Currently, there are 5 common commercial ways of identifying bacteria, API strips, VITEK 2, Biolog, Sherlock, and DNA sequencing. Each one of them has its own advantages and disadvantages. The following opinions are based on their accuracy and cost.

Biolog (Biolog, Inc.) uses the profile of different carbohydrates that can be "metabolized" by bacteria (as nutrients) for identification. Those characteristics could potentially change if new generations of microorganisms migrate to a new environment and adapt to new type of nutrients. Therefore, same species/strain of bacteria could have different profiles after many many generations. This method is better to be used to character microorganisms for their metabolic "fingerprints" to track their source or for other studies.

API strips (bioMerieux INDUSTRY) has a long history in clinical usage. It uses chemical reactions to differentiate physiological characteristics of bacteria for identification. Historically, it was designed for clinical isolates. Although it is the cheapest option, if it is used for an environmental isolate, you may not get a correct match in the database because there is no such entry. The reaction results may also be variable for environmental isolates. Therefore, the usage of this method for environmental bacteria is limited. If a lab offers to identify three isolates for less than $100, be sure to check what method they uses and understand its limitations.

VITEK 2 (bioMerieux INDUSTRY) system is a more advance system based on the same principal as API strips. It uses an automated system to incubate and analyze the results. Its database is more focused on clinical bacteria isolates. It has been working on expanding the database for environmental isolates in recent years. The cost is about $100 to $120 per bacteria isolate.

Sherlock System (MIDI, Inc.) uses fatty acid profile of bacteria cell wall for identifications, which is believed to be a more conservative indicator than physiological characteristics. It costs about $80 to $100 per isolate. The Aerobe library contains over 430 clinical species and 695 environmental species. It is more suitable for bacteria isolated from environmental samples than VITEK 2 because it has more extensive database for environmental bacteria.

DNA sequencing uses 16s rRNA gene sequence for bacterial identification. It is much more conservative, which means this region of DNA sequence doesn't change much, generations after generations. Therefore, it is the most accurate and reliable identification tool and also the most expensive one. It used to cost much more. Currently, its price has dropped to about $110 to $130 per bacterial isolate. This is the recommended method for environmental bacteria identification unless budget is a concern, then fatty acid analysis should be used.

We have been helping companies that were frustrated with unsatisfying services from their microbiology labs on issues such as:
(1) poor technical support
(2) no personal attention
(3) questionable results
(4) project delay; slow turnaround time
(5) reports not making sense
(6) lack of ethics

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Host: Joe Hughes/Cliff Zlotnik

Episode Notes: Sam Teitelbaum is President of AllerAir Industries, a company that designs and manufactures air purifiers for industrial, residential, military and medical applications. Since 1996 when AllerAir was established, Sam has been on a mission to raise awareness about the importance of clean indoor air quality, while emphasizing the critical role of combination carbon-HEPA air filters to remove dangerous airborne chemicals, gases, odors and particles. His initiative for cleaner air and high quality, deep-bed carbon air purifiers began almost two decades ago when his wife developed sensitivity to chemicals, and they were unable to find a viable air purifying solution. Since then, Sam has had an integral role in the research and development of over 100 types of air purification systems, that are now providing worldwide IAQ solutions.

Scheduled Time:
Date: Fri, October 31, 2008
Time: 12:00 PM EDT