El papel del laboratorio de microbiología en la práctica clínica / The role of the microbiology laboratory in clinical practice

Los seres humanos albergamos en el cuerpo a cientos de miles de microbios (bacterias, virus, hongos, archaea). Con la mayoría convivimos armónicamente, y obtenemos beneficios mutuos. Ellos participan activamente en nuestros procesos metabólicos e inmunológicos, y nosotros les damos vivienda y nutrientes [1]. Si el equilibrio se altera, como ocurre cuando el sistema inmune se suprime, algunos de estos microorganismos aprovechan la oportunidad y desencadenan infección [2], siendo este el origen de la mayoría de las infecciones, pero no el único, pues los ambientes externos al cuerpo humano también están poblados de microbios, y si bien pocos se consideran patógenos, al entrar en contacto con ellos adquirimos infecciones que llamamos exógenas. De acuerdo con la Organización Mundial de la Salud (OMS), las enfermedades transmisibles están entre las 10 principales causas de muerte en el mundo, y excluyendo la infección por SARS-CoV-2 (COVID-19) en 2021, las infecciones respiratorias agudas fueron la cuarta causa más frecuente de defunción a nivel mundial [3]. El laboratorio de microbiología clínica tiene un papel crucial en el proceso diagnóstico, terapéutico y preventivo de las enfermedades infecciosas causadas por bacterias, hongos, virus y parásitos, pues determinar el agente causal de manera eficaz permite tomar acciones oportunas para definir el manejo individual de las personas infectadas y cortar la cadena de transmisión cuando se requiera [2]

Mikros, aplicación androide para Microbiología y Parasitología en la Universidad de Ciencias Médicas de Camagüey / Mikros, an Android Application for the Microbiology and Parasitology Subject in the University of Medical Sciences of Camagüey

Introducción: El aprendizaje móvil (m-learning) es la inclusión de dispositivos móviles en las actividades de aprendizaje. En la enseñanza de Microbiología y Parasitología médica estos ofrecen un alto poder de ilustración y contribuyen al aprendizaje de la asignatura de los estudiantes de la carrera de medicina; además, sirven de apoyo a otros perfiles como Tecnología de la Salud. Objetivo: Exponer la actualización del curso de Microbiología y Parasitología en la Universidad de Ciencias Médicas de Camagüey mediante una aplicación androide. Métodos: Se realizó una aplicación optimizada para androide 4.4 o superior con el lenguaje de programación Java. Esta investigación se desarrolló en la Universidad de Ciencias Médicas Carlos J. Finlay y se aplicó a estudiantes de la carrera de medicina en los cursos 2018-2019 y 2019-2020. El universo del estudio fueron 1446 estudiantes de los cursos de 2016-2020. Se realizó una encuesta validada por expertos a una muestra probabilística de 88 estudiantes de la Universidad de Ciencias Médicas de Camagüey, en el período comprendido entre noviembre y diciembre de 2020. Se calculó el coeficiente concordancia general W de Kendall en cuanto a las respuestas a las preguntas. Resultados: Mikros fue una herramienta de apoyo a la docencia, fruto de un proyecto de colaboración entre el Centro de Inmunología y Productos Biológicos de la Universidad de Ciencias Médicas y la Facultad de Ingeniería Informática de la Universidad Ignacio Agramonte, de Camagüey, que permitió introducir al profesor en una modalidad de enseñanza muy a tono con estos tiempos. Conclusiones: La aplicación Mikros incluyó conceptos básicos y un alto nivel de actualización. También contribuyó a elevar el índice académico y a una mayor satisfacción del alumno en el aprendizaje, y resultó una herramienta de consulta práctica para estudiantes de años posteriores de la carrera en rotación por el área clínica y útil para el aprendizaje a distancia en tiempos de COVID-19(AU)

Introduction: Mobile learning (m-learning) consists in the inclusion of mobile devices into learning activities. In the teaching of medical parasitology and microbiology, such devices offer a high power of illustration and contribute to medical students' learning of the subject; in addition, they serve as support to other profiles such as health technology. Objective: To present the update, by means of an android application, of the Microbiology and Parasitology course at the University of Medical Sciences of Camagüey. Methods: An optimized application for android 4.4 or higher was created with the Java programming language. This research was carried out at Carlos J. Finlay University of Medical Sciences and applied to medical students in the 2018-2019 and 2019-2020 academic years. The study universe was made up of 1446 students from the academic years from 2016 to 2020. A survey validated by experts was carried out, in the period between November and December 2020, with a probabilistic sample of 88 students from the University of Medical Sciences of Camagüey. Kendall's coefficient of general concordance (W) was calculated for the answers to the questions. Results: Mikros was a teaching support tool, the result of a collaborative project between the Center of Immunology and Biological Products at the University of Medical Sciences and the School of Computer Engineering at Ignacio Agramonte University, in Camagüey, which allowed to present the professor in a teaching modality much in tune with the current times. Conclusions: The Mikros application included basic concepts and a high update level. It also contributed to raising the student's academic index and satisfaction with learning. It turned out to be a practical consultation tool for students of higher academic years of the major who are rotating through the clinical area, as well as a useful tool for distance learning in COVID-19 times(AU)

Does ascitic fluid filtration improve the microbiological diagnosis of spontaneous bacterial peritonitis? An experimental laboratory study / A filtração do líquido ascítico melhora o diagnóstico microbiológico da peritonite bacteriana espontânea? Um estudo experimental laboratorial

