| 1. |
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| 2. |
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| 3. |
- Bighiu, Maria, et al.
(författare)
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Assessing microbial contamination and antibiotic resistant bacteria using zebra mussels (Dreissena polymorpha)
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 650, s. 2141-2149
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Tidskriftsartikel (refereegranskat)abstract
- Aquatic pollution with faecal bacteria and subsequent consumption of contaminated water or food is a worldwide issue that causes severe health effects (e.g. meningitis, salmonellosis, dysentery). In addition, the excessive use of antibiotics in animal husbandry and human medicine has enhanced the selective pressure on pathogenic bacteria, further increasing human health risks and detrimental effects on natural microbial communities. This urges the need to monitor faecal contamination using a time-integrated approach, as grab water samples can miss pathogen peaks. We tested the ability of zebra mussels (Dreissena polymorpha) to take up and depurate faecal indicator bacteria such as Escherichia coli and intestinal enterococci. Furthermore, we quantified the frequency of antibiotic resistant bacteria in water and mussels both in controlled laboratory tests and under in situ conditions downstream of a sewage treatment plant (STP). Laboratory results show that bacterial indicators in mussels were 132 times higher than their concentration in water, and that mussels retained bacteria up to 2 days after pulse exposure. Field results show decreasing bacterial concentrations in both water and mussels downstream the STP, with maximum E. coli concentrations ranging 173-9 cfu mL(-1) in water and 2970-330 cfu g(-1) in mussels. Similarly, enterococci ranged 59-4 cfu mL(-1) and 1450-240 cfu g(-1) in water and mussels, respectively. High proportions of antibiotic resistant E. coli were found in mussels (72%) and water (65%), and slightly lower proportion of resistant enterococci was found in mussels (47%) and in water (34%). Moreover, 33% of the bacteria isolated from mussels were resistant to multiple antibiotics, which emphasizes that resistance is a common feature in surface waters and highlights the need for safe water management. Our results show that zebra mussels provide an efficient, time-integrating tool for quantifying faecal indicators, including resistant and multidrug resistant bacteria. (C) 2018 The Authors. Published by Elsevier B.V.
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| 4. |
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| 5. |
- Cars, Otto, et al.
(författare)
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Building bridges to operationalise one health : A Sino-Swedish collaboration to tackle antibiotic resistance
- 2016
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Ingår i: One Health. - : Elsevier. - 2352-7714. ; 2, s. 139-143
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance is a complex global health challenge. The recent Global Action Plan on antimicrobial resistance highlights the importance of adopting One Health approaches that can cross traditional disciplinary boundaries. We report on the early experiences of a multisectoral Sino-Swedish research project that aims to address gaps in our current knowledge and seeks to improve the situation through system-wide interventions. Our research project is investigating antibiotic use and resistance in a rural area of China through a combination of epidemiological, health systems and laboratory investigations. We reflect here on the challenges inherent in conducting long distance cross-disciplinary collaborations, having now completed data and sample collection for a baseline situation analysis. In particular, we recognise the importance of investing in aspects such as effective communication, shared conceptual frameworks and leadership. We suggest that our experiences will be instructive to others planning to develop similar international One Health collaborations.
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| 6. |
- Chi, Xiaohui, et al.
(författare)
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Characterization of Clinically Relevant Strains of Extended-Spectrum beta-Lactamase-Producing Klebsiella pneumoniae Occurring in Environmental Sources in a Rural Area of China by Using Whole-Genome Sequencing
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media S.A.. - 1664-302X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Klebsiella pneumoniae is a gram-negative, opportunistic pathogen, and a common cause of healthcare-associated infections such as pneumonia, septicemia, and urinary tract infection. The purpose of this study was to survey the occurrence of and characterize K. pneumoniae in different environmental sources in a rural area of Shandong province, China. Two hundred and thirty-one samples from different environmental sources in 12 villages were screened for extended-spectrum beta-lactamase-(ESBL)-producing K. pneumoniae, and 14 (6%) samples were positive. All isolates were multidrug-resistant and a few of them belonged to clinically relevant strains which are known to cause hospital outbreaks worldwide. Serotypes, virulence genes, serum survival, and phagocytosis survival were analyzed and the results showed the presence of virulence factors associated with highly virulent clones and a high degree of phagocytosis survivability, indicating the potential virulence of these isolates. These results emphasize the need for further studies designed to elucidate the role of the environment in transmission and dissemination of ESBL-producing K. pneumoniae and the potential risk posed to human and environmental health.
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| 7. |
- Chi, Xiaohui, et al.
(författare)
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Characterization of Clinically Relevant Strains of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Occurring in Environmental Sources in a Rural Area of China by Using Whole-Genome Sequencing
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media S.A.. - 1664-302X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Klebsiella pneumoniae is a gram-negative, opportunistic pathogen, and a common cause of healthcare-associated infections such as pneumonia, septicemia, and urinary tract infection. The purpose of this study was to survey the occurrence of and characterize K. pneumoniae in different environmental sources in a rural area of Shandong province, China. Two hundred and thirty-one samples from different environmental sources in 12 villages were screened for extended-spectrum β-lactamase-(ESBL)-producing K. pneumoniae, and 14 (6%) samples were positive. All isolates were multidrug-resistant and a few of them belonged to clinically relevant strains which are known to cause hospital outbreaks worldwide. Serotypes, virulence genes, serum survival, and phagocytosis survival were analyzed and the results showed the presence of virulence factors associated with highly virulent clones and a high degree of phagocytosis survivability, indicating the potential virulence of these isolates. These results emphasize the need for further studies designed to elucidate the role of the environment in transmission and dissemination of ESBL-producing K. pneumoniae and the potential risk posed to human and environmental health.
