Ciencia e Ingeniería en Alimentos y Biotecnología

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

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Diseño de cócteles de bacteriófagos con sinergia lítica y estabilidad funcional para el control de Salmonella enterica serovar Infantis de origen avícola ecuatoriano
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Silva Arellano, Katherine Gabriela
;
Calero Cáceres, William Ricardo
This study presents a comprehensive approach for the rational design of bacteriophage cocktails aimed at controlling Salmonella enterica serovar Infantis, a pathogen of increasing public health concern within the Ecuadorian poultry industry. Using an initial collection of lytic phages isolated in the country, we conducted an exhaustive characterization of their lytic spectra, bactericidal activity, and functional stability under conditions simulating poultry processing environments, including refrigeration and exposure to controlled chlorine concentrations. This analysis enabled the identification of phages with robust performance, as well as the exclusion of those exhibiting limited or unstable activity. Subsequently, experimental combinations were assessed to determine phage compatibility, distinguishing synergistic interactions from antagonistic effects that could compromise cocktail efficacy. The selected mixtures demonstrated complementary lytic activity, expanded host range coverage, and consistent stability under the operational conditions evaluated. The formulation process was supported by multifactorial statistical modeling and estimated marginal means analyses, ensuring that the final selection was guided by quantitative and reproducible criteria. Overall, the findings demonstrate the feasibility of developing phage cocktails with strong potential for implementation in microbiological control programs within the poultry production chain. This study provides evidence supporting the use of phages as a biotechnological alternative against multidrug-resistant S. Infantis and establishes a solid foundation for subsequent efficacy assessments in meat matrices and real production systems, ultimately contributing to enhanced food safety and mitigation of risks associated with emerging pathogens in Ecuador.
Diseño de cócteles de bacteriófagos con sinergia lítica y estabilidad funcional para el control de Salmonella enterica serovar Infantis de origen avícola ecuatoriano
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2026-01)
Santamaria Rodríguez, Justin Alexander
;
Calero Cáceres, William Ricardo
This study presents a comprehensive approach for the rational design of bacteriophage cocktails aimed at controlling Salmonella enterica serovar Infantis, a pathogen of increasing public health concern within the Ecuadorian poultry industry. Using an initial collection of lytic phages isolated in the country, we conducted an exhaustive characterization of their lytic spectra, bactericidal activity, and functional stability under conditions simulating poultry processing environments, including refrigeration and exposure to controlled chlorine concentrations. This analysis enabled the identification of phages with robust performance, as well as the exclusion of those exhibiting limited or unstable activity. Subsequently, experimental combinations were assessed to determine phage compatibility, distinguishing synergistic interactions from antagonistic effects that could compromise cocktail efficacy. The selected mixtures demonstrated complementary lytic activity, expanded host range coverage, and consistent stability under the operational conditions evaluated. The formulation process was supported by multifactorial statistical modeling and estimated marginal means analyses, ensuring that the final selection was guided by quantitative and reproducible criteria. Overall, the findings demonstrate the feasibility of developing phage cocktails with strong potential for implementation in microbiological control programs within the poultry production chain. This study provides evidence supporting the use of phages as a biotechnological alternative against multidrug-resistant S. Infantis and establishes a solid foundation for subsequent efficacy assessments in meat matrices and real production systems, ultimately contributing to enhanced food safety and mitigation of risks associated with emerging pathogens in Ecuador.