Background: Spontaneous Bacterial Peritonitis (SBP) is a serious and frequent complication among cirrhotic patients with ascites and can be diagnosed by cytological analysis of the ascitic fluid. The microbiological culture of ascitic fluid, however, is positive in less than 40% of SBP cases, which often results in inappropriate antimicrobial therapy. Empirical therapy may be suboptimal, increasing patient's risk of aggravation, or overestimated, unnecessarily boosting bacterial resistance. Objective: This experimental laboratory study aimed to standardize and verify the technical feasibility of ascitic fluid vacuum filtration, as a way to optimize the etiological diagnosis of SBP, compared to the automated method. Method: The method evaluated and standardized in this study was ascitic fluid vacuum filtration. Its principle is the concentration of bacteria on a filter membrane. Results: This study included 36 cirrhotic patients treated at a public university hospital between 11.13.2017 and 06.30.2019. Among them, 47.2% (17/36) presented cytology test results compatible with SBP. For these patients, culture sensitivity using the automated method was 35.3% (6/17), against 11.8% (2/17) with the vacuum filtration method. Conclusion: In conclusion, vacuum filtration does not improve the microbiological diagnosis of SBP in this population compared to the automated method (AU)

Contexto: A Peritonite Bacteriana Espontânea (PBE) é uma complicação grave e frequente entre pacientes cirróticos com ascite, diagnosticada por meio da análise citológica do líquido ascítico. A cultura microbiológica do líquido ascítico, por sua vez, é positiva em menos de 40% dos casos de PBE, o que resulta frequentemente na instituição de terapia antimicrobiana inapropriada. A terapia empírica pode ser subótima, aumentando o risco de agravamento do paciente, ou superestimada, impulsionando desnecessariamente a resistência bacteriana. Objetivo: Estudo experimental laboratorial, propôs padronizar e verificar a viabilidade técnica da filtração a vácuo do líquido ascítico, como forma de otimizar o diagnóstico etiológico na PBE, comparativamente ao sistema automatizado de culturas de sangue. Método: O método avaliado e padronizado neste estudo foi a da filtragem a vácuo do líquido ascítico. Esse tem como princípio a concentração da bactéria em uma membrana filtrante. Resultados: Nesse estudo, foram incluídos 36 pacientes cirróticos atendidos em um hospital público universitário, entre 13.11.2017 e 30.06.2019. Entre eles, 47,2% (17/36) apresentaram citologia compatível com PBE. Nesses, a sensibilidade da cultura pelo método semi-automatizado foi de 35,3% (6/17) e da cultura pelo método da filtragem a vácuo foi de 11,8% (2/17). Conclusão: Em conclusão, a filtragem a vácuo não melhora o diagnóstico microbiológico da PBE em relação ao método automatizado (AU)

Semina morbi o semillas de enfermedad / Semina morbi or seeds of disease

Resumen Ya en la antigüedad existía la idea de que pequeñísimos animales o insectos podían causar enfermedades al ser ingeridos o respirados. En forma paralela, varios filósofos desarrollaron el concepto de semillas para explicar la composición del mundo. Ambos conceptos fueron amalgamados en la genial idea de semillas de enfermedad que fue difundida en el célebre poema del filósofo epicúreo Lucrecio denominado "De rerum natura" o "Sobre la naturaleza de las cosas". La idea fue refinada en el Renacimiento por el destacado médico renacentista Gerónimo Fracastorius con sus famosas semina morbi (semillas de enfermedad) que explicaban el contagio. La teoría germinal de los microbios del s. XIX no hizo más que adjudicarle a esta idea ya milenaria un substrato material.

Abstract Already in ancient times there was the idea that tiny animals or insects could cause diseases when ingested or breathed. In parallel, several philosophers developed the concept of seeds to explain the composition of the world. Both concepts were amalgamated in the brilliant idea of seeds of disease that was spread in the famous poem "De rerum natura" by the Epicurean philosopher Lucretius. The idea was refined in the Renaissance by the prominent physician Girolamo Fracastorius with his famous semina morbi (seeds of disease) that explained contagion. The germinal theory of microbes of the s. XIX did nothing more than assign to this already millenary idea a material substratum.

Identificación directa de microorganismos a partir de hemocultivos positivos utilizando espectrometría de masas (MALDI-TOF MS) / Direct identification of microorganisms in positive blood culture bottles by mass spectrometry (MALDI-TOF MS)

Resumen La espectrometría de masas (MALDI-TOF MS) permite la identificación de microorganismos directamente de las colonias en pocos minutos. En este estudio se ha desarrollado y evaluado un protocolo reducido para identificar microorganismos directamente de las botellas de hemocultivos positivos en 30 minutos con una alta sensibilidad y especificidad, utilizando MALDITOF. Un total de 2535 hemocultivos positivos fueron estudiados por el método directo de MALDI-TOF MS, a partir de una alícuota de sangre de las botellas y el método de colonia, utilizando los cultivos desarrollados en medios sólidos. Del total de hemocultivos positivos incluidos en este estudio, 2381 (93,9%) fueron monomicrobianos y 146 (5,8%) polimicrobianos. Mil trescientos treinta (55,9%) de los aislamientos correspondieron a cocos gram positivos, 922 (38,7%) a bacilos gram negativos, 60 (2,5%) a anaerobios, 36 (1,5%) a bacilos gram positivos y 13 a levaduras. La concordancia global entre ambos métodos fue del 81,7% a nivel de especie (90,0% para bacilos gram negativos, 76,7% para cocos gram positivos y 33,3% para bacilos gram positivos). Se identificó al menos un germen en el 88% de las botellas positivas con desarrollo polimicrobiano. Los resultados del presente estudio demostraron que el protocolo basado en MALDI-TOF MS permite la identificación microbiana directamente de hemocultivos positivos en un tiempo corto, con una alta precisión, con excepción de los bacilos gram positivos.

