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Aims: To isolate aerobic mesophilic bacilli and thermophilic bacteria from different paper mill samples and to evaluate their potential harmfulness. Methods and Results: A total of 109 mesophilic and 68 thermophilic isolates were purified and characterized by automated ribotyping and partial 16S rDNA sequencing. The mesophilic isolates belonged to the genera Bacillus (13 taxa), Brevibacillus (three taxa) and Paenibacillus (five taxa). The thermophilic bacteria represented seven taxa of Bacillus, Geobacillus or Paenibacillus, four of proteobacteria and one of actinobacteria. The most frequently occurring bacteria were Bacillus cereus, B. licheniformis, Pseudoxanthomonas taiwanensis and bacteria closely related to Paenibacillus stellifer, P. turicensis or Leptothrix sp. One mill was contaminated throughout with bacteria of a novel mesophilic genus most closely related to Brevibacillus centrosporus and another with bacteria of a novel thermophilic genus most closely related to Hydrogenophilus thermoluteolus. One B. cereus isolate producing haemolytic diarrhoeal enterotoxin was detected and all the tested B. licheniformis isolates produced a metabolite toxic to boar sperm cells. Conclusions: The bacilli and thermophilic bacteria isolated represent species which should not present occupational hazards in paper mill environments. The most harmful bacterium detected was B. licheniformis and potentially also B. cereus. Significance and Impact of the Study: Knowledge of the microbial diversity in a paper mill provides a rational basis for development of an effective controlling programme. A database constructed from the fingerprints generated using automated ribotyping helps to identify and trace the contamination routes of bacteria occurring in paper mills.

Forty-four B. pumilus isolates of food poisoning, clinical, environmental and industrial origins were investigated for toxin production using the boar spermatozoan motility assay, previously shown to be a sensitive method for detecting non-protein toxins from B. cereus and B. licheniformis. The three toxic isolates originated from live tree, indoor air and recycled paper pulp and were more toxic than the previously described food poisoning isolates of B. licheniformis, whereas the B. pumilus food poisoning and clinical isolates were lower in toxicity. The type strain also produced inhibitory substances. The toxic substances were insensitive to heat (100 degrees C, 20 min), to pH 2 or pH 10 and to digestion with pronase. The substances were readily soluble in methanol and chloroform, but less soluble in toluene. Exposure of boar spermatozoa to 1-10 microg ml(-1) (EC50) of methanol soluble substance from the four strains disrupted the plasma membrane permeability barrier, induced abnormalities in the postacrosomal sheath, collapsed the mitochondrial and suppressed cytoplasmic NAD reduction. No change was observed in human peripheral blood lymphocytes exposed to concentrations of B. pumilus extract that affected spermatozoa. The toxin producing isolates were 99.4 to 99.6% similar in 16SrDNA (500 bp) to the type strain and could not be distinguished from the 41 non-toxic isolates by biochemical properties or whole cell fatty acid composition.

Safety of water was for a long time and still is one of the most pressing needs for many countries and different communities. Despite the fact that there are potentially many methods to evaluate water safety, finding a simple, rapid, versatile, and inexpensive method for detection of toxins in everyday items is still a great challenge. In this study, we extend the concept of composites obtained impregnation of porous fibrous materials, such as fabrics and papers, by single walled carbon-nanotubes (SWNTs) toward very simple but high-performance biosensors. They utilize the strong dependence of electrical conductivity through nanotubes percolation network on the width of nanotubes-nanotube tunneling gap and can potentially satisfy all the requirements outlined above for the routine toxin monitoring. An antibody to the microcystin-LR (MC-LR), one of the common culprits in mass poisonings, was dispersed together with SWNTs. This dispersion was used to dip-coat the paper rendering it conductive. The change in conductivity of the paper was used to sense the MC-LR in the water rapidly and accurately. The method has the linear detection range up to 10 nmol/L and non-linear detection up to 40 nmol/L. The limit of detection was found to be 0.6 nmol/L (0.6 ng/mL), which satisfies the strictest World Health Organization standard for MC-LR content in drinking water (1 ng/mL), and is comparable to the detection limit of traditional ELISA method of MC-LR detection, while drastically reducing the time of analysis by more than an order of magnitude, which is one of the major hurdles in practical applications. Similar technology of sensor preparation can also be used for a variety of other rapid environmental sensors.

Spirotox is a short-term acute toxicity test with a large ciliated protozoan Spirostomum ambiguum. The test was created in the Department of Environmental Health Sciences, Medical University of Warsaw, Poland, during the early 1990s. It was presented for the first time during the 6th International Symposium on Toxicity Assessment, in Berlin in 1993. S. ambiguum was very resistant to a wide range of environmental conditions, especially to pH and dissolved oxygen. Over the last 10 years the sensitivity of S. ambiguum to many classes of toxicants was evaluated. Spirotox was found to be very sensitive to heavy metals, fungicides, and pharmaceuticals used to cure diseases of the human nervous system. On the other hand, it was generally less sensitive than standard bioassays to simple organics. Spirotox was also used for analysis of cyanobacterial blooms. Though it was moderately sensitive to hepatotoxins, the test seems to be a good tool for evaluation of the entire toxicity of blooms. The last but not the least of the applications of the Spirotox test was evaluation of the toxicity of extracts from medical devices. Protozoa, which are the simplest eukaryotes, seem to be good screening bioassays for monitoring the technology of medical device production.

Clostridium perfringens type C and type D toxins were absorbed on filter paper, dried and stored at room temperature (18-20 degrees C), at 37 degrees C, at 4 degrees C and at -20 degrees C. Type specific toxin was correctly identified in the EIA for 74 days. Absorption on filter paper may offer a simple method for conservation and transport of post mortem samples from cases of suspected enterotoxaemia.

The affinity of epidermolytic toxin from Staphylococcus aureus for proteins from the target tissue has been tested by a Western blotting procedure. Particular proteins in a l M phosphate extract of epidermis reacted on nitrocellulose blots with a probe prepared by the conjugation of toxin with peroxidase. Protein extracted into 50 mM Tris-HCl did not react. The probe detected profilaggrin, filaggrin and a smaller unidentified polypeptide. It is suggested that the interaction is relevant to the mode of action of the toxin.