La amenaza silenciosa de las resistencias bacterianas / The silent threat of bacterial resistance

Las resistencias bacterianas a antimicrobianos representan uno de los principales problemas en la actualidad, encontrándose dentro de las principales causas de muerte en todo el mundo. Latinoamérica y Argentina, lejos de ser una excepción,presentan incidencias crecientes de infecciones por gérmenes resistentes. Cada día, se conocen mejor los mecanismos de resistencia que presentan los bacilos gram negativos y algunos cocos positivos. El problema no surge sólo por el sobreuso de antimicrobianos en la medicina clínica. Su sobreutilización para maximizar los beneficios productivos en la pesca, la ganadería y la agricultura contribuyen a esta situación. Desde la perspectiva de la atención primaria de la salud,consideramos fundamental conocer todos los aspectos que forman parte de esta problemática para intentar mitigar el daño que las resistencias bacterianas generan a nivel global. Argentina se transformó en el primer país de la región y del continente en contar con una ley para prevenir y controlar la resistencia a los Antimicrobianos. Consideramos de vital importancia que se fomenten más y mejores políticas sanitarias de orden público para enfrentar este creciente desafío. (AU)

Nowadays, bacterial resistance to antimicrobials is one of the main problems, being one of the leading causes of death worldwide. Latin America and Argentina, far from being an exception, have an increasing incidence of infections by resistant germs. Every day, the resistance mechanisms of gram-negative bacilli and some positive cocci are better known. The problem does not arise only because of the overuse of antimicrobials in clinical medicine. Its overuse to maximize productive benefits in fishing, livestock, and agriculture also contributes to this issue. From the perspective of primary health care,it is essential to know all the aspects of this problem to mitigate the damage that bacterial resistance generates at a global level. Argentina became the first country in the region and the continent to have a law to prevent and control antimicrobial resistance. We consider it vitally important that more and better public health policies are promoted to face this growing challenge. (AU)

Perfil de uso de tigeciclina en un hospital universitario en Chile / Profile of tigecycline use in a university hospital in Chile

INTRODUCCIÓN: El uso de tigeciclina ha ido en aumento en los últimos años, debido al incremento de la resistencia bacteriana y la escasez de alternativas terapéuticas. OBJETIVO: Caracterizar y evaluar las prescripciones de tigeciclina en pacientes internados en un hospital universitario, durante los años 2017 y 2018. METODOLOGÍA: Estudio observacional retrospectivo, donde se caracterizaron los pacientes, las terapias, la microbiología asociada, los desenlaces clínicos y las reacciones adversas asociadas a los tratamientos con tigeciclina. Se determinó la proporción de prescripciones apropiadas por un comité de expertos y el consumo de tigeciclina medido en DDD/100 camas-día. RESULTADOS: Se caracterizaron 89 pacientes, de los cuales 67 (75,3%) cumplieron los criterios de selección. El 53,7% de los pacientes eran hombres, con una edad promedio de 60 ± 15 años. El principal motivo de hospitalización fue quirúrgico (65,7%). El 67,1% de los tratamientos con tigeciclina se inició en una Unidad de Paciente Critico y el foco de infección predominante fue abdominal (64,3%). El 50% de las terapias con tigeciclina fueron dirigidas según la microbiología identificada. En 65,7% de los casos se usó tigeciclina como monoterapia en la dosis habitual (62,9%). Náuseas (8,6%), diarrea (7,1%) y vómitos (4,3%) fueron los efectos adversos más reportados. El 84,3% de los tratamientos se consideraron apropiados. El año 2017 se consumió 0,4 DDD/100 camas-día y 0,6 DDD/100 camas/día el 2018, siendo la UCI el servicio que presentó el mayor uso en ambos años. DISCUSIÓN: Tigeciclina fue utilizada principalmente en monoterapia para el tratamiento de infecciones intraabdominales en pacientes hospitalizados, por motivos quirúrgicos, en una unidad de paciente crítico, en las dosis habituales recomendadas de 100 mg como dosis de carga seguida de 50 mg cada 12 hs IV. En 50% de los casos, la terapia fue dirigida según microbiología. Los eventos adversos más habituales fueron los gastrointestinales. CONCLUSIÓN: La mayoría de las terapias prescritas fueron consideradas apropiadas por el comité de expertos.

BACKGROUND: The use of tigecycline has been increasing in recent years, due to increase in bacterial resistance and the scarcity of therapeutics alternatives. AIM: To characterize and evaluate the tigecycline prescriptions of patients hospitalized in a university hospital, during the years 2017 and 2018. METHODS: A retrospective observational study was carried out, where the patients, the therapies, the associated microbiology, the clinical outcomes and the adverse reactions associated with tigecycline were characterized. The proportion of appropriate prescriptions was determined by committee of experts and the consumption of tigecycline measure in DDD/100 bed-days. RESULTS: 89 patients who used tigecycline were characterized, of which 67 (75.3%) met the selection criteria. 53.7% of the patients were male, with a mean age of 60 +/- 15 years The main reason for hospitalization was surgical (65.7%). 67.1% of the treatments with tigecycline were started in a critical patient unit and the predominant focus of the infection was the abdomen (64.3%). 50% of the therapies with tigecycline were ordered according to the identified microbiology. In 65.7% of the cases, tigecyclin was used as monotherapy at the usual dose (62.9%). Nausea (8.6%), diarrhea (7.1%) and vomiting (4.3%) were the most reported adverse events. 84.3% of the treatments were considered appropriate. In 2017, 0.4 DDD/100 bed/days were consumed and 0.6 DDD/100 bed/days in 2018, with de ICU being the service that presented the highest use in both years. DISCUSSION: Tigecycline was mainly used as monotherapy for the treatment of intra-abdominal infections in patients hospitalized for surgical reasons in a critical patient unit at the usual doses of 100 mg loading followed by 50 mg every 12 hours IV. In 50% of the case the therapy was directed according to microbiology. The most common adverse events were gastrointestinal. CONCLUSION: Most of the prescribed therapies were considered appropriate by the expert committee.

Bacterias resistentes a los antibióticos en alimentos de origen animal. Revisión sistemática / Antibiotic-resistant bacteria in foods of animal origin. Systematic review

Introducción. La problemática alrededor de la resistencia a los antibióticos se intensifica por la presencia de patógenos resistentes en alimentos de origen animal. Objetivo. Presentar el estado de la prevalencia de bacterias resistentes a antibióticos (BRA) y los principales genes de resistencia a antibióticos (GRAs) que se reportan en alimentos de origen animal y en animales destinados al consumo humano. Materiales y métodos. Se realizó una revisión sistemática basada en la guía PRISMA, empleando las bases de datos: Science Direct, Redalyc, Scopus, Hinari, Scielo, Dialnet, PLOS, ProQuest, Taylor, Lilacs y PubMed/ Medline con estudios originales realizados entre enero de 2017 y abril 2023. Resultados. Un total de 2620 estudios fueron identificados y 71 estudios cumplieron los criterios de inclusión. La carne de res, leche cruda/productos lácteos no pasteurizados y las heces de animales de granja fueron las muestras más estudiadas. Las BRAs más frecuentes fueron Escherichia coli productora de ß-lactamasas de espectro extendido (BLEE), Salmonella spp. resistente a múltiples fármacos (MDR) y Stahylococcus aureus resistente a meticilina (SARM). Los GRAs más reportados fueron bla, tet y sul mediados por plásmidos e integrones, principalmente. Conclusiones. En esta revisión sistemática se encontró, que los aislamientos de E. coli, Salmonella spp. y S. aureus son los que más frecuentemente presentaron resistencia a la tetraciclina ampicilina y el sulfametoxazol/ trimetoprima con el predominio de los genes bla, tet y sul, que están siendo diseminados por elementos genéticos móviles entre bacterias y a humanos a través de clones zoonóticos con una alta estabilidad en el tiempo(AU)