Abstract Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) enables the identification of microorganisms directly from colonies within minutes. In this study this technology was adapted and tested for use with blood culture bottles, thus allowing identification in 30 minutes once the blood culture is detected as positive by the automate. A total of 2535 blood culture bottles reported as positive were tested by MALDI-TOF MS directly from positive blood culture bottles and colonies. A total of 2381 (93.9%) and 146 (5.8%) of the positive blood cultures were monomicrobial and polymicrobial, respectively. And 1330 (55.9%), 922 (38.7%), 60 (2.5%), 36 (1.5%) and 13 of the isolates were gram-positive cocci (GPC), gram-negative bacilli (GNB), anaerobic bacteria, gram-positive bacilli (GPB) and yeast respectively. Concordance between both methods was 81.7% (76.7% of GPC, 90% of GNB, 74.2% of anaerobic bacteria and 33.3% of GPB) in monomicrobial cultures. Eighty eight per cent of the polymicrobial cultures were identified correctly in at least one of the two bacteria. The results of the present study show that this fast, MALDI-TOF MS based method allows microbial identification directly from positive blood culture in a short time, with a high accuracy, with the exception of gram-positive bacilli.

Resumo A espectrometria de massa (MALDI-TOF MS) permite a identificação de microorganismos diretamente das colônias em minutos. Nesse estudo, foi desenvolvido um protocolo reduzido para identificar microrganismos diretamente das garrafas de hemoculturas positivas em 30 minutos com alta sensibilidade e especificidade, utilizando MALDI-TOF. Um total de 2535 hemoculturas positivas foram relatadas -o método direto de MALDI-TOF MS, a partir de uma alíquota de sangue dos vidros e o método de colônia, a partir das culturas desenvolvidas em meios sólidos. Do total de hemoculturas positivas incluídas neste estudo, 2.381 (93,9%) eram monomicrobianas e 146 (5,8%) eram polimicrobianas. Mil trezentos e trinta (55,9%) dos isolados corresponderam a cocos gram-positivos, 922 (38,7%) bacilos gram-negativos, 60 (2,5%) anaeróbios, 36 (1,5%) bacilos gram-positivos e 13 leveduras. A concordância geral entre os dois métodos foi de 81,7% em nivel de especie (90,0% para bacilos gram-negativos, 76,7% para cocos gram-positivos e 33,3% para bacilos gram-positivos). Pelo menos um germe foi identificado em 88% dos vidros positivos com desenvolvimento polimicrobiano. Os resultados do presente estudo demonstraram que o protocolo baseado em MALDI-TOF MS permite a identificação microbiana diretamente de hemoculturas positivas em um curto espaço de tempo, com alta precisão, com exceção de bacilos gram-positivos.

Estudio de la actividad antimicrobiana de Xenophyllum poposum sobre microorganismos de la cavidad bucal por el método de difusión radial / Study of the antimicrobial activity of Xenophyllum poposum on microorganisms of the oral cavity by the radial diffusion method

Resumen En este estudio se evaluó la actividad antimicrobiana in vitro de extractos de Xenophyllum poposum sobre microorganismos bucales como Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Actinomyces naeslundii, Actinomyces odontolyticus, Candida albicans y Veillonella sp. Se empleó el método de difusión radial en agar y como controles negativo y positivo de inhibición se emplearon etanol y clorhexidina al 0,12% (Plac out NF®) respectivamente. Los extractos con mayor actividad antimicrobiana fueron el etanólico y el clorofórmico. La diferencia entre ambos no fue estadísticamente significativa (p≥0,05). Tampoco se observó diferencia significativa con respecto a la clorhexidina, excepto sobre Veillonella sp., ya que el extracto etanólico presentó halos de inhibición significativamente menores sobre este microorganismo. Esto es importante ya que Veillonella se considera indicador de salud en relación a la caries dental. En base a esto, el extracto etanólico de Xenophyllum poposum podría ser usado como control químico de la biopelícula dental.

Abstract In this study, the in vitro antimicrobial activity of Xenophyllum poposum extracts on oral microorganisms such as Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Actinomyces naeslundii, Actinomyces odontolyticus, Candida albicans, Veillonella sp. was evaluated. The radial diffusion method in agar was used and 0.12% ethanol and chlorhexidine (Plac out NF®) were used as negative and positive inhibition controls, respectively. The extracts with the highest antimicrobial activity were the ethanolic and chloroform extracts. The difference between the two was not statistically significant (p≥0.05). No significant difference was observed with respect to chlorhexidine, except on Veillonella sp., since the ethanolic extract presented significantly lower inhibition halos on this microorganism. This is important as Veillonella is considered an indicator of health in relation to dental caries. Based on this, the ethanolic extract of Xenophyllum poposum could be used as chemical control of dental biofilm.

