Waller, Andrew
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
- Intervacc AB
Research article2023Peer reviewed
Morris, Ellen Ruth A.; Schroeder, Megan E.; Ferro, Pamela J.; Waller, Andrew S.; McGlennon, Abigail A.; Bustos, Carla P.; Gressler, Leticia T.; Wu, Jing; Lawhon, Sara D.; Boyle, Ashley G.; Lingsweiler, Sonia; Paul, Narayan; Dimitrov, Kiril; Swinford, Amy K.; Bordin, Angela I.; Cohen, Noah D.
Strangles is a contagious bacterial disease of horses caused by Streptococcus equi subspecies equi (SEE) that occurs globally. Rapid and accurate identification of infected horses is essential for controlling strangles. Because of limitations of existing PCR assays for SEE, we sought to identify novel primers and probes that enable simultaneous detection and differentiation of infection with SEE and S. equi subsp. zooepidemicus (SEZ). Comparative genomics of U.S. strains of SEE and SEZ (n = 50 each) identified SE00768 from SEE and comB from SEZ as target genes. Primers and probes for real-time PCR (rtPCR) were designed for these genes and then aligned in silico with the genomes of strains of SEE (n = 725) and SEZ (n = 343). Additionally, the sensitivity and specificity relative to microbiologic culture were compared between 85 samples submitted to an accredited veterinary medical diagnostic laboratory. The respective primer and probe sets aligned with 99.7 % (723/725) isolates of SEE and 97.1 % (333/343) of SEZ. Of 85 diagnostic samples, 20 of 21 (95.2 %) SEE and 22 of 23 SEZ (95.6 %) culturepositive samples were positive by rtPCR for SEE and SEZ, respectively. Both SEE (n = 2) and SEZ (n = 3) were identified by rtPCR among 32 culture-negative samples. Results were rtPCR-positive for both SEE and SEZ in 21 of 44 (47.7 %) samples that were culture-positive for SEE or SEZ. The primers and probe sets reported here reliably detect SEE and SEZ from Europe and the U.S., and permit detection of concurrent infection with both subspecies.
Real-time PCR; Streptococcus equi subsp; equi; zooepidemicus; Coinfection; Diagnostic laboratory
Veterinary Microbiology
2023, Volume: 284, article number: 109797
Publisher: ELSEVIER
Infectious Medicine
Pathobiology
DOI: https://doi.org/10.1016/j.vetmic.2023.109797
https://res.slu.se/id/publ/122843