Many eubacteria are resistant to the toxic oxidizing agent potassium tellurite, and tellurite resistance involves diverse biochemical mechanisms. Expression of the iscS gene from Geobacillus stearothermophilus V, which is naturally resistant to tellurite, confers tellurite resistance in Escherichia coli K-12, which is naturally sensitive to tellurite. The G. stearothermophilus iscS gene encodes...

Tellurite containing compounds are in use for industrial processes and increasing delivery into the environment generates specific pollution that may well result in contamination and subsequent potential adverse effects on public health. It was the aim of the current study to reveal mechanism of toxicity in tellurite-sensitive and tellurite-resistant E. coli at the protein level. In this work a...

Tellurite (TeO3(2-)) is highly toxic to most microorganisms. The mechanisms of toxicity or resistance are poorly understood. It has been shown that tellurite rapidly depletes the reduced thiol content within wild-type Escherichia coli. We have shown that the presence of plasmid-borne tellurite-resistance determinants protects against general thiol oxidation by tellurite. In the present study we...

Potassium tellurite (K2TeO3) was found to be a potent antisickling agent that inhibited red cell sickling at concentrations less than 10 mumol/L. The inhibitory effect depended on the incubation time, with the effect increasing with longer incubation periods. Because tellurite causes swelling of red cells, and because the antisickling effect of tellurite correlated with the degree of red cell s...

Several transporters suspected to be involved in tellurite uptake in Escherichia coli were analyzed. Results showed that the PitA phosphate transporter was related to tellurite uptake. Escherichia coli ΔpitA was approximately four-fold more tolerant to tellurite, and cell viability remained almost unchanged during prolonged exposure to the toxicant as compared with wild type or ΔpitB cells. Not...

Seven species of obligately aerobic photosynthetic bacteria of the genera Erythromicrobium, Erythrobacter, and Roseococcus demonstrated high-level resistance to tellurite and accumulation of metallic tellurium crystals. High-level resistance without tellurite reduction was observed for Roseococcus thiosulfatophilus and Erythromicrobium ezovicum grown with certain organic carbon sources, implyin...

Corynebacterium vaginale (Haemophilus vaginalis) does not reduce potassium tellurite. When a 1% aqueous solution of tellurite is added to starch agar plates previously inoculated with vaginal discharge material, other starch-fermenting and most non-starch-fermenting bacteria rapidly reduce tellurite to produce black or gray colonies. This test is a useful adjunct to methods for rapid presumptiv...

The metalloid tellurite is highly toxic to microorganisms. Several mechanisms of action have been proposed, including thiol depletion and generation of hydrogen peroxide and superoxide, but none of them can fully explain its toxicity. Here we use a combination of directed evolution and chemical and biochemical approaches to demonstrate that tellurite inhibits heme biosynthesis, leading to the a...

The oxyanion of tellurium, tellurite (TeO3(2-)), is toxic to most micro-organisms, particularly gram-negative bacteria. The mechanism of tellurite toxicity is presently unknown. Many heavy metals and oxyanions, including tellurite, interact with reduced thiols (RSH). To determine if tellurite interaction with RSH groups is involved in the toxicity mechanism, the RSH content of Escherichia coli ...

BACKGROUND Yersinia pestis initiates infection by parasitism of host macrophages. In response to macrophage infections, intracellular Y. pestis can assume a filamentous cellular morphology which may mediate resistance to host cell innate immune responses. We previously observed the expression of Y. pestis tellurite resistance proteins TerD and TerE from the terZABCDE operon during macrophage in...