The effect of experimental fusarium mycotoxicosis on microbiota diversity in porcine ascending colon contents.

The objective of the study was to determine the effect of exposure of pigs to the Fusarium mycotoxins zearalenone (ZEN) and deoxynivalenol (DON), administered together and separately, on the colon microbiota. An experiment was conducted for 42 days on gilts, randomly assigned to four groups and administered either ZEN, DON, ZEN+DON, or a placebo. The number of aerobic mesophilic bacteria, yeasts, molds, anaerobic Clostridium perfringens, fecal streptococci, Enterobacteriaceae, Escherichia coli, and lactic acid bacteria (LAB) were determined in the contents of the ascending colon. The influence of mycotoxins on the functional diversity of the colonic microbiota was assessed using EcoPlate tests (Biolog). Analysis revealed the predominance of LAB in all groups of pigs. Zearalenone, administered separately and together with DON, was found to have an adverse effect on mesophilic aerobic bacteria, but only after long exposure to this mycotoxin. During the six weeks of the experiment, the concentration of C. perfringens, E. coli, and other bacteria in the family Enterobacteriaceae was most considerably reduced in the experimental groups exposed to zearalenone, both separately and together with DON. Mycotoxins also affected the functional biodiversity of microorganisms. Both Shannon's diversity index and the number of catabolized substrates in Biolog plate (the R index) were much higher in the group subjected to mixed mycotoxicosis.

Resistance of bacterial biofilms formed on stainless steel surface to disinfecting agent.

The natural ability of microorganisms for adhesion and biofilm formation on various surfaces is one of the factors causing the inefficiency of a disinfection agent, despite its proven activity in vitro. The aim of the study was to determine the effectiveness of disinfecting substances on bacterial biofilms formed on stainless steel surface. A universally applied disinfecting agent was used in the tests. Bacterial strains: Listeria innocua, Pseudomonas putida, Micrococcus luteus, Staphylococcus hominis strains, were isolated from food contact surfaces, after a cleaning and disinfection process. The disinfecting agent was a commercially available acid specimen based on hydrogen peroxide and peroxyacetic acid, the substance that was designed for food industry usage. Model tests were carried out on biofilm formed on stainless steel (type 304, no 4 finish). Biofilms were recorded by electron scanning microscope. The disinfecting agent in usable concentration, 0.5% and during 10 minutes was ineffective for biofilms. The reduction of cells in biofilms was only 1-2 logarithmic cycles. The use of the agent in higher concentration--1% for 30 minutes caused reduction of cell number by around 5 logarithmic cycles only in the case of one microorganism, M. luteus. For other types: L. innocua, P. putida, S. hominis, the requirements placed on disinfecting agents were not fulfilled. The results of experiments proved that bacterial biofilms are resistant to the disinfectant applied in its operational parameters. Disinfecting effectiveness was achieved after twofold increase of the agent's concentration.

Biodeterioration of optical glass induced by lubricants used in optical instruments technology.

The process of biodeterioration of optical glass was studied after being induced by an auxiliary material (lubricant 4CKP) used in the production of optical instruments. It was determined that the lubricant can initiate growth of conidia of Aspergillus niger fungus. Acid spawn metabolites cause deterioration of the glass surface. Measurements of laser light beam transmittance through the glass plate and the AAS chemical analysis method of the post-culture fluid allowed to determine that glass with a high SiO2 content is most resistant to corrosion caused by the growth of A. niger fungi spawn.

Exopolysaccharide production by Bacillus strains colonizing packaging foils.

The influence of the chemical composition of medium, availability of glucose and pH on the production of exopolysaccharides (EPS) by different Bacillus strains were investigated. Bacillus strains were isolated from the surface of polyethylene foils modified with mineral compounds after their biodegradation in compost soil. Moreover, the effect ofEPS production on bacterial adhesion onto the surface of the materials was examined. The enhanced synthesis of exopolysaccharides in nutrient-starved conditions was revealed. The most effective synthesis of polymers was observed during the logarithmic phase of culture growth. The increased amount of EPS facilitated bacterial adhesion to material surfaces. It was determined that the biofilm on the material surface positively affects its biodegradation. Based on the results, we conclude that the biodegradation of polymers may be accelerated in low-nutrient environment.