Introduction. The problem around antibiotic resistance is intensified by the presence of resistant pathogens in foods of animal origin. Objective. Present the state of the prevalence of antibiotic resistant bacteria (ARB) and the main antibiotic resistance genes (AGRs) that are reported in foods of animal origin and in animals intended for human consumption. Materials and methods. A systematic review was carried out based on the PRISMA guide, from the Science Direct, Redalyc, Scopus, Hinari, Scielo, Dialnet, PLOS, ProQuest, Taylor, Lilacs and PubMed/Medline databases with original studies carried out between January 2017 and April of 2023. Results. A total of 2620 studies were identified, and 71 studies met the inclusion criteria. Beef, raw milk/unpasteurized dairy products, and farm animal feces were the most studied samples. The most common resistant bacteria were extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli, Salmonella spp. multidrug resistant (MDR) and methicillin resistant Stahylococcus aureus (MRSA). The AGRs most reported were bla, tet and sul, mediated mainly through plasmids and integrons. Conclusions. In this systematic review it was found that the isolates of E. coli, Salmonella spp. and S. aureus are the ones that most frequently presented resistance to tetracycline ampicillin and sulfamethoxazole/ trimethoprim with a predominance of the bla, tet and sul genes, which are being disseminated by mobile genetic elements between bacteria and humans through zoonotic clones with high stability over time(AU)

Caracterización de ß-lactamasas de espectro extendido en aislamientos clínicos colombianos de Salmonella enterica no tifoidea de 1997 a 2022 / Characterization of extended spectrum ß-lactamases in Colombian clinical isolates of non-typhoidal Salmonella enterica between 1997 and 2022

Introducción. Salmonella spp. es un agente patógeno zoonótico transmitido al humano por el agua o los alimentos contaminados. La presencia de ß-lactamasas de espectro extendido es un creciente problema para la salud pública debido a que estas enzimas confieren resistencia contra las cefalosporinas de tercera y cuarta generación. Objetivo. Caracterizar las ß-lactamasas de espectro extendido en aislamientos de Salmonella spp. recibidos por el programa de vigilancia de enfermedad diarreica aguda o enfermedad transmitida por alimentos del Grupo de Microbiología del Instituto Nacional de Salud. Materiales y métodos. Entre enero de 1997 y junio de 2022, se recibieron 444 aislamientos de Salmonella spp. resistentes, por lo menos, a una de las cefalosporinas de tercera generación. El fenotipo de las ß-lactamasas de espectro extendido se identificó con la prueba de doble disco. El ADN se extrajo por ebullición y mediante PCR se amplificaron los genes bla CTX-M, bla SHVy : ' a ILM. Resultados. Todos los aislamientos fueron positivos para la prueba de ß-lactamasas de espectro extendido. Los resultados de la amplificación por PCR fueron: bla CTX-M + bla TLM (n=200), bla CTX-M (n=177), bla SHV(n=16), bla SHV + bla CTX-M (n=6), bla TLM (n=13) y bla SHV + bla CTX-M + bla TLM (n=3). Del total, 26 aislamientos fueron negativos para los genes evaluados. Los aislamientos positivos para ß-lactamasas de espectro extendido se identificaron en Bogotá y en 21 departamentos: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusión. La resistencia a las cefalosporinas de tercera generación en aislamientos de Salmonella spp. fue generada principalmente por bla CTX-M. El 44 % (197/444) de los aislamientos presentó resistencia a ampicilina, tetraciclina, cloranfenicol y trimetoprim- sulfametoxazol Los serotipos portadores de ß-lactamasas de espectro extendido más frecuentes fueron S. Typhimurium y S. Infantis.

Introduction. Salmonella spp. is a zoonotic pathogen transmitted to humans through contaminated water or food. The presence of extended-spectrum ß-lactamases is a growing public health problem because these enzymes are resistant to third and fourth generation cephalosporins. Objective. To characterize extended-spectrum ß-lactamases in Salmonella spp. isolates received by the acute diarrheal disease/foodborne disease surveillance program of the Grupo de Microbiología of the Instituto Nacional de Salud. Materials and methods. A total of 444 Salmonella spp. isolates, resistant to at least one of the cephalosporins, were obtained between January 1997 and June 2022. The extended- spectrum ß-lactamases phenotype was identified by the double disk test. DNA extraction was carried out by the boiling method, and the bla CTX-M, bla SHV, and bla TLM genes were amplified by PCR. Results. All the isolates were positive for the extended-spectrum ß-lactamases test. The genes identified were: bla CTX-M + ba TLM (n=200), bla CTX-M (n=177), bla SHV(n=16), bla SHV + bla CTX-M (n=6), bla TLM (n=13) and bla SHV + bla CTX-M + bla TLM (n=3). Twenty-six isolates were negative for the evaluated genes. Positive extended-spectrum ß-lactamases isolates were identified in Bogotá and 21 departments: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusion. Resistance to third generation cephalosporins in Salmonella spp. isolates was mainly caused by bla CTX-M. Isolates were resistant to ampicillin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole (44 %; 197/444). The most frequent extended-spectrum ß-lactamases-expressing serotypes were Salmonella Typhimurium and Salmonella Infantis.

Epidemiología y prevalencia de Mycoplasma genitalium y resistencia a azitromicina en el Área Norte de Tenerife, Islas Canarias / Epidemiology and prevalence of Mycoplasma genitalium and resistance to azithromycin in the North Area of Tenerife, Canary Islands

INTRODUCCIÓN: La infección y resistencia antimicrobiana de Mycoplasma genitalium está infradiagnósticada en nuestra comunidad ya que no es una Enfermedad de Declaración Obligatoria y requiere técnicas de biología molecular, no siempre disponibles. OBJETIVO: Estudiar la epidemiología y prevalencia de M. genitalium y la tasa de resistencia frente a azitromicina en nuestra Área de Salud. MÉTODOS: Estudio retrospectivo, desde abril de 2019 a julio de 2020, realizado en el Área de Salud del Norte de Tenerife, la cual atiende el Hospital Universitario Canarias. Para el diagnóstico de las infecciones de transmisión sexual (ITS) se utilizó la RT-PCR Allplex™ STI Essential Assay (Seegene, South Korea). Las muestras en las que se detectó M. genitalium fueron congeladas a −80°C para posteriormente realizar estudio de resistencia a azitromicina con la RT-PCR Allplex™ MG y AziR Assay (Seegene, South Korea). RESULTADOS: Se identificaron 111/3.849 (prevalencia de 2,8%) pacientes con M. genitalium, de los cuales la mayoría, 59(53,1%) eran hombres con una mediana de 32 años (15-74) y cuyas muestras procedían principalmente de Atención Primaria: 55 (49,5%). Para la detección de resistencia a azitromicina, de los 111 pacientes solo se pudo analizar las muestras de 79, detectándose resistencia in vitro en 15(18,3%): 10 con A2059G, 4 con A2058G y 1 con ambas. La resistencia a azitromicina fue más frecuente en hombres 12 (15,8%). DISCUSIÓN Y CONCLUSIONES: Con este estudio se pone de manifiesto la importancia de la prevalencia de M. genitalium en nuestro entorno, así como su alta tasa de resistencia a azitromicina por lo que se hace necesario vigilar dicha resistencia en nuestro Área de Salud para su adecuado tratamiento.

