A novel virus lytic for Pseudomonas aeruginosa has been purified. Its viral particles have a siphoviral morphology with a head 60 nm in diameter and a noncontractile tail 184 nm long. The dsDNA genome consists of 16,449 bp, has cohesive 3' termini, and encodes 28 putative proteins in a single strain. The peptidoglycan endopeptidase encoded by ORF 16 was found to be the lytic enzyme of this virus. The recombinant, purified enzyme was active up to 55 °C in the pH range 6-9 against all tested isolates of P. aeruginosa, but, surprisingly, also against the distant Gram-positive micrococci Arthrobacter globiformis and A. pascens. Both this virus and its endolysin are further candidates for possible treatment against P. aeruginosa and probably also other bacteria.

• Klíčová slova
• G+ and G− activity, adaiavirus, endolysin, host range,
• Publikační typ
• časopisecké články MeSH

The escalation of antibiotic resistance has revitalized bacteriophage (phage) therapy. Recently, phage therapy has been gradually applied in medicine, agriculture, food, and environmental fields due to its distinctive features of high efficiency, specificity, and environmental friendliness compared to antibiotics. Likewise, phage therapy also holds great promise in controlling pathogenic bacteria in aquaculture. The application of phage therapy instead of antibiotics to eliminate pathogenic bacteria such as Vibrio, Pseudomonas, Aeromonas, and Flavobacterium and to reduce fish mortality in aquaculture has been frequently reported. In this context, the present review summarizes and analyzes the current status of phage therapy in aquaculture, focusing on the key parameters of phage application, such as phage isolation, selection, dosage, and administration modes, and introducing the strategies and methods to boost efficacy and restrain the emergence of resistance. In addition, we discussed the human safety, environmental friendliness, and techno-economic practicability of phage therapy in aquaculture. Finally, this review outlines the current challenges of phage therapy application in aquaculture from the perspectives of phage resistance, phage-mediated resistance gene transfer, and effects on the host immune system.

• Klíčová slova
• Aquaculture, Efficacy, Phage resistance, Phage therapy,
• MeSH
• antibakteriální látky MeSH
• bakteriofágy * genetika   MeSH
• fágová terapie * MeSH
• Vibrio * MeSH
• vodní hospodářství metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH

Upsurge in the instances of antibiotic-resistant uropathogenic Escherichia .coli (UPECs) strains has repositioned the attention of researchers towards a century old antimicrobial approach popularly known as phage therapy. Rise of extended spectrum beta lactamase (ESBL) and biofilm producing strains has added another step of hurdle in treatment of uropathogens with conventional antibiotics, thus providing a further impetus for search for exploring new therapeutic measures. In this direction, bacteriophages, commonly called phages, are recently being considered as potential alternatives for treatment of UPECs. Phages are the tiniest form of viruses which are ubiquitous in nature and highly specific for their host. This review discusses the possible ways of using natural phages, genetically engineered phages, and phage lytic enzymes (PLEs) as an alternative antimicrobial treatment for urinary tract infections. The review also sheds light on the synergistic use of conventional antibiotics with phages or PLEs for treatment of uropathogens. These methods of using phages and their derivatives, alone or in combination with antibiotics, have proved fruitful so far in in vitro studies. However, in vivo studies are required to make them accessible for human use. The present review is a concerted effort towards putting together all the information available on the subject.

• MeSH
• bakteriofágy genetika   fyziologie   MeSH
• fágová terapie * MeSH
• infekce močového ústrojí mikrobiologie   terapie   MeSH
• infekce vyvolané Escherichia coli mikrobiologie   terapie   MeSH
• lidé MeSH
• uropatogenní Escherichia coli genetika   fyziologie   virologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Antibiotic resistance is increasing among Staphylococcus saprophyticus strains isolated from urinary tract infection. This necessitates alternative therapies. For this, a lytic phage (vB_SsapS-104) against S. saprophyticus, which formed round and clear plaques on bacterial culture plates, was isolated from hospital wastewater and characterized. Microscopy analysis showed that it had a small head (about 50 nm), tail (about 80 nm), and a collar (about 22 nm in length and 19 nm in width) indicating to be a phage within Siphoviridae family. Phage vB_SsapS-104 showed a large latency period of about 40 min, rapid adsorption rate that was significantly enhanced by MgCl2 and CaCl2, and high stability to a wide range of temperatures and pH values. Restriction analyses demonstrated that phage consists of a double-stranded DNA with an approximate genome size of 40 Kb. BLAST results did not show high similarity (megablast) with other previously identified phages. But, in Blastn, similarity with Staphylococcus phages was observed. Phage vB_SsapS-104 represented high anti-bacterial activity against S. saprophyticus isolates in vitro as it was able to lyse 8 of the 9 clinical isolates (%88.8) obtained from a hospital in Gorgan, Iran. It was a S. saprophyticus-specific phage because no lytic activity was observed on some other pathogenic bacteria tested. Therefore, phage vB_SsapS-104 can be considered as a specific virulent phage against of S. saprophyitcus isolated from urinary tract infection. This study provided the partial genomic characterization of S. saprophyticus phage and its application against urinary tract infection associated with S. saprophyticus. This phage also can be considered as a good candidate for a therapeutic alternative in the future.

