Lytic bacteriophages are valuable therapeutic agents against bacterial infections. There is continual effort to obtain new phages to increase the effectivity of phage preparations against emerging phage-resistant strains. Here we described the genomic diversity of spontaneous host-range mutants of kayvirus 812. Five mutant phages were isolated as rare plaques on phage-resistant Staphylococcus aureus strains. The host range of phage 812-derived mutants was 42% higher than the wild type, determined on a set of 186 methicillin-resistant S. aureus strains representing the globally circulating human and livestock-associated clones. Comparative genomics revealed that single-nucleotide polymorphisms from the parental phage 812 population were fixed in next-step mutants, mostly in genes for tail and baseplate components, and the acquired point mutations led to diverse receptor binding proteins in the phage mutants. Numerous genome changes associated with rearrangements between direct repeat motifs or intron loss were found. Alterations occurred in host-takeover and terminal genomic regions or the endolysin gene of mutants that exhibited the highest lytic activity, which implied various mechanisms of overcoming bacterial resistance. The genomic data revealed that Kayvirus spontaneous mutants are free from undesirable genes and their lytic properties proved their suitability for rapidly updating phage therapeutics.

• MeSH
• bakteriální léková rezistence MeSH
• bakteriofágy genetika   MeSH
• délka genomu MeSH
• genom virový MeSH
• genomika MeSH
• jednonukleotidový polymorfismus MeSH
• methicilin farmakologie   MeSH
• mutace * MeSH
• Staphylococcus aureus růst a vývoj   virologie   MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• methicilin MeSH

Staphylococcus sciuri is a bacterial pathogen associated with infections in animals and humans, and represents a reservoir for the mecA gene encoding methicillin-resistance in staphylococci. No S. sciuri siphophages were known. Here the identification and characterization of two temperate S. sciuri phages from the Siphoviridae family designated ϕ575 and ϕ879 are presented. The phages have icosahedral heads and flexible noncontractile tails that end with a tail spike. The genomes of the phages are 42,160 and 41,448 bp long and encode 58 and 55 ORFs, respectively, arranged in functional modules. Their head-tail morphogenesis modules are similar to those of Staphylococcus aureus ϕ13-like serogroup F phages, suggesting their common evolutionary origin. The genome of phage ϕ575 harbours genes for staphylokinase and phospholipase that might enhance the virulence of the bacterial hosts. In addition both of the phages package a homologue of the mecA gene, which is a requirement for its lateral transfer. Phage ϕ879 transduces tetracycline and aminoglycoside pSTS7-like resistance plasmids from its host to other S. sciuri strains and to S. aureus. Furthermore, both of the phages efficiently adsorb to numerous staphylococcal species, indicating that they may contribute to interspecies horizontal gene transfer.

• MeSH
• bakteriální geny * MeSH
• fosfolipasy metabolismus   MeSH
• genom virový MeSH
• genomika metody   MeSH
• hostitelská specificita MeSH
• metaloendopeptidasy metabolismus   MeSH
• plazmidy genetika   MeSH
• přenos genů horizontální MeSH
• přichycení viru MeSH
• stafylokokové bakteriofágy fyziologie   ultrastruktura   MeSH
• Staphylococcus virologie   MeSH
• transdukce genetická * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• auR protein, Staphylococcus aureus MeSH Prohlížeč
• fosfolipasy MeSH
• metaloendopeptidasy MeSH

Exfoliative toxin A (ETA)-coding temperate bacteriophages are leading contributors to the toxic phenotype of impetigo strains of Staphylococcus aureus. Two distinct eta gene-positive bacteriophages isolated from S. aureus strains which recently caused massive outbreaks of pemphigus neonatorum in Czech maternity hospitals were characterized. The phages, designated ϕB166 and ϕB236, were able to transfer the eta gene into a prophageless S. aureus strain which afterwards converted into an ETA producer. Complete phage genome sequences were determined, and a comparative analysis of five designed genomic regions revealed major variances between them. They differed in the genome size, number of open reading frames, genome architecture, and virion protein patterns. Their high mutual sequence similarity was detected only in the terminal regions of the genome. When compared with the so far described eta phage genomes, noticeable differences were found. Thus, both phages represent two new lineages of as yet not characterized bacteriophages of the Siphoviridae family having impact on pathogenicity of impetigo strains of S. aureus.

• MeSH
• DNA virů chemie   genetika   MeSH
• DNA viry genetika   izolace a purifikace   MeSH
• epidemický výskyt choroby MeSH
• exfoliatiny genetika   MeSH
• fylogeneze MeSH
• genom virový * MeSH
• impetigo epidemiologie   mikrobiologie   MeSH
• infekce spojené se zdravotní péčí epidemiologie   MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• novorozenec MeSH
• otevřené čtecí rámce MeSH
• polymorfismus délky restrikčních fragmentů MeSH
• pořadí genů MeSH
• porodnice MeSH
• přenos genů horizontální MeSH
• profágy klasifikace   genetika   izolace a purifikace   MeSH
• sekvenční analýza DNA MeSH
• sekvenční homologie MeSH
• shluková analýza MeSH
• stafylokokové bakteriofágy klasifikace   genetika   izolace a purifikace   MeSH
• stafylokokové infekce epidemiologie   mikrobiologie   MeSH
• Staphylococcus aureus izolace a purifikace   virologie   MeSH
• syntenie MeSH
• transdukce genetická MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• DNA virů MeSH
• exfoliatiny MeSH