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| 8. |
- Collentine, Dennis, et al.
(författare)
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Consequences of future nutrient load scenarios on multiple benefits of agricultural production
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Nutrient load rates to the Baltic Sea need to be reduced. Agricultural land is regarded as the most significant contributor to the loads, and measures to reduce losses of nitrogen (N) and phosphorus (P) loads have been proposed, both for the near and far future. Agricultural production was to a large extent considered in these scenarios, whereas effects on other ecosystem services were not evaluated. The question to be answered by this report is whether the measures adopted to reduce N and P losses improve or impair multiple benefits of agriculture. The question is answered for a specific catchment (Svärtaån) located in Sweden, but the method is thoroughly described to provide a potential method to also evaluate other catchments. This work was performed as a part of the Baltic Compass project (2013). The answer to the main question of whether the measures adopted to reduce N and P losses from agricultural fields improved or impaired multiple benefits of agriculture, seems to be that they improved. Most of the BAP measures had a positive influence on most of the MB-categories, the clearest exception being liming in tile drains which only improved the cost effectiveness. Except for water protection, the biosecurity MB-category was positively influenced by the most measures (6 out of 9) and with soil quality the next highest (5 out of 9). It is less clear how the absolute values evaluated for the MB index, can be compared among MB-categories. Among the BAP-measures, structural liming was the most positive measure (summing up the indices of all MB-categories), followed by buffer-zones and spring cultivation the next, although the cost effectiveness of these latter measures was evaluated to decrease. In the “unavoidable” future (Future scenarios) GHG emissions strongly increased. The only measure that mitigated that effect was reduced N fertilisation, providing more arguments for applying reduced fertilisation than only to reduce leaching.
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| 9. |
- Elving, Josefine, et al.
(författare)
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Composting for avian influenza virus elimination
- 2012
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 78, s. 3280-3285
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Tidskriftsartikel (refereegranskat)abstract
- Effective sanitization is important in viral epizootic outbreaks to avoid further spread of the pathogen. This study examined thermal inactivation as a sanitizing treatment for manure inoculated with highly pathogenic avian influenza virus H7N1 and bacteriophages MS2 and phi 6. Rapid inactivation of highly pathogenic avian influenza virus H7N1 was achieved at both mesophilic (35 degrees C) and thermophilic (45 and 55 degrees C) temperatures. Similar inactivation rates were observed for bacteriophage phi 6, while bacteriophage MS2 proved too thermoresistant to be considered a valuable indicator organism for avian influenza virus during thermal treatments. Guidelines for treatment of litter in the event of emergency composting can be formulated based on the inactivation rates obtained in the study.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
- Emmoth, Eva, et al.
(författare)
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Ammonia Disinfection of Hatchery Waste for Elimination of Single-Stranded RNA Viruses
- 2011
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 77, s. 3960-3966
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Tidskriftsartikel (refereegranskat)abstract
- Hatchery waste, an animal by-product of the poultry industry, needs sanitation treatment before further use as fertilizer or as a substrate in biogas or composting plants, owing to the potential presence of opportunistic pathogens, including zoonotic viruses. Effective sanitation is also important in viral epizootic outbreaks and as a routine, ensuring high hygiene standards on farms. This study examined the use of ammonia at different concentrations and temperatures to disinfect hatchery waste. Inactivation kinetics of high-pathogenic avian influenza virus H7N1 and low-pathogenic avian influenza virus H5N3, as representatives of notifiable avian viral diseases, were determined in spiked hatchery waste. Bovine parainfluenza virus type 3, feline coronavirus, and feline calicivirus were used as models for other important avian pathogens, such as Newcastle disease virus, infectious bronchitis virus, and avian hepatitis E virus. Bacteriophage MS2 was also monitored as a stable indicator. Coronavirus was the most sensitive virus, with decimal reduction (D) values of 1.2 and 0.63 h after addition of 0.5% (wt/wt) ammonia at 14 and 25 degrees C, respectively. Under similar conditions, high-pathogenic avian influenza H7N1 was the most resistant, with D values of 3.0 and 1.4 h. MS2 was more resistant than the viruses to all treatments and proved to be a suitable indicator of viral inactivation. The results indicate that ammonia treatment of hatchery waste is efficient in inactivating enveloped and naked single-stranded RNA viruses. Based on the D values and confidence intervals obtained, guidelines for treatment were proposed, and one was successfully validated at full scale at a hatchery, with MS2 added to hatchery waste.
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| 14. |
- Emmoth, Eva, et al.
