pediatrics
Neonatal Listeriosis
Diagnosis of Neonatal Listeriosis
Culture or polymerase chain reaction (PCR) testing of blood, cervix, and amniotic fluid (if available) of febrile pregnant woman Culture or PCR of blood, cerebrospinal fluid (CSF), gastric aspirate, meconium, and infected tissues of sick neonate . A sick neonate whose mother has listeriosis should be evaluated for Diagnosis , including cultures or PCR of either umbilical cord or peripheral blood, CSF, gastric aspirate, meconium, any potentially infected tissue, the mother’s lochia and exudates from cervix and vagina, grossly diseased parts of the placenta, and amniotic fluid (if available). CSF examination may show a predominance of mononuclear cells, but usually polymorphonuclear cells predominate. Gram-stained smears frequently are negative but may show pleomorphic, gram-variable coccobacillary forms, which should not be disregarded as diphtheroid contaminants. Laboratory confirmation of the organism involves biochemical testing and observation of motility using a slide test or showing motility in semisolid media. To do the slide test, colonies of the organism that have grown on solid media are mixed with saline and examined under a microscope.L. monocytogenesexhibits a distinctive end-over-end “tumbling” motility due to the presence of flagella at both ends. Serologic tests are not useful. 