BACKGROUND: Infection and antimicrobial resistance of Mycoplasma genitalium is under-diagnosed in our community as it is not a Notifiable Infectious Disease and requires for its detection molecular biology techniques, which are not always available. AIM: To study the epidemiology and prevalence of M. genitalium and the rate of resistance to azithromycin in our Health Care Area. METHODS: We conducted a retrospective study from April 2019 to July 2020 in the Northern Health Care Area of Tenerife, which is attended to the Universitary Hospital Complex of the Canary Islands. The RT-PCR Allplex™ STI Essential Assay (Seegene, South Korea) to diagnose Sexually Transmitted Infections (STI) was used. Samples in which M. genitalium was detected were stored at −80°C for subsequent diagnosis of resistance to azithromycin with the RT-PCR Allplex™ MG and AziR Assay (Seegene, South Korea). RESULTS: Of a total of 111/3,849 (2.8% prevalence) patients diagnosed with M. genitalium, 59 (53.1%) were male with a mean age of 30 (19-61) years and mainly from Primary Care 55 (49.5%). Only 79 samples of the 111 patients could be tested to detect azithromycin resistance, of which 15 (18.3%) were resistant in vitro: 10 with A2059G, 4 with A2058G and 1 with both. Azithromycin resistance was more frequent in men 12 (15.8%) and detected mainly in urine samples 6 (60%). Discussion and CONCLUSIONS: This study highlights the prevalence of M. genitalium in our setting as well as the high rate of resistance to azithromycin, making it necessary to detect resistance to azithromycin in M. genitalium for its appropriate treatment in our Health Care Area.

Intervención educativa para mejorar la prescripción de ceftriaxona en un servicio de urgencias / Educational intervention to improve ceftriaxone prescription in an emergency department

Objetivo: Evaluar prevalencia y adecuación de ceftriaxona tras una intervención educativa en un servicio de urgencias.Métodos: Estudio cuasi experimental que incluyó un mues-treo consecutivo de consultas no programadas de pacien-tes adultos, durante dos meses preintervención y posin-tervención. Dicha intervención consistió en capacitación a médicos para limitar su indicación sólo a situaciones clínicas específicas (meningitis, enfermedad pélvica infla-matoria y abdomen agudo). Se utilizaron datos retrospecti-vos, con adicional revisión manual de historias, para validar adecuación de inicio antibiótico y apropiabilidad de droga. Se utilizó estadística descriptiva y analítica.Resultados: De un total de 28.570 consultas, 512 recibie-ron ceftriaxona (1,79%; IC95% 1,64-1,95), y sólo 60,54% se hospitalizaron. En cuanto a la comparación antes-después, se observó una reducción en la tasa de uso (de 3,66% a 0,63%; p<0,001), la adecuación en el inicio de un antimicro-biano se mantuvo (de 84,52% a 86,21%; p=0,778), aunque la adecuación de ceftriaxona aumentó en forma significativa (de 41,78% a 84,00% respectivamente; p<0,001). Adicional-mente, se redujo el tiempo de estadía hospitalaria (media-na de 6 a 5 días; p=0,014), sin diferencias en la mortalidad intrahospitalaria (19,44% vs 17,24%; p=0,691), ni en la mor-talidad a los 30 días (23,41% vs 18,96%; p=0,464).Conclusiones: Esta intervención resultó eficaz. Los hallaz-gos representan un paso fundamental en los programas de optimización del uso de antimicrobianos hospitalarios, que apuntan a reducir su sobreutilización y la consecuente resistencia.

Objective: To evaluate the prevalence and appropriateness of ceftriaxone after an educational intervention in an emergency department.Methods: Quasi-experimental study, which included a consecutive sampling of unscheduled consultations of adult patients, during 2 months pre-intervention and post-intervention. The intervention consisted of training physicians to limit its indication only to specific clinical situations (meningitis, pelvic inflammatory disease, and acute abdomen). Retrospective data were used, with additional manual chart review, to validate appropriateness of antibiotic initiation and drug appropriateness. Descriptive and analytical statistics were used.Results: Among 28570 visits, 512 received ceftriaxone (1.79%; 95%CI 1.64-1.95), and only 60.54% were hospitalized. Regarding the before-after comparison, we observed a reduction in the rate of use (from 3.66% to 0.63%; p<0.001), the appropriateness in starting an antimicrobial was maintained (from 84.52% to 86.21%; p=0.778), and the appropriateness of ceftriaxone increased significantly (from 41.78% to 84.00% respectively; p<0.001). Additionally, hospital length of stay was reduced (median 6 to 5 days; p=0.014), with no difference in in-hospital mortality (19.44% vs 17.24%; p=0.691), nor in 30-day mortality (23.41% vs 18.96%; p=0.464)

Epidemiología de la faringitis estreptocócica. Período enero de 2018 - diciembre de 2021 / Epidemiology of streptococcal pharyngitis. January 2018 - December 21

La faringoamigdalitis es uno de los motivos más frecuentes de consulta en pediatría. Aproximadamente un 70-80% de las faringoamigdalitis son de etiología viral. El 20-30% restante son de origen bacteriano. El agente causal más frecuente es Streptococcus pyogenes (estreptococo ß-hemolítico del grupo A). El rol de Streptococcus dysgalactiae subsp. equisimilis, (estreptococos ß-hemolíticos grupos C y G) fue claramente establecido como agente etiológico en la faringitis bacteriana, tanto en niños como en adultos. Se realizó un análisis descriptivo y retrospectivo entre enero 2018 y diciembre de 2021. Se evaluó la prevalencia de faringitis estreptocócica, la edad, el período estacional, los agentes etiológicos y la resistencia a macrólidos durante los períodos pre-COVID-19 (2018-2019) y COVID-19 (2020-2021). Se analizaron 11 396 muestras de exudados de fauces de pacientes con sospecha de faringitis bacteriana; las mismas se procesaron mediante el uso de técnicas microbiológicas convencionales. En el período estudiado el porcentaje de positividad de los cultivos de exudados de fauces se mantuvo constante. Al comparar los períodos pre-COVID-19 (2018-2019) y COVID-19 (2020-2021) se observó una disminución en el número de aislados de S. pyogenes con un aumento de S. dysgalactiae subsp. equisimilis, mientras que la resistencia a macrólidos encontrada fue superior en S. pyogenes y para S. dysgalactiae subsp. equisimilis se mantuvo constante. Es importante realizar el cultivo para la identificación del agente etiológico y determinar la sensibilidad antibióticapara continuar con la vigilancia epidemiológica de la resistencia a los macrólidos, porque representan una opción en pacientes alérgicos a ß-lactámicos (AU)

