Ciencia e Ingeniería en Alimentos y Biotecnología

URI permanente para esta comunidadhttp://repositorio.uta.edu.ec/handle/123456789/412

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Evaluación de la diversidad genómica y las relaciones filogenéticas de Salmonella enterica aislada a partir de pollo comercializado en mercados de la ciudad de Ambato mediante secuenciación de Tercera Generación
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-07)
Constante Chimborazo, Sasha Carolina
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Calero Cáceres, William Ricardo
Salmonellosis is one of the most important foodborne diseases worldwide, with S. enterica being one of the main pathogens associated with the poultry production chain. In Ecuador, the commercialization of chicken in traditional markets constitutes a potential source of exposure, especially in cities such as Ambato, where information on the genomic characterization of circulating strains is limited. The present study evaluated the genetic diversity and phylogenetic relationships of 12 S. enterica strains isolated from chicken carcasses and giblets marketed in Ambato markets. The strains were sequenced using Oxford Nanopore technology and characterized through bioinformatics tools to determine serotypes, sequence types, virulence genes, antimicrobial resistance genes, plasmids, and prophages. Phylogenetic relationships were established through comparative analysis of single nucleotide polymorphisms with reference strains. The genomes showed completeness levels ranging from 95.52 percent to 100 percent. Eleven isolates belonged to the Infantis serotype and one to the Kentucky serotype. All strains carried genes associated with resistance to aminoglycosides and sulfonamides, whereas blaCTX-M-65 was detected in seven isolates. Phylogenetic analysis revealed the circulation of a predominant clonal lineage of S. Infantis related to poultry isolates previously reported in Ecuador. The results demonstrate the presence of multidrug-resistant strains of epidemiological importance and highlight the value of third-generation sequencing for strengthening genomic surveillance under the One Health approach.
Evaluación de la diversidad genómica y las relaciones filogenéticas de Salmonella enterica aislada a partir de pollo comercializado en mercados de la ciudad de Ambato mediante secuenciación de Tercera Generación
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-07)
Castelo Fiallos, Yajaira Ivanova
;
Calero Cáceres, William Ricardo
Salmonellosis is one of the most important foodborne diseases worldwide, with S. enterica being one of the main pathogens associated with the poultry production chain. In Ecuador, the commercialization of chicken in traditional markets constitutes a potential source of exposure, especially in cities such as Ambato, where information on the genomic characterization of circulating strains is limited. The present study evaluated the genetic diversity and phylogenetic relationships of 12 S. enterica strains isolated from chicken carcasses and giblets marketed in Ambato markets. The strains were sequenced using Oxford Nanopore technology and characterized through bioinformatics tools to determine serotypes, sequence types, virulence genes, antimicrobial resistance genes, plasmids, and prophages. Phylogenetic relationships were established through comparative analysis of single nucleotide polymorphisms with reference strains. The genomes showed completeness levels ranging from 95.52 percent to 100 percent. Eleven isolates belonged to the Infantis serotype and one to the Kentucky serotype. All strains carried genes associated with resistance to aminoglycosides and sulfonamides, whereas blaCTX-M-65 was detected in seven isolates. Phylogenetic analysis revealed the circulation of a predominant clonal lineage of S. Infantis related to poultry isolates previously reported in Ecuador. The results demonstrate the presence of multidrug-resistant strains of epidemiological importance and highlight the value of third-generation sequencing for strengthening genomic surveillance under the One Health approach.