(författare)
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Inactivation of Viruses and Bacteriophages as Models for Swine Hepatitis E Virus in Food Matrices
- 2017
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Ingår i: Food and Environmental Virology. - : Springer Science and Business Media LLC. - 1867-0334 .- 1867-0342. ; 9, s. 20-34
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E virus has been recognised as a food-borne virus hazard in pork products, due to its zoonotic properties. This risk can be reduced by adequate treatment of the food to inactivate food-borne viruses. We used a spectrum of viruses and bacteriophages to evaluate the effect of three food treatments: high pressure processing (HPP), lactic acid (LA) and intense light pulse (ILP) treatments. On swine liver at 400 MPa for 10 min, HPP gave log(10) reductions of ae4.2, ae5.0 and 3.4 for feline calicivirus (FCV) 2280, FCV wildtype (wt) and murine norovirus 1 (MNV 1), respectively. Escherichia coli coliphage I center dot X174 displayed a lower reduction of 1.1, while Escherichia coli coliphage MS2 was unaffected. For ham at 600 MPa, the corresponding reductions were 4.1, 4.4, 2.9, 1.7 and 1.3 log(10). LA treatment at 2.2 M gave log(10) reductions in the viral spectrum of 0.29-2.1 for swine liver and 0.87-3.1 for ham, with I center dot X174 and MNV 1, respectively, as the most stable microorganisms. The ILP treatment gave log(10) reductions of 1.6-2.8 for swine liver, 0.97-2.2 for ham and 1.3-2.3 for sausage, at 15-60 J cm(-2), with MS2 as the most stable microorganism. The HPP treatment gave significantly (p < 0.05) greater virus reduction on swine liver than ham for the viruses at equivalent pressure/time combinations. For ILP treatment, reductions on swine liver were significantly (p < 0.05) greater than on ham for all microorganisms. The results presented here could be used in assessments of different strategies to protect consumers against virus contamination and in advice to food producers. Conservative model indicators for the pathogenic viruses could be suggested.
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| 15. |
- Hanna, Nada, et al.
(författare)
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Presence of antibiotic residues in various environmental compartments of Shandong province in eastern China: Its potential for resistance development and ecological and human risk
- 2018
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Ingår i: Environment International. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0160-4120 .- 1873-6750. ; 114, s. 131-142
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the occurrence of antibiotic residues in different types of environmental samples including water samples in rural Shandong province, China. Further, to characterize the potential ecological risk for development of antibiotic resistance in the environment, and the potential direct human health risk of exposure to antibiotics via drinking water and vegetables. Methods: Environmental samples (n = 214) (river water, waste water, drinking water, sediments, manure, soil and edible parts of vegetables) were collected in twelve villages in Shandong province in eastern China. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to determine the concentration of antibiotic residues. The ratio of the measured environmental concentrations (MEC) to the predicted no-effect concentrations (PNEC) was used to evaluate the ecological risk (risk quotient, RQ) for development of antibiotic resistance. The potential risks to human health through exposure to antibiotics in drinking water were assessed by comparing measured environmental concentrations (MEC) and predicted no-effect concentration in drinking water (PNECDW), and in vegetables by comparing estimated daily intake (EDI) to ADI. Results: Sulfapyridine, sulfamethoxazole, ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, chloramphenicol, florfenicol, doxycycline, and metronidazole were detected at concentrations ranging between 0.3 and 3.9 ng/L in river water, 1.3 and 12.5 ng/L in waste water, 0.5 and 21.4 ng/L in drinking water, 0.31 and 1.21 mu g/kg in river sediment, 0.82 and 1.91 mu g/kg in pig manure, 0.1 and 11.68 mu g/kg in outlet sediment, 0.5 and 2.5 mu g/kg in soil, and 6.3 and 27.2 mu g/kg in vegetables. The RQs for resistance development were amp;gt; 1 for enrofloxacin, levofloxacin, and ranged between 0.1 and 1 for ciprofloxacin. MECs/PNECDW ratios were amp;lt; 1 from exposure to antibiotics through drinking water for both adults and children. EDI/ADI ratios were amp;lt; 0.1 from exposure to antibiotics by vegetable consumption. Conclusions: Antibiotic pollutants were ubiquitous in various environmental compartments of Shandong province of China. Risk estimates indicated a potential for the measured levels of enrofloxacin, levofloxacin and ciprofloxacin in waste water to pose an ecological risk for resistance selection, and further studies are needed to validate this finding. The investigated antibiotics did not appear to pose an appreciable direct human health risk from environmental exposure through drinking water or vegetables consumption. However, they might still pose a risk for resistance development.
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| 16. |
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| 17. |
- Jarnheimer, Per-åke, et al.
(författare)
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Fluoroquinolone Antibiotics in a Hospital Sewage Line; Occurrence, Distribution and Impact on Bacterial Resistance
- 2004
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 36:10, s. 752-5
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Tidskriftsartikel (refereegranskat)abstract
- In hospital sewage lines, human faecal bacteria are exposed to antibiotics, posing a risk for selection of antibiotic resistant microorganisms. We constructed a system for continuous sampling in a hospital sewage line that allowed us to study longitudinal establishment of bacteria, concentrations of antibiotics, and selection of bacterial resistance in waste water, sediment and biofilm. The focus in this study was on fluoroquinolones, a widely used group of antibiotics with increasing resistance problems. We found low levels of ciprofloxacin and ofloxacin in waste water but high concentrations in sediment. Despite the high levels of fluoroquinolones bound to sediment, we did not find any development of resistance against fluoroquinolones in Enterobacteriacae spp. and faecal enterococci isolated from sediment.
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| 18. |
- Ji, Xiang, et al.
