Resumen Introducción : Los retrasos en el tratamiento anti microbiano adecuado de las bacteriemias prolongan la estadía hospitalaria, aumentan la mortalidad e in crementan los costos. Aún hoy en día se requiere un tiempo considerable para obtener la identificación y antibiograma de los microorganismos en los hemocul tivos positivos. El objetivo fue evaluar el impacto de la implementa ción del panel BCID2 de FilmArray® (FA) sobre el tiempo de inicio de tratamientos antimicrobianos adecuados y sobre los costos potenciales de los mismos. Métodos : Estudio observacional retrospectivo de los hemocultivos positivos de pacientes hospitalizados, procesados por FA y por metodología tradicional. Se evaluaron los cambios de antimicrobianos en base a los resultados del FA. Se calcularon los días de reducción de tratamiento antimicrobiano y el ahorro potencial en el uso de los mismos, teniendo en cuenta también los costos del FA. Resultados : Se analizaron 87 episodios de bacte riemia. En 42 (48.3%) de ellos se desescaló el trata miento a antimicrobianos de menor espectro, en 7 (8%) se escaló a antimicrobianos de mayor espectro, en 8 (9.2%) se cambió el antimicrobiano sin variar el espectro y en 30 (34.5%) no se realizaron cambios con los resultados del FA. Los cambios de antimicrobianos se realizaron en promedio 2.3 días más rápido que con los métodos convencionales. Se calculó un ahorro potencial de US$ 7408. Conclusión : La implementación del panel BCID2 de FilmArray ® permitió adecuar los tratamientos antimi crobianos más rápidamente acortando la duración de los tratamientos empíricos de amplio espectro, lo cual resultó costo-efectivo.

Abstract Introduction : Delay in initiating appropriate anti microbial therapy prolongs hospitalization, increases in-hospital mortality, and raises economic costs. Cur rently, the identification and susceptibility testing of bacteria in positive blood cultures require a considerable amount of time. The objective of this study was to assess the impact of the BCID2 FilmArray® (FA) panel on the timing of appropriate antimicrobial therapy and potential anti microbial costs. Methods : This is a retrospective observational study focused on positive blood cultures in hospitalized pa tients. FA processing was conducted concurrently with routine sample processing. Changes in antibiotic treat ments based on FA results were evaluated, and the re duction in antimicrobial therapy duration and associated cost savings were calculated. Results : Eighty-seven bacteremia episodes were ana lysed. In 42 (48%) of them antimicrobial therapy was de-escalated to narrower spectrum agents, while in 7 (8%) therapy was escalated to broader spectrum anti microbials. Additionally, in 8 (9%) antimicrobials were switched without changing spectrum and in 30 (34%) no changes were made based on FA results. Antimicrobial changes were made 2.3 days faster than with routine sample processing resulting in calculated potential sav ings of US$ 7408. Conclusion : The implementation of FA facilitated a faster administration of appropriate antimicrobial therapy, leading to a reduction in the duration of broad-spectrum empirical antimicrobial therapy and subse quent economic savings.

Resumen Listeria monocytogenes es una bacteria aeróbica Gram positiva; encontrada enforma ubicua en la naturaleza; que afecta sobre todo a recién nacidos, adultos mayores, pacientes inmunodeprimidos y mujeres embarazadas. Sin embargo, la enfermedad por Listeria puede ocurrir en la población sana. La listeriosis invasiva posee 3 formas clínicas do minantes, bacteriemia, neurolisteriosis e infección materno-neonatal. Las formas localizadas se describen infrecuentemente. La enfermedad se produce fun damentalmente en forma secundaria al consumo de alimentos contaminados, incluidos leche o queso no pasteurizados, y sepresenta en forma de casos aislados o brotes, soliendo comenzar a los pocos días del con sumo de éstos; aunque se ha descripto hasta 2 meses después de ingerirlos. También existela posibilidad de transmisión directa desde animales y transmisión vertical. La listeriosis sistémica sin cuadro neurológico do minante es un evento raro. Se presentan dos casos. El primero, una espondilodiscitis en huésped normal y el segundo una bacteriemia por Listeria en un paciente inmunocomprometido febril.

