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

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.

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.

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.

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.

Clinical trial number: not applicable.