Status Quo of Soil Contamination with Inorganic and Organic Pollutants of the River Oka Floodplains (Russia)

The contamination status of rivers and their floodplains with inorganic and organic pollutants in central Russia is poorly known. We investigated the concentrations of inorganic (As, Cd, Cu, Hg, Ni, Pb and Zn) and persistent organic pollutants (hexachlorocyclohexane, PCBs, cyclodienes, DDX and other pesticides) in floodplain soils of the Oka River catchment (Russia). The level of contamination was generally lower than in the Elbe River floodplain but in the same range as in other European river systems such as floodplains of the rivers Rhine, D?evnice and Yachroma. Only soil samples from the periphery of the city of Ryazan (200 km southeast of Moscow) had a higher anthropogenic enrichment of Cd, Cu and Zn which was comparable to the contaminated Elbe River floodplains. These soils also had the largest concentrations of persistent organic pollutants among all samples from the Oka River catchment. Therefore, the need for large-scale remediation seems to be less urgent than in Central European river catchments and mainly restricted to some “hot spot” areas.     

Target-site resistance to pyrethroids in European populations of pollen beetle, Meligethes aeneus F.

Pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae) is a major univoltine pest of oilseed rape in many European countries. Winter oilseed rape is cultivated on several million hectares in Europe and the continuous use of pyrethroid insecticides to control pollen beetle populations has resulted in high selection pressure and subsequent development of resistance. Resistance to pyrethroid insecticides in this pest is now widespread and the levels of resistance are often sufficient to result in field control failures at recommended application rates. Recently, metabolic resistance mediated by cytochrome P450 monooxygenases was implicated in the resistance of several pollen beetle populations from different European regions. Here, we have also investigated the possible occurrence of a target-site mechanism caused by modification of the pollen beetle para-type voltage-gated sodium channel gene. We detected a single nucleotide change that results in an amino acid substitution (L1014F) within the domain IIS6 region of the channel protein. The L1014F mutation, often termed kdr, has been found in several other insect pests and is known to confer moderate levels of resistance to pyrethroids. We developed a pyrosequencing-based diagnostic assay that can detect the L1014F mutation in individual beetles and tested more than 350 populations collected between 2006 and 2010 in 13 European countries. In the majority of populations tested the mutation was absent, and only samples from two countries, Denmark and Sweden, contained pollen beetles heterozygous or homozygous for the L1014F mutation. The mutation was first detected in a sample from Denmark collected in 2007 after reports of field failure using tau-fluvalinate, and has since been detected in 7 out of 11 samples from Denmark and 25 of 33 samples from Sweden. No super-kdr mutations (e.g. M918T) known to cause resistance to pyrethroids were detected. The implications of these results for resistance management strategies of pollen beetle populations in oilseed rape crops are discussed.     

Treatment of feline giardiasis with metronidazole

Seven cats from a single household with 17 cats were shedding cysts of Giardia species as detected by a modified zinc sulfate concentration technique. All the cats were housed individually in Horsfal isolation units for the duration of the evaluation, treatment, and follow-up monitoring. Each of the infected cats was treated with metronidazole at a dose of 22 mg per kg of body weight, twice a day, for 5 days. Post-treatment examination of four or five stool samples from each cat during the following 17 days did not reveal the presence of any giardial cysts in the treated cats. After treatment, the diarrhea either ceased or was markedly diminished. Therefore, metronidazole appears to be an effective form of therapy for feline giardiasis.     

Food allergen-specific serum IgG and IgE before and after elimination diets in allergic dogs

Serum food allergen-specific antibody testing is widely offered to identify suitable ingredients for diets to diagnose adverse food reaction (AFR) in dogs with allergic skin disease. Antibody concentrations in blood samples obtained during an unsuccessful diet to help in the choice of diet changes may be influenced by the previous diet. The objective of this paper was to measure food antigen-specific IgE and IgG for the most commonly used 16 food antigens before and after an elimination diet. Levels of food-specific serum IgE and IgG antibodies were measured by enzyme-linked immunosorbent assay (ELISA). Dogs had detectable IgE antibodies to beef, pork, lamb and cows' milk; and detectable IgG antibodies to beef, pork, lamb, cows' milk, chicken and turkey. Of 19 dogs with complete data sets, 14 dogs showed clear improvement during diet and in 7 dogs AFR could be diagnosed by deterioration on rechallenge and subsequent improvement on refeeding the diet. Serum was obtained before and 6-8 weeks after beginning such a diet. There was no significant difference in pre- and post-diet levels for any of the individual allergens nor for the total IgE and IgG concentrations of all antigens (P=0.55 and P=0.53 respectively). In these 19 dogs in which an elimination diet was used for the diagnosis of food allergy and in which 14 were probably food allergic and 7 were proven food allergic there were no significant differences in food-specific antibodies before and after an elimination diet of 6-8 weeks.     

Suppression of Soil Microorganisms by Emissions of a Magnesite Plant in the Slovak Republic

In April 1996, we collected soil samples in thevicinity of a magnesite plant at Lubeník, southernSlovakia, and screened them for soil microbial biomassand activity. Six investigated sites were chosen alonga transect, with distances ranging from 600 to 8000 mfrom the plant, to represent a gradient ofintoxication. Soil microbial cellulase activity,respiration, biomass, metabolic quotient of the soilmicrobiota, and numbers of platable fungi increasedwith increasing distance from the plant, i.e.decreasing degree of intoxication. The observedgradients of soil microbial characteristics of theinvestigated sites reflect the physico-chemical soilparameters and the floristic characteristics of thesesites, and may be used to predict transitory changesduring amelioration.