RIVAS JIMENEZ, LINA MARIA
Preferred name
RIVAS JIMENEZ, LINA MARIA
Main Affiliation
Email
lrivas@udd.cl
ORCID
0000-0002-8075-9812
Scopus Author ID
55921716700
29 results
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Item type:Product, Dataset - Geographic divergence of methicillin-resistant Staphylococcus aureus ST5-SCCmecI in the aftermath of a major earthquake and tsunami: impact of a plasmid harboring heavy metal resistance genes(United States National Library of Medicine, 2025); ; ; ;ROBERTO ANDRES RIQUELME NEIRA - Some of the metrics are blocked by yourconsent settings
Item type:Publication, P-175. Assessing the Dynamics of Fecal Colonization with Antibiotic-Resistant Bacteria in a Chilean Cohort: A Longitudinal Study(Oxford University Press (OUP), 2025-01-29) ;Rafael, Araos ;Jara, Alejandro ;Sanchez, Felipe ;Adell, AikoOlivares, JorgeBackground In low- and middle-income countries, the community burden of antibiotic-resistant Gram-negative bacteria (AR-GNB) colonization is high. Understanding factors influencing AR-GNB colonization is crucial for controlling antimicrobial resistance. Methods We conducted a cohort study from December 2019 to November 2020 with community-dwelling adults in Molina, an agricultural town in Central Chile. We collected questionnaires and fecal samples every two weeks for six months to identify colonization by extended-spectrum cephalosporin-resistant Enterobacterales (ESCRE). ESCRE detection involved selective media screening, MALDI-TOF identification, and disk-diffusion antibiotic-susceptibility testing. We assessed the impact of epidemiological and clinical features and exposure to various water sources, foods, and animals on i) baseline ESCRE fecal colonization, ii) ESCRE acquisition during follow-up, and iii) ESCRE clearance. The study included 198 subjects, using multiple imputations for missing predictor values. We used two hidden Markov models for each dataset, with Model 1 assuming perfect sensitivity and specificity and Model 2 estimating sensitivity. A Bayesian approach with Markov chain Monte Carlo algorithms estimated odds ratios (OR) and credible intervals (CI). Results The sample consisted of 198 residents with a mean age of 60.9 and a predominance of women (75%). Model 1 showed that treating drinking water before consumption reduced the risk of baseline ESCRE colonization (OR: 0.38; 95% CI: 0.02 – 0.89). No significant associations were found for ESCRE acquisition during follow-up. Males and individuals with comorbidities had a lower risk of clearing ESCRE (ORs: 0.58, 0.54; CIs: 0.24 – 0.97, 0.258 – 0.88, respectively). Model 2, with imperfect sensitivity, showed similar results. Conclusion This study highlights the significance of environmental and individual health factors in ESCRE colonization. Interventions like treating drinking water could reduce baseline ESCRE colonization risk. The varied impacts of gender and comorbidities on ESCRE clearance provide insights for targeted AR-GNB management strategies. Further research is needed to understand these associations and develop effective community-level interventions against AMR. Disclosures All Authors: No reported disclosures - Some of the metrics are blocked by yourconsent settings
Item type:Publication, P-310. Evolutionary dynamics of the Chilean-Cordobes MRSA clone allowed the emergence of new MRSA clones in Chile(Oxford University Press (OUP), 2025-01-29) ;Martínez, Jose R W ;Campbell, Amy; ; Background The global spread of methicillin-resistant Staphylococcus aureus (MRSA) is associated with distinct clones predominating in specific geographical regions. Available evidence suggests that the Chilean-Cordobes clone (ChC), an ST5-SCCmecI lineage, has predominated in Chilean hospitals ever since its first description in 1998. However, we recently reported a gradual decrease in this lineage over time, with frequencies dropping from 94% (2000) to 52% (2016). To understand this clonal replacement event, we aimed to reconstruct the genomic evolution