Identification of Bacteria using API kits - Anyone a pro at this? (May/28/2008 )

Dear all,

As I will be purchasing the API kit from bioMerieux for work with Gram negative rods, does anyone know if the API 20E or API 20NE is better? If I have a choice, I"d get both but since each kit tests for specific bacteria (NE = non-fermenters, E = enterics), do they overlap?

Thanks.

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Depends on what you want to do! Maybe you can tell us more about the kind of gram negative rods you are working with!
E.g. you wont get a useful determination of Pseudomonas with 20E and as far as I can rember you wont be able to differentiate E. coli from E. aerogenes (or was it E. cloaceae? or both, cant remember was a long time since) with 20NE....

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Ah, that's the thing here... Wanted to keep options open for Gram negatives regardless whether they ferment or not. So, guess it's API20E as well as 20NE to be purchased...

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There has been an API 50E some years ago, detected more rods, but I think I heard that they dont produce it anymore....

Otherwise: have you thought about Biolog-Plates; I think they have a system for gram-negative rods too, but it has been nearly 6 years now since I worked with this kind of stuff, so maybe there are new products around!

But nevertheless: the more nutrients you test the better you will characterize your isolates....

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Thanks. Got it. More nutrients will detect a wider range of gram negatives. Now that they're offering only 20 tests in each kits, I'm sure both are specific to that particular groups only. Thanks people.

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Be aware that API's are directed primarily at clinical isolates and may miss on environmentals isolates.

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Thanks Jorge for that. Yes, I'm working with some environmental strains as well. Let's hope the 20NE can successfully identify them.

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had trouble esp with some of the Burkholderia's with both vitek and API.

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Ah, yes! I'm dealing with Burkholderia. 16s rDNA analyses showed similarity to B. cepacia and B. cenocepacia. Perhaps the fact that B. cepacia exists as a complex of many strains (genomovars) that makes biochemical identification inaccurate; what more when I did it the conventional way. Hoping this time that the commercial kit like API could back the 16s analyses up.

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for the cepacia group - I'd drop the commercial kits and systems if you want a good ID. Lit search on pubmed will pull up report of the misses. Don't underestimate the the turmoil a mistaken ID of pseudomallei might cause with limited time to report to authorities and potnetial before draconian consequences.

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