Browsing by Author "Castro-Gutierrez, Victor"

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    Editorial: Fundamental and practical advances in bioremediation of emerging pollutants as add-on treatments for polluted waters
    (Frontiers, 2024) Hassard, Francis; Castro-Gutierrez, Victor
    Editorial on the Research Topic: Fundamental and practical advances in bioremediation of emerging pollutants as add-on treatments for polluted waters
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    First insights into the prokaryotic community structure of Lake Cote, Costa Rica: influence on nutrient cycling
    (Frontiers, 2022-10-03) Brenes-Guillén, Laura; Vidaurre-Barahona, Daniela; Avilés-Vargas, Lidia; Castro-Gutierrez, Victor; Gómez-Ramírez, Eddy; González-Sánchez, Kaylen; Mora-López, Marielos; Umaña-Villalobos, Gerardo; Uribe-Lorío, Lorena; Hassard, Francis
    Prokaryotic diversity in lakes has been studied for many years mainly focusing on community structure and how the bacterial assemblages are driven by physicochemical conditions such as temperature, oxygen, and nutrients. However, little is known about how the composition and function of the prokaryotic community changes upon lake stratification. To elucidate this, we studied Lake Cote in Costa Rica determining prokaryotic diversity and community structure in conjunction with physicochemistry along vertical gradients during stratification and mixing periods. Of the parameters measured, ammonium, oxygen, and temperature, in that order, were the main determinants driving the variability in the prokaryotic community structure of the lake. Distinct stratification of Lake Cote occurred (March 2018) and the community diversity was compared to a period of complete mixing (March 2019). The microbial community analysis indicated that stratification significantly altered the bacterial composition in the epi-meta- and hypolimnion. During stratification, the Deltaproteobacteria, Chloroflexi, Bacteroidetes, Nitrospirae, and Euryarchaeota were dominant in the hypolimnion yet largely absent in surface layers. Among these taxa, strict or facultative anaerobic bacteria were likely contributing to the lake nitrogen biogeochemical cycling, consistent with measurements of inorganic nitrogen measurements and microbial functional abundance predictions. In general, during both sampling events, a higher abundance of Alphaproteobacteria, Betaproteobacteria, Actinobacteria, and Cyanobacteria was found in the oxygenated layers. Lake Cote had a unique bacterial diversity, with 80% of Amplicon Sequence Variant (ASV) recovered similar to unclassified/uncultured strains and exhibits archetypal shallow lake physicochemical but not microbial fluctuations worthy of further investigation. This study provides an example of lake hydrodynamics impacts to microbial community and their function in Central American lakes with implications for other shallow, upland, and oligotrophic lake systems.
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    How bioaugmentation for pesticide removal influences the microbial community in biologically active sand filters
    (Elsevier, 2024-07-30) Pickering, Laura; Castro-Gutierrez, Victor; Holden, Barrie; Haley, John; Jarvis, Peter; Campo, Pablo; Hassard, Francis
    Removing pesticides from biological drinking water filters is challenging due to the difficulty in activating pesticide-degrading bacteria within the filters. Bioaugmented bacteria can alter the filter's microbiome, affecting its performance either positively or negatively, depending on the bacteria used and their interaction with native microbes. We demonstrate that adding specific bacteria strains can effectively remove recalcitrant pesticides, like metaldehyde, yielding compliance to regulatory standards for an extended period. Our experiments revealed that the Sphingobium CMET-H strain was particularly effective, consistently reducing metaldehyde concentrations to levels within regulatory compliance, significantly outperforming Acinetobacter calcoaceticus E1. This success is attributed to the superior acclimation and distribution of the Sphingobium strain within the filter bed, facilitating more efficient interactions with and degradation of the pesticide, even when present at lower population densities compared to Acinetobacter calcoaceticus E1. Furthermore, our study demonstrates that the addition of pesticide-degrading strains significantly impacts the filter's microbiome at various depths, despite these strains making up less than 1% of the total microbial community. The sequence in which these bacteria are introduced influences the system's ability to degrade pesticides effectively. This research shows the potential of carefully selected and dosed bioaugmented bacteria to improve the pesticide removal capabilities of water filtration systems, while also highlighting the dynamics between bioaugmented and native microbial communities. Further investigation into optimizing bioaugmentation strategies is suggested to enhance the resilience and efficiency of drinking water treatment systems against pesticide contamination.
