. 2004 Jan;42(1):60–64. doi: 10.1128/JCM.42.1.60-64.2004

TABLE 2.

Pure culture results for which CHROMagar and conventional plates failed to agree on interpretation

Organism	No. of occasions	Medium with correct interpretation	Description of inconsistency
E. coli	1	Blood agar-MacConkey	K. pneumoniae recovered on CO but not BAP; E. coli seen on BAP not recovered on CO^a
E. coli	5	Blood agar-MacConkey	CFU <10,000 on CO^a
Group B streptococci	3	Blood agar	Growth on CO called mixed skin flora
Viridans streptococci	1	Blood agar	Reported as “skin flora” from CO; questionable identification of viridans streptococci as a uropathogen; CO might have been correct
Enterococci	2	Blood agar	Low CFU on CO or PYR^b test result equivocal on CO
E. coli	6	CO	More than one colony type worked up on routine media; all were the same organism with identical susceptibilities
E. coli	5	CO	CFU below threshold on BAP-MacConkey^a
Yeast species	4	CO	Not detected or reported from BAP
Enterococci	7	CO	Lower CFU on BAP^a or called “mixed flora” on BAP
Group B streptococci	1	CO	CFU below threshold on BAP^a
Enterobacter species	1	CO	CFU below threshold on BAP^a
Other species	4	CO	Not detected on BAP^a

Most discrepancies were based on differences in CFU counts. Observations of urine plating by paratechnical personnel showed varying expertise, and this likely accounts for most of the discrepancies.

PYR; l-pyrrolidonyl β-naphthylimide aminopeptidase.