OK Medium: A Fluorogenic Selective and Differential Medium for Isolation of Enterobacter sakazakii

Unmet Need: Method to isolate and differentially identify a single type of bacteria from a mixture

Due to the extensive quantity and variety of bacteria present in the clinical environment, it is desirable to have methods for isolating and differentially identifying a single type of bacteria from a mixture of bacteria. A common approach to identifying bacteria is based on their appearance and/or growth characteristics in different types of culture media. To aid in bacterial isolation and identification, a growth medium may be both “selective” and “differential”. A selective medium is designed to suppress the growth of some microorganisms while allowing the growth of others (i.e., they select for certain microbes). A differential medium is designed to allow the growth of more than one microorganism of interest, but with visually or morphologically distinguishable colonies.

The Technology: A Fluorogenic Selective and Differential Medium for Isolation of Enterobacter sakazakii

Enterobacter sakazakii was implicated in severe neonatal infections such as meningitis and sepsis.  Though the natural habitat of E. sakazakii remains unknown, dried infant formula has been identified as the source of E. sakazakii infections.  The “OK Medium” was developed to facilitate the isolation and detection of E. sakazakii using a fluorogenic compound.  Tests of the "OK medium," as formulated and optimized, indicate that 100% of the fluorescent colonies were confirmed to be E. sakazakii, while none of the non-fluorescent colonies were identified as E. sakazakii.  The test has thus been proven to be an excellent indicator of E. sakazakii contamination in infant formula.


•      Isolation and identification of various microorganisms with α-glucosidase activity, specifically E. sakazakii.


•    Provides an effective and useful method for the isolation and detection of microorganisms with α-glucosidase activity and ensure efficient and contamination-free from other types of bacteria.

Patent Information:

Issued US patent - US7749724 B2 - https://www.google.com/patents/US7749724




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Jessica McGowan
Professional Worker I
Washington State University
(509) 335-9865
Reference No: 0793-U2RF-OC


Dong-Hyun Kang
Se-Wook Oh

Key Words

Global Human and Animal Health