Poster abstracts

Poster number 12 submitted by Marissa Gittrich

Insights into P. aeruginosa phage infection using RB-TnSeq

Marissa R. Gittrich (Department of Microbiology, The Ohio State University, Columbus, OH, USA.), Courtney Sanderson (Department of Microbiology, The Ohio State University, Columbus, OH, USA.), Jonathan Leopold (Department of Microbiology, The Ohio State University, Columbus, OH, USA.), Cara Noel (Department of Microbiology, The Ohio State University, Columbus, OH, USA.), Vivek K. Mutalik (Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America)

Abstract:
Pseudomonas aeruginosa causes an estimated 32,600 multi-drug resistant infections in hospitalized patients yearly and is categorized as a serious threat by the CDC due to intrinsic and acquired resistance to many current antibiotics. Due to this resistance, there have been studies into other antimicrobials, including phages viruses that infect bacteria, to treat bacterial infections. For a phage to successfully infect a host, the phage must enter the host and modify the host metabolism. Due to the phage reliance on the host, the bacteria can rapidly develop phage resistance by mutation of host genes necessary for the phage. There have been many studies testing the therapeutic capabilities of various Pseudomonas phages, but little is known about the host genes required by many Pseudomonas phages beyond receptor genes. To rapidly and comprehensively identify host factors involved in phage infection, we used random barcode transposon site sequencing (RB-TnSeq) to generate a 3000 mutant genome-wide loss-of-function transposon library in Pseudomonas aeruginosa PAO1. We challenged this library with two well-characterized Pseudomonas phages, phiKZ and LUZ19, at MOIs ranging from 10 to 0.01. Using RB-TnSeq, we confirmed receptors and a gene that increased mucoid production previously shown to confer resistance to the phages as well as additional host factors formerly not known to be involved in phage infection. This library will allow us to expand our knowledge on the dynamics of phage-host interactions that can then be applied to guide phage therapeutics.

Keywords: Phages, P aeruginosa, RB-TnSeq