Salmonella is often associated with retail poultry products. Our research evaluated the effect of temperature on the biofilm formation by Salmonella spp. and the efficacy of essential oils in controlling these biofilms on stainless steel surfaces. The sublethal concentrations of thyme, oregano and carvacrol at 0.006-0.012% suppressed biofilm formation by Salmonella spp. while concentrations at 0.05-0.1% reduced the biofilms of a three-strain mixture of Salmonella spp. by 7 logs. Carvacrol was evaluated in combination with lauric arginate for controlling the three-strain mixture of Salmonella spp. in ground turkey containing 1%, 7% or 15% fat. Higher concentrations of carvacrol (1%) or lauric arginate (2000 ppm) when applied individually did not reduce Salmonella counts in ground turkey containing 7% fat. The combined mixture of carvacrol and lauric arginate at these higher concentrations was found to be synergistic in reducing the Salmonella counts by 4 log CFU/g in ground turkey containing 7% fat.

No description available.

<p>Poznavanje i razumevanje adhezivne sposobnosti i formiranja biofilma patogenih bakterija, kao i njihovog odnosa prema faktorima koji mogu stimulisati ili inhibirati razvoj biofilma, je od fundamentalnog značaja za iznalaženje mera za njihovu efikasnu prevenciju i eliminaciju.<br />Imajući u vidu navedenu činjenicu kao i da je Salmonella enterica serotip Enteritidis epidemiolo&scaron;ki najfrekventniji serotip cilj ovog istraživanja je bio da se ispita: sposobnost različitih sojeva Salmonella Enteritidis izolovanih iz kliničkog materijala, hrane za životinje i odabranog referentnog soja da formiraju biofilm, adherentnost na povr&scaron;ine od stakla i nerđajućeg čelika, sposobnost preživljavanja odabranih biofilm produkujućih sojeva kao i mogućnost primene konfokalne laserske i skening elektronske mikroskopije u vizuelizaciji trodimenzionalne strukture biofilma.<br />Određivanjem morfotipa kolonija na Kongo red agaru na temperaturi inkubiranja od 25&deg;C među testiranim izolatima detektovana su tri morfotipa RDAR (red, dry and rough), BDAR (brown dry and rough) i SAW (smooth and white). Polovina testiranih izolata je eksprimirala RDAR morfotip. Izolati koji su eksprimirali karakterističan morfotip na ovoj temperaturi su formirali na vazduh tečnost međufazi isti tip pelikule.<br />Uporednom analizom rezultata primenjenih skrining testova za utvrđivanje sposobnosti formiranja biofilma pri temperaturi inkubiranja od 25&deg;C ustanovljena je korelacija između pojave određenog morfotipa na Kongo crvenom agaru i sposobnosti formiranja biofilma u kristal violet i pelikula testu. Međutim, sa povećanjem temperature inkubiranja na 37oC, ova korelacija nije ustanovljena, sa izuzetkom izolata SE8.<br />Svi testirani izolati su pokazali sposobnost adherencije na povr&scaron;inu stakla i nerđajućeg čelika, ali u različitoj meri. Na sposobnost adherencije povoljniji uticaj je imala temperatura inkubiranja od 25&deg;C (p&lt;0,05), sa izuzetkom izolata SE3 (p&gt;0,05). Između stepena adherencije izolata na povr&scaron;ine stakla i nerđajućeg čelika nisu ustanovljene statistički značajne razlike (p&gt;0,05).<br />Praćenjem stope preživljavanja tokom 28 dana u uslovima isu&scaron;ivanja evidentirana je znatno veća stopa preživljavanja ćelija izolata RDAR morfotipa u odnosu na stopu preživljavanja ćelija BDAR morfotipa (p&lt;0,05). Praćenjem stope preživljavanja tokom 90 dana u uslovima povremene dostupnosti hranljivih materija, zabeležena je veća stopa preživljavanja u odnosu na stopu preživljavanja u uslovima isu&scaron;ivanja. U uslovima povremene dostupnosti hranljivih materija nakon devedeset dana ispitivanja kod obe grupe izolata procenat vijabilnih ćelija je iznosio vi&scaron;e od 50%.<br />Primenjenim mikroskopskim tehnikama (CLSM i SEM) omogućena je detaljna vizualizacija formiranih biofilmova. Na modelu izolata SERDAR morfotipa, ustanovljeno je da se formiranje biofilma pod primenjenim eksperimentalnim uslovima, odvija u tri faze: 1) inicijalna adhezija za povr&scaron;inu i formiranje manjih ćelijskih agregata (24h); 2) formiranje većih ćelijskih agregata uz produkciju EPS (48h); 3) sazrevanje biofilma uz značajnu produkciju EPS &scaron;to omogućava formiranje stabilne trodimenzionalne strukture biofilma (96h).