Herpesvirus diseases of domestic animals and game species in the Slovak Republic.

Herpesviruses are DNA viruses that cause serious latent infections in humans and animals. These pathogens significantly influence the animal health and economy of animal husbandry. The reduction of production parameters, abortions, birth of weak individuals and by costs associated with the elimination and monitoring of herpesvirus diseases are among the most serious harms caused by herpesviruses. In our review we focused mainly on herpesvirus diseases in pigs and cattle (Aujeszky's disease, bovine infectious pustular vulvovaginitis and balanoposthitis, infectious bovine rhinotracheitis) and herpesvirus diseases in red deer, dogs, and carps. In the past, these herpesvirus diseases have caused considerable economic losses in livestock. At present, several of these diseases are eliminated in the Slovak territory. Currently, a continuous monitoring is carried out not only in populations of domestic animals, but also in wild animals, which are the main reservoirs of the mentioned herpesviruses. Keywords: herpesvirus; Aujeszky's disease; animals; fish; eradication; Slovak Republic.

Historical analysis of epizootiological situation of rabies on the territory of the Slovak Republic.

Currently, Slovakia is a rabies-free country, but the epizootiological situation of rabies was not always favorable. The main reservoir species of rabies virus in the first half of the last century was the domestic dog. Since 1906, hundreds of cases were reported, of which approximately 90% were infected dogs. The disease had a typical urban character. Since 1929, the number of rabid domestic animals decreased due to the implementation of dog vaccination campaigns in particular parts of Slovakia. From the second half of 1950s, red foxes (Vulpes vulpes) have become an important reservoir of the RABV. In this time period urban rabies in Slovakia changed into sylvatic form. One effective method of prevention and control of wildlife rabies is an oral rabies vaccination of red foxes. It is carried out in Slovakia since 1993. A detailed development of the rabies epizootiological situation on the territory of the Slovak Republic until the application of oral antirabies immunisation of foxes and the current situation after its performance is the main object of this review. Keywords: rabies; Lyssavirus; red fox; incidence; oral vaccination.

Detection of Mycobacterium avium subsp. paratuberculosis in Slovakian wildlife.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of infectious enteritis called paratuberculosis that has a high economic impact on the worldwide livestock production. A central important question arises: Can wildlife animals serve as a reservoir for transmission of MAP to domestic ruminants? With this in mind, we devised a study to detect MAP in various Slovakian wildlife species found in the areas where paratuberculosis had been documented in domestic ruminants. The samples of parenchymatous organs (intestines, ileocecal valve and mesenteric lymphatic nodes) from 83 wildlife animals representing 13 species, inclu- ding 7 herbivorous, 5 carnivorous and 1 omnivorous species were collected during a four-year period. The clinical and pathological examinations failed to demonstrate any manifestations of paratuberculosis in any of the wildlife samples. The detection of MAP was done by widely used tests, i.e. cultivation and the PCR analysis. The bacterial cultures revealed the growth of Mycobacterium spp. colonies in 58 (70%) of all of the wild animals, but the PCR testing demonstrated paratuberculosis only in one (7.69%) of the roe deer population.

Detection of rabies antibodies in dog sera.

In the presented work, we compared the results of determination of rabies antibodies using three in vitro methods: rapid fluorescent focus inhibition test (RFFIT), fluorescent antibody virus neutralisation test (FAVNT) and the immunoenzymatic assay (ELISA). 196 dog sera samples were examined with FAVNT, RFFIT methods and the ELISA test. Sera with low and sufficiently high titre of antibodies had a similar result in determining by all methods. A critical level of rabies antibodies close to the required protection level (0.5 IU/cm3) was seen in sera of 18 dogs (9.18%); these were the sera obtained after primary vaccination of dogs. At this level, even small differences can cause a change in the assessment of the patient's serum seronegativity or seropositivity. Therefore, it is important to choose the appropriate method that has sufficiently strict criteria while having a good reproducibility.

Interlaboratory variability of CD34+ stem cell enumeration. A pilot study to national external quality assessment within the Czech Republic.

We present the results of a pilot study concerning the interlaboratory variability of CD34+ enumeration. Three surveys, each including a set of samples, were sent to participating Czech flow cytometry laboratories. The efficacy of this exercise was determined by the reduction in interlaboratory variation and the influence of method used on assay outcome. The variability in results of CD34+ enumeration declined with time. The mean coefficient of variation (CV) of measurement among laboratories dropped, from 58% in first survey to 32% in last survey. All tested variables (gating strategy, platform methodology, sample preparation) affected the variability of the assay. Sample preparation method was associated with a significant bias of absolute CD34+ cell counts. Initially, the outcome of the measurement was also affected by the participating laboratory (identified by a unique laboratory number; ULN). However, laboratories with poorer performance modified their protocols during the study, and the ULN ceased to influence the variability. This study was successful in reducing the interinstitutional variability of CD34+ enumeration. It was shown that the implementation of a standardized protocol does not guarantee accurate measurement. Our research design represents a useful tool, which allows verification of the proper use of a standardized method, the training of operators and feedback in response to the survey results.

[Correction of measurement errors in the ELISA test]. / Korekcia chýb merania v teste ELISA.

The authors followed the influence of the arrangement of measured and control samples on microtitration plate on the ELISA test results by quantitative evaluation of rabies antibodies titres in human blood serum. They performed the test under identical conditions in all microtitration plate wells. They calculated the result according to five calibration curves--four of them were obtained by different positioning of the control positive and negative sera and the fifth curve was obtained from average values. The results from the four various positional calibration curves were significantly statistically different from the average. However, the average calibration curve--obtained from four measurements--led to identical value of rabies antibodies in cases with different dilutions of sera. The authors propose to follow some principles of measured and control samples arrangement on microtitration plates in order to minimalize the errors, caused by their dishomogeneity. (Tab. 2, Fig. 3, Ref. 10.)

Preculturing of Chinese hamster V79 cells with sublethal concentration of theophylline sensitizes cells to cytotoxic effects of MNNG.

In our previous work concerning the biologic effects of theophylline, we found that cells incubated during 48 h at low concentrations of theophylline (0.3 mg/ml of medium) manifested short-term deviations in the rate of DNA replication; however, this short-term inhibition of DNA replication did not reduce either the growth rate or the colony-forming ability of cells. In the present study, we concentrated on cytotoxic and DNA-damaging effects of MNNG on V79 cells precultured with sublethal concentration of methylxanthine theophylline. Cytotoxicity was evaluated on the basis of growth rate of treated cells as well as by colony-forming ability (plating efficiency) test and by trypan blue exclusion test. The level of DNA lesions (strand breaks) induced by MNNG was measured by alkaline DNA unwinding and by the comet assay. In an effort to explain higher cytotoxic effects of MNNG on precultured cells, we studied rejoining of damaged parental DNA after 4 h incubation post-MNNG-treatment as well. We found differences as against the controls in theophylline-precultured cells after treatment with the mutagen and carcinogen MNNG. The higher cytotoxic effect of MNNG in precultured cells was accompanied by a higher level of ss breaks of DNA and by more unrepaired lesions which remained after 4 h in parental DNA. Our results demonstrate that theophylline belongs to the group of agents inhibiting repair of potentially lethal DNA lesions.