A gene homologous to rpoS was cloned from a fatal human pathogen, Vibrio vulnificus. The functional role of rpoS in V. vulnificus was accessed by using an rpoS knockout mutant strain. This mutant was impaired in terms of the ability to survive under oxidative stress, nutrient starvation, UV irradiation, or acidic conditions. The increased susceptibility of the V. vulnificus mutant in the expone...

A system for the tetracycline-inducible regulation of gene expression in mycobacteria has been developed. We have sub-cloned the tetRO region from the Corynebacterium glutamicum TetZ locus into a mycobacterial shuttle plasmid, making expression of genes cloned downstream of tetRO responsive to tetracycline. Using the luxAB-encoded luciferase from Vibrio harveyi as a reporter (pMind-Lx), we obse...

To show, as a model system, that mycobacteria can express heterologous luciferase genes and that bioluminescence can be a rapid method of measuring antimycobacterial activity, a bioluminescent form of Mycobacterium smegmatis was made by transformation with a Mycobacterium-Escherichia coli shuttle vector containing the luxAB genes from Vibrio harveyi. The antimycobacterial effects of antibiotics...

Yersinia pestis is a tier 1 agent due to its contagious pneumopathogenicity, extremely rapid progression, and high mortality rate. As the disease is usually fatal without appropriate therapy, rapid detection from clinical matrices is critical to patient outcomes. We previously engineered the diagnostic phage ΦA1122 with luxAB to create a "light-tagged" reporter phage. ΦA1122::luxAB rapidly dete...

Our understanding of staphylococcal pathogenesis depends on reliable genetic tools for gene expression analysis and tracing of bacteria. Here, we have developed and evaluated a series of novel versatile Escherichia coli-staphylococcal shuttle vectors based on PCR-generated interchangeable cassettes. Advantages of our module system include the use of (i) staphylococcal low-copy-number, high-copy...

Streptomyces clavuligerus ATCC 27064 and S. clavuligerus ΔccaR::tsr cultures were grown in asparagine-starch medium, and samples were taken in the exponential and stationary growth phases. Transcriptomic analysis showed that the expression of 186 genes was altered in the ccaR-deleted mutant. These genes belong to the cephamycin C gene cluster, clavulanic acid gene cluster, clavams, holomycin, d...

The regulation of the nutrient-deprivation-induced Sinorhizobium meliloti homogentisate dioxygenase (hmgA) gene, involved in tyrosine degradation, was examined. hmgA expression was found to be independent of the canonical nitrogen regulation (ntr) system. To identify regulators of hmgA, secondary mutagenesis of an S. meliloti strain harboring a hmgA-luxAB reporter gene fusion (N4) was carried o...

Horizontal gene transfer plays a significant role in bacterial evolution and has major clinical importance. Thus, it is vital to understand the mechanisms and kinetics of genetic transformations. Natural transformation is the driving mechanism for horizontal gene transfer in diverse genera of bacteria. Our study introduces a simple and rapid method for the investigation of natural transformatio...

Five transcriptional promoters of biphenyl-degradation genes in Rhodococcus sp. RHA1 were characterized. We newly identified the etbA4 promoter region, which was located adjacent upstream from a ferredoxin reductase gene, etbA4 and a dihydrodiol dehydrogenase gene, bphB2. The etbA4 promoter activity was determined in RHA1 using a promoter probe vector with a luxAB luciferase reporter gene, and ...

In this paper we describe construction of a luciferase-based vector, pPL2lux, and use of this vector to study gene expression in Listeria monocytogenes. pPL2lux is a derivative of the listerial integration vector pPL2 and harbors a synthetic luxABCDE operon encoding a fatty acid reductase complex (LuxCDE) involved in synthesis of the fatty aldehyde substrate for the bioluminescence reaction cat...