<br />Nasuprot karakteristikama koje bakterije pokazuju tokom rasta u medijumima koji obiluju hranljivim materijama, bakterije u biofilmovima pokazuju drugačije osobine u pogledu ekspresije gena i karakteristika rasta. Zahvaljujući ovim razlikama, bakterije u biofilmovima pokazuju povećanu rezistenciju na antibiotike i dezinficijense, zbog čega se konstantno razvijaju nove kontrolne strategije u cilju iznalaženja potencijalnih biolo&scaron;kih re&scaron;enja koja pored različitih enzima, faga, antimikrobnih jedinjenja proizvedenih od strane mikroorganizama uključuju i antimkrobna jedinjenja biljnog porekla kao &scaron;to su biljni ekstrakti, etarska ulja i različiti začini. Stoga, je u okviru drugog segmenta ovog istraživanja ispitivan hemijski sastav etarskih ulja, antimikrobni efekat etarskih ulja (O. heracleoticum , O. vulgare , Th. vulgaris i Th. serpyllum) i pojedinačnih komponenti etarskog ulja (karvakrola i timola) na bujonske kulture testiranih sojeva Salmonella Enteritidis kao i uticaj odabranih koncentracija etarskih ulja na inicijalnu adheziju i već formirani biofilm odabranih sojeva Salmonella Enteritidis.<br />Etarska ulja je karakterisao visok zbirni udeo glavnih fenolnih komponenti karvakrola i timola: O. heracleoticum (71,6%), O. vulgare (63,6%), Th. vulgaris (59,77%), Th. serpyllum (40,04%). Etarska ulja su ispoljila antimikrobni efekat sledećim redosledom: O. heracleoticum &gt;O. vugare =Th. vulgaris &gt;Th. serpyllum. Antimikrobni efekat etarskih ulja je bio direktno srazmeran zbiru fenolnih komponenti (karvakrola i timola) u etarskom ulju. U odgovoru na tretman etarskim uljima između izolata S. Enteritidis nisu ustanovljene razlike.<br />Etarska ulja, karvakrol i timol su pokazali inhibitorni efekat na inicijalnu adheziju i posledično na formiranje biofilma testiranih izolata S. Enteritidis na dozno zavisan način. Upoređivanjem uticaja etarskih ulja na inhibiciju inicijalne adhezije i metabolitičke aktivnosti ćelija između izolata RDAR i BDAR morfotipa ustanovljene razlike nisu bile statistički značajne (p&gt;0,05).<br />Ispitivanjem uticaja etarskih ulja, karvakrola i timola na ukupnu biomasu biofilma i metabolitičku aktivnost ćelija dokazano je da etarska ulja u primenjenim koncentracijama ispoljavaju uticaj na redukciju ukupne biomase formiranog biofilma i metaboličke aktivnosti bakterijskih ćelija na dozno zavisan način u funkciji vremena. Znatno veća efikasnost primenjenih tretmana je pokazana u slučaju njihove primene na biofilmove formirane od strane izolata BDAR morfotipa (p&lt;0,05).</p> / <p><span style="font-size:10px;">Knowledge and understanding ability of the pathogenic bacteria that adhere to surface and form biofilm, as well as their relationship between these abilities and factors that stimulate or inhibit biofilm development, are essential to develop strategies for their prevention and elimination.<br />Considering also the fact that Salmonella enterica serotype Enteritidis has been epidemiologically the most frequently found serotype, the aims of this study were to evaluate: biofilm forming ability of several Salmonella Enteritidis strains isolated from clinical material, feed and selected control strain, their ability to adhere to glass and stainless steel surfaces, survival of selected biofilm-producing strains, as well as the possibility of applying confocal laser scanning (CLSM) and scanning electron microscopy (SEM) for visualization of biofilm three-dimensional structure.<br />Determination of colony morphotype on Congo red agar at incubation temperature of 25&deg;C revealed that among all tested isolates three morphotypes were detected: RDAR (red, dry and rough), BDAR (brown dry and rough) and SAW (smooth and white). Half of all tested isolates expressed RDAR morphotype. All isolates that expressed specific morphotype at this incubation temperature also formed the corresponding type of pellicle at air-liquid interface.<br />Comparing the results of the applied assays was ascertained the correlation between specific morphotype on Congo red agar and biofilm forming ability in Cristal violet and pellicle tests, at incubation temperature of 25&ordm;C. In the case of assays conducted at 37&deg;C, this correlation was not established, except for the isolate SE8.<br />All tested isolates showed varying degree of the ability to adhere to glass and stainless steel surfaces. Incubation temperature of 25&ordm;C had more favorable effect on the adherence, with the exception of isolate SE3 (p&gt;0.05). There were no statistically significant differences between adherence ability of all isolates to glass and stainless steel surfaces (p&gt;0.05).