Zbigniew Osadowski

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.

The Antibacterial Activity Of Certain Sansevieria Thunb. Species Against Escherichia Coli

The present study was aimed to investigate in vitro antimicrobial activity of ethanolic extracts of seventeen species of Sansevieria Thunb. genus (Sansevieria canaliculata Carrière, Sansevieria trifasciata Prain, Sansevieria cylindrica Bojer ex Hook., Sansevieria parva N.E.Br., Sansevieria fischeri (Baker) Marais, Sansevieria kirkii Baker, Sansevieria aethiopica Thunb., Sansevieria metallica Gérôme & Labroy, Sansevieria caulescens N.E.Br., Sansevieria francisii Chahin., Sansevieria arborescens Cornu ex Gérôme & Labroy, Sansevieria volkensii Gürke, Sansevieria forskaliana (Schult. & Schult.f.) Hepper & J.R.I.Wood, Sansevieria gracilis N.E.Br., Sansevieria hyacinthoides (L.) Druce, Sansevieria roxburghiana Schult. & Schult.f., Sansevieria suffruticosa N.E.Br.) against Escherichia coli (ATCC 25922). The crude extracts were screened for antimicrobial activity using agar disk diffusion method. All the extracts showed variable degree of inhibition against tested bacterium. Therefore, the results revealed the antimicrobial potential of these extracts. In fact, the test organism was susceptible to extracts of Sansevieria kirkii, Sansevieria arborescens, Sansevieria roxburghiana, Sansevieria francisii, Sansevieria forskaliana, Sansevieria cylindrica, Sansevieria trifasciata, Sansevieria canaliculata, Sansevieria caulescens, Sansevieria metallica, Sansevieria aethiopica with diameters of inhibition zone from 12 to 24 mm. Escherichia coli isolate was resistant only to S. hyacinthoides extract and the diameter of zone inhibition around the rest ranged from 8 to 10 mm. Thus, the ethanolic extracts obtained from leaves of Sansevieria kirkii, Sansevieria arborescens, Sansevieria roxburghiana, Sansevieria francisii, Sansevieria forskaliana, Sansevieria cylindrica, Sansevieria trifasciata, Sansevieria canaliculata, Sansevieria caulescens, Sansevieria metallica, Sansevieria aethiopica possess antibacterial potency against Escherichia coli isolates and may be used as natural antiseptics and antimicrobial agents in medicine.