Peer-reviewed veterinary case report
Metagenomic and 16S rRNA analysis of culture-negative uterine samples identifies Brucella spp. in a female dog with pyometra.
- Journal:
- Topics in companion animal medicine
- Year:
- 2025
- Authors:
- Xavier, Rafael Gariglio Clark et al.
- Affiliation:
- Escola de Veteriná · Brazil
- Species:
- dog
Plain-English summary
In this study, researchers looked at the uterine samples from female dogs with a serious infection called pyometra, which is common in unspayed females. They found that while most samples showed typical bacteria like E. coli, a small number didn’t grow anything using standard lab techniques. To investigate further, they used advanced genetic testing on these samples and discovered that one sample contained Brucella spp., a type of bacteria that can be harmful to both dogs and humans. This suggests that there are other hard-to-detect germs that could be involved in pyometra, which might require different testing methods to identify. Overall, the findings highlight the importance of looking for these less common pathogens in affected dogs.
Abstract
Canine pyometra is the most prevalent reproductive disease in female dogs and involves a complex interplay of hormonal and microbial factors. Although Enterobacteriaceae are known to be the main cause of pyometra, up to 25 % of samples remain negative when classic culture methods are used. The lack of growth in conventional media raises the intriguing possibility that non-cultivable microorganisms participate in the disease. Our study aimed to address this knowledge gap by investigating the microbiota in culture-negative uterine samples from dogs with pyometra. The purulent uterine contents of dogs with pyometra (n = 79) were subjected to bacterial culture. Most of the samples showed bacterial growth of Escherichia coli (48/79, 60.7 %) or other bacterial species (25/79, 31.8 %). Samples that tested negative using the classic culture method (6/79=7.5 %) were further analyzed using 16S rRNA gene sequencing, high-throughput 16S rRNA sequencing, and shotgun metagenomics. Only three of these provided DNA of sufficient quality for further analysis, which revealed a mixture of Haemophilus/Aggregatibacter and Fusobacterium/Porphyromonas in two uterine content. In the third sample, Brucella spp. was identified as the main genus. This study suggests that pathogens that are not easily isolated by classical culture methods, including zoonotic species, may be present in the uterus of dogs with pyometra.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/40339985/