Gemma Saucedo - Academia.edu (original) (raw)
Papers by Gemma Saucedo
Nuevos métodos para proteger la salud de los europeos ante potenciales patógenos del agua potable
Water Science and Technology, 2008
Free-living amoebae have been detected in a large number of man-made water systems, including dri... more Free-living amoebae have been detected in a large number of man-made water systems, including drinking water distribution systems. Some of these amoebae can host amoebae-resisting bacteria, and thus act potentially as reservoirs and vehicles for a number of pathogens. The objectives of this study were to characterize the amoebae and amoebae-resisting bacteria present in different raw waters used for drinking water production, and to assess the efficiency of different treatments applied for drinking water production in removing or inactivating these amoebae. The preliminary results of this study confirm the presence of amoebae and amoebae-resisting bacteria in raw waters used for drinking water production. Due to their capacity to encyst, most of these amoebae are extremely resistant to disinfection processes. In these conditions, preventing the dissemination of these micro-organisms through drinking water will mainly require their physical removal by clarification and filtration pro...
Élimination Des Amibes Libres Par Les Procédés De Traitement De L’Eau Potable
European journal of water quality, 2008
La presence d’amibes libres a ete decrite dans de nombreux systemes d’eau artificiels, dont les r... more La presence d’amibes libres a ete decrite dans de nombreux systemes d’eau artificiels, dont les reseaux de distribution d’eau potable. Certaines de ces amibes peuvent heberger des bacteries, et se comporter ainsi potentiellement comme des reservoirs ou des voies de transmission pour un certain nombre de pathogenes. Les objectifs de cette etude etaient de quantifier les amibes libres presentes dans differentes ressources utilisees pour la production d’eau potable, et d’evaluer l’efficacite de differents traitements appliques en production et distribution d’eau potable, vis-a-vis de ces amibes. Des campagnes d’echantillonnage ont ete realisees en Europe sur differentes eaux brutes utilisees pour la production d’eau potable, ainsi qu’a differentes etapes du traitement. Des essais de traitement ont egalement ete realises en laboratoire et a l’echelle pilote. Les resultats de cette etude confirment la presence d’amibes libres dans les eaux de surface utilisees pour la production d’eau potable. En raison de leur capacite a s’enkyster, la plupart de ces amibes sont extremement resistantes aux traitements de desinfection. Le danger particulier lie a ces microorganismes doit etre pris en compte dans la gestion des installations de production et distribution d’eau potable, et des moyens de maitrise adaptes, bases sur une elimination physique plutot que sur des procedes de desinfection, doivent etre mis en place si necessaire.
Water Llobregat River ERIC-PCR 16S rDNA-RFLP Faecal indicators a b s t r a c t The presence of Ar... more Water Llobregat River ERIC-PCR 16S rDNA-RFLP Faecal indicators a b s t r a c t The presence of Arcobacter species in faecally contaminated environmental waters has previously been studied. However, the ability to eliminate Arcobacter during the water treatment processes that produce drinking water has been little studied. We have investigated the prevalence and diversity of Arcobacter spp. throughout the year at 12 sampling points in the Llobregat River catchment (Catalonia, Spain) including 3 sites at a drinking water treatment plant. Positive samples for Arcobacter spp., came predominantly from the most faecally polluted sites. Recovery rates from all sites were greater in the spring (91.7%) and summer (83.3%) than in autumn and winter (75.0% in both cases), but this trend was not statistically evaluated due to the limited number of samples. Among the 339 colonies analyzed, the most prevalent species by multiplex PCR and 16S rDNA restriction fragment length polymorphism were Arcob...
Elimination of SARS-CoV-2 along wastewater and sludge treatment processes
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is shed in the feces of infected... more The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is shed in the feces of infected people. As a consequence, genomic RNA of the virus can be detected in wastewater. Although the presence of viral RNA does not inform on the infectivity of the virus, this presence of genetic material raised the question of the effectiveness of treatment processes in reducing the virus in wastewater and sludge. In this work, treatment lines of 16 wastewater treatment plants were monitored to evaluate the removal of SARS-CoV-2 RNA in raw, processed waters and sludge, from March to May 2020. Viral RNA copies were enumerated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in 5 different laboratories. These laboratories participated in proficiency testing scheme and their results demonstrated the reliability and comparability of the results obtained for each one. SARS-CoV-2 RNA was found in 50.5% of the 101 influent wastewater samples characterized. Positive resu...
Occurrence and diversity of< i> Arcobacter spp. along the Llobregat River catchment, at sewage effluents and in a drinking water treatment plant
Water research, 2010
The presence of Arcobacter species in faecally contaminated environmental waters has previously b... more The presence of Arcobacter species in faecally contaminated environmental waters has previously been studied. However, the ability to eliminate Arcobacter during the water treatment processes that produce drinking water has been little studied. We have ...
