Virulent Drexlervirial Bacteriophage MSK, Morphological and Genome Resemblance With Rtp Bacteriophage Inhibits the Multidrug-Resistant Bacteria

Phage-host interactions are likely to have the most critical aspect of phage biology. Phages are the most abundant and ubiquitous infectious acellular entities in the biosphere, where their presence remains elusive. Here, the novel Escherichia coli lytic bacteriophage, named MSK, was isolated from the lysed culture of E. coli C (phix174 host). The genome of phage MSK was sequenced, comprising 45,053 bp with 44.8% G + C composition. In total, 73 open reading frames (ORFs) were predicted, out of which 24 showed a close homology with known functional proteins, including one tRNA-arg; however, the other 49 proteins with no proven function in the genome database were called hypothetical. Electron Microscopy and genome characterization have revealed that MSK phage has a rosette-like tail tip. There were, in total, 46 ORFs which were homologous to the Rtp genome. Among these ORFs, the tail fiber protein with a locus tag of MSK_000019 was homologous to Rtp 43 protein, which determines the host specificity. The other protein, MSK_000046, encodes lipoprotein (cor gene); that protein resembles Rtp 45, responsible for preventing adsorption during cell lysis. Thirteen MSK structural proteins were identified by SDS-PAGE analysis. Out of these, 12 were vital structural proteins, and one was a hypothetical protein. Among these, the protein terminase large (MSK_000072) subunit, which may be involved in DNA packaging and proposed packaging strategy of MSK bacteriophage genome, takes place through headful packaging using the pac-sites. Biosafety assessment of highly stable phage MSK genome analysis has revealed that the phage did not possess virulence genes, which indicates proper phage therapy. MSK phage potentially could be used to inhibit the multidrug-resistant bacteria, including AMP, TCN, and Colistin. Further, a comparative genome and lifestyle study of MSK phage confirmed the highest similarity level (87.18% ANI). These findings suggest it to be a new lytic isolated phage species. Finally, Blast and phylogenetic analysis of the large terminase subunit and tail fiber protein put it in Rtp viruses’ genus of family Drexlerviridae.

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Phage Digestion of a Bacterial Capsule Imparts Resistance to Two Antibiotic Agents

Microorganisms ◽

10.3390/microorganisms9040794 ◽

2021 ◽

Vol 9 (4) ◽

pp. 794

Author(s):

Cheng-Hung Luo ◽

Ya-Han Hsu ◽

Wen-Jui Wu ◽

Kai-Chih Chang ◽

Chen-Sheng Yeh

Keyword(s):

Cell Wall ◽

Multidrug Resistant ◽

Host Susceptibility ◽

Multiple Drug ◽

Tail Fiber ◽

Drug Resistant ◽

Tail Fiber Protein ◽

Host Interaction ◽

Fiber Protein ◽

Multiple Drug Resistant

Bacteriophages are viruses that infect bacteria, replicating and multiplying using host resources. For specific infections, bacteriophages have developed extraordinary proteins for recognizing and degrading their host. Inspired by the remarkable development of viral proteins, we used the tail fiber protein to treat multiple drug-resistant Acinetobacter baumannii. The tail fiber protein exhibits polysaccharide depolymerases activity which specifically degrades exopolysaccharide (EPS) during the phage–host interaction. However, EPS-degraded cells are observed altering host susceptibility to bacterial lysis peptide, the endolysin-derived peptide. Notably, endolysin is necessary in the process of progeny liberation by breaking the bacterial cell wall. Surprisingly, peeling the EPS animated host to resist colistin, the last-resort antibiotic used in multidrug-resistant Gram-negative bacteria infection. Tail fiber-modified cell wall reduces colistin attachment, causing temporary antibiotic-resistance and possibly raising clinical risks in treating multiple drug-resistant A. baumannii.

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Crystal Structure of the putative tail fiber protein gp53 from the Acinetobacter baumannii bacteriophage AP22

10.1101/518761 ◽

2019 ◽

Cited By ~ 1

Author(s):

Lada V. Sycheva ◽

Mikhail M. Shneider ◽

Anastasia V. Popova ◽

Rustam H. Ziganshin ◽

Nikolay V. Volozhantsev ◽

...

Keyword(s):

Crystal Structure ◽

Ethylene Glycol ◽

Acinetobacter Baumannii ◽

Host Cell ◽

Infection Process ◽

Tail Fiber ◽

Lytic Bacteriophage ◽

Cell Binding ◽

Tail Fiber Protein ◽

Fiber Protein

AbstractThis report describes the structure of a putative tail fiber protein of the Acinetobacter baumannii bacteriophage AP22. The target host range of strictly lytic bacteriophage AP22 includes many clinical isolates of A. baumannii from hospitals in Chelyabinsk, Nizhny Novgorod, Moscow and St. Petersburg (Russia), but its host cell binding apparatus remains uncharacterized. Here, we report the crystal structure of the C-terminal fragment of AP22 gene product 53 (gp53) one of its two putative host cell-binding proteins. We show that gp53 forms a trimeric fiber and binds ethylene glycol and glycerol molecules that represent known surrogates of the oligosaccharide backbone. However, despite its structural similarities to other phage/virus host cell-binding fibers and its binding to small sugar-like molecules, gp53 did not inhibit AP22 infection and its role in the infection process remains unclear.

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