Bacterial spores survive treatment with commercial sterilants and disinfectants.

Science.gov (United States)

Sagripanti, J L; Bonifacino, A

1999-09-01

This study compared the activity of commercial liquid sterilants and disinfectants on Bacillus subtilis spores deposited on three types of devices made of noncorrodible, corrodible, or polymeric material. Products like Renalin, Exspor, Wavicide-01, Cidexplus, and cupric ascorbate were tested under conditions specified for liquid sterilization. These products, at the shorter times indicated for disinfection, and popular disinfectants, like Clorox, Cavicide, and Lysol were also studied. Data obtained with a sensitive and quantitative test suggest that commercial liquid sterilants and disinfectants are less effective on contaminated surfaces than generally acknowledged.

The differential effects of heat-shocking on the viability of spores from Bacillus anthracis, Bacillus subtilis, and Clostridium sporogenes after treatment with peracetic acid- and glutaraldehyde-based disinfectants.

Science.gov (United States)

March, Jordon K; Pratt, Michael D; Lowe, Chinn-Woan; Cohen, Marissa N; Satterfield, Benjamin A; Schaalje, Bruce; O'Neill, Kim L; Robison, Richard A

2015-10-01

This study investigated (1) the susceptibility of Bacillus anthracis (Ames strain), Bacillus subtilis (ATCC 19659), and Clostridium sporogenes (ATCC 3584) spores to commercially available peracetic acid (PAA)- and glutaraldehyde (GA)-based disinfectants, (2) the effects that heat-shocking spores after treatment with these disinfectants has on spore recovery, and (3) the timing of heat-shocking after disinfectant treatment that promotes the optimal recovery of spores deposited on carriers. Suspension tests were used to obtain inactivation kinetics for the disinfectants against three spore types. The effects of heat-shocking spores after disinfectant treatment were also determined. Generalized linear mixed models were used to estimate 6-log reduction times for each spore type, disinfectant, and heat treatment combination. Reduction times were compared statistically using the delta method. Carrier tests were performed according to AOAC Official Method 966.04 and a modified version that employed immediate heat-shocking after disinfectant treatment. Carrier test results were analyzed using Fisher's exact test. PAA-based disinfectants had significantly shorter 6-log reduction times than the GA-based disinfectant. Heat-shocking B. anthracis spores after PAA treatment resulted in significantly shorter 6-log reduction times. Conversely, heat-shocking B. subtilis spores after PAA treatment resulted in significantly longer 6-log reduction times. Significant interactions were also observed between spore type, disinfectant, and heat treatment combinations. Immediately heat-shocking spore carriers after disinfectant treatment produced greater spore recovery. Sporicidal activities of disinfectants were not consistent across spore species. The effects of heat-shocking spores after disinfectant treatment were dependent on both disinfectant and spore species. Caution must be used when extrapolating sporicidal data of disinfectants from one spore species to another. Heat

Combination Treatment of Spores of Cl. Botulinum with Heat plus Radiation

Energy Technology Data Exchange (ETDEWEB)

Grecz, N.; Upadhyay, J.; Tang, T. C.; Lin, C. A. [Illinois Institute of Technology, Chicago, IL (United States)

1967-11-15

Radiation resistance of spores of Cl. botulinum is strongly affected by the temperature during irradiation. Very low radiation resistance was consistently observed at 0 Degree-Sign C when samples were in the liquid state. Below 0 Degree-Sign C, the resistance of spores increased because the solidly frozen medium presumably decreased the diffusion of free radicals. As temperature increased above 0 Degree-Sign C processes of radiation protection occurred. When spores were subjected to low levels of radiation (0.6-0.8 Mrad) the heat resistance of the surviving spores was very remarkedly decreased. Experiments were designed to study what kind of radiation damage, i.e. direct hit or indirect action, is responsible for the loss of heat resistance of spores. Indirect effects were reduced by freezing the medium and lowering the temperature during irradiation down to -196 Degree-Sign C. Spores of Cl. botulinum 33A in phosphate buffer were irradiated to 0.6, 0.8 and 1.0 Mrad at irradiation temperatures ranging from +25 to -196 Degree-Sign C and subsequently heated at 99 Degree-Sign C. Survival curves revealed that all spores irradiated at +25 and 0 Degree-Sign C were highly sensitive to heat with D{sub 10} = 5.5 min (after 0.6 Mrad), D{sub 10} = 3.0 min (after 0.8 Mrad) and D{sub 10} = 2.3 min (after 1.0 Mrad). For nonTirradiated controls D10 was 23 min. Pre-irradiation at -25 through -196 Degree-Sign C resulted in a much smaller loss of heat resistance with D{sub 10} clustering around 17.4 min (after 0.6 Mrad), 13. 5 min (after 0.8 Mrad) and 11.5 min (after 1.0 Mrad). Loss of heat resistance after pre-irradiation at +25 and 0 Degree-Sign C was highly influenced by the liquid state of suspending medium whereas at -25 through -196 Degree-Sign C it depended primarily on radiation dose. The mechanism of heat sensitization of spores seems to be related primarily to migrating active free radicals at +25 and 0 Degree-Sign C and to random splitting of molecular bonds at -25 to -196

Limit for the Survivability from Potassium Decay of Bacterial Spores in Halite Fluid Inclusions

Science.gov (United States)

Kminek, G.; Bada, J. L.

2001-12-01

DNA damage-tolerant organism known today is Deinococcus radiodurans. The viability of D. radiodurans falls to undetectable levels6 at about 18 kGy. The survival curve of dry Bacillus megaterium spores shows a 4-log reduction at about 8-10 kGy7,8. These numbers can be compared to the 87 kGy in the case for a Permian fluid inclusion. The ability to tolerate radiation induced damage lies in the efficient repair mechanism employed by D. radiodurans, which is not operative in a dormant spore. It would thus be highly unusual for a bacterial spore to survive intact for 100's of millions of years unless these bacteria are extremely radiation tolerant. Based on these considerations and without active DNA repair mechanisms, viability of a dormant bacterial spore and the survival of viable genetic material over extended periods of geologic time is probably limited by exposure to natural background radiation. 1. Vreeland, R. H., Rosenzweig, W. D., Powers, D. W. Nature 407, 897-900 (2000) 2. Cano, P. J., Borucki, M. K. Science 268, 1060-1064 (1995) 3. Parkes, R. J.Nature, 407, 844-845 (2000) 4. Lindahl, T. Nature 362, 709-715 (1993) 5. Setlow, P. J. Bacteriol., 174 (9), 2737-2741 (1992) 6. Battista, J. R. Annu. Rev. Micriobiol. 51, 203-224 (1997) 7. Powers, E. L., Kaleta, B. F. Science 132, 959-960 (1960) 8. Ewing, D., Powers, E. L. Science 194, 1049-1051 (1976)

Influence of food matrix on outgrowth heterogeneity of heat damaged Bacillus cereus spores.

Science.gov (United States)

Warda, Alicja K; den Besten, Heidy M W; Sha, Na; Abee, Tjakko; Nierop Groot, Masja N

2015-05-18

Spoilage of heat treated foods can be caused by the presence of surviving spore-formers. It is virtually impossible to prevent contamination at the primary production level as spores are ubiquitous present in the environment and can contaminate raw products. As a result spore inactivation treatments are widely used by food producing industries to reduce the microbial spore loads. However consumers prefer mildly processed products that have less impact on its quality and this trend steers industry towards milder preservation treatments. Such treatments may result in damaged instead of inactivated spores, and these spores may germinate, repair, and grow out, possibly leading to quality and safety issues. The ability to repair and grow out is influenced by the properties of the food matrix. In the current communication we studied the outgrowth from heat damaged Bacillus cereus ATCC 14579 spores on Anopore membrane, which allowed following outgrowth heterogeneity of individual spores on broccoli and rice-based media as well as standard and mildly acidified (pH 5.5) meat-based BHI. Rice, broccoli and BHI pH 5.5 media resulted in delayed outgrowth from untreated spores, and increased heterogeneity compared to BHI pH 7.4, with the most pronounced effect in rice media. Exposure to wet heat for 1 min at 95 °C caused 2 log inactivation and approximately 95% of the spores in the surviving fraction were damaged resulting in substantial delay in outgrowth based on the time required to reach a maximum microcolony size of 256 cells. The delay was most pronounced for heat-treated spores on broccoli medium followed by spores on rice media (both untreated and treated). Interestingly, the increase in outgrowth heterogeneity of heat treated spores on BHI pH 7.4 was more pronounced than on rice, broccoli and BHI pH 5.5 conceivably reflecting that conditions in BHI pH 7.4 better support spore damage repair. This study compares the effects of three main factors, namely heat treatment, p

Bacillus subtilis spore survival and expression of germination-induced bioluminescence after prolonged incubation under simulated Mars atmospheric pressure and composition: implications for planetary protection and lithopanspermia

Science.gov (United States)

Nicholson, Wayne L.; Schuerger, Andrew C.

2005-01-01

Bacterial endospores in the genus Bacillus are considered good models for studying interplanetary transfer of microbes by natural or human processes. Although spore survival during transfer itself has been the subject of considerable study, the fate of spores in extraterrestrial environments has received less attention. In this report we subjected spores of a strain of Bacillus subtilis, containing luciferase resulting from expression of an sspB-luxAB gene fusion, to simulated martian atmospheric pressure (7-18 mbar) and composition (100% CO(2)) for up to 19 days in a Mars simulation chamber. We report here that survival was similar between spores exposed to Earth conditions and spores exposed up to 19 days to simulated martian conditions. However, germination-induced bioluminescence was lower in spores exposed to simulated martian atmosphere, which suggests sublethal impairment of some endogenous spore germination processes.

DESTRUCTION OF ASPERGILLUS VERSICOLOR, PENICILLIUM CRYSOGENUM, STACHYBOTRYS CHARTARUM, AND CLADOSPORIUM CLADOSPORIDES SPORES USING CHEMICAL OXIDATION TREATMENT PROCESS

Science.gov (United States)

The survival of aqueous suspensions of Penicillium chrysogenum, Stachybotrys chartarum, Aspergillus versicolor, and Cladosporium cladosporioides spores was evaluated using various combinations of hydrogen peroxide and iron (II) as catalyst. Spores were suspended in water and trea...

The combined effect of pasteurization intensity, water activity, pH and incubation temperature on the survival and outgrowth of spores of Bacillus cereus and Bacillus pumilus in artificial media and food products.

Science.gov (United States)

Samapundo, S; Heyndrickx, M; Xhaferi, R; de Baenst, I; Devlieghere, F

2014-07-02

The objective of the study was to evaluate the combined effects of pasteurization intensity (no heat treatment and 10 min at 70, 80 and 90 °C), water activity (aw) (0.960-0.990), pH (5.5-7.0) and storage temperature (7 and 10 °C) on the survival and outgrowth of psychrotolerant spores of Bacillus cereus FF119b and Bacillus pumilus FF128a. The experiments were performed in both artificial media and a validation was performed on real food products (cream, béchamel sauce and mixed vegetable soup). It was determined that in general, heat treatments of 10 min at 70 °C or 80 °C activated the spores of both B. cereus FF119b and B. pumilus FF128a, resulting in faster outgrowth compared to native (non-heat treated) spores. A pasteurization treatment of 10 min at 90 °C generally resulted in the longest lag periods before outgrowth of both isolates. Some of the spores were inactivated by this heat treatment, with more inactivation being observed the lower the pH value of the heating medium. Despite this, it was also observed that under some conditions the remaining (surviving) spores were actually activated as their outgrowth took place after a shorter period of time compared to native non-heated spores. While the response of B. cereus FF119b to the pasteurization intensity in cream and béchamel sauce was similar to the trends observed in the artificial media at 10 °C, in difference, outgrowth was only observed at 7 °C in both products when the spores had been heated for 10 min at 80 °C. Moreover, no inactivation was observed in cream or béchamel sauce when the spores were heated for 10 min at 90 °C in these two products. This was attributed to the protective effect of fat in the cream and the ingredients in the béchamel sauce. The study provides some insight into the potential microbial (stability and safety) consequences of the current trend towards milder heat treatments which is being pursued in the food industry. Copyright © 2014. Published by Elsevier B.V.

Effect of individual or combined treatment of heat or radiation on clostridium perfringens spores

Energy Technology Data Exchange (ETDEWEB)

El-Zawahry, Y A; El-Fouly, M Z; Aziz, N H

1986-01-01

Separate treatments of high temperature had considerable effect on Cl.perfrigens spores suspended in saline solution especially at 90 and 100[sup 0]C, while 70 and 80[sup 0]C had only slight effect on the spores viabilty. The decimal reduction times (D[sub T]) were 33.7, 26, 4, 10.7 and 2.8 at 70, 80, 90 and 100[sup 0]C for NCTC 8798 strain and were 45.1, 27.1, 10.2 and 4.0 for the Egyptian strain at the same degrees of temperature respectively. Heat treatment pre-irradiation at 70 and 80[sup 0]C for 30 and 60 min decreased the viable spore numbers by about 0.5 to 3.0 log cycles, but the treatment had no effect on increasing the sensitivity of the rest spores to radiation. The decimal reduction dose (D[sub 10]-value) for the spores was almost the same as the control but there was a tendency to reduce the shoulder part in the radiation response curve especially when the spores were subjected to 80[sup 0]C for 60 min. On the other hand, irradiation pre-heat treatment with doses from 1-10 KGY was sufficient to decrease the spore numbers from 0.2 to 5.0 log cycles and had a sensitizing effect on subsequently heated spores especially those exposed to 90 and 100[sup 0]C. Meanwhile the rate of inactivation for spores exposed to 70 and 80[sup 0]C after irradiation increased only during the first ten minutes. Thereafter, the rate of inactivation was almost the same for the non-irradiated spores. The D[sub 10]-values for the spores irradiated with 10 KGY were 0.77 and 0.84 minutes for NCTC 8798 strain and Egyptian strain at 100[sup 0]C respectively and the spores were completely destroyed before 5 minutes.

The role of heat resistance in thermorestoration of hydrated bacterial spores

International Nuclear Information System (INIS)

Friedman, Y.S.; Grecz, N.

1973-01-01

This study for the first time presents evidence of the distinct role played in thermorestoration by cellular determinants such as the resistance to heat and radiation, and the ionic state of spores. In the past only radiochemical determinants associated with radical annealment have been studied in hydrated systems. The basic heat resistance of spores plays a significant role in the precipitous drop in spore survival due to 0.45 Mrad radiation plus heat above 65-75 0 C for B.cereus and 75-95 0 C for B.stearothermophilus. The effect of the spores radiation resistance was not distinct except in the frozen state and at the saturation plateau of thermorestoration where the radiation resistant B.cereus showed ca. 1 log cycle higher survival than the radiation sensitive B.stearothermophilus. When spores are chemically converted into their H + and Ca ++ ionic forms, the H + spores are distinctly more responsive than Ca ++ spores to processes of radical annealment responsible for thermorestoration in hydrated spore systems. At temperatures of extensive thermorestoration of water radicals, H + spores showed higher survival than Ca ++ spores. (F.J.)

Factors influencing the inactivation of Alicyclobacillus acidoterrestris spores exposed to high hydrostatic pressure in apple juice

Science.gov (United States)

Sokołowska, B.; Skąpska, S.; Fonberg-Broczek, M.; Niezgoda, J.; Chotkiewicz, M.; Dekowska, A.; Rzoska, S. J.

2013-03-01

Alicyclobacillus acidoterrestris, a thermoacidophilic and spore-forming bacterium, survives the typical pasteurization process and can cause the spoilage of juices, producing compounds associated with disinfectant-like odour (guaiacol, 2,6 - dibromophenol, 2,6 - dichlorophenol). Therefore, the use of other more effective techniques such as high hydrostatic pressure (HHP) is considered for preserving juices. The aim of this study was to search for factors affecting the resistance of A. acidoterrestris spores to HHP. The baroprotective effect of increased solute concentration in apple juice on A. acidoterrestris spores during high pressure processing was observed. During the 45 min pressurization (200 MPa, 50°C) of the spores in concentrated apple juice (71.1°Bx), no significant changes were observed in their number. However, in the juices with a soluble solids content of 35.7, 23.6 and 11.2°Bx, the reduction in spores was 1.3-2.4 log, 2.6-3.3 log and 2.8-4.0 log, respectively. No clear effect of age of spores on the survival under high pressure conditions was found. Spores surviving pressurization and subjected to subsequent HHP treatment showed increased resistance to pressure, by even as much as 2.0 log.

Effects of steam autoclave treatment on Geobacillus stearothermophilus spores.

Science.gov (United States)

Huesca-Espitia, L C; Suvira, M; Rosenbeck, K; Korza, G; Setlow, B; Li, W; Wang, S; Li, Y-Q; Setlow, P

2016-11-01

To determine the mechanism of autoclave killing of Geobacillus stearothermophilus spores used in biological indicators (BIs) for steam autoclave sterilization, and rates of loss of spore viability and a spore enzyme used in BIs. Spore viability, dipicolinic acid (DPA) release, nucleic acid staining, α-glucosidase activity, protein structure and mutagenesis were measured during autoclaving of G. stearothermophilus spores. Loss of DPA and increases in spore core nucleic acid staining were slower than loss of spore viability. Spore core α-glucosidase was also lost more slowly than spore viability, although soluble α-glucosidase in spore preparations was lost more rapidly. However, spores exposed to an effective autoclave sterilization lost all viability and α-glucosidase activity. Apparently killed autoclaved spores were not recovered by artificial germination in supportive media, much spore protein was denatured during autoclaving, and partially killed autoclave-treated spore preparations did not acquire mutations. These results indicate that autoclave-killed spores cannot be revived, spore killing by autoclaving is likely by protein damage, and spore core α-glucosidase activity is lost more slowly than spore viability. This work provides insight into the mechanism of autoclave killing of spores of an organism used in BIs, and that a spore enzyme in a BI is more stable to autoclaving than spore viability. © 2016 The Society for Applied Microbiology.

The distribution of Paenibacillus larvae spores in adult bees and honey and larval mortality, following the addition of American foulbrood diseased brood or spore-contaminated honey in honey bee (Apis mellifera) colonies.

Science.gov (United States)

Lindström, Anders; Korpela, Seppo; Fries, Ingemar

2008-09-01

Within colony transmission of Paenibacillus larvae spores was studied by giving spore-contaminated honey comb or comb containing 100 larvae killed by American foulbrood to five experimental colonies respectively. We registered the impact of the two treatments on P. larvae spore loads in adult bees and honey and on larval mortality by culturing for spores in samples of adult bees and honey, respectively, and by measuring larval survival. The results demonstrate a direct effect of treatment on spore levels in adult bees and honey as well as on larval mortality. Colonies treated with dead larvae showed immediate high spore levels in adult bee samples, while the colonies treated with contaminated honey showed a comparable spore load but the effect was delayed until the bees started to utilize the honey at the end of the flight season. During the winter there was a build up of spores in the adult bees, which may increase the risk for infection in spring. The results confirm that contaminated honey can act as an environmental reservoir of P. larvae spores and suggest that less spores may be needed in honey, compared to in diseased brood, to produce clinically diseased colonies. The spore load in adult bee samples was significantly related to larval mortality but the spore load of honey samples was not.

Influence of heat and radiation on the germinability and viability of B. cereus BIS-59 spores

International Nuclear Information System (INIS)

Kamat, A.S.; Lewis, N.F.

1983-01-01

Spores of Bicillus cereus BIS-59, isolated in this laboratory from shrimps, exhibited an exponential gamma radiation survival curve with a d 10 value of 400 krad as compared with a D 10 value of 30 krad for the vegetative cells. The D 10 value of DPA-depleted spores was also 400 krad indicating that DPA does not influence the radiation response of these spores. Maximum germination monitored with irradiated spores was 60 percent as compared with 80 percent in case of unirradiated spores. Radiation-induced inhibition of the germination processes was not dose dependent. Heat treatment (15 min at 80 C) to spores resulted in activation of the germination process; however, increase in heating time (30 min and 60 min) increased the germination lag period. DPA-depleted spores were less heat resistant than normal spores and exhibited biphasic exponential inactivation. (author)

Live cell imaging of germination and outgrowth of individual Bacillus subtilis spores; the effect of heat stress quantitatively analyzed with SporeTracker

NARCIS (Netherlands)

Pandey, R.; ter Beek, A.; Vischer, N.O.E.; Smelt, J.P.P.M.; Brul, S.; Manders, E.M.M.

2013-01-01

Spore-forming bacteria are a special problem for the food industry as some of them are able to survive preservation processes. Bacillus spp. spores can remain in a dormant, stress resistant state for a long period of time. Vegetative cells are formed by germination of spores followed by a more

Sterilization Resistance of Bacterial Spores Explained with Water Chemistry.

Science.gov (United States)

Friedline, Anthony W; Zachariah, Malcolm M; Middaugh, Amy N; Garimella, Ravindranath; Vaishampayan, Parag A; Rice, Charles V

2015-11-05

Bacterial spores can survive for long periods without nutrients and in harsh environmental conditions. This survival is influenced by the structure of the spore, the presence of protective compounds, and water retention. These compounds, and the physical state of water in particular, allow some species of bacterial spores to survive sterilization schemes with hydrogen peroxide and UV light. The chemical nature of the spore core and its water has been a subject of some contention and the chemical environment of the water impacts resistance paradigms. Either the spore has a glassy core, where water is immobilized along with other core components, or the core is gel-like with mobile water diffusion. These properties affect the movement of peroxide and radical species, and hence resistance. Deuterium solid-state NMR experiments are useful for examining the nature of the water inside the spore. Previous work in our lab with spores of Bacillus subtilis indicate that, for spores, the core water is in a more immobilized state than expected for the gel-like core theory, suggesting a glassy core environment. Here, we report deuterium solid-state NMR observations of the water within UV- and peroxide-resistant spores from Bacillus pumilus SAFR-032. Variable-temperature NMR experiments indicate no change in the line shape after heating to 50 °C, but an overall decrease in signal after heating to 100 °C. These results show glass-like core dynamics within B. pumilus SAFR-032 that may be the potential source of its known UV-resistance properties. The observed NMR traits can be attributed to the presence of an exosporium containing additional labile deuterons that can aid in the deactivation of sterilizing agents.

Can spores survive in interstellar space

Energy Technology Data Exchange (ETDEWEB)

Weber, P.; Greenberg, J.M.

1985-08-01

Inactivation of spores (Bacillus subtilis) has been investigated in the laboratory by vacuum ultraviolet radiation in simulated interstellar conditions. Damage produced at the normal interstellar particle temperature of 10 K is less than at higher temperatures: the major damage being produced by radiation in the 2,000-3,000 A range. The results place constraints on the panspermia hypothesis. (author).

Using Thermal Inactivation Kinetics to Calculate the Probability of Extreme Spore Longevity: Implications for Paleomicrobiology and Lithopanspermia

Science.gov (United States)

Nicholson, Wayne L.

2003-12-01

Thermal inactivation kinetics with extrapolation were used to model the survival probabilities of spores of various Bacillus species over time periods of millions of years at the historical ambient temperatures (25-40 °) encountered within the 250 million-year-old Salado formation, from which the putative ancient spore-forming bacterium Salibacillus marismortui strain 2-9-3 was recovered. The model indicated extremely low-to-moderate survival probabilities for spores of mesophiles, but surprisingly high survival probabilities for thermophilic spores. The significance of the results are discussed in terms of the survival probabilities of (i) terrestrial spores in ancient geologic samples and (ii) spores transported between planets within impact ejecta.

Inactivation of B. Pumilus spores by combination hydrostatic pressure-radiation treatment of parenteral solutions

International Nuclear Information System (INIS)

Wills, P.A.

1975-01-01

Bacterial spores are inactivated by moderate hydrostatic pressures. The radiation dose required to sterilize radiation sensitive pharmaceuticals can be considerably reduced using a combination hydrostatic pressure-radiation treatment. This paper describes a combination pressure-radiation sterilization process using Bacillus pumilus spores suspended in water, 0.9% saline, and 5% dextrose solutions. The optimum temperatures for spore inactivation at 35 MPa and the degree of inactivation at 35, 70 and 105 MPa applied for times up to 100 min have been determined. Inactivation was greatest in saline and least in dextrose. Spores in dextrose were only slightly less radiation resistant than in saline or water. It was calculated that the radiation dose required for sterilization could be halved with appropriate compression treatment. Examples of combinations of pressure-radiation suitable for sterilization are given. One combination is compression at 105 MPa for 18 min for a dose of 1.25 Mrad. (author)

The Fungal Spores Survival Under the Low-Temperature Plasma

Science.gov (United States)

Soušková, Hana; Scholtz, V.; Julák, J.; Savická, D.

This paper presents an experimental apparatus for the decontamination and sterilization of water suspension of fungal spores. The fungicidal effect of stabilized positive and negative corona discharges on four fungal species Aspergillus oryzae, Clacosporium sphaerospermum, Penicillium crustosum and Alternaria sp. was studied. Simultaneously, the slower growing of exposed fungal spores was observed. The obtained results are substantially different in comparison with those of the analogous experiments performed with bacteria. It may be concluded that fungi are more resistant to the low-temperature plasma.

Expression and characterization of a novel spore wall protein from ...

African Journals Online (AJOL)

Microsporidia are obligate intracellular, eukaryotic, spore-forming parasites. The environmentally resistant spores, which harbor a rigid cell wall, are critical for their survival outside their host cells and host-to-host transmission. The spore wall comprises two major layers: the exospore and the endospore. In Nosema ...

Fate of pathogenic Bacillus cereus spores after ingestion by protist grazers

DEFF Research Database (Denmark)

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

The aim of this study is to understand the symbiosis between bacterivorous protists and pathogenic bacterial spores, in order to gain insight on survival and dispersal of pathogenic bacteria in the environment. It is generally accepted that resistance to grazing by protists has contributed...... to the evolution of Bacillus cereus group bacteria (e.g. B. cereus, B. anthracis, B. thuringiensis) as a pathogen. It has been hypothesized that the spore stage protects against digestion by predating protists. Indeed, B. thuringiensis spores have been shown to be readily ingested by ciliated protists but failed...... to be digested (Manasherob et al 1998 AEM 64:1750-). Here we report how diverse protist grazers grow on both vegetative cells and spores of B. cereus and how the bacteria survive ingestion and digestion, and even proliferate inside the digestive vacuoles of ciliated protists. The survival ability of B. cereus...

Live-imaging of Bacillus subtilis spore germination and outgrowth

NARCIS (Netherlands)

Pandey, R.

2014-01-01

Spores of Gram-positive bacteria such as Bacillus and Clostridium cause huge economic losses to the food industry. In food products, spores survive under food preservation conditions and subsequent germination and outgrowth eventually causes food spoilage. Therefore efforts are being made to

Survival of spores of the UV-resistant Bacillus subtilis strain MW01 after exposure to low-earth orbit and simulated martian conditions: data from the space experiment ADAPT on EXPOSE-E.

Science.gov (United States)

Wassmann, Marko; Moeller, Ralf; Rabbow, Elke; Panitz, Corinna; Horneck, Gerda; Reitz, Günther; Douki, Thierry; Cadet, Jean; Stan-Lotter, Helga; Cockell, Charles S; Rettberg, Petra

2012-05-01

In the space experiment "Molecular adaptation strategies of microorganisms to different space and planetary UV climate conditions" (ADAPT), bacterial endospores of the highly UV-resistant Bacillus subtilis strain MW01 were exposed to low-Earth orbit (LEO) and simulated martian surface conditions for 559 days on board the European Space Agency's exposure facility EXPOSE-E, mounted outside the International Space Station. The survival of B. subtilis MW01 spores from both assays (LEO and simulated martian conditions) was determined by a colony-formation assay after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few spore survivors were recovered from B. subtilis MW01 spores exposed in monolayers. However, if shielded from solar irradiation, about 8% of MW01 spores survived in LEO conditions, and 100% survived in simulated martian conditions, compared to the laboratory controls. The results demonstrate the effect of shielding against the high inactivation potential of extraterrestrial solar UV radiation, which limits the chances of survival of even the highly UV-resistant strain of B. subtilis MW01 in the harsh environments of outer space and the martian surface.

Mutation Induction with UV- and X-radiations in spores and vegetative cells of Bacillus subtilis

International Nuclear Information System (INIS)

Tanooka, H.; Munakata, N.; Kitahara, S.

1978-01-01

Spores and vegetative cells of Bacillus subtilis strains with various defects in DNA-repair capacities (hcr - , ssp - , hcr - ssp - ) were irradiated with UV radiation or X-rays. Induced mutation frequency was determined from the observed frequency of prototrophic reversion of a suppressible auxotropic mutation. At equal physical dose, after either UV- or X-irradiation, spores were more resistant to mutations as well as to killing than were vegetative cells. However, quantitative comparison revealed that, at equally lethal doses, spores and vegetative cells were almost equally mutable by X-rays whereas spores were considerably less mutable by UV than were vegetative cells. Thus, as judged from their mutagenic efficiency relative to the lethality, X-ray-induced damage in the spore DNA and the vegetative DNA were equally mutagenic, while UV-induced DNA photoproducts in the spore were less mutagenic than those in vegetative cells. Post-treatment of UV-irradiated cells with caffeine decreased the survival and the induced mutation frequency for either spores or vegetative cells for all the strains. In X-irradiated spores however, a similar suppressing effect of caffeine was observed only for mutability of a strain lacking DNA polymerase I activity

Sensitivity of thermally treated Bacillus subtilis spores to subsequent irradiation

International Nuclear Information System (INIS)

Mostafa, S.A.; El-Zawahry, Y.A.; Awny, N.M.

1986-01-01

B. subtilis spores exposed to thermal treatment at 70 or 80 0 C for 1 hr were more sensitive to subsequent radiation exposure than non-heated spores. Deactivation of previously heated spores by increasing dose of 0-radiation followed an exponential function while, for non-heated spores a shoulder followed by exponential deactivation was noticed. Combined heat-radiation treatment exhibited a synergistic effect on spore deactivation at low irradiation doses, while at high irradiation doses, the effect was more or less additive. Added values of spore injury was higher for B. subtilis spores that received heat and radiation separately than the observed injury for spores that received combined treatment (heat followed by radiation). Results of spore deactivation and injury due to heat followed by radiation treatment are discussed in comparison to those of spores that received radiation-heat sequence

Inactivation of Bacillus anthracis Spores during Laboratory-Scale Composting of Feedlot Cattle Manure

Science.gov (United States)

Xu, Shanwei; Harvey, Amanda; Barbieri, Ruth; Reuter, Tim; Stanford, Kim; Amoako, Kingsley K.; Selinger, Leonard B.; McAllister, Tim A.

2016-01-01

Anthrax outbreaks in livestock have social, economic and health implications, altering farmer’s livelihoods, impacting trade and posing a zoonotic risk. Our study investigated the survival of Bacillus thuringiensis and B. anthracis spores sporulated at 15, 20, or 37°C, over 33 days of composting. Spores (∼7.5 log10 CFU g-1) were mixed with manure and composted in laboratory scale composters. After 15 days, the compost was mixed and returned to the composter for a second cycle. Temperatures peaked at 71°C on day 2 and remained ≥55°C for an average of 7 days in the first cycle, but did not exceed 55°C in the second. For B. thuringiensis, spores generated at 15 and 21°C exhibited reduced (P composting for spores generated at 15, 21, and 37°C, respectively. For both species, spore viability declined more rapidly (P composting cycle. Our findings suggest that the duration of thermophilic exposure (≥55°C) is the main factor influencing survival of B. anthracis spores in compost. As sporulation temperature did not influence survival of B. anthracis, composting may lower the viability of spores associated with carcasses infected with B. anthracis over a range of sporulation temperatures. PMID:27303388

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.

Two distinct groups within the Bacillus subtilis group display significantly different spore heat resistance properties.

Science.gov (United States)

Berendsen, Erwin M; Zwietering, Marcel H; Kuipers, Oscar P; Wells-Bennik, Marjon H J

2015-02-01

The survival of bacterial spores after heat treatment and the subsequent germination and outgrowth in a food product can lead to spoilage of the food product and economical losses. Prediction of time-temperature conditions that lead to sufficient inactivation requires access to detailed spore thermal inactivation kinetics of relevant model strains. In this study, the thermal inactivation kinetics of spores of fourteen strains belonging to the Bacillus subtilis group were determined in detail, using both batch heating in capillary tubes and continuous flow heating in a micro heater. The inactivation data were fitted using a log linear model. Based on the spore heat resistance data, two distinct groups (p subtilis group could be identified. One group of strains had spores with an average D120 °C of 0.33 s, while the spores of the other group displayed significantly higher heat resistances, with an average D120 °C of 45.7 s. When comparing spore inactivation data obtained using batch- and continuous flow heating, the z-values were significantly different, hence extrapolation from one system to the other was not justified. This study clearly shows that heat resistances of spores from different strains in the B. subtilis group can vary greatly. Strains can be separated into two groups, to which different spore heat inactivation kinetics apply. Copyright © 2014 Elsevier Ltd. All rights reserved.

A novel photosensitization treatment for the inactivation of fungal spores and cells mediated by curcumin.

Science.gov (United States)

Al-Asmari, Fahad; Mereddy, Ram; Sultanbawa, Yasmina

2017-08-01

The global concerns regarding the emergence of fungicide-resistant strains and the impact of the excessive use of fungicidal practises on our health, food, and environment have increased, leading to a demand for alternative clean green technologies as treatments. Photosensitization is a treatment that utilises a photosensitiser, light and oxygen to cause cell damage to microorganisms. The effect of photosensitization mediated by curcumin on Aspergillus niger, Aspergillus flavus, Penicillium griseofulvum, Penicillium chrysogenum, Fusarium oxysporum, Candida albicans and Zygosaccharomyces bailii was investigated using three methods. The viability of spores/cells suspended in aqueous buffer using different concentrations of curcumin solution (100-1000μM) and light dose (0, 24, 48, 72 and 96J/cm 2 ) were determined. Spraying curcumin solution on inoculated surfaces of agar plates followed by irradiation and soaking spores/cells in curcumin solution prior to irradiation was also investigated. In aqueous mixtures, photosensitised spores/cells of F. oxysporum and C. albicans were inhibited at all light doses and curcumin concentrations, while inactivation of A. niger, A. flavus P. griseofulvum, P. chrysogenum and Z. bailii were highly significant (Pcurcumin at 800μM showed complete inhibition for A. niger, F. oxysporum, C. albicans and Z. bailii, while A. flavus P. griseofulvum, and P. chrysogenum reduced by 75%, 80.4% and 88.5% respectively. Soaking spores/cells with curcumin solution prior to irradiation did not have a significant effect on the percentage reduction. These observations suggest that a novel photosensitization mediated curcumin treatment is effective against fungal spores/cells and the variation of percentage reduction was dependent on curcumin concentration, light dosage and fungal species. Copyright © 2017 Elsevier B.V. All rights reserved.

The Conserved Spore Coat Protein SpoVM Is Largely Dispensable in Clostridium difficile Spore Formation.

Science.gov (United States)

Ribis, John W; Ravichandran, Priyanka; Putnam, Emily E; Pishdadian, Keyan; Shen, Aimee

2017-01-01

transform into vegetative, toxin-secreting cells. During infection, C. difficile must also induce spore formation to survive exit from the host. Since spore formation is essential for transmission, understanding the basic mechanisms underlying sporulation in C. difficile could inform the development of therapeutic strategies targeting spores. In this study, we determine the requirement of the C. difficile homolog of SpoVM, a protein that is essential for spore formation in Bacillus subtilis due to its regulation of coat and cortex formation. We observed that SpoVM plays a minor role in C. difficile spore formation, in contrast with B. subtilis , indicating that this protein would not be a good target for inhibiting spore formation.

Nitrogen gas plasma treatment of bacterial spores induces oxidative stress that damages the genomic DNA.

Science.gov (United States)

Sakudo, Akikazu; Toyokawa, Yoichi; Nakamura, Tetsuji; Yagyu, Yoshihito; Imanishi, Yuichiro

2017-01-01

Gas plasma, produced by a short high‑voltage pulse generated from a static induction thyristor power supply [1.5 kilo pulse/sec (kpps)], was demonstrated to inactivate Geobacillus stearothermophilus spores (decimal reduction time at 15 min, 2.48 min). Quantitative polymerase chain reaction and enzyme‑linked immunosorbent assays further indicated that nitrogen gas plasma treatment for 15 min decreased the level of intact genomic DNA and increased the level of 8-hydroxy-2'-deoxyguanosine, a major product of DNA oxidation. Three potential inactivation factors were generated during operation of the gas plasma instrument: Heat, longwave ultraviolet-A and oxidative stress (production of hydrogen peroxide, nitrite and nitrate). Treatment of the spores with hydrogen peroxide (3x2‑4%) effectively inactivated the bacteria, whereas heat treatment (100˚C), exposure to UV-A (75‑142 mJ/cm2) and 4.92 mM peroxynitrite (•ONOO‑), which is decomposed into nitrite and nitrate, did not. The results of the present study suggest the gas plasma treatment inactivates bacterial spores primarily by generating hydrogen peroxide, which contributes to the oxidation of the host genomic DNA.

Sensitizing Clostridium difficile Spores With Germinants on Skin and Environmental Surfaces Represents a New Strategy for Reducing Spores via Ambient Mechanisms

Directory of Open Access Journals (Sweden)

Michelle Marie Nerandzic

2017-10-01

Full Text Available Background: Clostridium difficile is a leading cause of healthcare-associated infections worldwide. Prevention of C. difficile transmission is challenging because spores are not killed by alcohol-based hand sanitizers or many commonly used disinfectants. One strategy to control spores is to induce germination, thereby rendering the spores more susceptible to benign disinfection measures and ambient stressors. Methods/Results: C. difficile spores germinated on skin after a single application of cholic acid-class bile salts and co-germinants; for 4 C. difficile strains, recovery of viable spores from skin was reduced by ~0.3 log10CFU to 2 log10CFU after 2 hours and ~1 log10CFU to >2.5 log 10CFU after 24 hours. The addition of taurocholic acid to 70% and 30% ethanol significantly enhanced reduction of viable spores on skin and on surfaces. Desiccation, and to a lesser extent the presence of oxygen, were identified as the stressors responsible for reductions of germinated spores on skin and surfaces. Additionally, germinated spores became susceptible to killing by pH 1.5 hydrochloric acid, suggesting that germinated spores that remain viable on skin and surfaces might be killed by gastric acid after ingestion. Antibiotic-treated mice did not become colonized after exposure to germinated spores, whereas 100% of mice became colonized after exposure to the same quantity of dormant spores. Conclusions: Germination could provide a new approach to reduce C. difficile spores on skin and in the environment and to render surviving spores less capable of causing infection. Our findings suggest that it may be feasible to develop alcohol-based hand sanitizers containing germinants that reduce spores on hands.

INCREASING NUTRITIONAL CONTENT OF ARTIFICIAL FEED WITH WHOLE SPORE PROTEIN OF MYXOBOLUS KOI AS AN IMMUNOSTIMULTANT ON GOLDFISH (CYPRINUS CARPIO L.

Directory of Open Access Journals (Sweden)

Qusairi A.

2018-02-01

Full Text Available The production of goldfish in Indonesia in 2010-2013 has increased by 7.09%, the lowest average production increase compared with other main commodities such as shrimp, tilapia, catfish, and others. One of the primary causes of the low increase in production is the presence of disease and high price of feed in some central goldfish productions. The purpose of this study was to analyze the effect of whole spore protein of Myxobolus koi on goldfish (Cyprinus carpio L. through feed to immune response, growth rate, feed efficiency and survival rate. This research was conducted with complete randomized design with 5 replications. This study used two types of treatment, control (100% artificial feed and artificial feed + immunostimulant (whole spore protein of Myxobolus koi + Boster® Progol adhesive spores. The results showed that whole spore protein of Myxobolus koi given to the feed as immunostimulant can cause response of the immune through the increase of monocytes and lymphocytes in white blood cells on days 7, 14 and 28 observations, daily growth rate of 5.55% compared without immunostimulant with the rate of 1.13%; feed efficiency of 36.57% compared with no immunostimulant, which is only 23.84%, and the treatment gives a 99% survival rate.

Detecting bacterial spores in soup manufacturing

NARCIS (Netherlands)

van Zuijlen, A.C.M.; Oomes, S.J.C.M.; Vos, P.; Brul, S.

2009-01-01

Spores from mesophilic aerobic sporeforming bacteria (Bacillus) are sometimes able to survive the thermal process of commercial sterile products and sporadically cause spoilage or food poisoning. Because of an increasing demand for more fresh products, ideally the processing temperatures should be

Spore membrane(s) as the site of damage within heated Clostridium perfringens spores.

Science.gov (United States)

Flowers, R S; Adams, D M

1976-02-01

Clostridium perfringens spores were injured by ultrahigh-temperature treatment at 105 C for 5 min. Injury was manifested as an increased sensitivity to polymyxin and neomycin. Since many of the survivors could not germinate normally the ultrahigh-temperature-treated spores were sensitized to and germinated by lysozyme. Polymyxin reportedly acts upon the cell membrane. Neomycin may inhibit protein synthesis and has surface-active properties. Injured spores were increasingly sensitive to known surface-active agents, sodium lauryl sulfate, sodium deoxycholate, and Roccal, a quaternary ammonium compound. Injured spores sensitive to polymyxin and neomycin also were osmotically fragile and died during outgrowth in a liquid medium unless the medium was supplemented with 20% sucrose, 10% dextran, or 10% polyvinylpyrrolidone. The results suggested that a spore structure destined to become cell membrane or cell wall was the site of injury. Repair of injury during outgrowth in the presence of protein, deoxyribonucleic acid, ribonucleic acid and cell wall synthesis inhibitors was consistent with this hypothesis.

The role of water radicals in thermorestoration of bacterial spores

International Nuclear Information System (INIS)

Friedman, Y.S.; Grecz, N.

1974-01-01

Fully hydrated bacterial spores exposed to 0.45 Mrad showed a characteristic pattern of survival associated with thermorestoration. When temperature during radiation was controlled at -15 0 to +120 0 C, the lowest viable cell counts were at 0 0 C. Above 0 0 C radiosurvival gradually increased by 2 to 3 log cycles reaching peak at 75 0 C (Bacillus cereus T heat sensitive spores) and at 95 0 C (B.stearothermophilus, heat resistant spores). Simultaneously high survival was observed in the solidly frozen state at -15 0 C to -5 0 C since harmful radicals produced by radiation were trapped in ice. Radiation modifying effects, i.e., protection by 2M ethanol (a scavenger of OH radicals) and sensitization by 1M sodium nitrate (a scavenger of H radicals and hydrated electrons), were studied. The results with ethanol and nitrate confirm the idea that in aqueous sytems below 50 0 C the lethal action is due to oxidizing OH radicals known to attack cell DNA. However, the reversal of scavenger actions above 50 0 C indicates that at those high temperatures lethal effects may also involve the reducing H and esub(aq), which at lower temperatures appear not to affect spore survival though they are known to attack proteins. In this case, it is proposed that radiation inactivation of spores at temperatures below 50 0 C is due to DNA damage inflicted by OH radicals whereas spore death above 50 0 C seems to involve protein /enzyme/ inactivation due to a combined action of heat plus reducing (H, esub(aq)) as well as oxidizing (OH) radical species. From the practical point of view it is important that normally radioprotective effects of such substances as ethanol or ground beef are progressively lost when radiation is carried out at temperatures above 50 0 C. (F.J.)

Effect of pre-irradiation on thermal inactivation of B. pumilus E 601 dry spores irradiated with EB and. gamma. -rays

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yuhei; Ito, Hitoshi; Ishigaki, Isao [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1989-11-01

The survival fraction of B. pumilus spores irradiated with {gamma} -rays and electron beams in vacuum were increased when the spores were heated or allowed to stand in vacuum for a long time at room temperature. The survival curves of the spores thus treated after irradiation might give apparent radiation sensitivities which were lower than true ones obtained just after irradiation. On the contrary, the radiation sensitivities of the spores irradiated in dry air and then heated or allowed to stand in dry air became high. To elucidate the characteristics of th spores, the effect of heating on the radiation sensitivity of the B. pumilus spores has been studied. By heating the pre-irradiated spores in vacuum, its survival fraction was increased, in other words, the spores inactivated with radiation were recovered. However, the thermal sensitivity of the recovered spores was found to be high compared with that of the original spores. On the other hand, when B. pumilus spores were irradiated in dry air and then heated in dry air, the survival curves of the spores were found to be composed of two exponential curves, suggesting that two kinds of thermal inactivation mechanism existed. From Arrhenius plots of unirradiated B. pumilus spores, the activation energies of the thermal inactivation in the range of 90degC to 120degC in vacuum and in air were found to be about 38 kcal/mol and 29 kcal/mol, respectively. The activation energy of the spores at a temperature of higher than 120degC, however increased to give the same value (about 38 kcal/mol) as found in vacuum. This fact suggests the main mechanism of the thermal inactivation of the spores varies near 120degC. Arrhenius plots of irradiated spores in vacuum was similar to that of unirradiated ones. Thermal inactivation rates of the irradiated spores in the presence of air will also be discussed as compared with those of unirradiated ones. (author).

Carvacrol suppresses high pressure high temperature inactivation of Bacillus cereus spores.

Science.gov (United States)

Luu-Thi, Hue; Corthouts, Jorinde; Passaris, Ioannis; Grauwet, Tara; Aertsen, Abram; Hendrickx, Marc; Michiels, Chris W

2015-03-16

The inactivation of bacterial spores generally proceeds faster and at lower temperatures when heat treatments are conducted under high pressure, and high pressure high temperature (HPHT) processing is, therefore, receiving an increased interest from food processors. However, the mechanisms of spore inactivation by HPHT treatment are poorly understood, particularly at moderately elevated temperature. In the current work, we studied inactivation of the spores of Bacillus cereus F4430/73 by HPHT treatment for 5 min at 600MPa in the temperature range of 50-100°C, using temperature increments of 5°C. Additionally, we investigated the effect of the natural antimicrobial carvacrol on spore germination and inactivation under these conditions. Spore inactivation by HPHT was less than about 1 log unit at 50 to 70°C, but gradually increased at higher temperatures up to about 5 log units at 100°C. DPA release and loss of spore refractility in the spore population were higher at moderate (≤65°C) than at high (≥70°C) treatment temperatures, and we propose that moderate conditions induced the normal physiological pathway of spore germination resulting in fully hydrated spores, while at higher temperatures this pathway was suppressed and replaced by another mechanism of pressure-induced dipicolinic acid (DPA) release that results only in partial spore rehydration, probably because spore cortex hydrolysis is inhibited. Carvacrol strongly suppressed DPA release and spore rehydration during HPHT treatment at ≤65°C and also partly inhibited DPA release at ≥65°C. Concomitantly, HPHT spore inactivation was reduced by carvacrol at 65-90°C but unaffected at 95-100°C. Copyright © 2014 Elsevier B.V. All rights reserved.

New insights in the bacterial spore resistance to extreme terrestrial and extraterrestrial factors

Science.gov (United States)

Moeller, Ralf; Horneck, Gerda; Reitz, Guenther

Based on their unique resistance to various space parameters, Bacillus endospores are one of the model systems used for astrobiological studies. The extremely high resistance of bacterial endospores to environmental stress factors has intrigued researchers since long time and many characteristic spore features, especially those involved in the protection of spore DNA, have already been uncovered. The disclosure of the complete genomic sequence of Bacillus subtilis 168, one of the often used astrobiological model system, and the rapid development of tran-scriptional microarray techniques have opened new opportunities of gaining further insights in the enigma of spore resistance. Spores of B. subtilis were exposed to various extreme ter-restrial and extraterrestrial stressors to reach a better understanding of the DNA protection and repair strategies, which them to cope with the induced DNA damage. Following physical stress factors of environmental importance -either on Earth or in space -were selected for this thesis: (i) mono-and polychromatic UV radiation, (ii) ionizing radiation, (iii) exposure to ultrahigh vacuum; and (iv) high shock pressures simulating meteorite impacts. To reach a most comprehensive understanding of spore resistance to those harsh terrestrial or simulated extraterrestrial conditions, a standardized experimental protocol of the preparation and ana-lyzing methods was established including the determination of the following spore responses: (i) survival, (ii) induced mutations, (iii) DNA damage, (iv) role of different repair pathways by use of a set of repair deficient mutants, and (v) transcriptional responses during spore germi-nation by use of genome-wide transcriptome analyses and confirmation by RT-PCR. From this comprehensive set of data on spore resistance to a variety of environmental stress parameters a model of a "built-in" transcriptional program of bacterial spores in response to DNA damaging treatments to ensure DNA restoration

The role of water radicals in thermorestoration of bacterial spores

Energy Technology Data Exchange (ETDEWEB)

Friedman, Y S; Grecz, N [Illinois Inst. of Tech., Chicago (USA). Dept. of Biology

1974-01-01

Fully hydrated bacterial spores exposed to 0.45 Mrad showed a characteristic pattern of survival associated with thermorestoration. When temperature during radiation was controlled at -15/sup 0/ to +120/sup 0/C, the lowest viable cell counts were at 0/sup 0/C. Above 0/sup 0/C radiosurvival gradually increased by 2 to 3 log cycles reaching peak at 75/sup 0/C (Bacillus cereus T heat sensitive spores) and at 95/sup 0/C (B.stearothermophilus, heat resistant spores). Simultaneously high survival was observed in the solidly frozen state at -15/sup 0/C to -5/sup 0/C since harmful radicals produced by radiation were trapped in ice. Radiation modifying effects, i.e., protection by 2M ethanol (a scavenger of OH radicals) and sensitization by 1M sodium nitrate (a scavenger of H radicals and hydrated electrons), were studied. The results with ethanol and nitrate confirm the idea that in aqueous sytems below 50/sup 0/C the lethal action is due to oxidizing OH radicals known to attack cell DNA. However, the reversal of scavenger actions above 50/sup 0/C indicates that at those high temperatures lethal effects may also involve the reducing H and esub(aq), which at lower temperatures appear not to affect spore survival though they are known to attack proteins. In this case, it is proposed that radiation inactivation of spores at temperatures below 50/sup 0/C is due to DNA damage inflicted by OH radicals whereas spore death above 50/sup 0/C seems to involve protein /enzyme/ inactivation due to a combined action of heat plus reducing (H, esub(aq)) as well as oxidizing (OH) radical species. From the practical point of view it is important that normally radioprotective effects of such substances as ethanol or ground beef are progressively lost when radiation is carried out at temperatures above 50/sup 0/C.

Biomarkers of Aspergillus spores

Science.gov (United States)

Sulc, Miroslav; Peslova, Katerina; Zabka, Martin; Hajduch, Marian; Havlicek, Vladimir

2009-02-01

We applied both matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometric and 1D sodium dodecylsulfate polyacrylamide gel electrophoretic (1D-PAGE) approaches for direct analysis of intact fungal spores of twenty four Aspergillus species. In parallel, we optimized various protocols for protein extraction from Aspergillus spores using acidic conditions, step organic gradient and variable sonication treatment. The MALDI-TOF mass spectra obtained from optimally prepared samples provided a reproducible fingerprint demonstrating the capability of the MALDI-TOF approach to type and characterize different fungal strains within the Aspergillus genus. Mass spectra of intact fungal spores provided signals mostly below 20 kDa. The minimum material amount represented 0.3 [mu]g (10,000 spores). Proteins with higher molecular weight were detected by 1D-PAGEE Eleven proteins were identified from three selected strains in the range 5-25 kDa by the proteomic approach. Hemolysin and hydrophobin have the highest relevance in host-pathogen interactions.

Physical determinants of radiation sensitivity in bacterial spores

International Nuclear Information System (INIS)

Powers, E.L.

1982-01-01

Several factors modifying radiation sensitivity in dry bacterial spores are described and discussed. Vacuum inducing the loss of critical structural water, very low dose rates of radiation from which the cell may recover, radiations of high linear energy transfer, and the action of temperature over long periods of time on previously irradiated cells are recognized from extensive laboratory work as important in determining survival of spores exposed to low radiation doses at low temperatures for long periods of time. Some extensions of laboratory work are proposed

Germination and inactivation of Bacillus coagulans and Alicyclobacillus acidoterrestris spores by high hydrostatic pressure treatment in buffer and tomato sauce.

Science.gov (United States)

Vercammen, Anne; Vivijs, Bram; Lurquin, Ine; Michiels, Chris W

2012-01-16

Acidothermophilic bacteria like Alicyclobacillus acidoterrestris and Bacillus coagulans can cause spoilage of heat-processed acidic foods because they form spores with very high heat resistance and can grow at low pH. The objective of this work was to study the germination and inactivation of A. acidoterrestris and B. coagulans spores by high hydrostatic pressure (HP) treatment at temperatures up to 60°C and both at low and neutral pH. In a first experiment, spores suspended in buffers at pH 4.0, 5.0 and 7.0 were processed for 10min at different pressures (100-800MPa) at 40°C. None of these treatments caused any significant inactivation, except perhaps at 800MPa in pH 4.0 buffer where close to 1 log inactivation of B. coagulans was observed. Spore germination up to about 2 log was observed for both bacteria but occurred mainly in a low pressure window (100-300MPa) for A. acidoterrestris and only in a high pressure window (600-800MPa) for B. coagulans. In addition, low pH suppressed germination in A. acidoterrestris, but stimulated it in B. coagulans. In a second series of experiments, spores were treated in tomato sauce of pH 4.2 and 5.0 at 100 - 800MPa at 25, 40 and 60°C for 10min. At 40°C, results for B. coagulans were similar as in buffer. For A. acidoterrestris, germination levels in tomato sauce were generally higher than in buffer, and showed little difference at low and high pressure. Remarkably, the pH dependence of A. acidoterrestris spore germination was reversed in tomato sauce, with more germination at the lowest pH. Furthermore, HP treatments in the pH 4.2 sauce caused between 1 and 1.5 log inactivation of A. acidoterrestris. Germination of spores in the high pressure window was strongly temperature dependent, whereas germination of A. acidoterrestris in the low pressure window showed little temperature dependence. When HP treatment was conducted at 60°C, most of the germinated spores were also inactivated. For the pH 4.2 tomato sauce, this

Resistance and recovery studies on ultraviolet-irradiated spores of Bacillus pumilus

International Nuclear Information System (INIS)

Abshire, R.L.; Bain, B.; Williams, T.

1980-01-01

A spore suspension model and a procedure for recovering ultraviolet (uv)-irradiated spores of Bacillus pumilus were investigated. A most-probable-number tube dilution method using double-strength Trypticase soy broth was found to be superior to the agar plate method for recovering optimal numbers of spores irradiated with sublethal doses of uv energy. Aqueous suspensions of B. pumilus survived uv doses up to 108,000 ergs/mm 2 as determined by a most-probable-number recovery and estimation procedure. Resistance and stability data were consistent and reproducible, indicating the dependability of this method for recovering uv-damaged spores. The procedures used to collect information concerning resistance characteristics for two strains of B. pumilus are discussed

Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival.

Science.gov (United States)

Al-Laaeiby, Ayat; Kershaw, Michael J; Penn, Tina J; Thornton, Christopher R

2016-03-24

The dematiaceous (melanised) fungus Lomentospora (Scedosporium) prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H₂O₂), UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN)-melanin biosynthetic enzymes polyketide synthase (PKS1), tetrahydroxynapthalene reductase (4HNR) and scytalone dehydratase (SCD1). Infectious propagules (spores) of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H₂O₂ treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not

The cellulose-binding activity of the PsB multiprotein complex is required for proper assembly of the spore coat and spore viability in Dictyostelium discoideum.

