Colonization of extended-spectrum beta-lactamase-producing bacteria in healthy pregnant women and its impact on perinatal care: A cross-sectional study.

BackgroundColonization of extended-spectrum beta-lactamase (ESBL)-producing organisms is increasing becoming more frequent not only in hospitalized patients but also in healthy individuals. Although these bacteria are thought to be transmitted to newborns on their way through the birth canal, molecular evidence for this is scarce. In this study, we aimed to survey the current prevalence of resistant bacterial colonization in this area by examining the colonization carriage of this organism before and after delivery.MethodsWe examined the colonization rate of ESBL-producing bacteria in healthy pregnant women, the colonization rate in newborns, and the transmission rate from pregnant women who are carriers of the bacteria to their newborns. We also performed resistance gene and similarity analyses for each strain in pairs of mother-child carriers.ResultsOf 494 pregnant women, 33 carried ESBL-producing bacteria, all of whom were identified as Escherichia coli. The colonization carriage rate among pregnant women was 6.7%. Among newborns, the rate rose from 1.0% immediately after birth to 6.9% at the one-month checkup. Furthermore, of the 13 strains detected among mothers and children, 10 pairs had matching resistance genes.ConclusionsSome ESBL-producing bacterial carriers exist even among healthy pregnant women, and about half of them go on to infect their newborns. However, routes of transmission beyond vertical transmission cannot be ruled out. Therefore, it is important to promote infection control in the healthcare environment and in the families of newborns, as well as antimicrobial stewardship among pregnant women.