New Bacteriological Patterns in Primary Infected Aorto-iliac Aneurysms: A Single-centre Experience

AbstractObjectivesTo assess causative pathogens and surgical outcomes in patients with primary infected aorto-iliac aneurysms at our institution.DesignRetrospective study of patients treated at a university hospital between 1992 and 2009.ResultsWe identified 26 patients (median age, 63 years) with primary infected aneurysms on the aorta (descending thoracic, n = 2; thoraco-abdominal, n = 3; suprarenal, n = 2; infrarenal, n = 15) or iliac arteries (n = 4). Among them, 22 were symptomatic, including 13 with ruptured aneurysms. The causative organisms, identified in 25/26 patients, were Campylobacter fetus, n = 6; Streptococcus pneumoniae, n = 4; Listeria, n = 3; Salmonella, n = 2; Mycobacterium tuberculosis, n = 2; Staphylococcus aureus, n = 1; and other, n = 7. Immune suppression was a feature in 10 (38.4%) patients. Revascularisation was performed in situ in 23 patients (10 allografts, eight grafts, three superficial femoral veins, and 2 stentgrafts) and by extra-anatomic bypass in three patients.Hospital mortality was 23% (in situ group, 17.4%; extra-anatomic group, 66.7%; χ2 Yates, P = 0.24). During follow-up in the 20 survivors (median, 48.5 months), there were two non-infection-related deaths (five and 24 months) and six (30%) vascular complications.ConclusionsThe bacteriological spectrum of primary infected aorto-iliac aneurysms was wider than previously reported. The availability of new diagnostic tests and increased prevalence of immunosuppression may explain this finding

Think twice: A cognitive perspective of an antibiotic timeout intervention to improve antibiotic use

ObjectivesTo understand clinicians' impressions of and decision-making processes regarding an informatics-supported antibiotic timeout program to re-evaluate the appropriateness of continuing vancomycin and piperacillin/tazobactam.MethodsWe implemented a multi-pronged informatics intervention, based on Dual Process Theory, to prompt discontinuation of unwarranted vancomycin and piperacillin/tazobactam on or after day three in a large Veterans Affairs Medical Center. Two workflow changes were introduced to facilitate cognitive deliberation about continuing antibiotics at day three: (1) teams completed an electronic template note, and (2) a paper summary of clinical and antibiotic-related information was provided to clinical teams. Shortly after starting the intervention, six focus groups were conducted with users or potential users. Interviews were recorded and transcribed. Iterative thematic analysis identified recurrent themes from feedback.ResultsThemes that emerged are represented by the following quotations: (1) captures and controls attention ("it reminds us to think about it"), (2) enhances informed and deliberative reasoning ("it makes you think twice"), (3) redirects decision direction ("…because [there was no indication] I just [discontinued] it without even trying"), (4) fosters autonomy and improves team empowerment ("the template… forces the team to really discuss it"), and (5) limits use of emotion-based heuristics ("my clinical concern is high enough I think they need more aggressive therapy…").ConclusionsRequiring template completion to continue antibiotics nudged clinicians to re-assess the appropriateness of specified antibiotics. Antibiotic timeouts can encourage deliberation on overprescribed antibiotics without substantially curtailing autonomy. An effective nudge should take into account clinician's time, workflow, and thought processes

Impact of interleukin-6 on hypoxia-induced pulmonary hypertension and lung inflammation in mice

