Endogenous Synthesis of Tetrahydroisoquinoline Derivatives from Dietary Factors: Neurotoxicity Assessment on a 3D Neurosphere Culture.

Tetrahydroisoquinoline (THIQ) alkaloids and their derivatives have a structural similarity to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a well-known neurotoxin. THIQs seem to present a broad range of actions in the brain, critically dependent on their catechol moieties and metabolism. These properties make it reasonable to assume that an acute or chronic exposure to some THIQs might lead to neurodegenerative diseases including essential tremor (ET).

Correction to: Affinity capillary electrophoresis for identification of active drug candidates in myotonic dystrophy type 1.

Unfortunately the name of Jean Jacques Vanden Eynde was missing as co-author of this contribution. The correct list of authors is: Ioan O. Neaga, Stephanie Hambye, Ede Bodoki, Claudio Palmieri, Jean Jacques Vanden Eynde, Eugénie Ansseau, Alexandra Belayew, Radu Oprean, Bertrand Blankert.

Affinity capillary electrophoresis for identification of active drug candidates in myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is an autosomal dominantly inherited degenerative disease with a slow progression. At the present, there is no commercially available treatment, but sustained effort is currently undertaken for the development of a promising lead compound. In the present paper we report the development of a fast, versatile, and cost-effective affinity capillary electrophoresis (ACE) method for the screening and identification of potential drug candidates targeting pathological ARN probes relevant for DM1.

Identification, antimicrobial resistance and molecular characterization of the human emerging pathogen Streptococcus gallolyticus subsp. pasteurianus.

This study aimed to retrospectively identify 22Streptococcus bovis clinical strains based on the new taxonomy, as well as to investigate their antibiotic-resistance and clonality. Strains were identified by Phoenix100 system, 16S rRNA sequencing, and two MALDI-TOF MS platforms (Bruker Biotyper, Vitek MS). Antibiotic resistance was determined both phenotypically and genotypically, and clonality was assessed by PFGE.

Recombination between Streptococcus suis ICESsu32457 and Streptococcus agalactiae ICESa2603 yields a hybrid ICE transferable to Streptococcus pyogenes.

Integrative conjugative elements (ICEs) are mobile genetic elements that reside in the chromosome but retain the ability to undergo excision and to transfer by conjugation. Genes involved in drug resistance, virulence, or niche adaptation are often found among backbone genes as cargo DNA. We recently characterized in Streptococcus suis an ICE (ICESsu32457) carrying resistance genes [tet(O/W/32/O), tet(40), erm(B), aphA, and aadE] in the 15K unstable genetic element, which is flanked by two ∼1.

Genetic determinants and elements associated with antibiotic resistance in viridans group streptococci.

Objectives: To investigate the distribution of erythromycin, tetracycline and chloramphenicol resistance mechanisms and determinants and the relevant genetic environments and elements in viridans group streptococci (VGS).

Methods: A total of 263 VGS collected from routine throat swabs in 2010-12 and identified to the species level were studied. Antibiotic resistance determinants and the relevant genetic contexts and elements were determined using amplification and sequencing assays and restriction analysis.

Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources.

A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS).

Dysbiosis contributes to fibrogenesis in the course of chronic liver injury in mice.

Unlabelled: Nonalcoholic fatty liver disease (NAFLD) may lead to hepatic fibrosis. Dietary habits affect gut microbiota composition, whereas endotoxins produced by Gram-negative bacteria stimulate hepatic fibrogenesis. However, the mechanisms of action and the potential effect of microbiota in the liver are still unknown.

Pitfalls encountered while investigating genetic elements by PCR.

The unprecedented wealth of databases that have become available in the era of next-generation sequencing has considerably increased our knowledge of bacterial genetic elements (GEs). At the same time, the advent of single-cell based approaches has brought realization that unsuspected heterogeneity may occur in the bacterial population from a single colony. The increasing use of PCR-based techniques to study new GEs requires careful consideration of the possible different PCR targets associated with different subpopulations if incorrect or incomplete interpretations are to be avoided.

Interspecies mobilization of an ermT-carrying plasmid of Streptococcus dysgalactiae subsp. equisimilis by a coresident ICE of the ICESa2603 family.

Objectives: The recently documented presence of almost identical, small, non-self-transmissible, erm(T)-carrying plasmids in clonally unrelated erythromycin-resistant isolates of Streptococcus pyogenes and Streptococcus agalactiae suggests that these plasmids somehow circulate in the streptococcal population. The objective of this study was to characterize the erm(T)-carrying genetic element in a clinical isolate of Streptococcus dysgalactiae subsp. equisimilis (Sde5580) and to provide a possible explanation for the spread of erm(T)-carrying plasmids in streptococci.

Streptococcus pneumoniae transposon Tn1545/Tn6003 changes to Tn6002 due to spontaneous excision in circular form of the erm(B)- and aphA3-containing macrolide-aminoglycoside-streptothricin (MAS) element.

The macrolide-aminoglycoside-streptothricin (MAS) element, an ∼4.2-kb insertion containing erm(B) and aphA3 resistance determinants, distinguishes Streptococcus pneumoniae transposon Tn1545/Tn6003 from Tn6002. Here, it is shown to be an unstable genetic element that, although it lacks recombinase genes, can exploit long, erm(B)-containing direct repeats acting as att sites for spontaneous excision that may result in loss.

Characterization of a Streptococcus suis tet(O/W/32/O)-carrying element transferable to major streptococcal pathogens.

Mosaic tetracycline resistance determinants are a recently discovered class of hybrids of ribosomal protection tet genes. They may show different patterns of mosaicism, but their final size has remained unaltered. Initially thought to be confined to a small group of anaerobic bacteria, mosaic tet genes were then found to be widespread.

Streptococcus suis, an Emerging Drug-Resistant Animal and Human Pathogen.

Streptococcus suis, a major porcine pathogen, has been receiving growing attention not only for its role in severe and increasingly reported infections in humans, but also for its involvement in drug resistance. Recent studies and the analysis of sequenced genomes have been providing important insights into the S. suis resistome, and have resulted in the identification of resistance determinants for tetracyclines, macrolides, aminoglycosides, chloramphenicol, antifolate drugs, streptothricin, and cadmium salts.

Different genetic elements carrying the tet(W) gene in two human clinical isolates of Streptococcus suis.

The genetic support for tet(W), an emerging tetracycline resistance determinant, was studied in two strains of Streptococcus suis, SsCA and SsUD, both isolated in Italy from patients with meningitis. Two completely different tet(W)-carrying genetic elements, sharing only a tet(W)-containing segment barely larger than the gene, were found in the two strains. The one from strain SsCA was nontransferable, and aside from an erm(B)-containing insertion, it closely resembled a genomic island recently described in an S.