Early bacteremia following allogeneic hematopoietic stem cell transplantation without antibiotic prophylaxis: epidemiology and antimicrobial resistance.

OBJECTIVE: Bacteremia is a serious complication in patients undergoing allogeneic hematopoietic stem cell transplantation. The aim of this study was to determine the frequency, epidemiological profile, and risk factors of bacteremia early after allogeneic hematopoietic stem cell transplantation. METHODS: An observational descriptive retrospective study was conducted in patients who received transplants between January 2016 and December 2021. Early bacteremia was defined as blood stream infection occurring between Day 0 and Day 100 after transplantation. RESULTS: Forty episodes of early bacteremia occurred in 36/245 transplanted patients. Fifteen episodes (37.5%) were due to gram-positive bacteria and 25 (62.5%) to gram-negative bacteria. The most frequent species isolated were coagulase negative staphylococci (CoNS) in gram-positive bacteremia (n = 8/15), and Klebsiella species (8/25) and Pseudomonas species (8/25) in gram-negative bacteremia. Twenty-nine episodes of bacteremia (72.5%) occurred during the first 30 days after transplantation with a median time of nine days (range: 0-90 days). Coagulase negative staphylococci were methicillin-resistant in 75% of cases, the only Staphylococcus aureus isolated was methicillin-resistant. All gram-positive bacilli were penicillin-resistant. Gram-negative bacilli were multidrug resistant in 61.5% of cases. In multivariate analysis, bone marrow as source of graft (p-value = 0.02) and cytomegalovirus reactivation (p-value = 0.02) were significantly associated with an increased risk of bacteremia. Mortality attributable to bacteremia was 2.8%. The one-year overall survival was not significantly different between those with and without bacteremia. CONCLUSIONS: Bacteremia was more frequent within the first 30 days after transplantation indicating the crucial role of neutropenia. An increase in multidrug resistant gram-negative bacteremia was noted.

Genomic Dissection of an Enteroaggregative Escherichia coli Strain Isolated from Bacteremia Reveals Insights into Its Hybrid Pathogenic Potential.

Escherichia coli is a frequent pathogen isolated from bloodstream infections. This study aimed to characterize the genetic features of EC092, an E. coli strain isolated from bacteremia that harbors enteroaggregative E. coli (EAEC) genetic markers, indicating its hybrid pathogenic potential. Whole-genome sequencing showed that EC092 belongs to phylogroup B1, ST278, and serotype O165:H4. Genes encoding virulence factors such as fimbriae, toxins, iron-uptake systems, autotransporter proteins (Pet, Pic, Sat, and SepA), and secretion systems were detected, as well as EAEC virulence genes (aggR, aatA, aaiC, and aap). EC092 was found to be closely related to the other EAEC prototype strains and highly similar in terms of virulence to three EAEC strains isolated from diarrhea. The genomic neighborhood of pet, pic, sat, sepA, and the EAEC virulence genes of EC092 and its three genetically related fecal EAEC strains showed an identical genomic organization and nucleotide sequences. Also, EC092 produced and secreted Pet, Pic, Sat, and SepA in the culture supernatant and resisted the bactericidal activity of normal human serum. Our results demonstrate that the strain EC092, isolated from bacteremia, is a hybrid pathogenic extraintestinal E. coli (ExPEC)/EAEC with virulence features that could mediate both extraintestinal and intestinal infections.

Microbiological performance and adherence in blood culture protocols: The role of a second anaerobic bottle.

Background: Bacteremia represents high rates of morbidity and mortality, especially in developing countries, highlighting the need for a diagnostic method that allows prompt and appropriate patient treatment. This study compared microbiological performance and adherence of two blood culture protocols for the diagnosis of bacteremia. Methods: Quasi-experimental study conducted between June 2022 and February 2023. Two blood culture protocols were evaluated. Protocol 1 included two aerobic bottles and one anaerobic bottle. Protocol 2 included two aerobic and two anaerobic bottles. Protocols were analyzed in three phases: evaluation of protocol 1 (Phase 1); evaluation of protocol 1 plus educational activities for healthcare staff (Phase 2) and evaluation of protocol 2 (Phase 3). Results: 342 patients and 1155 blood culture bottles (732 aerobic and 423 anaerobic) were included. Positivity was 17.6 %, 22.8 % and 19.4 % in phases 1, 2 and 3, respectively. Among patients with bacteremia, 84.5 % had positive anaerobic bottles, with 9.9 % showing growth only in this bottle. The contamination rates were 1.9 %, 0.3 %, and 0.8 % for each phase, mainly in aerobic bottles. Median positivity time was 11 h for both bottes aerobic and anaerobic. Overall nursing adherence increased from 13.1 % in Phase 1, 25.9 % in Phase 2, and 28.1 % in Phase 3 (p = 0.009). Conclusions: The findings indicate that adding a second anaerobic bottle does not enhance blood culture positivity. Rather than increasing bottle quantity, staff training might be a more effective approach to optimize results.

