Sepsis: a more faster report from blood culture

Abstract

Introduction: Sepsis is a leading cause of morbidity and mortality. Several studies demonstrated that the earliness of the intervention therapy, including antimicrobial treatment active on the specific pathogen, is associated with a reduction of mortality. In order to permit the use of a quicker appropriate treatment in respect to using the conventional method,we evaluated both the accuracy of strain identification and in vitro antimicrobial susceptibilities directly from the haemocultural bottles. Methods:We examined 112 samples of positive blood cultures through traditional technique of subculture, identification and susceptibility testing, and a diagnostic alternative method in the following way: 5-6 ml from positive blood cultures (BACTEC 9640) were transferred into a test tube fitted with a sterile gel separator and centrifuged at 3200 rpm for 15 minutes. After the removal of supernatant, the microbial pellet was suspended in a saline buffer to obtain an 0.5 McFarland inoculum; this turbidity was needed to set up the direct identification and the susceptibility testing (VITEK 2). Results: The correlation between the two procedures has demonstrated a correlation of 98% for the strains identification; the correlation was of 100% for MRSA and ESBL recognition. Conclusions: The results showed that the use of the direct test for both Gram positive and Gram negative bacteria can give a complete report regarding the identification and susceptibility testing within 24 hours from when the sample becomes positive instead of 48h required using the conventional method.The procedure has demonstrated a high reliability both in terms of strains identification and of antibioticsusceptibility. We therefore can suggest, in the diagnostic of sepsis, the introduction of direct method in normal laboratory practice.

Keywords

• Emocoltura, Sepsi, Febbre