Protective effects of bacteriophage on experimental Lactococcus garvieae infection in yellowtail

Abstract

ABSTRACT. The present study describes the in vitro and in vivo survival of Lactococcus garvieae bacteriophages and the potential of the phage for controlling experimental L. garvieae infection in yellowtail. Anti-L. garvieae phages persisted well in various physicochemical (water temperature, salinity, pH) and biological (feed, serum and alimentary tract extracts of yellowtail) conditions, except for low acidity. In the in vivo, the phage PLgY-16 was detected in the spleens of yellowtail until 24 h after intraperitoneal (i.p.) injection, or the phage was recovered from the intestine of yellowtail 3 h after the oral administration of phage-impregnated feed but undetectable 10 h later. Simultaneous administration of Live L. garvieae and phage enhanced recovery of the phage from the spleen or intestine. The survival rate was much higher in yellowtail that received 1.p. injection of the phage after i.p. challenge with L. garvieae, compared with that of control fish without phage injection. When fish were i.p.-injected with phage at different hours after L. garvieae challenge, higher protective effects were demonstrated in fish that received phage treatment at the earlier time. Protection was also obtained in yellowtail receiving phage-impregnated feed, in which fish were challenged by an anal intubation with L. garvieae. Anal-intubated L. garvieae were detected constantly In the spleens of the control fish, while they were detected sporadically and disappeared from the phage-treated fish 48 h later. On the other hand, orally administered phage was detected at high plaque-forming units from the intestines and spleens of the phage-treated fish until 48 h later. These results indicate that intraperitoneally or orally administered anti-L. garvieae phage prevented fish from experimental L, garvieae infection, suggesting potential use of the phage for controlling the disease.

Bacteriophage control of Pseudomonas plecoglossicida infection in ayu, Plectoglossis altivelis

“…In addition to successful phage therapy in Pseudomonas plecoglossicida infection of ayu and Lactococcus garvieae infection of the yellowtail Seriola quinqueradiata (Nakai et al 1999), our preliminary study suggests that phage treatment is useful in controlling Vibrio splendidus infection (Sugumar et al 1998) in cultured larvae of the Pacific oyster Crassostrea gigas. Thus, phage therapy may have many applications in the aquaculture field.…”

“…Phages which do not encounter host cells are fated to disappear quickly from fish tissue (Nakai et al 1999, Park et al 2000. Therefore, fish from which phages were detected were those in which phages attacked host bacterial cells proliferating in the fish organs, and thus produced detectable levels of progeny.…”

Antibiotics in Aquaculture – Use, Abuse and Alternatives

“…An anti-Lactococcus garvieae phage was intraperitoneally or orally administered to yellowtail and protected the fish from experimental L. garvieae infection, suggesting a potential use for the phage in controlling this disease (Nakai et al, 1999). The oral administration of phageimpregnated feed to ayu (Plecoglossus altivelis) resulted in protection against infection with Pseudomonas plecoglossicida, which quickly disappeared from the kidneys of the phagetreated fish (Park et al, 2000).…”

“…The use of phage therapy in aquaculture began with the work of Nakai et al (1999) and has been recently reviewed (Almeida et al, 2009). The first studies evaluated the ability of phages to prevent the infection of yellowtail (Seliora quinqueradiata) and ayu (Plecoglossus altivelis) with Lactococcus garvieae and Pseudomonas plecoglossicida, respectively.…”

Evaluating seasonal dynamics of bacterial communities in marine fish aquaculture: a preliminary study before applying phage therapy

“…Enterobactereaceae such as Salmonella, Shigella, and Escherichia coli). [4][5][6] These non-indigenous bacteria can be originated from point source discharges such as raw sewage, storm water, effluent from wastewater treatment plants and industrial sources. In addition, non-point source discharges such as agriculture, forestry, wildlife and urban run-off can also impair water quality.…”