Identificación de genes de resistencia a desinfectantes en cepas pre y post pandémicas de Staphylococcus aureus aisladas desde matrices alimentarias.
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Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Staphylococcus aureus es la especie más importante del género Staphylococcus. Se describe como un microorganismo coco Gram-positivo no formador de esporas, anaerobio facultativo, oportunista y coagulasa positivo. Se caracteriza por ser un patógeno nosocomial que coloniza la piel, nariz y/o aparato gastrointestinal de las personas provocando una gran variedad de enfermedades; y la OMS lo ha catalogado como un patógeno de prioridad alta debido a que presenta resistencia a la meticilina. Investigaciones recientes dan cuenta que a través de los años S. aureus no solo ha generado resistencia a antimicrobianos sino también a desinfectantes como los compuestos de amonio cuaternario. Como consecuencia a la pandemia de COVID-19, se ha aumentado notablemente el uso de estos compuestos y se desconoce el estado actual de la resistencia a desinfectantes en cepas de S. aureus en nuestro país. El objetivo de esta investigación fue determinar la prevalencia de genes de resistencia a desinfectantes en cepas de S. aureus pre y post pandemia aisladas desde matrices alimentarias. Para ello se seleccionaron 54 cepas comprendidas entre los años 2012 y 2023, y se identificó la presencia de los genes de resistencia a desinfectantes qacA/B y smr mediante el uso de la técnica de PCR. Solo el 1.9% presentó el gen qacA/B y resultados similares se obtuvieron al realizar la amplificación del gen smr, dando indicios de que las cepas de S. aureus de origen alimentario no sufren del mismo modo la presión selectiva ejercida por los antimicrobianos y/o desinfectantes que las cepas encontradas entornos hospitalarios. Sin embargo, es necesario contar con un tamaño de muestra mayor y realizar más ensayos a futuro para poder tener resultados estadísticos robustos y significativos que confirmen esta conjetura.
Staphylococcus aureus is the most important species of the genus Staphylococcus. It is described as a non-spore-forming, facultative anaerobic, opportunistic, coagulase-positive Gram-positive coccus microorganism. It is characterized by being a nosocomial pathogen that colonizes the skin, nose and/or gastrointestinal tract of people, causing a wide variety of diseases; and the WHO has classified it as a high priority pathogen because it presents resistance to methicillin. Recent research shows that through the years, S. aureus has not only generated resistance to antimicrobials but also to disinfectants such as quaternary ammonium compounds. As a consequence of the COVID-19 pandemic, the use of these compounds has increased significantly and the current state of resistance to disinfectants in strains of S. aureus in our country is unknown. The objective of this research was to determine the prevalence of disinfectant resistance genes in pre- and post-pandemic S. aureus strains isolated from food matrices. For this, 54 strains between the years 2012 and 2023 were selected, and the presence of the genes for resistance to disinfectants qacA/B and smr was identified by using the PCR technique. Only 1.9% presented the qacA/B gene and similar results were obtained when performing the amplification of the smr gene, giving indication that S. aureus strains of food origin, do not suffer in the same way from the selective pressure exerted by antimicrobials and/or disinfectants than the strains found in hospital settings. However, it is necessary to have a larger sample size and perform more trials in the future in order to have robust and significant statistical results that confirm this conjecture.
Staphylococcus aureus is the most important species of the genus Staphylococcus. It is described as a non-spore-forming, facultative anaerobic, opportunistic, coagulase-positive Gram-positive coccus microorganism. It is characterized by being a nosocomial pathogen that colonizes the skin, nose and/or gastrointestinal tract of people, causing a wide variety of diseases; and the WHO has classified it as a high priority pathogen because it presents resistance to methicillin. Recent research shows that through the years, S. aureus has not only generated resistance to antimicrobials but also to disinfectants such as quaternary ammonium compounds. As a consequence of the COVID-19 pandemic, the use of these compounds has increased significantly and the current state of resistance to disinfectants in strains of S. aureus in our country is unknown. The objective of this research was to determine the prevalence of disinfectant resistance genes in pre- and post-pandemic S. aureus strains isolated from food matrices. For this, 54 strains between the years 2012 and 2023 were selected, and the presence of the genes for resistance to disinfectants qacA/B and smr was identified by using the PCR technique. Only 1.9% presented the qacA/B gene and similar results were obtained when performing the amplification of the smr gene, giving indication that S. aureus strains of food origin, do not suffer in the same way from the selective pressure exerted by antimicrobials and/or disinfectants than the strains found in hospital settings. However, it is necessary to have a larger sample size and perform more trials in the future in order to have robust and significant statistical results that confirm this conjecture.
Description
Tesis presentada para optar al título de Bioquímico/a.
Keywords
Microorganismos, Infecciones, Staphylococcus aureus, Noxas, Antiinfecciosos