Academic Field

Biological Sciences

Faculty Mentor Name

Holly Ahern

Presentation Type

Poster Presentation

Abstract

Strangles is a highly contagious respiratory disease in horses which is caused by the bacterium Streptococcus equi. The name of the disease is related to symptoms of acute swelling and abscess formation in submandibular and retropharyneal lymph nodes that may obstruct the airway. Transmission may occur through direct horse-to-horse contact or by indirect transfer of S. equi via fomites in the stable area (such as feed and water buckets, contaminated bedding, or stall surfaces). Some laboratory-based studies indicate that the bacteria may survive on inanimate surfaces including wood and glass for a month or longer, even at cold temperatures. This study was undertaken to assess whether S. equi bacteria would persist on fomites in a barn where a horse with strangles had been stabled. I took samples from fomites in the barn 1 month after an infected horse produced its first negative test result for the disease and the stable had been cleaned using veterinarian-recommended procedures. Samples were taking by swabbing the horse’s halter, stall door, and grain dish. The swabs were transported to the laboratory and plated on culture medium within an hour of sample collection. Colonies that grew on the plates were characterized by phenotype and presumptively identified. All of the samples were negative for S. equi, however, other types of Gram positive bacteria were found in the grain dish. Therefore my tests indicate that Streptococcus equi did not persist on barn objects in regular contact with the infected horse, and that the recommended cleaning procedures were effective in preventing spread of the disease to other horses in the stable.

Keywords

Streptococcus equi, strangles, disease transmission, fomites, horses

Start Date

10-4-2015 2:00 PM

End Date

10-4-2015 2:45 PM

Location

SERC House of Fields

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Apr 10th, 2:00 PM Apr 10th, 2:45 PM

Transmission of Streptococcus equi by fomites among stabled horses

SERC House of Fields

Strangles is a highly contagious respiratory disease in horses which is caused by the bacterium Streptococcus equi. The name of the disease is related to symptoms of acute swelling and abscess formation in submandibular and retropharyneal lymph nodes that may obstruct the airway. Transmission may occur through direct horse-to-horse contact or by indirect transfer of S. equi via fomites in the stable area (such as feed and water buckets, contaminated bedding, or stall surfaces). Some laboratory-based studies indicate that the bacteria may survive on inanimate surfaces including wood and glass for a month or longer, even at cold temperatures. This study was undertaken to assess whether S. equi bacteria would persist on fomites in a barn where a horse with strangles had been stabled. I took samples from fomites in the barn 1 month after an infected horse produced its first negative test result for the disease and the stable had been cleaned using veterinarian-recommended procedures. Samples were taking by swabbing the horse’s halter, stall door, and grain dish. The swabs were transported to the laboratory and plated on culture medium within an hour of sample collection. Colonies that grew on the plates were characterized by phenotype and presumptively identified. All of the samples were negative for S. equi, however, other types of Gram positive bacteria were found in the grain dish. Therefore my tests indicate that Streptococcus equi did not persist on barn objects in regular contact with the infected horse, and that the recommended cleaning procedures were effective in preventing spread of the disease to other horses in the stable.