Utility of in vivo transcription profiling for identifying Pseudomonas aeruginosa genes needed for gastrointestinal colonization and dissemination

TY - JOUR

T1 - Utility of in vivo transcription profiling for identifying Pseudomonas aeruginosa genes needed for gastrointestinal colonization and dissemination

AU - Koh, Andrew Y

AU - Mikkelsen, Per J

AU - Smith, Roger S

AU - Coggshall, Kathleen T

AU - Kamei, Akinobu

AU - Givskov, Michael

AU - Lory, Stephen

AU - Pier, Gerald B

PY - 2010/12/1

Y1 - 2010/12/1

N2 - Microarray analysis of Pseudomonas aeruginosa mRNA transcripts expressed in vivo during animal infection has not been previously used to investigate potential virulence factors needed in this setting. We compared mRNA expression in bacterial cells recovered from the gastrointestinal (GI) tracts of P. aeruginosa-colonized mice to that of P. aeruginosa in the drinking water used to colonize the mice. Genes associated with biofilm formation and type III secretion (T3SS) had markedly increased expression in the GI tract. A non-redundant transposon library in P. aeruginosa strain PA14 was used to test mutants in genes identified as having increased transcription during in vivo colonization. All of the Tn-library mutants in biofilm-associated genes had an attenuated ability to form biofilms in vitro, but there were no significant differences in GI colonization and dissemination between these mutants and WT P. aeruginosa PA14. To evaluate T3SS factors, we tested GI colonization and neutropenia-induced dissemination of both deletional (PAO1 and PAK) and insertional (PA14) mutants in four genes in the P. aeruginosa T3SS, exoS or exoU, exoT, and popB. There were no significant differences in GI colonization among these mutant strains and their WT counterparts, whereas rates of survival following dissemination were significantly decreased in mice infected by the T3SS mutant strains. However, there was a variable, strain-dependent effect on overall survival between parental and T3SS mutants. Thus, increased transcription of genes during in vivo murine GI colonization is not predictive of an essential role for the gene product in either colonization or overall survival following induction of neutropenia.

AB - Microarray analysis of Pseudomonas aeruginosa mRNA transcripts expressed in vivo during animal infection has not been previously used to investigate potential virulence factors needed in this setting. We compared mRNA expression in bacterial cells recovered from the gastrointestinal (GI) tracts of P. aeruginosa-colonized mice to that of P. aeruginosa in the drinking water used to colonize the mice. Genes associated with biofilm formation and type III secretion (T3SS) had markedly increased expression in the GI tract. A non-redundant transposon library in P. aeruginosa strain PA14 was used to test mutants in genes identified as having increased transcription during in vivo colonization. All of the Tn-library mutants in biofilm-associated genes had an attenuated ability to form biofilms in vitro, but there were no significant differences in GI colonization and dissemination between these mutants and WT P. aeruginosa PA14. To evaluate T3SS factors, we tested GI colonization and neutropenia-induced dissemination of both deletional (PAO1 and PAK) and insertional (PA14) mutants in four genes in the P. aeruginosa T3SS, exoS or exoU, exoT, and popB. There were no significant differences in GI colonization among these mutant strains and their WT counterparts, whereas rates of survival following dissemination were significantly decreased in mice infected by the T3SS mutant strains. However, there was a variable, strain-dependent effect on overall survival between parental and T3SS mutants. Thus, increased transcription of genes during in vivo murine GI colonization is not predictive of an essential role for the gene product in either colonization or overall survival following induction of neutropenia.

KW - Animals

KW - Antibodies, Monoclonal

KW - Biofilms

KW - Gastrointestinal Tract

KW - Gene Expression Profiling

KW - Mice

KW - Mice, Inbred C3H

KW - Mutation

KW - Neutropenia

KW - Nucleic Acid Hybridization

KW - Polymerase Chain Reaction

KW - Pseudomonas Infections

KW - Pseudomonas aeruginosa

KW - Transcription, Genetic

KW - Virulence Factors

U2 - 10.1371/journal.pone.0015131

DO - 10.1371/journal.pone.0015131

M3 - Journal article

C2 - 21170272

SN - 1932-6203

VL - 5

SP - e15131

JO - P L o S One

JF - P L o S One

IS - 12

ER -