Optimización de un protocolo de extracción de ADN para la detección molecular de ooquistes de Toxoplasma gondii en coles verdes (Brassica oleracea var. Capitata) procedentes del mercado Central de Ambato
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-07)
Barreno Vargas, Carlos Alexander
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De La Torre Olvera, Helena Maritza
Toxoplasmosis is a foodborne zoonosis of public health relevance, particularly in pregnant women, neonates, and immunocompromised individuals. Raw vegetables may act as vehicles for Toxoplasma gondii oocysts due to contact with contaminated water, soil, and handling practices. In this context, green cabbage marketed in Ambato represents a sanitary matrix of interest, since its compact leaf structure favors the retention of parasitic particles and hinders their removal through washing. This study was framed within the Microbiology and Biotechnology research line, linked to food safety, and was developed using an experimental approach. Green cabbage samples were analyzed through recovery with PBS 1X whit Tween® 80, concentration using the Ritchie technique, microscopic observation with Lugol and safranin staining, and molecular evaluation. To optimize DNA extraction, a 2 cubed factorial design was applied, considering thermal lysis, mechanical lysis, and proteinase K digestion. The recovered DNA was quantified by spectrophotometry, assessed using A260 out of 280 and A260 out of 230 ratios, and verified by conventional PCR and electrophoresis, amplifying a 196 bp fragment. The results showed structures compatible with oocysts in 8 of 21 samples using Lugol staining and in 6 samples using safranin staining. The treatment with 10 thermal shock cycles, 2 mechanical lysis cycles, and 20 microliter of proteinase K showed the best overall performance. The scientific novelty lies in proposing a combined, cost-efficient protocol adapted to plant matrices, achieving 100 percentage PCR detection compared with 50 percentage using the GeneJET® kit.
Análisis de la contaminación por el parásito Toxoplasma gondii en el canal de riego Latacunga–Salcedo–Ambato, en el sector Izamba
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Vivanco Valverde, Sandy Adamary
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De La Torre Olvera, Helena Maritza
Toxoplasma gondii is a zoonotic parasite with a wide global distribution that poses a risk to public and veterinary health, causing catastrophic diseases such as toxoplasmosis. Its transmission through irrigation water constitutes a potential route of contamination for both crops and animals intended for human consumption. This study employed direct microscopy and PCR to analyze Toxoplasma gondii oocyst contamination in the Latacunga–Salcedo–Ambato (LSA) irrigation canal, in the Izamba sector. Microscopic results revealed a 45.73 percent contamination with oocysts compatible with Toxoplasma gondii, with a higher frequency in the localities of San Miguel Arcángel, San Francisco de Quillanloma, and Quillanloma la Playa. Physicochemical analyses of the water revealed that the presence of oocysts is not associated with water quality, but rather with factors such as local anthropogenic contamination. In contrast, the results of molecular identification targeting the B1 gene fragment did not detect the presence of Toxoplasma gondii genetic material due to inhibitors during PCR, caused by a mixed parasite load. The LSA canal did not show sufficient Toxoplasma gondii contamination to support the claim of a risk of transmission through irrigation water. However, the canal is a vital water infrastructure for the country's agricultural productivity, and its potential to act as an environmental reservoir for pathogenic parasites poses a threat to food safety, public health, and local veterinary health.
Caracterización de genomas completos de aislamientos de Salmonella spp. aisladas de muestras de agua del canal de riego Mocha-Quero-Ladrillos mediante secuenciación de tercera generación
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Portero Regalado, María José
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Arancibia Soria, Mirari Yosune
The presence of Salmonella enterica in the Mocha-Quero-Ladrillos irrigation canal represents a significant public health risk, as this water resource is used in agricultural activities and can serve as a vehicle for the transfer of pathogens to plant-based food products. The detection of the microorganism at multiple points along the system revealed that the canal functions as a reservoir capable of supporting the survival and dispersion of this pathogen in non-clinical environments, thereby increasing its potential impact on food safety and public health. To characterize the isolates, microbiological techniques and biochemical verification were applied, complemented by third-generation sequencing using Oxford Nanopore and specialized bioinformatic pipelines. This approach enabled the generation of complete genome assemblies and the identification of coding regions, mobile genetic elements, virulence factors, and intrinsic resistance determinants, including an aminoglycoside acetyltransferase conferring resistance to tobramycin and kanamycin. In silico serotyping confirmed that all isolates corresponded to the serovar Salmonella Typhimurium, while genomic parameters described their organization, variability, and degree of fragmentation. The phylogenetic analysis, integrating forty-nine isolates from different sources, demonstrated that the nine environmental strains from the canal exhibit a close evolutionary relationship with zoonotic sublineages ST19 and ST1649 associated with animal and food-related matrices in Ecuador. These findings indicate that the genotypes present in the canal are not exclusive aquatic variants but rather lineages circulating across multiple ecological niches.
