Dimorphic yeast fungi infections in beef cattle.
Abstract
In an investigation primarily to determine the prevalence of bovine tuberculosis in slaughter cattle
in Kenya, smears of tuberculous lesions and of cultures in BBLTM MGITTM Mycobacterium growth
indicator tubes were stained by Ziehl-Neelsen procedure and examined microscopically. Sections
of formalin- fixed lesions were stained with the periodic acid Schiff reagent and examined for yeast
fungi. Of the 176 animals with tuberculoses lesions, dimorphic yeast fungi were detected, as acid
fast negative cell, in 70 (39.8 %) cases either alone (42, 23.8 %) or concurrent with acid fast bacilli
(28, 15.9 %) in lesion smears. Yeast fungi were also detected in some BBLTM MGITTM culture smears
and in some tissue sections. The fungi comprised of Paracoccidiodes brasiliensis or Blastomyces
dermatitidis species. The present report documents native P. brasiliensis infections outside the endemic
region, and B. dermatitidis infection in a livestock species of animal. It also speculates infections
in other animals, including humans, in the region of origin of the infected animals. The findings
emphasize further the importance of including dimorphic yeast fungi infection in the differential
diagnosis of bovine tuberculosis during meat inspection in the region.