Pharyngotonsillitis is one of the most frequent reasons for consultation in children. Approximately 70-80% of pharyngotonsillitis are of viral etiology. The remaining 20-30% are bacterial in origin. The most frequent causative agent is Streptococcus pyogenes (group A ß-hemolytic streptococcus). Streptococcus dysgalactiae subsp. equisimilis (ß-hemolytic streptococcus groups C and G) was clearly established as an etiologic agent in bacterial pharyngitis in both children and adults. A descriptive and retrospective analysis was conducted between January 2018 and December 2021. The prevalence of streptococcal pharyngitis, age, seasonal period, etiologic agents, and macrolide resistance during the pre-COVID-19 (2018-2019) and COVID-19 (2020-2021) periods were evaluated. We analyzed 11 396 specimens of swabs from patients with suspected bacterial pharyngitis. Conventional microbiological techniques were used. In the study period, the percentage of positivity of swab cultures remained constant. When comparing the preCOVID-19 (2018-2019) and COVID-19 (2020-2021) periods, a decrease in the number of S. pyogenes isolates was observed with an increase in S. dysgalactiae subsp. equisimilis, while the resistance to macrolides found was higher for S. pyogenes and remained constant for S. dysgalactiae subsp. equisimilis. The identification of the etiologic agent and determination of antibiotic sensitivity are important for epidemiological surveillance of macrolide resistance, as they are a treatment option in patients who are allergic to ß-lactams (AU)

Microorganismos aislados de hemocultivos en niños con leucemia y linforma: Seis años de seguimiento / Microorganisms isolated from blood cultures in children with leukemia and lymphoma: six years of follow-up

Las Leucemias y linfomas constituyen las enfermedades oncológicas más frecuentes en pediatría y las bacteriemias representan infecciones graves en estos pacientes. Objetivos: describir los microorganismos aislados de sangre en pacientes con leucemia aguda o linfoma pediátrico; comparar la incidencia de aislamientos según enfermedad de base; detallar las variaciones en la incidencia de dichos aislamientos y la evolución de su resistencia antimicrobiana. Estudio retrospectivo, observacional. Se incluyeron 823 episodios de bacteriemia en 467 pacientes pediátricos, entre julio-2016 y junio-2022, dividido en tres períodos (período-1: años 2016- 2018, período-2: años 2018-2020, período-3: años 2020-2022). Se aislaron 880 microorganismos: 55,3% gram negativos (GN), 40% gram positivos (GP) y 4,7% levaduras. En GN predominaron: enterobacterias (72%) y en GP: estreptococos del grupo viridans (SGV) (34,1%). Se encontró asociación entre LLA-enterobacterias (p=0,009) y LMA-SGV (p<0,001). Hubo aumento de GN entre los períodos 1 y 3 (p=0,02) y 2 y 3 (p=0,002) y disminución de GP entre 2 y 3 (p=0,01). Se registraron los siguientes mecanismos de resistencia: BLEE (16,4%), carbapenemasas: KPC (2,5%); MBL (2,7%) y OXA (0,2%); meticilinorresistencia en Staphylococcus aureus (20%) y estafilococos coagulasa negativos (95%), vancomicina resistencia en Enterococcus spp. (39%), SGV no sensibles a penicilina (44%) y a cefotaxima (13%). Hubo aumento de MBL entre los períodos 1 y 2 (p=0,02) y una tendencia en disminución de sensibilidad a penicilina en SGV entre el 1 y 3 (p=0,058). El conocimiento dinámico y análisis de estos datos es esencial para generar estadísticas a nivel local, fundamentales para el diseño de guías de tratamientos empíricos (AU)

Leukemias and lymphomas are the most common cancers in children and bacteremia is a severe infection in these patients. Objectives: to describe the microorganisms isolated from blood in pediatric patients with acute leukemia or lymphoma; to compare the incidence of isolates according to the underlying disease; and to detail the variations in the incidence of these isolates and the evolution of their antimicrobial resistance. Retrospective, observational study. We included 823 episodes of bacteremia in 467 pediatric patients seen between July-2016 and June-2022, divided into three periods (period-1: 2016- 2018, period-2: 2018-2020, period-3: 2020-2022). A total of 880 microorganisms were isolated: 55.3% were gram-negative (GN), 40% gram-positive (GP) and 4.7% yeasts. In GN there was a predominance of: enterobacteria (72%) and in GP viridans group streptococci (VGS) (34.1%). An association was found between ALL-enterobacteria (p=0.009) and AML-VGS (p<0.001). There was an increase in GN between periods 1 and 3 (p=0.02) and 2 and 3 (p=0.002) and a decrease in GP between 2 and 3 (p=0.01). The following resistance mechanisms were recorded: BLEE (16.4%), carbapenemases: KPC (2.5%), MBL (2.7%), and OXA (0.2%); methicillin resistance in Staphylococcus aureus (20%) and coagulase negative staphylococci (95%), vancomycin resistance in Enterococcus spp. (39%), VGS resistant to penicillin (44%) and to cefotaxime (13%). There was an increase in MBL between periods 1 and 2 (p=0.02) and a decreasing trend in penicillin sensitivity in VGS between periods 1 and 3 (p=0.058). Dynamic knowledge and analysis of these data is essential to generate statistics at the local level, which is fundamental for the design of empirical treatment guidelines (AU)

Development of a multiplex PCR assay for the detection of metallo-beta-lactamase genes in Pseudomonas aeruginosa / Desarrollo de un PCR múltiple para la detección de genes metalo-beta-lactamasa en Pseudomonas aeruginosa

SUMMARY: The appearance of Pseudomonas aeruginosa strains with multi-resistance to antibiotics is a clinical problem of great relevance. The methods for detecting these resistances are laborious and slow, which is a complication when treating patients promptly. In this work, we developed a simple method for simultaneous detection of several carbapenem resistance genes using a multiplex PCR assay. The PCR assay developed, followed by electrophoretic separation of fragments, allows to simultaneously identify the presence of 6 antibiotic resistance genes: bla-VIM (261 bp), bla-IMP (587 bp), bla-SPM (648 bp), bla-GIM-1 (753 bp), bla-NDM-1 (813 bp) and bla-KPC (882 bp). We analyzed 7 clinical isolates of P. aeruginosa obtained in Chile, finding the resistance genes bla-VIM, bla-IMP, bla-SPM, bla-GIM, and bla-NDM in 5 of them. We found a perfect correlation between the detection of various resistance genes by PCR and the results obtained by antibiograms. Interestingly, 2 of the strains possessed 3 different resistance genes simultaneously. Finally, in this work, we found the presence of 3 genes never described before in clinical isolates of P. aeruginosa in Chile (bla-IMP, bla-SPM, and bla-GIM-1). We developed a rapid multiplex PCR test for the simultaneous detection of up to 6 antibiotic resistance genes of the metallo-β-lactamase family in P. aeruginosa.

