Publication Date:
2012-06-11
Description:
Background: Staphylococcus epidermidis is a commensal bacterium but can colonize the hospitalenvironment due to its ability to form biofilms favouring adhesion to host tissues, medicaldevices and increasing resistance to antibiotics. In this context, the use of phages to destroybiofilms is an interesting alternative. Results: The complete genomes of two Staphylococcus epidermidis bacteriophages, vB_SepiSphiIPLA5and vB_SepiS-phiIPLA7, have been analyzed. Their genomes are 43,581 bp and42,123 bp, and contain 67 and 59 orfs. Bioinformatic analyses enabled the assignment ofputative functions to 36 and 29 gene products, respectively, including DNA packaging andmorphogenetic proteins, lysis components, and proteins necessary for DNA recombination,regulation, modification and replication. A point mutation in vB_SepiS-phiIPLA5 lysogenycontrol-associated genes explained its strictly lytic behaviour. Comparative analysis of phi-IPLA5 and phi-IPLA7 genome structure resembled those of S. epidermidis phiPH15 andphiCNPH82 phages. A mosaic structure of S. epidermidis prophage genomes was revealed byPCR analysis of three marker genes (integrase, major head protein and holin). Using thesegenes, high prevalence (73%) of phage DNA in a representative S. epidermidis straincollection consisting of 60 isolates from women with mastitis and healthy women wasdetermined. Putative pectin lyase-like domains detected in virion-associated proteins of bothphages could be involved in exopolysaccharide (EPS) depolymerization, as evidenced by both the presence of a clear halo surrounding the phage lysis zone and the phage-mediatedbiofilm degradation. Conclusions: Staphylococcus epidermidis bacteriophages, vB_SepiS-phiIPLA5 and vB_SepiS-phiIPLA7,have a mosaic structure similar to other widespread S. epidermidis prophages. Virions ofthese phages are provided of pectin lyase-like domains, which may be regarded as promisinganti-biofilm tools.
Electronic ISSN:
1471-2164
Topics:
Biology
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