<br />Accompaniment of the survival rate during 28 days in the conditions of desiccation, the significantly higher survival rate was</span> <span style="font-size:10px;">obtained for RDAR than BDAR morphotype isolates (p&lt;0.05). Accompaniment of the survival rate during 90 days in the conditions of occasional availability of nutrients, it was detected the higher survival rate than in condition of desiccation. Under these conditions, after 90 days, there were more than 50% of viable cells among both groups of isolates.<br />Applied microscopic techniques (CLSM and SEM) provided detailed visualization of formed biofilms. On model of SERDAR morphotype isolate, it was established that biofilm formation under this experimental conditions has three phases: 1) initial adhesion to the surface and formation of small cell aggregates (24h); 2) formation of large cell aggregates followed with production of extracellular polymer substance (EPS) (48h); 3) maturation of biofilm followed with significant EPS production, which allows formation of stabile three dimensional structure of the biofilm (96h).<br />Contrary to characteristics that bacteria expressed during their growth in the nutrient media, bacteria in biofilms show different properties in terms of genes expression and growth characteristics. Due to these differences, bacteria in biofilms showed higher resistance to antibiotics and disinfectants. For these reasons are being constantly developed new potential biological control strategies that aim at finding the potential biological solutions that besides different enzymes, phages, antimicrobial compounds produced by microorganisms, also include antimicrobial compounds of plant origin, such as extracts, essential oils and different spices.<br />Therefore, the other segment of this research was investigation of the chemical composition and antimicrobial properties of different essential oils (O. heracleoticum, O. vulgare, Th. vulgaris and Th. serpyllum) and their components (carvacrol and thymol), against broth cultures of Salmonella Enteritidis. Also, selected concentrations of essential oils were tested against initial adhesion and preformed biofilm of selected Salmonella Enteritidis isolates.<br />Essential oils were characterized by high amount of phenol compounds carvacrol and thymol: O. heracleoticum (71.6%), O. vulgare (63.6%), Th. vulgaris (59.77%) and Th. serpyllum (40.04%). Essential oils showed antimicrobial potential as follows: O. heracleoticum &gt; O. vugare = Th. vulgaris &gt; Th. serpyllum. Antimicrobial effect was directly proportional to the total content of phenolic components (carvacrol and thymol) in essential oil. Between responses of different S. Enteritidis isolates to essential oil treatment, there was no significant difference.<br />Essential oils, carvacrol and thymol demonstrated inhibitory effect on initial adhesion and consequently, on biofilm formation of S. Enteritidis isolates, in a dose-dependent manner. Comparing influence of essential oil on the inhibition of initial cell adhesion and metabolic activity of cells RDAR and BDAR morphotype, no statistically significant differences were established (p&gt;0.05).<br />Examination of the influence of essential oils, carvacrol and thymol on total biomass of preformed biofilms and metabolic activity of cells, it was revealed that essential oils in applied concentrations cause reduction of total biomass of preformed biofilm and metabolic activity</span> <span style="font-size:10px;">of bacterial cells in a time and dose dependent manner. Applied treatments demonstrated significantly higher efficiency on BDAR morphotype biofilms (p&lt;0.05).</span></p>

Zuzana Bílková, Biological activities of Lavandula angustifolia essential oil, Thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, thesis author: PharmDr. Jan Martin, PhD., Hradec Králové, 2013, 72 pages. The thesis called "Biological activities of Lavandula angustifolia essential oil" is interested in biological activities of Lavandula angustifolia essential oil, specifically antifungal, antioxidant, anti-inflammatory, cytotoxicity, nematicidal and repellency activities. The aim of work was to find out, if the oil can be used in these indications and become natural substitution to the chemical compound toxic to the environment. Antifungal activity was tested against the most common human patogenes, low toxicity proves that essential oil can be used on human cells without causing any harm. Antioxidant activity was tested on NO reaction, nematicidal activity was tried on proctection of crop where nematodes cause huge economic loss. Repellency activity can protect both decorative and agricultural plants. Key words: Lavandula angustifolia, biological activities, anti-inflammatory, antifungal, cytotoxicity, repellency, antioxidant, nematicidal, essential oil.

