BACKGROUND: Next Generation Sequencing (NGS) technologies provide exciting possibilities for whole genome sequencing of a plethora of organisms including bacterial strains and phages, with many possible applications in research and diagnostics. No Streptomyces flavovirens phages have been sequenced to date; there is therefore a lack in available information about S. flavovirens phage genomics. We report biological and physiochemical features and use NGS to provide the complete annotated genomes for two new strains (Sf1 and Sf3) of the virulent phage Streptomyces flavovirens, isolated from Egyptian soil samples. RESULTS: The S. flavovirens phages (Sf1 and Sf3) examined in this study show higher adsorption rates (82 and 85%, respectively) than other actinophages, indicating a strong specificity to their host, and latent periods (15 and 30 min.), followed by rise periods of 45 and 30 min. As expected for actinophages, their burst sizes were 1.95 and 2.49 virions per mL. Both phages were stable and, as reported in previous experiments, showed a significant increase in their activity after sodium chloride (NaCl) and magnesium chloride (MgCl2.6H2O) treatments, whereas after zinc chloride (ZnCl2) application both phages showed a significant decrease in infection. The sequenced phage genomes are parts of a singleton cluster with sizes of 43,150 bp and 60,934 bp, respectively. Bioinformatics analyses and functional characterizations enabled the assignment of possible functions to 19 and 28 putative identified ORFs, which included phage structural proteins, lysis components and metabolic proteins. Thirty phams were identified in both phages, 10 (33.3%) of them with known function, which can be used in cluster prediction. Comparative genomic analysis revealed significant homology between the two phages, showing the highest hits among Sf1, Sf3 and the closest Streptomyces phage (VWB phages) in a specific 13Kb region. However, the phylogenetic analysis using the Major Capsid Protein (MCP) sequences highlighted that the isolated phages belong to the BG Streptomyces phage group but are clearly separated, representing a novel sub-cluster. CONCLUSION: The results of this study provide the first physiological and genomic information for S. flavovirens phages and will be useful for pharmaceutical industries based on S. flavovirens and future phage evolution studies.

• Klíčová slova
• Bacteriophage, Biological stability, Comparative genomics, NGS, Whole genome sequence,
• MeSH
• bakteriofágy genetika   izolace a purifikace   patogenita   fyziologie   MeSH
• biologická evoluce MeSH
• chlorid hořečnatý farmakologie   MeSH
• chlorid sodný farmakologie   MeSH
• chloridy farmakologie   MeSH
• DNA virů izolace a purifikace   MeSH
• fylogeneze MeSH
• genom virový genetika   fyziologie   MeSH
• genomika MeSH
• hostitelská specificita MeSH
• otevřené čtecí rámce genetika   MeSH
• půda MeSH
• půdní mikrobiologie MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční analýza DNA MeSH
• sekvenční homologie nukleových kyselin MeSH
• sloučeniny zinku farmakologie   MeSH
• Streptomyces virologie   MeSH
• virion MeSH
• virové geny MeSH
• virové plášťové proteiny genetika   MeSH
• virové proteiny genetika   MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Egypt MeSH
• Názvy látek
• chlorid hořečnatý MeSH
• chlorid sodný MeSH
• chloridy MeSH
• DNA virů MeSH
• půda MeSH
• sloučeniny zinku MeSH
• virové plášťové proteiny MeSH
• virové proteiny MeSH
• zinc chloride MeSH Prohlížeč

Forty strains of Salmonella enterica (S. enterica) subspecies salamae (II), arizonae (IIIa), diarizonae (IIIb), and houtenae (IV) were isolated from human or environmental samples and tested for bacteriophage production. Production of bacteriophages was observed in 15 S. enterica strains (37.5%) belonging to either the subspecies salamae (8 strains) or diarizonae (7 strains). Activity of phages was tested against 52 pathogenic S. enterica subsp. enterica isolates and showed that phages produced by subsp. salamae had broader activity against pathogenic salmonellae compared to phages from the subsp. diarizonae. All 15 phages were analyzed using PCR amplification of phage-specific regions and 9 different amplification profiles were identified. Five phages (SEN1, SEN4, SEN5, SEN22, and SEN34) were completely sequenced and classified as temperate phages. Phages SEN4 and SEN5 were genetically identical, thus representing a single phage type (i.e. SEN4/5). SEN1 and SEN4/5 fit into the group of P2-like phages, while the SEN22 phage showed sequence relatedness to P22-like phages. Interestingly, while phage SEN34 was genetically distantly related to Lambda-like phages (Siphoviridae), it had the morphology of the Myoviridae family. Based on sequence analysis and electron microscopy, phages SEN1 and SEN4/5 were members of the Myoviridae family and phage SEN22 belonged to the Podoviridae family.

• MeSH
• DNA virů genetika   izolace a purifikace   MeSH
• druhová specificita MeSH
• elektronová mikroskopie MeSH
• fágy salmonel klasifikace   izolace a purifikace   fyziologie   ultrastruktura   MeSH
• fylogeneze MeSH
• genom virový MeSH
• lyzogenie MeSH
• mikrobiologie životního prostředí MeSH
• Salmonella enterica izolace a purifikace   virologie   MeSH
• salmonelóza mikrobiologie   MeSH
• sekvenční analýza DNA MeSH
• sekvenční homologie nukleových kyselin MeSH
• virová nálož MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Geografické názvy
• Československo MeSH
• Názvy látek
• DNA virů MeSH