Most bacterial toxins derived from chromosomally encoded toxin-antitoxin (TA) systems that have been studied to date appear to protect cells from relatively short pulses of stress by triggering a reversible state of growth arrest. In contrast to many bacterial toxins that are produced as defense mechanisms and secreted from their hosts, TA toxins exert their protective effect from within the ce...

Background and Objective: Salmonella typhi is one of the major challenges for the human and animal health. Salmonella with high pathogenicity can be harmful factor for human health. The control of this pathogen is a big challenge as it can cause serious infectious diseases such as gastroenteritis, septicemia and typhoid fever. On the other side, there are many factors such as toxin-antitoxin (T...

Toxin/antitoxin (TA) systems are widespread in prokaryotic chromosomes and in mobile genetic elements including plasmids and prophages. The first characterized Type IV TA system CbtA/CbeA was found in cryptic prophage CP4-44 in Escherichia coli K-12. Two homologous TA loci of CbtA/CbeA also reside in cryptic prophages of E. coli K-12, YkfI/YafW in CP4-6 and YpjF/YfjZ in CP4-57. In this study, w...

Through the formation of persister cells, bacteria exhibit tolerance to multidrug and other environmental stresses without undergoing genetic changes. The toxin-antitoxin (TA) systems are involved in the formation of persister cells because they are able to induce cell dormancy. Among the TA systems, the MqsRA system has been observed to be highly induced in persister cells of Xylella fastidios...

Toxin-antitoxin (TA) systems are widely represented on mobile genetic elements as well as in bacterial chromosomes. TA systems encode a toxin and an antitoxin neutralizing it. We have characterized a homolog of the ccd TA system of the F plasmid (ccd(F)) located in the chromosomal backbone of the pathogenic O157:H7 Escherichia coli strain (ccd(O157)). The ccd(F) and the ccd(O157) systems coexis...

This presentation is based on joint work with F. Cassez*, S. Haddad**, D. Lime* and O. H. Roux* (*IRCCyN, Nantes and **LSV, Cachan), published in the proceedings of ATVA’05, CONCUR’05, FSTTCS’05, with an extended version of the third paper to appear in Theoretical Computer Science. The aim of this work was to compare the expressive power of Timed Automata (TA) and Time Petri Nets (TPN). Time Pe...