Science.gov (United States)

Srinivasan, S; Griffiths, K R; McGuire, V; Champion, A; Williams, K L; Alexander, S

2000-08-01

The terminal event of spore differentiation in the cellular slime mould Dictyostelium discoideum is the assembly of the spore coat, which surrounds the dormant amoeba and allows the organism to survive during extended periods of environmental stress. The spore coat is a polarized extracellular matrix composed of glycoproteins and cellulose. The process of spore coat formation begins by the regulated secretion of spore coat proteins from the prespore vesicles (PSVs). Four of the major spore coat proteins (SP96, PsB/SP85, SP70 and SP60) exist as a preassembled multiprotein complex within the PSVs. This complete complex has an endogenous cellulose-binding activity. Mutant strains lacking either the SP96 or SP70 proteins produce partial complexes that do not have cellulose-binding activity, while mutants lacking SP60 produce a partial complex that retains this activity. Using a combination of immunofluorescence microscopy and biochemical methods we now show that the lack of cellulose-binding activity in the SP96 and SP70 mutants results in abnormally assembled spore coats and spores with greatly reduced viability. In contrast, the SP60 mutant, in which the PsB complex retains its cellulose-binding activity, produces spores with apparently unaltered structure and viability. Thus, it is the loss of the cellulose-binding activity of the PsB complex, rather than the mere loss of individual spore coat proteins, that results in compromised spore coat structure. These results support the idea that the cellulose-binding activity associated with the complete PsB complex plays an active role in the assembly of the spore coat.

Development of Protective Immunity in New Zealand White Rabbits Challenged with Bacillus anthracis Spores and Treated with Antibiotics and Obiltoxaximab, a Monoclonal Antibody against Protective Antigen.

Science.gov (United States)

Henning, Lisa N; Carpenter, Sarah; Stark, Gregory V; Serbina, Natalya V

2018-02-01

The recommended management of inhalational anthrax, a high-priority bioterrorist threat, includes antibiotics and antitoxins. Obiltoxaximab, a chimeric monoclonal antibody against anthrax protective antigen (PA), is licensed under the U.S. Food and Drug Administration's (FDA's) Animal Rule for the treatment of inhalational anthrax. Because of spore latency, disease reemergence after treatment cessation is a concern, and there is a need to understand the development of endogenous protective immune responses following antitoxin-containing anthrax treatment regimens. Here, acquired protective immunity was examined in New Zealand White (NZW) rabbits challenged with a targeted lethal dose of Bacillus anthracis spores and treated with antibiotics, obiltoxaximab, or a combination of both. Survivors of the primary challenge were rechallenged 9 months later and monitored for survival. Survival rates after primary and rechallenge for controls and animals treated with obiltoxaximab, levofloxacin, or a combination of both were 0, 65, 100, and 95%, and 0, 100, 95, and 89%, respectively. All surviving immune animals had circulating antibodies to PA and serum toxin-neutralizing titers prior to rechallenge. Following rechallenge, systemic bacteremia and toxemia were not detected in most animals, and the levels of circulating anti-PA IgG titers increased starting at 5 days postrechallenge. We conclude that treatment with obiltoxaximab, alone or combined with antibiotics, significantly improves the survival of rabbits that received a lethal inhalation B. anthracis spore challenge dose and does not interfere with the development of immunity. Survivors of primary challenge are protected against reexposure, have rare incidents of systemic bacteremia and toxemia, and have evidence of an anamnestic response. Copyright © 2018 Henning et al.

Formation and characterization of non-growth states in Clostridium thermocellum: spores and L-forms

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Mearls Elizabeth B

2012-08-01

Full Text Available Abstract Background Clostridium thermocellum is an anaerobic thermophilic bacterium that exhibits high levels of cellulose solublization and produces ethanol as an end product of its metabolism. Using cellulosic biomass as a feedstock for fuel production is an attractive prospect, however, growth arrest can negatively impact ethanol production by fermentative microorganisms such as C. thermocellum. Understanding conditions that lead to non-growth states in C. thermocellum can positively influence process design and culturing conditions in order to optimize ethanol production in an industrial setting. Results We report here that Clostridium thermocellum ATCC 27405 enters non-growth states in response to specific growth conditions. Non-growth states include the formation of spores and a L-form-like state in which the cells cease to grow or produce the normal end products of metabolism. Unlike other sporulating organisms, we did not observe sporulation of C. thermocellum in low carbon or nitrogen environments. However, sporulation did occur in response to transfers between soluble and insoluble substrates, resulting in approximately 7% mature spores. Exposure to oxygen caused a similar sporulation response. Starvation conditions during continuous culture did not result in spore formation, but caused the majority of cells to transition to a L-form state. Both spores and L-forms were determined to be viable. Spores exhibited enhanced survival in response to high temperature and prolonged storage compared to L-forms and vegetative cells. However, L-forms exhibited faster recovery compared to both spores and stationary phase cells when cultured in rich media. Conclusions Both spores and L-forms cease to produce ethanol, but provide other advantages for C. thermocellum including enhanced survival for spores and faster recovery for L-forms. Understanding the conditions that give rise to these two different non-growth states, and the implications that

Use of aerobic spores as a surrogate for cryptosporidium oocysts in drinking water supplies.

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Headd, Brendan; Bradford, Scott A

2016-03-01

Waterborne illnesses are a growing concern among health and regulatory agencies worldwide. The United States Environmental Protection Agency has established several rules to combat the contamination of water supplies by cryptosporidium oocysts, however, the detection and study of cryptosporidium oocysts is hampered by methodological and financial constraints. As a result, numerous surrogates for cryptosporidium oocysts have been proposed by the scientific community and efforts are underway to evaluate many of the proposed surrogates. The purpose of this review is to evaluate the suitability of aerobic bacterial spores to serve as a surrogate for cryptosporidium oocysts in identifying contaminated drinking waters. To accomplish this we present a comparison of the biology and life cycles of aerobic spores and oocysts and compare their physical properties. An analysis of their surface properties is presented along with a review of the literature in regards to the transport, survival, and prevalence of aerobic spores and oocysts in the saturated subsurface environment. Aerobic spores and oocysts share many commonalities with regard to biology and survivability, and the environmental prevalence and ease of detection make aerobic spores a promising surrogate for cryptosporidium oocysts in surface and groundwater. However, the long-term transport and release of aerobic spores still needs to be further studied, and compared with available oocyst information. In addition, the surface properties and environmental interactions of spores are known to be highly dependent on the spore taxa and purification procedures, and additional research is needed to address these issues in the context of transport. Published by Elsevier Ltd.

Pre-treatment Of Thermoduric Spores In Co2 Modified Atmosphere And Their Survivability During Food Extrusion [pré-tratamento De Esporos Termodúricos Em Atmosfera Modificada De Co2 E Sua Sobrevivência Ao Processo De Extrusão

OpenAIRE

Fraiha M.; Ferraz A.C.O.; Biagi J.D.

2011-01-01

The aim of this experiment was to evaluate how susceptible spores become to mechanical damage during food extrusion after being submitted to CO2. B. stearothermophilus spores sowed to corn and soy mix were submitted to 99% CO2 for 10 days and extruded in a single-screw extruder. The treatments were: T1 - spore-containing samples, extruded at screw rotational speed of 65 rpm and barrel wall temperature of 80 °C; T2 - as T1, except for screw rotational speed of 150 rpm; and T3 - as T2, except t...

Spore Coat Architecture of Clostridium novyi-NT spores

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Plomp, M; McCafferey, J; Cheong, I; Huang, X; Bettegowda, C; Kinzler, K; Zhou, S; Vogelstein, B; Malkin, A

2007-05-07

Spores of the anaerobic bacterium Clostridium novyi-NT are able to germinate in and destroy hypoxic regions of tumors in experimental animals. Future progress in this area will benefit from a better understanding of the germination and outgrowth processes that are essential for the tumorilytic properties of these spores. Towards this end, we have used both transmission electron microscopy and atomic force microscopy to determine the structure of dormant as well as germinating spores. We found that the spores are surrounded by an amorphous layer intertwined with honeycomb parasporal layers. Moreover, the spore coat layers had apparently self-assembled and this assembly was likely to be governed by crystal growth principles. During germination and outgrowth, the honeycomb layers as well as the underlying spore coat and undercoat layers sequentially dissolved until the vegetative cell was released. In addition to their implications for understanding the biology of C. novyi-NT, these studies document the presence of proteinaceous growth spirals in a biological organism.

Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

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Kevin eEgan

2016-04-01

Full Text Available Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB. Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural, approach, while ensuring both food safety and product shelf life. Bacteriocins also show additive/synergistic effects when used in combination with other treatments, such as heating, high pressure, organic compounds, and as part of food packaging. These features are particularly attractive from the perspective of controlling sporeforming bacteria. Bacterial spores are common contaminants of food products, and their outgrowth may cause food spoilage or food-borne illness. They are of particular concern to the food industry due to their thermal and chemical resistance in their dormant state. However, when spores germinate they lose the majority of their resistance traits, making them susceptible to a variety of food processing treatments. Bacteriocins represent one potential treatment as they may inhibit spores in the post-germination/outgrowth phase of the spore cycle. Spore eradication and control in food is critical, as they are able to spoil and in certain cases compromise the safety of food by producing dangerous toxins. Thus, understanding the mechanisms by which bacteriocins exert their sporostatic/sporicidal activity against bacterial spores will ultimately facilitate their optimal use in food. This review will focus on the use of bacteriocins alone, or in combination with other innovative processing methods to control spores in food, the current knowledge and gaps therein with regard to bacteriocin-spore interactions and discuss future research approaches to enable

Bacteriocins: Novel Solutions to Age Old Spore-Related Problems?

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Egan, Kevin; Field, Des; Rea, Mary C; Ross, R Paul; Hill, Colin; Cotter, Paul D

2016-01-01

Bacteriocins are ribosomally synthesized antimicrobial peptides produced by bacteria, which have the ability to kill or inhibit other bacteria. Many bacteriocins are produced by food grade lactic acid bacteria (LAB). Indeed, the prototypic bacteriocin, nisin, is produced by Lactococcus lactis, and is licensed in over 50 countries. With consumers becoming more concerned about the levels of chemical preservatives present in food, bacteriocins offer an alternative, more natural approach, while ensuring both food safety and product shelf life. Bacteriocins also show additive/synergistic effects when used in combination with other treatments, such as heating, high pressure, organic compounds, and as part of food packaging. These features are particularly attractive from the perspective of controlling sporeforming bacteria. Bacterial spores are common contaminants of food products, and their outgrowth may cause food spoilage or food-borne illness. They are of particular concern to the food industry due to their thermal and chemical resistance in their dormant state. However, when spores germinate they lose the majority of their resistance traits, making them susceptible to a variety of food processing treatments. Bacteriocins represent one potential treatment as they may inhibit spores in the post-germination/outgrowth phase of the spore cycle. Spore eradication and control in food is critical, as they are able to spoil and in certain cases compromise the safety of food by producing dangerous toxins. Thus, understanding the mechanisms by which bacteriocins exert their sporostatic/sporicidal activity against bacterial spores will ultimately facilitate their optimal use in food. This review will focus on the use of bacteriocins alone, or in combination with other innovative processing methods to control spores in food, the current knowledge and gaps therein with regard to bacteriocin-spore interactions and discuss future research approaches to enable spores to be more

Ectomycorrhizal fungal spore bank recovery after a severe forest fire: some like it hot.

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Glassman, Sydney I; Levine, Carrie R; DiRocco, Angela M; Battles, John J; Bruns, Thomas D

2016-05-01

After severe wildfires, pine recovery depends on ectomycorrhizal (ECM) fungal spores surviving and serving as partners for regenerating forest trees. We took advantage of a large, severe natural forest fire that burned our long-term study plots to test the response of ECM fungi to fire. We sampled the ECM spore bank using pine seedling bioassays and high-throughput sequencing before and after the California Rim Fire. We found that ECM spore bank fungi survived the fire and dominated the colonization of in situ and bioassay seedlings, but there were specific fire adapted fungi such as Rhizopogon olivaceotinctus that increased in abundance after the fire. The frequency of ECM fungal species colonizing pre-fire bioassay seedlings, post-fire bioassay seedlings and in situ seedlings were strongly positively correlated. However, fire reduced the ECM spore bank richness by eliminating some of the rare species, and the density of the spore bank was reduced as evidenced by a larger number of soil samples that yielded uncolonized seedlings. Our results show that although there is a reduction in ECM inoculum, the ECM spore bank community largely remains intact, even after a high-intensity fire. We used advanced techniques for data quality control with Illumina and found consistent results among varying methods. Furthermore, simple greenhouse bioassays can be used to determine which fungi will colonize after fires. Similar to plant seed banks, a specific suite of ruderal, spore bank fungi take advantage of open niche space after fires.

Enzyme-driven Bacillus spore coat degradation leading to spore killing.

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Mundra, Ruchir V; Mehta, Krunal K; Wu, Xia; Paskaleva, Elena E; Kane, Ravi S; Dordick, Jonathan S

2014-04-01

The bacillus spore coat confers chemical and biological resistance, thereby protecting the core from harsh environments. The primarily protein-based coat consists of recalcitrant protein crosslinks that endow the coat with such functional protection. Proteases are present in the spore coat, which play a putative role in coat degradation in the environment. However these enzymes are poorly characterized. Nonetheless given the potential for proteases to catalyze coat degradation, we screened 10 commercially available proteases for their ability to degrade the spore coats of B. cereus and B. anthracis. Proteinase K and subtilisin Carlsberg, for B. cereus and B. anthracis spore coats, respectively, led to a morphological change in the otherwise impregnable coat structure, increasing coat permeability towards cortex lytic enzymes such as lysozyme and SleB, thereby initiating germination. Specifically in the presence of lysozyme, proteinase K resulted in 14-fold faster enzyme induced germination and exhibited significantly shorter lag times, than spores without protease pretreatment. Furthermore, the germinated spores were shown to be vulnerable to a lytic enzyme (PlyPH) resulting in effective spore killing. The spore surface in response to proteolytic degradation was probed using scanning electron microscopy (SEM), which provided key insights regarding coat degradation. The extent of coat degradation and spore killing using this enzyme-based pretreatment approach is similar to traditional, yet far harsher, chemical decoating methods that employ detergents and strong denaturants. Thus the enzymatic route reduces the environmental burden of chemically mediated spore killing, and demonstrates that a mild and environmentally benign biocatalytic spore killing is achievable. © 2013 Wiley Periodicals, Inc.

Diverse microbial species survive high ammonia concentrations

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Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

2012-04-01

Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

Synergistic Effects of High Hydrostatic Pressure, Mild Heating, and Amino Acids on Germination and Inactivation of Clostridium sporogenes Spores

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Ishimori, Takateru; Takahashi, Katsutoshi; Goto, Masato; Nakagawa, Suguru; Kasai, Yoshiaki; Konagaya, Yukifumi; Batori, Hiroshi; Kobayashi, Atsushi

2012-01-01

The synergistic effects of high hydrostatic pressure (HHP), mild heating, and amino acids on the germination of Clostridium sporogenes spores were examined by determining the number of surviving spores that returned to vegetative growth after pasteurization following these treatments. Pressurization at 200 MPa at a temperature higher than 40°C and treatment with some of the 19 l-amino acids at 10 mM or higher synergistically facilitated germination. When one of these factors was omitted, the level of germination was insignificant. Pressures of 100 and 400 MPa were less effective than 200 MPa. The spores were effectively inactivated by between 1.8 and 4.8 logs by pasteurization at 80°C after pressurization at 200 MPa at 45°C for 120 min with one of the amino acids with moderate hydrophobicity, such as Leu, Phe, Cys Met, Ala, Gly, or Ser. However, other amino acids showed poor inactivation effects of less than 0.9 logs. Spores in solutions containing 80 mM of either Leu, Phe, Cys, Met, Ala, Gly, or Ser were successfully inactivated by pasteurization by more than 5.4 logs after pressurization at 200 MPa at 70°C for 15 to 120 min. Ala and Met reduced the spore viability by 2.8 and 1.8 logs, respectively, by pasteurization at a concentration of 1 mM under 200 MPa at 70°C. These results indicate that germination of the spores is facilitated by a combination of high hydrostatic pressure, mild heating, and amino acids. PMID:22983975

Spore formation and toxin production in Clostridium difficile biofilms.

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Semenyuk, Ekaterina G; Laning, Michelle L; Foley, Jennifer; Johnston, Pehga F; Knight, Katherine L; Gerding, Dale N; Driks, Adam

2014-01-01

The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA), polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

Spore formation and toxin production in Clostridium difficile biofilms.

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Ekaterina G Semenyuk

Full Text Available The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA, polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival

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Ayat Al-Laaeiby

2016-03-01

Full Text Available The dematiaceous (melanised fungus Lomentospora (Scedosporium prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H2O2, UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN-melanin biosynthetic enzymes polyketide synthase (PKS1, tetrahydroxynapthalene reductase (4HNR and scytalone dehydratase (SCD1. Infectious propagules (spores of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H2O2 treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not

Detection and differentiation of bacterial spores in a mineral matrix by Fourier transform infrared spectroscopy (FTIR and chemometrical data treatment

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Brandes Ammann Andrea

2011-07-01

Full Text Available Abstract Background Fourier transform infrared spectroscopy (FTIR has been used as analytical tool in chemistry for many years. In addition, FTIR can also be applied as a rapid and non-invasive method to detect and identify microorganisms. The specific and fingerprint-like spectra allow - under optimal conditions - discrimination down to the species level. The aim of this study was to develop a fast and reproducible non-molecular method to differentiate pure samples of Bacillus spores originating from different species as well as to identify spores in a simple matrix, such as the clay mineral, bentonite. Results We investigated spores from pure cultures of seven different Bacillus species by FTIR in reflection or transmission mode followed by chemometrical data treatment. All species investigated (B. atrophaeus, B. brevis, B. circulans, B. lentus, B. megaterium, B. subtilis, B. thuringiensis are typical aerobic soil-borne spore formers. Additionally, a solid matrix (bentonite and mixtures of benonite with spores of B. megaterium at various wt/wt ratios were included in the study. Both hierarchical cluster analysis and principal component analysis of the spectra along with multidimensional scaling allowed the discrimination of different species and spore-matrix-mixtures. Conclusions Our results show that FTIR spectroscopy is a fast method for species-level discrimination of Bacillus spores. Spores were still detectable in the presence of the clay mineral bentonite. Even a tenfold excess of bentonite (corresponding to 2.1 × 1010 colony forming units per gram of mineral matrix still resulted in an unambiguous identification of B. megaterium spores.

Effect of Shadowing on Survival of Bacteria under Conditions Simulating the Martian Atmosphere and UV Radiation▿ †

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Osman, Shariff; Peeters, Zan; La Duc, Myron T.; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

2008-01-01

Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-μm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-μm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (∼5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars. PMID:18083857

Lethality of chlorine, chlorine dioxide, and a commercial fruit and vegetable sanitizer to vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis.

Science.gov (United States)

Beuchat, Larry R; Pettigrew, Charles A; Tremblay, Mario E; Roselle, Brian J; Scouten, Alan J

2004-08-01

Chlorine, ClO2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis. The ultimate goal was to use one or both species as a potential surrogate(s) for Bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. Treatment with alkaline (pH 10.5 to 11.0) ClO2 (200 microg/ml) produced by electrochemical technologies reduced populations of a five-strain mixture of vegetative cells and a five-strain mixture of spores of B. cereus by more than 5.4 and more than 6.4 log CFU/ml respectively, within 5 min. This finding compares with respective reductions of 4.5 and 1.8 log CFU/ml resulting from treatment with 200 microg/ml of chlorine. Treatment with a 1.5% acidified (pH 3.0) solution of Fit powder product was less effective, causing 2.5- and 0.4-log CFU/ml reductions in the number of B. cereus cells and spores, respectively. Treatment with alkaline ClO2 (85 microg/ml), acidified (pH 3.4) ClO2 (85 microg/ml), and a mixture of ClO2 (85 microg/ml) and Fit powder product (0.5%) (pH 3.5) caused reductions in vegetative cell/spore populations of more than 5.3/5.6, 5.3/5.7, and 5.3/6.0 log CFU/ml, respectively. Treatment of B. cereus and B. thuringiensis spores in a medium (3.4 mg/ml of organic and inorganic solids) in which cells had grown and produced spores with an equal volume of alkaline (pH 12.1) ClO2 (400 microg/ml) for 30 min reduced populations by 4.6 and 5.2 log CFU/ml, respectively, indicating high lethality in the presence of materials other than spores that would potentially react with and neutralize the sporicidal activity of ClO2.

Obiltoxaximab Prevents Disseminated Bacillus anthracis Infection and Improves Survival during Pre- and Postexposure Prophylaxis in Animal Models of Inhalational Anthrax

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Yamamoto, Brent J.; Shadiack, Annette M.; Carpenter, Sarah; Sanford, Daniel; Henning, Lisa N.; Gonzales, Nestor; O'Connor, Edward; Casey, Leslie S.

2016-01-01

The Centers for Disease Control and Prevention recommend adjunctive antitoxins when systemic anthrax is suspected. Obiltoxaximab, a monoclonal antibody against protective antigen (PA), is approved for treatment of inhalational anthrax in combination with antibiotics and for prophylaxis when alternative therapies are not available. The impact of toxin neutralization with obiltoxaximab during pre- and postexposure prophylaxis was explored, and efficacy results that supported the prophylaxis indication are presented here. New Zealand White rabbits and cynomolgus macaques received obiltoxaximab as a single intramuscular or intravenous dose of 2 to 16 mg/kg of body weight at various times relative to Bacillus anthracis aerosol spore challenge. The primary endpoint was survival, and effect of treatment timing was explored. In rabbits, obiltoxaximab administration 9 h postchallenge singly or combined with a 5-day levofloxacin regimen protected 89% to 100% of animals compared to 33% with levofloxacin monotherapy. In cynomolgus macaques, a single intramuscular dose of 16 mg/kg obiltoxaximab led to 100% survival when given 1 to 3 days preexposure and 83% to 100% survival when given 18 to 24 h postexposure and prior to systemic bacteremia onset. Obiltoxaximab administration after bacteremia onset resulted in lower (25% to 50%) survival rates reflective of treatment setting. Prophylactic administration of obiltoxaximab before spore challenge or to spore-challenged animals before systemic bacterial dissemination is efficacious in promoting survival, ameliorating toxemia, and inhibiting bacterial spread to the periphery. PMID:27431219

Predicting Bacillus coagulans spores inactivation in tomato pulp under nonisothermal heat treatments.

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Zimmermann, Morgana; Longhi, Daniel A; Schaffner, Donald W; Aragão, Gláucia M F

2014-05-01

The knowledge and understanding of Bacillus coagulans inactivation during a thermal treatment in tomato pulp, as well as the influence of temperature variation during thermal processes are essential for design, calculation, and optimization of the process. The aims of this work were to predict B. coagulans spores inactivation in tomato pulp under varying time-temperature profiles with Gompertz-inspired inactivation model and to validate the model's predictions by comparing the predicted values with experimental data. B. coagulans spores in pH 4.3 tomato pulp at 4 °Brix were sealed in capillary glass tubes and heated in thermostatically controlled circulating oil baths. Seven different nonisothermal profiles in the range from 95 to 105 °C were studied. Predicted inactivation kinetics showed similar behavior to experimentally observed inactivation curves when the samples were exposed to temperatures in the upper range of this study (99 to 105 °C). Profiles that resulted in less accurate predictions were those where the range of temperatures analyzed were comparatively lower (inactivation profiles starting at 95 °C). The link between fail prediction and both lower starting temperature and magnitude of the temperature shift suggests some chemical or biological mechanism at work. Statistical analysis showed that overall model predictions were acceptable, with bias factors from 0.781 to 1.012, and accuracy factors from 1.049 to 1.351, and confirm that the models used were adequate to estimate B. coagulans spores inactivation under fluctuating temperature conditions in the range from 95 to 105 °C. How can we estimate Bacillus coagulans inactivation during sudden temperature shifts in heat processing? This article provides a validated model that can be used to predict B. coagulans under changing temperature conditions. B. coagulans is a spore-forming bacillus that spoils acidified food products. The mathematical model developed here can be used to predict the spoilage

Electron Beam Irradiation Dose Dependently Damages the Bacillus Spore Coat and Spore Membrane

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S. E. Fiester

2012-01-01

Full Text Available Effective control of spore-forming bacilli begs suitable physical or chemical methods. While many spore inactivation techniques have been proven effective, electron beam (EB irradiation has been frequently chosen to eradicate Bacillus spores. Despite its widespread use, there are limited data evaluating the effects of EB irradiation on Bacillus spores. To study this, B. atrophaeus spores were purified, suspended in sterile, distilled water, and irradiated with EB (up to 20 kGy. Irradiated spores were found (1 to contain structural damage as observed by electron microscopy, (2 to have spilled cytoplasmic contents as measured by spectroscopy, (3 to have reduced membrane integrity as determined by fluorescence cytometry, and (4 to have fragmented genomic DNA as measured by gel electrophoresis, all in a dose-dependent manner. Additionally, cytometry data reveal decreased spore size, increased surface alterations, and increased uptake of propidium iodide, with increasing EB dose, suggesting spore coat alterations with membrane damage, prior to loss of spore viability. The present study suggests that EB irradiation of spores in water results in substantial structural damage of the spore coat and inner membrane, and that, along with DNA fragmentation, results in dose-dependent spore inactivation.

Inactivation of Clostridium perfringens spores adhered onto stainless steel surface by agents used in a clean-in-place procedure.

Science.gov (United States)

Alzubeidi, Yasmeen S; Udompijitkul, Pathima; Talukdar, Prabhat K; Sarker, Mahfuzur R

2018-07-20

Enterotoxigenic Clostridium perfringens, a leading foodborne pathogen can be cross-contaminated from food processing stainless steel (SS) surfaces to the finished food products. This is mostly due to the high resistance of C. perfringens spores adhered onto SS surfaces to various disinfectants commonly used in food industries. In this study, we aimed to investigate the survivability and adherence of C. perfringens spores onto SS surfaces and then validate the effectiveness of a simulated Clean-in-Place (CIP) regime on inactivation of spores adhered onto SS surfaces. Our results demonstrated that, 1) C. perfringens spores adhered firmly onto SS surfaces and survived for at-least 48 h, unlike their vegetative cells who died within 30 min, after aerobic incubation at refrigerated and ambient temperatures; 2) Spores exhibited higher levels of hydrophobicity than vegetative cells, suggesting a correlation between cell surface hydrophobicity and adhesion to solid surfaces; 3) Intact spores were more hydrophobic than the decoated spores, suggesting a positive role of spore coat components on spores' hydrophobicity and thus adhesion onto SS surfaces; and finally 4) The CIP regime (NaOH + HNO 3 ) successfully inactivated C. perfringens spores adhered onto SS surfaces, and most of the effect of CIP regime appeared to be due to the NaOH. Collectively, our current findings may well contribute towards developing a strategy to control cross-contamination of C. perfringens spores into food products, which should help reducing the risk of C. perfringens-associated food poisoning outbreaks. Copyright © 2018 Elsevier B.V. All rights reserved.

Sporulation environment influences spore properties in Bacillus: evidence and insights on underlying molecular and physiological mechanisms.

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Bressuire-Isoard, Christelle; Broussolle, Véronique; Carlin, Frédéric

2018-05-17

Bacterial spores are resistant to physical and chemical insults, which make them a major concern for public health and for industry. Spores help bacteria to survive extreme environmental conditions that vegetative cells cannot tolerate. Spore resistance and dormancy are important properties for applications in medicine, veterinary health, food safety, crop protection, and other domains. The resistance of bacterial spores results from a protective multilayered structure and from the unique composition of the spore core. The mechanisms of sporulation and germination, the first stage after breaking of dormancy, and organization of spore structure have been extensively studied in Bacillus species. This review aims to illustrate how far the structure, composition and properties of spores are shaped by the environmental conditions in which spores form. We look at the physiological and molecular mechanisms underpinning how sporulation media and environment deeply affect spore yield, spore properties like resistance to wet heat and physical and chemical agents, germination, and further growth. For example, spore core water content decreases as sporulation temperature increases, and resistance to wet heat increases. Controlling the fate of Bacillus spores is pivotal to controlling bacterial risks and process efficiencies in, for example, the food industry, and better control hinges on better understanding how sporulation conditions influence spore properties.

Handling technique of spore-forming bacteria in radiation sterilization. 1. Preparation of spores

International Nuclear Information System (INIS)

Koshikawa, Tomihiko

1994-01-01

This paper deals with a handling technique of spore-forming bacteria in radiation sterilization. An explanation is given under three sections: (1) life cycle of spore-forming bacteria, medium to form bacterial spores, and colony and purification methods of bacterial spores; (2) methods for measuring the number of bacterial spores and resistance against gamma radiation (D values); and (3) a test method for identifying spore-forming bacteria and a simple identification method. (N.K.)

Development of Spore Protein of Myxobolus koi as an Immunostimulant for Prevent of Myxobolusis on Gold Fish (Cyprinus carpio Linn) by Oral Immunisation

Science.gov (United States)

Mahasri, Gunanti

2017-02-01

Production of Gold fish (Cyprinus carpio Linn) in Indonesia has always increased from 2013 to 2015 year by year with increasing average 2% per year. The amount of production was respectively 571.892 tonnes, 1129.273 tonnes, and 1186.674 tonnes. There were almost no problems to sale of gold fish because it had a good enough prospect. The aims of this research were Isolation of spore protein of Myxobolus koi by using SDS-PAGE to analyze immun respons and survival rate gold fish that immunized with spore protein of Myxobolus koi. The method of this research used experimental method, and belonged to 4 treatments that are: Controle = the group of gold fish not immunized with protein spore of Myxobolus koi neither infected by Myxobolus koi (T1). The group immunized and infested by spore of Myxobolus koi (T2), The group which immunized and not infested by Myxobolus koi (T3), and The group only infested by Myxobolus koi (T4). The dose of immunostimulant was 5 ml in 1 kg of food. The result showed that there were two bands of whole spore protein with molecule weight (MW) 150 kDa and 72 kDa and one band of crude protein Myxobolus koi with molecule weight 73 kD and the optical density point was 0.132 on the first day and increased to 0.769 on the 56 th day. The result also showed that the immun respons and survival rate increased from 27% to 86% in chellence test. The protein spore of Myxobolus koi can used to develops material for immunostimulant and to prevent the myxobolusis.

High-Resolution Spore Coat Architecture and Assembly of Bacillus Spores

Energy Technology Data Exchange (ETDEWEB)

Malkin, A J; Elhadj, S; Plomp, M

2011-03-14

Elucidating the molecular architecture of bacterial and cellular surfaces and its structural dynamics is essential to understanding mechanisms of pathogenesis, immune response, physicochemical interactions, environmental resistance, and provide the means for identifying spore formulation and processing attributes. I will discuss the application of in vitro atomic force microscopy (AFM) for studies of high-resolution coat architecture and assembly of several Bacillus spore species. We have demonstrated that bacterial spore coat structures are phylogenetically and growth medium determined. We have proposed that strikingly different species-dependent coat structures of bacterial spore species are a consequence of sporulation media-dependent nucleation and crystallization mechanisms that regulate the assembly of the outer spore coat. Spore coat layers were found to exhibit screw dislocations and two-dimensional nuclei typically observed on inorganic and macromolecular crystals. This presents the first case of non-mineral crystal growth patterns being revealed for a biological organism, which provides an unexpected example of nature exploiting fundamental materials science mechanisms for the morphogenetic control of biological ultrastructures. We have discovered and validated, distinctive formulation-specific high-resolution structural spore coat and dimensional signatures of B. anthracis spores (Sterne strain) grown in different formulation condition. We further demonstrated that measurement of the dimensional characteristics of B. anthracis spores provides formulation classification and sample matching with high sensitivity and specificity. I will present data on the development of an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures on the B. anthracis surfaces. These studies demonstrate that AFM can probe microbial surface architecture, environmental dynamics and the life cycle of bacterial and cellular systems at near

Protein Composition of Infectious Spores Reveals Novel Sexual Development and Germination Factors in Cryptococcus.

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Mingwei Huang

2015-08-01

Full Text Available Spores are an essential cell type required for long-term survival across diverse organisms in the tree of life and are a hallmark of fungal reproduction, persistence, and dispersal. Among human fungal pathogens, spores are presumed infectious particles, but relatively little is known about this robust cell type. Here we used the meningitis-causing fungus Cryptococcus neoformans to determine the roles of spore-resident proteins in spore biology. Using highly sensitive nanoscale liquid chromatography/mass spectrometry, we compared the proteomes of spores and vegetative cells (yeast and identified eighteen proteins specifically enriched in spores. The genes encoding these proteins were deleted, and the resulting strains were evaluated for discernable phenotypes. We hypothesized that spore-enriched proteins would be preferentially involved in spore-specific processes such as dormancy, stress resistance, and germination. Surprisingly, however, the majority of the mutants harbored defects in sexual development, the process by which spores are formed. One mutant in the cohort was defective in the spore-specific process of germination, showing a delay specifically in the initiation of vegetative growth. Thus, by using this in-depth proteomics approach as a screening tool for cell type-specific proteins and combining it with molecular genetics, we successfully identified the first germination factor in C. neoformans. We also identified numerous proteins with previously unknown functions in both sexual development and spore composition. Our findings provide the first insights into the basic protein components of infectious spores and reveal unexpected molecular connections between infectious particle production and spore composition in a pathogenic eukaryote.

Low-energy ion bombardment of frozen bacterial spores and its relevance to interplanetary space

Energy Technology Data Exchange (ETDEWEB)

Tuleta, M.; Gabla, L. [Jagiellonian Univ., Institute of Physics, Cracow (Poland); Szkarlat, A. [Clinical Children' s Hospital of the Jagiellonian Univ., Medical College, Lab. of Microbiology, Cracow (Poland)

2005-04-01

The panspermia hypothesis is concerned with the dissemination of life in space in the form of simple micro-organisms. During an interplanetary journey the micro-organisms are subjected to the action of, among others, the solar wind. We have simulated experimentally such conditions bombarding frozen bacterial spores with low-energy hydrogen ions. On the basis of the results obtained and our earlier research, a new look at the panspermia hypothesis is discussed. The general conclusion is that unprotected naked spores, their conglomerates and protected spores can survive attack of the solar wind, although to various degrees. (authors)

Low-energy ion bombardment of frozen bacterial spores and its relevance to interplanetary space

International Nuclear Information System (INIS)

Tuleta, M.; Gabla, L.; Szkarlat, A.

2005-01-01

The panspermia hypothesis is concerned with the dissemination of life in space in the form of simple micro-organisms. During an interplanetary journey the micro-organisms are subjected to the action of, among others, the solar wind. We have simulated experimentally such conditions bombarding frozen bacterial spores with low-energy hydrogen ions. On the basis of the results obtained and our earlier research, a new look at the panspermia hypothesis is discussed. The general conclusion is that unprotected naked spores, their conglomerates and protected spores can survive attack of the solar wind, although to various degrees. (authors)

Spore-to-spore agar culture of the myxomycete Physarum globuliferum.

Science.gov (United States)

Liu, Pu; Wang, Qi; Li, Yu

2010-02-01

The ontogeny of the myxomycete Physarum globuliferum was observed on corn meal agar and hanging drop cultures without adding sterile oat flakes, bacteria or other microorganisms. Its complete life cycle including spore germination, myxamoebae, swarm cells, plasmodial development, and maturity of fructifications was demonstrated. Details of spore-to-spore development are described and illustrated.

Influence of Heat Shock Temperatures and Fast Freezing on Viability of Probiotic Sporeformers and the Issue of Spore Plate Count Versus True Numbers

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Mojtaba Jafari

2016-02-01

Full Text Available Background and Objectives: The purpose of the present study was to investigate effects of various heat shock conditions and fast freezing and subsequent thawing on the viability and recovery of Bacillus coagulans and Bacillus subtilis as probiotic sporeformers, and also to compare spore plate and microscopic counts. Materials and Methods: After preparing the final suspensions of B. coagulans and Bacillus subtilis subsp. Natto spores, they were spread-plated before and after fast freezing treatment (-70°C for about 1 min. Heat shock treatments of the spores were carried out at 68oC for 15, 20, and 30 min as well as at 80oC for 10 and 15 min. Concentrations of the examined probiotic sporeformers were determined simultaneously by plate enumerations and microscopically determined counts. Student’s t-test and one-way analysis of variance (ANOVA of SPSS were used for statistical analysis of the data. Analysis of DoE results was carried out using Minitab. Results: The results presented here show that the highest recovery rates for B. coagulans (14.75 log CFU/mL and B. subtilis spores (14.80 log CFU/mL were under a heat shock condition of 68°C for 20 min in nutrient agar (p<0.05. In addition, the survival rates of B. coagulans and B. subtilis spores under the fast freezing and subsequent thawing condition were about 90% and 88%, respectively. Plate counts differed significantly from counts determined microscopically, with differences of almost 0.5 and 0.8 log for B. coagulans and B. subtilis spores, respectively (p<0.05. In addition, DoE results of the study revealed that both factors of spore count method and only freezing factor in fast freezing treatment have a significant effect on concentrations of the spores examined (p<0.05. Conclusions: Heat shock conditions, freezing and subsequent thawing circumstances, and plate counts or enumerations determined microscopically have significant influences on the viability of probiotic sporeformers and

Inhibition of spore germination of Alternaria tenuis by sulfur dioxide

Energy Technology Data Exchange (ETDEWEB)

Couey, H.M.

1962-08-01

As a part of a continuing study of SO/sub 2/ fumigation of table grapes, the effect of SO/sub 2/ on spores of an isolate of A. tenuis Auct. causing decay of table grapes was determined. The amount of SO/sub 2/ required to inhibit completely spore germination depended on availability of moisture and the temperature. At 20/sup 0/C, wet spores required 20-min exposure to 100 ppm SO/sub 2/ to prevent germination, but spores equilibrated at 90% relative humidity (RH) required 10-min exposure to 1000 ppm SO/sub 2/. Dry spores at 60% RH were unaffected by a 20-min exposure to 4000 ppm SO/sub 2/. Increasing the temperature in the range 5-20/sup 0/C increased effectiveness of the SO/sub 2/ treatment. A comparison of Alternaria with Botrytis cinerea Fr. (studied earlier) showed that wet spores of these organisms were about equally sensitive to SO/sub 2/, but that dry Alternaria spores were more resistant to SO/sub 2/ than dry Botrytis spores under comparable conditions.

Distinction of broken cellular wall Ganoderma lucidum spores and G. lucidum spores using FTIR microspectroscopy

Science.gov (United States)

Chen, Xianliang; Liu, Xingcun; Sheng, Daping; Huang, Dake; Li, Weizu; Wang, Xin

2012-11-01

In this paper, FTIR microspectroscopy was used to identify broken cellular wall Ganoderma lucidum spores and G. lucidum spores. For IR spectra, broken cellular wall G. lucidum spores and G. lucidum spores were mainly different in the regions of 3000-2800, 1660-1600, 1400-1200 and 1100-1000 cm-1. For curve fitting, the results showed the differences in the protein secondary structures and the polysaccharide structures/content between broken cellular wall G. lucidum spores and G. lucidum spores. Moreover, the value of A1078/A1741 might be a potentially useful factor to distinguish broken cellular wall G. lucidum spores from G. lucidum spores. Additionally, FTIR microspectroscopy could identify broken cellular wall G. lucidum spores and G. lucidum spores accurately when it was combined with hierarchical cluster analysis. The result suggests FTIR microspectroscopy is very simple and efficient for distinction of broken cellular wall G. lucidum spores and G. lucidum spores. The result also indicates FTIR microspectroscopy may be useful for TCM identification.

Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

Science.gov (United States)

Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Victor; Iliyin, Vyacheslav

2015-01-01

One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

Directory of Open Access Journals (Sweden)

Alexander Slobodkin

Full Text Available One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite. After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

Distinction of broken cellular wall Ganoderma lucidum spores and G. lucidum spores using FTIR microspectroscopy.

Science.gov (United States)

Chen, Xianliang; Liu, Xingcun; Sheng, Daping; Huang, Dake; Li, Weizu; Wang, Xin

2012-11-01

In this paper, FTIR microspectroscopy was used to identify broken cellular wall Ganoderma lucidum spores and G. lucidum spores. For IR spectra, broken cellular wall G. lucidum spores and G. lucidum spores were mainly different in the regions of 3000-2800, 1660-1600, 1400-1200 and 1100-1000 cm(-1). For curve fitting, the results showed the differences in the protein secondary structures and the polysaccharide structures/content between broken cellular wall G. lucidum spores and G. lucidum spores. Moreover, the value of A1078/A1741 might be a potentially useful factor to distinguish broken cellular wall G. lucidum spores from G. lucidum spores. Additionally, FTIR microspectroscopy could identify broken cellular wall G. lucidum spores and G. lucidum spores accurately when it was combined with hierarchical cluster analysis. The result suggests FTIR microspectroscopy is very simple and efficient for distinction of broken cellular wall G. lucidum spores and G. lucidum spores. The result also indicates FTIR microspectroscopy may be useful for TCM identification. Copyright © 2012 Elsevier B.V. All rights reserved.

Arbuscular mycorrhizal fungi spore propagation using single spore as starter inoculum and a plant host.

Science.gov (United States)

Selvakumar, G; Shagol, C C; Kang, Y; Chung, B N; Han, S G; Sa, T M

2018-06-01

The propagation of pure cultures of arbuscular mycorrhizal fungal (AMF) is an essential requirement for their large-scale agricultural application and commercialization as biofertilizers. The present study aimed to propagate AMF using the single-spore inoculation technique and compare their propagation ability with the known reference spores. Arbuscular mycorrhizal fungal spores were collected from salt-affected Saemangeum reclaimed soil in South Korea. The technique involved inoculation of sorghum-sudangrass (Sorghum bicolor L.) seedlings with single, healthy spores on filter paper followed by the transfer of successfully colonized seedlings to 1-kg capacity pots containing sterilized soil. After the first plant cycle, the contents were transferred to 2·5-kg capacity pots containing sterilized soil. Among the 150 inoculated seedlings, only 27 seedlings were colonized by AMF spores. After 240 days, among the 27 seedlings, five inoculants resulted in the production of over 500 spores. The 18S rDNA sequencing of spores revealed that the spores produced through single-spore inoculation method belonged to Gigaspora margarita, Claroideoglomus lamellosum and Funneliformis mosseae. Furthermore, indigenous spore F. mosseae M-1 reported a higher spore count than the reference spores. The AMF spores produced using the single-spore inoculation technique may serve as potential bio-inoculants with an advantage of being more readily adopted by farmers due to the lack of requirement of a skilled technique in spore propagation. The results of the current study describe the feasible and cost-effective method to mass produce AMF spores for large-scale application. The AMF spores obtained from this method can effectively colonize plant roots and may be easily introduced to the new environment. © 2018 The Society for Applied Microbiology.

Resting spore formation of aphid-pathogenic fungus Pandora nouryi depends on the concentration of infective inoculum.

Science.gov (United States)

Huang, Zhi-Hong; Feng, Ming-Guang

2008-07-01

Resting spore formation of some aphid-pathogenic Entomophthorales is important for the seasonal pattern of their prevalence and survival but this process is poorly understood. To explore the possible mechanism involved in the process, Pandora nouryi (obligate aphid pathogen) interacted with green peach aphid Myzus persicae on cabbage leaves under favourable conditions. Host nymphs showered with primary conidia of an isolate (LC(50): 0.9-6.7 conidia mm(-2) 4-7 days post shower) from air captures in the low-latitude plateau of China produced resting spores (azygospores), primary conidia or both spore types. Surprisingly, the proportion of mycosed cadavers forming resting spores (P(CFRS)) increased sharply within the concentrations (C) of 28-240 conidia mm(-2), retained high levels at 240-1760, but was zero or extremely low at 0.3-16. The P(CFRS)-C relationship fit well the logistic equation P(CFRS) = 0.6774/[1 + exp(3.1229-0.0270C)] (r(2) = 0.975). This clarified for the first time the dependence of in vivo resting spore formation of P. nouryi upon the concentration of infective inoculum. A hypothesis is thus proposed that some sort of biochemical signals may exist in the host-pathogen interaction so that the fungal pathogen perceives the signals for prompt response to forthcoming host-density changes by either producing conidia for infecting available hosts or forming resting spores for surviving host absence in situ.

Indole and 3-indolylacetonitrile inhibit spore maturation in Paenibacillus alvei

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Cho Moo

2011-05-01

Full Text Available Abstract Background Bacteria use diverse signaling molecules to ensure the survival of the species in environmental niches. A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole that functions as an intercellular signal controlling diverse aspects of bacterial physiology. Results In this study, we sought a novel role of indole in a Gram-positive bacteria Paenibacillus alvei that can produce extracellular indole at a concentration of up to 300 μM in the stationary phase in Luria-Bertani medium. Unlike previous studies, our data show that the production of indole in P. alvei is strictly controlled by catabolite repression since the addition of glucose and glycerol completely turns off the indole production. The addition of exogenous indole markedly inhibits the heat resistance of P. alvei without affecting cell growth. Observation of cell morphology with electron microscopy shows that indole inhibits the development of spore coats and cortex in P. alvei. As a result of the immature spore formation of P. alvei, indole also decreases P. alvei survival when exposed to antibiotics, low pH, and ethanol. Additionally, indole derivatives also influence the heat resistance; for example, a plant auxin, 3-indolylacetonitrile dramatically (2900-fold decreased the heat resistance of P. alvei, while another auxin 3-indoleacetic acid had a less significant influence on the heat resistance of P. alvei. Conclusions Together, our results demonstrate that indole and plant auxin 3-indolylacetonitrile inhibit spore maturation of P. alvei and that 3-indolylacetonitrile presents an opportunity for the control of heat and antimicrobial resistant spores of Gram-positive bacteria.

Genotoxic action of sunlight upon Bacillus subtilis spores

International Nuclear Information System (INIS)

Munakata, Nobuo

1989-01-01

Samples of Bacillus subtilis spores dried on membrane filter were exposed to natural sunlight from solar-noon time at Tokyo. The survival and mutation induction of wild-type (UVR) and repair-deficient (UVS) spores were determined on 66 occasions since 1979. Two of the values were considered to be useful in monitoring solar UV intensity; the inverse of the time (in minutes) of exposure to kill 63% of the UVS spores ('sporocidal index') and the induced mutation frequency at 60 minutes of exposure of the UVR spores ('mutagenic index'). Both values were varied greatly due to time of a year, weather and other conditions. Estimates of year-round changes under clear skies were obtained by connecting the maximum values attained in these years. In these curves, there are more than 7-fold differences in the genotoxicity between winter and summer months, with major increases observed in early spring and decreases through autumn. Using a series of UV cut-off filters, the wavelengths most effective for the sporocidal actions were estimated to be in the range of 308 - 325 nm, shorter wavelengths being effective when the genotoxicity was higher. Sunburn meter of Robertson-Berger type seems to respond to slightly longer wavelength components of the solar spectrum. However, a reasonable correlation was obtained between the reading of the meter and the sporocidal index. (author)

Role of visible light-activated photocatalyst on the reduction of anthrax spore-induced mortality in mice.

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Jyh-Hwa Kau

Full Text Available BACKGROUND: Photocatalysis of titanium dioxide (TiO(2 substrates is primarily induced by ultraviolet light irradiation. Anion-doped TiO(2 substrates were shown to exhibit photocatalytic activities under visible-light illumination, relative environmentally-friendly materials. Their anti-spore activity against Bacillus anthracis, however, remains to be investigated. We evaluated these visible-light activated photocatalysts on the reduction of anthrax spore-induced pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Standard plating method was used to determine the inactivation of anthrax spore by visible light-induced photocatalysis. Mouse models were further employed to investigate the suppressive effects of the photocatalysis on anthrax toxin- and spore-mediated mortality. We found that anti-spore activities of visible light illuminated nitrogen- or carbon-doped titania thin films significantly reduced viability of anthrax spores. Even though the spore-killing efficiency is only approximately 25%, our data indicate that spores from photocatalyzed groups but not untreated groups have a less survival rate after macrophage clearance. In addition, the photocatalysis could directly inactivate lethal toxin, the major virulence factor of B. anthracis. In agreement with these results, we found that the photocatalyzed spores have tenfold less potency to induce mortality in mice. These data suggest that the photocatalysis might injury the spores through inactivating spore components. CONCLUSION/SIGNIFICANCE: Photocatalysis induced injuries of the spores might be more important than direct killing of spores to reduce pathogenicity in the host.

A fluorescence in situ staining method for investigating spores and vegetative cells of Clostridia by confocal laser scanning microscopy and structured illuminated microscopy.

Science.gov (United States)

D'Incecco, P; Ong, L; Gras, S; Pellegrino, L

2018-04-18

Non-pathogenic spore-forming Clostridia are of increasing interest due to their application in biogas production and their capability to spoil different food products. The life cycle for Clostridium includes a spore stage that can assist in survival under environmentally stressful conditions, such as extremes of temperature or pH. Due to their size, spores can be investigated by a range of microscopic techniques, many of which involve sample pre-treatment. We have developed a quick, simple and non-destructive fluorescent staining procedure that allows a clear differentiation between spores and vegetative cells and effectively stains spores, allowing recovery and tracking in subsequent experiments. Hoechst 34580, Propidium iodide and wheat germ agglutinin WGA 488 were used in combination to stain four strains of Clostridia at different life cycle stages. Staining was conducted without drying the sample, preventing changes induced by dehydration and cells observed by confocal laser scanner microscopy or using a super-resolution microscope equipped with a 3D-structured illumination module. Dual staining with Hoechst/Propidium iodide differentiated spores from vegetative cells, provided information on the viability of cells and was successfully applied to follow spore production induced by heating. Super-resolution microscopy of spores probed by Hoechst 34580 also allowed chromatin to be visualised. Direct staining of a cheese specimen using Nile Red and Fast Green allowed in situ observation of spores within the cheese and their position within the cheese matrix. The proposed staining method has broad applicability and can potentially be applied to follow Clostridium spore behaviour in a range of different environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of High Pressure on Bacillus licheniformis Spore Germination and Inactivation.

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Borch-Pedersen, Kristina; Mellegård, Hilde; Reineke, Kai; Boysen, Preben; Sevenich, Robert; Lindbäck, Toril; Aspholm, Marina

2017-07-15

Bacillus and Clostridium species form spores, which pose a challenge to the food industry due to their ubiquitous nature and extreme resistance. Pressurization at 300 MPa likely triggers germination by opening dipicolinic acid (DPA) channels present in the inner membrane of the spores. In this work, we expose spores of Bacillus licheniformis , a species associated with food spoilage and occasionally with food poisoning, to high pressure (HP) for holding times of up to 2 h. By using mutant spores lacking one or several GRs, we dissect the roles of the GerA, Ynd, and GerK GRs in moderately HP (mHP; 150 MPa)-induced spore germination. We show that Ynd alone is sufficient for efficient mHP-induced spore germination. GerK also triggers germination with mHP, although at a reduced germination rate compared to that of Ynd. GerA stimulates mHP-induced germination but only in the presence of either the intact GerK or Ynd GR. These results suggests that the effectiveness of the individual GRs in mHP-induced germination differs from their effectiveness in nutrient-induced germination, where GerA plays an essential role. In contrast to Bacillus subtilis spores, treatment with very HP (vHP) of 550 MPa at 37°C did not promote effective germination of B. licheniformis spores. However, treatment with vHP in combination with elevated temperatures (60°C) gave a synergistic effect on spore germination and inactivation. Together, these results provide novel insights into how HP affects B. licheniformis spore germination and inactivation and the role of individual GRs in this process. IMPORTANCE Bacterial spores are inherently resistant to food-processing regimes, such as high-temperature short-time pasteurization, and may therefore compromise food durability and safety. The induction of spore germination facilitates subsequent inactivation by gentler processing conditions that maintain the sensory and nutritional qualities of the food. High-pressure (HP) processing is a nonthermal

Strategy to inactivate Clostridium perfringens spores in meat products.

Science.gov (United States)

Akhtar, Saeed; Paredes-Sabja, Daniel; Torres, J Antonio; Sarker, Mahfuzur R

2009-05-01

The current study aimed to develop an inactivation strategy for Clostridium perfringens spores in meat through a combination of spore activation at low pressure (100-200 MPa, 7 min) and elevated temperature (80 degrees C, 10 min); spore germination at high temperatures (55, 60 or 65 degrees C); and inactivation of germinated spores with elevated temperatures (80 and 90 degrees C, 10 and 20 min) and high pressure (586 MPa, at 23 and 73 degrees C, 10 min). Low pressures (100-200 MPa) were insufficient to efficiently activate C. perfringens spores for germination. However, C. perfringens spores were efficiently activated with elevated temperature (80 degrees C, 10 min), and germinated at temperatures lethal for vegetative cells (>or= 55 degrees C) when incubated for 60 min with a mixture of L-asparagine and KCl (AK) in phosphate buffer (pH 7) and in poultry meat. Inactivation of spores (approximately 4 decimal reduction) in meat by elevated temperatures (80-90 degrees C for 20 min) required a long germination period (55 degrees C for 60 min). However, similar inactivation level was reached with shorter germination period (55 degrees C for 15 min) when spore contaminated-meat was treated with pressure-assisted thermal processing (568 MPa, 73 degrees C, 10 min). Therefore, the most efficient strategy to inactivate C. perfringens spores in poultry meat containing 50 mM AK consisted: (i) a primary heat treatment (80 degrees C, 10 min) to pasteurize and denature the meat proteins and to activate C. perfringens spores for germination; (ii) cooling of the product to 55 degrees C in about 20 min and further incubation at 55 degrees C for about 15 min for spore germination; and (iii) inactivation of germinated spores by pressure-assisted thermal processing (586 MPa at 73 degrees C for 10 min). Collectively, this study demonstrates the feasibility of an alternative and novel strategy to inactivate C. perfringens spores in meat products formulated with germinants specific for C

Spectroscopy and viability of Bacillus subtilis spores after ultraviolet irradiation: implications for the detection of potential bacterial life on Europa.

Science.gov (United States)

Noell, Aaron C; Ely, Tucker; Bolser, Diana K; Darrach, Halley; Hodyss, Robert; Johnson, Paul V; Hein, Jeffrey D; Ponce, Adrian

2015-01-01

One of the most habitable environments in the Solar System outside of Earth may exist underneath the ice on Europa. In the near future, our best chance to look for chemical signatures of a habitable environment (or life itself) will likely be at the inhospitable icy surface. Therefore, it is important to understand the ability of organic signatures of life and life itself to persist under simulated europan surface conditions. Toward that end, this work examined the UV photolysis of Bacillus subtilis spores and their chemical marker dipicolinic acid (DPA) at temperatures and pressures relevant to Europa. In addition, inactivation curves for the spores at 100 K, 100 K covered in one micron of ice, and 298 K were measured to determine the probability for spore survival at the surface. Fourier transform infrared spectra of irradiated DPA showed a loss of carboxyl groups to CO2 as expected but unexpectedly showed significant opening of the heterocyclic ring, even for wavelengths>200 nm. Both DPA and B. subtilis spores showed identical unknown spectral bands of photoproducts after irradiation, further highlighting the importance of DPA in the photochemistry of spores. Spore survival was enhanced at 100 K by ∼5× relative to 298 K, but 99.9% of spores were still inactivated after the equivalent of ∼25 h of exposure on the europan surface.