Análisis genómico comparativo de los bacteriófagos líticos F7M1, F4M1B y F8M2 de Salmonella enterica serovar Infantis. Articulado al proyecto de investigación aprobado mediante Resolución Nro. UTA-CONIN-2023 0294-R
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-07)
Galarza Mayorga Priscila Jael
;
Calero Cáceres William Ricardo
Poultry production represents a favorable environment for the spread of pathogenic bacteria such as S. enterica. The intensive use of antibiotics has contributed to the emergence of multidrug-resistant strains, making lytic bacteriophages a promising alternative. However, it is essential to analyze the complete genomes of bacteriophages to identify the presence of genes that may produce toxins, virulence factors, or antibiotic resistance. This study used Oxford Nanopore technology to sequence three lytic bacteriophages of S. enterica serovar Infantis named F7M1-Monchaphage, F4M1B-Cloudphage, and F8M2-Gilionphage. According to the genomic characterization, F7M1 encodes 41 functional proteins and has a length of 59,185 bp with a GC content of 56.46 percent, while F4M1B encodes 43 functional proteins and has a length of 38,972 bp with a GC content of 47.52 percent. Finally, F8M2 encodes 13 functional proteins and has a length of 17,011 bp with a GC content of 48.99 percent. Genetic comparison and phylogenetic analysis placed F7M1, F4M1B, and F8M2 within the genera Chivirus, Lederbergvirus, and Berlinvirus, respectively. In F7M1 and F8M2, no genes associated with toxin production or antibiotic resistance were detected. However, F4M1B contained lysogeny-related genes, confirming it as a temperate phage, and thus it was excluded as a candidate. In contrast, F7M1 and F8M2 are considered promising candidates for the biocontrol of Salmonella in Ecuador's poultry sector.
Uso de la endolisina fágica LysK recombinante frente a cepas de Staphylococcus warneri
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-07)
Castañeda Chinga Jean Carlos
;
Garcés Moncayo María Daniela
Antimicrobial resistance represents one of the main threats to global public health, with projections estimating 10 million annual deaths by 2050 if effective therapeutic alternatives are not developed. In this context, bacteriophage endolysins emerge as promising antimicrobial agents due to their specificity, efficacy, and low potential for resistance generation. The present research work is focused on the recombinant expression, purification, and characterization of the LysK endolysin derived from bacteriophage vB_G30_01. The implemented methodology comprised three main phases: first, heterologous expression of the endolysin in Escherichia coli BL21 using the pET-28a(+) system, optimizing induction conditions with IPTG; second, purification of the recombinant protein through Ni-NTA affinity chromatography and verification by SDS-PAGE; and third, evaluation of in vitro antimicrobial activity against Staphylococcus warneri through determination of minimum inhibitory and bactericidal concentrations.The scientific novelty of the study lies in the functional characterization of a native endolysin identified in the genome of an autochthonous bacteriophage, constituting the first report of recombinant expression and antimicrobial evaluation of this specific lytic enzyme. The obtained antimicrobian results provide solid foundations for the future development of this endolysin as a therapeutic alternative in the treatment of staphylococcal infections, contributing significantly to the arsenal of biotechnological tools available to combat antimicrobial resistance.
Bioprospección de bacteriófagos líticos contra bacterias patógenas causantes de marchitez bacteriana en cultivos selectos de tomate riñón en Tungurahua. Articulado al proyecto de investigación aprobado mediante Resolución Nro. UTA-CONIN-2023-0294-R.
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-02)
Orozco Burbano, Erika Tatiana
;
Calero Cáceres, William Ricardo
Bacterial wilt is one of the most serious plant diseases worldwide, caused by the presence of pathogenic bacteria in soil and plants. It mainly affects the Solanaceae family, including tomato crops, causing large economic losses due to the destruction of crops. In this study, bacteria present in crops with bacterial wilt symptoms of tomato crops in Tungurahua were isolated, identified and characterized. Biochemical and morphological tests were performed to rule out strains of no interest in the study. A MALDI-ToF analysis was then performed in order to identify the pathogen strains causing the disease. K. cowanii and C. flaccumfaciens were found to be the main plant pathogenic bacteria in the area. Additionally, 20 bacteriophages present in soil samples with different types of morphology were isolated and purified, only against K. cowanii, due to the absence of bacteriophages for C. flaccumfaciens. By performing the drop test with different bacterial hosts, it was shown that the isolated bacteriophages have a high specific lytic capacity for K. cowanii and do not present any risk against beneficial bacteria. Bioprospecting of the bacteriophages found suggests their use as a potential biological control agent against important phytopathogenic diseases such as bacterial wilt. The results obtained highlight the use of bacteriophages as a sustainable alternative benefiting the agricultural systems of the province of Tungurahua.