La aparición de cepas de Pseudomonas aeruginosa con resistencias a diversos antibióticos es un problema clínico de gran relevancia. Los métodos de detección de dichas resistencias son laboriosos y lentos, lo que genera una complicación al momento de tratar a los pacientes oportunamente. En este trabajo desarrollamos un método simple de detección simultánea de varios genes de resistencia a carbapenem, mediante un sistema de PCR múltiple. El ensayo de PCR desarrollado, seguido de una separación electroforética de los amplicones, permite distinguir simultáneamente la presencia de 6 genes de resistencia a antibióticos: bla-VIM (261 pb), bla-IMP (587 pb), bla-SPM (648 pb), bla-GIM-1 (753 pb), bla-NDM-1 (813 pb) y bla-KPC (882 pb). Analizamos 7 aislados clínicos obtenidos en Chile, encontrando en 5 de ellos los genes de resistencia bla-VIM, bla-IMP, bla-SPM, bla-GIM y bla-NDM. Encontramos una perfecta correlación entre la detección de diversos genes de resistencia y los resultados obtenidos mediante antibiogramas. Interesantemente, 2 de las cepas mostraron poseer simultáneamente 3 genes de resistencia distintos. Por último, en este trabajo encontramos la presencia de 3 genes nunca antes descritos en aislados clínicos de P. aeruginosa en Chile (bla-IMP, bla-SPM y bla-GIM-1). Hemos desarrollado un test rápido de PCR múltiple, para la detección simultánea de hasta 6 genes de resistencia a antibióticos de la familia.a de las metallo-b-lactamases en P. aeruginosa.

Tratamiento de primera línea para erradicación de Helicobacter pylori: todavía una terapia eficaz / First-line treatment for eradication of Helicobacter pylori: Still an effective therapy

Resumen Objetivo: Este estudio tiene como objetivo principal determinar la respuesta al esquema de tratamiento de primera línea con triple terapia estándar (amoxicilina, claritromicina, omeprazol), para erradicación de Helicobacter pylori en una determinada población, para determinar si este esquema propuesto en guías internacionales es aún una opción adecuada para pacientes en una determinada región de Costa Rica. Métodos: Se realizó una búsqueda en el servicio de gastroenterología del Hospital San Francisco de Asís, Grecia, Alajuela, Costa Rica; de todos los pacientes con infección por Helicobacter pylori y que recibieron tratamiento de primera línea con triple terapia (amoxicilina, claritromicina y omeprazol) por 14 días, en el periodo comprendido entre febrero 2017 a febrero 2019, incluyendo para el análisis solamente en los que se contaba con una prueba confirmatoria posterior a tratamiento, ya fuera por antígeno fecal de H. pylori o biopsia convencional. Resultados: Se identificaron un total de 369 casos. El diagnóstico se realizó con biopsia en el 96,4% de los pacientes. La respuesta al tratamiento de primera línea se alcanzó en un 90.5% corroborada por antígeno fecal en el 92.1% de los casos. Conclusiones: Este estudio muestra que la terapia triple con amoxicilina, claritromicina e Inhibidor de bomba de protones por 14 días mantiene un adecuado nivel de eficacia. Sin embargo, hay que tomar en cuenta que estos datos son únicamente de un área de atracción determinada y puede que no reflejen la realidad de todo el país.

Abstract Aim: The main objective of this study is to determine the response to the firstline treatment regimen with triple standard therapy (amoxicillin, clarithromycin, omeprazole), to eradicate Helicobacter pylori in a certain population. The goal is to determine if the proposed regimen in international guidelines services is still a suitable option for patients in a certain region of Costa Rica. Methods: The study took place in San Francisco de Asís Hospital, Grecia, Alajuela, Costa Rica. All patients with a Helicobacter pylori infection that were given first- line treatment with triple therapy (amoxicillin, clarithromycin and omeprazole) for its eradication for 14 days, in the period between February of 2017 and February of 2019, were included in the study. Results: A total of 369 cases were identified. The diagnosis was made with biopsy in 96.4% of patients. Response to first-line treatment was achieved in 90.5% corroborated by fecal antigen in 92.1% of all cases. Conclusions: This study shows that triple therapy with amoxicillin, clarithromycin and omeprazole for 14 days maintains an adequate level of efficacy. However, it must be considered that these results are from a specific area and may not reflect the reality of the entire country.

Atividade in vitro de extratos e frações de Copernicia prunifera (Arecaceae) contra bactérias de importância clínica em saúde pública / In vitro activity of extracts and fractions of Copernicia prunifera (Arecaceae) against bacteria of clinical importance in public health / Actividad in vitro de extractos y fracciones de Copernicia prunifera (Arecaceae) frente a bacterias de importancia clínica en salud pública

Introdução: O aumento contínuo da resistência bacteriana aos antibióticos convencionais é um problema de importância global. Encontrar produtos como alternativas terapêuticas naturais é essencial. As plantas medicinais possuem uma composição química muito rica, que podem ser estruturalmente otimizadas e processadas em novos antimicrobianos. Objetivo: Avaliar o potencial antibacteriano frente a microrganismos humanos potencialmente patogênicos do extrato etanólico e frações de Copernicia prunifera. Metodologia: A triagem fitoquímica de plantas foi realizada usando métodos de precipitação e coloração e a atividade antibacteriana utilizando o método de difusão em disco e microdiluição em caldo contra cepas padronizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus. Resultados: A triagem fitoquímica revela a presença de taninos, flavonoides, esteroides, triterpernóides, saponinas e alcaloides. Os extratos etanólico e frações da casca do caule e folhas tiveram atividade inibitória contra S. aureus e K. pneumonie com zona de inibição que variou de 7,0±1,73 a 9,33±0,58 mm pelo método de difusão em disco. Pelo método de microdiluição em caldo os extratos foram satisfatórios somente contra K. pneumoniae (CIM = 125 a 1000 µg/mL) S. aureus, P. aeruginosa e E. coli se mostraram resistentes aos testes (CIM > 1000 µg/mL). Conclusão: Esses resultados fornecem uma base para futuras investigações em modelos in vivo, para que os compostos de C. prunifera possam ser aplicados no desenvolvimento de novos agentes antimicrobianos contra K. pneumoniae.

