Higher order taxa
Bacteria (Domain); Firmicutes (Phylum); Bacilli (Class); Lactobacillales (Order); Streptococcaceae (Family); Streptococcus (Genus)
Description and significance
The Streptococcus troglodytidis is a coccus-shaped bacterium. It has recently been found in the foot abscess of a chimpanzee, giving rise to its name from the scientific name for the common chimpanzee, Pan troglodytes. This microbe is notable because it has been identified as another form of the Group B Streptococcus, which is a pathogenic form of bacteria that can colonize the human body, but generally only causes disease in newborns and the immunosuppressed.
Currently, the genome of the S. trogloydytidis has not been fully sequenced but partial sequence data from the 16S rRNA allowed researchers to identify it as a unique species. The use of the well conserved 16S rRNA sequence provided enough distinction from the other members of the Streptococcus family that this microbe was identified as a novel species. The use of several housekeeping genes such as sodA, gdh, ddl, and rpoB nucleotide gene sequences aided researchers in distinguishing this new species from other similar strains of Streptococcus. The housekeeping genes are gene sequences that code for different cellular functions and maintenance.
Cell and colony structure
The coccus-shaped cell is β-haemolytic and thus displays a complete lysis of the red blood cells around its colonies when grown in blood agar. It has also been identified as non-motile and non-spore forming.
S. troglodytidis has been identified to be a facultative anaerobe which means that the bacterium can produce ATP from aerobic respiration when oxygen is available, but can also utilize fermentation if oxygen is not present in its environment. This species is negative for the activity or presence of the catalase enzyme, which helped lead to its identification as a species of Streptococcus. It also lacks the enzymatic oxidase activity which indicates that it does not have the cytochrome c system found in many aerobic microbes and is consistent with the identification as a facultative anaerobe.
Currently, the only identified sample of this microbe is from a foot abscess on a common chimpanzee.
The discovery of S. troglodytidis is significant because it is another form of Group B Streptococcus (GBS) which can cause serious infections in newborns as well as adults with compromised immune systems. Generally pregnant women will be screened for GBS colonization during their third trimester of pregnancy because of the risk of transmission during labor. Approximately a quarter of all pregnant women are GBS positive and generally treatment can be provided through antibiotics given to the mother during delivery. Infection typically presents with fever, breathing issues, and exhaustion and can be treated with antibiotics such as ampicillin or penicillin. Previously, GBS referred to Streptococcus agalactiae but may now be expanded to include this additional species.
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Edited by Jordan Beall of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences. http://www.usm.maine.edu/bio
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