A Novel Protocol for Decoating and Permeabilizing Bacterial Spores for Epifluorescent Microscopy

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LaDuc, Myron T.; Mohapatra, Bidyut

2014-01-01

Based on previously reported procedures for permeabilizing vegetative bacterial cells, and numerous trial-and-error attempts with bacterial endospores, a protocol was developed for effectively permeabilizing bacterial spores, which facilitated the applicability of fluorescent in situ hybridization (FISH) microscopy. Bacterial endospores were first purified from overgrown, sporulated suspensions of B. pumilus SAFR-032. Purified spores at a concentration of approx equals 10 million spores/mL then underwent proteinase-K treatment, in a solution of 468.5 µL of 100 mM Tris-HCl, 30 µL of 10% SDS, and 1.5 microL of 20 mg/mL proteinase-K for ten minutes at 35 ºC. Spores were then harvested by centrifugation (15,000 g for 15 minutes) and washed twice with sterile phosphate-buffered saline (PBS) solution. This washing process consisted of resuspending the spore pellets in 0.5 mL of PBS, vortexing momentarily, and harvesting again by centrifugation. Treated and washed spore pellets were then resuspended in 0.5 mL of decoating solution, which consisted of 4.8 g urea, 3 mL Milli-Q water, 1 mL 0.5M Tris, 1 mL 1M dithiothreitol (DTT), and 2 mL 10% sodium-dodecylsulfate (SDS), and were incubated at 65 ºC for 15 minutes while being shaken at 165 rpm. Decoated spores were then, once again, washed twice with sterile PBS, and subjected to lysozyme/mutanolysin treatment (7 mg/mL lysozyme and 7U mutanolysin) for 15 minutes at 35 C. Spores were again washed twice with sterile PBS, and spore pellets were resuspended in 1-mL of 2% SDS. This treatment, facilitating inner membrane permeabilization, lasted for ten minutes at room temperature. Permeabilized spores were washed two final times with PBS, and were resuspended in 200 mkcroL of sterile PBS. At this point, the spores were permeable and ready for downstream processing, such as oligonucleotideprobe infiltration, hybridization, and microscopic evaluation. FISH-microscopic imagery confirmed the effective and efficient (˜50

Effect of gamma irradiation on thermal inactivation and injury of Bacillus subtilis spores

International Nuclear Information System (INIS)

El-Zawahry, Y.A.; Mostafa, S.A.; Awny, N.M.

1986-01-01

Bacillus subtilis spores which received preliminary irradiation doses were more sensitive to subsequent heating than non-irradiated spores. The thermal inactivation increased by increasing any of exposure temperature, thermal exposure time or preliminary irradiation dose. The thermal (D T -) value was much higher for non-irradiated spores than the D TR value for the pre-thermal irradiated spores. The radiosensitizing effect was directly proportional to the preliminary irradiation dose. The pre-thermal irradiation treatment of B. subtilis spores resulted in a synergistic effect in spore deactivation. This synergistic effect increased gradually by increasing the preliminary irradiation dose and/or the thermal temperature from 60 to 80 0 C, but decreased for 90 0 C and for the longer exposure periods at any of the examined temperature. Thermal injury of B. subtilis spores was more for the non-irradiated than for the irradiated spores

Impact of spores on the comparative efficacies of five antibiotics for treatment of Bacillus anthracis in an in vitro hollow fiber pharmacodynamic model.

Science.gov (United States)

Louie, Arnold; VanScoy, Brian D; Brown, David L; Kulawy, Robert W; Heine, Henry S; Drusano, George L

2012-03-01

Bacillus anthracis, the bacterium that causes anthrax, is an agent of bioterrorism. The most effective antimicrobial therapy for B. anthracis infections is unknown. An in vitro pharmacodynamic model of B. anthracis was used to compare the efficacies of simulated clinically prescribed regimens of moxifloxacin, linezolid, and meropenem with the "gold standards," doxycycline and ciprofloxacin. Treatment outcomes for isogenic spore-forming and non-spore-forming strains of B. anthracis were compared. Against spore-forming B. anthracis, ciprofloxacin, moxifloxacin, linezolid, and meropenem reduced the B. anthracis population by 4 log(10) CFU/ml over 10 days. Doxycycline reduced the population of this B. anthracis strain by 5 log(10) CFU/ml (analysis of variance [ANOVA] P = 0.01 versus other drugs). Against an isogenic non-spore-forming strain, meropenem killed the vegetative B. anthracis the fastest, followed by moxifloxacin and ciprofloxacin and then doxycycline. Linezolid offered the lowest bacterial kill rate. Heat shock studies using the spore-producing B. anthracis strain showed that with moxifloxacin, ciprofloxacin, and meropenem therapies the total population was mostly spores, while the population was primarily vegetative bacteria with linezolid and doxycycline therapies. Spores have a profound impact on the rate and extent of killing of B. anthracis. Against spore-forming B. anthracis, the five antibiotics killed the total (spore and vegetative) bacterial population at similar rates (within 1 log(10) CFU/ml of each other). However, bactericidal antibiotics killed vegetative B. anthracis faster than bacteriostatic drugs. Since only vegetative-phase B. anthracis produces the toxins that may kill the infected host, the rate and mechanism of killing of an antibiotic may determine its overall in vivo efficacy. Further studies are needed to examine this important observation.

Ultra high pressure homogenization (UHPH) inactivation of Bacillus amyloliquefaciens spores in phosphate buffered saline (PBS) and milk

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Dong, Peng; Georget, Erika S.; Aganovic, Kemal; Heinz, Volker; Mathys, Alexander

2015-01-01

Ultra high pressure homogenization (UHPH) opens up new areas for dynamic high pressure assisted thermal sterilization of liquids. Bacillus amyloliquefaciens spores are resistant to high isostatic pressure and temperature and were suggested as potential surrogate for high pressure thermal sterilization validation. B. amyloliquefaciens spores suspended in PBS buffer (0.01 M, pH 7.0), low fat milk (1.5%, pH 6.7), and whole milk (3.5%, pH 6.7) at initial concentration of ~106 CFU/mL were subjected to UHPH treatments at 200, 300, and 350 MPa with an inlet temperature at ~80°C. Thermal inactivation kinetics of B. amyloliquefaciens spores in PBS and milk were assessed with thin wall glass capillaries and modeled using first-order and Weibull models. The residence time during UHPH treatments was estimated to determine the contribution of temperature to spore inactivation by UHPH. No sublethal injury was detected after UHPH treatments using sodium chloride as selective component in the nutrient agar medium. The inactivation profiles of spores in PBS buffer and milk were compared and fat provided no clear protective effect for spores against treatments. Treatment at 200 MPa with valve temperatures lower than 125°C caused no reduction of spores. A reduction of 3.5 log10CFU/mL of B. amyloliquefaciens spores was achieved by treatment at 350 MPa with a valve temperature higher than 150°C. The modeled thermal inactivation and observed inactivation during UHPH treatments suggest that temperature could be the main lethal effect driving inactivation. PMID:26236296

Effect of Coat Layers in Bacillus Subtilis Spores Resistance to Photo-Catalytic Inactivation

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Luz del Carmen Huesca-Espitia

2017-10-01

Full Text Available Different water treatment processes (physical and chemical exist to obtain safe water for human or food industry supply. The advanced oxidation technologies are rising as a new alternative to eliminate undesirable chemicals and waterborne diseases. In this work, we analyze the power of the photo-assisted Fenton process using Fe(II/H2O2 and UV radiation (365 nm to inactivate Bacillus subtilis spores, considered among the most resistant biological structures known. Different concentrations of Fe(II, H2O2 and UV radiation (365 nm were used to inactivate wt and some coat spore mutants of B. subtilis. Wt spores of B. subtilis were inactivated after 60 min using this process. In general, all defective coat mutants were more sensitive than the wt spores and, particularly, the double mutant was 10 folds more sensitive than others being inactivated during the first 10 minutes using soft reaction conditions. Presence of Fe(II ions was found essential for spore inactivating process and, for those spores inactivated using the Fe(II/H2O2 under UV radiation process, it is suggested that coat structures are important to their resistance to the treatment process. The photo-assisted Fenton process using Fe(II, H2O2 and UV radiation (365 nm can be used to inactivate any water microorganisms with the same or less resistance that B. subtilis spores to produce safe drinking water in relatively short treatment time.

PHYLOGENETIC ANALYSIS AND AUTECOLOGY OF SPORE-FORMING BACTERIA FROM HYPERSALINE ENVIRONMENTS.

Science.gov (United States)

Gladka, G V; Romanovskaya, V A; Tashyreva, H O; Tashyrev, O B

2015-01-01

Multi-resistant to extreme factors spore-forming bacteria of Bacillus genus are isolated from hypersaline environments of the Crimea (Ukraine) and the Dead Sea (Israel). Phylogenetic analysis showed distinction of dominating extremophilic culturable species in studied regions. In Crimean environments they are B. mojavensis and B. simplex, in the Dead Sea ecosystem--B. subtilis subsp. spizizenii, B. subtilis subsp. subtilis, B. licheniformis and B. simplex. Isolates are simultaneously halotolerant and resistant to UV radiation. Strains isolated from the Dead Sea and the Crimea environments were resistant to UV: LD90 and LD99.99 made 100-170 J/m2 and 750-1500 J/m2 respectively. Spores showed higher UV-resistance (LD99.99-2500 J/m2) than the vegetative cells. However the number of spores made 0.02-0.007% of the whole cell population, and should not significantly affect the UV LD99.99 value. Isolates of both environments were halotolerant in the range of 0.1-10% NaCl and thermotolerant in the range of 20-50 °C, and didn't grow at 15 °C. Survival strategy of spore-forming bacteria from hypersaline environments under high UV radiation level can be performed by spore formation which minimize cell damage as well as efficient DNA-repair systems that remove damages.

A Clostridium difficile alanine racemase affects spore germination and accommodates serine as a substrate.

Science.gov (United States)

Shrestha, Ritu; Lockless, Steve W; Sorg, Joseph A

2017-06-23

Clostridium difficile has become one of the most common bacterial pathogens in hospital-acquired infections in the United States. Although C. difficile is strictly anaerobic, it survives in aerobic environments and transmits between hosts via spores. C. difficile spore germination is triggered in response to certain bile acids and glycine. Although glycine is the most effective co-germinant, other amino acids can substitute with varying efficiencies. Of these, l-alanine is an effective co-germinant and is also a germinant for most bacterial spores. Many endospore-forming bacteria embed alanine racemases into their spore coats, and these enzymes are thought to convert the l-alanine germinant into d-alanine, a spore germination inhibitor. Although the C. difficile Alr2 racemase is the sixth most highly expressed gene during C. difficile spore formation, a previous study reported that Alr2 has little to no role in germination of C. difficile spores in rich medium. Here, we hypothesized that Alr2 could affect C. difficile l-alanine-induced spore germination in a defined medium. We found that alr2 mutant spores more readily germinate in response to l-alanine as a co-germinant. Surprisingly, d-alanine also functioned as a co-germinant. Moreover, we found that Alr2 could interconvert l- and d-serine and that Alr2 bound to l- and d-serine with ∼2-fold weaker affinity to that of l- and d-alanine. Finally, we demonstrate that l- and d-serine are also co-germinants for C. difficile spores. These results suggest that C. difficile spores can respond to a diverse set of amino acid co-germinants and reveal that Alr2 can accommodate serine as a substrate. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Biosorption of radionuclide Americium-241 by A. niger spore and hyphae

International Nuclear Information System (INIS)

Yang Yuanyou; Liu Ning; Jin Jiannan; Hua Xinfeng; Zhang Taiming; Luo Shunzhong; Sun Qiling

2002-01-01

The biosorption of radionuclide 241 Am from solution was studied by a. niger spore and hyphae, and the effects of the operational conditions on the treatment were investigated. The results showed the treatment by A. niger spore and hyphae were very efficient. An average of 96% of the total 241 Am was removed from 241 Am solutions of 5.6-111 MBq/L (C 0 ), with adsorption capacities (W) of 7.2-142.4 MBq/g biomass, 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 h and the optimum pH value ranged 3-0.1 mol/L HNO 3 and 3-2 for spore and hyphae of A. niger, respectively. No significant effects on 241 Am biosorption were observed at 15 degree C-45 degree C, or challenged with containing Au 3+ or Ag + , even 2000 times above 241 Am amount. the index relationship between concentrations and adsorption capacities of 241 Am indicated that the 241 Am biosorption by A. niger spore and hyphae obey to Freundlich adsorption equation. The adsorption behavior of A. niger spore and hyphae were basically coincident

Benign meningiomas: primary treatment selection affects survival

International Nuclear Information System (INIS)

Condra, Kellie S.; Buatti, John M.; Mendenhall, William M.; Friedman, William A.; Marcus, Robert B.; Rhoton, Albert L.

1997-01-01

Purpose: To examine the effect of primary treatment selection on outcomes for benign intracranial meningiomas at the University of Florida. Methods and Materials: For 262 patients, the impact of age, Karnofsky performance status, pathologic features, tumor size, tumor location, and treatment modality on local control and cause-specific survival was analyzed (minimum potential follow-up, 2 years; median follow-up, 8.2 years). Extent of surgery was classified by Simpson grade. Treatment groups: surgery alone (n = 229), surgery and postoperative radiotherapy (RT) (n = 21), RT alone (n = 7), radiosurgery alone (n = 5). Survival analysis: Kaplan-Meier method with univariate and multivariate analysis. Results: At 15 years, local control was 76% after total excision (TE) and 87% after subtotal excision plus RT (SE+RT), both significantly better (p = 0.0001) than after SE alone (30%). Cause-specific survival at 15 years was reduced after treatment with SE alone (51%), compared with TE (88%) or SE+RT (86%) (p = 0.0003). Recurrence after primary treatment portended decreased survival, independent of initial treatment group or salvage treatment selection (p = 0.001). Atypical pathologic features predicted reduced 15-year local control (54 vs. 71%) and cause-specific survival rates (57 vs. 86%). Multivariate analysis for cause-specific survival revealed treatment group (SE vs. others; p = 0.0001), pathologic features (atypical vs. typical; p = 0.0056), and Karnofsky performance status (≥80 vs. <80; p = 0.0153) as significant variables. Conclusion: Benign meningiomas are well managed by TE or SE+RT. SE alone is inadequate therapy and adversely affects cause-specific survival. Atypical pathologic features predict a poorer outcome, suggesting possible benefit from more aggressive treatment. Because local recurrence portends lower survival rates, primary treatment choice is important

New pressure and temperature effects on bacterial spores

Science.gov (United States)

Mathys, A.; Heinz, V.; Knorr, D.

2008-07-01

The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122°C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80°C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa with 37�

New pressure and temperature effects on bacterial spores

Energy Technology Data Exchange (ETDEWEB)

Mathys, A; Knorr, D [Berlin University of Technology, Department of Food Biotechnology and Food Process Engineering, Koenigin-Luise-Str. 22, D-14195 Berlin (Germany); Heinz, V [German Institute of Food Technology, p. o. box 1165, D-49601, Quackenbrueck (Germany)], E-mail: alexander.mathys@tu-berlin.de

2008-07-15

The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122 deg. C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80 deg. C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa

New pressure and temperature effects on bacterial spores

International Nuclear Information System (INIS)

Mathys, A; Knorr, D; Heinz, V

2008-01-01

The mechanism of inactivation of bacterial spores by heat and pressure is still a matter of discussion. Obviously, the change of the dissociation equilibrium under pressure and temperature plays a dominant role in inactivation of microorganisms. Heat and pressure inactivation of Geobacillus. stearothermophilus spores at different initial pH-values in ACES and phosphate buffer confirmed this view. Thermal inactivation in ACES buffer at 122 deg. C resulted in higher logarithmic reductions. Contrary, after pressure treatment at 900 MPa with 80 deg. C phosphate buffer showed higher inactivation. These results indicated the different dissociation equilibrium shifts in buffer systems by heat and pressure. Due to preparation, storage and handling of highly concentrated spore suspensions the clumping and the formation of aggregates can hardly be avoided. Consequently, the impact of the agglomeration size distribution on the quantitative assessment of G. stearothermophilus spore inactivation was determined by using a three-fold dynamic optical backreflexion measurement. Two limiting cases have been discriminated in mathematical modelling: three dimensional, spherical packing for maximum spore count and two dimensional, circular packing for minimum spore count of a particular agglomerate. Thermal inactivation studies have been carried out in thin glass capillaries, where by using numerical simulations the non isothermal conditions were modelled and taken into account. It is shown that the shoulder formation often found in thermal spore inactivation can sufficiently be described by first-order inactivation kinetics when the agglomeration size is considered. In case of high pressure inactivation agglomerations could be strongly changed by high forces at compression and especially decompression phase. The physiological response of Bacillus licheniformis spores to high pressure was investigated using multiparameter flow cytometry. Spores were treated by high pressure at 150 MPa

Inactivation of Bacillus spores inoculated in milk by Ultra High Pressure Homogenization.

Science.gov (United States)

Amador Espejo, Genaro Gustavo; Hernández-Herrero, M M; Juan, B; Trujillo, A J

2014-12-01

Ultra High-Pressure Homogenization treatments at 300 MPa with inlet temperatures (Ti) of 55, 65, 75 and 85 °C were applied to commercial Ultra High Temperature treated whole milk inoculated with Bacillus cereus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus coagulans, Geobacillus stearothermophilus and Bacillus subtilis spores in order to evaluate the inactivation level achieved. Ultra High-Pressure Homogenization conditions at 300 MPa with Ti = 75 and 85 °C were capable of a spore inactivation of ∼5 log CFU/mL. Furthermore, under these processing conditions, commercial sterility (evaluated as the complete inactivation of the inoculated spores) was obtained in milk, with the exception of G. stearothermophilus and B. subtilis treated at 300 MPa with Ti = 75 °C. The results showed that G. stearothermophilus and B. subtilis have higher resistance to the Ultra High-Pressure Homogenization treatments applied than the other microorganisms inoculated and that a treatment performed at 300 MPa with Ti = 85 °C was necessary to completely inactivate these microorganisms at the spore level inoculated (∼1 × 10(6) CFU/mL). Besides, a change in the resistance of B. licheniformis, B. sporothermodurans, G. stearothermophilus and B. subtilis spores was observed as the inactivation obtained increased remarkably in treatments performed with Ti between 65 and 75 °C. This study provides important evidence of the suitability of UHPH technology for the inactivation of spores in high numbers, leading to the possibility of obtaining commercially sterile milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

The solar UV environment and bacterial spore UV resistance: considerations for Earth-to-Mars transport by natural processes and human spaceflight

Science.gov (United States)

Nicholson, Wayne L.; Schuerger, Andrew C.; Setlow, Peter

2005-01-01

The environment in space and on planets such as Mars can be lethal to microorganisms because of the high vacuum and high solar radiation flux, in particular UV radiation, in such environments. Spores of various Bacillus species are among the organisms most resistant to the lethal effects of high vacuum and UV radiation, and as a consequence are of major concern for planetary contamination via unmanned spacecraft or even natural processes. This review focuses on the spores of various Bacillus species: (i) their mechanisms of UV resistance; (ii) their survival in unmanned spacecraft, space flight and simulated space flight and Martian conditions; (iii) the UV flux in space and on Mars; (iv) factors affecting spore survival in such high UV flux environments.

The solar UV environment and bacterial spore UV resistance: considerations for Earth-to-Mars transport by natural processes and human spaceflight

International Nuclear Information System (INIS)

Nicholson, Wayne L.; Schuerger, Andrew C.; Setlow, Peter

2005-01-01

The environment in space and on planets such as Mars can be lethal to microorganisms because of the high vacuum and high solar radiation flux, in particular UV radiation, in such environments. Spores of various Bacillus species are among the organisms most resistant to the lethal effects of high vacuum and UV radiation, and as a consequence are of major concern for planetary contamination via unmanned spacecraft or even natural processes. This review focuses on the spores of various Bacillus species: (i) their mechanisms of UV resistance; (ii) their survival in unmanned spacecraft, space flight and simulated space flight and Martian conditions; (iii) the UV flux in space and on Mars; (iv) factors affecting spore survival in such high UV flux environments

The solar UV environment and bacterial spore UV resistance: considerations for Earth-to-Mars transport by natural processes and human spaceflight

Energy Technology Data Exchange (ETDEWEB)

Nicholson, Wayne L. [Department of Microbiology and Cell Science, University of Florida, Mail Code UF-1, Building M6-1025/SLSL, Kennedy Space Center, FL 32899 (United States)]. E-mail: WLN@ufl.edu; Schuerger, Andrew C. [Department of Plant Pathology, University of Florida, Mail Code UF-1, Space Life Sciences Laboratory, Kennedy Space Center, FL 32899 (United States)]. E-mail: acschuerger@ifas.ufl.edu; Setlow, Peter [Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030 (United States)]. E-mail: setlow@nso2.uchc.edu

2005-04-01

The environment in space and on planets such as Mars can be lethal to microorganisms because of the high vacuum and high solar radiation flux, in particular UV radiation, in such environments. Spores of various Bacillus species are among the organisms most resistant to the lethal effects of high vacuum and UV radiation, and as a consequence are of major concern for planetary contamination via unmanned spacecraft or even natural processes. This review focuses on the spores of various Bacillus species: (i) their mechanisms of UV resistance; (ii) their survival in unmanned spacecraft, space flight and simulated space flight and Martian conditions; (iii) the UV flux in space and on Mars; (iv) factors affecting spore survival in such high UV flux environments.

Optical and structural properties of plasma-treated Cordyceps bassiana spores as studied by circular dichroism, absorption, and fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Lee, Geon Joon, E-mail: gjlee@kw.ac.kr; Sim, Geon Bo; Choi, Eun Ha [Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, Seoul 139-701 (Korea, Republic of); Kwon, Young-Wan [KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701 (Korea, Republic of); Kim, Jun Young; Jang, Siun; Kim, Seong Hwan, E-mail: piceae@naver.com [Department of Microbiology and Institute of Basic Sciences, Dankook University, Cheonan 330-714 (Korea, Republic of)

2015-01-14

To understand the killing mechanism of fungal spores by plasma treatment, the optical, structural, and biological properties of the insect pathogenic fungus Cordyceps bassiana spores were studied. A nonthermal atmospheric-pressure plasma jet (APPJ) was used to treat the spores in aqueous solution. Optical emission spectra of the APPJ acquired in air indicated emission peaks corresponding to hydroxyl radicals and atomic oxygen. When the APPJ entered the aqueous solution, additional reactive species were derived from the interaction of plasma radicals with the aqueous solution. Fluorescence and absorption spectroscopy confirmed the generation of hydroxyl radicals and hydrogen peroxide in the plasma-activated water (PAW). Spore counting showed that plasma treatment significantly reduced spore viability. Absorption spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis of the DNA extracted from plasma-treated spores showed a reduction in spore DNA content. The magnitude of the dip in the CD spectrum was lower in the plasma-treated spores than in the control, indicating that plasma treatment causes structural modifications and/or damage to cellular components. Tryptophan fluorescence intensity was lower in the plasma-treated spores than in the control, suggesting that plasma treatment modified cell wall proteins. Changes in spore viability and DNA content were attributed to structural modification of the cell wall by reactive species coming from the APPJ and the PAW. Our results provided evidence that the plasma radicals and the derived reactive species play critical roles in fungal spore inactivation.

Effect of the medium characteristics and the heating and cooling rates on the nonisothermal heat resistance of Bacillus sporothermodurans IC4 spores.

Science.gov (United States)

Esteban, María-Dolores; Huertas, Juan-Pablo; Fernández, Pablo S; Palop, Alfredo

2013-05-01

In recent years, highly thermo-resistant mesophilic spore-forming bacteria belonging to the species Bacillus sporothermodurans have caused non-sterility problems in industrial sterilization processes. The aim of this research was to evaluate the effect of the heating medium characteristics (pH and buffer/food) on the thermal inactivation of B. sporothermodurans spores when exposed to isothermal and non-isothermal heating and cooling treatments and the suitability of non-linear Weibull and Geeraaerd models to predict the survivors of these thermal treatments. Thermal treatments were carried out in pH 3, 5 and 7 McIlvaine buffer and in a courgette soup. Isothermal survival curves showed shoulders that were accurately characterized by means of both models. A clear effect of the pH of the heating medium was observed, decreasing the D120 value from pH 7 to pH 3 buffer down to one third. Differences in heat resistance were similar, regardless of the model used and were kept at all temperatures tested. The heat resistance in courgette soup was similar to that shown in pH 7 buffer. When the heat resistance values obtained under isothermal conditions were used to predict the survival in the non-isothermical experiments, the predictions estimated the experimental data quite accurately, both with Weibull and Geeraerd models. Copyright © 2012 Elsevier Ltd. All rights reserved.

Removal of dissolved heavy metals and radionuclides by microbial spores

International Nuclear Information System (INIS)

Revis, N.W.; Hadden, C.T.; Edenborn, H.

1997-01-01

Microbial systems have been shown to remove specific heavy metals from contaminated aqueous waste to levels acceptable to EPA for environmental release. However, systems capable of removing a variety of heavy metals from aqueous waste to environmentally acceptable levels remain to be reported. The present studies were performed to determine the specificity of spores of the bacterium Bacillus megaterium for the adsorption of dissolved metals and radionuclides from aqueous waste. The spores effectively adsorbed eight heavy metals from a prepared metal mix and from a plating rinse waste to EPA acceptable levels for waste water. These results suggest that spores have multiple binding sites for the adsorption of heavy metals. Spores were also effective in adsorbing the radionuclides 85 strontium and 197 cesium. The presence of multiple sites in spores for the adsorption of heavy metals and radionuclides makes this biosorbent a good candidate for the treatment of aqueous wastes associated with the plating and nuclear industries. 17 refs., 4 tabs

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

Characterizing aeroallergens by infrared spectroscopy of fungal spores and pollen.

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Boris Zimmermann

Full Text Available Fungal spores and plant pollen cause respiratory diseases in susceptible individuals, such as asthma, allergic rhinitis and hypersensitivity pneumonitis. Aeroallergen monitoring networks are an important part of treatment strategies, but unfortunately traditional analysis is time consuming and expensive. We have explored the use of infrared spectroscopy of pollen and spores for an inexpensive and rapid characterization of aeroallergens.The study is based on measurement of spore and pollen samples by single reflectance attenuated total reflectance Fourier transform infrared spectroscopy (SR-ATR FTIR. The experimental set includes 71 spore (Basidiomycota and 121 pollen (Pinales, Fagales and Poales samples. Along with fresh basidiospores, the study has been conducted on the archived samples collected within the last 50 years.The spectroscopic-based methodology enables clear spectral differentiation between pollen and spores, as well as the separation of confamiliar and congeneric species. In addition, the analysis of the scattering signals inherent in the infrared spectra indicates that the FTIR methodology offers indirect estimation of morphology of pollen and spores. The analysis of fresh and archived spores shows that chemical composition of spores is well preserved even after decades of storage, including the characteristic taxonomy-related signals. Therefore, biochemical analysis of fungal spores by FTIR could provide economical, reliable and timely methodologies for improving fungal taxonomy, as well as for fungal identification and monitoring. This proof of principle study shows the potential for using FTIR as a rapid tool in aeroallergen studies. In addition, the presented method is ready to be immediately implemented in biological and ecological studies for direct measurement of pollen and spores from flowers and sporocarps.

The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores.

Science.gov (United States)

Abhyankar, Wishwas R; Kamphorst, Kiki; Swarge, Bhagyashree N; van Veen, Henk; van der Wel, Nicole N; Brul, Stanley; de Koster, Chris G; de Koning, Leo J

2016-01-01

Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14 N spores prepared on solid Schaeffer's-glucose (SG) agar plates and 15 N metabolically labeled spores prepared in shake flasks containing 3-( N -morpholino) propane sulfonic acid (MOPS) buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14 N: 15 N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the

The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores

Science.gov (United States)

Abhyankar, Wishwas R.; Kamphorst, Kiki; Swarge, Bhagyashree N.; van Veen, Henk; van der Wel, Nicole N.; Brul, Stanley; de Koster, Chris G.; de Koning, Leo J.

2016-01-01

Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14N spores prepared on solid Schaeffer’s-glucose (SG) agar plates and 15N metabolically labeled spores prepared in shake flasks containing 3-(N-morpholino) propane sulfonic acid (MOPS) buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14N:15N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the

The influence of sporulation conditions on the spore coat protein composition of Bacillus subtilis spores.

Directory of Open Access Journals (Sweden)

Wishwas R. Abhyankar

2016-10-01

Full Text Available Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14N spores prepared on solid SG agar plates and 15N metabolically labelled spores prepared in shake flasks containing MOPS buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14N: 15N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the differences in the coat protein composition and

Effects of produced water discharges on the colonization potential of Macrocystis pyrifera spores

International Nuclear Information System (INIS)

Lewis, R.J.; Reed, D.C.

1993-01-01

Point sources of pollution (e.g. industrial outfalls) may produce ecological impacts at distant locations if pollutants affect dispersive propagules. The authors used laboratory experiments to determine how exposure to produced water (PW; aqueous fraction of petroleum production that is typically discharged into coastal waters) in the water column influences the colonization potential of giant kelp (Macrocystis pyrifera) spores on the bottom. Spores were maintained in suspension in 18 L containers and exposed to one of five concentrations of PW (0 to 10%) for varying amounts of time. Spore swimming generally decreased with increasing PW concentration and exposure duration, with the specific pattern of decrease differing between experimental trials done at different dates. The effect of exposure duration in the water column on the ability of swimming spores to attach to plastic dishes placed the bottom varied with PW concentration. Spores placed in 1 and 10% PW showed a steady decline in their ability to attach with increased exposure; lower concentrations of PW had no such effects. The proportion of spores that germinated after attachment varied tremendously with exposure duration and date of experimental trial. A low proportion of spores that settled during the first 12 h germinated, indicative of a short period of precompetency. Surprisingly, water column exposure to high concentrations of PW during the first 12 h reduced this precompetent period and greatly improved germination success. The magnitude of this enhancement, however, varied among dates. Delayed expression of PW effects were not observed in developing gametophytes; survival of individuals that successfully germinated and gamete production was not affected by previous exposure to PW as a spore

Use of bacterial spores in monitoring water quality and treatment

Science.gov (United States)

Because Clostridium perfringens spores are both specific to sewage contamination and environmentally stable, they are considered as possible conservative indicators of human fecal contamination and possible surrogates for environmentally stable pathogens. This review discusses th...

A novel method for standardized application of fungal spore coatings for mosquito exposure bioassays.

Science.gov (United States)

Farenhorst, Marit; Knols, Bart G J

2010-01-20

Interest in the use of fungal entomopathogens against malaria vectors is growing. Fungal spores infect insects via the cuticle and can be applied directly on the insect to evaluate infectivity. For flying insects such as mosquitoes, however, application of fungal suspensions on resting surfaces is more realistic and representative of field settings. For this type of exposure, it is essential to apply specific amounts of fungal spores homogeneously over a surface for testing the effects of fungal dose and exposure time. Contemporary methods such as spraying or brushing spore suspensions onto substrates do not produce the uniformity and consistency that standardized laboratory assays require. Two novel fungus application methods using equipment developed in the paint industry are presented and compared. Wired, stainless steel K-bars were tested and optimized for coating fungal spore suspensions onto paper substrates. Different solvents and substrates were evaluated. Two types of coating techniques were compared, i.e. manual and automated coating. A standardized bioassay set-up was designed for testing coated spores against malaria mosquitoes. K-bar coating provided consistent applications of spore layers onto paper substrates. Viscous Ondina oil formulations were not suitable and significantly reduced spore infectivity. Evaporative Shellsol T solvent dried quickly and resulted in high spore infectivity to mosquitoes. Smooth proofing papers were the most effective substrate and showed higher infectivity than cardboard substrates. Manually and mechanically applied spore coatings showed similar and reproducible effects on mosquito survival. The standardized mosquito exposure bioassay was effective and consistent in measuring effects of fungal dose and exposure time. K-bar coating is a simple and consistent method for applying fungal spore suspensions onto paper substrates and can produce coating layers with accurate effective spore concentrations. The mosquito bioassay

A novel method for standardized application of fungal spore coatings for mosquito exposure bioassays

Directory of Open Access Journals (Sweden)

Knols Bart GJ

2010-01-01

Full Text Available Abstract Background Interest in the use of fungal entomopathogens against malaria vectors is growing. Fungal spores infect insects via the cuticle and can be applied directly on the insect to evaluate infectivity. For flying insects such as mosquitoes, however, application of fungal suspensions on resting surfaces is more realistic and representative of field settings. For this type of exposure, it is essential to apply specific amounts of fungal spores homogeneously over a surface for testing the effects of fungal dose and exposure time. Contemporary methods such as spraying or brushing spore suspensions onto substrates do not produce the uniformity and consistency that standardized laboratory assays require. Two novel fungus application methods using equipment developed in the paint industry are presented and compared. Methods Wired, stainless steel K-bars were tested and optimized for coating fungal spore suspensions onto paper substrates. Different solvents and substrates were evaluated. Two types of coating techniques were compared, i.e. manual and automated coating. A standardized bioassay set-up was designed for testing coated spores against malaria mosquitoes. Results K-bar coating provided consistent applications of spore layers onto paper substrates. Viscous Ondina oil formulations were not suitable and significantly reduced spore infectivity. Evaporative Shellsol T solvent dried quickly and resulted in high spore infectivity to mosquitoes. Smooth proofing papers were the most effective substrate and showed higher infectivity than cardboard substrates. Manually and mechanically applied spore coatings showed similar and reproducible effects on mosquito survival. The standardized mosquito exposure bioassay was effective and consistent in measuring effects of fungal dose and exposure time. Conclusions K-bar coating is a simple and consistent method for applying fungal spore suspensions onto paper substrates and can produce coating layers

Hexane abatement and spore emission control in a fungal biofilter-photoreactor hybrid unit

Energy Technology Data Exchange (ETDEWEB)

Saucedo-Lucero, J.O. [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid (Spain); IPICyT, Instituto Potosino de Investigación Científica y Tecnológica, División de Ciencias Ambientales, Camino a la Presa San José No. 2055, C.P., 78216 San Luis Potosí (Mexico); Quijano, G. [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid (Spain); Arriaga, S. [IPICyT, Instituto Potosino de Investigación Científica y Tecnológica, División de Ciencias Ambientales, Camino a la Presa San José No. 2055, C.P., 78216 San Luis Potosí (Mexico); Muñoz, R., E-mail: mutora@iq.uva.es [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid (Spain)

2014-07-15

Highlights: • A fungal biofilter/photoreactor was evaluated in terms of hexane and spore removal. • Biofilter supported elimination capacities of ≈35 g m{sup −3} h{sup −1} and CO{sub 2} yields of ≈75%. • The photocatalytic process slightly boosted the hexane abatement performance. • Biofilter emitted fungal spores at concentrations of 2.4 × 10{sup 3}–9.0 × 10{sup 4} CFU m{sup −3}. • Photo-assisted post-treatments resulted in spore deactivation efficiencies of 98%. - Abstract: The performance of a fungal perlite-based biofilter coupled to a post-treatment photoreactor was evaluated over 234 days in terms of n-hexane removal, emission and deactivation of fungal spores. The biofilter and photoreactor were operated at gas residence times of 1.20 and 0.14 min, respectively, and a hexane loading rate of 115 ± 5 g m{sup −3} h{sup −1}. Steady n-hexane elimination capacities of 30–40 g m{sup −3} h{sup −1} were achieved, concomitantly with pollutant mineralization efficiencies of 60–90%. No significant influence of biofilter irrigation frequency or irrigation nitrogen concentration on hexane abatement was recorded. Photolysis did not support an efficient hexane post-treatment likely due to the short EBRT applied in the photoreactor, while overall hexane removal and mineralization enhancements of 25% were recorded when the irradiated photoreactor was packed with ZnO-impregnated perlite. However, a rapid catalyst deactivation was observed, which required a periodic reactivation every 48 h. Biofilter irrigation every 3 days supported fungal spore emissions at concentrations ranging from 2.4 × 10{sup 3} to 9.0 × 10{sup 4} CFU m{sup −3}. Finally, spore deactivation efficiencies of ≈98% were recorded for the photolytic and photocatalytic post-treatment processes. This study confirmed the potential of photo-assisted post-treatment processes to mitigate the emission of hazardous fungal spores and boost the abatement performance of

The regulated synthesis of a Bacillus anthracis spore coat protein that affects spore surface properties.

Science.gov (United States)

Aronson, A; Goodman, B; Smith, Z

2014-05-01

Examine the regulation of a spore coat protein and the effects on spore properties. A c. 23 kDa band in coat/exosporial extracts of Bacillus anthracis Sterne spores varied in amount depending upon the conditions of sporulation. It was identified by MALDI as a likely orthologue of ExsB of Bacillus cereus. Little if any was present in an exosporial preparation with a location to the inner coat/cortex region established by spore fractionation and immunogold labelling of electron micrograph sections. Because of its predominant location in the inner coat, it has been renamed Cotγ. It was relatively deficient in spores produced at 37°C and when acidic fermentation products were produced a difference attributable to transcriptional regulation. The deficiency or absence of Cotγ resulted in a less robust exosporium positioned more closely to the coat. These spores were less hydrophobic and germinated somewhat more rapidly. Hydrophobicity and appearance were rescued in the deletion strain by introduction of the cotγ gene. The deficiency or lack of a protein largely found in the inner coat altered spore hydrophobicity and surface appearance. The regulated synthesis of Cotγ may be a paradigm for other spore coat proteins with unknown functions that modulate spore properties in response to environmental conditions. © 2014 The Society for Applied Microbiology.

Fifth international fungus spore conference

Energy Technology Data Exchange (ETDEWEB)

Timberlake, W.E.

1993-04-01

This folio contains the proceedings of the Fifth International Fungal Spore Conference held August 17-21, 1991 at the Unicoi State Park at Helen, Georgia. The volume contains abstracts of each oral presentation as well as a collection of abstracts describing the poster sessions. Presentations were organized around the themes (1) Induction of Sporulation, (2) Nuclear Division, (3) Spore Formation, (4) Spore Release and Dispersal, and (4) Spore Germination.

Cryopreservation of spores of Dicksonia sellowiana: an endangered tree fern indigenous to South and Central America.

Science.gov (United States)

Rogge, G D; Viana, A M; Randi, A M

2000-01-01

Spores of Dicksonia sellowiana (Presl.) Hook., an endangered tree fern, were stored in liquid nitrogen. Surface sterilized spores were placed in 1 ml sterile polypropylene cryotubes and were plunged into liquid nitrogen cryo-cans for 15 minutes, 15 days, 1 month and 3 months. In all, of the treatments the percentage of germination was higher than the control (fresh spores). Germination in Dyer and MS media supplement with 10 (-7) M and 5 x 10(-7) M BA was also promoted as comparing to control. There was no difference between the germination of spores thawed rapidly in a water bath at 45 degree C during 5 minutes or slowly at room temperature. Cryopreservation seems to promote germination of some dormant spores of D. sellowiana. The pre-treatment in cryoprotective solution of dimethyl sulphoxide 15%(v/v) in 1 M glycerol inhibited the germination of cryopreserved spores

Ultra high pressure homogenization (UHPH inactivation of Bacillus amyloliquefaciens spores in phosphate buffered saline (PBS and milk

Directory of Open Access Journals (Sweden)

Peng eDong

2015-07-01

Full Text Available Ultra high pressure homogenization (UHPH opens up new areas for dynamic high pressure assisted thermal sterilization of liquids. Bacillus amyloliquefaciens spores are resistant to high isostatic pressure and temperature and were suggested as potential surrogate for high pressure thermal sterilization validation. B. amyloliquefaciens spores suspended in PBS buffer (0.01 M, pH 7.0, low fat milk (1.5%, pH 6.7 and whole milk (3.5%, pH 6.7 at initial concentration of ~106 CFU/mL were subjected to UHPH treatments at 200, 300 and 350 MPa with an inlet temperature at ~80 °C. Thermal inactivation kinetics of B. amyloliquefaciens spores in PBS and milk were assessed with thin wall glass capillaries and modeled using mechanistic linear first order and Weibull models. The residence time during UHPH treatments was estimated to determine the contribution of temperature to spore inactivation by UHPH. No sublethal injury was detected after UHPH treatments using sodium chloride as selective component in the nutrient agar medium. The inactivation profiles of spores in PBS buffer and milk were compared and fat provided no clear protective effect for spores against treatments. Treatment at 200 MPa with valve temperatures lower than 125 °C caused no reduction of spores. A reduction of 3.5 log10 CFU/mL of B. amyloliquefaciens spores was achieved by treatment at 350 MPa with a valve temperature higher than 150 °C. The modeled thermal inactivation and observed inactivation during UHPH treatments suggest that temperature could be the main lethal effect driving inactivation.

Ultrastructure and properties of Paecilomyces lilacinus spores

Energy Technology Data Exchange (ETDEWEB)

Holland, R.J.; Gunasekera, T.S. [Macquarie Univ., Dept. of Biological Sciences, Sydney (Australia); Williams, K.L. [Proteome Systems Ltd., Sydney (Australia); Nevalainen, K.M.H. [Dept. of Biological Sciences, Macquarie University, Sydney (Australia)

2002-10-01

Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability. (author)

Ultrastructure and properties of Paecilomyces lilacinus spores

International Nuclear Information System (INIS)

Holland, R.J.; Gunasekera, T.S.; Williams, K.L.; Nevalainen, K.M.H.

2002-01-01

Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability. (author)

Gel-free proteomic identification of the Bacillus subtilis insoluble spore coat protein fraction.

NARCIS (Netherlands)

Abhyankar, W; Beek, A.T.; Dekker, H.; Kort, R.; Brul, S.; de Koster, C. G.

2011-01-01

Species from the genus Bacillus have the ability to form endospores, dormant cellular forms that are able to survive heat and acid preservation techniques commonly used in the food industry. Resistance characteristics of spores towards various environmental stresses are in part attributed to their

Gel-free proteomic identification of the Bacillus subtilis insoluble spore coat protein fraction

NARCIS (Netherlands)

Abhyankar, W.; Beek, A.T.; Dekker, H.; Kort, R.; Brul, S.; Koster, C.G. de

2011-01-01

Species from the genus Bacillus have the ability to form endospores, dormant cellular forms that are able to survive heat and acid preservation techniques commonly used in the food industry. Resistance characteristics of spores towards various environmental stresses are in part attributed to their

Stump treatment against Heterobasidion annosum - Techniques and biological effect in practical forestry

Energy Technology Data Exchange (ETDEWEB)

Thor, M. [SkogForsk, Uppsala (Sweden)

1997-12-31

This thesis summarises and discusses results from two studies on mechanized stump treatment to control the root rot fungus Heterobasidion annosum (Fr.) Bref. In Sweden, stump treatment is at present carried out with two chemical compounds, urea and disodium octaborate tetrahydrate (DOT), and a biological control agent, Phlebiopsis gigantea (Fr.) Juel. The first study investigated the H. annosum colonization of Norway spruce (Picea abies (L.) Karst) stumps following mechanized thinning and stump treatment with the three control agents mentioned. The stumps were treated in the summer and were compared with untreated stumps, cut in the summer and winter, respectively. Experimental plots were established in 12 first thinning stands of Norway spruce. Six to seven weeks after thinning and treatment, sample discs were collected (N=1246) and examined for presence of H. annosum. Stump treatment with any of the control agents reduced the colonized stump area 6-7 weeks after thinning by 88-98% as compared with untreated stumps cut in the summer. The effects of the different treatments differed neither from each other nor from the effect of winter thinning. The variation between the stands was considerable, but mechanized stump treatment provided as good protection as manual treatment against H. annosum infections. Study II examined the survival of P. gigantea oidiospores in aqueous suspension when exposed to high temperature or pressure, which are potential problems in mechanized application. In the laboratory, temperatures of 20, 30 or 35 deg C did not affect the survival. The spores could withstand 40 deg C for a short period, but died at 60 deg C. Pressure of up to 2 200 kPa for 24 h did not affect P. gigantea spore germination. In the field, temperatures of the working suspension (10{sup 7} spores I{sup -1}) was assessed during practical operations. Spore viability was maintained through the applicator system. As long as the prescriptions are followed up to the time of

Photometric immersion refractometry of bacterial spores.

Science.gov (United States)

Gerhardt, P; Beaman, T C; Corner, T R; Greenamyre, J T; Tisa, L S

1982-01-01

Photometric immersion refractometry was used to determine the average apparent refractive index (n) of five types of dormant Bacillus spores representing a 600-fold range in moist-heat resistance determined as a D100 value. The n of a spore type increased as the molecular size of various immersion solutes decreased. For comparison of the spore types, the n of the entire spore and of the isolated integument was determined by use of bovine serum albumin, which is excluded from permeating into them. The n of the sporoplast (the structures bounded by the outer pericortex membrane) was determined by use of glucose, which was shown to permeate into the spore only as deeply as the pericortex membrane. Among the various spore types, an exponential increase in the heat resistance correlated with the n of the entire spore and of the sporoplast, but not of the isolated perisporoplast integument. Correlation of the n with the solids content of the entire spore provided a method of experimentally obtaining the refractive index increment (dn/dc), which was constant for the various spore types and enables the calculation of solids and water content from an n. Altogether, the results showed that the total water content is distributed unequally within the dormant spore, with less water in the sporoplast than in the perisporoplast integument, and that the sporoplast becomes more refractile and therefore more dehydrated as the heat resistance becomes greater among the various spore types. PMID:6802796

Effect of incubation temperature and pH on the recovery of Bacillus weihenstephanensis spores after exposure to a peracetic acid-based disinfectant or to pulsed light.

Science.gov (United States)

Trunet, C; Mtimet, N; Mathot, A-G; Postollec, F; Leguérinel, I; Couvert, O; Carlin, F; Coroller, L

2018-04-12

The recovery at a range of incubation temperatures and pH of spores of Bacillus weihenstephanensis KBAB4 exposed to a peracetic acid-based disinfectant (PABD) or to pulsed light was estimated. Spores of B. weihenstephanensis were produced at 30 °C and pH 7.00, at 30 °C and pH 5.50, or at 12 °C and pH 7.00. The spores were treated with a commercial peracetic acid-based disinfectant at 80 mg·mL -1 for 0 to 200 min at 18 °C or by pulsed light at fluences ranging between 0.4 and 2.3 J·cm -2 for pulsed light treatment. After each treatment, the spores were incubated on nutrient agar at 12 °C, 30 °C or 37 °C, or at pH 5.10, 6.00 or 7.40. Incubation temperature during recovery had a significant impact only near the recovery limits, beyond which surviving spores previously exposed to a PABD or to pulsed light were not able to form colonies. In contrast, a decrease in pH of the recovery nutrient agar had a progressive impact on the ability of spores to form colonies. The time to first log reduction after PABD treatment was 29.5 ± 0.7 min with recovery at pH 7.40, and was tremendously shortened 5.1 ± 0.2 min with recovery at pH 5.10. Concerning the fluence necessary for the first log reduction, it was 1.5 times higher when the spores were recovered at pH 6.00 compared to a recovery at pH 5.10. The impact of recovery temperature and pH can be described with a mathematical model using cardinal temperature and pH as parameters. These effects of temperature and pH on recovery of Bacillus weihenstephanensis spores exposed to a disinfectant combining peracetic acid and hydrogen peroxide, or pulsed light are similar, although these treatments are of different natures. Sporulation temperature or pH did not impact resistance to the peracetic acid-based disinfectant or pulsed light. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of pH on Thermoanaerobacterium thermosaccharolyticum DSM 571 growth, spore heat resistance and recovery.

Science.gov (United States)

Mtimet, Narjes; Guégan, Stéphanie; Durand, Lucile; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

2016-05-01

Thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °C) in the manufacturing process. Among those thermophilic spore-forming bacteria, Thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. The aim of this study was to investigate and to model pH effect on growth, heat resistance and recovery abilities after a heat-treatment of T. thermosaccharolyticum DSM 571. Growth and sporulation were conducted on reinforced clostridium media and liver broth respectively. The highest spore heat resistances and the greatest recovery ability after a heat-treatment were obtained at pH condition allowing maximal growth rate. Growth and sporulation boundaries were estimated, then models using growth limits as main parameters were extended to describe and quantify the effect of pH on recovery of injured spores after a heat-treatment. So, cardinal values were used as a single set of parameters to describe growth, sporulation and recovery abilities. Besides, this work suggests that T. thermosaccharolyticum preserve its ability for germination and outgrowth after a heat-treatment at a low pH where other high resistant spore-forming bacteria like Geobacillus stearothermophilus are unable to grow. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inactivation of bacterial spores by combination processes: ultraviolet plus gamma radiation. [Streptococcus faecium, micrococcus radiodurans, clostridium botulinum

Energy Technology Data Exchange (ETDEWEB)

Grecz, N; Durban, E

1973-01-01

Bacterial spores, viruses and some vegetative bacteria such as Streptococcus faecium and Micrococcus radiodurans are distinguished by high radiation resistance. In order to lay a theoretical basis for biomedical sterilization applications, we have investigated the combined action of uv and gamma rays. Spores of two strains of C. botulinum were selected, a highly radiation resistant strain, 33A having a D/sub 10/-value of 0.32 Mrad, and a relatively radiation sensitive strain, 51B having a D/sub 10/-value of 0.12 Mrad. Strain 33A exhibits an extensive initial ''shoulder'' in its uv as well as gamma ray survival curves; strain 51B shows only a slight shoulder. The shoulder in the gamma ray survival curve of spores of strain 33A could be reduced or completely eliminated by preirradiation with uv. Simultaneously the D/sub 10/-value for gamma inactivation of spores of 33A was reduced substantially. For example, the gamma resistance was reduced almost to half of its original D/sub 10/-value by uv-preirradiation for only one minute under an 8 watt GE germicidal lamp. The effect of uv-preirradiation on the radiation sensitive strain 51B was less pronounced. In fact, there was about seven fold higher positive interaction (synergism) between uv and gamma radiation in 33A spores than in 51B spores. The experiments suggest that interference with DNA repair enzymes in the radiation resistant strain are responsible for lethal synergism between uv and gamma radiation. A hypothesis is developed attempting to explain the combined effect of these two radiations in terms of a special summation of known DNA lesions in the cell. These observations emphasize the potential practical advantages of combining uv and gamma rays for effective sterilization of certain biomedical devices, drugs and biologicals.

The influence of lime and nitrogen fertilisers on spore counts of Pithomyces chartarum in pasture.

Science.gov (United States)

Cuttance, E L; Laven, R A; Mason, W A; Stevenson, M

2016-11-01

To determine whether the application of lime or nitrogen to pasture affected the spore counts of Pithomyces chartarum. The lime application studies were undertaken on a spring-calving, pasture-based, commercial dairy farm near Te Awamutu, New Zealand. On 6 November 2012, five randomly selected paddocks were split into three equal sections. In two of the sections, lime was applied at either 1.5 or 2.5 t/ha, and the central section was left as an untreated control. Each section was sampled for spore counting weekly from 16 January to 15 May 2013. Starting in January 2013, five other randomly selected paddocks were monitored for spore counts. On 20 March 2013 the average spore counts in three paddocks were >100,000 spores/g of pasture. These paddocks were then divided into three equal sections and lime was applied as described above. Spore counting in each section continued weekly until 15 May 2013. The nitrogen application study was carried out on three commercial dairy farms near Te Awamutu, New Zealand. Two randomly selected paddocks on each farm were divided into three equal sections and, on 20 December 2012, nitrogen in the form of urea was applied at either 50 or 80 kg urea/ha to two of the sections; the central section remained as an untreated control. Each section was sampled for spore counting weekly from 16 January to 15 May 2013. Following pre-summer lime application, treatment at 1.5 or 2.5 t/ha did not affect spore counts over time compared with the control section (p>0.26). Similarly following autumn lime application, treatment at 1.5 or 2.5 t/ha did not affect spore counts over time compared with the control section (p>0.11). Following nitrogen application median spore counts remained 0.49). This study found that application of lime before the risk period for facial eczema, in November, application of lime after a spore count rise, in March, or urea application in December did not affect changes in number of spores produced by P. chartarum. This

Enhancement of intrinsic antitumor activity in spore-endotoxin mixtures of Bacillus thuringiensis by exposure to ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Zamola, B; Karminski-Zamola, G; Fuks, Z; Kubovic, M [Zagreb Univ. (Yugoslavia); Wrishcer, M [Institut Rudjer Boskovic, Zagreb (Yugoslavia)

1985-03-01

Irradiation of spore-endotoxin mixtures from Bacillus thuringiensis cultures at 254 nm (60 ..mu..W cm/sup -2/) enhances their intrinsic antitumor potency as well as that of either component. The extent of enhancement depends on the length of exposure (optimum: 35 min) and may thus be due to photochemical changes of the endotoxin protein or/and to photoproduction of additional compounds with antitumor activity. Antitumor effects, expressed as survival rates of C57BL/6 mice inoculated with Lewis' mouse lung carcinoma and subjected to treatments 24 h later, depended on the number of doses of preparations administered (mixture, separated components).

Assessment of Gamma Radiation Resistance of Spores Isolated from the Spacecraft Assembly Facility During MSL Assembly

Science.gov (United States)

Chopra, Arsh; Ramirez, Gustavo A.; Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.

2011-01-01

Spore forming bacteria, a common inhabitant of spacecraft assembly facilities, are known to tolerate extreme environmental conditions such as radiation, desiccation, and high temperatures. Since the Viking era (early 1970's), spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. There is a growing concern that desiccation and extreme radiation resistant spore forming microorganisms associated with spacecraft surfaces can withstand space environmental conditions and subsequently proliferate on another solar body. Such forward contamination would certainly jeopardize future life detection or sample return technologies. It is important to recognize that different classes of organisms are critical while calculating the probability of contamination, and methods must be devised to estimate their abundances. Microorganisms can be categorized based on radiation sensitivity as Type A, B, C, and D. Type C represents spores resistant to radiation (10% or greater survival above 0.8 Mrad gamma radiation). To address these questions we have purified 96 spore formers, isolated during planetary protection efforts of Mars Science Laboratory assembly for gamma radiation resistance. The spores purified and stored will be used to generate data that can be used further to model and predict the probability of forward contamination.

The search and identification of the new immunodiagnostic targets of bacillus anthracis spore

International Nuclear Information System (INIS)

Biketov, S.; Dunaytsev, I.; Baranova, E.; Marinin, L.; Dyatlov, I.

2009-01-01

Spores of Bacillus anthracis have been used as bio warfare agent to bio terrorize purposes. As efficiency of anti-epidemic measures included urgent prevention and treatment is determined by terms within which the bio agent is identified. Direct and rapid spore detection by antibodies based detection system is very attractive alternative to current PCR-based assays or routine phenotyping which are the most accurate but are also complex, time-consumption and expensive. The main difficulty with respect to such kind of anthrax spores detection is a cross-reaction with spores of closely related bacteria. For development of species-specific antibodies to anthrax spores recombinant scFvs or hybridoma technique were used. In both case surface spore antigens contained species-specific epitopes are need. Among exosporium proteins only ExsF(BxpB), ExsK and SoaA are specific to B.cereus group. On the surface of B. anthracis spores, a unique tetrasaccharides containing an novel monosaccharide - anthrose, was discovered. It was shown that anthrose can be serving as species-specific target for B. anthracis spores detection. We have revealed that EA1 isolated from spore of Russians strain STI-1 contain carbohydrate which formed species-specific epitopes and determine immunogenicity of this antigen. Antibodies to this antigen specifically recognized the surface target of B. anthracis spores and do not reacted with others Bacillus spore. Based on these antibodies we developed the test-systems in different formats for rapid direct detection and identification of B. anthracis spores. The results of trial these test-systems with using more than 50 different Bacillus strains were indicated that carbohydrate of EA1 isolated from spore is effective immunodiagnostic target for anthrax spores bio detection.(author)

Soil spore bank communities of ectomycorrhizal fungi in endangered Chinese Douglas-fir forests.