(författare)
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Dissemination of extended-spectrum beta-lactamase-producing Escherichia coli carrying mcr-1 among multiple environmental sources in rural China and associated risk to human health
- 2019
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Ingår i: Environmental Pollution. - : ELSEVIER SCI LTD. - 0269-7491 .- 1873-6424. ; 251, s. 619-627
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Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance among gram-negative bacteria is increasingly becoming a problem of global concern. Particularly problematic is the emergence of resistance to last-resort antibiotics such as carbapenems and colistin. The increasing number of reports on the plasmid-mediated colistin resistance gene mcr-1 in isolates worldwide is raising concerns for the future usefulness of this class of antibiotics. Dissemination of mcr-1 is believed to have originated mainly from animal breeding, however, the role of the environment as a transmission source is not yet fully understood. In the current study, 89 extended spectrum beta-lactamase-producing Escherichia coli isolated from 231 samples from different environmental sources in 12 villages in a rural area of Shandong, China, were screened for mcr-1.17 (19.1%) mcr-1-positive isolates were found from different environmental sources, aggregated in 6 villages. Plasmids of three different Inc-groups carrying mcr-1 were confirmed, indicating that the widespread geographical distribution of mcr-1 in the local area is due to a number of different plasmids. Additionally, almost a third (29.4%) of the isolates carried virulence factors associated to intestinal pathogenic E. coli. These results illustrate the high complexity of the transmission patterns of mcr-1 among different environmental matrices on a local scale and the potential for the environment to facilitate dissemination and emergence of antibiotic-resistant and virulent strains of bacteria. (C) 2019 Elsevier Ltd. All rights reserved.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Ottoson et. al., Jakob
(författare)
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Tracking the origin of faecal pollution in surface water. An ongoing project within the European Union research programme
- 2004
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Ingår i: Journal of Water and Health. - 1477-8920 .- 1996-7829. ; 2:4, s. 249-260
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study are to generate knowledge about methods to track the sources of faecal pollution in surface waters, with the aim of having one or a few easy procedures applicable to different geographic areas in Europe. For this, a first field study using already proposed methods (genotypes of F-specific RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, phenotypes of faecal coliforms and enterococci, and sterols) has been done in five areas representing a wide array of conditions in Europe. The present faecal indicators (faecal coliforms, enterococci, sulfite reducing clostridia and somatic coliphages) have also been included in this first field study. At the same time some emerging methods have been settled or adapted to water samples and assayed in a limited number of samples. The results of this first field study indicate that no single parameter alone is able to discriminate the sources, human or non-human, of faecal pollution, but that a 'basket' of 4 or 5 parameters, which includes one of the present faecal indicators, will do so. In addition, numerical analysis of the data shows that this 'basket' will allow the successful building of predictive models. Both the statistical analyses and the studied predictive models indicate that genotype II of F-specific RNA bacteriophages, the coprostanol and the ratio coprostanol: coprostanol+epicoprostanol are, out of the studied parameters, those with a greater discriminating power. Either because unsuccessful adaptation of the methods to water samples or because the preliminary assays in water samples indicated low discriminating capability, only three (sorbitol-fermenting bifidobacteria, some species of bifidobacteria detected by PCR with specific primers and phages infecting Bacteroides tethaiotaomicron) of the newly assayed methods have been considered for a second field study, which is currently underway. Expectations are that these new tools will minimize the number of parameters in the 'basket', or at least minimize the difficulty in assaying them
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| 23. |
- Ottoson, Jakob, et al.
(författare)
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A longitudinal study of antimicrobial resistant faecal bacteria in sediments collected from a hospital wastewater system
- 2012
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 2, s. 7438-
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Tidskriftsartikel (refereegranskat)abstract
- Objective:The objective with this study was to determine and follow antimicrobial resistance in faecal bacteria over time in hospital wastewater pipe sediment. A further aim was to determine bacterial growth rates of sensitive, intermediate and resistant intestinal enterococci in different ciprofloxacin concentrations as a measure of bacterial fitness.Methods:A system enabling the collection of settled particles over time was installed at Kalmar County Hospital. Samples were collected bi-monthly for a 14-month period. Coliform bacteria and enterococci were isolated from the sediment with standard methods and investigated for resistance to ciprofloxacin (CIP), imipenem (IMI), trimetroprim-sulfamethoxazole (TS), ampicillin (AMP) and vancomycin (VAN) by the disc diffusion method. Resistant isolates were further typed with the PhenePlateTM system. Growth assessments were performed with an automated spectrophotometer.Results:The rate of intestinal enterococci resistance was < 0.6, 1.3, 1.9 and 13% to VAN, IMI, AMP and CIP respectively. Coliform resistance frequencies were 1.1, 2.2 and 2.2% to CIP, IMI and TS respectively. At two sampling occasions, significantly higher rates of ciprofloxacin resistant enterococci were found and the establishment of a resistant clone in the sewer was indicated by the PhP-analysis. Ciprofloxacin resistant intestinal enterococci had a significantly longer lag-phase time than sensitive isolates, but from 500 µg ml-1 (half MIC) resistant isolates had a competitive advantage in terms of significantly faster generation time.Discussion:Despite high concentration of antimicrobials in the sediment, resistance frequencies were generally low. This can depend on limited growth possibilities for faecal bacteria. However, the establishment of a resistant clone shows that hospital sewers can serve as a reservoir for antibiotic resistant bacteria.
