Cryptic prophages help bacteria cope with adverse environments

Phages are the most abundant entity in the biosphere and outnumber bacteria by a factor of 10. Phage DNA may also constitute 20% of bacterial genomes; however, its role is ill defined. Here, we explore the impact of cryptic prophages on cell physiology by precisely deleting all nine prophage elements (166 kbp) using Escherichia coli. We find that cryptic prophages contribute significantly to resistance to sub-lethal concentrations of quinolone and β-lactam antibiotics primarily through proteins that inhibit cell division (for example, KilR of rac and DicB of Qin). Moreover, the prophages are beneficial for withstanding osmotic, oxidative and acid stresses, for increasing growth, and for influencing biofilm formation. Prophage CPS-53 proteins YfdK, YfdO and YfdS enhanced resistance to oxidative stress, prophages e14, CPS-53 and CP4-57 increased resistance to acid, and e14 and rac proteins increased early biofilm formation. Therefore, cryptic prophages provide multiple benefits to the host for surviving adverse environmental conditions

Genomic analysis of Acinetobacter baumannii prophages reveals remarkable diversity and suggests significant impact on bacterial virulence and fitness

[Abstract] Bacterial genomics has revealed substantial amounts of prophage DNA in bacterial genomes. This integrated viral DNA has been shown to play important roles in the evolution of bacterial pathogenicity. Acinetobacter baumannii has shown a fast progression as a nosocomial multi-resistant pathogen in recent years, and is now considered one of the most dangerous microorganisms in hospital environments. The role of prophages in the evolution of A. baumannii pathogenicity has not yet been explored. In this context, we aimed at evaluating the impact of prophages on A. baumannii genomic diversity and pathogenicity. [...]info:eu-repo/semantics/publishedVersio