Posts filed under ‘Bacteriemias’

REVISION – Nuevas cefalosporinas

Revista Chilena de Infectología Julio 2018 V.35 N.5

La resistencia bacteriana se ha incrementado en América Latina y el mundo, por lo que se requiere investigación y creación de nuevos antimicrobianos capaces de erradicar a los microorganismos resistentes. Se realizó una revisión acerca de nuevas cefalosporinas y sus combinaciones con un inhibidor de β-lactamasas, recopilando información de espectro, farmacocinética, farmacodinamia y estudios clínicos de las indicaciones actuales para:


ceftazidima/avibactam y


La primera, con actividad frente a Staphylococcus aureus y Staphylococcus coagulasa negativa sensibles y resistentes a meticilina, y contra Streptococcus pneumoniae resistente a penicilina; por lo tanto, aprobada para uso en neumonía bacteriana adquirida en comunidad e infecciones bacterianas de piel y tejidos blandos. Entre las nuevas combinaciones, ceftazidima, una cefalosporina de tercera generación con actividad anti-pseudomonas, asociada a avibactam, un inhibidor de β-lactamasas, ha demostrado efectividad en el tratamiento de infecciones abdominales e infecciones urinarias complicadas.

Por último, la combinación ceftolozano y el conocido tazobactam presenta acción comparable a la combinación de ceftazidima y avibactam por su actividad contra bacilos gramnegativos y, en combinación con metronidazol no presenta inferioridad a meropenem en infecciones intra-abdominales. Se presentan los estudios clínicos y las potenciales indicaciones y escenarios de uso de estas cefalosporinas.


August 5, 2020 at 6:20 pm

EDITORIAL – Efficacy of Early Oral Switch with β-Lactams for Low-Risk Staphylococcus aureus Bacteremia

Antimicrobial Agents and Chemotherapy July 2020 V.64 N.7

The aim of this study was to assess the safety of early oral switch (EOS) prior to 14 days for low-risk Staphylococcus aureus bacteremia (LR-SAB), which is the primary treatment strategy used at our institution. The usual recommended therapy is 14 days of intravenous (i.v.) antibiotics. All patients with SAB at our hospital were identified between 1 January 2014 and 31 December 2018. Those meeting low-risk criteria (health care-associated, no evidence of deep infection or demonstrated involvement of prosthetic material, and no further positive blood cultures after 72 h) were included in the study. The primary outcome was occurrence of a SAB-related complication within 90 days. There were 469 SAB episodes during the study period, 100 (21%) of whom met inclusion criteria. EOS was performed in 84 patients. In this group, line infection was the source in 79%, methicillin-susceptible S. aureus caused 95% of SABs and 74% of patients received i.v. flucloxacillin. The median durations of i.v. and oral antibiotics in the EOS group were 5 days (interquartile range [IQR], 4 to 6) and 10 days (IQR, 9 to 14), respectively. A total of 71% of patients received flucloxacillin as their EOS agent. Overall, 86% of oral step-down therapy was with beta-lactams. One patient (1%) undergoing EOS had SAB relapse within 90 days. No deaths attributable to SAB occurred within 90 days. In this low-MRSA-prevalence LR-SAB cohort, EOS was associated with a low incidence of SAB-related complications. This was achieved with oral beta-lactam therapy in most patients. Larger prospective studies are needed to confirm these findings.



July 22, 2020 at 7:43 pm

Commentary – Early Oral Antibiotic Switch for Staphylococcus aureus Bacteremia: Many Are Called, but Few Are Chosen

Antimicrobial Agents and Chemotherapy July 2020 V.64 N.7

La bacteriemia por Staphylococcus aureus (SAB) es una enfermedad complicada y de alto riesgo. Para SAB de bajo riesgo seleccionado, se desconoce el papel de la terapia de reducción antibiótica oral. Bupha-Intr y col. informan una cohorte retrospectiva de pacientes con SAB de bajo riesgo que obtuvieron buenos resultados con una corta duración de los antibióticos intravenosos, seguidos de ∼10 días adicionales de antibióticos orales, principalmente con betalactámicos. Los ensayos prospectivos ayudarán a definir aún más la eficacia de este enfoque.



