Browsing by Author "Opazo-Capurro, Andres"

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    ESBL-Producing Escherichia coli Carrying CTX-M Genes Circulating among Livestock, Dogs, and Wild Mammals in Small-Scale Farms of Central Chile
    (2021) Benavides, Julio A.; Salgado-Caxito, Marilia; Opazo-Capurro, Andres; Gonzalez Munoz, Paulina; Pineiro, Ana; Otto Medina, Macarena; Rivas, Lina; Munita, Jose; Millan, Javier
    Antibiotic-resistant bacteria of critical importance for global health such as extended-spectrum beta-lactamases-producing (ESBL)-Escherichia coli have been detected in livestock, dogs, and wildlife worldwide. However, the dynamics of ESBL-E. coli between these animals remains poorly understood, particularly in small-scale farms of low and middle-income countries where contact between species can be frequent. We compared the prevalence of fecal carriage of ESBL-E. coli among 332 livestock (207 cows, 15 pigs, 60 horses, 40 sheep, 6 goats, 4 chickens), 82 dogs, and wildlife including 131 European rabbits, 30 rodents, and 12 Andean foxes sharing territory in peri-urban localities of central Chile. The prevalence was lower in livestock (3.0%) and wildlife (0.5%) compared to dogs (24%). Among 47 ESBL-E. coli isolates recovered, CTX-M-group 1 was the main ESBL genotype identified, followed by CTX-M-groups 2, 9, 8, and 25. ERIC-PCR showed no cluster of E. coli clones by either host species nor locality. To our knowledge, this is the first report of ESBL-E. coli among sheep, cattle, dogs, and rodents of Chile, confirming their fecal carriage among domestic and wild animals in small-scale farms. The high prevalence of ESBL-E. coli in dogs encourages further investigation on their role as potential reservoirs of this bacteria in agricultural settings.
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    Genomic Analysis of Carbapenem-Resistant Acinetobacter baumannii Strains Recovered from Chilean Hospitals Reveals Lineages Specific to South America and Multiple Routes for Acquisition of Antibiotic Resistance Genes
    (2022) Brito, Barbara P.; Koong, Jonathan; Wozniak Banchero, Aniela; Opazo-Capurro, Andres; To, Joyce; Garcia, Patricia; Hamidian, Mehrad
    Carbapenem-resistant Acinetobacter baumannii (CRAb) is a public health threat accounting for a significant number of hospital-acquired infections. Despite the importance of this pathogen, there is scarce literature on A. baumannii molecular epidemiology and evolutionary pathways relevant to resistance emergence in South American strains. We analyzed the genomic context of 34 CRAb isolates recovered from clinical samples between 2010 and 2013 from two hospitals in Santiago, Chile, using whole-genome sequencing. Several Institut Pasteur scheme sequence types (STs) were identified among the 34 genomes studied here, including ST1, ST15, ST79, ST162, and ST109. No ST2 (the most widespread sequence type) strain was detected. Chilean isolates were phylogenetically closely related, forming lineages specific to South America (e.g., ST1, ST79, and ST15). The genomic contexts of the resistance genes were diverse: while genes were present in a plasmid in ST15 strains, all genes were chromosomal in ST79 strains. Different variants of a small Rep_3 plasmid played a central role in the acquisition of the oxa58 carbapenem and aacC2 aminoglycoside resistance genes in ST1, ST15, and ST79 strains. The aacC2 gene along with blaTEM were found in a novel transposon named Tn6925 here. Variants of Tn7 were also found to play an important role in the acquisition of the aadA1 and dfrA1 genes. This work draws a detailed picture of the genetic context of antibiotic resistance genes in a set of carbapenem-resistant A. baumannii strains recovered from two Chilean hospitals and reveals a complex evolutionary picture of antibiotic resistance gene acquisition events via multiple routes involving several mobile genetic elements.
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    Multiple clonal transmissions of clinically relevant extended-spectrum beta-lactamase-producing Escherichia coli among livestock, dogs, and wildlife in Chile
    (2023) Hayer, Juliette; Salgado-Caxito, Marilia; Opazo-Capurro, Andres; Munoz, Paulina Gonzalez; Millan, Javier; Pineiro, Ana; Munita, Jose M.; Rivas, Lina; Benavides, Julio A.
    Objectives: Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) are a main cause of human deaths associated with antimicrobial resistance (AMR). Despite hundreds of reports of the faecal carriage of ESBL-E. coli in domestic and wild animals, the dynamics of its circulation remains poorly understood.