# Treatment response evaluation in an ex vivo model of E. coli-infected central venous catheter system

## TL;DR

This study compares treatments for E. coli-infected catheters in children and finds ceftriaxone to be the most effective and fastest option in an ex vivo model.

## Contribution

The study evaluates treatment efficacy for E. coli-infected catheters using an ex vivo model and isothermal microcalorimetry.

## Key findings

- Ceftriaxone showed the fastest and most effective bacterial elimination in the ex vivo model.
- Ethanol and TauroLock also eliminated bacteria but required more time compared to ceftriaxone.
- The study highlights the importance of considering antibiotic resistance patterns in clinical settings.

## Abstract

Despite all precautions, central line-associated bloodstream infections (CLABSI) are inevitable, especially in children. Different treatment strategies exist for those situations. This study aims to compare the different treatment strategies.

In this study, central venous catheters (CVC, Broviac single lumen) were contaminated with E. coli in vitro. Different treatments (70% ethanol, ceftriaxone, TauroLock) were applied, and the effect was measured by isothermal microcalorimetry.

A rapid decrease in heat release corresponds to a rapid decrease in the number of living bacteria. Ceftriaxone had the quickest effect followed by ethanol in combination with ceftriaxone, ethanol, and TauroLock.

Antibiotics must be based on patient risk factors, the severity of infection, and local resistance pattern; therefore, it is difficult to publish general guidelines applying to all children. In this in vitro study, ceftriaxone demonstrated the most the highest efficacy on the bacteria. Taurolidine locks are recommended for preventing CLABSI, but no data are available in regards using it for treatment. In this setting, it was efficient, as was ethanol. However, the bacteria used in this study, have not been exposed to antibiotics before—this is most likely in contrast to patients, who have a central venous catheter.

Under in vitro conditions, systemic ceftriaxone is the most efficient and fastest treatment for an E. coli-infected CVC. Elimination of bacteria was also reached with 70% ethanol and TauroLock, but it needed more time.