H. Schmitt
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18 records found
1
The global rise of extended-spectrum β-lactamase (ESBL) and plasmid-borne cephalosporinase (pAmpC) producing Enterobacterales is a major health concern. Their increasing prevalence in both humans and animals underscores the need for One Health surveillance, for which Escherichia coli has been recognized as a key indicator. While many studies have investigated the circulation of ESBL/pAmpC-producing E. coli (ESBL/pAmpC-Ec) across human, animal, and environmental sectors, the extent to which animals contribute to human acquisition remains unclear.
Objectives
This review provides an overview of the intersectoral circulation of ESBL/pAmpC-Ec and evaluates the potential role of animals as a reservoir for human colonization.
Sources
Publications (2010–2024) identified through PubMed, Scopus, and Google Scholar, on ESBL/pAmpC-Ec circulation across human, animal, and environmental sectors (excluding studies on human-environment, animal-environment, and human-food only) were reviewed considering the included sectors, comparison methods, and geographical context.
Content
Surveillance approaches varied widely between studies, shaped by sampling strategies, geographical context, and isolated comparison methods. Advances in genomic methods have refined our understanding of ESBL/pAmpC-Ec circulation between sectors. Early studies, mostly conducted in high-income countries (HICs), suggested human-animal transmission based on comparisons of ESBL/pAmpC-Ec sequence types, resistance genes, and plasmid replicons. However, these findings were challenged by the introduction of more discriminating comparison methods such as whole-genome sequencing, which revealed a largely compartmentalized circulation of ESBL/pAmpC-Ec in HICs. Similar studies in low- and middle-income countries (LMICs) shifted this paradigm, demonstrating frequent cross-sectoral transmission across humans, animals, and the environment. Many authors also highlighted the likely underestimated role of plasmids in the circulation of ESBL/pAmpC genes.
Implications
Despite the heterogeneity of the studies, two distinct scenarios emerged: predominantly intrasectoral ESBL/pAmpC-Ec circulation in HICs and significant intersectoral circulation in LMICs. These findings underscore the need for region-specific antimicrobial resistance control strategies, focusing on limiting human-to-human transmission in HICs and enhancing sanitation and biosecurity in LMICs. ...
The global rise of extended-spectrum β-lactamase (ESBL) and plasmid-borne cephalosporinase (pAmpC) producing Enterobacterales is a major health concern. Their increasing prevalence in both humans and animals underscores the need for One Health surveillance, for which Escherichia coli has been recognized as a key indicator. While many studies have investigated the circulation of ESBL/pAmpC-producing E. coli (ESBL/pAmpC-Ec) across human, animal, and environmental sectors, the extent to which animals contribute to human acquisition remains unclear.
Objectives
This review provides an overview of the intersectoral circulation of ESBL/pAmpC-Ec and evaluates the potential role of animals as a reservoir for human colonization.
Sources
Publications (2010–2024) identified through PubMed, Scopus, and Google Scholar, on ESBL/pAmpC-Ec circulation across human, animal, and environmental sectors (excluding studies on human-environment, animal-environment, and human-food only) were reviewed considering the included sectors, comparison methods, and geographical context.
Content
Surveillance approaches varied widely between studies, shaped by sampling strategies, geographical context, and isolated comparison methods. Advances in genomic methods have refined our understanding of ESBL/pAmpC-Ec circulation between sectors. Early studies, mostly conducted in high-income countries (HICs), suggested human-animal transmission based on comparisons of ESBL/pAmpC-Ec sequence types, resistance genes, and plasmid replicons. However, these findings were challenged by the introduction of more discriminating comparison methods such as whole-genome sequencing, which revealed a largely compartmentalized circulation of ESBL/pAmpC-Ec in HICs. Similar studies in low- and middle-income countries (LMICs) shifted this paradigm, demonstrating frequent cross-sectoral transmission across humans, animals, and the environment. Many authors also highlighted the likely underestimated role of plasmids in the circulation of ESBL/pAmpC genes.
Implications
Despite the heterogeneity of the studies, two distinct scenarios emerged: predominantly intrasectoral ESBL/pAmpC-Ec circulation in HICs and significant intersectoral circulation in LMICs. These findings underscore the need for region-specific antimicrobial resistance control strategies, focusing on limiting human-to-human transmission in HICs and enhancing sanitation and biosecurity in LMICs.