Drinking water quality has been regulated in most European countries for nearly two decades by th... more Drinking water quality has been regulated in most European countries for nearly two decades by the drinking water directive 98/83/EC. The directive is now under revision with the goal of meeting stricter demands for safe water for all citizens, as safe water has been recognized as a human right by the United Nations. An important change to the directive is the implementation of a risk-based approach in all regulated water supplies. The European Union Framework Seventh Programme Aquavalens project has developed several new detection technologies for pathogens and indicators and tested them in water supplies in seven European countries. One of the tasks of the project was to evaluate the impact of these new techniques on water safety and on water safety management. Data were collected on risk factors to water safety for five large supplies in Denmark, Germany, Spain and the UK, and for fifteen small water supplies in Scotland, Portugal and Serbia, via a questionnaire aiming to ascerta...
Environmental Microbiology, 2009
Chlamydiae are obligate intracellular bacteria infecting free-living amoebae, vertebrates and som... more Chlamydiae are obligate intracellular bacteria infecting free-living amoebae, vertebrates and some invertebrates. Novel members are regularly discovered, and there is accumulating evidence supporting a very important diversity of chlamydiae in the environment. In this study, we investigated the presence of chlamydiae in a drinking water treatment plant. Samples were used to inoculate Acanthamoeba monolayers (Acanthamoeba co-culture), and to recover autochthonous amoebae onto non-nutritive agar. Chlamydiae were searched for by a pan-chlamydia 16S rRNA gene PCR from both Acanthamoeba co-cultures and autochthonous amoebae, and phylotypes determined by 16S rRNA gene sequencing. Autochthonous amoebae also were identified by 18S rRNA gene amplification and sequencing. From a total of 79 samples, we recovered eight chlamydial strains by Acanthamoeba co-culture, but only one of 28 amoebae harboured a chlamydia. Sequencing results and phylogenetic analysis showed our strains belonging to four distinct chlamydial lineages. Four strains, including the strain recovered within its natural host, belonged to the Parachlamydiaceae; two closely related strains belonged to the Criblamydiaceae; two distinct strains clustered with Rhabdochlamydia spp.; one strain clustered only with uncultured environmental clones. Our results confirmed the usefulness of amoeba co-culture to recover novel chlamydial strains from complex samples and demonstrated the huge diversity of chlamydiae in the environment, by identifying several new species including one representing the first strain of a new family.
Water Research, 2010
Water Llobregat River ERIC-PCR 16S rDNA-RFLP Faecal indicators a b s t r a c t
Nuevos métodos para proteger la salud de los europeos ante potenciales patógenos del agua potable
Water Science and Technology, 2008
Free-living amoebae have been detected in a large number of man-made water systems, including dri... more Free-living amoebae have been detected in a large number of man-made water systems, including drinking water distribution systems. Some of these amoebae can host amoebae-resisting bacteria, and thus act potentially as reservoirs and vehicles for a number of pathogens. The objectives of this study were to characterize the amoebae and amoebae-resisting bacteria present in different raw waters used for drinking water production, and to assess the efficiency of different treatments applied for drinking water production in removing or inactivating these amoebae. The preliminary results of this study confirm the presence of amoebae and amoebae-resisting bacteria in raw waters used for drinking water production. Due to their capacity to encyst, most of these amoebae are extremely resistant to disinfection processes. In these conditions, preventing the dissemination of these micro-organisms through drinking water will mainly require their physical removal by clarification and filtration pro...
Élimination Des Amibes Libres Par Les Procédés De Traitement De L’Eau Potable
European journal of water quality, 2008
La presence d’amibes libres a ete decrite dans de nombreux systemes d’eau artificiels, dont les r... more La presence d’amibes libres a ete decrite dans de nombreux systemes d’eau artificiels, dont les reseaux de distribution d’eau potable. Certaines de ces amibes peuvent heberger des bacteries, et se comporter ainsi potentiellement comme des reservoirs ou des voies de transmission pour un certain nombre de pathogenes. Les objectifs de cette etude etaient de quantifier les amibes libres presentes dans differentes ressources utilisees pour la production d’eau potable, et d’evaluer l’efficacite de differents traitements appliques en production et distribution d’eau potable, vis-a-vis de ces amibes. Des campagnes d’echantillonnage ont ete realisees en Europe sur differentes eaux brutes utilisees pour la production d’eau potable, ainsi qu’a differentes etapes du traitement. Des essais de traitement ont egalement ete realises en laboratoire et a l’echelle pilote. Les resultats de cette etude confirment la presence d’amibes libres dans les eaux de surface utilisees pour la production d’eau potable. En raison de leur capacite a s’enkyster, la plupart de ces amibes sont extremement resistantes aux traitements de desinfection. Le danger particulier lie a ces microorganismes doit etre pris en compte dans la gestion des installations de production et distribution d’eau potable, et des moyens de maitrise adaptes, bases sur une elimination physique plutot que sur des procedes de desinfection, doivent etre mis en place si necessaire.
