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The ability of soil bacteria to successfully compete with a range of other microbial species is crucial for their growth and survival in the nutrient-limited soil environment. In the present work, we studied the behavior and transcriptional responses of soil-inhabiting Pseudomonas fluorescens strain Pf0-1 on nutrient-poor agar to confrontation with strains of three phylogenetically different bacterial genera, that is, Bacillus, Brevundimonas and Pedobacter. Competition for nutrients was apparent as all three bacterial genera had a negative effect on the density of P. fluorescens Pf0-1; this effect was most strong during the interaction with Bacillus. Microarray-based analyses indicated strong differences in the transcriptional responses of Pf0-1 to the different competitors. There was higher similarity in the gene expression response of P. fluorescens Pf0-1 to the Gram-negative bacteria as compared with the Gram-positive strain. The Gram-negative strains did also trigger the production of an unknown broad-spectrum antibiotic in Pf0-1. More detailed analysis indicated that expression of specific Pf0-1 genes involved in signal transduction and secondary metabolite production was strongly affected by the competitors' identity, suggesting that Pf0-1 can distinguish among different competitors and fine-tune its competitive strategies. The results presented here demonstrate that P. fluorescens Pf0-1 shows a species-specific transcriptional and metabolic response to bacterial competitors and provide new leads in the identification of specific cues in bacteria-bacteria interactions and of novel competitive strategies, antimicrobial traits and genes. [ABSTRACT FROM AUTHOR]

The optimism of the early period of antimicrobial discovery has been tempered by the emergence of bacterial strains with resistance to these therapeutics. Today, clinically important bacteria are characterized not only by single drug resistance but also by multiple antibiotic resistance-the legacy of past decades of antimicrobial use and misuse. Drug resistance presents an ever-increasing global public health threat that involves all major microbial pathogens and antimicrobial drugs. [ABSTRACT FROM AUTHOR]

MarR is a regulator of multiple antibiotic resistance in Escherichia coli. It is the prototypical member of the MarR family of regulatory proteins found in bacteria and archaea that play important roles in the development of antibiotic resistance, a global health problem. Here we describe the crystal structure of the MarR protein, determined at a resolution of 2.3 Å. This is the first reported crystal structure of a member of this newly-described protein family. The structure shows MarR as a dimer with each subunit containing a winged-helix DNA binding motif. [ABSTRACT FROM AUTHOR]

The authors discuss the move of the U.S. National Science Advisory Board for Biosecurity to explain its recommendations on the communication of experimental work on H5N1 influenza. They mentions that highly pathogenic avian influenza A infection has been a serious public health concern since its identification in Asia. The state that to date, no human pandemic has occurred.

Focuses on triclosan. Use as an anti-bacterial and anti-fungal agent; Experiments with five independent triclosan-resistant mutants of E. coli K12 strain; Results; Effect of ethanol and diazaborine; Use in inhibiting E. coli and Salmonella typhimurium; The most resistant triclosan mutant.