Identification of Gram-negative bacilli directly from positive blood culture vials

Abstract

The provision of rapid results from positive blood cultures is important for the clinical management of septicaemia. This study tested the accuracy of direct inoculation of biochemical tests from positive blood culture vials for the identification of members of theEnterobacteriaceaeandAcinetobacterspecies. A hundred and eighty-one samples were included in the study, with 25 % subsequently excluded as a result of mixed colonial growth. The study method successfully identified 133 (98 %) isolates from 136 vials to genus level and was technically simple to perform, requiring an additional 3 min for the processing of each positive vial. The results of this study demonstrate that a direct inoculation method provides acceptable genus identification of Gram-negative bacilli in positive blood culture vials, with a potential saving of 24 h compared with traditional methods.