Isolation and Characterization of Two Virulent Phages to Combat Staphylococcus aureus and Enterococcus faecalis causing Dental Caries

Abstract

This study aimed to isolate and characterize bacteriophages, as a biocontrol agent, against certain antibiotic-resistant bacteria causing dental caries. Here, two dental caries-causing bacteria S. aureus and E. faecalis were isolated and characterized biochemically using the automated VITEK® 2 system. Antibiotic sensitivity pattern of the isolated dental caries bacteria was assessed against selection of antibiotics. The two isolates showed resistance against most of the tested antibiotics. To overcome this problem, two lytic phages vB_SauM-EG-AE3 and vB_EfaP-EF01 were isolated, identified, and applied to control the growth of S. aureus and E. faecalis, respectively. Phages were identified morphologically using TEM and showed that vB_SauM-EG-AE3 phage is related to Myoviridae and vB_EfaP-EF01 phage belongs to Podoviridae. The two phages exhibited high lytic activity, high stability, and a narrow host range. The one-step growth curve of phages showed burst sizes of 78.87 and 113.55 PFU/cell with latent periods of 25 and 30 minutes for S. aureus phage and E. faecalis phage respectively. In addition, the two phages showed different structural protein profiles and exhibited different patterns using different restriction enzymes. The genome sizes were estimated to be 13.30 Kb and 15.60 Kb for phages vB_SauM-EGAE3, vB_EfaP-EGAE1, respectively. Complete inhibition of bacterial growth was achieved using phages with MOIs of 103, 102 and 10 after 1, 3, 5, and 24 h of incubation at 37°C. Hence, this study indicates that the isolated bacteriophages are promising biocontrol agents that could challenge antibiotic-resistant dental caries bacteria to announce new successful alternatives to antibiotics.

Fully Characterized Effective Bacteriophages Specific against Antibiotic-Resistant Enterococcus faecalis, the Causative Agent of Dental Abscess

“…Several studies have demonstrated the importance of using bacteriophages against E. faecalis for the treatment of dental problems [ 33 , 34 , 37 , 38 ]. In the work by Nasr-Eldin et al [ 39 ], the isolated potential bacteria were identified biochemically, microscopically described using traditional techniques, and validated using the Vitek2 system. Over the past 30 years, antibiotic-resistant Enterococcus strains have become increasingly related to nosocomial infections, with increasingly high levels of antibiotic resistance and multidrug resistance [ 40 ].…”