Introduction: The continuous increase in bacterial resistance to conventional antibiotics is a problem of global importance. Finding products as natural therapeutic alternatives is essential. Medicinal plants have a very rich chemical composition, which can be structurally optimized and processed into novel antimicrobials. Objective: To evaluate the antibacterial potential against potentially pathogenic human microorganisms of the ethanolic extract and fractions of Copernicia prunifera. Methodology: Phytochemical screening of plants was performed using precipitation and staining methods and antibacterial activity using the disk diffusion and broth microdilution method against standardized strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Results: Phytochemical screening reveals the presence of tannins, flavonoids, steroids, triterpernoids, saponins and alkaloids. The ethanolic extracts and fractions of stem bark and leaves had inhibitory activity against S. aureus and K. pneumonie with zone of inhibition ranging from 7.0±1.73 to 9.33±0.58 mm by disc diffusion method. By broth microdilution method the extracts were satisfactory only against K. pneumoniae (MIC = 125 to 1000 µg/mL) S. aureus, P. aeruginosa and E. coli were resistant to the tests (MIC > 1000 µg/mL). Conclusion: These results provide a basis for further investigation in in vivo models, so that compounds from C. prunifera can be applied in the development of new antimicrobial agents against K. pneumoniae.

Introducción: El continuo aumento de la resistencia bacteriana a los antibióticos convencionales es un problema de importancia mundial. Es esencial encontrar productos como alternativas terapéuticas naturales. Las plantas medicinales tienen una composición química muy rica, que puede optimizarse estructuralmente y transformarse en nuevos antimicrobianos. Objetivo: Evaluar el potencial antibacteriano frente a microorganismos humanos potencialmente patógenos del extracto etanólico y fracciones de Copernicia prunifera. Metodología: Se realizó el cribado fitoquímico de las plantas mediante los métodos de precipitación y tinción y la actividad antibacteriana mediante el método de difusión en disco y microdilución en caldo frente a cepas estandarizadas de Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa y Staphylococcus aureus. Resultados: El cribado fitoquímico revela la presencia de taninos, flavonoides, esteroides, triterpernoides, saponinas y alcaloides. Los extractos etanólicos y las fracciones de la corteza del tallo y las hojas presentaron actividad inhibitoria contra S. aureus y K. pneumonie con una zona de inhibición que osciló entre 7,0±1,73 y 9,33±0,58 mm por el método de difusión en disco. Por el método de microdilución en caldo, los extractos sólo fueron satisfactorios frente a K. pneumoniae (CMI = 125 a 1000 µg/mL). S. aureus, P. aeruginosa y E. coli fueron resistentes a las pruebas (CMI > 1000 µg/mL). Conclusiones: Estos resultados proporcionan una base para futuras investigaciones en modelos in vivo, de modo que los compuestos de C. prunifera puedan aplicarse en el desarrollo de nuevos agentes antimicrobianos contra K. pneumoniae.

Evolución histórica de la Organización Mundial de la Salud y la resistencia a los antimicrobianos / Historical evolution of World Health Organization guidelines on antimicrobial resistance / Evolução histórica da Organização Mundial da Saúde e a resistência aos antimicrobianos

RESUMEN Objetivo. Mostrar la evolución de los lineamientos sobre políticas públicas en salud enfocadas en farmacorresistencia microbiana o resistencia a los antimicrobianos (RAM) que la Organización Mundial de la Salud (OMS) ha emitido desde 1948 hasta 2022. Además, se mencionan otras acciones gubernamentales relacionadas. Métodos. Se llevó a cabo una revisión detallada de los archivos de la Asamblea Mundial de la Salud y el Consejo Ejecutivo de la OMS. Se realizó un análisis textual de resoluciones sobre la RAM, que dan pauta al diseño de políticas y acciones gubernamentales para los Estados Miembros de la OMS. También se realizó una búsqueda sistemática en SCOPUS, Pubmed y literatura gris con categoría de análisis: políticas públicas en salud sobre la RAM. Resultados. La RAM se ha convertido en la mayor amenaza para la salud pública, y compromete el cumplimiento de los objetivos de desarrollo sostenible. Presentamos resoluciones de la OMS como evidencia de lineamientos para combatir la RAM. En consonancia, se menciona el enfoque "Una salud", estrategias, iniciativas, planes y programas relacionados. Se identificó una brecha en la investigación y el desarrollo de antimicrobianos nuevos, que requiere un análisis más profundo. Conclusiones. La OMS ha realizado esfuerzos para combatir la RAM. Esto ha generado un desarrollo integral de políticas públicas en salud, para que los Estados Miembros las apliquen según la soberanía de sus gobiernos.

ABSTRACT Objective. Show the evolution of guidelines on public health policies focused on antimicrobial resistance (AMR) issued by the World Health Organization (WHO) between 1948 and 2022. Other related government actions are also mentioned. Methods. A detailed review was conducted of World Health Assembly and WHO Executive Board archives. A textual analysis was conducted of AMR-related resolutions that guide the design of government policies and actions for WHO Member States. A systematic search was carried out in SCOPUS, PubMed, and grey literature under the category of public health policies on AMR. Results. AMR has become the greatest threat to public health, putting at risk the achievement of the Sustainable Development Goals. WHO resolutions are presented as evidence of guidelines to combat AMR. The One Health approach and related strategies, initiatives, plans, and programs are mentioned. A gap was identified in the research and development of new antimicrobials, requiring further analysis. Conclusions. WHO has made efforts to combat AMR. This has generated comprehensive development of public health policies to be implemented by the governments of Member States as they see fit.

RESUMO Objetivo. Apresentar a evolução das diretrizes sobre políticas públicas de saúde voltadas para a resistência microbiana a medicamentos ou resistência aos antimicrobianos (RAM) publicadas pela Organização Mundial da Saúde (OMS) de 1948 a 2022. Além disso, mencionam-se outras ações governamentais relacionadas. Métodos. Procedeu-se a uma revisão detalhada dos arquivos da Assembleia Mundial da Saúde e do Conselho Executivo da OMS. Realizou-se uma análise textual das resoluções sobre RAM, que orientam a formulação de políticas e ações governamentais para os Estados Membros da OMS. Fez-se também uma busca sistemática nas plataformas SCOPUS e Pubmed e na literatura cinzenta, com a categoria de análise "políticas públicas de saúde sobre RAM". Resultados. A RAM tornou-se a maior ameaça à saúde pública e prejudica o cumprimento dos Objetivos de Desenvolvimento Sustentável. Apresentamos as resoluções da OMS como evidência de diretrizes para combater a RAM. Nesses termos, mencionam-se a abordagem "Saúde Única" e estratégias, iniciativas, planos e programas relacionados. Identificou-se uma lacuna na pesquisa e no desenvolvimento de novos antimicrobianos, o que requer uma análise mais aprofundada. Conclusões. A OMS envidou esforços para combater a RAM, o que levou ao desenvolvimento integral de políticas públicas de saúde a serem aplicadas pelos Estados Membros, em conformidade com a soberania de seus governos.