Resumo Neste estudo, a atividade antimicrobiana de extratos de Xenophyllum poposum sobre microrganismos orais como Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Actinomyces naeslundii, Actinomyces odontolyticus, Candida albicans e Veillonella sp. Foi utilizado o método de difusão radial em ágar e etanol 0,12% e clorexidina (Plac out NF®) como controles de inibição negativa e positiva, respectivamente. Os extratos com maior atividade antimicrobiana foram os extratos etanólico e clorofórmio. A diferença entre os dois não foi estatisticamente significativa (p≥0,05). Não foi observada diferença significativa em relação à clorexidina 0,12%, exceto em Veillonella sp., uma vez que o extrato etanólico apresentou halos de inibição significativamente menores neste microrganismo. Isso é importante, pois a Veillonella é considerada um indicador de saúde em relação à cárie dentária. Com base nisso, o extrato etanólico de Xenophyllum poposum pode ser utilizado como controle químico do biofilme dental.

Effect of handling, time of use and photoactivation on the contamination of dental composite resins

This study evaluated the effect of contamination of composite resins (CRs) handled by undergraduate students during restorative procedures, varying the time (baseline, 30 days and 60 days) and experimental condition (before and after handling, contamination with saliva [positive control] and photoactivation). Eight CR tubes were randomly distributed at the dental clinic and the samples were organized into four groups: CR fragments collected before (GB) and after (GA) the restorative procedure; CR fragments contaminated with saliva (GS) and photoactivated (GP) both collected after the procedure. These 4 groups were evaluated in 3 different times: baseline (after sealing), 30 days and 60 days of use of the CR. Samples that had positive turbidity in Brain HeartInfusion (BHI) broth were sown in BHI and Sabouraud Dextrose (SB) agars for subsequent counting of Colony Forming Units (CFU mL-1). The results showed that the handling was responsible for increasing contamination (p < 0.05) at the baseline (GB [n = 0] and GA [n = 3]), as well as after 30 (GB [n = 1] and GA [n = 6]) and 60 (GB [n = 1] and GA [n = 5]) days of use. Photoactivation was responsible for the reduction for microorganisms in T0 and T60. Additionally, the time use and conservation did not influencethe contamination of CRs. Handling was responsible for the increase of contamination of CR, the photoactivation seems to reduce the number of viable microorganisms and the time of use seems not to potentiate the effect of tube contamination.

Does ascitic fluid filtration improve the microbiological diagnosis of spontaneous bacterial peritonitis? An experimental laboratory study / A filtração do líquido ascítico melhora o diagnóstico microbiológico da peritonite bacteriana espontânea? Um estudo experimental laboratoria

ABSTRAC: Background: Spontaneous Bacterial Peritonitis (SBP) is a serious and frequent complication among cirrhotic patients with ascites and can be diagnosed by cytological analysis of the ascitic fluid. The microbiological culture of ascitic fluid, however, is positive in less than 40% of SBP cases, which often results in inappropriate antimicrobial therapy. Empirical therapy may be suboptimal, increasing patient's risk of aggravation, or overestimated, unnecessarily boosting bacterial resistance. Objective: This experimental laboratory study aimed to standardize and verify the technical feasibility of ascitic fluid vacuum filtration, as a way to optimize the etiological diagnosis of SBP, compared to the automated method. Method: The method evaluated and standardized in this study was ascitic fluid vacuum filtration. Its principle is the concentration of bacteria on a filter membrane. Results: This study included 36 cirrhotic patients treated at a public university hospital between 11.13.2017 and 06.30.2019. Among them, 47.2% (17/36) presented cytology test results compatible with SBP. For these patients, culture sensitivity using the automated method was 35.3% (6/17), against 11.8% (2/17) with the vacuum filtration method. Conclusion: In conclusion, vacuum filtration does not improve the microbiological diagnosis of SBP in this population compared to the automated method. (AU)

RESUMO:Contexto: A Peritonite Bacteriana Espontânea (PBE) é uma complicação grave e frequente entre pacientes cirróticos com ascite, diagnosticada por meio da análise citológica do líquido ascítico. A cultura microbiológica do líquido ascítico, por sua vez, é positiva em menos de 40% dos casos de PBE, o que resulta frequentemente na instituição de terapia antimicrobiana inapropriada. A terapia empírica pode ser subótima, aumentando o risco de agravamento do paciente, ou superestimada, impulsionando desnecessariamente a resistência bacteriana. Objetivo: Estudo experimental laboratorial, propôs padronizar e verificar a viabilidade técnica da filtração a vácuo do líquido ascítico, como forma de otimizar o diagnóstico etiológico na PBE, comparativamente ao sistema automatizado de culturas de sangue. Método: O método avaliado e padronizado neste estudo foi a da filtragem a vácuo do líquido ascítico. Esse tem como princípio a concentração da bactéria em uma membrana filtrante. Resultados: Nesse estudo, foram incluídos 36 pacientes cirróticos atendidos em um hospital público universitário, entre 13.11.2017 e 30.06.2019. Entre eles, 47,2% (17/36) apresentaram citologia compatível com PBE. Nesses, a sensibilidade da cultura pelo método semi-automatizado foi de 35,3% (6/17) e da cultura pelo método da filtragem a vácuo foi de 11,8% (2/17). Conclusão: Em conclusão, a filtragem a vácuo não melhora o diagnóstico microbiológico da PBE em relação ao método automatizado. (AU)

La lucha antimicrobiana: Desarrollo de competencias en 6 universidades ecuatorianas / The antimicrobial fight: Development of skills in 6 Ecuadorian universities

