Comparative Semen Microbiota Composition of a Stallion in a Taylorella equigenitalis Carrier and Non-Carrier State

Contagious equine metritis is receiving renewed attention due to the continuous detection of carriers in apparent agent-free farms. Interactions of Taylorella with the seminal microflora may be the plausible cause behind these spontaneous changes of the carrier state. Accordingly, the aim of this study was to compare the differences in the seminal microbiome composition of one stallion in the contagious equine metritis carrier state and non-carrier state. Samples were cryopreserved after their extraction. Cell disruption was performed by high-speed homogenization in grinding media. Bacterial families were identified via V3 amplification of the 16S rRNA gene and Ion Torrent sequencing. Only bacterial families with relative abundance above 5% were taken into consideration. The positive sample contained a strong dominance of Corynebacteriaceae (37.75%) and Peptoniphilaceae (28.56%). In the negative sample, the Porphyromonadaceae (20.51%), Bacteroidaceae (19.25%) and Peptoniphilaceae (18.57%) families prevailed. In conclusion, the microbiome seminal composition varies when an individual carries Taylorella from when it is free of it. The wider differences were found in the Corynebacteriaceae, Porphyromonadaceae and Bacteroidaceae families. Due to the limitations of a single-case analysis, further studies are needed for a better understanding of the stallion seminal microflora interactions.

Direct culture–independent sequence typing of Taylorella equigenitalis obtained from genital swabs and frozen semen samples from South African horses

We report herein the use of crude extracts obtained from samples of Taylorella equigenitalis–infected horses for the purpose of multi-locus sequence typing (MLST). Samples ( n = 36) were collected from horses in South Africa from 1996 to 2017: 34 from genital swabs (stored at −20°C for 2–3 y) and 2 from cryopreserved raw semen aliquots (stored at −70°C for 18 y) prior to assay. The MLST assay showed a single sequence type (ST), designated ST4, that supported a point introduction and thus a common source for the South African outbreak of contagious equine metritis.

Draft Genome Sequence of Taylorella equigenitalis Strain 210217RC10635, Isolated from a Pony Stallion in Germany

Here, we report the draft genome sequence of Taylorella equigenitalis strain 210217RC10635, a Gram-negative bacterium belonging to the genus Taylorella and the order Burkholderiales. Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM).

Towards European harmonisation of contagious equine metritis diagnosis through interlaboratory trials

The performance of culture and PCR methods routinely used to diagnose contagious equine metritis (CEM) was evaluated and compared by two interlaboratory trials involving a total of 24 European laboratories, including 22 National Reference Laboratories for CEM. Samples were swab specimens artificially contaminated with bacteria present in the genital tract of Equidae, some with and some without Taylorella equigenitalis, the causative agent of CEM, and T asinigenitalis, responsible for possible misidentification as T equigenitalis. Throughout both interlaboratory trials, PCR performed better in terms of specificity and sensitivity than the culture method, supporting the assertion that PCR should be accepted for CEM diagnosis. However, the culture performance during the second interlaboratory trial was better than during the first one, suggesting that the expertise of participants improved. This reveals the advantage of regular interlaboratory trials to constantly improve the expertise of laboratories. It also shows the need to develop new culture media that are more selective and/or better geared to the metabolism of T equigenitalis in order to improve the bacteriological diagnosis of CEM.