Determinación de los subtipos de Toxoplasma gondii en muestras de lechuga (Lactuca sativa l.) del mercado América de Ambato
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Pacheco Jiménez, Yesenia Camila
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De La Torre Olvera, Helena Maritza
Toxoplasma gondii is a parasite that causes ocular toxoplasmosis, a zoonosis that affects one-third of the world's population and significantly harms pregnant women and immunocompromised individuals. It has been shown to have several routes of transmission, mainly related to cat feces and undercooked meat. However, there are also routes of transmission through raw vegetables, especially green leafy vegetables such as lettuce (Lactuca sativa L). In Ecuador, there is no information on the presence of this parasite in vegetable matrices, nor on its molecular characterization. The objective of this research was to determine the presence of T. gondii in lettuce sold in the América market in Ambato and to identify whether it belongs to subtype II or III by amplifying the SAG2 gene and using nested PCR. A descriptive and exploratory analysis was carried out, in which 21 samples from seven market stalls were analyzed. Eleven of these samples were identified microscopically, and seven of them showed molecular evidence of the presence of T. gondii (33, percent). However, none of the samples were compatible with subtypes II or III, suggesting that non-archetypal strains of T. gondii may be circulating in the city. In conclusion, the study determined the presence of T. gondii in lettuce samples and provides preliminary evidence on the genetic variability of the parasite, laying the groundwork for future research.
Determinación de las condiciones óptimas de cultivo de Haematococcus pluvialis para la producción de biomasa y astaxantina
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Esquivel Galvez, Kevin Wladimir
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García Solís, Mario Daniel
This study evaluated the optimization of culture conditions for Haematococcus pluvialis to maximize biomass and astaxanthin production, a pigment of high biotechnological value. The main objective was to determine the optimal cultivation conditions by comparing three media (BBM, Fuerza Verde, and Bonanza) under two aeration rates (250 and 1000 mL per min). The methodology included a factorial design, monitoring of growth kinetics through cell counting, biomass quantification by dry weight, induction of carotenogenesis using light and salt stress, and pigment extraction assisted by ultrasound. The results showed that Bonanza achieved the highest cell densities and productivities, confirming its non-limiting nutrient profile. Fuerza Verde exhibited intermediate values, while BBM displayed moderate growth with a final decline associated with nutrient limitation. ANOVA revealed a significant effect of the culture medium and the medium per aeration interaction on cell density. Regarding astaxanthin, only BBM showed the characteristic absorption peak at 482 nm and measurable pigment concentrations, whereas Fuerza Verde and Bonanza maintained chlorophyll-dominated profiles linked to their higher NPK availability. Overall, enriched media favored biomass accumulation, whereas nutrient-limited conditions, such as those in BBM, promoted carotenoid induction. This work provides comparative evidence on the combined influence of nutrients and aeration on the physiology of Haematococcus pluvialis, contributing to the development of more efficient cultivation strategies for biotechnological applications.
Desarrollo de un manjar libre de lactosa bajo en calorías a partir de la combinación de leche de coco (Cocos nucifera L.) y piña (Ananas comosus L.
