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PubMed2006

Effects of amoebae on the growth of microbes isolated from moisture-damaged buildings.

Dampness, moisture, and mold in buildings are associated with adverse health outcomes. In addition to fungi and bacteria, amoebae have been found in moisture-damaged building materials. Amoebae and a growing list of bacteria have been shown to have mutual effects on each other's growth, but the interactions between amoebae and microbes common in moisture-damaged buildings have not been reported. We co-cultivated the amoeba Acanthamoeba polyphaga with bacteria and fungi isolated from moisture-damaged buildings in laboratory conditions for up to 28 days. The microbes selected were the bacteria Streptomyces californicus, Bacillus cereus, and Pseudomonas fluorescens, and the fungi Stachybotrys chartarum, Aspergillus versicolor, and Penicillium spinulosum. Fungi and bacteria generally benefited from the presence of the amoebae, whereas the growth of amoebae was hindered by Streptomyces californicus, Stachybotrys chartarum, and Bacillus cereus. Pseudomonas fluorescens slightly enhanced amoebae viability. Amoebae were indifferent to the presence of Aspergillus versicolor and Penicillium spinulosum. Thus, our results show that amoebae can alter the survival and growth of some microbes in moisture-damaged buildings.

Acanthamoeba↗

PubMed1999

HOST VARIATION FOR INTERACTIONS WITH BENEFICIAL PLANT-ASSOCIATED MICROBES.

Beneficial plant-associated microbes can profoundly influence plant health by suppressing disease, enhancing nutrient uptake, fixing atmospheric nitrogen, and promoting plant growth. Host variation, among cultivars or plant genotypes, for response to beneficial microorganisms suggests that plant genes play a role in supporting these interactions. Such host variation can be found among diverse groups of microorganisms including rhizobia, mycorrhizal fungi, and microbial biocontrol agents. Discrete variation among plant genotypes for interaction with beneficial microbes has led to the discovery of single genes that specify compatible interactions. Continuous variation for interaction phenotypes such as disease suppression, plant growth, or nutrient uptake have led to hypotheses, and in some cases genetic descriptions, of multigenic control of these interactions. Future research into the role of plant genes involved in hosting beneficial plant-associated microbes will provide greater insight into this relatively unexplored area of biology and should provide new tools to improve plant health in agriculture.

Journal Article↗

PubMed2000

Advances in Imaging the Cell Biology of Plant-Microbe Interactions.

All plant-microbe interactions are initiated at the level of the cell. Recently, the light microscope has increased in popularity as an investigative tool in plant cell biology, in part because of the parallel developments of confocal laser scanning and video microscopy, computerized image processing, and an ever-increasing array of fluorescent probes that can be applied to living cells. In addition, transgenic plants and cells can be generated in which specific components are fluorescently labeled without any invasive experimental manipulation. The application of such techniques to plant-microbe interactions has revealed microbe-induced changes in cytosolic calcium levels, the visualization of reactive oxygen species generation, cytoskeleton rearrangements, DNA cleavage, and the detailed resolution of intercellular and intracellular trafficking of viral components. These techniques, integrated with electron microscopy, molecular genetics, and other types of investigations, are likely to play an increasingly important role in future studies of plant responses to microbial pathogens or mutualists.

DNA cleavage↗

PubMed2005

Erythema toxicum neonatorum is an innate immune response to commensal microbes penetrated into the skin of the newborn infant.

Erythema toxicum neonatorum is a common rash of unknown etiology affecting healthy newborn infants. In this study, we postulated that the rash reflects a response to microbial colonization of the skin at birth, and that the hair follicle constitutes an "easily opened door" for microbes into the skin of the newborn. We collected microbial cultures from the skin of 69 healthy, 1-d-old infants with and without erythema toxicum to identify the colonizing flora and correlate culture results with clinical findings. We also analyzed biopsies from lesions of erythema toxicum with scanning and transmission electron microscopy in the search for microbes. Finally, each infant's body temperature was measured as a sign of acute phase response. We found that 84% of 1-d-old healthy infants, with and without erythema toxicum were colonized with coagulase-negative staphylococci. In all lesions of erythema toxicum, TEM identified cocci-like bacteria localized in the hair follicle epithelium and into recruited immune cells surrounding the hair follicle; morphology and dimension supported their identification as belonging to the genus Staphylococcus. SEM revealed 10 times more hair structures per skin surface unit in newborns compared with adults. Infants with erythema toxicum also had higher body temperature. In erythema toxicum, commensal microbes gain entry into the skin tissue, most probably through the hair canal. This triggers the local immune system and a systemic acute phase response, including an increase in body temperature. We speculate that early microbial exposure to the newborn may be important for the maturation of the immune system.

