Browsing by Author "Rivera Sánchez, Sandra Patricia"
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Item Acerca de autores y pares evaluadores - La contaminación industrial de aguas. Una mirada microbiológica y molecular(Editorial Universidad Santiago de Cali, 2018) Oñate Garzón, José; Meléndez Gelvez, Iván; Paruma Velasco, Ary Fabián; Zuleta, Margarita; Cárdenas, Héctor Hugo; Peláez, Carlos Alberto; Bonilla Millán, Fernando; Rodríguez Estrada, Jhon Alexander; Rojas Álvarez, Oscar Eduardo; Andreas Toba, Faustino; Falco, Aura; Aranaga, Carlos Andrés; Alonso, Guillermina; Rivera Sánchez, Sandra Patricia; Flórez, Liliana; Sanabria, JanethItem Antimicrobial contribution of chitosan surface-modified nanoliposomes combined with colistin against sensitive and colistin-resistant clinical Pseudomonas aeruginosa(2021) Laverde Rojas, Valentina; Liscano, Yamil; Rivera Sánchez, Sandra Patricia; Ocampo Ibáñez, Ivan Darío; Betancourt, Yeiston; Alhajj, Maria José; Yarce, Cristhian J.; Salamanca, Constain H.; Oñate Garzón, JoseColistin is a re-emergent antibiotic peptide used as a last resort in clinical practice to overcome multi-drug resistant (MDR) Gram-negative bacterial infections. Unfortunately, the dissemination of colistin-resistant strains has increased in recent years and is considered a public health problem worldwide. Strategies to reduce resistance to antibiotics such as nanotechnology have been applied successfully. In this work, colistin was characterized physicochemically by surface tension measurements. Subsequently, nanoliposomes coated with highly deacetylated chitosan were prepared with and without colistin. The nanoliposomes were characterized using dynamic light scattering and zeta potential measurements. Both physicochemical parameters fluctuated relatively to the addition of colistin and/or polymer. The antimicrobial activity of formulations increased by four-fold against clinical isolates of susceptible Pseudomona aeruginosa but did not have antimicrobial activity against multidrug-resistant (MDR) bacteria. Interestingly, the free coated nanoliposomes exhibited the same antibacterial activity in both sensitive and MDR strains. Finally, the interaction of colistin with phospholipids was characterized using molecular dynamics (MD) simulations and determined that colistin is weakly associated with micelles constituted by zwitterionic phospholipidsItem Efficacy of Vaporized Hydrogen Peroxide Combined with Silver Ions against Multidrug-Resistant Gram-Negative and Gram-Positive Clinical Isolates(2022-12) Rivera Sánchez, Sandra Patricia; Rojas Abadía, José María; Ríos Acevedo, John Jairo; Mejía Hurtado, Ana Fernanda; Espinosa Moya, Luz Natalia; Ocampo Ibáñez, Iván DaríoAntimicrobial resistance (AMR) is a serious public health problem that results in high morbidity and mortality rates. In particular, multidrug-resistant (MDR) strains circulating in hospital settings pose a major threat as they are associated with serious nosocomial infections. Therefore, regular cleaning and disinfection procedures, usually using chemical disinfectants, must be implemented in these facilities. Hydrogen peroxide (HP)-based disinfectants have proven high microbicidal activity and several comparative advantages over conventional disinfectants. We assessed the in vitro biocidal activity of an 8% HP solution combined with 30 mg/L silver ions (HP + Ag) against MDR clinical isolates of Klebsiella pneumoniae (MDRKp) and Pseudomonas aeruginosa (MDRPa), and methicillin-resistant Staphylococcus aureus (MRSA). Accordingly, the in vitro antibacterial activity was determined using the macrodilution method, and the efficacy was determined for 30 min in terms of (1) activity on bacteria in suspension and (2) activity on surfaces using vaporized HP + Ag on a 20 cm2 stainless steel surface. A strong bactericidal effect of HP + Ag was observed against MDRKp, MDRPa, and MRSA strains, with minimum inhibitory concentrations and minimum bactericidal concentrations between 362.5 and 5800 mg/L. A strong effect was observed during the 30 min of HP + Ag exposure to the resistant clinical isolates, with over 4-Log10 reduction in CFUs. Regarding