How to identify coagulase-negative staph from clinical samples - (Oct/01/2008 )
Was wondering if there is a way to delineate coagulase-negative staph from staph aureus directly from clinical samples (I am particularly interested in ophthalmologic specimens such as aqueous humor or vitreous). I realize such samples can be gram stained and thus one can quickly identify whether a sample contains gram positive cocci, however, is it possible to perform a coagulase test on a clinical sample without first culturing the specimen? Are there alternative methods to these typical biochemical tests? Can you do fatty acid analysis via GLC on clinical samples? Can you use clinical samples with the API screens from Biomerieux? Many thanks.
-EricWS-
QUOTE (EricWS @ Oct 2 2008, 04:35 AM)
Was wondering if there is a way to delineate coagulase-negative staph from staph aureus directly from clinical samples (I am particularly interested in ophthalmologic specimens such as aqueous humor or vitreous). I realize such samples can be gram stained and thus one can quickly identify whether a sample contains gram positive cocci, however, is it possible to perform a coagulase test on a clinical sample without first culturing the specimen? Are there alternative methods to these typical biochemical tests? Can you do fatty acid analysis via GLC on clinical samples? Can you use clinical samples with the API screens from Biomerieux? Many thanks.
for culture dependent methods I think you must obtain pure cultures as you can not be sure which organism you are dealing with. And not all gram positive cocci are Staph aureus!!! So for good results: take some selective medium for S aureus and plate your samples on it, isolate the bacteria and then do your tests.
If only interested in coagulase-negative or not and stap or not: why not looking for a PCR based protocol
-gebirgsziege-