# Evaluation of alternative blood culture systems in detecting pathogenic bacteria: a multi-site, observational prospective study

## TL;DR

This study compares the performance and cost of alternative blood culture systems to standard ones, finding them effective for detecting bacteria in sepsis, which could help low-income regions.

## Contribution

The study provides a multi-site evaluation of alternative blood culture systems in real-world clinical settings, focusing on their performance and affordability.

## Key findings

- DL and MH instruments showed high concordance rates (96.5-98.0%) compared to BD and bioMérieux systems.
- MH bottles detected more bacterial isolates than BD and bioMérieux bottles in some comparisons.
- MH was less effective than BD in detecting anaerobic bacteria, and DL had a lower overall detection rate compared to bioMérieux.

## Abstract

Sepsis, is a severe, life-threatening response to infection with rising incidence and significant mortality. Although blood culture (BC) systems are critical for sepsis diagnosis and the detection of pathogens bacteria, their high cost limits their use in low-income regions. This study evaluates the performance and affordability of bottles with gold-standard systems.

From September 2023 to June 2024, we conducted a nine-month evaluation of alternative BC instruments (Meihua Medical [MH] and DL-Biotech [DL]) and BC bottles (BCBs) against bioMérieux and Becton Dickinson (BD) across five tertiary hospitals in Zhejiang province, China. Before processing clinical samples, we examined the performance of BCBs and instruments including time to positivity (TTP) and sensitivity after spiking bottles with Escherichia coli and ESKAPE bacteria. Over the course of the study, a total of 37,480 BCBs were assessed.

DL and MH instruments performed well in TTP across commonly isolated bacteria. In the non-inferiority observational study, we compared instruments between MH versus BD, DL versus BD, MH versus bioMérieux, and DL versus bioMérieux, giving concordance rates of 97.2%, 97.7%, 98.0%, and 96.5%, respectively. However, when comparing sensitivity between MH and BD, and MH and bioMérieux, the number of detected bacterial isolates was 163 versus 122, and 116 versus 108, respectively. When comparing BCBs, MH versus BD bottles, and MH versus bioMérieux bottles, gave 209 and 193, and 205 and 200 positive growths, respectively. However, MH was less effective than BD in detecting anaerobic bacteria. DL had a lower overall detection rate compared to bioMérieux (130 versus 199) but exhibited similar TTP for E. coli and ESKAPE pathogens, except for Enterococcus spp., where DL demonstrated a longer TTP.

Our evaluation of DL and MH BC systems suggests that both are comparable to BD, and bioMérieux. Their performance of alternative BC instruments and bottles, suggest that BC alternatives should be considered in providing clinical support for low- and middle-income countries, and augment appropriate antimicrobial stewardship.

This study was funded by the 10.13039/501100012166National Key Research and Development Program of China (No. 2022YFD1800400) and the Theme Based Research Scheme (T11-104/22-R) from the Research Grant Council of the Government of Hong Kong SAR.