Surface-groundwater interactions play an important role in microbial community compositions of river bank filtrates. Surface water contaminations deriving from environmental influences are attenuated by biogeochemical processes in the hyporheic zone, which are essential for providing clean and high-quality drinking water in abstraction wells. Characterizing the flow regime of surface water into the groundwater body can provide substantial information on water quality, but complex hydraulic dynamics make predictions difficult. Thus, a bottom up approach using microbial community shifting patterns as an overall outcome of dynamic water characteristics could provide more detailed information on the influences that affect groundwater quality. The combination of high-throughput sequencing data together with flow cytometric measurements of total cell counts reveals absolute abundances among taxa, thus enhancing interpretation of bacterial dynamics. 16S rRNA high-throughput sequencing of 55 samples among six wells in a well field in Austria that is influenced by river bank filtrate within a time period of 3 months has revealed both, clear differences as well as strong similarity in microbiome compositions between wells and dates. A significant community shift from April to May occurred in four of six wells, suggesting that surface water flow regimes do affect these wells stronger than others. Triplicate sampling and subsequent sequencing of wells at different dates proved the method to be reproducible. Flow cytometric measurements of total cells indicate microbial shifts due to increased cell counts and emphasize the rise of allochthonous microorganisms. Typical freshwater bacterial lineages (Verrucomicrobia, Bacteroidetes, Actinobacteria, Cyanobacteria, Armatimonadetes) were identified as most increasing phyla during community shifts. The changes are most likely a result of increased water abstraction in the wells together with constant river water levels rather than rain events. The results provide important knowledge for future implementations of well utilization in dependency of the nearby Danube River water levels and can help drawing conclusions about the influence of surface water in the groundwater such that hygienically save and clean drinking water with a stable microbial community can be provided.
Mitoxantrone, a recent anthracenedione derivative is a potentially useful drug for direct intraperitoneal (i.p.) application because of its high tissue-binding and therapeutic index. We have carried out studies to establish maximum tolerated doses as well as pharmacokinetic studies with i.p. mitoxantrone in 21 patients (5 male, 16 female) with gastrointenstinal (9), ovarian (6), unknown (2) and other (4) primary cancers and peritoneal carcinomatosis. Increasing doses (10–40 mg/m2) were given i.p. every 4 weeks. Five partial remissions (2–8+ months) and 7 stable disease courses (2–6+ months) were achieved. A reduction or disappearance of ascites was seen in an additional 3 patients. Severe toxicity (leukopenia) was observed in 4 patients only after 35 mg/m2 and 40 mg/m2 i.p. Pharmacokinetic analysis using high-performance liquid chromatography yielded the following data: The mean ratio of area under curve peritoneal fluid to serum was 1,108. The peritoneal clearance ranged from 2 ml/min to 9,617 ml/min and the disappearance half-life from 0.6–28.9 h. Mean urinary excretion within 24 h was 0.42% of the i.p. dose. These data indicate that mitoxantrone is sequestered in the intraperitoneal tissue compartment and only slowly released. Based on the outcome of this phase-I study we recommend phase-II studies at a dose of 30 mg/m2 i.p., repeated every 3–4 weeks.
The last decades have seen extensive scientific and technological improvements in many fields of microbiology and molecular biology. Correspondingly, flow cytometry—a rapid, precise and straightforward method for cultivation-independent detection of cells in liquids—has been a major topic in aquatic microbiology and drinking water analysis. Flow cytometry provides information at the single-cell level, including total cell counts, size measurements, nucleic acid content and bacterial viability and activity. While regulatory requirements for water testing rely on cultivation-based methods, flow cytometry can be considered a powerful tool to complement standard procedures.This article provides insights into the methodology and applicability of flow cytometry in the field of microbiological drinking water analysis and presents an overview on several case studies that cover a broad range of different objectives. The later are comprised of a study on flow cytometric characterization of Austrian drinking water resources, of an example for advanced data analysis methods of flow cytometric data, of a study on monitoring microbial regrowth within the distribution network, of an exemplary case of the application of online flow cytometry for high-frequency monitoring and of an introduction to the combination of flow cytometry and sequencing information.Finally, it is argued that due to the high microbiological variability of different water resources, unusual changes of flow cytometric parameters, rather than specific limits, could act as an indicator for further investigation. In this way flow cytometry can provide a good basis for risk assessments in water safety plans. The application of flow cytometry still remains utility-specific and a huge need for standardization of data analysis and interpretation exists in order to achieve a better cooperation of water utilities.
