Vapour-phase activities of essential oils against antibiotic sensitive and resistant bacteria including MRSA.

AIMS: To determine whether essential oil (EO) vapours could reduce surface and airborne levels of bacteria including methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: The antibacterial activity of geranium and lemongrass EO individually and blended were evaluated over a range of concentrations by direct contact and vapour diffusion. The EO were tested in vitro against a selection of antibiotic-sensitive and -resistant bacteria, including MRSA, vancomycin-resistant Enterococci (VRE), Acinetobacter baumanii and Clostridium difficile. An EO blend containing lemongrass and geranium was used to formulate BioScent that was dispersed into the environment using the ST Pro machine. The effects were variable depending on the methods used. In a sealed box environment, MRSA growth on seeded plates was reduced by 38% after 20 h exposure to BioScent vapour. In an office environment, the ST Pro machine dispersing BioScent effected an 89% reduction of airborne bacteria in 15 h, when operated at a constant output of 100%. CONCLUSIONS: EO vapours inhibited growth of antibiotic-sensitive and -resistant bacteria in vitro and reduced surface and airborne levels of bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Results suggest that EO vapours, particularly Bioscent, could be used as a method of air disinfection.

AFLP analysis of genetic diversity within and among Coffea arabica cultivars.

Genetic diversity of Coffea arabica cultivars was estimated using amplified fragment length polymorphism (AFLP) markers. Sixty one Coffea accessions composed of six arabica cultivars, including Typica, Bourbon, Catimor, Catuai, Caturra and Mokka Hybrid, plus two diploid Coffea species, were analyzed with six EcoRI- MseI primer combinations. A total of 274 informative AFLP markers were generated and scored as binary data. These data were analyzed using cluster methods in the software package NTSYSpc. The differences among cultivars at the DNA level were small, with an average genetic similarity of 0.933. Most accessions within a cultivar formed a cluster, although deviant samples occurred in five of the six cultivars examined due to residual heterozygosity from ancestral materials. Among the six cultivars fingerprinted, the highest level of genetic diversity was found within the cultivar Catimor, with an average genetic similarity of 0.880. The lowest level was found within Caturra accessions, with an average genetic similarity of 0.993. Diversity between C. arabica and two other Coffea species, Coffea canephora and Coffea liberica, was also estimated with average genetic similarities of 0.540 and 0.413, respectively, suggesting that C. canephora is more closely related to C. arabica than is C. liberica. The genetic variation among arabica cultivars was similar to the variation within cultivars, and no cultivar-specific DNA marker was detected. Although arabica cultivars appear to have a narrow genetic base, our results show that sufficient polymorphism can be found among some arabica cultivars with a genetic similarity as low as 0.767 for genetic/QTL mapping and breeding. The assessment of genetic diversity among arabica cultivars provided the necessary information to estimate the potential for using marker-assisted breeding for coffee improvement.

Detection and identification of morphine in urine extracts using thin-layer chromatography and tandem mass spectrometry.

The application of tandem mass spectrometry to the analysis and identification of morphine following thin-layer chromatography is described. FAB-mass spectrometry and mass spectrometry-mass spectrometry were performed following chromatography on silica gel high-performance thin-layer chromatography plates. The successful application of this simple methodology to a urine extract suggests that this approach has practical utility for confirming the identity of abused drugs detected by thin-layer chromatography.

An inhibitor of the sodium pump obtained from human placenta.

BACKGROUND: Much effort has been expended in the search for an endogenous inhibitor of the cellular sodium/potassium pump, a compound of major physiological importance, which has been implicated in the mechanism of essential hypertension. Others have suggested that ouabain or an isomer of ouabain may be the endogenous pump inhibitor. Neonatal cord serum contains an inhibitor of the sodium pump; we attempted to isolate and characterise this substance from human placentas. METHODS: Homogenised placentas were dialysed and the resulting solutes were trapped on octadecylsilyl silica and then separated by high-performance liquid chromatography. Measurement of the activity of the sodium pump of human leucocytes was used to test each fraction for the presence of the inhibitor. FINDINGS: An inhibitor of the sodium pump was obtained by this technique in a mass spectrometrically pure form with a mass of 370 Da, an empirical formula of C24H34O3 and only one hydroxyl group. The characteristic fragmentation pattern observed in negative-ion mass spectrometry was compared with those of various model compounds; this comparison suggested that the active material was a dihydropyrone-substituted steroid. INTERPRETATION: These results suggest that a dihydropyrone-substituted steroid is an endogenous regulator of the sodium pump in humans and, presumably, other mammals. Proof of the endogenous origin will require the demonstration of a previously unrecognised biosynthetic pathway.

The detection and characterization of analgesics and anti-inflammatory drugs on high performance thin-layer chromatography plates using tandem mass spectrometry: application to drugs and metabolites in urine.

The application of tandem mass spectrometry to the analysis and identification of analgesics and non-steroidal anti-inflammatory drugs such as paracetamol, ibuprofen and indomethacin following thin-layer chromatography (TLC) is described. TLC was combined successfully with mass spectrometry and with tandem mass spectrometry using silica gel and diol-bonded silica gel high performance TLC plates. The diol-bonded phase was found to be superior for use with biological samples and enabled the identification of paracetamol, ibuprofen and salicylhippuric acid (the major metabolite of acetylsalicylic acid) in human urine extracts following normal therapeutic doses.

Study of an actinomycin complex by mass spectrometry-mass spectrometry.

The characterization of components within actinomycin complexes may often be complicated by the lack of material and standards of known actinomycins. Mass spectrometry-mass spectrometry can be employed both as a separatory device and as a means of structural analysis. This technique has been applied to an actinomycin complex obtained from a previously unidentified Streptomyces strain. The method involved initial work on a known material, in this case actinomycin D, and application to the unknown material. Three major components within the unknown complex were characterized as actinomycins D, F(8), and F(9).