Immune-guided calibration of metagenomic next-generation sequencing (mNGS) results in a pregnant patient with Listeria infection: a case report.

BACKGROUND

Listeriosis during pregnancy is a rare but life-threatening infection that often presents with nonspecific symptoms, making timely diagnosis difficult. This article reports a case in which the clinical presentation and immune profile were highly consistent with Listeria monocytogenes infection, leading to a presumptive clinical diagnosis. The patient was successfully treated following a diagnostic approach that integrated host immune profiling with AI-assisted decision-making, despite dual interference from Ureaplasma urealyticum detected by metagenomic next-generation sequencing (mNGS) and Staphylococcus capitis detected by blood culture.

CASE PRESENTATION: A 25-year-old female patient, at 37+6 weeks of gestation, presented with persistent high fever following induced labor due to intrauterine fetal death. External hospital blood culture and our hospital's reproductive tract mNGS suggested Staphylococcus capitis and Ureaplasma urealyticum, respectively. However, intensified treatment targeting these pathogens was ineffective.

DIAGNOSTIC PROCESS: Further investigation revealed a characteristic immune imbalance in the patient: a concurrent significant elevation of IFN-γ and IL-10, accompanied by activated CD8+ T cells. With AI-assisted analysis, this immune profile was found to be highly consistent with Listeria monocytogenes infection.

TREATMENT AND OUTCOME: After switching to ampicillin combined with gentamicin, the patient's body temperature rapidly normalized, and she recovered and was discharged.

CONCLUSION

When etiological diagnosis reaches an impasse, integrating host immune characteristics with AI-assisted decision-making can provide crucial diagnostic clues for infections caused by rare pathogens when microbiological confirmation is unavailable.