Gene expression characteristics of a cystic fibrosis epidemic strain of Pseudomonas aeruginosa during biofilm and planktonic growth.
Epidemic Pseudomonas aeruginosa have been identified in cystic fibrosis (CF) patients worldwide. The Australian Epidemic Strain-2 (AES-2) infects up to 40% of patients in three eastern Australian CF clinics. To investigate whether AES-2 isolates from chronically infected CF adults differentially express well-conserved genes potentially associated with transmissibility, we compared the transcriptomes of planktonic and biofilm-grown AES-2, infrequent P. aeruginosa clones and the reference P. aeruginosa PAO1 using the Affymetrix PAO1 array. The most interesting findings emerged from comparisons of planktonic and biofilm AES-2. AES-2 biofilms upregulated Type III secretion system genes, but downregulated quorum-sensing (QS)-regulatory genes, except lasR, QS-regulated, oxidative-stress and iron-storage genes. QS-regulated and iron-storage genes were downregulated to a greater extent in AES-2 biofilms compared with infrequent clone and PAO1 biofilms, suggesting enhanced anaerobic respiration in AES-2. Chitinase and chitin-binding protein maintained high expression in AES-2 biofilms compared with infrequent clone and PAO1 biofilms. Planktonic AES-2 upregulated QS regulators and QS-regulated genes, iron acquisition and aerobic respiration genes, and had high expression of Group III Type IV pilA compared with low expression of Group I Type IV pilA in infrequent clones. Together, these properties may enhance long-term survival of AES-2 in CF lung and contribute to its transmissibility.
Manos
Jim
J
Department of Infectious Diseases and Immunology, University of Sydney, Sydney, NSW, Australia. jmanos@infdis.usyd.edu.au
Arthur
Jonathan
J
Rose
Barbara
B
Bell
Scott
S
Tingpej
Pholawat
P
Hu
Honghua
H
Webb
Jeremy
J
Kjelleberg
Staffan
S
Gorrell
Mark Douglas
MD
Bye
Peter
P
Harbour
Colin
C
D000328:Adult; D000693:Anaerobiosis; D018441:Biofilms / Q000254:growth & development*; D003550:Cystic Fibrosis / Q000382:microbiology; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D053858:Metabolic Networks and Pathways / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000254:growth & development* / Q000302:isolation & purification / Q000502:physiology; D055815:Young Adult