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PubMed2001

Correlation of spring spore concentrations and meteorological conditions in Tulsa, Oklahoma.

Different spore types are abundant in the atmosphere depending on the weather conditions. Ascospores generally follow precipitation, while spore types such as Alternaria and Cladosporium are abundant in dry conditions. This project attempted to correlate fungal spore concentrations with meteorological data from Tulsa, Oklahoma during May 1998 and May 1999. Air samples were collected and analyzed by the 12-traverse method. The spore types included were Cladosporium, Alternaria, Epicoccum, Curvularia, Pithomyces, Drechslera, smut spores, ascospores, basidiospores, and other spores. Weather variables included precipitation levels, temperature, dew point, air pressure, wind speed, wind direction and wind gusts. There were over 242.57 mm of rainfall in May 1999 and only 64.01 mm in May 1998. The most abundant spore types during May 1998 and May 1999 were Cladosporium, ascospores, and basidiospores. Results showed that there were significant differences in the dry-air spora between May 1998 and May 1999. There were twice as many Cladosporium in May 1998 as in May 1999; both ascospores and basidiospores showed little change. Multiple regression analysis was used to determine which meteorological variables influenced spore concentrations. Results showed that there was no single model for all spore types. Different combinations of factors were predictors of concentration for the various fungi examined; however, temperature and dew point seemed to be the most important meteorological factors.

Alternaria↗
PubMed1984

The stage specific inhibition of Dictyostelium discoideum spore germination by the mutagen 4-nitroquinoline 1-oxide.

The drug 4-nitroquinoline 1-oxide (4NQO) is a potent inhibitor of Dictyostelium discoideum spore germination. This inexpensive, water soluble drug is active at a concentration of 5 micrograms/ml (26 microM) and permeates the spore at all stages in germination. Spores subjected to 4NQO treatment exhibit an irreversible blockage of myxamoebae emergence, but spore activation, post-activation lag, and swelling are not affected. Swollen 4NQO-treated spores lose the outer two spore walls but lack the ability to degrade the innermost wall. The drug does not affect oxygen uptake during post-activation lag or swelling, and only a stage specific depression in O2 uptake is observed when control spores begin to release myxamoebae. When added early in germination, 4NQO blocks the incorporation of [3H] uracil into a cold trichloroacetic acid (TCA) insoluble fraction by 98%. However, when the drug is added midway through germination and followed by a pulse labelling period of 1 h, only 65% inhibition of RNA synthesis is observed. This lack of complete inhibition may occur because the drug requires metabolic activation; thus, new rounds of RNA synthesis may have initiated before the drug became fully activated. 4NQO also blocks the de novo expression of beta-glucosidase activity when added early in germination. Additionally, we observe that vegetative cellular slime mold cells are 100 times more resistant than spores to 4NQO-induced damage. Taken together, our results support the observation that RNA synthesis is only required for the emergence stage of germination and that dormant D. discoideum spores may lack efficient excision repair mechanisms.

4-Nitroquinoline-1-oxide↗
PubMed1975

Effects of DNA-polymerase-defective and recombination-deficient mutations on the ultraviolet sensitivity of Bacillus subtilis spores.

The DNA of UV-irradiated Bacillus subtilis spores, which contains 5-thyminyl-5,6-dihydrothymine (TDHT) as the major thymine photoproduct, is known to be repaired during germination by two complementary mechanisms: (I) the well-known excision repair, and (2) a special process, "spore repair", which destroys TDHT in situ without rendering it acid-soluble. In the absence of both mechanisms TDHT is not removed, and spores are highly UV-sensitive. When either of two mutations (pol-59 and pol-151) giving defective DNA polymerase, or one (rec-A1) giving a recombination deficiency are introduced into strains defective in one of these known TDHT removal processes, the chemically measured elimination of TDHT from spore DNA is unaltered, but spore UV-sensitivity is increased. The pol mutations produce their greatest sensitivity increase in spores of strains already deficient for the in situ destruction of TDHT, while the rec mutation gives its maximum sensitivity increase to spores of strains lacking excision. These facts argue that the pol mutations interfere mostly with excision repair (presumably its later resynthesis step), shile the rec mutation impairs "spore repair" in some step occurring subsequent to the TDHT destruction in situ. With either of these impairments of the later repair steps, DNA of UV-irradiated and germinated spores is considerably degraded, unless germination is carried out in the presence of chloramphenicol.

