1,721,112 research outputs found
Wasser - Landschaft - Mensch in Vergangenheit, Gegenwart und Zukunft : Beiträge zum Tag der Hydrologie am 20./21. März 2014 an der Katholischen Universität Eichstätt-Ingolstadt
No full textAuen und Hochwasser : Beiträge zum Internationalen Symposium Auen und Hochwasser am 10./11. Februar 2010 in Ingolstadt
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Occurrence and spread of human- induced antimicrobial resistance in a large river water system: developing a holistic picture based on the Joint Danube Survey 4 activities
No full textThe problem of human-induced antimicrobial resistance (acquired due to human activities) is an
emerging concern in aquatic environments. The isolation of (facultative) pathogenic organisms with
acquired antibiotic resistance, even concerning last-line antibiotics, from rivers and lakes, is well
documented throughout the world. In the last few years, there has been a rapid increase in the number
of studies addressing these topics and their possible implications for human health. However, most
studies concentrate on a relatively limited methodology, e.g. applying non-quantitative and either
cultivation-based or direct-detection based molecular biological methods. In addition, often only small
geographic areas and short periods of time are covered. This is one of the reasons why many relevant
questions concerning the occurrence and spread of antimicrobial resistance in aquatic ecosystems still
remain unanswered.
The largest European river water survey (Joint Danube Survey 4) offered a unique opportunity to study
the occurrence and spread of human-induced antimicrobial resistance along the whole Danube River.
Within the research project, isolates from samples from the entire course of the Danube and their
main tributaries, including high frequency sampling at selected locations, have been collected and
analysed. Samples from the water compartment but also from submerged biofilms have been
considered. State-of-the-art quantitative molecular biological techniques and culture-based analyses
targeting different bacterial organisms have been combined with a large set of physical, chemical and
biological parameters to obtain a robust and comprehensive picture of the occurrence and spread of
human-induced antimicrobial resistance in the Danube River.
Based on the findings of this quantitative, integrative study approach, it seems likely to significantly
improve the current understanding on the importance on the spread and stabilization of human -
induced antibiotic resistance in large rivers. The results of this study will also be useful to guide future
monitoring and management strategies.Sandu C, Cyffka B, editors. Proceedings: 43rd IAD Conference: Rivers and Floodplains in the Anthropocene: Upcoming Challenges in the Danube River Basin; 2021 Jun 9-11; Neuburg, Germany. 2021. p. 20
Non-wild type antibiotic resistant Escherichia coli in the River Danube: a six-year-comparison
No full textIntroduction
The emerging occurrence of human induced antibiotic resistant bacteria (ARB) is not only limited to
clinical surroundings: they can also be found in the human population, animals and the water
environment. Large rivers are of great concern as regards the spreading of ARB. Thus, this ongoing
study ́s aim is to analyze the major propagation pathways and sources of ARB in the Danube, and to
do a six-year-comparison with data obtained in 2013.
Study design and methods
Within the frame of the 4th Joint Danube Survey (JDS) of the International Commission for the
Protection of the Danube River (ICPDR), water samples were taken at 36 sampling points along the
whole Danube. Escherichia coli as clinically relevant organisms were isolated and tested for their
susceptibility to 20 different antibiotics.
Results
1298 E. coli isolates have been tested so far. 11.33 % of them were multiresistant and 23.19 % were
resistant to one or two classes of antibiotics. The preliminary data show a very similar pattern
compared to the data obtained in 2013 (629 isolates) when 9.70 % of the isolates were multiresistant
and 29.09 % were resistant to one or two classes of antibiotics. Most of the resistances are still to
ampicillin and tetracycline. There are no resistances to carbapenems, colistin, amikacin and tigecycline.
But there is a significant increase in resistances to amoxicillin with clavulanic acid, moxifloxacin and
piperacillin with tazobactam and a significant decrease regarding tetracycline. 21 isolates are
confirmed ESBL-producers while in 2013 there were four.
Discussion
In comparison the data of 2013 and 2019 show a similar pattern regarding multiresistance. Regarding
resistances to single antibiotics significant changes could be determined. However, there are still many
of the isolates to be tested until the final analysis.Sandu C, Cyffka B, editors. Proceedings: 43rd IAD Conference: Rivers and Floodplains in the Anthropocene: Upcoming Challenges in the Danube River Basin; 2021 Jun 9-11; Neuburg, Germany. 2021. p. 30
Water Resources and Riverine Ecosystems in Eastern Central Asia : Management Perspectives in the Context of Multiple Stressors
No full textGenotoxicity assessment of Danube River: in situ and in vitro methods
No full textWater quality in the Danube River Basin is largely influenced by the inputs of pollutants - particularly
excessive nutrients, organic material, and hazardous substances, which affects the whole ecosystem
at various levels. The major goal of this study was to evaluate the level of genotoxic potential at the
site at Danube River, Novi Banovci, which is under significant anthropogenic pressure of untreated
municipal and industrial waste waters.
DNA damage in situ was assessed in 5 specimens of white bream (Blicca bjoerkna) erythrocytes, liver
and gills cells with comet assay and in erythrocytes with micronucleus test. Additionally, genotoxicity
of native water samples collected from the site and upstream and downstream of the site was
evaluated by the comet assay on HepG2 cells. Microscopic images of comets were scored using Comet
IV Computer Software (Perceptive Instruments, UK) and tail intensity was chosen as parameters to
assess the DNA damage.
