In vitro antimicrobial activity of ethanolic extracts obtained from Ficus spp. leaves against the fish pathogen Aeromonas hydrophila

Abstract

The main goal of this study was to determine in vitro antimicrobial activity of ethanolic extracts obtained from the leaves of various Ficus species against Aeromonas hydrophila isolated locally from infected rainbow trout (Oncorhynchus mykiss Walbaum) with the aim of providing scientific rationale for the use of the plant in the treatment of bacterial infections induced by Aeromonas spp. in fish. Antimicrobial susceptibility testing was done on Muller-Hinton agar with the disc diffusion method. In the present study, most ethanolic extracts proved effective against the A. hydrophila tested, with 10-12 mm inhibition zones observed. A. hydrophila demonstrated the highest susceptibility to F. pumila. Among various species of Ficus with moderate activity against A. hydrophila, the highest antibacterial activities were noted for F. benghalensis, F. benjamina, F. deltoidea, F. hispida, and F. lyrata. Thus, Ficus can be used as a natural antiseptic and antimicrobial agent in veterinary practice. Further investigations need to be conducted to isolate and identify the bioactive compounds that can then be subjected to detailed pharmacological studies and the development of clinical applications. The alarming rate of increasing resistance in bacterial pathogens in aquaculture environments means that medicinal plants with antibacterial properties are very important as natural resources of new active compounds.

Preliminary in Vitro Screening of Antibacterial Activity of Leaf Extract from Ficus Natalensis Subsp. Natalensis Hochst. (Moraceae) Against Fish Pathogens

“…A. hydrophila revealed intermediate susceptibility concerning to ethanolic extract obtained from leaves of F. hispida (inhibition zone diameters were ranged from 8 to 12 mm). The most effective at least causing a zone of inhibition within 14-16 mm was an ethanolic extract from F. hispida leaves against P. fluorescens both in 200 µL of standardized inoculum of the bacterium (inhibition zone ranged from 15 to 16 mm in diameter) and 400 µL (14-15 mm) (Tkachenko et al, 2017d). Our results also indicated that extract obtained from F. mucuso offer a promising alternative to the use of antibiotics in controlling of infection caused by A. hydrophila, C. freundii, P. fluorescens, Y. ruckeri.…”

The Antibacterial Activity of the Ethanolic Leaf Extract of Ficus Vasta Forssk. (Moraceae) Against Aeromonas Spp. Strains

“…This study aimed to find a natural source, antimicrobial substance to replace antibiotics and chemotherapeutics for the treatment of Aeromonas-induced infections in fish aquaculture. According to our preliminary study and studies of other researchers [24,26,[28][29][30][31][32][33][34][35][36][37][38][39], it has been demonstrated that a number of ethanolic extracts derived from various Ficus species and their cultivars showed antibacterial activity against pathogenic isolates as well as antibiotic-resistant bacteria. The plant extracts of the above plant species can be used as a source which could yield alternative drugs to improve the treatment of infection caused by these Aeromonas strains.…”

An in Vitro Assessment of the Anti-Aeromonas Properties of Leaf Extract Obtained From Ficus Lyrata Warb. (Moraceae)

“…A. hydrophila demonstrated the highest susceptibility to F. pumila. The highest antibacterial activity against A. hydrophila (200 µL of standardized inoculum) was displayed by F. benghalensis, F. benjamina, F. deltoidea, F. hispida, F. lyrata leaf extracts [39]. Among various species of Ficus genus exhibiting moderate activity against A. hydrophila (400 µL of standardized inoculum), the highest antibacterial activity was displayed by F. benghalensis, F. benjamina, F. deltoidea, F. hispida, F. lyrata leaf extracts [41].…”

“…In our previous studies, the therapeutic potential for the use of various plants of Ficus genus in the control of bacterial diseases was evaluated against fish pathogens in in vitro study with promising results [33][34][35][36][37][38][39][40][41][42][43][44]. Most ethanolic extracts obtained from Ficus spp.…”

“…We have reported already data on the antioxidant and antibacterial effects of extracts from various plant belonged to the Ficus genus [33][34][35][36][37][38][39][40][41][42][43][44]. Our current scientific project undertaken in the frame of cooperation programme between Institute of Biology and Environmental Protection (Pomeranian University in Slupsk, Poland), Department of Fish Diseases, National Veterinary Research Institute (Pulawy, Poland), M. M. Gryshko National Botanic Gardens of National Academy of Sciences of Ukraine (Kyiv, Ukraine), and Ivan Franko Lviv National University (Lviv, Ukraine) directed to assessment of medicinal properties of tropical plants.…”