Abstract Listeria monocytogenes is a Gram-positive aerobic bac terium; found ubiquitously in nature; which mainly affects newborns, older adults, immunosuppressed pa tients and pregnant women. However, Listeria disease can occur in the healthy population. Invasive listeriosis has three dominant clinical forms, bacteremia, neurolisteriosis and maternal-neonatal in fection. Localized forms are infrequently described. The disease occurs mainly secondary to the consumption of contaminated food, including unpasteurized milk or cheese, and occurs in the form of isolated cases or outbreaks, usually beginning a few days after consump tion of the contaminated food; although it has been described up to 2 months after ingesting them. There is also the possibility of direct transmission from animals and vertical transmission. Systemic listeriosis without dominant neurological symp toms is a rare event. Two cases are presented. The first was spondylodiscitis in a normal host and the second was Listeria bacteremia in a febrile immunocompromised patient.

Resumen Introducción : A pesar de las mejoras en los cuidados de la salud, la mortalidad asociada a neumonía continúa siendo alta. El objetivo de este estudio fue analizar los factores asociados a mortalidad en neumonía bacterié mica por neumococo. Métodos : Estudio de cohorte retrospectiva en pacien tes adultos con diagnóstico de neumonía y neumococo aislado en hemocultivos, entre enero 2012 y mayo 2021. Se analizaron: variables clínicas y de laboratorio, com promiso radiológico, evolución y mortalidad durante la internación. Se comparó el grupo de pacientes fallecidos con el de sobrevivientes. Resultados : Se incluyeron 152 pacientes. La mediana de edad fue de 58 años y el 58.9% fueron hombres. El 33% presentó un CURB-65 mayor a 2 al momento de internación. La mortalidad global fue 34% (n=52). Los pacientes fallecidos se encontraban más frecuente mente taquipneicos al ingreso (frecuencia respiratoria 26 vs. 22; p=0.003), presentaban más frecuentemente alteración del sensorio (58% vs. 14%; p< 0.001), PaO2/ fracción inspirada de oxígeno (PAFI) < 250 (58% vs. 22%; p<0.001), compromiso radiológico bilateral (50% vs. 32%; p=0.03), necesidad de asistencia respiratoria mecánica (ARM) (50% vs. 12%; p< 0.001), mayor valor de creati nina en sangre (1.6 vs. 1.15; p=0.01), menor recuento de glóbulos blancos (10 900 vs. 17 400; p=0.002), menor valor de glucemia (111 vs. 120; p=0.01) y menos días de estancia hospitalaria (6 vs. 9; p=0.015). En el análisis de regresión logística multivariable se mantuvieron diferen cias significativas en los siguientes factores asociados a mortalidad: ventilación mecánica (OR=3.54), confusión (OR=5.95), radiografía con compromiso bilateral (OR= 3.20) y PAFI < 250 (OR=3.62). Conclusión : Los factores relacionados con mortalidad, a pesar de la presencia de bacteriemia, no difieren de los publicados en la literatura y forman parte de los scores pronósticos de práctica habitual.

Abstract Introduction : Despite improvements in health care, pneumonia-associated mortality remains high. The ob jective of this study was to analyze the factors associated with mortality in bacteremic pneumonia caused by pneumococcus. Methods : Retrospective cohort study in adult pa tients with pneumonia diagnosis and isolation of pneu mococcus in blood cultures, between January 2012 and May 2021, was carried out. Clinical and laboratory vari ables, radiological involvement, evolution and mortal ity during hospitalization were analyzed. The group of deceased patients was compared with that of survivors. Results : 152 patients were included. Median age: 58 years; men: 58.9%; 33% presented a CURB-65 > than 2 at admission. Overall mortality: 34% (n=52). Deceased patients were more tachypneic on admission (respira tory rate 26 vs. 22; p=0.003), presented sensory alteration more frequently (58% vs. 14%; p< 0.001), PaO2/fraction of inspired oxygen ratio < 250 (58% vs. 22%; p<0.001), bilateral radiological compromise (50% vs. 32%; p=0.03), needed mechanical ventilation (50% vs 12%; p< 0.001), higher blood creatinine values (1.6 vs. 1.15; p=0.01), lower white blood cell count (10 900 vs 17 400; p=0.002), a lower glucose dosage (111 vs. 120; p=0.01), and fewer days of hospital stay (6 vs. 9; p=0.015). In logistic regression model, significant differences were maintained in the following factors associated with mortality: mechanical ventilation (OR=3.54), altered mental status (OR=5.95), chest X-ray with bilateral compromise (OR 3.20) and PAFI less than 250 (OR=3.62). Conclusion : In our series, the factors related to mor tality, despite the presence of bacteremia, do not differ from those published in the literature and which are part of the different prognostic scores used in routine practice.

