Comparison of Bactec NR-660 and Signal systems.
Department of Medical Microbiology, Royal Liverpool Hospital.
Bactec NR-660, a computerised blood culture system using infrared analysis of microbial generated carbon dioxide, was compared with the Signal system, which detects gaseous pressure (due to bacterial metabolism) by a manometer. Four trials were undertaken: an in vitro evaluation of 99 bacteria in simulated blood cultures, and three prospective comparisons of a total of 2588 paired patient samples. Combined results for bacteria in simulated blood cultures showed a highly significant difference (p less than 0.001) between Bactec NR-660 aerobic medium (6A) and any other phial under test. Detection rates for most bacteria by Signal were on average three times slower than the first Bactec phial (mean delay 58.3 hours). Overall, the systems were not comparable.
Register for free content
The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.
Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.