the efficacy of the disinfectant on surfaces, bacterial load reductions of >99% were observed. These results suggest that HP + Ag is potentially useful as an effective disinfectant for decontaminating surfaces in hospital settings suspected of contamination with MDR bacteria.Item Introducción - La contaminación industrial de aguas. Una mirada microbiológica y molecular(Editorial Universidad Santiago de Cali, 2018) Oñate Garzón, José; Meléndez Gelvez, Iván; Paruma Velasco, Ary Fabián; Zuleta, Margarita; Cárdenas, Héctor Hugo; Peláez, Carlos Alberto; Bonilla Millán, Fernando; Rodríguez Estrada, Jhon Alexander; Rojas Álvarez, Oscar Eduardo; Andreas Toba, Faustino; Falco, Aura; Aranaga, Carlos Andrés; Alonso, Guillermina; Rivera Sánchez, Sandra Patricia; Flórez, Liliana; Sanabria, JanethLos Grupos de Investigación en Química y Biotecnología (QUIBIO) y Microbiología Industrial y Medio Ambiente (GIMIA) hacen parte del Centro de Estudios e Investigaciones en Ciencias Básicas Ambientales y Desarrollo Tecnológico (CICBA), adscrito a la Facultad de Ciencias Básicas de la Universidad Santiago de Cali. Desde su nacimiento el CICBA, a propendido por estar a la vanguardia al interior de la Universidad en la investigación, conciencia por el medio ambiente y desarrollo tecnológico. Los grupos de investigación acordes con esta macrolinea, se han preocupado por aportar sus desarrollos investigativos y de innovación en un marco de responsabilidad social, es así como en este libro de investigación titulado “LA CONTAMINACIÓN INDUSTRIAL DE AGUAS: Una Mirada Microbiológica y Molecular” se recopilan 4 trabajos de investigadores pertenecientes a los dos grupos de investigación con el fin de dar a conocer estudios realizados en Colombia y Venezuela sobre la problemática de la contaminación en cuerpos acuíferos.Item La contaminación industrial de aguas. Una mirada microbiológica y molecular(Editorial Universidad Santiago de Cali, 2018) Oñate Garzón, José; Meléndez Gelvez, Iván; Paruma Velasco, Ary Fabián; Zuleta, Margarita; Cárdenas, Héctor Hugo; Peláez, Carlos Alberto; Bonilla Millán, Fernando; Rodríguez Estrada, Jhon Alexander; Rojas Álvarez, Oscar Eduardo; Toba, Faustino Andreas; Falco, Aura; Aranaga, Carlos Andrés; Alonso, Guillermina; Rivera Sánchez, Sandra Patricia; Flórez, Liliana; Sanabria, JanethLos Grupos de Investigación en Química y Biotecnología (QUIBIO) y Microbiología Industrial y Medio Ambiente (GIMIA) hacen parte del Centro de Estudios e Investigaciones en Ciencias Básicas Ambientales y Desarrollo Tecnológico (CICBA), adscrito a la Facultad de Ciencias Básicas de la Universidad Santiago de Cali. Desde su nacimiento el CICBA, a propendido por estar a la vanguardia al interior de la Universidad en la investigación, conciencia por el medio ambiente y desarrollo tecnológico.Item Presence of Listeria monocytogenes in fresh artisanal cheese marketed in Cali-Colombia(Universidad Nacional de Colombia, 2019-04-09) Ocampo Ibáñez, Iván Darío; González, Carlos; Moreno, Sara Lucia; Calderón, Cristina; Flórez Elvira, Liliana Janeth; Beatriz Olaya, María; Rivera Sánchez, Sandra Patricia; Lesmes, María CristinaListeria monocytogenes is the causative agent of the foodborne illness called listeriosis. The invasive form of this disease can cause meningoencephalitis, septicemia and spontaneous abortions. The consumption of food contaminated with this bacterium is the main route of infection, and the fresh artisanal cheeses cause the greatest concern in public health. In this study, different types of fresh artisanal cheeses (campesino, costeño, cuajada, doble crema, mozarella and pastuso) were collected in market squares in Cali (Alameda, El Cortijo, La Floresta and Santa Elena) and analyzed using the VIDAS® and VITEK®2 platforms to detect and identify L. monocytogenes. According to the results obtained from 126 fresh artisanal cheeses analyzed in the different market squares, 27% were positive for L. monocytogenes. Among the positive samples, cuajada had the highest number of positive samples for L. monocytogenes with 44.1%. Alameda with 62% of positive samples for L. monocytogenes had the highest number of positive samples among