Los microorganismos son seres vivos, que han ido adaptándose y evolucionando permitiendo su supervivencia, evadiendo las respuesta innata de los hospedadores e incluso modificando sus estructuras biológicas antes moléculas farmacológicas, que se han, en los últimos años, empleado de manera inadecuadas, bien sea por abuso o por deficiencia en el cumplimiento del esquema del tratamiento, o desaciertos para tratar un germen en específico y, como consecuencia, la actual crisis mundial por la resistencia a los antimicrobianos; considerado un problema de salud pública, requiere de esfuerzos multisectoriales e integrales que aporten soluciones mediatas, a corto y mediano plazo, sostenibles en el tiempo. Para ellos, es clave la formación de los nuevos profesionales, en el área de microbiología, de las diferentes carreras biomédicas. Es por ello, el presente estudio identificó las competencias que deben desarrollar los estudiantes, de seis universidades ecuatorianas. Se aplicaron cuestionarios, inquiriendo la importancia atribuida y el grado de desarrollo percibido de cada competencia mediante escala tipo Likert, además de seis dimensiones distribuidas en 40 indicadores. Se identificó mayor desarrollo de competencias en la identificación del patógeno, diagnóstico y análisis e interpretación de los resultados; además las seis dimensiones educativas fueron clasificadas como relevantes. Sin embargo, los resultados sugieren falencia en el desarrollo de competencias en la temática de resistencia antimicrobiana, por lo que se sugiere la revisión de los contenidos programáticos y aplicar nuevas herramientas pedagógicas que permitan al estudiantado aprender a aprender, aplicando un modelo socio-critico, y como base la investigación y el conocimiento científico actualizado(AU)

Microorganisms are living beings, which have been adapting and evolving allowing their survival, evading the innate response of the hosts and even modifying their biological structures before pharmacological molecules, which have, in recent years, been used inappropriately, either by abuse or deficiency in compliance with the treatment scheme, or failure to treat a specific germ and, as a consequence, the current global crisis due to antimicrobial resistance; considered a public health problem, it requires multisectoral and comprehensive efforts that provide immediate, short- and medium-term solutions that are sustainable over time. For them, the training of new professionals in the area of microbiology, of the different biomedical careers, is key. For this reason, this study identified the skills that students from six Ecuadorian universities should develop. Questionnaires were applied, inquiring about the importance attributed and the perceived degree of development of each competency using a Likert-type scale, in addition to six dimensions distributed in 40 indicators. Greater development of skills in the identification of the pathogen, diagnosis and analysis and interpretation of the results was identified; In addition, the six educational dimensions were classified as relevant. However, the results suggest a lack in the development of skills in the subject of antimicrobial resistance, so it is suggested to review the program contents and apply new pedagogical tools that allow students to learn to learn, applying a socio-critical model, and as a basis research and updated scientific knowledge(AU)

Resistência bacteriana aos antimicrobianos: uma revisão das principais espécies envolvidas em processos infecciosos / Bacterial resistance to antimicrobials: a review of the main species involved in infectious processes

Os mecanismos de resistência bacteriana podem existir de maneira intrínseca ou adquirida, porém em ambos os casos podem dificultar a terapia antimicrobiana preconizada para tratamento de infecções. Este artigo tem como objetivo apresentar estudos recentes sobre o assunto. Foi realizada uma revisão da literatura sobre resistência bacteriana aos antimi- crobianos, utilizando as bases de dados MEDLINE, LILACS, Scopus e Web of Science. A busca identificou o total de 16 artigos, que foram publicados entre os anos de 2017 a 2021. A maioria dos artigos sobre Gram-negativos tratou do grupo das enterobactérias, assim como os de Gram-positivos tratou dos gêneros Staphylococcus , Enterococcus e Streptococcus. A resistência bacteriana foi encontrada em cefalosporinas, carbapenêmicos, quinolonas, aminoglicosídeos, entre outros. Em relação aos mecanismos de resistência, as ß-Lactamases de espectro estendido (ESBL), enterobactérias resistentes aos carbape- nêmicos (ERC), Staphylococcus aureus resistentes à meticilina (MRSA) e Enterococcus resistentes à vancomicina (VRE) foram relatados e observa-se que a maioria dos trabalhos corrobora que seu rastreamento visa minimizar a transmissão em instituições de saúde.

Bacterial resistance mechanisms can exist intrinsically or acquired, but in both cases they can make the antimicrobial therapy recommended for the treatment of infections difficult. This article aims to present recent studies on the subject. A literature review on bacterial resistance to antimicrobials was carried out using the MEDLINE, LILACS, Scopus and Web of Science databases. The search identified a total of 16 articles, which were published between 2017 and 2021. Most articles on Gram-negatives dealt with the enterobacteria group, as well as Gram-positive articles from the Staphylococcus, Enterococcus and Streptococcus genera. Bacterial resistance was found in cephalosporins, carbapenems, quinolones, aminoglycosides, among others. Regarding resistance mechanisms, Extended Spectrum Beta-Lactamases (ESBL), Carbapenem-Resistant Enterobacteria (ERC), Methicillin- Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant Enterococcus (VRE) have been reported and it is observed that most works corroborate that its tracking aims to minimize transmission in health institutions.