[Molecular diagnosis of bacteriaemia: benefits of using the FilmArray® BCID2 sepsis panel in a third level hospital]. / Diagnóstico molecular de bacteriemias: beneficios del empleo del panel de sepsis BCID2 de Filmarray® en un hospital de tercer nivel.

INTRODUCTION: Delay in initiating appropriate antimicrobial therapy prolongs hospitalization, increases in-hospital mortality, and raises economic costs. Currently, 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 antimicrobial costs. METHODS: This is a retrospective observational study focused on positive blood cultures in hospitalized patients. FA processing was conducted concurrently with routine sample processing. Changes in antibiotic treatments based on FA results were evaluated, and the reduction in antimicrobial therapy duration and associated cost savings were calculated. RESULTS: Eighty-seven bacteremia episodes were analysed. In 42 (48%) of them antimicrobial therapy was de-escalated to narrower spectrum agents, while in 7 (8%) therapy was escalated to broader spectrum antimicrobials. 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 savings of US$ 7408. CONCLUSION: The implementation of FA facilitated a faster administration of appropriate antimicrobial therapy, leading to a reduction in the duration of broadspectrum empirical antimicrobial therapy and subsequent economic savings.

Introducción: Los retrasos en el tratamiento antimicrobiano adecuado de las bacteriemias prolongan la estadía hospitalaria, aumentan la mortalidad e incrementan los costos. Aún hoy en día se requiere un tiempo considerable para obtener la identificación y antibiograma de los microorganismos en los hemocultivos positivos. El objetivo fue evaluar el impacto de la implementación 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 bacteriemia. En 42 (48.3%) de ellos se desescaló el tratamiento 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 antimicrobianos más rápidamente acortando la duración de los tratamientos empíricos de amplio espectro, lo cual resultó costo-efectivo.

[On two cases of systemic listeriosis without dominant neurological compromise]. / Sobre dos casos de listeriosis sistémica sin compromiso neurológico dominante.

Listeria monocytogenes is a Gram-positive aerobic bacterium; found ubiquitously in nature; which mainly affects newborns, older adults, immunosuppressed patients and pregnant women. However, Listeria disease can occur in the healthy population. Invasive listeriosis has three dominant clinical forms, bacteremia, neurolisteriosis and maternal-neonatal infection. 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 consumption 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 symptoms 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.

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 dominantes, bacteriemia, neurolisteriosis e infección materno-neonatal. Las formas localizadas se describen infrecuentemente. La enfermedad se produce fundamentalmente 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 consumo 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 dominante 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.

Diagnóstico molecular de bacteriemias: beneficios del empleo del panel de sepsis BCID2 de Filmarray en un hospital de tercer nivel / Molecular diagnosis of bacteriaemia: benefits of using the FilmArray® BCID2 sepsis panel in a third level hospital

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.

Sobre dos casos de listeriosis sistémica sin compromiso neurológico dominante / On two cases of systemic listeriosis without dominant neurological compromise

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.

Seven-day antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients: toward a new paradigm.

PURPOSE: Data on short courses of antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients are limited. The aim of the study was to describe and compare the frequency of bacteremia relapse, 30-day overall and infection-related mortality, Clostridiodes difficile infection and length of hospital stay since bacteremia among those who received antibiotic therapy for 7 or 14 days. METHODS: This is a multicenter, prospective, observational cohort study in adult high-risk neutropenic patients with hematologic malignancies or hematopoietic stem cell transplant and monomicrobial Enterobacterales bacteremia. They received appropriate empirical antibiotic therapy, had a clinical response within 7 days, and infection source control. Clinical, epidemiological and outcomes variables were compared based on 7 or 14 days of AT. RESULTS: Two hundred patients were included (100, 7-day antibiotic therapy; 100, 14-day antibiotic therapy). Escherichia coli was the pathogen most frequently isolated (47.5%), followed by Klebsiella sp. (40.5%). Among those patients that received 7-day vs. 14-day antibiotic course, a clinical source of bacteremia was found in 54% vs. 57% (p = 0.66), multidrug-resistant Enterobacterales isolates in 28% vs. 30% (p = 0.75), and 40% vs. 47% (p = 0.31) received combined empirical antibiotic therapy. Overall mortality was 3% vs. 1% (p = 0.62), in no case related to infection; bacteremia relapse was 7% vs. 2% (p = 0.17), and length of hospital stay since bacteremia had a median of 9 days (IQR: 7-15) vs. 14 days (IQR: 13-22) (p = < 0.001). CONCLUSIONS: These data suggest that seven-day antibiotic therapy might be adequate for patients with high-risk neutropenia and Enterobacterales bacteremia, who receive appropriate empirical therapy, with clinical response and infection source control.

