Lipoteichoic acid (LTA), a glycerol phosphate polymer, is a component of the envelope of Gram-positive bacteria that has hitherto not been identified in Bacillus anthracis, the causative agent of anthrax. LTA synthesis in Staphylococcus aureus and other microbes is catalyzed by the product of the ltaS gene, a membrane protein that polymerizes polyglycerol phosphate from phosphatidyl glycerol. H...

Anthrax is a potentially fatal disease resulting from infection with Bacillus anthracis. The outcome of infection is influenced by pathogen-encoded virulence factors such as lethal toxin (LT), as well as by genetic variation within the host. To identify host genes controlling susceptibility to anthrax, a library of congenic mice consisting of strains with homozygous chromosomal segments from th...

OBJECTIVES To determine the susceptibility of southern African strains of Bacillus anthracis to new, investigational agents as well as conventional antibiotics. MATERIALS AND METHODS The MICs of 26 isolates of B. anthracis from South Africa and Zimbabwe, as well as the Sterne vaccine strain and a type culture strain, were determined by agar dilution. RESULTS The most active antimicrobial ag...

We report a highly sensitive, rapid and reliable method for the detection of Bacillus Anthracis spores at 300/mL using a piezoelectric-excited millimeter-sized cantilever (PEMC) sensor. Antibody specific to Bacillus anthracis (BA, Sterne strain 7702) spores was immobilized on PEMC sensors, and exposed to spores (300 to 3x10 spores/mL). The resonant frequency decreased at a rate proportional to ...

Bacillus cereus G9241 was isolated from a welder with a pulmonary anthrax-like illness. The organism contains two megaplasmids, pBCXO1 and pBC218. These plasmids are analogous to the Bacillus anthracis Ames plasmids pXO1 and pXO2 that encode anthrax toxins and capsule, respectively. Here we evaluated the virulence of B. cereus G9241 as well as the contributions of pBCXO1 and pBC218 to virulence...

The efficacy of passive immunization as a postexposure prophylactic measure for treatment of guinea pigs intranasally infected with Bacillus anthracis spores was evaluated. Antisera directed either against the lethal toxin components (PA or LF) or against a toxinogenic strain (Sterne) were used for this evaluation. All antisera exhibited high enzyme-linked immunosorbent assay titers against the...

BACKGROUND Bacillus anthracis produces two catecholate siderophores, petrobactin and bacillibactin, under iron-limited conditions. Here, we investigate how variable iron and oxygen concentrations influence the biosynthetic output of both siderophores in B. anthracis. In addition, we describe the differential levels of transcription of select genes within the B. anthracis siderophore biosyntheti...

Density-dependent gene expression, quorum sensing (QS), involves the synthesis and detection of low-molecular-weight molecules known as autoinducers. Inhibitors of bacterial QS systems offer potential treatment of infections with highly virulent or multidrug-resistant agents. We studied the effects on Bacillus anthracis growth and the virulence gene (pagA, lef, and cya) expression of the QS inh...

The Bacillus anthracis toxinogenic Sterne strain is currently used as a live veterinary vaccine against anthrax. The capacity of a toxin-deficient derivative strain to produce a heterologous antigen by using the strong inducible promoter of the B. anthracis pag gene was investigated. The expression of the foreign gene ibp, encoding the Ib component of iota toxin from Clostridium perfringens, wa...