Biological control of Aeromonas salmonicida infection in juvenile Senegalese sole (Solea senegalensis) with Phage AS-A

Characterization of bacteriophage HN48 and its protective effects in Nile tilapia Oreochromis niloticus against Streptococcus agalactiae infections

“…Indeed, phage addition to control A. salmonicida infections in Atlantic salmon resulted in an approximately 30% higher survival rate than that of non-treated fish, while a similar treatment in rainbow trout led to survival rates as high as 90%. It should also be noted that different MOI were used in our study and other studies; specifically, 1 in our study and an investigation by Imbeault et al (2006), 100 in a study Silva et al (2016) and 10,000 in a study by Kim et al (2015).…”

“…In studies by Silva et al. () and Vernerjeffreys et al. () who investigated the use of a phage to control A. salmonicida infection, a high MOI was also not beneficial for increasing efficiency of phage therapy, and there were contrary results in vitro and in vivo.…”

“…However, the optimal MOI was 0.1 in vitro, while it was 1 in vivo, therefore, results of the in vitro must be verified in fish and should not be used directly. In studies by Silva et al (2016) and Vernerjeffreys et al (2007) who investigated the use of a phage to control A. salmonicida infection, a high MOI was also not beneficial for increasing efficiency of phage therapy, and there were contrary results in vitro and in vivo. However, when compared to the control group, although there were deaths in phage-administrated groups, the mean time to death (6.5 AE 0.5 day) was delayed, indicating that HN48 has indeed exerted some protective effects against S. agalactiae infection.…”

“…Phages, which are abundant in nature, have the ability to lyse bacteria effectively; therefore, phage therapy is gradually becoming an alternative environmentally friendly biological strategy for controlling bacterial diseases (Carlton, ; Housby & Mann, ; Summers, ). As no drug residues or drug toxicity are associated with this therapy, bacteriophages have been proposed as an alternative to antibiotics usage for biological control of pathogens in cultured fish and shrimp (Jun et al., ; Nakai et al., ; Silva et al., ; Wu & Chao, ). In recent years, increasing studies on their application in aquaculture such as Vibrio harveyi infection in shrimp, S. iniae infection in flounder, Aeromonas hydrophila infection in loaches and A. salmonicida infection in juvenile Senegalese sole (Matsuoka et al., ; Silva et al., ) have been reported, and the experimental results have indicated that most of the phages could be successfully used for both prophylaxis and treatment.…”

“…S. agalactiae infection produces symptoms including erratic swimming, haemorrhaging, corneal opacity, exophthalmia, swelling and ascites [Colour figure can be viewed at wileyonlinelibrary.com] LUO ET AL.| 1481Chang (1981) andWu and Chao (1982) to control A. Hydrophila and E. tarda infections. The administration of PAS-A and PAS-1 showed notable protective effects in S. senegalensis juveniles and rainbow trout against infection by A. salmonicidai, with increased survival rates and delayed mean death times(Silva et al, 2016;Kim et al, 2015). Moreover, use of bacteriophage VPp1 in depuration techniques successfully eliminated V. parahaemolyticus in oysters and shrimp(Lomeli-Ortega & Martinez-Diaz, 2014;Rong, Lin, Wang, Kan, & Li, 2014).…”