Reproductive loss attributed to Lactococcus petauri infection in a black-and-white ruffed lemur

Abstract

Lactococci have been associated with fetal and neonatal infections in humans and cattle. Here we describe a case of reproductive loss attributed to Lactococcus petauri in a lemur. A full-term black-and-white ruffed lemur (Varecia variegata) was found dead in the indoor area of a zoologic exhibit. Classification as a late-term abortion or stillbirth was unclear as the precise gestational time was unknown. A medical checkup of the dam revealed fever and neutrophilic leukocytosis; recovery followed treatment with enrofloxacin. The main histologic findings were placental edema and hemorrhage, hepatic necrosis, desquamated amniotic epithelial cells in alveoli, and subendocardial and myocardial hemorrhages. Tissue Gram stain revealed abundant gram-positive cocci arranged in short chains in the placenta and liver. Toxoplasma gondii was not detected by immunohistochemistry. Bacterial isolates from the placenta and fetal liver were identified as Lactococcus garvieae by MALDI-TOF MS. However, the isolates were found to be L. petauri by determining their in-silico DNA–DNA hybridization and average nucleotide identity values using pairwise comparisons of their whole-genome sequences and the genomes of the type strains. The antimicrobial susceptibility of isolates by the disk diffusion method revealed resistance to tylosin, gentamicin, apramycin, neomycin, amikacin, ampicillin, and florfenicol. We attributed the reproductive loss in this lemur to placental and fetal infection by L. petauri.