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During a post mortem of a six year old simmental bull with severe paratuberculosis infection the testicles were further examined by pathological, histological and microbiological methods. No gross or histological lesions could be observed. Single acid fast organisms were detected in smears taken from sterile testicle tissue. Tissue material was additionally cultured in mycostatin culture media and after 8 weeks of incubation acid fast colonies were demonstrated. Polymerase chain reaction with DNA extracted from cultured bacteria and testicle tissue material resulted in M. avium subsp. paratuberculosis-specific amplicons. The detection of M. avium subsp. paratuberculosis in the testicle of the bull demonstrates the possibility of bacteriemia in the final stage of clinical paratuberculosis infection. The evidence of transmitting paratuberculosis through contaminated semen and its relevance for artificial insemination is being discussed in the presented paper.

Serum samples from healthy, infected (n=11) and diseased (n=2) cattle as well as positive (n=17) and negative (n=41) reference sera were tested for antibodies to Mycobacterium avium subsp. paratuberculosis with two ELISA-methods (A-ELISA, Allied Monitors, Fayette, USA; H-ELISA, Institute of Microbiology and Animal Diseases, Veterinary University Hannover). Fecal samples of these animals were examined by PCR and culture. Also field serum samples found to be positive (n=664) or inconclusive (n=1589) by A-ELISA during a survey done on 11028 cattle of 2757 farms at different districts in Austria were retested with H-ELISA (Gasteiner et al., 1999). In both ELISA-methods total agreement between antibody detection and shedding of M. avium subsp. paratuberculosis (PCR, culture) in cases of diseased animals during the testing period was found. In subclinically infected animals H-ELISA showed a better correlation with the results of PCR and fecal culture. Reference serum samples of culturally negative cattle were negative in 98% by H-ELISA and in 82% by A-ELISA, and those of positive animals were positive in 59% by H-ELISA and in 82% by A-ELISA. The 664 A-ELISA positive field serum samples were positive in 20.5%, inconclusive in 32.5% and negative in 47% by H-ELISA. A-ELISA inconclusive sera gave positive reactions by H-ELISA in 5.2%, negative in 74.8% and inconclusive results in 20%. The highest prevalence of antibodies (7.9% by A- and 2.2% by H-ELISA) against M. avium subsp. paratuberculosis were found in cattle at the age of six and seven years. Seropositive animals were found at all tested ages. The A-ELISA gave two to three times more positive reactors than the H-ELISA. Also both tests showed the highest prevalence of reagents among Holstein Friesian (6.2% by A-ELISA, 2.5% by H-ELISA) followed by other cattle breeds. Seropositive cattle were observed in all districts of Austria in 3. 3-7.1% and in 0.5-1.8% of herds according to A- and H-ELISA, respectively.

The polymerase chain reaction and cultural method was applied to detect Mycobacterium avium subspecies paratuberculosis (M. p.) in fecal samples of 165 suspected and of 35 diseased cattle, 18 intestinal tissues and 14 lymph nodes of diseased ruminants as well as organ material (n = 10) were also tested. An agreement (+/+, -/-) in the results between both methods was found in 89.7% of all cases examined. 12.7% of samples of suspected and 9.1% of diseased animals were only positive by PCR. In cases of intestinal lymph node and tissue as well as udder tissue of diseased cattle a total agreement between PCR and culture was observed. Lymph node of lung of one diseased cow was positive only in PCR.

A serologic survey study of 5,076 Austrian cattle farming herds was carried out in the period of December 1988 till March 1990. One animal was randomly selected from each herd and the antibody titer against Anaplasma marginale in blood serum samples was evaluated by means of the complement fixation test. The number of these tested blood samples was 3.6% of 140,081 cattle herd farms of Austria. 109 (2.1%) of the tested animals showed positive titers (1:10) against Anaplasma marginale, in relation to the 140,081 cattle herds 0.08%, 4,786 (94.3%) blood serum samples were sero-negative, 188 (3.8%) reacted anticomplementary. The highest number of antibody-positive animals of 8 tested Austrian districts could be found in Carinthia (46 = 5.7%). In Burgenland all tested sera turned out to be negative. Concerning the distribution of sero-positive animals in Austria it can be stated that a decrease of positive reactors from southern to northern region is evident. A connection between the occurrence of anaplasmosis in Italy, Yugoslavia, Switzerland and Hungary, is postulated as a result of the different systems of keeping cattle in the provinces and the regional increase of tick invasion. Possibly an intensive animal transportation is of importance due to the introduction of the disease mentioned before. The results obtained show that anaplasmosis does occur in different areas of Austria. For control of this disease in Austria it is proposed that all imported cattle should be tested serologically for antibodies against Anaplasma marginale. Other diseases in connection with anemia should be excluded by clinical, serological, blood-, as well as pathological examinations.