CRIS

Permanent URI for this communityhttps://investigadores.udd.cl/handle/123456789/1

Browse

Search Results

Now showing 1 - 6 of 6

Some of the metrics are blocked by your
consent settings
Copper-Modified Cellulose Paper: A Comparative Study of How Antimicrobial Activity Is Affected by Particle Size and Testing Standards
(MDPI AG, 2025-01-08)
Sara Ramírez
;
Fabian Zúñiga
;
Alejandra Amenábar
;
CONTRERAS CORREA, PAULINA DEL PILAR
;
Viviana Benavides
This study aims to provide evidence that when testing cellulose paper modified with copper particles (CuPs), the particle size and the analysis method influence the antimicrobial activity observed by this material. Commercial CuPs of nanometric size (2.7 nm, CuNPs) and micrometric size (2.5 µm, CuMPs) were used to modify cellulose paper sheets. CuPs were incorporated during the pulp disintegration phase (stage 1) of the sheet formation process, according to the ISO 5269-1:2005 standard. Modified paper sheets retained 16% and 14% of CuNPs and CuMPs, respectively. Additionally, CuPs were distributed randomly on the fiber surfaces, often forming aggregates. Finally, the antimicrobial activity of the modified paper sheets was evaluated using ISO 20645:2004 and ISO 20743:2013. The results showed that the antimicrobial activity assessed using each standard method is conditioned by the mechanism of action of the CuPs and, therefore, by their size. It was concluded that ISO 20645:2004 is suitable for evaluating the antibacterial effect of paper/CuNPs, as nanoparticles diffuse from the paper and are released into the culture medium. In contrast, ISO 20743:2013 can be used for both CuNP- and CuMP-based paper, as it evaluates the antibacterial effect based on the direct interaction between the copper particle and the bacteria.
Scopus© Citations 2 14
Some of the metrics are blocked by your
consent settings
Porcentaje de éxito de erradicación de Helicobacter pylori con tratamiento antibiótico empírico en pacientes pediátricos de un Hospital Terciario
(2023)
Sofía Darritchon Lama
;
Diego Díaz García
;
Marcela Toledo Cumplido
;
LUCERO ALVAREZ, YALDA CECILIA
<jats:p>La infección por Helicobacter pylori es una condición frecuente, que a largo plazo se asocia con desarrollo de enfermedad ulceropéptica y eventualmente cáncer gástrico, que se podrían prevenir con un tratamiento oportuno. Lo óptimo sería lograr un éxito de erradicación mayor al 90%, pero los tratamientos empíricos recomendados no logran esas tasas en condiciones reales.Objetivo: Determinar el porcentaje de éxito del tratamiento empírico de erradicación de primera línea contra H. pylori en pacientes pediátricos atendidos en un hospital terciario.Pacientes y Método: Estudio descriptivo retrospectivo en pacientes con infección por H. pylori detectado en biopsias gástricas y que hubieran recibido tratamiento antibiótico de primera línea durante el periodo 2017-2021. Se consideró erradicación exitosa el resultado negativo de test de antígeno en deposiciones o nuevas biopsias luego de ≥ 1 mes de finalizado el tratamiento.Resultados: Se identificaron 82 pacientes con infección por H. pylori, de los cuales 53 recibieron tratamiento de erradicación. De éstos, 26 (49%) fueron controlados con test de erradicación luego del tratamiento y en ellos el porcentaje de éxito fue de solo 38% (10/26).Conclusiones: La tasa de erradicación con los esquemas empíricos utilizados fue menor a la esperada, lo que evidencia el desafío de buscar estrategias más efectivas de tratamiento incluyendo el estudio de susceptibilidad a antimicrobianos. La adherencia de los pacientes al protocolo de seguimiento también fue baja, lo que deberá reforzarse en el futuro para poder realizar un manejo clínico más adecuado. </jats:p>
Scopus© Citations 4 2
Some of the metrics are blocked by your
consent settings
High Burden of Intestinal Colonization With Antimicrobial-Resistant Bacteria in Chile: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study
(2023)
ARAOS BRALIC, RAFAEL IGNACIO
;
Rachel M Smith
;
Ashley Styczynski
;
Felipe Sánchez
;
Lea Maureira
<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal colonization prevalence in hospitalized and community-dwelling adults in Chile before the coronavirus disease 2019 pandemic.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>From December 2018 to May 2019, we enrolled hospitalized adults in 4 public hospitals and community dwellers from central Chile, who provided fecal specimens and epidemiological information. Samples were plated onto MacConkey agar with ciprofloxacin or ceftazidime added. All recovered morphotypes were identified and characterized according to the following phenotypes: fluoroquinolone-resistant (FQR), extended-spectrum cephalosporin-resistant (ESCR), carbapenem-resistant (CR), or multidrug-resistant (MDR; as per Centers for Disease Control and Prevention criteria) GNB. Categories were not mutually exclusive.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>A total of 775 hospitalized adults and 357 community dwellers were enrolled. Among hospitalized subjects, the prevalence of colonization with FQR, ESCR, CR, or MDR-GNB was 46.4% (95% confidence interval [CI], 42.9–50.0), 41.2% (95% CI, 37.7–44.6), 14.5% (95% CI, 12.0–16.9), and 26.3% (95% CI, 23.2–29.4). In the community, the prevalence of FQR, ESCR, CR, and MDR-GNB colonization was 39.5% (95% CI, 34.4–44.6), 28.9% (95% CI, 24.2–33.6), 5.6% (95% CI, 3.2–8.0), and 4.8% (95% CI, 2.6–7.0), respectively.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>A high burden of antimicrobial-resistant GNB colonization was observed in this sample of hospitalized and community-dwelling adults, suggesting that the community is a relevant source of antibiotic resistance. Efforts are needed to understand the relatedness between resistant strains circulating in the community and hospitals.</jats:p> </jats:sec>
Scopus© Citations 10 2
Some of the metrics are blocked by your
consent settings
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 Martínez
;
Maria 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 your
consent settings
New Perspectives on Antimicrobial Agents: Long-Acting Lipoglycopeptides
(2022)
Truc T. Tran
;
Sara Gomez Villegas
;
Samuel L. Aitken
;
Susan M. Butler-Wu
;
Alex Soriano
<jats:p>The long-acting lipoglycopeptides (LGPs) dalbavancin and oritavancin are semisynthetic antimicrobials with broad and potent activity against Gram-positive bacterial pathogens. While they are approved by the Food and Drug Administration for acute bacterial skin and soft tissue infections, their pharmacological properties suggest a potential role of these agents for the treatment of deep-seated and severe infections, such as bloodstream and bone and joint infections.</jats:p>
5Scopus© Citations 29
Some of the metrics are blocked by your
consent settings
The human microbiota and infection prevention
(2019)
ARAOS BRALIC, RAFAEL IGNACIO
;
Erika M.C. D’Agata
<jats:title>Abstract</jats:title><jats:p>The human microbiome participates in numerous aspects of human physiology and disease states. Recently, studies have begun to explore the role of the microbiome in colonization, infection and transmission of pathogens. This review provides a summary of the methodological principles used in microbiome studies and the published evidence of the impact of microbiome dysbiosis in infection prevention.</jats:p>
Scopus© Citations 12 1

CRIS

Browse

Filters

Settings

Sort By

Results per page

Search Results