The spoOJ gene of BaciUlus subtilis is required for the initiation of sporulation. We show that the sporulation defect caused by null mutations in spoOJ is suppressed by a null mutation in the gene located directly upstream from spoOJ, soj (suppressor of spoOJ). These results indicate that Soj inhibits the initiation of sporulation and that SpoOJ antagonizes that inhibition. Further genetic experiments indicated that Soj ultimately affects sporulation by inhibiting the activation (phosphorylation) of the developmental transcription factor encoded by spoOA. In addition, the temperature-sensitive sporulation phenotpe caused by the fts4279 (spoIIN279) mutation was partly suppressed by the soj null mutation, indicating that FtsA might also affect the activity of Soj. Soj and SpoOJ are known to be similar in sequence to a family of proteins involved in plasmid partitioning, including ParA and ParB of prophage P1, SopA and SopB of F, and IncC and KorB of RK2. spoOJ was found to be required for normal chromosome partitioning as well as for sporulation. spoOJ null mutants produced a significant proportion of anucleate cells during vegetative growth. The dual functions of SpoOJ could provide a mechanism for regulating the initiation of sporulation in response to activity of the chromosome partition machinery.The generation of new cells during growth or development requires proper replication, repair, and segregation of chromosomes. Conditions that perturb chromosome replication or damage DNA often inhibit cell cycle progression or development through checkpoint mechanisms. Such regulatory mechanisms are present in organisms as diverse as bacteria, yeasts, and mammals and act to prevent the unproductive formation of cells lacking intact chromosomes.Spore formation by the gram-positive bacterium Bacillus subtilis is a developmental process requiring two different cell types. Each cell type has an intact chromosome and a characteristic and distinct pattern of gene expression. The two cell types are created by formation of an asymmetric division septum early during development. The smaller cell, known as the forespore, develops into the mature spore while enclosed in the larger mother cell (30).One of the most important early events necessary for the initiation of sporulation is the activation of the developmental transcription factor encoded by spoOA. SpoOA is activated by phosphorylation, and SpoOA-P induces expression of several genes, including spoIL4, spoIIE, and spoIIG (4,6,46,47,55,58) that are essential for sporulation and the establishment of cell type-specific gene expression (30). Phosphorylation of SpoOA requires histidine protein kinases, i.e., KinA, -B, and -C (2, 27, 38, 56), and two phospho-transfer proteins, SpoOF and SpoOB (7). The histidine protein kinases autophosphorylate on a histidine residue, and phosphate is transferred to SpoOF, and then from

Extraintestinal pathogenic Escherichia coli (ExPEC) possesses virulence traits that allow it to invade, colonize, and induce disease in bodily sites outside of the gastrointestinal tract. Human diseases caused by ExPEC include urinary tract infections, neonatal meningitis, sepsis, pneumonia, surgical site infections, as well as infections in other extraintestinal locations. ExPEC-induced diseases represent a large burden in terms of medical costs and productivity losses. In addition to human illnesses, ExPEC strains also cause extraintestinal infections in domestic animals and pets. A commonality of virulence factors has been demonstrated between human and animal ExPEC, suggesting that the organisms are zoonotic pathogens. ExPEC strains have been isolated from food products, in particular from raw meats and poultry, indicating that these organisms potentially represent a new class of foodborne pathogens. This review discusses various aspects of ExPEC, including its presence in food products, in animals used for food or as companion pets; the diseases ExPEC can cause; and the virulence factors and virulence mechanisms that cause disease.

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