Ciencias Agropecuarias

URI permanente para esta comunidadhttp://repositorio.uta.edu.ec/handle/123456789/870

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2020 - 20263

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Fecha de inicio: 2020Tema: search.filters.subject.BETALACTÁMICOS

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  • Miniatura
    Item type:Ítem,
    Evaluación de la resistencia de Proteus mirabilis a Quinolonas y Betalactámicos y su relación con factores de virulencia
    (Universidad Técnica de Ambato Maestría En Medicina Veterinaria, 2026-07)
    Borja Ramos, Alva Tatiana
    ;
    Cruz Quintana, Sandra Margarita
    Antimicrobial resistance is a growing threat to public health, veterinary medicine and food safety. Proteus mirabilis is an opportunistic Gram-negative bacillus recognized for its occurrence in animals, animal-derived foods and environments associated with the food chain. The aim of this study was to evaluate the resistance of P. mirabilis isolated from chicken meat to quinolones and β-lactams, and to determine its relationship with virulence factors of clinical, veterinary and epidemiological importance. The study was conducted using a non-experimental, cross-sectional and descriptive design. A total of 41 P. mirabilis strains preserved at the Microbiology and Molecular Biology Laboratory of the Universidad Técnica de Ambato were analysed. These strains originated from registered and non-registered retail outlets in Ambato canton. Resistance genes were detected by PCR: gyrA and aac (6’)-Ib-cr, associated with quinolone resistance, and blaTEM and blaCTX-M, associated with β-lactam resistance. The amplified products were visualised by agarose gel electrophoresis. In addition, virulence factors were assessed through haemolysis on blood agar and swarming motility. The results showed high frequencies of resistance genes. The gyrA gene was detected in 85.37% of the isolates and aac (6’)-Ib-cr in 80.49%. Regarding β-lactams, blaTEM was identified in 80.49% and blaCTX-M in 58.54% of the strains. These findings demonstrate that chicken meat may act as a reservoir of P. mirabilis carrying genetic determinants of antimicrobial resistance. The coexistence of resistance genes with haemolysis and swarming suggests a potential health risk; therefore, strengthening molecular surveillance, food safety measures and the rational use of antimicrobials under the One Health approach is recommended.
  • Miniatura
    Item type:Ítem,
    Presencia de genes de resistencia a fluoroquinolonas y betalactámicos en Proteus mirabilis aislados en carne de pollo en el cantón Ambato
    (2024-08)
    Fiallos Barros, Lizbeth Estefanía
    ;
    Cruz Quintana, Sandra Margarita
    This study focused on the identification and analysis of antimicrobial resistance genes in Proteus mirabilis strains isolated from chicken meat samples from the city of Ambato. In particular, two key genes were investigated: gyrA associated with resistance to fluoroquinolones, and blaTEM-1, related to beta-lactam resistance. For the detection and analysis of these genes, advanced molecular techniques were used, including Polymerase Chain Reaction (PCR) and gel electrophoresis. First, DNA extraction from the samples was performed using standardized methods that ensure purity and adequate concentration of DNA for subsequent amplification, in the PCR phase, specific primers were used to amplify the target sequences of the gyrA and blaTEM-1 genes. The results showed successful amplification of the gyrA gene in all samples analyzed, with a base size of 850 bp, confirming a 100% prevalence of this gene in Proteus mirabilis strains. On the other hand, the amplification of the blaTEM- 1 gene was not universal in all samples, it was detected in 58.3% of the strains analyzed. This finding suggests the presence of variability in beta-lactam resistance in the samples, indicating that although blaTEM-1 is a prevalent gene it is not the only resistance mechanism present. This result underscores the need to consider other betalactam resistance genes and other resistance mechanisms in future studies. This research provides detailed insight into antimicrobial resistance, the high prevalence of the gyrA gene and the considerable presence of the blaTEM-1 gene indicate significant resistance to fluoroquinolones and beta-lactams, respectively. These findings emphasize the importance of continuous and detailed monitoring of antimicrobial resistance in the food chain to implement effective control strategies and protect public health.
  • Miniatura
    Item type:Ítem,
    Determinación de la presencia de genes de resistencia a betalactámicos y evaluación de diversidad clonal en aislados de Escherichia coli de origen canino de la ciudad de Ambato
    (2020-03-19)
    Garcés Arias, Xiomara Sthefanny
    ;
    Calero Cáceres, William Ricardo
    The evolution and spread of multiresistant bacteria is considered prioritary, considering their impact in public health and animal safety worldwide. Therefore, the detection of reservoirs, routes of dissemination and evolution of these bacteria is aimed in order to limit their negative effects on public and animal health. Extended-spectrum-betalactamase Escherichia coli producer is considered an emerging health problem. In Ecuador, there are few available data on the molecular epidemiology of those of ESBL- E. coli producing bacteria in animals and environment. In the present study, the presence of beta-lactam resistance genes was evaluated as well as the clonal diversity of E. coli isolates of canine origin from the city of Ambato. The highest presence of beta-lactam resistance genes occurred in dogs with owners, in contrast to stray dogs. The most frequently detected genes were blaCTX-M and blaTEM. The blaSHV and blaCMY genes had a lower detection rate, however, these were found in combination with the blaCTX-M and blaTEM genes, indicating that they are isolates with considerable virulence. The analysis of clonal relatedness through the amplification of palindromic repetitive regions (GTG5) detected that the isolates comes from different lineages, discarding the hypothesis that suggest the presence of multi-resistant clones with a common ancestor, suggesting that their genotypes were acquired through recent horizontal genetic transmission. Dogs can act as a silent reservoir of microorganisms with antibiotic multiresistance genotypes. It is necessary an extended review of waste management procedures is necessary, as well as interactions with humans and animals under certain circumstances like immunological disorders.