Bacillus subtilis↗
PubMed1978

Effect of central air conditioning and meteorologic factors on indoor spore counts.

We have studied the effect of residential central air conditioning on indoor spore counts. The air of 6 pairs of homes (air-conditioned and non-air-conditioned) was sampled volumetrically 4 times daily for 3 consecutive days at 2-hr intervals in the kitchens, bedrooms, and basements with an Anderson sampler. Nearly simultaneous samples were taken outdoors at the same intervals. The total spore count was significantly lower (p less than 0.05) in the kitchens and bedrooms of air-conditined as compared to non-air-conditioned homes. Logarithmic conversion of the total spore count showed significant reduction in all indoor locations of air-conditioned homes. Multiple regression analysis revealed the lower relative humidity of air-conditioned homes to be associated with the lower spore counts. There was no difference in the percent concentration of the major genera within both types of homes. Since reducing the influx of outdoor spores decreases the total spore count without altering the relative concentration of the genera whereas filtration preferentially removes the larger spores, we conclude that the major mechanism in reducing spore counts in air-conditioned homes is the closed windows, although the lower relative humidity and perhaps filtration are also associated with lower spore counts.

Air Conditioning↗
PubMed1993

Comparison of Psilocybe cubensis spore and mycelium allergens.

BACKGROUND: Basidiospores are an important cause of respiratory allergy in mold-sensitive atopic subjects. Collection of the large amounts of spores required for extract preparation is tedious and difficult. A desirable alternative could be mycelium grown in vitro if it is allergenically similar to spores. METHODS: Therefore this study compared the allergen contents of Psilocybe cubensis spore and mycelium extracts by different techniques with the use of pooled sera from subjects who had skin test and RAST results that were positive to P. cubensis spores. RESULTS: Isoelectric focusing immunoprints revealed six common IgE-binding bands at isoelectric points 4.7, 5.0, 5.5, 5.6, 8.7, and 9.3. Two additional bands at isoelectric points 3.9 and 5.7 were detected only in the spore extract. Sodium dodecylsulfate-polyacrylamide gel electrophoresis immunoblots exhibited six common IgE-binding bands at 16, 35, 487, 52, 62, and 76 kd; 20 and 40 kd bands were present only in the spore extract. Although RAST and isoelectric focusing inhibition demonstrated that P. cubensis spore and mycelium extracts share many allergens, spores were allergenically more potent than mycelium. CONCLUSION: The results indicate that mycelium is a useful source of P. cubensis allergen, even though several spore allergens were not detected in mycelium.

Agaricales↗
PubMed2005

Activity of selected oxidizing microbicides against the spores of Clostridium difficile: relevance to environmental control.

