The inability of tapeworm Hymenolepis diminuta and fluke Dicrocoelium dendriticum to metabolize praziquantel

Biotransformation enzymes can, to a certain extent, protect parasitic worms against the toxic effects of anthelmintics and can contribute to drug-resistance development. The objective of our work was (1) to find and identify phase I and II metabolites of the anthelmintic praziquantel (PZQ) formed by the lancet fluke (Dicrocoelium dendriticum) and the rat tapeworm (Hymenolepis diminuta) and (2) to compare PZQ metabolites in helminths with PZQ biotransformation in rat as host species. Ultra high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) was used for this purpose. During in vitro incubations, mitochondria-like and microsomes-like fractions (prepared from homogenates of adult worms or from rat liver homogenate) were incubated with 10 and 100 μM PZQ. Liquid/liquid extraction was used for samples during in vitro experiments. In the ex vivo study, living D. dendriticum and H. diminuta adults were incubated in RPMI-1640 medium in the presence of 50 nM or 100 nM PZQ for 24h. After incubation, the worms were removed from the medium and homogenized. Homogenates of worms, medium from the incubation of worms or rat hepatocytes and rat urine (collected during 24h after oral PZQ administration) were separately extracted using solid-phase extraction. The results showed that both D. dendriticum and H. diminuta enzymatic systems are not able to metabolize PZQ. On the other hand, thirty one different phase I and four phase II PZQ metabolites were detected in rat samples using UHPLC/MS/MS analyses. These results show that our experimental helminths, as the members of tapeworm and fluke groups of parasites, are not able to deactivate PZQ, and that the biotransformation enzymes of the studied helminths do not contribute to PZQ-resistance.     

Demonstration of neuraminidase activity in Mycoplasma neurolyticum and of neuraminidase proteins in three canine Mycoplasma species

Neuraminidases are virulence factors in many pathogenic microorganisms. They are present also in some Mycoplasma species that cause disease in birds, dogs and alligators. Thirty-seven Mycoplasma species have been examined previously for neuraminidase (sialidase) activity, whereas many of the species causing disease in man, ruminants, pigs, rodents and other animals have not. In this study neuraminidase enzymatic activity (NEAC) was examined in 45 previously untested Mycoplasma species, including those causing diseases in man, farm animals and laboratory animals. The only species in which NEAC was found was Mycoplasma neurolyticum, specifically, its type strain (Type A(T)) which is capable of inducing neurologic signs in inoculated young mice and rats. The NEAC of washed cells was relatively weak, but it differed even more than 10-fold among cells of cultures derived from individual colonies of M. neurolyticum. A weak NEAC was also detected in the supernatant of the M. neurolyticum broth culture. Canine Mycoplasma spp. with high sialidase activity reported previously, Mycoplasma canis, Mycoplasma cynos and Mycoplasma molare had 100-fold more NEAC than M. neurolyticum, but apparent differences in NEAC levels existed among strains of M. canis and of M. cynos. Zymograms using neuraminidase-specific chromogenic substrate were used to show proteins having NEAC. In M. canis (a field isolate Larissa and the type strain PG14(T)), M. cynos (isolate 896) and M. molare (type strain H542(T)) proteins with NEAC had molecular masses of ～130kDa, 105kDa and 110kDa, respectively. Identification of these neuraminidases could provide the basis for their molecular characterization.     

糙隐子草种群在不同放牧强度下的小尺度空间格局

利用Ripley's K函数, 在0～100 cm的空间尺度域上定量分析了4种放牧强度--无牧(0 只/hm2羊)、轻牧(1.33 只/hm2羊)、中牧(4.00 只/hm2羊)、重牧(6.67 只/hm2羊)下糙隐子草种群的空间格局及其随尺度的变化规律;用蒙特卡罗(Monte Carlo)随机模拟方法估计了(t)的置信限.研究了放牧对糙隐子草种群空间格局的影响以及糙隐子草在不同放牧条件下的斑块大小,并进一步以放牧条件下糙隐子草的生活史特征、生态适应对策以及群落内植物种间的相互作用为基础,探讨产生和维持这些格局的机理.研究结果表明:1)放牧显著影响糙隐子草种群空间格局,即使在同一放牧强度下在不同尺度(0～100 cm)上糙隐子草种群的空间格局也显著不同;2)在0～100 cm尺度上,糙隐子草种群的空间格局在无牧条件下为均匀分布,在轻牧和中牧条件下为集聚分布.重牧条件下,糙隐子草种群的空间分布在0～42 cm尺度上为集聚分布,而在42～100 cm尺度上为均匀分布,这与其自身的生物学特性和种群对放牧压力的生态适应对策密切相关;3)不同放牧条件下,糙隐子草种群的斑块大小不同;4)放牧活动的加剧改变了群落中的各种过程,并最终代替群落中的种间竞争过程而成为决定群落内物种分布的主导过程,这为在放牧活动的干预下,退化草原群落演替规律的研究提供了理论依据.     

