Transcriptional adaptations during long-term persistence of Staphylococcus aureus in the airways of a cystic fibrosis patient

AbstractThe lungs of Cystic fibrosis (CF) patients are often colonized and/or infected by Staphylococcus aureus for years, mostly by one predominant clone. For long-term survival in this environment, S. aureus needs to adapt during its interactions with host factors, antibiotics, and other pathogens. Here, we study long-term transcriptional as well as genomic adaptations of an isogenic pair of S. aureus isolates from a single patient using RNA sequencing (RNA-Seq) and whole genome sequencing (WGS). Mimicking in vivo conditions, we cultivated the S. aureus isolates using artificial sputum medium before harvesting RNA for subsequent analysis. We confirmed our RNA-Seq data using quantitative real-time (qRT)-PCR and additionally investigated intermediate isolates from the same patient representing in total 13.2 years of persistence in the CF airways. Comparative RNA-Seq analysis of the first and the last (“late”) isolate revealed significant differences in the late isolate after 13.2 years of persistence. Of the 2545 genes expressed in both isolates that were cultivated aerobically, 256 genes were up- and 161 were down-regulated with a minimum 2-fold change (2f). Focusing on 25 highly (≥8f) up- (n=9) or down- (n=16) regulated genes, we identified several genes encoding for virulence factors involved in immune evasion, bacterial spread or secretion (e.g. spa, sak, and esxA). Moreover, these genes displayed similar expression trends under aerobic, microaerophilic and anaerobic conditions. Further qRT-PCR-experiments of highly up- or down-regulated genes within intermediate S. aureus isolates resulted in different gene expression patterns over the years. Using sequencing analysis of the differently expressed genes and their upstream regions in the late S. aureus isolate resulted in only few genomic alterations. Comparative transcriptomic analysis revealed adaptive changes affecting mainly genes involved in host-pathogen interaction. Although the underlying mechanisms were not known, our results suggest adaptive processes beyond genomic mutations triggered by local factors rather than by activation of global regulators

Complete versus culprit vessel percutaneous coronary intervention in multivessel disease: A randomized comparison

Background The purpose of this study was to compare the safety, efficacy, and costs of complete versus "culprit" vessel revascularization in multivessel coronary artery disease treated with percutaneous coronary interventions (PCI). Methods Patients with multivessel disease and an identified culprit vessel were randomly assigned to complete revascularization of vessels greater than or equal to50% stenoses (n = 108) versus revascularization limited to the culprit vessel (n = 111). The primary end point, major adverse cardiac events (MACE), were defined as cardiac or noncardiac death, myocardial infarction, need for coronary artery bypass graft surgery, and repeat PCI up to 1 year. Results Despite equal MACE at 24 hours (6.3% vs 7.4%), strategy success was higher in the culprit vessel than in the complete revascularization group (93.7% vs 81.5%, P = .007). MACE rates at 1 month (14.4% vs 9.3%), 1 year (32.4% vs 26.9%), and 4.6 +/- 1.2 years (40.4% vs 34.6%) were similar in both groups. Repeat PCI was performed more often in the culprit vessel group (31.2% vs 21.2%, P = .06). A lower consumption of medical material was associated with lower procedural costs in the culprit vessel group (5784 vs 7315 Euros; P <.001). However, between 1 year and the end of follow-up, costs had equalized in both groups. Conclusions Complete versus culprit vessel revascularization in multivessel coronary disease treated with PCI was associated with a lower strategy success rate, similar MACE rates, and initially higher costs. However, over the long term, more repeat PCIs were conducted in patients treated by culprit revascularization only, mostly because of the need to treat lesions initially left untreated. As a consequence, incremental costs had equalized within 1 year. The decision of whether to perform culprit vessel or complete revascularization can be made on an individual basi

Lack of long-term clinical benefit of thrombus aspiration during primary percutaneous coronary intervention with paclitaxel-eluting stents or bare-metal stents: post-hoc analysis of the PASSION-trial

Although current clinical guidelines recommend the use of thrombus aspiration (TA) during primary percutaneous coronary intervention (PPCI), previous studies evaluating TA demonstrated contradictory results. The aim of this study was to evaluate long-term clinical outcome after TA in adjunct to PPCI for acute ST-segment myocardial infarction (STEMI), as compared with conventional treatment, with the use of paclitaxel-eluting stents or bare-metal stents. We analyzed data of the PASSION trial, in which 619 patients with STEMI were randomly assigned to a paclitaxel-eluting stent or a bare-metal stent. TA was performed in 311 patients (50.2%). Clinical endpoints at 2 years were compared between patients who received TA during PPCI with patients who underwent conventional PPCI. The primary outcome of interest was a composite of cardiac death, recurrent myocardial infarction (MI), or target-lesion revascularization (TLR). A propensity score model was made to account for baseline differences that could have affected the probability of performing TA. Complete follow-up was available for 598 patients (96.6%). The cumulative incidence of the combined outcome measure of cardiac death, recurrent MI, or TLR was 40 (13.0%) in the TA group and 41 (13.5%) in the conventional PPCI group (HR 0.96; 95% CI 0.62-1.47; P = 0.84). Also after adjusting for propensity score, no significant difference in event rate was observed between both treatment groups. In this post-hoc analysis of the PASSION trial, TA in adjunct to PPCI did not affect rates of major adverse cardiac events at 2 years follow-up, as compared with conventional PPC

Magnetically navigated percutaneous coronary intervention in distal and/or complex lesions may improve procedural outcome and material consumption

Aims: Comparison of magnetic guidewire navigation in percutaneous coronary intervention (magnetic PCI) across distal and /or complex lesions versus conventional navigation (conventional PCI). Methods and results: Forty-seven consecutive patients (age 61±10yr) undergoing elective single vessel magnetic PCI for distal and/or complex lesions were matched by age and lesion location with 45 patients undergoing conventional PCI (age 63±10yr). Technical success rate was defined