Faculty of Sciences School of Pharmacy and Pharmacology 0000073k moollaaneesa@yahoo.com / As part of an investigation of the biological activities of South African plants and due to their extensive traditional use and lack of scientific evidence, a phytochemical and pharmacological investigation was performed on 17 indigenous Agathosma species (19 samples). The chemical composition of the essential oils was determined using gas chromatography coupled to mass spectroscopy (GC-MS). Analysis resulted in the identification of 333 compounds. To evaluate the chemical similarities and differences, cluster analysis was used to assess the essential oil composition of the samples. The results showed qualitative and quantitative differences amongst the taxa. The essential oils of Agathosma hirsuta and A. zwartbergense are particularly rich in citronellal, hence they are tightly clustered in the dendrogram obtained from the cluster analysis. Linalool, myrcene and limonene are the major constituents of both A. capensis (Gamka) and A. capensis (Besemfontein). Qualitative and quantitative differences are noted in the chemical compositions of the leaf oils of Agathosma capensis (Gamka) and A. capensis (Besemfontein). Agathosma arida and A. lanata are united in a single cluster due to the compounds β-pinene, linalool and spathulenol being major components in both species. The presence of 1,8-cineole in large quantities in both Agathosma namaquensis (23.5%) and A. ovalifolia (9.7%), unites them in a single cluster. A wide chemical variability for the essential oils of indigenous Agathosma species has been demonstrated. There was considerable variation in the percentage oil yield of the essential oils. Agathosma hirsuta produced the highest yield (1.15%) whilst A. ovalifolia produced the lowest yield (0.16%). vi Previous studies have revealed that the coumarin and flavonoid components of Agathosma species are responsible for their biological activities. High performance liquid chromatography (HPLC) was used to document the non-volatile composition of Agathosma species and to establish if phenolic patterns were present amongst the species. All species were found to be rich in flavonoids (i.e. flavones and flavonols). Many of the compounds detected were common to most of the species. A pure coumarin, puberulin, was identified in the diethyl ether extract of Agathosma ovata (round-leaf) and detected in the dichloromethane and methanol (1:1) extract of A. namaquensis. Agathosma species have been used traditionally to treat a wide variety of infections. They has been used as a cough remedy, for the treatment of colds and flu, kidney and urinary tract infections, for the treatment of cholera and other stomach ailments. Based on the extensive use and lack of scientific evidence, a study was embarked upon to determine its bioactivity. Using the disc diffusion assay as a preliminary screening and thereafter the minimum inhibitory concentration (MIC) assay, the antimicrobial activity of the essential oils and non-volatile compounds was assessed on two Gram-positive bacteria, Staphylococcus aureus and Bacillus cereus, one Gram-negative bacterium, Klebsiella pneumoniae, and one yeast, Candida albicans. All of the extracts proved to be active against the four pathogens tested with the exception of Agathosma bathii which showed poor activity against Klebsiella pneumoniae (MIC value of 32mg/ml). The extracts exhibited stronger activity against the pathogens as compared to the essential oils. Both the essential oils and extracts exhibited higher activity towards the Gram-positive bacteria than the Gram-negative bacterium, with the extract of Agathosma ovata (round-leaf) displaying the greatest vii activity against Staphylococcus aureus (MIC value of 0.156mg/ml) and Bacillus cereus (MIC value of 0.125mg/ml). The extract of Agathosma parva displayed the greatest activity against Candida albicans and Klebsiella pneumoniae (MIC value of 1.5mg/ml). Amongst the essential oils, Agathosma pungens proved to be the most active against the Gram-positive pathogen, Bacillus cereus (MIC value of 3mg/ml). Agathosma collina was the most active against Candida albicans (MIC value of 3mg/ml) whilst A. zwartbergense proved to be the least active against most of the tested pathogens. The antimicrobial activity of the essential oils may be ascribed to oxygenated constituents, such as 1,8-cineole, linalool and carvacrol. The activity of the extracts may be ascribed to constituents such as flavonoids, coumarins and alkaloids. Due to the availability and accessibility of Agathosma ovata, a seasonal variation study was performed on the chemical composition of the essential oils and how this may impact on the antimicrobial activity. Furthermore, this species has recently been earmarked for commercial development by the flavour and fragrance industry and information on variability is required to establish the harvesting protocol. Ten samples were harvested in total. There was a substantial variation in the oil yield throughout the year, ranging from 0.23% in early Spring to 0.85% in late Autumn. A higher yield was observed during the flowering season as compared to the non-flowering season. Oil yields were low during Summer (0.44%-0.48%) which may have been due to the low oil content in stems and higher proportion of stems after flowering. The proportion of oil-rich green leaves also decreased markedly, hence affecting the yield. Overall the yields were dependant on the season harvested and proportion of plant parts distilled. viii The chemical composition of the essential oils was determined