July 22, 2020 at 7:40 pm

IDSA GUIDELINES Therapeutic Monitoring of Vancomycin for Serious Methicillin-resistant Staphylococcus aureus Infections

Clinical Infectious Diseases July 13, 2020

Therapeutic Monitoring of Vancomycin for Serious Methicillin-resistant Staphylococcus aureus Infections: A Revised Consensus Guideline and Review by the American Society of Health-system Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists

Recent clinical data on vancomycin pharmacokinetics and pharmacodynamics suggest a reevaluation of current dosing and monitoring recommendations. The previous 2009 vancomycin consensus guidelines recommend trough monitoring as a surrogate marker for the target area under the curve over 24 hours to minimum inhibitory concentration (AUC/MIC). However, recent data suggest that trough monitoring is associated with higher nephrotoxicity. This document is an executive summary of the new vancomycin consensus guidelines for vancomycin dosing and monitoring. It was developed by the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists vancomycin consensus guidelines committee. These consensus guidelines recommend an AUC/MIC ratio of 400–600 mg*hour/L (assuming a broth microdilution MIC of 1 mg/L) to achieve clinical efficacy and ensure safety for patients being treated for serious methicillin-resistant Staphylococcus aureus infections.



July 15, 2020 at 9:40 am

REVIEW – Empiric therapy for hospital-acquired, Gram-negative complicated intra-abdominal infection and complicated urinary tract infections: a systematic literature review of current and emerging treatment options

BMC Infect Dis. August 2015 V.15 P.313. 



Empiric therapy for healthcare-associated infections remains challenging, especially with the continued development of Gram-negative organisms producing extended-spectrum β-lactamases (ESBLs) and the threat of multi-drug-resistant organisms. Current treatment options for resistant Gram-negative infections include carbapenems, tigecycline, piperacillin-tazobactam, cefepime, ceftazidime, and two recently approved therapies, ceftolozane-tazobactam and ceftazidime-avibactam.


This systematic literature review surveys the published clinical trial evidence available since 2000 in support of both current and emerging treatment options in the settings of complicated intra-abdominal infection (cIAI) and complicated urinary tract infection (cUTI). When available, clinical cure rates for patients with infections from ESBL-producing strains are provided, as is information about efficacy against Pseudomonas aeruginosa.


Clinical trial evidence to guide selection of empiric antibiotic therapy in patients with complicated, hospital-acquired, Gram-negative IAIs and UTIs is limited. Though most of the clinical trials explored in this overview enrolled patients with complicated infections, often patients with severe infections and multiple comorbidities were excluded.


Practitioners in the clinical setting who are treating patients with complicated, hospital-acquired, Gram-negative IAIs and UTIs need to consider the possibility of polymicrobial infections, antibiotic-resistant organisms, and/or severely ill patients with multiple comorbidities. There is a severe shortage of evidence-based research to guide the selection of empiric antibiotic therapy for many patients in this setting. New therapies recently approved or in late-stage development promise to expand the number of options available for empiric therapy of these hospital-acquired, Gram-negative infections.



July 14, 2020 at 5:34 pm

REVIEW – Treatment strategies for persistent methicillin-resistant Staphylococcus aureus bacteraemia

J Clin Pharm Ther. 2018;43:614–625

What is known and objective

Treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia is a long-standing challenge to health care, often complicated by metastatic infections, treatment failure and mortality. When MRSA bacteraemia persists despite adequate initial treatment, current Infectious Diseases Society of America guidelines recommend evaluation and removal of possible sources of infection. In addition, a change in therapy may be considered. The objective of this review was to explore the therapeutic options for the treatment of persistent MRSA bacteraemia.


A literature search of PubMed, MEDLINE and Google Scholar was performed using the following search terms: [methicillin-resistant Staphylococcus aureus OR MRSA] AND [bacteraemia OR bloodstream infection] AND [persistent OR persistence OR refractory OR treatment failure OR salvage] AND treatment. We evaluated relevant, adult, English-language, peer-reviewed studies published between 1985 and May 2018. In vitro and animal studies were considered as supportive of in vivo data.