of the ChC in Latin America. Characterization of clades and sub-lineages of the ChC clone.Figure 1.Characterization of clades and sub-lineages of the ChC clone. A) Maximum clade credibility molecular clock analysis of the 596 MRSA genomes. A Bayesian molecular clock analysis was performed with BEAST using the isolation date of each genome as calibrator. The vertical lines show the scale of years. The colored strip showed the country of origin. The dots show the presence of mecA genotypes, heavy metal resistance genes (HMRGs), and SNPs in Sau1. The branches are colored based on the sub-lineage identification: ChC-I (magenta), ChC-II (orange), and ChC-III (green). B) Characterization of the ChC clades. The presence of each genetic element considered to characterize the clades are marked by a + symbol. C) Relative frequency of the ChC sub-lineages in Chile over time. The colored bars represent the relative frequency of each sub-lineage: ChC-I (magenta), ChC-II (orange), ChC-III (green), and unclassified (gray). Methods A total of 596 ChC MRSA isolates obtained from 6 Latin American countries between 1999-2018 were whole-genome sequenced and characterized using a Bayesian molecular clock analysis (MCA). Sub-lineages (SLs) observed in major divergence events were further characterized. Additionally, the frequency of each SL observed in our 1999-2018 collection was assessed in an independent group of genomes from 274 Chilean clinical MRSA isolates collected in 2022. Results Our MCA of ChC MRSA revealed 3 clades strongly related with different genomic traits, including: i) mecA genotype, ii) heavy metal resistance genes (HMRGs), and iii) changes in the Sau1 restriction-modification system (Sau1) (Fig. 1A). Each clade was classified as sub-lineage: ChC-I, ChC-II, and ChC-III (Fig. 1B). All the genomes from Argentina, Colombia, and Venezuela – countries where ChC was largely replaced - belonged to the ChC-II SL and harbored a Sau1 mutation (Fig. 1A). On the other hand, genomes obtained from Chile distributed in different SLs and exhibited a dynamic interchange over time (Fig. 1C). While between 1999-2003 most of the genomes belonged to SLs ChC-I and ChC-II, both SLs virtually disappeared in 2013-2018, period were >90% ChC genomes corresponded to ChC-III (Fig. 1C). In 2022, a majority of ChC MRSA had genomic features compatible with the ChC-III SL (Fig. 1C). Finally, the MCA revealed an evolutionary event within ChC-III dated in 2005, which was accompanied by the loss of HMRGs (Fig. 1A) Conclusion We describe the time evolution of several ChC clades, giving rise to sub-lineages that seem to play a role in the loss of dominance of the ChC MRSA clone in Chile and a consequent change in its epidemiology in the country. Disclosures José M Munita, MD, MSD: Grant/Research Support|Pfizer: Grant/Research Support - Some of the metrics are blocked by yourconsent settings
Item type:Publication, P-2214. The Microbiome of Community-Dwelling Adults and Risk Factors for Colonization with Antibiotic-Resistant Bacteria in Chile(Oxford University Press (OUP), 2025-01-29) ;Rafael, Araos ;Ugalde, Juan ;Jara, Alejandro ;Sanchez, FelipeBackground Intestinal colonization due to antibiotic-resistant bacteria (ARB) often precedes episodes of infection and fosters the spread of antibiotic resistance. This study explores the clinical, epidemiological, and microbiome factors associated with ARB colonization in Chilean adults. Methods A cross-sectional study of 357 community-dwelling individuals from a community in central Chile was conducted between December 2018 - May 2019, using stool samples and health questionnaires. Stool samples were cultured on selective media, followed by identification with MALDI-TOF and disc diffusion susceptibility method. Fecal microbiome assessments were conducted using 16S rRNA gene sequencing performed on Illumina MiSeq. ARB colonization was defined as phenotypic resistance of recovered isolates to extended-spectrum cephalosporins, fluoroquinolones, and/or