Evaluation of molecular inhibitors of loop-mediated isothermal amplification (LAMP).

Loop-mediated isothermal amplification (LAMP) is a cost-effective and easy-to-perform assay that enables the direct detection of DNA. Its use in point-of-care diagnostic tests is growing, while it has the potential to be used in presumptive on-the-field forensic tests. Samples are often collected from complex matrices that contain high levels of contaminants. Herein, we evaluate the effect of seven common DNA amplification inhibitors on LAMP - bile salts, calcium chloride, hematin, humic acid, immunoglobulin G, tannic acid and urea. We study the effect of each inhibitor individually in real-time detection systems coupled with end-point measurements to delineate their inhibitory effects from the matrix in which they may be found. Our studies show LAMP inhibitors generally delay the onset of amplicon formation and quench fluorescence at similar or higher concentrations compared to PCR, but that end-point measurements of LAMP amplicons are unaffected. This is important as LAMP amplicons can be detected in non-fluorometric ways thus contributing to the assertions that LAMP is more robust to inhibitors than PCR.

Polyarteritis nodosa presenting with posterior reversible leukoencephalopathy syndrome.

A man in his 20s presented following a generalised tonic-clonic seizure on a background of a recent diagnosis of hepatitis B (HBV). During admission, he was severely hypertensive and imaging findings confirmed a diagnosis of posterior reversible leukoencephalopathy syndrome (PRES). The patient subsequently developed multiorgan involvement with an axonal sensorimotor neuropathy, vascular cutaneous lesions and multiple bilateral renal and splenic infarcts. Based on the 2012 Revised International Chapel Hill Consensus Criteria, a diagnosis of polyarteritis nodosa (PAN) with secondary PRES was made. The patient was given intravenous methylprednisolone, followed by a prolonged course of oral prednisolone, and tenofovir antiviral therapy to target HBV seroconversion. He made a good neurological recovery with resolution of imaging changes. This case highlights the importance of a low threshold for systemic screening for young patients presenting with PRES secondary to uncontrolled hypertension and the importance of viral screening, particularly for HBV.

Primary biodegradation and mineralization of aryl organophosphate flame retardants by Rhodococcus-Sphingopyxis consortium.

In this study, the biodegradation towards aryl organophosphate flame retardants (aryl-OPFRs) was investigated by the Rhodococcus-Sphingopyxis consortium, mixture of strain Rhodococcus sp. YC-JH2 and Sphingopyxis sp. YC-JH3. The optimal ratio between the two composition strains was determined as 1:1. Under the optimum condition (pH 8, 35 °C and 0% salinity), the consortium could utilize aryl-OPFRs as sole carbon source and degrade them rapidly with half-life of 4.53, 21.11 and 23.0 h for triphenyl phosphate (TPhP), tricresyl phosphate (TCrP) and 2-ethylhexyl diphenyl phosphate (EHDPP) respectively. The consortium maintained high degrading efficiency under a wide of range of pH (6-10), temperature (20-40 °C) and salinity (0-6%). Besides, the consortium could rapidly degrade high concentration of TPhP and no inhibitory effect towards degradation speed was observed up to 500 mg/L. The effect of metal ions and surfactants was estimated. Most metal ions exhibited significant inhibition, except Zn2+ and Pb2+, which showed no effect or slight promotion. Ionic surfactants could severely reduce the degrading capacity, while nonionic surfactants showed no effect. With abundant inoculation of the consortium, mineralization higher than 75% could be achieved within a week. This study provides efficient microorganisms for bioremediation of aryl-OPFRs contamination.

Biodegradation of Bisphenol A by Sphingobium sp. YC-JY1 and the Essential Role of Cytochrome P450 Monooxygenase.

Bisphenol A (BPA) is a widespread pollutant threatening the ecosystem and human health. An effective BPA degrader YC-JY1 was isolated and identified as Sphingobium sp. The optimal temperature and pH for the degradation of BPA by strain YC-JY1 were 30 °C and 6.5, respectively. The biodegradation pathway was proposed based on the identification of the metabolites. The addition of cytochrome P450 (CYP) inhibitor 1-aminobenzotriazole significantly decreased the degradation of BPA by Sphingobium sp. YC-JY1. Escherichia coli BL21 (DE3) cells harboring pET28a-bisdAB achieved the ability to degrade BPA. The bisdB gene knockout strain YC-JY1ΔbisdB was unable to degrade BPA indicating that P450bisdB was an essential initiator of BPA metabolism in strain YC-JY1. For BPA polluted soil remediation, strain YC-JY1 considerably stimulated biodegradation of BPA associated with the soil microbial community. These results point out that strain YC-JY1 is a promising microbe for BPA removal and possesses great application potential.

Using Cellulolytic Nitrogen Fixing Bacterium, Azomonas agilis for Effective Degradation of Agricultural Residues.

INTRODUCTION: Azomonas agilis, a nitrogen-fixing bacterium, was isolated from rhizospheric soil in central Myanmar. METHODS & MATERIALS: The nitrogen-fixing activity of this bacterium was detected by plate screening method using glucose nitrogen free mineral medium and ammonium test-kit Cellulolytic activity was screened by plat assay and detected by Dinitrosalicyclic acid method (DNS). RESULTS & DISCUSSION: The isolated A. agilis grew in media containing 3-12% of NaCl, although the growth became poor when NaCl concentrations increased. Among various carbon sources, sucrose was the best source for ammonium accumulation of this bacterium, whereas arabinose was not the suitable carbon source. Although the nitrogen-fixing activity of A. agilis was highest after one week incubation, cellulase enzyme production was highest after 2-3 days of incubation. It was observed that cellulase enzyme activity of A. agilis for cellulose and sodium carboxymethyl cellulose (CMC) was almost the same. Three agricultural wastes were used to detect the cellulase enzyme activity of A. agilis, cellulase activity was better on filter paper as a substrate when compared to rice-straw and sawdust. CONCLUSION: So, the isolated A. agilis has high potential as an effective bacterial strain to use in sustainable agriculture and degradation of some agricultural residues.