Maternal cytokine profile and anti-bacterial specific antibody response associated with neonatal infection by E. coli and K. pneumoniae

BACKGROUND: The transmission of pathogenic Gram-negative bacteria such as Escherichia coli and Klebsiella pneumoniae from mother to child during pregnancy contributes significantly to neonatal morbidity and mortality, particularly in low and middle-income countries. Identifying maternal risk factors associated with vertical transmission is crucial. This prospective study aimed to investigate the maternal cytokine profile and anti-LPS-specific antibodies in pregnant mothers with positive cultures for E. coli and K. pneumoniae, exploring their potential association with neonatal invasive disease. METHODS: This prospective study examined groups of pregnant women with a positive culture for E. coli or K. pneumoniae, who had or had not given birth to newborns with invasive diseases. A group of age-matched mothers negative for E coli and K. pneumoniae was used as a control. A panel of circulating inflammatory cytokines was measured in mother-infant dyads using Luminex multiplex assays or ELISA in maternal and cord blood, as well as in the supernatants of blood leucocytes stimulated with TLR4 and TLR1/2 ligands. The serum levels of specific IgG anti-LPS E. coli and anti-LPS K. pneumoniae were quantified using ELISA. RESULTS: Mothers with a positive culture for E. coli and K. pneumoniae and their newborns exhibited elevated plasma levels of IL-6, IL-8, and TNF-α compared to healthy mothers and their newborns. Similar results were observed for IL-6 and TNF-α when blood leucocytes were stimulated by TLR4 and TLR1/2 ligands. Mothers who gave birth to newborns with severe infectious diseases had higher IL-6 levels and lower specific IgG anti-LPS E. coli or anti-LPS K. pneumoniae levels compared to those with healthy newborns. Receiver operating characteristic (ROC) analysis demonstrated a strong association between maternal IL-6 and specific IgG levels and perinatal bacterial transmission. CONCLUSION: Pregnant women with positive cultures for E. coli or K. pneumoniae, as well as higher plasma levels of IL-6 and lower levels of specific anti-bacterial IgG, are at increased risk of perinatal bacterial transmission. This data could help improve the monitoring of mother-child dyads and optimize prenatal care. TRIAL REGISTRATION: Clinical trial number: not applicable.