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Author: search.filters.author.Carmen VarelaSubject: search.filters.subject.chile

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    Performance of the VITEK® MS system for the identification of filamentous fungi in a microbiological laboratory in Chile
    (Public Library of Science (PLoS), 2024-12-23)
    PORTE TORRE, LORENA ISABEL  
    ;
    Rodrigo Cruz
    ;
    Pérez Villa, Inia
    ;
    Carmen Varela
    ;
    Cristina Díaz
    <jats:p>Filamentous fungi are an emergent cause of severe infections in immunocompromised patients. Timely and accurate identification is crucial to initiate appropriate therapy. Traditional identification methods are time-consuming, labor-intensive, and operator-dependent. Matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry is a rapid and easy-to-perform identification method. The effectiveness of a commercial MALDI-TOF MS platform to identify filamentous fungi in a clinical laboratory was evaluated. The study included 67 fungal isolates from 35 species/species complexes, which were identified and confirmed in mycology reference laboratories; 32 derived from clinical samples, 34 from strain collections and one was an ATCC strain. The study used the VITEK<jats:sup>®</jats:sup> MS system (v3.2.0 database), after sample extraction by VITEK<jats:sup>®</jats:sup> MS Mould Kit. Results were classified as “correct species”, “correct species complex”, “correct genus”and “no identification”. VITEK<jats:sup>®</jats:sup> MS correctly identified 91.0% of isolates (58.2% to species, 29.9% to species complex, and 1.5% to genus level only). In 82%, the result matched the species/species complex identified by reference methods. No misidentifications were observed. The kit was rapid and easy to use. In conclusion, the VITEK<jats:sup>®</jats:sup> MS system showed a high capability to accurately identify filamentous fungi in a clinical laboratory.</jats:p>
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    Genomic analysis of the diversity, antimicrobial resistance and virulence potential of clinical Campylobacter jejuni and Campylobacter coli strains from Chile
    (2021)
    Veronica Bravo
    ;
    Assaf Katz
    ;
    PORTE TORRE, LORENA ISABEL  
    ;
    WEITZEL, THOMAS  
    ;
    Carmen Varela
    <jats:p><jats:italic>Campylobacter jejuni</jats:italic> and <jats:italic>Campylobacter coli</jats:italic> are the leading cause of human gastroenteritis in the industrialized world and an emerging threat in developing countries. The incidence of campylobacteriosis in South America is greatly underestimated, mostly due to the lack of adequate diagnostic methods. Accordingly, there is limited genomic and epidemiological data from this region. In the present study, we performed a genome-wide analysis of the genetic diversity, virulence, and antimicrobial resistance of the largest collection of clinical <jats:italic>C</jats:italic>. <jats:italic>jejuni</jats:italic> and <jats:italic>C</jats:italic>. <jats:italic>coli</jats:italic> strains from Chile available to date (n = 81), collected in 2017–2019 in Santiago, Chile. This culture collection accounts for more than one third of the available genome sequences from South American clinical strains. cgMLST analysis identified high genetic diversity as well as 13 novel STs and alleles in both <jats:italic>C</jats:italic>. <jats:italic>jejuni</jats:italic> and <jats:italic>C</jats:italic>. <jats:italic>coli</jats:italic>. Pangenome and virulome analyses showed a differential distribution of virulence factors, including both plasmid and chromosomally encoded T6SSs and T4SSs. Resistome analysis predicted widespread resistance to fluoroquinolones, but low rates of erythromycin resistance. This study provides valuable genomic and epidemiological data and highlights the need for further genomic epidemiology studies in Chile and other South American countries to better understand molecular epidemiology and antimicrobial resistance of this emerging intestinal pathogen.</jats:p>
    Scopus© Citations 23  4
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    Draft Whole-Genome Sequences of 51 Campylobacter jejuni and 12 Campylobacter coli Clinical Isolates from Chile
    (2020)
    Verónica Bravo
    ;
    Carmen Varela
    ;
    PORTE TORRE, LORENA ISABEL  
    ;
    WEITZEL, THOMAS  
    ;
    George J. Kastanis
    <jats:p> <jats:italic>Campylobacter</jats:italic> species are the leading cause of gastroenteritis worldwide and an emerging threat in developing countries. Here, we report the draft whole-genome sequences of 51 <jats:named-content content-type="genus-species">Campylobacter jejuni</jats:named-content> and 12 <jats:named-content content-type="genus-species">Campylobacter coli</jats:named-content> strains isolated from patients with gastroenteritis in Santiago, Chile. </jats:p>
      17Scopus© Citations 4
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    Scopus© Citations 11  2
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    Scopus© Citations 28  1
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    Genomic Analysis of Chilean Strains of Campylobacter jejuni from Human Faeces
    (2019)
    Arturo Levican
    ;
    Ignacio Ramos-Tapia
    ;
    Isabel Briceño
    ;
    Francisco Guerra
    ;
    Benjamin Mena
    <jats:p><jats:italic>Campylobacter</jats:italic>spp., especially<jats:italic>C. jejuni</jats:italic>, are recognized worldwide as the bacterial species that most commonly cause food-related diarrhea.<jats:italic>C. jejuni</jats:italic>possesses many different virulence factors, has the ability to survive in different reservoirs, and has shown among isolates the emergence of Antimicrobial Resistance (AMR). Genome association analyses of this bacterial pathogen have contributed to a better understanding of its pathogenic and AMR associated determinants. However, the epidemiological information of these bacteria in Latin American countries is scarce and no genomic information is available in public databases from isolates in these countries. Considering this, the present study is aimed to describe the genomic traits from representative<jats:italic>Campylobacter</jats:italic>spp. strains recovered from faecal samples of patients with acute diarrhoea from Valparaíso, Chile.<jats:italic>Campylobacter</jats:italic>spp. was detected from the faeces of 28 (8%) out of 350 patients with acute diarrhoea, mainly from young adults and children, and 26 (93%) of the isolates corresponded to<jats:italic>C. jejuni</jats:italic>. 63% of the isolates were resistant to ciprofloxacin, 25.9% to tetracycline, and 3.5% to erythromycin. Three isolates were selected for WGS on the basis of their<jats:italic>flaA</jats:italic>-RFLP genotype. They belonged to the multilocus sequence typing (MLST) clonal clomplex (CC) 21(PUCV-1), CC-48 (PUCV-3), and CC-353 (PUCV-2) and presented several putative virulence genes, including the Type IV and Type VI Secretion Systems, as well as AMR-associated genes in agreement with their susceptibility pattern. On the basis of the wgMLST, they were linked to strains from poultry and ruminants. These are the first genomes of Chilean<jats:italic>C. jejuni</jats:italic>isolates available in public databases and they provide relevant information about the<jats:italic>C. jejuni</jats:italic>isolates associated with human infection in this country.</jats:p>
      28Scopus© Citations 18