The synthesis of seven monoazo benzotriazole dyes for use in surface enhanced resonance Raman scattering, SERRS, is reported. The dyes are all capable of complexing to the silver surface used to provide the surface enhancement found in SERRS and hence act as 'model' analytes. One dye was examined in detail and showed a quantitative relationship between concentration and signal intensity.

PNA and DNA have been detected for the first time with a specifically designed non-fluorescent SERRS active label; this is also the first use of SERRS to detect PNA

The polycyclic aromatic hydrocarbon 7-isopropyl-1-methylphenanthrene (retene) induces mixed function oxygenase (MFO) activity of fish. Bile levels of retene and its metabolite(s) were measured in relation to exposure time, exposure concentration, and induction of MFO activity. Synchronous fluorescence spectrometry provided a rapid means of measuring the amount of retene present in the bile of exposed fish, whereas conventional fluorescence spectrometry was used to quantify the amount of retene metabolites. Based on bile analysis, increased retene exposure resulted in an increased uptake of retene and a curvilinear increase in hepatic MFO activity. Retene was present in the bile within 6 h of initial exposure. However, retene metabolite(s) only appeared in the bile after MFO induction had occurred, 12 h after exposure had commenced, suggesting that MFO activity is required for metabolism. Transfer of fish to clean water after 48 h of exposure resulted in a rapid decrease in the presence of retene and its metabolite(s) in the bile, with a calculated half-life of about 14 h. In vitro additions of retene directly to the ethoxyresorufin O-deethylase assay demonstrated that retene is capable of acting as a competitive inhibitor. Thus, retene contamination of postmitochondrial supernatant (S9 fraction) could result in false-negative results in the MFO assay. The MFO activity in extrahepatic tissues (gills, heart, and kidney) was not significantly induced with retene exposure. Thus, the major site of retene metabolism seems to be in the liver. These results confirm that retene is rapidly taken up, metabolized, and excreted by rainbow trout, and that retene metabolism and excretion are linked to hepatic MFO induction.

Acta Crystallogr. Sect. D 1998, 54, 905 ± 921) to an R factor of 22.3 % and a free R factor of 28.0 %. The refined model consists of protein residues 3 to 214, a Mg 2 ion, 16 water molecules, and 3. 88.8 % of the residues are in the most favored regions of the Ramachandran plot. The atomic coordinates have been deposited to the Brookhaven Protein Databank, with the PDB entry code 1JR4.

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Background Wastewater treatment plants (WWTPs) are considered hotspots for the environmental dissemination of antimicrobial resistance (AMR) determinants. Vancomycin-Resistant Enterococcus (VRE) are candidates for gauging the degree of AMR bacteria in wastewater. Enterococcus faecalis and Entercoccus faecium are recognized indicators of fecal contamination in water. Comparative genomics of enterococci isolated from conventional activated sludge (CAS) and biological aerated filter (BAF) WWTPs was conducted. Results VRE isolates, including E. faecalis (n=24), E. faecium (n=11), E. casseliflavus (n=2) and E. gallinarum (n=2), were selected for sequencing based on WWTP source, species and AMR phenotype. The pangenomes of E. faecium and E. faecalis were both open. The genomic fraction related to the mobilome was positively correlated with genome size in E. faecium ( p < 0.001) and E. faecalis ( p < 0.001) and with the number of AMR genes in E. faecium ( p = 0.005). Genes conferring vancomycin resistance, including van A and van M ( E. faecium ), van G ( E. faecalis ), and van C ( E. casseliflavus / E. gallinarum ), were detected in 20 genomes. The most prominent functional AMR genes were efflux pumps and transporters. A minimum of 16, 6, 5 and 3 virulence genes were detected in E. faecium , E. faecalis , E. casseliflavus and E. gallinarum, respectively. Virulence genes were more common in E. faecalis and E. faecium , than E. casseliflavus and E. gallinarum . A number of mobile genetic elements were shared among species. Functional CRISPR/Cas arrays were detected in 13 E. faecalis genomes, with all but one also containing a prophage. The lack of a functional CRISPR/Cas arrays was associated with multi-drug resistance in E. faecium . Phylogenetic analysis demonstrated differential clustering of isolates based on source but not based on WWTP. Genes related to phage and CRISPR/Cas arrays could potentially serve as environmental biomarkers. Conclusions There was no discernible difference between enterococcal genomes from the CAS and BAF WWTPs. E. faecalis and E. faecium have smaller genomes and harbor more virulence, AMR, and mobile genetic elements than other Enterococcus spp .

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