How to Identify & confirm Staphylococcus Saprophyticus in Lab
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Hope you all know about s.aureus. This Staphylococcus saprophyticus is also belong to the same staphylococcus spp, but there are few differences.
Staphylococcus saprophyticus is one of skin commensal microbe. However, it is the second most common cause for UTIs In females between the ages of 17-27
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Staphylococcus saprophyticus is one of skin commensal microbe. However, it is the second most common cause for UTIs In females between the ages of 17-27
And also it is common causative organism of Cystitis in women due to its occurance as common vaginal flora. Usually it sensitive to wide range of antibiotics. But resist to drug Novobiocin. we can distinguish it from S.epidermidis and other coagulase negative staphylococci due to its resistance to novobiocin.
Let’s see how to detect Staphylococcus saprophyticus in laboratory,
First, important one is to look at the growth pattern and colony morphology to have a idea about culture growth.Â
When we consider the Growth on Blood agar, Staphylococcus saprophyticus  give White flat non hemolytic colonies. Small LF colonies are the results of growth of macconkey agar.
then we can prepare a smear for Gram stain, Staphylococcus saprophyticus  are Gram positive cocci in clusters.
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Usually once we detect a particular organism as gram positive cocci, what we need to do is the catalase test. Catalase test is Positive for Staphylococcus saprophyticus .
Depending on all above diagnostic results, and with the use of clinical history we should have a direction to perform the next testing panel.
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If we suspect stap spp then we can perform the Coagulase test. For the Staphylococcus saprophyticus it give negative results.
There are two common coagulase negative stap spp are clinically significant. They are s.epidermidis and this s.saprophyticus.
If we need further differentiation, we can perform Novobiocin sensitivity test and other sugar fermentation tests. Staphylococcus saprophyticus is novobiocin resistant while s.epidermidis is sensitive.
If we consider some of Sugar fermentation results, it give,
 Mannose:negative
Trehalose:positive
Mannitol:Negative
Through these diagnostic tests along with clinical suspicion we can identify Staphylococcus saprophyticus in clinical laboratory set up.
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