Publications by authors named "Jarkko Rapala"

The purpose of this equivalence study was to compare an alternative method, Colilert-18 Quanti-Tray (ISO 9308-2) with the European bathing water directive (2006/7/EC) reference method, the miniaturised most probable number (MMPN) method (ISO 9308-3), for the analysis of Escherichia coli. Six laboratories analysed a total of 263 bathing water samples in Finland. The comparison was carried out according to ISO 17994:2004.

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Exposure to cyanobacterial water blooms has been associated with various kinds of adverse health effects. In addition to cyanobacteria and their toxins, the bacteria associated with cyanobacteria could also be the etiological agents. We isolated Aeromonas strains (n = 176) from water samples (n = 38) taken from sites where cyanobacteria were suspected to have caused human health symptoms, of which fever and gastrointestinal symptoms were the most common.

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Bacteria colonizing BAC filters used in drinking water purification from lake water were characterized by morphology, physiological tests, whole cell protein profiles and PLFA (phospholipid fatty acid) composition, and identified by partial 16S rRNA gene sequencing. Epifluorescence revealed prothecate bacteria to dominate in BAC. The majority of the isolates belonged to order Burkholderiales of beta-Proteobacteria, a few to Comamonadaceae but the majority to an undescribed family and the related sequences belonged mainly to uncultured bacteria.

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Cyanobacterial mass occurrences (water blooms) cause ecological, economic and health problems worldwide. Still, little is known about heterotrophic bacteria associated with cyanobacteria and the interactions between those organisms. We isolated 460 bacterial strains from more than 40 lakes and rivers (151 samples), Baltic Sea (32 samples) and treated drinking water of seven treatment plants (29 samples).

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The cyanobacterial cytotoxin cylindrospermopsin has been mostly associated with cyanobacteria present in tropical and subtropical regions. Cylindrospermopsin has recently been found in cyanobacterial samples in central and southern Europe but the possible presence of the toxin in northern Europe has been unknown. Fifty-eight field and laboratory culture samples of Finnish cyanobacteria were analyzed by high-performance liquid chromatography combined with UV diode-array detection, multiple reactant monitoring in a triple-quadrupole mass spectrometer (MS), and accurate mass measurements using a time-of-flight MS instrument.

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Thirteen bacterial isolates from lake sediment, capable of degrading cyanobacterial hepatotoxins microcystins and nodularin, were characterized by phenotypic, genetic and genomic approaches. Cells of these isolates were Gram-negative, motile by means of a single polar flagellum, oxidase-positive, weakly catalase-positive and rod-shaped. According to phenotypic characteristics (carbon utilization, fatty acid and enzyme activity profiles), the G+C content of the genomic DNA (66.

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This study is the first report of saxitoxin in cyanobacterial blooms in Finland. Bloom samples (n = 50) were collected from Finnish freshwater sites during summer months of 2002 and 2003. These samples were screened for the presence of paralytic shellfish toxins (PSTs) using the Jellett rapid PSP screening test.

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The aim of this study was to investigate endotoxin concentrations in cyanobacterial water blooms and strains, and to assess the removal of endotoxins during drinking water treatment. Endotoxin concentrations were measured from 151 hepatotoxic, neurotoxic and non-toxic cyanobacterial water blooms by using Limulus amebocyte lysate (LAL) assay, and the results were compared to bacterial data. Endotoxin activities ranged from 20 to 3.

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