Jorge Parra-Ruiz

Activity of linezolid and high-dose daptomycin, alone or in combination, in an in vitro model of Staphylococcus aureus biofilm

OBJECTIVES The aim of the study was to assess the in vitro activity of linezolid and daptomycin, alone and in combination, against three Staphylococcus aureus isolates using a pharmacokinetic/pharmacodynamic (PK/PD) model of biofilm for 3 days. METHODS One non-clinical methicillin-resistant S. aureus isolate (N315) and two clinical methicillin-resistant S. aureus isolates were evaluated. Simulated regimens included high-dose daptomycin (10 mg/kg once daily) and linezolid (600 mg twice daily), alone and in combination. RESULTS Against all three strains, neither linezolid nor daptomycin alone was bactericidal against biofilm-embedded bacteria (BB). Against planktonic bacteria (PB) only daptomycin was bactericidal. In contrast, the combination of linezolid and daptomycin demonstrated greater activity than either of the two agents alone, being bactericidal against both PB and BB, almost reaching the limit of detection at 72 h. CONCLUSIONS In this in vitro PK/PD model of mature biofilms, a combination of linezolid plus daptomycin was more effective than each agent alone, representing another potential option to treat S. aureus biofilm-associated infections.

Septic Arthritis Due to Cellulosimicrobium cellulans

ABSTRACT Cellulosimicrobium cellulans has been reported as a rare cause of human pathogenesis. Infections mainly occur in immunocompromised patients and very often are associated with a foreign body. We report the first case of septic arthritis caused by C. cellulans in an immunocompetent patient. Our patient suffered a penetrating palm tree thorn injury to his left knee 8 weeks before admission. Although no foreign objects were found, they were suspected because previous reports suggest a frequent association with this microorganism, and open debridament was performed. Removal of foreign bodies related to this organism must be considered a high-priority treatment in these patients to achieve a complete recovery.

Tratamiento de las infecciones fúngicas invasoras

Las infecciones fungicas invasoras (IFI) son un grupo de enfermedades en aumento progresivo en las dos ultimas decadas, con morbilidad y mortalidad elevadas. En los ultimos anos han aparecido avances en el tratamiento de estas enfermedades, como consecuencia de la aparicion de nuevos medicamentos y de nuevos conocimientos derivados de diferentes tipos de estudios, los cuales mejoran el pronostico de algunas de las IFI y aumentan las opciones terapeuticas en diversos tipos de situaciones clinicas. Estos conocimientos necesitan valorarse para su aplicacion a la practica clinica, en base a la evidencia cientifica disponible y a la experiencia clinica. Por ello, la Sociedad Andaluza de Enfermedades Infecciosas ha desarrollado este documento de consenso sobre las recomendaciones para el tratamiento de las IFI.

Eficacia y seguridad de daptomicina en dosis elevadas (≥ 8mg/kg/día)

INTRODUCTION There is a paucity of data regarding efficacy and safety of high dose (>8mg/kg/day) daptomycin. MATERIAL AND METHODS This ambispective study included all patients that received ≥8 mg/kg/day of daptomycin and had efficacy and safety data. RESULTS Sixty-nine patients were included. Fifty-nine patients (85.5%) were recorded as having been cured or improved. Six patients (8.6%) had a raised CPK during follow-up with no clinical signs of myopathy in any of them. CONCLUSIONS High dose daptomycin shows good efficacy without concerns about toxicity.

Tratamiento con daptomicina en el paciente anciano y con pluripatología

Serious Gram-positive bacterial infections are a major cause of morbidity and mortality among older adults and can pose a significant challenge to clinicians. Although more than 50% of patients treated with daptomycin are > 65 years old, there are few data evaluating the efficacy and safety of daptomcyn in this population. Analysis of data from patients > 65 years old included in the Cubicin Outcomes Registry and Experience (CORE), a multicenter, retrospective registry designed to collect post-marketing clinical data on patients who received daptomycin, and in its European version, the EUCORE, showed similar rates of efficacy and safety in this population to those in younger patients, suggesting that daptomycin is also a valuable option in older patients with serious Gram-positive infections.

Clinical efficacy of fosfomycin combinations against a variety of gram-positive cocci

INTRODUCTION Over recent years we have witnessed an increase in the resistance of microorganisms to the available antimicrobials and a decrease in the number of new antimicrobials. Fosfomycin is a safe and cheap broad-spectrum antibiotic which has shown very promising results in combination therapy, mainly against gram-negative microorganisms. Little is known, however, about its clinical efficacy against gram-positive microorganisms. METHODS We performed a retrospective review of all patients with severe gram-positive infections who received fosfomycin as part of their treatment from 2011 to 2017. We also performed in vitro time-kill assays to study the behaviour of fosfomycin with different antimicrobials against two strains of methicillin-resistant Staphylococcus aureus (MRSA) and two strains of methicillin-susceptible S. aureus (MSSA). RESULTS Seventy-five patients were treated with different fosfomycin combinations. Among them, 61 (81%) were successfully treated. Daptomycin plus fosfomycin was the most effective combination. Overall, the treatment with fosfomycin was safe, and side effects were minor. There was only one major side effect that resolved after discontinuation of therapy. Time-kill studies demonstrated increased activity of fosfomycin combinations, with daptomycin-fosfomycin being the most active combination against both MRSA and MSSA strains. CONCLUSIONS Our results suggest that antimicrobial combinations including fosfomycin are an alternative and effective approach for gram-positive infections.