Mette Myrmel

Neonatal diarrhoea in calves is one of the major health problems in the cattle industry. Although co-infections are often associated with greater severity of disease, there is limited information on any impact on the pathogens themselves. Herein, we studied Cryptosporidium parvum and bovine coronavirus (BCoV) in human HCT-8 cells, inoculated either sequentially or simultaneously, to investigate any influence from the co-infections. Quantitative results from (RT)-qPCR showed that prior inoculation with either of the two pathogens had no influence on the other. However, the results from simultaneous co-inoculation showed that entry of viral particles was higher when C. parvum sporozoites were present, although elevated virus copy numbers were no longer evident after 24 h. The attachment of BCoV to the sporozoites was probably due to specific binding, as investigations with bovine norovirus or equine herpes virus-1 showed no attachment between sporozoites and these viruses. Flow cytometry results at 72 h post inoculation revealed that C. parvum and BCoV infected 1-11% and 10-20% of the HCT-8 cells, respectively, with only 0.04% of individual cells showing double infections. The results from confocal microscopy corroborated those results, showing an increase in foci of infection from 24-72 h post inoculation for both pathogens, but with few double infected cells.

The aquaculture industry needs a simple, inexpensive and safe method for the treatment of fish waste without heat. Microbial inactivation by inorganic acid (HCl) or base (KOH) was determined using infectious pancreatic necrosis virus (IPNV) as a model organism for fish pathogens. Salmonella and spores of Clostridium perfringens were general hygiene indicators in supplementary examinations. IPNV, which is considered to be among the most chemical- and heat-resistant fish pathogens, was reduced by more than 3 log in 4 h at pH 1.0 and pH 12.0. Salmonella was rapidly inactivated by the same treatment, whereas spores of C. perfringens were hardly affected. The results indicate that low and high pH treatment could be particularly suitable for fish waste destined for biogas production. pH treatment at aquaculture production sites could reduce the spread of fish pathogens during storage and transportation without disturbing the anaerobic digestion process. The treatment could also be an alternative to the current energy-intensive steam pressure sterilization of fish waste to be used by the bioenergy, fertilizer and soil improver industries.

In this case study, the impact of a temporary (4 days) interruption of a sewage treatment works on the microbial quality of a drinking water source in SE Norway to which the sewage was discharged was investigated. Samples of wastewater and river water were taken before and during the interruption of the sewage treatment and analysed for various microbial indicators and pathogens: faecal indicator bacteria (E. coli and total coliforms); F-specific RNA bacteriophages; pathogenic viruses (norovirus GI and GII, adenovirus); protozoan parasites (Giardia and Cryptosporidium). Water at the inlet to the drinking water treatment plant, 20 km downstream from the sewage discharge, was not found to be significantly affected with respect to bacteria and parasites, with higher concentrations measured prior to the sewage treatment interruption, probably associated with a period of heavy rainfall. For viruses, however, the heavy rainfall appeared to be of lesser relevance to the contamination levels. These data demonstrate the importance of water providers having a clear overview not only of sewage discharge in water catchment areas but also of other potential sources of contamination with different pathogens and indicators, and the effects of weather conditions on contamination events.

In March 2014, after an increase of notifications of domestically acquired hepatitis A virus infections, an outbreak investigation was launched in Norway. Sequenced-based typing results showed that these cases were associated with a strain that was identical to one causing an ongoing multinational outbreak in Europe linked to frozen mixed berries. Thirty-three confirmed cases with the outbreak strain were notified in Norway from November 2013 to June 2014. Epidemiological evidence and trace-back investigations linked the outbreak to the consumption of a berry mix cake. Identification of the hepatitis A virus outbreak strain in berries from one of the implicated cakes confirmed the cake to be the source. Subsequently, a cluster in Germany linked to the cake was also identified.

Among the causative agents of neonatal diarrhoea in calves, two of the most prevalent are bovine coronavirus (BCoV) and the intracellular parasite Cryptosporidium parvum. Although several studies indicate that co-infections are associated with greater symptom severity, the host-pathogen interplay remains unresolved. Here, our main objective was to investigate the modulation of the transcriptome of HCT-8 cells during single and co-infections with BCoV and C. parvum. For this, HCT-8 cells were inoculated with (1) BCoV alone, (2) C. parvum alone, (3) BCoV and C. parvum simultaneously. After 24 and 72 h, cells were harvested and analyzed using high-throughput RNA sequencing. Following differential expression analysis, over 6000 differentially expressed genes (DEGs) were identified in virus and co-infected cells at 72 hpi, whereas only 52 DEGs were found in C. parvum-infected cells at the same time point. Pathway (KEGG) and gene ontology (GO) analysis showed that DEGs in the virus-infect...