Abstract Brain abscess is a focal suppurative process pro duced in most cases by bacterial agents. Aggregati bacter aphrophilus is a gram-negative bacteria belong ing to the HACEK group, which causes infective endo carditis, liver abscesses, among others. Brain abscesses secondary to this germ are rare and, in most cases, it is associated with contact with pets, poor dental hygiene or dental procedures. Treatment consists of drainage of the abscess (greater than 2.5 cm) combined with antibiotic therapy, ideally beta-lactams. The case of a 64-year-old male patient with no relevant history is here presented. He was admitted to the emergency service due to headache, hemianopsia of a week’s duration and later tonic-clonic seizures, in whom imaging studies and culture of a brain lesion subse quently revealed a brain abscess due to A. aphrophilus. This case aims to illustrate about the rarity of this infection, because A. aphrophilus is a normal part of the oropharyngeal flora and respiratory tract, in which it rarely causes invasive bacteremia.

Resumen El absceso cerebral es un proceso supurativo focal producido en la mayoría de los casos por agentes bacte rianos. Aggregatibacter aphrophilus es una bacteria gram negativa perteneciente al grupo HACEK, causante de endocarditis infecciosa, abscesos hepáticos, entre otras. Los abscesos cerebrales secundarios a este germen son infrecuentes y en la mayoría de los casos asociados a contactos con animales domésticos, pobre higiene dental o procedimientos odontológicos. El tratamiento consiste en drenaje del absceso (mayores de 2.5 cm) combinado con terapia antibiótica, idealmente betalactámicos. Se presenta el caso de un paciente varón de 64 años sin antecedentes de relevancia quien ingresó al servicio de emergencias por cuadro de cefalea, hemianopsias de una semana de evolución y posteriormente crisis tónico clónicas, en quien posteriormente en estudios imageno lógicos y cultivo de lesión cerebral se arribó al diagnóstico de absceso cerebral por A. aphrophilus. Este informe tiene como objetivo ilustrar al lector sobre la rareza de esta infección, debido a que A. aphrophilus forma parte normal de la flora orofaríngea y del tracto respiratorio, en los que rara vez ocasiona bacteriemias invasivas.

ABSTRACT Infective endocarditis (IE) is a disease caused by microorganisms that settle mainly in the heart valves. They frequently occur due to oral, gastrointestinal and urogenital lacerations, in addition to medical procedures that can cause bacteremia which leads to bacterial adhesion and local inflammation and these to valve destruction(1,2).. Gram-positive bacteria are mostly associated with IE, and to a lesser extent, those of the HACEK group, saprophytes of the oropharynx, which are responsible for less than 5% of cases(2-4). We present the case of a 23-year-old man with a 1-month history of fever, sweating, and asthenia; to which a productive cough is later added. A probable cardiological focus is proposed due to history and physical findings, returning isolation of the Haemophilus aphrophilus germ, an unusual microorganism.

RESUMEN La endocarditis infecciosa (EI) es una enfermedad causada por microorganismos que se asientan principalmente en las válvulas cardiacas. Frecuentemente ocurren por laceraciones orales, gastrointestinales y urogenitales, además de procedimientos médicos que pueden causar bacteriemia la cual conlleva a adherencia bacteriana e inflamación local y éstas a destrucción valvular(1,2). Las bacterias grampositivas son mayoritariamente asociadas a EI, y en menor proporción, las del grupo HACEK, saprofitos de la orofaringe, que son responsables de menos del 5% de casos(2-4). Se presenta el caso de un varón de 23 años con cuadro de 1 mes de evolución de sensación febril, sudoración y astenia; al que posteriormente se agrega tos productiva. Se plantea foco probable cardiológico por antecedentes y hallazgos físicos, retornando aislamiento del germen Haemophilus aphrophilus, microorganismo poco habitual.

