I am using a media that is selective for vancomycin-resistant enterococci, but it keeps giving me Pediococcus (since Pediococcus is intrinsically resistant to vancomycin and has similar characteristics). The only way that could tell me it's not a VRE was using VITEK. Is there another way to differentiate between them?
Thank you in advance.
The simplest method is heat tolerance, Enterococci survive for hours (60 -90 min) at 60C but pediococcus get killed within minutes (less than 10 min).
Bhoj R Singh
I'll give that a try.
Thank you so much for your help!
Pediococcus sp. growth occurs in mixture of MRS-vancomycin at 45C where as Enterococcus sp. growth occurs in 15C with in 24 hours, In Grams stained method, Pediococcus sp. shows coccus in tetrad where as Enterococcus sp visualize in coccus uniformity. In biochemical test Sucrose and Mannitol utilzation is negative for Pediococcus sp. where as vice versa for Enterococcus sp. If you measure the resistance range and MIC value of them following methodology of "Kirby bauer disc method"on Muller Hinton Agar by set up Vencomycin disc, you will easily differentiate the zone of inhibition range among them. And calculation will lead lot of data by set up lot of samples on differentiating their state of resistant range, than for plotting a graphical variation, it need to count in Macfarland scale at range of 0.62 to 0.68 after mixing in 3ml distilled water for spread plate technique. Than you can easily verify the significance by developing your own protocols manually except VITEK Compact automated system. Thank you.
Avra Pratim Chowdhury Thank you so much for your detailed answer!
I will take these methods into consideration.
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