Emerging infection: streptococcal toxic shock-like syndrome caused by group B Streptococcus (GBS), Streptococcus agalactiae.

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.

Impact of Vancomycin trough levels monitoring on uncomplicated methilcillin-resistant Staphylococcus aureus bacteremia in chronic kidney disease on hemodialysis, retrospective cohort.

BACKGROUND: CKD patients on hemodialysis (HD) with Staphylococcus aureus (SA) bacteremia present high morbidity, mortality and increased risk of MRSA. Vancomycin is the antibiotic of choice in these cases, it has a narrow therapeutic margin and inadequate dosage generates a risk of toxicity, therefore, the recommendation is to dosage it through serum levels. METHODS: This is a retrospective cohort study in 3 hospitals of third level of complexity in the city of Medellin in which there were differences in the measurement and implementation of vancomycin25 dosage based on trough levels (VL) in patients with chronic kidney disease on hemodialysis (CKD- HD) with uncomplicated bacteremia based infection by methilcillin-resistant Staphyloccocus aureus (MRSA). The primary outcome was the composite of hospital mortality, clinical response (fever, hemodynamic instability and altered consciousness), complications associated with bacteremia, or bacteriological response failure (positive cultures at first week follow-up) at 7 days. The composite variables were analyzed individually as secondary outcomes. RESULTS: The main unadjusted outcome (OR 1.3, CI 0.6 - 2.7) and adjusted for age, Charlson index, loading dose, initial dose, dosing frequency and MIC to vancomycin (OR 1.2, CI 0.5 - 2.7). Regarding adjusted secondary outcomes: clinical response (OR 1.4 CI 0.3 - 5.8), death (OR 1.3 CI 0.3 - 4.6) and complications (OR 0.9, CI 0.37 - 2.2). CONCLUSIONS: We conclude that the measurement of trough levels in patients with HD-CKD does not modify the composite outcome. The main limitation is the sample size and type of study, randomized control trials may be required to confirm the results presented.

A non-surgical approach: Ampicillin's success in Listeria monocytogenes endocarditis.

Background: Listeria monocytogenes, a Gram-positive bacillus, primarily affects immunocompromised individuals. Endocarditis is a rare but severe complication of L. monocytogenes bacteremia, irrespective of native or prosthetic valves. While there is no standardized treatment, the use of ampicillin proves effective in most cases. Surgical intervention is reserved for cases involving valve dehiscence, heart failure, or myocardial abscess. Case presentation: A 54-year-old female, with mitral valve replacement, presented with fever, chest pain and dyspnea at rest. Patient was initially diagnosed with bacterial pneumonia; however, subsequent evaluation revealed L. monocytogenes bacteremia, resulting in endocarditis. Surgical management was contraindicated due to multiple prior valve replacement surgeries. Symptoms resolution, along with improvements in echocardiographic and clinical parameters, was achieved through extended antibiotic treatment only with no surgical intervention. Conclusion - key takeaways: This case underscores the critical importance of individualized treatment approaches in endocarditis, particularly in patients with surgery approach contraindication, and emphasized the success achieved through ampicillin-based management.

Síndrome de piel escaldada asociado a estafilococcemia en un neonato: reporte de un caso / Scalded skin syndrome associated with staphylococcemia in a neonate: a case report

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.

Predictors of Invasive Bacterial Infection in Febrile Infants Aged 2 to 6 Months in the Emergency Department.

Our goal was to identify predictors of invasive bacterial infection (ie, bacteremia and bacterial meningitis) in febrile infants aged 2-6 months. In our multicenter retrospective cohort, older age and lower temperature identified infants at low risk for invasive bacterial infection who could safely avoid routine testing.