Body Temperature↗

PubMed2006

Effect of total mixed ration composition on amino acid profiles of different fractions of ruminal microbes in vitro.

The objective was to study the variation in the amino acid profile of microbial fractions obtained after feeding 16 total mixed rations for dairy cows in a Rusitec. Each ration was incubated for 15 d in 3-fold replicate. The rations showed high variation in the inclusion level of different ingredients and the content of proximal nutrients, fiber fractions, and energy. Three microbial fractions were isolated by centrifugation. The reference microbes (RM) were isolated from the liquid effluent of vessels between d 7 and 15 of incubation. Solid-associated microbes (SAM) were detached with methylcellulose from feed residues after incubation, and liquid-associated microbes (LAM) were obtained from the liquid content of the vessel. Both SAM and LAM were obtained only once for each vessel at the end of the incubation period. Across all rations, significant differences were found between RM, LAM, and SAM in amino acid concentration for some, but not all, amino acids. Within each microbial fraction, significant differences in the content of amino acids were found between rations. Multiple linear regression analysis did not show that the content of a certain nutrient or the inclusion rate of single feedstuffs could be used to predict the amino acid profile of microbial protein with an adequate level of accuracy. Further studies are necessary before the supply of individual microbial amino acids to the cows' duodenum can be modeled and predicted in dependence of diet data.

Amino Acids↗

PubMed2001

Microbes, inflammation and atherosclerosis: will old pathology lessons guide new therapies?

Although attractive, the microbial pathogenesis theory for atherosclerosis remains unproven. Over the last century, microbiologists have invoked fulfillment of Koch's postulates to determine pathogen causality. Certainly a multifactorial disease process such as atherosclerosis unlikely will be due to a single microbial agent, an agent when transferred to another host, will always induce atherosclerosis. Conflicting epidemiological data also do not support a single causative agent. However, as presented here, considerable in vitro, animal, and human epidemiological data support the plausibility that infectious agents can promote a proinflammatory, procoagulant and proatherogenic environment in the vessel wall. Microbial genes and molecules can catalyze these processes and foil normal cellular events. But, must intact microbes enter the vessel wall or can microbial molecules incite immune responses from afar? A new focus on pathogen-induced auto-immunity toward vasculature has been presented. For example, microbes contain molecules that mimic host cellular components (55). An immune response to a pathogen may cross react with vessel wall cellular structures. This immune response enhanced by infection may lead to high levels of cross reacting auto-antibodies or auto-aggressive T-cells. Epstein has championed the concept of pathogen burden in support of this auto-immune theory (56). Individuals infected with multiple pathogens such as HSV-1, HSV-2, CMV, Helicobacter pylori, and Hepatitis A, have high C-reative protein levels (markers of inflammation) and the greatest relative risk for coronary artery disease (57). Thus, pathogens might contribute to the atherosclerotic process by promoting inflammatory responses. It is this author's view that microbes and inflammation do play a role in the pathogenesis of atherosclerosis (58). Infection may contribute to the process promoting vessel wall injury initiated by oxidized lipids, smoking derived oxidants, hypertensive shear or diabetes glyoxidized molecules. Inflammation and immune reactions in response to infection can exacerbate and act synergistically with all of the aforementioned vasculotoxic moieties. Continued investigations in the 21st century will determine if vaccines, antibiotics, anti-inflammatory agents or immunosuppressants will alter the picture the early 19th century pathologists observed under their monocular microscopes.

Arteriosclerosis↗

PubMed2000

[Detection of microbes adherent to particles in a closed environment].

OBJECTIVE: In order to provide reference for controlling and monitoring the environmental contamination in the spacecraft, the species and amount of microbes, which adhere to the suspended particles with different size in a closed environment were detected. METHOD: According to USA EPA IP-10, particles were continuously sampled by an impactor in a closed environment. The particles were divided into three grades by their aerodynamic diameters (AD): 100 micrometers > or = AD > 10 micrometers, 10 micrometers > or = AD>2 micrometers and AD < or = 2 micrometers. Clean outdoor air was collected as control by the same way. The collected particles were precisely weighed. The microbes that adhere to the particles were cultivated, counted and identified. RESULT: By calculating total suspended particles (TSP) and inhalant particles (IP) of the closed environment, counting, clarifying and identifying the microbes, 6 kinds of bacteria, 2 genus of actinomyces and 6 kinds of fungi that adhere to the particles were detected. CONCLUSION: The particles in a closed environment may have some effect on human health and instruments.