carbapenems. Associations between colonization and clinical and epidemiological factors were analyzed through classification trees and logistic regression, while diversity and composition of microbiomes were compared between participants based on colonization status. Results No exposures were associated with the risk of ARB colonization. The microbiomes of colonized individuals featured Firmicutes, with Bacteroidetes, Actinobacteria, and Proteobacteria also present, paralleling the microbiome profile of the non-colonized individuals. However, ARB-colonized individuals had an overrepresentation of Escherichia/Shigella, Klebsiella, and Enterococcus genera. There were no differences in alpha or beta diversity by ARB colonization status. Conclusion The lack of risk factors regarding ARB colonization suggests that such colonization might occur without overt selective pressures. However, the overrepresentation of specific genera in colonized individuals could subtly indicate the influence of unrecognized selective pressures, such as environmental exposure to antibiotic residues. This scenario underscores the complexity of ARB dynamics and the need for further studies to explore potential environmental and indirect factors contributing to ARB colonization in the community setting. Disclosures All Authors: No reported disclosures - Some of the metrics are blocked by yourconsent settings
Item type:Product, Dataset - Dynamics of the MRSA Population in a Chilean Hospital: a Phylogenomic Analysis (2000-2016)(2023) ;MARTINEZ SOLIS, JOSE RODRIGO WALDEMAR ;SPENCER SANDINO, MARÍA DE LOS ÁNGELES; ;DIAZ ORTIZ, SANDRA5 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ceftazidime/avibactam resistance is associated with PER-3-producing ST309 lineage in Chilean clinical isolates of non-carbapenemase producing Pseudomonas aeruginosa(2024) ;Katherine D. Soto; ;UGALDE, JUAN ANTONIO ;Jorge Olivares PachecoValeria Quiroz<jats:sec><jats:title>Introduction</jats:title><jats:p>Ceftazidime/avibactam (CZA) is indicated against multidrug-resistant <jats:italic>Pseudomonas aeruginosa</jats:italic>, particularly those that are carbapenem resistant. CZA resistance in <jats:italic>P. aeruginosa</jats:italic> producing PER, a class A extended-spectrum β-lactamase, has been well documented <jats:italic>in vitro</jats:italic>. However, data regarding clinical isolates are scarce. Our aim was to analyze the contribution of PER to CZA resistance in non-carbapenemase-producing <jats:italic>P. aeruginosa</jats:italic> clinical isolates that were ceftazidime and/or carbapenem non-susceptible.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Antimicrobial susceptibility was determined through agar dilution and broth microdilution, while <jats:italic>bla</jats:italic><jats:sub>PER</jats:sub> gene was screened through PCR. All PER-positive isolates and five PER-negative isolates were analyzed through Whole Genome Sequencing. The mutational resistome associated to CZA resistance was determined through sequence analysis of genes coding for PBPs 1b, 3 and 4, MexAB-OprM regulators MexZ, MexR, NalC and NalD, AmpC regulators AmpD and AmpR, and OprD porin. Loss of <jats:italic>bla</jats:italic><jats:sub>PER-3</jats:sub> gene was induced in a PER-positive isolate by successive passages at 43°C without antibiotics. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Twenty-six of 287 isolates studied (9.1%) were CZA-resistant. Thirteen of 26 CZA-resistant isolates (50%) carried <jats:italic>bla</jats:italic><jats:sub>PER</jats:sub>. One isolate carried <jats:italic>bla</jats:italic><jats:sub>PER</jats:sub> but was CZA-susceptible. PER-producing isolates had significantly higher MICs for CZA, amikacin, gentamicin, ceftazidime, meropenem and ciprofloxacin than non-PER-producing isolates. All PER-producing isolates were ST309 and their <jats:italic>bla</jats:italic><jats:sub>PER-3</jats:sub> gene was associated to ISCR1, an insertion sequence known to mobilize adjacent DNA. PER-negative isolates were classified