Differential transcription profiling of the phage LUZ19 infection process in different growth media

RNA sequencing (RNA-seq) of phage infected bacterial cultures offers a snapshot of transcriptional events occurring during the infection process, providing insights into the phage transcriptional organization as well as the bacterial response. To better mimic real environmental contexts, we performed RNA-seq of P. aeruginosa PAO1 cultures infected with phage LUZ19 in a mammalian cell culture medium (MCCM) to better simulate a phage therapy event, and the data were compared to LB medium. Regardless of the media, phage LUZ19 induces significant transcriptional changes in the bacterial host over time, particularly during early infection (t= 5 min) and gradually shuts down bacterial transcription. In a common response in both media, 56 P. aeruginosa PAO1 genes are differentially transcribed and clustered into several functional categories such as metabolism, translation and transcription. Our data allowed us to tease apart a medium-specific response during infection from the identified infection-associated responses. This reinforces the concept that phages overtake bacterial transcriptome in a strict manner to gain control of the bacterial machinery and reallocate resources for infection, in this case overcoming the nutritional limitations of the mammalian cell culture medium. From a phage therapy perspective, this study contributes towards a better understanding of phage-host interaction in human physiological conditions and demonstrates the versatility of phage LUZ19 to adapt to different environments. Study of transcriptome from P. aeruginosa PAO1 infected with LUZ19 phage in LB and MCCM media at time points 0, 5, 10 and 15 min post-infection. Foe each time point there was triplicates. Control samples correspond to time point 0 min (uninfected cultures).