Bioprospección de bacteriófagos líticos contra bacterias patógenas causantes de marchitez bacteriana en cultivos selectos de tomate riñón en Tungurahua. Articulado al proyecto de investigación aprobado mediante Resolución Nro. UTA-CONIN-2023-0294-R.
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2025-02)
Altamirano Chérrez, Edgar Ricardo
;
Calero Cáceres William Ricardo
Bacterial wilt is one of the most serious plant diseases worldwide, caused by the presence of pathogenic bacteria in soil and plants. It mainly affects the Solanaceae family, including tomato crops, causing large economic losses due to the destruction of crops. In this study, bacteria present in crops with bacterial wilt symptoms of tomato crops in Tungurahua were isolated, identified and characterized. Biochemical and morphological tests were performed to rule out strains of no interest in the study. A MALDI-ToF analysis was then performed in order to identify the pathogen strains causing the disease. K. cowanii and C. flaccumfaciens were found to be the main plant pathogenic bacteria in the area. Additionally, 20 bacteriophages present in soil samples with different types of morphology were isolated and purified, only against K. cowanii, due to the absence of bacteriophages for C. flaccumfaciens. By performing the drop test with different bacterial hosts, it was shown that the isolated bacteriophages have a high specific lytic capacity for K. cowanii and do not present any risk against beneficial bacteria. Bioprospecting of the bacteriophages found suggests their use as a potential biological control agent against important phytopathogenic diseases such as bacterial wilt. The results obtained highlight the use of bacteriophages as a sustainable alternative benefiting the agricultural systems of the province of Tungurahua.
Evaluación de la producción y conservación de bacteriófagos líticos de Salmonella enterica con medios de cultivo económicos y sustancias crioprotectoras alternativas
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2024-02)
Romero Rovayo, Nathaly Johanna
;
Calero Cáceres, William Ricardo
Bacteriophages represent an alternative for the elimination of potentially pathogenic microorganisms. However, their use involves numerous stages that include selection, generation of high phage titers, preservation, characterization, and assessments of their effectiveness. These processes require a significant financial investment in culture media and preservation methods, which could limit their applicability in scaling up. Therefore, in this study, cost-effective culture media were generated and alternative cryoprotective substances were used to improve the efficiency in obtaining and preserving high phage titers, thus facilitating their future industrial use. The formulation of culture media was carried out, using the avian-origin strain S. enterica serovar Infantis S11V23 as the host, and the bacteriophage Berlinvirus sp. F6_melonhead. Initially, the behavior of the bacteria and the phage against each formulation was analyzed. Finally, alternative cryoprotective substances were employed to evaluate the preservation of the titer over a period of 56 days at temperatures of 4, 20, and -70 degrees Celsius. The feasibility of obtaining bacterial and phage biomass using cost-effective culture media based on malt extract and brewer's yeast extract was proven, being effective for generating high phage titers. Furthermore, the stability of the bacteriophages at -70 Degrees Celsius was achieved using de-lactosed milk as a cryoprotective substance. The results highlight the possibility of scaling up bacteriophage production with limited resources and greater efficiency in generating bioproducts for the control of S. enterica useful for the poultry industry.