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    Monitoring occurrence of SARS-CoV-2 in school populations: a wastewater-based approach
    (PLOS (Public Library of Science), 2022-06-17) Castro-Gutierrez, Victor; Hassard, Francis; Vu, Milan; Leitao, Rodrigo; Burczynska, Beata; Wildeboer, Dirk; Stanton, Isobel; Rahimzadeh, Shadi; Baio, Gianluca; Garelick, Hemda; Hofman, Jan; Kasprzyk-Hordern, Barbara; Kwiatkowska, Rachel; Majeed, Azeem; Priest, Sally; Grimsley, Jasmine; Lundy, Lian; Singer, Andrew C.; Di Cesare, Mariachiara
    Clinical testing of children in schools is challenging, with economic implications limiting its frequent use as a monitoring tool of the risks assumed by children and staff during the COVID-19 pandemic. Here, a wastewater-based epidemiology approach has been used to monitor 16 schools (10 primary, 5 secondary and 1 post-16 and further education) in England. A total of 296 samples over 9 weeks have been analysed for N1 and E genes using qPCR methods. Of the samples returned, 47.3% were positive for one or both genes with a detection frequency in line with the respective local community. WBE offers a low cost, non-invasive approach for supplementing clinical testing and can provide longitudinal insights that are impractical with traditional clinical testing.
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    Wastewater monitoring for detection of public health markers during the COVID-19 pandemic: near-source monitoring of schools in England over an academic year
    (PLOS (Public Library of Science), 2023-05-30) Hassard, Francis; Vu, Milan; Rahimzadeh, Shadi; Castro-Gutierrez, Victor; Stanton, Isobel; Burczynska, Beata; Wildeboer, Dirk; Baio, Gianluca; Brown, Mathew R.; Garelick, Hemda; Hofman, Jan; Kasprzyk-Hordern, Barbara; Majeed, Azeem; Priest, Sally; Denise, Hubert; Khalifa, Mohammad; Bassano, Irene; Wade, Matthew J.; Grimsley, Jasmine; Lundy, Lian; Singer, Andrew C.; Di Cesare, Mariachiara
    Background: Schools are high-risk settings for infectious disease transmission. Wastewater monitoring for infectious diseases has been used to identify and mitigate outbreaks in many near-source settings during the COVID-19 pandemic, including universities and hospitals but less is known about the technology when applied for school health protection. This study aimed to implement a wastewater surveillance system to detect SARS-CoV-2 and other public health markers from wastewater in schools in England. Methods: A total of 855 wastewater samples were collected from 16 schools (10 primary, 5 secondary and 1 post-16 and further education) over 10 months of school term time. Wastewater was analysed for SARS-CoV-2 genomic copies of N1 and E genes by RT-qPCR. A subset of wastewater samples was sent for genomic sequencing, enabling determination of the presence of SARS-CoV-2 and emergence of variant(s) contributing to COVID-19 infections within schools. In total, >280 microbial pathogens and >1200 AMR genes were screened using RT-qPCR and metagenomics to consider the utility of these additional targets to further inform on health threats within the schools. Results: We report on wastewater-based surveillance for COVID-19 within English primary, secondary and further education schools over a full academic year (October 2020 to July 2021). The highest positivity rate (80.4%) was observed in the week commencing 30th November 2020 during the emergence of the Alpha variant, indicating most schools contained people who were shedding the virus. There was high SARS-CoV-2 amplicon concentration (up to 9.2x106 GC/L) detected over the summer term (8th June - 6th July 2021) during Delta variant prevalence. The summer increase of SARS-CoV-2 in school wastewater was reflected in age-specific clinical COVID-19 cases. Alpha variant and Delta variant were identified in the wastewater by sequencing of samples collected from December to March and June to July, respectively. Lead/lag analysis between SARS-CoV-2 concentrations in school and WWTP data sets show a maximum correlation between the two-time series when school data are lagged by two weeks. Furthermore, wastewater sample enrichment coupled with metagenomic sequencing and rapid informatics enabled the detection of other clinically relevant viral and bacterial pathogens and AMR. Conclusions: Passive wastewater monitoring surveillance in schools can identify cases of COVID-19. Samples can be sequenced to monitor for emerging and current variants of concern at the resolution of school catchments. Wastewater based monitoring for SARS-CoV-2 is a useful tool for SARS-CoV-2 passive surveillance and could be applied for case identification and containment, and mitigation in schools and other congregate settings with high risks of transmission. Wastewater monitoring enables public health authorities to develop targeted prevention and education programmes for hygiene measures within undertested communities across a broad range of use cases.