using GC-MS and resulted in the identification of 145 compounds in 10 of the samples. All samples contained a large number of common monoterpenes and had very similar compositions, with minor quantitative variation. Some components common to all samples include: sabinene, p-cymene, β-pinene, α-pinene, α-thujene, myrcene, limonene, linalool and terpinen-4-ol. Sabinene was found to be the most dominant component in all samples, ranging between 25.6% and 44.4%. Myrcene levels dropped sharply between the beginning of Spring and end of Summer, from 14.9% to 1.0%. β-pinene followed a similar trend, peaking during Spring and decreasing during the Summer months. The lowest levels of linalool (4.3%), myrcene (1.0%), β-pinene (3.9%), limonene (1.9%) and sabinene (25.6%), occurred during the Summer months when the temperatures were high. There was a Springtime increase in the levels of β- pinene, terpinen-4-ol, linalool, sabinene, limonene and p-cymene in the non-flowering Agathosma ovata. These changes may have been due to the higher proportion of young leaves during Spring, which may have oil compositions slightly different to those of mature leaves. A rare thiol derivative (tr) that could not be identified was detected in the March sample. Many of the changes were associated with flowering and the results obtained reveal that the chemical composition of the essential oil of Agathosma ovata is subject to seasonal variation. Using the MIC assay, the antimicrobial activity of the essential oils was assessed on two Gram-positive bacteria, Staphylococcus aureus and Bacillus cereus, one Gramnegative bacterium, Klebsiella pneumoniae, and one yeast, Candida albicans. The study demonstrated differences in the potency of antimicrobial activity of the essential oils distilled each month. The Winter samples were more active against Bacillus cereus, Staphylococcus aureus and Klebsiella pneumoniae. Activity in mid Spring ix was greater against Staphylococcus aureus (MIC value of 3mg/ml) and Klebsiella pneumoniae (MIC value of 3mg/ml), whilst activity decreased in Summer. There was a correlation between the concentrations of the active compounds each month and the oils antimicrobial activity. The results reveal that the antimicrobial activity of the essential oil of Agathosma ovata may not depend on the level of one component but rather the ratio of several components. ‘Buchu’ has been used traditionally as a general tonic and medicine. Tonics generally have a high anti-oxidant content in order to promote the overall well-being of the user. The anti-oxidant properties of the essential oils and non-volatile compounds was investigated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azinobis(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Only the non-volatile compounds exhibited activity. Their activities may be ascribed to the flavonoid components. Most of the species portrayed moderate to poor activity in the DPPH assay with the exception of Agathosma capensis (Gamka) (IC50 value of 24.08 + 4.42μg/ml) and A. pubigera (IC50 value of 35.61 + 0.86μg/ml) which were two of the most active species, although their activities were inferior when compared to vitamin C. The results from the ABTS assay differed from that of the DPPH assay. All extracts showed greater activity in this assay with Agathosma namaquensis (IC50 value of 15.66 ± 4.57μg/ml) and A. capensis (Besemfontein) (IC50 value of 19.84 ± 0.09μg/ml) being the most active species. This may be due to the ABTS assay having an additional reaction system. ‘Buchu’ has been used traditionally as an antipyretic, topically for the treatment of burns and wounds and for the relief of rheumatism, gout and bruises. The antix inflammatory activity of the essential oils and non-volatile compounds was assessed using the 5-lipoxygenase (LOX) assay. Only the essential oils exhibited activity. All proved to be active with the exception of Agathosma stipitata which was UV active and caused interference. This was due to its major compounds neral (39.9%) and geranial (10.1%) which absorbed strongly at 234 nm and hence rendered its spectrophotometric measurement impossible. The essential oil of Agathosma collina displayed the most promising activity (IC50 value of 25.98 ± 1.83μg/ml). It is well known that many herbal medicines can have adverse effects, in which case it is necessary to evaluate the benefit-risk profile. The toxic effects of Agathosma species have been poorly studied and no information is available in this regard. Hence the toxicity profile of the non-volatile compounds and essential oils was assessed on transformed human kidney epithelium (Graham) cells using the microculture tetrazolium (MTT) cellular viability assay. The extracts of Agathosma lanata (IC50 value of 26.17 ± 9.58μg/ml) and A. ovata (round-leaf) (IC50 value of 25.20 ± 6.30μg/ml) proved to be the most toxic, whilst the extracts of Agathosma bathii, A. capensis (Besemfontein), A. betulina, A. crenulata and A. namaquensis did not prove to be toxic at the concentrations tested. Serial dilutions displayed different inhibitions of cell growth and the species proved to be toxic in a dose-dependant manner. The essential oils of all 19 species proved to be much more toxic (IC50 values < 0.0001μg/ml) than a plant-derived compound that is considered relatively safe, namely quinine (IC50 value of 136.06 ± 4.06μg/ml). The toxicities of the essential oils may be due to compounds like methyl chavicol, eugenol, methyl eugenol, pulegone and methyl salicylate whilst the toxicities of the extracts may be due to the alkaloid and coumarin components.