Abstract Objective: Estimating which patients might require surgical intervention is crucial. Patients with complete bowel obstructions exhibit disrupted enterohepatic cycles of bile and bacteremia due to bacterial translocation. The goal of this study was to develop a prediction index using laboratory inflammatory data to identify patients who may need surgery. Materials and methods: The patients were divided into two groups based on their management strategy: Non-operative management (Group 1) and surgical management (Group 2). Results: The indirect bilirubin, direct bilirubin, and total bilirubin were significantly higher in Group 2 than in Group 1 (p = 0.001, p < 0.001, and p < 0.001, respectively). The neutrophil-to-lymphocyte ratio (NLR), platelet-to-NLR (PNLR), and direct bilirubin-to-lymphocyte ratio (DBR) were significantly higher in Group 2 compared to Group 1 (p = 0.041, p = 0.020, and p < 0.001, respectively). In group 2, 78% have viable bowels. Resection was performed in 40% of cases, with 12% mortality and a 10-day average hospital stay. DLR performs the best overall accuracy (72%), demonstrating a well-balanced sensitivity (62%) and specificity (81%). Conclusions: This study suggested that DBR is a more accurate predictive index for surgical intervention in pediatric adhesive small bowel obstruction patients compared to NLR and PNLR, providing valuable guidance for treatment strategies.

Resumen Objetivo: Desarrollar un índice de predicción utilizando datos inflamatorios de laboratorio para identificar qué pacientes podrían necesitar cirugía. Método: Los pacientes se dividieron en dos grupos según su estrategia de manejo: no quirúrgico (grupo 1) o quirúrgico (grupo 2). Resultados: Las bilirrubinas indirecta, directa y total fueron significativamente más altas en el grupo 2 que en el grupo 1 (p = 0.001, p < 0.001 y p < 0.001, respectivamente). Las relaciones neutrófilos-linfocitos, plaquetas-neutrófilos-linfocitos y bilirrubina directa-linfocitos fueron significativamente más altas en el grupo 2 que en el grupo 1 (p = 0.041, p = 0.020 y p < 0.001, respectivamente). En el grupo 2, el 78% tenían intestino viable. Se realizó resección en el 40% de los casos, con un 12% de mortalidad y una estancia hospitalaria promedio de 10 días. La relación bilirrubina directa-linfocitos tuvo la mejor precisión general (72%), demostrando una sensibilidad bien equilibrada (62%) y una buena especificidad (81%). Conclusiones: Este estudio sugiere que la relación bilirrubina directa-linfocitos es un índice predictivo más preciso para la intervención quirúrgica en pacientes pediátricos con obstrucción adhesiva de intestino delgado en comparación con la de neutrófilos-linfocitos y la de plaquetas-neutrófilos-linfocitos, proporcionando una valiosa orientación para las estrategias de tratamiento.

Abstract Objective: To investigate the effectiveness of linezolid and vancomycin for the treatment of nosocomial infections in children under 12 years old. Data sources: This is a systematic review in which five randomized clinical trials about the effectiveness of linezolid and vancomycin, involving a total of 429 children with nosocomial infections, were evaluated. They were searched in scientific databases: PubMed, Bvs, and SciELO. Summary of findings: The main nosocomial infections that affected children were bacteremia, skin, and soft tissue infections followed by nosocomial pneumonia. Most infections were caused by Gram-positive bacteria, which all studies showed infections caused by Staphylococcus aureus, with methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci strains being isolated. Both linezolid and vancomycin showed high therapeutic efficacy against different types of nosocomial infections, ranging from 84.4% to 94% for linezolid and 76.9% to 90% for vancomycin. Patients receiving linezolid had lower rates of rash and red man syndrome compared to those receiving vancomycin. However, despite the adverse reactions, antimicrobials can be safely administered to children to treat nosocomial infections caused by resistant Gram-positive bacteria. Conclusion: Both linezolid and vancomycin showed good efficacy in the treatment of bacterial infections caused by resistant Gram-positive bacteria in hospitalized children. However, linezolid stands out regarding its pharmacological safety. Importantly, to strengthen this conclusion, further clinical trials are needed to provide additional evidence. Objective 1 old sources 42 evaluated databases PubMed Bvs SciELO findings bacteremia skin pneumonia Grampositive Gram positive methicillinresistant methicillin S MRSA (MRSA coagulasenegative coagulase negative isolated 844 84 4 84.4 94 769 76 9 76.9 90 However reactions Conclusion safety Importantly conclusion evidence 8 84. 7 76.