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| 24. |
- Ottoson, Jakob
(författare)
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A theoretical approach to using faecal indicator data to model norovirus concentration in surface water for QMRA: Glomma River, Norway
- 2016
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 91, s. 31-37
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Tidskriftsartikel (refereegranskat)abstract
- Monitoring of faecal indicator organisms, such as Escherichia coil, in environmental and drinking waters is inadequate for the protection public health, primarily due to the poor relationship between E. coli and the occurrence of human pathogens, especially viruses, in environmental samples. Nevertheless, measurements of faecal indicator organisms within the risk based approach, can provide valuable information related to the magnitude and variability of faecal contamination, and hence provide insight into the expected level of potential pathogen contamination. In this study, a modelling approach is presented that estimates the concentration of norovirus in surface water relying on indicator monitoring data, combined with specific assumptions regarding the source of faecal contamination. The model is applied to a case study on drinking water treatment intake from the Glomma River in Norway. Norovirus concentrations were estimated in two sewage sources discharging into the river upstream of the drinking water offtake, and at the source water intake itself. The characteristics of the assumed source of faecal contamination, including the norovirus prevalence in the community, the size of the contributing population and the relative treatment efficacy for indicators and pathogens in the sewage treatment plant, influenced the magnitude and variability in the estimated norovirus concentration in surface waters. The modelling exercise presented is not intended to replace pathogen enumeration from environmental samples, but rather is proposed as a complement to better understand the sources and drivers of viruses in surface waters. The approach has the potential to inform sampling regimes by identifying when the best time would be to collect environmental samples; fill in the gaps between sparse datasets; and potentially extrapolate existing datasets in order to model rarer events such as an outbreak in the contributing population. In addition, and perhaps most universally, in the absence of pathogen data, this approach can be used as a first step to predict the source water pathogen concentration under different contamination scenarios for the purpose of quantifying microbial risks. (C) 2016 Elsevier Ltd. All rights reserved.
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| 25. |
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| 26. |
- Ottoson, Jakob, 1970-
(författare)
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Comparative analysis of pathogen occurrence in wastewater : management strategies for barrier function and microbial control
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This project was initiated to fill knowledge gaps on the occurrence of pathogens in different streams of wastewater, e.g. greywater and domestic wastewater. The aims were also to measure the removal of pathogens in different treatment processes, conventional and innovative, and correlate the removal to that of common microbial process indicators, such as faecal coliforms, enterococci, Cl. perfringens spores and bacteriophages. One study also assessed the correlation between the removal of microorganisms and some commonly measured physico-chemical process indicators. The results can be applied in microbial risk assessments (MRAs) of urban wastewater systems. Indicators and parasitic (oo)cysts were enumerated with standard methods and viruses with rtPCR. High levels of Giardia cysts and enteroviruses were found in untreated wastewater (103.2 and 104.2 L-1 respectively) indicating high incidences in the society. Noroviruses were also often found in high numbers (103.3 L-1) during winter, but less frequent and in lower numbers (102.3 L-1) during the rest of the year. This temporal variation correlated to the clinical laboratory reporting of noroviruses. A temporal variation was also shown for Giardia with significantly lower cyst counts in untreated wastewater during spring. Cryptosporidium oocysts were not as numerous in untreated wastewater (5 L-1) reflecting a lower incidence in the society than for the other pathogens during the time of the study. Since temporal variation had a larger impact than spatial, site-specific measurements may not be necessary to perform screening level MRAs of wastewater discharge and reuse. Good data can be found in the literature and corrected for by recovery of the detection method, flow and incidence in the society. Removal of microorganisms in wastewater treatments varied from 0 to >5.8 log due to process combination and organism in question. Treatment in integrated hydroponics removed microorganism more efficiently than did secondary conventional treatment, though having longer hydraulic retention time. Tertiary treatment and treatment in a membrane bioreactor (MBR) showed better removal potential than treatment in upflow anaerobic sludge blankets (UASB) in a pilot plant. Human virus genomes were less removed and Giardia cysts more removed than all of the studied indicators. Enumeration with PCR, however, may underestimate infectious virion removal. Spores of sulphite-reducing anaerobes and somatic coliphages were significantly less removed than E. coli and enterococci in all the studied processes. Bacterial indicator and spore removals correlated to enterovirus genome removal (p<0.05), but the predictive values were low (R<0.4). Removals between microbial indicators and NH4-N, Kjeldal-N, COD and TOC correlated stronger (10-18 To manage the risk with reuse and discharge of wastewater, treatment performance targets have been calculated as a step in a hazard analysis and critical control point (HACCP) approach. These targets varied from 0 to 10.4 log removal due to water (grey or wastewater), organism (rotavirus, Campylobacter or parasitic (oo)cysts) and exposure (drinking water, surface water, aerosols, irrigation of crops or public parks). Faecal contamination in greywater was measured by coprostanol and was shown to be 980 times lower than in wastewater, corresponding to 2.9 log removal in treatment. Somatic coliphages were suggested to function as an index of virus removal in wastewater treatment processes as well as to be included in the monitoring of bathing water. The guideline level was suggested to be 300 PFU 100 mL-1 based on MRA of enteroviruses. This level in a water sample would equal a probability of infection of 0.3% (95th percentile 4%). The risk is overestimated if animal sources dominate the faecal pollution. Development in methods to track sources of faecal pollution showed that if somatic coliphages are enumerated together with phages infecting Bacteroides strain GA17, discriminating human from animal faecal pollution is possible based on the ratio between the phages
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| 27. |
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| 28. |
- Ottoson, Jakob, et al.
