Mucinophilic and chemotactic properties of Pseudomonas aeruginosa in relation to pulmonary colonization in cystic fibrosis

Abstract

Representative isolates of nonmucoid Pseudomonas aeruginosa were studied to investigate the hypothesis that mucinophilic and chemotactic properties in this species act as potential factors in the initial stages of pulmonary colonization in patients with cystic fibrosis (CF). Transmission electron microscopy with a surfactant monolayer technique was used in a novel manner to demonstrate the adhesion of all 10 P. aeruginosa strains examined to porcine gastric mucin and tracheobronchial mucin from a patient with CF. Control experiments showed that Escherichia coli K-12 and single representatives of Proteus mirabilis and KlebsieUa aerogenes did not bind to these mucins. The Adler capillary technique, used to measure bacterial chemotactic response, showed that purified CF mucin acted as a chemoattractant for most P. aeruginosa strains, with the exception of the nonmotile mutant M2Flaand the nonchemotactic mutant WR-5. The ability of the major sugar and amino acid components of mucin to act as chemoattractants was investigated. The degree of chemotaxis was strain specific; optimum chemotaxis was observed toward serine, alanine, glycine, proline, and threonine. No strain showed chemotaxis to N-acetylneuraminic acid, but all strains showed a strain-dependent chemotactic response to the sugars L-fucose, D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine. These results provide new information on the mucinophilic and chemotactic properties of nonmucoid P. aeruginosa and support the hypothesis that these properties could play a role in the initial stages of pulmonary colonization in patients with CF.

Nonmotility and phagocytic resistance of Pseudomonas aeruginosa isolates from chronically colonized patients with cystic fibrosis

“…tal isolates, expressing flagellin and pilin in a normal manner; these findings are in agreement with published data suggesting the importance of these virulence factors for respiratory adherence and colonization in CF (6,22,24,25,27). However, our study indicates that once chronic colonization is established, expression of these virulence factors may not be necessary for survival of P. aeruginosa in certain CF patients.…”

Longitudinal survey of microbiome associated with particulate matter in a megacity

“…More importantly, although most of the species identified in PM 10 samples displayed significant differences in relative abundance between a low AQI level (I or II) and a high AQI level (IV or V), none in PM 2.5 exhibited such patterns (Wilcoxon rank-sum test, adjusted P < 0.1, Additional file 1: Tables 12). The microbes included those associated with human infections, such as Pseudomonas aeruginosa [26,27], with a positive correlation with pollutant concentration for both PM 2.5 and PM 10 samples (adjusted P < 0.05), and Stenotrophomonas maltophilia [28], with a positive correlation with the pollutant concentration in PM 10 samples. In addition, 72 microbes manifested prominent peaks in January (Additional file 2: Figure S12) when the air pollution was most severe.…”

Role of Flagella in Pathogenesis ofPseudomonas aeruginosaPulmonary Infection

“…In the model of acute P. aeruginosa pulmonary infection presented, Pseudomonas flagella are essential to the virulence of the organism just as they have been found to be important in the pathogenesis of other mucosal infections in which chemotaxis and motility are required for pathogenicity (18). Functional flagella provide a means for the organism to spread throughout the respiratory tract, and associated chemotaxis directs the organisms toward preferred substrates, which for P. aeruginosa include amino acids and P i as well as other known components of human mucin (17,20). The most striking feature of the infections ascribed to the fliC mutants was their extremely focal distribution.…”