Science.gov (United States)

Wen, Zhugui; Shi, Liang; Tang, Yangze; Hong, Lizhou; Xue, Jiawang; Xing, Jincheng; Chen, Yahua; Nara, Kazuhide

2018-01-01

Chinese Douglas-fir (Pseudotsuga sinensis) is an endangered Pinaceae species found in several isolated regions of China. Although soil spore banks of ectomycorrhizal (ECM) fungi can play an important role in seedling establishment after disturbance, such as in the well-known North American relative (Pseudotsuga menziesii), we have no information about soil spore bank communities in relict forests of Chinese Douglas-fir. We conducted bioassays of 73 soil samples collected from three Chinese Douglas-fir forests, using North American Douglas-fir as bait seedlings, and identified 19 species of ECM fungi. The observed spore bank communities were significantly different from those found in ECM fungi on the roots of resident trees at the same sites (p = 0.02). The levels of potassium (K), nitrogen (N), organic matter, and the pH of soil were the dominant factors shaping spore bank community structure. A new Rhizopogon species was the most dominant species in the spore banks. Specifically, at a site on Sanqing Mountain, 22 of the 57 surviving bioassay seedlings (representing 21 of the 23 soil samples) were colonized by this species. ECM fungal richness significantly affected the growth of bioassay seedlings (R 2  = 0.20, p = 0.007). Growth was significantly improved in seedlings colonized by Rhizopogon or Meliniomyces species compared with uncolonized seedlings. Considering its specificity to Chinese Douglas-fir, predominance in the soil spore banks, and positive effect on host growth, this new Rhizopogon species could play critical roles in seedling establishment and forest regeneration of endangered Chinese Douglas-fir.

Evaluation of citric acid and GDL in the recovery at different pH levels of Clostridium sporogenes PA 3679 spores subjected to HTST treatment conditions.

Science.gov (United States)

Silla Santos, M H; Torres Zarzo, J

1996-04-01

Spores of Clostridium sporogenes PA 3679 were treated at different temperatures (121, 126, 130 and 135 degrees C) in white asparagus purée (pH 5.8) and acidified with glucono-delta-lactone (GDL) and citric acid to pH levels of 5.5, 5.0 and 4.5. Afterwards, the spores were recovered in MPA3679 medium in various conditions: unacidified (pH 7.5), acidified with GDL (500 ppm) and acidified with citric acid (500 and 250 ppm) to pH levels of 6.5, 6.0 and 5.0. The results indicated that the pH levels, concentration and type of acid used act synergistically rather than independently. Citric acid has a stronger inhibiting effect than GDL on the recovery of C. sporogenes PA 3679 spores. At the higher heat treatments (130 and 135 degrees C) the major injury on the spores sensitize more than against the acids and low pH values.

The effects of salinity and temperature shock on Kappaphycus alvarezii seaweed spores release

Science.gov (United States)

Harwinda, F. K.; Satyantini, W. H.; Masithah, E. W.

2018-04-01

One of the reproductive aspects of development step that is considered as the solution of this issue is seaweed sporulation technique through which is induced through salinity and temperature shock. This study aims to determine the effect of combination and interaction of salinity and temperature shock on the release of K. alvarezii spores in order to produce superior seeds. This research was conducted using Complete Randomized Design Factorial which consists of nine combinations of treatments and three replications. The used treatment in this study is the combination of different environmental factors such as salinity shock and temperature shock. The data were analyzed using ANOVA (Analysis of Variance) followed by Duncan Multiple Range Test. The results showed that salinity (31 ppt, 33 ppt, and 35 ppt) and temperature (30°C, 32°C, and 34°C). shock affected the osmoregulation system and the release of K. alvarezii spores. The salinity shock and temperature shock had interaction with K. alvarezii spore release on the sixth and seventh day with the best treatment at 32°C temperature and 31 ppt salinity and released 5413 cells/ml spores on the seventh day.

Maternal parentage influences spore production but not spore pigmentation in the anisogamous and hermaphroditic fungus Neurospora crassa

DEFF Research Database (Denmark)

Zimmerman, Kolea; Levitis, Daniel; Pringle, Anne

2014-01-01

. In this fungus, pigmented spores are viable and unpigmented spores are inviable. These results show that while both parents influence all these traits, maternal influence is strongest on both fertility and mortality traits until the spores are physiologically independent of the maternal cytoplasm.......In this study, we tested the hypothesis that maternal effects on offspring production and quality are greater than paternal effects in both offspring number (fertility) and offspring viability (mortality). We used the model filamentous fungus Neurospora crassa. This fungus is anisogamous......, and various ascospore characteristics. Mixed effects models of these data show that the female parent accounts for the majority of variation in perithecial production, number of spores produced, and spore germination. Surprisingly, both sexes equally influence the percentage of spores that are pigmented...

Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

International Nuclear Information System (INIS)

Koshikawa, Tomihiko

1994-01-01

Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.)

Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

Energy Technology Data Exchange (ETDEWEB)

Koshikawa, Tomihiko [Japan Radioisotope Association, Shiga (Japan). Koka Laboratory

1994-12-01

Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.).

Fluorescence-based methods for the detection of pressure-induced spore germination and inactivation

Science.gov (United States)

Baier, Daniel; Reineke, Kai; Doehner, Isabel; Mathys, Alexander; Knorr, Dietrich

2011-03-01

The application of high pressure (HP) provides an opportunity for the non-thermal preservation of high-quality foods, whereas highly resistant bacterial endospores play an important role. It is known that the germination of spores can be initiated by the application of HP. Moreover, the resistance properties of spores are highly dependent on their physiological states, which are passed through during the germination. To distinguish between different physiological states and to detect the amount of germinated spores after HP treatments, two fluorescence-based methods were applied. A flow cytometric method using a double staining with SYTO 16 as an indicator for germination and propidium iodide as an indicator for membrane damage was used to detect different physiological states of the spores. During the first step of germination, the spore-specific dipicolinic acid (DPA) is released [P. Setlow, Spore germination, Curr. Opin. Microbiol. 6 (2003), pp. 550-556]. DPA reacts with added terbium to form a distinctive fluorescent complex. After measuring the fluorescence intensity at 270 nm excitation wavelength in a fluorescence spectrophotometer, the amount of germinated spores can be determined. Spores of Bacillus subtilis were treated at pressures from 150 to 600 MPa and temperatures from 37 °C to 60 °C in 0.05 M ACES buffer solution (pH 7) for dwell times of up to 2 h. During the HP treatments, inactivation up to 2log 10 cycles and thermal sensitive populations up to 4log 10 cycles could be detected by plate counts. With an increasing number of thermal sensitive spores, an increased proportion of spores in germinated states was detected by flow cytometry. Also the released amount of DPA increased during the dwell times. Moreover, a clear pressure-temperature-time-dependency was shown by screening different conditions. The fluorescence-based measurement of the released DPA can provide the opportunity of an online monitoring of the germination of spores under HP inside

Influence of Long-Term Fertilization on Spore Density and Colonization of Arbuscular Mycorrhizal Fungi in a Brown Soil

Science.gov (United States)

Li, Dongdong; Luo, Peiyu; Yang, Jinfeng

2017-12-01

This study aims to explore changes of long-term fertilization on spore density and colonization of AMF (Arbuscular mycorrhizal fungi) under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm,20-40cm,40-60cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen andphosphate fertilizer).Spores were isolated from soils by wet sieving and sucrose density gradient centrifugation; mycorrhizal colonization levels were determined by the gridline intersect. The spore density was highest in the topsoils (0-20 cm), and was decreased with increasing of soil depth in each treatment. The spores density of M2N1P treatment was significantly higher than that of other treatments in each soil layer. Application of inorganic fertilizer (especially inorganic with organic fertilizer) can greatly improve the level of colonization. Our results suggested that long-term fertilization significantly affects spore density and colonization of AMF, however, spore density is not related to colonization rate.

Effects of irradiation on the survival of bacterial contaminants in food

Directory of Open Access Journals (Sweden)

Lily Natalia

2016-01-01

Full Text Available The primary concern about microbial safety of irradiated food is the survival of pathogenic spore forming bacteria. Clostridium sporogenes was selected as the spore forming test organism for conducting inoculated pack studies for its similarities to the most toxigenic Cl. botulinum, in radiation resistance. Minimum radiation dose applied (45 kGy under cryogenic condition, in -790C was determined to eliminate Cl. sporogenes spores and other bacterial contaminants in different kind of Indonesian chicken and beef dishes. In separate studies, irradiation doses of 3 – 7 kGy at cryogenic condition was used to improve the microbiological safety of a number chilled prepared meals. The dishes or ready to eat foods were packaged in air impermeable pouches. Irradiation process was carried out after inoculation on chicken and beef dishes with certain amounts of Cl. sporogenes spores. The evaluation of colony count differences between the irradiated and unirradiated foods revealed the effect of radiation on the survival of bacterial spores or other bacterial contaminants. It was demonstrated that a minimum dose of 45 kGy under cryogenic condition eliminated the spore of Cl. sporogenes, Bacillus spp and Staphylococcus spp. Irradiation at doses 5-7 kGy significantly reduced some potential pathogenic microorganisms in samples without affecting quality up to 3 months of storage at the refrigeration temperature.

Longitudinal assessment of dairy farm management practices associated with the presence of psychrotolerant Bacillales spores in bulk tank milk on 10 New York State dairy farms

NARCIS (Netherlands)

Masiello, S. N.; Kent, D.V.; Martin, N. H.; Schukken, Y. H.; Wiedmann, M.; Boor, K. J.

2017-01-01

The ability of certain spore-forming bacteria in the order Bacillales (e.g., Bacillus spp., Paenibacillus spp.) to survive pasteurization in spore form and grow at refrigeration temperatures results in product spoilage and limits the shelf life of high temperature, short time (HTST)-pasteurized

Absence of transient elevated uv resistance during germination of Bacillus subtilis spores lacking small, acid-soluble spore proteins α and β

International Nuclear Information System (INIS)

Setlow, B.; Setlow, P.

1988-01-01

Dormant spores of various Bacillus species are much more resistant to UV irradiation than are the corresponding vegetative cells. This elevated spore UV resistance appears to have two causes. First, UV irradiation of spores does not produce the pyrimidine dimers formed in vegetative-cell DNA, but rather produces several other photoproducts, the most predominant of which is termed the spore photoproduct, a 5-thyminyl-5,6-dihydrothymine adduct (1, 10). Second, spores have at least two mechanisms which efficiently repair this spore photoproduct during spore germination, including one which monomerizes the adduct back to two thymines. This study shows that germinating spores of bacillus subtilis mutants which lack small, acid-soluble spore proteins α and β did not exhibit the transient elevated UV resistance seen during germination of wild-type spores

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

Science.gov (United States)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S.; Pantoya, M. L.

2013-12-01

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300-2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%-1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine.

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

International Nuclear Information System (INIS)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S.; Pantoya, M. L.

2013-01-01

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300–2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%–1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

Energy Technology Data Exchange (ETDEWEB)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Pantoya, M. L. [Mechanical Engineering Department, Texas Tech University, Lubbock, Texas 79409 (United States)

2013-12-21

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300–2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%–1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine.

Inhibition of Lipopolysaccharide-Induced Interleukin 8 in Human Adenocarcinoma Cell Line HT-29 by Spore Probiotics: B. coagulans and B. subtilis (natto).

Science.gov (United States)

Azimirad, Masoumeh; Alebouyeh, Masoud; Naji, Tahereh

2017-03-01

Probiotics are used as a treatment for different intestinal disorders. They confer health benefits by different ways. This study was aimed to investigate immunomodulatory effect of Bacillus probiotic spores on the production of lipopolysaccharide (LPS)-induced interleukin 8 (IL-8) in HT-29 intestinal epithelial cells. Differentiated intestinal epithelial cell line was used as a model for the study of colonization of purified spores (Bacillus subtilis (natto) and B. coagulans) and their anti-inflammatory effects. MTT assay and trypan blue staining were used for the detection of optimal concentration of the purified spores and LPS. Pre-treatment assay was done by treatment of the cells with the purified spores for 2 h, followed by challenges with LPS for 3 and 18 h. Post-treatment assay was done by initial treatment of the cells with LPS for 18 h, followed by the spores for 3 and 6 h. Levels of IL-8 secretion and its mRNA expression were measured by ELISA and relative Q real-time PCR. Our results showed similar rates of adherence to intestinal epithelial cells by the spore probiotics, while displaying no cytotoxic effect. In the pre-treatment assay, a significant decrease in IL-8, at both protein and mRNA levels, was measured for B. coagulans spores after the addition of LPS, which was higher than those observed for Bacillus subtilis (natto) spores. In the post-treatment assay, while Bacillus subtilis (but not B. coagulans) diminished the LPS-stimulated IL-8 levels after 3 h of incubation, the inhibitory effect was not constant. In conclusion, ability of Bacillus spore probiotics for adherence to intestinal epithelial cell and their anti-inflammatory effects, through interference with LPS/IL-8 signaling, was shown in this study. Further studies are needed to characterize responsible bacterial compounds associated with these effects.

Differential survival of Ichthyophonus isolates indicates parasite adaptation to its host environment.

Science.gov (United States)

Hershberger, P K; Pacheco, C A; Gregg, J L; Purcell, M K; LaPatra, S E

2008-10-01

In vitro viability of Ichthyophonus spp. spores in seawater and freshwater corresponded with the water type of the host from which the spores were isolated. Among Ichthyophonus spp. spores from both marine and freshwater fish hosts (Pacific herring, Clupea pallasii, and rainbow trout, Oncorhynchus mykiss, respectively), viability was significantly greater (P < 0.05) after incubation in seawater than in freshwater at all time points from 1 to 60 min after immersion; however, magnitude of the spore tolerances to water type differed with host origin. Ichthyophonus sp. adaptation to its host environment was indicated by greater seawater tolerance of spores from the marine host and greater freshwater tolerance of spores from the freshwater host. Prolonged aqueous survival of Ichthyophonus spp. spores in the absence of a host provides insight into routes of transmission, particularly among planktivorous fishes, and should be considered when designing strategies to dispose of infected fish carcasses and tissues.

Effects of microbial loading and sporulation temperature on atmospheric plasma inactivation of Bacillus subtilis spores

Science.gov (United States)

Deng, X. T.; Shi, J. J.; Shama, G.; Kong, M. G.

2005-10-01

Current inactivation studies of Bacillus subtilis spores using atmospheric-pressure glow discharges (APGD) do not consider two important factors, namely microbial loading at the surface of a substrate and sporulation temperature. Yet these are known to affect significantly microbial resistance to heat and hydrogen peroxide. This letter investigates effects of microbial loading and sporulation temperature on spore resistance to APGD. It is shown that microbial loading can lead to a stacking structure as a protective shield against APGD treatment and that high sporulation temperature increases spore resistance by altering core water content and cross-linked muramic acid content of B. subtilis spores.

High-Level Heat Resistance of Spores of Bacillus amyloliquefaciens and Bacillus licheniformis Results from the Presence of a spoVA Operon in a Tn1546 Transposon

NARCIS (Netherlands)

Berendsen, Erwin M; Koning, Rosella A; Boekhorst, Jos; de Jong, Anne; Kuipers, Oscar P; Wells-Bennik, Marjon H J

2016-01-01

Bacterial endospore formers can produce spores that are resistant to many food processing conditions, including heat. Some spores may survive heating processes aimed at production of commercially sterile foods. Recently, it was shown that a spoVA operon, designated spoVA(2mob), present on a Tn1546

Germination and Inactivation of Alicyclobacillus acidoterrestris Spores Induced by Moderate Hydrostatic Pressure.

Science.gov (United States)

Sokołowska, Barbara; Skapska, Sylwia; Fonberg-Broczek, Monika; Niezgoda, Jolanta; Porebska, Izabela; Dekowska, Agnieszka; Rzoska, Sylwester J

2015-01-01

Given the importance of spoilage caused by Alicyclobacillus acidoterrestris for the fruit juice industry, the objective of this work was to study the germination and inactivation of A. acidoterrestris spores induced by moderate hydrostatic pressure. Hydrostatic pressure treatment can induce the germination and inactivation of A. acidoterrestris spores. At low pH, spore germination of up to 3.59-3.75 log and inactivation of 1.85-2.04 log was observed in a low pressure window (200-300 MPa) applied at 50 degrees C for 20 min. Neutral pH suppressed inactivation, the number of spores inactivated at pH 7.0 was only 0.24-1.06 log. The pressurization temperature significantly affected spore germination and inactivation. The degree of germination in apple juice after pressurization for 30 min with 200 MPa at 20 degrees C was 2.04 log, with only 0.61 log of spores being inactivated, while at 70 degrees C spore germination was 5.94 log and inactivation 4.72 log. This temperature strongly stimulated germination and inactivation under higher (500 MPa) than lower (200 MPa) pressure. When the oscillatory mode was used, the degree of germination and inactivation was slightly higher than at continuous mode. The degree of germination and inactivation was inversely proportional to the soluble solids content and was lowest in concentrated apple juice.

Characterization of Wet-Heat Inactivation of Single Spores of Bacillus Species by Dual-Trap Raman Spectroscopy and Elastic Light Scattering▿

Science.gov (United States)

Zhang, Pengfei; Kong, Lingbo; Setlow, Peter; Li, Yong-qing

2010-01-01

Dual-trap laser tweezers Raman spectroscopy (LTRS) and elastic light scattering (ELS) were used to investigate dynamic processes during high-temperature treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis in water. Major conclusions from these studies included the following. (i) After spores of all three species were added to water at 80 to 90°C, the level of the 1:1 complex of Ca2+ and dipicolinic acid (CaDPA; ∼25% of the dry weight of the spore core) in individual spores remained relatively constant during a highly variable lag time (Tlag), and then CaDPA was released within 1 to 2 min. (ii) The Tlag values prior to rapid CaDPA release and thus the times for wet-heat killing of individual spores of all three species were very heterogeneous. (iii) The heterogeneity in kinetics of wet-heat killing of individual spores was not due to differences in the microscopic physical environments during heat treatment. (iv) During the wet-heat treatment of spores of all three species, spore protein denaturation largely but not completely accompanied rapid CaDPA release, as some changes in protein structure preceded rapid CaDPA release. (v) Changes in the ELS from individual spores of all three species were strongly correlated with the release of CaDPA. The ELS intensities of B. cereus and B. megaterium spores decreased gradually and reached minima at T1 when ∼80% of spore CaDPA was released, then increased rapidly until T2 when full CaDPA release was complete, and then remained nearly constant. The ELS intensity of B. subtilis spores showed similar features, although the intensity changed minimally, if at all, prior to T1. (vi) Carotenoids in B. megaterium spores' inner membranes exhibited two changes during heat treatment. First, the carotenoid's two Raman bands at 1,155 and 1,516 cm−1 decreased rapidly to a low value and to zero, respectively, well before Tlag, and then the residual 1,155-cm−1 band disappeared, in parallel

The Use of Germinants to Potentiate the Sensitivity of Bacillus anthracis Spores to Peracetic Acid.

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Celebi, Ozgur; Buyuk, Fatih; Pottage, Tom; Crook, Ant; Hawkey, Suzanna; Cooper, Callum; Bennett, Allan; Sahin, Mitat; Baillie, Leslie

2016-01-01

Elimination of Bacillus anthracis spores from the environment is a difficult and costly process due in part to the toxicity of current sporicidal agents. For this reason we investigated the ability of the spore germinants L-alanine (100 mM) and inosine (5 mM) to reduce the concentration of peracetic acid (PAA) required to inactivate B. anthracis spores. While L-alanine significantly enhanced (p = 0.0085) the bactericidal activity of 500 ppm PAA the same was not true for inosine suggesting some form of negative interaction. In contrast the germinant combination proved most effective at 100 ppm PAA (p = 0.0009). To determine if we could achieve similar results in soil we treated soil collected from the burial site of an anthrax infected animal which had been supplemented with spores of the Sterne strain of B. anthracis to increase the level of contamination to 10(4) spores/g. Treatment with germinants followed 1 h later by 5000 ppm PAA eliminated all of the spores. In contrast direct treatment of the animal burial site using this approach delivered using a back pack sprayer had no detectable effect on the level of B. anthracis contamination or on total culturable bacterial numbers over the course of the experiment. It did trigger a significant, but temporary, reduction (p < 0.0001) in the total spore count suggesting that germination had been triggered under real world conditions. In conclusion, we have shown that the application of germinants increase the sensitivity of bacterial spores to PAA. While the results of the single field trial were inconclusive, the study highlighted the potential of this approach and the challenges faced when attempting to perform real world studies on B. anthracis spores contaminated sites.

The use of germinants to potentiate the sensitivity of Bacillus anthracis spores to peracetic acid

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Ozgur eCelebi

2016-01-01

Full Text Available Elimination of Bacillus anthracis spores from the environment is a difficult and costly process due in part to the toxicity of current sporicidal agents. For this reason we investigated the ability of the spore germinants L-alanine (100 mM and inosine (5 mM to reduce the concentration of peracetic acid (PAA required to inactivate B.anthracis spores. While L-alanine significantly enhanced (p=0.0085 the bactericidal activity of 500 ppm PAA the same was not true for inosine suggesting some form of negative interaction. In contrast the germinant combination proved most effective at 100 ppm PAA (p=0.0009. To determine if we could achieve similar results in soil we treated soil collected from the burial site of an anthrax infected animal which had been supplemented with spores of the Sterne strain of B.anthracis to increase the level of contamination to 104 spores/g. Treatment with germinants followed one hour later by 5000 ppm PAA eliminated all of the spores. In contrast direct treatment of the animal burial site using this approach delivered using a back pack sprayer had no detectable effect on the level of B.anthracis contamination or on total culturable bacterial numbers over the course of the experiment. It did trigger a significant, but temporary, reduction (p<0.0001 in the total spore count suggesting that germination had been triggered under real world conditions. In conclusion, we have shown that the application of germinants increase the sensitivity of bacterial spores to PAA. While the results of the single field trial were inconclusive, the study highlighted the potential of this approach and the challenges faced when attempting to perform real world studies on B.anthracis spores contaminated sites.

Use of yeast spores for microencapsulation of enzymes.

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Shi, Libing; Li, Zijie; Tachikawa, Hiroyuki; Gao, Xiao-Dong; Nakanishi, Hideki

2014-08-01

Here, we report a novel method to produce microencapsulated enzymes using Saccharomyces cerevisiae spores. In sporulating cells, soluble secreted proteins are transported to the spore wall. Previous work has shown that the spore wall is capable of retaining soluble proteins because its outer layers work as a diffusion barrier. Accordingly, a red fluorescent protein (RFP) fusion of the α-galactosidase, Mel1, expressed in spores was observed in the spore wall even after spores were subjected to a high-salt wash in the presence of detergent. In vegetative cells, however, the cell wall cannot retain the RFP fusion. Although the spore wall prevents diffusion of proteins, it is likely that smaller molecules, such as sugars, pass through it. In fact, spores can contain much higher α-galactosidase activity to digest melibiose than vegetative cells. When present in the spore wall, the enzyme acquires resistance to environmental stresses including enzymatic digestion and high temperatures. The outer layers of the spore wall are required to retain enzymes but also decrease accessibility of the substrates. However, mutants with mild spore wall defects can retain and stabilize the enzyme while still permitting access to the substrate. In addition to Mel1, we also show that spores can retain the invertase. Interestingly the encapsulated invertase has significantly lower activity toward raffinose than toward sucrose.This suggests that substrate selectivity could be altered by the encapsulation.

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

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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

Survival frequency and spectrum of induced mutations in Penicillium vermiculatum dangeard following

International Nuclear Information System (INIS)

Mitra, Jharna; Chaudhari, K.L.

1974-01-01

A comparative study on the sensitivity of UV, X-rays and gamma rays on conidia of Penicillium vermiculatum has been done. LD50 with UV-rays was shown with less than 60 second treatment at a dose of 6 x 10 3 ergs/mm 2 . Beyond 240 second treatment i.e. 2.4 x 10 4 ergs/mm 2 the survival percent remained almost the same, indicating resistance of surviving spores to the action of UV radiation. With X-rays an increase in the germination percent of conidia was noticed at dosages of 5 and 10 Kr. Abrupt fall in the survival percent was observed with increasing dosage of X-rays. A wide range of biochemical morphological mutants was obtained with UV irradiation as compared to those with X-rays. Nicotinic acid requiring mutants occurred frequently with X-rays and methionine requiring ones with gamma-rays. Compact colonial mutants were induced freely with X-rays and violet pigment producing ones with gamma-rays. (author)

In vitro propagation of Cyathea atrovirens (Cyatheaceae): spore storage and sterilization conditions.

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Vargas, Isabel Beatriz de; Droste, Annette

2014-03-01

Cyathea atrovirens occurs in a wide range of habitats in Brazil, Paraguay, Uruguay and Argentina. In the Brazilian State of Rio Grande do Sul, this commonly found species is a target of intense exploitation, because of its ornamental characteristics. The in vitro culture is an important tool for propagation which may contribute toward the reduction of extractivism. However, exogenous contamination of spores is an obstacle for the success of aseptic long-term cultures. This study evaluated the influence of different sterilization methods combined with storage conditions on the contamination of the in vitro cultures and the gametophytic development of C. atrovirens, in order to establish an efficient propagation protocol. Spores were obtained from plants collected in Novo Hamburgo, State of Rio Grande do Sul, Brazil. In the first experiment, spores stored at 7 degrees C were surface sterilized with 0.5, 0.8 and 2% of sodium hypochlorite (NaClO) for 15 minutes and sown in Meyer's culture medium. The cultures were maintained in a growth room at 26 +/- 1 degrees C for a 12-h photoperiod and photon flux density of 100 micromol/m2/s provided by cool white fluorescent light. Contamination was assessed at 60 days, and gametophytic development was scored at 30, 60, 120 and 130 days of in vitro culture, analyzing 300 individuals for each treatment. There was no significant difference in culture contamination among the different sodium hypochlorite concentrations tested, and all treatments allowed for the development of cordiform gametophytes at 130 days of culture. In the second experiment, spores stored at 7 and -20 degrees C were divided into two groups. Half of the spores were surface sterilized with 2% of NaClO for 15 minutes and the other half was not sterilized. All spores were sown in Meyer's medium supplemented with one of the following antibiotics: nystatin, Micostatin and actidione. The culture conditions and the procedures used for evaluating contamination and

Identification and characterization of a spore-like morphotype in chronically starved Mycobacterium avium subsp. paratuberculosis cultures.

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Elise A Lamont

Full Text Available Mycobacteria are able to enter into a state of non-replication or dormancy, which may result in their chronic persistence in soil, aquatic environments, and permissive hosts. Stresses such as nutrient deprivation and hypoxia provide environmental cues to enter a persistent state; however, a clear definition of the mechanism that mycobacteria employ to achieve this remains elusive. While the concept of sporulation in mycobacteria is not novel, it continues to spark controversy and challenges our perceptions of a non-replication. We investigated the potential role of sporulation in one-year old broth cultures of Mycobacterium subsp. paratuberculosis (MAP. We show that dormant cultures of MAP contain a mix of vegetative cells and a previously unknown morphotype resembling a spore. These spore-like structures can be enriched for using sporulating media. Furthermore, purified MAP spore forms survive exposure to heat, lysozyme and proteinase K. Heat-treated spores are positive for MAP 16SrRNA and IS900. MAP spores display enhanced infectivity as well as maintain acid-fast characteristics upon germination in a well-established bovine macrophage model. This is the first study to demonstrate a new MAP morphotype possessing spore-like qualities. Data suggest that sporulation may be a viable mechanism by which MAP accomplishes persistence in the host and/or environment. Thus, our current understanding of mycobacterial persistence, pathogenesis, epidemiology and rational drug and vaccine design may need to be reevaluated.

Dynamics of Spore Coat Morphogenesis in Bacillus subtilis

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McKenney, Peter T.; Eichenberger, Patrick

2011-01-01

SUMMARY Spores of Bacillus subtilis are encased in a protective coat made up of at least 70 proteins. The structure of the spore coat has been examined using a variety of genetic, imaging and biochemical techniques, however, the majority of these studies have focused on mature spores. In this study we use a library of 41 spore coat proteins fused to the Green Fluorescent Protein (GFP) to examine spore coat morphogenesis over the time-course of sporulation. We found considerable diversity in the localization dynamics of coat proteins and were able to establish 6 classes based on localization kinetics. Localization dynamics correlate well with the known transcriptional regulators of coat gene expression. Previously, we described the existence of multiple layers in the mature spore coat. Here, we find that the spore coat initially assembles a scaffold that is organized into multiple layers on one pole of the spore. The coat then encases the spore in multiple coordinated waves. Encasement is driven, at least partially, by transcription of coat genes and deletion of sporulation transcription factors arrests encasement. We also identify the trans-compartment SpoIIIAH-SpoIIQ channel as necessary for encasement. This is the first demonstration of a forespore contribution to spore coat morphogenesis. PMID:22171814

Reduced spore germination explains sensitivity of reef-building algae to climate change stressors.

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Alexandra Ordoñez

Full Text Available Reduced seawater pH and changes in carbonate chemistry associated with ocean acidification (OA decrease the recruitment of crustose coralline algae (CCAcf., an important coral-reef builder. However, it is unclear whether the observed decline in recruitment is driven by impairment of spore germination, or post-settlement processes (e.g. space competition. To address this, we conducted an experiment using a dominant CCA, Porolithon cf. onkodes to test the independent and combined effects of OA, warming, and irradiance on its germination success and early development. Elevated CO2 negatively affected several processes of spore germination, including formation of the germination disc, initial growth, and germling survival. The magnitude of these effects varied depending on the levels of temperature and irradiance. For example, the combination of high CO2 and high temperature reduced formation of the germination disc, but this effect was independent of irradiance levels, while spore abnormalities increased under high CO2 and high temperature particularly in combination with low irradiance intensity. This study demonstrates that spore germination of CCA is impacted by the independent and interactive effects of OA, increasing seawater temperature and irradiance intensity. For the first time, this provides a mechanism for how the sensitivity of critical early life history processes to global change may drive declines of adult populations of key marine calcifiers.

Genotoxic action of sunlight upon Bacillus subtilis spores: monitoring studies at Tokyo, Japan.

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Munakata, N

1989-12-01

Samples of Bacillus subtilis spores dried on membrane filter were exposed to natural sunlight from solar-noon time at Tokyo. The survival and mutation induction of wild-type (UVR) and repair-deficient (UVS) spores were determined on 66 occasions since 1979. Two of the values were considered to be useful in monitoring solar UV intensity; the inverse of the time (in minutes) of exposure to kill 63% of the UVS spores ("sporocidal index") and the induced mutation frequency at 60 minutes of exposure of the UVR spores ("mutagenic index"). Both values were varied greatly due to time of a year, weather and other conditions. Estimates of year-round changes under clear skies were obtained by connecting the maximum values attained in these years. In these curves, there are more than 7-fold differences in the genotoxicity between winter and summer months, with major increases observed in early spring and decreases through autumn. Using a series of UV cut-off filters, the wavelengths most effective for the sporocidal actions were estimated to be in the range of 308-325 nm, shorter wavelengths being effective when the genotoxicity was higher. Sunburn meter of Robertson-Berger type seems to respond to slightly longer wavelength components of the solar spectrum. However, a reasonable correlation was obtained between the reading of the meter and the sporocidal index.

A continental view of pine-associated ectomycorrhizal fungal spore banks: a quiescent functional guild with a strong biogeographic pattern.

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Glassman, Sydney I; Peay, Kabir G; Talbot, Jennifer M; Smith, Dylan P; Chung, Judy A; Taylor, John W; Vilgalys, Rytas; Bruns, Thomas D

2015-03-01

Ecologists have long acknowledged the importance of seed banks; yet, despite the fact that many plants rely on mycorrhizal fungi for survival and growth, the structure of ectomycorrhizal (ECM) fungal spore banks remains poorly understood. The primary goal of this study was to assess the geographic structure in pine-associated ECM fungal spore banks across the North American continent. Soils were collected from 19 plots in forests across North America. Fresh soils were pyrosequenced for fungal internal transcribed spacer (ITS) amplicons. Adjacent soil cores were dried and bioassayed with pine seedlings, and colonized roots were pyrosequenced to detect resistant propagules of ECM fungi. The results showed that ECM spore banks correlated strongly with biogeographic location, but not with the identity of congeneric plant hosts. Minimal community overlap was found between resident ECM fungi vs those in spore banks, and spore bank assemblages were relatively simple and dominated by Rhizopogon, Wilcoxina, Cenococcum, Thelephora, Tuber, Laccaria and Suillus. Similar to plant seed banks, ECM fungal spore banks are, in general, depauperate, and represent a small and rare subset of the mature forest soil fungal community. Yet, they may be extremely important in fungal colonization after large-scale disturbances such as clear cuts and forest fires. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

The influence of sporulation conditions on the spore coat protein composition of Bacillus subtilis spores.

OpenAIRE

Wishwas R. Abhyankar; Wishwas R. Abhyankar; Kiki Kamphorst; Bhagyashree N. Swarge; Bhagyashree N. Swarge; Henk van Veen; Nicole N. van der Wel; Stanley Brul; Chris G. de Koster; Leo J. de Koning

2016-01-01

Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for t...

The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores

OpenAIRE

Abhyankar, Wishwas R.; Kamphorst, Kiki; Swarge, Bhagyashree N.; van Veen, Henk; van der Wel, Nicole N.; Brul, Stanley; de Koster, Chris G.; de Koning, Leo J.

2016-01-01

Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for t...

Spores of most common airborne fungi reveal no ice nucleation activity

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Pummer, B. G.; Atanasova, L.; Bauer, H.; Bernardi, J.; Druzhinina, I. S.; Grothe, H.

2013-06-01

Fungal spores are ubiquitous biological aerosols, which are considered to show ice nucleation (IN) activity. In this study the respective IN activity was tested in oil emulsion in the immersion freezing mode. The focus was laid on species of economical, ecological or sanitary significance. For the first time, not only common moulds, but also edible mushrooms (Basidiomycota, Agaricomycetes) were investigated, as they contribute massively to the total amount of fungal spores in the atmosphere. Only Fusarium avenaceum showed freezing events at low subzero-temperatures, while the other investigated fungal spores showed no significant IN activity. Furthermore, we selected a set of fungal strains from different sites and exposed them to occasional freezing stress during cultivation. Although the total protein expression was altered by this treatment, it had no significant impact on the IN activity.

Dynamic phase microscopy, a new method to detect viable and killed spores and to estimate the heterogeneity of spore populations

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Tychinsky, Vladimir P.; Mulyukin, Andrey L.; Lisovskii, Vitalii V.; Nikolaev, Yury A.; Kretushev, Aleksander V.; Vyshenskaya, Tatyana V.; Suzina, Nataliya E.; Duda, Vitalii I.; El-Registan, Galina I.

One of the challenging tasks in monitoring studies is to estimate heterogeneity of microbial populations by the physiological state and potential viability of individual cells, especially with regard of their ability to withstand various environmental assaults. Previously, we described some approaches based on electron microscopy methods to discriminate vegetative, dormant, and dead cells in both aged microbial cultures and environmental samples, including permafrost. We propose to extend the arsenal of microscopy methods for monitoring studies by a new non-invasive and informative method - dynamic phase microscopy (DPM). The substantial advantage of DPM is that it gives quantitative (digitized) data of undestroyed (living) microscopic objects, exemplified in our work by Bacillus licheniformis spores. Using DPM made it possible to record interference images of objects (spores) and to produce picture of their "phase thickness" (PT) that is the optical path difference in nm. Thus, it was demonstrated the remarkable difference in the PT of spores at different physiological states: dormant, germinating, and heat-killed spores had PT values of 80, 40-50, and 20 nm, respectively. The other found criterion to distinguish between spores was the PT fluctuations. In contrast to dormant and killed spores, the PT of germinating spores oscillated with amplitude of up to 7 nm, with typical frequencies of 1.3 and 3.4 Hz. A combination of the recorded PT values and PT fluctuations gave a key to detect viable and dead cells. Under the conditions that did not support germination (the lack of nutrients), we were able to follow the response of a single dormant spore and a spore population to heating from 25 °C to 70 °C. Thus, a very small temperature change (from 40 °C to 42 °C) under conditions non-favorable for germination, caused a drastic decrease in the spores' PT; the second drop in the PT values was observed during heating from 60 °C to 70 °C. These changes were

Spore coat protein synthesis in cell-free systems from sporulating cells of Bacillus subtilis.

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Nakayama, T; Munoz, L E; Sadaie, Y; Doi, R H

1978-09-01

Cell-free systems for protein synthesis were prepared from Bacillus subtilis 168 cells at several stages of sporulation. Immunological methods were used to determine whether spore coat protein could be synthesized in the cell-free systems prepared from sporulating cells. Spore coat protein synthesis first occurred in extracts from stage t2 cells. The proportion of spore coat protein to total proteins synthesized in the cell-free systems was 2.4 and 3.9% at stages t2 and t4, respectively. The sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis patterns of immunoprecipitates from the cell-free systems showed the complete synthesis of an apparent spore coat protein precursor (molecular weight, 25,000). A polypeptide of this weight was previously identified in studies in vivo (L.E. Munoz, Y. Sadaie, and R.H. Doi, J. Biol. Chem., in press). The synthesis in vitro of polysome-associated nascent spore coat polypeptides with varying molecular weights up to 23,000 was also detected. These results indicate that the spore coat protein may be synthesized as a precursor protein. The removal of proteases in the crude extracts by treatment with hemoglobin-Sepharose affinity techniques may be preventing the conversion of the large 25,000-dalton precursor to the 12,500-dalton mature spore coat protein.

Sphagnum moss disperses spores with vortex rings.

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Whitaker, Dwight L; Edwards, Joan

2010-07-23

Sphagnum spores, which have low terminal velocities, are carried by turbulent wind currents to establish colonies many kilometers away. However, spores that are easily kept aloft are also rapidly decelerated in still air; thus, dispersal range depends strongly on release height. Vascular plants grow tall to lift spores into sufficient wind currents for dispersal, but nonvascular plants such as Sphagnum cannot grow sufficiently high. High-speed videos show that exploding capsules of Sphagnum generate vortex rings to efficiently carry spores high enough to be dispersed by turbulent air currents. Spores launched ballistically at similar speeds through still air would travel a few millimeters and not easily reach turbulent air. Vortex rings are used by animals; here, we report vortex rings generated by plants.

In vitro propagation of Cyathea atrovirens (Cyatheaceae: spore storage and sterilization conditions

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Isabel Beatriz de Vargas

2014-03-01

Full Text Available Cyathea atrovirens occurs in a wide range of habitats in Brazil, Paraguay, Uruguay and Argentina. In the Brazilian State of Rio Grande do Sul, this commonly found species is a target of intense exploitation, because of its ornamental characteristics. The in vitro cultura is an important tool for propagation which may contribute toward the reduction of extractivism. However, exogenous contamination of spores is an obstacle for the success of aseptic long-term cultures. This study evaluated the influence of different sterilization methods combined with storage conditions on the contamination of the in vitro cultures and the gametophytic development of C. atrovirens, in order to establish an efficient propagation protocol. Spores were obtained from plants collected in Novo Hamburgo, State of Rio Grande do Sul, Brazil. In the first experiment, spores stored at 7oC were surface sterilized with 0.5, 0.8 and 2% of sodium hypochlorite (NaClO for 15 minutes and sown in Meyer’s culture medium. The cultures were maintained in a growth room at 26±1ºC for a 12-h photoperiod and photon flux density of 100μmol/m²/s provided by cool white fluorescent light. Contamination was assessed at 60 days, and gametophytic development was scored at 30, 60, 120 and 130 days of in vitro culture, analyzing 300 individuals for each treatment. There was no significant difference in culture contamination among the different sodium hypochlorite concentrations tested, and all treatments allowed for the development of cordiform gametophytes at 130 days of culture. In the second experiment, spores stored at 7 and -20°C were divided into two groups. Half of the spores were surface sterilized with 2% of NaClO for 15 minutes and the other half was not sterilized. All spores were sown in Meyer’s medium supplemented with one of the following antibiotics: nystatin, Micostatin® and actidione. The culture conditions and the procedures used for evaluating contamination and

Efficiency of peracetic acid in inactivating bacteria, viruses, and spores in water determined with ATP bioluminescence, quantitative PCR, and culture-based methods.

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Park, Eunyoung; Lee, Cheonghoon; Bisesi, Michael; Lee, Jiyoung

2014-03-01

The disinfection efficiency of peracetic acid (PAA) was investigated on three microbial types using three different methods (filtration-based ATP (adenosine-triphosphate) bioluminescence, quantitative polymerase chain reaction (qPCR), culture-based method). Fecal indicator bacteria (Enterococcus faecium), virus indicator (male-specific (F(+)) coliphages (coliphages)), and protozoa disinfection surrogate (Bacillus subtilis spores (spores)) were tested. The mode of action for spore disinfection was visualized using scanning electron microscopy. The results indicated that PAA concentrations of 5 ppm (contact time: 5 min), 50 ppm (10 min), and 3,000 ppm (5 min) were needed to achieve 3-log reduction of E. faecium, coliphages, and spores, respectively. Scanning electron microscopy observation showed that PAA targets the external layers of spores. The lower reduction rates of tested microbes measured with qPCR suggest that qPCR may overestimate the surviving microbes. Collectively, PAA showed broad disinfection efficiency (susceptibility: E. faecium > coliphages > spores). For E. faecium and spores, ATP bioluminescence was substantially faster (∼5 min) than culture-based method (>24 h) and qPCR (2-3 h). This study suggests PAA as an effective alternative to inactivate broad types of microbial contaminants in water. Together with the use of rapid detection methods, this approach can be useful for urgent situations when timely response is needed for ensuring water quality.

Biofilm formation and sporulation by Bacillus cereus on a stainless steel surface and subsequent resistance of vegetative cells and spores to chlorine, chlorine dioxide, and a peroxyacetic acid-based sanitizer.

Science.gov (United States)

Ryu, Jee-Hoon; Beuchat, Larry R

2005-12-01

Biofilm formation by Bacillus cereus 038-2 on stainless steel coupons, sporulation in the biofilm as affected by nutrient availability, temperature, and relative humidity, and the resistance of vegetative cells and spores in biofilm to sanitizers were investigated. Total counts in biofilm formed on coupons immersed in tryptic soy broth (TSB) at 12 and 22 degrees C consisted of 99.94% of vegetative cells and 0.06% of spores. Coupons on which biofilm had formed were immersed in TSB or exposed to air with 100, 97, 93, or 85% relative humidity. Biofilm on coupons immersed in TSB at 12 degrees C for an additional 6 days or 22 degrees C for an additional 4 days contained 0.30 and 0.02% of spores, respectively, whereas biofilm exposed to air with 100 or 97% relative humidity at 22 degrees C for 4 days contained 10 and 2.5% of spores, respectively. Sporulation did not occur in biofilm exposed to 93 or 85% relative humidity at 22 degrees C. Treatment of biofilm on coupons that had been immersed in TSB at 22 degrees C with chlorine (50 microg/ml), chlorine dioxide (50 microg/ml), and a peroxyacetic acid-based sanitizer (Tsunami 200, 40 microg/ml) for 5 min reduced total cell counts (vegetative cells plus spores) by 4.7, 3.0, and 3.8 log CFU per coupon, respectively; total cell counts in biofilm exposed to air with 100% relative humidity were reduced by 1.5, 2.4, and 1.1 log CFU per coupon, respectively, reflecting the presence of lower numbers of vegetative cells. Spores that survived treatment with chlorine dioxide had reduced resistance to heat. It is concluded that exposure of biofilm formed by B. cereus exposed to air at high relative humidity (> or =97%) promotes the production of spores. Spores and, to a lesser extent, vegetative cells embedded in biofilm are protected against inactivation by sanitizers. Results provide new insights to developing strategies to achieve more effective sanitation programs to minimize risks associated with B. cereus in biofilm formed on

Adaptation of the spore discharge mechanism in the basidiomycota.

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Jessica L Stolze-Rybczynski

Full Text Available Spore discharge in the majority of the 30,000 described species of Basidiomycota is powered by the rapid motion of a fluid droplet, called Buller's drop, over the spore surface. In basidiomycete yeasts, and phytopathogenic rusts and smuts, spores are discharged directly into the airflow around the fungal colony. Maximum discharge distances of 1-2 mm have been reported for these fungi. In mushroom-forming species, however, spores are propelled over much shorter ranges. In gilled mushrooms, for example, discharge distances of <0.1 mm ensure that spores do not collide with opposing gill surfaces. The way in which the range of the mechanism is controlled has not been studied previously.In this study, we report high-speed video analysis of spore discharge in selected basidiomycetes ranging from yeasts to wood-decay fungi with poroid fruiting bodies. Analysis of these video data and mathematical modeling show that discharge distance is determined by both spore size and the size of the Buller's drop. Furthermore, because the size of Buller's drop is controlled by spore shape, these experiments suggest that seemingly minor changes in spore morphology exert major effects upon discharge distance.This biomechanical analysis of spore discharge mechanisms in mushroom-forming fungi and their relatives is the first of its kind and provides a novel view of the incredible variety of spore morphology that has been catalogued by traditional taxonomists for more than 200 years. Rather than representing non-selected variations in micromorphology, the new experiments show that changes in spore architecture have adaptive significance because they control the distance that the spores are shot through air. For this reason, evolutionary modifications to fruiting body architecture, including changes in gill separation and tube diameter in mushrooms, must be tightly linked to alterations in spore morphology.

Responses to accelerated heavy ions of spores of Bacillus subtilis of different repair capacity

International Nuclear Information System (INIS)

Baltschukat, K.; Horneck, G.

1991-01-01

Inactivation, mutagenesis of histidine reversion and the involvement of DNA repair were studied in spores of Bacillus subtilis irradiated with heavy ions at LBL, Berkeley and GSI, Darmstadt. Five groups of ions (from boron to uranium) were used with residual energies from 0.2 MeV/u up to 18.6 MeV/u; in addition, carbon ions were used with a residual energy of 120 MeV/u. Action cross sections of both inactivation and mutagenesis show a similar dependence on ion mass and energy: For lighter ions (Z≤10), the lethal response is nearly energy independent (Z=10) or decreasing with energy (Z≤6); these light ions, up to 18.6 MeV/u, induce hardly any mutations. For heavier ions (Z≥26), the lethal as well as the mutagenic responses increase with ion mass and energy up to a maximum or saturation. The efficiency of DNA repair to improve survival and the mutagenic efficiency per lethal event, both, increase with ion energy up to a saturation value which, depending on strain and endpoint, either roughtly coincides with the X-ray value or is smaller than that after X-ray treatment. For repair based on recombination events, the increase in the survival effects with ion energy is more pronounced than for that based on repair replication. At energies of 1 MeV/u or below, neither DNA repair nor mutation induction appear to be significant. The results support previous suggestions on the importance of the radial distribution of the energy around the ion track in biological action cross section and the evidence that the entire core of the spore represents the sensitive site in responses to heavy ions. (orig.)

The Role of Aquaporins in pH-Dependent Germination of Rhizopus delemar Spores.

Directory of Open Access Journals (Sweden)

Tidhar Turgeman

Full Text Available Rhizopus delemar and associated species attack a wide range of fruit and vegetables after harvest. Host nutrients and acidic pH are required for optimal germination of R. delemar, and we studied how this process is triggered. Glucose induced spore swelling in an acidic environment, expressed by an up to 3-fold increase in spore diameter, whereas spore diameter was smaller in a neutral environment. When suspended in an acidic environment, the spores started to float, indicating a change in their density. Treatment of the spores with HgCl2, an aquaporin blocker, prevented floating and inhibited spore swelling and germ-tube emergence, indicating the importance of water uptake at the early stages of germination. Two putative candidate aquaporin-encoding genes-RdAQP1 and RdAQP2-were identified in the R. delemar genome. Both presented the conserved NPA motif and six-transmembrane domain topology. Expressing RdAQP1 and RdAQP2 in Arabidopsis protoplasts increased the cells' osmotic water permeability coefficient (Pf compared to controls, indicating their role as water channels. A decrease in R. delemar aquaporin activity with increasing external pH suggested pH regulation of these proteins. Substitution of two histidine (His residues, positioned on two loops facing the outer side of the cell, with alanine eliminated the pH sensing resulting in similar Pf values under acidic and basic conditions. Since hydration is critical for spore switching from the resting to activate state, we suggest that pH regulation of the aquaporins can regulate the initial phase of R. delemar spore germination, followed by germ-tube elongation and host-tissue infection.

The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores

NARCIS (Netherlands)

Abhyankar, Wishwas R.; Kamphorst, Kiki; Swarge, Bhagyashree N.; van Veen, Henk; van der Wel, Nicole N.; Brul, Stanley; de Koster, Chris G.; de Koning, Leo J.

2016-01-01

Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has

The effects of meteorological factors on airborne fungal spore concentration in two areas differing in urbanisation level

Science.gov (United States)

Oliveira, M.; Ribeiro, H.; Delgado, J. L.; Abreu, I.

2009-01-01

Although fungal spores are an ever-present component of the atmosphere throughout the year, their concentration oscillates widely. This work aims to establish correlations between fungal spore concentrations in Porto and Amares and meteorological data. The seasonal distribution of fungal spores was studied continuously (2005-2007) using volumetric spore traps. To determine the effect of meteorological factors (temperature, relative humidity and rainfall) on spore concentration, the Spearman rank correlation test was used. In both locations, the most abundant fungal spores were Cladosporium, Agaricus, Agrocybe, Alternaria and Aspergillus/Penicillium, the highest concentrations being found during summer and autumn. In the present study, with the exception of Coprinus and Pleospora, spore concentrations were higher in the rural area than in the urban location. Among the selected spore types, spring-autumn spores ( Coprinus, Didymella, Leptosphaeria and Pleospora) exhibited negative correlations with temperature and positive correlations both with relative humidity and rainfall level. On the contrary, late spring-early summer (Smuts) and summer spores ( Alternaria, Cladosporium, Epicoccum, Ganoderma, Stemphylium and Ustilago) exhibited positive correlations with temperature and negative correlations both with relative humidity and rainfall level. Rust, a frequent spore type during summer, had a positive correlation with temperature. Aspergillus/Penicillium, showed no correlation with the meteorological factors analysed. This knowledge can be useful for agriculture, allowing more efficient and reliable application of pesticides, and for human health, by improving the diagnosis and treatment of respiratory allergic disease.

Elastic and inelastic light scattering from single bacterial spores in an optical trap allows the monitoring of spore germination dynamics

Science.gov (United States)

Peng, Lixin; Chen, De; Setlow, Peter; Li, Yong-qing

2009-01-01

Raman scattering spectroscopy and elastic light scattering intensity (ESLI) were used to simultaneously measure levels of Ca-dipicolinic acid (CaDPA) and changes in spore morphology and refractive index during germination of individual B. subtilis spores with and without the two redundant enzymes (CLEs), CwlJ and SleB, that degrade spores’ peptidoglycan cortex. Conclusions from these measurements include: 1) CaDPA release from individual wild-type germinating spores was biphasic; in a first heterogeneous slow phase, Tlag, CaDPA levels decreased ∼15% and in the second phase ending at Trelease, remaining CaDPA was released rapidly; 2) in L-alanine germination of wild-type spores and spores lacking SleB: a) the ESLI rose ∼2-fold shortly before Tlag at T1; b) following Tlag, the ESLI again rose ∼2-fold at T2 when CaDPA levels had decreased ∼50%; and c) the ESLI reached its maximum value at ∼Trelease and then decreased; 3) in CaDPA germination of wild-type spores: a) Tlag increased and the first increase in ESLI occurred well before Tlag, consistent with different pathways for CaDPA and L-alanine germination; b) at Trelease the ESLI again reached its maximum value; 4) in L-alanine germination of spores lacking both CLEs and unable to degrade their cortex, the time ΔTrelease (Trelease–Tlag) for excretion of ≥75% of CaDPA was ∼15-fold higher than that for wild-type or sleB spores; and 5) spores lacking only CwlJ exhibited a similar, but not identical ESLI pattern during L-alanine germination to that seen with cwlJ sleB spores, and the high value for ΔTrelease. PMID:19374431

β-1,6-glucan synthesis-associated genes are required for proper spore wall formation in Saccharomyces cerevisiae.

Science.gov (United States)

Pan, Hua-Ping; Wang, Ning; Tachikawa, Hiroyuki; Nakanishi, Hideki; Gao, Xiao-Dong

2017-11-01

The yeast spore wall is an excellent model to study the assembly of an extracellular macromolecule structure. In the present study, mutants defective in β-1,6-glucan synthesis, including kre1∆, kre6∆, kre9∆ and big1∆, were sporulated to analyse the effect of β-1,6-glucan defects on the spore wall. Except for kre6∆, these mutant spores were sensitive to treatment with ether, suggesting that the mutations perturb the integrity of the spore wall. Morphologically, the mutant spores were indistinguishable from wild-type spores. They lacked significant sporulation defects partly because the chitosan layer, which covers the glucan layer, compensated for the damage. The proof for this model was obtained from the effect of the additional deletion of CHS3 that resulted in the absence of the chitosan layer. Among the double mutants, the most severe spore wall deficiency was observed in big1∆ spores. The majority of the big1∆chs3∆ mutants failed to form visible spores at a higher temperature. Given that the big1∆ mutation caused a failure to attach a GPI-anchored reporter, Cwp2-GFP, to the spore wall, β-1,6-glucan is involved in tethering of GPI-anchored proteins in the spore wall as well as in the vegetative cell wall. Thus, β-1,6-glucan is required for proper organization of the spore wall. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

The radiation effects of aspergillus oryzae spores with soft x-rays near the K shell absorption edges of C, N, O elements from synchrotron radiation

International Nuclear Information System (INIS)

Chen Liang; Jiang Shiping; Wan Libiao; Ma Xiaodong; Li Meifang

2007-01-01

The dose deposition of different parts of Aspergillus oryzae spores were analyzed with soft X-ray energies near the K-shell absorption edges of C, N, O elements (4.4nm, 3.2nm and 2.3nm), respectively. At the same time, the spores were irradiated with the three wavelengths of soft X-rays on the soft X-ray microscopy from synchrotron radiation at NSRL, and the survivals were compared. The theoretical analyses showed that the deposition doses of different parts of the spore were varying with X-ray energies because of the effects of C, N, O K-shell absorption edges and elemental contents of the different parts of spore. The experimental studies proved three wavelengths of soft X-rays all had high killing abilities. Among these, 2.3nm wavelength X-rays had higher radiation damage to spore than that of 3.2nm, 4.4nm. (authors)

Investigation of Sterilization Mechanism for Geobacillus stearothermophilus Spores with Plasma-Excited Neutral Gas

Science.gov (United States)

Matsui, Kei; Ikenaga, Noriaki; Sakudo, Noriyuki

2015-09-01

We investigate the mechanism of the sterilization with plasma-excited neutral gas that uniformly sterilizes both the space and inner wall of the reactor chamber at atmospheric pressure. Only reactive neutral species such as plasma-excited gas molecules and radicals are separated from the plasma and sent to the reactor chamber for chemical sterilization. The plasma source gas uses humidified mixture of nitrogen and oxygen. Geobacillus stearothermophilus spores and tyrosine which is amino acid are treated by the plasma-excited neutral gas. Shape change of the treated spore is observed by SEM, and chemical modification of the treated tyrosine is analyzed by HPLC. As a result, the surface of the treated spore shows depression. Hydroxylation and nitration of tyrosine are shown after the treatment. For these reasons, we believe that the sterilization with plasma-excited neutral gas results from the deformation of spore structure due to the chemical modification of amino acid.

Protection of Bacillus pumilus spores by catalases.

Science.gov (United States)

Checinska, Aleksandra; Burbank, Malcolm; Paszczynski, Andrzej J

2012-09-01

Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present.