Comet assay on white bream showed that gills were the most affected tissue, while liver showed the
smallest values. Micronuclei frequency was low in general, with mean of 1 micronuclei in 5000 scored
erythrocytes, with no significant correlation to the values of comet assay in erythrocytes. Comet assay
on HepG2 cells showed significant difference between values of negative control samples and samples
of water from effluent site and downstream of wastewater discharge. There was no significant
difference between negative control and upstream samples of water.
Our results showed that great impact of municipal and industrial wastewaters on the river ecosystem.
The application of in vitro and in situ tests gives a better insight into genotoxic effects. More
importantly, because Serbia still doesn’t have waste water treatme nt plants, this kind of research
points out the imperative for implementation of this facilities.Sandu C, Cyffka B, editors. Proceedings: 43rd IAD Conference: Rivers and Floodplains in the Anthropocene: Upcoming Challenges in the Danube River Basin; 2021 Jun 9-11; Neuburg, Germany. 2021. p. 18
Mapping of the microbiological water quality of surface waters in Serbia overlooked by the National monitoring programme
No full textSurface waters in Serbia are under high anthropogenic pressure. One of the major problems is untreated municipal and industrial wastewaters. Unfortunately, Serbia processes only 5 % of wastewaters before discharging. As a consequence, pollutants such as metals and metalloids from industrial wastewaters, pharmaceuticals, compounds from personal care products, etc. directly endure into surface water. Microbial faecal pollution, as an indicator of presence of human or/and animal pathogens, due to health hazard limits water usage for drinking, recreation, irrigation, etc. In regulations, faecal coliforms, with Escherichia coli as dominant representative, are widely used as faecal indicator bacteria. The aim of this study was to investigate the microbiological al water quality in the Republic of Serbia at the sites which are not routinely investigated within the national monitoring program. In this purpose 78 sites situated on canals, mountain springs, as well as lowland rivers were selected. Defined Substrate Technology was used for determination Most Probable Number (MPN) of E. coli using Colilert-18 System. The water classification system, developed for the Danube River (Kavka et al., 2006) was used.
The results indicated that more than 47 % of selected sites are under critical (21.79 %) or strong (25.64 %) faecal pollution. On the other hand, about 32 % (32.05 %) of sites are little polluted and 20.51 % of sites showed moderate pollution. The increasing levels of faecal pollution detected on sites situated downstream of settlements indicated discharge of untreated municipal wastewaters directly into surface water. In further research, the focus will be placed on the determination of the origin of pollution by the employment of microbial source tracking technique. Obtained data will be used for modelling and predicting the effect of detected contamination on the water quality of the major water bodies in the Republic of SerbiaSandu C, Cyffka B, editors. Proceedings: 43rd IAD Conference: Rivers and Floodplains in the Anthropocene: Upcoming Challenges in the Danube River Basin; 2021 Jun 9-11; Neuburg, Germany. 2021. p. 19
Invasive alien species in the Danube River Basin: Results of the JDS4
No full textThe co-existential pattern of native and alien species was investigated along the Danube River Basin (DRB) during JDS4 (2019). A total of 51 JDS4 sites was sampled in the entire Danube River, and additional sites in the Lower Danube. The standard operational procedures adopted by ICPDR, and – for the first time – eDNA-based tools were used for the sampling. A smartphone application ‘Invasive Alien Species in Europe’ developed by the European Commission’s Joint Research Centre and specifically updated to include invasive alien species concerning the DRB was additionally applied for data collection.
Six alien aquatic plants, 35 benthic macroinvertebrates and 17 fish species were recorded in DRB during the survey. Two groups of invasive species should be mentioned: 1) Ponto-Caspian species that do not have to cross very strong hydro- and geographical barriers during their spreading; and 2) Species that cross large geographical distances to arrive to the DRB (originated from North America and Asia). An overall decrease of the former abundance of Corbicula fluminea was recognised in some Danube sections. An extreme large amount of Ponto-Caspian amphipods was detected in the Upper Danube: Echinogammarus sp. and Gammaridae gen. sp., representing one third of the overall individual number of the macroinvertebrates detected in the Upper Danube (Austria). New Decapoda species (Procambarus clarkii, Pacifastacus leniusculus) appeared at new locations of the Middle Danube, indicating their recent spreading. A new Ponto-Caspian snail species (Clathrocaspia knipowitschii) was distributed along extended sections of the Lower and Middle Danube. The magnificent bryozoan Pectinatella magnifica was recorded for the first time in the Bulgarian shoreline zone of the Danube River. The (e)DNA-based detection revealed the presence of 5 macroinvertebrate species which were not recorded by other methods. The level of biocontamination of the Danube River was estimated as moderate to high, with higher levels for the Upper (high to severe biocontamination) and Middle
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Danube (moderate to high biocontamination), in comparison to the Lower Danube (low biocontamination). The results show that DRB is under considerable influence of biological invasions. The number of identified alien species has increased over three times since 2007. The (e)DNA-based method has proved to be an effective additional tool in aquatic IAS monitoring. The smartphone app may greatly facilitate the access and update of IAS records for management and control purposes and contribute to IAS awareness raising in the Danube countries by involving actively the citizens in future surveys.Sandu C, Cyffka B, editors. Proceedings: 43rd IAD Conference: Rivers and Floodplains in the Anthropocene: Upcoming Challenges in the Danube River Basin; 2021 Jun 9-11; Neuburg, Germany. 2021. p. 40-1
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