Browsing by Autor "Jorge Agramont"

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Antibiotic resistance genes and class 1 integron: Evidence of fecal pollution as a major driver for their abundance in water and sediments impacted by metal contamination and wastewater in the Andean region of Bolivia
(2020) Jorge Agramont; Sergio Gutiérrez-Cortez; Enrique Joffré; Åsa Sjöling; Carla Calderon Toledo
Abstract Water and sediment samples affected by mining activities were collected from three lakes in Bolivia, the pristine Andean lake Pata Khota, the Milluni Chico lake directly impacted by acid mine drainage, and the Uru-Uru lake located close to Oruro city and highly polluted by mining activities and human wastewater discharges. Physicochemical parameters, including metal compositions, were analyzed in water and sediment samples. Antibiotic resistance genes (ARGs), were screened for, and verified by quantitative PCR together with the mobile element class 1 integron ( intl1 ) as well as crAssphage, a marker of human fecal pollution. The gene intl1 showed a positive correlation with sul1, sul2, tetA and blaOXA-2 . CrAssphage was only detected in Uru-Uru lake and its tributaries and significantly higher abundance of ARGs were found in these sites. Multivariate analysis showed that crAssphage abundance, electrical conductivity and pH were positively correlated with higher levels of intl1 and ARGs. Taken together our results suggest that fecal pollution is the major driver of higher ARGs and intl1 in wastewater and mining contaminated environments.
Circulation of enterotoxigenic Escherichia coli (ETEC) isolates expressing CS23 from the environment to clinical settings
(American Society for Microbiology, 2023) Carla Calderon Toledo; Astrid von Mentzer; Jorge Agramont; Kaisa Thorell; Yingshun Zhou; Miklós Szabó; Patricia Colque; Inger Kühn; Sergio Gutiérrez-Cortez; Enrique Joffré
The importance of clean water cannot be overstated. It is a vital resource for maintaining health and well-being. Unfortunately, water sources contaminated with fecal discharges from animal and human origin due to a lack of wastewater management pose a significant risk to communities, as they can become a means of transmission of pathogenic bacteria like enterotoxigenic E. coli (ETEC). ETEC is frequently found in polluted water in countries with a high prevalence of diarrheal diseases, such as Bolivia. This study provides novel insights into the circulation of ETEC between diarrheal cases and polluted water sources in areas with high rates of diarrheal disease. These findings highlight the Choqueyapu River as a potential reservoir for emerging pathogens carrying antibiotic-resistance genes, making it a crucial area for monitoring and intervention. Furthermore, the results demonstrate the feasibility of a low-cost, high-throughput method for tracking bacterial pathogens in low- and middle-income countries, making it a valuable tool for One Health monitoring efforts.
Circulation of enterotoxigenic Escherichia coli (ETEC) isolates expressing CS23 from the environment to clinical settings
(2023) Carla Calderon Toledo; Astrid von Mentzer; Jorge Agramont; Kaisa Thorell; Yingshun Zhou; Miklós Szabó; Patricia Colque; Inger Kühn; Sergio Gutiérrez-Cortez; Enrique Joffré
Abstract Enterotoxigenic Escherichia coli (ETEC) is one of the leading causes of infant diarrhea in low- and middle-income countries (LMICs). Diarrheal pathogens are transmitted through environmental reservoirs; however, the bacterial clones that spread across the human-environment interphases remind unexplored. We aimed to determine the relationship and clonal dissemination of ETEC between children with diarrhea (> 5 years of age) and polluted water samples from local river in La Paz, Bolivia. Our study used whole genome sequencing and phenotypic fingerprinting system (PhenePlates) to analyze ETEC strains. We showed that ST218 and ST410 LT+STh CS23 ETEC were found with high frequency in both samples. The CS23 ETEC isolates were found within several STs, E. coli phylogroups A, B1, C, and D, and across ETEC lineages. Our comparative genomic analysis and PhenePlate screening of globally distributed clinical ETEC strains suggested that virulent CS23 plasmids acquisition occurs independently of the bacterial chromosomal background. Environmental strains were more often multidrug-resistant (MDR) than clinical isolates and harbored the class 1 integron-integrase gene intI1 next to the MDR cassettes. Retrospective analysis of antibiotic resistance in ETEC revealed a high frequency of MDR in clinical isolates. The LT+STh CS23 ETEC isolates showed an increased biofilm ability at environmental temperature, equal cytotoxicity, and significantly lower adherence to human epithelial cells compared to ETEC expressing other CFs. Together, our findings suggest that CS23 is more prevalent in ETEC than previously estimated, and the Choqueyapu River is a reservoir for LT+STh CS23 ETEC containing strains capable of causing diarrheal cases in children. Importance The importance of clean water cannot be overstated. It is a vital resource for maintaining health and well-being. Unfortunately, water sources contaminated with fecal discharges from animal and human origin due to a lack of wastewater management poses a significant risk to communities, as they can become a means of transmission pathogenic bacteria like enterotoxigenic E. coli (ETEC). ETEC is frequently found in polluted water in countries with a high prevalence of diarrheal diseases, such as Bolivia. This study provides novel insights into the circulation of ETEC between diarrheal cases and polluted water sources in areas with high rates of diarrheal disease. The findings highlight the Choqueyapu River as a potential reservoir for emerging pathogens carrying antibiotic-resistance genes, making it a crucial area for monitoring and intervention. Furthermore, the results demonstrate the feasibility of a low-cost, high-throughput method for tracking bacterial pathogens in low- and middle-income countries, making it a valuable tool for One Health monitoring efforts.
