The genomic sequence of the accidental pathogen Legionella pneumophila

We present the genomic sequence of Legionella pneumophila, the bacterial agent of Legionnaires' disease, a potentially fatal pneumonia acquired from aerosolized contaminated fresh water. The genome includes a 45-kilobase pair element that can exist in chromosomal and episomal forms, selective expansions of important gene families, genes for unexpected metabolic pathways, and previously unknown candidate virulence determinants. We highlight the genes that may account for Legionella's ability to survive in protozoa, mammalian macrophages, and inhospitable environmental niches and that may define new therapeutic targets.     

Stir bar sorptive extraction combined with GC-MS analysis and chemometric methods for the classification of South African Wines according to the volatile composition

A simple method for the analysis of major wine volatiles and semivolatiles by stir bar sorptive extraction in combination with thermal desorption and gas chromatography-mass spectrometry (SBSE-TD-GC-MS) was developed. Significant experimental parameters such as extraction time, temperature, salt addition, pH, and thermal desorption parameters were optimized to provide a sensitive and robust analytical method. The method provided good repeatability (%RSD < 10%) for 38 major wine volatile compounds, including alcohols, acids, esters, phenols, aldehydes, ketones, and lactones. Quantitative data for 62 South African red and white wines were used to study the suitability of major volatile data for the differentiation of wine samples according to grape variety or cultivar. Principal component analysis (PCA) and cluster analysis (CA) showed that most of the variation in volatile composition between wine samples could be ascribed to differences in wine age, wood contact, and fermentation practices. Despite the contribution of these factors, discriminant analysis (DA) was successfully applied to the classification of red and white wine samples according to cultivar.     

In Vitro Anticancer and Cancer-Preventive Activity of New Triterpene Glycosides from the Far Eastern Starfish Solaster pacificus

Sea stars or starfish (class Asteroidea) and holothurians or sea cucumbers (class Holothuroidea), belonging to the phylum Echinodermata (echinoderms), are characterized by different sets of glycosidic metabolites: the steroid type in starfish and the triterpene type in holothurians. However, herein we report the isolation of eight new triterpene glycosides, pacificusosides D–K (1–3, 5–9) along with the known cucumarioside D (4), from the alcoholic extract of the Far Eastern starfish Solaster pacificus. The isolated new compounds are closely related to the metabolites of sea cucumbers, and their structures of 1–3 and 5–9 were determined by extensive NMR and ESIMS techniques. Compounds 2, 5, and 8 have a new type of tetrasaccharide chain with a terminal non-methylated monosaccharide unit. Compounds 3, 6, and 9 contain another new type of tetrasaccharide chain, having 6-O-SO₃-Glc as one of the sugar units. The cytotoxic activity of 1–9 against non-cancerous mouse epidermal cells JB6 Cl41 and human melanoma cell lines SK-MEL-2, SK-MEL-28, and RPMI-7951 was determined by MTS assay. Compounds 1, 3, 4, 6, and 9 showed potent cytotoxicity against these cell lines, but the cancer selectivity (SI > 9) was observed only against the SK-MEL-2 cell line. Compounds 1, 3, 4, 6, and 9 at the non-toxic concentration of 0.1 μM significantly inhibited neoplastic cell transformation of JB6 Cl41 cells induced by chemical carcinogens (EGF, TPA) or ionizing radiation (X-rays and UVB). Moreover, compounds 1 and 4 at the non-toxic concentration of 0.1 µM possessed the highest inhibiting activity on colony formation among the investigated compounds and decreased the colonies number of SK-MEL-2 cells by 64% and 70%, respectively. Thus, triterpene glycosides 1 and 4 can be considered as prospective cancer-preventive and anticancer-compound leaders.     