Ptaquiloside in bracken spores from Britain

DEFF Research Database (Denmark)

Rasmussen, Lars Holm; Schmidt, Bjørn; Sheffield, Elizabeth

2013-01-01

Secondary metabolites from bracken fern (Pteridium aquilinum (L.) Kuhn) are suspected of causing cancer in humans. The main carcinogen is the highly water-soluble norsesquiterpene glucoside ptaquiloside, which may be ingested by humans through food, e.g. via contaminated water, meat or milk. It has...... been postulated that carcinogens could also be ingested through breathing air containing bracken spores. Ptaquiloside has not previously been identified in bracken spores. The aim of the study was to determine whether ptaquiloside is present in bracken spores, and if so, to estimate its content...

Asynchronous spore germination in isogenic natural isolates of Saccharomyces paradoxus.

Science.gov (United States)

Stelkens, Rike B; Miller, Eric L; Greig, Duncan

2016-05-01

Spores from wild yeast isolates often show great variation in the size of colonies they produce, for largely unknown reasons. Here we measure the colonies produced from single spores from six different wild Saccharomyces paradoxus strains. We found remarkable variation in spore colony sizes, even among spores that were genetically identical. Different strains had different amounts of variation in spore colony sizes, and variation was not affected by the number of preceding meioses, or by spore maturation time. We used time-lapse photography to show that wild strains also have high variation in spore germination timing, providing a likely mechanism for the variation in spore colony sizes. When some spores from a laboratory strain make small colonies, or no colonies, it usually indicates a genetic or meiotic fault. Here, we demonstrate that in wild strains spore colony size variation is normal. We discuss and assess potential adaptive and non-adaptive explanations for this variation. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The Cooperative and Interdependent Roles of GerA, GerK, and Ynd in Germination of Bacillus licheniformis Spores.

Science.gov (United States)

Borch-Pedersen, Kristina; Lindbäck, Toril; Madslien, Elisabeth H; Kidd, Shani W; O'Sullivan, Kristin; Granum, Per Einar; Aspholm, Marina

2016-07-15

When nutrients are scarce, Bacillus species form metabolically dormant and extremely resistant spores that enable survival over long periods of time under conditions not permitting growth. The presence of specific nutrients triggers spore germination through interaction with germinant receptors located in the spore's inner membrane. Bacillus licheniformis is a biotechnologically important species, but it is also associated with food spoilage and food-borne disease. The B. licheniformis ATCC 14580/DSM13 genome exhibits three gerA family operons (gerA, gerK, and ynd) encoding germinant receptors. We show that spores of B. licheniformis germinate efficiently in response to a range of different single l-amino acid germinants, in addition to a weak germination response seen with d-glucose. Mutational analyses revealed that the GerA and Ynd germination receptors function cooperatively in triggering an efficient germination response with single l-amino acid germinants, whereas the GerK germination receptor is essential for germination with d-glucose. Mutant spores expressing only GerA and GerK or only Ynd and GerK show reduced or severely impaired germination responses, respectively, with single l-amino acid germinants. Neither GerA nor Ynd could function alone in stimulating spore germination. Together, these results functionally characterize the germination receptor operons present in B. licheniformis We demonstrate the overlapping germinant recognition patterns of the GerA and Ynd germination receptors and the cooperative functionalities between GerA, Ynd, and GerK in inducing germination. To ensure safe food production and durable foods, there is an obvious need for more knowledge on spore-forming bacteria. It is the process of spore germination that ultimately leads to food spoilage and food poisoning. Bacillus licheniformis is a biotechnologically important species that is also associated with food spoilage and food-borne disease. Despite its importance, the

Spore coat protein of Bacillus subtilis. Structure and precursor synthesis.

Science.gov (United States)

Munoz, L; Sadaie, Y; Doi, R H

1978-10-10

The coat protein of Bacillus subtilis spores comprises about 10% of the total dry weight of spores and 25% of the total spore protein. One protein with a molecular weight of 13,000 to 15,000 comprises a major portion of the spore coat. This mature spore coat protein has histidine at its NH2 terminus and is relatively rich in hydrophobic amino acids. Netropsin, and antibiotic which binds to A-T-rich regions of DNA and inhibits sporulation, but not growth, decreased the synthesis of this spore coat protein by 75%. A precursor spore coat protein with a molecular weight of 25,000 is made initially at t1 of sporulation and is converted to the mature spore coat protein with a molecular weight of 13,500 at t2 - t3. These data indicate that the spore coat protein gene is expressed very early in sporulation prior to the modifications of RNA polymerase which have been noted.

Inhibiting Inosine Hydrolase and Alanine Racemase to Enhance the Germination of Bacillus anthracis Sterne Spores: Potential Spore Decontamination Strategies

Science.gov (United States)

2015-06-19

decontamination strategies>> Maryline DEFEZ 1𔃼, Melissa HUNTER3J Susan WELKOS :~J Christopher COTE3 1 University Grenoble-Alpes, Grenoble, France. 1...inosine hydrolase and alanine racemase to enhance the germination of Bacillus anthracis Sterne spores potential spore decontamination strategies 5a...8217 • Accidentally in Humans • Natural reservoir is soil • Anthrax Disease Cycle: - animals infected by soilborne spores in food and water or bites from certain

Thermophilic spore-forming bacteria isolated from spoiled canned food and their heat resistance. Results of a French ten-year survey.

Science.gov (United States)

André, S; Zuber, F; Remize, F

2013-07-15

Thermal processing of Low Acid Canned Foods (LACF), which are safe and shelf-stable at ambient temperature for several years, results in heat inactivation of all vegetative microorganisms and the partial or total inactivation of spores. Good Manufacturing Hygienic Practices include stability tests for managing the pathogen risk related to surviving mesophilic bacterial spores. LACF are also often submitted to additional incubation conditions, typically 55 °C for 7 days, to monitor spoilage by thermophiles. In this study we identified the bacterial species responsible for non-stability after prolonged at 55 °C of incubation of LACF from 455 samples collected from 122 French canneries over 10 years. Bacteria were identified by microsequencing or a recent developed tool for group-specific PCR detection (SporeTraQ™). A single species was identified for 93% of examined samples. Three genera were responsible for more than 80% of all non-stability cases: mostly Moorella (36%) and Geobacillus (35%), and less frequently Thermoanaerobacterium (10%). The other most frequent bacterial genera identified were Bacillus, Thermoanaerobacter, Caldanaerobius, Anoxybacillus, Paenibacillus and Clostridium. Species frequency was dependent on food category, i.e. vegetables, ready-made meals containing meat, seafood or other recipes, products containing fatty duck, and related to the intensity of the thermal treatment applied in these food categories. The spore heat resistance parameters (D or δ and z values) from 36 strains isolated in this study were determined. Taken together, our results single out the species most suitable for use as indicators for thermal process settings. This extensively-documented survey of the species that cause non-stability at 55 °C in LACF will help canneries to improve the management of microbial contamination. Copyright © 2013 Elsevier B.V. All rights reserved.

Spore analysis and tetrad dissection of Schizosaccharomyces pombe

DEFF Research Database (Denmark)

Ekwall, Karl; Thon, Genevieve

2017-01-01

Here we describe the processing of Schizosaccharomyces pombe spores in batches (random spore analysis) or through tetrad dissections. Spores are usually prepared from matings between haploid strains (producing zygotic asci) or from sporulating diploids (producing azygotic asci). In random spore...

Dispersal of spores following a persistent random walk.

Science.gov (United States)

Bicout, D J; Sache, I

2003-03-01

A model of a persistent random walk is used to describe the transport and deposition of the spore dispersal process. In this model, the spore particle flies along straight line trajectories, with constant speed v, which are interrupted by scattering, originating from interaction of spores with the field and wind variations, which randomly change its direction. To characterize the spore dispersal gradients, we have derived analytical expressions of the deposition probability epsilon (r|v) of airborne spores as a function of the distance r from the spore source in an infinite free space and in a disk of radius R with an absorbing edge that mimics an agricultural field surrounded with fields of nonhost plants and bare land. It is found in the free space that epsilon (r|v) approximately e(-alphar/l), with alpha a function of l(d)/l, where l and l(d) are the scattering and deposition mean free paths, respectively. In the disk, however, epsilon (r|v) is an infinite series of Bessel functions and, exhibits three regimes: absorbing (Rl(d)).

Fifth international fungus spore conference. [Abstracts]: Final technical report

Energy Technology Data Exchange (ETDEWEB)

Timberlake, W.E.

1993-04-01

This folio contains the proceedings of the Fifth International Fungal Spore Conference held August 17-21, 1991 at the Unicoi State Park at Helen, Georgia. The volume contains abstracts of each oral presentation as well as a collection of abstracts describing the poster sessions. Presentations were organized around the themes (1) Induction of Sporulation, (2) Nuclear Division, (3) Spore Formation, (4) Spore Release and Dispersal, and (4) Spore Germination.

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.

DNA repair in ultraviolet-irradiated spores of Bacillus subtilis

International Nuclear Information System (INIS)

Wang, T.C.V.

1976-01-01

It has been shown previously by others that at least two independent repair mechanisms are present in Bacillus subtilis for removing ''spore photoproduct'' from DNA of ultraviolet (254 nm)-irradiated spores after germination. One of these, designated as ''spore repair,'' is shown in this study to restore ''spore photoproduct'' to two thymine residues, leaving the DNA backbone intact at the end of the process in vivo. The circumstances under which this repair can occur and some characteristics of its energy requirements have been clarified. The second repair process is identified as excision repair, which can excise both ''spore photoproduct'' from DNA of irradiated spores and cyclobutane-type pyrimidine dimers from DNA of irradiated vegetative cells. In this study it is shown that the gene hcr 1 affects an enzyme activity for the incision step initiating this repair, while the gene hcr 42 affects a step subsequent to incision in the mechanism. In addition a third, independent repair system, termed ''germinative excision repair,'' is discovered and shown to be specific for excising only cyclobutane-type pyrimidine dimers but not ''spore photoproduct.'' This repair system is responsible for the observed high ultraviolet-resistance and temporary capacity for host cell reactivation on recently germinated spores of Bacillus subtilis HCR - strains

The Role of the Electrostatic Force in Spore Adhesion

Energy Technology Data Exchange (ETDEWEB)

Chung, Eunhyea [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Lee, Ida [University of Tennessee, Knoxville (UTK); Tsouris, Costas [ORNL

2010-01-01

Electrostatic force is investigated as one of the components of the adhesion force between Bacillus thuringiensis (Bt) spores and planar surfaces. The surface potentials of a Bt spore and a mica surface are experimentally obtained using a combined atomic force microscopy (AFM)-scanning surface potential microscopy technique. On the basis of experimental information, the surface charge density of the spores is estimated at 0.03 {micro}C/cm{sup 2} at 20% relative humidity and decreases with increasing humidity. The Coulombic force is introduced for the spore-mica system (both charged, nonconductive surfaces), and an electrostatic image force is introduced to the spore-gold system because gold is electrically conductive. The Coulombic force for spore-mica is repulsive because the components are similarly charged, while the image force for the spore-gold system is attractive. The magnitude of both forces decreases with increasing humidity. The electrostatic forces are added to other force components, e.g., van der Waals and capillary forces, to obtain the adhesion force for each system. The adhesion forces measured by AFM are compared to the estimated values. It is shown that the electrostatic (Coulombic and image) forces play a significant role in the adhesion force between spores and planar surfaces.

Poor survival of treatment-related acute nonlymphocytic leukemia

International Nuclear Information System (INIS)

Neugut, A.I.; Nieves, J.; Murray, T.; Tsai, Weiyann; Robinson, E.

1990-01-01

Population-based data on more than 1 million patients registered in the Surveillance, Epidemiology, and End-Results Program of the National Cancer Institute, 1973-1984, were analyzed to determine the survival of patients with de novo acute nonlymphocytic leukemia (ANLL) and following a first primary tumor treated (with chemotherapy and/or radiation therapy) or untreated. Cases that occurred within 12 months of the first malignant neoplasm were excluded. Survival was estimated using Cox proportional-hazards modeling, with age, sex, and specific type of ANLL as covariates. The 6,271 patients with de novo ANLL had an estimated 12-month survival of 30%, while the 107 patients with treatment-related ANLL had an estimated 12-month survival of 10%. The authors conclude that ANLL that occurs after chemotherapy or radiation therapy is biologically more aggressive and/or resistant to therapy than spontaneous ANLL. This provides a rationale for current studies on treatment-induced cellular changes and on more aggressive therapy for these patients

Decreased UV light resistance of spores of Bacillus subtilis strains deficient in pyrimidine dimer repair and small, acid-soluble spore proteins

International Nuclear Information System (INIS)

Setlow, B.; Setlow, P.

1988-01-01

Loss of small, acid-soluble spore protein alpha reduced spore UV resistance 30- to 50-fold in Bacillus subtilis strains deficient in pyrimidine dimer repair, but gave only a 5- to 8-fold reduction in UV resistance in repair-proficient strains. However, both repair-proficient and -deficient spores lacking this protein had identical heat and gamma-radiation resistance

Prognostic Factors, Treatment, and Survival in Dermatofibrosarcoma Protuberans.

Science.gov (United States)

Criscito, Maressa C; Martires, Kathryn J; Stein, Jennifer A

2016-12-01

There is limited information regarding the influence of patient demographics, tumor characteristics, and treatment type on the survival of patients with dermatofibrosarcoma protuberans (DFSP). To assess prognostic factors and to evaluate the influence of treatment modality on overall survival of patients with DFSP. We examined DFSP using data for 3686 patients with histologically confirmed cases of DFSP diagnosed between 1972 and 2012 from the 18 US regional registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program, with linkage to demographic data from the US Census Bureau for median household income (MHI). The analysis was performed in February 2016. The primary outcome measures were tumor characteristics, prognostic factors, and overall survival in months. There were 3686 cases of DFSP examined. Older age (hazard ratio [HR], 1.08; 95% CI, 1.06-1.10; P < .001), male sex (HR, 1.97; 95% CI, 1.09-3.55; P = .03), and tumor size (HR, 1.09; 95% CI, 1.01-1.18; P = .04) were significantly associated with poorer overall survival in a controlled analysis. Older age (odds ratio [OR], 1.01; 95% CI, 1.00-1.02; P = .01), male sex (OR, 1.95; 95% CI, 1.57-2.42; P < .001), and black race (OR, 1.78; 95% CI, 1.37-2.32; P < .001) were associated with larger (≥3.0 cm) tumors at presentation. Treatment modality did not influence overall survival; however, differences in patient characteristics affected the treatment received. Older age at presentation (OR, 1.02; 95% CI, 1.01-1.03; P =.01), black race (OR, 1.82; 95% CI, 1.13-2.92; P = .01), large tumor size (OR, 1.15; 95% CI, 1.09-1.21; P < .001), and head or neck location (OR, 4.63; 95% CI, 2.66-8.07; P <.001) increased the likelihood of a patient receiving surgery and radiation over surgery alone. In addition, white patients (OR, 0.51; 95% CI, 0.30-0.87; P=.01), women (OR, 0.53; 95% CI, 0.36-0.78; P <.001), and patients with a higher MHI (OR, 1.27; 95

Sporulation and germination gene expression analysis of Bacillus anthracis Sterne spores in skim milk under heat and different intervention techniques

Science.gov (United States)

To investigate how B. anthracis Stene spores survive in milk under heat (80 degree C, 10 minutes), pasteurization (72 degree C, 15 seconds) and pasteurization plus microfiltration, the expression levels of genes that related to sporulation and germination were tested using real-time PCR assays. Tw...

Radiobiological investigations of soft X-rays near carbon, nitrogen, oxygen K-shell edges on Aspergillus oryzae spores

International Nuclear Information System (INIS)

Chen, L.; Jiang, S. P.; Wan, L. B.; Ma, X. D.; Li, M. F.

2008-01-01

Soft X-rays at carbon, nitrogen, oxygen K-shell edges have special radiobiological effects. Using Aspergillus oryzae spores as sample, the radiation effects of soft X-rays near the K-shell edges of C, N and O elements from synchrotron radiation were investigated. Also the dose depositions of different X-ray energies in spore were discussed. At the same time, the spores were irradiated by gamma rays from 60 Co and relative biological effects were compared with those produced by soft X-rays. The results showed that soft X-rays near K-shell edges of O element had higher ability of radiation damage than that of X-rays near K-shell edges of C and N elements as compared with one another. But they all had higher killing abilities per unit dose than that of gamma rays from 60 Co. The relative biological effects (RBEs), the comparison of dose to gamma rays at 10% survival level, of the three soft X-rays were 1.65, 1.73 and 1.91, respectively. (authors)

Macroalgal spore dysfunction: ocean acidification delays and weakens adhesion.

Science.gov (United States)

Guenther, Rebecca; Miklasz, Kevin; Carrington, Emily; Martone, Patrick T

2018-04-01

Early life stages of marine organisms are predicted to be vulnerable to ocean acidification. For macroalgae, reproduction and population persistence rely on spores to settle, adhere and continue the algal life cycle, yet the effect of ocean acidification on this critical life stage has been largely overlooked. We explicitly tested the biomechanical impact of reduced pH on early spore adhesion. We developed a shear flume to examine the effect of reduced pH on spore attachment time and strength in two intertidal rhodophyte macroalgae, one calcified (Corallina vancouveriensis) and one noncalcified (Polyostea robusta). Reduced pH delayed spore attachment of both species by 40%-52% and weakened attachment strength in C. vancouveriensis, causing spores to dislodge at lower flow-induced shear forces, but had no effect on the attachment strength of P. robusta. Results are consistent with our prediction that reduced pH disrupts proper curing and gel formation of spore adhesives (anionic polysaccharides and glycoproteins) via protonation and cation displacement, although experimental verification is needed. Our results demonstrate that ocean acidification negatively, and differentially, impacts spore adhesion in two macroalgae. If results hold in field conditions, reduced ocean pH has the potential to impact macroalgal communities via spore dysfunction, regardless of the physiological tolerance of mature thalli. © 2017 Phycological Society of America.

A spore counting method and cell culture model for chlorine disinfection studies of Encephalitozoon syn. Septata intestinalis.

Science.gov (United States)

Wolk, D M; Johnson, C H; Rice, E W; Marshall, M M; Grahn, K F; Plummer, C B; Sterling, C R

2000-04-01

suggest that chlorine treatment may be an effective water treatment for E. intestinalis and that spectrophotometric methods may be substituted for labor-intensive hemacytometer methods when spores are counted in laboratory-based chlorine disinfection studies.

Elastic and inelastic light scattering from single bacterial spores in an optical trap allows the monitoring of spore germination dynamics

OpenAIRE

Peng, Lixin; Chen, De; Setlow, Peter; Li, Yong-qing

2009-01-01

Raman scattering spectroscopy and elastic light scattering intensity (ESLI) were used to simultaneously measure levels of Ca-dipicolinic acid (CaDPA) and changes in spore morphology and refractive index during germination of individual B. subtilis spores with and without the two redundant enzymes (CLEs), CwlJ and SleB, that degrade spores’ peptidoglycan cortex. Conclusions from these measurements include: 1) CaDPA release from individual wild-type germinating spores was biphasic; in a first h...

Audit in radiation therapy: long-term survival and cost of treatment

International Nuclear Information System (INIS)

Stevens, G.; Firth, I.

1997-01-01

In order to determine the cost of radiation treatment and the survival rate of a cohort of patients treated in a 6 month period in 1988, estimates of the capital and recurrent costs of this service were made for the calendar year 1988, expressed as $A(1988). Data collected prospectively included workload statistics (including number of attendances), field treated and complexity of treatment. Patient and tumour-related data included tumour site, intent of treatment and survival. The survival rate of patients during this period was determined in June 1995. The cost per field in 1988 was estimated at $A44.32. The 1988 costs of courses of definitive, adjuvant and palliative radiation therapy were estimated at $A2545, $A2482 and $A929, respectively. The major contributor to the cost of salaries and consumables within the Radiation Oncology Department (81.6%), with capital costs accounting for 13.5%, overheads accounting for 4.5% of the costs and planned admissions accounting for 0.2%. The median survival time of 580 patients with malignant disease treated during this period in 1988 was 12.4 months. The overall 5 year survival rate was 27%. For 105 patients treated definitively with radiation therapy, the median and 5 year survival rate figures were 26.0 months and 40%. For 149 patients treated with adjuvant radiation therapy, the 5 year survival rate was 62% (median survival rate not reached). For 279 patients treated palliatively, median and 5 year survival rate figures were 5.2 months and 3%. The cost per month of survival for all patients with malignancy was $A67; the figures for definitive , adjuvant and palliative treatments being $A74, $A48 and $A105, respectively. A sensitivity analysis indicated that these figures were robust. The cost of radiation treatment per field was comparable to reports for other centres and emphasizes the utility of radiation therapy as a cost-effective cancer treatment modality. 7 refs., 6 tabs., 2 figs

Atmospheric mold spore counts in relation to meteorological parameters

Science.gov (United States)

Katial, R. K.; Zhang, Yiming; Jones, Richard H.; Dyer, Philip D.

Fungal spore counts of Cladosporium, Alternaria, and Epicoccum were studied during 8 years in Denver, Colorado. Fungal spore counts were obtained daily during the pollinating season by a Rotorod sampler. Weather data were obtained from the National Climatic Data Center. Daily averages of temperature, relative humidity, daily precipitation, barometric pressure, and wind speed were studied. A time series analysis was performed on the data to mathematically model the spore counts in relation to weather parameters. Using SAS PROC ARIMA software, a regression analysis was performed, regressing the spore counts on the weather variables assuming an autoregressive moving average (ARMA) error structure. Cladosporium was found to be positively correlated (Pmodel was derived for Cladosporium spore counts using the annual seasonal cycle and significant weather variables. The model for Alternaria and Epicoccum incorporated the annual seasonal cycle. Fungal spore counts can be modeled by time series analysis and related to meteorological parameters controlling for seasonallity; this modeling can provide estimates of exposure to fungal aeroallergens.

A study of Ganoderma lucidum spores by FTIR microspectroscopy

Science.gov (United States)

Wang, Xin; Chen, Xianliang; Qi, Zeming; Liu, Xingcun; Li, Weizu; Wang, Shengyi

2012-06-01

In order to obtain unique information of Ganoderma lucidum spores, FTIR microspectroscopy was used to study G. lucidum spores from Anhui Province (A), Liaoning Province (B) and Shangdong Province (C) of China. IR micro-spectra were acquired with high-resolution and well-reproducibility. The IR spectra of G. lucidum spores from different areas were similar and mainly made up of the absorption bands of polysaccharide, sterols, proteins, fatty acids, etc. The results of curve fitting indicated the protein secondary structures were dissimilar among the above G. lucidum spores. To identify G. lucidum spores from different areas, the H1078/H1640 value might be a potentially useful factor, furthermore FTIR microspectroscopy could realize this identification efficiently with the help of hierarchical cluster analysis. The result indicates FTIR microspectroscopy is an efficient tool for identification of G. lucidum spores from different areas. The result also suggests FTIR microspectroscopy is a potentially useful tool for the study of TCM.

Inactivation of Bacillus anthracis spores by a combination of biocides and heating under high-temperature short-time pasteurization conditions.

Science.gov (United States)

Xu, Sa; Labuza, Theodore P; Diez-Gonzalez, Francisco

2008-06-01

The milk supply is considered a primary route for a bioterrorism attack with Bacillus anthracis spores because typical high-temperature short-time (HTST) pasteurization conditions cannot inactivate spores. In the event of intentional contamination, an effective method to inactivate the spores in milk under HTST processing conditions is needed. This study was undertaken to identify combinations and concentrations of biocides that can inactivate B. anthracis spores at temperatures in the HTST range in less than 1 min. Hydrogen peroxide (HP), sodium hypochlorite (SH), and peroxyacetic acid (PA) were evaluated for their efficacy in inactivating spores of strains 7702, ANR-1, and 9131 in milk at 72, 80, and 85 degrees C using a sealed capillary tube technique. Strains ANR-1 and 9131 were more resistant to all of the biocide treatments than strain 7702. Addition of 1,260 ppm SH to milk reduced the number of viable spores of each strain by 6 log CFU/ml in less than 90 and 60 s at 72 and 80 degrees C, respectively. After neutralization, 1,260 ppm SH reduced the time necessary to inactivate 6 log CFU/ml (TTI6-log) at 80 degrees C to less than 20 s. Treatment of milk with 7,000 ppm HP resulted in a similar level of inactivation in 60 s. Combined treatment with 1,260 ppm SH and 1,800 ppm HP inactivated spores of all strains in less than 20 s at 80 degrees C. Mixing 15 ppm PA with milk containing 1,260 ppm SH resulted in TTI6-log of 25 and 12 s at 72 and 80 degrees C, respectively. TTI6-log of less than 20 s were also achieved at 80 degrees C by using two combinations of biocides: 250 ppm SH, 700 ppm HP, and 150 ppm PA; and 420 ppm SH (pH 7), 1,100 ppm HP, and 15 ppm PA. These results indicated that different combinations of biocides could consistently result in 6-log reductions in the number of B. anthracis spores in less than 1 min at temperatures in the HTST range. This information could be useful for developing more effective thermal treatment strategies which could be

Validated modified Lycopodium spore method development for ...

African Journals Online (AJOL)

Validated modified lycopodium spore method has been developed for simple and rapid quantification of herbal powdered drugs. Lycopodium spore method was performed on ingredients of Shatavaryadi churna, an ayurvedic formulation used as immunomodulator, galactagogue, aphrodisiac and rejuvenator. Estimation of ...

Treatment Extends Survival for Women with Cervical Cancer

Science.gov (United States)

Patients with locally advanced cervical cancer who received gemcitabine (Gemzar®) both as part of initial treatment and as part of therapy following primary treatment had improved survival compared with patients whose treatment did not include gemcitabine, according to findings presented at the 2009 ASCO meeting in Orlando.

Fate of ingested Clostridium difficile spores in mice.

Directory of Open Access Journals (Sweden)

Amber Howerton

Full Text Available Clostridium difficile infection (CDI is a leading cause of antibiotic-associated diarrhea, a major nosocomial complication. The infective form of C. difficile is the spore, a dormant and resistant structure that forms under stress. Although spore germination is the first committed step in CDI onset, the temporal and spatial distribution of ingested C. difficile spores is not clearly understood. We recently reported that CamSA, a synthetic bile salt analog, inhibits C. difficile spore germination in vitro and in vivo. In this study, we took advantage of the anti-germination activity of bile salts to determine the fate of ingested C. difficile spores. We tested four different bile salts for efficacy in preventing CDI. Since CamSA was the only anti-germinant tested able to prevent signs of CDI, we characterized CamSa's in vitro stability, distribution, and cytotoxicity. We report that CamSA is stable to simulated gastrointestinal (GI environments, but will be degraded by members of the natural microbiota found in a healthy gut. Our data suggest that CamSA will not be systemically available, but instead will be localized to the GI tract. Since in vitro pharmacological parameters were acceptable, CamSA was used to probe the mouse model of CDI. By varying the timing of CamSA dosage, we estimated that C. difficile spores germinated and established infection less than 10 hours after ingestion. We also showed that ingested C. difficile spores rapidly transited through the GI tract and accumulated in the colon and cecum of CamSA-treated mice. From there, C. difficile spores were slowly shed over a 96-hour period. To our knowledge, this is the first report of using molecular probes to obtain disease progression information for C. difficile infection.

Small acid soluble proteins for rapid spore identification.

Energy Technology Data Exchange (ETDEWEB)

Branda, Steven S.; Lane, Todd W.; VanderNoot, Victoria A.; Jokerst, Amanda S.

2006-12-01

This one year LDRD addressed the problem of rapid characterization of bacterial spores such as those from the genus Bacillus, the group that contains pathogenic spores such as B. anthracis. In this effort we addressed the feasibility of using a proteomics based approach to spore characterization using a subset of conserved spore proteins known as the small acid soluble proteins or SASPs. We proposed developing techniques that built on our previous expertise in microseparations to rapidly characterize or identify spores. An alternative SASP extraction method was developed that was amenable to both the subsequent fluorescent labeling required for laser-induced fluorescence detection and the low ionic strength requirements for isoelectric focusing. For the microseparations, both capillary isoelectric focusing and chip gel electrophoresis were employed. A variety of methods were evaluated to improve the molecular weight resolution for the SASPs, which are in a molecular weight range that is not well resolved by the current methods. Isoelectric focusing was optimized and employed to resolve the SASPs using UV absorbance detection. Proteomic signatures of native wild type Bacillus spores and clones genetically engineered to produce altered SASP patterns were assessed by slab gel electrophoresis, capillary isoelectric focusing with absorbance detection as well as microchip based gel electrophoresis employing sensitive laser-induced fluorescence detection.

Parapiptadenia rigida MYCORRHIZATION WITH SPORES OF Scleroderma citrinum

Directory of Open Access Journals (Sweden)

Gerusa Pauli Kist Steffen

2017-06-01

Full Text Available Ectomycorrhizal fungal inoculation in forestry seedlings aids plant establishment and growth in the field. The objectives of this study were: to determine the mycorrhizal capacity of the ectomycorrhizal fungus Scleroderma citrinum in Parapiptadenia rigida (red angico seedlings and to evaluate the viability of a mycorrhizal inoculation technique for forest seedlings involving the use of spores. Mature spores were inoculated in the substrate (75% soil and 25% carbonized rice husk, totaling 1.5 grams of fungal spores per liter of substrate. P. rigida seeds were sown in substrates inoculated or not inoculated with fungal spores in presence or absence of Pinus echinata and Eucalyptus citriodora essential oil: not inoculated (T1, inoculated (T2, inoculated more pine essential oil (T3, inoculated more eucalyptus essential oil (T4. Seedlings of Pinus elliottii were used for a positive control of mycorrhizal inoculation (T5 and not inoculated (T6 with fungal spores. At 90 days after sowing, the base stem diameter, height, fresh and dry weight of shoots and roots, percentage of root colonization and Dickson Index were determined. The presence of fungal structures in P. rigida and P. elliottii roots inoculated with S. citrinum spores was observed, demonstrating the occurrence of an ectomycorrhizal association. The application of pine and eucalyptus essential oils in the substrate increased the percentage of ectomycorrhizal colonization in P. rigida seedlings. The addition of S. citrinum mature spores in the substrate used for seedling production is a viable practice for ectomycorrhizal inoculation and it can be used in forest nurseries in controlled mycorrhization programs.

Dothistroma septosporum: spore production and weather conditions

Energy Technology Data Exchange (ETDEWEB)

Dvorak, M.; Drapela, K.; Kankovsky, L.

2012-11-01

Dartmouth's septosporum, the causal agent of Dothistroma needle blight is a widespread fungus which infects more than 80 species of coniferous trees through the entire world. Spreading of the infection is strongly affected by climatic factors of each locality where it is recorded. We attempt to describe the concrete limiting climatic factors necessary for the releasing of conidia of D. septosporum and to find out the timing of its spore production within the year. For this purpose we used an automatic volumetric spore trap and an automatic meteorological station. We found that a minimum daily average temperature of 10 degree centigrade was necessary for any spore production, as well as a long period of high air humidity. The values obtained in the present study were a little bit higher than those previously published, which may arise questions about a possible changing trend of the behaviour in the development of the Dothistroma needle blight causal agent. We used autoregressive integrated moving average (ARIMA) models to predict the spore counts on the base of previous values of spore counts and dew point. For a locality from Hackerovka, the best ARIMA model was 1,0,0; and for a locality from Lanzhot, the best was 3,1,0. (Author) 19 refs.

Practical aspects of temperature intervention in germination and post-germination development of bacterial spores

International Nuclear Information System (INIS)

Stastna, J.; Vinter, V.; Babicka, J.

1974-01-01

Temperature dependence of germination and post-germination growth was studied in the spores of B a c i l l u s c e r e u s NCIB 8122. It was found that a temperature of 5 0 C slowed down germination, with the cells showing the capacity of synthetizing only a limited amount of proteins. The synthesis of the cellular wall, however, went on for another few hours. Thick-walled, less permeable and less metabolically active cells formed having an altered ultrastructure. A prolonged cultivation at 30 0 C resulted in the reduction of living cells while the low cultivation temperature (5 0 C) was found to have a protective effect. Pre-irradiation with 30g krad of gamma radiation increased the sensitivity of surviving cells to the cultivation conditions. Spores in the post-germination period were found to be much more resistent and alternating use of low and higher temperatures had little effect on growth

Decontamination Options for Drinking Water Contaminated with Bacillus anthracis Spores

Energy Technology Data Exchange (ETDEWEB)

Raber, E; Burklund, A

2010-02-16

Five parameters were evaluated with surrogates of Bacillus anthracis spores to determine effective decontamination options for use in a contaminated drinking water supply. The parameters were: (1) type of Bacillus spore surrogate (B. thuringiensis or B. atrophaeus); (2) spore concentration in suspension (10{sup 2} to 10{sup 6} spores/ml); (3) chemical characteristics of decontaminant [sodium dicholor-s-triazinetrione dihydrate (Dichlor), hydrogen peroxide, potassium peroxymonosulfate (Oxone), sodium hypochlorite, and VirkonS{reg_sign}]; (4) decontaminant concentration (0.01% to 5%); and (5) decontaminant exposure time (10 min to 24 hr). Results from 162 suspension tests with appropriate controls are reported. Hydrogen peroxide at a concentration of 5%, and Dichlor and sodium hypochlorite at a concentration of 2%, were effective at spore inactivation regardless of spore type tested, spore exposure time, or spore concentration evaluated. This is the first reported study of Dichlor as an effective decontaminant for B. anthracis spore surrogates. Dichlor's desirable characteristics of high oxidation potential, high level of free chlorine, and more neutral pH than that of other oxidizers evaluated appear to make it an excellent alternative. All three oxidizers were effective against B. atrophaeus spores in meeting EPA's biocide standard of greater than a 6 log kill after a 10-minute exposure time and at lower concentrations than typically reported for biocide use. Solutions of 5% VirkonS{reg_sign} and Oxone were less effective decontaminants than other options evaluated in this study and did not meet the EPA's efficacy standard for biocides. Differences in methods and procedures reported by other investigators make quantitative comparisons among studies difficult.

Detection of spore coat protein of Bacillus subtilis by immunological method

International Nuclear Information System (INIS)

Uchida, Aritsune; Kadota, Hajime

1976-01-01

The spore coat protein of Bacillus subtilis was separated, and the qualitative assay for the spore coat protein was made by use of the immunological technique. The immunological method was found to be useful for judging the maturation of spore coat in the course of sporulation. The spore coat protein antigen appeared at t 2 stage of sporulation. The addition of rifampicin at the earlier stages of sporulation inhibited the increase in content of the spore coat antigen. (auth.)

Mucorales spores induce a proinflammatory cytokine response in human mononuclear phagocytes and harbor no rodlet hydrophobins.

Science.gov (United States)

Wurster, Sebastian; Thielen, Vanessa; Weis, Philipp; Walther, Paul; Elias, Johannes; Waaga-Gasser, Ana Maria; Dragan, Mariola; Dandekar, Thomas; Einsele, Hermann; Löffler, Jürgen; Ullmann, Andrew J

2017-11-17

Mucormycoses are life-threatening infections in immunocompromised patients. This study characterizes the response of human mononuclear cells to different Mucorales and Ascomycota. PBMC, monocytes, and monocyte derived dendritic cells (moDCs) from healthy donors were stimulated with resting and germinated stages of Mucorales and Ascomycota. Cytokine response and expression of activation markers were studied. Both inactivated germ tubes and resting spores of Rhizopus arrhizus and other human pathogenic Mucorales species significantly stimulated mRNA synthesis and secretion of proinflammatory cytokines. Moreover, R. arrhizus spores induced the upregulation of co-stimulatory molecules on moDCs and a specific T-helper cell response. Removal of rodlet hydrophobins by hydrofluoric acid treatment of A. fumigatus conidia resulted in enhanced immunogenicity, whereas the cytokine response of PBMCs to dormant R. arrhizus spores was not influenced by hydrofluoric acid. Scanning electron micrographs of Mucorales spores did not exhibit any morphological correlates of rodlet hydrophobins. Taken together, this study revealed striking differences in the response of human mononuclear cells to resting stages of Ascomycota and Mucorales, which may be explained by absence of an immunoprotective hydrophobin layer in Mucorales spores.

Detection of Bacillus anthracis spores by super-paramagnetic lateral-flow immunoassays based on "Road Closure".

Science.gov (United States)

Wang, Dian-Bing; Tian, Bo; Zhang, Zhi-Ping; Wang, Xu-Ying; Fleming, Joy; Bi, Li-Jun; Yang, Rui-Fu; Zhang, Xian-En

2015-05-15

Detection of Bacillus anthracis in the field, whether as a natural infection or as a biothreat remains challenging. Here we have developed a new lateral-flow immunochromatographic assay (LFIA) for B. anthracis spore detection based on the fact that conjugates of B. anthracis spores and super-paramagnetic particles labeled with antibodies will block the pores of chromatographic strips and form retention lines on the strips, instead of the conventionally reported test lines and control lines in classic LFIA. As a result, this new LFIA can simultaneously realize optical, magnetic and naked-eye detection by analyzing signals from the retention lines. As few as 500-700 pure B. anthracis spores can be recognized with CV values less than 8.31% within 5 min of chromatography and a total time of 20 min. For powdery sample tests, this LFIA can endure interference from 25% (w/v) milk, 10% (w/v) baking soda and 10% (w/v) starch without any sample pre-treatment, and has a corresponding detection limit of 6×10(4) spores/g milk powder, 2×10(5) spores/g starch and 5×10(5) spores/g baking soda. Compared with existing methods, this new approach is very competitive in terms of sensitivity, specificity, cost and ease of operation. This proof-of-concept study can also be extended for detection of many other large-sized analytes. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Inactivation of Bacillus anthracis Spores by a Combination of Biocides and Heating under High-Temperature Short-Time Pasteurization Conditions ▿

Science.gov (United States)

Xu, Sa; Labuza, Theodore P.; Diez-Gonzalez, Francisco

2008-01-01

The milk supply is considered a primary route for a bioterrorism attack with Bacillus anthracis spores because typical high-temperature short-time (HTST) pasteurization conditions cannot inactivate spores. In the event of intentional contamination, an effective method to inactivate the spores in milk under HTST processing conditions is needed. This study was undertaken to identify combinations and concentrations of biocides that can inactivate B. anthracis spores at temperatures in the HTST range in less than 1 min. Hydrogen peroxide (HP), sodium hypochlorite (SH), and peroxyacetic acid (PA) were evaluated for their efficacy in inactivating spores of strains 7702, ANR-1, and 9131 in milk at 72, 80, and 85°C using a sealed capillary tube technique. Strains ANR-1 and 9131 were more resistant to all of the biocide treatments than strain 7702. Addition of 1,260 ppm SH to milk reduced the number of viable spores of each strain by 6 log CFU/ml in less than 90 and 60 s at 72 and 80°C, respectively. After neutralization, 1,260 ppm SH reduced the time necessary to inactivate 6 log CFU/ml (TTI6-log) at 80°C to less than 20 s. Treatment of milk with 7,000 ppm HP resulted in a similar level of inactivation in 60 s. Combined treatment with 1,260 ppm SH and 1,800 ppm HP inactivated spores of all strains in less than 20 s at 80°C. Mixing 15 ppm PA with milk containing 1,260 ppm SH resulted in TTI6-log of 25 and 12 s at 72 and 80°C, respectively. TTI6-log of less than 20 s were also achieved at 80°C by using two combinations of biocides: 250 ppm SH, 700 ppm HP, and 150 ppm PA; and 420 ppm SH (pH 7), 1,100 ppm HP, and 15 ppm PA. These results indicated that different combinations of biocides could consistently result in 6-log reductions in the number of B. anthracis spores in less than 1 min at temperatures in the HTST range. This information could be useful for developing more effective thermal treatment strategies which could be used in HTST milk plants to process

Meteorological factors associated with abundance of airborne fungal spores over natural vegetation

Science.gov (United States)

Crandall, Sharifa G.; Gilbert, Gregory S.

2017-08-01

The abundance of airborne fungal spores in agricultural and urban settings increases with greater air temperature, relative humidity, or precipitation. The same meteorological factors that affect temporal patterns in spore abundance in managed environments also vary spatially across natural habitats in association with differences in vegetation structure. Here we investigated how temporal and spatial variation in aerial spore abundance is affected by abiotic (weather) and biotic (vegetation) factors as a foundation for predicting how fungi may respond to changes in weather and land-use patterns. We measured the phenology of airborne fungal spores across a mosaic of naturally occurring vegetation types at different time scales to describe (1) how spore abundance changes over time, (2) which local meteorological variables are good predictors for airborne spore density, and (3) whether spore abundance differs across vegetation types. Using an air volumetric vacuum sampler, we collected spore samples at 3-h intervals over a 120-h period in a mixed-evergreen forest and coastal prairie to measure diurnal, nocturnal, and total airborne spore abundance across vegetation types. Spore samples were also collected at weekly and monthly intervals in mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types from 12 field sites across two years. We found greater airborne spore densities during the wetter winter months compared to the drier summer months. Mean total spore abundance in the mixed-evergreen forest was twice than in the coastal prairie, but there were no significant differences in total airborne spore abundance among mixed-evergreen forest, redwood forest, and maritime chaparral vegetation types. Weekly and monthly peaks in airborne spore abundance corresponded with rain events and peaks in soil moisture. Overall, temporal patterns in meteorological factors were much more important in determining airborne fungal spore abundance than the

Improved survival in HIV treatment programs in Asia

Science.gov (United States)

De La Mata, Nicole L; Kumarasamy, Nagalingeswaran; Khol, Vohith; Ng, Oon Tek; Van Nguyen, Kinh; Merati, Tuti Parwati; Pham, Thuy Thanh; Lee, Man Po; Durier, Nicolas; Law, Matthew

2016-01-01

Background Antiretroviral treatment (ART) for HIV-positive patients has expanded rapidly in Asia over the last ten years. Our study aimed to describe the time trends and risk factors for overall survival in patients receiving first-line ART in Asia. Methods We included HIV-positive adult patients who initiated ART between 2003–2013 (n=16 546), from seven sites across six Asia-Pacific countries. Patient follow-up was to May 2014. We compared survival for each country and overall by time period of ART initiation using Kaplan-Meier curves. Factors associated with mortality were assessed using Cox regression, stratified by site. We also summarized first-line ART regimens, CD4 count at ART initiation, and CD4 and HIV viral load testing frequencies. Results There were 880 deaths observed over 54 532 person-years of follow-up, a crude rate of 1.61 (1.51, 1.72) per 100 person-years. Survival significantly improved in more recent years of ART initiation. The survival probabilities at 4 years follow-up for those initiating ART in 2003–05 was 92.1%, 2006–09 was 94.3% and 2010–2013 was 94.5% (pAsia have improved survival in more recent years of ART initiation. This is likely a consequence of improvements in treatment and, patient management and monitoring over time. PMID:26961354

Pollen and spores of terrestrial plants

Science.gov (United States)

Bernhardt, Christopher E.; Willard, Debra A.; Shennan, Ian; Long, Antony J.; Horton, Benjamin P.

2015-01-01

Pollen and spores are valuable tools in reconstructing past sea level and climate because of their ubiquity, abundance, and durability as well as their reciprocity with source vegetation to environmental change (Cronin, 1999; Traverse, 2007; Willard and Bernhardt, 2011). Pollan is found in many sedimentary environments, from freshwater to saltwater, terrestrial to marine. It can be abundant in a minimal amount of sample material, for example half a gram, as concentrations can be as high as four million grains per gram (Traverse, 2007). The abundance of pollen in a sample lends it to robust statistical analysis for the quantitative reconstruction of environments. The outer cell wall is resistant to decay in sediments and allows palynomorphs (pollen and spores) to record changes in plant communities and sea level over millions of years. These characteristics make pollen and spores a powerful tool to use in sea-level research.This chapter describes the biology of pollen and spores and how they are transported and preserved in sediments. We present a methodology for isolating pollen from sediments and a general language and framework to identify pollen as well as light micrographs of a selection of common pollen grains, We then discuss their utility in sea-level research.

Longitudinal assessment of dairy farm management practices associated with the presence of psychrotolerant Bacillales spores in bulk tank milk on 10 New York State dairy farms.

Science.gov (United States)

Masiello, S N; Kent, D; Martin, N H; Schukken, Y H; Wiedmann, M; Boor, K J

2017-11-01

The ability of certain spore-forming bacteria in the order Bacillales (e.g., Bacillus spp., Paenibacillus spp.) to survive pasteurization in spore form and grow at refrigeration temperatures results in product spoilage and limits the shelf life of high temperature, short time (HTST)-pasteurized fluid milk. To facilitate development of strategies to minimize contamination of raw milk with psychrotolerant Bacillales spores, we conducted a longitudinal study of 10 New York State dairy farms, which included yearlong monthly assessments of the frequency and levels of bulk tank raw milk psychrotolerant spore contamination, along with administration of questionnaires to identify farm management practices associated with psychrotolerant spore presence over time. Milk samples were first spore pasteurized (80°C for 12 min) and then analyzed for sporeformer counts on the initial day of spore pasteurization (SP), and after refrigerated storage (6°C) for 7, 14, and 21 d after SP. Overall, 41% of samples showed sporeformer counts of >20,000 cfu/mL at d 21, with Bacillus and Paenibacillus spp. being predominant causes of high sporeformer counts. Statistical analyses identified 3 management factors (more frequent cleaning of the bulk tank area, the use of a skid steer to scrape the housing area, and segregating problem cows during milking) that were all associated with lower probabilities of d-21 Bacillales spore detection in SP-treated bulk tank raw milk. Our data emphasize that appropriate on-farm measures to improve overall cleanliness and cow hygiene will reduce the probability of psychrotolerant Bacillales spore contamination of bulk tank raw milk, allowing for consistent production of raw milk with reduced psychrotolerant spore counts, which will facilitate production of HTST-pasteurized milk with extended refrigerated shelf life. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

High-Level Heat Resistance of Spores of Bacillus amyloliquefaciens and Bacillus licheniformis Results from the Presence of a spoVA Operon in a Tn1546 Transposon

Science.gov (United States)

Berendsen, Erwin M.; Koning, Rosella A.; Boekhorst, Jos; de Jong, Anne; Kuipers, Oscar P.; Wells-Bennik, Marjon H. J.

2016-01-01

Bacterial endospore formers can produce spores that are resistant to many food processing conditions, including heat. Some spores may survive heating processes aimed at production of commercially sterile foods. Recently, it was shown that a spoVA operon, designated spoVA2mob, present on a Tn1546 transposon in Bacillus subtilis, leads to profoundly increased wet heat resistance of B. subtilis spores. Such Tn1546 transposon elements including the spoVA2mob operon were also found in several strains of Bacillus amyloliquefaciens and Bacillus licheniformis, and these strains were shown to produce spores with significantly higher resistances to wet heat than their counterparts lacking this transposon. In this study, the locations and compositions of Tn1546 transposons encompassing the spoVA2mob operons in B. amyloliquefaciens and B. licheniformis were analyzed. Introduction of these spoVA2mob operons into B. subtilis 168 (producing spores that are not highly heat resistant) rendered mutant 168 strains that produced high-level heat resistant spores, demonstrating that these elements in B. amyloliquefaciens and B. licheniformis are responsible for high level heat resistance of spores. Assessment of growth of the nine strains of each species between 5.2°C and 57.7°C showed some differences between strains, especially at lower temperatures, but all strains were able to grow at 57.7°C. Strains of B. amyloliquefaciens and B. licheniformis that contain the Tn1546 elements (and produce high-level heat resistant spores) grew at temperatures similar to those of their Tn1546-negative counterparts that produce low-level heat resistant spores. The findings presented in this study allow for detection of B. amyloliquefaciens and B. licheniformis strains that produce highly heat resistant spores in the food chain. PMID:27994575

Surface tension propulsion of fungal spores by use of microdroplets

OpenAIRE

Noblin, Xavier; Yang, Sylvia; Dumais, Jacques

2010-01-01

Many edible mushrooms eject their spores (about 10 microns in size) at high speed (about 1 m/s) using surface tension forces in a few microseconds. Basically the coalescence of a droplet with the spore generates the necessary momentum to eject the spore. We have detailed this mechanism in \\cite{noblin2}. In this article, we give some details about the high speed movies (up to 250000 fps) of mushrooms' spores ejection attached to this submission. This video was submitted as part of the Gallery...

Differential modification of oxic and anoxic components of radiation damage in Bacillus megaterium spores by caffeine

International Nuclear Information System (INIS)

Kesavan, P.C.; Powers, E.L.

1985-01-01

Studies were carried out on the effect of caffeine on the X-irradiation sensitivity of B. megaterium spores with the following results: Caffeine exerts a concentration-dependent modifying action on oxygen-dependent components of X-ray-induced damage in B. megaterium spore suspensions causing an 'over-O 2 effect' at about 1 x 10 -4 mol dm -3 , and as the concentration is increased to 1 10 -3 mol dm -3 or above, a small but consistent protection is seen. In the absence of O 2 , at a wide range of concentrations (8.5 x 10 -5 to 1 x 10 -1 mol dm -3 ), caffeine enhances the inactivation constant, k, from 1.17 to about 1.50 kGy -1 . Both ethanol and t-butanol (5 x 10 -2 mol dm -3 ) remove the 'over O 2 -effect' produced by 1 x 10 -4 mol dm -3 caffeine in O 2 ; such an effect, however, is not accompanied by reduction in the H 2 O 2 concentrations in the spore suspensions. Ethanol prevents caffeine-induced anoxic sensitization, as well as H 2 O 2 buildup. t-BuOH has no influence on either the low dose part of the log fraction survival curve or on the H 2 O 2 yield in the spore suspensions. Caffeine reacts with radiation-induced e - sub(aq) and radicalOH with rate constants of 1.5 x 10 10 and 6.9 x 10 9 dm 3 mol -1 s -1 , respectively. (author)

NanoSIMS analysis of Bacillus spores for forensics

Energy Technology Data Exchange (ETDEWEB)

Weber, P K; Davisson, M L; Velsko, S P

2010-02-23

The threat associated with the potential use of radiological, nuclear, chemical and biological materials in terrorist acts has resulted in new fields of forensic science requiring the application of state-of-the-science analytical techniques. Since the anthrax letter attacks in the United States in the fall of 2001, there has been increased interest in physical and chemical characterization of bacterial spores. While molecular methods are powerful tools for identifying genetic differences, other methods may be able to differentiate genetically identical samples based on physical and chemical properties, as well as provide complimentary information, such as methods of production and approximate date of production. Microanalysis has the potential to contribute significantly to microbial forensics. Bacillus spores are highly structured, consisting of a core, cortex, coat, and in some species, an exosporium. This structure provides a template for constraining elemental abundance differences at the nanometer scale. The primary controls on the distribution of major elements in spores are likely structural and physiological. For example, P and Ca are known to be abundant in the spore core because that is where P-rich nucleic acids and Cadipicolinic acid are located, respectively. Trace elements are known to bind to the spore coat but the controls on these elements are less well understood. Elemental distributions and abundances may be directly related to spore production, purification and stabilization methodologies, which are of particular interest for forensic investigation. To this end, we are developing a high-resolution secondary ion mass spectrometry method using a Cameca NanoSIMS 50 to study the distribution and abundance of trace elements in bacterial spores. In this presentation we will review and compare methods for preparing and analyzing samples, as well as review results on the distribution and abundance of elements in bacterial spores. We use NanoSIMS to

Early quantitative method for measuring germination in non-green spores of Dryopteris paleacea using an epifluorescence-microscope technique

Science.gov (United States)

Scheuerlein, R.; Wayne, R.; Roux, S. J.

1988-01-01

A method is described to determine germination by blue-light excited red fluorescence in the positively photoblastic spores of Dryopteris paleacea Sw. This fluorescence is due to chlorophyll as evidenced from 1) a fluorescence-emission spectrum in vivo, where a bright fluorescence around 675 nm is obtained only in red light (R)-irradiated spores and 2) in vitro measurements with acetone extracts prepared from homogenized spores. Significant amounts of chlorophyll can be found only in R-treated spores; this chlorophyll exhibits an emission band around 668 nm, when irradiated with 430 nm light at 21 degrees C. Compared to other criteria for germination, such as swelling of the cell, coat splitting, greening, and rhizoid formation, which require longer periods after induction for their expression, chlorophyll fluorescence can be used to quantify germination after two days. This result is confirmed by fluence-response curves for R-induced spore germination; the same relationship between applied R and germination is obtained by the evaluation with the epifluorescence method 2 days after the light treatment as compared with the evaluation with bright-field microscopy 5 days after the inducing R. Using this technique we show for the first time that Ca2+ contributes to the signal-transduction chain in phytochrome-mediated chlorophyll synthesis in spores of Dryopteris paleacea.

Discrimination of Spore-Forming Bacilli Using spoIVA

Science.gov (United States)

Venkateswaran, Kasthuri; LaDuc, Myron; Stuecker, Tara

2009-01-01

A method of discriminating between spore-forming and non-spore-forming bacteria is based on a combination of simultaneous sporulation-specific and non-sporulation-specific quantitative polymerase chain reactions (Q-PCRs). The method was invented partly in response to the observation that for the purposes of preventing or reducing biological contamination affecting many human endeavors, ultimately, only the spore-forming portions of bacterial populations are the ones that are problematic (or, at least, more problematic than are the non-spore-forming portions). In some environments, spore-forming bacteria constitute small fractions of the total bacterial populations. The use of sporulation-specific primers in Q-PCR affords the ability to assess the spore-forming fraction of a bacterial population present in an environment of interest. This assessment can provide a more thorough and accurate understanding of the bacterial contamination in the environment, thereby making it possible to focus contamination- testing, contamination-prevention, sterilization, and decontamination resources more economically and efficiently. The method includes the use of sporulation-specific primers in the form of designed, optimized deoxyribonucleic acid (DNA) oligonucleotides specific for the bacterial spoIVA gene (see table). [In "spoIVA," "IV" signifies Roman numeral four and the entire quoted name refers to gene A for the fourth stage of sporulation.] These primers are mixed into a PCR cocktail with a given sample of bacterial cells. A control PCR cocktail into which are mixed universal 16S rRNA primers is also prepared. ["16S rRNA" denotes a ribosomal ribonucleic acid (rRNA) sequence that is common to all organisms.] Following several cycles of heating and cooling according to the PCR protocol to amplify amounts of DNA molecules, the amplification products can be analyzed to determine the types of bacterial cells present within the samples. If the amplification product is strong

Modeling Thermal Inactivation of Bacillus Spores

Science.gov (United States)

2009-03-01

information is preserved and replicated by the Watson - Crick base pairing in which 4-3 complementary bases recognize each other. One incorrect amino acid can...hydrolysis reactions to take place with the spore’s DNA and other proteins. These chemical reactions degrade the DNA and proteins to such an extent that the... DNA cannot be repaired or replicated, thus causing spore death. We further assert that damage to a spore is based on a certain initial DNA information

Spore-Forming Bacteria that Resist Sterilization

Science.gov (United States)

LaDuc, Myron; Venkateswaran, Kasthuri

2003-01-01

A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building

Directory of Open Access Journals (Sweden)

Michael Oberle

2015-10-01

Full Text Available Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m3 (inter-quartile range = IQR 1–4, and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m3 (IQR 26–126 in summer and 9 spores/m3 (IQR 6–15 in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m3. This variability may explain the variability of study results in the literature.

Antitumor effects and mechanisms of Ganoderma extracts and spores oil.

