Isolation and Characterization of the New Mosaic Filamentous Phage VFJ Φ of Vibrio cholerae

Abstract

Filamentous phages have distinguished roles in conferring many pathogenicity and survival related features to Gram-negative bacteria including the medically important Vibrio cholerae, which carries factors such as cholera toxin on phages. A novel filamentous phage, designated VFJΦ, was isolated in this study from an ampicillin and kanamycin-resistant O139 serogroup V. cholerae strain ICDC-4470. The genome of VFJΦ is 8555 nucleotides long, including 12 predicted open reading frames (ORFs), which are organized in a modular structure. VFJΦ was found to be a mosaic of two groups of V. cholerae phages. A large part of the genome is highly similar to that of the fs2 phage, and the remaining 700 bp is homologous to VEJ and VCYΦ. This 700 bp region gave VFJΦ several characteristics that are not found in fs2 and other filamentous phages. In its native host ICDC-4470 and newly-infected strain N16961, VFJΦ was found to exist as a plasmid but did not integrate into the host chromosome. It showed a relatively wide host range but did not infect the classical biotype O1 V. cholerae strains. After infection, the host strains exhibited obvious inhibition of both growth and flagellum formation and had acquired a low level of ampicillin resistance and a high level of kanamycin resistance. The antibiotic resistances were not directly conferred to the hosts by phage-encoded genes and were not related to penicillinase. The discovery of VFJΦ updates our understanding of filamentous phages as well as the evolution and classification of V. cholerae filamentous phage, and the study provides new information on the interaction between phages and their host bacteria.

Filamentous Pseudomonas Phage Pf4 in the Context of Therapy-Inducibility, Infectivity, Lysogenic Conversion, and Potential Application

“…However, the method comprises immediate treatment of planktonic bacteria with antibiotics, so the antibiotic exhibits its activity prior to possibility of biofilm formation. The increased sensitivity upon filamentous phage infection was previously documented for other phage-host systems; e.g., Wang et al, (2013) [74] found that Vibrio phage VEJ increased Vibrio cholerae sensitivity to ampicillin. Hagens et al, (2006) [75] indicated that filamentous phages in combination with small doses of antibiotics can inhibit and even kill P. aeruginosa strains.…”

Correlation between viral production and carbon mineralization under nitrate-reducing conditions in aquifer sediment

“…These VLPs are morphologically similar to other filamentous bacteriophage. Similarly sized filamentous phage have been identified in pure culture as well as environmental samples: KSF-1F 1200 nm long 7 nm wide (Faruque et al, 2005), Pf1 2000 nm wide (Lorieau et al, 2008), VFJF 1400 nm long 7 nm wide (Wang et al 2013), B5 620 nm long 12 nm wide (Chopin et al, 2002); alpine lake filamentous viruses 450-730 nm long 30-40 nm wide (Hofer and Sommaruga, 2001). Together, these results indicate that Pseudomonas sp.…”

Widespread distribution of prophage-encoded virulence factors in marine Vibrio communities

“…parahaemolyticus phage Vf33 14 appears to be more closely related to V . cholerae phages VGJ 15 , fs1 16 , fs2 17 , VSK 18 , VEJ 19 and VFJ 20 than with V . parahaemolyticus filamentous phages VfO3:K6 and VfO4:K68 21 , which made up a distinct branch in the phylogenetic tree (Fig.…”