Actinomyces↗

PubMed2001

Young farmers with cellular reactivity to airborne microbes suffer more frequently from work-related skin symptoms and allergic dermatitis.

UNLABELLED: 75 farming students (49 males and 26 females aged 16-23 years) underwent dermatological, laryngological and pulmonary examination, skin prick tests with common and farm allergens, Phadiatop and total IgE measurement. After that, the migration inhibition tests with antigens of airborne microbes typical for farm environment (Saccharopolyspora rectivirgula, Pantoea agglomerans, and Aspergillus fumigatus) were carried out. Possible differences between students with positive results and those non-reactive were sought. RESULTS: 10 students reacted to at least one microbial antigen in the migration inhibition test. There were no significant differences in distribution of atopy, prick test results, total IgE, and Phadiatop between the reactive students and their classmates. Only one case of asthma was found, hence a further statistical analysis was not feasible. Allergic rhinitis has been found in 30% of the reactive and in 9.2% of non-reactive students; the difference, however, was not statistically significant (p=0.06). Significant differences were found with respect to the frequency of allergic skin diseases (40% reactive versus 9.2% non-reactive, p = 0.009); no other triggering factors than microbial antigens could be identified in 2 out of 4 reactive students with dermatitis. Work-related symptoms were present in all reactive students (100% versus 27.7%, p=0.001); 8 out of 10 reactive students did not show any other specific sensitisation. Antigens of airborne microbes are commonly associated with lung diseases. Our results, however, suggest that the skin may be affected as well. Relatively strong association between cellular reactivity to airborne microbes and skin diseases deserves further studies.

Adolescent↗

PubMed1999

[Development of air microbe sampler with micropore filter membrane].

Dual head air microbe sampler with a large flow capacity of 100 liters per minute was manufactured. The sampler possesses simple structures, light weight, convenient operation and higher sampling efficiency, equal to 77%-96% of the grade six Anderson sampler. Sampling time is a main factor affecting sampling efficiency. This device is suitable for the determination of degree of biological clean air in clean environment and the detection of the pathogenic microbes in ward and public places and also microbes in ordinary environment.

Air Microbiology↗

PubMed1992

[Effect of subinhibitory concentrations of antibiotics on catalase activity of plague microbes].

It was shown that the presence of subinhibitory concentrations of ampicillin, cefotaxime or gentamicin in the cultivation medium had a marked inhibitory effect on the catalase activity of plague microbe. The effect depended on the characteristic features of plague microbe strains and the incubation temperature. When the cells of a virulent strain of the plague microbe Y. pestis 1300 were cultivated at a temperature of 37 degrees C on a medium containing the subinhibitory concentrations of ampicillin or cefotaxime, the pathogen virulence for albino mice significantly decreased.

Ampicillin↗

PubMed2003

[Effect of atmospheric CO2 enrichment on soil microbes and related factors].

This paper summarized the effects of atmospheric CO2 enrichment on soil microbes and their related factors, including soil microflora, soil respiration, soil microbial biomass, and higher plant-microbe symbiosis. The factors related to soil microbic activity such as litter decomposition, root exudates, soil nutrient availability, nutrient use efficiency and soil fauna were also affected by the CO2 enrichment.

Air↗

PubMedDate not supplied

Studies of polyester fiber as carrier for microbes in a quantitative test method for disinfectants.

Tests were conducted by a Task Force on Disinfectant Test Methods that was appointed to investigate controversies regarding the accuracy of AOAC test methods for disinfectants as presented in AOAC's Official Methods of Analysis, Chapter 6. The general principles for new and improved AOAC tests are discussed, and a disinfectant test using microbes labeled onto a polyester fiber surface is described. The quantitative test measures the survival of test microbes as a function of exposure time as well as the exposure conditions required to kill 6 log10 of the test microbes. The time required was similar to that for the kinetics of the kill of Bacillus subtilis-labeled cylinders as tested by methods of the AOAC Sporicidal Test 966.04.

Bacillus subtilis↗

PubMed2004

[Epidemiology and drug resistance of the pathogenic microbes in the complicated infection of hematological malignancies].

