Search

Trichuris nematodes were isolated from roe deer (Capreolus capreolus). At first, nematodes were determined using morphological and biometrical methods. Subsequently genomic DNA was isolated and the ITS1-5.8S-ITS2 segment from ribosomal DNA (RNA) was amplified and sequenced using PCR techniques. With u sing morphological and biometrical methods, female nematodes were identified as Trichuris globulosa, and the only male was identified as Trichuris ovis. The females were classified into four morphotypes. However, analysis of the internal transcribed spacers (ITS1-5.8S-ITS2) of specimens did not confirm this classification. Moreover, the female individuals morphologically determined as T. globulosa were molecularly identified as Trichuris discolor. In the case of the only male molecular analysis match the result of the molecular identification. Furthermore, a comparative phylogenetic study was carried out with the ITS1 and ITS2 sequences of the Trichuris species from various hosts. A comparison of biometric information from T. discolor individuals from this study was also conducted.

This study focuses on the comparison of three selected modifications of the McMaster counting technique, namely the McMaster method modified by Wetzel (W) and Zajíček (Z), as well as the concentration McMaster technique according to Roepstorff and Nansen (R&N). These modifications differ in the weights of faeces examined (W, 2 g/Z, 1 g/R&N, 4 g), flotation solutions (W, NaCl/Z, MgSO(4) + Na(2)S(2)O(3)/R&N, NaCl + glucose), centrifugation (W, none/Z, 2,000 RPM for 2 min and 2,000 RPM for 1 min/R&N, 1,200 RPM for 5 min), number of McMaster chambers investigated (W, 3/Z, 2/R&N, 2), and multiplication factors used (W, 67/Z, 33/R&N, 20). To investigate the sensitivity and reliability of these methods, nematode eggs (Teladorsagia circumcincta) were used. Parasite elements are distributed through negative binomial distribution in naturally infected host faeces, and the number of parasite elements in a given amount of faeces sample is unknown to man. Therefore, we decided to prepare the exact number of eggs which were added to the parasite negative faeces; the faecal sample was then investigated. From this perspective, this is the first time a comparison of the McMaster methods has been so accurately investigated. This approach allows us to evaluate the real sensitivity and reliability of the tested method. As the findings of this study indicate, the highest sensitivity and reliability were obtained using the Roepstorff and Nansen modification. This McMaster modification is able to detect 20 eggs per sample (in 70% of samples). Concentrations of 200 and 500 eggs can be found in almost 100% of samples. Moreover, this method is simple, cheap and fast. For these reasons, we can recommend this method for routine veterinary practice.

Two tracer tests were conducted between August 2004 and March 2007 at an ecological farm in western Bohemia. The first tracer test was performed for the summer-autumn grazing period (onset of arrested development), the second for spring (resumption of arrested development). In the first tracer test, the percentage of nematodes arresting development over the winter months reached 87.7% for Teladorsagia circumcincta, 66.7% for Haemonchus contortus, 89.9% for Nematodirus filicollis, 21.6% for Trichostrongylus axei, and 23.9% for both Trichostrongylus vitrinus and Trichostrongylus colubriformis. None of the arrested larvae were observed with species Cooperia curticei, Nematodirus battus, and Oesophagostomum venulosum. In the second tracer test, a significant increase of adult worms was discovered in March of species T. circumcincta and N. filicollis and Trichostrongylus spp. in February. Redundancy analysis and generalized linear models analyses have confirmed that environmental conditions play a crucial role in hypobiosis of sheep strongyles in the Czech Republic. The analysis of influences of various environmental factors revealed that the number of arrested larvae was negatively influenced by light-day length, sunshine, or daylight decrease (p < 0.01).