Simple Sequence Repeats Together with Mismatch Repair Deficiency Can Bias Mutagenic Pathways in Pseudomonas aeruginosa during Chronic Lung Infection

MOYANO AJ; FELIZIANI S; DI RIENZO JA; SMANIA AM

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2013 vol. 8 p. 80514 - 80514

1932-6203

seudomonas aeruginosa is an opportunistic pathogen that chronically infects the airways of cystic fibrosis (CF) patients and undergoes a process of genetic adaptation based on mutagenesis. We evaluated the role of mononucleotide G:C and A:T simple sequence repeats (SSRs) in this adaptive process. An in silico survey of the genome sequences of 7 P. aeruginosa strains showed that mononucleotide G:C SSRs but not A:T SSRs were greatly under-represented in coding regions, suggesting a strong counterselection process for G:C SSRs with lengths .5 bp but not for A:T SSRs. A meta-analysis of published whole genome sequence data for a P. aeruginosa strain from a CF patient with chronic airway infection showed that G:C SSRs but not A:T SSRs were frequently mutated during the infection process through the insertion or deletion of one or more SSR subunits. The mutation tendency of G:C SSRs was length-dependent and increased exponentially as a function of SSR length. When this strain naturally be