Streptococcus zooepidemicus: Difference between revisions
No edit summary |
No edit summary |
||
Line 45: | Line 45: | ||
==Ecology== | ==Ecology== | ||
''Streptococcus zooepidemicus'' is facultively anaerobic and host-associated. Its optimal temperature for growth is 37° C. It is a commensal of horses, and its host range also includes swine, cattle, poultry, and human (21). This microorganism can be found in various parts of horses and cattle, including nasopharynx, tonsils, respiratory tract, and the genital muscous membranes (24). In fact, subspecies zooepidemicus is the one bacterium that is most commonly recovered from wounds and abscesses, guttural pouches, transtracheal washes (TTW), and uterus of horses (12). | |||
<br> | |||
==Pathology== | ==Pathology== |
Revision as of 02:35, 29 August 2007
A Microbial Biorealm page on the genus Streptococcus zooepidemicus
Classification
Higher order taxa
Bacteria; Firmicutes; Bascilli; Lactobacillales; Streptococcaceae; Streptococcus
Species
NCBI: Taxonomy |
Streptococcus equi
Subspecies
zooepidemicus
Other names
“Animal pyogenes, type A” [Edwards 1934]
“Streptococcus pyogene animalis” [Seelemann 1942]
“Streptococcus equi subsp. zooepidemicus” [Farrow and Collins 1985]
Type Strains
ATCC 43079
DSM 20727
NCDO 1358
Description and significance
Streptococcus zooepidemicus is one of the two subspecies of Streptococcus equi; it is suggested to be the species from which subspecies equi has been derived (5). Subspecies zooepidemicus is a normal bacterial flora in horses. It is isolated from wound infections of horses, and it has been isolated from other mammals such as cows, rabbits, and swine (3). In some cases, subspecies zooepidemicus is also isolated from humans through throat swabs (4). It occasionally causes human infection that can be traced back to contact with horses or consumption of unpasteurized dairy products (4).
Like other streptococci, Streptococcus zooepidemicus is a non-motile, non-sporulating, encapsulated, gram-positive, catalse-negative, and coccoid bacterium. It is a beta hemolytic streptococcus that produces hyaluronic acid but not streptolysin O and occurs in pairs or long chains (2). It is also lactose positive and is capable of fermenting sorbitol but not trehalose (3, 28).
Genome structure
Although the shotgun sequencing is complete with an available database of reads, the genome project of Streptococcus zooepidemicus is still in progress. At present, the genome size of this microorganism is about 2.3 Mb with a G+C content of approximately 41%, and 33,640 reads totaling 23.629Mb covering theoretically 99.99% of the genome (14). The similarity between the DNA of the two subspecies, zooepidemicus and equi, is over 92%. However, their biological behaviors in horses differ significantly. Subspecies zooepidemicus is a commensal of equine nasopharynx and external genitalia and causes infections in various areas, while subspecies equi is a contributing agent that causes strangles (3, 18). In addition, S. zooepidemicus has Szp proteins that may have an antiphagocytic role similar to the M proteins in group A streptococci (GAS) in the case of causing human infection. The Szp proteins not only share structural similarities with the M proteins but also stimulate opsonic antibodies just like the M proteins do (13).
Cell structure and metabolism
Cell wall
In general, Lancefield group C streptococci (GCS) have cell walls consisting of group-specific carbohydrate and mucopeptide polymer (20). The group-specific antigens of GCS are polysaccharides that are made up of hexoamine and rhamnose. Unlike group A streptococci (GAS), GCS carbohydrate has a terminal antigenic determinant of N-acetyl-galactosamine (3).
Metabolism
Ecology
Streptococcus zooepidemicus is facultively anaerobic and host-associated. Its optimal temperature for growth is 37° C. It is a commensal of horses, and its host range also includes swine, cattle, poultry, and human (21). This microorganism can be found in various parts of horses and cattle, including nasopharynx, tonsils, respiratory tract, and the genital muscous membranes (24). In fact, subspecies zooepidemicus is the one bacterium that is most commonly recovered from wounds and abscesses, guttural pouches, transtracheal washes (TTW), and uterus of horses (12).
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Enter summaries of the most recent research here--at least three required
References
Edited by Jenny Chong, student of Rachel Larsen