Determinación de los perfiles de susceptibilidad a antibióticos y genes blaCMY-2 y blaCTX-M en bacterias del género Salmonella aisladas de tres matrices de la cadena de producción avícola de Costa Rica
Fecha
2022
Autores
Hernández, Raquel
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Editor
Universidad Nacional, Costa Rica
Resumen
El objetivo de esta investigación fue determinar la susceptibilidad a 20
antibióticos y la presencia de genes de resistencia a betalactámicos, específicamente
blaCMY-2 y blaCTX-M en aislamientos de Salmonella enterica recuperados de pollo de
engorde en tres matrices dentro de la cadena avícola de Costa Rica. Para lograrlo se
recurrió a la determinación de los perfiles de susceptibilidad a los antibióticos por el
método de Kirby-Bauer y técnicas de caracterización molecular.
Se encontró resistencia en todas las familias de antibióticos en estudio, siendo
un 91.3% de las bacterias multirresistentes. Aislamientos con perfil de resistencia a los
betalactámicos evidenciado por el método de Kirby-Bauer fueron seleccionados para
determinar la presencia de los genes mediante la técnica de PCR.
En un estudio paralelo se efectuó secuenciación de genoma completo a 71 de
los aislamientos de la presente investigación, la información generada fue utilizada
para la detección de genes de resistencia de interés en salud pública mediante
ResFinder versión 4.0. El gen blaCTX-M-65, fue encontrado en un 67.6% y el gen
blaCMY-2 no fue detectado, por lo que se recurrió a la validación de estos resultados por
medio de la técnica de PCR convencional, confirmándose la ausencia del gen
blaCMY-2 en los aislamientos con perfil de resistencia a los betalactámicos. Además, se
encontraron genes de resistencia a los aminoglucósidos, al cloranfenicol, a la
fosfomicina, a las sulfonamidas y a las tetraciclinas.
Se establecieron los serovares de Salmonella por medio del software The
Salmonella In Silico Typing Resource (SISTR) versión 1.1.1, obteniendo un 2.8% de
prevalencia del serovar S. Kentucky, 2.8% de S. Anatum y un 94.4% del serovar
xv
S. Infantis, siendo este último reportado como uno de los principales serovares
aislados de infecciones por Salmonella en seres humanos de Costa Rica.
Dados los resultados obtenidos, se recomienda indagar sobre las vías por
medio de las cuales las bacterias adquieren la resistencia con el fin de determinar las
medidas de intervención más efectivas. Asimismo, reforzar los sistemas de Buenas
Prácticas de Higiene, así como Análisis de Riesgos y Puntos Críticos de Control a nivel
de planta de cosecha, evitar la contaminación en punto de venta y educar al
consumidor final sobre la correcta preparación de la carne de pollo siguiendo estrictas
normas de manipulación de alimentos, con el fin de prevenir las infecciones en seres
humanos y en animales.
The research objective was to determine the susceptibility to twenty antibiotics and the presence of beta-lactam resistance genes, specifically blaCMY-2 and blaCTX-M in isolates of Salmonella enterica recovered from broiler chickens in three areas in the poultry chain in Costa Rica. The Kirby-Bauer method and molecular characterization techniques were used to achieve the determination of the antibiotic’s susceptibility. Resistance was found in all families of antibiotics within the study, with 91.3% of isolates resistant to three or more families of antibiotics, classifying them as multiresistant. Isolates with a resistance profile to beta-lactams, shown by the Kirby-Bauer method, were selected to determine the presence of genes with the PCR technique. Complete genome sequencing in a parallel study of this investigation was used for the detection of resistance with interest in public health by means of ResFinder version 4.0. The blaCTX-M-65 gene was found in 67.6% of the isolates, while the blaCMY-2 gene was not detected. These results were validated with the conventional PCR technique, whereas the absence of the blaCMY-2 gene was confirmed in isolates with a beta-lactam resistance profile. Genes resistant to aminoglycosides, chloramphenicol, fosfomycin, sulfonamides and tetracyclines were also detected. The Salmonella serovars were determined using the software The Salmonella In Silico Typing Resource (SISTR) version 1.1.1 software, obtaining a 2.8% prevalence of the serovar S. Kentucky, 2.8% of S. Anatum and 94.4% of the serovar S. Infantis, the latter being reported as one of the main serovars isolated from Salmonella infections in humans from Costa Rica. xvii Based on the resistance statistics found within this study, further investigation is recommended to determine how the bacteria acquires resistance to implement the most effective intervention measures. To prevent infections in both humans and animals, strict protocols must be reinforced and implemented. This includes following the systems of Good Hygiene Practices (GHP) and Hazard Analysis and Critical Control Points (HACCP) in slaughterhouses, avoid contamination at sales, and educate the final consumer on the correct preparation of poultry meat, following strict food handling standards.
The research objective was to determine the susceptibility to twenty antibiotics and the presence of beta-lactam resistance genes, specifically blaCMY-2 and blaCTX-M in isolates of Salmonella enterica recovered from broiler chickens in three areas in the poultry chain in Costa Rica. The Kirby-Bauer method and molecular characterization techniques were used to achieve the determination of the antibiotic’s susceptibility. Resistance was found in all families of antibiotics within the study, with 91.3% of isolates resistant to three or more families of antibiotics, classifying them as multiresistant. Isolates with a resistance profile to beta-lactams, shown by the Kirby-Bauer method, were selected to determine the presence of genes with the PCR technique. Complete genome sequencing in a parallel study of this investigation was used for the detection of resistance with interest in public health by means of ResFinder version 4.0. The blaCTX-M-65 gene was found in 67.6% of the isolates, while the blaCMY-2 gene was not detected. These results were validated with the conventional PCR technique, whereas the absence of the blaCMY-2 gene was confirmed in isolates with a beta-lactam resistance profile. Genes resistant to aminoglycosides, chloramphenicol, fosfomycin, sulfonamides and tetracyclines were also detected. The Salmonella serovars were determined using the software The Salmonella In Silico Typing Resource (SISTR) version 1.1.1 software, obtaining a 2.8% prevalence of the serovar S. Kentucky, 2.8% of S. Anatum and 94.4% of the serovar S. Infantis, the latter being reported as one of the main serovars isolated from Salmonella infections in humans from Costa Rica. xvii Based on the resistance statistics found within this study, further investigation is recommended to determine how the bacteria acquires resistance to implement the most effective intervention measures. To prevent infections in both humans and animals, strict protocols must be reinforced and implemented. This includes following the systems of Good Hygiene Practices (GHP) and Hazard Analysis and Critical Control Points (HACCP) in slaughterhouses, avoid contamination at sales, and educate the final consumer on the correct preparation of poultry meat, following strict food handling standards.
Descripción
Mención de Honor Cum Laude en Tesis de grado (Escuela de Medicina Veterinaria)
Modalidad: Tesis
Modalidad: Tesis
Palabras clave
SALMONELLA, POLLOS, ANTIBIÓTICOS, PRODUCCIÓN DE CARNE, BACTERIOLOGIA VETERINARIA, CHICKENS, ANTIBIOTICS, MEAT PRODUCTION, VETERINARY BACTERIOLOGY