• Klíčová slova
• Lytic bacteriophage, Siphoviridae, Staphylococcus saprophyticus, Urinary tract infection,
• MeSH
• antibakteriální látky farmakologie   MeSH
• DNA virů MeSH
• fágová terapie MeSH
• genom virový MeSH
• hostitelská specificita MeSH
• infekce močového ústrojí mikrobiologie   MeSH
• koncentrace vodíkových iontů MeSH
• latence viru MeSH
• lidé MeSH
• odpadní voda virologie   MeSH
• sekvenční analýza DNA MeSH
• Siphoviridae genetika   izolace a purifikace   ultrastruktura   MeSH
• stafylokokové bakteriofágy genetika   MeSH
• stafylokokové infekce mikrobiologie   MeSH
• Staphylococcus saprophyticus účinky léků   virologie   MeSH
• teplota MeSH
• transmisní elektronová mikroskopie MeSH
• virulence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Írán MeSH
• Názvy látek
• antibakteriální látky MeSH
• DNA virů MeSH
• odpadní voda MeSH

The spontaneous host-range mutants 812F1 and K1/420 are derived from polyvalent phage 812 that is almost identical to phage K, belonging to family Myoviridae and genus Kayvirus. Phage K1/420 is used for the phage therapy of staphylococcal infections. Endolysin of these mutants designated LysF1, consisting of an N-terminal cysteine-histidine-dependent aminohydrolase/peptidase (CHAP) domain and C-terminal SH3b cell wall-binding domain, has deleted middle amidase domain compared to wild-type endolysin. In this work, LysF1 and both its domains were prepared as recombinant proteins and their function was analyzed. LysF1 had an antimicrobial effect on 31 Staphylococcus species of the 43 tested. SH3b domain influenced antimicrobial activity of LysF1, since the lytic activity of the truncated variant containing the CHAP domain alone was decreased. The results of a co-sedimentation assay of SH3b domain showed that it was able to bind to three types of purified staphylococcal peptidoglycan 11.2, 11.3, and 11.8 that differ in their peptide bridge, but also to the peptidoglycan type 11.5 of Streptococcus uberis, and this capability was verified in vivo using the fusion protein with GFP and fluorescence microscopy. Using several different approaches, including NMR, we have not confirmed the previously proposed interaction of the SH3b domain with the pentaglycine bridge in the bacterial cell wall. The new naturally raised deletion mutant endolysin LysF1 is smaller than LysK, has a broad lytic spectrum, and therefore is an appropriate enzyme for practical use. The binding spectrum of SH3b domain covering all known staphylococcal peptidoglycan types is a promising feature for creating new chimeolysins by combining it with more effective catalytic domains.

• Klíčová slova
• Endolysin, Endopeptidases, Enzybiotics, Src homology domains, Staphylococcal infections, Staphylococcus bacteriophage,
• MeSH
• endopeptidasy genetika   izolace a purifikace   metabolismus   MeSH
• hostitelská specificita * MeSH
• mutantní proteiny genetika   izolace a purifikace   metabolismus   MeSH
• Myoviridae enzymologie   genetika   fyziologie   MeSH
• peptidoglykan metabolismus   MeSH
• proteinové domény MeSH
• sekvenční delece * MeSH
• Staphylococcus virologie   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• endolysin MeSH Prohlížeč
• endopeptidasy MeSH
• mutantní proteiny MeSH
• peptidoglykan MeSH