Antibiotics and antibiotic-resistant bacteria in waters associated with a hospital in Ujjain, India

<p>Abstract</p> <p>Background</p> <p>Concerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies on antibiotic prescription quantity in a hospital and antibiotic residue levels and resistant bacteria in the effluent of the same hospital are few. Therefore, we quantified antibiotic residues in waters associated with a hospital in India and assessed their association, if any, with quantities of antibiotic prescribed in the hospital and the susceptibility of <it>Escherichia coli </it>found in the hospital effluent.</p> <p>Methods</p> <p>This cross-sectional study was conducted in a teaching hospital outside the city of Ujjain in India. Seven antibiotics - amoxicillin, ceftriaxone, amikacin, ofloxacin, ciprofloxacin, norfloxacin and levofloxacin - were selected. Prescribed quantities were obtained from hospital records. The samples of the hospital associated water were analysed for the above mentioned antibiotics using well developed and validated liquid chromatography/tandem mass spectrometry technique after selectively isolating the analytes from the matrix using solid phase extraction. <it>Escherichia coli </it>isolates from these waters were tested for antibiotic susceptibility, by standard Kirby Bauer disc diffusion method using Clinical and Laboratory Standard Institute breakpoints.</p> <p>Results</p> <p>Ciprofloxacin was the highest prescribed antibiotic in the hospital and its residue levels in the hospital wastewater were also the highest. In samples of the municipal water supply and the groundwater, no antibiotics were detected. There was a positive correlation between the quantity of antibiotics prescribed in the hospital and antibiotic residue levels in the hospital wastewater. Wastewater samples collected in the afternoon contained both a higher number and higher levels of antibiotics compared to samples collected in the morning hours. No amikacin was found in the wastewater, but <it>E.coli </it>isolates from all wastewater samples were resistant to amikacin. Although ciprofloxacin was the most prevalent antibiotic detected in the wastewater, <it>E.coli </it>was not resistant to it.</p> <p>Conclusions</p> <p>Antibiotics are entering the aquatic environment of countries like India through hospital effluent. In-depth studies are needed to establish the correlation, if any, between the quantities of antibiotics prescribed in hospitals and the levels of antibiotic residues found in hospital effluent. Further, the effect of this on the development of bacterial resistance in the environment and its subsequent public health impact need thorough assessment.</p

Sustainable Phosphorus Loadings from Effective and Cost-Effective Phosphorus Management Around the Baltic Sea

Nutrient over-enrichment of the Baltic Sea, accompanied by intensified algal blooms and decreasing water clarity, has aroused widespread concern in the surrounding countries during the last four decades. This work has used a well-tested dynamic mass-balance model to investigate which decrease in total phosphorus loading would be required to meet the environmental goal to restore the trophic state in the Baltic Sea to pre-1960s levels. Furthermore, the extent to which various abatement options may decrease the phosphorus loading in a cost-effective manner has been studied. Upgrading urban sewage treatment in the catchment could, alone or in combination with banning phosphates in detergents, be sufficient to meet the set environmental goal, at an estimated annual basin-wide cost of 0.21–0.43 billion euro. Such a plan would potentially decrease the total phosphorus loading to the Baltic Sea with 6,650–10,200 tonnes per year

The Baltic Sea as a time machine for the future coastal ocean

Coastal global oceans are expected to undergo drastic changes driven by climate change and increasing anthropogenic pressures in coming decades. Predicting specific future conditions and assessing the best management strategies to maintain ecosystem integrity and sustainable resource use are difficult, because of multiple interacting pressures, uncertain projections, and a lack of test cases for management. We argue that the Baltic Sea can serve as a time machine to study consequences and mitigation of future coastal perturbations, due to its unique combination of an early history of multistressor disturbance and ecosystem deterioration and early implementation of cross-border environmental management to address these problems. The Baltic Sea also stands out in providing a strong scientific foundation and accessibility to long-term data series that provide a unique opportunity to assess the efficacy of management actions to address the breakdown of ecosystem functions. Trend reversals such as the return of top predators, recovering fish stocks, and reduced input of nutrient and harmful substances could be achieved only by implementing an international, cooperative governance structure transcending its complex multistate policy setting, with integrated management of watershed and sea. The Baltic Sea also demonstrates how rapidly progressing global pressures, particularly warming of Baltic waters and the surrounding catchment area, can offset the efficacy of current management approaches. This situation calls for management that is (i) conservative to provide a buffer against regionally unmanageable global perturbations, (ii) adaptive to react to new management challenges, and, ultimately, (iii) multisectorial and integrative to address conflicts associated with economic trade-offs