<p>Abstract</p> <p>Background</p> <p>Inflammation may contribute to the pathogenesis of various forms of pulmonary hypertension (PH). Recent studies in patients with idiopathic PH or PH associated with underlying diseases suggest a role for interleukin-6 (IL-6).</p> <p>Methods</p> <p>To determine whether endogenous IL-6 contributes to mediate hypoxic PH and lung inflammation, we studied IL-6-deficient (IL-6^-/-) and wild-type (IL-6^+/+) mice exposed to hypoxia for 2 weeks.</p> <p>Results</p> <p>Right ventricular systolic pressure, right ventricle hypertrophy, and the number and media thickness of muscular pulmonary vessels were decreased in IL-6^-/-mice compared to wild-type controls after 2 weeks' hypoxia, although the pressure response to acute hypoxia was similar in IL-6^+/+and IL-6^-/-mice. Hypoxia exposure of IL-6^+/+mice led to marked increases in IL-6 mRNA and protein levels within the first week, with positive IL-6 immunostaining in the pulmonary vessel walls. Lung IL-6 receptor and gp 130 (the IL-6 signal transducer) mRNA levels increased after 1 and 2 weeks' hypoxia. In vitro studies of cultured human pulmonary-artery smooth-muscle-cells (PA-SMCs) and microvascular endothelial cells revealed prominent synthesis of IL-6 by PA-SMCs, with further stimulation by hypoxia. IL-6 also markedly stimulated PA-SMC migration without affecting proliferation. Hypoxic IL-6^-/-mice showed less inflammatory cell recruitment in the lungs, compared to hypoxic wild-type mice, as assessed by lung protein levels and immunostaining for the specific macrophage marker F4/80, with no difference in lung expression of adhesion molecules or cytokines.</p> <p>Conclusion</p> <p>These data suggest that IL-6 may be actively involved in hypoxia-induced lung inflammation and pulmonary vascular remodeling in mice.</p

Antibiotiques chez le patient insuffisant rénal : actualisation des adaptations posologiques à la pratique clinique en infectiologie

Antibiotic prescription in chronic kidney disease patients poses a twofold problem. The appropriate use of antibacterial agents is essential to ensure efficacy and to prevent the emergence of resistance, and dosages should be adapted to the renal function to prevent adverse effects. SiteGPR is a French website for health professionals to help with prescriptions to chronic kidney disease patients. A working group of infectious disease specialists and nephrology pharmacists reviewed the indications, dosing regimens, administration modalities, and dose adjustments of antibiotics marketed in France for patients with renal failure. Data available on the SiteGPR website and detailed in the present article aims to provide an evidence-based update of infectious disease recommendations to health professionals managing patients with chronic kidney disease

Candida albicans-produced farnesol stimulates Pseudomonas quinolone signal production in LasR-defective Pseudomonas aeruginosa strains

Candida albicans has been previously shown to stimulate the production of Pseudomonas aeruginosa phenazine toxins in dual-species colony biofilms. Here, we report that P. aeruginosa lasR mutants, which lack the master quorum sensing system regulator, regain the ability to produce quorum-sensing-regulated phenazines when cultured with C. albicans. Farnesol, a signalling molecule produced by C. albicans, was sufficient to stimulate phenazine production in LasR− laboratory strains and clinical isolates. P. aeruginosa ΔlasR mutants are defective in production of the Pseudomonas quinolone signal (PQS) due to their inability to properly induce pqsH, which encodes the enzyme necessary for the last step in PQS biosynthesis. We show that expression of pqsH in a ΔlasR strain was sufficient to restore PQS production, and that farnesol restored pqsH expression in ΔlasR mutants. The farnesol-mediated increase in pqsH required RhlR, a transcriptional regulator downstream of LasR, and farnesol led to higher levels of N-butyryl-homoserine lactone, the small molecule activator of RhlR. Farnesol promotes the production of reactive oxygen species (ROS) in a variety of species. Because the antioxidant N-acetylcysteine suppressed farnesol-induced RhlR activity in LasR− strains, and hydrogen peroxide was sufficient to restore PQS production in las mutants, we propose that ROS are responsible for the activation of downstream portions of this quorum sensing pathway. LasR mutants frequently arise in the lungs of patients chronically infected with P. aeruginosa. The finding that C. albicans, farnesol or ROS stimulate virulence factor production in lasR strains provides new insight into the virulence potential of these strains