RESUMEN El síndrome de piel escaldada estafilocócica es una patología poco frecuente que principalmente afecta a población pediátrica. Si bien en la mayoría de los casos tiene un desenlace favorable, un buen diagnóstico diferencial y manejo antibiótico oportuno son cruciales para un buen pronóstico. Objetivo: Describir un caso de síndrome de piel escaldada con aislamiento en hemocultivos de S. Aureus meticilino resistente en un neonato. Caso clínico: Femenina de 25 días de vida, nacida a término y sin antecedentes perinatales relevantes que cursa con fiebre, dermatosis eritemato-descamativa generalizada, edema palpebral y de miembros inferiores. Se hospitalizó con diagnóstico de sepsis neonatal tardía y sindrome de piel escaldada. Reporte de hemocultivos con crecimiento de S. Aureus meticilino resistente, manejada con vancomicina durante 14 días. Control de hemocultivos negativos, evolución satisfactoria y de alta hospitalaria sin complicaciones. Conclusiones: A pesar de la baja incidencia del síndrome de piel escaldada, es importante incluir dentro del diagnóstico diferencial de la fiebre y las dermatosis tardías del neonato la infecciones por toxinas del S. Aureus, ya que su identificación y tratamiento oportuno son de gran importancia en el pronóstico del menor.

ABSTRACT Staphylococcal scalded skin syndrome is a rare pathology, which mainly affects pediatric population. Although in most cases it has a favorable outcome, making a good differential diagnosis and early antibiotic management are crucial for a good prognosis. Objective: To describe a case of scalded skin syndrome with methicillin-resistant S. aureus bloodstream infection in a newborn. Clinical case: A 25-day-old female, born at term and with no relevant perinatal history, presented with fever, generalized scaly erythematous dermatosis, eyelid and lower limb edema. She is hospitalized with a diagnosis of late neonatal sepsis and scalded skin syndrome. Report of blood cultures with growth of methicillin-resistant S. Aureus, managed with vancomycin for 14 days. Control cultures were negative, satisfactory evolution and hospital discharge without complications. Conclusions: Despite the low incidence of scalded skin syndrome, it is important to include S. aureus toxin infections in the differential diagnosis of fever and late-onset dermatoses in the newborn. The identification and early treatment are of great importance in the prognosis of the child.

Abstract: Bacteremia is a major cause of morbidity and mortality in patients with cancer and episodes of high-risk febrile neutropenia (HRFN). Objective: To identify the frequency of microorganisms isolated from blood cultures (BC) and their antimicrobial resistance (R) profile in children with HRFN, compared with the same data from previous studies of the same group. Method: Prospective, multicenter, epidemiological surveillance study of microorganisms isolated from BC in patients under 18 years of age, from 7 PINDA network hospitals, between 2016 and 2021. Results: 284 episodes of HRFN with positive BC were analyzed out of 1091 enrolled episodes (26%). Median age 7.2 years [3.0-12.3]. The main isolates were gram-negative bacilli (GNB) 49.2%, gram-positive cocci (GPC) 43.8%, and fungi 3.6%. The most frequently isolated microorganisms were viridans group Streptococci (VGS) (25.8%), Escherichia coli (19.8%), Pseudomonas spp. (11.2%), Klebsiella spp. (10.9%), and coagulase negative Staphylococci (CoNS) (10.9%). There was an increase in R to third-generation cephalosporins (p = 0.011) in GNB and to oxacillin in CoNS (p = 0.00), as well as a decrease in R to amikacin in non-fermenting GNB (p = 0.02) and to penicillin in VGS (p = 0.04). Conclusion: VGS is the main agent isolated in BC from pediatric patients with cancer and episodes of HRFN, followed by E. coli, Pseudomonas spp., and Klebsiella spp. Having epidemiological surveillance of microorganisms isolated from BC and their antimicrobial R profile is essential to favor the rational use of antimicrobials.

