Comparative Genomics Provides Insights into the Taxonomy of Azoarcus and Reveals Separate Origins of Nif Genes in the Proposed Azoarcus and Aromatoleum Genera.

Among other attributes, the Betaproteobacterial genus Azoarcus has biotechnological importance for plant growth-promotion and remediation of petroleum waste-polluted water and soils. It comprises at least two phylogenetically distinct groups. The "plant-associated" group includes strains that are isolated from the rhizosphere or root interior of the C4 plant Kallar Grass, but also strains from soil and/or water; all are considered to be obligate aerobes and all are diazotrophic. The other group (now partly incorporated into the new genus Aromatoleum) comprises a diverse range of species and strains that live in water or soil that is contaminated with petroleum and/or aromatic compounds; all are facultative or obligate anaerobes. Some are diazotrophs. A comparative genome analysis of 32 genomes from 30 Azoarcus-Aromatoleum strains was performed in order to delineate generic boundaries more precisely than the single gene, 16S rRNA, that has been commonly used in bacterial taxonomy. The origin of diazotrophy in Azoarcus-Aromatoleum was also investigated by comparing full-length sequences of nif genes, and by physiological measurements of nitrogenase activity using the acetylene reduction assay. Based on average nucleotide identity (ANI) and whole genome analyses, three major groups could be discerned: (i) Azoarcus comprising Az. communis, Az. indigens and Az. olearius, and two unnamed species complexes, (ii) Aromatoleum Group 1 comprising Ar. anaerobium, Ar. aromaticum, Ar. bremense, and Ar. buckelii, and (iii) Aromatoleum Group 2 comprising Ar. diolicum, Ar. evansii, Ar. petrolei, Ar. toluclasticum, Ar. tolulyticum, Ar. toluolicum, and Ar. toluvorans. Single strain lineages such as Azoarcus sp. KH32C, Az. pumilus, and Az. taiwanensis were also revealed. Full length sequences of nif-cluster genes revealed two groups of diazotrophs in Azoarcus-Aromatoleum with nif being derived from Dechloromonas in Azoarcus sensu stricto (and two Thauera strains) and from Azospira in Aromatoleum Group 2. Diazotrophy was confirmed in several strains, and for the first time in Az. communis LMG5514, Azoarcus sp. TTM-91 and Ar. toluolicum TT. In terms of ecology, with the exception of a few plant-associated strains in Azoarcus (s.s.), across the group, most strains/species are found in soil and water (often contaminated with petroleum or related aromatic compounds), sewage sludge, and seawater. The possession of nar, nap, nir, nor, and nos genes by most Azoarcus-Aromatoleum strains suggests that they have the potential to derive energy through anaerobic nitrate respiration, so this ability cannot be usefully used as a phenotypic marker to distinguish genera. However, the possession of bzd genes indicating the ability to degrade benzoate anaerobically plus the type of diazotrophy (aerobic vs. anaerobic) could, after confirmation of their functionality, be considered as distinguishing phenotypes in any new generic delineations. The taxonomy of the Azoarcus-Aromatoleum group should be revisited; retaining the generic name Azoarcus for its entirety, or creating additional genera are both possible outcomes.

Vascular phenotype and subclinical inflammation in diabetic Asian Indians without overt cardiovascular disease.

Although Asian Indian (AI) patients with diabetes mellitus type 2 (DM2) are at high risk for cardiovascular disease (CVD), not all patients develop CVD. The vascular phenotype of AI-DM2 without CVD has not been elucidated and may point to protective features. Using baseline data from a clinical trial we provide an initial description of vascular parameters in AI-DM2 compared to Europid Caucasian controls (ECs) matched for age and gender. Endpoints of the study were endothelial function, low-grade systemic inflammation (CRP) and carotid intima-media thickness (cIMT). AIs had longer duration of diabetes, worse glycemic control and more microangiopathy. Both groups demonstrated marked endothelial dysfunction. CRP levels were similar: 1.7 (4.9) mg/L in AIs and 2.8 (3.6) mg/L in ECs. cIMT values were significantly lower in AI-DM2 than EC-DM2 (0.655mm (0.12) versus 0.711mm (0.15), p=0.03). Multiple regression analysis showed that variability in CRP was mainly determined by waist circumference, not by ethnicity. In contrast, ethnicity was a significantly explanatory variable for cIMT. Vascular phenotype of AI-DM2 without CVD was characterized by endothelial dysfunction and relatively low levels of CRP, comparable to EC-DM2 controls. In contrast, lower cIMT values were observed in AI-DM2 despite longer duration of diabetes and worse metabolic control. We propose that mechanisms slowing its progression may have atheroprotective potential in AI-DM2.

Biodegradable-polymer-based, paclitaxel-elutingInfinnium™ stent: 9-Month clinical and angiographic follow-up results from the SIMPLE II prospectivemulti-centre registry study

Background: SIMPLE II was a multi-centre, prospective registry study aimed at investigating the safety andefficacy of the Infinnium™ (Sahajanand Medical Technologies Pvt. Ltd, India) paclitaxel-eluting stent forthe treatment of single de novo lesions in the native coronary arteries.Methods: One hundred and three patients with symptomatic coronary artery disease were treated for singlede novo native coronary artery lesions using the Infinnium™ stent (paclitaxel concentration1.4 mcg/mm2 released over 48 days) in a multi-centre, prospective study performed on 3 continents (Asia,Europe and South America). The primary safety endpoint was major adverse cardiac events at 30 days(MACE 30d) and efficacy was assessed by in-stent binary restenosis as measured by quantitative coronaryangiography (QCA) at six-month follow-up. A clinical follow-up was scheduled at nine months.Results: The mean patient age was 58.5 years; 70.9% were males; 43.7% had unstable angina and 38.8%previous myocardial infarction. Risk factors included hypertension in 62.1%, hypercholesterolemia in52.4%, current smoking in 32.0% and diabetes in 28.2%. Stent implantation was successful in all patients,with more than one stent being implanted in 9 patients (8.7%). Hierarchical MACE 30d was 2.9%. At ninemonths, 101 patients had clinical follow-up (1 patient had died and 1 refused). There was one death(1.0%), one Q-wave myocardial infarction (Q MI) (1.0%), three non-Q MIs (2.9%), one clinically-driven targetlesion Coronary Artery Bypass Grafting (CABG) (1.0%), and one clinically-driven target lesion repeatpercutaneous coronary intervention (re-PCI) (1.0%). The overall event-free rate at nine months was 93.2%.QCA revealed in-stent and in-segment late loss of 0.38±0.49 mm and 0.18±0.46 mm, resulting in binaryrestenosis rates of 7.3% and 8.3%, respectively. There was one case of late stent thrombosis in the patientexperiencing the Q MI and subsequent re-PCI...