Multisystemic Streptococcus gallinaceus infection in a six-banded armadillo from a zoo collection

A six-banded armadillo ( Euphractus sexcinctus ) from a zoo collection in central California developed acute neurologic signs followed by death. Postmortem examination revealed multisystemic bacterial disease (fibrinosuppurative meningoencephalomyelitis, splenitis, and endocarditis) with fibrinous necrotizing vasculitis and thrombosis. Streptococcus gallinaceus was isolated from the heart, lung, and meninges. To our knowledge, this microorganism has not been reported previously in association with systemic disease in an armadillo. Although the source of infection remains unknown, the animal was housed in the same building as chickens, a species that historically is associated with outbreaks of this bacterial infection. This case further broadens our understanding of the possible host range of S. gallinaceus and emphasizes the risk of interspecies pathogen transmission in captive environments.