Listeria in Pregnancy-The Forgotten Culprit

Abstract

Listeria monocytogenes is a Gram-positive bacterium that causes listeriosis, a severe foodborne illness that is particularly dangerous during pregnancy. It thrives in diverse environments, including refrigerated conditions and food production facilities, due to its adaptability to varying temperatures, pH levels, and salt concentrations. Its virulence stems from the ability to invade host cells, particularly macrophages and epithelial cells, and avoid, or at least postpone, immune detection by utilizing virulence factors such as internalins, listeriolysin O, and actin assembly-inducing protein. This intracellular motility and biofilm formation make LM a persistent pathogen in food safety and public health. Pregnant women are at a much higher risk of listeriosis, which can result in serious fetal complications such as miscarriage, stillbirth, and preterm labor due to LM's affinity for placental tissues. The vertical transmission of LM from mother to fetus can lead to neonatal listeriosis, which can result in sepsis and meningitis, with high mortality rates if not promptly treated. Early diagnosis and treatment with antibiotics, such as ampicillin or gentamicin, are crucial for maternal and neonatal outcomes.

Keywords: Listeria monocytogenes; granulomatosis infantisepticum; listeriosis; neonatal listeriosis; pregnancy.

Figure 1

Listeria monocytogenes is highly resilient and can survive under a wide range of environmental conditions.

Figure 2

Listeria monocytogenes forms robust biofilms on various surfaces, providing protection against environmental stresses and sanitizing agents.

Figure 3

Listeria monocytogenes infects neighboring cells by utilizing a process called cell-to-cell spread. While a similar process is used by different intracellular pathogens, ActA is a unique tool in the arsenal of LM.

Figure 4

Two forms of listeriosis, with its symptoms.

Figure 5

Placenta-specific affinity of LM based on internalin P–afadin complex formation.

Figure 6

Early- and late-onset neonatal listeriosis, with its symptoms.