Efficacy of Continuous vs. Intermittent Administration of Cefepime in Adult ICU Patients with Gram-Negative Bacilli Bacteremia: A Randomized Double-Blind Clinical Study.

INTRODUCTION: The objective of this study was to compare the continuous infusion of cefepime with the intermittent infusion in patients with sepsis caused by Gram-negative bacilli (GNB). METHODS: Randomized 1:1 multicenter double-blinded placebo-controlled study with allocation concealment; multicenter study in the intensive care units of Colombia. Patients with sepsis, severe sepsis or septic shock, and GNB-suspected bacteremia. Cefepime was administered for 7 to 14 days over 30 m intermittently every 8 h over 24 h plus continuous saline solution (0.9%) (G1) or 3 g administered continuously plus saline solution every 8 h (0.9%) (G2). The percentage of clinical response at 3, 7, and 14 days, relapse at 28 days, and mortality at discharge were measured. RESULTS: The recruitment was stopped at the suggestion of the Institutional Review Board (IRB) following an FDA alert about cefepime. Thirty-two patients were randomized; 25 received the intervention, and GNB bacteremia was confirmed in 16 (9 G1 and 7 G2). Favorable clinical response in days 3, 7, and 14 was 88.8%, 88.8%, and 77.8% (G1) and was similar for G2 (85.7%). There were no relapses or deaths in G2, while in G1, one relapse and two deaths were observed. CONCLUSIONS: The results of this study support the use of cefepime for the treatment of Gram-negative infections in critically ill patients, but we could not demonstrate differences between continuous or intermittent administration because of the small sample size, given the early suspension of the study.

Short-term versus usual-term antibiotic treatment for uncomplicated Staphylococcus aureus bacteremia: a systematic review and meta-analysis.

Introduction: Uncomplicated Staphylococcus aureus bacteremia remains a leading cause of morbidity and mortality in hospitalized patients. Current guidelines recommend a minimum of 14 days of treatment. Objective: To evaluate the efficacy and safety of short versus usual antibiotic therapy in adults with uncomplicated S. aureus bacteremia (SAB). Methods: We developed a search strategy to identify systematic review and meta-analysis of non-randomized studies (NRS), comparing short versus usual or long antibiotic regimens for uncomplicated SAB in MEDLINE, Embase, and the Cochrane Register up to June 2023. The risk of bias was assessed using the ROBINS I tool. The meta-analysis was performed using Review Manager software with a random effect model. Results: Six NRS with a total of 1700 patients were included. No significant differences were found when comparing short versus prolonged antibiotic therapy as defined by the authors for 90-day mortality [odds ratio (OR): 1.09; 95% confidence interval (CI): 0.82-1.46, p: 0.55; I2 = 0%] or 90-day recurrence or relapse of bacteremia [OR: 0.72; 95% CI: 0.31-1.68, p: 0.45; I2 = 26%]. Sensitivity analysis showed similar results when comparing a predefined duration of <14 days versus ⩾14 days and when excluding the only study with a high risk of bias. Conclusion: Shorter-duration regimens could be considered as an alternative option for uncomplicated SAB in low-risk cases. However, based on a small number of studies with significant methodological limitations and risk of bias, the benefits and harms of shorter regimens should be analyzed with caution. Randomized clinical trials are needed to determine the best approach regarding the optimal duration of therapy.

Comparing short and regular antibiotic treatment duration, for a type of blood infection caused by S. aureus We investigated the optimal duration of antibiotic treatment for adults with a specific type of blood infection (uncomplicated Staphylococcus aureus), a condition with a significant global impact on mortality and costs. After a thorough search, only six trials involving 1700 patients were identified. We therefore decided to perform a meta-analysis (a type of statistical analysis). The results showed that the duration of antibiotics, whether short or long (less or more than 14 days), did not significantly affect mortality or recurrence of infection within 90 days. Consequently, we suggested that shorter courses of antibiotics might be appropriate for less severe cases. However, we emphasized caution because of the limitations of the studies. We recommended further research with improved methods to determine the optimal approach to treating this type of infection.

Ceftazidime-Avibactam Improves Outcomes in High-Risk Neutropenic Patients with Klebsiella pneumoniae Carbapenemase-Producing Enterobacterales Bacteremia.

