ASSESSMENT OF ROUTINE USE OF AN ANAEROBIC BOTTLE IN A 3-COMPONENT, HIGH-VOLUME BLOOD CULTURE SYSTEM

The relative value of routine anaerobic blood culture for recovery of organisms and identification of episodes of bloodstream infection was assessed in a three-component, high-volume blood culture system which employs aerobic and anaerobic bottles of BacT/Alert (Organon-Teknika, Durham, N.C.) and aerobic cultures of Isolator (Wampole Laboratories, Cranbury, N.J.), The results of 5,595 blood culture sets from patients with suspected bloodstream infection were analyzed. Compared with eit her the aerobic BacT/Alert bottle or aerobic culture of Isolator, the BacT/Alert anaerobic bottle recovered significantly fewer isolates (24 2 versus 294, P < 0.05; 242 versus 298, P < 0.05) but did not detect s ignificantly fewer episodes of bloodstream infection (141 versus 157, P > 0.05; 141 versus 147, P > 0.05), The BacT/Alert anaerobic bottle r ecovered significantly more isolates of obligately anaerobic bacteria (16 versus 4, P < 0.05; 16 versus 0, P < 0.05) and detected significan tly more episodes of bloodstream infection caused by obligately anaero bic bacteria (10 versus 3, P < 0.05; 10 versus 0, P < 0.05) than eithe r the aerobic bottle of BacT/Alert or the aerobic culture of Isolator, The combination of the BacT/Alert anaerobic bottle and the aerobic cu lture of Isolator recovered as many isolates (374 versus 377) and dete cted as many episodes of bloodstream infection (194 versus 191) as the combination of the aerobic bottle of BacT/Alert and the aerobic cultu re of Isolator, and both of these combinations identified at least 8% more isolates and detected at least 3% more bloodstream infections tha n the combination of the BacT/Alert aerobic and anaerobic bottles, Fur ther analysis of the data revealed that the utility of the BacT/Alert anaerobic bottle, especially when combined with the aerobic culture of Isolator, resulted from not only enhanced recovery of obligately anae robic bacteria but also effective recovery of facultatively anaerobic bacteria, These results demonstrate the utility of the anaerobic BacT/ Alert bottle for detecting bloodstream infection caused by either facu ltatively anaerobic bacteria or obligately anaerobic bacteria and supp ort the routine inclusion of anaerobic blood culture in the three-comp onent blood culture system used in our hospital.