Genetic diversity of flagellins of <i>Pseudomonas aeruginosa</i>

Spangenberg, C.; Heuer, Thomas; Bürger, Christiane; Tümmler, Burkhard

doi:10.1016/0014-5793(96)01099-x

Cited by 71 publications

(60 citation statements)

References 36 publications

(37 reference statements)

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“…These 19 strains were assigned to 14 genotypes by cluster analysis of their SpeI macrorestriction fragment patterns (see below). Six chromosomal loci of the strains' common gene repertoire that met the following criteria were compared: (i) even distribution on the chromosome; (ii) different functions of the encoded proteins, ranging from housekeeping to accessory functions; and (iii) various cellular localization of the gene products representing all cell compartments: the origin of replication oriC (59), the citrate synthase gene citS (11), the ␤-lactamase gene ampC (24), the lipoprotein I gene oprI (40), the flagellin gene fliC (50,55) and the type IV pilin gene pilA (42,49) were taken as a representative collection of the genetic repertoire of P. aeruginosa. Figure 1 shows a SpeI-DpnI map of the circular PAO chromosome, indicating the location of the selected genes.…”

Section: Resultsmentioning

confidence: 99%

“…Despite similar localization at the bacterial cell surface, the flagellin gene (fliC) was more conserved than the hypervariable pilA. Genetic diversity of a-type and b-type flagellins, respectively, was limited to several nucleotide substitutions and, in the case of strains ATCC 21776 and DSM 1128, to a variable 141-bp central cassette showing 28% nucleotide and 40% amino acid diversity (50,52). Significant nonrandom clustering of polymorphic sites within this cassette indicated an intragenic recombination event and a mosaic gene structure (Fig.…”

Section: Resultsmentioning

confidence: 99%

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Sequence Diversity of Pseudomonas aeruginosa : Impact on Population Structure and Genome Evolution

2000

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Comparative sequencing of Pseudomonas aeruginosa genes oriC, citS, ampC, oprI, fliC, and pilA in 19 environmental and clinical isolates revealed the sequence diversity to be about 1 order of magnitude lower than in comparable housekeeping genes of Salmonella. In contrast to the low nucleotide substitution rate, the frequency of recombination among different P. aeruginosa genotypes was high, leading to the random association of alleles. The P. aeruginosa population consists of equivalent genotypes that form a net-like population structure. However, each genotype represents a cluster of closely related strains which retain their sequence signature in the conserved gene pool and carry a set of genotype-specific DNA blocks. The codon adaptation index, a quantitative measure of synonymous codon bias of genes, was found to be consistently high in the P. aeruginosa genome irrespective of the metabolic category and the abundance of the encoded gene product. Such uniformly high codon adaptation indices of 0.55 to 0.85 fit the ubiquitous lifestyle of P. aeruginosa.The ␥-subdivision proteobacterium Pseudomonas aeruginosa is capable of thriving in a great number of seemingly dissimilar ecological niches. It is ubiquitously distributed in aquatic habitats and in soil (6) but is also found as part of the normal bacterial flora of the intestine, mouth, and skin of animals (35). Under normal circumstances, colonization is harmless and infection only occurs when local or general defense mechanisms are reduced (6). In susceptible animals, P. aeruginosa may cause infection at any site, particularly wounds and the respiratory tract (6). Moreover, P. aeruginosa is an opportunistic invader of plants (5). P. aeruginosa has become one of the most important nosocomial opportunistic pathogens in humans (6). A peculiar feature is chronic airway infections in patients with cystic fibrosis (CF) (15).Common approaches for analyzing the structure of natural populations of bacteria are multilocus enzyme electrophoresis (MLEE) (45) and multilocus sequence typing (MLST) (25). Allelic variation is indexed in MLEE by the electrophoretic mobilities of housekeeping enzymes (45) and in MLST by single nucleotide polymorphisms (SNPs) in selected genes (25). By applying either method, isolates within bacterial populations are assigned to specific clones due to their multilocus allelic profiles. Population structures of taxospecies range from the effectively panmictic Neisseria gonorrhoeae to the almost strictly clonal Salmonella (12,13,27,46,54,58).The population structure of P. aeruginosa has so far not been analyzed by MLST. MLEE has been applied to P. aeruginosa to study the association between electrophoretic types and lipopolysaccharide O-antigen serotypes (7) and to detect the nosocomial spread of strains in cancer (16) or CF patients (3, 26). In our study, comparative sequence analysis was applied to a variety of environmental and clinical isolates in order to assess genetic diversity of P. aeruginosa and hence to gain insights into the molecular...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Sequence Diversity of Pseudomonas aeruginosa : Impact on Population Structure and Genome Evolution

