Characterization of the first double-stranded RNA bacteriophage infecting Pseudomonas aeruginosa

Abstract

Bacteriophages (phages) are widely distributed in the biosphere and play a key role in modulating microbial ecology in the soil, ocean, and humans. Although the role of DNA bacteriophages is well described, the biology of RNA bacteriophages is poorly understood. More than 1900 phage genomes are currently deposited in NCBI, but only 6 dsRNA bacteriophages and 12 ssRNA bacteriophages genome sequences are reported. The 6 dsRNA bacteriophages were isolated from legume samples or lakes with Pseudomonas syringae as the host. Here, we report the first Pseudomonas aeruginosa phage phiYY with a three-segmented dsRNA genome. phiYY was isolated from hospital sewage in China with the clinical P. aeruginosa strain, PAO38, as a host. Moreover, the dsRNA phage phiYY has a broad host range, which infects 99 out of 233 clinical P. aeruginosa strains isolated from four provinces in China. This work presented a detailed characterization of the dsRNA bacteriophage infecting P. aeruginosa.

Recognition of six additional cystoviruses: Pseudomonas virus phi6 is no longer the sole species of the family Cystoviridae

“…Since the late 1990's, dsRNA phages have been readily isolated from environmental samples, indicating that the members of the Cystoviridae are far more widespread and abundant than has been previously acknowledged [6][7][8][13][14][15]. The complete nucleotide sequences of six of these phage isolates (Pseudomonas phages phi8, phi12, phi13, phi2954, phiNN and phiYY) have been determined to date [9][10][11][12][13][14][15].…”

“…The complete nucleotide sequences of six of these phage isolates (Pseudomonas phages phi8, phi12, phi13, phi2954, phiNN and phiYY) have been determined to date [9][10][11][12][13][14][15]. Similarly to phi6, phages phi8, phi12, phi13 and phi2954 were isolated from bacteria-infested legumes in the USA [8,13].…”

“…B314 from a fresh water sample in Finland [14], whereas the isolation source of Pseudomonas phage phiYY was hospital sewage in China [15]. PhiYY was isolated together with Pseudomonas aeruginosa strain PAO38, and it also infects several other clinical strains of P. aeruginosa [15]. P. aeruginosa is an opportunistic human pathogen, which causes serious infections in immune-compromised individuals.…”

“…All the proposed members of the Cystoviridae family have a dsRNA genome, which is divided into three separate segments designated according to their size as L (large, 6.4 -7.1 kb), M (medium, 3.6 -4.7 kb) and S (small, 2.3 -3.2 kb) [9][10][11][12][13][14][15][28][29][30]. The total genome size varies from 12.7 kb (phi2954) to 15.0 kb (phi8).…”

“…Until now, phi6 has remained the sole representative of the Cystoviridae family (and Cystovirus genus), recognised by the ICTV. However, additional dsRNA phages have been isolated [6,7] and some characterized in more detail [8][9][10][11][12][13][14][15] (Table 1). These viruses share notable genetic and structural similarities with phage phi6.…”