Microbial and endotoxin contamination of water-soluble metalworking fluids.

UNLABELLED: The present study is a part of a larger project on assessment of exposure to biological agents and respiratory health effects among metal workers. OBJECTIVES: The aim of this study was to evaluate the level of microbial contamination of metalworking coolants as a potential source of harmful biological agents in three different metal industry plants in Poland. MATERIAL AND METHODS: Ten samples of coolants with a different state of wear, including four fresh fluids, were analyzed. Qualitative and quantitative analysis of bacteria and mould content was performed using standard analytical methods. Bacterial endotoxin concentration was determined by the kinetic, chromogenic version of the LAL test. RESULTS: The analysis showed the total bacterial counts ranging from 1.0x10(1) CFU/ml to 3.2x10(7) CFU/ml, 60% to 100% of which were Gram-negative bacteria capable of producing endotoxins. Among the highly contaminated coolants, one unused concentrate was also found. The predominant species of bacteria was Shewanella putrefaciens present in 60% of the samples. As for moulds, the predominant species was Acremonium butyri. The average concentration of bacterial endotoxins was 773 EU/ml in the old coolants, and much lower in the fresh fluids 285 EU/ml. A correlation (r=0.66) was found between endotoxin concentration and the number of Gram-negative bacteria detected in the coolants. CONCLUSION: Procedures should be developed for cleaning tanks during fluid replacement to minimize the risk of bacterial growth in the coolants and limit bioaerosol emission in workplace. Due to the affinity of microflora for the water phase, it is advisable to use effective biocides with appropriate partition coefficient between the water phase and oil phase.

Influence of N,N-bis(3-aminopropyl)dodecylamine on the mycelium growth and the cell wall composition of resistance and sensitive strains belonging to the genus Aspergillus.

Resistance causes of moulds to N,N-bis(3-aminopropyl)dodecylamine (APDA) for selected species of Aspergillus niger and Aspergillus flavus was examined. Control (sensitive) strains and resistant strains, cultured at 0.05% triamine, were used in the experiments. The non-resistant strains did not have growth capacity in this amount of ADPA while the resistant strains were characterised by a smaller biomass increase. Individual stages of the development of the mycelium occurred later than those in the control samples. The participation of the cell wall in the mycelium biomass of the resistant strains was higher by 7.5%. The glucan content in the wall dry mass was lower by 11% than that in the sensitive strains. A 41% increase in the lipid content was recorded in the cell wall of resistant Aspergillus flavus. A 21% protein increase occurred in the wall of Aspergillus niger comparing to the control strain. Infrared spectrophotometric analysis of the cell wall did not reveal the presence of triamine. Most absorption bands disappeared in the wall of Aspergillus flavus while no additional absorption bands were registered in Aspergillus niger; some bands were only stronger than those in the control sample. The resistant strains were characterised by a smaller ergosterol content, the main constituent of cell membranes. Spectrophotometric analysis of the mycelium did not reveal significant qualitative changes; only quantitative changes were observed. It was noticed that the resistance reaction did not occur with the same intensity in both species studied. The resistant strain of Aspergillus niger was characterised by a slightly more intensive absorption within its entire spectrum range in comparison to control strain. In case of Aspergillus flavus the absorption was higher for control strain.

The elimination of ochratoxin A by lactic acid bacteria strains.

The aim of this study was to examine 29 strains of lactic acid bacteria of the Lactobacillus and Lactococcus genera, assessing their sensitivity to ochratoxin A and their ability to remove it from a liquid medium. It was demonstrated that most strains are insensitive to the presence of OTA at the quantity of 5 microg/disc. It was demonstrated that all strains caused a reduction of the toxin amount in the liquid medium. The highest decrease, exceeding 50% of the initial OTA content, was caused by the strains Lactobacillus acidophilus CH-5, L. rhamnosus GG, L. plantarum BS, L. brevis and L. sanfranciscensis. The example of three selected strains confirmed the negative effect of the toxin on the dynamics of bacterial growth. A sharp decrease of ochratoxin A was observed during the first 15 hours of culture growth. In the course of cultivation the amount of the toxin in the medium increased, indicating that the toxin elimination is partially reversible. A small quantity of ochratoxin A became bound to the bacterial biomass.

