Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species

The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in particular in the intensive care unit; this persistence could be partially explained by the capacity of these microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different species. Findings: Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus 5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface; between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than for Acinetobacter G3 (36%, 27% & 9% respectively). Conclusions: Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not observed in other Acinetobacter species.

Necrotising pneumonia due to influenza A (H1N1) and community-acquired methicillin-resistant Staphylococcus aureus clone USA300: successful management of the first documented paediatric case.

Necrotising pneumonia in young, previously healthy patients due to Panton–Valentine leucocidin (PVL) producing Staphylococcus aureus has been increasingly recognised. PVL pneumonia is often associated with influenza co-infection and high mortality. This case report describes the successful management of the first documented paediatric case of a previous healthy adolescent who developed necrotising pneumonia due to community-acquired methicillin-resistant (CA-MRSA) clone USA300 with pandemic influenza A (H1N1) co-infection, and highlights the importance of early recognition and initiation of appropriate therapy for this potentially fatal co-infection. PCR remains the gold standard to diagnose pandemic H1N1 since it may not be detected by rapid antigen tests. Bacterial necrotising pneumonia should be suspected in those presenting with worsening flu-like symptoms and clinical and/or radiological evidence of PVL infection (multifocal infiltrates, effusion and cavitation). These patients may benefit from the administration of toxin neutralising agents. In light of the current H1N1 pandemic, healthcare professionals will be increasingly confronted with this clinical scenario.

Three-year multicenter surveillance of community-acquired Listeria monocytogenes meningitis in adults

BACKGROUND. Listeria monocytogenes is the third most frequent cause of bacterial meningitis. The aim of this study is to know the incidence and risk factors associated with development of acute community-acquired Lm meningitis in adult patients and to evaluate the clinical features, management, and outcome in this prospective case series. METHODS. A descriptive, prospective, and multicentric study carried out in 9 hospitals in the Spanish Network for Research in Infectious Diseases (REIPI) over a 39-month period. All adults patients admitted to the participating hospitals with the diagnosis of acute community-acquired bacterial meningitis (Ac-ABM) were included in this study. All these cases were diagnosed on the basis of a compatible clinical picture and a positive cerebrospinal fluid (CSF) culture or blood culture. The patients were followed up until death or discharge from hospital. RESULTS. Two hundred and seventy-eight patients with Ac-ABM were included. Forty-six episodes of Lm meningitis were identified in 46 adult patients. In the multivariate analysis only age (OR 1.026; 95% CI 1.00-1.05; p = 0.042), immunosuppression (OR 2.520; 95% CI 1.05-6.00; p = 0.037), and CSF/blood glucose ratio (OR 39.42; 95% CI 4.01-387.50; p = 0.002) were independently associated with a Lm meningitis. The classic triad of fever, neck stiffness and altered mental status was present in 21 (49%) patients, 32% had focal neurological findings at presentation, 12% presented cerebellum dysfunction, and 9% had seizures. Twenty-nine (68%) patients were immunocompromised. Empirical antimicrobial therapy was intravenous ampicillin for 34 (79%) of 43 patients, in 11 (32%) of them associated to aminoglycosides. Definitive ampicillin plus gentamicin therapy was significantly associated with unfavourable outcome (67% vs 28%; p = 0.024) and a higher mortality (67% vs 32%; p = 0.040).The mortality rate was 28% (12 of 43 patients) and 5 of 31 (16.1%) surviving patients developed adverse clinical outcome. CONCLUSIONS Elderly or immunocompromised patients, and a higher CSF/blood glucose ratio in patients with Ac-ABM must alert clinicians about Lm aetiology. Furthermore, we observed a high incidence of acute community-acquired Lm meningitis in adults and the addition of aminoglycosides to treatment should be avoid in order to improve the patients' outcome. Nevertheless, despite developments in intensive care and antimicrobial therapy, this entity is still a serious disease that carries high morbidity and mortality rates.

International recommendations on the diagnosis and treatment of patients with acquired hemophilia A.

Acquired hemophilia A (AHA) is a rare bleeding disorder characterized by autoantibodies directed against circulating coagulation factor (F) VIII. Typically, patients with no prior history of a bleeding disorder present with spontaneous bleeding and an isolated prolonged aPTT. AHA may, however, present without any bleeding symptoms, therefore an isolated prolonged aPTT should always be investigated further irrespective of the clinical findings. Control of acute bleeding is the first priority, and we recommend first-line therapy with bypassing agents such as recombinant activated FVII or activated prothrombin complex concentrate. Once the diagnosis has been achieved, immediate autoantibody eradication to reduce subsequent bleeding risk should be performed. We recommend initial treatment with corticosteroids or combination therapy with corticosteroids and cyclophosphamide and suggest second-line therapy with rituximab if first-line therapy fails or is contraindicated. In contrast to congenital hemophilia, no comparative studies exist to support treatment recommendations for patients with AHA, therefore treatment guidance must rely on the expertise and clinical experience of specialists in the field. The aim of this document is to provide a set of international practice guidelines based on our collective clinical experience in treating patients with AHA and contribute to improved care for this patient group.

Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species.

BACKGROUND The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in particular in the intensive care unit; this persistence could be partially explained by the capacity of these microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different species. FINDINGS Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus 5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface; between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than for Acinetobacter G3 (36%, 27% & 9% respectively). CONCLUSIONS Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not observed in other Acinetobacter species.

Effectiveness of holistic neuropsychological rehabilitation for Spanish population with acquired brain injury measured using Rasch analysis.

INTRODUCTION The Rasch model is increasingly used in the field of rehabilitation because it improves the accuracy of measurements of patient status and their changes after therapy. OBJECTIVE To determine the long-term effectiveness of a holistic neuropsychological rehabilitation program for Spanish outpatients with acquired brain injury (ABI) using Rasch analysis. METHODS Eighteen patients (ten with long evolution - patients who started the program > 6 months after ABI- and eight with short evolution) and their relatives attended the program for 6 months. Patients' and relatives' answers to the European Brain Injury Questionnaire and the Frontal Systems Behavior Scale at 3 time points (pre-intervention. post-intervention and 12 month follow-up) were transformed into linear measures called logits. RESULTS The linear measures revealed significant improvements with large effects at the follow-up assessment on cognitive and executive functioning, social and emotional self-regulation, apathy and mood. At follow-up, the short evolution group achieved greater improvements in mood and cognitive functioning than the long evolution patients. CONCLUSIONS The program showed long-term effectiveness for most of the variables, and it was more effective for mood and cognitive functioning when patients were treated early. Relatives played a key role in the effectiveness of the rehabilitation program.