2000

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“…Indeed, we found that a factor was present in the supernatant of overnight bacterial cultures and that it was heat-stable and sensitive to proteinase degradation. We identified flagellin, the monomeric component of bacterial flagella (16,23), as the secreted protein that induced matrilysin expression. Similarly, flagellin from Salmonella, enteroaggregative E. coli, and Pseudomonas species induces a program of epithelial cell activation and is a potent pro-inflammatory mediator in intestinal and lung epithelial cells (17, 24 -27).…”

Section: Resultsmentioning

confidence: 99%

Regulation of Matrilysin Expression in Airway Epithelial Cells by Pseudomonas aeruginosa Flagellin

López-Boado

Wilson

Parks

2001

Journal of Biological Chemistry

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Matrilysin (matrix metalloproteinase-7) is expressed by mucosal epithelia throughout the body and functions in host defense by activating murine intestinal ␣-defensins. In normal adult human lung, matrilysin is expressed at low levels in the airway epithelium, but is markedly up-regulated in cystic fibrosis (CF). Because CF lungs support a heavy bacterial load, we assessed if relevant CF pathogens regulate matrilysin expression in human lung epithelial cells. Indeed, acute infection with Pseudomonas aeruginosa (but not Staphylococcus aureus, Haemophilus influenzae, or Klebsiella pneumoniae) induced the expression of matrilysin in Calu-3 lung epithelial cells. Increased matrilysin mRNA levels were detectable at 3 h post-infection and peaked at a 25-fold induction between 6 and 8 h. Both P. aeruginosa CF isolates and laboratory strains induced matrilysin expression to similar levels. Flagellin, the monomeric precursor of bacterial flagella, was identified as the inductive factor released by P. aeruginosa that regulated matrilysin expression. In addition, flagellin-null mutants failed to stimulate matrilysin expression in cultured cells or in lungs infected in vivo. These data show that P. aeruginosa (and specifically flagellin) potently stimulates matrilysin expression in lung epithelial cells and may mediate the overexpression of this proteinase in CF lungs.

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“…fliC sequence analysis. A fragment of the coding region of the fliC gene from each strain was amplified by primers fla1 and fla2 (37). DNA was extracted by boiling a 100-l suspension of bacterial cells in sterile water.…”

Section: Methodsmentioning

confidence: 99%

Establishing Clonal Relationships between VIM-1-Like Metallo-β-Lactamase-Producing Pseudomonas aeruginosa Strains from Four European Countries by Multilocus Sequence Typing

et al. 2006

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Ten multidrug-resistant Pseudomonas aeruginosa strains producing VIM-1-like acquired metallo-␤-lactamases (MBLs), isolated from four European countries (Greece, Hungary, Italy, and Sweden), were analyzed for genetic relatedness by several methodologies, including fliC sequence analysis, macrorestriction profiling of genomic DNA by pulsed-field gel electrophoresis (PFGE), random amplification of polymorphic DNA (RAPD), and multilocus sequence typing (MLST). The four approaches yielded consistent results overall but showed different resolution powers in establishing relatedness between isolates (PFGE > RAPD > MLST > fliC typing) and could usefully complement each other to address issues in the molecular epidemiology of P. aeruginosa strains producing acquired MBLs. In particular, the recently developed MLST approach was useful in revealing clonal relatedness between isolates when this was not readily apparent using RAPD and PFGE, and it suggested a common ancestry for some of the VIM-1-like MBL-positive P. aeruginosa strains currently spreading in Europe. The MBL producers belonged in three clonal complexes/burst groups (BGs). Of these, one corresponded to the previously described BG4 and included serotype O12 strains from Hungary and Sweden, while the other two were novel and included serotype O11 or nonserotypable strains from Greece, Sweden, and/or Italy. Comparison of the integrons carrying bla VIM-1 -like cassettes of various isolates revealed a remarkable structural heterogeneity, suggesting the possibility that multiple independent events of acquisition of different bla VIM -containing integrons had occurred in members of the same clonal lineage, although a contribution of integrase-mediated cassette shuffling or other recombination mechanisms during the evolution of similar strains could also have played a role in determining this variability.

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Genetic diversity of flagellins of Pseudomonas aeruginosa

Cited by 71 publications

References 36 publications

Sequence Diversity of Pseudomonas aeruginosa : Impact on Population Structure and Genome Evolution

Sequence Diversity of Pseudomonas aeruginosa : Impact on Population Structure and Genome Evolution

Regulation of Matrilysin Expression in Airway Epithelial Cells by Pseudomonas aeruginosa Flagellin

Establishing Clonal Relationships between VIM-1-Like Metallo-β-Lactamase-Producing Pseudomonas aeruginosa Strains from Four European Countries by Multilocus Sequence Typing

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