Phosphorus dynamics and retention in non-point source wetlands in southern Sweden

Seven constructed wetlands receiving diffuse pollution from agricultural land in the south of Sweden were investigated with respect to water flow patterns and phosphorus (P) dynamics. P retention was positive, and correlated to P load in all wetlands. However, there was a large variation in both specific and relative retention, both between wetlands and between years. Thus, the phosphorus retention in a specific wetland is difficult to predict using simple loadretention models. The water flow was correlated to P concentrations in most wetlands; however, there were some exceptions. For instance, one wetland showed a negative relationship between water flow and P concentration during summer, which indicated that other factors than the water flow determined the dynamics of P during this season. This investigation will provide a better understanding of factors affecting phosphorus retention in constructed wetlands, with further implications for wetland research and monitoring. Furthermore, the results can assist when formulating models for phosphorus removal in wetlands receiving nonpoint source runoff

Potential denitrification in wetland sediments with different plant species detritus

The effect of detritus originating from different plant species on denitrifying capacity was investigated in a Swedish wastewater treatment wetland. Intact sediment cores containing sediment with a detritus layer were collected from wetland basins dominated by Typha latifolia, Phragmites australis, or Elodea canadensis in November 2000 and potential denitrification was measured using the acetylene-inhibition method. The cores from stands of E. canadensis showed more than three times higher denitrification capacity than the cores of the other plants. Bacterial abundance per unit dry weight was both highest and lowest in the detritus of R australis, whereas the C/N ratio was lower in the cores of E. canadensis. This suggests that the submerged plant provided more organic material of high quality to support heterotrophic organisms. It is also possible that the surfaces of E. canadensis offered more or more suitable surfaces for bacterial growth and thereby increased the bacterial population. It is apparent that denitrifying bacteria were more favored by E. canadensis detritus than by detritus from the emergent plant species at the time of sampling. Since the turnover of plant detritus varies considerably among species, the seasonal variation in denitrification capacity is likely to be quite different for different plants

Seasonal denitrification potential in wetland sediments with organic matter from different plant species

Vegetation both physically and biochemically influences denitrification in wetlands. Litter from various plant species supplies various amounts and qualities of organic carbon to denitrifying bacteria, and may thus affect denitrification capacity. We explore whether there is seasonal variation in the denitrification potential in stands of Glyceria maxima, Phragmites australis, Typha latifolia, and Potamogeton pectinatus (the stands differed in terms of which species was predominant). Experiments and measurements investigated whether denitrification potential was related to organic matter and its availability to denitrifying bacteria, suitability for bacterial growth, and amount in the wetland. Availability of organic material, as measured in the slurries, was highest in the G. maxima and P. pectinatus samples, with the highest availability in May and August. However, when the samples were closer to wetland conditions, i.e., intact sediment cores containing litter and organic sediment, the denitrifying capacity was highest in the cores from G. maxima stands, but lowest in P. pectinatus cores. In addition, the denitrification potential of the intact cores was highest in November. Differences in denitrification capacity between the slurries and intact sediment cores, considering the organic material of the plant species and the seasonal pattern, were attributed to differences in the amount of plant litter generated

Zrównoważone rolnictwo: badanie percepcji i praktyk rolników w zakresie zarządzania składnikami pokarmowymi i zmniejszania ucieczki nutrientów

