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    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
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    Head-to-head comparison of CAMPYAIR aerobic culture medium versus standard microaerophilic culture for Campylobacter isolation from clinical samples
    (2023)
    Arturo Levican
    ;
    Carmen Varela
    ;
    Lorena Porte  
    ;
    WEITZEL, THOMAS  
    ;
    Isabel Briceño
    <jats:p><jats:italic>Campylobacter</jats:italic> spp. are considered the most frequent cause of acute gastroenteritis worldwide. However, outside high-income countries, its burden is poorly understood. Limited published data suggest that <jats:italic>Campylobacter</jats:italic> prevalence in low- and middle-income countries is high, but their reservoirs and age distribution are different. Culturing <jats:italic>Campylobacter</jats:italic> is expensive due to laboratory equipment and supplies needed to grow the bacterium (e.g., selective culture media, microaerophilic atmosphere, and a 42°C incubator). These requirements limit the diagnostic capacity of clinical laboratories in many resource-poor regions, leading to significant underdiagnosis and underreporting of isolation of the pathogen. CAMPYAIR, a newly developed selective differential medium, permits <jats:italic>Campylobacter</jats:italic> isolation without the need for microaerophilic incubation. The medium is supplemented with antibiotics to allow <jats:italic>Campylobacter</jats:italic> isolation in complex matrices such as human feces. The present study aims to evaluate the ability of the medium to recover <jats:italic>Campylobacter</jats:italic> from routine clinical samples. A total of 191 human stool samples were used to compare the ability of CAMPYAIR (aerobic incubation) and a commercial <jats:italic>Campylobacter</jats:italic> medium (CASA, microaerophilic incubation) to recover <jats:italic>Campylobacter</jats:italic>. All <jats:italic>Campylobacter</jats:italic> isolates were then identified by MALDI-TOF MS. CAMPYAIR showed sensitivity and specificity values of 87.5% (95% CI 47.4%–99.7%) and 100% (95% CI 98%–100%), respectively. The positive predictive value of CAMPYAIR was 100% and its negative predictive value was 99.5% (95% CI 96.7%–99.9%); Kappa Cohen coefficient was 0.93 (95% CI 0.79–1.0). The high diagnostic performance and low technical requirements of the CAMPYAIR medium could permit <jats:italic>Campylobacter</jats:italic> culture in countries with limited resources.</jats:p>
    Scopus© Citations 3  1
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    An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles
    (2023)
    Robert S Bresalier
    ;
    Carlo Senore
    ;
    Graeme P Young
    ;
    James Allison
    ;
    Robert Benamouzig
    <jats:sec><jats:title>Objective</jats:title><jats:p>New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers.</jats:p></jats:sec><jats:sec><jats:title>Design</jats:title><jats:p>A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test’s ability to discriminate between CRC and non-cancer states (<jats:italic>phase I</jats:italic>), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (<jats:italic>phase II</jats:italic>). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations.<jats:italic>Phase III</jats:italic>prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold.<jats:italic>Phase IV</jats:italic>studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact.</jats:p></jats:sec>
      8Scopus© Citations 37
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      20  1Scopus© Citations 6
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      16  1Scopus© Citations 14
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      11Scopus© Citations 4
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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