Wrażliwość bakterii beztlenowych na australijski olejek mirtowy (Backhousia citriodora F. Muell.)
Authors: Kędzia Anna , Kędzia Andrzej W. , Ostrowski-Meissner Henry , Wiśniewska Joanna 
Published: January 2021

Introduction. Herbs have been known and utilize since ancient Times in China, Europe and America. The ancient Egiptians used the myrtle to treat fever and infections. The plant have been mentioned in the Bible six times. Dioscorides recommended myrtle oil on patients with blader and lung infections. The herb and essential oil were used in Ayuveric treating infections respiratory tract and neuralgic. Backhousia citriodora F. Muell. belonging to the genus Backhousia and family Myrtaceae. It grown to 20-30 m high, on plantations in Australia, in subtropical rainforests of central and south-eastern Queensland. The leaves of the tree Backhousia citriodora produces an essential oil. It is obtained via hydro distillation. Lemon myrtle oil is known for its characteristic lemon flavor, related with presence of citral. Research indicated, that constituents of oil showed antibacterial activity against aerobic bacteria. There are no information about its activity towards anaerobic bacteria. Aim. The aim of the study was to determine activity of myrtle oil against anaerobic bacteria isolated from patients. Material and methods. The anaerobic bacteria were isolated from various infections of oral cavity. A total 135 strains isolated from patients and 7 reference strains were tested. The suscibility anaerobes to myrtle oil was carried out using plate dilution technique in Brucella agar supplemented with 5% defibrynated sheep blood, menadione and hemin. Inoculum containing 106 in CFU per spot was seeded with Steers replicator upon the surface of agar with myrtle oil and without oil (strains growth control). Incubation the plates was performed in anaerobic jars (10% C02 , 10% H2 , 80% N2 , palladic catalyst and anaerobic indicator) at 37°C for 48 hrs. The MIC was defined as the lowest concentrations of the myrtle oil that completely inhibited growth the tested anaerobic bacteria. Results. The results indicated that the myrtle oil was active against the 44 (50%) from all the tested strains of anaerobes to the concentrations from ranges < 0.12-1.0 mg/ml. The rods from genus of Prevotella oralis and Prevotella oris were sensitive on concentrations < 0.12 mg/ml. The oil was less active against the Gram-negative anaerobes from genus of Prevotella buccalis, Prevotella levii, Prevotella loescheii, Bacteroides uniformis and Parabacteroides distasonis (MIC > 4.0 mg/ml). The Clostridial strains were very sensitive. The growth of this strains was inhibited by concentrations of < 0.12 mg/ml. The volatile oil did appeared to be equally effective against both Gram-negative and Gram-positive anaerobic rods. The growth of 50 and 47% of this bacteria was inhibited in ranges from < 0.12 to 1.0 mg/ml. The tested Gram-negative cocci from genus Veillonella parvula were less sensitive (MIC 1.0-> 4.0 mg/ml). The strains of Gram-positive cocci were the least sensitive. Its growth was inhibited by concentrations 2.0-> 4.0 mg/ml. Conclusions. The myrtle oil was more active against anaerobic bacteria from genus Prevotella oralis, Prevotella oris and strains from genera of Clostridium. The strains from genus Prevotella buccalis, Prevotella levii, Prevotella loescheii, Bacteroides uniformis and Parabacteroides distasonis were the lowest sensitive. The oil was equally effective against Gram-negative and Gram-positive anaerobic bacteria.