Biological characteristics and genomic analysis of a novel Vibrio parahaemolyticus phage phiTY18 isolated from the coastal water of Xiamen China

Abstract

Vibrio parahaemolyticus is a common pathogen usually controlled by antibiotics in mariculture. Notably, traditional antibiotic therapy is becoming less effective because of the emergence of bacterial resistance, hence new strategies need to be found to overcome this challenge. Bacteriophages, a class of viruses that lyse bacteria, can help us control drug-resistant bacteria. In this study, a novel Vibrio parahaemolyticus phage phiTY18 isolated from the coastal water of Xiamen was explored. Transmission electron microscopy showed that phiTY18 had an icosahedral head of 130.0 ± 1.2 nm diameter and a contractile tail of length of 66.7 ± 0.6 nm. The phage titer could reach 7.2×1010 PFU/mL at the optimal MOI (0.01). The phage phiTY18 had a degree of tolerance to heat and acid and base. At the temperature of 50°C (pH7.0, 1h) the survival phages reached 1.28×106 PFU/mL, and at pH 5-9 (30°C, 1h), the survival phages was greater than 6.37×107 PFU/mL Analysis of the phage one-step growth curve revealed that it had a latent period of 10min, a rise period of 10min, and an average burst size of the phage was 48 PFU/cell. Genome sequencing and analysis drew that phage phiTY18 had double-stranded DNA (191,500 bp) with 34.90% G+C content and contained 117 open reading frames (ORFs) and 24 tRNAs. Phylogenetic tree based on major capsid protein (MCP) revealed that phage phiTY18 (MW451250) was highly related to two Vibrio phages phiKT1024 (OM249648) and Va1 (MK387337). The NCBI alignment results showed that the nucleotide sequence identity was 97% and 93%, respectively. In addition, proteomic tree analysis indicated that phage phiTY18, phiKT1024, and Va1 were belong to the same virus sub-cluster within Myoviridae. This study provides a theoretical basis for understanding the genomic characteristics and the interaction between Vibrio parahaemolyticus phages and their host.

Characteristics and Whole-Genome Analysis of Limosilactobacillus fermentum Phage LFP02

“…Similar to our results, Foschino et al reported the optimal MOI for L. sanfranciscensis phage EV3, which was isolated from sourdough, was 0.01 [26]. Liu et al found that the optimal MOI of phage phiTY18 was 0.01 [27]. The optimal MOI for L. brevis phage was 10 [28].…”

“…At the same time, Figure 1 showed that with the increase in MOI, the titer of the LFP02 phage had two peaks, yet the maximum titer was only one. A similar situation also appeared in the studies by Liu et al [27] and Mercanti et al [29]. As for the reasons for the decline, Mercanti et al suggested that this may be due to the limited number of attachment sites available to phages on the cell wall, or another type of spatial obstruction [29].…”

A review: Marine aquaculture impacts marine microbial communities

“…Vibrio parahaemolyticus , which is a prevalent pathogenic bacterium, poses a threat to both marine organisms and humans, thus resulting in illnesses. V. parahaemolyticus phages such as F23s2, H256D1, and the recently discovered phage phiTY18 showed inhibitory effects, thus offering alternatives to antibiotics to control V. parahaemolyticus [65] , [66] . However, certain viruses, such as the white spot syndrome virus, the Singapore grouper iridovirus, and the infectious subcutaneous and hematopoietic necrosis viruses in aquaculture, exhibit a high fatality rate, thus posing a severe threat to crustaceans and groupers and hindering economic development [67] – [69] .…”

Antimicrobial and antibiofilm activities of formylchromones against Vibrio parahaemolyticus and Vibrio harveyi

“…In contrast, Vibrio mimicus ( Li et al., 2020 ) and Vibrio cholerae ( Silva and Benitez, 2016 ) are most common in freshwater. Among them, V. parahaemolyticus , a Gram-negative bacterium, is found in various marine and freshwater products, including shrimp, crabs, and oysters ( Mahmoud, 2014 ; Liu et al., 2022 ). More gravely, it is the prominent cause of seafood-related contagions and mortality globally, encompassing three categories of diseases: septicemia, infections in wound, and gastroenteritis ( Kim et al., 2022a ).…”