Resumen: Las bacteriemias son una causa importante de morbimortalidad en pacientes con cáncer y episodios de neutropenia febril de alto riesgo (NFAR). Objetivo: Determinar la frecuencia de microorganismos aislados de hemocultivos (HC) y su perfil de resistencia (R) antimicrobiana en niños con NFAR, comparado con iguales datos de estudios previos del mismo grupo. Material y Método: Estudio prospectivo, multicéntrico, de vigilancia epidemiológica de microorganismos aislados de HC en pacientes menores de 18 años, en siete hospitales de la red PINDA, 2016-2021. Resultados: Se analizaron 284 episodios de NFAR con HC positivos de 1091 episodios enrolados (26%). Mediana de edad 7,2 años [3,0-12,3]. Los aislados principales fueron bacilos gramnegativos (BGN) 49,2%, cocáceas grampositivas (CGP) 43,8% y hongos 3,6%, con mayor frecuencia de Streptococcus grupo viridans (SGV) (25,8%), Escherichia coli (19,8%), Pseudomonas spp. (11,2%), Klebsiella spp. (10,9%) y Staphylococcus coagulasa negativa (SCN) (10,9%). Hubo aumento de R a cefalosporinas de tercera generación en enterobacterales (p = 0,011) y de R a oxacilina en SCN (p = 0,00), así como disminución de R a amikacina en BGN no fermentadores (p = 0,02) y de R a penicilina en SGV (p = 0,04). Conclusión: SGV es el principal agente aislado en HC de pacientes pediátricos con cáncer y episodios de NF, seguido de E. coli, Pseudomonas spp. y Klebsiella spp. Contar con vigilancia epidemiológica de microorganismos aislados de HC y su perfil de R antimicrobiana es esencial para favorecer el uso racional de antimicrobianos.

Abstract A previously healthy 16-year-old male with a ten-day history of proptosis and pain in the left upper eyelid and inflammatory signs of the left lower limb, without fever, was admitted to the Emergency Department. Computed tomography (CT) scan revealed an extensive intraorbital lesion and a multiloculated collection in the muscle planes of the thigh. The boy underwent surgical drainage and was started on empiric antibiotics. Methicillin-susceptible Staphylococcus aureus was isolated from blood and exudate cultures. Because the boy remained febrile, a chest CT scan was performed, which revealed bilateral cavitary lung lesions. He completed a long course of antibiotherapy. The study for potential immunodeficiency disorders was unremarkable. Most pediatric cases of community-associated Staphylococcus aureus bacteremia are associated with a localized source of infection. Diagnosis depends on isolation from blood and fluid aspirates. Treatment usually requires surgical drainage and intravenous antibiotherapy. Staphylococcus aureus bacteremia may be associated with multiple foci of infection, which should be recognized promptly.

Resumo Um adolescente do sexo masculino de 16 anos de idade, previamente saudável, foi admitido no Serviço de Urgência por proptose e dor na pálpebra superior esquerda e sinais inflamatórios no membro inferior esquerdo, sem febre, com dez dias de evolução. A tomografia computorizada (TC) revelou uma lesão expansiva intraorbitária e coleção multiloculada nos planos musculares da coxa. O rapaz foi submetido a drenagem cirúrgica e iniciou antibioterapia empírica. A hemocultura e cultura dos exsudados permitiram o isolamento de Staphylococcus aureus sensível à meticilina. Dado que o rapaz continuava febril, foi realizada TC torácica, que evidenciou lesões pulmonares cavitadas bilateralmente, tendo sido efetuado um esquema prolongado de antibioterapia. O estudo de potenciais imunodeficiências foi negativo. A maioria dos casos de bacteremia a Staphylococcus aureus na comunidade estão associados a focos infeciosos localizados. O diagnóstico requer isolamento no sangue ou exsudados. A abordagem implica drenagem cirúrgica e antibioterapia endovenosa. A bacteremia a Staphylococcus aureus pode associar-se a múltiplos focos de infeção, pelo que deve ser precocemente reconhecida.

