Listeria infection in Chinese pregnant women and neonates from Shandong.

OBJECTIVE This study aims to investigate the characters of pregnant women and neonates with listeria monocytogenes infections (L. monocytogenes) in Shandong of China. METHOD Pregnant women with premature delivery or prenatal fever were recruited in 2013. Bacterial culture was performed for the umbilical cord blood and placental swab after delivery. The strains isolated were then analyzed for the virulence factors and classified based on the serotype and MLST typing. RESULTS Four cases (0.34‰) of the neonates were identified with listeriosis. Prenatal fever was observed in mothers of all infected neonates. The pathological examination of placenta showed non-specific inflammatory manifestations and two serotypes including 1/2b and 4b were detected. Six kinds of virulence factors including hly, inlA, actA, plcB, prfA and iap were all identified in the inflected neonates. CONCLUSION The results suggested that mother-to-infant was an important transmission mode for listeria. Antibiotic treatment, bacterial culture and placenta pathological examination were highly recommended in the diagnosis and treatment of listeriosis.