Streptococcus hillyeri isolated from septic pleuritis in a horse

Area of Science:

• Veterinary Microbiology
• Equine Infectious Diseases
• Bacterial Pathogenesis

Background:

• Septic pleuritis is a severe thoracic infection in horses.
• Accurate identification of causative agents is crucial for effective treatment and understanding disease.
• Streptococcus species are common bacterial pathogens in various animal species.

Purpose of the Study:

• To identify the bacterial agent responsible for septic pleuritis in a horse.
• To characterize the isolated bacterium using molecular methods.
• To investigate the potential pathogenicity of Streptococcus hillyeri in equids.

Main Methods:

• Sample collection from a horse with suspected pleuritis.
• Thoracic ultrasonography and cytology for diagnosis.
• Anaerobic bacterial culture and identification using 16S rDNA and whole-genome sequencing.
• Bioinformatic analysis of related bacterial sequences.

Main Results:

• Isolation of gram-positive cocci, identified as Streptococcus hillyeri, from pleural effusion.
• Confirmation of septic pleuritis via cytology and culture.
• Identification of Streptococcus hillyeri in previous equine abortion and donkey mastitis cases.

Conclusions:

• Streptococcus hillyeri was the causative agent of septic pleuritis in the presented case.
• This study provides evidence for the pathogenic role of Streptococcus hillyeri in horses, donkeys, and potentially in equine abortions.
• Further research is warranted to understand the full spectrum of Streptococcus hillyeri infections in equids.