Abstract: Bacteremia is a major cause of morbidity and mortality in patients with cancer and episodes of high-risk febrile neutropenia (HRFN). Objective: To identify the frequency of microorganisms isolated from blood cultures (BC) and their antimicrobial resistance (R) profile in children with HRFN, compared with the same data from previous studies of the same group. Method: Prospective, multicenter, epidemiological surveillance study of microorganisms isolated from BC in patients under 18 years of age, from 7 PINDA network hospitals, between 2016 and 2021. Results: 284 episodes of HRFN with positive BC were analyzed out of 1091 enrolled episodes (26%). Median age 7.2 years [3.0-12.3]. The main isolates were gram-negative bacilli (GNB) 49.2%, gram-positive cocci (GPC) 43.8%, and fungi 3.6%. The most frequently isolated microorganisms were viridans group Streptococci (VGS) (25.8%), Escherichia coli (19.8%), Pseudomonas spp. (11.2%), Klebsiella spp. (10.9%), and coagulase negative Staphylococci (CoNS) (10.9%). There was an increase in R to third-generation cephalosporins (p = 0.011) in GNB and to oxacillin in CoNS (p = 0.00), as well as a decrease in R to amikacin in non-fermenting GNB (p = 0.02) and to penicillin in VGS (p = 0.04). Conclusion: VGS is the main agent isolated in BC from pediatric patients with cancer and episodes of HRFN, followed by E. coli, Pseudomonas spp., and Klebsiella spp. Having epidemiological surveillance of microorganisms isolated from BC and their antimicrobial R profile is essential to favor the rational use of antimicrobials.

Resumen: Las bacteriemias son una causa importante de morbimortalidad en pacientes con cáncer y episodios de neutropenia febril de alto riesgo (NFAR). Objetivo: Determinar la frecuencia de microorganismos aislados de hemocultivos (HC) y su perfil de resistencia (R) antimicrobiana en niños con NFAR, comparado con iguales datos de estudios previos del mismo grupo. Material y Método: Estudio prospectivo, multicéntrico, de vigilancia epidemiológica de microorganismos aislados de HC en pacientes menores de 18 años, en siete hospitales de la red PINDA, 2016-2021. Resultados: Se analizaron 284 episodios de NFAR con HC positivos de 1091 episodios enrolados (26%). Mediana de edad 7,2 años [3,0-12,3]. Los aislados principales fueron bacilos gramnegativos (BGN) 49,2%, cocáceas grampositivas (CGP) 43,8% y hongos 3,6%, con mayor frecuencia de Streptococcus grupo viridans (SGV) (25,8%), Escherichia coli (19,8%), Pseudomonas spp. (11,2%), Klebsiella spp. (10,9%) y Staphylococcus coagulasa negativa (SCN) (10,9%). Hubo aumento de R a cefalosporinas de tercera generación en enterobacterales (p = 0,011) y de R a oxacilina en SCN (p = 0,00), así como disminución de R a amikacina en BGN no fermentadores (p = 0,02) y de R a penicilina en SGV (p = 0,04). Conclusión: SGV es el principal agente aislado en HC de pacientes pediátricos con cáncer y episodios de NF, seguido de E. coli, Pseudomonas spp. y Klebsiella spp. Contar con vigilancia epidemiológica de microorganismos aislados de HC y su perfil de R antimicrobiana es esencial para favorecer el uso racional de antimicrobianos.

ABSTRACT Introduction: Infection is a serious complication among patients with hematologic malignancies (HMs) and in hematopoietic cell transplant (HCT) recipients. In most centers, the management of these complications is provided by the hematologist in person, thus demanding a knowledge of basic aspects of infection. Methods: To evaluate the knowledge of the hematologist on infections, we invited clinicians to answer two questionnaires with 20 multiple-choice questions covering epidemiology, prophylaxis, diagnosis and treatment of infection in patients with HMs and HCT. Results: We obtained 289 answers: 223 in survey 1 (febrile neutropenia) and 66 in survey 2 (infection in HCT). The median score was 5.0 in both surveys (range 0.5 - 9.0). In survey 1, the questions with the lowest number of correct answers were Q3 (8%), concerning the cefepime dose, and Q1 (9%), which asked about the epidemiologic link between the use of high dose cytarabine and viridans streptococcal bacteremia. In survey 2, two questions about cytomegalovirus (CMV) infection had the lowest percentage of correct answers (Q4, 12% and Q11, 18%). Clinicians attending to HCT recipients had higher scores, compared to clinicians attending to patients with HM only (median score of 5.0 and 4.5, p = 0.03, in survey 1 and 6.0 and 4.5, p = 0.001, in survey 2). In both surveys staff clinicians, residents and professors had similar scores. Conclusion: This is the first study in Brazil assessing the knowledge of hematologists on infectious complications. The low median score overall indicates an urgent need for continuous education. Such initiatives will eventually result in better patient care. Introduction (HMs (HCT centers person Methods infections multiplechoice multiple choice epidemiology prophylaxis Results 28 22 febrile neutropenia 6 . HCT) 50 5 0 5. range 05 0. 9.0. 90 9.0 9 9.0) Q 8%, 8 8% , (8%) 9%, 9% (9%) bacteremia CMV (CMV Q4, Q4 (Q4 12 Q11 18%. 18 18% 18%) scores 45 4 4.5 003 03 0.03 60 6. 0001 001 0.001 2. 2) Conclusion education care 9. (8% (9% (Q 4. 00 0.0 000 0.00 (8 (9 (

