[Evaluation of chromogenic media compared to traditional culture methods for presumptive identification of entrococci from urine specimen]

ABSTRACT

Entrococci is a clinically important pathogenic bacterium in UTIs. CHROMagar orientation is a recently method for rapid, easy and economic isolation and identification of entrococci. This study compares the chromogenic media with traditional methods for presumptive identification of entrococci from urine specimen. We evaluated 240 gram positive cocci from urine specimens. These isolated microorganisms were inoculated on CHROMagar orientation and were presumptively identified according to manufacturer instruction. The identity of all isolated microorganisms was then confirmed by conventional identification tests and compared with the results obtained from CHROMagar orientation. In this study, the sensitivity and specificity of CHROMagar orientation to identify entrococci, solely, were 100% and 40.8%, respectively. Although CHROMagar orientation was rapid and sensitive method for identification of entrococci in urine culture, CHROMagar orientation alone appeared not to be very specific for entrococci and needed to be combined with other tests for greater exclusivity. So, CHROMagar orientation media is not recommended for routine usages in medical laboratories in Iran