all market squares evaluated. This study represents the first evaluation of the presence of L. monocytogenes in fresh artisanal cheeses marketed in the most important market squares of Cali. Accordingly, this study pretends to generate an alert about the urgent need to implement surveillance and control mechanisms of L. monocytogenes in the manufacture and commercialization of food, considering that Colombian legislation does not currently establish the obligatory for surveillance of L. monocytogenes in fresh cheeses. © 2019 Universidad Nacional de Colombia. All rights reserved.Item Validación de método microbiológico cilindro en placa para determinación de la potencia de neomicina en producto farmacéutico triconjugado crema (neomicina, clotrimazol y betametasona)(Universidad Santiago de Cali, 2023) Álzate González, Diego Alejandro; Rivera Sánchez, Sandra Patricia; Cruz Bolaños, Yimi WilliamThe finished product Betamethasone, clotrimazole, neomician cream, is manufactured for sale and export to the main countries of the world, such as: Mexico, the western part of South America, Ecuador, Peru and India. The determination of the potency of neomycin with the cylinder plate method allows demonstrating the effectiveness of the methodology, and can be used as a quality control method, in the plant located in the industrial zone of the city of Cali. The present work was carried out at the pharmaceutical company Lafrancol S.A.S plant Cali, where the challenge organism used in each stage of the process was evaluated, respectively the ATCC 12228 S. epidermidis strain. The stages of the process were: a) standardization of the inoculum, b) productivity tests of the culture media, c) development of the validation technique for the cylinder-in-plate microbiological method for the determination of neomycin potency. During the validation process, the comparison of the results obtained by two observers was included, demonstrating that the reproducibility complies, since the data shows that the coefficient of variation between each repetition with the different results of the standard and inoculum analyzed are less than 10 % being very homogeneous; Regarding accuracy, it was evidenced with the correlation coefficient of concordance between the counts of the observers, very consistent results were found. The effectiveness of the validation of the method was demonstrated, for the different stages of selectivity, which only evidenced the degradation of less than 70 % of the neomycin molecule in the acid conditionItem Validación de métodos microbiológicos para cuantificar salmonella spp, presente en aguas tratadas con fotofenton - La contaminación industrial de aguas. Una mirada microbiológica y molecular(Editorial Universidad Santiago de Cali, 2018) Rivera Sánchez, Sandra Patricia; Flórez, Liliana; Sanabria, JanethLos procesos avanzados de desinfección de aguas han arrojado resultados prometedores al ser evaluados utilizando el indicador bacteriano Escherichia coli (E. coli). Sin embargo, también se ha demostrado que E. coli es menos resistente a la desinfección que otras bacterias entéricas como Salmonella spp. Este estudio propone evaluar la efectividad de las técnicas recuento en placa y NMP frente al gold estándar DVC-FISH para la cuantificación de Salmonella sp., presente en aguas artificiales tratadas mediante el proceso de desinfección foto-fenton. Para el estudio, se realizaron pruebas diagnósticas donde se calculó la sensibilidad, especificidad y valores predictivos. Se observó que el método tradicional recuento en placa y NMP, tienen una mayor sensibilidad cuando hay alta concentración bacteriana. Sin embargo cuando se tiene a una dilución 10-2, la sensibilidad es del 51% con la técnica recuento en placa y del 100% con la técnica NMP. En conclusión, el proceso de desinfección con Foto-fenton, las bacterias no lograron ser inactivadas o inhibidas totalmente, debido a que presentaron daños reversibles que las hacen viables no cultivables en los métodos de recuento en placa presentando altos falsos negativos, pero en medios líquido como el método NMP se hizo cuantificable al tener bajas concentraciones de la bacteria.