant SEPs to median and tibial nerve stimuli. SEPs wave shapes were identified on the basis of polarity-latency components (e.g. P15-N20-P25) as defined by earlier studies and guidelines. At EEG recording, the SEP giant component did not appear in the latency range of the first cortical component for median nerve SEP (N20), but appeared instead in the range of the P37 tibial nerve SEP, which is currently identified as the first cortical component elicited by tibial nerve stimuli. Our MEG and EEG SEPs recordings also showed that components in the latency range of P37 were preceded by other cortical components. These findings suggest that lower limb P37 does not correspond to upper limb N20. MEG results confirmed that giant SEFs are the second component from both tibial (N43m-P43m) and median (N27m-P27m) nerve stimulation. MEG dipolar sources of these giant components were located in the primary sensory and motor area.
Topics: Adult; Cerebral Cortex; Electric Stimulation; Electroencephalography; Evoked Potentials, Somatosensory; Female; Humans; Magnetoencephalography; Median Nerve; Myoclonus; Tibial Nerve
PubMed: 27489768
DOI: 10.1016/j.nicl.2016.07.001 -
The Science of the Total Environment Jan 2024Salt marshes are sensitive highly productive habitats crucial for carbon cycling. This study presents a comprehensive analysis of organic geochemical indicators and...
Salt marshes are sensitive highly productive habitats crucial for carbon cycling. This study presents a comprehensive analysis of organic geochemical indicators and geochronology in the Mira salt marsh (SW Portugal) over eight centuries. The closely intertwined carbon and bromine (Br) biogeochemical cycles in these environments can influence the fluxes of volatile compounds such as ozone-depleting methyl bromide, emphasizing the importance of understanding sediment organic matter (OM) origin, budget, and composition in salt marshes. To characterize the strong Br-OM relationship, we used n-alkane signatures, bulk elemental data (total carbon, total nitrogen, C/N ratio), and stable isotopes (δN, δC) from a sediment core. Findings revealed a mixed composition of terrestrial and marine OM, posing challenges in distinguishing ex situ higher plant sources from in situ production by marsh vegetation. n-Alkanes (C to C) were found in all the sediment samples, predominantly C-C. Changes in their presence were linked to marsh succession, evolving from a vegetation-free tidal flat to a C halophyte-dominated high marsh ecosystem. Despite the area's low industrial and population impact, regulation of water flow through the dam affected the balance between continental and marine waters. This study aimed to create a cost-effective predictive model for total Br, enhancing paleoclimatic studies using sedimentary samples. The n-alkane model had limited resolution, but an alternative infrared (IR) spectroscopy-based model, requiring less time and smaller sample sizes, was developed. Combining FT-IR spectra with statistical analysis enabled the creation of a reliable total Br concentration prediction model (mean absolute error = 14.39). These findings have implications for controlling Br enrichment in marsh environments and can be applied in various coastal wetlands with different mineralogical and organic characteristics.
PubMed: 37863236
DOI: 10.1016/j.scitotenv.2023.167931 -
PloS One 2017Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is a serious pest of stored agricultural products and one of the most common insects found in grain storage and...
Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is a serious pest of stored agricultural products and one of the most common insects found in grain storage and food processing facilities. Heat treatment has been revisited to control stored-product insects as a potential alternative to methyl bromide for disinfesting mills and food-processing facilities. The influence of acclimation of T. castaneum adults, pupae, larvae, and eggs to sublethal temperatures of 36, and 42°C on their subsequent susceptibility to lethal temperature of 50°C was respectively investigated. The acclimation of T. castaneum eggs, larvae, pupae, and adults to 36, and 42°C significantly decreased their subsequent susceptibility to lethal high temperature of 50°C. The influence of acclimation to 42°C was significantly greater than that of acclimation to 36°C. The most influential acclimation times at 42°C for mortality of T. castaneum eggs, larvae, pupae, and adults were 15, 5, 5, and 5 h, respectively, and their corresponding mortality were 41.24, 5.59, 20.19, and 4.48%, compared to 100% mortality of T. castaneum eggs, larvae, pupae, and adults without acclimation when exposed to 50°C for 35 min, respectively. The present results have important implications for developing successful heat treatment protocols to control T. castaneum, improving disinfestation effectiveness of heat treatment and understanding insect response to high temperatures.
Topics: Analysis of Variance; Animals; Gene Expression Regulation; HSP70 Heat-Shock Proteins; Hot Temperature; Insect Proteins; Random Allocation; TRPC Cation Channels; Thermotolerance; Time Factors; Tribolium
PubMed: 28786992
DOI: 10.1371/journal.pone.0182269 -
Turkish Journal of Anaesthesiology and... Apr 2015Methyl bromide (CH3Br) is a halogenated aliphatic hydrocarbon that may cause acute and chronic toxicities. We describe a case of a 44-year-old male patient who developed...
Methyl bromide (CH3Br) is a halogenated aliphatic hydrocarbon that may cause acute and chronic toxicities. We describe a case of a 44-year-old male patient who developed toxic brain syndrome (TBS) and central nervous system (CNS) toxicity after exposure to CH3Br by inhalation. Toxicity began with progressive nervousness, dysarthria and coordination disorder. The complaints on admission to the hospital were speech defect, balance disorder, consciousness disorder and involuntary movements. The patient was treated symptomatically in the intensive care unit (ICU), and organic reasons were excluded. Findings in the magnetic resonance imaging were considered secondary demyelination related to systemic intoxication. Because of the CH3Br, alkylates the crucial sulfhydryl-containing enzymes, N-acetylcysteine was used as a source of sulfhydryl groups for the treatment of the patient. He was hospitalised for nearly 1.5 months in the ICU.
PubMed: 27366483
DOI: 10.5152/TJAR.2014.84756