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1
artículo
Publicado 2021
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
2
artículo
Publicado 2024
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Objetives. Bacterial resistance to antibiotics is a public health problem, however, few studies are performed in natural water ecosystems in middle-low-income countries. The objective of this study was to evaluate the presence and sensitivity to antimicrobials of Escherichia coli strains isolated from 24 irrigation water samples from the Rimac River in eastern Lima. Materials and methods. E.coli were identified by PCR. Antibiotic susceptibility was determined by disk diffusion method. The extended-spectrum beta-lactamase (ESBL), quinolones and virulence involved genes were determined by PCR. Results. All samples exceeded the permissible limits established in the Environmental Quality Standards for vegetable irrigation. Of the 94 strains, 72.3% showed resistance to at least one antibiotic, 24.5% were multidrug-resistant (MDR), and 2.1% were extremely drug resistant. The highest percentage...
3
artículo
Publicado 2018
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Antibiotic resistance mediated by bacterial production of extended-spectrum beta-lactamase (ESBL) is a global threat to public health. ESBL resistance is most commonly hospital-acquired; however, infections acquired outside of hospital settings have raised concerns over the role of livestock and wildlife in the zoonotic spread of ESBL-producing bacteria. Only limited data are available on the circulation of ESBL-producing bacteria in animals. Here, we report ESBL-producing Escherichia coli in wild common vampire bats Desmodus rotundus and livestock near Lima, Peru. Molecular analyses revealed that most of this resistance resulted from the expression of blaCTX-M-15 genes carried by plasmids, which are disseminating worldwide in hospital settings and have also been observed in healthy children of Peru. Multilocus sequence typing showed a diverse pool of E. coli strains carrying this resist...
4
tesis doctoral
Publicado 2020
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Los avances en la síntesis y secuenciación del ADN y una comprensión más profunda de los mecanismos biológicos y bioquímicos han permitido el desarrollo de microbios modificados y ha acelerado la velocidad a la que se construyen, prueban y optimizan. Esto ha llevado a la revolución de la biotecnología y su posterior aplicación a través de diferentes campos industriales. Si bien estos avances han tenido repercusiones significativas en el descubrimiento de nuevos fármacos y una mayor eficiencia en las capacidades de producción derivadas de fermentaciones microbianas, el sector médico no se ha beneficiado completamente del inmenso potencial que ofrece la biotecnología. Con el advenimiento de la investigación del microbioma, las enfermedades se están entendiendo desde una perspectiva diferente, teniendo en cuenta el papel que las bacterias que habitan en nuestro cuerpo tienen...
5
artículo
Publicado 2009
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Las fitasas son una clase especial de fosfatasas que catalizan la hidrólisis secuencial del fitato. La incapacidad de las plantas para utilizar el fósforo a partir de los fitatos del suelo es debido a la baja actividad de fitasas en sus raíces. Los microorganismos del suelo juegan un importante papel en los procesos que afectan la trans- formación de los compuestos fosforados. Muchos de ellos pueden solubilizar el fósforo a partir de los fitatos, mediante la liberación de fitasas. Este proceso permite la movilización del fósforo hacia las plantas y un mejor aprovechamiento de este nutriente. Sin embargo, muchas bacterias carecen de los genes que codifican para estas enzimas, lo que disminuye la disponibilidad de este elemento en el suelo. Una alternativa es mejorar las rizobacterias en cuanto a su capacidad de solubilizar los fitatos del suelo, mediante la transformación genéti...
6
artículo
Construction of a vector for stable chromosomal integration of a Bacillus licheniformis phytase gene
Publicado 2009
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Phytases are a special class of phosphatases that catalyze the sequential hydrolysis of phytate. The inability of plants to utilize phosphorous from soil phytates is due to the low phytase activity in plant roots. Soil microorgan- isms play an important role in the processes that affect the transformation of phosphate containing compounds. Many of them can solubilize phosphorus from phytates, by means of the liberation of phytases. This process allows the mobilization of phosphorus towards the plants and a better utilization of this nutrient. Nevertheless, many soil bacteria lack gene coding for these enzymes, which diminishes the availability of this element in soil. One alternative to obtain improved rhizobacteria in relation to their capacity to solubilize soil phytates is by their genetic transformation with genes that codify for those enzymes. In this work, the gene phyL from B. lic...
7
objeto de conferencia
Publicado 2019
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Introduction: Enteroagregative Escherichia coli (EAEC) is a group of enteric pathogens that cause acute and persistent diarrhea among children, in patients infected with human immunodeficiency virus, which causes traveler's diarrhea and are associated with important outbreaks that have caused death. AIM: The aims of this study were to quantify and compare the bacterial load of stool samples from children under 2 years of age with and without diarrhea in a periurban community in Lima, Peru. Materials and methods: We randomly selected 165 stool samples (80 from diarrhea and 85 from asymptomatic patients) that previously were identified as EAEC for the presence of aggR plasmidic gene by Real Time-PCR for Diagnostic of Diarrheagenic E. coli (DEC) from bacteria isolated of stool culture, placebocontrolled trial conducted in children living in the district of Independencia, Lima, Peru. This st...
