A novel vibriophage exhibits inhibitory activity against host protein synthesis machinery

Khrongkhwan Thammatinna,Joseph Sugie,Anchalee Tassanakajon,Joe Pogliano,Mackennon E Egan,Htut Htut Htoo,Jason F Nideffer,Kanika Khanna,Vorrapon Chaikeeratisak,Poochit Nonejuie,Elizabeth Villa

doi:10.1038/s41598-020-59396-3

Abstract

Since the emergence of deadly pathogens and multidrug-resistant bacteria at an alarmingly increased rate, bacteriophages have been developed as a controlling bioagent to prevent the spread of pathogenic bacteria. One of these pathogens, disease-causing Vibrio parahaemolyticus (VPAHPND) which induces acute hepatopancreatic necrosis, is considered one of the deadliest shrimp pathogens, and has recently become resistant to various classes of antibiotics. Here, we discovered a novel vibriophage that specifically targets the vibrio host, VPAHPND. The vibriophage, designated Seahorse, was classified in the family Siphoviridae because of its icosahedral capsid surrounded by head fibers and a non-contractile long tail. Phage Seahorse was able to infect the host in a broad range of pH and temperatures, and it had a relatively short latent period (nearly 30 minutes) in which it produced progeny at 72 particles per cell at the end of its lytic cycle. Upon phage infection, the host nucleoid condensed and became toroidal, similar to the bacterial DNA morphology seen during tetracycline treatment, suggesting that phage Seahorse hijacked host biosynthesis pathways through protein translation. As phage Seahorse genome encodes 48 open reading frames with many hypothetical proteins, this genome could be a potential untapped resource for the discovery of phage-derived therapeutic proteins.

Highlights

Since the emergence of deadly pathogens and multidrug-resistant bacteria at an alarmingly increased rate, bacteriophages have been developed as a controlling bioagent to prevent the spread of pathogenic bacteria
As observed in negative staining by transmission electron microscopy (TEM), the phage belongs to the order Caudovirales and the family Siphoviridae as it has an icosahedral capsid with a long non-contractile tail with short tail fibers (Fig. 1b)
The infection resulted in mass production losses in southern China and within several years, the incidence of VPAPHND infection had expanded to other neighboring countries such as Vietnam, Malaysia and Thailand[11]

Summary

Introduction

Since the emergence of deadly pathogens and multidrug-resistant bacteria at an alarmingly increased rate, bacteriophages have been developed as a controlling bioagent to prevent the spread of pathogenic bacteria. One of these pathogens, disease-causing Vibrio parahaemolyticus (VPAHPND) which induces acute hepatopancreatic necrosis, is considered one of the deadliest shrimp pathogens, and has recently become resistant to various classes of antibiotics. VPAHPND has become a leading cause in tremendous reduction of shrimp farming yield, which could lend itself to global financial detriments in key shrimp aquaculture industries To prevent these detriments, antibiotics are top candidate for control agents because of their ease of use and high accessibility in many countries. Its application on VPAHPND-infected penaeid shrimp in a lab-scale tank revealed high effectiveness in both prophylactic and therapeutic aspects indicating the potential method of phage therapy, so there is evidence that phage therapy can overcome the specificity concern[28,29,30]

Methods

Results

Conclusion