Klebsiella pneumoniae (family Enterobacteriaceae) is a gram-negative bacterium that has strong pathogenicity to humans and can cause sepsis, pneumonia, and urinary tract infection. In recent years, the unreasonable use of antibacterial drugs has led to an increase in drug-resistant strains of K. pneumoniae, a serious threat to public health. Bacteriophages, viruses that infect bacteria, are ubiquitous in the natural environment. They are considered to be the most promising substitute for antibiotics because of their high specificity, high efficiency, high safety, low cost, and short development cycle. In this study, a novel phage designated vB_KpnP_IME279 was successfully isolated from hospital sewage using a multidrug-resistant strain of K. pneumoniae as an indicator. A one-step growth curve showed that vB_KpnP_IME279 has a burst size of 140 plaque-forming units/cell and a latent period of 20 min at its optimal multiplicity of infection (MOI = 0.1). Phage vB_KpnP_IME279 survives in a wide pH range between 3 and 11 and is stable at temperatures ranging from 40 to 60 °C. Ten of the 20 strains of K. pneumoniae including the host bacteria were lysed by the phage vB_KpnP_IME279, and the multilocus sequence typing and wzi typing of the 10 strains were ST11, ST37, ST375, wzi209, wzi52, and wzi72, respectively. The genome of vB_KpnP_IME279 is 42,518 bp long with a G + C content of 59.3%. Electron microscopic observation showed that the phage belongs to the family Podoviridae. BLASTN alignment showed that the genome of the phage has low similarity with currently known phages. The evolutionary relationship between phage vB_KpnP_IME279 and other Podoviridae was analyzed using a phylogenetic tree based on sequences of phage major capsid protein and indicates that the phage vB_KpnP_IME279 belongs to the Podoviridae subfamily. These data enhance understanding of K. pneumoniae phages and will help in development of treatments for multidrug-resistant bacteria using phages.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriofágy klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• fylogeneze MeSH
• genom virový MeSH
• hostitelská specificita MeSH
• Klebsiella pneumoniae účinky léků   izolace a purifikace   virologie   MeSH
• lidé MeSH
• mikrobiologické techniky MeSH
• mnohočetná bakteriální léková rezistence MeSH
• multilokusová sekvenční typizace MeSH
• nemocnice MeSH
• odpadní vody mikrobiologie   virologie   MeSH
• Podoviridae klasifikace   genetika   izolace a purifikace   MeSH
• RNA ribozomální 16S MeSH
• sekvenování celého genomu MeSH
• techniky typizace bakterií MeSH
• teplota MeSH
• zastoupení bazí MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Bacteriophages are ubiquitous in nature and represent a vast repository of genetic diversity, which is driven by the endless coevolution cycle with a diversified group of bacterial hosts. Studying phage-host interactions is important to gain novel insights into their dynamic adaptation. In this study, we isolated 12 phages infecting species of the Acinetobacter baumannii-Acinetobacter calcoaceticus complex which exhibited a narrow host range and similar morphological features (podoviruses with short tails of 9-12 nm and isometric heads of 50-60 nm). Notably, the alignment of the newly sequenced phage genomes (40-41 kb of DNA length) and all Acinetobacter podoviruses deposited in Genbank has shown high synteny, regardless of the date and source of isolation that spans from America to Europe and Asia. Interestingly, the C-terminal pectate lyase domain of these phage tail fibres is often the only difference found among these viral genomes, demonstrating a very specific genomic variation during the course of their evolution. We proved that the pectate lyase domain is responsible for phage depolymerase activity and binding to specific Acinetobacter bacterial capsules. We discuss how this mechanism of phage-host co-evolution impacts the tail specificity apparatus of Acinetobacter podoviruses.

• MeSH
• Acinetobacter baumannii virologie   MeSH
• Acinetobacter calcoaceticus virologie   MeSH
• genom virový genetika   MeSH
• hostitelská specificita fyziologie   MeSH
• Podoviridae klasifikace   genetika   metabolismus   MeSH
• polygalakturonasa metabolismus   MeSH
• polysacharid-lyasy metabolismus   MeSH
• proteinové domény fyziologie   MeSH
• sekvence nukleotidů MeSH
• virion genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Asie MeSH
• Evropa MeSH

Pseudomonas aeruginosa is an opportunistic pathogen that causes serious infections, especially in patients with immunodeficiency. It exhibits multiple mechanisms of resistance, including efflux pumps, antibiotic modifying enzymes and limited membrane permeability. The primary reason for the development of novel therapeutics for P. aeruginosa infections is the declining efficacy of conventional antibiotic therapy. These clinical problems caused a revitalization of interest in bacteriophages, which are highly specific and have very effective antibacterial activity as well as several other advantages over traditional antimicrobial agents. Above all, so far, no serious or irreversible side effects of phage therapy have been described. Five newly purified P. aeruginosa phages named vB_PaeM_WP1, vB_PaeM_WP2, vB_PaeM_WP3, vB_PaeM_WP4 and vB_PaeP_WP5 have been characterized as potential candidates for use in phage therapy. They are representatives of the Myoviridae and Podoviridae families. Their host range, genome size, structural proteins and stability in various physical and chemical conditions were tested. The results of these preliminary investigations indicate that the newly isolated bacteriophages may be considered for use in phagotherapy.

• MeSH
• bakteriofágy klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• biologická terapie MeSH
• hostitelská specificita MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• Myoviridae klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• odpadní vody virologie   MeSH
• Podoviridae klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• pseudomonádové infekce mikrobiologie   terapie   MeSH
• Pseudomonas aeruginosa virologie   MeSH
• virové proteiny genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH