Clinical Microbiology



Click on the picture for
Packaging / Colonies appearance

For detection of Colistin resistant

Gram-negative pathogens

Typical Appearance of microrganisms

COL-R E. coli → dark pink to reddish
COL-R Coliforms → metallic blue
COL-R Pseudomonas → translucent, +/- natural pigmentation cream to green
COL-R Acinetobacter → cream
Other Gram negative COL-R → colourless, natural pigmentation
Other Gram negative COL-S → inhibited
Other gram positive bacteria→ inhibited

Order References 

Please use these references when
contacting your local distributor:

5000 mL .......... CO262

To download the certificate of analysis, please indicate your lot number below :


Medium Description

CHROMagarTM COL-APSE is a sensitive and specific medium for the growth of Colistin resistant bacterial pathogens. It is particularly useful as a primary isolation medium in the surveillance and recovery of Colistin resistant bacteria from complex human, veterinary and environmental samples especially those with plasmid mediated MCR-1 or novel mechanisms of polymyxin resistance. 

Gain flexibility using powder rather than ready to use plates: Use the entire pack, or if there is a need for a smaller number of plates, just a portion. If kept under appropriate storage temperature, CHROMagarTM COL-APSE has more than 18 months shelf life. This flexibility is essential to avoid the waste resulting from expired-unused plates. 

Please refer to our IFU and Material Safety data sheet for complete information about the medium. 
CHROMagar™, Rambach™, AquaCHROM™ are trademarks created by Dr. A. Rambach.
All pictures of our products are CHROMagar property and should not be used without our acceptance. 
                                                                                                      Last Update: 09-Jul-2019

Focus on Colistin resistance

Polymyxin E (colistin) and B are increasingly used as antimicrobials in the treatment of multi-drug resistant bacterial infections. Polymyxin resistance, although intrinsic in Gram-positive and some Gram-negative species (Proteus, Morganella, Serratia) is now a problem in a number of other pathogens (Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica, Klebsiella pneumoniae).
Resistance arises due to mutations / insertions in genes involved in LPS biosynthesis (lpx, pmrA/B, mgrB, phoP/Q) and/ or the acquisition of phosphoethanolomine transferases (PEtN).

Of great concern is the recently described plasmid-encoded PEtN, MCR-1, now found worldwide in a range of animal, human and environmental bacterial isolates.



Gulls as Sources of Environmental Contamination by Colistin-resistant Bacteria


Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. McCurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler Scientific reports, Nature research 2020, 10:4408

Comparative Evaluation of CHROMagar COL-APSE, MicroScan Walkaway, ComASP Colistin, and Colistin MAC Test in Detecting Colistin-resistant Gram-negative Bacteria


John Osei Sekyere, Arnold Karabo Sephofane, Nontombi Marylucy Mbelle Scientific reports, Nature research 2020, 10:6221

Assessment of two selective agar media to isolate colistin-resistant bovine Escherichia coli: Correlation with minimal inhibitory concentration and presence of mcr genes


D. Thiry, et al. Journal of Microbiological Methods 159 (2019) 174–178 176
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