CF-associated AES-1R was the only strain with detectable flagellin in the protein extracts analysed by 2-DE. AES-1R FliC has significant protein
sequence HDAC inhibitors list differences compared with PAO1 and PA14, and has greater sequence similarity with the type A flagellin of strain PAK (Additional file 5). Increased flagellin in AES-1R is consistent with our phenotypic data for swimming motility and with previous work showing AES-1 isolates displayed greater motility than non-clonal CF isolates [59]. Several differences in the OMP profile of AES-1R were observed. The loss of OprD in AES-1R is characteristic of carbapenem antibiotic resistance [60]. Decreased OprG expression was originally associated with selleck compound increased fluoroquinolone resistance [61], however a recent study showed no significant difference in the antibiotic susceptibility profile of an oprG-deficient strain [62]. ΔoprG P. aeruginosa do show a 3-fold decrease in cytotoxicity toward the human bronchial epithelial cell line HBE, however transcriptomics revealed a rapid down-regulation of oprG in wild-type P. Blebbistatin aeruginosa upon interaction with these cells [62]. MexX, a component of the MexXY-OprM multidrug efflux transporter, was markedly increased in abundance in AES-1R and is known to confer resistance to a number of antibiotics including erythromycin, fluoroquinolones, aminoglycosides and the ß-lactams, cefepime and ceftobiprole [63–66],
correlating well with the antibiotic resistance associated with CF infections. Quinolones are the antibiotic of choice for treatment of P. aeruginosa CF lung infections and resistance to this class of drug second can result from mutations within DNA gyrase GyrA (PA3168), which is essential for DNA replication. The AES-1R gyrA gene sequence revealed an amino acid substitution (Thr83Ile) previously reported to result in
quinolone resistance [34] and observed in the Liverpool epidemic strain LESB58. Increased abundance of PA5178 (putative LysM domain protein), a protein containing a domain with predicted bacterial wall degradation properties may suggest a potential advantage against competing pathogens. P. aeruginosa is predicted to contain approximately 185 genes encoding lipoproteins [67]. A number of lipoproteins were observed at increased abundance in AES-1R. Induction of lipoprotein genes has been associated with an excessive proinflammatory response in lung epithelial cells via Toll-like receptor 2 [68]. OprI (PA2853) is an immunogenic lipoprotein that has been proposed as part of a multivalent vaccine [69]. We observed reduced OprI abundance in AES-1R, which may influence the efficacy of an OprI-based vaccine. LPS is a major virulence factor that is involved in initiating the pro-inflammatory response in the host. P. aeruginosa strains produce different LPS types, which are currently classified into 20 serotypes.