Quorum sensing (QS) systems communicate bacterial population and stimulate microbial pathogenesis through signaling molecules. Inhibition of QS signals potentially suppresses microbial infections. Antimicrobial properties of Streptomyces have been extensively studied, however, less is known about quorum sensing inhibitory (QSI) activities of Streptomyces. This study explored the QSI potential o...

BACKGROUND/AIMS Pseudomonas aeruginosa (PA) is one of the major opportunistic pathogens which can cause chronic lung infection of cystic fibrosis (CF). The formation of PA biofilm promotes CF development and restricts the antimicrobial efficacies of current antibiotics. METHODS The antimicrobial effects of azithromycin (AZM) and berberine (BER) alone and in combination were evaluated using mi...

Corticosteroid-binding globulin (CBG) is a plasma carrier of glucocorticoids. Human and rat CBGs have six N-glycosylation sites. Glycosylation of human CBG influences its steroid-binding activity, and there are N-glycosylation sites in the reactive center loops (RCLs) of human and rat CBGs. Proteolysis of the RCL of human CBG causes a structural change that disrupts steroid binding. We now show...

Our previous studies showed that surfactant protein D (SP-D) is present in human tear fluid and that it can protect corneal epithelial cells against bacterial invasion. Here we developed a novel null-infection model to test the hypothesis that SP-D contributes to the clearance of viable Pseudomonas aeruginosa from the healthy ocular surface in vivo. Healthy corneas of Black Swiss mice were inoc...

Biofilm formation and persistence are essential components for the continued survival of pathogens inside the host and constitute a major contributor to the development of chronic wounds with resistance to antimicrobial compounds. Understanding these processes is crucial for control of biofilm-mediated disease. Though chronic wound infections are often polymicrobial in nature, much of the resea...

BACKGROUND & OBJECTIVES The pathogenicity of the nosocomial pathogens, Pseudomonas aeruginosa and Acinetobacter baumannii is regulated by their quorum sensing (QS) systems. The objective of the present study was to examine the effect of the cold ethyl acetate extract of Tinospora cordifolia stem on virulence and biofilm development in the wild type and clinical strains of P. aeruginosa and A. b...

Septal necrosis + peripheral left blocks. Because of an extensive septal necrosis, the manifestation of the initial ventricular activation forces decreases in the precordial leads. With left bifascicular block (LASB + LPSB), the first ventricular activation forces become more evident and the electrical signs of septal necrosis can be concealed. In the presence of a trifascicular block, manifest...

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...

N-acylhomoserine lactone (AHL)-mediated quorum-sensing (QS) regulates virulence functions in plant and animal pathogens such as Agrobacterium tumefaciens and Pseudomonas aeruginosa. A chemolibrary of more than 3500 compounds was screened using two bacterial AHL-biosensors to identify QS-inhibitors (QSIs). The purity and structure of 15 QSIs selected through this screening were verified using HP...