(författare)
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Faecal contamination of greywater and associated microbial risks
- 2003
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Ingår i: Water Research. - 0043-1354 .- 1879-2448. ; 37:3, s. 645-655
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Tidskriftsartikel (refereegranskat)abstract
- The faecal contamination of greywater in a local treatment system at Vibyasen, north of Stockholm, Sweden was quantified using faecal indicator bacteria and chemical biomarkers. Bacterial indicator densities overestimated the faecal load by 100-1000-fold when compared to chemical biomarkers. Based on measured levels of coprostanol, the faecal load was estimated to be 0.04 g person(-1) day(-1). Prevalence of pathogens in the population and the faccal load were used to form the basis of a screening-level quantitative microbial risk assessment (QMRA) that was undertaken for rotavirus, Salmonella typhimurium, Campylobacter jejuni, Giardia lamblia and Cryptosporidium parvum. The different exposure scenarios simulated-direct contact, irrigation of sport fields and groundwater recharge-gave unacceptably high rotavirus risks (0.04
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| 29. |
- Ottoson, Jakob, et al.
(författare)
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Fate and survival of Salmonella Typhimurium and Escherichia coli O157:H7 in repacked soil lysimeters after application of cattle slurry and human urine
- 2014
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 0022-5142 .- 1097-0010. ; 94, s. 2541-2546
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Use of cattle slurry as a fertiliser is common practice around the world. Human urine use is not as common, but owing to its fertiliser value this might change in the future. It is essential to minimise the transfer of enteric pathogens through fertilisation, with respect to both animal and public health. Therefore the objective of this research was to study the survival and transport of Salmonella Typhimurium and Escherichia coli O157:H7 in two agricultural soils when applied to soil along with either cattle slurry or human urine over a period of 180 days.RESULTS: Both Salmonella and E. coli O157: H7 were more rapidly reduced when applied together with human urine than when applied with cattle slurry. However, both pathogens persisted in low amounts at 20 and 50 cm depth in both soils throughout the whole study period. No Salmonella or E. coli O157: H7 was detected in the leachate over the 180 day study.CONCLUSION: The risk of disease transmission is higher when cattle slurry is used as fertiliser compared with human urine. However, the risk of groundwater infiltration would be low as long as water velocity through the soil is moderate. Increased knowledge of pathogen persistence in soil after fertiliser application is a valuable tool for improving risk evaluations and formulating guidelines for the use of cattle and/or human wastes in cropping soils. (C) 2014 Society of Chemical Industry
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| 33. |
- Ottoson, Jakob, et al.
(författare)
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Removal of viruses, parasitic protozoa microbial indicators and correlation with process indicators in conventional and membrane processes in a wastewater pilot plant
- 2006
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 40:7, s. 1449-1457
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate variations in the occurrence and removal of enterovirus and norovirus genomes, Giardia cysts, Cryptosporidium oocysts and the most commonly used faecal indicators in a Swedish wastewater pilot plant. Paired samples were taken from the inlet and outlet of each treatment line: tertiary filtration, membrane bioreactor (MBR) and upflow anaerobic sludge blankets (UASB). (Oo)cysts and indicators were enumerated using standard methods and viruses using RT-PCR. Giardia cysts and enteroviruses were constantly detected, mean numbers 10(3.11) cysts and 10(4.0) PCR units L-1, respectively. Oocysts were found in 5/19 samples, mean number 5 L-1. Noroviruses were found in 6/7 influent samples, with an average titre of 10(3 28) L-1, during winter, but only in 2/15 in the rest of the year (mean 200 L-1). MBR treatment removed indicators more efficiently than did the other two lines, with 5 log removal of E. coli. Human virus genome removal did not differ between the MBR and tertiary treatment line. Microorganism removal in UASB was significantly lower for all the organisms studied. E. coli, enterococci and Cl. perfringens removal was correlated (p < 0.05) with enterovirus genome removal, with R-values around 0.4. However, values for removal of indicators were more strongly correlated to each other. Removal of viruses based on enumeration using RT-PCR probably underestimates infectious virion removal.
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| 34. |
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| 37. |
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| 38. |
- Ottoson, Jakob, et al.
(författare)
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Removal of micro-organisms in a small-scale hydroponics wastewater treatment system
- 2005
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Ingår i: Letters in Applied Microbiology. - 0266-8254 .- 1472-765X. ; 40:6, s. 443-447
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To measure the microbial removal capacity of a small-scale hydroponics wastewater treatment plant. Methods and Results: Paired samples were taken from untreated, partly-treated and treated wastewater and analysed for faecal microbial indicators, i.e. coliforms, Escherichia, coli, enterococci, Clostridium perfringens spores and somatic coliphages, by culture based methods. Escherichia coli was never detected in effluent water after >5.8-log removal. Enterococci, coliforms, spores and coliphages were removed by 4.5, 4.1, 2.3 and 2.5 log respectively. Most of the removal (60-87%) took place in the latter part of the system because of settling, normal inactivation (retention time 12.7 d) and sand filtration. Time-dependent log-linear removal was shown for spores (k = -0.17 log d-1, r2 = 0.99). Conclusions: Hydroponics wastewater treatment removed micro-organisms satisfactorily. Significance and Impact of the Study: Investigations on the microbial removal capacity of hydroponics have only been performed for bacterial indicators. In this study it has been shown that virus and (oo)cyst process indicators were removed and that hydroponics can be an alternative to conventional wastewater treatment.
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| 39. |
- Perez Mercado, Luis Fernando, et al.