Few studies have evaluated the efficacy of ceftazidime-avibactam (CA) for Klebsiella pneumoniae carbapenemase-producing Enterobacterales bacteremia (KPC-PEB) in high-risk neutropenic patients. This is a prospective multicenter observational study in high-risk neutropenic patients with multi-drug resistant Enterobacterales bacteremia. They were compared according to the resistance mechanism and definitive treatment provided: KPC-CPE treated with CA (G1), KPC-CPE treated with other antibiotics (G2), and patients with ESBL-producing Enterobacterales bacteremia who received appropriate definitive therapy (G3). Thirty-day mortality was evaluated using a logistic regression model, and survival was analyzed with Kaplan-Meier curves. A total of 238 patients were included: 18 (G1), 52 (G2), and 168 (G3). Klebsiella spp. (60.9%) and Escherichia coli (26.4%) were the Enterobacterales most frequently isolated, and 71% of the bacteremias had a clinical source. The resistance profile between G1 and G2 was colistin 35.3% vs. 36.5%, amikacin 16.7% vs. 40.4%, and tigeclycline 11.1% vs. 19.2%. The antibiotics prescribed in combination with G2 were carbapenems, colistin, amikacin, fosfomycin, tigecycline, and fluoroquinolones. Seven-day clinical response in G1 vs. G2 vs. G3 was 94.4% vs. 42.3% vs. 82.7%, respectively (p < 0.001). Thirty-day overall mortality in G1 vs. G2 vs. G3 was 22.2% vs. 53.8% vs. 11.9%, respectively (p < 0.001), and infection-related mortality was 5.5% vs. 51.9% vs. 7.7% (p < 0.001). The independent risk factors for mortality were Pitt score > 4: OR 3.63, 95% CI, 1.18-11.14 (p = 0.025) and KPC-PEB treated with other antibiotics: OR 8.85, 95% CI, 2.58-30.33 (p = 0.001), while 7-day clinical response was a protective factor for survival: OR 0.02, 95% CI, 0.01-0.08 (p < 0.001). High-risk neutropenic patients with KPC-CPE treated with CA had an outcome similar to those treated for ESBL-producing Enterobacterales, with higher 7-day clinical response and lower overall and infection-related mortality than those treated with other antibiotics. In view of these data, CA may be considered the preferred therapeutic option for KPC-PEB in high-risk neutropenic patients.

Epidemiology of bloodstream infections and the impact of antimicrobial resistance in pediatric hematopoietic cell transplant.

Bloodstream infections (BSI) pose a substantial threat to the well-being and survival of patients undergoing hematopoietic stem cell transplantation (HSCT). Risk factors for these infections vary across the different post-HSCT phases. In the pre-engraftment period, patients are particularly susceptible to infection due to prolonged neutropenia, mucosal damage, and extensive use of central venous line (CVL). In the post-engraftment phase, the emergence of graft versus host diseases further compounds the risk. The epidemiology of these infections has undergone notable changes over the years due to multifactorial reasons, including the evolution of protocols that intensify immunosuppression. In this context, the emergence of multi-drug resistance (MDR) microorganisms can be a challenge due to the elevated risk of mortality in these vulnerable patients. Unfortunately, there is a lack of comprehensive data on this topic, particularly in pediatrics. This article aims to provide a summary of the epidemiology of BSI in the different post-transplant phases and the impact of MDR pathogens. Having knowledge about the local epidemiology of BSI can be instrumental in tailoring targeted therapies, leading to improved survival rates in HSCT recipients.

The Changing Epidemiology and Antimicrobial Susceptibility of Staphylococcus aureus Isolated from Blood Cultures in a University Hospital from Argentina.

Staphylococcus aureus bacteremia (SAB) is one of the most common serious bacterial infections worldwide. In this study, we demonstrated changes in SAB epidemiology in an Argentinean University Hospital during an 8-year period (2009-2016). A total of 326 S. aureus clinical isolates were recovered in three periods: P1: 2009-2010, P2: 2012-2014, and P3: 2015-2016. Among these, 127 were methicillin-resistant S. aureus (MRSA) and were characterized by phenotypic and molecular methods. We hereby report a significant decline in multiple drug resistance among MRSA isolates associated with an increase in SCCmec IV between the three periods. A diversity of MRSA-IV clones (mainly ST30-MRSA-IV, ST5-MRSA-IV, and ST8-MRSA-IV) replaced between 2009 and 2016 the previous prevalent MRSA clone causing bloodstream infections at this hospital (ST5-MRSA-I). MRSA population structure continued to diversify between P2 and P3. Notably, ST8-MRSA-IV-t008 related to USA300 was first detected during P2, and ST8-MRSA-IV together with ST30-MRSA-IV related to the Southwest Pacific clone were the more prevalent MRSA genotypes circulating during P3.