Science.gov (United States)

Chen, Chun; Li, Peng; Li, Ye; Yao, Guan; Xu, Jian-Hua

2016-11-01

Ganoderma lucidum is a popular herbal medicine used in China to promote health. Modern studies have disclosed that the active ingredients of Ganoderma can exhibit several effects, including antitumor effects and immunomodulation. The present study evaluated the antitumor effects of self-prepared Ganoderma extracts and spores oil, and investigated the possible underlying mechanisms by observing the effects of the extracts and oil on topoisomerases and the cell cycle. The results showed that Ganoderma extracts and spores oil presented dose-dependent inhibitory effects on tumor cells. The half maximal inhibitory concentration (IC 50 ) values of Ganoderma extracts on HL60, K562 and SGC-7901 cells for 24 h were 0.44, 0.39 and 0.90 mg/ml, respectively; for Ganoderma spores oil, the IC 50 values were 1.13, 2.27 and 6.29 mg/ml, respectively. In the in vivo study, the inhibitory rates of Ganoderma extracts (4 g/kg/d, intragastrically) on S180 and H22 cells were 39.1 and 44.6%, respectively, and for Ganoderma spores oil (1.2 g/kg/d, intragastrically) the inhibitory rates were 30.9 and 44.9%, respectively. Ganoderma extracts and spores oil inhibited the activities of topoisomerase I and II. Ganoderma spores oil was shown block the cell cycle at the transition between the G1 and S phases and induce a marked decrease in cyclin D1 levels in K562 cells, with no significant change in cyclin E level. These results suggest that the Ganoderma extracts and spores oil possessed antitumor effects in the in vitro and in vivo studies. The antitumor mechanisms of the extracts and spores oil were associated with inhibitory effects on topoisomerase I and II activities, and for Ganoderma spores oil, the antitumor effects may also be associated with decreased cyclin D1 levels, thus inducing G1 arrest in the cell cycle.

Availability of websites offering to sell psilocybin spores and psilocybin.

Science.gov (United States)

Lott, Jason P; Marlowe, Douglas B; Forman, Robert F

2009-09-01

This study assesses the availability of websites offering to sell psilocybin spores and psilocybin, a powerful hallucinogen contained in Psilocybe mushrooms. Over a 25-month period beginning in March 2003, eight searches were conducted in Google using the term "psilocybin spores." In each search the first 100 nonsponsored links obtained were scored by two independent raters according to standardized criteria to determine whether they offered to sell psilocybin or psilocybin spores. No attempts were made to procure the products offered for sale in order to ascertain whether the marketed psilocybin was in fact "genuine" or "counterfeit." Of the 800 links examined, 58% led to websites offering to sell psilocybin spores. Additionally, evidence that whole Psilocybe mushrooms are offered for sale online was obtained. Psilocybin and psilocybin spores were found to be widely available for sale over the Internet. Online purchase of psilocybin may facilitate illicit use of this potent psychoactive substance. Additional studies are needed to assess whether websites offering to sell psilocybin and psilocybin spores actually deliver their products as advertised.

Inactivation of Bacillus subtilis spores by high pressure CO2 with high temperature.

Science.gov (United States)

Rao, Lei; Xu, Zhenzhen; Wang, Yongtao; Zhao, Feng; Hu, Xiaosong; Liao, Xiaojun

2015-07-16

The objective of this study was to investigate the inactivation of the Bacillus subtilis spores by high pressure CO2 combined with high temperature (HPCD+HT) and to analyze the clumping effect of the spores on their HPCD+HT resistance. The spores of B. subtilis were subjected to heat at 0.1 MPa and HPCD at 6.5-25 MPa, and 82 °C, 86 °C, and 91 °C for 0-120 min. The spores were effectively inactivated by HPCD+HT, but a protective effect on the spores was also found, which was closely correlated to the pressure, temperature and time. The spores treated by HPCD+HT at 6.5 and 10 MPa exhibited a two-stage inactivation curve of shoulder and log-linear regions whereas the spores at 15-25 MPa exhibited a three-stage inactivation curve of shoulder, log-linear and tailing regions, and these curves were well fitted to the Geeraerd model. Approximately 90% of pyridine-2,6-dicarboxylic acid (DPA) was released after HPCD+HT and the 90% DPA release time depend on the pressure and temperature. Moreover, the spore clumping in suspensions was examined by dynamic light scattering. The particle size of the spore suspensions increased with the increase of pressure, temperature and time, indicating the spore clumping. 0.1% Tween 80 as a surfactant inhibited the spore clumping and increased the inactivation ratio of the spores by HPCD+HT. These results indicated that the spore clumping enhanced the spores' resistance to HPCD+HT and induced a protective effect. Copyright © 2015 Elsevier B.V. All rights reserved.

[Distribution and spatial ordering of biopolymer molecules in resting bacterial spores].

Science.gov (United States)

Duda, V I; Korolev, Iu N; El'-Registan, G I; Duzha, M V; Telegin, N L

1978-01-01

The presence, distribution and spatial arrangement of biopolymers in situ were studied in both a total intact spore and in a certain cellular layer using a spectroscopic technique of attenuated total refraction (ATR-IR) in the IR region. In contrast to vegetative cells, intact spores were characterized by isotropic distribution of protein components. This feature can be regarded as an index of the cryptobiotic state of spores. However, the distribution of protein components among individual layers of a spore was anisotropic. Bonds characterized by amide I and amide II bands were most often ordered in a layer which comprised cellular structures from the exosporium to the inner spore membrane.

Micromotors to capture and destroy anthrax simulant spores.

Science.gov (United States)

Orozco, Jahir; Pan, Guoqing; Sattayasamitsathit, Sirilak; Galarnyk, Michael; Wang, Joseph

2015-03-07

Towards addressing the need for detecting and eliminating biothreats, we describe a micromotor-based approach for screening, capturing, isolating and destroying anthrax simulant spores in a simple and rapid manner with minimal sample processing. The B. globilli antibody-functionalized micromotors can recognize, capture and transport B. globigii spores in environmental matrices, while showing non-interactions with excess of non-target bacteria. Efficient destruction of the anthrax simulant spores is demonstrated via the micromotor-induced mixing of a mild oxidizing solution. The new micromotor-based approach paves a way to dynamic multifunctional systems that rapidly recognize, isolate, capture and destroy biological threats.

Thermal inactivation kinetics of Bacillus coagulans spores in tomato juice.

Science.gov (United States)

Peng, Jing; Mah, Jae-Hyung; Somavat, Romel; Mohamed, Hussein; Sastry, Sudhir; Tang, Juming

2012-07-01

The thermal characteristics of the spores and vegetative cells of three strains of Bacillus coagulans (ATCC 8038, ATCC 7050, and 185A) in tomato juice were evaluated. B. coagulans ATCC 8038 was chosen as the target microorganism for thermal processing of tomato products due to its spores having the highest thermal resistance among the three strains. The thermal inactivation kinetics of B. coagulans ATCC 8038 spores in tomato juice between 95 and 115°C were determined independently in two different laboratories using two different heating setups. The results obtained from both laboratories were in general agreement, with z-values (z-value is defined as the change in temperature required for a 10-fold reduction of the D-value, which is defined as the time required at a certain temperature for a 1-log reduction of the target microorganisms) of 8.3 and 8.7°C, respectively. The z-value of B. coagulans 185A spores in tomato juice (pH 4.3) was found to be 10.2°C. The influence of environmental factors, including cold storage time, pH, and preconditioning, upon the thermal resistance of these bacterial spores is discussed. The results obtained showed that a storage temperature of 4°C was appropriate for maintaining the viability and thermal resistance of B. coagulans ATCC 8038 spores. Acidifying the pH of tomato juice decreased the thermal resistance of these spores. A 1-h exposure at room temperature was considered optimal for preconditioning B. coagulans ATCC 8038 spores in tomato juice.

Genetic Factors and Host Traits Predict Spore Morphology for a Butterfly Pathogen

Directory of Open Access Journals (Sweden)

Jacobus C. de Roode

2013-08-01

Full Text Available Monarch butterflies (Danaus plexippus throughout the world are commonly infected by the specialist pathogen Ophryocystis elektroscirrha (OE. This protozoan is transmitted when larvae ingest infectious stages (spores scattered onto host plant leaves by infected adults. Parasites replicate internally during larval and pupal stages, and adult monarchs emerge covered with millions of dormant spores on the outsides of their bodies. Across multiple monarch populations, OE varies in prevalence and virulence. Here, we examined geographic and genetic variation in OE spore morphology using clonal parasite lineages derived from each of four host populations (eastern and western North America, South Florida and Hawaii. Spores were harvested from experimentally inoculated, captive-reared adult monarchs. Using light microscopy and digital image analysis, we measured the size, shape and color of 30 replicate spores per host. Analyses examined predictors of spore morphology, including parasite source population and clone, parasite load, and the following host traits: family line, sex, wing area, and wing color (orange and black pigmentation. Results showed significant differences in spore size and shape among parasite clones, suggesting genetic determinants of morphological variation. Spore size also increased with monarch wing size, and monarchs with larger and darker orange wings tended to have darker colored spores, consistent with the idea that parasite development depends on variation in host quality and resources. We found no evidence for effects of source population on variation in spore morphology. Collectively, these results provide support for heritable variation in spore morphology and a role for host traits in affecting parasite development.

Conversion of xylan by recyclable spores of Bacillus subtilis displaying thermophilic enzymes.

Science.gov (United States)

Mattossovich, Rosanna; Iacono, Roberta; Cangiano, Giuseppina; Cobucci-Ponzano, Beatrice; Isticato, Rachele; Moracci, Marco; Ricca, Ezio

2017-11-28

The Bacillus subtilis spore has long been used to display antigens and enzymes. Spore display can be accomplished by a recombinant and a non-recombinant approach, with the latter proved more efficient than the recombinant one. We used the non-recombinant approach to independently adsorb two thermophilic enzymes, GH10-XA, an endo-1,4-β-xylanase (EC 3.2.1.8) from Alicyclobacillus acidocaldarius, and GH3-XT, a β-xylosidase (EC 3.2.1.37) from Thermotoga thermarum. These enzymes catalyze, respectively, the endohydrolysis of (1-4)-β-D-xylosidic linkages of xylans and the hydrolysis of (1-4)-β-D-xylans to remove successive D-xylose residues from the non-reducing termini. We report that both purified enzymes were independently adsorbed on purified spores of B. subtilis. The adsorption was tight and both enzymes retained part of their specific activity. When spores displaying either GH10-XA or GH3-XT were mixed together, xylan was hydrolysed more efficiently than by a mixture of the two free, not spore-adsorbed, enzymes. The high total activity of the spore-bound enzymes is most likely due to a stabilization of the enzymes that, upon adsorption on the spore, remained active at the reaction conditions for longer than the free enzymes. Spore-adsorbed enzymes, collected after the two-step reaction and incubated with fresh substrate, were still active and able to continue xylan degradation. The recycling of the mixed spore-bound enzymes allowed a strong increase of xylan degradation. Our results indicate that the two-step degradation of xylans can be accomplished by mixing spores displaying either one of two required enzymes. The two-step process occurs more efficiently than with the two un-adsorbed, free enzymes and adsorbed spores can be reused for at least one other reaction round. The efficiency of the process, the reusability of the adsorbed enzymes, and the well documented robustness of spores of B. subtilis indicate the spore as a suitable platform to display enzymes

Spore Heat Activation Requirements and Germination Responses Correlate with Sequences of Germinant Receptors and with the Presence of a Specific spoVA2mob Operon in Foodborne Strains of Bacillus subtilis.

Science.gov (United States)

Krawczyk, Antonina O; de Jong, Anne; Omony, Jimmy; Holsappel, Siger; Wells-Bennik, Marjon H J; Kuipers, Oscar P; Eijlander, Robyn T

2017-04-01

Spore heat resistance, germination, and outgrowth are problematic bacterial properties compromising food safety and quality. Large interstrain variation in these properties makes prediction and control of spore behavior challenging. High-level heat resistance and slow germination of spores of some natural Bacillus subtilis isolates, encountered in foods, have been attributed to the occurrence of the spoVA 2mob operon carried on the Tn 1546 transposon. In this study, we further investigate the correlation between the presence of this operon in high-level-heat-resistant spores and their germination efficiencies before and after exposure to various sublethal heat treatments (heat activation, or HA), which are known to significantly improve spore responses to nutrient germinants. We show that high-level-heat-resistant spores harboring spoVA 2mob required higher HA temperatures for efficient germination than spores lacking spoVA 2mob The optimal spore HA requirements additionally depended on the nutrients used to trigger germination, l-alanine (l-Ala), or a mixture of l-asparagine, d-glucose, d-fructose, and K + (AGFK). The distinct HA requirements of these two spore germination pathways are likely related to differences in properties of specific germinant receptors. Moreover, spores that germinated inefficiently in AGFK contained specific changes in sequences of the GerB and GerK germinant receptors, which are involved in this germination response. In contrast, no relation was found between transcription levels of main germination genes and spore germination phenotypes. The findings presented in this study have great implications for practices in the food industry, where heat treatments are commonly used to inactivate pathogenic and spoilage microbes, including bacterial spore formers. IMPORTANCE This study describes a strong variation in spore germination capacities and requirements for a heat activation treatment, i.e., an exposure to sublethal heat that increases

Time to treatment as a quality metric in lung cancer: Staging studies, time to treatment, and patient survival

International Nuclear Information System (INIS)

Gomez, Daniel R.; Liao, Kai-Ping; Swisher, Stephen G.; Blumenschein, George R.; Erasmus, Jeremy J.; Buchholz, Thomas A.; Giordano, Sharon H.; Smith, Benjamin D.

2015-01-01

Purpose: Prompt staging and treatment are crucial for non-small cell lung cancer (NSCLC). We determined if predictors of treatment delay after diagnosis were associated with prognosis. Materials and methods: Medicare claims from 28,732 patients diagnosed with NSCLC in 2004–2007 were used to establish the diagnosis-to-treatment interval (ideally ⩽35 days) and identify staging studies during that interval. Factors associated with delay were identified with multivariate logistic regression, and associations between delay and survival by stage were tested with Cox proportional hazard regression. Results: Median diagnosis-to-treatment interval was 27 days. Receipt of PET was associated with delays (57.4% of patients with PET delayed [n = 6646/11,583] versus 22.8% of those without [n = 3908/17,149]; adjusted OR = 4.48, 95% CI 4.23–4.74, p < 0.001). Median diagnosis-to-PET interval was 15 days; PET-to-clinic, 5 days; and clinic-to-treatment, 12 days. Diagnosis-to-treatment intervals <35 days were associated with improved survival for patients with localized disease and those with distant disease surviving ⩾1 year but not for patients with distant disease surviving <1 year. Conclusion: Delays between diagnosing and treating NSCLC are common and associated with use of PET for staging. Reducing time to treatment may improve survival for patients with manageable disease at diagnosis

Diurnal Variations of Airborne Pollen and Spores in Taipei City, Taiwan

Directory of Open Access Journals (Sweden)

Yueh-Lin Yang

2003-09-01

Full Text Available The diurnal variation of airborne pollen and spores in Taipei City, Taiwan, was investigated during a two-year survey from 1993 to 1994. The pollen and spores were sampled using a Burkard seven-day volumetric pollen trap. The diurnal trends of the total amount of pollen and spores in 1993 and in 1994 were similar to each other, and peaked at 3 to 10 o’clock. The diurnal patterns of airborne pollen and spores of Broussonetia, Fraxinus, Cyathea and Gramineae in 1993 were similar to those in 1994. High concentrations of Broussonetia and Fraxinus were obtained from midnight to the next morning. Cyathea spores peaked from morning till noon, and Gramineae peaked in the afternoon. The diurnal patterns of airborne pollen of Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae in 1993 were different to those in 1994. Regular diurnal patterns also associated with the taxa, which produce large pollen or spores, such as Gramineae and Cyathea. In contrast, Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae produce relatively small pollen and the diurnal patterns of their airborne pollen were found irregular. The source plants Broussonetia and Fraxinus were close to the collection site so the diurnal patterns of their airborne pollen were regular, suggesting that the diurnal fluctuations of the pollen or spores in air might be affected by the source of plants and the sizes of pollen or spores. The transportation of the smaller pollen or spores in air is probably more easily affected by instability of air currents; they are therefore more likely to exhibit irregular diurnal patterns.

Architecture and assembly of the Bacillus subtilis spore coat.

Science.gov (United States)

Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J

2014-01-01

Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of "nanodot" particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

Architecture and Assembly of the Bacillus subtilis Spore Coat

Science.gov (United States)

Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

2014-01-01

Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

Phosphorescence In Bacillus Spores

National Research Council Canada - National Science Library

Reinisch, Lou; Swartz, Barry A; Bronk, Burt V

2003-01-01

.... Our present work attempts to build on this approach for environmental applications. We have measured a change in the fluorescence spectra of suspensions of Bacillus bacteria between the vegetative bacteria and their spores at room temperature...

Pollen and spore monitoring in the world.

Science.gov (United States)

Buters, J T M; Antunes, C; Galveias, A; Bergmann, K C; Thibaudon, M; Galán, C; Schmidt-Weber, C; Oteros, J

2018-01-01

Ambient air quality monitoring is a governmental duty that is widely carried out in order to detect non-biological ("chemical") components in ambient air, such as particles of monitoring networks are publicly funded and air quality data are open to the public. The situation for biological particles that have detrimental effects on health, as is the case of pollen and fungal spores, is however very different. Most pollen and spore monitoring networks are not publicly funded and data are not freely available. The information regarding which biological particle is being monitored, where and by whom, is consequently often not known, even by aerobiologists themselves. This is a considerable problem, as local pollen data are an important tool for the prevention of allergic symptoms. The aim of this study was to review pollen monitoring stations throughout the world and to create an interactive visualization of their distribution. The method employed to collect information was based on: (a) a review of the recent and historical bibliography related to pollen and fungal spore monitoring, and (b) personal surveys of the managers of national and regional monitoring networks. The interactive application was developed using the R programming language. We have created an inventory of the active pollen and spore monitoring stations in the world. There are at least 879 active pollen monitoring stations in the world, most of which are in Europe (> 500). The prevalent monitoring method is based on the Hirst principle (> 600 stations). The inventory is visualised as an interactive and on-line map. It can be searched, its appearance can be adjusted to the users' needs and it is updated regularly, as new stations or changes to those that already exist can be submitted online. The map shows the current situation of pollen and spore monitoring and facilitates collaboration among those individuals who are interested in pollen and spore counts. It might also help to improve the

Impact of different treatment methods on survival in advanced pancreatic cancer

International Nuclear Information System (INIS)

Brasiuniene, B.; Juozaityte, E.; Barauskas, G.

2005-01-01

The aim of the study was to evaluate the impact of different treatment methods on survival of patients treated for advanced pancreatic cancer at Kaunas University of Medicine Hospital from 1987 to 2003. Data on 262 patients with advanced pancreatic cancer treated from 1987 to 2003 were analyzed retrospectively. Four groups of patients were analyzed. One hundred eighty patients underwent palliative bypass or endoscopic bile duct stenting or observation alone. Forty three patients in addition to surgery were treated by radiotherapy. Twenty five patients received gemcitabine in standard doses and schedules. Fourteen patients received concomitant chemoradiotherapy (with gemcitabine or 5-fluorouracil). All patients were grouped by treatment method and median survival was analyzed. Median survival of patients treated by palliative surgery only or observation alone was 1.9 month, and for patients treated by palliative surgery and radiotherapy was 6.1 months (p=0.00007). Median survival of patients treated with gemcitabine was 9.5 months (p<0.001), and median survival of patients treated with concomitant chemoradiotherapy was 8.5 months (p=0.00003). Patients diagnosed with advanced pancreatic cancer in addition to surgical treatment should be treated by chemotherapy, concomitant chemoradiotherapy or radiotherapy. (author)

Quantification of Nonproteolytic Clostridium botulinum Spore Loads in Food Materials.

Science.gov (United States)

Barker, Gary C; Malakar, Pradeep K; Plowman, June; Peck, Michael W

2016-01-04

We have produced data and developed analysis to build representations for the concentration of spores of nonproteolytic Clostridium botulinum in materials that are used during the manufacture of minimally processed chilled foods in the United Kingdom. Food materials are categorized into homogenous groups which include meat, fish, shellfish, cereals, fresh plant material, dairy liquid, dairy nonliquid, mushroom and fungi, and dried herbs and spices. Models are constructed in a Bayesian framework and represent a combination of information from a literature survey of spore loads from positive-control experiments that establish a detection limit and from dedicated microbiological tests for real food materials. The detection of nonproteolytic C. botulinum employed an optimized protocol that combines selective enrichment culture with multiplex PCR, and the majority of tests on food materials were negative. Posterior beliefs about spore loads center on a concentration range of 1 to 10 spores kg(-1). Posterior beliefs for larger spore loads were most significant for dried herbs and spices and were most sensitive to the detailed results from control experiments. Probability distributions for spore loads are represented in a convenient form that can be used for numerical analysis and risk assessments. Copyright © 2016 Barker et al.

The structural bases of long-term anabiosis in non-spore-forming bacteria

Science.gov (United States)

Suzina, Natalia E.; Mulyukin, Andrey L.; Dmitriev, Vladimir V.; Nikolaev, Yury A.; Shorokhova, Anna P.; Bobkova, Yulia S.; Barinova, Ekaterina S.; Plakunov, Vladimir K.; El-Registan, Galina I.; Duda, Vitalii I.

2006-01-01

Peculiarities of the structural organization in non-spore-forming bacteria associated with long-term anabiosis were revealed both in laboratory cultures and in natural populations isolated from 1 3-Myr-old Eastern Siberian permafrost and tundra soil. Different advanced methods were used, including (a) high-resolution electron microscopy; (b) simulation of in situ conditions in the laboratory by varying the composition of growth medium and cultivation conditions; (c) low-temperature fractionation to isolate and concentrate microbial cells from natural soils; (d) comparative morphological analysis of microbial cells in model cultures and natural soils (in situ). Under laboratory conditions, the intense formation of resting cells by representatives of various taxa of eubacteria and halophilic archaea occurred in 2 9-month-old cultures grown in carbon-, nitrogen-, or phosphorus-limited media, in starved cell suspensions in the presence of sodium silicate, or on soil agar. Among resting cells, we revealed cystlike forms having a complicated structure and common features. These included a thick capsule; a thickened and multiprofile cell wall; the presence of large intramembrane particles on PF- and EF-fracture surfaces; fine-grained or lumpy cytoplasm; and a condensed nucleoid. The general morphological properties, ultrastructural organization, physiological features of cystlike cells, and their ability to germinate under the appropriate conditions suggest the existence of constitutive dormancy in non-spore-forming bacteria. It was found that the majority of microorganisms in permafrost and tundra soil are cystlike cells, very similar to those in laboratory cultures. Anabiotic (resting) cystlike cells are responsible for the survival of non-spore-formers in extreme Earth habitats and may be regarded as possible analogs of extraterrestrial forms of microbial life.

Rare vulvar malignancies; incidence, treatment and survival in the Netherlands

NARCIS (Netherlands)

Pleunis, N.; Schuurman, M.S.; Rossum, M.M. van; Bulten, J.; Massuger, L.F.A.G.; Hullu, J.A. de; Aa, M.A. van der

2016-01-01

OBJECTIVE: To describe trends in incidence, treatment and survival of patients with basal cell carcinomas and melanomas of the vulva. Also to compare survival of vulvar and cutaneous melanoma patients. METHODS: All women with a vulvar malignancy between 1989 and 2012 were selected from the Dutch

Antitumor effects and mechanisms of Ganoderma extracts and spores oil

Science.gov (United States)

Chen, Chun; Li, Peng; Li, Ye; Yao, Guan; Xu, Jian-Hua

2016-01-01

Ganoderma lucidum is a popular herbal medicine used in China to promote health. Modern studies have disclosed that the active ingredients of Ganoderma can exhibit several effects, including antitumor effects and immunomodulation. The present study evaluated the antitumor effects of self-prepared Ganoderma extracts and spores oil, and investigated the possible underlying mechanisms by observing the effects of the extracts and oil on topoisomerases and the cell cycle. The results showed that Ganoderma extracts and spores oil presented dose-dependent inhibitory effects on tumor cells. The half maximal inhibitory concentration (IC50) values of Ganoderma extracts on HL60, K562 and SGC-7901 cells for 24 h were 0.44, 0.39 and 0.90 mg/ml, respectively; for Ganoderma spores oil, the IC50 values were 1.13, 2.27 and 6.29 mg/ml, respectively. In the in vivo study, the inhibitory rates of Ganoderma extracts (4 g/kg/d, intragastrically) on S180 and H22 cells were 39.1 and 44.6%, respectively, and for Ganoderma spores oil (1.2 g/kg/d, intragastrically) the inhibitory rates were 30.9 and 44.9%, respectively. Ganoderma extracts and spores oil inhibited the activities of topoisomerase I and II. Ganoderma spores oil was shown block the cell cycle at the transition between the G1 and S phases and induce a marked decrease in cyclin D1 levels in K562 cells, with no significant change in cyclin E level. These results suggest that the Ganoderma extracts and spores oil possessed antitumor effects in the in vitro and in vivo studies. The antitumor mechanisms of the extracts and spores oil were associated with inhibitory effects on topoisomerase I and II activities, and for Ganoderma spores oil, the antitumor effects may also be associated with decreased cyclin D1 levels, thus inducing G1 arrest in the cell cycle. PMID:27900038

Effect of high hydrostatic pressure on mycelial development, spore viability and enzyme activity of Penicillium Roqueforti.

Science.gov (United States)

Martínez-Rodríguez, Yamile; Acosta-Muñiz, Carlos; Olivas, Guadalupe I; Guerrero-Beltrán, José; Rodrigo-Aliaga, Dolores; Mujica-Paz, Hugo; Welti-Chanes, Jorge; Sepulveda, David R

2014-01-03

This study investigated the effect of high hydrostatic pressure treatments on mycelial development, spore viability, and total proteolytic and lipolytic activity of Penicillium roqueforti PV-LYO 10 D. Fungus growing in liquid medium was pressure-treated at 300, 400, and 500 MPa for 10 min at 20°C following seven days of incubation at 25°C and analyzed periodically up to day 9 after treatments to evaluate the effect on fungal growth. Mycelial mass of P. roqueforti was significantly affected at all pressure treatments evaluated, being 15.48%, 22.28%, 30.03%, and 12.53% lower than controls on day 1, 3, 6, and 9 after 300 MPa treatment, respectively. In a similar way, at 400 and 500 MPa, mycelial mass was 31.08% and 60.34% lower than controls one day after treatments and 49.74% and 80.85% lower on day 9, respectively. The viability of P. roqueforti spores decreased by 36.53% at 300 MPa, and complete inactivation took place at ≥400 MPa from an initial count of 7 log cfu/mL. Total proteolytic activity was not significantly affected at 300 MPa but was reduced by 18.22% at 400 MPa and by 43.18% at 500 MPa. Total lipolytic activity also decreased as the intensity of the pressure treatments increased. 21.69%, 39.12%, and 56.26% activity reductions were observed when treatments of 300, 400 and 500 MPa were applied, respectively. The results from this study show that pressure treatments are able to control growth, inactivate spores, and alter enzyme activity of P. roqueforti, which could be of interest in extending the shelf-life of blue-veined cheeses and other food products. © 2013.

Natural Diversity in Heat Resistance of Bacteria and Bacterial Spores: Impact on Food Safety and Quality.

Science.gov (United States)

den Besten, Heidy M W; Wells-Bennik, Marjon H J; Zwietering, Marcel H

2018-03-25

Heat treatments are widely used in food processing often with the aim of reducing or eliminating spoilage microorganisms and pathogens in food products. The efficacy of applying heat to control microorganisms is challenged by the natural diversity of microorganisms with respect to their heat robustness. This review gives an overview of the variations in heat resistances of various species and strains, describes modeling approaches to quantify heat robustness, and addresses the relevance and impact of the natural diversity of microorganisms when assessing heat inactivation. This comparison of heat resistances of microorganisms facilitates the evaluation of which (groups of) organisms might be troublesome in a production process in which heat treatment is critical to reducing the microbial contaminants, and also allows fine-tuning of the process parameters. Various sources of microbiological variability are discussed and compared for a range of species, including spore-forming and non-spore-forming pathogens and spoilage organisms. This benchmarking of variability factors gives crucial information about the most important factors that should be included in risk assessments to realistically predict heat inactivation of bacteria and spores as part of the measures for controlling shelf life and safety of food products.

Mechanism of Bacillus subtilis spore inactivation by and resistance to supercritical CO2 plus peracetic acid.

Science.gov (United States)

Setlow, B; Korza, G; Blatt, K M S; Fey, J P; Setlow, P

2016-01-01

Determine how supercritical CO2 (scCO2 ) plus peracetic acid (PAA) inactivates Bacillus subtilis spores, factors important in spore resistance to scCO2 -PAA, and if spores inactivated by scCO2 -PAA are truly dead. Spores of wild-type B. subtilis and isogenic mutants lacking spore protective proteins were treated with scCO2 -PAA in liquid or dry at 35°C. Wild-type wet spores (aqueous suspension) were more susceptible than dry spores. Treated spores were examined for viability (and were truly dead), dipicolinic acid (DPA), mutations, permeability to nucleic acid stains, germination under different conditions, energy metabolism and outgrowth. ScCO2 -PAA-inactivated spores retained DPA, and survivors had no notable DNA damage. However, DPA was released from inactivated spores at a normally innocuous temperature (85°C), and colony formation from treated spores was salt sensitive. The inactivated spores germinated but did not outgrow, and these germinated spores had altered plasma membrane permeability and defective energy metabolism. Wet or dry coat-defective spores had increased scCO2 -PAA sensitivity, and dry spores but not wet spores lacking DNA protective proteins were more scCO2 -PAA sensitive. These findings suggest that scCO2 -PAA inactivates spores by damaging spores' inner membrane. The spore coat provided scCO2 -PAA resistance for both wet and dry spores. DNA protective proteins provided scCO2 -PAA resistance only for dry spores. These results provide information on mechanisms of spore inactivation of and resistance to scCO2 -PAA, an agent with increasing use in sterilization applications. © 2015 The Society for Applied Microbiology.

Scanning Surface Potential Microscopy of Spore Adhesion on Surfaces

Energy Technology Data Exchange (ETDEWEB)

Lee, Ida [University of Tennessee, Knoxville (UTK); Chung, Eunhyea [Georgia Institute of Technology; Kweon, Hyojin [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Tsouris, Costas [ORNL

2012-01-01

The adhesion of spores of Bacillus anthracis - the cause of anthrax and a likely biological threat - to solid surfaces is an important consideration in cleanup after an accidental or deliberate release. However, because of safety concerns, directly studying B. anthracis spores with advanced instrumentation is problematic. As a first step, we are examining the electrostatic potential of Bacillus thuringiensis (Bt), which is a closely related species that is often used as a simulant to study B. anthracis. Scanning surface potential microscopy (SSPM), also known as Kelvin probe force microscopy (KPFM), was used to investigate the influence of relative humidity (RH) on the surface electrostatic potential of Bt that had adhered to silica, mica, or gold substrates. AFM/SSPM side-by-side images were obtained separately in air, at various values of RH, after an aqueous droplet with spores was applied on each surface and allowed to dry before measurements. In the SSPM images, a negative potential on the surface of the spores was observed compared with that of the substrates. The surface potential decreased as the humidity increased. Spores were unable to adhere to a surface with an extremely negative potential, such as mica.

Detection of Bacillus spores using PCR and FTA filters.

Science.gov (United States)

Lampel, Keith A; Dyer, Deanne; Kornegay, Leroy; Orlandi, Palmer A

2004-05-01

Emphasis has been placed on developing and implementing rapid detection systems for microbial pathogens. We have explored the utility of expanding FTA filter technology for the preparation of template DNA for PCR from bacterial spores. Isolated spores from several Bacillus spp., B. subtilis, B. cereus, and B. megaterium, were applied to FTA filters, and specific DNA products were amplified by PCR. Spore preparations were examined microscopically to ensure that the presence of vegetative cells, if any, did not yield misleading results. PCR primers SRM86 and SRM87 targeted a conserved region of bacterial rRNA genes, whereas primers Bsub5F and Bsub3R amplified a product from a conserved sequence of the B. subtilis rRNA gene. With the use of the latter set of primers for nested PCR, the sensitivity of the PCR-based assay was increased. Overall, 53 spores could be detected after the first round of PCR, and the sensitivity was increased to five spores by nested PCR. FTA filters are an excellent platform to remove PCR inhibitors and have universal applications for environmental, clinical, and food samples.

Nanoscale Structural and Mechanical Analysis of Bacillus anthracis Spores Inactivated with Rapid Dry Heating

Science.gov (United States)

Felker, Daniel L.; Burggraf, Larry W.

2014-01-01

Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating. PMID:24375142

Bacterial spore inactivation at 45-65 °C using high pressure processing: study of Alicyclobacillus acidoterrestris in orange juice.

Science.gov (United States)

Silva, Filipa V M; Tan, Eng Keat; Farid, Mohammed

2012-10-01

High pressure processing (HPP) is a new non-thermal technology commercially used to pasteurize fruit juices and extend shelf-life, while preserving delicate aromas/flavours and bioactive constituents. Given the spoilage incidents and economic losses due to Alicyclobacillus acidoterrestris in the fruit juice industry, the use of high pressure (200 MPa - 600 MPa) in combination with mild temperature (45 °C-65 °C) for 1-15 min, to inactivate these spores in orange juice were investigated. As expected, the higher the temperature, pressure and time, the larger was the A. acidoterrestris inactivation. The survival curves were described by the first order Bigelow model. For 200 MPa, D(45 °C) = 43.9 min, D(55 °C) = 28.8 min, D(65 °C) = 5.0 min and z-value = 21.3 °C. At 600 MPa, D(45 °C) = 12.9 min, D(55 °C) = 7.0 min, D(65 °C) = 3.4 min and z-value = 34.4 °C. Spores were inactivated at 45 °C and 600 MPa, and at 65 °C only 200 MPa was needed to achieve reduction in spore numbers. Results demonstrated that HPP allowed A. acidoterrestris spore inactivation at lower temperatures (45-65 °C) than conventional thermal processing (85-95 °C) without pressure, yielding a fresher and higher quality preserved food. Copyright © 2012 Elsevier Ltd. All rights reserved.

RNA synthesis during germination of UV-irradiated Dictyostelium discoideum spores

International Nuclear Information System (INIS)

Okaichi, Kumio

1987-01-01

UV irradiation to the spores of Dictyostelium discoideum NC4 resulted in a more prolonged delay of amoeba-emergence from swollen spores with increasing UV fluence. During the germination, an inhibition of total RNA synthesis and a shift of stage of maximum RNA synthesis to the later period were observed. The maximum poly(A) + RNA synthetic activity was found on an early stage of amoeba-emergence prior about 1 h to the beginning of rRNA synthesis in unirradiated spore germination; but, in UV-irradiated spore germination, the stage of maximum poly(A) + RNA synthesis shifted to the later stage of germination with increasing UV fluence. A decreased synthesis of poly(A) + RNA and a severe inhibition of rRNA synthesis were observed on UV-irradiated and germinated spores, but no significant inhibition of 4 - 5 S RNA synthesis was detected. Actinomycin D suppressed almost completely the rRNA synthesis of emerged amoebae but the drug apparently did not affect the emergence of amoebae at any stage of germination. It was postulated that the delay of amoeba-emergence in UV-irradiated spore must be mainly due to the shift of the stage of maximum synthesis of poly(A) + RNA to the later stage of germination. (author)

LEVELS AND TYPES OF AEROBIC SPORE FORMING BACTERIA ...

African Journals Online (AJOL)

The four companies whose packaged product were studied had an average plate total spore counts as follows: Company A=6.2x 103; Company B= 3.1x 104; Company C= 6.0x 104 and Company D= 3.1x102 colony forming units per gram, respectively. Identification tests showed that among the aerobic spore formers were ...

Biotoxicity of Mars soils: 2. Survival of Bacillus subtilis and Enterococcus faecalis in aqueous extracts derived from six Mars analog soils

Science.gov (United States)

Schuerger, Andrew C.; Ming, Doug W.; Golden, D. C.

2017-07-01

The search for an extant microbiota on Mars depends on exploring sites that contain transient or permanent liquid water near the surface. Examples of possible sites for liquid water may be active recurring slope lineae (RSL) and fluid inclusions in ice or salt deposits. The presence of saline fluids on Mars will act to depress the freezing points of liquid water to as low as ‒60 °C, potentially permitting the metabolism and growth of halophilic microorganisms to temperatures significantly below the freezing point of pure water at 0 °C. In order to predict the potential risks of forward contamination by Earth microorganisms to subsurface sites on Mars with liquid brines, experiments were designed to characterize the short-term survival of two bacteria in aqueous soil solutions from six analog soils. The term ''soil'' is used here to denote any loose, unconsolidated matrix with no implications for the presence or absence of organics or biology. The analog soils were previously described (Schuerger et al., 2012, Planetary Space Sci., 72, 91-101), and represented crushed Basalt (benign control), Salt, Acid, Alkaline, Aeolian, and Phoenix analogs on Mars. The survival rates of spores of Bacillus subtilis and vegetative cells of Enterococcus faecalis were tested in soil solutions from each analog at 24, 0, or ‒70 °C for time periods up to 28 d. Survival of dormant spores of B. subtilis were mostly unaffected by incubation in the aqueous extracts of all six Mars analogs. In contrast, survival rates of E. faecalis cells were suppressed by all soil solutions when incubated at 24 °C but improved at 0 and ‒70 °C, except for assays in the Salt and Acid soil solutions in which most cells were killed. Results suggest that Earth microorganisms that form spores may persist in liquid brines on Mars better than non-spore forming species, and thus, spore-forming species may pose a potential forward contamination risk to sites with liquid brines.

Properties of spores of Bacillus subtilis strains which lack the major small, acid-soluble protein

International Nuclear Information System (INIS)

Hackett, R.H.; Setlow, P.

1988-01-01

Bacillus subtilis strains containing a deletion in the gene coding for the major small, acid-soluble, spore protein (SASP-gamma) grew and sporulated, and their spores initiated germination normally, but outgrowth of SASP-gamma- spores was significantly slower than that of wild-type spores. The absence of SASP-gamma had no effect on spore protoplast density or spore resistance to heat or radiation. Consequently, SASP-gamma has a different function in spores than do the other major small, acid-soluble proteins

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.

Dendritic Cells Endocytose Bacillus Anthracis Spores: Implications for Anthrax Pathogenesis

National Research Council Canada - National Science Library

Brittingham, Katherine C; Ruthel, Gordon; Panchal, Rekha G; Fuller, Claudette L; Ribot, Wilson J

2005-01-01

Phagocytosis of inhaled Bacillus anthracis spores and subsequent trafficking to lymph nodes are decisive events in the progression of inhaled anthrax because they initiate germination and dissemination of spores...

Spore: Spawning Evolutionary Misconceptions?

Science.gov (United States)

Bean, Thomas E.; Sinatra, Gale M.; Schrader, P. G.

2010-10-01

The use of computer simulations as educational tools may afford the means to develop understanding of evolution as a natural, emergent, and decentralized process. However, special consideration of developmental constraints on learning may be necessary when using these technologies. Specifically, the essentialist (biological forms possess an immutable essence), teleological (assignment of purpose to living things and/or parts of living things that may not be purposeful), and intentionality (assumption that events are caused by an intelligent agent) biases may be reinforced through the use of computer simulations, rather than addressed with instruction. We examine the video game Spore for its depiction of evolutionary content and its potential to reinforce these cognitive biases. In particular, we discuss three pedagogical strategies to mitigate weaknesses of Spore and other computer simulations: directly targeting misconceptions through refutational approaches, targeting specific principles of scientific inquiry, and directly addressing issues related to models as cognitive tools.

Plutonium uptake by a soil fungus and transport to its spores

International Nuclear Information System (INIS)

Beckert, W.F.; Au, F.H.F.

1976-01-01

Three concentrations of plutonium-238 nitrate, citrate and dioxide were each added to separate plates of malt agar buffered to pH 2.5 and 5.5 to determine the uptake of plutonium from these chemical forms and concentrations by a common soil fungus, Aspergillus niger. After inoculation and incubation, the aerial spores of Aspergillus niger were collected using a technique that excluded the possibility of cross-contamination of the spores by the culture media or by mycelial fragments. 238 Pu was taken up from all three chemical forms and transported to the aerial spores of Aspergillus niger at each concentration and at both pH levels. The specific activities of the spores grown at pH 5.5 were generally at least twice those of the spores grown at pH 2.5. The uptake of plutonium from the dioxide form was about one-third of that from the nitrate and citrate forms at both pH levels. The term 'transport factor' is used as a means to compare the transport of plutonium from the media to the fungal spores; the concentration-independent transport factor is defined as the specific activity of the spores divided by the specific activity of the dry culture medium. Though the transport factors were less than 1, which indicates discrimination against the transport of 238 Pu from the culture media to the spores, these findings suggest that this common soil fungus may be solubilizing soil-deposited plutonium and rendering it more biologically available for higher plants and animals. (author)

Differential effects of sporulation temperature on the high pressure resistance of Clostridium botulinum type E spores and the interconnection with sporulation medium cation contents.

Science.gov (United States)

Lenz, Christian A; Vogel, Rudi F

2015-04-01

High pressure thermal (HPT) processing can be used to improve traditional preservation methods and increase food safety and durability, whereas quality related characteristics can be largely maintained. Clostridium (C.) botulinum type E is a non-proteolytic, psychrotrophic, toxin-producing spore former, commonly associated with aquatic environments in temperate regions of the northern hemisphere. Sporulation in nature is likely to occur under varying conditions including temperature and nutrient availability, which might affect resistance properties of resulting spores. In our study, we determined the effect of sporulation temperature (13-38 °C) on the resistance of three Clostridium botulinum type E strains to differently intense HPT treatments (200 MPa at 40 and 80 °C, and 800 MPa at 40 and 80 °C). Furthermore, the effect of cations on sporulation temperature-mediated alterations in HHP resistance was investigated. Results indicate that low and high sporulation temperatures can increase and decrease sporal HPT resistance, respectively, in a treatment-dependent (pressure level, treatment temperature) manner, whereas the trends observed are largely unaffected by pressure dwells (1 s-10 min). Furthermore, results show that the cation content of the sporulation medium (Ca(2+), Mg(2+), Mn(2+)) marginally influences and partially counteracts effects on the HPT resistance of spores grown at low and elevated temperatures, respectively. This suggests that sporulation temperature and medium cations provoke changes in some common spore resistance structures. Sporulation conditions can markedly affect spore resistance properties and, thus, should be considered for the experimental setup of worst case studies aiming to evaluate the effectiveness of food processes in terms of the inactivation of C. botulinum type E spores. Copyright © 2014 Elsevier Ltd. All rights reserved.

Significance of air humidity and air velocity for fungal spore release into the air

Science.gov (United States)

Pasanen, A.-L.; Pasanen, P.; Jantunen, M. J.; Kalliokoski, P.

Our previous field studies have shown that the presence of molds in buildings does not necessarily mean elevated airborne spore counts. Therefore, we investigated the release of fungal spores from cultures of Aspergillus fumigatus, Penicillium sp. and Cladosporium sp. at different air velocities and air humidities. Spores of A. fumigatus and Penicillium sp. were released from conidiophores already at air velocity of 0.5 ms -1, whereas Cladosporium spores required at least a velocity of 1.0 ms -1. Airborne spore counts of A. fumigatus and Penicillium sp. were usually higher in dry than moist air, being minimal at relative humidities (r.h.) above 70%, while the effect of r.h. on the release of Cladosporium sp. was ambivalent. The geometric mean diameter of released spores increased when the r.h. exceeded a certain level which depends on fungal genus. Thus, spores of all three fungi were hygroscopic but the hygroscopicity of various spores appeared at different r.h.-ranges. This study indicates that spore release is controlled by external factors and depends on fungal genus which can be one reason for considerable variation of airborne spore counts in buildings with mold problems.

Fighting Ebola with novel spore decontamination technologies for the military.

Science.gov (United States)

Doona, Christopher J; Feeherry, Florence E; Kustin, Kenneth; Olinger, Gene G; Setlow, Peter; Malkin, Alexander J; Leighton, Terrance

2015-01-01

Recently, global public health organizations such as Doctors without Borders (MSF), the World Health Organization (WHO), Public Health Canada, National Institutes of Health (NIH), and the U.S. government developed and deployed Field Decontamination Kits (FDKs), a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2) produced from a patented invention developed by researchers at the US Army Natick Soldier RD&E Center (NSRDEC) and commercialized as a dry mixed-chemical for bacterial spore decontamination. In fact, the NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies. We present herein the unique attributes of NSRDEC's novel decontamination technologies and a Case Study of the development of FDKs that were deployed in West Africa by international public health organizations to sterilize Ebola-contaminated medical equipment. FDKs use bacterial spores as indicators of sterility. We review the properties and structures of spores and the mechanisms of bacterial spore inactivation by ClO2. We also review mechanisms of bacterial spore inactivation by novel, emerging, and established non-thermal technologies for food preservation, such as high pressure processing, irradiation, cold plasma, and chemical sanitizers, using an array of Bacillus

Rapid Detection of Bacillus anthracis Spores Using Immunomagnetic Separation and Amperometry

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David F. Waller

2016-12-01

Full Text Available Portable detection and quantitation methods for Bacillus anthracis (anthrax spores in pure culture or in environmental samples are lacking. Here, an amperometric immunoassay has been developed utilizing immunomagnetic separation to capture the spores and remove potential interferents from test samples followed by amperometric measurement on a field-portable instrument. Antibody-conjugated magnetic beads and antibody-conjugated glucose oxidase were used in a sandwich format for the capture and detection of target spores. Glucose oxidase activity of spore pellets was measured indirectly via amperometry by applying a bias voltage after incubation with glucose, horseradish peroxidase, and the electron mediator 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid. Target capture was mediated by polyclonal antisera, whereas monoclonal antibodies were used for signal generation. This strategy maximized sensitivity (500 target spores, 5000 cfu/mL, while also providing a good specificity for Bacillus anthracis spores. Minimal signal deviation occurs in the presence of environmental interferents including soil and modified pH conditions, demonstrating the strengths of immunomagnetic separation. The simultaneous incubation of capture and detection antibodies and rapid substrate development (5 min result in short sample-to-signal times (less than an hour. With attributes comparable or exceeding that of ELISA and LFDs, amperometry is a low-cost, low-weight, and practical method for detecting anthrax spores in the field.

A Clostridium difficile-Specific, Gel-Forming Protein Required for Optimal Spore Germination

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M. Lauren Donnelly

2017-01-01

Full Text Available Clostridium difficile is a Gram-positive spore-forming obligate anaerobe that is a leading cause of antibiotic-associated diarrhea worldwide. In order for C. difficile to initiate infection, its aerotolerant spore form must germinate in the gut of mammalian hosts. While almost all spore-forming organisms use transmembrane germinant receptors to trigger germination, C. difficile uses the pseudoprotease CspC to sense bile salt germinants. CspC activates the related subtilisin-like protease CspB, which then proteolytically activates the cortex hydrolase SleC. Activated SleC degrades the protective spore cortex layer, a step that is essential for germination to proceed. Since CspC incorporation into spores also depends on CspA, a related pseudoprotease domain, Csp family proteins play a critical role in germination. However, how Csps are incorporated into spores remains unknown. In this study, we demonstrate that incorporation of the CspC, CspB, and CspA germination regulators into spores depends on CD0311 (renamed GerG, a previously uncharacterized hypothetical protein. The reduced levels of Csps in gerG spores correlate with reduced responsiveness to bile salt germinants and increased germination heterogeneity in single-spore germination assays. Interestingly, asparagine-rich repeat sequences in GerG’s central region facilitate spontaneous gel formation in vitro even though they are dispensable for GerG-mediated control of germination. Since GerG is found exclusively in C. difficile, our results suggest that exploiting GerG function could represent a promising avenue for developing C. difficile-specific anti-infective therapies.

Effect of individual or combined treatment by γ-irradiation or temperature (high or low) on bacillus subtilis spores and its application for sterilization of ground beef

International Nuclear Information System (INIS)

El-Zawahry, Y.A.; Mostafa, S.A.; Awny, N.M.

1986-01-01

The combination of two lethal agents such as irradiation and temperature (high or sub zero) resulted in synergistic death or B. subtilis spores (as indicated by decrease in the thermal D-value). The extent of this synergism in killing a spore population depended mainly on the sequence on application of the two physical agents. Irradiation-temperature (high or sub zero) sequence killed more but injured less B. subtilis spores than temperature irradiation sequence or irradiation and temperature applied separately. Storage at -20 0 C killed more spores than storage at -2 0 C if carried after irradiation, while the reverse was true of storage was prior irradiation. An irradiation dose of 8 KGY followed by thermal exposure to 70 0 C for 1 hr is suggested for the sterilization of ground beef. Irradiation induced certain quantitative changes on the amino-N, protein-N, RNA and DNA of the first subcultures of irradiated spores with stimulatory effect at low irradiation doses and inhibitory effect at the high irradiation doses. This might explain the increased sensitivity of irradiated spores to subsequent exposure to unfavourable temperature (high or sub zero). Exposure of B. subtilis spore to 70 0 C induced a stimulation in the amino- and protein-N of the resulting cells while exposure to 80 0 C resulted in a significant decrease in the amino-N. The protein-N remained more or less the same

Contamination pathways of spore-forming bacteria in a vegetable cannery.

Science.gov (United States)

Durand, Loïc; Planchon, Stella; Guinebretiere, Marie-Hélène; André, Stéphane; Carlin, Frédéric; Remize, Fabienne

2015-06-02

Spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery. Copyright © 2015 Elsevier B.V. All rights reserved.

Size matters for violent discharge height and settling speed of Sphagnum spores: important attributes for dispersal potential.

Science.gov (United States)

Sundberg, Sebastian

2010-02-01

Initial release height and settling speed of diaspores are biologically controlled components which are key to modelling wind dispersal. Most Sphagnum (peat moss) species have explosive spore liberation. In this study, how capsule and spore sizes affect the height to which spores are propelled were measured, and how spore size and spore number of discharged particles relate to settling speed in the aspherical Sphagnum spores. Spore discharge and spore cloud development were filmed in a closed chamber (nine species). Measurements were taken from snapshots at three stages of cloud development. Settling speed of spores (14 species) and clusters were timed in a glass tube. The maximum discharge speed measured was 3.6 m s(-1). Spores reached a maximum height of 20 cm (average: 15 cm) above the capsule. The cloud dimensions at all stages were related positively to capsule size (R(2) = 0.58-0.65). Thus species with large shoots (because they have large capsules) have a dispersal advantage. Half of the spores were released as singles and the rest as clusters (usually two to four spores). Single spores settled at 0.84-1.86 cm s(-1), about 52 % slower than expected for spherical spores with the same diameters. Settling speed displayed a positive curvilinear relationship with spore size, close to predictions by Stokes' law for spherical spores with 68 % of the actual diameters. Light-coloured spores settled slower than dark spores. Settling speed of spore clusters agrees with earlier studies. Effective spore discharge and small, slowly settling spores appear particularly important for species in forested habitats. The spore discharge heights in Sphagnum are among the greatest for small, wind-dispersed propagules. The discharge heights and the slow settling of spores affect dispersal distances positively and may help to explain the wide distribution of most boreal Sphagnum species.

Subboiling Moist Heat Favors the Selection of Enteric Pathogen Clostridium difficile PCR Ribotype 078 Spores in Food

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Alexander Rodriguez-Palacios

2016-01-01

Full Text Available Emerging enteric pathogens could have not only more antibiotic resistance or virulence traits; they could also have increased resistance to heat. We quantified the effects of minimum recommended cooking and higher temperatures, individually on a collection of C. difficile isolates and on the survival probability of a mixture of emerging C. difficile strains. While minimum recommended cooking time/temperature combinations (63–71°C allowed concurrently tested strains to survive, higher subboiling temperatures reproducibly favored the selection of newly emerging C. difficile PCR ribotype 078. Survival ratios for “ribotypes 078” :  “other ribotypes” (n=49 : 45 isolates from the mid-2000s increased from 1 : 1 and 0.7 : 1 at 85°C (for 5 and 10 minutes, resp. to 2.3 : 1 and 3 : 1 with heating at 96°C (for 5 and 10 minutes, resp. indicating an interaction effect between the heating temperature and survival of C. difficile genotypes. In multistrain heating experiments, with PCR ribotypes 027 and 078 from 2004 and reference type strain ATCC 9689 banked in the 1970s, multinomial logistic regression (P<0.01 revealed PCR ribotype 078 was the most resistant to increasing lethal heat treatments. Thermal processes (during cooking or disinfection may contribute to the selection of emergent specific virulent strains of C. difficile. Despite growing understanding of the role of cooking on human evolution, little is known about the role of cooking temperatures on the selection and evolution of enteric pathogens, especially spore-forming bacteria.

Airway inflammation among compost workers exposed to actinomycetes spores

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Kari Kulvik Heldal

2015-05-01

Full Text Available Objectives. To study the associations between exposure to bioaerosols and work-related symptoms, lung function and biomarkers of airway inflammation in compost workers. Materials and method. Personal full-shift exposure measurements were performed on 47 workers employed at five windrow plants (n=20 and five reactor plants (n=27. Samples were analyzed for endotoxins, bacteria, fungal and actinomycetes spores. Health examinations were performed on workers and 37 controls before and after work on the day exposure was measured. The examinations included symptoms recorded by questionnaire, lung function by spirometry and nasal dimensions by acoustic rhinometry (AR. The pneumoproteins CC16, SP-D and SP-A were measured in a blood sample drawn at the end of the day. Results. The levels of endotoxins (median 3 EU/m[sup]3[/sup] , range 0–730 EU/m[sup]3[/sup] and actinomycetes spores (median 0.2 × 10[sup]6[/sup] spores/m[sup]3[/sup] , range 0–590 × 10[sup]6[/sup] spores/m[sup]3[/sup] were significantly higher in reactor plants compared to windrow plants. However, windrow composting workers reported more symptoms than reactor composting workers, probably due to use of respiratory protection. Exposure-response relationships between actinomycetes spores exposure and respiratory effects, found as cough and nose irritation during a shift, was significantly increased (OR 4.3, 95% CI 1.1–16, OR 6.1, 95% CI 1.5–25, respectively, p<0.05 among workers exposed to 0.02–0.3 × 10[sup]6[/sup] actinomycetes spores/m 3 , and FEV1/FVC% decreased cross shift (b=–3.2, SE=1.5%, p<0.01. Effects were weaker in the highest exposed group, but these workers used respiratory protection, frequently limiting their actual exposure. No relationships were found between exposure and pneumoprotein concentrations. Conclusions. The major agent in the aerosol generated at compost plants was actinomycetes spores which was associated with work related cough symptoms and work

Incidence, treatment, and survival patterns for sacral chordoma in the United States, 1974-2011

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Esther Yu

2016-09-01

Full Text Available IntroductionSacral chordomas represent one half of all chordomas, a rare neoplasm of notochordal remnants. Current NCCN guidelines recommend surgical resection with or without adjuvant radiotherapy, or definitive radiation for unresectable cases. Recent advances in radiation for chordomas include conformal photon and proton beam radiation. We investigated incidence, treatment, and survival outcomes to observe any trends in response to improvements in surgical and radiation techniques over a near 40 year time period.Materials and Methods345 microscopically confirmed cases of sacral chordoma were identified between 1974 and 2011 from the Surveillance, Epidemiology, and End Results (SEER program of the National Cancer Institute. Cases were divided into three cohorts by calendar year, 1974-1989, 1990-1999, and 2000-2011, as well as into two groups by age less than or equal to 65 versus greater than 65 to investigate trends over time and age via Chi-square analysis. Kaplan-Meier analyses were performed to determine effects of treatment on survival. Multivariate Cox regression analysis was performed to determine predictors of overall survival.Results5-year overall survival for the entire cohort was 60.0%. Overall survival correlated significantly with treatment modality, with 44% surviving at 5 years with no treatment, 52% with radiation alone, 82% surgery alone, and 78% surgery and radiation (p<.001. Age greater than 65 was significantly associated with non-surgical management with radiation alone or no treatment (p<.001. Relatively fewer patients received radiation between 2000 and 2011 compared to prior time periods (p=.03 versus surgery, for which rates which did not vary significantly over time (p=.55. However, 5-year overall survival was not significantly different by time period. Age group and treatment modality were predictive for overall survival on multivariate analysis (p<.001. ConclusionSurgery remains an important component in the

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.

