First Report of Chlamydia abortus in Farmed Fur Animals

Abstract

Chlamydia (C.) abortus, a globally distributed obligate intracellular bacterium, has attracted increasing interest according to its veterinary importance and zoonotic nature. C. abortus can infect a variety of animals and cause foetal loss in livestock resulting in economic loss. In this study, the samples collected from two farms of foxes (n=20), raccoon dogs (n=15) and minks (n=20), were investigated by Chlamydiaceae- and Chlamydia species-specific real-time PCR. The results showed that all the tested foxes (20/20) and raccoon dogs (15/15) harbored Chlamydia spp., while 5% of minks (1/20) were positive for Chlamydia spp. C. abortus was identified in all positive samples as the dominant Chlamydia species, with C. pecorum DNA coexistence in some of the rectal samples (7/20) taken from foxes. Phylogenetic analysis based on specific gene fragments of 16S rRNA, IGS-23S rRNA, and ompA revealed that all sequences obtained in this study were assigned to the Chlamydiaceae family with high similarity to C. abortus S26/3 and B577 previously identified in ruminants. This is the first report confirming that farmed foxes, raccoon dogs, and minks carry C. abortus. Further studies are needed to fully elucidate the epidemiology and pathogenicity of this pathogen in farmed fur animals as well as the potential risks to public health.

Figure 1

Phylogenetic tree based on 16S rRNA gene fragment (1358 bp) (a), 16S-23S intergenic spacer and full length of 23S rRNA domain I fragment (990 bp) (b), and ompA gene fragment (940 bp) (c). Representative sequences of established Chlamydiaceae species as well as the sequences obtained from this study (Genbank accession number was shown in bold) were included. S. negevensis strain Z was used as an outgroup. Based on these alignments, phylogenetic trees were constructed by the neighbor-joining method using the Maximum Composite Likelihood model with MEGA 5.05.