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The paper summarizes the current state of knowledge regarding the role of filamentous microorganisms (i.e., fungi and actinomycetes) and their submicrometer propagules (fragments) in formation of indoor bioaerosol. It discusses the importance of water damages in buildings and the role of humidity as a cause of fungal and actinomycetal contamination and subsequent deterioration of indoor spaces. The importance of the size of airborne microbial propagules for adverse health effects is broadly commented as well. Regarding the microbial fragments, the method of their release from the contaminated surfaces (including factors influencing their aerosolization, i.e., air velocity, colony structure, moisture conditions, vibration of the surface, time factor), modern measurement techniques and newly obtained results of the immunological reactivity of fragments are discussed. The novel ideas concerning the dynamic description of the release process of microbial propagules from their sources are also presented.
Uzyskano wstępną charakterystykę aerozolu bakteryjnego i grzybowego, występującego w tzw. zdrowych pomieszczeniach mieszkalnych i biurach oraz w środowisku zewnętrznym. Na charakterystykę bioaerozolu składała się przede wszystkim informacja o występujących zakresach stężeń oraz analiza rozkładu frakcyjnego (ziarnowego). Otrzymane dane umożliwiły naświetlenie problemu mikrobiologicznego zanieczyszczenia powietrza w mieszkaniach i biurach, a uzupełnione o kolejne badania pozwolą w przyszłości zdefiniować tzw. najwyższe normalne stężenie bioaerozolu w obu rodzajach pomieszczeń.
Fast and sensitive techniques are needed to determine microorganism presence in liquid samples. In this research, the feasibility of using light scattering spectrometry for enumerating the biological particles in liquid samples was investigated. A particle size spectrometer was used to count six commonly found microbial species suspended in liquid with and without microbiological stains applied: Pseudomonas fluorescens, Micrococcus spp. vegetative cells and Bacillus subtilis var. niger endospores were stained with Acridine Orange and Crystal Violet, while Cladosporium cladosporioides, Penicillium melinii and Aspergillus versicolor fungi were stained with Acridine Orange and Lactophenol Cotton Blue. The counts obtained with the spectrometer were compared with those obtained with a phase-contrast microscope. It was found that the spectrometer counted about 32% of non-stained B. subtilis endospores and this percentage increased to almost 90% for stained endospores. Among the investigated species of fungi, the counting efficiency of P. melinii was the only one significantly affected by the application of the stain Lactophenol Cotton Blue: the fraction of counted fungal spores increased from 64% (non-stained spores) to about 100% (stained spores). The observed difference in counting efficiency may serve as a basis for differentiating biological from non-biological particles in liquid samples.
The aim of the presented study was to assess the exposure of poultry workers to airborne microorganisms, endotoxins and β-glucans during different stages of the chicken production cycle in 3 commercially-operated poultry houses. Personal and stationary sampling was carried out to assess exposure to both viable and total microbial aerosols. The stationary measurements of PM10 were performed to establish the level of endotoxins and β-glucans. The concentrations of bacterial and fungal aerosols ranged from 2.5×102 CFU/m3 – 2.9×106 CFU/m3, and from 1.8×102 CFU/m3 – 1.8×105 CFU/m3, respectively. The number of culturable microorganisms was significantly lower than their total counts, constituting from 0.0004% – 6.4% of the total microbial flora. The level of PM10 in poultry facilities did not exceed 4.5 mg/m3. After the flock entered the clean house, the level of endotoxins and β-glucans increased from below detection limit to 8,364 ng/m3 and from 0.8 ng/m3 to 6,886 ng/m3, respectively. The presented study shows that professional activities in poultry farms are associated with constant exposure to bioaerosol, which may pose a health hazard to workers. It was found that workers’ exposure to airborne microorganisms increased with consecutive stages of the chicken production cycle.
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