Zusammenfassung Die Bereitstellung von mikrobiologisch sicherem Trinkwasser ist eine der Hauptaufgaben der Trinkwasserversorgungsinfrastruktur. Regelmäßige Trinkwasseruntersuchungen sind ein wesentlicher Garant zur Einhaltung hygienischer Anforderungen und können in der Zusammenschau Hinweise auf längerfristige Entwicklungen und generelle Zusammenhänge liefern. Im Rahmen eines Projekts zur Ermittlung des Temperatureinflusses in der Trinkwasserversorgung wurde vom Land Niederösterreich ein anonymisierter Auszug der Befunddatenbank zur Auswertung übermittelt. Der wesentliche Fokus liegt dementsprechend auf der Analyse der Temperaturmessungen im Zusammenhang mit den mikrobiologischen Parameter KBE bei 22 °C, 37 °C und den coliformen Bakterien. Zudem wurden die meisten Auswertungen für den Bereich der Trinkwasserverteilung vorgenommen. Hinsichtlich langfristiger Trends zeigen die Daten eine jährliche Zunahme der gemessenen Temperatur bei Netzprobenahmen von etwa 0,064 °C. Perioden mit sehr hohen Werten (>20 °C) der Wassertemperatur wurden im August 2015 und 2018 verzeichnet (jede dritte Netzprobe). Überwiegend abnehmende Trends wurden für die mikrobiologischen Parameter ermittelt. Für die KBE bei 22 °C beträgt der Rückgang etwa 0,5 KBE/ml pro Jahr. Trotz dieser gegenläufigen Tendenzen ist nicht davon auszugehen, dass die Zunahme der Temperaturen keine (negativen) Auswirkungen auf die mikrobiologische Situation haben kann. Im Rahmen einer Regressionsanalyse wurde der Einfluss der Temperatur für die KBE bei 37 °C als signifikant ermittelt. So erhöht eine Zunahme der Temperatur von 15 °C auf 20 °C die Wahrscheinlichkeit von Werten >20 KBE/ml von 0,077 auf 0,109. Dieser Befund ist aus mikrobiologischer Hinsicht als plausibel zu bezeichnen, wenngleich die Temperatur hier auch lediglich längere Netzaufenthaltszeiten anzeigen könnte. Der Einfluss weiterer Faktoren, etwa des Organik-Gehalts im Wasser, kann aufgrund der Datenlage weniger gut abgebildet werden, ist aber sicher als ebenso wichtig zu bezeichnen.
Zusammenfassung Trinkwassergewinnung mittels Uferfiltration gewinnt weltweit und auch in Österreich zunehmend an Bedeutung. Entlang der Donau existieren verschiedene Uferfiltratstandorte, deren Brunnen zu verschiedenen saisonalen Zeitpunkten 2016 und 2017 mittels High-Throughput-Sequencing (Ermittlung der mikrobiellen Zusammensetzung bzw. des Mikrobioms) und mittels Durchflusszytometrie (Gesamtzellzahl) untersucht wurden. Dabei konnten räumliche Unterschiede zwischen den Brunnenfeldern, saisonale Änderungen sowie insbesondere Einflüsse durch Hochwasserereignisse festgestellt werden. Die Erweiterung der Datenbasis durch die Hinzunahme von Sequenzierungsdaten einer Donau-Studie zeigt interessante Möglichkeiten, vorhandenes Wissen mit bioinformatischen Mitteln einzubinden und neue Erkenntnisse zu generieren.
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