Integrating AMR surveillance into wastewater monitoring systems in 2025
A position on the implementation of Article 17 of the Urban Wastewater Treatment Directive (UWWTD)
Sources and Transmission Routes of Carbapenem-Resistant Pseudomonas aeruginosa
Study Design and Methodology of the SAMPAN Study
Background/Objectives: The global spread of carbapenem-resistant Pseudomonas aeruginosa (CRPA) warrants collaborative action. Guidance should come from integrated One Health surveillance; however, a surveillance strategy is currently unavailable due to insufficient knowledge on the sources and transmission routes of CRPA. The aim of the SAMPAN study (“A Smart Surveillance Strategy for Carbapenem-resistant Pseudomonas aeruginosa”) is to develop a globally applicable surveillance strategy. Methods: First, an international cross-sectional study will be conducted to investigate CRPA in clinical and environmental settings in Rotterdam (The Netherlands), Rome (Italy), and Jakarta (Indonesia). Screening cultures and risk factor questionnaires will be taken from healthy individuals and patients upon hospital admission. Clinical CRPA isolates will also be included. Additionally, samples will be taken twice from wet hospital environments and monthly from the hospitals’ (drinking) water system, hospital and municipal wastewater treatment plants, and receiving rivers. Whole-genome sequencing will be performed to characterize CRPA isolates and determine the genetic relatedness among the isolates from different reservoirs. Findings from the cross-sectional study, combined with expert elicitation using a Delphi method, will serve as the input for the surveillance strategy. Conclusions: The SAMPAN study will provide a broader understanding of the sources and transmission routes of CRPA. Therewith, the development of a globally applicable smart surveillance strategy will be made possible, delivering information that is needed to guide actions against the spread of CRPA.
The first therapeutic use of antimicrobial agents initiated their endless arms race with antimicrobial resistance (AMR). Although the genes encoding antimicrobial resistance are ancient and ubiquitous in various environmental compartments, including aquatic environments, over eight decades of exposure to selective pressure has changed the way antimicrobial resistance genes (ARGs) emerge and transmit among the three One Health sectors (that is, the intersected sectors of humans, animals and the environment). The dissemination of ARGs has been facilitated by the widespread use of antimicrobials, along with direct and secondary pollution pathways. Current global consensus dictates that AMR should be addressed under a One Health framework. AMR National Action Plans have frequently been formulated. However, the capacity for implementation is not ready in most countries, especially in low- and middle-income regions. This is in part due to the substantial challenges in documenting and controlling cross-sector AMR connectivity. Here we describe the past and current status of AMR, emphasizing the contribution of connectivity to global AMR burden. We discuss connectivity at ecological, microbial and genetic levels; propose an approach based on genomics and metagenomics to assess connectivity; and finally advocate for cross-sector studies to better understand AMR connectivity and mitigate dissemination. We believe that such harmonized connectivity studies will facilitate coordinated actions and investments across sectors and regions to scale up AMR management globally.
Pseudomonas aeruginosa may colonize humans, however, epidemiological data are scarce. Here, we determined overall and body site-specific carriage rates and associated risk factors among healthy individuals and newly admitted patients in three major cities. This cross-sectional study was conducted in Rotterdam (The Netherlands), Rome (Italy), and Jakarta (Indonesia) between 2022–2024. Adult healthy individuals and newly admitted patients were asked to provide throat, navel, and rectal/perianal swabs, and to complete a questionnaire. Univariable and multivariable analyses were performed to determine factors associated with P. aeruginosa carriage. Carriage rates differed significantly between cities (p < 0.001), and were lowest in Rome (healthy individuals 4.8%; patients 6.5%), followed by Rotterdam (healthy individuals 12.0%; patients 12.7%), and Jakarta (healthy individuals 28.6%; patients 24.0%). In carriers from Rotterdam, P. aeruginosa was most often detected in perianal swabs, while mostly in throat swabs among carriers from Rome and Jakarta. P. aeruginosa carriage had a seasonal association in patients from Rotterdam (p = 0.014) and Jakarta (p = 0.020). Among patients from Jakarta, female sex (aOR 1.98, 95% CI 1.02–3.84; p = 0.045) was associated with P. aeruginosa carriage. Overall, P. aeruginosa carriage rates and colonized body sites differ between cities and are likely associated with climate differences. Our findings warrant setting-specific adaptations of screening strategies and surveillance programs.
