dc.description.abstract | Background: The combination of some plant extracts to prevent and treat
bacterial infections is gaining momentum, because of effectiveness against
certain bacteria. This study aims to describe the antibacterial and
immunostimulant abilities of Boesenbergia pandurata (BP), Solanum ferox (SF)
and Zingiber Zerumbet (ZZ) plant extracts to treat and prevent Aeromonas
hydrophila and Pseudomonas fluorescens infection on Tilapia (Oreochromis
niloticus).
Methods: Tilapia (initial weight 15±2 g) were injected intramuscularly (0.1
ml/fish) with a combination of A. hydrophila and P. fluorescens at a density of
1×10 CFU ml of each bacteria. Treatment trials were performed at day 7
post-injection with each combined extract, while the prevention trial was
performed by including the combined extract into the commercial diet for six
and seven days prior to injection. Various extract combinations were 60 mg SF
extract/kg feed with 40 mg ZZ/kg feed (SF60/ZZ40), SF50/ZZ50, BP90/SF10,
and BP50/SF50. Haemato-immunological parameters were performed for four
weeks.
Results: In prevention trials, tilapia fed SF50/ZZ50 showed a significant
increase of white and red blood cells. Similarly, significantly increased
haematocrit was found in tilapia fed SF50/ZZ50 in the treatment trial but not in
the prevention trial. In both trials, haemoglobin of tilapia was not affected by any
combined extracts but decreased the number of bacteria. Phagocytic index,
respiratory burst, lysozyme activity and survival rate of fish fed combined
extracts were found significantly higher than controls. The amount of
pathogenic bacteria in fish fed combined extracts was lower than the control pathogenic bacteria in fish fed combined extracts was lower than the control at
week 4 (P<0.05). In both trials The percentage of survival rate and relative
percent survival of tilapia fed SF 50/ZZ 50, showed the optimum results
compared to the other combinations.
Conclusions: The combined extract in feed, especially SF50/ZZ50 has a
positive effect on the tilapia's innate immune system of tilapia to treat and
prevent bacterial infections. | |