ABSTRACT Twenty essential oil constituents (EOC′s) from seven structural groups were tested for their antimalarial, antimicrobial (both bacterial and fungal), anti-oxidant, anticholinesterase and toxicity properties. To test for their antimalarial property, the tritiated hypoxanthine incorporation assay was used, while the disc diffusion and minimum inhibitory concentration (MIC) microplate assays were employed for the antimicrobial properties. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used to test the anti-oxidant property and their toxicity profile was assessed with the 3-(4,5-dimethyl-2-thiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cellular viability assay. The anticholinesterase activity was determined using the thin layer chromatography (TLC) bioautographic method. The EOC´s were found to inhibit the growth of Plasmodium falciparum with IC50 values ranging between 0.9 to 1528.8μM with E- and Z-(±)-nerolidol, (-)-pulegone, (+)-α-pinene and linalyl acetate being the most active. In combination p-cymene (the least active) and E- and Z-(±)-nerolidol (the most active) displayed the most synergistic interaction (ΣFIC = 0.09), with their antimalarial activity comparable to that of the interaction between E- and Z-(±)-nerolidol and quinine (ΣFIC = 0.01). Eugenol had the most favourable safety index and was the only EOC with anti-oxidant activity comparable to vitamin C. Combination studies showed that E- and Z-(±)-nerolidol and (-)-pulegone or quinine, p-cymene and γ-terpinene or (-)-pulegone potentiated each other′s toxicity. The EOC´s inhibited the growth of Gram-positive, Gram-negative bacteria and yeast with MIC values ranging from 1.66 to >238.4mM. When combined, synergism was observed between (+)-β-pinene and carvacrol or γ-terpinene; γ-terpinene and geranyl acetate when tested against Staphylococcus aureus, while (+)-β-pinene and (-)-menthone showed antagonism against C. albicans. The combinations of EOC′s and a standard antimicrobial resulted in synergistic interactions between carvacrol and ciprofloxacin against Bacillus cereus, eugenol and ciprofloxacin against Eschericia coli, carvacrol and amphotericin B against C. albicans. The trans-geraniol and E- and Z-(±)-nerolidol combination demonstrated an additive interaction against B. cereus, while for eugenol and E- and Z-(±)-nerolidol an indifferent interaction against E. coli was noted. These results show that the biological activities of EOC′s can vary when used alone and in combination. They do have the potential to be used as templates for novel drugs and as adjuncts to modern medicines in the combat against drug resistance.

