Comparison of nadA and nadB in 14 Shigella strains and enteroinvasive Escherichia coli versus E. coli showed that at least one locus is altered in all strains. These observations explain the characteristic nicotinic acid auxotrophy of Shigella organisms and are consistent with the previously identified antivirulence nature of these genes for these pathogens.

A variety of intercellular signal molecules, such as, the most studied N-acyl-homoserinelactones (AHLs) in Gram-negative bacteria, autoinducer (AI-2) in both Gram-negative and Gram-positive bacteria, and signal peptides in Gram-positive bacteria, have been discovered over the last 20 years. Although it has been known for over 100 years that many bacteria produce indole, the real biological role...

The emergence of widespread antimicrobial resistance has led to the need for development novel therapeutic interventions. Antivirulence strategies are an attractive alternative classic therapy; however, they require identification new specific targets which can be exploited in drug discovery programs.

Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio chol...

Lactic acid bacteria are known to exhibit probiotic properties through various mechanisms, including competitive exclusion, pathogen inhibition, production of antimicrobial substances, and maintenance of eubiosis. Here, we present the draft genome sequence of a novel probiotic strain, Lactobacillus rhamnosus strain NRRL B-442, which exhibits potent antivirulence activity against Salmonella ente...

Antibiotics represent our bulwark to combat bacterial infections, but the spread of antibiotic resistance compromises their clinical efficacy. Alternatives to conventional antibiotics are urgently needed in order to complement the existing antibacterial arsenal. The macrolide antibiotic azithromycin (AZM) provides a paradigmatic example of an "unconventional" antibacterial drug. Besides its gro...

We present a simple assay to examine effects of compounds on virulence gene expression in the human pathogen Staphylococcus aureus. The assay employs transcriptional reporter strains carrying lacZ fused to central virulence genes. Compounds affecting virulence gene expression and activity of the agr locus are scored based on color change in the presence of a chromogenic beta-galactosidase subst...