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Ingeniería en Alimentos, 2026-01)
Guamán Cóndor Evelyn Nataly
;
Ortiz Escobar Jacqueline de las Mercedes
The objective of this thesis was to develop an alternative delicacy based on coconut milk and pineapple pulp. The proposal arose as an alternative response to the creation of new, innovative, and healthy products with low caloric content that provide nutritional value and are palatable to today's consumers, using products that are rich in vitamins, well-known in the market, and used in everyday diets. Three formulations were developed, keeping the content of sucralose, sodium bicarbonate, vanilla essence, liquid glucose, carboxymethyl cellulose (CMC), and carrageenan constant to maintain the desired flavor and texture, with different amounts of coconut milk and pineapple pulp. To select the best treatment, a sensory evaluation of color, smell, taste, texture, and acceptability was analyzed, with the best treatment being T3, which contains 50.68 percent coconut milk and 33.78 percent pineapple pulp. Physical-chemical analyses were performed to determine the content of soluble solids, ash, moisture, pH, Brix degrees, and nutritional characteristics such as total protein, fat content, dietary fiber, and total sugars, as well as microbiological characteristics (molds, yeasts, coliforms, and E. coli). The resulting delicacy was of high quality and complies with current regulations. It was concluded that the delicacy obtained is a low-calorie food alternative that also contains fiber and protein, ensuring nutritional value for consumption by adults and children.
Análisis de la contaminación por el parásito Cryptosporidium en fresas (Fragaria × ananassa) comercializados en el Mercado Central del Cantón Ambato, Ecuador
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Balseca Amán, Jennifer Fernanda
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De la Torre Olvera, Helena Maritza
The microbiological safety of fresh fruits intended for raw consumption, such as strawberries (Fragaria × ananassa), is essential for public health, especially in regions with limited surveillance of parasitic pathogens. Cryptosporidium spp. is a protozoan of global importance due to its environmental resistance and its ability to cause severe diarrhea invulnerable populations. Its potential presence in food represents a silent transmission route, making it necessary to assess contamination at points of direct sale to consumers to generate local evidence that guides sanitary control policies. This study analyzed strawberry samples collected at the Central Market of Ambato using an integrated methodology. The Sheather sucrose solution flotation technique was applied for concentration and preliminary microscopic observation of oocysts, complemented by molecular confirmation using polymerase chain reaction (PCR) targeting the 18S rRNA gene, ensuring specificity in detection. The results showed the absence of Cryptosporidium spp. in all samples, ruling out its presence at detectable levels. Although favorable for immediate risk, this finding underscores the need to maintain good agricultural and post-harvest handling practices, reinforce domestic washing, and consolidate molecular surveillance as a key tool for future research in the local food chain.
Análisis de la contaminación microbiológica por patógenos alimentarios en el chorizo ambateño de los mercados de la zona urbana del cantón Ambato
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Alimentos, 2025-07)
Chávez Poaquiza Stiven Alexander
;
Sánchez Garnica Manoella Alejandra
Food safety is a critical challenge for artisanal meat products marketed in traditional markets in Latin America. This study evaluated the presence of microbiological pathogens in chorizo ambateño sausage sold in eight urban markets in Ambato Canton, Ecuador. Samples of unbranded chorizo were collected and analyzed using official NTE INEN methodologies for the detection and quantification of Escherichia coli, Staphylococcus aureus, and Salmonella spp. at 0, 7, and 15 days of storage under controlled refrigeration conditions. The results showed critical storage conditions: 75 percent of the points of sale lacked adequate refrigeration and air-tight packaging. In the case of E. coli, 100 percent of the initial samples exceeded the regulatory limit (less than 1x10 to the third power CFU per-g), increasing to 100 percent non-compliance by day 15. S. aureus showed a similar pattern, with 37,5 percent of non-compliant samples at the beginning, also increasing to 100 percent by the end of the period. In contrast, Salmonella spp. were not detected in any of the samples analyzed. Comprehensive strategies aimed at improving product safety have been proposed, including the implementation of a cold chain, standardized hygiene protocols, optimized packaging systems, and training programs for vendors. The application of these measures could reduce the proportion of non-conforming samples by up to 80 percent, significantly improving the food safety of chorizo ambateño and contributing to the protection of public health in Ecuador.

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