Architecture and Assembly of the Bacillus subtilis Spore Coat

Science.gov (United States)

2014-09-26

with chromosomal DNA was as described [32]. Table 1. 8. subtifis strains used in this study. Stra in Genotype Phenotype• PS832 wild type PS3394...of the morphology of fully hydrated and air dried spores demonstrate that surface ridges on dehydrated spores mostly disappear or decrease in size

Diurnal variations of airborne fungal spores concentration in the town and rural area

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Idalia Kasprzyk

2012-12-01

Full Text Available Airborne fungal spores were monitored in 2001-2002 in Rzeszów (town and its neighborhood. The aim of investigations was to ascertain if there were differences in diurnal variations of airborne fungal spores concentration between town and rural area. The sampling was carried out using volumetric method. Traps were located at the same heights - app. 12 m. Airborne spores were sampled continuously. Microscopical slides were prepared for each day. Analysis was carried out on one longitudinal band of 48 mm long divided into 24 segments corresponding following hours of day. The results were expressed as mean number of fungal spores per cubic meter per 24 hours. For this survey, five geni of allergenic fungi were selected: Alternaria, Botrytis, Cladosporium, Epicoccum, Ganoderma. The concentrations of their airborne spores were high or very high. It was calculated theoretical day, where the hourly count was the percentage mean of number of spores at that time every chosen day without rainfall from 2001 and 2001 years. The diurnal periodicity of Alternaria, Cladosporium, Epicoccum and Ganoderma showed one peak, while Botrytis two. Anamorphic spores peaked in the afternoon, while their minima occurred in the morning. The highest concentrations of Ganoderma basidiospores were at down or at night, but minima during the day. There were no clear differences in the peak values between two studied sites. The results indicate that maximum concentrations of all spores generally occurred a few hour earlier in the rural area than in the town. Probably, in the rural area airborne spores came from many local sources and their diurnal periodicity reflected rhythm of spore liberation. Towns are characterized by specific microclimate with higher temperature and wind blowing to the centre. In Rzeszów fungal spores could be transported outside and carried out by wind from distant sources. This study showed, among others, that habitat conditions are an important factors

Using Spores for Fusarium spp. Classification by MALDI-Based Intact Cell/Spore Mass Spectrometry

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Wolfgang Winkler

2012-01-01

Full Text Available Fusarium is a widespread genus of filamentous fungi and a member of the soil microbial community. Certain subspecies are health threatening because of their mycotoxin production that affects the human and animal food chain. Thus, for early and effective pest control, species identification is of particular interest; however, differentiation on the subspecies level is challenging and time-consuming for this fungus. In the present study, we show the possibilities of intact cell mass spectrometry for spore analysis of 22 different Fusarium strains belonging to six Fusarium subspecies. We found that species differentiation is possible if mass spectrometric analyses are performed under well-defined conditions with fixed parameters. A critical point for analysis is a proper sample preparation of spores, which increases the quality of mass spectra with respect to signal intensity and m/z value variations. It was concluded that data acquistion has to be performed automatically; otherwise, user-specific variations are introduced generating data which cannot fit the existing datasets. Data that show clearly that matrix-assisted laser desorption ionization-based intact cell/intact spore mass spectrometry (IC/ISMS can be applied to differentiate closely related Fusarium spp. are presented. Results show a potential to build a database on Fusarium species for accurate species identification, for fast response in the case of infections in the cornfield. We furthermore demonstrate the high precision of our approach in classification of intact Fusarium species according to the location of their collection.

Recent progress in Bacillus subtilis spore-surface display: concept, progress, and future.

Science.gov (United States)

Wang, He; Wang, Yunxiang; Yang, Ruijin

2017-02-01

With the increased knowledge on spore structure and advances in biotechnology engineering, the newly developed spore-surface display system confers several inherent advantages over other microbial cell-surface display systems including enhanced stability and high safety. Bacillus subtilis is the most commonly used Bacillus species for spore-surface display. The expression of heterologous antigen or protein on the surface of B. subtilis spores has now been practiced for over a decade with noteworthy success. As an update and supplement to other previous reviews, we comprehensively summarize recent studies in the B. subtilis spore-surface display technique. We focus on its benefits as well as the critical factors affecting its display efficiency and offer suggestions for the future success of this field.

Delay of Treatment Initiation Does Not Adversely Affect Survival Outcome in Breast Cancer.

Science.gov (United States)

Yoo, Tae-Kyung; Han, Wonshik; Moon, Hyeong-Gon; Kim, Jisun; Lee, Jun Woo; Kim, Min Kyoon; Lee, Eunshin; Kim, Jongjin; Noh, Dong-Young

2016-07-01

Previous studies examining the relationship between time to treatment and survival outcome in breast cancer have shown inconsistent results. The aim of this study was to analyze the overall impact of delay of treatment initiation on patient survival and to determine whether certain subgroups require more prompt initiation of treatment. This study is a retrospective analysis of stage I-III patients who were treated in a single tertiary institution between 2005 and 2008. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to evaluate the impact of interval between diagnosis and treatment initiation in breast cancer and various subgroups. A total of 1,702 patients were included. Factors associated with longer delay of treatment initiation were diagnosis at another hospital, medical comorbidities, and procedures performed before admission for surgery. An interval between diagnosis and treatment initiation as a continuous variable or with a cutoff value of 15, 30, 45, and 60 days had no impact on disease-free survival (DFS). Subgroup analyses for hormone-responsiveness, triple-negative breast cancer, young age, clinical stage, and type of initial treatment showed no significant association between longer delay of treatment initiation and DFS. Our results show that an interval between diagnosis and treatment initiation of 60 days or shorter does not appear to adversely affect DFS in breast cancer.

Improved survival with an innovative approach to the treatment of severely burned patients: development of a burn treatment manual.

Science.gov (United States)

Morisada, S; Nosaka, N; Tsukahara, K; Ugawa, T; Sato, K; Ujike, Y

2015-09-30

The management of severely burned patients remains a major issue worldwide as indicated by the high incidence of permanent debilitating complications and poor survival rates. In April 2012, the Advanced Emergency & Critical Care Medical Center of the Okayama University Hospital began implementing guidelines for severely burned patients, distributed as a standard burn treatment manual. The protocol, developed in-house, was validated by comparing the outcomes of patients with severe extensive burns (SEB) treated before and after implementation of these new guidelines at this institution. The patients included in this study had a burn index (BI) ≥30 or a prognostic burn index (PBI = BI + patient's age) ≥100. The survival rate of the patients with BI ≥30 was 65.2% with the traditional treatment and 100% with the new guidelines. Likewise, the survival rate of the patients with PBI ≥100 was 61.1% with the traditional treatment compared to 100% with the new guidelines. Together, these data demonstrate that the new treatment guidelines dramatically improved the treatment outcome and survival of SEB patients.

Disinfection and regrowth potential of bacillus subtilis spores by ozone, ultraviolet rays and gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Kim, Hae Yeon; Lee, O Mi; Kim, Tae Hun; Lee, Myun Joo; Yu, Seung Ho [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2009-06-15

Chlorination has been the most commonly adopted disinfection process for the treatment of drinking water. However, Cryptosporidium parvum oocysts and Giardia lamblia cysts were not treated effectively by the common chlorine-based disinfectants. Additionally the regrowth of pathogenic microorganisms is associated with hygienic and aesthetic problems for the consumers of drinking water. Study on alternative disinfection processes such as ozone, UV-C, VUV and gamma irradiation were conducted. Bacillus subtilis spores have been used as a surrogate microorganism for Cryptosporidium parvum oocysts and Giardia lamblia cyst. Inactivation efficiency by ozone was from 30% to 96% within the range of 5 min to 120 min exposures. Inactivation efficiencies by UV-C and VUV were 95.18%, 95.07% at 30 sec, respectively. Inactivation efficiency at gamma irradiation dose of 2 kGy was 99.4%. Microbial regrowths after ozone, UV-C, VUV and gamma irradiation disinfections were also evaluated for 4 days. Bacillus subtilis spores after ozone treatment for 120 min exposure at the rate of 1.68 mg {center_dot} min{sup -1} showed 96.02% disinfection efficiency and significant microbial regrowth. Bacillus subtilis spores after UV-C (99.25% disinfection efficiency) and VUV (99.67% disinfection efficiency) treatments for 5 min showed gradual regrowth. However, inactivation efficiency of gamma irradiation at dose of 1 kGy was 98.8% and the disinfected sample showed no microbial regrowth for 4 days. Therefore, gamma irradiation is the most effective process for the disinfection of pathogenic microorganisms such as oocysts of protozoan parasites among four disinfection process.

Disinfection and regrowth potential of bacillus subtilis spores by ozone, ultraviolet rays and gamma irradiation

International Nuclear Information System (INIS)

Kim, Hae Yeon; Lee, O Mi; Kim, Tae Hun; Lee, Myun Joo; Yu, Seung Ho

2009-01-01

Chlorination has been the most commonly adopted disinfection process for the treatment of drinking water. However, Cryptosporidium parvum oocysts and Giardia lamblia cysts were not treated effectively by the common chlorine-based disinfectants. Additionally the regrowth of pathogenic microorganisms is associated with hygienic and aesthetic problems for the consumers of drinking water. Study on alternative disinfection processes such as ozone, UV-C, VUV and gamma irradiation were conducted. Bacillus subtilis spores have been used as a surrogate microorganism for Cryptosporidium parvum oocysts and Giardia lamblia cyst. Inactivation efficiency by ozone was from 30% to 96% within the range of 5 min to 120 min exposures. Inactivation efficiencies by UV-C and VUV were 95.18%, 95.07% at 30 sec, respectively. Inactivation efficiency at gamma irradiation dose of 2 kGy was 99.4%. Microbial regrowths after ozone, UV-C, VUV and gamma irradiation disinfections were also evaluated for 4 days. Bacillus subtilis spores after ozone treatment for 120 min exposure at the rate of 1.68 mg · min -1 showed 96.02% disinfection efficiency and significant microbial regrowth. Bacillus subtilis spores after UV-C (99.25% disinfection efficiency) and VUV (99.67% disinfection efficiency) treatments for 5 min showed gradual regrowth. However, inactivation efficiency of gamma irradiation at dose of 1 kGy was 98.8% and the disinfected sample showed no microbial regrowth for 4 days. Therefore, gamma irradiation is the most effective process for the disinfection of pathogenic microorganisms such as oocysts of protozoan parasites among four disinfection process

Effect of enterogermina (Bacillus clausii spores) on the productive performance of broilers

OpenAIRE

Núñez Torres, Oscar; Arévalo Castro, Renato P.; Kelly, Gerardo; Guerrero, Jorge R.

2017-01-01

The effect of a commercial probiotic, Enterogermina (Bacillus clausii spores) in the drinking water on the productive performance of broilers was evaluated. A total of 280 male broilers, Cobb line, of one day of age were used for 49 days. The chicks were distributed in four treatments with seven replicates per treatment: T0 = balanced feed (control), T1, T2 and T3 = balanced feed + 0.25, 0.50 and 0.75 ml of enterogermina per liter of water, respectively, in a randomized complete block design....

Effect of Nanoencapsulated Vitamin B1 Derivative on Inhibition of Both Mycelial Growth and Spore Germination of Fusarium oxysporum f. sp. raphani

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Hyeon Yong Lee

2013-02-01

Full Text Available Nanoencapsulation of thiamine dilauryl sulfate (TDS, a vitamin B1 derivative, was proved to effectively inhibit the spore germination of Fusarium oxysporum f. sp. raphani (F. oxysporum, as well as mycelial growth. The average diameter of nanoparticles was measured as 136 nm by being encapsulated with an edible encapsulant, lecithin, whose encapsulation efficiency was about 55% in containing 200 ppm of TDS concentration: the 100 ppm TDS nanoparticle solution showed a mycelial growth inhibition rate of 59%. These results were about similar or even better than the cases of treating 100 ppm of dazomet, a positive antifungal control (64%. Moreover, kinetic analysis of inhibiting spore germination were estimated as 6.6% reduction of spore germination rates after 24 h treatment, which were 3.3% similar to the case of treating 100 ppm of a positive control (dazomet for the same treatment time. It was also found that TDS itself could work as an antifungal agent by inhibiting both mycelial growth and spore germination, even though its efficacy was lower than those of nanoparticles. Nanoparticles especially played a more efficient role in limiting the spore germination, due to their easy penetration into hard cell membranes and long resident time on the surface of the spore shell walls. In this work, it was first demonstrated that the nanoparticle of TDS not a harmful chemical can control the growth of F. oxysporum by using a lower dosage than commercial herbicides, as well as the inhibiting mechanism of the TDS. However, field trials of the TDS nanoparticles encapsulated with lecithin should be further studied to be effectively used for field applications.

Breaking the spores of Ganoderma lucidum by fermentation with ...

African Journals Online (AJOL)

In this paper, fermentation of G. lucidum with Lactobacillus plantarum was applied to break down the sporoderm. Scanning electron microscope (SEM) was used to characterize the spores. The broken spores were found on the 3rd day and complete breaking on the 5th day of fermentation. Lactic acid, acetic acid and ...

Bacillus subtilis spores as vaccine adjuvants: further insights into the mechanisms of action.

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Renata Damásio de Souza

Full Text Available Bacillus subtilis spores have received growing attention regarding potential biotechnological applications, including the use as probiotics and in vaccine formulations. B. subtilis spores have also been shown to behave as particulate vaccine adjuvants, promoting the increase of antibody responses after co-administration with antigens either admixed or adsorbed on the spore surface. In this study, we further evaluated the immune modulatory properties of B. subtilis spores using a recombinant HIV gag p24 protein as a model antigen. The adjuvant effects of B. subtilis spores were not affected by the genetic background of the mouse lineage and did not induce significant inflammatory or deleterious effects after parenteral administration. Our results demonstrated that co-administration, but not adsorption to the spore surface, enhanced the immunogenicity of that target antigen after subcutaneous administration to BALB/c and C57BL/6 mice. Spores promoted activation of antigen presenting cells as demonstrated by the upregulation of MHC and CD40 molecules and enhanced secretion of pro-inflammatory cytokines by murine dendritic cells. In addition, in vivo studies indicated a direct role of the innate immunity on the immunomodulatory properties of B. subtilis spores, as demonstrated by the lack of adjuvant effects on MyD88 and TLR2 knockout mouse strains.

Bacterial spores as possible contaminants of biomedical materials and devices. [Bacillus anthracis, clostridium botulinum, C. perfringens, C. tetani

Energy Technology Data Exchange (ETDEWEB)

Grecz, N; Kang, T

1973-01-01

Destruction of spores on biomedical devices in drugs, and biologicals is essential for prevention of infection of patients with pathogenic sporeformers. Of particular concern are Clostridium tetani, C. perfringens, C. botulinum, Bacillus anthracis and other sporeforming pathogens. Spores are ubiquitous in nature and contamination of biomedical devices varies depending on manufacturing process, handling, raw materials and other variables. In the last 20 years the number of cases per year of specific notifiable diseases in the United States was as follows: tetanus, 120 to 500 cases, botulism, 7 to 47 cases, and anthrax, 2 to 10 cases. Gas gangrene is caused by a mixed flora consisting predominantly of sporeformers. C botulinum, which usually acts as saprophytic agent of food poisoning, may also initiate pathogenic processes; there are nine cases on record in the United States of botulism wound infections almost half of which ended in death. The spores of these organisms are distinguished by high radiation resistance and their erradication often requires severe radiation treatments. Representative bacterial spores in various suspending media show D/sub 10/ values (dose necessary to destroy 90 percent of a given population) ranging from approximately 0.1 to 0.4 Mrad. Some viruses show D/sub 10/ values up to greater than 1 Mrad. The D/sub 10/-values of spores vary depending on physical, chemical and biological factors. This variability is important in evaluation and selection of biological indicator organisms. Radiation sterilization of biomedical devices and biomedical materials must provide safety from infectious microorganisms including radiation resistant spores and viruses.

Assessment of Clostridium perfringens spore response to high hydrostatic pressure and heat with nisin.

Science.gov (United States)

Gao, Yulong; Qiu, Weifen; Wu, Ding; Fu, Qiang

2011-08-01

The elimination of spores from low-acid foods presents food-processing and food-safety challenges to high-pressure processing (HPP) developers as bacterial spores are extremely resistant to pressure. Therefore, the effects of pressure (400-800 MPa), temperature (35-95 °C), and nisin (0-496 IU/mL) on the inactivation of Clostridium perfringens AS 64701 spores at various pressure-holding times (7.5-17.5 min) were explored. A second-order polynomal equation for HPP- and nisin-induced inactivation of C. perfringens spores was constructed with response surface methodology. Experiment results showed that the experimental values were shown to be significantly in agreement with the predicted values because the adjusted determination coefficient (R (Adj)²) was 0.9708 and the level of significance was P pressure of 654 Mpa, temperature of 74 °C, pressure-holding time of 13.6 min, and nisin concentration of 328 IU/mL. The validation of the model equation for predicting the optimum response values was verified effectively by ten test points that were not used in the establishment of the model. Compared with conventional HPP techniques, the main process advantages of HPP-nisin combination sterilization in the UHT milk are, lower pressure, temperature, natural preservative (nisin), and in a shorter treatment time. The synergistic inactivation of bacteria by HPP-nisin combination is a promising and natural method to increase the efficiency and safety of high-pressure pasteurization.

Microfungal spores (Ustilago maydis and U. digitariae) immobilised chitosan microcapsules for heavy metal removal.

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Sargın, İdris; Arslan, Gulsin; Kaya, Murat

2016-03-15

Designing effective chitosan-based biosorbents from unexploited biomass for heavy metal removal has received much attention over the past decade. Ustilago, loose smut, is a ubiquitous fungal plant pathogen infecting over 4000 species including maize and weed. This study aimed to establish whether the spores of the phytopathogenic microfungi Ustilago spores can be immobilised in cross-linked chitosan matrix, and it reports findings on heavy metal sorption performance of chitosan/Ustilago composite microcapsules. Immobilisation of Ustilago maydis and U. digitariae spores (from maize and weed) in chitosan microcapsules was achieved via glutaraldehyde cross-linking. The cross-linked microcapsules were characterised using scanning electron microscopy, FT-IR spectroscopy and thermogravimetric analysis. Sorption capacities of chitosan-U. maydis and chitosan-U. digitariae microcapsules were investigated and compared to cross-linked chitosan beads: Cu(II): 66.72, 69.26, 42.57; Cd(II): 49.46, 53.96, 7.87; Cr(III): 35.88, 49.40, 43.68; Ni(II): 41.67, 33.46, 16.43 and Zn(II): 30.73, 60.81, 15.04mg/g, respectively. Sorption experiments were conducted as a function of initial metal ion concentration (2-10mg/L), contact time (60-480min), temperature (25, 35 and 45°C), amount of the sorbent (0.05-0.25g) and pH of the metal solution. The microcapsules with spores exhibited better performance over the plain chitosan beads, demonstrating their potential use in water treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stingless bees (Hymenoptera, Meliponini feeding on stinkhorn spores (Fungi, Phallales: robbery or dispersal?

Directory of Open Access Journals (Sweden)

Marcio L. Oliveira

2000-09-01

Full Text Available Records about stingless bee-fungi interaction are very rare. In Brazilian Amazonia, workers of Trigona crassipes (Fabricius, 1793 and Trigona fulviventris Guérin, 1835 visiting two stinkhorn species, Dictyophora sp. and Phallus sp., respectively, were observed. The workers licked the fungi gleba, a mucilaginous mass of spores covering the pileum. Neither gleba residue nor spores were found on the body surface of these bee workers. These observations indicate that these bee species include spores as a complement in their diet. On the other hand, they also suggest that these stingless bees can, at times, facilitale spore dispersal, in case intact spores are eliminated with the feces.

Food sensing: selection and characterization of DNA aptamers to Alicyclobacillus spores for trapping and detection from orange juice.

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Hünniger, Tim; Fischer, Christin; Wessels, Hauke; Hoffmann, Antonia; Paschke-Kratzin, Angelika; Haase, Ilka; Fischer, Markus

2015-03-04

The quality of the beverage industry's products has to be constantly monitored to fulfill consumers' high expectations. The thermo-acidophilic Gram-positive Alicyclobacillus spp. are not pathogenic, but their heat-resistant endospores can survive juice-processing conditions and have become a major economic concern for the fruit juice industry. Current detection methods rely on cultivation, isolation, and organism identification, which can take up to a week, resulting in economic loss. This work presents the selection and identification of DNA aptamers targeting Alicyclobacillus spores by spore-SELEX (systematic evolution of ligands by exponential enrichment) in orange-juice-simulating buffer. The selection process was verified by various techniques, including flow cytometric binding assays, radioactive binding assays, and agarose gel electrophoresis. The subsequent aptamer characterization included the determination of dissociations constants and selectivity by different techniques, such as surface plasmon resonance spectroscopy and fluorescence microscopy. In summary, 10 different aptamers with an affinity to Alicyclobacillus spp. have been developed, analyzed, and characterized in terms of affinity and specificity.

Proteomic Analysis of Bacillus cereus Spores

National Research Council Canada - National Science Library

Schwandt, Kerrie

2002-01-01

.... All of the identified proteins were plausible spore components, and included chaperonins, sporulation regulators, ribosomal proteins, proteases, and metabolic enzymes involved in energy production...

Reinforcement of Bacillus subtilis spores by cross-linking of outer coat proteins during maturation.

Science.gov (United States)

Abhyankar, Wishwas; Pandey, Rachna; Ter Beek, Alexander; Brul, Stanley; de Koning, Leo J; de Koster, Chris G

2015-02-01

Resistance characteristics of bacterial endospores towards various environmental stresses such as chemicals and heat are in part attributed to their coat proteins. Heat resistance is developed in a late stage of sporulation and during maturation of released spores. Using our gel-free proteomic approach and LC-FT-ICR-MS/MS analysis we have monitored the efficiency of the tryptic digestion of proteins in the coat during spore maturation over a period of eight days, using metabolically (15)N labeled mature spores as reference. The results showed that during spore maturation the loss of digestion efficiency of outer coat and crust proteins synchronized with the increase in heat resistance. This implicates that spore maturation involves chemical cross-linking of outer coat and crust layer proteins leaving the inner coat layer proteins unmodified. It appears that digestion efficiencies of spore surface proteins can be linked to their location within the coat and crust layers. We also attempted to study a possible link between spore maturation and the observed heterogeneity in spore germination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Demulsification of crude oil-in-water emulsions by means of fungal spores.

Directory of Open Access Journals (Sweden)

Alba Adriana Vallejo-Cardona

Full Text Available The present feature describes for the first time the application of spores from Aspergillus sp. IMPMS7 to break out crude oil-in-water emulsions (O/W. The fungal spores were isolated from marine sediments polluted with petroleum hydrocarbons. The spores exhibited the ability to destabilize different O/W emulsions prepared with medium, heavy or extra-heavy Mexican crude oils with specific gravities between 10.1 and 21.2°API. The isolated fungal spores showed a high hydrophobic power of 89.3 ± 1.9% and with 2 g of spores per liter of emulsion, the half-life for emulsion destabilization was roughly 3.5 and 0.7 h for extra-heavy and medium crude oil, respectively. Then, the kinetics of water separation and the breaking of the O/W emulsion prepared with heavy oil through a spectrofluorometric technique were studied. A decrease in the fluorescence ratio at 339 and 326 nm (I339/I326 was observed in emulsions treated with spores, which is similar to previously reported results using chemical demulsifiers.

Mechanism and site of inhibition of Bacillus cereus spore outgrowth by nitrosothiols

International Nuclear Information System (INIS)

Morris, S.L.

1982-01-01

Structure vs. activity studies demonstrate that nitrosothiols inhibit outgrowth of B. cereus spores by reversible covalent bond formation with sensitive spore components. Kinetic studies of the binding of nitrosothiols and iodoacetate, a known sulfhydryl reagent, show that they complete for the same spore sites. Since two other nitrite derivatives, the Perigo factor and the transferrin inhibitor, interfere with iodoacetate label uptake in a kinetically similar fashion, all of these compounds may inhibit spore outgrowth by interacting with the same spore thiol groups. Disruption of spores which have been inhibited by radioactive iodoacetate demonstrates that much of the label is incorporated into a membrane-rich fraction that sediments as a single peak on a sucrose density gradient. SDS gel electrophoresis and autofluorography allows the identification of four intensely labelled proteins with molecular weights of 13,000, 28,000, 29,000, and 30,000. If the iodoacetate labelling is carried out in the presence of nitrosothiol, incorporation is greatly reduced into all components. When germinating spores are labelled with succinate or the lactose analog, o-nitrophenylgalactopyranoside, a significant reduction in the amount of label bound is also observed suggesting that two iodoacetate-reactive sites may be the succinate and lactose permease systems. Severe decreases in the transport of succinate and lactose into iodoacetate and nitrosothiol inhibited spores further implicates a nitrosothiol (iodoacetate) permease interaction. Iodoacetate and nitrosothiols therefore may exert their inhibitory effects by interfering with critical membrane protein sulfhydryl groups, possibly by a a covalent modification mechanism. Some of these sensitive thiols may be involved in active transport processes

A Novel Spectroscopic Methodology for the Investigation of Individual Bacillus Spores

National Research Council Canada - National Science Library

Alexander, Troy A; Pellegrino, Paul; Gillespie, James B

2005-01-01

A methodology has been developed for the investigation of bacterial spores. Specifically, this method has been used to probe the spore coat composition of two different Bacillus stearothermophilus variants...

Effect of a new fluorochrome on pre- and post-UV treatment of Taphrina maculans Butler

International Nuclear Information System (INIS)

Singh, U.P.; Nagai, S.

1977-01-01

Taphrina maculans Butler incites leaf spots disease in turmeric (Curcuma longa L.) plants. The patogen forms two types of colonies namely, salmon-red and creamy-white in the artifical medium when isolated from a single infection spot. Both strains resemble yeasts in morphology. The two strains were subjected to UV irradiation. The salmon-red one showed higher resistance to UV than the white one, presumably due to the presence of a red pigment in the former. When spores of the salmon-red strain were pre-treated with a new fluorochrome Hoechst 33258 the survival decreased. Decreased survival of the salmon-red strain was also oberved during post-treatment which is probably due to the combined effect of UV and dye. The creamy-white strain differs from the salmon-red one in UV sensitivity, and also during combined treatment with UV and dye. During pre-treatment the organism shows more survival than during post-treatment with the fluorochrome. This differential response is discussed in the light of repair mechanisms involved in the organism. (author)

Modeling the recovery of heat-treated Bacillus licheniformis Ad978 and Bacillus weihenstephanensis KBAB4 spores at suboptimal temperature and pH using growth limits.

Science.gov (United States)

Trunet, C; Mtimet, N; Mathot, A-G; Postollec, F; Leguerinel, I; Sohier, D; Couvert, O; Carlin, F; Coroller, L

2015-01-01

The apparent heat resistance of spores of Bacillus weihenstephanensis and Bacillus licheniformis was measured and expressed as the time to first decimal reduction (δ value) at a given recovery temperature and pH. Spores of B. weihenstephanensis were produced at 30°C and 12°C, and spores of B. licheniformis were produced at 45°C and 20°C. B. weihenstephanensis spores were then heat treated at 85°C, 90°C, and 95°C, and B. licheniformis spores were heat treated at 95°C, 100°C, and 105°C. Heat-treated spores were grown on nutrient agar at a range of temperatures (4°C to 40°C for B. weihenstephanensis and 15°C to 60°C for B. licheniformis) or a range of pHs (between pH 4.5 and pH 9.5 for both strains). The recovery temperature had a slight effect on the apparent heat resistance, except very near recovery boundaries. In contrast, a decrease in the recovery pH had a progressive impact on apparent heat resistance. A model describing the heat resistance and the ability to recover according to the sporulation temperature, temperature of treatment, and recovery temperature and pH was proposed. This model derived from secondary mathematical models for growth prediction. Previously published cardinal temperature and pH values were used as input parameters. The fitting of the model with apparent heat resistance data obtained for a wide range of spore treatment and recovery conditions was highly satisfactory. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Fungal spores as potential ice nuclei in fog/cloud water and snow

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Bauer, Heidi; Goncalves, Fabio L. T.; Schueller, Elisabeth; Puxbaum, Hans

2010-05-01

INTRODUCTION: In discussions about climate change and precipitation frequency biological ice nucleation has become an issue. While bacterial ice nucleation (IN) is already well characterized and even utilized in industrial processes such as the production of artificial snow or to improve freezing processes in food industry, less is known about the IN potential of fungal spores which are also ubiquitous in the atmosphere. A recent study performed at a mountain top in the Rocky Mountains suggests that fungal spores and/or pollen might play a role in increased IN abundance during periods of cloud cover (Bowers et al. 2009). In the present work concentrations of fungal spores in fog/cloud water and snow were determined. EXPERIMENTAL: Fog samples were taken with an active fog sampler in 2008 in a traffic dominated area and in a national park in São Paulo, Brazil. The number concentrations of fungal spores were determined by microscopic by direct enumeration by epifluorescence microscopy after staining with SYBR Gold nucleic acid gel stain (Bauer et al. 2008). RESULTS: In the fog water collected in the polluted area at a junction of two highly frequented highways around 22,000 fungal spores mL-1 were counted. Fog in the national park contained 35,000 spores mL-1. These results were compared with cloud water and snow samples from Mt. Rax, situated at the eastern rim of the Austrian Alps. Clouds contained on average 5,900 fungal spores mL-1 cloud water (1,300 - 11,000) or 2,200 spores m-3 (304 - 5,000). In freshly fallen snow spore concentrations were lower than in cloud water, around 1,000 fungal spores mL-1 were counted (Bauer et al. 2002). In both sets of samples representatives of the ice nucleating genus Fusarium could be observed. REFERENCES: Bauer, H., Kasper-Giebl, A., Löflund, M., Giebl, H., Hitzenberger, R., Zibuschka, F., Puxbaum, H. (2002). The contribution of bacteria and fungal spores to the organic carbon content of cloud water, precipitation and aerosols

Absorption edge imaging of sporocide-treated and non-treated bacterial spores

International Nuclear Information System (INIS)

Panessa-Warren, B.J.; Tortora, G.T.; Warren, J.B.

1987-01-01

When deprived of nutrients, spore forming bacilli produce endospores which are remarkably resistant to chemical sterilization. Little is known about the morphology and response fo these spores following exposure to sporocidal agents. Light microscopy does not provide sufficient resolution for studying the rupture of the spore coat and fate of intracellular material. Transmission and scanning electron microscopy offer superior resolution but require specimen preparation methods that induce physiologic as well as morphologic changes in the spores, thereby making accurate interpretation of micrographs difficult. To eliminate the possible artifacts induced by chemical fixation, dehydration, embeddment, staining and sectioning, treated and non-sporocide-treated endospores of B. thuringiensis and B. subtilis were imaged by x-ray contact microscopy using monochromatic x-rays. 6 refs., 2 figs

Mushroom's spore size and time of fruiting are strongly related: is moisture important?

Science.gov (United States)

Kauserud, Håvard; Heegaard, Einar; Halvorsen, Rune; Boddy, Lynne; Høiland, Klaus; Stenseth, Nils Chr

2011-04-23

Most basidiomycete fungi produce annual short-lived sexual fruit bodies from which billions of microscopic spores are spread into the air during a short time period. However, little is known about the selective forces that have resulted in some species fruiting early and others later in the fruiting season. This study of relationships between morphological and ecological characteristics, climate factors and time of fruiting are based upon thorough statistical analyses of 66 520 mapped records from Norway, representing 271 species of autumnal fruiting mushroom species. We found a strong relationship between spore size and time of fruiting; on average, a doubling of spore size (volume) corresponded to 3 days earlier fruiting. Small-spored species dominate in the oceanic parts of Norway, whereas large-spored species are typical of more continental parts. In separate analyses, significant relationships were observed between spore size and climate factors. We hypothesize that these relationships are owing to water balance optimization, driven by water storage in spores as a critical factor for successful germination of primary mycelia in the drier micro-environments found earlier in the fruiting season and/or in continental climates.

1-Octanol, a self-inhibitor of spore germination in Penicillium camemberti.

Science.gov (United States)

Gillot, Guillaume; Decourcelle, Nicolas; Dauer, Gaëlle; Barbier, Georges; Coton, Emmanuel; Delmail, David; Mounier, Jérôme

2016-08-01

Penicillium camemberti is a technologically relevant fungus used to manufacture mold-ripened cheeses. This fungal species produces many volatile organic compounds (VOCs) including ammonia, methyl-ketones, alcohols and esters. Although it is now well known that VOCs can act as signaling molecules, nothing is known about their involvement in P. camemberti lifecycle. In this study, spore germination was shown to be self-regulated by quorum sensing in P. camemberti. This phenomenon, also called "crowding effect", is population-dependent (i.e. observed at high population densities). After determining the volatile nature of the compounds involved in this process, 1-octanol was identified as the main compound produced at high-spore density using GC-MS. Its inhibitory effect was confirmed in vitro and 3 mM 1-octanol totally inhibited spore germination while 100 μM only transiently inhibited spore germination. This is the first time that self-inhibition of spore germination is demonstrated in P. camemberti. The obtained results provide interesting perspectives for better control of mold-ripened cheese processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of delay to treatment upon survival in 1067 patients with breast-cancer.

Science.gov (United States)

Rabinovich, M; Vallejo, C; Perez, J; Rodriguez, R; Cuevas, M; Machiavelli, M; Lacava, J; Leone, B; Romero, A; Mickiewicz, E; Chacon, R; Estevez, R

1993-02-01

The medical records of 1067 patients with breast cancer were reviewed to evaluate the influence of delay between first symptom and first treatment upon survival. Three delay intervals were considered: 6 months. At a follow-up of 120 months, survival analyses identified a statistically significant difference (p=0.029) favoring patients with 3 months delay between first symptom and first treatment. Better survival rate for patients with a short delay would obey to a greater number of patients in favorable stages and a higher proportion of women aged 50 or older in this group.

Treatment for occult hepatocellular carcinoma: does it offer survival advantages over symptom-driven treatment?

Science.gov (United States)

Kim, Kwang Min; Kim, Jiyu; Sinn, Dong Hyun; Kim, Hye Seung; Kim, Kyunga; Kang, Wonseok; Gwak, Geum-Youn; Paik, Yong-Han; Choi, Moon Seok; Lee, Joon Hyeok; Koh, Kwang Cheol; Paik, Seung Woon

2018-04-03

In order to claim a benefit of screen-based diagnosis for asymptomatic individuals, treatment of occult disease needs to offer survival advantages compared to the treatment of symptomatic disease, yet information on this issue is scarce with regard to hepatocellular carcinoma (HCC) screening. A total of 3353 treatment-naïve, consecutive, newly diagnosed HCC patients [age: 57.9 ± 10.3, male: 2,689 (80.2%), hepatitis B virus: 2555 (76.2%)], diagnosed between 2010 and 2013 were analyzed. Data on the mode of detection was prospectively collected at the time of HCC diagnosis and was used to group patients into occult or symptomatic cases. Overall, 643 (19.2%) patients were symptomatic cases. The proportion of patients undergoing resection, radiofrequency ablation or transplantation were lower in symptomatic cases than occult cases (20.8 vs. 56.2%, p offered a survival benefit to patients over symptomatic cases. These data support screening practices for asymptomatic individuals to diagnose occult HCC.

Measurement and analysis on optical characteristics of Aspergillus oryzae spores in infrared band

Science.gov (United States)

Li, Le; Hu, Yihua; Gu, Youlin; Chen, Wei; Xu, Shilong; Zhao, Xinying

2015-10-01

Spore is an important part of bioaerosols. The optical characteristics of spore is a crucial parameter for study on bioaerosols. The reflection within the waveband of 2.5 to15μm were measured by squash method. Based on the measured data, Complex refractive index of Aspergillus oryzae spores within the waveband of 3 to 5μm and 8 to 14 μm were calculated by using Krames-Kronig (K-K) relationship. Then,the mass extinction coefficient of Aspergillus oryzae spores within the waveband of 3 to 5μm and 8 to 14μm were obtained by utilizing Mie scattering theory, and the results were analyzed and discussed. The average mass extinction coefficient of Aspergillus oryzae spores is 0.51 m2/g in the range of 3 to 5μm and 0.48m2/g in the range of 8 to 14μm. Compared with common inorganic compounds, Aspergillus oryzae spores possesses a good extinction performance in infrared band.

Evidence for the monomerization of spore photoproduct to two thymines by the light-independent 'spore repair' process in Bacillus subtilis

International Nuclear Information System (INIS)

Van Wang, T.-C.; Rupert, C.S.

1977-01-01

Ultraviolet irradiation of bacterial spores induces a unique DNA photoproduct, which yields mostly 5-thyminyl-5,6-dihydrothymine (Thy(α-5)hThy, or TDHT) on acid hydrolysis. One of the possible mechanisms for the observed removal of the photoproduct on spore germination ivolves its direct conversion back to two adjacent thymine residues, and additional evidence is presented in support of this theory. Studies were made of the fate of the TDHT radioactivity in irradiated, germinated B. subtilis spores labelled with 3 H-thymine or 14 C-thymine, and of the homogeneity of the thymine-peak radioactivity. The radioactivity disappearing from the TDHT peak on germination seemed to be stoichiometrically recovered in the thymine peak, and no new materials were detected under the thymine-peak radioactivity. No intermediates were detected in B. subtilis mutant 25D4 (hcr 42 - recA 1 - ), a strain which had given some promise of accumulating intermediates from an incomplete repair process. (U.K.)

The nature of water within bacterial spores: protecting life in extreme environments

Science.gov (United States)

Rice, Charles V.; Friedline, Anthony; Johnson, Karen; Zachariah, Malcolm M.; Thomas, Kieth J., III

2011-10-01

The bacterial spore is a formidable container of life, protecting the vital contents from chemical attack, antimicrobial agents, heat damage, UV light degradation, and water dehydration. The exact role of the spore components remains in dispute. Nevertheless, water molecules are important in each of these processes. The physical state of water within the bacterial spore has been investigated since the early 1930's. The water is found two states, free or bound, in two different areas, core and non-core. It is established that free water is accessible to diffuse and exchange with deuterated water and that the diffusible water can access all areas of the spore. The presence of bound water has come under recent scrutiny and has been suggested the water within the core is mobile, rather than bound, based on the analysis of deuterium relaxation rates. Using an alternate method, deuterium quadrupole-echo spectroscopy, we are able to distinguish between mobile and immobile water molecules. In the absence of rapid motion, the deuterium spectrum of D2O is dominated by a broad line, whose line shape is used as a characteristic descriptor of molecular motion. The deuterium spectrum of bacterial spores reveals three distinct features: the broad peak of immobilized water, a narrow line of water in rapid motion, and a signal of intermediate width. This third signal is assigned this peak from partially deuterated proteins with the spore in which N-H groups have undergone exchange with water deuterons to form N-D species. As a result of these observations, the nature of water within the spore requires additional explanation to understand how the spore and its water preserve life.

Spore inactivation and DPA release in Alicyclobacillus acidoterrestris under different stress conditions.

Science.gov (United States)

Bevilacqua, Antonio; Ciuffreda, Emanuela; Sinigaglia, Milena; Corbo, Maria Rosaria

2015-04-01

This paper reports on the inactivation of spores of 5 strains of Alicyclobacillus acidoterrestris under different stress conditions (acidic and alkaline pH, high temperature, addition of lysozyme, hydrogen peroxide and p-coumaric acid). The research was divided into two different steps; first, each stress was studied alone, thus pointing out a partial uncoupling between spore inactivation and DPA release, as H2O2 reduced spore level below the detection but it did not cause the release of DPA. A partial correlation was found only for acidic and alkaline pH. 2nd step was focused on the combination of pH, temperature and H2O2 through a factorial design; experiments were performed on both fresh and 4 month-old spores and pinpointed a different trend for DPA release as a function of spore age. Copyright © 2014 Elsevier Ltd. All rights reserved.

Thermal Inactivation of Bacillus anthracis Spores Using Rapid Resistive Heating

Science.gov (United States)

2016-03-24

agents. There is motivation for using thermal decontamination of B.a. spores for agent defeat scenarios. Spore-forming microorganisms are much...the top soil on Gruinard Island for over 40 years after the British detonated experimental anthrax bombs on the island during World War II (U.S

Hygiene Aspects of the Biogas Process with Emphasis on Spore-Forming Bacteria

Energy Technology Data Exchange (ETDEWEB)

Bagge, Elisabeth

2009-07-01

Biogas is a renewable source of energy which can be obtained from processing of biowaste. The digested residues can be used as fertiliser. Biowaste intended for biogas production contains pathogenic micro-organisms. A pre-pasteurisation step at 70 deg C for 60 min before anaerobic digestion reduces non spore-forming bacteria such as Salmonella spp. To maintain the standard of the digested residues it must be handled in a strictly hygienic manner to avoid recontamination and re-growth of bacteria. The risk of contamination is particularly high when digested residues are transported in the same vehicles as the raw material. However, heat treatment at 70 deg C for 60 min will not reduce spore-forming bacteria such as Bacillus spp. and Clostridium spp. Spore-forming bacteria, including those that cause serious diseases, can be present in substrate intended for biogas production. The number of species and the quantity of Bacillus spp. and Clostridium spp. in manure, slaughterhouse waste and in samples from different stages during the biogas process were investigated. The number of species of clostridia seemed to decrease following digestion, likewise the quantity. However, Bacillus spp. seemed to pass unaffected through the biogas process. In laboratory-scale experiments the effects on clostridia during pasteurisation and digestion were investigated. Pathogenic clostridia were inoculated in substrates from homogenisation tanks and digester tanks. The inoculated clostridia remained after pasteurisation, but the impacts of digestion differ between different species. Culture followed by identification of C. chauvoei by PCR in samples from cattle died from blackleg, is faster and safer than culture followed by biochemical identification of C. chauvoei. However, for environmental samples the PCR method is not practically applicable for detection of C. chauvoei. To avoid spreading of diseases via biogas plants when digested residues are spread on arable land, a pasteurisation

Adsorption of β-galactosidase of Alicyclobacillus acidocaldarius on wild type and mutants spores of Bacillus subtilis

Directory of Open Access Journals (Sweden)

Sirec Teja

2012-08-01

Full Text Available Abstract Background The Bacillus subtilis spore has long been used as a surface display system with potential applications in a variety of fields ranging from mucosal vaccine delivery, bioremediation and biocatalyst development. More recently, a non-recombinant approach of spore display has been proposed and heterologous proteins adsorbed on the spore surface. We used the well-characterized β-galactosidase from the thermoacidophilic bacterium Alicyclobacillus acidocaldarius as a model to study enzyme adsorption, to analyze whether and how spore-adsorption affects the properties of the enzyme and to improve the efficiency of the process. Results We report that purified β-galactosidase molecules were adsorbed to purified spores of a wild type strain of B. subtilis retaining ca. 50% of their enzymatic activity. Optimal pH and temperature of the enzyme were not altered by the presence of the spore, that protected the adsorbed β-galactosidase from exposure to acidic pH conditions. A collection of mutant strains of B. subtilis lacking a single or several spore coat proteins was compared to the isogenic parental strain for the adsorption efficiency. Mutants with an altered outermost spore layer (crust were able to adsorb 60-80% of the enzyme, while mutants with a severely altered or totally lacking outer coat adsorbed 100% of the β-galactosidase molecules present in the adsorption reaction. Conclusion Our results indicate that the spore surface structures, the crust and the outer coat layer, have an negative effect on the adhesion of the β-galactosidase. Electrostatic forces, previously suggested as main determinants of spore adsorption, do not seem to play an essential role in the spore-β-galactosidase interaction. The analysis of mutants with altered spore surface has shown that the process of spore adsorption can be improved and has suggested that such improvement has to be based on a better understanding of the spore surface structure

Perioperative blood transfusion does not decrease survival after surgical treatment of spinal metastases

DEFF Research Database (Denmark)

Clausen, Caroline; Lönn, Lars; Morgen, Søren Schmidt

2014-01-01

PURPOSE: To assess whether perioperative allogenic blood transfusions in patients undergoing surgical treatment for spinal metastases independently influence patient survival. METHODS: A retrospective study including 170 consecutive patients undergoing surgical treatment for spinal metastases in ...... 12-month survival. Future studies should assess if a liberal transfusion regime can be applied to this group of patients; thereby, prioritizing early postoperative mobilization....

Estimating the average treatment effect on survival based on observational data and using partly conditional modeling.

Science.gov (United States)

Gong, Qi; Schaubel, Douglas E

2017-03-01

Treatments are frequently evaluated in terms of their effect on patient survival. In settings where randomization of treatment is not feasible, observational data are employed, necessitating correction for covariate imbalances. Treatments are usually compared using a hazard ratio. Most existing methods which quantify the treatment effect through the survival function are applicable to treatments assigned at time 0. In the data structure of our interest, subjects typically begin follow-up untreated; time-until-treatment, and the pretreatment death hazard are both heavily influenced by longitudinal covariates; and subjects may experience periods of treatment ineligibility. We propose semiparametric methods for estimating the average difference in restricted mean survival time attributable to a time-dependent treatment, the average effect of treatment among the treated, under current treatment assignment patterns. The pre- and posttreatment models are partly conditional, in that they use the covariate history up to the time of treatment. The pre-treatment model is estimated through recently developed landmark analysis methods. For each treated patient, fitted pre- and posttreatment survival curves are projected out, then averaged in a manner which accounts for the censoring of treatment times. Asymptotic properties are derived and evaluated through simulation. The proposed methods are applied to liver transplant data in order to estimate the effect of liver transplantation on survival among transplant recipients under current practice patterns. © 2016, The International Biometric Society.

Survival and behavior of silver catfish, Rhamdia quelen, submitted to antibiotics and sodium chloride treatments

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Andrade Luciana Segura de

2006-01-01

Full Text Available In order to evaluate the use of antibiotics and NaCl on the behavior and survival of silver catfish, Rhamdia quelen, infested by Ichthyophthirius multifiliis and infected with Aeromonas hydrophila, juveniles were treated with chloramphenicol, chloramphenicol + salt, oxytetracycline, oxytetracycline + salt and water alone (control. Fish survival in the treatments with chloramphenicol + salt and oxytetracycline + salt was significantly higher than in the other treatments. The treatment with chloramphenicol presented higher survival than the treatment with oxytetracycline and both showed significantly higher survival than control. Swimming activity was higher in the fish treated with antibiotics and salt compared to control fish. A combination of the studied antibiotics plus salt is more effective to treat both A. hydrophila infection and I. multifiliis infestation in silver catfish, but since the use of chloramphenicol is not allowed in Brazil, oxytetracycline plus salt seems to be the best treatment option.

Sporangium Exposure and Spore Release in the Peruvian Maidenhair Fern (Adiantum peruvianum, Pteridaceae.

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Simon Poppinga

Full Text Available We investigated the different processes involved in spore liberation in the polypod fern Adiantum peruvianum (Pteridaceae. Sporangia are being produced on the undersides of so-called false indusia, which are situated at the abaxial surface of the pinnule margins, and become exposed by a desiccation-induced movement of these pinnule flaps. The complex folding kinematics and functional morphology of false indusia are being described, and we discuss scenarios of movement initiation and passive hydraulic actuation of these structures. High-speed cinematography allowed for analyses of fast sporangium motion and for tracking ejected spores. Separation and liberation of spores from the sporangia are induced by relaxation of the annulus (the 'throwing arm' of the sporangium catapult and conservation of momentum generated during this process, which leads to sporangium bouncing. The ultra-lightweight spores travel through air with a maximum velocity of ~5 m s(-1, and a launch acceleration of ~6300 g is measured. In some cases, the whole sporangium, or parts of it, together with contained spores break away from the false indusium and are shed as a whole. Also, spores can stick together and form spore clumps. Both findings are discussed in the context of wind dispersal.

Esterase activity as a novel parameter of spore germination in Bacillus anthracis

International Nuclear Information System (INIS)

Ferencko, Linda; Cote, Mindy A.; Rotman, Boris

2004-01-01

Spores of Bacillus anthracis were shown to produce esterase activity about 4 min after exposure to conventional germinants such as combinations of amino acids and purine ribosides. Neither amino acids nor ribosides alone induce germination and esterase activity. Expression of esterase activity was chloramphenicol resistant, and correlated with loss of spore refractivity, a traditional parameter of early germination. Based on these observations, we hypothesized that esterase activity could be used as a novel parameter for quantifying early events during spore germination. To test this hypothesis, we measured expression of esterase activity under a variety of germinating conditions. Using diacetyl fluorescein as fluorogenic substrate of esterases, we demonstrated that esterase activity was invariably induced whenever spores were triggered by known germinants. Moreover, D-alanine, an inhibitor of L-alanine-mediated germination, was found to significantly inhibit expression of esterase activity. In terms of molecular mechanisms, esterase expression could represent activation of proteases at the onset of spore germination

Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency.

Science.gov (United States)

Diekman, Eugene F; de Koning, Tom J; Verhoeven-Duif, Nanda M; Rovers, Maroeska M; van Hasselt, Peter M

2014-02-01

The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. MEDLINE, EMBASE, and Cochrane databases between January 1960 and December 2012. Studies that described patients with severe MTHFR deficiency who received betaine treatment. We identified 15 case reports and case series, totaling 36 patients. Data included the following: (1) families with 2 or more patients with severe MTHFR deficiency, of whom at least 1 received betaine, or (2) single patients with severe MTHFR deficiency treated with betaine. To define severe MTHFR deficiency, methionine, homocysteine, MTHFR enzyme activity in fibroblasts, or mutations (in the MTHFR gene) had to be described as well as the effect of treatment (survival and/or psychomotor development). We compared the outcome in treated vs untreated patients and early- vs late-treated patients. Sensitivity analysis was performed to address definition of early treatment. To further assess the impact of treatment on mortality, we performed a subanalysis in families with at least 1 untreated deceased patient. Survival and psychomotor development. Eleven of 36 patients (31%) died. All deaths occurred in patients who did not receive treatment or in patients in whom treatment was delayed. In contrast, all 5 early-treated patients survived. Subgroup analysis of patients with deceased siblings-their genotypically identical controls-revealed that betaine treatment prevented mortality (P = .002). In addition, psychomotor development in surviving patients treated with betaine was normal in all 5 early-treated patients but in none of the 19 surviving patients with delayed treatment (P psychomotor development in patients with severe MTHFR deficiency, highlighting the importance of timely recognition through newborn screening.

Survival analysis of patients with uveal melanoma after organ preserving and liquidation treatment

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E. E. Grishina

2018-01-01

Full Text Available Rationale: Uveal melanoma is the most common primary malignancy of the eye.Aim: To evaluate survival in patients with uveal melanoma stratified according to the type of treatment and to identify factors significantly associated with their survival.Materials and methods: The study was performed on the data extracted from medical files and follow-up forms of patients with uveal melanoma seen in the Ophthalmological Clinical Hospital of the Department of Healthcare, Moscow, from 1977 to 2012. Analysis of survival was used to assess the life longevity of patients with uveal melanoma. The analysis was censored at January 2013, when vital status (dead or alive of all patients was assessed. The factors included into the study analysis, were those taken from the follow-up forms. The incidence of uveal melanoma in Moscow (2012 was 0.9 per 100,000 of the population, whereas its prevalence was 11.1 per 100,000.Results: 698 patients with uveal melanoma were included into the study, among them 260 (37% men (aged from 19 to 87 years, median age 60 years and 438 (63% women (aged from 18 to 93 years, median age 63 years; therefore, the proportion of women under the follow-up monitoring was by 26% higher than that of men. The liquidation treatment (mostly enucleation was performed in 358 (51% of the patients, whereas the organ preserving treatment in 340 (49%. At 5, 7, and 10 years of the follow-up, the disease-specific survival of patients with uveal melanoma after the organ preserving treatment (median survival has not been reached and after the liquidation treatment (median, 88 months were 89 ± 2, 83 ± 3, and 75 ± 4% versus 63 ± 3, 52 ± 4, and 47 ± 5%, respectively (р = 0.001. Overall survival and disease-specific survival of the patients after the liquidation treatment were significantly lower than in the patients after the organ-preserving treatment. According to multiple regression analysis, this was associated not with the type of

Use of the mice passive protection test to evaluate the humoral response in goats vaccinated with Sterne 34F2 live spore vaccine.

Science.gov (United States)

Phaswana, P H; Ndumnego, O C; Koehler, S M; Beyer, W; Crafford, J E; van Heerden, H

2017-09-07

The Sterne live spore vaccine (34F2) is the most widely used veterinary vaccine against anthrax in animals. Antibody responses to several antigens of Bacillus anthracis have been described with a large focus on those against protective antigen (PA). The focus of this study was to evaluate the protective humoral immune response induced by the live spore anthrax vaccine in goats. Boer goats vaccinated twice (week 0 and week 12) with the Sterne live spore vaccine and naive goats were used to monitor the anti-PA and toxin neutralizing antibodies at week 4 and week 17 (after the second vaccine dose) post vaccination. A/J mice were passively immunized with different dilutions of sera from immune and naive goats and then challenged with spores of B. anthracis strain 34F2 to determine the protective capacity of the goat sera. The goat anti-PA ELISA titres indicated significant sero-conversion at week 17 after the second doses of vaccine (p = 0.009). Mice receiving undiluted sera from goats given two doses of vaccine (twice immunized) showed the highest protection (86%) with only 20% of mice receiving 1:1000 diluted sera surviving lethal challenge. The in vitro toxin neutralization assay (TNA) titres correlated to protection of passively immunized A/J mice against lethal infection with the vaccine strain Sterne 34F2 spores using immune goat sera up to a 1:10 dilution (r s  ≥ 0.522, p = 0.046). This study suggests that the passive mouse protection model could be potentially used to evaluate the protective immune response in livestock animals vaccinated with the current live vaccine and new vaccines.

Effect of different heat treatments and disinfectants on the survival of Prototheca zopfii.

Science.gov (United States)

Lassa, Henryka; Jagielski, Tomasz; Malinowski, Edward

2011-03-01

Bovine mastitis caused by the yeast-like alga Prototheca zopfii represents a serious veterinary problem and may result in heavy economic losses to particular dairy farms. The purpose of this study was to evaluate the survival of 50 isolates of P. zopfii in milk subjected to different heat treatments and the survival of further 106 P. zopfii isolates after exposure to three classes of teat disinfectants: iodine (Dipal), quaternary ammonium compounds (Teat), and dodecylbenzenesulphonic acid (Blu-gard). Of the 50 isolates tested for thermal tolerance, 29 (58%) survived heat treatment at 62 °C for 30 s and 13 (26% of all isolates) of those survived after heat treatment at 72 °C for 15 s. None of the 106 isolates were able to withstand the in-use concentrations of the three disinfectants tested. The highest disinfectant concentrations that permitted survival of at least one isolate were dilutions: 1:1,000 for Dipal (survival rate of 52.8-57.5%), 1:100 for Teat (88.7-90.6%), and 1:10 for Blu-gard (100%). No differences in the survival rates of P. zopfii were observed with respect to the duration of exposure to disinfectant. The results of this study support the previous findings that P. zopfii may resist high-temperature treatments, including that applied in the high-temperature, short-time (HTST) pasteurization process. The obtained data also demonstrate the efficacy of the three classes of teat disinfectants against P. zopfii, with the efficacy of iodine being most pronounced. The study emphasizes the necessity of using higher temperatures in the pasteurization of raw milk to kill the Prototheca algae, as well as the particular suitability of the iodine for the control procedures of protothecal mastitis.

