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Characterization of JG024, a pseudomonas aeruginosa PB1-like broad host range phage under simulated infection conditions.

Garbe J, Wesche A, Bunk B, Kazmierczak M, Selezska K, Rohde C, Sikorski J, Rohde M, Jahn D, Schobert M - BMC Microbiol. (2010)

Bottom Line: The receptor of phage JG024 was determined as lipopolysaccharide.Alginate production was identified as a factor reducing phage infectivity.Phage JG024 is a suitable broad host range phage which could be used in phage therapy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Microbiology, Technische Universit├Ąt Braunschweig, Spielmannstr, 7, 38106 Braunschweig, Germany.

ABSTRACT

Background: Pseudomonas aeruginosa causes lung infections in patients suffering from the genetic disorder Cystic Fibrosis (CF). Once a chronic lung infection is established, P. aeruginosa cannot be eradicated by antibiotic treatment. Phage therapy is an alternative to treat these chronic P. aeruginosa infections. However, little is known about the factors which influence phage infection of P. aeruginosa under infection conditions and suitable broad host range phages.

Results: We isolated and characterized a phage, named JG024, which infects a broad range of clinical and environmental P. aeruginosa strains. Sequencing of the phage genome revealed that the phage JG024 is highly related to the ubiquitous and conserved PB1-like phages. The receptor of phage JG024 was determined as lipopolysaccharide. We used an artificial sputum medium to study phage infection under conditions similar to a chronic lung infection. Alginate production was identified as a factor reducing phage infectivity.

Conclusions: Phage JG024 is a suitable broad host range phage which could be used in phage therapy. Phage infection experiments under simulated chronic lung infection conditions showed that alginate production reduces phage infection efficiency.

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Related in: MedlinePlus

Genome of JG024. Schematic representation of the JG024 genome with its assumed ORFs and some functional assignments. The arrowheads point in the direction of transcription. Detected putative sigma70-promoters as well as potential terminator hairpin structures are indicated. The complete genome is submitted with GenBank (NCBI, accession number: GU815091).
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Figure 3: Genome of JG024. Schematic representation of the JG024 genome with its assumed ORFs and some functional assignments. The arrowheads point in the direction of transcription. Detected putative sigma70-promoters as well as potential terminator hairpin structures are indicated. The complete genome is submitted with GenBank (NCBI, accession number: GU815091).

Mentions: The schematic representation of the genome, with its assumed ORFs, some functional assignments and overall genetic organization is depicted in Figure 3. The genome of JG024 is compact organized with only 7.1% intergenic space. No genes encoding for tRNAs were found in the genome of JG024 using the program RNAscan-SE 1.21 [29]. Interestingly, the GC content of phage JG024 differs from its host (55.62% to 68%). Comparison of the codon usage of JG024 with its host P. aeruginosa showed that the phage shares the same dominant codons for each amino acid except for valin, serin and glutamate. To test if the genome of phage JG024 is linear or circular, we used a method described previously [30]. A linear genome of phage JG024 was identified by treatment with exonuclease Bal31 which degrades only double-stranded linear DNA from both ends simultaneously (data not shown). However, we did not identify the exact genome ends. This would indicate that the genome of phage JG024 is circular permuted in contradiction to the PB1 phages, which have been reported to have non-permuted linear genomes [15]. Since the terminase protein of JG024 is highly (up to 99.6%) identical to that of the PB1 phages, we assume phage JG024 to have a non-permuted linear genome.


Characterization of JG024, a pseudomonas aeruginosa PB1-like broad host range phage under simulated infection conditions.

Garbe J, Wesche A, Bunk B, Kazmierczak M, Selezska K, Rohde C, Sikorski J, Rohde M, Jahn D, Schobert M - BMC Microbiol. (2010)

Genome of JG024. Schematic representation of the JG024 genome with its assumed ORFs and some functional assignments. The arrowheads point in the direction of transcription. Detected putative sigma70-promoters as well as potential terminator hairpin structures are indicated. The complete genome is submitted with GenBank (NCBI, accession number: GU815091).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3008698&req=5

Figure 3: Genome of JG024. Schematic representation of the JG024 genome with its assumed ORFs and some functional assignments. The arrowheads point in the direction of transcription. Detected putative sigma70-promoters as well as potential terminator hairpin structures are indicated. The complete genome is submitted with GenBank (NCBI, accession number: GU815091).
Mentions: The schematic representation of the genome, with its assumed ORFs, some functional assignments and overall genetic organization is depicted in Figure 3. The genome of JG024 is compact organized with only 7.1% intergenic space. No genes encoding for tRNAs were found in the genome of JG024 using the program RNAscan-SE 1.21 [29]. Interestingly, the GC content of phage JG024 differs from its host (55.62% to 68%). Comparison of the codon usage of JG024 with its host P. aeruginosa showed that the phage shares the same dominant codons for each amino acid except for valin, serin and glutamate. To test if the genome of phage JG024 is linear or circular, we used a method described previously [30]. A linear genome of phage JG024 was identified by treatment with exonuclease Bal31 which degrades only double-stranded linear DNA from both ends simultaneously (data not shown). However, we did not identify the exact genome ends. This would indicate that the genome of phage JG024 is circular permuted in contradiction to the PB1 phages, which have been reported to have non-permuted linear genomes [15]. Since the terminase protein of JG024 is highly (up to 99.6%) identical to that of the PB1 phages, we assume phage JG024 to have a non-permuted linear genome.

Bottom Line: The receptor of phage JG024 was determined as lipopolysaccharide.Alginate production was identified as a factor reducing phage infectivity.Phage JG024 is a suitable broad host range phage which could be used in phage therapy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Microbiology, Technische Universit├Ąt Braunschweig, Spielmannstr, 7, 38106 Braunschweig, Germany.

ABSTRACT

Background: Pseudomonas aeruginosa causes lung infections in patients suffering from the genetic disorder Cystic Fibrosis (CF). Once a chronic lung infection is established, P. aeruginosa cannot be eradicated by antibiotic treatment. Phage therapy is an alternative to treat these chronic P. aeruginosa infections. However, little is known about the factors which influence phage infection of P. aeruginosa under infection conditions and suitable broad host range phages.

Results: We isolated and characterized a phage, named JG024, which infects a broad range of clinical and environmental P. aeruginosa strains. Sequencing of the phage genome revealed that the phage JG024 is highly related to the ubiquitous and conserved PB1-like phages. The receptor of phage JG024 was determined as lipopolysaccharide. We used an artificial sputum medium to study phage infection under conditions similar to a chronic lung infection. Alginate production was identified as a factor reducing phage infectivity.

Conclusions: Phage JG024 is a suitable broad host range phage which could be used in phage therapy. Phage infection experiments under simulated chronic lung infection conditions showed that alginate production reduces phage infection efficiency.

Show MeSH
Related in: MedlinePlus