Suspicion of Mycobacterium avium subsp. paratuberculosis Transmission between Cattle and Wild-Living Red Deer (Cervus elaphus) by Multitarget Genotyping

For epidemiological tracing of paratuberculosis (Johne's disease), multi-target genotyping of the etiologic agent Mycobacterium avium subsp. paratuberculosis (MAP) is necessary. The study was undertaken to assess the informative value of different typing techniques and individual genome markers by investigation of MAP transmission between wild-living red deer and farmed cattle with known shared habitats. 53 MAP-type-II-isolates were differentiated by short-sequence repeat (SSR, 4 loci)-, mycobacterial interspersed repetitive unit-variable number tandem-repeat (MIRU-VNTR, 8 loci)-, and restriction fragment length polymorphism analysis based on IS900 (IS900-RFLP) using BstEII- and PstI-digestion. Isolates originated from free-living red deer (Cervus elaphus) from the Eifel-Nationalpark (n=13), six cattle herds living in the area of this park (n=23), and five cattle herds without any contact to these red deer (n=17). Data based on individual herds and genotypes verified that SSR-G2-repeats exhibited no sufficient stability for epidemiological studies. Two common SSR profiles (without G2 repeats), nine MIRU-VNTR-, and nine IS900-RFLP-patterns were detected resulting in 17 genotypes when combined. A high genetic variability was found for red deer and cattle isolates within and outside the Eifel-Nationalpark, but was revealed only by combination of different typing techniques. Results imply that within this restricted area wild-living and farmed animals maintain a reservoir for specific MAP genotypes. No host relation of genotypes was obtained. Results suggested that four genotypes had been inter- and intra-species transmitted and one type between cattle herds only. Use of multi-target genotyping for MAP-type-II-strains and sufficiently stable genetic markers is essential for reliable interpretations of epidemiological studies on paratuberculosis.