8
artículo
Publicado 2021
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Acknowledgments: The authors are grateful to CIENCIACTIVA from the “Consejo Nacional de Ciencia, Tecnología e Inovación Tecnológica” (CONCYTEC, Peru; Contract 278-2015-FONDECYT) and to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil) for Carmen M.S. Ambrosio Ph.D. scholarship. The current manuscript is part of the doctoral thesis (10.11606/T.11.2020.tde-18052020-151325) authored by Carmen M.S. Ambrosio at University of São Paulo.
9
artículo
Publicado 1923
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The concept of the pathogenic role of the bacterium coli wins - since the first description of the germ to make Escherich - a series of vicissitudes. Sometimes exaggerated, denied others, has been the emphasis desmedrandose regular guest of this organism and, between us, hardly gives any pathogenicity. In recent years I have had the opportunity to test the pathogenic action of the colon bacillus in various abnormal states, in terms that deserve attention.
10
artículo
Publicado 2024
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Hydrobiological products are highly perishable, which is why this research was carried out Hydrobiological products are highly perishable, which is why this research was carried out with the objective of evaluating the microbial load in the disinfection of rainbow trout (Oncorhynchus mykiss) fillets concerning Staphylococcus aureus, aerobic mesophiles, Salmonella sp. and Escherichia coli, submerging at different times (30, 60 and 90 s) and concentrations (0.5, 1.5 and 2.5 ppm). Microbiological analysis was performed on days 1, 8, 15, and 22 of refrigeration (4 °C), controlling pH according to AOAC 981.12 (1990). The experimental design was 3O x 3T factorial, with three replicates per treatment. R Project was used to perform ANOVA and Tukey's tests. The results revealed that treatment with ozonated water, especially using 2.5 ppm ozone and 30 seconds of immersion (O3T1), showed a sig...
11
artículo
Publicado 2019
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The aim of this study was to determine the presence of zoonotic gastrointestinal parasites by coprological examination in ferrets (Mustela putorius furo) reared as pets and the role of sex and age. The faeces of 30 ferrets were analysed, 16 [53.3%] from pet stores and 14 [46.7%] from homes in the city of Santiago and Concepción, Chile. Burrows' coprological technique was used for the diagnosis, which allows detecting eggs of protozoan helminths, cysts and trophozoites Three samples (10%) tested positive for protozoa, one for Entamoeba coli, in a 6 month old male from a pet store, and two for Endolimax nana in a 3-month-old female and a 2-year-old male from private homes. This would be the first record for the two species of protozoa commensals in ferrets in Chile, which were probably acquired by the close contact of mustelids with humans.
12
artículo
Publicado 2019
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The aim of this study was to determine the presence of zoonotic gastrointestinal parasites by coprological examination in ferrets (Mustela putorius furo) reared as pets and the role of sex and age. The faeces of 30 ferrets were analysed, 16 [53.3%] from pet stores and 14 [46.7%] from homes in the city of Santiago and Concepción, Chile. Burrows' coprological technique was used for the diagnosis, which allows detecting eggs of protozoan helminths, cysts and trophozoites Three samples (10%) tested positive for protozoa, one for Entamoeba coli, in a 6 month old male from a pet store, and two for Endolimax nana in a 3-month-old female and a 2-year-old male from private homes. This would be the first record for the two species of protozoa commensals in ferrets in Chile, which were probably acquired by the close contact of mustelids with humans.
13
artículo
The latest amendments to the "SLU" means make this media play a key role in preminal and basic differentiation that is required for screening of pathogenic forms of Enterobacteriaceae in practice the diagnosis of intestinal bacterial infections. In general all Enterobacteriaceae grown in this medium can lead to three types of changes according to their physiological properties: First, crops that produce blue shift without gas. Second, making a half turn to red and; third, they do not produce any modification or change except rare gas bubbles. In these three variations all Enterobacteriaceae are grouped, the first comprising at Proteus only; the sequndo to E. coli, E. freudii, Klebsiella and Aerobacter and; the third, to Groups: Salmonella, Arizona, Providence and Shigella. Differentiation of each group within each variation is done with the help of other tests already mentioned in the pr...
14
tesis de grado
Publicado 2025
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Due to its essential role in nucleotide synthesis, dihydrofolate reductase (DHFR) is a crucial enzyme present in various organisms, ranging from bacteria to mammals, including humans. In malaria-causing parasites, DHFR plays a vital role in parasite survival, contributing to its ability to resist and evade antifolate treatments. Although extensive genetic and enzymatic information is available for Plasmodium falciparum DHFR, data on Plasmodium vivax remain limited. Therefore, the main objective of this study was to standardize a protocol for the expression and purification of wild-type and mutant variants of P. vivax DHFR. Expression vectors carrying the recombinant genes were cloned and expressed in Escherichia coli Rosetta. After enzyme induction, they were purified using standard chromatographic techniques and characterized using spectrophotometric and electrophoretic methods, confirm...
