# Evaluating eravacycline’s efficacy against pediatric carbapenem-resistant Klebsiella pneumoniae in China: a 6-year study

## TL;DR

This study evaluates eravacycline's effectiveness against a type of antibiotic-resistant bacteria in children in China, finding it generally effective but with variation based on bacterial type and age.

## Contribution

The study provides the first 6-year assessment of eravacycline's in vitro efficacy against pediatric CRKP isolates in China.

## Key findings

- Eravacycline showed 87.8% susceptibility against 74 CRKP isolates from children.
- Susceptibility varied significantly by carbapenemase type and age group, with the lowest rates for blaKPC-2 and ST11 isolates.
- Eravacycline had lower or equal MIC90 values compared to tigecycline for most common CRKP sequence types.

## Abstract

Eravacycline (ERV) has demonstrated promising in vitro antibacterial activity against carbapenem-resistant Klebsiella pneumoniae (CRKP). Nonetheless, its clinical application in pediatric cases remains underexplored. Therefore, we assessed the in vitro activities of ERV and tigecycline (TGC) against CRKP isolates obtained from pediatric patients in China between 2019 and 2024. The susceptibility rates of the 74 CRKP strains to TGC and ERV were 100% and 87.8%, respectively. Both TGC and ERV had MIC ranges of 0.125–2 μg/mL, with MIC50 at 0.25 µg/mL and MIC90 at 1 µg/mL. Statistically significant differences in ERV susceptibility were observed across different carbapenemases, sequence types (STs), and age groups, with the type of carbapenemase emerging as the primary determinant. The lowest susceptibility was noted for blaKPC-2 (64.3%) and ST11 (54.6%), while blaNDM-1 (97.4%), ST25, and ST17 (100%) exhibited the highest. The lowest susceptibility was observed in CRKP strains isolated from >3-year group (46.7%), whereas strains from both neonates and toddlers exhibited 100% susceptibility. When the MIC was below 0.5 µg/mL, ERV exhibited higher inhibition rates against CRKP compared to TGC. However, at MIC values of 0.5, 0.75, 1.5, and 2 µg/mL, the inhibition rates of both drugs were comparable. Among CRKP strains carrying blaKPC-2, blaNDM-1, and blaNDM-5, both the MIC50 and MIC90 values of ERV were less than or equal to TGC’s. ERV consistently had lower or equal MIC90 values compared to TGC for common STs, except for ST11, where ERV’s MIC50 was also lower or equal. ERV demonstrated significant in vitro activity against pediatric CRKP isolates collected over a 6-year period, supporting its potential benefits in treating pediatric CRKP infections, although further in vivo validation is necessary.

Eravacycline (ERV) has demonstrated promising in vitro antibacterial activity against carbapenem-resistant Klebsiella pneumoniae (CRKP). Current research predominantly addresses adult populations, leaving its clinical application in pediatric cases insufficiently explored. Given that the resistance mechanisms of CRKP in pediatric patients differ from those in adults, primarily due to the production of metallo-β-lactamases, and considering that ERV, like tigecycline, may be used off-label in pediatric populations, this study was conducted. The results demonstrate that ERV exhibited significant in vitro efficacy against pediatric CRKP isolates. However, unlike previous studies, the susceptibility rates of ERV vary considerably across different carbapenemases, sequence types, and age groups of CRKP, with the type of carbapenemase emerging as the primary determinant. These findings suggest that ERV has promising in vitro activity against CRKP isolates from pediatric patients, indicating potential clinical applicability for this demographic.