Browsing by Author "Rivas, Lina"

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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, Rafael; Smith, Rachel M.; Styczynski, Ashley; Sánchez Barría, Felipe Andrés; Acevedo, Johanna; Maureira, Lea; Paredes, Catalina; Gonzalez, Maite; Rivas, Lina; Spencer-Sandino, Maria; Peters, Anne; Khan, Ayesha; Sepulveda, Dino; Rojas Wettig, Loreto; Rioseco, Maria Luisa; Usedo, Pedro; Rojas Soto, Pamela; Huidobro, Laura Andrea; Ferreccio Readi, Catterina; Park, Benjamin J.; Undurraga Fourcade, Eduardo Andrés; D'Agata, Erika M. C.; Jara Vallejos, Alejandro Antonio; Munita, Jose M.
    We report a high colonization burden resulting from antimicrobial-resistant Gram-negative bacteria in hospitals and a community in Chile. Strikingly, 29% (95% confidence interval, 24-34) of community-dwelling adults carried extended-spectrum cephalosporin-resistant Enterobacterales, highlighting the magnitude of the community reservoir of antimicrobial resistance., Background 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. Methods 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. Results 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. Conclusions 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.
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    Isolation of Ciprofloxacin and Ceftazidime-Resistant Enterobacterales From Vegetables and River Water Is Strongly Associated With the Season and the Sample Type
    (FRONTIERS MEDIA SA, 2021) Diaz Gavidia, Constanza; Barria, Carla; Rivas, Lina; Garcia, Patricia; Alvarez, Francisca P.; Gonzalez Rocha, Gerardo; Opazo Capurro, Andres; Araos, Rafael; Munita, Jose M.; Cortes, Sandra; Olivares Pacheco, Jorge; Adell, Aiko D.; Moreno Switt, Andrea I.
    The dissemination of antibiotic-resistant bacteria (ARB) from water used for crop irrigation to vegetables is poorly studied. During a year, five farmer markets in a city in Central Chile were visited, and 478 vegetable samples (parsleys, corianders, celeries, lettuces, chards, and beets) were collected. Simultaneously, 32 water samples were collected from two rivers which are used to irrigate the vegetables produced in the area. Resistant Enterobacterales were isolated and identified. Colistin resistance gene mcr-1 and extended spectrum beta-lactamases (ESBL) were molecularly detected. The association of environmental factors was evaluated, with the outcomes being the presence of Enterobacterales resistant to four antibiotic families and the presence of multidrug resistance (MDR) phenotypes. Parsley, coriander, and celery showed the highest prevalence of resistant Enterobacterales (41.9% for ciprofloxacin and 18.5% for ceftazidime). A total of 155 isolates were obtained, including Escherichia coli (n = 109), Citrobacter sp. (n = 20), Enterobacter cloacae complex (n = 8), Klebsiella pneumoniae (n = 8), and Klebsiella aerogenes (n = 1). Resistance to ampicillin (63.2%) and ciprofloxacin (74.2%) was most frequently found; 34.5% of the isolates showed resistance to third-generation cephalosporins, and the MDR phenotype represented 51.6% of the isolates. In two E. coli isolates (1.29%), the gene mcr-1 was found and ESBL genes were found in 23/62 isolates (37%), with bla(CTX-M) being the most frequently found in 20 isolates (32%). Resistant Enterobacterales isolated during the rainy season were less likely to be MDR as compared to the dry season. Understanding environmental associations represent the first step toward an improved understanding of the public health impact of ARB in vegetables and water.
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    Real-World Performance of Susceptibility Testing for Ceftolozane/Tazobactam against Non-Carbapenemase- Producing Carbapenem-Resistant Pseudomonas aeruginosa
    (2022) Rivas, Lina; Martinez, José R.W.; Munita, José M.; Alcalde-Rico, Manuel; Olivares Pacheco, Jorge; García Cañete, Patricia; Olivares-Pacheco J.; Moreno, María Victoria; Rojas, Pamela; Wozniak Banchero, Aniela; Miller, William; Arias, Cesar A.; Khan, Ayesha
    Ceftolozane/tazbactam (C/T) is a potent anti-pseudomonal agent that has clinical utility against infections caused by non-carbapenemase, producing-carbapenemresistant Pseudomonas aeruginosa (non-CP-CR-PA). Accurate, precise, and reliable antimicrobial susceptibility testing (AST) is crucial to guide clinical decisions. However, studies assessing the performance of different AST methods against non-CP-CR-PA (the main clinical niche for C/T), are lacking. Here, we evaluated performance of gradient strips (Etest and MIC test strip [MTS], and disk diffusion [DD]) using CLSI breakpoints. Additionally, we assessed the performance of DD using EUCAST breakpoints. For all susceptibility tests, we used a collection of 97 non-CP-CR-PA clinical isolates recovered from 11 Chilean hospitals. Both gradient strips and DD had acceptable performance when using CLSI breakpoints, yielding a categorical agreement (CA) of .90% and 92%, respectively. In contrast, DD using EUCAST breakpoints performed suboptimally (CA 81%). MTS yielded a higher essential agreement (EA, .90%) than Etest (84%). Importantly, the performance of all methods varied significantly when the isolates were stratified by their degree of susceptibility to other anti-pseudomonal b-lactams. All methods had 100% CA when testing isolates that were pan-susceptible to all b-lactams (Pan-β-S). However, the CA markedly decreased when testing isolates resistant to all b-lactams (Pan-β-R). Indeed, the CA was 81% for Etest (six errors), 78% for MTS (seven errors), and 78% and 56% for DD when using CLSI (seven errors) or EUCAST breakpoints (14 errors), respectively. Our results suggest that all manual AST methods have strikingly decreased performance in the context of Pan-β-R P. aeruginosa with potentially major clinical implications.