| Congresso Brasileiro de Microbiologia 2023 | Resumo: 984-1 | ||||
Resumo:The toxin-antitoxin (TA) systems are genetic modules associated with some bacterial processes, such as cell formation persistence, biofilm formation, and responses to stressful environments. In these systems, the toxin is related to the inhibition of physiological processes and the antitoxin protects the cell against the toxin. The hybrid strain BA1250 (atypical enteropathogenic E. coli and extraintestinal E. coli strain) can colonize two extremely different host niches, facing unlike stress environments. Herein, after genome analysis, the role of TA type II genes as CcdB-CcdA, YhaV-PrlF, MazF-MazE, YoeB-YefM, and PasT-PasI systems were assessed in the hybrid strain BA1250 under different stress conditions by transcription analysis. Genome analysis of the BA1250 strain was performed in order to predict type II TA genes. Transcription analyses of these genes were evaluated under stress conditions such as nutritional, oxidative, osmotic, and acid; both in the log and stationary phases of the BA1250 strain. Genomic analysis revealed 21 TA loci and five TA type II systems in the chromosome. The qPCR results showed significant differences in the expression levels of the CcdB-CcdA, YhaV-PrlF, YoeB-YefM, and PasT-PasI systems. In the log phase, only the CcdB-CcdA system was up-regulated in osmotic conditions. The PasT-PasI system is up-regulated in nutritional and acid conditions in stationary phase; on the other hand, in the same conditions only the YhaV toxin expression was increased, and the expression of YoeB toxin was increased only in acid stress. These data indicate that in BA 1250 strain the CcdB-CcdA system is implicated in oxidative stress in log phase and in stationary phase the YhaV-PrlF, YoeB-YefM, and PasT-PasI systems were involved in acid and nutritional stresses. Palavras-chave: hybrid strain, gene transcription, stress conditions, toxin-antitoxin type II Agência de fomento:FAPESP | |||||