The paper presents the results of a scientific project focused on limiting nutrient losses from farms by introducing measures to apply fertilizers in a more sustainable way. It is a case study of selected aspects of farm management, focussing on the issue of sustainable agriculture and their tools. The main aim of the study was to analyse and evaluate farmers’ knowledge of the fertilizing process and its aspects, as well as applying sustainable agricultural activities on farms. The study emphasised the importance of nutrient management, as very important for sustainable farming. Also, the links between farmers’ opinions and their activities were analysed. The important issue concerned measures for sustainable farm management introduced on the farms, as well as measures to limit nutrient leaching into groundwater. Twenty-eight farmers from two regions in Poland were interviewed about their perceptions for the case study. In general, the farmers considered their farm activities to be more sustainable than in the past. They demonstrated an understanding of the general idea of sustainable agriculture. However, many farmers still demonstrated a poor grasp of nutrient flows and nutrient balances on farms. Their knowledge and perception was based on general, rather than specific knowledge gleaned from an academic/ vocational course. The farmers demonstrated a realization that there were some new, or low-cost measures that could be introduced to make management more sustainable and pro-environmental, but there was still a need for wider adoption of sustainable agricultural practices.W pracy przedstawiono wybrane wyniki polsko-szwedzkiego projektu badawczego, realizowanego w latach 2013–2016, dotyczącego upowszechniania metod zmniejszania strat składników odżywczych w gospodarstwach rolnych oraz narzędzi służących zarządzaniu składnikami nawozowymi w sposób bardziej racjonalny i zrównoważony. W badaniu wzięło udział 28 rolników z dwóch województw Polski. Głównym celem niniejszego artykułu była analiza i ocena sposobów zarządzania gospodarstwem rolnym, ze szczególnym uwzględnieniem aspektów rolnictwa zrównoważonego. Nacisk został położony przede wszystkim na zarządzanie składnikami pokarmowymi, jako jeden z najważniejszych czynników rolnictwa zrównoważonego. Analizie poddano opinie rolników na temat zależności między procesami nawożenia a zanieczyszczeniem wody, a następnie także zweryfikowano ich działania prowadzone w gospodarstwach rolnych. Istotną część analizy stanowiły wybrane narzędzia zrównoważonego zarządzania gospodarstwem rolnym, wdrożone w badanych gospodarstwach, jak również wybrane metody zmniejszania ucieczki składników pokarmowych do wód powierzchniowych. Przeprowadzone badania dają podstawy do stwierdzenia, że – mimo wzrostu świadomości rolników – nadal wielu z nich nie dysponuje specjalistyczną wiedzą w zakresie obiegu składników pokarmowych oraz bilansów składników w swoich gospodarstwach. Wiedza rolników i ich percepcja w dużej mierze bazuje na wiedzy ogólnej lub wynika z własnego doświadczenia. Dzięki wdrożonemu projektowi rolnicy uświadomili sobie istnienie nowych, bezkosztowych sposobów gospodarowania, które można wdrożyć w celu prowadzenia bardziej zrównoważonej produkcji rolnej. Nadal jednak istnieje duża potrzeba upowszechniania zrównoważonych praktyk w rolnictwie, w tym również przez agencje rolnicze i okołorolnicze, jak i instytucje doradcze, które powinny szczególnie podkreślać wagę tego zagadnienia we wszystkich swoich działaniach

Potential nitrification and denitrification on different surfaces in a constructed treatment wetland

Improved understanding of the importance of different surfaces in supporting attached nitrifying and denitrifying bacteria is essential if we are to optimize the N removal capacity of treatment wetlands. The aim of this study was therefore to examine the nitrifying and denitrifying capacity of different surfaces in a constructed treatment wetland and to assess the relative importance of these surfaces for overall N removal in the wetland. Intact sediment cores, old pine and spruce twigs, shoots of Eurasian watermilfoil (Myriophyllum spicatum L.), and filamentous macro-algae were collected in July and November 1999 in two basins of the wetland system. One of the basins had been constructed on land that contained lots of wood debris, particularly twigs of coniferous trees. Potential nitrification was measured using the isotope-dilution technique, and potential denitrification was determined using the acetylene-inhibition technique in laboratory microcosm incubations. Nitrification rates were highest on the twigs. These rates were three and 100 times higher than in the sediment and on Eurasian watermilfoil, respectively. Potential denitrification rates were highest in the sediment. These rates were three times higher than on the twigs and 40 times higher than on Eurasian watermilfoil. The distribution of denitrifying bacteria was most likely due to the availability of organic material, with higher denitrification rates in the sediment than on surfaces in the water column. Our results indicate that denitrification, and particularly nitrification, in treatment wetlands could be significantly increased by addition of surfaces such as twigs