Fate and Survivability of Fish Bacteriophage Inoculated in BALB/c Mice

Abstract

Understanding of bacteriophage kinetics in mammals or higher organisms is needed, as this determines the potential phage activity in antibacterial treatment. We demonstrated the fate and survivability of fish phage particles in different organs and fluids inoculated into mice. Phage (PPpW-4) specific to Pseudomonas plecoglossicida was intraperitoneally injected to mice with a dose of 108.1 PFU/ml/mouse. Phage titers (103.0~105.2 PFU/g) were detected in blood and other organs within 10 min after injection except in the urine samples. Phage titers in blood (105.1~106.9 PFU/g) were 10~100 times higher than that of the other organs from 10 min until 24 h. It shows that phage was distributed quickly to the different organs by circulatory system via the blood. Phage titers in all organs showed the highest level in 1 h (104.2~106.9 PFU/g) and reduced rapidly until no phage was detected in 72 h. Although phage disappeared in blood within 72 h, phage can still survived in the spleen and kidney until 96 h. Spleen in particular, had an appreciable phage titer of 102.7 PFU/g. There were comparatively high phage titers (103.0~104.7 PFU/g) in urine from 1 h up to 24 h. It means that one possible mechanism of phage elimination is by urinary excretion.