We observed notable sorption (>40% removal) for 10 of the 24 OMPs tested in our study (Figure 1). The 10 OMPs include 3 fluoroquinolones (norfloxacin, ofloxacin, and ciprofloxacin), 3 macrolides (clarithromycin, azithromycin, and erythromycin), 2 beta-blockers (propranolol and atenolol), tetracycline, and citalopram. We noted that all of these 10 compounds are ionizable, with 6 positively charged compounds and 4 zwitterionic compounds at pH 7. Considering that sludge biomass typically has a negative charge, this seems to indicate electrostatic interactions between the 10 OMPs and th e sludge. Larger fractions contributed more to sorption than smaller granules and flocs, as expressed per unit of biomass. Specifically, the normalized Kd¬ for large fractions was up to 100%larger than for small fractions, suggesting that larger fractions contribute more to sorption in real AGS systems than smaller fractions and flocs. However, sorption kinetics were most likely retarded by diffusion limitations in large granules. Biodegradation was observed for a number of compounds. Overall, this study elucidated the roles of sorption and biodegradation in the removal of OMPs in AGS WWTPs, showing that these processes are size fraction dependent. ...
We observed notable sorption (>40% removal) for 10 of the 24 OMPs tested in our study (Figure 1). The 10 OMPs include 3 fluoroquinolones (norfloxacin, ofloxacin, and ciprofloxacin), 3 macrolides (clarithromycin, azithromycin, and erythromycin), 2 beta-blockers (propranolol and atenolol), tetracycline, and citalopram. We noted that all of these 10 compounds are ionizable, with 6 positively charged compounds and 4 zwitterionic compounds at pH 7. Considering that sludge biomass typically has a negative charge, this seems to indicate electrostatic interactions between the 10 OMPs and th e sludge. Larger fractions contributed more to sorption than smaller granules and flocs, as expressed per unit of biomass. Specifically, the normalized Kd¬ for large fractions was up to 100%larger than for small fractions, suggesting that larger fractions contribute more to sorption in real AGS systems than smaller fractions and flocs. However, sorption kinetics were most likely retarded by diffusion limitations in large granules. Biodegradation was observed for a number of compounds. Overall, this study elucidated the roles of sorption and biodegradation in the removal of OMPs in AGS WWTPs, showing that these processes are size fraction dependent.
Healthcare-based surveillance (HBS) of AMR provides incomplete information about the scope of the AMR threat. HBS screens only patients seeking medical attention, lacking community-level representativeness, and suffers from underreporting. (2) Consequently, researchers are turning to wastewater-based surveillance (WBS) to complement HBS. (3) WBS can provide information about AMR circulating within communities and hospitals, offering a comprehensive understanding of AMR prevalence. However, the surveillance targets and data obtained from WBS are distinct from those derived from HBS, creating uncertainty regarding their utility to the public health sector and ability to yield policy relevant information. In May 2024, participants in a workshop during the 7th Environmental Dimension of Antimicrobial Resistance (EDAR7) conference (Montréal, Canada) sought to answer four questions aimed at advancing the policy relevance of AMR data generated by WBS. ...
Healthcare-based surveillance (HBS) of AMR provides incomplete information about the scope of the AMR threat. HBS screens only patients seeking medical attention, lacking community-level representativeness, and suffers from underreporting. (2) Consequently, researchers are turning to wastewater-based surveillance (WBS) to complement HBS. (3) WBS can provide information about AMR circulating within communities and hospitals, offering a comprehensive understanding of AMR prevalence. However, the surveillance targets and data obtained from WBS are distinct from those derived from HBS, creating uncertainty regarding their utility to the public health sector and ability to yield policy relevant information. In May 2024, participants in a workshop during the 7th Environmental Dimension of Antimicrobial Resistance (EDAR7) conference (Montréal, Canada) sought to answer four questions aimed at advancing the policy relevance of AMR data generated by WBS.
The results show that Influent concentrations of 5 pharmaceuticals and 1 industrial compound exceeded 1 ?g L-1, which were diluted by rainfall. Influent loadings of 7 OMPs (absolute OMP amount in ?g day -1) were significantly increased during wet weather, likely from sewage sediment resuspen sion and urban runoff. Average removal efficiencies of 11 compounds achieved greater than 20%, with 5 of them exceeding 50%, in the AGS plants. Simple linear regression results between OMP removal efficiencies and flow rates showed that biodegradable OMPs were more strongly affected by increased influent volumes (as indicated by steeper slopes) than OMPs primarily removed through sorption. Additionally, correlation analysis results showed that the removal of soluble organic matter was significantly correlated (p-value < 0.05) with the removal of 14 OMPs, suggesting that organic matter removal may be an indicator for OMP removal in the AGS plant. After AGS treatment, 8 compounds in the effluent remained above their predicted no-effect concentration levels, indicating potential ecological and human health risks in the receiving water. During wet weather, effluent OMP loadings increased mainly driven by reduced removal efficiency. Additionally, compared to activated sludge plants, the AGS plant exhibited comparable or slightly higher OMP removal efficiency during dry weather. Overall, this study is the first to investigate OMP removal during wet weather in a full-scale AGS plant and propose the potential impact of increased flow rates on biodegradable OMPs or OMPs mainly removed through sorption. ...
