Effect of Rosemary (Rosmarinus officinalis) and Sage (Salvia officinalis) Essential Oils on Disease Resistance against Aeromonas sobria in Goldfish (Carassius auratus)

Abstract

In this study, the chemical composition and the antibacterial properties against Aeromonas sobria of the essential oils of rosemary and sage in gold fish were evaluated in vitro and in vivo for the first time. The major constituents were eucalyptol (26.36 %) and camphor (29.17 %) for rosemary essential oil and eucalyptol (27.08 %), thujone (20.52 %) and camphor (16.99 %) for sage oil. In vitro antibacterial effects of essential oils against A. sobria were detected by agar diffusion assay. The in vitro antibacterial effect of rosemary (20±2.82 mm) and sage (18.5±2.12 mm) essential oils (1000 µl ml-1) were determined to be strong against A. sobria (p˂0.05). The effects of the essential oils on the disease resistance of goldfish were also investigated. Fish (5±0.15 g) were fed with different concentrations (0, 1.0 and 3.0 ml kg-1) of each essential oil for 45 days. After feeding, the fish were challenged with A. sobria. Dietary administration of sage essential oil (1.0 and 3.0 ml kg-1) and rosemary oil (3 ml kg-1) resulted in a significant reduction in mortality due to A. sobria compared to control fish. Our results suggest that these plant oils could provide an alternative for A. sobria infection control in aquaculture. preventive measures are not taken, the disease is easily transmitted to other fish. Motile aeromonad septicaemia (MAS), is probably the most common bacterial disease in freshwater aquarium fish (Lewbart, 2001; Jagoda et al., 2014). Among the motile aeromonads, Aeromonas hydrophila, A. sobria and A. caviae are most commonly associated with fish. A. hydrophila has gained much attention as the most common fish pathogenic motile Aeromonas species, but other Aeromonas species may also play an essential role in infection (Beaz-Hidalgo and Figueras, 2012). The goldfish, Carrassius auratus has high susceptibility to Motile aeromonads (Citarasu et al., 2011). It is often an opportunistic infection, characterized by non-specific signs such as fin rot, ulceration, haemorrhages, exophthalmia and dropsy (Beaz-Hidalgo and Figueras, 2012). Antibiotics are commonly used for the treatment of fish infections in aquaculture. However, they cause significant problems including resistance development in bacteria, residue in fish tissue, suppression of immune system and damage of beneficial microbial flora (Defoirdt et al., 2007; Sapkota et al., 2008). For these reasons, alternative products have become more important for the control of fish diseases (Sivaram et al., 2004). The use of natural substances obtained from plants to control of fish diseases in aquaculture has increased (

Effects of Dietary Sage, Myrtle and/or Probiotic Mixture on Growth, Intestinal Health, Antioxidant Capacity, and Diseases Resistance of Oncorhynchus mykiss

“…Medicinal plants may have provided a protection against this pathogen due to the phenolic compounds that are known to restrict or inhibit the growth of bacteria (Dorman & Deans 2000). The antimicrobial activity of sage and myrtle was based on the 1,8-cineole component (Metin et al 2020).…”