Listeria adhesion protein-expressing bioengineered probiotics prevent fetoplacental transmission of Listeria monocytogenes in a pregnant Guinea pig model

Pregnancy is a high-risk factor for foodborne pathogen Listeria monocytogenes (Lm), which causes abortion, premature birth, or stillbirth. The primary route of Lm transmission oral hence intestinal epithelial barrier crossing prerequisite systemic spread. Intestinal crossing, in part, attributed to the interaction adhesion protein (LAP) with its cognate receptor, Hsp60. In recent study, we showed that oral-dosing bioengineered Lactobacillus casei probiotic (BLP) expressing LAP protected nonpregnant mice from lethal infection; however, ability prevent listeriosis during pregnancy not known. Therefore, investigated whether BLP could fetoplacental pregnant guinea pig model. After 14 consecutive days on (~109 CFU/ml drinking water), pigs (gestational 24–28) were orally challenged (9 × 108–2.5 109 CFU/animal) and euthanized 72 h post-infection. Maternal mesenteric lymph node (MLN), liver, spleen, lungs, blood, placenta, fetal liver analyzed presence/absence Lm. All tissues/organs Lm-challenged naïve dams fetuses positive. Similar tissue distribution was also seen received wild-type (LbcWT). Remarkably, absent maternal kidney, BLP-fed group even though present MLN. feeding suppressed Lm-induced inflammatory response mothers. These data highlight potential prevention by LAP-expressing pregnancy.