Shotgun metagenomic screening to improve the retrospective diagnosis of undocumented intrauterine infections on embedded placenta samples: Lessons from a brucellosis case

E Canouï; P L Woerther; A Soulier; N Benhaddou; S Seng; M Belan; C Rodriguez; C Charlier

doi:10.1016/j.idnow.2023.104770

Shotgun metagenomic screening to improve the retrospective diagnosis of undocumented intrauterine infections on embedded placenta samples: Lessons from a brucellosis case

Infect Dis Now. 2023 Oct;53(7):104770. doi: 10.1016/j.idnow.2023.104770. Epub 2023 Aug 11.

Authors

E Canouï¹, P L Woerther², A Soulier³, N Benhaddou⁴, S Seng³, M Belan⁵, C Rodriguez³, C Charlier⁶

Affiliations

¹ Equipe mobile d'Infectiologie, Maladies Infectieuses et Tropicales, Hôpitaux Universitaires Paris Centre-Cochin Port Royal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France. Electronic address: Etienne.canoui@aphp.fr.
² Département de Microbiologie, hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France; EA 7380 Dynamyc, Université Paris-Est Créteil, F-94000 Créteil, France.
³ Département de Microbiologie, hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
⁴ Service de Bactériologie, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpitaux Universitaires Paris Centre-Cochin Port Royal, Paris, France.
⁵ Equipe mobile d'Infectiologie, Maladies Infectieuses et Tropicales, Hôpitaux Universitaires Paris Centre-Cochin Port Royal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France; Université Paris Cité, Paris France.
⁶ Equipe mobile d'Infectiologie, Maladies Infectieuses et Tropicales, Hôpitaux Universitaires Paris Centre-Cochin Port Royal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France; Université Paris Cité, Paris France; Centre National de référence Listeria, Centre collaborateur OMS, Institut Pasteur, Paris, France; Unité de Biologie des Infections, Inserm U1117, Institut Pasteur, Paris, France.

PMID: 37574126
DOI: 10.1016/j.idnow.2023.104770

Abstract

Background: Microbiological diagnosis of intrauterine infections (IIU) still relies on bacteriological cultures or targeted DNA amplification lacking in sensitivity. Shotgun metagenomics (SMg) is an emerging unbiased molecular approach that makes it possible to sequence all the nucleic acids from any sample. It had never previously been used for IIU.

Methods: We here report the case of a patient with an unexplained IIU and fetal loss that could be documented by a combined SMg/microbiological approach, leading to the diagnosis of maternal brucellosis.

Results: A 31-year-old woman presented with an undocumented IIU with fetal loss at 24 weeks of gestation. Culture-based work-up failed to identify the pathogen involved. Paraffin-embedded placenta sample was retrospectively analyzed by SMg. Brucella spp nucleic acids were detected, and subacute maternal brucellosis was confirmed by targeted PCR and serological testing.

Conclusion: This case provides grounds for further utilization of SMg for the microbiological diagnosis of unexplained obstetrical infections.

Keywords: Brucella; Diagnosis; Intrauterine Infection; Shotgun metagenomics.