As florestas plantadas de eucalipto tem sido muito importantes para o suprimento de materia prima para diversas finalidades, principalmente a partir da madeira. O gênero é também conhecido por apresentar uma gama importante de espécies potenciais para fornecimento de óleos essenciais a partir das folhas. No Brasil, no entanto, a produção de óleo essencial tem ficado restrita a algumas poucas espécies. Dessa forma, é importante a condução de estudos, que possam ampliar a base de novos materiais para obtenção de óleo essencial. Visando suprir tal demanda, que se propôs esse estudo, o qual procurou avaliar novos materiais, incluindo não só as folhas mas também as flores das árvores de diferentes espécies e clones de eucalipto, para produção de óleos essenciais. Fora realizadas extrações de óleos essenciais por arraste a vapor, para determinação de seus rendimentos, além de análises cromatográficas para identificação de seus componentes químicos. Os resultados indicaram: a) os maiores rendimentos nos óleos essenciais das folhas foram observados para E. staigeriana (1,599%) e C. citriodora (1,26%), e os menores para C. ptychocarpa (0,021%); b) E. exserta (0,613%) e o E. resinifera (0,587%) apresentaram potencial para utilização de seus óleos essenciais, frente ao seus elevados rendimentos, e a presença importante de 1,8 cineol; c) Os maiores rendimentos para óleo essencial das flores foram observados para GFMO 03 (0,518%) e os menores para E. exserta (0,109%); d) o clone GFMO 03 apresentou flores com maior rendimento em relação as folhas, o que pode estar relacionado ao melhoramento genético realizado para favorecer suas características de floração; e) as substâncias dos óleos essenciais das folhas podem auxiliar na identificação e diferenciação das espécies; f) os óleos essencias das flores apresentaram 6 substâncias que não foram encontradas nas folhas; g) muitas das substâncias que compõem os óleos essenciais das flores estão presentes no própolis, sugerindo que estas possuem vínculo com a ação de polinizadores atrelados a produção apícola; h) a elevada concentração de substâncias de interesse nos óleos essenciais de eucalipto demonstram sua importância como fornecedores de matéria prima para indústria; i) as espécies foram agrupadas a partir da composição química dos óleos essenciais das folhas, o que determinou 4 grupos e 6 subgrupos, os quais podem estar relacionados com a área de ocorrência natural das espécies estudadas; j) GFMO 03 e GFMO 10 estão, respectivamente no mesmo grupo de E. grandis e E. tereticornis, espécies as quais compõem o material genético dos clones, indicando que as características de óleo essencial são possivemente preservadas mesmo após hibridação. / The planted eucalyptus forests have been very important to supply material for a variety of purposes, mostly from wood. The genus is also known to have an important range of potential species to source essential oils from the leaves. In Brazil, however, essential oil production has been restricted to a few species. Hence, it is important to conduct studies that may extend the number of new materials to obtain essential oil. In order to meet such demand, this study was proposed, which sought to assess new materials, including not only the leaves but also the flowers of trees of different species and clones of eucalyptus, for the production of essential oils. Essential oil extractions were performed by steam distillation, to determine their yield, and chromatographic analysis to identify their chemical components. The results indicated: a) the highest yields in essential oils of leaves were observed for E. staigeriana (1,599%) and C. citriodora (1,262%), and the lowest for C. ptychocarpa (0,021%); b) E. exserta (0,613%) and E. resinifera (0,587%) had potential for use of their essential oils, due to their high yields and the important presence of 1,8 cineole; c) the highest yields in essential oils of flowers were observed for GFMO 03 (0,518%) and the lowest for E. exserta (0,109%); d) the clone GFMO 03 showed flowers with highest yield in essential oil than the leaves, which may be related to genetic improvement done in order to favor their flowering characteristics; e) the substances in essential oils of leaves may assist the identification and differentiation of species; f) the essential oils of flowers had 6 substances that were not found in the leaves; g) many of the substances in essential oils of flowers are present in propolis, suggesting that they have connection with pollinators activities linked to beekeeping; h) the high concentration of substances of interest in essential oils of eucalyptus demonstrate its importance as suppliers of raw materials for industry; i) the species were grouped by the chemical composition in essential oils of their leaves, which resulted in 4 groups and 6 subgroups, which may be related to the area of natural occurrence of the studied species; j) GFMO 03 and GFMO 10 are, respectively, in the same group of E. grandis and E. tereticornis, species which compound the genetic material of the clones, indicating that the essential oil features are probably preserved even after hybridization.

The objective of these studies was to evaluate the effect of piglet nursing location on weaning weight, and its dependence on essential oil supplementation on sow and piglet performances. Piglets that nursed anterior teat pairs had heavier weaning weights and higher gain for the lactation period. Additionally, piglet birthweight did not impact their overall teat selection and nursing location. These results provide some insight into the biological aspects of sow milk production, and implied that milk yield may vary between teat pairs along the udder line. Supplementation of essential oils (EO) during late gestation and lactation had no effect on sow fecal dry matter (DM), immunoglobulin content of colostrum and milk, but it did increase the lactose content in milk from sows supplemented with EO, with an increase from 5.84% to 5. 97% (P = 0.04). There was an increase in sow weight loss during lactation (P = 0.002), and there was a significant effect on piglet birthweight, with sows supplemented with EO producing heavier piglets at birth, 1.56 kg in EO sows, compared to 1.49 kg in the control (CON) sows (P = 0.03). Overall, piglet weaning weight is impacted by their selected nursing location along the udder line. Supplementation of EO may have limited effects on sow performance, such as fecal dry matter (DM) but may positively impact piglet birthweight. Furthermore, including EO into sow diets during late gestation and lactation can potentially impact the nutrient levels of sow milk.

