Browsing by Author "Opazo Capurro, Andres"

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    Comparative Analysis of Felixounavirus Genomes Including Two New Members of the Genus That Infect Salmonella Infantis
    (MDPI, 2021) Barron Montenegro, Rocio; Garcia, Rodrigo; Duenas, Fernando; Rivera, Dacil; Opazo Capurro, Andres; Erickson, Stephen; Moreno Switt, Andrea, I
    Salmonella spp. is one of the most common foodborne pathogens worldwide; therefore, its control is highly relevant for the food industry. Phages of the Felixounavirus genus have the characteristic that one phage can infect a large number of different Salmonella serovars and, thus, are proposed as an alternative to antimicrobials in food production. Here, we describe two new members of the Felixounavirus genus named vB_Si_35FD and vB_Si_DR94, which can infect Salmonella Infantis. These new members were isolated and sequenced, and a subsequent comparative genomic analysis was conducted including 23 publicly available genomes of Felixounaviruses that infect Salmonella. The genomes of vB_Si_35FD and vB_Si_DR94 are 85,818 and 85,730 bp large and contain 129 and 125 coding sequences, respectively. The genomes did not show genes associated with virulence or antimicrobial resistance, which could be useful for candidates to use as biocontrol agents. Comparative genomics revealed that closely related Felixounavirus are found in distinct geographical locations and that this genus has a conserved genomic structure despite its worldwide distribution. Our study revealed a highly conserved structure of the phage genomes, and the two newly described phages could represent promising biocontrol candidates against Salmonella spp. from a genomic viewpoint.
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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.