Conjugative transfer of multi-drug resistance IncN plasmids from environmental waterborne bacteria to Escherichia coli
(Frontiers Media, 2022) Jessica Guzman-Otazo; Enrique Joffré; Jorge Agramont; Nataniel Mamani; Jekaterina Jutkina; Fredrik Boulund; Yue Hu; Daphne Jumilla-Lorenz; Anne Farewell; D. G. Joakim Larsson
Watersheds contaminated with municipal, hospital, and agricultural residues are recognized as reservoirs for bacteria carrying antibiotic resistance genes (ARGs). The objective of this study was to determine the potential of environmental bacterial communities from the highly contaminated La Paz River basin in Bolivia to transfer ARGs to an Escherichia coli lab strain used as the recipient. Additionally, we tested ZnSO4 and CuSO4 at sub-inhibitory concentrations as stressors and analyzed transfer frequencies (TFs), diversity, richness, and acquired resistance profiles. The bacterial communities were collected from surface water in an urban site close to a hospital and near an agricultural area. High transfer potentials of a large set of resistance factors to E. coli were observed at both sites. Whole-genome sequencing revealed that putative plasmids belonging to the incompatibility group N (IncN, IncN2, and IncN3) were predominant among the transconjugants. All IncN variants were verified to be mobile by a second conjugation step. The plasmid backbones were similar to other IncN plasmids isolated worldwide and carried a wide range of ARGs extensively corroborated by phenotypic resistance patterns. Interestingly, all transconjugants also acquired the class 1 integron intl1, which is commonly known as a proxy for anthropogenic pollution. The addition of ZnSO4 and CuSO4 at sub-inhibitory concentrations did not affect the transfer rate. Metal resistance genes were absent from most transconjugants, suggesting a minor role, if any, of metals in the spread of multidrug-resistant plasmids at the investigated sites.
Fecal Pollution Drives Antibiotic Resistance and Class 1 Integron Abundance in Aquatic Environments of the Bolivian Andes Impacted by Mining and Wastewater
(Multidisciplinary Digital Publishing Institute, 2020) Jorge Agramont; Sergio Gutiérrez-Cortez; Enrique Joffré; Åsa Sjöling; Carla Calderon Toledo
An increased abundance of antibiotic resistance genes (ARGs) in aquatic environments has been linked to environmental pollution. Mining polluted sites with high concentration of metals could favor the in situ coselection of ARGs, whereas wastewater discharges release fecal antibiotic resistant bacteria in the environment. To study the effect of human fecal contamination and mining pollution, water and sediment samples affected by mining activities and sewage discharges were collected from three lakes in Bolivia, the pristine Andean lake Pata Khota, the Milluni Chico lake directly impacted by acid mine drainage, and the Uru-Uru lake located close to Oruro city and highly polluted by mining activities and human wastewater discharges. Physicochemical parameters, including metal composition, were analyzed in water and sediment samples. ARGs were screened for and verified by quantitative polymerase chain reaction (PCR) together with the mobile element class 1 integron (intl1), as well as crAssphage, a marker of human fecal pollution. The gene intl1 was positively correlated with sul1, sul2, tetA, and blaOXA-2. CrAssphage was only detected in the Uru-Uru lake, and its tributaries and significantly higher abundance of ARGs were found in these sites. Multivariate analysis showed that crAssphage abundance, electrical conductivity, and pH were positively correlated with higher levels of intl1 and ARGs. Taken together, our results suggest that fecal pollution is the major driver of higher levels of ARGs and intl1 in environments contaminated by wastewater and mining activities.
Prevalence of enteric pathogens in mothers and children from communities in the La Paz River Basin Bolivia; associations with water, sanitation, and hygiene conditions
(UWA Publishing, 2026) Cinthia Copeticona-Callejas; Sònia Jiménez; Alejandra Torrez-Mamani; Belén Choque-Pardo; Jorge Agramont; Josué Mamani-Jarro; Lucia Inchauste; Stéphane Priet; Adriana Espinoza Soto; Carla Liera
Enteric infections remain a major public health challenge in low- and middle-income countries, disproportionately affecting young children. We conducted a cross-sectional study to characterize the prevalence of enteropathogens among mothers and children from peri-urban and rural communities in the La Paz River Basin Bolivia, and to examine associations with water, sanitation, and hygiene (WASH) conditions. Fecal samples were analyzed by real-time PCR to detect 21 viral, bacterial, and parasitic pathogens, alongside household surveys and water quality assessments. Sixteen pathogens were detected, 85% of participants carried at least one pathogen, with frequent coinfections. The most prevalent pathogens were Helicobacter pylori, adenovirus, EPEC, Giardia lamblia, and Shigella. Pathogen carriage was higher in rural than in peri-urban settings, with bacterial infections predominating in the lower basin and viral infections in the upper basin. Children carried more viral and parasitic pathogens, while mothers had more bacterial pathogens. Significant mother-child concordance was observed for several pathogens, supporting shared household exposures. Enteric pathogen carriage was strongly associated with drinking water source, sanitation practices, housing quality, and hygiene behaviors, particularly reliance on cistern/spring water, open defecation, and inadequate hand hygiene. These findings highlight a substantial and heterogeneous burden of enteric infections, underscoring the need for integrated WASH interventions.