Secretos detectados de la naturaleza por Antoine van Leeuwenhoek / Detected secrets for nature by Antoine van Leeuwenhoek

Resumen Una de las obras, probablemente menos conocidas, de Antoine van Leeuwenhoek (1632-1723) es su Arcana naturae detecta (Secretos detectados de la naturaleza) publicada en su primera edición en 1695. Esta obra es una recopilación de 38 cartas sobre temas científicos y está bellamente ilustrada. Una sección notable de ella es la observación y descripción por primera vez de levaduras de la fermentación y sus experimentos sobre la generación espontánea de microorganismos.

Abstract One of the works, probably less known, of Antoine van Leeuwenhoek (1632-1723) is his Arcana naturae detecta (Detected secrets of nature) published in its first edition in 1695. This work is a compilation of 38 letters on scientific issues and it is beautifully illustrated. A notable section of the work is the observation and description for the first time of fermentation yeasts and his experiments on the spontaneous generation of microorganisms.

Corynebacterium kroppenstedtii y patología mamaria / Corynebacterium kroppenstedtii and breast pathology

Resumen Corynebacterium kroppenstedtii es un bacilo gram positivo corineforme lipofílico, poco frecuente en la clínica humana. Forma parte de la microbiota cutánea de los seres humanos y, por esta razón, su interpretación clínica es compleja. La mastitis granulomatosa es una enfermedad inflamatoria de origen incierto con baja incidencia. Se presentan dos casos clínicos en los que se describe la asociación de C. kroppenstedtii con mastitis granulomatosa. El tejido mamario es rico en lípidos. El carácter lipofílico de este microorganismo podría explicar su presencia en dicho tejido.

Abstract Corynebacterium kroppenstedtii is a rare lipophilic coryneform gram-positive bacillus. It is part of the human skin microbiota and, for this reason, its clinical interpretation is complex. Granulomatous mastitis is an inflammatory disease of uncertain origin with a low incidence. The association of C. kroppenstedtii with granulomatous mastitis was described in two clinical case reports. The lipophilic characteristics of this microorganism explains why it can be found in lipid-rich breast tissue.

Resumo Corynebacterium kroppenstedtii é um bacilo gram-positivo corineforme lipofílico poco frecuente. Faz parte da microbiota do seres humanos, por isso sua interpretação clínica é complexa. A mastite granulomatosa é uma doença inflamatória de origem incerta com baixa incidência. Foram apresentados dois casos clínicos nos quais é descrita a associação de C. kroppenstedtii com mastite granulomatosa. O tecido mamário é rico em lipídios. O caráter lipofílico desse microrganismo pode explicar sua presença em tal tecido.

Estreptococos del grupo Streptococcus anginosus Parte IIIb. Infecciones en localizaciones diferentes de las de cabeza y cuello / Streptococcus anginosus group. Part IIIb. Other than head and neck infections

Resumen Las bacterias del grupo Streptococcus anginosus (EGA) son colonizantes habituales de las mucosas orofaríngea, intestinal y genitourinaria, pero, cada vez más frecuentemente, son reconocidas como patógenos humanos. En esta parte III se describen las tendencias de los EGA a la producción de distintas patologías humanas. Por su extensión debió ser desdoblada a su vez en otras dos partes (IIIa y IIIb). Es ampliamente conocida su capacidad de formar abscesos en órganos sólidos, especialmente abscesos cerebrales, pulmonares y hepáticos. También producen sinusitis, empiemas y colecciones en piel y tejidos blandos, huesos, articulaciones, etc. Se han encontrado asociados con infecciones urinarias, vaginitis aeróbica y con exacerbaciones pulmonares en pacientes con fibrosis quística y con enfermedad pulmonar obstructiva crónica. Producen también infecciones posteriores a mordeduras humanas, infecciones diseminadas, bacteriemia sin foco aparente y, en menor medida, endocarditis infecciosas, generalmente complicadas con abscesos perivalvulares. Esta parte IIIb está focalizada en las infecciones que no comprometen la cabeza y el cuello.

Abstract Streptococcus anginosus (SGA) group streptococci are common colonizers of the oropharyngeal, intestinal, and genitourinary mucosa, but they are increasingly recognized as human pathogens. In this part III, tendencies of the EGA to the production of different human pathologies are described. Due to its length, it had to be divided into two other parts (IIIa and IIIb). Its ability to form abscesses in solid organs, especially brain, lung and liver abscesses, is widely known. They also cause sinusitis, empyema and collections in skin and soft tissues, bones, joints, etc. They have been found associated with urinary tract infections, aerobic vaginitis and with pulmonary exacerbations in patients with cystic fibrosis and chronic obstructive pulmonary disease. They also cause infections after human bites, disseminated infections, bacteremia without apparent focus and, to a lesser extent, infective endocarditis, generally complicated by perivalvular abscesses. This part IIIb is focused on other than head and neck infections.