Two case studies were carried out in central Norway in order to assess the performance of bank filtration systems in cold-climate fluvial aquifers relying on recharge from humic-rich surface waters with moderate microbial contamination. Three municipal wells and two surface-water sources at operative bank filtration systems were monitored for naturally occurring bacteriophages, fecal indicators, natural organic matter (NOM) and physico-chemical water quality parameters during a 4-month period. Aquifer passage effectively reduced the microorganism and NOM concentrations at both study sites. Bacteriophages were detected in 13 of 16 (81%) surface-water samples and in 4 of 24 (17%) well-water samples, and underwent 3 ± 0.3 log10 reduction after 50–80-m filtration and 20–30 days of subsurface passage. NOM reductions (color: 74–97%; dissolved organic carbon: 54–80%; very hydrophobic acids: 70%) were similar to those achieved by conventional water-treatment processes and no further treatment was needed. Both groundwater dilution and sediment filtration contributed to the hygienic water quality improvements, but sediment filtration appeared to be the most important process with regard to microbial and NOM reductions. A strengths-weaknesses-opportunities-threats analysis showed that bank filtration technology has a high potential as a pretreatment method for the provision of hygienically safe drinking water in Norway.RésuméDeux études de cas ont été menées dans le centre de la Norvège afin d’évaluer la performance des systèmes de filtration par les berges dans des aquifères alluviaux sous climat froid en se fondant sur une recharge à partir d’eaux de surface riches en humus avec une contamination microbienne modérée. Trois puits municipaux et deux sources d’eaux superficielles appartenant aux dispositifs opérationnels de filtration par les berges ont été suivis pour ce qui est des bactériophages qui surviennent naturellement, des indicateurs fécaux, de la matière organique naturelle (MON) et des paramètres de qualité physico-chimique de l’eau, pendant une période de 4 mois. Le transit dans l’aquifère a réduit efficacement la concentration des microorganismes et de MON dans les deux sites. Les bactériophages ont été détectés dans 13 des 16 (81%) échantillons d’eau de surface et dans 4 des 24 (17%) échantillons d’eau des puits, et ont subi une réduction de 3 ± 0.3 log10 après 50–80 m de filtration et 20–40 jours de transit dans le sous-sol. Les réductions de MON (couleur: 74–97%: carbone organique dissous: 54–80%: acides très hydrophobes: 70%) étaient similaires à celles obtenues par les procédés de traitement conventionnels de l’eau et aucun traitement supplémentaire n’a été nécessaire. Tant la dilution par les eaux souterraines que la filtration par les sédiments ont contribué à l’amélioration de la qualité hygiénique de l’eau, mais la filtration par les sédiments apparaît comme étant le processus le plus important concernant les réductions microbiennes et de MON. Une analyse des forces-faiblesses-opportunités-menaces a montré que la technologie de la filtration par les berges offre un fort potentiel en tant que méthode de prétraitement pour l’approvisionnement d’eau potable hygiéniquement sure en Norvège.ResumenSe realizaron dos estudios de casos en el centro de Noruega con el fin de evaluar el rendimiento de los sistemas de filtración de banco en los acuíferos fluviales en clima frío que dependen de la recarga del agua superficial rica en humus con contaminación microbiana moderada. Se monitorearon durante un período de 4 meses tres pozos municipales y dos fuentes de agua superficial en la operación de los sistemas de filtración de banco para la presencia natural de bacteriófagos, indicadores fecales, materia orgánica natural (NOM) y parámetros físico-químicos de la calidad del agua. El pasaje por el acuífero redujo eficazmente las concentraciones de microorganismos y el NOM en ambos sitios de estudio. Se detectaron bacteriófagos en 13 de 16 (81%) de las muestras de agua de superficie y en 4 de 24 (17%) de las muestras de agua de pozo y se sometieron a una reducción de 3 ± 0.3 log10 después de 50–80 m de filtración y 20–30 días de pasaje subsuperficial . Las reducciones de NOM (color: 74–97%, carbono orgánico disuelto: 54–80%, ácidos muy hidrófobos: 70%) fueron similares a las obtenidas por los procesos convencionales de tratamiento de agua y no se necesitó tratamiento adicional. Tanto la dilución de agua subterránea como la filtración por sedimentos contribuyeron a mejorar la calidad del agua, pero la filtración por sedimentos parecía ser el proceso más importante con respecto a las reducciones microbianas y de ONM. Un análisis de fortalezas-debilidades-oportunidades-amenazas mostró que la tecnología de filtración de banco tiene un alto potencial como método de pretratamiento para el suministro de agua potable higiénicamente segura en…

Bovine coronavirus (BCoV) is one of the major viral pathogens of cattle, responsible for economic losses and causing a substantial impact on animal welfare. Several in vitro 2D models have been used to investigate BCoV infection and its pathogenesis. However, 3D enteroids are likely to be a better model with which to investigate host–pathogen interactions. This study established bovine enteroids as an in vitro replication system for BCoV, and we compared the expression of selected genes during the BCoV infection of the enteroids with the expression previously described in HCT-8 cells. The enteroids were successfully established from bovine ileum and permissive to BCoV, as shown by a seven-fold increase in viral RNA after 72 h. Immunostaining of differentiation markers showed a mixed population of differentiated cells. Gene expression ratios at 72 h showed that pro-inflammatory responses such as IL-8 and IL-1A remained unchanged in response to BCoV infection. Expression of other immu...

