Untersuchung zum Vorkommen und zur Bedeutung ausgewählter Mykobakterien bei Zootieren

Prevalence and relevance of mycobacteria in zoo animals Mycobacteria are acid fast rod-bacteria. Their presence in zoo animals may be linked to various health disorders and cases of disease. Due to international exchange of (breeding) animals and the common existence of clinical unapparent mycobacterial infections of animals there is a high risk of spread. Unfortunately, comprehensive data on incidence and prevalence of mycobacteria in zoological gardens in Germany are not available. The aim of this study was to evaluate the prevalence of mycobacteria in German zoological gardens in order to derive an assessment of the zoonotic risk potential. Therefore, 1,090 field samples from six zoological gardens in Germany were tested. This included samples from mammals (n = 860) and birds (n = 230). A quantitative PCR, amplifying a sequence of the mycobacterial 16S rRNA amplification, was applied. The resulting overall mycobacterial prevalence was 14,4 %. Faecal excretion of mycobacteria was significantly higher than oral excretion. The resulting prevalence from testing oral swabs was 2,5 % and from rectal swabs 26,8 %. In all cases presence of mycobacteria from the tuberculosis-complex could be excluded. The highest prevalence was detected in samples taken during the spring. These results showed that zoo animals shedding mycobacteria do not usually present clinical symptoms. For further characterization at the (sub-) species level, some of the samples (n = 26) were PCR amplified and sequenced applying a conventional PCR for the rpoB gene amplification. All PCR confirmed samples were non-tuberculous mycobacteria. As there was no 100% match with any of the known mycobacteria species from the current data bases the possible unknown mycobacterial species may have been observed. Based on these results further studies of the occurrence and epidemiology of the identified Mycobacterium spp. in zoo animals could prevent their further spread.