Resumo As bactérias do grupo Streptococcus anginosus (EGA) são colonizadores comuns da mucosa orofaríngea, intestinal e geniturinária, mas são cada vez mais reconhecidos como patógenos humanos. Nesta parte III são descritas as tendências do EGA à produção de diferentes patologias humanas. Devido ao seu comprimento, teve que ser dividido em duas outras partes (IIIa e IIIb). Sua capacidade de formar abcessos em órgãos sólidos, principalmente cérebro, pulmão e fígado, é amplamente conhecida. Eles também causam sinusite, empiema e coleções na pele e tecidos moles, ossos, articulações, etc. Eles foram encontrados associados à infecções urinárias, vaginite aeróbia e às exacerbações pulmonares em pacientes com fibrose cística e doença pulmonar obstrutiva crônica. Também causam infecções após picadas humanas, infecções disseminadas, bacteremia sem origem aparente e, em menor grau, endocardite infecciosa, geralmente complicada por abscessos perivalvulares. Seu papel na faringite é controverso, embora algumas das subespécies possam estar envolvidas em tais infecções. Seu potencial carcinogênico também é postulado pela associação com carcinomas orofaríngeos, gástricos ou esofágicos. Esta parte IIIb enfoca infecções em diferentes locais da cabeça e pescoço.

Análisis temático desde el Observatorio Métrico de Coronavirus de las investigaciones publicadas en PubMed / Thematic analysis from the Coronavirus Metric Observatory of the research published in PubMed

La experiencia científica de los últimos meses contra la pandemia de la COVID-19 muestra una celeridad nunca vista, así mismo, es inédita la velocidad en la publicación de los resultados de tales investigaciones. El contexto revela la carrera sostenida que tiene la ciencia contra la expansión de este letal virus. En el presente estudio se documentan evidencias bibliográficas para reconocer a PubMed como uno de los principales recursos de información científica sobre medicina que existen en el mundo. Es una necesidad del gremio científico médico e investigativo en el contexto de la COVID-19 conocer las temáticas que abordan los principales artículos de la base de datos. El objetivo de esta investigación es analizar el comportamiento temático de los artículos publicados por PubMed sobre coronavirus en el primer semestre del año 2020 utilizando como herramienta de análisis al Observatorio Métrico de Coronavirus de la Universidad de Pinar del Río. El interés científico del estudio se concentra en las variables materia, MeSH y palabras clave; las que son analizadas con diferentes técnicas métricas que facilitan la visualización e interpretación de los resultados. Se demostró que PubMed, entre los temas más recurrentes, ha socializado investigaciones en virología, microbiología, farmacéutica, medicina general integral y sus relaciones con la oncología, neurología, pediatría, psicología, psiquiatría, oftalmología, nutrición, telemedicina y dispositivos médicos(AU)

The scientific experience of recent months against the COVID-19 pandemic shows a speed never seen before, likewise, the speed in the publication of the results of such investigations is unprecedented. The context reveals the sustained race in science against the spread of this deadly virus. In this study, bibliographic evidence is documented to recognize PubMed as one of the main sources of scientific information on medicine that exist in the world. In the context of COVID-19, it is a necessity for the scientific, medical and research union to know the issues addressed by the main articles in the database. The objective of this research is to analyze the thematic behavior of the articles published by PubMed on coronavirus in the first half of 2020, using the Coronavirus Metric Observatory of the University of Pinar del Río as an analysis tool. The scientific interest of the study is concentrated in the variables subject, MeSH and keywords; those that are analyzed with different metric techniques that facilitate the visualization and interpretation of the results. It was shown that PubMed, among the most recurrent topics, has socialized research in virology, microbiology, pharmaceuticals, comprehensive general medicine and their relationships with oncology, neurology, pediatrics, psychology, psychiatry, ophthalmology, nutrition, telemedicine and medical devices(AU)

RESISTANCE TO ANTIBIOTIC AGENTS: PERSPECTIVE AND REALITY

Microorganisms have infected humans since time immemorial and in this context, we have lived through an endless war that has produced increasingly complex adaptation and selection pressure. Although antibiotics marked a new era beginning in 1928, it is interesting to mention that traces of tetracycline were found in human bone samples from ancient Sudanese Nubia dating from 350­550 AD. C (1). Paul Erlich, by his staining methods, already deduced at the end of the 19th century and the beginning of the 20th century, that there may be a magic bullet that acts on microorganisms to eliminate them, without affecting other cell types. This molecule is currently known as an antibiotic or antimicrobial in relation to its natural or synthetic origin. Of this interest, in 1910 the first molecule with studies in rabbits infected with syphilis to demonstrate antimicrobial activity was described (2,3).

Endocarditis infecciosa en hospital clínico Herminda Martín de Chillán: experiencia de los últimos cinco años / Infective endocarditis at Herminda Martin clinical hospital of Chillan: last five years experience

Introducción: la endocarditis infecciosa es una afección con elevada morbilidad y mortalidad, con una incidencia en Chile de 2-3 casos por 100.000 habitantes al año, con una edad de presentación en ascenso y una clínica diversa e inespecífica que requiere un manejo multidisciplinario para el manejo de estos pacientes. Materiales y métodos: estudio observacional descriptivo, se consideró el número total de fichas clínicas del hospital clínico Herminda Martín de Chillán durante los años 2015 al 2019, con diagnóstico confirmado de endocarditis infecciosa. Los datos se registraron en la hoja de recolección de datos elaborada, realizándose los análisis estadísticos pertinentes. Resultados:la muestra (n=17) que pudo ser analizada tenía una edad promedio de 53,5 años; 70,5% (DE 14,50) fueron hombres y el agente más común identificado fue Staphylococcus aureus sensible a meticilina. En promedio los pacientes recibieron 28,8 días de antibióticos y la válvula más afectada fue la aórtica. Conclusiones: la endocarditis infecciosa es una patología con una gran morbimortalidad, que presenta un cuadro clínico inespecífico capaz de simular cualquier enfermedad. Se requieren aún de más estudios que reflejen la realidad nacional.