Sprout control is essential for successful management of stored potatoes. This study examined the effect of dill weed, spearmint and clove essential oils on sprouting of potatoes. Extracts of steam distilled dill weed whole plants containing 41.5-42.7% of S-(+)-carvone and spearmint foliage extracts containing 97.2-97.6% of R-(-)-carvone, were applied to tubers in a series of experiments using either 1-L glass jars or 63-L steel drums. The composition of the essential oils was consistent between years but evaporation rate varied among the oils as dill weed extract evaporated the fastest while clove oil evaporated the slowest under the same conditions. After exposure to essential oil treatments, tuber sprout number and weight were assessed and compared to untreated control and tubers treated with commercially marketed clove oil product (Biox-CTM, containing 78.5-82.3% eugenol). Applications of 32.5 and 47.6 mg L-1 headspace of dill weed oil and 21.5 and 22.3 mg L-1 headspace of spearmint oil achieved 50% reduction in 'Russet Burbank' sprout weight and sprout number respectively, 30 days after the initial treatment. Tubers stored in environments with 60-240 mg L-1 headspace of dill weed or spearmint oils suppressed sprouting at least 5 weeks longer than that of the controls. In 63-L steel drums, repeated dill and spearmint oil vapor treatments effectively and consistently suppressed sprouting of 'Russet Norkotah' and 'Piccolo' tubers for 7-8 months when doses were 25 mg L-1 headspace or higher and when treatments were repeated at least every four weeks. Within this range, sprout suppression was not sensitive to treatment variations, and, therefore, an optimal treatment level could not be determined. Clove oil was less effective in suppressing sprouting, likely due to its slower vaporization compared to dill and spearmint oils. Essential oil treatment effects on seed tuber viability were evaluated on 'Piccolo'. Tubers were planted after exposure to dill or spearmint oil vapor environments ranging from 15-240 mg L-1 headspace for seven days. There were no adverse effects on seed viability at doses less than 120 mg L-1 headspace. Although environments with <120 mg L-1 headspace had no significant adverse impact on sprouting, sprout emergence was delayed at higher doses. Dill weed and spearmint oils could potentially be used as potato sprout inhibitors but further studies are needed to demonstrate its commercial feasibility.

Sprout control is essential for successful management of stored potatoes. This study examined the effect of dill weed, spearmint and clove essential oils on sprouting of potatoes. Extracts of steam distilled dill weed whole plants containing 41.5-42.7% of S-(+)-carvone and spearmint foliage extracts containing 97.2-97.6% of R-(-)-carvone, were applied to tubers in a series of experiments using either 1-L glass jars or 63-L steel drums. The composition of the essential oils was consistent between years but evaporation rate varied among the oils as dill weed extract evaporated the fastest while clove oil evaporated the slowest under the same conditions. After exposure to essential oil treatments, tuber sprout number and weight were assessed and compared to untreated control and tubers treated with commercially marketed clove oil product (Biox-CTM, containing 78.5-82.3% eugenol). Applications of 32.5 and 47.6 mg L-1 headspace of dill weed oil and 21.5 and 22.3 mg L-1 headspace of spearmint oil achieved 50% reduction in 'Russet Burbank' sprout weight and sprout number respectively, 30 days after the initial treatment. Tubers stored in environments with 60-240 mg L-1 headspace of dill weed or spearmint oils suppressed sprouting at least 5 weeks longer than that of the controls. In 63-L steel drums, repeated dill and spearmint oil vapor treatments effectively and consistently suppressed sprouting of 'Russet Norkotah' and 'Piccolo' tubers for 7-8 months when doses were 25 mg L-1 headspace or higher and when treatments were repeated at least every four weeks. Within this range, sprout suppression was not sensitive to treatment variations, and, therefore, an optimal treatment level could not be determined. Clove oil was less effective in suppressing sprouting, likely due to its slower vaporization compared to dill and spearmint oils. Essential oil treatment effects on seed tuber viability were evaluated on 'Piccolo'. Tubers were planted after exposure to dill or spearmint oil vapor environments ranging from 15-240 mg L-1 headspace for seven days. There were no adverse effects on seed viability at doses less than 120 mg L-1 headspace. Although environments with <120 mg L-1 headspace had no significant adverse impact on sprouting, sprout emergence was delayed at higher doses. Dill weed and spearmint oils could potentially be used as potato sprout inhibitors but further studies are needed to demonstrate its commercial feasibility.