An Investigation of Techniques used for the Isolation and Further .
Identification of Streptococci of the Pharynx .
Unknown streptococcal species were obtained from the pharynx. Also, three unknown streptococcal samples were given. Through a series of physiological tests on the pharyngeal isolates and the unknown samples, their likely identity was presumed. .
The hemolysis of the throat samples were determined; alpha hemolysis. Further, the throat sample gave negative results for salt tolerance, optochin and bile esculin hydrolysis. Thus, it was concluded the pharyngeal isolate must belong to the group viridans of streptococci.
Through some similar, but more extensive, testing of the unknown samples (x,y,z) their respective groups were also determined. Unknown sample X was found to belong to group A. therefore, S. pyogenes was the streptococci present in sample X. Sample Y was found to belong to group C of streptococci. Sample Z was found to belong to group D, more specifically, the enterococci.
Through these various physiological tests we were able to deduce the nature of each unknown through a process of elimination according to its positive or negative results towards the specific tests.
The microorganisms isolated in this lab belong to the genus streptococci. Streptococci are part of the normal flora, more specifically, some species of this genus live regularly on the pharynx, teeth, skin, colon, vagina and also in saliva (1). Streptococci are Gram positive cocci organisms usually arranged in chains. Streptococci, upon opportunity, can work with Staphylococci to collectively induce an infection, nevertheless, streptococci on their own can prove to be capable of harm, causing diseases such as pneumonia, meningitis, endocarditis, pharyngitis, erysipelas and glomerularnephritis (1). The following streptococci are of great medical importance; S. pyogenes, S.