Isolation and Characterization of a Novel Siphoviridae Phage, vB_AbaS_TCUP2199, Infecting Multidrug-Resistant Acinetobacter baumannii

Abstract

Multidrug-resistant Acinetobacter baumannii (MDRAB) is a pathogen recognized as antimicrobial-resistant bacteria involved in healthcare-associated infections. Resistance to antibiotics has made alternative therapies necessary. Bacteriophage therapy is considered a potential solution to treat MDRAB. In this study, we isolated and characterized the phage vB_AbaS_TCUP2199 (TCUP2199), which can infect MDRAB. Morphological analysis revealed that TCUP2199 belongs to the Siphoviridae family. TCUP2199 has a wide host range, can adsorb rapidly (68.28% in 2 min), and has a burst size of 196 PFU/cell. At least 16 distinct structural proteins were visualized by SDS polyacrylamide gel electrophoresis. A stability test showed that TCUP2199 was stable at 37 °C and pH 7. Genome analysis of TCUP2199 showed that it consists of a double-stranded DNA genome of 79,572 bp with a G+C content of 40.39%, which contains 98 putative open reading frames, none of which is closely related to the bacteriophage genome sequence that was found in the public database. TCUP2199 shows similarity in genomic organization and putative packaging mechanism with Achromobacter phage JWF and Pseudoalteromonas phage KB12-38 based on protein BLAST and phylogenetic analysis. Because of those unique characteristics, we consider TCUP2199 to be a novel phage that is suitable for inclusion in a phage cocktail to treat A. baumannii infection.

Acinetobacter Baumannii Phages: Past, Present and Future

“…Morphogenesis of the tail occurs frequently, the mutant Ab105-2phiΔCI404ad, genomic rearrangement increases the host range of the phage nearly 3-fold [ 51 ]. There is no genome similarity of vB_AbaS_TCUP2199 to other known phages [ 52 ]. It has been documented that most of the genes of bacteriophages are unknown [ 53 ].…”

How to treat severe Acinetobacter baumannii infections

“…Phage therapy is currently one of the best hopes for the future control of Gram-negative severe infections that are difficult to eradicate with antibiotics [189 ▪ –192 ▪ ]. This form of treatment first requires the availability of phages with lytic capacity for a specific bacterium, in this case, AB, of which more than 100 have been isolated to date [193,194 ▪ –201 ▪ ]. Hospital wastewater can be a good search source of such phages [202 ▪ ].…”

“…There is already data in ABI suggesting the efficacy of phage therapy in animal or in vitro models [195 ▪ ,196 ▪ ,198 ▪ ,209 ▪ –211 ▪ ,212–214,215 ▪ ].…”

Recent Progress in Phage‐Based Nanoplatforms for Tumor Therapy

“…[19] First, most phages can be divided into three tail phage families based on their unique morphology, namely Myoviridae (contractile tail), Podoviridae (short tail), and Siphoviridae (long and noncontractile tail). [21] Additionally, phages can be categorized into four groups according to the types of genetic material in the capsid core, i.e., single-stranded DNA (ssDNA) phages, Morphology Siphoviridae Phage vB_AbaS_TCUP2199 [23] Myoviridae Phage vB_PlaM_Pd22F [24] Podoviridae Phage HH109 [25] Lifecycle Lytic phage Phage T7 [26] Temperate phage Phage 𝜆 [27] Nucleic acid dsRNA Phage phiZ98 [28] ssRNA Phage MS2 [29] ssDNA Vibriophage vB_VpaM_PG19 [30] dsDNA Phage vB_SalP_TR2 [31] Host range Narrow-host-range phage Bacteriophage of Marinobacter D1S9 [32] Broad-host-range phage R9Y-phage [33] double-stranded DNA (dsDNA) phages, single-stranded RNA (ss-RNA) phages, and double-stranded RNA (dsRNA) phages. [22] Moreover, more and more categorizations of phages are discovered, and new genome-based families are found.…”