Performance evaluation of the BactInsight simplified blood culture system developed for resource-limited settings using a simulated test design

Abstract BactInsight is a simplified blood culture system designed for resource-limited settings. It consists of in-house produced blood culture bottles and a turbidimeter to detect microbial growth on top of visual inspection of blood culture bottles. A first proof-of-concept using simulated commercial blood cultures showed that the turbidimeter was able to detect growth in nine out of ten tested microbial species (i.e. by growth detection through turbidity and a colour indicator), however detection of turbidity was only successful in four of these species. In this study, we extended the in vitro testing to 20 microbial species spiked in fresh human blood and we used a second-generation turbidimeter prototype and in-house produced blood culture bottles. The BactInsight system’s performance was acceptable when compared with the automated BACT/ALERT system (bioMérieux). Moreover, the addition of the turbidimeter to visual inspection decreased the time-to-positivity for some microorganism groups. The system is cheap (~ 50 USD), robust and able to withstand high temperature and humidity. In conclusion, the BactInsight system has the potential to improve access to blood cultures in resource-limited settings.