Print E-mail
Volume 41, Number 5, October 2008

Comparison of CPS ID 3 and CHROMagar Orientation chromogenic agars with standard biplate technique for culture of clinical urine samples

Jen-Chyi Chang, Mei-Lin Chien, Hung-Mo Chen, Jing-Jou Yan, Jiunn-Jong Wu
Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University; and Division of Microbiology, Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan

Received: November 30, 2007    Revised: December 1, 2007    Accepted: January 9, 2008   


Corresponding author:

Dr Jiunn-Jong Wu, Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan. E-mail: Dr Jiunn-Jong Wu This e-mail address is being protected from spam bots, you need JavaScript enabled to view it


Background and purpose: 

Chromogenic agars have been developed to recognize frequently occurring microorganisms directly on primary cultures, thus reducing the daily workload in a clinical microbiology laboratory. We compare two chromogenic agars, CHROMagar Orientation (CO) and CPS ID 3 (CPS3), with routine media (biplate technique using trypticase soy blood agar and eosin methylene blue agar) for the isolation, enumeration and identification of organisms in urinary tract infection (UTI).



The clinical significance of the urine samples was categorized as probable UTI, possible UTI, no UTI (negative), or contaminated according to the culture result. Discrepancy analysis with the categories of minor error, major error and very major error was used to compare the culture media.




Of 1386 urine specimens, the consistencies in clinical significance of CO and CPS3 to routine media were 90.7% and 89.8%, respectively. For the enumeration of microorganisms, 524, 514, and 521 clinically significant isolates were isolated on routine media, CO, and CPS3, respectively. Of the 524 significant isolates on routine media, results for 473 and 474 isolates agreed on CO and CPS3, respectively. Approximately 91.9% of Escherichia coli and 100.0% of Enterococcus spp. could be identified directly on CO media, while 97.5% of E. coli and 94.4% of Enterococcus spp. could be identified on CPS3 media.




The use of CO and CPS3 as single media is promising for clinical urine culture.


Key words:

Agar; Chromogenic compounds; Culture media; Urine



J Microbiol Immunol Infect. 2008;41:422-427.