ABSTRACT
BACKGROUND: In this paper, we have studied the essential oils chemical composition of the leaves of seven Eucalyptus species developed in Tunisia. Eucalyptus leaves were picked from trees growing in different arboretums in Tunisia. Choucha and Mrifeg arboretums located in Sedjnene, region of Bizerte (Choucha: E. maideni, E. astrengens et E. cinerea; Mrifeg : E. leucoxylon), Korbous arboretums located in the region of Nabeul, North East Tunisia with sub-humid bioclimate, (E. lehmani), Souiniet-Ain Drahem arboretum located in region of Jendouba (E. sideroxylon, E. bicostata). Essential oils were individually tested against a large panel of microorganisms includingStaphylococcus aureus (ATCC 6539), Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC29212), Listeria ivanovii (RBL 30), Bacillus cereus (ATCC11778). RESULTS: The yield of essential oils ranged from 1.2% to 3% (w/w) for the different Eucalyptus species. All essential oils contain α-pinene, 1,8-cineol and pinocarveol-trans for all Eucalyptus species studied. The 1,8-cineol was the major compound in all species (49.07 to 83.59%). Diameter of inhibition zone of essential oils of Eucalyptus species varied from 10 to 29 mm. The largest zone of inhibition was obtained for Bacillus cereus (E. astrengens) and the lowest for Staphylococcus aureus (E. cinerea). The essential oils from E. maideni, E. astrengens, E. cinerea (arboretum of Bizerte), E. bicostata(arboretum of Aindraham) showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus. CONCLUSION: The major constituents of Eucalyptus leaves essential oils are 1,8-cineol (49.07 to 83.59%) and α-pinene (1.27 to 26.35%). The essential oils from E. maideni, E. astrengens, E. cinerea, E. bicostatashowed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus, they may have potential applications in food and pharmaceutical products.
Subject(s)
Anti-Bacterial Agents/pharmacology , Eucalyptus/chemistry , Eucalyptus/classification , Oils, Volatile , Plant Leaves/chemistry , Bacillus cereus/drug effects , Cell Proliferation/drug effects , Cyclohexanols/analysis , Enterococcus faecalis/drug effects , Escherichia coli/drug effects , Gas Chromatography-Mass Spectrometry , Listeria/classification , Listeria/drug effects , Monoterpenes/analysis , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Plant Extracts/pharmacology , Staphylococcus aureus/drug effects , TunisiaSubject(s)
Penicillin G , Penicillins/classification , Haemophilus influenzae/drug effects , Enterococcus/drug effects , Drug Hypersensitivity/classification , Gram-Negative Bacteria/classification , Gram-Positive Bacteria/classification , Ampicillin/pharmacology , Lactams/therapeutic use , Listeria/drug effectsABSTRACT
El contacto de polimixina B, sobre hematíes humanos produjo un efecto sobre la actividad hemolítica de las hemolisinas del género Listeria. A bajas concentraciones de antibiótico, se observó un efecto promotor de la hemólisis; verificándose una inhibición de la lisis eritrocitaria a altas concentraciones de polimixina B. Este comportamiento permitió definir perfiles hemolíticos para cada una de las especies hemolíticas del género en estudio. Listeria monocytogenes y Listeria seeligeri presentaron perfiles superponibles con un máximo hemolítico a 1.000 U/ml de polimixina B. Listeria ivanovii presentó dos picos hemolíticos: uno coincidente con aquél presentado por Listeria monocytogenes y Listeria seeligeri a 1.000 U/ml y un segundo pico a 4.000 U/ml de polimixina B
Subject(s)
Listeria/drug effects , Polymyxin B/pharmacology , Species Specificity , Hemolysin Proteins/physiology , Hemolysis , Listeria/physiology , Philippines , Heat-Shock Proteins/physiologyABSTRACT
Em 298 amostras de Listeria, isoladas no período de 1966 - 1986 provenientes de diferentes fontes (humana, animal e vegetal) e de algumas regiöes do país, determinou-se o nível de suscetibilidade frente a 14 antimicrobianos, através da técnica de difusäo em agar, com discos impregnados. O padräo de sensibilidade obtido, revelou uma extrema homogeneidade, näo possibilitando distinçöes em alguns dos parâmetros confrontados (fonte e período de isolamento, origem geográfica e sorotipo). Uma acentuada sensibilidade (>-90% das amostras) foi observada em relaçäo à gentamicina, sisomicina, cefalotina, ampicilina, sulfametoxazol-trimetroprim e tetraciclina
Subject(s)
Animals , Humans , Listeria/drug effects , Anti-Bacterial Agents/pharmacology , Brazil , Drug Resistance, MicrobialABSTRACT
Se han efectuado estudios comparativos de velocidad de crecimiento, cosecha máxima y duración de la fase de adaptación de poblaciones de Listeria monocytogenes (CCMA 29454, ATCC 15313) a 37-C, en medios de cultivo líquidos conteniendo concentraciones variables de antimicrobianos con diferente espectro de acción. Concentraciones de 160microng/ml de ácido nalidíxico, 80microng/ml de ácido pipemédico, 40microng/ml de ácido oxolínico, 0,8U/ml de bacitracina y 200U/ml de nistatina, constituyen límites confiables que permiten la sobrevivencia y multiplicación de Listeria monocytogenes y ejercen una importante acción inhibitoria sobre el crecimiento de gran parte de la flora habitual de materiales normalmente sépticos. Es de importancia la potencial capacidad selectiva de diversas asociaciones de los agentes ensayados en la formulación de medios de cultivo destinados a un enriquecimiento de Listeria monocytogenes, que posibilite su aislamiento a partir de cultivos mixtos