BioProject

Phages have emerged as prime suspects in the adaptation of pathogens to new hosts and the emergence of new pathogens or epidemic clones. More...

Phages have emerged as prime suspects in the adaptation of pathogens to new hosts and the emergence of new pathogens or epidemic clones. Here we describe the genomic features of two related prophages (Ab105-1Ø and Ab105-2Ø) present in the ST-2 epidemic clone of Acinetobacter baumannii clinical strain Ab105_GEIH-2010 and not present in genetically related Ab155_GEIH-2000 strain isolated 10 years before. The Quasicore genome of Ab105-1Ø and Ab105-2Ø prophages revealed genes that promote bacterial-host fitness. The results of microarray analysis under stress conditions, SOS response activation revealed 5% and 30% of genes expressed by Ab105-1Ø and Ab105-2Ø prophages (which produce bacterial lysis) in the first case and underexpression of these genes from prophages in the second case. Hence, the QS system plays a major role in the evolution of phages in their natural hosts and environments. Interestingly, in host-virus interactions, RT-PCR showed several mechanisms of overexpression of the SOS response in relation to phage defence mechanisms: i) SAM or AdoMet-MTase (methyltransferases) and MazG protein (pyrophosphohydrolase) associated with phage defence in response to bacterial attack; ii) eukaryotic-like protein kinase (glutamate 5-kinase) associated with prevention of secondary infection by the same or a closely related virus. Overexpression of secretory virulence factors such as oxidoreductase (DsbA-like), anfo-nitrogenase and chromosome segregation proteins were also observed. In conclusion, study of the co-evolution of phages (virus) and bacteria may be essential in the search for means of combatting multi-resistant epidemic clones. Overall design: Three replicates from RNA of the Ab105_GEIH-2010 strain x1 condition (SOS response by Mitomycin). Less...