BACKGROUND: Clostridium difficile is an increasingly common nosocomial pathogen, and its spores are resistant to common environmental surface disinfectants. Many high-level disinfectants (eg, aldehydes) are unsuitable for environmental decontamination because they need several hours of contact to be sporicidal. This study tested the potential of selected oxidative microbicides to inactivate C. difficile spores on hard surfaces in relatively short contact times at room temperature. METHODS: The spores of a clinical isolate of C. difficile were tested using disks (1 cm diameter) of brushed stainless steel in a quantitative carrier test. The spores of C. sporogenes and Bacillus subtilis, common surrogates for evaluating sporicides, were included for comparison. The clostridia were grown separately in Columbia broth (CB), and B. subtilis was grown in a 1:10 dilution of CB. Each disk received 10 microL test spores with an added soil load, and the inoculum was dried. One disk each was placed in a glass vial and overlaid with 50 microL test formulation; controls received an equivalent volume of normal saline with 0.1% Tween 80. At the end of the contact time the microbicide was neutralized, the inoculum recovered from the disks by vortexing, the eluates were membrane filtered, and the filters placed on plates of recovery medium. The colony-forming units (CFU) on the plates were recorded after 5 days of incubation. The performance criterion was > or = 6 log(10) (> or = 99.9999%) reduction in the viability titer of the spores. The microbicides tested were domestic bleach with free-chlorine (FC) levels of 1000, 3000, and 5000 mg/L; an accelerated hydrogen peroxide (AHP)-based product with 70,000 mg/L H2O2 (Virox STF); chlorine dioxide (600 mg/L FC); and acidified domestic bleach (5000 mg/L FC). RESULTS: Acidified bleach and the highest concentration of regular bleach tested could inactivate all the spores in < or = 10 minutes; Virox STF could do the same in < or = 13 minutes. Regular bleach with 3000 mg/L FC required up to 20 minutes to reduce the viability of the all the spores tested to undetectable levels; chlorine dioxide and the lowest concentration of regular bleach tested needed approximately 30 minutes for the same level of activity. CONCLUSIONS: Acidified bleach, Virox STF, and regular bleach (3000-5000 mg/L FC) could inactivate C. difficile spores on hard environmental surfaces in approximately 10 to 15 minutes under ambient conditions. All of these products are strong oxidizers and should be handled with care for protection of staff, but acidified and regular bleach with high levels of FC also release chlorine gas, which can be hazardous if inhaled by staff or patients.

Chlorine Compounds↗
PubMed2004

Inactivation of Bacillus cereus spores in milk by mild pressure and heat treatments.

The objective of this work was to study the germination and subsequent inactivation of Bacillus cereus spores in milk by mild hydrostatic pressure treatment. In an introductory experiment with strain LMG6910 treated at 40 degrees C for 30 min at 0, 100, 300 and 600 MPa, germination levels were 1.5 to 3 logs higher in milk than in 100 mM potassium phosphate buffer (pH 6.7). The effects of pressure and germination-inducing components present in the milk on spore germination were synergistic. More detailed experiments were conducted in milk at a range of pressures between 100 and 600 MPa at temperatures between 30 and 60 degrees C to identify treatments that allow a 6 log inactivation of B. cereus spores. The mildest treatment resulting in a 6 log germination was 30 min at 200 MPa/40 degrees C. Lower treatment pressures or temperatures resulted in considerably less germination, and higher pressures and temperatures further increased germination, but a small fraction of spores always remained ungerminated. Further, not all germinated spores were inactivated by the pressure treatment, even under the most severe conditions (600 MPa/60 degrees C). Two possible approaches to achieve a 6 log spore inactivation were identified, and validated in three additional B. cereus strains. The first is a single step treatment at 500 MPa/60 degrees C for 30 min, the second is a two-step treatment consisting of pressure treatment for 30 min at 200 MPa/45 degrees C to induce spore germination, followed by mild heat treatment at 60 degrees C for 10 min to kill the germinated spores. Reduction of the pressurization time to 15 min still allows a 5 log inactivation. These results illustrate the potential of high-pressure treatment to inactivate bacterial spores in minimally processed foods.

Animals↗
PubMed2002

Antitumor activity of the sporoderm-broken germinating spores of Ganoderma lucidum.

The inhibitory effects of the dormant spores, the germinating spores, the sporoderm-broken germinating spores (SBGS), and the lipids extracted from the germinating spores of Ganoderma lucidum on the growth of mouse hepatoma, sarcoma S-180, and reticulocyte sarcoma L-II cells were investigated, respectively. The dormant spores could be activated by germination, and thus the bioactivities of the spores might be enhanced. The sporoderm-broken spores could show much higher bioactivities than the whole spores. Both the lipids extracted from the germinating spores and the SBGS of G. lucidum had remarkable antitumor effects in a dose-dependent manner, and could significantly inhibit three tumors with an inhibition of 80-90%.

Administration, Oral↗
PubMed2005

Variation assessment of airborne Alternaria and Cladosporium spores at different bioclimatical conditions.