Results and discussion

Randomized, controlled trials are lacking. However, case series and case reports support multiple treatment options including high-dose daptomycin in combination with an antistaphylococcal β-lactam, ceftaroline, trimethoprim-sulfamethoxazole (TMP-SMX) or fosfomycin; ceftaroline alone or in combination with vancomycin or TMP-SMX; linezolid alone or in combination with a carbapenem, or telavancin.

What is new and conclusion

Given the heterogeneity of the data, a preferred regimen has not emerged. Prescribers must take into consideration recent exposure, source control, and available synergy and clinical data. Further comparative trials are needed to establish a preferred regimen and the creation of a universal treatment algorithm



July 13, 2020 at 3:55 pm

Prevalence and Etiology of Community-acquired Pneumonia in Immunocompromised Patients

Clin Infect Dis. April 24, 2019 V.68 N.9 P.1482-1493. 


The correct management of immunocompromised patients with pneumonia is debated. We evaluated the prevalence, risk factors, and characteristics of immunocompromised patients coming from the community with pneumonia.


We conducted a secondary analysis of an international, multicenter study enrolling adult patients coming from the community with pneumonia and hospitalized in 222 hospitals in 54 countries worldwide. Risk factors for immunocompromise included AIDS, aplastic anemia, asplenia, hematological cancer, chemotherapy, neutropenia, biological drug use, lung transplantation, chronic steroid use, and solid tumor.


At least 1 risk factor for immunocompromise was recorded in 18% of the 3702 patients enrolled. The prevalences of risk factors significantly differed across continents and countries, with chronic steroid use (45%), hematological cancer (25%), and chemotherapy (22%) the most common. Among immunocompromised patients, community-acquired pneumonia (CAP) pathogens were the most frequently identified, and prevalences did not differ from those in immunocompetent patients. Risk factors for immunocompromise were independently associated with neither Pseudomonas aeruginosa nor non-community-acquired bacteria. Specific risk factors were independently associated with fungal infections (odds ratio for AIDS and hematological cancer, 15.10 and 4.65, respectively; both P = .001), mycobacterial infections (AIDS; P = .006), and viral infections other than influenza (hematological cancer, 5.49; P < .001).


Our findings could be considered by clinicians in prescribing empiric antibiotic therapy for CAP in immunocompromised patients. Patients with AIDS and hematological cancer admitted with CAP may have higher prevalences of fungi, mycobacteria, and noninfluenza viruses.




July 13, 2020 at 3:53 pm

The Cefazolin Inoculum Effect Is Associated With Increased Mortality in Methicillin-Susceptible Staphylococcus aureus Bacteremia

Open Forum Infect Dis. May 23, 2018 V.5 N.6 


Recent studies have favored the use of cefazolin over nafcillin for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. The clinical influence of the cefazolin inoculum effect (CzIE) in the effectiveness of cephalosporins for severe MSSA infections has not been evaluated.


We prospectively included patients from 3 Argentinian hospitals with S. aureus bacteremia. Cefazolin minimum inhibitory concentrations (MICs) were determined at standard (105 colony-forming units [CFU]/mL) and high (107 CFU/mL) inoculum. The CzIE was defined as an increase of MIC to ≥16 µg/mL when tested at high inoculum. Whole-genome sequencing was performed in all isolates.


A total of 77 patients, contributing 89 MSSA isolates, were included in the study; 42 patients (54.5%) had isolates with the CzIE. In univariate analysis, patients with MSSA exhibiting the CzIE had increased 30-day mortality (P = .034) and were more likely to have catheter-associated or unknown source of bacteremia (P = .033) compared with patients infected with MSSA isolates without the CzIE. No statistically significant difference between the groups was observed in age, clinical illness severity, place of acquisition (community vs hospital), or presence of endocarditis. The CzIE remained associated with increased 30-day mortality in multivariate analysis (risk ratio, 2.65; 95% confidence interval, 1.10-6.42; P = .03). MSSA genomes displayed a high degree of heterogeneity, and the CzIE was not associated with a specific lineage.


In patients with MSSA bacteremia where cephalosporins are used as firstline therapy, the CzIE was associated with increased 30-day mortality. Clinicians should be cautious when using cefazolin as firstline therapy for these infections.