Introduction: Infective endocarditis is a condition with high morbidity and mortality, with an incidence in Chile of 2-3 cases per 100,000 inhabitants per year, with increasing age of presentation and a diverse and nonspecific clinic that requires multidisciplinary management for treatment of these patients. Materials and methods: Descriptive observational study, the total number of clinical records of the Herminda Martín de Chillán clinical hospital during the years 2015 to 2019, with a confirmed diagnosis of infective endocarditis, was considered. The data were recorded in the data collection sheet prepared, performing the relevant statistical analyses. Results: The sample (n = 17) that could be analysed had an average age of 53.5 years (DS 14.50), 70.5% were men, and the most common agent identified was methicillin-sensitive Staphylococcus aureus. On average, patients received 28.8 days of antibiotics, and the most affected valve was the aortic valve. Conclusions: Infective endocarditis is a pathology with high morbidity and mortality, which presents a nonspecific clinical spectrum, capable of simulating any disease. Still, more studies are required that reflect the national reality

Investigation of Microbial Contamination in the Clinic and Laboratory of the Prosthodontics Department of Dental School

ABSTRACT Objective: To determine the level of clinical contamination in the clinic and laboratory of the prosthodontics department of Kerman Dental School. Material and Methods: Clinical surfaces of the dental units, the laboratory, and the professors' lounge of the prosthodontics department were randomly sampled. The sampled surfaces included the dental units' console, light switch, light handle, headrest, and air-water spray syringe in the clinic, plastering tables, buttons of the vibrator, polishing, and trimmer machines, acryl tables, handles of pressure pot and press machine, handpiece holders, work desks, and drawer handles in the laboratory, and desks, computer mouse and keyboard, telephone sets, and doorknob in the professor's lounge. The samples were examined for the type and growth of microorganisms. The data were entered into SPSS, where they were analyzed using the chi-square test at the 0.05 significance level. Results: Of all the samples taken, 89.9% showed microbial contamination. The most common type of contamination was fungus (34.8%) and the least common types were Enterococcus faecalis and Staphylococcus epidermidis (1.1%). The second and third most common types of bacteria in the samples were Staphylococcus aureus (18%) and Pseudomonas aeruginosa (12.4%), respectively. There was no significant difference between the frequencies of microbial contamination in the clinic, the laboratory, and the professors' lounge. Conclusion: Given the strong chance of cross-infection in the examined department and laboratory, it is necessary to enforce protocols for proper disinfection of surfaces before, between and after treatments.

Relato sobre estrategias de enseñanza para desarrollar habilidades de pensamiento y educar en valores / Story about teaching strategies to develop thinking skills and educate in values

Introducción: La sociedad actual demanda ciudadanos integrales, críticos, reflexivos y capaces de generar respuestas a los problemas de un mundo cambiante y globalizado. Mediante el uso de diversas estrategias de enseñanza, el maestro puede contribuir a que los estudiantes, desde edades tempranas, desarrollen las aptitudes necesarias para convertirse en seres humanos poseedores de la actitud investigativa que se requiere en la actualidad. Objetivo: desarrollar habilidades de pensamiento en jóvenes en edad escolar y educarles en valores relacionados con las ciencias. Metodología: a investigación se abordó desde la perspectiva del paradigma constructivista, utilizó un enfoque cualitativo y empleó el método Investigación-Acción. La práctica docente se cualificó a partir de la sistematización, análisis y reflexión de la implementación de estrategias de enseñanza como: buenas preguntas, red conceptual, experimentos de laboratorio y proyecto de investigación escolar con jóvenes. Resultados: ampliaron sus conocimientos sobre algunos temas de microbiología, mejoraron el manejo del lenguaje científico, desarrollaron habilidades analíticas y argumentativas, progresaron en la capacidad de señalar lo esencial para una investigación, mostraron una actitud responsable y crítica frente al ambiente y ejecutaron su proyecto de investigación escolar en el que emplearon un controlador biológico; todo lo anterior para desarrollar habilidades, actitudes y pensamiento científico que favorecieron la construcción de conocimiento. Conclusión: a la luz del método de Investigación-Acción, los estudiantes lograron desarrollar capacidades como el análisis, síntesis, argumentación, sentido crítico y actitud responsable con el ambiente.

Introduction: Today's society demands integral, critical, reflective citizens capable of generating answers to the problems of a changing and globalized world. Through the use of different teaching strategies, the teacher can contribute to help students, from an early age, to develop the necessary skills to become human beings with the investigative attitude that is required today. Objective: this research was carried out with the purpose of achieving two objectives: to develop thinking skills in school-age children and to educate them in values related to science. Methodology: The research was approached from the perspective of the constructivist paradigm, used a qualitative approach and employed the Action Research method. The teaching practice was qualified based on the systematization, analysis and reflection of the implementation of teaching strategies such as: good questions, conceptual network, laboratory experiments and school research project with young people. Results: they broadened their knowledge on some microbiology topics, improved their handling of scientific language, developed analytical and argumentative skills, progressed in the ability to point out what is essential for an investigation, showed a responsible and critical attitude towards the environment and executed their school research project in which they used a biological controller; all of the above to develop skills, attitudes and scientific thinking that favored the construction of knowledge. Conclusion: It is concluded that, in light of the Research-Action method, the students were able to develop skills such as analysis, synthesis, argumentation, critical sense and responsible attitude towards the environment.