Salmonella plasmid virulence (spv) genes are organized into two transcriptional units: one formed by the spvR gene and the other by the spvA, spvB, spvC and spvD genes. Transcription of both units is activated by SpvR, a regulatory protein of the LysR family. The effect of RpoS, a stationary phase-associated sigma factor, on the expression of spv genes was studied using lacZ transcriptional fus...

Poliovirus initiates infection by binding to its cellular receptor (Pvr). We have studied this interaction by using cryoelectron microscopy to determine the structure, at 21-A resolution, of poliovirus complexed with a soluble form of its receptor (sPvr). This density map aided construction of a homology-based model of sPvr and, in conjunction with the known crystal structure of the virus, allo...

The spv region of Salmonella virulence plasmids is essential for the development of a systemic infection in mice. Transcriptional activation of the spvABCD operon occurs during stationary growth phase and is mediated by the regulatory gene product SpvR. We have previously shown that expression of a spvRAB'-cat fusion in Escherichia coli was dependent on the katF (rpoS) locus which encodes an al...

The spv region of the Salmonella virulence plasmids consists of five genes located on an 8-kb fragment previously shown to be essential for virulence in mice. Four structural genes, spvABCD, form an operon that is transcriptionally activated by the spvR gene product in the stationary phase of growth. The role of the individual spv genes in the virulence phenotype was tested by isolating transla...

Mutational inactivation of the cold-shock-associated exoribonuclease polynucleotide phosphorylase (PNPase; encoded by the pnp gene) in Salmonella enterica serovar Typhimurium was previously shown to enable the bacteria to cause chronic infection and to affect the bacterial replication in BALB/c mice (M. O. Clements et al., Proc. Natl. Acad. Sci. USA 99:8784-8789, 2002). Here, we report that PNP...

AIM The aim was to detect virulence gene associated with the Salmonella serovars isolated from pork and Slaughterhouse environment. MATERIALS AND METHODS Salmonella isolates (n=37) used in this study were isolated from 270 pork and slaughter house environmental samples collected from the Ahmedabad Municipal Corporation Slaughter House, Ahmedabad, Gujarat, India. Salmonella serovars were isola...

The quantity of seafood imported and produced by domestic aquaculture farming has increased. Recently, it been reported that multidrug-resistant (MDR) Salmonella Typhimurium may be associated with seafood. However, information is limited to the antimicrobial resistance, virulence properties, genetic diversity S. recovered from This study investigated isolated catfish, shrimp, tilapia. A total 1...

Salmonella infection causes a self-limiting gastroenteritis in humans but can also result in a life-threatening invasive disease, especially in old, young, and/or immunocompromised patients. The prevalence of antimicrobial and multidrug-resistant Salmonella has increased worldwide since the 1980s. However, the impact of antimicrobial resistance on the pathogenicity of Salmonella strains is not ...