ABSTRACT Streptococcus agalactiae or Group B Streptococcus (GBS) infections are commonly associated with infections in neonates and pregnant women. However, there has been a rising incidence in nonpregnant adults. The risk of GBS infection in nonpregnant adults is increased for patients of advanced age and those with underlying medical conditions such as diabetes mellitus and cancer. We present a 77-year-old female with type-2 diabetes mellitus, hypertension, and bilateral foot ulcers that presented in probable septic shock with necrotic foot ulcers and necrotizing fasciitis and underwent bilateral lower limb amputations. The patient fulfilled the Streptococcal Toxic Shock Syndrome (STSS) criteria as defined by The Working Group on Severe Streptococcal Infections. These criteria were created for group A Streptococcus (Streptococcus pyogenes). Our patient fulfilled the Working Group’s criteria, except that the blood culture was positive for group B Streptococcus (Streptococcus agalactiae). Numerous studies demonstrate the importance of early detection and antibiotic treatment for GBS infections in general and early surgical management for necrotizing soft tissue infections (NSTIs) such as necrotizing fasciitis. (GBS women However cancer 77yearold yearold 77 year old type2 type 2 type- hypertension amputations STSS (STSS Infections pyogenes. pyogenes . pyogenes) Groups s agalactiae. agalactiae) NSTIs (NSTIs 7

Abstract Background Streptococcus pneumoniae bacteremia may result in Infective Endocarditis (IE). In the pre-antibiotic era, it caused 10 %‒15 % of IE, decreasing to < 3 % after penicillin availability. Although infrequent, it causes aggressive disease. Methods Retrospective analysis of endocarditis databases, prospectively implemented in 4 Brazilian institutions, 2005‒2023. Results From the prospective cohorts comprising 2321 adult patients with IE, we identified 11 (0.47%) with pneumococcal IE. Males represented 7/11 and mean age was 54 years (22‒77). All had native valve involvement; perivalvular abscess was present in 6/11. Only one patient had concurrent meningitis. Beta-lactams were the antibiotics used in 10/11. All had surgical indication, but only 6 had it, as the others were seriously ill. Overall, in hospital mortality was 6/11, but only 1/6 of those who underwent surgery died, compared to 5/5 of those who had an indication for surgery and did not have it. Conclusions The high mortality rates and need for surgical intervention emphasize the need to promptly identify and manage pneumococcal endocarditis. Physicians ought to recommend vaccination to all patients at risk for severe pneumococcal disease. IE . (IE) preantibiotic pre antibiotic era 1 15 %‒1 availability infrequent disease databases institutions 20052023 2005 2023 2005‒2023 232 0.47% 047 0 47 (0.47% 711 7 7/1 5 22‒77. 2277 22‒77 22 77 (22‒77) involvement 611 6/11 meningitis Betalactams Beta lactams 1011 10/11 ill Overall 16 1/ died 55 5/ (IE %‒ 2005202 200 202 2005‒202 23 0.47 04 (0.47 71 7/ 227 22‒7 2 (22‒77 61 6/1 101 10/1 200520 20 2005‒20 0.4 (0.4 22‒ (22‒7 6/ 10/ 20052 2005‒2 0. (0. (22‒ 2005‒ (0 (22 ( (2