Browsing by Autor "Jessica Guzman-Otazo"

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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.
Diarrheal bacterial pathogens and multi-resistant enterobacteria in the Choqueyapu River in La Paz, Bolivia
(Public Library of Science, 2019) Jessica Guzman-Otazo; Lucia Gonzales‐Siles; Violeta Poma; Johan Bengtsson‐Palme; Kaisa Thorell; Carl‐Fredrik Flach; Volga Iñiguez; Åsa Sjöling
Water borne diarrheal pathogens might accumulate in river water and cause contamination of drinking and irrigation water. The La Paz River basin, including the Choqueyapu River, flows through La Paz city in Bolivia where it is receiving sewage, and residues from inhabitants, hospitals, and industry. Using quantitative real-time PCR (qPCR), we determined the quantity and occurrence of diarrheagenic Escherichia coli (DEC), Salmonella enterica, Klebsiella pneumoniae, Shigella spp. and total enterobacteria in river water, downstream agricultural soil, and irrigated crops, during one year of sampling. The most abundant and frequently detected genes were gapA and eltB, indicating presence of enterobacteria and enterotoxigenic E. coli (ETEC) carrying the heat labile toxin, respectively. Pathogen levels in the samples were significantly positively associated with high water conductivity and low water temperature. In addition, a set of bacterial isolates from water, soil and crops were analyzed by PCR for presence of the genes blaCTX-M, blaKPC, blaNDM, blaVIM and blaOXA-48. Four isolates were found to be positive for blaCTX-M genes and whole genome sequencing identified them as E. coli and one Enterobacter cloacae. The E. coli isolates belonged to the emerging, globally disseminated, multi-resistant E. coli lineages ST648, ST410 and ST162. The results indicate not only a high potential risk of transmission of diarrheal diseases by the consumption of contaminated water and vegetables but also the possibility of antibiotic resistance transfer from the environment to the community.
Genomic surveillance of SARS-CoV-2 in the Andean Community (2020–2024): integrating regional sequencing efforts from Colombia, Ecuador, Peru, and Bolivia through “ORAS-CONHU” program
(Frontiers Media, 2025) Alfredo Bruno; Doménica de Mora; Paola Rojas-Estévez; Héctor Alejandro Ruiz-Moreno; Jessica Guzman-Otazo; Omar Cáceres; Verónica Sambra; Jimmy Garcés; Maritza Olmedo; Carlos Franco-Muñoz
While each country exhibits some specific characteristics, the phylogenetic analysis underscored a common pattern in the lineage evolution of SARS-CoV-2 in the Andean Community supporting a rapid transnational transmission of the virus. This study was part of a regional effort to develop an integrative transnational genomic surveillance network for SARS-CoV-2 as a proxy for a more ambitious regional infectious diseases genomic surveillance program.
Molecular Analyses of Fecal Bacteria and Hydrodynamic Modeling for Microbial Risk Assessment of a Drinking Water Source
(Multidisciplinary Digital Publishing Institute, 2019) Olga D. Chuquimia; Viktor Bergion; Jessica Guzman-Otazo; Kaisa Sörén; Lars Rosén; Thomas J. R. Pettersson; Ekaterina Sokolova; Åsa Sjöling
Safe water is a global concern, and methods to accurately monitor quality of water are vital. To assess the risks related to bacterial pathogen load in Lake Vomb that provides drinking water to the southern part of Sweden, this study combined molecular analyses of enterobacteria and bacterial pathogens in water using quantitiative real-time PCR with hydrodynamic modeling and quantitative microbial risk assessment (QMRA). A real-time PCR assay to detect enterobacteria was set up by primers targeting ssrA. Between February 2015 and May 2016, presence of ssrA gene copies as well as Campylobacter spp., Salmonella spp., and EHEC O157 DNA was analyzed by real-time PCR at several locations in the catchment of Lake Vomb and its tributaries Björkaån, Borstbäcken, and Torpsbäcken. Björkaån had the highest detected concentrations of the ssrA gene and, according to the results of hydrodynamic modeling, contributed most to the contamination of the water intake in the lake. None of the water samples were positive for genes encoding EHEC O157 and Campylobacter spp., while invA (Salmonella spp.) was present in 11 samples. The QMRA showed that the suggested acceptable risk level (daily probability of infection <2.7 × 10−7) is achieved with a 95% probability, if the Salmonella concentrations in the water intake are below 101 bacteria/100 mL. If a UV-disinfection step is installed, the Salmonella concentration at the water intake should not exceed 106 bacteria/100 mL.