Drug resistance and susceptibility testing of Gram negative bacterial isolates from healthy cattle with different β – Lactam resistance Phenotypes from Shandong province China / Teste de resistência a drogas e suscetibilidade de isolados bacterianos Gram negativos de bovinos saudáveis com diferentes fenótipos de resistência a β - lactâmicos da província de Shandong, China

The objective of this study was to evaluate the effectiveness of common antibiotics against different microorganisms in apparently healthy cattle in Shandong province and its suburb. A total of 220 nasal swab samples were collected and cultured for bacteriological evaluation. All the bacteria isolates after preliminary identification were subjected to antibiogram studies following disc diffusion method. It was found in the study that E. coli is the most commonly associated isolate (21%), followed by Klebsiella spp. (18%), Pseudomonas aeruginosa (13%), Salmonella spp. (15%), Shigella spp (12%), and Proteus spp (11%). While the antibiogram studies reveled that highest number of bacterial isolates showed resistance to Ampicillin (95%), followed by Augmentin (91%), Cefuroxime (85%) and Tetracycline (95%) of (Escherichia coli and Klebsiella spp). In the case of pseudomonas spp. and Salmonella the highest resistance was showed by Ampicillin (90%) followed by Amoxicillin + Clavulanic Acid (80%), Cefixime (90%), and Erythromycin (80%). In Shigella spp and Salmonella spp highest resistance was showed by Amoxicillin, Ceftazidime, Augmentin (60%), and Amoxicillin + Clavulanic Acid (50%). It is concluded that in vitro antibiogram studies of bacterial isolates revealed higher resistance for Ampicillin, Augmentin, Cefuroxime, Cefixime, Tetracycline, Erythromycin, and Amoxicillin + Clavulanic Acid. The high multiple Antibiotics resistance indexes (MARI) observed in all the isolates in this study ranging from 0.6 to 0.9. MARI value of >0.2 is suggests multiple antibiotic resistant bacteria and indicate presence of highly resistant bacteria.

O objetivo deste estudo foi avaliar a eficácia dos antibióticos comuns contra diferentes microrganismos em bovinos aparentemente saudáveis na província de Shandong e seus subúrbios. Um total de 220 amostras de esfregaço nasal foi coletado e cultivado para avaliação bacteriológica. Todos os isolados de bactérias após identificação preliminar foram submetidos a estudos de antibiograma seguindo o método de difusão em disco. Verificou-se no estudo que E. coli é o isolado mais comumente associado (21%), seguido por Klebsiella spp. (18%), Pseudomonas aeruginosa (13%), Salmonella spp. (15%), Shigella spp (12%) e Proteus spp (11%). Enquanto os estudos de antibiograma revelaram que o maior número de isolados bacterianos apresentou resistência à Ampicilina (95%), seguido por Augmentin (91%), Cefuroxima (85%) e Tetraciclina (95%) de (Escherichia coli e Klebsiella spp). No caso de Pseudomonas spp. e Salmonella, a maior resistência foi apresentada pela Ampicilina (90%) seguida pela Amoxicilina + Ácido Clavulânico (80%), Cefixima (90%) e Eritromicina (80%). Em Shigella spp e Salmonella spp, a maior resistência foi demonstrada por Amoxicilina, Ceftazidima, Augmentina (60%) e Amoxicilina + Ácido Clavulânico (50%). Conclui-se que estudos de antibiograma in vitro de isolados bacterianos revelaram maior resistência para Ampicilina, Augmentina, Cefuroxima, Cefixima, Tetraciclina, Eritromicina e Amoxicilina + Ácido Clavulânico. Os altos índices de resistência a antibióticos múltiplos (MARI) observados em todos os isolados neste estudo variaram de 0,6 a 0,9. O valor MARI de > 0,2 sugere várias bactérias resistentes a antibióticos e indica a presença de bactérias altamente resistentes.

Caracterización microbiológica y fenotipificación de la resistencia bacteriana en las infecciones intraabdominales en el Instituto Autónomo Hospital Universitario de los Andes, 2014-2017 / Microbiological characterization and phenotyping of bacterial resistance in intra-abdominal infections at the Instituto Autonomo Hospital Universitario de los Andes, 2014-2017

Objetivo: caracterizar los microorganismos involucrados en las infecciones intraabdominales, y fenotipificar sus perfiles de resistencia al uso de los antibióticos en el Servicio de Cirugía General del Instituto Autónomo Hospital Universitario de Los Andes, entre los años 2014 al 2017. Metodología: enfoque cuantitativo; tipo descriptivo, diseño no experimental de estudio de casos y transversal, a través de toma de muestras de secreciones abdominales en quirófano a las cuales se les realizó cultivo en medios de agar sangre y McConkey, tinción Gram, contaje de leucocitos, y prueba Kirby-Bauer de sensibilidad antimicrobiana. Muestra de 211 pacientes mayores de 16 años que acudieron a la institución con el diagnóstico de abdomen agudo quirúrgico infeccioso. Resultados: el abdomen agudo quirúrgico infeccioso por apendicitis aguda fue la infección intraabdominal más común, grupo etario que acudió con más frecuencia: <26 años. Agentes etiológicos más frecuentemente aislados: bacilos Gram negativos, especies más frecuentes: E. col i (57,3%), K. pneumon iae (10,9%) y P. a e rug i nosa (6,16%). De todos los microorganismos aislados 57,6% expresaron al menos un fenotipo de resistencia. Fenotipo más común: betalactamasa de espectro extendido y bomba de eflujo de quinolonas (18,8%). Microorganismos con mayores porcentajes de resistencia: Staphylococcus sp. y Enterococcus sp (~100%). Los mejores porcentajes de sensibilidad de la E. col i , K . p neumon ia e y P . a e rug i nosa fueron hacia al colistin, carbapenémicos y amikacina (100%). Conclusión: Los carbapenémicos y los aminoglucósidos seguirán siendo los fármacos de elección en las infecciones intraabdominales del Instituto Autónomo Hospital Universitario de Los Andes(AU)

Objective: to characterize the microorganisms involved in intraabdominal infections, and to phenotype their resistance profiles to the use of antibiotics in the General Surgery Service of the Instituto Autónomo Hospital Universitario de Los Andes, from 2014 to 2017. Methodology: quantitative approach; descriptive type, nonexperimental design of case study and transversal, through sampling of abdominal secretions in the operating room which were cultured in blood agar and McConkey media, Gram stain, leukocyte count, and Kirby-Bauer test for antimicrobial sensitivity. Sample of 211 patients older than 16 years who attended the institution with the diagnosis of acute surgical infectious abdomen. Results: acute surgical infectious abdomen due to acute appendicitis was the most common intra-abdominal infection, most frequent age group: <26 years. Most frequently isolated etiologic agents: Gram-negative bacilli, most frequent species: E. co l i (57.3%), K. p neumon ia e (10.9%) and P . a e rug i nosa (6.16%). Of all the isolated microorganisms, 57.6% expressed at least one resistance phenotype. Most common phenotype: extended-spectrum beta-lactamase and quinolone efflux pump (18.8%). Microorganisms with the highest percentages of resistance: Staphylococcus sp. and Enterococcus sp (~100%). The best percentages of sensitivity of E. col i , K . pneumoniae and P . a e rug i nosa were to colistin, carbapenemics and amikacin (100%). Conclusion: Carbapenemics and aminoglycosides will remain the drugs of choice in intra-abdominal infections at Instituto Autónomo Hospital Universitario de Los Andes(AU)

Distribution and Drug Resistance of Pathogens in Oral Mucositis Associated with Chemotherapy in Patients with Malignant Hematopathy / 中国实验血液学杂志

