Clinical Comparison of the Roche Septi-Chek® and Dupont Isolator® Blood Culture Systems

Abstract

A study was conducted to compare the recovery of clinical isolates by the DuPont Isolator® and Roche Septi-Chek® blood culture systems. A total of 5,262 blood culture specimens were processed by the two systems. Of these, 358 cultures contained significant isolates: 219 were positive in both systems, 68 were recovered only by Isolator, 71 were recovered by Septi-Chek only (not statistically significant). Of the isolates recovered in both systems, 159 were positive the same day, 55 were recovered first by Isolator, and 5 were recovered first by Septi-Chek. In cases where Isolator recovered organisms first, the average difference in time was one to two days. Regarding particular groups of organisms, there was no difference between the systems in recovery of Enterobacteriaceae, anaerobes, yeast, and gram-positive bacteria, except for Streptococcus pneumoniae. Septi-Chek recovered S. pneumoniae significantly more often. These results suggest that these two systems are essentially comparable, except with S. pneumoniae, although the Isolator frequently provided results more rapidly.