# Molecular Relatedness of Maternal and Neonatal Multidrug-Resistant Gram-Negative Colonization Isolates in Low- and Middle-Income Countries: A Systematic Review

## TL;DR

This review examines whether mothers in low- and middle-income countries pass multidrug-resistant bacteria to their newborns, finding that such vertical transmission is rare.

## Contribution

The study systematically reviews molecular evidence of vertical transmission of MDR-GN colonization in low- and middle-income countries.

## Key findings

- Vertical transmission of MDR-GN colonization is rare in low- and middle-income countries.
- Most studies suggest horizontal transmission rather than vertical transmission as the main route of neonatal MDR-GN colonization.
- There is significant heterogeneity in sampling methods across studies.

## Abstract

Multidrug-resistant gram-negative (MDR-GN) sepsis is a significant cause of neonatal mortality in low- and middle-income countries (LMICs). The role of vertical transmission in neonatal MDR-GN colonization and thereby invasive infection remains unknown. The aim of this study was to systematically review literature detailing the molecular relatedness of maternal and neonatal MDR-GN colonization isolates in LMICs, characterizing the extent of vertical transmission.

Following PRISMA guidelines, PubMed and Scopus databases were searched for LMIC literature reporting molecular evidence of MDR-GN concordance for mother-neonate dyads.

Of 90 articles identified by the search, 11 met inclusion criteria. Findings demonstrated substantial MDR-GN colonization in dyads from LMICs, although with significant heterogeneity in sampling methods. From MDR-GN dyads, molecular methods rarely found relatedness. Many studies suggested horizontal transmission within the environment.

In LMICs, maternal MDR-GN colonization rarely results in vertical transmission to neonates. However, literature remains scarce and further research is needed.

This review summarizes literature from low- and middle-income countries detailing molecular evidence of vertical transmission as a cause of neonatal multidrug-resistant gram-negative colonization. Contrary to findings in high-income settings, vertical transmission of multidrug-resistant gram-negative colonization appears rare in low- and middle-income countries.