The flagellar transcriptional regulator FleQ appears to be the highest-level regulator in the hierarchical regulatory cascade of flagellar biogenesis in Pseudomonas aeruginosa. Except for the posttranslational downregulation of FleQ activity by FleN, an antiactivator, not much is known about the regulation of the fleQ gene or its gene product. Some FleQ homologs in other bacterial species eithe...

The spread of multidrug-resistant Pseudomonas aeruginosa isolates constitutes a serious clinical challenge. Bacterial efflux machinery is a crucial mechanism of resistance among P. aeruginosa. Efflux inhibitors such as phenylalanine arginyl β-naphthylamide (PAβN) promote the bacterial susceptibility to antimicrobial agents. The pathogenesis of P. aeruginosa is coordinated via quorum sensing (QS...

Photothermal radiometry and modulated luminescence (PTR-LUM) is an emerging nondestructive methodology applied toward the characterization and quantification of dental caries. We evaluate the efficacy of PTR-LUM in vitro to detect, monitor, and quantify human enamel caries. Artificial caries are created in extracted human molars (n = 15) using an acidified gel system (pH 4.5) for 10 or 40 days....

Wood is an essential renewable raw material for industrial products and energy. However, knowledge of the genetic regulation of wood formation is limited. We developed a genome-wide high-throughput system for the discovery and validation of specific transcription factor (TF)-directed hierarchical gene regulatory networks (hGRNs) in wood formation. This system depends on a new robust procedure f...

Targeted bacterial delivery of anticancer proteins has the ability to overcome therapeutic resistance in tumors that limits the efficacy of chemotherapeutics. The ability of bacteria to specifically target tumors allows for delivery of aggressive proteins that directly kill cancer cells and cannot be administered systemically. However, few proteins have been tested for this purpose. To identify...

Host-adapted strains of Salmonella enterica cause systemic infections and have the ability to persist systemically for long periods of time despite the presence of a robust immune response. Chronically infected hosts are asymptomatic and transmit disease to naïve hosts via fecal shedding of bacteria, thereby serving as a critical reservoir for disease. We show that the bacterial effector protei...

We have shown that Pasteurella multocida toxin (PMT) directly causes transient activation of Gqalpha protein that is coupled to phosphatidylinositol-specific phospholipase Cbeta1 in Xenopus oocytes (B. A. Wilson, X. Zhu, M. Ho, and L. Lu, J. Biol. Chem. 272:1268-1275, 1997). We found that antibodies directed against an N-terminal peptide of PMT inhibited the toxin-induced response in Xenopus oo...

PvdS is an alternative sigma factor regulated by the global iron regulator Fur. It has been demonstrated that PvdS plays a role in the iron-dependent regulation of exotoxin A (ETA) in Pseudomonas aeruginosa strain PAO1. The goals of this research were to determine if pvdS was transcribed by the bacteria in the chronic lung infections associated with cystic fibrosis (CF) and to determine how Pvd...

Race 1 isolates of the filamentous fungus Cochliobolus carbonum are exceptionally virulent on certain genotypes of maize due to production of a cyclic tetrapeptide, HC-toxin. In crosses between toxin-producing (Tox2+) and toxin-nonproducing (Tox2-) isolates, toxin production segregates in a simple 1:1 pattern, suggesting the involvement of a single genetic locus, which has been named TOX2. Earl...