OBJECTIVE@#To analyze the distribution and drug resistance of pathogens in oral mucositis associated with chemotherapy in hospitalized patients with malignant hematopathy, so as to provide scientific evidences for rational selection of antibiotics and infection prevention and control.@*METHODS@#From July 2020 to June 2022, 167 patients with malignant hematopathy were treated with chemical drugs in the Department of Hematology, Hainan Hospital, and secretions from oral mucosal infected wounds were collected. VITEK2 COMPECT automatic microbial identification system (BioMerieux, France) and bacterial susceptibility card (BioMerieux) were used for bacterial identification and drug susceptibility tests.@*RESULTS@#A total of 352 strains of pathogens were isolated from 167 patients, among which 220 strains of Gram-positive bacteria, 118 strains of Gram-negative bacteria and 14 strains of fungi, accounted for 62.50%, 33.52% and 3.98%, respectively. The Gram-positive bacteria was mainly Staphylococcus and Streptococcus, while Gram-negative bacteria was mainly Klebsiella and Proteus. The resistance of main Gram-positive bacteria to vancomycin, ciprofloxacin and gentamicin was low, and the resistance to penicillin, cefuroxime, ampicillin, cefotaxime, erythromycin and levofloxacin was high. The main Gram-negative bacteria had low resistance to gentamicin, imipenem and penicillin, but high resistance to levofloxacin, cefotaxime, cefuroxime, ampicillin and vancomycin. The clinical data of oral mucositis patients with oral ulcer (severe) and without oral ulcer (mild) were compared, and it was found that there were statistically significant differences in poor oral hygiene, diabetes, sleep duration less than 8 hours per night between two groups (P<0.05).@*CONCLUSION@#Gram-positive bacteria is the main pathogen of oral mucositis in patients with malignant hematopathy after chemotherapy. It is sensitive to glycopeptide antibiotics and aminoglycosides antibiotics. Poor oral hygiene, diabetes and sleep duration less than 8 hours per night are risk factors for oral mucositis with oral ulcer (severe).

Clinical value of the MeltPro MTB assays in detection of drug-resistant tuberculosis in paraffin-embedded tissues / 中华病理学杂志

Objective: To evaluate the clinical value of the MeltPro MTB assays in the diagnosis of drug-resistant tuberculosis. Methods: A cross-sectional study design was used to retrospectively collect all 4 551 patients with confirmed tuberculosis between January 2018 and December 2019 at Beijing Chest Hospital, Capital Medical University. Phenotypic drug sensitivity test and GeneXpert MTB/RIF (hereafter referred to as "Xpert") assay were used as gold standards to analyze the accuracy of the probe melting curve method. The clinical value of this technique was also evaluated as a complementary method to conventional assays of drug resistance to increase the detective rate of drug-resistant tuberculosis. Results: By taking the phenotypic drug susceptibility test as the gold standard, the sensitivity of the MeltPro MTB assays to detect resistance to rifampicin, isoniazid, ethambutol and fluoroquinolone was 14/15, 95.7%(22/23), 2/4 and 8/9,respectively; and the specificity was 92.0%(115/125), 93.2%(109/117), 90.4%(123/136) and 93.9%(123/131),respectively; the overall concordance rate was 92.1%(95%CI:89.6%-94.1%),and the Kappa value of the consistency test was 0.63(95%CI:0.55-0.72).By taking the Xpert test results as the reference, the sensitivity of this technology to the detection of rifampicin resistance was 93.6%(44/47), the specificity was100%(310/310), the concordance rate was 99.2%(95%CI:97.6%-99.7%), and the Kappa value of the consistency test was 0.96(95%CI:0.93-0.99). The MeltPro MTB assays had been used in 4 551 confirmed patients; the proportion of patients who obtained effective drug resistance results increased from 83.3% to 87.8%(P<0.01); and detection rate of rifampicin, isoniazid, ethambutol, fluoroquinolone resistance, multidrug and pre-extensive drug resistance cases were increased by 3.2%, 14.7%, 22.2%, 13.7%, 11.2% and 12.5%, respectively. Conclusion: The MeltPro MTB assays show satisfactory accuracy in the diagnosis of drug-resistant tuberculosis. This molecular pathological test is an effective complementary method in improving test positivity of drug-resistant tuberculosis.

Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020 / 中华预防医学杂志

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies / 中华血液学杂志

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Analysis of Pathogenic Bacterial Spectrum, Drug Resistance and Risk Factors for Mortality of Bloodstream Infection in Patients with Hematologic Diseases / 中国实验血液学杂志

OBJECTIVE@#To analyze the pathogenic bacterial spectrum, drug resistance, and risk factors associated with multidrug-resistant bacterial infection and mortality in patients with hematologic diseases complicated by bloodstream infections, so as to provide reference for rational drug use and improving prognosis.@*METHODS@#Positive blood culture specimens of patients with hematologic diseases in two Class A tertiary hospitals of Shanxi province from January 2019 to December 2021 were retrospectively analyzed. Pathogen distribution, drug resistance and outcomes of patients with bloodstream infection were investigated, then the multivariate logistic analysis was performed to analyze the risk factors of multidrug-resistant bacterial infection and factors affecting prognosis.@*RESULTS@#203 strains of pathogens were identified, mainly Gram-negative bacteria (GNB) (69.46%, 141/203), of which Escherichia coli (E.coli) had the highest incidence (41.13%, 58/141), followed by Klebsiella pneumoniae (20.57%, 29/141) and Pseudomonas aeruginosa (12.77%, 18/141). Extended-spectrum beta-lactamase (ESBL)-producing E.coli and Klebsiella pneumoniae were 46.55% (27/58) and 37.93% (11/29), respectively. Carbapenem-resistant Gram-negative bacteria accounted for 10.64% (15/141). And Gram-positive bacteria accounted for 27.59% (56/203), Staphylococcus epidermidis, Streptococcus pneumoniae, and Staphylococcus aureus were the most frequently isolated pathogen among Gram-positive bacteria (14.29%, 12.50% and 10.71%, respectively), of which methicillin-resistant Staphylococcus aureus accounted for 33.33% (2/6), coagulase-negative staphylococci accounted for 87.50% (7/8), without vancomycin- or linezolid-resistant strain. Additionally, fungi accounted for 2.95% (6/203), all of which were Candida. Multidrug-resistant Gram-negative bacteria (MDR-GNB) accounted for 53.90% (76/141). Duration of neutropenia >14 days was a risk factor for developing MDR-GNB infection. The 30-day all-cause mortality was 10.84%. Multivariate logistic regression analysis showed that the significant independent risk factors for mortality were age≥60 years (P <0.01, OR =5.85, 95% CI: 1.80-19.07) and use of vasopressor drugs (P <0.01, OR =5.89, 95% CI: 1.83-18.94).@*CONCLUSION@#The pathogenic bacteria of bloodstream infection in patients with hematological diseases are widely distributed, and the detection rate of multidrug-resistant bacteria is high. The clinicians should choose suitable antibiotics according to the results of bacterial culture and antibiotic susceptibility test.