Exposure to moulds in flats and the prevalence of allergic diseases--preliminary study.

The presented study concerned mycological analysis of buildings in Lódz and evaluation of the role between filamentous fungi contaminated flats and inhabitants health (allergic airway diseases). 49 inhabitants of 20 flats with signs of moulds contamination were examined. Air samples were collected in houses and outdoors. In all inhabitants skin prick tests (SPT) to common allergens and to standardized particular fungal extracts were performed. Moreover, total and serum specific IgE to moulds, rest spirometry were measured in all subjects. Level of moulds contamination in the air of flats was high and in 75% cases exceed accepted limits. The most frequent species isolated from examined rooms were: Penicillium, Cladosporium, Aspergillus, Acremoniu and Alternaria. The most frequent symptoms reported by examined subjects were rhinitis (N = 29, 59.2%), conjunctivitis (N = 29, 59.2%), chronic cough (N = 24, 49%), dyspnea (N = 15, 30.6%) and skin symptoms (N = 24, 49%). Elevated IgE level was found in 12 subjects (24.5%) and in three patients (6.1%) mould specific serum IgE were detected. Nineteen out of all subjects (38.8%) had positive SPT to common allergens (house dust mites, grass and tree pollens). Eight out of these patients (16.3% of the group) were sensitized to moulds (Candida albicans, Alternaria alternata, Botrytis cinerea, Trichophyton mentagrophytes, Helminthosporium halodes, Aspergillus). In all cases sensitisation to moulds was accompanied by allergy to other common allergens. No isolated hypersensitivity to moulds was found. Although the frequency of self-reported symptoms was high, the prevalence of atopy and allergic diseases seems to be similar to that found in general population, but that statement must be confirmed by comparison of the control group.

Mycological analysis of cereal samples and screening of Fusarium strains' ability to form deoxynivalenole (DON) and zearalenone (ZEA) mycotoxins--a pilot study.

Filamentous fungi are cosmopolitan microorganisms found in almost all environments. It should be pointed out that occurance of moulds on food or feed may cause health disorders in humans and animals. Mycoflora appears as a source of toxic methabolites, mycotoxins, which hepatotoxic, genotoxic, nefrotoxic and carcinogenic abilities were already proven in several studies. Hense mycological analysis of cereal grains raises as an important manner in evaluation of food and feed health features. Among the most frequent cereal contaminants Alternaria, Aspergillus, Fusarium and Penicillium strains are mentioned. Due to their ability to grow on cereals during both its field growth and storage, Fusarium moulds occure to be an important contamination factors in food and feed industry. In this study Fusarium strains isolates from wheat and maize were examined in order to recognize their abilities to produce two toxins: zearalenon (ZEA) and deoxynivalenole (DON). Mycological analysis shown differentiation within fungal microflora occuring in samples of different storage conditions, where Fusarium strains represented aproximately 20-70% of all mould species present. In purpose of Fusarium strains species evaluation, isolates were mycologically analysed. In the second step of the project, toxicological screening of isolates was performed using Thin Liquid Chromatography (TLC) evaluating toxigenic potential of single strains' production of ZEA and DON. This data gives the possibility of pointing the most toxigenic strains and also shows differentiations in their occurance in cereals. This paper presents introductory research data, which can be useful in recognition of cereal contamination with moulds and their toxic methabolites.

[Moulds--occupational and environmental hazards]. / Grzyby plesniowe w srodowisku komunalnym i w miejscu pracy--istotne zagrozenie zdrowotne.

This paper reviews the most common health effects of exposure to moulds. Allergens of mould may induce rhinitis or bronchial asthma, whereas occupational exposure frequently leads to hypersensitivity pneumonitis. Moulds also reveal cancerogenic and neurotoxic properties. They may cause serious infections, organic dust toxic syndrome and sick building syndrome. Methods used to evaluate exposures and decrease concentrations of spores in the house environment are also presented.