Pathogenic Elizabethkingia miricola Infection in Cultured Black-Spotted Frogs, China, 2016

Abstract

Multiregional outbreaks of meningitis-like disease caused by Elizabethkingia miricola were confirmed in black-spotted frog farms in China in 2016. Whole-genome sequencing revealed that this amphibian E. miricola strain is closely related to human clinical isolates. Our findings indicate that E. miricola can be epizootic and may pose a threat to humans.

Keywords: China; Elizabethkingia miricola; Pelophylax nigromaculatus; amphibian; bacillus; bacteria; black-spotted frog; frog; genetic diversity; zoonoses; zoonotic pathogen.

Figure 1

Clinical signs (arrows) in frogs with Elizabethkingia miricola infection in Hunan Province, China. A) Diseased frogs had neurologic signs of torticollis. B–D) Clinical signs with different appearances showing cataracts, proptosis, or hyperemia. E) Symptoms of abdominal distension. Scale bars indicate 1 cm.

Video

Diseased frogs sampled at Yiyang, Hunan Province, China. The diseased frogs had symptoms including neurologic signs of torticollis, disorientation, and agitation or lethargy.

Figure 2

Maximum-likelihood phylogenetic tree of Elizabethkingia miricola FL160902 from an infected frog in Hunan Province, China, and reference genomes. The tree was constructed by using the single-copy orthologous genes of all the 38 genomes with 100 bootstrap replicates. Species identifications strictly followed the National Center for Biotechnology Information submitted names. Isolates assigned into UB groups and subgroups are according to Holmes et al. (12) and Bruun and Ursing (13).Solid circles indicate type strains; open circle indicates a former type strain. Bold indicates strain isolated in this study. Scale bar indicates nucleotide substitutions per site.