Interspecific small molecule interactions between clinical isolates of Pseudomonas aeruginosa and Staphylococcus aureus from adult cystic fibrosis patients.
Pseudomonas aeruginosa and Staphylococcus aureus are the most prevalent pathogens in airway infections of cystic fibrosis (CF) patients. We studied how these pathogens coexist and interact with each other. Clinical isolates of both species were retrieved from adult CF patients. Culture supernatants from 63 P. aeruginosa isolates triggered a wide range of biofilm-stimulatory activities when added to the culture of a control S. aureus strain. The extent of biofilm formation by S. aureus was positively correlated to the levels of the 2-alkyl-4-(1H)-quinolones (AQs) Pseudomonas Quinolone Signal (PQS) and 2-heptyl-4-hydroxy quinoline N-oxide (HQNO) produced by the P. aeruginosa isolates. Supernatants from P. aeruginosa isogenic mutants deficient in PQS and HQNO production stimulated significantly less biofilm formation by S. aureus than that seen with the parental strain PA14. When studying co-isolated pairs of P. aeruginosa and S. aureus retrieved from patients showing both pathogens, P. aeruginosa supernatants stimulated less biofilm production by the S. aureus counterparts compared to that observed using the control S. aureus strain. Accordingly, some P. aeruginosa isolates produced low levels of exoproducts and also some of the clinical S. aureus isolates were not stimulated by their co-isolates or by PA14 despite adequate production of HQNO. This suggests that colonization of the CF lungs promotes some type of strain selection, or that co-existence requires specific adaptations by either or both pathogens. Results provide insights on bacterial interactions in CF.
Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Alexandre
A
Fugère
Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
David
D
Lalonde Séguin
Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Gabriel
G
Mitchell
INRS-Institut Armand-Frappier, Laval, Quebec, Canada.
Eric
E
Déziel
INRS-Institut Armand-Frappier, Laval, Quebec, Canada.
Valérie
V
Dekimpe
Service de pneumologie, Département de médecine, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
André M
AM
Cantin
Département de microbiologie et d'infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Eric
E
Frost
Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
François
F
Malouin
D000293:Adolescent; D000328:Adult; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002853:Chromatography, Liquid; D003550:Cystic Fibrosis / Q000150:complications / Q000378:metabolism / Q000382:microbiology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D056265:Microbial Interactions / Q000187:drug effects*; D011552:Pseudomonas Infections / Q000150:complications / Q000378:metabolism / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification* / Q000502:physiology; D015363:Quinolones / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013203:Staphylococcal Infections / Q000150:complications / Q000378:metabolism / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D055815:Young Adult
D015363:Quinolones