(författare)
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Managing microbial risks in informal wastewater-irrigated agriculture through irrigation water substitution
- 2022
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Ingår i: Agricultural Water Management. - : Elsevier BV. - 0378-3774. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- On-farm measures can be used in multi-barrier schemes to manage microbial risks from consumption of wastewater-irrigated vegetables, especially where informality of the practice determines minimal external support for farmers. Evidence indicates that cessation of irrigation greatly reduces microbial contamination on leafy vegetables, but at the expense of produce quality. Replacing wastewater with higher-quality irrigation water during the last days of cultivation is an alternative to cessation of irrigation that does not compromise produce quality. This study evaluated the effect of wastewater substitution under on-farm conditions on different indicators of microbial contamination of lettuce. Lettuce was cultivated in experimental plots and irrigated with three water sources: spring water, water from a wastewater-polluted river and effluent from a primary wastewater treatment plant, but with the river water replaced by spring water in half the plots about two weeks before harvest. The experiment was repeated four times in different seasons. Irrigation water samples collected during cultivation and lettuce samples collected at harvest were analysed for helminth eggs, Escherichia coli and coliphages. Variables characterizing the irrigation practices and environmental conditions were recorded. There were no significant differences in helminth egg or E. coli concentrations on lettuce (medians ranged from -0.7 to -0.1 log(10) eggs g(-1) and 0.6-1.4 log(10) cfu g(-1), respectively) between any of the treatments involving wastewater irrigation; no statistical analysis was possible for coliphages because concentrations on lettuce were mostly at or below the detection limit (94% of samples). Variables associated with temperature and soil explained helminth egg and E. coli concentrations on lettuce, while number of days of irrigation with spring water (representing wastewater substitution) was significant only for E. coli. It was concluded that the experimental conditions were suboptimal for successful implementation of wastewater substitution for on-farm microbial risk management, but key variables for successful implementation were identified.
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| 40. |
- Perez Mercado, Luis Fernando, et al.
(författare)
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Pathogens in crop production systems irrigated with low-quality water in Bolivia
- 2018
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Ingår i: Journal of Water and Health. - : IWA Publishing. - 1477-8920 .- 1996-7829. ; 16, s. 980-990
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Tidskriftsartikel (refereegranskat)abstract
- In dry areas, the need for irrigation to ensure agricultural production determines the use of all available water sources. However, the water sources used for irrigation are often contaminated by untreated or minimally treated wastewater. Microbial risks from reusing wastewater for vegetable irrigation can be addressed by installing environmental barriers that pathogens must cross to reach humans in the reuse system. Knowledge of pathogen flows inside the system and pathogen removal potential is the first step towards devising a risk management strategy. This study assessed microbe prevalence in farming systems in the Bolivian highlands that use wastewater-polluted sources for irrigation of lettuce. Samples of soil, lettuce and different water sources used in the farming systems were taken during one crop season and concentrations of coliphages, Escherichia coli and helminth eggs were measured. The results showed high spread of these microorganisms throughout the whole system. There was a significant correlation between microbial quality of water and of the harvested produce for several microorganisms. The microbial prevalence in protected shallow wells was found to be significantly lower than in other water sources. These findings can help formulate feasible risk management strategies in contexts where conventional technologies for microbial removal are not possible.
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| 41. |
- Sun, Qiang, et al.
(författare)
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Study protocol for One Health data collections, analyses and intervention of the Sino-Swedish integrated multisectoral partnership for antibiotic resistance containment (IMPACT)
- 2018
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: To effectively minimise the emergence and dissemination of antibiotic resistant bacteria, a holistic One Health approach is called for. The Sino-Swedish Integrated Multisectoral Partnership for Antibiotic Resistance Containment is a cross-sectoral and integrated project on antibiotic resistance, conducted in Shandong Province in China. This paper outlines the overall study protocol for the project. To our knowledge, this is the first research programme aiming to take a true holistic approach across multiple sectors simultaneously in China, and the first to incorporate both antibiotic use and infection prevention and control in addition to antibiotic resistance patterns. The project aims to address gaps in current knowledge and seeks to improve the situation through a system-wide intervention. By using a One Health approach we can address important research questions that individual discipline investigations are unable to. The results obtained should thus more closely reflect the world in which human health, animal health and the environment are inextricably and intimately interlinked.METHODS AND ANALYSIS: Both quantitative and qualitative studies are included for households from 12 villages, their surrounding environment and a tertiary care hospital in a nearby town. The studies include analyses of antibiotic consumption for humans and pigs; qualitative and quantitative data on perceptions, knowledge and attitudes; faecal carriage of extended spectrum β-lactamase and carbapenemase-producing Enterobacteriaceae from pigs and humans, and occurrence in household drinking water, surface water, waste water and clinical bacterial isolates from the hospital. Carriage of methicillin-resistant Staphylococcus aureus in humans, household pigs and clinical bacterial isolates is also investigated. Furthermore, potential inter-relationships between these sources are analysed. A multifaceted One Health intervention is designed and implemented in 6 of the 12 villages. Repeated and continuous data collections take place over 2 years, where the repeated data collection is performed after 1 year of intervention. Comparisons are made between intervention and control villages, before and after the intervention.ETHICS: Ethics approval was obtained from the first Affiliated Hospital, College of Medicine, Zhejiang University, China, reference number 2015#185 and 2015#283.
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| 42. |
- Vinnerås, Björn, et al.