Water Llobregat River ERIC-PCR 16S rDNA-RFLP Faecal indicators a b s t r a c t The presence of Ar... more Water Llobregat River ERIC-PCR 16S rDNA-RFLP Faecal indicators a b s t r a c t The presence of Arcobacter species in faecally contaminated environmental waters has previously been studied. However, the ability to eliminate Arcobacter during the water treatment processes that produce drinking water has been little studied. We have investigated the prevalence and diversity of Arcobacter spp. throughout the year at 12 sampling points in the Llobregat River catchment (Catalonia, Spain) including 3 sites at a drinking water treatment plant. Positive samples for Arcobacter spp., came predominantly from the most faecally polluted sites. Recovery rates from all sites were greater in the spring (91.7%) and summer (83.3%) than in autumn and winter (75.0% in both cases), but this trend was not statistically evaluated due to the limited number of samples. Among the 339 colonies analyzed, the most prevalent species by multiplex PCR and 16S rDNA restriction fragment length polymorphism were Arcob...
Elimination of SARS-CoV-2 along wastewater and sludge treatment processes
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is shed in the feces of infected... more The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is shed in the feces of infected people. As a consequence, genomic RNA of the virus can be detected in wastewater. Although the presence of viral RNA does not inform on the infectivity of the virus, this presence of genetic material raised the question of the effectiveness of treatment processes in reducing the virus in wastewater and sludge. In this work, treatment lines of 16 wastewater treatment plants were monitored to evaluate the removal of SARS-CoV-2 RNA in raw, processed waters and sludge, from March to May 2020. Viral RNA copies were enumerated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in 5 different laboratories. These laboratories participated in proficiency testing scheme and their results demonstrated the reliability and comparability of the results obtained for each one. SARS-CoV-2 RNA was found in 50.5% of the 101 influent wastewater samples characterized. Positive resu...
Occurrence and diversity of< i> Arcobacter spp. along the Llobregat River catchment, at sewage effluents and in a drinking water treatment plant
Water research, 2010
The presence of Arcobacter species in faecally contaminated environmental waters has previously b... more The presence of Arcobacter species in faecally contaminated environmental waters has previously been studied. However, the ability to eliminate Arcobacter during the water treatment processes that produce drinking water has been little studied. We have ...
Drinking water quality has been regulated in most European countries for nearly two decades by th... more Drinking water quality has been regulated in most European countries for nearly two decades by the drinking water directive 98/83/EC. The directive is now under revision with the goal of meeting stricter demands for safe water for all citizens, as safe water has been recognized as a human right by the United Nations. An important change to the directive is the implementation of a risk-based approach in all regulated water supplies. The European Union Framework Seventh Programme Aquavalens project has developed several new detection technologies for pathogens and indicators and tested them in water supplies in seven European countries. One of the tasks of the project was to evaluate the impact of these new techniques on water safety and on water safety management. Data were collected on risk factors to water safety for five large supplies in Denmark, Germany, Spain and the UK, and for fifteen small water supplies in Scotland, Portugal and Serbia, via a questionnaire aiming to ascerta...
Environmental Microbiology, 2009
Chlamydiae are obligate intracellular bacteria infecting free-living amoebae, vertebrates and som... more Chlamydiae are obligate intracellular bacteria infecting free-living amoebae, vertebrates and some invertebrates. Novel members are regularly discovered, and there is accumulating evidence supporting a very important diversity of chlamydiae in the environment. In this study, we investigated the presence of chlamydiae in a drinking water treatment plant. Samples were used to inoculate Acanthamoeba monolayers (Acanthamoeba co-culture), and to recover autochthonous amoebae onto non-nutritive agar. Chlamydiae were searched for by a pan-chlamydia 16S rRNA gene PCR from both Acanthamoeba co-cultures and autochthonous amoebae, and phylotypes determined by 16S rRNA gene sequencing. Autochthonous amoebae also were identified by 18S rRNA gene amplification and sequencing. From a total of 79 samples, we recovered eight chlamydial strains by Acanthamoeba co-culture, but only one of 28 amoebae harboured a chlamydia. Sequencing results and phylogenetic analysis showed our strains belonging to four distinct chlamydial lineages. Four strains, including the strain recovered within its natural host, belonged to the Parachlamydiaceae; two closely related strains belonged to the Criblamydiaceae; two distinct strains clustered with Rhabdochlamydia spp.; one strain clustered only with uncultured environmental clones. Our results confirmed the usefulness of amoeba co-culture to recover novel chlamydial strains from complex samples and demonstrated the huge diversity of chlamydiae in the environment, by identifying several new species including one representing the first strain of a new family.
Water Research, 2010
Water Llobregat River ERIC-PCR 16S rDNA-RFLP Faecal indicators a b s t r a c t