Evaluation of serological responses in horses challenged with Burkholderia pseudomallei using current diagnostic...

Area of Science:

• Veterinary Microbiology
• Equine Infectious Diseases
• Bacteriology

Background:

• Melioidosis, caused by Burkholderia pseudomallei, is an emerging infectious disease with potential implications for equine health.
• A strain of B. pseudomallei from a fatal dromedary camel case was used for experimental infection in horses.
• Glanders, caused by Burkholderia mallei, is a historically significant equine disease.

Purpose of the Study:

• To assess the susceptibility of horses to Burkholderia pseudomallei.
• To evaluate the efficacy of existing serological tests for glanders in detecting B. pseudomallei infection in horses.
• To determine if current diagnostic methods can differentiate between glanders and melioidosis in equine cases.

Main Methods:

• Six horses were experimentally infected with B. pseudomallei via subcutaneous inoculation (3 horses) or oral administration (3 horses).
• Serological testing using OIE-described glanders tests was performed.
• B. pseudomallei re-isolation was attempted from infected horses.
• Clinical signs, including fever, and hematological parameters (white blood cell counts, neutrophil counts) were monitored.

Main Results:

• Four out of six horses became serologically positive for glanders based on standard tests.
• B. pseudomallei was successfully re-isolated from these four serologically positive horses.
• Only one horse, infected subcutaneously, exhibited clinical signs (fever) and elevated white blood cell and neutrophil counts.

Conclusions:

• Experimental infection with Burkholderia pseudomallei in horses can lead to serological reactions indistinguishable from glanders.
• Existing serological tests for glanders are insufficient to differentiate between glanders and melioidosis in horses.
• This finding has significant implications for the accurate diagnosis and control of both diseases in equine populations.