Copper deficiency and posterior paralysis (shalal) in small ruminants in the sultanate of oman

Summary A posterior ataxia or paralysis in goats and sheep is a syndrome known as Shalal within the Sultanate of Oman. An investigation was carried out into the etiology of the syndrome. Samples of blood and tissues were obtained from normal and Shalal-affected goats and sheep. Samples of feed were collected from the affected areas of the Sultanate. Chemical analyses of samples showed that affected animals suffered from severe copper deficiency in spite of sufficient copper contents in feed. However, concentrations of sulphur and iron in the feed were high. It was concluded that the Shalal syndrome in Oman is the condition generally known as swayback or enzootic ataxia caused by conditioned copper deficiency. The deficiency is probably due to copper-sulphur and copper-iron interactions in the rumen, enhanced by feeding of fresh roughage containing rumen degradable proteins.

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Deficiencia De Cobre En Oman

Resumen La atoxia posterior o parálisis en cabras y ovejas, es un síndrome conocido como Shadal en el Sultanato de Oman. Se llevó a cabo una investigación para detectar la etiología del síndrome, tomando muestras de sangre, tejidos de cabras y ovejas normales y enfermas. También se colectaron muestras de alimento, de las áreas problema del Sultanato. Análisis químicos llevados a cabo revelaron una deficiencia severa de cobre, a pesar que el alimento tenía un contenido de cobre suficiente. Sin embargo, el contenido de azufre y hierro en el alimento se encontró alto. Se concluyó, que el síndrome Shadal en Oman es la condición conocida con el nombre de atoxia enzootica, causada por una deficiencia condicionada de cobre. La deficiencia es debida probablemente a la interacción cobre-azufre y cobre-hierro en el rumen, exacerbada por el consumo de forrajes frescos, con un contenido de proteina degradable en el rumen.

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Carence En Cuivre Dans Le Sultanat D'Oman

Résumé L'ataxie locomotrice ou la paralysie due train postérieur chez les moutons et les chèvres est un syndrome connu sous le nom de Shalal dans le sultanat d'Oman où son étiologie a fait l'objet de recherches. Des prélèvements de sang et de tissus ont été effectués à partir d'animaux indemnes ou atteints de la maladie de même que des échantillons ont été prélevés dans les régions du sultanat ou elle sévit. Les analyses chimiques ont relevé que les animaux malades souffraient d'une sévère carence cuprique, malgré une quantité suffisante dans l'alimentation. Cependant les concentrations en soufre et en fer étaient également élevées dans les aliments. On en conclut que le syndrome de Shalal en Oman correspond à l'affection généralement connue sous le nom de Swayback ou ataxie enzootique due à une carence particulière en cuivre. Il est probable que celle-ci résulte d'interactions cuivre/soufre et cuivre/fer au niveau du rumen, aggravées par l'ingestion de fourrages verts contenant des protéines dégradables dans le rumen.

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Contribution No. 1491 from the Animal Research Centre, Ottawa, Canada.     

Das Vorkommen von Mehltaupilz auf der Wiesen-Platterbse (Lathyrus pratensis L.)