Regional phenotypic diversity of Puccinia triticina and wheat host resistance in western Europe, 1995

Pathogenicity data from surveys of Puccinia triticina (formerly P. recondita f. sp. tritici) conducted in western Europe in 1995 were analysed to compare the structure of regional populations of the pathogen. Many of the populations differed in phenotypic diversity and pathotypic composition, even though they occurred within a single epidemiological unit, suggesting that local factors may influence the establishment and propagation of individual pathotypes in the regional populations. Neighbouring regions were more similar than distant regions, and all regions shared at least one pathotype, except populations in northern Italy and Scotland. A high degree of similarity was found between populations in northern France and Great Britain, providing strong evidence of free movement of inoculum between these regions. Resistance genes were postulated for a selection of 91 wheat cultivars, representing those most commonly grown in western Europe in 1995. Thirteen cultivars lacked detectable seedling resistance genes and the remaining 78 possessed from one to three resistance genes; those detected were Lr1, Lr3a, Lr10, Lr13, Lr14a, Lr17b, Lr20, Lr26 and Lr37. The most commonly detected resistance gene was Lr13, which was present singly or in combination with other resistance genes in 48 cultivars (53%). The gene Lr14a was detected in 18 cultivars, Lr26 was present in 16 cultivars. The role of host selection in the composition of the regional populations of P. triticina in western Europe in 1995 was difficult to assess on the basis of the results obtained, since virulence data were not available for Lr13 and Lr14a. This revised version was published online in August 2006 with corrections to the Cover Date.     

Endogenous development of Hemolivia mauritanica (Apicomplexa: Adeleina: Haemogregarinidae) in the marginated tortoise Testudo marginata (Reptilia: Testudinidae): evidence from experimental infection

Six young tortoises Testudo marginata Schoepff, 1792 were experimentally infected with Hemolivia mauritanica (Sergent et Sergent, 1904). The prepatent period ranged from 6 to 8 weeks. Young, smaller, club-like forms (6-9 x 3-6 Am) of gametocytes appeared in the peripheral blood first, whereas mature, elongated, cylindrical forms (9-12 x 5-7 Am) were detected after 1-2 weeks and predominated during later patency. Three of the infected tortoises were euthanized and dissected to study the endogenous stages. Meronts occurred in the cells of the reticulo-endothelial system and in the erythrocytes; these were observed mostly in parenchymatous organs. Mature forms measured 14.2 x 9.3 microm and contained 7-12 merozoites. Cysts with two (exceptionally one) cystozoites were also found predominantly in parenchymatous organs and measured 14.8 x 7.9 microm. Pathological changes attributable to Hemolivia were mild and limited to liver and kidneys. The role of individual developmental stages of haemogregarines is discussed with respect to evolution of heteroxenous life cycle and long-term persistence of parasites in their intermediate hosts.     

HPLC analysis of rosmarinic acid in feed enriched with aerial parts of Prunella vulgaris and its metabolites in pig plasma using dual-channel coulometric detection

This paper describes a sensitive isocratic HPLC/ECD method developed for the determination of rosmarinic acid (RA) in plant material, animal feed, and pig plasma. The plasma sample preparation only includes protein precipitation and adjustment of the pH. The applicability of the method was tested on plasma samples of pigs that were exposed to a 91-day oral intake of RA via feed enriched by aerial parts of Prunella vulgaris. The plasma was directly analyzed using the method described as well as after enzymatic hydrolysis. When no hydrolysis step was included, RA and caffeic acid (CA) were quantified in the plasma. In hydrolyzed plasma samples, several other metabolites were determined, including dihydrocaffeic, ferulic, and dihydroferulic acid. The dual-channel coulometric detection employed, as an alternative to mass spectrometry, offers good selectivity and sensitivity owing to the electrochemical properties of the phenolic constituents.     

Bioaccumulation and Effects of Heavy Metals in Crayfish: A Review

Metal pollution is a global problem which represents a growing threat to the environment. Because of bioaccumulation and negative effects of heavy metals, their bioavailability needs to be monitored. Many studies showed accumulation of metals in crayfish tissues as dose- and time-dependent without significant differences in tissue concentration levels comparing males and females. Muscles and exoskeleton were considered as specific for accumulation of mercury and nickel, respectively. Cadmium, zinc, copper, lead, and chromium accumulated mainly in hepatopancreas. By analyzing these specific tissues, it is possible to deduce the bioavailability and, by presumption, the level of environmental pollution by specific metals. However, in the case of zinc and copper, their utility is limited to assessing bioavailability because rapid depuration of these metals renders them less useful for long-term environmental monitoring programs. The literature reporting heavy metal impacts on freshwater crayfish, with reference to accumulation levels, is reviewed and summarized with respect to their suitability as bioindicators. Summarized published data from unpolluted or control localities can be used as referential values in crayfish, and consequently help with evaluation of monitored sites.