Phage JS02, a putative temperate phage, a novel biofilm-degrading agent for Staphylococcus aureus.

L Zhang,R Wang,A Soleimani-Delfan,L Sun,K Shahin,H Wang,H Ding

doi:10.1111/lam.13663

Abstract

Staphylococcus aureus is a biofilm-producing organism that is frequently isolated from various environments worldwide. Because of the natural resistance of S. aureus biofilm to antibiotics, bacteriophages are considered as a promising alternative for its removal. The bacteriophage vB_SauS_JS02 was isolated from livestock wastewater and showed activity against multidrug-resistant S. aureus. The phage vB_SauS_JS02 exhibited a broad host range and possessed a large burst size (52 PFU/CFU) as well as moderate pH stability (4-11) and appropriate thermal tolerance (40-50°C). Electron microscopy and genome sequence revealed that vB_SauS_JS02 belonged to Triavirus genus in Siphoviridae family. Genetic analysis of the 46 kb sequence of vB_SauS_JS02 revealed 66 ORFs. The predicted protein products of the ORFs were clustered functionally into five groups as follows: replication/regulation, DNA packaging, structure/morphogenesis, lysis and lysogeny. Although the phage vB_SauS_JS02 was a temperate phage, it exhibited a higher inhibiting and degrading activity against planktonic cells (80~90% reduction), even to S. aureus biofilm (~68% reduction in biofilm formation). Moreover, the removal activity of the phage vB_SauS_JS02 against both planktonic cells and S. aureus biofilms was even better than that of the antibiotic (ceftazidime). In summary, the present study introduced the phage vB_SauS_JS02 as a potential biocontrol agent against biofilm-producing S. aureus after making it virulent. It may be applicable for phage therapy.

Highlights

Staphylococcus aureus is a biofilm-producing organism that is frequently isolated from various environments worldwide
The phage vB_SauS_JS02 was a temperate phage with a higher inhibiting and degrading activity against planktonic cells (~86% reduction) and S. aureus biofilm (∼68% reduction in biofilm formation)
The infectivity of the phage vB_SauS_JS02 remained intact when heated to 40 oC or 50 oC and decreased rapidly above 60 oC (Figure 1D)

Summary

Introduction

Staphylococcus aureus is a biofilm-producing organism that is frequently isolated from various environments worldwide. Because of the natural resistance of S. aureus biofilm to antibiotics, bacteriophages are considered as a promising alternative for its removal. Multidrug-resistant (MDR) Staphylococcus aureus is a clinical pathogen with worldwide occurrence that causes a wide range of health problems such as foodborne diseases, wound injuries, and urinary tract infections [1]. Methicillin-resistant S. aureus is frequently detected in contaminated dairy farms [2, 3]. It is important to control the occurrence of S. aureus in foods in order to ensure food safety. Because S. aureus has a high ability to form biofilms on a wide range of surfaces, alternative and safe approaches are required for its biocontrol in foods. Biofilms are aggregated structured communities of bacteria enclosed in a matrix (often referred to as extracellular polymeric substances), which is composed of proteins, DNA, and polysaccharides. Bacteria may evade host defenses and become tolerant to antimicrobial agents that can inhibit free-floating, single-cell (planktonic) bacteria, thereby making biofilms difficult to eradicate [4]

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Results

Discussion

Conclusion