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

Background: 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. Methods: Following PRISMA guidelines, PubMed and Scopus databases were searched for LMIC literature reporting molecular evidence of MDR-GN concordance for mother-neonate dyads. Results: 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. Conclusions: In LMICs, maternal MDR-GN colonization rarely results in vertical transmission to neonates. However, literature remains scarce and further research is needed.