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Investigation of a Large Collection of Pseudomonas aeruginosa Bacteriophages Collected from a Single Environmental Source in Abidjan, Côte d'Ivoire.

Essoh C, Latino L, Midoux C, Blouin Y, Loukou G, Nguetta SP, Lathro S, Cablanmian A, Kouassi AK, Vergnaud G, Pourcel C - PLoS ONE (2015)

Bottom Line: The vast majority of the genetic variations among virulent phages from the same genus resulted from seemingly non-random horizontal transfer events, inside a population of P. aeruginosa phages with limited diversity.This is the first study of P. aeruginosa phage diversity in an African city and it shows that a large variety of phage species can be recovered in a limited geographical site at least when different bacterial strains are used.The relative temporal and spatial stability of the Abidjan phage population might reflect equilibrium in the microbial community from which they are released.

View Article: PubMed Central - PubMed

Affiliation: Institute for Integrative Biology of the Cell, CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France.

ABSTRACT
Twenty two distinct bacteriophages were isolated from sewage water from five locations in the city of Abidjan, Côte d'Ivoire over a two-year period, using a collection of Pseudomonas aeruginosa strains with diverse genotypes. The phages were characterized by their virulence spectrum on a panel of selected P. aeruginosa strains from cystic fibrosis patients and by whole genome sequencing. Twelve virions representing the observed diversity were visualised by electron microscopy. The combined observations showed that 17 phages, distributed into seven genera, were virulent, and that five phages were related to temperate phages belonging to three genera. Some showed similarity with known phages only at the protein level. The vast majority of the genetic variations among virulent phages from the same genus resulted from seemingly non-random horizontal transfer events, inside a population of P. aeruginosa phages with limited diversity. This suggests the existence of a single environmental reservoir or ecotype in which continuous selection is taking place. In contrast, mostly point mutations were observed among phages potentially capable of lysogenisation. This is the first study of P. aeruginosa phage diversity in an African city and it shows that a large variety of phage species can be recovered in a limited geographical site at least when different bacterial strains are used. The relative temporal and spatial stability of the Abidjan phage population might reflect equilibrium in the microbial community from which they are released.

No MeSH data available.


Related in: MedlinePlus

Genomic organization of PA73-like phage Ab26.The different ORFs are colored according to their putative function: yellow, unknown; orange, terminase; red, biosynthesis; green, morphogenesis; blue, DNA replication; purple, lysis.
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pone.0130548.g010: Genomic organization of PA73-like phage Ab26.The different ORFs are colored according to their putative function: yellow, unknown; orange, terminase; red, biosynthesis; green, morphogenesis; blue, DNA replication; purple, lysis.

Mentions: Ab26 genome was 43,055 bp long and encoded 52 putative proteins (Fig 10). It showed 87% homology with vB_Pae-Kakheti25 from Georgia (42,844 bp; NC 007806) considered a lytic phage [64] and with PA73 from the Lindberg set (42,999 bp; DQ163913) [65]. The phage ends and the orientation of the genome map were aligned to that of related phages, and alignment showed a high overall conservation of gene organization between these phages except for three regions. The 296 bp at the beginning of the genome, encoding a protein found in a lysis cassette in phage vB_Pae-Kakheti25, were very different in the three phages. Interestingly, Ab26 possessed well conserved holin, endolysin, Rz and Rz1 spanin genes (ORF01 to ORF04) forming a lysis cassette similar to that described in ɸKMV-like phages [56]. One region of 1,600 bp encoding proteins found in mature virions (ORF21-ORF22), showed about 70% similarity with vB_Pae-Kakheti25 but 95% with PA73. Finally, from position 36,000, after the gene encoding a putative primase/helicase (ORF35), to the end of the genome a series a short hypothetical ORFs was observed showing a high degree of divergence as compared to the two closest phages. No integrase or other protein that could be involved in lysogeny were clearly identified. However ORF31, a recA-like recombinase, was shown to belong to the sak4 family of proteins, almost exclusively associated with temperate phages [66].


