Publications by authors named "Magdalena Wiesner"

In Salmonella enterica serovar Typhimurium (Typhimurium), multidrug resistance is associated with integrons carrying resistance genes dispersed by mobile genetic elements. This exploratory systematic review sought to identify integron types and their resistance genes in multidrug resistance Typhimurium isolates. We used Medline, PubMed, SciELO, ScienceDirect, Redalyc, and Google Scholar as motor searchers for articles in Spanish or English published between 2012 and 2020, including the keywords “integrons”, “antibiotic resistance”, and “Salmonella Typhimurium”.

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subsp. serovar Typhimurium (. Typhimurium) has been linked to outbreaks of foodborne gastroenteritis disease, and the emergence of antimicrobial-resistant clones.

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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause very high morbidity and mortality throughout Latin American countries. However, few population-based seroprevalence surveys have been conducted to quantify attack rates and characterize drivers of transmission.

Methods: We conducted a population-based cross-sectional study to assess the seroprevalence of antibodies against SARS-CoV-2 in ten cities in Colombia between September and December 2020.

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Article Synopsis
  • - SARS-CoV-2 has genetic diversity that can influence how easily the virus spreads and its ability to evade immunity from natural infections or vaccines.
  • - A study in Colombia identified the B.1.621 lineage of SARS-CoV-2 (a variant of interest) from genome sequencing of samples collected between January and April 2021, revealing several significant mutations in the Spike protein.
  • - The B.1.621 variant showed a rapid increase in prevalence in various regions of Colombia, raising concerns about its potential impact on public health and the effectiveness of existing immunity levels.
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COVID-19 pandemics has led to genetic diversification of SARS-CoV-2 and the appearance of variants with potential impact in transmissibility and viral escape from acquired immunity. We report a new and highly divergent lineage containing 21 distinctive mutations (10 non-synonymous, eight synonymous, and three substitutions in non-coding regions). The amino acid changes L249S and E484K located at the CTD and RBD of the Spike protein could be of special interest due to their potential biological role in the virus-host relationship.

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Introduction. The Salmonella Typhimurium monophasic variant (1,4,[5],12:i:-) is currently the most commonly detected variant in Salmonella surveillance programs worldwide. In Colombia, the Salmonella enterica monophasic variant is the fourth most common clinical isolate recovered through the laboratory surveillance of the Grupo de Microbiología from the Instituto Nacional de Salud; however, it is unknown whether these isolates are closely related to the monophasic Typhimurium variant, which circulates globally, and their genetic and phenotypic characteristics have not been reported.

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SARS-CoV-2 is a new member of the genus Betacoronavirus, responsible for the COVID-19 pandemic. The virus crossed the species barrier and established in the human population taking advantage of the spike protein high affinity for the ACE receptor to infect the lower respiratory tract. The Nucleocapsid (N) and Spike (S) are highly immunogenic structural proteins and most commercial COVID-19 diagnostic assays target these proteins.

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Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of in and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all -positive isolates, and these were further subjected to whole-genome sequencing (WGS).

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Introduction: Salmonella is an enteropathogen acquired through contaminated food or water. In Colombia, Salmonella spp. is included in the national surveillance of Acute Diarrhoeal Diseases and typhoid fever initiated in 1997.

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Background: Classical strains of Salmonella enterica serovar Typhimurium (Typhimurium) predominantly cause a self-limiting diarrheal illness in humans and a systemic disease in mice. In this study, we report the characterization of a strain isolated from a blood-culture taken from a 15-year old woman suffering from invasive severe salmonellosis, refractory to conventional therapy with extended-spectrum cephalosporin (ESC).

Results: The strain, named 33676, was characterized as multidrug-resistant Salmonella serogroup A by biochemical, antimicrobial and serological tests.

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Salmonella enterica subsp. enterica serovar Typhimurium strain 33676 was isolated in Mexico City, Mexico, from a patient with a systemic infection, and its complete genome sequence was determined using PacBio single-molecule real-time technology. Strain 33676 harbors an IncF plasmid carrying the extended-spectrum cephalosporin gene blaCMY-2 and a multidrug resistance IncA/C plasmid.

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In this work, IS200 and multi-locus sequence typing (MLST) were used to analyze 19 strains previously serotyped as Salmonella enterica serovar Typhi and isolated in Indonesia (16 strains), Mexico (2 strains), and Switzerland (1 strain). Most of the strains showed the most common Typhi sequence types, ST1 and ST2, and a new Typhi genotype (ST1856) was described. However, one isolate from Mexico and another from Indonesia were of the ST365 and ST426 sequence types, indicating that they belonged to serovars Weltevreden and Aberdeen, respectively.

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Salmonella enterica subsp. enterica serovar Typhimurium strain YU39 was isolated in 2005 in the state of Yucatán, Mexico, from a human systemic infection. The YU39 strain is representative of the multidrug-resistant emergent sequence type 213 (ST213) genotype.

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Background: Our observation that in the Mexican Salmonella Typhimurium population none of the ST19 and ST213 strains harbored both the Salmonella virulence plasmid (pSTV) and the prevalent IncA/C plasmid (pA/C) led us to hypothesize that restriction to horizontal transfer of these plasmids existed. We designed a conjugation scheme using ST213 strain YU39 as donor of the blaCMY-2 gene (conferring resistance to ceftriaxone; CRO) carried by pA/C, and two E. coli lab strains (DH5α and HB101) and two Typhimurium ST19 strains (SO1 and LT2) carrying pSTV as recipients.

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Background: Salmonella Typhimurium ST213 was first detected in the Mexican Typhimurium population in 2001. It is associated with a multi-drug resistance phenotype and a plasmid-borne blaCMY-2 gene conferring resistance to extended-spectrum cephalosporins. The objective of the current study was to examine the association between the ST213 genotype and blaCMY-2 plasmids.

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Background: Bacterial genomes are mosaic structures composed of genes present in every strain of the same species (core genome), and genes present in some but not all strains of a species (accessory genome). The aim of this study was to compare the genetic diversity of core and accessory genes of a Salmonella enterica subspecies enterica serovar Typhimurium (Typhimurium) population isolated from food-animal and human sources in four regions of Mexico. Multilocus sequence typing (MLST) and macrorestriction fingerprints by pulsed-field gel electrophoresis (PFGE) were used to address the core genetic variation, and genes involved in pathogenesis and antibiotic resistance were selected to evaluate the accessory genome.

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Introduction: The characterization of typhoid fever outbreaks is important because it is necessary to find the source of the infection and development control measures.

Objective: A typhoid fever outbreak is described from Apartadó and the Salmonella Typhi isolates characterized by phenotypic and genotypic methods.

Materials And Methods: From 44 patients, 15 blood cultures and 7 stools cultures were recovered.

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Salmonella Typhi is the etiological agent of typhoid fever with 16 million annual cases estimated worldwide. In Colombia and Argentina it is a notifiable disease but many cases have only a clinical diagnosis. Molecular subtyping of S.

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In 1997, the Microbiology Group of the Colombian Instituto Nacional de Salud set up a surveillance program with the National Public Health Laboratories to monitor the principal etiological agents responsible for acute diarrheal disease. The main goal of this study was to determine the XbaI DNA digestion patterns of clinical and food Salmonella spp. isolates recovered in Bogotá from 1997 to 2002, and related them to the susceptibility patterns to antimicrobial agents.

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