Streptococcus equi
A Microbial Biorealm page on the genus Streptococcus equi
Classification
Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae; Streptococcus; Equi; Equi [Others may be used. Use NCBI link to find]
Description and significance
The bacterium, Streptococcus equi, is what causes the disease in equine species (horses, donkeys, mules) called strangles. It got its name because historically, affected horses were sometimes suffocated from inflamed lymph nodes in their upper airway and trachea. It is a highly contagious disease that is transmitted directly by contact with infected horses or indirectly by contact with water troughs, feed buckets, pastures, stalls, trailers, tack, grooming equipment, etc. Flies can also act as vectors, spreading the bacteria from horse to horse. Strangles commonly affects young horses, but horses of any age can be infected. An infected horse will usually show signs of the disease for three to seven days. Signs include: decreased appetite, lethargy, fever greater than 102 degrees Fahrenheit, inflamed and enlarged lymph nodes that eventually abscess and drain. Definitive diagnosis is made by culture of the bacteria from a sample of nasal discharge, lymph node abscess, or nasal-pharyngeal wash. Polymerase chain reaction (PCR) is another test that detects bacterial DNA but cannot tell the difference between live and dead bacteria. Strangles vaccines are available, but are only about 50% effective. The best way to prevent a strangles outbreak is by quarantining all new animals in the facility, meaning no direct contact with other animals or equipment used by other horses.
Genome structure
S. equi has circular chromosomes and a length of 2253793. It has 2253793 nucleotides, 2001 protein genes and 94 RNA genes. It is believed to have evolved from an ancestral strain of Streptococcus equi subspecies zooepidemicus, which causes diseases in horses as well as other animals including humans. Both S.equi and S. zooepidemicus belong to the same group of streptococci as the human pathogen, Streptococcus pyogenes.
Cell structure, metabolism & life cycle
Provide a physical and biochemical description of the organism. What kind of organism is it, what does it look like, how is it built, what are its metabolic properties, how can it be identified, what is it's life cycle, &c. In other words, describe the organism from its perspective.
Ecology (including pathogenesis)
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Interesting feature
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