The study of mould spores is of major importance as many fungi can cause considerable economic losses worldwide acting as plant pathogens or triggering respiratory diseases and allergenic processes in humans. Knowledge of spore production relationships to different altitudes or weather patterns can be applied in a more efficient and reliable use of pesticides or improving diagnosis and treatment of respiratory allergic diseases. In this way monitoring of Cladosporium cladosporioides, C. herbarum and Alternaria spp. airborne spores during 2002 was carried out by means of three LANZONI VPPS 2000 pollen traps located in areas of north-west Spain at various altitudes and with various weather patterns. High spore counts were recorded in the late summer and early autumn, with a fairly similar hourly spore-count pattern, increasing the concentrations in the late evening (7-10 p.m.). High spore concentrations were detected in inland rural areas in front of coastal ones. As the continentality index increased, C. cladosporioides spore concentrations rose and Alternaria declined. C. herbarum concentrations increased with increasing height above sea level. The weather factor displaying the strongest positive correlation with mean daily spore counts was temperature. The optimal conditions for high airborne spore concentrations were recorded at temperatures ranging from 23-29 degrees C and RH values of around 80%, followed rapidly by rainfall in Vigo and Ourense and preceded by heavy rain two days prior to recording peak values in Trives.

Air Microbiology↗
PubMed2005

Comprehensive assignment of mass spectral signatures from individual Bacillus atrophaeus spores in matrix-free laser desorption/ionization bioaerosol mass spectrometry.

We have fully characterized the mass spectral signatures of individual Bacillus atrophaeus spores obtained using matrix-free laser desorption/ionization bioaerosol mass spectrometry (BAMS). Mass spectra of spores grown in unlabeled, 13C-labeled, and 15N-labeled growth media were used to determine the number of carbon and nitrogen atoms associated with each mass peak observed in mass spectra from positive and negative ions. To determine the parent ion structure associated with fragment ion peaks, the fragmentation patterns of several chemical standards were independently determined. Our results confirm prior assignments of dipicolinic acid, amino acids, and calcium complex ions made in the spore mass spectra. The identities of several previously unidentified mass peaks, key to the recognition of Bacillus spores by BAMS, have also been revealed. Specifically, a set of fragment peaks in the negative polarity is shown to be consistent with the fragmentation pattern of purine nucleobase-containing compounds. The identity of m/z = +74, a marker peak that helps discriminate B. atrophaeus from Bacillus thuringiensis spores grown in rich media is [N1C4H12]+. A probable precursor molecule for the [N1C4H12]+ ion observed in spore spectra is trimethylglycine (+N(CH3)3CH2COOH), which produces a m/z = +74 peak when ionized in the presence of dipicolinic acid. A clear assignment of all the mass peaks in the spectra from bacterial spores, as presented in this work, establishes their relationship to the spore chemical composition and facilitates the evaluation of the robustness of "marker" peaks. This is especially relevant for peaks that have been used to discriminate Bacillus spore species, B. thuringiensis and B. atrophaeus, in our previous studies.

Amino Acids↗
PubMedDate not supplied

An optimized method for Aspergillus niger spore production on natural carrier substrates.

Aspergillus niger spores have wide ranging applications in the fermentation industry as well as in wastewater treatment. We present an optimized method for production of A. niger spores on natural substrates such as rice, split pea, and millet. The specific productivity (number of spores per gram of dry substrate) was 31-fold greater and volumetric productivity was 750-fold greater compared to agar slopes. The important process variables were incubation temperature, moisture content, and inoculum quantity. We find that the optimal condition for total spore count is different from the viable spore count for millet. The optimum lies in a narrow region defined by the process parameters. Of the three substrates tested split pea gave the highest specific spore productivity of 3.1 x 10(10) spores per gram of dry substrate. This is the first report of systematic study on the effect of process parameters on spore viability. The method of A. niger spore production on natural substrate appears advantageous as compared to the currently practiced method in terms of scale-up, cost, and ease of operation.

Aspergillus niger↗
PubMed2004

Molecular methods clarify morphometric variation in triactinomyxon spores (Myxozoa) released from different oligochaete hosts.