The aim of small-site experiments carried out in the area of the foothills of the ?umava Mts. was to determine the etiological agent of the disease of meadow peavine (Lathyrus pratensis L.). The experimental locality (Kaplice-Chuchelec) was situated in an altitude of 655?m a.s.l. The investigation was accomplished in the years 2004–2005. During the vegetation period we observed whitish to grey-white soft cover of mycelium on the leaves of meadow peavine. These characteristic symptoms of powdery mildew (Erysiphe trifolii Grev.) were found on the plants in the observed area at the end of summer and in autumn. In the area of interest with permanent grassland we evaluated the following variants: first M – mulched stands (mulched once), second L – fallow stands, third K – mown stands (mowing once to three times), and fourth P – pasture stands (grazed by cattle twice to four times). The observed stands were managed in different ways from 2000, and in relation to the ways and intensity of management we observed the changes and coverage of creeping legumes including Lathyrus pratensis. Phytopathological analysis of plants with the symptoms of Erysiphe fungi attack was accomplished in all variants and repetitions during the whole vegetation period. The observation of particular variants was carried out in four repetitions, the size of the sites being 30?m² (4?×?30?m²), and we evaluated the total number of Lathyrus pratensis plants as well as the number of the plants attacked by powdery mildew. Powdery mildew occurrence on Lathyrus pratensis at different management methods of grass stands was statistically processed (in STATISTICA program). The three-year investigation of Lathyrus pratensis L. yielded statistical evidence that the most significant growth of fungal disease Erysiphe trifolii Grev. was recorded in fallow stands. On the other hand, the least occurrence of the disease was found in the pasture stands, which were grazed by the cattle.     

Accumulation of pest-arthropods in grain residues found in an empty store

Journal of Plant Diseases and Protection - The aim of this work was to explore the species composition and abundance of mites and insects in grain residues in an empty grain store. Sampling was...     

Nickel Uptake and its Effect on Some Nutrient Levels, Amino Acid Contents and Oxidative Status in Matricaria chamomilla Plants

Ustica is an island relatively far from continental, industrial and urban settlements and it has been designated as a marine protected area with the aim of preserving the natural diversity of flora and fauna of the surrounding sea. In such an environment, the assessment of the levels and origin of persistent organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) can shed light on the mechanisms and effects of pollutant long-distance transport in the western Mediterranean Sea. PAHs concentrations resulted relatively low when compared with those of other coastal areas of the Mediterranean Sea. The low values of the ratio between low- and high-molecular-weight (LMW and HMW, respectively) PAHs and the fluoranthene and pyrene ratios underlined a pyrolytic origin of these contaminants. The prevalence of HMW-PAHs, however, may also be due to the effect of LMW-PAH preferential degradation during transport and burial into sediments. On the other hand, petrogenic sources prevailed in the past. Whilst PAHs concentrations showed a recent increase, especially at the site close to the port, the estimated sedimentary fluxes of PAHs ranged from 0.5 to 25 μg m^?2 year^?1.     

A Survey of Organotin Compounds in the Northern Adriatic Sea

The extent of pollution with organotin compounds was investigated in water, sediment and bivalve mussels (Mytilus galloprovincialis) from the Northern Adriatic Sea. Butyl-, phenyl- and octyltin species were quantified after extraction and derivatisation by gas chromatography–mass spectrometry in a total of 99 samples from the period from 2000 to 2006. The accuracies of the analytical procedures were checked by spiking of unpolluted water samples and by the analysis of standard reference materials (harbour sediment PACS-2 and mussel tissue ERM-CE 477). Among organotin species analysed in samples butyltins were the predominant. Tributyltin was found to be present in the highest concentrations, suggesting its recent input into the marine environment. Butyltins were detected at all sites surveyed (sum of butyltins was up to 718 ng Sn L^?1, 3,552 ng Sn g^?1 d.w. and 9,991 ng Sn g^?1 d.w. in water, sediment and mussel samples, respectively), phenytins in much lower concentrations (up to 31 ng Sn L^?1, 326 ng Sn g^?1 d.w. and 442 ng Sn g^?1 d.w. in water, sediment and mussel samples) and to a much smaller extent, while octyltins were not detected at any location. The spatial distribution of tributyltin was closely related to boating, with the highest concentrations found in marinas (up to 586 ng Sn L^?1 for water samples, 1,995 ng Sn g^?1 d.w. for sediment and 6,434 ng Sn g^?1 d.w. for mussel samples). The temporal distribution clearly indicates a decrease of organotin pollution at all sites.