OBJECTIVE: To investigate the epidemiological characteristics and drug resistance profile of the infection in patients with hematological malignancies. METHODS: All the microbe strains isolated from the department of hematology in Ruijin hospital between 1998 and 2002 were collected for the assessment of antimicrobial susceptibility and the results were analysed by WHONET5 software. RESULTS: Out of the 536 strains isolated in the department of hematology, 230 (42.9%) were Gram positive and 301 (56.2%) Gram negative organisms. The first 6 strains of Gram (-) microbes in frequent order were Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Escherichia coli, Acinetobacter Baumannii and Stenotrophomonas (xantho) maltophi. The extended spectrum beta-lactamase (ESBLs) producing rates of Escherichia coli and Klebsiella pneumoniae were 27.3% and 33.3%, respectively. Methylcillin resistant coagulase negative staphylococcus (MRCNS) was the most prevalent Gram (+) bacteria in the complicated infection patients with hematological malignancies, which accounted for 88.5%. Carbapenems were most sensitive for all of the gram negative bacteria, with a drug resistance rate of 11.4 (5.0% approximately 15.8%) of imipenem. For ESBLs strains, carbapenems and cefapime were the best choice, with the resistance rate of 46.4% approximately 94.4% and 50.0% approximately 75.9%, respectively. The drug resistance rate of Acinetobacter Baumannii was 25.0% approximately 41.3% for the third generation cephalosporin, 22.7% for the fourth generation cephalosporin and 12.7% for imipenem. Pseudomonas aeruginosa was resistant to carbapenems, with a resistance rate of 12.7% of imipenem; however, it was more sensitive to the third generation cephalosporin. CONCLUSION: Antibiotics should be rationally administrated with more considerations to the characteristics of epidemiology and drug resistance profile of the microbes in the given department of hematology.

Bacterial Infections↗

PubMed2005

[Primary characterization of the properties and diagnostic value of the antigenic complex "fraction V" in a plague microbe].

The experimentally obtained antigenic complex isolated by extraction in the gradient surfactants from live and acetone-dried bacteria of the capsule-free vaccine strain EV76 of a plague microbe that had lost its ability to synthesize the diagnostic species-specific capsular antigen F1 was investigated. The antigenic complex fraction V (FV) was obtained after the fifth stage of extraction at a concentration of 1.28% of surfactants and after additional purification. The thermostable FV was found to consist mainly of protein. The protein having a molecular mass of about 43 kD predominates in the fraction. The latter is nontoxic for albino mice and antigenic. It forms a precipitate with commercial antiplague serum antibodies. FV antigenic sensitization of tanned sheep red blood cells gave rise to a diagnostic agent that specifically reacted with an antiplague serum rather than with heterologous sera against enterobacteria. The sera immunized with FV specifically reacted in the JDJFR with all the strains of the pathogen of plague irrespective of the temperature of their cultivation, including "fraction-free", which did not interact with a diagnosticum on F1. The animal sera immunized with capsule-free plague microbial strain reacted only with a FV-erythrocytic diagnosticum and they did not interact with F1 antigen-sensitized red blood cells. The erythrocytic FV diagnosticum was tested in ABNR with 130 typical and atypical plague microbial strains and with 133 strains of heterologous bacteria of different species of the family Enterobacteriaceae. The FV diagnosticum identified all the variants of a plague microbe, while the F1 diagnosticum revealed only its capsular variants. Among the heterologous bacteria, some strains of the closely related pathogen of pseudotuberculosis in those who were in the R form, rather than S form, positively reacted. The use of FV identified 2 groups of hybridomas obtained after immunization of albino mice with the capsule-free variant of a plague microbe. Some hybridomas reacted only with plague bacteria while others did with two above pathogens. The authors substantiate the expediency of using FV, its components, and obtained monoclonal plague pathogen antibodies to improve antiplague diagnosticums with an activity spectrum that exceeds that of the existing commercial F1 antigen-based diagnosticums. They also discuss the lines of further studies.

Animals↗

PubMed2003

Evaluation of growth activity of microbes in tea field soil using microbial calorimetry.