as ST41, ST235 (two isolates), ST395 and ST253. PER-negative isolates carried genes for narrow-spectrum β-lactamases and the mutational resistome showed that all isolates had one major alteration in at least one of the genes analyzed. Loss of <jats:italic>bla</jats:italic><jats:sub>PER-3</jats:sub> gene restored susceptibility to CZA, ceftolozane/tazobactam and other β-lactamsin the <jats:italic>in vitro</jats:italic> evolved isolate. </jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>PER-3-producing ST309 <jats:italic>P. aeruginosa</jats:italic> is a successful multidrug-resistant clone with <jats:italic>bla<jats:sub>PER-3</jats:sub></jats:italic> gene implicated in resistance to CZA and other β-lactams.</jats:p></jats:sec>4Scopus© Citations 7 - Some of the metrics are blocked by yourconsent settings
Item type:Product, 11 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Antibiotic Consumption During the Coronavirus Disease 2019 Pandemic and Emergence of Carbapenemase-Producing <i>Klebsiella pneumoniae</i> Lineages Among Inpatients in a Chilean Hospital: A Time-Series Study and Phylogenomic Analysis(2023) ;Kasim Allel ;Anne Peters ;José Conejeros ;José R W MartínezMaria Spencer-Sandino<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>The impact of coronavirus disease 2019 (COVID-19) on antimicrobial use (AU) and resistance has not been well evaluated in South America. These data are critical to inform national policies and clinical care.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>At a tertiary hospital in Santiago, Chile, between 2018 and 2022, subdivided into pre- (3/2018–2/2020) and post–COVID-19 onset (3/2020–2/2022), we evaluated intravenous AU and frequency of carbapenem-resistant Enterobacterales (CRE). We grouped monthly AU (defined daily doses [DDD]/1000 patient-days) into broad-spectrum β-lactams, carbapenems, and colistin and used interrupted time-series analysis to compare AU during pre- and post-pandemic onset. We studied the frequency of carbapenemase-producing (CP) CRE and performed whole-genome sequencing analyses of all carbapenem-resistant (CR) Klebsiella pneumoniae (CRKpn) isolates collected during the study period.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Compared with pre-pandemic, AU (DDD/1000 patient-days) significantly increased after the pandemic onset, from 78.1 to 142.5 (P &lt; .001), 50.9 to 110.1 (P &lt; .001), and 4.1 to 13.3 (P &lt; .001) for broad-spectrum β-lactams, carbapenems, and colistin, respectively. The frequency of CP-CRE increased from 12.8% pre–COVID-19 to 51.9% after pandemic onset (P &lt; .001). The most frequent CRE species in both periods was CRKpn (79.5% and 76.5%, respectively). The expansion of CP-CRE harboring blaNDM was particularly noticeable, increasing from 40% (n = 4/10) before to 73.6% (n = 39/53) after pandemic onset (P &lt; .001). Our phylogenomic analyses revealed the emergence of two distinct genomic lineages of CP-CRKpn: ST45, harboring blaNDM, and ST1161, which carried blaKPC.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>AU and the frequency of CP-CRE increased after COVID-19 onset. The increase in CP-CRKpn was driven by the emergence of novel genomic lineages. Our observations highlight the need to strengthen infection prevention and control and antimicrobial stewardship efforts.</jats:p> </jats:sec>30Scopus© Citations 36 - Some of the metrics are blocked by yourconsent settings
Item type:Product, Dataset - Ceftazidime/avibactam resistance is associated with PER-3-producing ST309 lineage in Chilean clinical isolates of non-carbapenemase producing Pseudomonas aeruginosa(NIH, 2024); ;UGALDE CASANOVA, JUAN ANTONIO; ; GARCIA CEBALLOS, PATRICIA1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mechanical and antimicrobial properties of low‐density‐polyethylene/
<scp>MgO</scp>
nanocomposites(2022) ;Alejandro Cament ;Viviana Moreno‐Serna ;Carlos Loyo ;Pabla QuintanaPablo Seura2Scopus© Citations 12
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