An Update Review on Listeria Infection in Pregnancy

Abstract

Listeria monocytogenes (LM) is an intracellular, aerobic and facultative anaerobic, Gram-positive bacterium, which is primarily transmitted to humans orally via food. LM could occur in asymptomatic pregnant women; however, fetal infection is a serious condition, entailing premature birth, abortion, sepsis, central nervous system (CNS) involvement, or even death. If a pregnant woman exhibits symptoms, the performance is almost like influenza, such as fever, headache, diarrhea, myalgia, or other digestive-related symptoms. This review collected clinical and empirical results regarding the mechanism, clinical manifestations, obstetrical outcome, diagnosis, treatment, vertical transmission, neonatal infection, and prevention of listeriosi according to articles published in PubMed from January 1, 1980, to March 20, 2021. The early detection and diagnosis of pregnancy-associated listeriosis are significant since sensitive antibiotics are effective at enhancing the prognosis of newborns. Listeriosis can be diagnosed using positive cultures from maternal or neonatal blood, neonatal cerebrospinal fluid (CSF), amniotic fluid, intrauterine mucosa, or the placenta. Two weeks of high-dose intravenous amoxicillin (more than 6 g/day) is recommended for LM pregnant women without allergy. Terminating the pregnancy to save the mother's life should be considered if maternal and fetal conditions aggravate. Neonatal Listeria infection is primarily transmitted through the placenta, which is a critical illness associated with a high mortality rate. The necessary dietary guidance for pregnant women can reduce the incidence rate of pregnancy-related listeriosis.

Keywords: Listeria monocytogenes; fever; infection; listeriosis; neonate; pregnancy.

Figure 1

The schematic diagram of Listeria penetrating the placental barrier. The associations of InlA and InlB with their corresponding receptor E-cadherin and c-Met behave in a conjugated and codependent way to regulate the invasion of the placenta. InlB-c-Met activity induces PI3K. Thus, phosphorylated PI3K is formed in the syncytiotrophoblast (SYN), which is crucial for the realignments of the actin cytoskeleton. In these two ways, Listeria monocytogenes (LM) invades the SYN and reduces the expressions of heme oxygenase (HO)-1 and B-cell lymphoma-extra large (Bcl-XL), causing the cell death and miscarriage finally. Besides, colony-stimulating factor-1 (CSF-1) stimulates macrophages against LM.