Calorimetry was used to study the heat evolution associated with microbial growth in tea field soils (growth thermograms) during the microbial degradation of added organic matter. From the actual heat evolution curves (f(t) curves) derived from the growth thermograms under various conditions of pH and water content of the tea field soils, the apparent growth rate constant (mu') of soil microbes was determined as an index of their growth activity. In addition, mu' was compared between tea field soils treated with organic versus compound fertilizer. From the results, the following conclusions were made: (i) In acidic tea field soil (pH less than about 6.0), the growth activity of soil microbes declined with decreasing pH, and mu' was twofold higher at pH 6.0 than at pH 4.3. (ii) In tea field soils (Andosol) with a water content less than about 50%maximum water holding capacity (MWHC), the growth activity declined with decreasing water content, and mu' at 52.5%MWHC was double that at 35.2%MWHC. (iii) The growth activity of microbes in tea field soil treated with organic fertilizer was approximately 1.2-fold higher than that treated with compound fertilizer.

Journal Article↗

PubMed2005

[Impacts of Cd and Pb pollution on soil microbes in tobacco root zone and on tobacco leaf quality].

A pot experiment was conducted to study the impacts of Cd and Pb pollution on soil microbes in tobacco root zone and the quality of tobacco leaves. The results indicated that the higher concentrations of Cd and Pb in soil, the less soil microbes in tobacco root zone. When the levels of Cd and Pb were < or = 10 and < or = 300 mg x kg(-1), respectively, the individuals of soil microbes decreased acutely. As for the quality indexes of tobacco leaves, the ratios of reductive sugar/nicotine and total-N/nicotine increased, and the main components became disharmony, which was disadvantage for the fragrance forming of tobacco leaves. The K content in tobacco leaves had a negative correlation with soil Cd and Pb concentrations, but a significantly positive correlation with the quantity of potassium bacteria in root zone under Cd pollution. No significant correlation was observed between the K content in tobacco leaves and the quantity of potassium bacteria in root zone under Pb pollution.

Cadmium↗

PubMedDate not supplied

Enumeration procedure for monitoring test microbe populations on inoculated carriers in AOAC use-dilution methods.

The AOAC Use-Dilution methods do not provide procedures to enumerate the test microbe on stainless steel carriers (penicylinders) or guidance on the expected target populations of the test microbe (i.e., a performance standard). This report describes the procedures used by the U.S. Environmental Protection Agency to enumerate the test microbe (carrier counts) associated with conducting the Use-Dilution method with Staphylococcus aureus (Method 955.15) and Pseudomonas aeruginosa (Method 964.02) and the examination of historical data. The carrier count procedure involves the random selection of carriers, shearing bacterial cells from the carrier surface through sonication, and plating of serially diluted inoculum on trypticase soy agar. For each Use-Dilution test conducted, the official AOAC method was strictly followed for carrier preparation, culture initiation, test culture preparation, and carrier inoculation steps. Carrier count data from 78 Use-Dilution tests conducted over a 6-year period were compiled and analyzed. A mean carrier count of 6.6 logs (approximately 4.0 x 10(6) colony-forming units/carrier) was calculated for both S. aureus and P. aeruginosa. Of the mean values, 95% fell within +/- 2 repeatability standard deviations. The enumeration procedure and target carrier counts are desirable for standardizing the Use-Dilution methods, increasing their reproducibility, and ensuring the quality of the data.

Colony Count, Microbial↗

PubMed1990

Serum IgG antibody concentrations against environmental microbes in mares and foals during different seasons and effect of stabling practices.

Over periods of 22 and 14 months, IgG antibody concentrations in serum samples obtained monthly from 14 mares and 19 foals, respectively, were measured by use of ELISA against antigens of the following environmental microbes: Aspergillus umbrosus, Penicillium brevicompactum, Rhodotorula glutinis, Absidia corymbifera, Aspergillus fumigatus, Humicola grisea, Micropolyspora faeni, and Thermoactinomyces vulgaris. The mares and foals were on pasture from early June until early October, then were stabled during the winter season until the following June. In the mares, increased antibody concentrations against most microbes were observed typically in midwinter and late spring when the horses were stabled; antibody concentrations against R glutinis, however, peaked in August. Concentrations differed between the summer and winter seasons and, in most instances, between 2 consecutive years and correlated with amounts of rainfall during the previous harvest season. In the foals, circulating passively acquired antibodies disappeared within 3 to 4 months after birth. During the first year of life, substantially increased autogenous antibody concentrations were observed only against R glutinis. Antibody concentrations against the other microbes increased gradually toward the end of the indoor season. In a group of foals transferred indoors in autumn, 6 weeks later than the other foals, antibody concentrations were lower when measured in December. Results supported the view that, to minimize exposure to microbial spores during the winter season, horses should be kept outdoors as much as possible and attention should be focused on improving the ventilation in stables and the quality of feeds and beddings.

Actinomycetales↗