Thirty-nine freshwater tubificid oligochaetes were isolated, each of which harboured a triactinomyxon infection. Spore characteristics include the typical triactinomyxon anchor shape, eight germ cells within the sporoplasm and three unequal (two long and one shorter) caudal processes with square tips. Despite morphological similarities between the spores from the different hosts, their morphometrical data varied considerably; significantly, the ranges of dimensions of the smallest and largest exemplars were mutually exclusive. In order to ascertain the true number of spore types present, molecular methods were employed. Samples of waterborne spores, including the smallest and largest representatives, were selected from 11 host oligochaetes (all Tubifex tubifex Müller) and a nested PCR-RFLP 'riboprint' analysis performed. The small subunit ribosomal DNA gene (18S rDNA) was targetted and amplified through two rounds of PCR, then digested with the restriction enzymes Dde I and Hha I. The resultant major cleavage patterns produced by both enzymes indicated a single triactinomyxon form; however, the pattern of several less intense bands varied between the samples. From a subset of five samples drawn from across the full spectrum of spore sizes, a 327 bp region near the 5' was sequenced and was identical for all five samples. Comparison of this 327 bp region with that of 12 other triactinomyxons in GenBank showed 68.7-96.9% similarity (at least 9 base differences). A further 469 bp generated for each of the smallest, largest and mid-range (= reference) spore samples was identical also. The reference sample was sequenced further to yield 1,554 bp of 18S rDNA (GenBank accession number AY162270); comparison with other Myxozoa indicated this sequence was novel. The morphometrics of our triactinomyxon did not correlate with any published description. The morphometrical variation exhibited by spores of the triactinomyxon type in this study raises questions about the validity of using morphometrical data to distinguish spore types and suggests that there could be taxonomic redundancy in the diversity of actinosporeans recorded in the literature. The additional information provided by molecular data in this study was pivotal in the clarification of morphometrical variation exhibited by morphologically similar triactinomyxon spores released from different oligochaete hosts.

Animals↗
PubMed2002

Studies on the mechanism of killing of Bacillus subtilis spores by hydrogen peroxide.

AIMS: To determine the mechanism of killing of Bacillus subtilis spores by hydrogen peroxide. METHODS AND RESULTS: Killing of spores of B. subtilis with hydrogen peroxide caused no release of dipicolinic acid (DPA) and hydrogen peroxide-killed spores were not appreciably sensitized for DPA release upon a subsequent heat treatment. Hydrogen peroxide-killed spores appeared to initiate germination normally, released DPA and hydrolysed significant amounts of their cortex. However, the germinated killed spores did not swell, did not accumulate ATP or reduced flavin mononucleotide and the cores of these germinated spores were not accessible to nucleic acid stains. CONCLUSIONS: These data indicate that treatment with hydrogen peroxide results in spores in which the core cannot swell properly during spore germination. SIGNIFICANCE AND IMPACT OF THE STUDY: The results provide further information on the mechanism of killing of spores of Bacillus species by hydrogen peroxide.

Adenosine Triphosphate↗
PubMed2002

A rapid staining technique for the detection of the initiation of germination of bacterial spores.

AIMS: We propose to apply the Wirtz-Conklin staining technique to evaluate spore germination. METHODS AND RESULTS: Spores at different stages of germination were stained with modified spore stain (Wirtz-Conklin) and evaluated for staining properties. Bacillus spores suspended in deionized water, which does not support germination, stained greenish-blue. Spores suspended in germination enhancers that did not form bacilli stained pink, indicating the initiation of germination. Spores suspended in culture media, which promotes bacterial outgrowth, formed bacilli and were also stained pink. CONCLUSIONS: Modified spore stain (Wirtz-Conklin) was found to be useful to detect the initiation of spore germination as early as 30 min following incubation in a germination environment. SIGNIFICANCE AND IMPACT OF THE STUDY: This simple staining procedure is useful in detecting the initiation of germination of bacterial spores.

Bacillus↗
PubMed1987

Involvement of calcium and dipicolinic acid in the resistance of Bacillus cereus BIS-59 spores to u.v. and gamma radiations.