(författare)
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Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in manure-amended soils studied in outdoor lysimeters
- 2010
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 46, s. 398-404
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Tidskriftsartikel (refereegranskat)abstract
- The inactivation of Escherichia coli O157:H7 (CCUG 44857) and Salmonella enterica serovar Typhimurium was investigated in two agricultural soils (sandy loam and silty clay) amended with poultry manure, cattle manure slurry or human urine. The study was performed in soil lysimeters placed outdoors, and was repeated over two consecutive years. The amendments, inoculated with E. coli O157:H7 and Salmonella Typhimurium, were mixed with soil on the top of the lysimeters. Samples were collected from the top 5-cm layer of each lysimeter at regular intervals, and the inactivation was monitored over 6 months, by the plate spread method and by enrichment. The inactivation was modelled by fitting a non-linear model to the data, and pathogen reduction times were calculated (90 and 99% reduction). The results showed that the inactivation of E. coli O157:H7 and Salmonella Typhimurium varied depending on the manure type used and its carbon content. The longest inactivation time occurred in samples amended with poultry manure, in which both E. coli O157:H7 and Salmonella Typhimurium were detected up to day 90 with the spread plate method. The most rapid inactivation for both pathogens occurred in soil amended with urine. However, low amounts of culturable E. coli O157:H7 and Salmonella Typhimurium were detected by enrichment throughout the study period (180 days), regardless of manure type
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| 43. |
- Vinnerås, Björn, et al.
(författare)
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Thermal treatment for pathogen inactivation as a risk mitigation strategy for safe recycling of organic waste in agriculture
- 2014
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Ingår i: Journal of Environmental Science and Health, Part B. - : Informa UK Limited. - 0360-1234 .- 1532-4109. ; 49, s. 679-689
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Tidskriftsartikel (refereegranskat)abstract
- Thermal treatment at temperatures between 46.0 degrees C and 55.0 degrees C was evaluated as a method for sanitization of organic waste, a temperature interval less commonly investigated but important in connection with biological treatment processes. Samples of dairy cow feces inoculated with Salmonella Senftenberg W775, Enterococcus faecalis, bacteriophage phi X174, and porcine parvovirus (PPV) were thermally treated using block thermostats at set temperatures in order to determine time-temperature regimes to achieve sufficient bacterial and viral reduction, and to model the inactivation rate. Pasteurization at 70 degrees C in saline solution was used as a comparison in terms of bacterial and viral reduction and was proven to be effective in rapidly reducing all organisms with the exception of PPV (decimal reduction time of 1.2h). The results presented here can be used to construct time-temperature regimes in terms of bacterial inactivation, with D-values ranging from 0.37h at 55 degrees C to 22.5h at 46.0 degrees C and 0.45h at 55.0 degrees C to 14.5h at 47.5 degrees C for Salmonella Senftenberg W775 and Enterococcus faecalis, respectively and for relevant enteric viruses based on the phi X174 phage with decimal reduction times ranging from 1.5h at 55 degrees C to 16.5h at 46 degrees C. Hence, the study implies that considerably lower treatment temperatures than 70 degrees C can be used to reach a sufficient inactivation of bacterial pathogens and potential process indicator organisms such as the phi X174 phage and raises the question whether PPV is a valuable process indicator organism considering its extreme thermotolerance.
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| 44. |
- Xia, Hongyan, et al.
(författare)
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Development of single-tube nested real-time PCR assays with long internally quenched probes for detection of norovirus genogroup II
- 2016
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Ingår i: BioTechniques. - : Future Science Ltd. - 0736-6205 .- 1940-9818. ; 60:1, s. 28-34
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Tidskriftsartikel (refereegranskat)abstract
- The high sequence variation of RNA viruses necessitates use of degenerate primers and probes or multiple primers and probes in molecular diagnostic assays. We showed previously that PCR amplification in two rounds, first with long target-specific primers and then with short generic primers, followed by detection using long probes, can tolerate sequence variation. Here we demonstrate that long primers and probes of up to 56 nucleotides can also be applied in real-time PCR for the detection of norovirus genogroup II with improved sensitivity. Probe design (method of incorporating quenchers, use of Zen internal quencher or traditional quenchers) greatly affects the sensitivity of the real-time PCR assays.
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| 45. |
- Zou, Huiyun, et al.
(författare)
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Evaluating Dissemination Mechanisms of Antibiotic-Resistant Bacteria in Rural Environments in China by Using CTX-M-Producing Escherichia coli as an Indicator
- 2019
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Ingår i: Microbial Drug Resistance. - : Mary Ann Liebert, Inc., publishers. - 1076-6294 .- 1931-8448. ; 25:7, s. 975-984
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Tidskriftsartikel (refereegranskat)abstract
- It is becoming increasingly recognized that the environment plays an important role both in the emergence and in dissemination of antibiotic-resistant bacteria (ARB), Mechanisms and factors facilitating this development are, however, not yet well understood. The high detection rate of CTX-M genes in environmental sources provides an opportunity to explore this issue. In this study, 88 CTX-M-producing Escherichia coli were isolated from 30 pig feces samples from 30 pig farms and 201 environmental samples. CTX-M-producing E. coli was detected with the following frequencies in the different types of samples: pig feces, 73%; river water, 64%; river sediment, 52%; wastewater, 31%; drinking water, 23%; outlet sediment, 21%; soil, 17%; and vegetables, 4.4%. Dissemination of CTX-M-producing E. coli to different environmental matrices was evaluated by analyzing the genetic relatedness of isolates from different environmental sources, and putative transmission routes through bird feces, pig feces, drinking water, river sediment, river water, and wastewater were hypothesized. Dissemination through these routes is likely facilitated by anthropogenic activities and environmental factors. Wild birds as potential vectors for dissemination of CTX-M-producing E. coli have the capacity to spread ARB across long distances. Regional dissemination between different environmental matrices of CTX-M-producing E. coli increases the exposure risk of humans and animals in the area.
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