Investigation of a Large Collection of Pseudomonas aeruginosa Bacteriophages Collected from a Single Environmental Source in Abidjan, Côte d'Ivoire.

Essoh C, Latino L, Midoux C, Blouin Y, Loukou G, Nguetta SP, Lathro S, Cablanmian A, Kouassi AK, Vergnaud G, Pourcel C - PLoS ONE (2015)

Genomic organization of PA73-like phage Ab26.The different ORFs are colored according to their putative function: yellow, unknown; orange, terminase; red, biosynthesis; green, morphogenesis; blue, DNA replication; purple, lysis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482731&req=5

pone.0130548.g010: Genomic organization of PA73-like phage Ab26.The different ORFs are colored according to their putative function: yellow, unknown; orange, terminase; red, biosynthesis; green, morphogenesis; blue, DNA replication; purple, lysis.
Mentions: Ab26 genome was 43,055 bp long and encoded 52 putative proteins (Fig 10). It showed 87% homology with vB_Pae-Kakheti25 from Georgia (42,844 bp; NC 007806) considered a lytic phage [64] and with PA73 from the Lindberg set (42,999 bp; DQ163913) [65]. The phage ends and the orientation of the genome map were aligned to that of related phages, and alignment showed a high overall conservation of gene organization between these phages except for three regions. The 296 bp at the beginning of the genome, encoding a protein found in a lysis cassette in phage vB_Pae-Kakheti25, were very different in the three phages. Interestingly, Ab26 possessed well conserved holin, endolysin, Rz and Rz1 spanin genes (ORF01 to ORF04) forming a lysis cassette similar to that described in ɸKMV-like phages [56]. One region of 1,600 bp encoding proteins found in mature virions (ORF21-ORF22), showed about 70% similarity with vB_Pae-Kakheti25 but 95% with PA73. Finally, from position 36,000, after the gene encoding a putative primase/helicase (ORF35), to the end of the genome a series a short hypothetical ORFs was observed showing a high degree of divergence as compared to the two closest phages. No integrase or other protein that could be involved in lysogeny were clearly identified. However ORF31, a recA-like recombinase, was shown to belong to the sak4 family of proteins, almost exclusively associated with temperate phages [66].

Bottom Line: The vast majority of the genetic variations among virulent phages from the same genus resulted from seemingly non-random horizontal transfer events, inside a population of P. aeruginosa phages with limited diversity.This is the first study of P. aeruginosa phage diversity in an African city and it shows that a large variety of phage species can be recovered in a limited geographical site at least when different bacterial strains are used.The relative temporal and spatial stability of the Abidjan phage population might reflect equilibrium in the microbial community from which they are released.

View Article: PubMed Central - PubMed

Affiliation: Institute for Integrative Biology of the Cell, CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France.

ABSTRACT
Twenty two distinct bacteriophages were isolated from sewage water from five locations in the city of Abidjan, Côte d'Ivoire over a two-year period, using a collection of Pseudomonas aeruginosa strains with diverse genotypes. The phages were characterized by their virulence spectrum on a panel of selected P. aeruginosa strains from cystic fibrosis patients and by whole genome sequencing. Twelve virions representing the observed diversity were visualised by electron microscopy. The combined observations showed that 17 phages, distributed into seven genera, were virulent, and that five phages were related to temperate phages belonging to three genera. Some showed similarity with known phages only at the protein level. The vast majority of the genetic variations among virulent phages from the same genus resulted from seemingly non-random horizontal transfer events, inside a population of P. aeruginosa phages with limited diversity. This suggests the existence of a single environmental reservoir or ecotype in which continuous selection is taking place. In contrast, mostly point mutations were observed among phages potentially capable of lysogenisation. This is the first study of P. aeruginosa phage diversity in an African city and it shows that a large variety of phage species can be recovered in a limited geographical site at least when different bacterial strains are used. The relative temporal and spatial stability of the Abidjan phage population might reflect equilibrium in the microbial community from which they are released.

No MeSH data available.


Related in: MedlinePlus