The role of dipicolinic acid (DPA) in determining the resistance of Bacillus cereus spores to u.v. and gamma radiation was investigated. B. cereus BIS-59 spores containing varying amounts of DPA were prepared by appropriate compositional adjustments in the secondary media. Compared with spores containing 6 per cent DPA (dry weight) those containing 0.8 per cent DPA were far more sensitive to u.v. radiation. Similar u.v. radiation sensitivity was also found in respect of a DPA-less mutant of B. cereus T 6A 1. Pre-treatment of DPA deficient spores (of wild type or mutant B. cereus) with DPA or the presence of DPA during irradiation resulted in increased resistance of these spores to u.v. radiation. In the range 0.2 to 1 per cent DPA content of spores of B. cereus BIS-59, a striking inverse relationship could be discerned between the DPA content and the number of spore photo-products (5-thymidyl, 5,6-dihydrothymine) formed in DNA and spore viability. The resistance of B. cereus spores to gamma radiation did not seem to be influenced by their DPA content.

Bacillus cereus↗
PubMed2006

Application of gaseous ozone for inactivation of Bacillus subtilis spores.

The effectiveness of gaseous ozone (O3) as a disinfectant was tested on Bacillus subtilis spores, which share the same physiological characteristics as Bacillus anthracis spores that cause the anthrax disease. Spores dried on surfaces of different carrier material were exposed to O3 gas in the range of 500-5000 ppm and at relative humidity (RH) of 70-95%. Gaseous O3 was found to be very effective against the B. subtilis spores, and at O3 concentrations as low as 3 mg/L (1500 ppm), approximately 3-log inactivation was obtained within 4 hr of exposure. The inactivation curves consisted of a short lag phase followed by an exponential decrease in the number of surviving spores. Prehydration of the bacterial spores has eliminated the initial lag phase. The inactivation rate increased with increasing O3 concentration but not >3 mg/L. The inactivation rate also increased with increase in RH. Different survival curves were obtained for various surfaces used to carry spores. Inactivation rates of spores on glass, a vinyl floor tile, and office paper were nearly the same. Whereas cut pile carpet and hardwood flooring surfaces resulted in much lower inactivation rates, another type of carpet (loop pile) showed significant enhancement in the inactivation of the spores.

Bacillus subtilis↗
PubMed1962

Formation and structure of the spore of Bacillus coagulans.

Spore formation in Bacillus coagulans has been studied by electron microscopy using an epoxy resin (Araldite) embedding technique. The developmental stages from the origin of the initial spore septum to the mature spore were investigated. The two forespore membranes developed from the double layer of cytoplasmic membrane. The cortex was progressively deposited between these two membranes. The inner membrane finally became the spore protoplasmic membrane, and the outer membrane part of the inner spore coat or the outer spore coat itself. In the mature spore the completed integuments around the spore protoplasm consisted of the cortex, a laminated inner coat, and a dense outer coat. No exosporium was observed. The method of formation of the cortex and the spore coats is discussed.

Animals↗
PubMed1997

Yeast spore germination: a requirement for Ras protein activity during re-entry into the cell cycle.

Saccharomyces cerevisiae spore germination is a process in which quiescent, non-dividing spores become competent for mitotic cell division. Using a novel assay for spore uncoating, we found that spore germination was a multi-step process whose nutritional requirements differed from those for mitotic division. Although both processes were controlled by nutrient availability, efficient spore germination occurred in conditions that did not support cell division. In addition, germination did not require many key regulators of cell cycle progression including the cyclin-dependent kinase, Cdc28p. However, two processes essential for cell growth, protein synthesis and signaling through the Ras protein pathway, were required for spore germination. Moreover, increasing Ras protein activity in spores resulted in an accelerated rate of germination and suggested that activation of the Ras pathway was rate-limiting for entry into the germination program. An early step in germination, commitment, was identified as the point at which spores became irreversibly destined to complete the uncoating process even if the original stimulus for germination was removed. Spore commitment to germination required protein synthesis and Ras protein activity; in contrast, post-commitment events did not require ongoing protein synthesis. Altogether, these data suggested a model for Ras function during transitions between periods of quiescence and cell cycle progression.

Culture Media↗