July 13, 2020 at 3:47 pm

International ERS/ESICM/ESCMID/ALAT guidelines for the management of hospital-acquired pneumonia and ventilator-associated pneumonia

Eur Respir J. September 10, 2017 V.50 N.3 

Guidelines for the management of hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP) of the European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Asociación Latinoamericana del Tórax (ALAT)

The most recent European guidelines and task force reports on hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) were published almost 10 years ago. Since then, further randomised clinical trials of HAP and VAP have been conducted and new information has become available. Studies of epidemiology, diagnosis, empiric treatment, response to treatment, new antibiotics or new forms of antibiotic administration and disease prevention have changed old paradigms. In addition, important differences between approaches in Europe and the USA have become apparent.The European Respiratory Society launched a project to develop new international guidelines for HAP and VAP. Other European societies, including the European Society of Intensive Care Medicine and the European Society of Clinical Microbiology and Infectious Diseases, were invited to participate and appointed their representatives. The Latin American Thoracic Association was also invited.A total of 15 experts and two methodologists made up the panel. Three experts from the USA were also invited (Michael S. Niederman, Marin Kollef and Richard Wunderink).Applying the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology, the panel selected seven PICO (population-intervention-comparison-outcome) questions that generated a series of recommendations for HAP/VAP diagnosis, treatment and prevention.



July 13, 2020 at 3:45 pm

Magnetic Resonance Imaging in Differentatial Diagnosis of Pyogenic Spondylodiscitis and Tuberculous Spondylodiscitis

Pol J Radiol. February 2017 V.82 P.71-87.


La espondilodiscitis infecciosa se caracteriza por la participación de dos vértebras adyacentes y el disco intermedio.

La tasa de incidencia de la enfermedad se estima en 0.4-2 casos por 100000 por año.

Staphylococcus aureus es el agente infeccioso más común que causa espondilodiscitis piógena.

Las infecciones no piógenas de la columna vertebral son causadas con mayor frecuencia por Mycobacterium tuberculosis y hongos.

Los síntomas clínicos son inespecíficos.

El diagnóstico temprano y el tratamiento adecuado pueden evitar secuelas irreversibles desfavorables para el paciente.

Los desarrollos significativos en las técnicas de imagen de tejidos patológicos aumentaron las expectativas entre los médicos con respecto a la posibilidad de distinguir entre la espondilodiscitis tuberculosa y la espondilodiscitis piógena en las imágenes de RM.

El objetivo de este estudio fue identificar y diferenciar las características de la espondilodiscitis tuberculosa y piógena en las imágenes de RM.


Realizamos un análisis retrospectivo de imágenes de RM obtenidas de 34 pacientes con espondilodiscitis confirmada (18 con espondilodiscitis piógena y 16 con espondilodiscitis tuberculosa). La adquisición de datos se realizó utilizando escáneres de resonancia magnética de 1,5 T, donde se obtuvieron imágenes utilizando protocolos similares. T2 TIRM y las imágenes ponderadas en T1 con y sin realce de contraste fueron sujetas a evaluación en planos coronal, axial y sagital.


Las características de la espondilodiscitis piógena incluyen: afectación de la columna lumbar, aumento del contraste anormal paraespinal mal definido, aumento del contraste difuso / homogéneo de los cuerpos vertebrales, destrucción de grado bajo de los cuerpos vertebrales, señal hiperintensa / homogénea de los cuerpos vertebrales en las imágenes T2 TIRM . Las características predominantes de la espondilodiscitis tuberculosa incluyeron: afectación de la columna torácica, afectación de 2 o más cuerpos vertebrales adyacentes, destrucción severa del cuerpo vertebral, realce de contraste focal / heterogéneo de los cuerpos vertebrales, señal heterogénea de los cuerpos vertebrales en imágenes T2 TIRM, bien Mejora de contraste anormal paraespinal -definido, abscesos paraespinales y epidurales, realce meníngeo a nivel de la columna afectada.


La comparación de imágenes de RM de pacientes diagnosticados con espondilodiscitis piógena y espondilodiscitis tuberculosa permitió la identificación de características individuales para la diferenciación preliminar entre TB y espondilodiscitis infecciosa y, por lo tanto, permitió un tratamiento adecuado.


July 12, 2020 at 1:39 pm

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