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16
tesis de grado
Publicado 2025
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Las enfermedades intrahospitalarias siguen teniendo un gran impacto en la morbimortalidad de las personas afectadas. Muchas de estas enfermedades son causadas por bacterias productoras de carbapenemasas, esta resistencia antimicrobiana solo agrava más la situación. Por esto los diferentes estudios realizados hasta el día de hoy siguen buscando alternativas viables y beneficiosas para hacer frente a dichos patógenos. Los probióticos han demostrado que regulan el habita gastrointestinal y con ello provoca grades beneficios en todo el organismo humano, pero, además, se ha visto que pueden ejercer actividad antimicrobiana. Objetivos: Evaluar el efecto in vitro de los Lactobacillus spp, aislados desde el microbioma neonatal, como agente antimicrobiano sobre Pseudomonas aeruginosa y Escherichia coli productoras de carbapenemasas. Diseño: Estudio Cuasi Experimental con muestreo no probab...
17
tesis doctoral
Publicado 2022
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La resistencia antimicrobiana (RAM) representa una de las mayores amenazas a la salud pública en todo el mundo. Es un problema que no solo afecta la salud humana, sino está relacionado también con la salud animal y ambiental. En este estudio, describimos el papel que cumplen los animales y el medio ambiente en la emergencia de resistencia y como vía de transmisión de enterobacterias resistentes a los seres humanos, utilizando el secuenciamiento del genoma completo y plataformas para análisis bioinformático. En el primer capítulo, describimos cómo la poca regulación del uso de antibióticos en la producción animal puede resultar en un incremento de la emergencia de RAM. Comparamos Escherichia coli de pollos y humanos con diferentes niveles de exposición a la carne de pollo en una comunidad en las afueras del sur de Lima, Perú. Se obtuvieron 315 aislaron de E. coli de humanos ...
18
tesis doctoral
Publicado 2022
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Se obtuvieron diecinueve VHHs (dominios variables únicos de los anticuerpos de cadena pesada) que unen a CD105 (endoglina) humano, un co-receptor endotelial de TFG-β implicado en la regulación de la angiogénesis y el desarrollo de tumores, mediante screening por phage display de una biblioteca de ADNc de VHH obtenida de alpacas inmunizadas con un lisado de una línea celular de cáncer de vejiga que sobreexpresa CD105 (T24). Las secuencias de los VHH se analizaron con ExPASY, GeneDoc y BLAST y mostraron las características estructurales típicas de los VHHs. Ellas se clonaron y expresaron en pET22b(+)/E.coli y los VHHs recombinantes se purificaron por cromatografía de afinidad. Trece VHHs anti-CD105 fueron microarreglados en biochips para determinar la especificidad y afinidad a CD105 unido a membrana celular por SPRi, Los datos de SPRi mostraron que los VHHs unen a las células SC...
19
tesis de grado
Publicado 2018
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Intestinal parasitosis continues to be a public health problem of great importance in Peru, socioeconomic and demographic conditions have a preponderant role. In this sense, the objective of the study was to determine the prevalence of intestinal parasitosis in children of children of the sector Victor Raul Haya de la Torre, Virú. La Libertad, Peru. A total of 197 children from three kindergartens were studied through the methods of direct coproparasitological study and the Graham method. A general prevalence of parasitosis was found of 74% (n = 145). The prevalence by sex was 76% (n = 78) for girls and 71% (n = 67) for boys; according to age, it was 66% (n = 29) for 3 years, 78% (n = 66) for 4 years and 74% (n = 50) for 5 years. The three schools had a prevalence of parasitosis of 70%, 74% and 78% respectively, Entererobius vermicularis 65% (n = 128), Ascaris lumbricoides 16% (n = 32),...
20
tesis de grado
Publicado 2021
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Antecedentes: Los altos índices de letalidad en casos de infecciones humanas causadas por amebas de vida libre y su papel como reservorio de microorganismos patógenos ha impulsado su identificación en ambientes como la tierra. Actualmente, se utilizan insumos para preparación de sustratos de plantas ornamentales en jardinería siendo la tierra de chacra uno de los más empleados porque puede mezclarse con otros materiales denominándose “mezclas de tierra”. Esta tierra comercial es distribuida en nuestro país. Objetivo: Aislar e identificar Acanthamoeba spp. y Balamuthia mandrillaris a partir de muestras de tierra comercial de un supermercado de Lima obtenidas en el mes de agosto del año 2019. Diseño de estudio: Se realizó un estudio tipo observacional descriptivo transversal. Materiales y métodos: Se utilizaron 30 bolsas con tierra comercial, las muestras de tierra obtenida...
