Burkholderia spp. Alter Pseudomonas aeruginosa Physiology through Iron Sequestration

Abstract

Pseudomonas aeruginosa and members of the Burkholderia cepacia complex often coexist in both the soil and the lungs of cystic fibrosis patients. To gain an understanding of how these different species affect each other's physiology when coexisting, we performed a screen to identify P. aeruginosa genes that are induced in the presence of Burkholderia. A random gene fusion library was constructed in P. aeruginosa PA14 by using a transposon containing a promoterless lacZ gene. Fusion strains were screened for their ability to be induced in the presence of Burkholderia strains in a cross-streak assay. Three fusion strains were induced specifically by Burkholderia species; all three had transposon insertions in genes known to be iron regulated. One of these fusion strains, containing a transposon insertion in gene PA4467, was used to characterize the inducing activity from Burkholderia. Biochemical and genetic evidence demonstrate that ornibactin, a siderophore produced by nearly all B. cepacia strains, can induce P. aeruginosa PA4467. Significantly, PA4467 is induced early in coculture with an ornibactin-producing but not an ornibactin-deficient B. cepacia strain, indicating that ornibactin can be produced by B. cepacia and detected by P. aeruginosa when the two species coexist.

Iron acquisition in the cystic fibrosis lung and potential for novel therapeutic strategies

“…Consistent with those data, we have recently demonstrated that pyoverdine from P. aeruginosa increases the expression of ornibactin synthesis genes by Burkholderia cenocepacia with a concomitant inhibition of growth (Tyrrell et al, 2015). Conversely, Weaver & Kolter (2004) demonstrated using microarray analysis that Burkholderia-conditioned medium and ornibactin induced genes involved in iron regulation in P. aeruginosa strains. However, P. aeruginosa is unable to utilize ornibactin for iron acquisition (Weaver & Kolter, 2004).…”

“…Conversely, Weaver & Kolter (2004) demonstrated using microarray analysis that Burkholderia-conditioned medium and ornibactin induced genes involved in iron regulation in P. aeruginosa strains. However, P. aeruginosa is unable to utilize ornibactin for iron acquisition (Weaver & Kolter, 2004). Bakkal et al (2010) have reported that bacteriocins produced by Pseudomonas and Burkholderia strains have intra-and interspecies bacteriocin-like inhibition ability within the CF lung (Bakkal et al, 2010).…”

Outcome and Prevention of Pseudomonas aeruginosa-Staphylococcus aureus Interactions During Pulmonary Infections in Cystic Fibrosis

“…Accordingly, and as previously underlined, infections of the CF airways is highly polymicrobic and there is growing evidence that many of these microorganisms interact (Sibley & Surette, 2011) as observed between P. aeruginosa and S. aureus (Biswas et al, 2009;Hoffman et al, 2006;Mitchell et al, 2010b;Qazi et al, 2006;Yang et al, 2011), P. aeruginosa and Burkholderia spp. (Bakkal et al, 2010;Chattoraj et al, 2010;Riedel et al, 2001;Weaver & Kolter, 2004), P. aeruginosa and S. maltophilia , P. aeruginosa and C. albicans (McAlester et al, 2008), and more generally with a large proportion of the organisms found in the CF airways (Duan et al, 2003;Sibley et al, 2008).…”

Enzymatic resistance to the lipopeptide surfactin as identified through imaging mass spectrometry of bacterial competition

“…antibiotic resistance | microbial ecology | secondary metabolism | surfactant C ompetition among bacterial species involves the exchange of natural product metabolites, including antibiotics, signals, and toxins (1)(2)(3)(4)(5)(6). Natural products benefit producing bacteria through signaling and inhibitory functions toward competitor bacteria (7)(8)(9).…”