A Rare Case of Severe Isolated Right Heart Failure with Secundum Type Atrial Septal Defect and Mitral Regurgitation Without Pulmonary Hypertension.

Typically, right heart failure (RHF) may occur following left heart failure (LHF) in chronic volume overload states such as chronic severe mitral regurgitation (MR) through chronically elevated pulmonary pressures. In Lutembacher syndrome (LS), the direct shunting through a secundum type atrial septal defect (ASD) results in congestive heart failure in the setting of severe mitral stenosis (MS) with or without elevated pulmonary arterial or venous pressures. We report a rare case of severe isolated RHF and bi-atrial enlargement resulting from the direct shunting through a secundum type ASD in the presence of a severe eccentric primary MR. There are no significant cases documented like this after a thorough search using PubMed, Medline, and Google Scholar. A review of the literature suggests that LS is also caused by a combination of mitral regurgitation and a secundum-type atrial septal defect without mitral stenosis, though rarely. Because this is a primary MR, we feel it is a case of LS with MR, ruling out a combination of secondary MR and secundum-type atrial septal defect.

Investigating degradation metabolites and underlying pathway of azo dye "Reactive Black 5" in bioaugmented floating treatment wetlands.

The direct discharge of azo dyes and/or their metabolites into the environment may exert toxic, mutagenic, and carcinogenic effects on exposed fauna and flora. In this study, we analyzed the metabolites produced during the degradation of an azo dye namely Reactive Black 5 (RB5) in the bacterial-augmented floating treatment wetlands (FTWs), followed by the investigation of their underlying toxicity. To this end, a FTWs system was developed by using a common wetland plant Phragmites australis in the presence of three dye-degrading bacteria (Acinetobacter junii strain NT-15, Pseudomonas indoloxydans strain NT-38, and Rhodococcus sp. strain NT-39). We found that the FTW system effectively degraded RB5 into at least 20 different metabolites with the successful removal of color (95.5%) from the water. The fish toxicity assay revealed the nontoxic characteristics of the metabolites produced after dye degradation. Our study suggests that bacterially aided FTWs could be a suitable option for the successful degradation of azo dyes, and the results presented in this study may help improve the overall textile effluent cleanup processes.

Combined use of alkane-degrading and plant growth-promoting bacteria enhanced phytoremediation of diesel contaminated soil.

Inoculation of plants with pollutant-degrading and plant growth-promoting microorganisms is a simple strategy to enhance phytoremediation activity. The objective of this study was to determine the effect of inoculation of different bacterial strains, possessing alkane-degradation and 1-amino-cyclopropane-1 -carboxylic acid (ACC) deaminase activity, on plant growth and phytoremediation activity. Carpet grass (Axonopus affinis) was planted in soil spiked with diesel (1% w/w) for 90 days and inoculated with different bacterial strains, Pseudomonas sp. ITRH25, Pantoea sp. BTRH79 and Burkholderia sp. PsJN, individually and in combination. Generally, bacterial application increased total numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere ofcarpet grass, plant biomass production, hydrocarbon degradation and reduced genotoxicity. Bacterial strains possessing different beneficial traits affect plant growth and phytoremediation activity in different ways. Maximum bacterial population, plant biomass production and hydrocarbon degradation were achieved when carpet grass was inoculated with a consortium of three strains. Enhanced plant biomass production and hydrocarbon degradation were associated with increased numbers of culturable hydrocarbon-degrading bacteria in the rhizosphere of carpet grass. The present study revealed that the combined use of different bacterial strains, exhibiting different beneficial traits, is a highly effective strategy to improve plant growth and phytoremediation activity.