Synthetic cystic fibrosis sputum medium diminishes Burkholderia cenocepacia antifungal activity against Aspergillus fumigatus independently of phenylacetic acid production.
Phenylacetic acid (PAA), an intermediate of phenylalanine degradation, is emerging as a signal molecule in microbial interactions with the host. In this work, we explore the presence of phenylalanine and PAA catabolism in 3 microbial pathogens of the cystic fibrosis (CF) lung microbiome: Pseudomonas aeruginosa, Burkholderia cenocepacia, and Aspergillus fumigatus. While in silico analysis of B. cenocepacia J2315 and A. fumigatus Af293 genome sequences showed complete pathways from phenylalanine to PAA, the P. aeruginosa PAO1 genome lacked several coding genes for phenylalanine and PAA catabolic enzymes. High-performance liquid chromatography analysis of supernatants from B. cenocepacia K56-2 detected PAA when grown in Luria-Bertani medium but not in synthetic cystic fibrosis sputum medium (SCFM). However, we were unable to identify PAA production by A. fumigatus or P. aeruginosa in any of the conditions tested. The inhibitory effect of B. cenocepacia on A. fumigatus growth was evaluated using agar plate interaction assays. Inhibition of fungal growth by B. cenocepacia was lessened in SCFM but this effect was not dependent on bacterial production of PAA. In summary, while we demonstrated PAA production by B. cenocepacia, we were not able to link this metabolite with the B. cenocepacia - A. fumigatus microbial interaction in CF nutritional conditions.
a Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Tasia Joy
TJ
Lightly
a Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Ryan R
RR
Phung
b Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
John L
JL
Sorensen
a Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.|c Department of Medical Microbiology & Infectious Disease, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
Silvia T
ST
Cardona
D000935:Antifungal Agents / Q000378:metabolism; D001232:Aspergillus fumigatus / Q000187:drug effects / Q000235:genetics; D001483:Base Sequence; D019121:Burkholderia Infections / Q000382:microbiology; D057508:Burkholderia cenocepacia / Q000187:drug effects* / Q000502:physiology; D003470:Culture Media / Q000138:chemical synthesis; D003550:Cystic Fibrosis / Q000382:microbiology; D006801:Humans; D010648:Phenylacetates / Q000378:metabolism / Q000494:pharmacology; D010649:Phenylalanine / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000235:genetics; D013183:Sputum / Q000737:chemistry*
D000935:Antifungal Agents; D003470:Culture Media; D010648:Phenylacetates; D010649:Phenylalanine; C025136:phenylacetic acid
Aspergillus fumigatus; Burkholderia cenocepacia; Pseudomonas aeruginosa; acide phénylacétique; cystic fibrosis; fibrose kystique; phenylacetic acid