Forecasting methodologies for Ganoderma spore concentration using combined statistical approaches and model evaluations

Science.gov (United States)

Sadyś, Magdalena; Skjøth, Carsten Ambelas; Kennedy, Roy

2016-04-01

High concentration levels of Ganoderma spp. spores were observed in Worcester, UK, during 2006-2010. These basidiospores are known to cause sensitization due to the allergen content and their small dimensions. This enables them to penetrate the lower part of the respiratory tract in humans. Establishment of a link between occurring symptoms of sensitization to Ganoderma spp. and other basidiospores is challenging due to lack of information regarding spore concentration in the air. Hence, aerobiological monitoring should be conducted, and if possible extended with the construction of forecast models. Daily mean concentration of allergenic Ganoderma spp. spores in the atmosphere of Worcester was measured using 7-day volumetric spore sampler through five consecutive years. The relationships between the presence of spores in the air and the weather parameters were examined. Forecast models were constructed for Ganoderma spp. spores using advanced statistical techniques, i.e. multivariate regression trees and artificial neural networks. Dew point temperature along with maximum temperature was the most important factor influencing the presence of spores in the air of Worcester. Based on these two major factors and several others of lesser importance, thresholds for certain levels of fungal spore concentration, i.e. low (0-49 s m-3), moderate (50-99 s m-3), high (100-149 s m-3) and very high (150 < n s m-3), could be designated. Despite some deviation in results obtained by artificial neural networks, authors have achieved a forecasting model, which was accurate (correlation between observed and predicted values varied from r s = 0.57 to r s = 0.68).

Survival of Bactericidal Antibiotic Treatment by a Persister Subpopulation of Listeria monocytogenes

DEFF Research Database (Denmark)

Knudsen, Gitte Maegaard; Ng, Yin; Gram, Lone

2013-01-01

Listeria monocytogenes can cause the serious infection listeriosis, which despite antibiotic treatment has a high mortality. Understanding the response of L. monocytogenes to antibiotic exposure is therefore important to ensure treatment success. Some bacteria survive antibiotic treatment...... by formation of persisters, which are a dormant antibiotic-tolerant subpopulation. The purpose of this study was to determine whether L. monocytogenes can form persisters and how bacterial physiology affects the number of persisters in the population. A stationary-phase culture of L. monocytogenes was adjusted...... that eradication of persisters is possible. Our study adds L. monocytogenes to the list of bacterial species capable of surviving bactericidal antibiotics in a dormant stage, and this persister phenomenon should be borne in mind when developing treatment regimens....

Effect of irradiation of bacteria on the formation of spores

International Nuclear Information System (INIS)

Szulc, M.; Tropilo, J.; Olszewski, G.

1980-01-01

Studies were carried out on bacteria: Bac. subtilis, Bac. cereus, Cl. perfringens, Cl. botulinum which were irradiated in two media (PBS and broth containing 1% of protein) with 100, 1000, 5000 and 10 000 X-radiation doses. The results obtained show that: all bacteria species studied (vegetative forms) are characterized by a high sensitivity to X-radiation, though distinctly lower than the species of Enterobacteriaceae family; the bacteria species studied are characterized by various sporing rate. The highest sporing rate was shown by Bac. cereus, the following: Bac. subtilis, Cl. perfringens and Cl. botulinum; increased X-radiation doses weaken sporing of Bac. subtilis and Bac. cereus. This effect could not be observed in Cl. perfringens and Cl. botulinum. (author)

Effect of irradiation of bacteria on the formation of spores

Energy Technology Data Exchange (ETDEWEB)

Szulc, M.; Tropilo, J.; Olszewski, G.

1980-01-01

Studies were carried out on bacteria: Bac. subtilis, Bac. cereus, Cl. perfringens, Cl. botulinum which were irradiated in two media (PBS and broth containing 1% of protein) with 100, 1000, 5000 and 10 000 X-radiation doses. The results obtained show that: all bacteria species studied (vegetative forms) are characterized by a high sensitivity to X-radiation, though distinctly lower than the species of Enterobacteriaceae family; the bacteria species studied are characterized by various sporing rate. The highest sporing rate was shown by Bac. cereus, the following: Bac. subtilis, Cl. perfringens and Cl. botulinum; increased X-radiation doses weaken sporing of Bac. subtilis and Bac. cereus. This effect could not be observed in Cl. perfringens and Cl. botulinum.

Phylogenetic placement of two species known only from resting spores

DEFF Research Database (Denmark)

Hajek, Ann E; Gryganskyi, Andrii; Bittner, Tonya

2016-01-01

resting spores, Zoophthora independentia, infecting Tipula (Lunatipula) submaculata in New York State, is now described as a new species and Tarichium porteri, described in 1942, which infects Tipula (Triplicitipula) colei in Tennessee, is transferred to the genus Zoophthora. We have shown that use......Molecular methods were used to determine the generic placement of two species of Entomophthorales known only from resting spores. Historically, these species would belong in the form-genus Tarichium, but this classification provides no information about phylogenetic relationships. Using DNA from...... of molecular methods can assist with determination of the phylogenetic relations of specimens within the form-genus Tarichium for an already described species and a new species for which only resting spores are available....

Spatial and temporal distribution of Alternaria spores in the Iberian Peninsula atmosphere, and meteorological relationships: 1993-2009.

Science.gov (United States)

Aira, María-Jesús; Rodríguez-Rajo, Francisco-Javier; Fernández-González, María; Seijo, Carmen; Elvira-Rendueles, Belén; Abreu, Ilda; Gutiérrez-Bustillo, Montserrat; Pérez-Sánchez, Elena; Oliveira, Manuela; Recio, Marta; Tormo, Rafael; Morales, Julia

2013-03-01

This paper provides an updated of airborne Alternaria spore spatial and temporal distribution patterns in the Iberian Peninsula, using a common non-viable volumetric sampling method. The highest mean annual spore counts were recorded in Sevilla (39,418 spores), Mérida (33,744) and Málaga (12,947), while other sampling stations never exceeded 5,000. The same cities also recorded the highest mean daily spore counts (Sevilla 109 spores m(-3); Mérida 53 spores m(-3) and Málaga 35 spores m(-3)) and the highest number of days on which counts exceeded the threshold levels required to trigger allergy symptoms (Sevilla 38 % and Mérida 30 % of days). Analysis of annual spore distribution patterns revealed either one or two peaks, depending on the location and prevailing climate of sampling stations. For all stations, average temperature was the weather parameter displaying the strongest positive correlation with airborne spore counts, whilst negative correlations were found for rainfall and relative humidity.

Preferential inclusion of extrachromosomal genetic elements in yeast meiotic spores.

Science.gov (United States)

Brewer, B J; Fangman, W L

1980-09-01

During meiosis and sporulation in the yeast Saccharomyces cerevisiae, extrachromosomal traits are efficiently transmitted to haploid spores. Although the pattern of inheritance of chromosomal traits reflects the mechanism of regular chromosomal segregation in meiosis, it is not known what processes are reflected by the efficient inheritance of extrachromosomal traits. Because extrachromosomal genetic elements in yeast are present in multiple copies, perpetuation of an extrachromosomal trait could occur by the passive envelopment of a subset of copies or by an active sequestering of all or a subset of copies within the four spores. We show that only subsets of the four extrachromosomal nucleic acids commonly found in yeast are transmitted through meiosis--55% of mitochondrial DNA copies, 82% of the 2-micron DNA plasmids, and about 70% of the L and M double-stranded RNAs. However, electron micrographs of serial sections through yeast asci indicate that the four spore enclose only 30% of the total ascus material. Thus these extrachromosomal elements are preferentially included within the spores, indicating that their inheritance is not a random process. Transmission of mitochondrial DNA can be accounted for by the observed enclosure of 52% of the mitochondrial volume within the spores. The high transmission frequencies of the double-stranded RNAs (which exist as virus-like particles in the cytoplasm) and 2-micron DNA must indicate that either these nucleic acids are actively recruited from the cytoplasm by some mechanism or they are associated in some way with the nucleus during meiosis.

Radiosensitivity of spores of Paenibacillus larvae ssp. larvae in honey

Energy Technology Data Exchange (ETDEWEB)

Almeida, Wanderley Mendes de [Ministerio da Agricultura, Pecuaria e Abastecimento, Rio de Janeiro, RJ (Brazil). Servico de Inspecao de Produtos de Origem Animal]. E-mail: sipa-rj@agricultura.gov.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito CTEx, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Schuch, Dulce Maria Tocchetto [Ministerio da Agricultura, Pecuaria e Abastecimento, Porto Alegre, RS (Brazil)]. E-mail: micro-lara-rs@agricultura.gov.br

2007-07-01

Irradiation, usually used in combination with other conventional methods of conservation, has been proven to be an efficient tool to ensure the safety of many types of foods by destroying pathogenic microorganisms and extending their shelf-lives. This work has investigated the efficacy of gamma irradiation to inactivate spores of the bacterium Paenibacillus larvae that causes the 'American foulbrood', a highly contagious disease still exotic in Brazil that kills bees and contaminates honey, preventing its commercialization and causing great economical losses. In this study, 60 g samples of two types of honey inoculated with 3.5x10{sup 3} spores/mL of that bacterium were irradiated with doses of 0, 5, 7.5, 10, 12.5 and 15 kGy and counted. The analyses indicated a mean reduction of 97.5{+-}0.7% in the number of viable spores exposed to 5 kGy. The application of doses of 7.5 kGy or higher yielded no viable spores above the detection threshold (10/mL). In addition the value of D{sub 10} (3.1{+-}0.3 kGy) was estimated and the logarithm of the population of viable spores of Paenibacillus larvae subsp. larvae was determined as linear and quadratic polynomial functions of the radiation dose. The results indicated that the dose of 10 kGy could be insufficient to assure complete sterilization of honey in some cases while suggesting that 25 kGy would perform such task adequately. (author)

The effect of growth medium on B. anthracis Sterne spore carbohydrate content.

Science.gov (United States)

Colburn, Heather A; Wunschel, David S; Antolick, Kathryn C; Melville, Angela M; Valentine, Nancy B

2011-06-01

The expressed characteristics of biothreat agents may be impacted by variations in the culture environment, including growth medium formulation. The carbohydrate composition of B. anthracis spores has been well studied, particularly for the exosporium, which is the outermost spore structure. The carbohydrate composition of the exosporium has been demonstrated to be distinct from the vegetative form containing unique monosaccharides. We have investigated the carbohydrate composition of B. anthracis Sterne spores produced using four different medium types formulated with different sources of medium components. The amount of rhamnose, 3-O-methyl rhamnose and galactosamine was found to vary significantly between spores cultured using different medium formulations. The relative abundance of these monosaccharides compared to other monosaccharides such as mannosamine was also found to vary with medium type. Specific medium components were also found to impact the carbohydrate profile. Xylose has not been previously described in B. anthracis spores but was detected at low levels in two media. This may represent residual material from the brewery yeast extract used to formulate these two media. These results illustrate the utility of this method to capture the impact of growth medium on carbohydrate variation in spores. Detecting carbohydrate profiles in B. anthracis evidentiary material may provide useful forensic information on the growth medium used for sporulation. Copyright © 2011 Elsevier B.V. All rights reserved.

Causal inference for long-term survival in randomised trials with treatment switching: Should re-censoring be applied when estimating counterfactual survival times?

OpenAIRE

Latimer, N.R.; White, I.R.; Abrams, K.R.; Sieburt, U.

2017-01-01

Treatment switching often has a crucial impact on estimates of effectiveness and cost-effectiveness of new oncology treatments. Rank preserving structural failure time models (RPSFTM) and two-stage estimation (TSE) methods estimate ‘counterfactual’ (i.e. had there been no switching) survival times and incorporate re-censoring to guard against informative censoring in the counterfactual dataset. However, re-censoring causes a loss of longer term survival information which is problematic when e...

Synthesis of a Bacillus subtilis small, acid-soluble spore protein in Escherichia coli causes cell DNA to assume some characteristics of spore DNA

International Nuclear Information System (INIS)

Setlow, B.; Hand, A.R.; Setlow, P.

1991-01-01

Small, acid-soluble proteins (SASP) of the alpha/beta-type are associated with DNA in spores of Bacillus subtilis. Induction of synthesis of alpha/beta-type SASP in Escherichia coli resulted in rapid cessation of DNA synthesis, followed by a halt in RNA and then protein accumulation, although significant mRNA and protein synthesis continued. There was a significant loss in viability associated with SASP synthesis in E. coli: recA+ cells became extremely long filaments, whereas recA mutant cells became less filamentous. The nucleoids of cells with alpha/beta-type SASP were extremely condensed, as viewed in both light and electron microscopes, and immunoelectron microscopy showed that the alpha/beta-type SASP were associated with the cell DNA. Induction of alpha/beta-type SASP synthesis in E. coli increased the negative superhelical density of plasmid DNA by approximately 20%; UV irradiation of E. coli with alpha/beta-type SASP gave reduced yields of thymine dimers but significant amounts of the spore photoproduct. These changes in E. coli DNA topology and photochemistry due to alpha/beta-type SASP are similar to the effects of alpha/beta-type SASP on the DNA in Bacillus spores, further suggesting that alpha/beta-type SASP are a major factor determining DNA properties in bacterial spores

Feasibility of flotation concentration of fungal spores as a method to identify toxigenic mushrooms

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Bazzle LJ

2014-12-01

Full Text Available Lisa J Bazzle,1 Marc A Cubeta,2 Steven L Marks,1 David C Dorman3 1Department of Clinical Sciences, College of Veterinary Medicine, 2Department of Plant Pathology, College of Agriculture and Life Sciences, Center for Integrated Fungal Research, 3Department of Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA Purpose: Mushroom poisoning is a recurring and challenging problem in veterinary medicine. Diagnosis of mushroom exposure in animals is hampered by the lack of rapid diagnostic tests. Our study evaluated the feasibility of using flotation concentration and microscopic evaluation of spores for mushroom identification. Evaluation of this method in living animals exposed to toxigenic mushrooms is limited by ethical constraints; therefore, we relied upon the use of an in vitro model that mimics the oral and gastric phases of digestion. Methods: In our study, mycologist-identified toxigenic (poisonous and nontoxigenic fresh mushrooms were collected in North Carolina, USA. In phase 1, quantitative spore recovery rates were determined following magnesium sulfate, modified Sheather's sugar solution, and zinc sulfate flotation (n=16 fungal species. In phase 2, mushrooms (n=40 fungal species were macerated and digested for up to 2 hours in a salivary and gastric juice simulant. The partially digested material was acid neutralized, filtered, and spores concentrated using zinc sulfate flotation followed by microscopic evaluation of spore morphology. Results: Mean spore recovery rates for the three flotation fluids ranged from 32.5% to 41.0% (P=0.82. Mean (± standard error of the mean Amanita spp. spore recovery rates were 38.1%±3.4%, 36.9%±8.6%, and 74.5%±1.6% (P=0.0012 for the magnesium sulfate, Sheather's sugar, and zinc sulfate solutions, respectively. Zinc sulfate flotation following in vitro acid digestion (phase 2 yielded spore numbers adequate for microscopic visualization in

Spores of many common airborne fungi reveal no ice nucleation activity in oil immersion freezing experiments

Science.gov (United States)

Pummer, B. G.; Atanasova, L.; Bauer, H.; Bernardi, J.; Druzhinina, I. S.; Fröhlich-Nowoisky, J.; Grothe, H.

2013-12-01

Fungal spores are ubiquitous biological aerosols, which are considered to act as ice nuclei. In this study the ice nucleation (IN) activity of spores harvested from 29 fungal strains belonging to 21 different species was tested in the immersion freezing mode by microscopic observation of water-in-oil emulsions. Spores of 8 of these strains were also investigated in a microdroplet freezing array instrument. The focus was laid on species of economical, ecological or sanitary significance. Besides common molds (Ascomycota), some representatives of the widespread group of mushrooms (Basidiomycota) were also investigated. Fusarium avenaceum was the only sample showing IN activity at relatively high temperatures (about 264 K), while the other investigated fungal spores showed no freezing above 248 K. Many of the samples indeed froze at homogeneous ice nucleation temperatures (about 237 K). In combination with other studies, this suggests that only a limited number of species may act as atmospheric ice nuclei. This would be analogous to what is already known for the bacterial ice nuclei. Apart from that, we selected a set of fungal strains from different sites and exposed them to occasional freezing stress during their cultivation. This was in order to test if the exposure to a cold environment encourages the expression of ice nuclei during growth as a way of adaptation. Although the total protein expression was altered by this treatment, it had no significant impact on the IN activity.

Effect of medium components and culture conditions in Bacillus subtilis EA-CB0575 spore production.

Science.gov (United States)

Posada-Uribe, Luisa F; Romero-Tabarez, Magally; Villegas-Escobar, Valeska

2015-10-01

Bacillus subtilis spores have important biotechnological applications; however, achieving both, high spore cell densities and sporulation efficiencies in fermentation, is poorly reported. In this study, medium components and culture conditions were optimized with different statistical methods to increase spore production of the plant growth promoting rhizobacteria B. subtilis EA-CB0575. Key medium components were determined with Plackett-Burman (PB) design, and the optimum concentration levels of two components (glucose, MgSO4·7H2O) were optimized with a full factorial and central composite design, achieving 1.37 × 10(9) CFU/mL of spore cell density and 93.5 % of sporulation efficiency in shake flask. The optimized medium was used to determine the effect of culture conditions on spore production at bioreactor level, finding that maintaining pH control did not affect significantly spore production, while the interaction of agitation and aeration rates had a significant effect on spore cell density. The overall optimization generated a 17.2-fold increase in spore cell density (8.78 × 10(9) CFU/mL) and 1.9-fold increase in sporulation efficiency (94.2 %) compared to that of PB design. These results indicate the potential of B. subtilis EA-CB0575 to produce both, high spore cell densities and sporulation efficiencies, with very low nutrient requirements and short incubation period which can represent savings of process production.

Caenorhabditis elegans Predation on Bacillus anthracis: Decontamination of Spore Contaminated Soil with Germinants and Nematodes.

Science.gov (United States)

Schelkle, Bettina; Choi, Young; Baillie, Leslie W; Richter, William; Buyuk, Fatih; Celik, Elif; Wendling, Morgan; Sahin, Mitat; Gallagher, Theresa

2017-01-01

Remediation of Bacillus anthracis -contaminated soil is challenging and approaches to reduce overall spore levels in environmentally contaminated soil or after intentional release of the infectious disease agent in a safe, low-cost manner are needed. B. anthracis spores are highly resistant to biocides, but once germinated they become susceptible to traditional biocides or potentially even natural predators such as nematodes in the soil environment. Here, we describe a two-step approach to reducing B. anthracis spore load in soil during laboratory trials, whereby germinants and Caenorhabditis elegans nematodes are applied concurrently. While the application of germinants reduced B. anthracis spore load by up to four logs depending on soil type, the addition of nematodes achieved a further log reduction in spore count. These laboratory based results suggest that the combined use of nematodes and germinants could represent a promising approach for the remediation of B. anthracis spore contaminated soil. Originality-Significance Statement: This study demonstrates for the first time the successful use of environmentally friendly decontamination methods to inactivate Bacillus anthracis spores in soil using natural predators of the bacterium, nematode worms.

Image Cytometric Analysis of Algal Spores for Evaluation of Antifouling Activities of Biocidal Agents.

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Il Koo, Bon; Lee, Yun-Soo; Seo, Mintae; Seok Choi, Hyung; Leng Seah, Geok; Nam, Taegu; Nam, Yoon Sung

2017-07-31

Chemical biocides have been widely used as marine antifouling agents, but their environmental toxicity impose regulatory restriction on their use. Although various surrogate antifouling biocides have been introduced, their comparative effectiveness has not been well investigated partly due to the difficulty of quantitative evaluation of their antifouling activity. Here we report an image cytometric method to quantitatively analyze the antifouling activities of seven commercial biocides using Ulva prolifera as a target organism, which is known to be a dominant marine species causing soft fouling. The number of spores settled on a substrate is determined through image analysis using the intrinsic fluorescence of chlorophylls in the spores. Pre-determined sets of size and shape of spores allow for the precise determination of the number of settled spores. The effects of biocide concentration and combination of different biocides on the spore settlement are examined. No significant morphological changes of Ulva spores are observed, but the amount of adhesive pad materials is appreciably decreased in the presence of biocides. It is revealed that the growth rate of Ulva is not directly correlated with the antifouling activities against the settlement of Ulva spores. This work suggests that image cytometric analysis is a very convenient, fast-processable method to directly analyze the antifouling effects of biocides and coating materials.

Mutagenic effect of tritated water on spores of Bacillus subtilis

International Nuclear Information System (INIS)

Tanooka, H.; Munakata, N.

1978-01-01

The mutagenic effect of tritiated water was observed with spores of Bacillus subtilis polA strain suspended in 50 mCi/ml of tritiated water for various intervals. Dose rate given by tritium beta particles to spore core was estimated to be 400 rad/hr from some assumptions and E. coli data computed by Bockrath et al. and Sands et al. The initial mutation rate was 4.2 x 10 -9 mutants/rad, as compared with 2.4 x 10 -9 mutants/rad for 60 Co γ rays and 3.3 x 10 -9 mutants/rad for 30-kVp x rays. The mutagenic effect of tritiated water on spores is most likely due to beta particle ionizing radiation damage

The combined effect of high pressure and nisin or lysozyme on the inactivation of Alicyclobacillus acidoterrestris spores in apple juice

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Sokołowska, B.; Skąpska, S.; Fonberg-Broczek, M.; Niezgoda, J.; Chotkiewicz, M.; Dekowska, A.; Rzoska, S.

2012-03-01

Alicyclobacillus acidoterrestris, a thermoacidophilic and spore-forming bacterium is one of the important target micro-organisms in the quality control of acidic canned foods. High pressure pasteurization (HPP) at 50°C was used for the inactivation of A. acidoterrestris spores in apple juice. Pressure applied both in a continuous and oscillatory mode gave the best results when 200 MPa was used. Increasing the pressure to 500 MPa, as well as lowering its value to 100 MPa, had an adverse effect on the effectiveness of the process. The best results were achieved with the use of a combined treatment, involving oscillatory pressurization at 200 MPa, followed by holding the sample for 60 min at atmospheric pressure and subsequent pressurization at 500 MPa, resulting in a reduction in the spore count of 6.15 log. Nisin significantly enhanced the effect of HPP at 300 MPa. Using pressure of 200 MPa for 45 min with a nisin concentration of 250 IU/mL enabled total spore inactivation (over 6 log). No significant effect of lysozyme at a concentration of 0.05 and 0.1 mg/L at 300 MPa was observed.

Treatment strategies and survival of older breast cancer patients - an international comparison between the Netherlands and Ireland.

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Kiderlen, Mandy; Walsh, Paul M; Bastiaannet, Esther; Kelly, Maria B; Audisio, Riccardo A; Boelens, Petra G; Brown, Chris; Dekkers, Olaf M; de Craen, Anton J M; van de Velde, Cornelis J H; Liefers, Gerrit-Jan

2015-01-01

Forty percent of breast cancers occur among older patients. Unfortunately, there is a lack of evidence for treatment guidelines for older breast cancer patients. The aim of this study is to compare treatment strategy and relative survival for operable breast cancer in the elderly between The Netherlands and Ireland. From the Dutch and Irish national cancer registries, women aged ≥65 years with non-metastatic breast cancer were included (2001-2009). Proportions of patients receiving guideline-adherent locoregional treatment, endocrine therapy, and chemotherapy were calculated and compared between the countries by stage. Secondly, 5-year relative survival was calculated by stage and compared between countries. Overall, 41,055 patients from The Netherlands and 5,826 patients from Ireland were included. Overall, more patients received guideline-adherent locoregional treatment in The Netherlands, overall (80% vs. 68%, adjusted pNetherlands. In The Netherlands, only 6% received chemotherapy, as compared 24% in Ireland. But relative survival was poorer in Ireland (5 years relative survival 89% vs. 83%), especially in stage II (87% vs. 85%) and stage III (61% vs. 58%) patients. Treatment for older breast cancer patients differed significantly on all treatment modalities between The Netherlands and Ireland. More locoregional treatment was provided in The Netherlands, and more systemic therapy was provided in Ireland. Relative survival for Irish patients was worse than for their Dutch counterparts. This finding should be a strong recommendation to study breast cancer treatment and survival internationally, with the ultimate goal to equalize the survival rates for breast cancer patients across Europe.

Socioeconomic disparities in breast cancer survival: relation to stage at diagnosis, treatment and race

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Yu Xue

2009-10-01

Full Text Available Abstract Background Previous studies have documented lower breast cancer survival among women with lower socioeconomic status (SES in the United States. In this study, I examined the extent to which socioeconomic disparity in breast cancer survival was explained by stage at diagnosis, treatment, race and rural/urban residence using the Surveillance, Epidemiology, and End Results (SEER data. Methods Women diagnosed with breast cancer during 1998-2002 in the 13 SEER cancer registry areas were followed-up to the end of 2005. The association between an area-based measure of SES and cause-specific five-year survival was estimated using Cox regression models. Six models were used to assess the extent to which SES differences in survival were explained by clinical and demographical factors. The base model estimated the hazard ratio (HR by SES only and then additional adjustments were made sequentially for: 1 age and year of diagnosis; 2 stage at diagnosis; 3 first course treatment; 4 race; and 5 rural/urban residence. Results An inverse association was found between SES and risk of dying from breast cancer (p Conclusion Stage at diagnosis, first course treatment and race explained most of the socioeconomic disparity in breast cancer survival. Targeted interventions to increase breast cancer screening and treatment coverage in patients with lower SES could reduce much of socioeconomic disparity.

The effect of ethylenediaminetetraacetic acid on heat resistance and recovery of Clostridium sporogenes PA 3679 spores treated in HTST conditions.

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Silla Santos, M H; Torres Zarzo, J

1997-03-03

The effect of ethylenediaminetetraacetic acid (EDTA) on the heat resistance of Clostridium sporogenes PA 3679 spores was studied. EDTA was added to heating substrates and recovery media in order to establish which stage of the heat treatment registered the greatest EDTA activity. The heating substrates assayed were phosphate buffer (pH 7.0) and white asparagus purée, at natural pH (5.8) and acidified with citric acid and glucono-delta-lactone (GDL) to pH 5.5, 5.0 and 4.5. Recovery of survivors was carried out in MPA3679A medium in various conditions of acidification with citric and GDL (250 and 500 ppm), at pH 7.5 6.5 and 6.0. The results show greater activity of EDTA on spores when it was applied in recovery of heat injured spores, than during heating. The strongest influence of EDTA during heating was found in phosphate buffer (pH 7.0), with the effect being most evident at 121 and 126 degrees C, and in asparagus purée, at 121 degrees C and pH 5.8 rather than acidified. In recovery, the inhibiting activity of EDTA was more evident in spores subjected to more severe heat treatment, either by increasing the exposure time or by raising the temperature to 130 or 135 degrees C. The pH level of the recovery medium also affected the antimicrobial activity of EDTA, which had a greater inhibiting effect at pH 7.5 than at lower pH levels (6.5, 6.0).

The infrared spectral transmittance of Aspergillus niger spore aggregated particle swarm

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Zhao, Xinying; Hu, Yihua; Gu, Youlin; Li, Le

2015-10-01

Microorganism aggregated particle swarm, which is quite an important composition of complex media environment, can be developed as a new kind of infrared functional materials. Current researches mainly focus on the optical properties of single microorganism particle. As for the swarm, especially the microorganism aggregated particle swarm, a more accurate simulation model should be proposed to calculate its extinction effect. At the same time, certain parameters deserve to be discussed, which helps to better develop the microorganism aggregated particle swarm as a new kind of infrared functional materials. In this paper, take Aspergillus Niger spore as an example. On the one hand, a new calculation model is established. Firstly, the cluster-cluster aggregation (CCA) model is used to simulate the structure of Aspergillus Niger spore aggregated particle. Secondly, the single scattering extinction parameters for Aspergillus Niger spore aggregated particle are calculated by using the discrete dipole approximation (DDA) method. Thirdly, the transmittance of Aspergillus Niger spore aggregated particle swarm is simulated by using Monte Carlo method. On the other hand, based on the model proposed above, what influences can wavelength causes has been studied, including the spectral distribution of scattering intensity of Aspergillus Niger spore aggregated particle and the infrared spectral transmittance of the aggregated particle swarm within the range of 8-14μm incident infrared wavelengths. Numerical results indicate that the scattering intensity of Aspergillus Niger spore aggregated particle reduces with the increase of incident wavelengths at each scattering angle. Scattering energy mainly concentrates on the scattering angle between 0-40°, forward scattering has an obvious effect. In addition, the infrared transmittance of Aspergillus Niger spore aggregated particle swarm goes up with the increase of incident wavelengths. However, some turning points of the trend are

[Study the rudimentary immunoregulatory mechanisms of Ganoderma Spore oil on immunocompromized mice].

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Yi, Youjin; Hu, Shun; Xiong, Xingyao; Liu, Dongbo; Zhong, Yingli

2012-09-01

To study the rudimentary immunoregulatory mechanisms of Ganoderma spore oil on immunocompromized mice model. Thrity KM mice were randomly selected and assigned into three groups (ten animals per group): the model control group, Ganoderma Lucidum spores oil group and the normal control group. The model control group and Ganoderma Lucidum spores oil group were injected intraperitoneally with cyclophosphamide at 40 mg x kg(-1) d to generate a immunocompromized mice model. The normal control group were administered with 0.9% NaCl solution 0.1 ml/10 g BW as placebo. All agents were given orally once a day, given for consecutive 30 days, Ganoderma Lucidum spores oil group 150 mg/kg, the others given maize 0.1 ml/10 g BW. The serum TNF-alpha , IFN-gamma content of the mice through ELISA kit and the expression levels of IL-2, IL-10, IL-12, IL-4, IFN-gamma, TNF-alpha mRNA in mouse spleen and thymus were examined by RT-PCR to rudimentary study its immunoregulatory mechanisms. Ganoderma spore oil can significantly increased the content of TNF-alpha and IFN-gamma in the serum and the expression levels of IL-2, IL-10, IL-12, IL-4, IFN-gamma, TNF-alpha mRNA in spleen and thymus, with obvious difference from the model control (P Ganoderma spore oil can be able to improve the above cytokine ion expression to immunoregulate the immunocompromized mice.

Assessing the cleanliness of surfaces: Innovative molecular approaches vs. standard spore assays

Energy Technology Data Exchange (ETDEWEB)

Cooper, M.; Duc, M.T. La; Probst, A.; Vaishampayan, P.; Stam, C.; Benardini, J.N.; Piceno, Y.M.; Andersen, G.L.; Venkateswaran, K.

2011-04-01

A bacterial spore assay and a molecular DNA microarray method were compared for their ability to assess relative cleanliness in the context of bacterial abundance and diversity on spacecraft surfaces. Colony counts derived from the NASA standard spore assay were extremely low for spacecraft surfaces. However, the PhyloChip generation 3 (G3) DNA microarray resolved the genetic signatures of a highly diverse suite of microorganisms in the very same sample set. Samples completely devoid of cultivable spores were shown to harbor the DNA of more than 100 distinct microbial phylotypes. Furthermore, samples with higher numbers of cultivable spores did not necessarily give rise to a greater microbial diversity upon analysis with the DNA microarray. The findings of this study clearly demonstrated that there is not a statistically significant correlation between the cultivable spore counts obtained from a sample and the degree of bacterial diversity present. Based on these results, it can be stated that validated state-of-the-art molecular techniques, such as DNA microarrays, can be utilized in parallel with classical culture-based methods to further describe the cleanliness of spacecraft surfaces.

Allergenic pollens and spores in the working environment of Japanese pear farmers.

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Teranishi, H; Uchida, M; Hayashi, S; Yamada, N

2007-01-01

Occupational allergies such as pollinosis are reported in several agricultural works in Japan. Many pollens and spores were observed in Japanese pear orchard during the artificial pollination season. By the study on daily symptoms in an allergic farmer, we confirmed that the pollinosis symptoms were most common and most severe during the artificial pollination. These results suggest that the exposure to allergenic pollens and spores induces allergic symptoms. Thus, caution should be paid for the avoidance of the exposure to these allergenic pollens and spores to prevent the allergy.

Evaluation of surface sampling method performance for Bacillus Spores on clean and dirty outdoor surfaces.

Energy Technology Data Exchange (ETDEWEB)

Wilson, Mollye C.; Einfeld, Wayne; Boucher, Raymond M.; Brown, Gary Stephen; Tezak, Matthew Stephen

2011-06-01

Recovery of Bacillus atrophaeous spores from grime-treated and clean surfaces was measured in a controlled chamber study to assess sampling method performance. Outdoor surfaces investigated by wipe and vacuum sampling methods included stainless steel, glass, marble and concrete. Bacillus atrophaeous spores were used as a surrogate for Bacillus anthracis spores in this study designed to assess whether grime-coated surfaces significantly affected surface sampling method performance when compared to clean surfaces. A series of chamber tests were carried out in which known amounts of spores were allowed to gravitationally settle onto both clean and dirty surfaces. Reference coupons were co-located with test coupons in all chamber experiments to provide a quantitative measure of initial surface concentrations of spores on all surfaces, thereby allowing sampling recovery calculations. Results from these tests, carried out under both low and high humidity conditions, show that spore recovery from grime-coated surfaces is the same as or better than spore recovery from clean surfaces. Statistically significant differences between method performance for grime-coated and clean surfaces were observed in only about half of the chamber tests conducted.

Characterization of single spore isolates of Agaricus bisporus (Lange) Imbach using conventional and molecular methods.

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Sharma, Manju; Suman, B C; Gupta, Dharmesh

2014-10-01

Strains A-15, S11, S-140, and U3 of Agaricus bisporus (Lange) Imbach, were used as parent strains for raising single spore homokaryotic isolates. Out of total 1,642 single spore isolates, only 36 single spore isolates were homokaryons and exhibited slow mycelial growth rate (≤2.0 mm/day) and appressed colony morphology. All these SSIs failed to produce pinheads in Petri plates even after 65 days of incubation, whereas the strandy slow growing SSIs along with parent strains were able to form the fructification in petriplates after 30 days. Out of 24, six ISSR primers, exhibited scorable bands. In the ISSR fingerprints, single spore isolates, homokaryons, lacked amplification products at multiple loci; they grow slowly and all of them had appressed types of colony morphology. The study revealed losses of ISSR polymorphic patterns in non-fertile homokaryotic single spore isolates compared to the parental control or fertile heterokaryotic single spore isolates.

Microencapsulation of Clostridium acetobutylicum ATCC 824 spores in gellan gum microspheres for the production of biobutanol.

Science.gov (United States)

Rathore, Sweta; Wan Sia Heng, Paul; Chan, Lai Wah

2015-01-01

The purpose of the present study was to provide further insights on the applicability of microencapsulation using emulsification method, to immobilise Clostridium acetobutylicum ATCC 824 spores, for biobutanol production. The encapsulated spores were revived using heat shock treatment and the fermentation efficiency of the resultant encapsulated cells was compared with that of the free (non-encapsulated) cells. The microspheres were easily recovered from the fermentation medium by filtration and reused up to five cycles of fermentation. In contrast, the free (non-encapsulated) cells could be reused for two cycles only. The microspheres remained intact throughout repeated use. Although significant cell leakage was observed during the course of fermentation, the microspheres could be reused with relatively high butanol yield, demonstrating their role as microbial cell nurseries. Both encapsulated and liberated cells contributed to butanol production.

Optimisation of a direct plating method for the detection and enumeration of Alicyclobacillus acidoterrestris spores.

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Henczka, Marek; Djas, Małgorzata; Filipek, Katarzyna

2013-01-01

A direct plating method for the detection and enumeration of Alicyclobacillus acidoterrestris spores has been optimised. The results of the application of four types of growth media (BAT agar, YSG agar, K agar and SK agar) regarding the recovery and enumeration of A. acidoterrestris spores were compared. The influence of the type of applied growth medium, heat shock conditions, incubation temperature, incubation time, plating technique and the presence of apple juice in the sample on the accuracy of the detection and enumeration of A. acidoterrestris spores was investigated. Among the investigated media, YSG agar was the most sensitive medium, and its application resulted in the highest recovery of A. acidoterrestris spores, while K agar and BAT agar were the least suitable media. The effect of the heat shock time on the recovery of spores was negligible. When there was a low concentration of spores in a sample, the membrane filtration method was superior to the spread plating method. The obtained results show that heat shock carried out at 80°C for 10 min and plating samples in combination with membrane filtration on YSG agar, followed by incubation at 46°C for 3 days provided the optimal conditions for the detection and enumeration of A. acidoterrestris spores. Application of the presented method allows highly efficient, fast and sensitive identification and enumeration of A. acidoterrestris spores in food products. This methodology will be useful for the fruit juice industry for identifying products contaminated with A. acidoterrestris spores, and its practical application may prevent economic losses for manufacturers. Copyright © 2012 Elsevier B.V. All rights reserved.

Efficiency of Artemia cysts removal as a model invasive spore using a continuous microwave system with heat recovery.

Science.gov (United States)

Balasubramanian, Sundar; Ortego, Jeffrey; Rusch, Kelly A; Boldor, Dorin

2008-12-15

A continuous microwave system to treat ballast water inoculated with Artemia salina cysts as a model invasive spore was tested for its efficacy in inactivating the cysts present. The system was tested at two different flow rates (1 and 2 L x min(-1)) and two different power levels (2.5 and 4.5 kW). Temperature profiles indicate that the system could deliver heating loads in excess of 100 degrees C in a uniform and near-instantaneous manner when using a heat recovery system. Except for a power and flow rate combination of 2.5 kW and 2 L x min(-1), complete inactivation of the cysts was observed at all combinations at holding times below 100 s. The microwave treatment was better or equal to the control treatment in inactivating the cysts. Use of heat exchangers increased the power conversion efficiency and the overall efficiency of the treatment system. Cost economics analysis indicates that in the present form of development microwave treatment costs are higher than the existing ballast water treatment methods. Overall, tests results indicated that microwave treatment of ballast water is a promising method that can be used in conjunction with other methods to form an efficient treatment system that can prevent introduction of potentially invasive spore forming species in non-native waters.

Heterogeneous photo-Fenton treatment for the reduction of pharmaceutical contamination in Madrid rivers and ecotoxicological evaluation by a miniaturized fern spores bioassay.

Science.gov (United States)

Rodríguez-Gil, José L; Catalá, Myriam; Alonso, Silvia González; Maroto, Raúl Romo; Valcárcel, Yolanda; Segura, Yolanda; Molina, Raúl; Melero, Juan A; Martínez, Fernando

2010-06-01

Fifty-six pharmaceuticals of various chemical groups, such as anti-inflammatory, antibacterial and cardiovascular drugs, were detected in four selected river waters receiving sewage effluents in the Community of Madrid (Spain). A promising approach for the degradation of those residues is the application of a photo-Fenton treatment. Several new bioassays using fern spores were employed for the evaluation of acute and chronic toxicity based on mitochondrial activity, DNA and chlorophyll quantifications of as-received river water and photo-Fenton-treated samples. photo-Fenton treatment provided a high degree of total organic carbon mineralization with up to 70% reduction for river water samples. In addition, the elimination of most of the studied pharmaceutical compounds was confirmed. A few compounds, however (salicylic acid, ofloxacin, caffeine, cotinine and nicotine), seemed more resistant, with after-treatment concentrations between 4 and 44ngL(-1). Nicotine showed the most refractory behaviour with concentrations ranging from 29 to 224ngL(-1) for treated samples. Photo-Fenton treatment yielded a significant decrease in acute and chronic toxicity, even though some residual toxicity remained after treatment. This fact seemed to be related to the presence of toxicants in the water matrix, probably of inorganic nature, rather than the toxic effect of the studied pharmaceutical compounds, as revealed by the effective removal of these compounds and high TOC mineralization of photo-Fenton treatments.

Assembly of an Oxalate Decarboxylase Produced under σK Control into the Bacillus subtilis Spore Coat

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Costa, Teresa; Steil, Leif; Martins, Lígia O.; Völker, Uwe; Henriques, Adriano O.

2004-01-01

Over 30 polypeptides are synthesized at various times during sporulation in Bacillus subtilis, and they are assembled at the surface of the developing spore to form a multilayer protein structure called the coat. The coat consists of three main layers, an amorphous undercoat close to the underlying spore cortex peptidoglycan, a lamellar inner layer, and an electron-dense striated outer layer. The product of the B. subtilis oxdD gene was previously shown to have oxalate decarboxylase activity when it was produced in Escherichia coli and to be a spore constituent. In this study, we found that OxdD specifically associates with the spore coat structure, and in this paper we describe regulation of its synthesis and assembly. We found that transcription of oxdD is induced during sporulation as a monocistronic unit under the control of σK and is negatively regulated by GerE. We also found that localization of a functional OxdD-green fluorescent protein (GFP) at the surface of the developing spore depends on the SafA morphogenetic protein, which localizes at the interface between the spore cortex and coat layers. OxdD-GFP localizes around the developing spore in a cotE mutant, which does not assemble the spore outer coat layer, but it does not persist in spores produced by the mutant. Together, the data suggest that OxdD-GFP is targeted to the interior layers of the coat. Additionally, we found that expression of a multicopy allele of oxdD resulted in production of spores with increased levels of OxdD that were able to degrade oxalate but were sensitive to lysozyme. PMID:14973022

Dynamics of Bacillus thuringiensis var. israelensis and Lysinibacillus sphaericus spores in urban catch basins after simultaneous application against mosquito larvae.

Directory of Open Access Journals (Sweden)

Valeria Guidi

Full Text Available Bacillus thuringiensis var. israelensis (Bti and Lysinibacillus sphaericus (Lsph are extensively used in mosquito control programs. These biocides are the active ingredients of a commercial larvicide. Quantitative data on the fate of both Bti and Lsph applied together for the control of mosquitoes in urban drainage structures such as catch basins are lacking. We evaluated the dynamics and persistence of Bti and Lsph spores released through their concomitant application in urban catch basins in southern Switzerland. Detection and quantification of spores over time in water and sludge samples from catch basins were carried out using quantitative real-time PCR targeting both cry4A and cry4B toxin genes for Bti and the binA gene for Lsph. After treatment, Bti and Lsph spores attained concentrations of 3.76 (± 0.08 and 4.13 (± 0.09 log ml(-1 in water, then decreased progressively over time, reaching baseline values. For both Bti and Lsph, spore levels in the order of 10(5 g(-1 were observed in the bottom sludge two days after the treatment and remained constant for the whole test period (275 days. Indigenous Lsph strains were isolated from previously untreated catch basins. A selection of those was genotyped using pulsed field gel electrophoresis of SmaI-digested chromosomal DNA, revealing that a subset of isolates were members of the clonal population of strain 2362. No safety issues related to the use of this biopesticide in the environment have been observed during this study, because no significant increase in the number of spores was seen during the long observation period. The isolation of native Lysinibacillus sphaericus strains belonging to the same clonal population as strain 2362 from catch basins never treated with Lsph-based products indicates that the use of a combination of Bti and Lsph for the control of mosquitoes does not introduce non-indigenous microorganisms in this area.

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

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Hariram, Upasana; Labbé, Ronald

2015-03-01

Recent incidents of foodborne illness associated with spices as the vehicle of transmission prompted this examination of U.S. retail spices with regard to Bacillus cereus. This study focused on the levels of aerobic-mesophilic spore-forming bacteria and B cereus spores associated with 247 retail spices purchased from five states in the United States. Samples contained a wide range of aerobic-mesophilic bacterial spore counts (spices had high levels of aerobic spores (> 10(7) CFU/g). Using a novel chromogenic agar, B. cereus and B. thuringiensis spores were isolated from 77 (31%) and 11 (4%) samples, respectively. Levels of B. cereus were spice isolates to form spores, produce diarrheal toxins, and grow at moderately abusive temperatures makes retail spices an important potential vehicle for foodborne illness caused by B. cereus strains, in particular those that produce diarrheal toxins.

Adhesion of Spores of Bacillus thuringiensis on a Planar Surface

Energy Technology Data Exchange (ETDEWEB)

Chung, Eunhyea [Georgia Institute of Technology; Kweon, Hyojin [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Lee, Ida [University of Tennessee, Knoxville (UTK); Joy, David Charles [ORNL; Palumbo, Anthony Vito [ORNL; Tsouris, Costas [ORNL

2010-01-01

Adhesion of spores of Bacillus thuringiensis (Bt) and spherical silica particles on surfaces was experimentally and theoretically investigated in this study. Topography analysis via atomic force microscopy (AFM) and electron microscopy indicates that Bt spores are rod shaped, {approx}1.3 {mu}m in length and {approx}0.8 {mu}m in diameter. The adhesion force of Bt spores and silica particles on gold-coated glass was measured at various relative humidity (RH) levels by AFM. It was expected that the adhesion force would vary with RH because the individual force components contributing to the adhesion force depend on RH. The adhesion force between a particle and a planar surface in atmospheric environments was modeled as the contribution of three major force components: capillary, van der Waals, and electrostatic interaction forces. Adhesion force measurements for Bt spore (silica particle) and the gold surface system were comparable with calculations. Modeling results show that there is a critical RH value, which depends on the hydrophobicity of the materials involved, below which the water meniscus does not form and the contribution of the capillary force is zero. As RH increases, the van der Waals force decreases while the capillary force increases to a maximum value.

Combined treatment with atorvastatin and imipenem improves survival and vascular functions in mouse model of sepsis.

Science.gov (United States)

Choudhury, Soumen; Kannan, Kandasamy; Pule Addison, M; Darzi, Sazad A; Singh, Vishakha; Singh, Thakur Uttam; Thangamalai, Ramasamy; Dash, Jeevan Ranjan; Parida, Subhashree; Debroy, Biplab; Paul, Avishek; Mishra, Santosh Kumar

2015-08-01

We have recently reported that pre-treatment, but not the post-treatment with atorvastatin showed survival benefit and improved hemodynamic functions in cecal ligation and puncture (CLP) model of sepsis in mice. Here we examined whether combined treatment with atorvastatin and imipenem after onset of sepsis can prolong survival and improve vascular functions. At 6 and 18h after sepsis induction, treatment with atorvastatin plus imipenem, atorvastatin or imipenem alone or placebo was initiated. Ex vivo experiments were done on mouse aorta to examine the vascular reactivity to nor-adrenaline and acetylcholine and mRNA expressions of α1D AR, GRK2 and eNOS. Atorvastatin plus imipenem extended the survival time to 56.00±4.62h from 20.00±1.66h observed in CLP mice. The survival time with atorvastatin or imipenem alone was 20.50±1.89h and 27.00±4.09h, respectively. The combined treatment reversed the hyporeactivity to nor-adrenaline through preservation of α1D AR mRNA/protein expression and reversal of α1D AR desensitization mediated by GRK2/Gβγ pathway. The treatment also restored endothelium-dependent relaxation to ACh through restoration of aortic eNOS mRNA expression and NO availability. In conclusion, combined treatment with atorvastatin and imipenem exhibited survival benefit and improved vascular functions in septic mice. Copyright © 2015 Elsevier Inc. All rights reserved.

The Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections

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Peterson, Tracy S.; Spitsbergen, Jan M.; Feist, Stephen W.; Kent, Michael L.

2014-01-01

Microsporidia in histologic sections are most often diagnosed by observing spores in host tissues. Spores are easy to identify if they occur in large aggregates or xenomas when sections are stained with hematoxylin and eosin (H&E). However, individual spores are not frequently detected in host tissues with conventional H&E staining, particularly if spores are scattered within the tissues, areas of inflammation or small spores in nuclei (i.e., Nucleospora salmonis). Hence, a variety of selective stains that enhance visualization of spores are recommended. We discovered that the Luna stain, used to highlight eosinophils, red blood cells and chitin in arthropods and other invertebrates, also stains spores of Pseudoloma neurophilia. We compared this stain to the Gram, Fite’s acid fast, Giemsa, and H&E stains on eight aquatic microsporidian organisms that were readily available in our two laboratories: Loma salmonae, Glugea anomala, Pseudoloma neurophilia, Pleistophora hyphessobryconis, Pleistophora vermiformis, Glugea sp., Steinhausia mytilovum and an unidentified microsporidian from E. sinensis, UK. Based on tinctorial properties and background staining, the Luna stain performed better for detection of 6 of the 8 microsporidia. Gram stain was superior for the two microsporidia from invertebrates, Steinhausia mytilovum and the unidentified microsporidian from E. sinensis. PMID:21848126

Oral delivery of Bacillus subtilis spore expressing enolase of Clonorchis sinensis in rat model: induce systemic and local mucosal immune responses and has no side effect on liver function.

Science.gov (United States)

Yu, Jinyun; Chen, Tingjin; Xie, Zhizhi; Liang, Pei; Qu, Honglin; Shang, Mei; Mao, Qiang; Ning, Dan; Tang, Zeli; Shi, Mengchen; Zhou, Lina; Huang, Yan; Yu, Xinbing

2015-07-01

Caused by the consumption of raw or undercooked freshwater fish containing infective metacercariae of Clonorchis sinensis, human clonorchiasis remains a major public health problem in China. In previous study, we had expressed enolase from C. sinensis (CsENO) on the surface of Bacillus subtilis spore and the recombinant spore induced a pronounced protection in terms of reduced worm burden and eggs per gram feces, suggesting B. subtilis spore as an ideal vehicle for antigen delivery by oral treatment and CsENO as a promising vaccine candidate against clonorchiasis. In the current study, we detected CsENO-specific IgG and IgA levels both in serum and in intestinal mucus from rats orally administrated with B. subtilis spore surface expressing CsENO by ELISA. Lysozyme levels in serum and in intestinal mucus were analyzed too. In addition, IgA-secreting cells in intestine epithelium of the rats were detected by immunohistochemistry assay. The intestinal villi lengths of duodenum, jejunum, and ileum were also measured. Rats orally treated with B. subtilis spore or normal saline were used as controls. Our results showed that, compared with the control groups, oral administration of B. subtilis spore expressing CsENO induced both systemic and local mucosal immune response. The recombinant spores also enhanced non-specific immune response in rats. The spores had no side effect on liver function. Moreover, it might facilitate food utilization and digestion of the rats. Our work will pave the way to clarify the involved mechanisms of protective efficacy elicited by B. subtilis spore expressing CsENO and encourage us to carry out more assessment trails of the oral treated spore to develop vaccine against clonorchiasis.

Universal nucleic acids sample preparation method for cells, spores and their mixture

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Bavykin, Sergei [Darien, IL

2011-01-18

The present invention relates to a method for extracting nucleic acids from biological samples. More specifically the invention relates to a universal method for extracting nucleic acids from unidentified biological samples. An advantage of the presently invented method is its ability to effectively and efficiently extract nucleic acids from a variety of different cell types including but not limited to prokaryotic or eukaryotic cells and/or recalcitrant organisms (i.e. spores). Unlike prior art methods which are focused on extracting nucleic acids from vegetative cell or spores, the present invention effectively extracts nucleic acids from spores, multiple cell types or mixtures thereof using a single method. Important that the invented method has demonstrated an ability to extract nucleic acids from spores and vegetative bacterial cells with similar levels effectiveness. The invented method employs a multi-step protocol which erodes the cell structure of the biological sample, isolates, labels, fragments nucleic acids and purifies labeled samples from the excess of dye.

Comparison of fungal spores concentrations measured with wideband integrated bioaerosol sensor and Hirst methodology

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Fernández-Rodríguez, S.; Tormo-Molina, R.; Lemonis, N.; Clot, B.; O'Connor, D. J.; Sodeau, John R.

2018-02-01

The aim of this work was to provide both a comparison of traditional and novel methodologies for airborne spores detection (i.e. the Hirst Burkard trap and WIBS-4) and the first quantitative study of airborne fungal concentrations in Payerne (Western Switzerland) as well as their relation to meteorological parameters. From the traditional method -Hirst trap and microscope analysis-, sixty-three propagule types (spores, sporangia and hyphae) were identified and the average spore concentrations measured over the full period amounted to 4145 ± 263.0 spores/m3. Maximum values were reached on July 19th and on August 6th. Twenty-six spore types reached average levels above 10 spores/m3. Airborne fungal propagules in Payerne showed a clear seasonal pattern, increasing from low values in early spring to maxima in summer. Daily average concentrations above 5000 spores/m3 were almost constant in summer from mid-June onwards. Weather parameters showed a relevant role for determining the observed spore concentrations. Coniferous forest, dominant in the surroundings, may be a relevant source for airborne fungal propagules as their distribution and predominant wind directions are consistent with the origin. The comparison between the two methodologies used in this campaign showed remarkably consistent patterns throughout the campaign. A correlation coefficient of 0.9 (CI 0.76-0.96) was seen between the two over the time period for daily resolutions (Hirst trap and WIBS-4). This apparent co-linearity was seen to fall away once increased resolution was employed. However at higher resolutions upon removal of Cladosporium species from the total fungal concentrations (Hirst trap), an increased correlation coefficient was again noted between the two instruments (R = 0.81 with confidence intervals of 0.74 and 0.86).

Observations on the migration of bacillus spores outside a contaminated facility during a decontamination efficacy study

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Silvestri, Erin E.; Perkins, Sarah; Lordo, Robert; Kovacik, William; Nichols, Tonya L.; Bowling, Charlena Yoder; Griffin, Dale W.; Schaefer, Frank W.

2015-01-01

The potential for an intentional wide-area or indoor release of Bacillus anthracis spores remains a concern, but the fate and transport of B. anthracis spores in indoor and outdoor environments are not well understood. Some studies have examined the possibility of spore transport within ventilation systems and in buildings and transport into a building following an outdoor release. Little research exists regarding the potential for spores to migrate to the outside of a building following an indoor release.

Impact of diabetes on treatment outcomes and long-term survival in multidrug-resistant tuberculosis.

Science.gov (United States)

Kang, Young Ae; Kim, Song Yee; Jo, Kyung-Wook; Kim, Hee Jin; Park, Seung-Kyu; Kim, Tae-Hyung; Kim, Eun Kyung; Lee, Ki Man; Lee, Sung Soon; Park, Jae Seuk; Koh, Won-Jung; Kim, Dae Yun; Shim, Tae Sun

2013-01-01

Few studies have investigated the impact of diabetes mellitus (DM), a globally increasing metabolic disease, on treatment outcomes and long-term survival in patients with multidrug-resistant forms of tuberculosis (MDR-TB). We analyzed outcomes in a large cohort to assess the impact of DM on treatment outcomes of patients with MDR-TB. MDR-TB patients newly diagnosed or retreated between 2000 and 2002 and followed for 8-11 years were retrospectively analyzed with respect to the effect of DM as a comorbidity on their treatment outcome and long-term survival. Of 1,407 patients with MDR-TB, 239 (17.0%) had coexisting DM. The mean age and body mass index were higher in MDR-TB patients with DM [MDR-TBDM(+)] than in those without DM [MDR-TBDM(-)]. Patients with MDR-TB and a comorbidity of DM had a significantly lower treatment success rate than those without a history of DM (36.0 vs. 47.2%, p = 0.002). In addition, DM was the negative predictor for MDR-TB treatment success in multivariate analyses [odds ratio 0.51, 95% confidence interval (CI) 0.26-0.99]. Mean survival times were also lower in MDR-TBDM(+) than in MDR-TBDM(-) patients (102 vs. 114 months, p = 0.001), with DM as a significant predictor of poor long-term survival in multivariate analyses (hazard ratio 1.59, 95% CI 1.01-2.50). Among MDR-TB patients, DM was a relatively common comorbidity. In patients undergoing treatment for MDR-TB and followed for 8-11 years, it was found to be independently associated with an increased risk of both treatment failure and death. Copyright © 2013 S. Karger AG, Basel.