The results show that Influent concentrations of 5 pharmaceuticals and 1 industrial compound exceeded 1 ?g L-1, which were diluted by rainfall. Influent loadings of 7 OMPs (absolute OMP amount in ?g day -1) were significantly increased during wet weather, likely from sewage sediment resuspen sion and urban runoff. Average removal efficiencies of 11 compounds achieved greater than 20%, with 5 of them exceeding 50%, in the AGS plants. Simple linear regression results between OMP removal efficiencies and flow rates showed that biodegradable OMPs were more strongly affected by increased influent volumes (as indicated by steeper slopes) than OMPs primarily removed through sorption. Additionally, correlation analysis results showed that the removal of soluble organic matter was significantly correlated (p-value < 0.05) with the removal of 14 OMPs, suggesting that organic matter removal may be an indicator for OMP removal in the AGS plant. After AGS treatment, 8 compounds in the effluent remained above their predicted no-effect concentration levels, indicating potential ecological and human health risks in the receiving water. During wet weather, effluent OMP loadings increased mainly driven by reduced removal efficiency. Additionally, compared to activated sludge plants, the AGS plant exhibited comparable or slightly higher OMP removal efficiency during dry weather. Overall, this study is the first to investigate OMP removal during wet weather in a full-scale AGS plant and propose the potential impact of increased flow rates on biodegradable OMPs or OMPs mainly removed through sorption.
Modelling Escherichia coli concentrations
45.6 %–78.1 % of China's rivers show poor microbial water quality
Each year, an estimated 7·7 million deaths are attributed to bacterial infections, of which 4.95 million are associated with drug-resistant pathogens, and 1·27 million are caused by bacterial pathogens resistant to the antibiotics available. Access to effective antibiotics when indicated prolongs life, reduces disability, reduces health-care expenses, and enables access to other life-saving medical innovations. Antimicrobial resistance undoes these benefits and is a major barrier to attainment of the Sustainable Development Goals, including targets for newborn survival, progress on healthy ageing, and alleviation of poverty. Adverse consequences from antimicrobial resistance are seen across the human life course in both health-care-associated and community-associated infections, as well as in animals and the food chain. The small set of effective antibiotics has narrowed, especially in resource-poor settings, and people who are very young, very old, and severely ill are particularly susceptible to resistant infections. This paper, the first in a Series on the challenge of antimicrobial resistance, considers the global scope of the problem and how it should be measured. Robust and actionable data are needed to drive changes and inform effective interventions to contain resistance. Surveillance must cover all geographical regions, minimise biases towards hospital-derived data, and include non-human niches.
Surveillance of antibiotic resistance genes (ARGs) has been increasingly conducted in environmental sectors to complement the surveys in human and animal sectors under the "One-Health"framework. However, there are substantial challenges in comparing and synthesizing the results of multiple studies that employ different test methods and approaches in bioinformatic analysis. In this article, we consider the commonly used quantification units (ARG copy per cell, ARG copy per genome, ARG density, ARG copy per 16S rRNA gene, RPKM, coverage, PPM, etc.) for profiling ARGs and suggest a universal unit (ARG copy per cell) for reporting such biological measurements of samples and improving the comparability of different surveillance efforts.
Evaluation of Membrane Integrity Monitoring Methods for Hollow Fiber Nanofiltration Membranes
Applicability in Gray Water Reclamation Systems
Source-separated gray water reclamation using nanofiltration as an advanced post-treatment option has received substantial interest in meeting the growing water demand. During reclamation, membrane integrity is crucial to ensure the water’s safety. This study evaluated several chemical and novel microbial indicators as indirect membrane integrity-monitoring methods for hollow fiber nanofiltration membranes in reclamation schemes. Under normal conditions, high retention of divalent ions and organic matter and near-complete removal of Escherichia coli (E. coli) were observed. Limited removal of the antibiotic gene (ARG) tetO was observed due to low feed concentrations and a higher detection limit (LOD). While 16S rRNA and ARG sul1 were not limited by their LODs, lower removals were observed, most likely due to free-floating DNA passing through the membranes. A broken fiber in a pilot-scale module reduced organic matter and microorganism removal substantially, while flux and ion rejection remained similar. Predictions made using the observed results and a previously proposed model allowed for the evaluation of the selected methods in upscaled reclamation systems. Based on these results, it was concluded that microorganisms could be employed as indicators in indirect membrane integrity-monitoring methods in large-scale reclamation schemes, while UV254nm absorbance (used in organic matter determination) could be a viable solution in pilot-scale systems.