In one placenta, and also in the lung tissues of fetuses, Ziehl-Neelsen staining revealed acid-fast bacilli in combination with infiltrations of neutrophils, macrophages and multinucleated giant cells. Acid-fast bacilli were also found in the mesenteric lymph nodes, liver and/or spleen and jejunum of pigs with wasting and in slaughtered animals. The specimen cultures were identified as Mycobacterium avium subspecies hominissuis using IS1245-specific PCR and IS1245 restriction fragment length polymorphism (RFLP). IS1245 RFLP revealed that the herd was infected with multiple M avium subspecies hominissuis strains belonging to at least two different clades. It is suggested that this infection may have played a more important role in the economic losses of the pig farm than had been assumed previously.
G. J. Wellenberg, P. E. W. de Haas, J. van Ingen, D. van Soolingen, I. J. R. Visser. Multiple strains of Mycobacterium avium subspecies hominissuis infections associated with aborted fetuses and wasting in pigs. Veterinary Record 2010;167:451-454.