Microorganism removal efficiencies in deep bed filters vary with time and depth in the filter bed as the filter collects particles. Improved knowledge of such dynamics is relevant for the design, operation and microbial risk assessment of filtration processes for drinking water treatment. Here we report on a highresolution spatio-temporal characterization of virus and bacteria removal in a pilot-scale dual-media filter, operated in contact-filtration mode. Microorganisms investigated were bacteriophage Salmonella typhimurium 28B (plaque assay, n ¼ 154)), fRNA phage MS2 (plaque assay/RT-qPCR, n ¼ 87) and E. coli (Colilert-18, n ¼ 73). Microscopic and macroscopic filtration models were used to investigate and characterize the removal dynamics. Results show that ripening/breakthrough fronts for turbidity, viruses and E. coli migrated in a wavelike manner across the depth of the filter. Virus removal improved continuously throughout the filter cycle and viruses broke through almost simu...

Microorganism removal efficiencies in deep bed filters vary with time and depth in the filter bed as the filter collects particles. Improved knowledge of such dynamics is relevant for the design, operation and microbial risk assessment of filtration processes for drinking water treatment. Here we report on a high-resolution spatio-temporal characterization of virus and bacteria removal in a pilot-scale dual-media filter, operated in contact-filtration mode. Microorganisms investigated were bacteriophage Salmonella typhimurium 28B (plaque assay,n¼154)), fRNA phage MS2 (plaque assay/RT-qPCR,n¼87) and E. coli(Colilert-18,n¼73). Microscopic and macroscopic filtration models were used to investigate and characterize the removal dynamics.Results show that ripening/breakthrough fronts for turbidity, viruses and E. coli migrated in a wave-like manner across the depth of the filter. Virus removal improved continuously throughout the filter cycle and viruses broke through almost simultaneousl...

Microorganism removal efficiencies in deep bed filters vary with time and depth in the filter bed as the filter collects particles. Improved knowledge of such dynamics is relevant for the design, operation and microbial risk assessment of filtration processes for drinking water treatment. Here we report on a highresolution spatio-temporal characterization of virus and bacteria removal in a pilot-scale dual-media filter, operated in contact-filtration mode. Microorganisms investigated were bacteriophage Salmonella typhimurium 28B (plaque assay, n ¼ 154)), fRNA phage MS2 (plaque assay/RT-qPCR, n ¼ 87) and E. coli (Colilert-18, n ¼ 73). Microscopic and macroscopic filtration models were used to investigate and characterize the removal dynamics. Results show that ripening/breakthrough fronts for turbidity, viruses and E. coli migrated in a wavelike manner across the depth of the filter. Virus removal improved continuously throughout the filter cycle and viruses broke through almost simu...

Prosjektet Water Quality Tools ble gjennomført i perioden 2012-2015. Målet med prosjektet var å fremskaffe ny kunnskap, analysemetoder og modellverktøy som kan være til nytte i arbeidet med å sikre god badevannskvalitet på lokaliteter der det i dag er eller planlegges å tilrettelegge for friluftsbading i Indre Oslofjord. Resultater fra prosjektet er presentert i ulike rapporter, artikler og på konferanser. Denne rapporten inneholder en sammenstilling av de viktigste resultatene og har også med data som ikke er presentert andre steder.The project Water Quality Tools was conducted in the period 2012-2015. Results from the project have been presented in various reports, articles, and at conferences. This report contains a summary of the main results and also includes data that have not been presented elsewhere. The aim of the project was to obtain new knowledge, analytical methods, and modeling tools, which may be useful for the municipalities in their efforts to ensure good hygienic w...

Currently, the prevalence of salmonid alphavirus (SAV) in Norwegian Atlantic salmon farms is largely surveyed via sacrificing fish and sampling of organ tissue on a monthly basis. However, a more cost-efficient, straightforward, rapid, reliable, reproducible and animal welfare friendly method based on the detection of SAV in water could be considered as an alternative method. In the present study, such a method was developed and optimized through a 6 wk cohabitant challenge trial, using post-smolt Atlantic salmon Salmo salar L challenged with high or low doses of SAV subtype 3 (SAV3). Tank water and tissue samples from cohabitant fish were collected at 16 time points. SAV3 was concentrated from the water by filtration, using either electronegative or electropositive membrane filters, which were subsequently rinsed with one of 4 different buffer solutions. SAV3 was detected first in tank water (7 d post-challenge, DPC), and later in cohabitant fish organ tissue samples (12 DPC). The ...