Análisis genómico de los bacteriófagos líticos f6 y f14 de Salmonella enterica Serovar Infantis
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2024-02)
Gavilanes Tiban, Joselyn Micaela
;
Calero Cáceres, William Ricardo
Food contamination by Salmonella represents an emerging global public health crisis, with poultry farms being the principal reservoirs of this pathogen. The excessive use of antibiotics on these farms contributes to the increase in antibiotic resistance. In response to this situation, lytic bacteriophages emerge as a promising alternative for the biocontrol of Salmonella. However, it is essential to perform a detailed analysis of the complete genome of these bacteriophages before their implementation, in order to identify the presence of virulence and antibiotic resistance genes that could affect the safety of their in vivo implementation. In this study, two lytic bacteriophages of S. enterica serovar Infantis, named F6_melonhead and F14_guaytamphage, were sequenced using third-generation Oxford Nanopore technology. Genomic characterization revealed that F6 has a length of 29,097 bp and a GC content of 48.57 percent, encoding 30 functional proteins, while F14 has a length of 59,339 bp, a GC content of 56.44 percent, and encodes 49 functional proteins. In both bacteriophages, the presence of genes producing toxins, bacterial virulence factors, or antibiotic resistance genes was ruled out. Genetic comparison and phylogenetic analysis placed F6_melonhead and F14_guaytamphage within the Berlinvirus and Chivirus genera, respectively. These findings position F6_melonhead and F14_guaytamphage as promising candidates for the biocontrol of Salmonella in the poultry sector in Ecuador.
Análisis genómico de los bacteriófagos líticos f6 y f14 de Salmonella enterica Serovar Infantis
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2024-02)
Altamirano Cisneros, Karen Analía
;
Calero Cáceres, William Ricardo
with poultry farms being the principal reservoirs of this pathogen. The excessive use of antibiotics on these farms contributes to the increase in antibiotic resistance. In response to this situation, lytic bacteriophages emerge as a promising alternative for the biocontrol of Salmonella. However, it is essential to perform a detailed analysis of the complete genome of these bacteriophages before their implementation, in order to identify the presence of virulence and antibiotic resistance genes that could affect the safety of their in vivo implementation. In this study, two lytic bacteriophages of S. enterica serovar Infantis, named F6_melonhead and F14_guaytamphage, were sequenced using third-generation Oxford Nanopore technology. Genomic characterization revealed that F6 has a length of 29,097 bp and a GC content of 48.57 percent, encoding 30 functional proteins, while F14 has a length of 59,339 bp, a GC content of 56.44 percent, and encodes 49 functional proteins. In both bacteriophages, the presence of genes producing toxins, bacterial virulence factors, or antibiotic resistance genes was ruled out. Genetic comparison and phylogenetic analysis placed F6_melonhead and F14_guaytamphage within the Berlinvirus and Chivirus genera, respectively. These findings position F6_melonhead and F14_guaytamphage as promising candidates for the biocontrol of Salmonella in the poultry sector in Ecuador.
Bioprospección de bacteriófagos líticos de Salmonella enterica multirresistente de origen avícola de la provincia de Tungurahua
(Universidad Técnica de Ambato. Facultad de Ciencia e Ingeniería en Alimentos y Biotecnología. Carrera de Biotecnología, 2023-09)
Topa Pila, Paulina Liseth
;
Calero Cáceres, William Ricardo
The use of bacteriophages has emerged as a promising alternative to address the antimicrobial resistance crisis, driven by the indiscriminate use of antibiotics in the poultry industry. This study isolated lytic bacteriophages specific to multi-resistant S. enterica of poultry origin in Tungurahua province from contaminated water sources and evaluated them based on their lytic profiles and low-temperature stability. Under the Microbiology and Biotechnology research line, the isolation and purification of bacteriophages was carried out using two strains of S. enterica serovar Infantis, by the double-layer agar method. Lytic profiles were evaluated by the gout test. The stability of the bacteriophages was tested through the reduction of the phage titre, at refrigeration and freezing temperatures, with pH 5.5 and 7.2. We isolated a total of 27 bacteriophages. Evaluation against 38 Salmonella isolates from poultry and five different S. enterica serovars revealed seven bacteriophages with a broad host range. Stability tests of bacteriophages F6, F7M1, and F4M1B, showed that temperature and pH significantly influenced phage titer reduction and bacterial lysis, underscoring the importance of understanding bacteriophages stability conditions for successful application. The results highlight the potential use of these lytic bacteriophages in designing biocontrol products for the poultry industry.

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