Preprint Case Report Version 1 Preserved in Portico This version is not peer-reviewed

From Investigating a Case of Cellulitis to Exploring Nosocomial Infection Control of ST1 Legionella pneumophila Using Genomic Approaches

Version 1 : Received: 29 March 2024 / Approved: 1 April 2024 / Online: 2 April 2024 (07:26:36 CEST)

A peer-reviewed article of this Preprint also exists.

Michel, C.; Echahidi, F.; Place, S.; Filippin, L.; Colombie, V.; Yin, N.; Martiny, D.; Vandenberg, O.; Piérard, D.; Hallin, M. From Investigating a Case of Cellulitis to Exploring Nosocomial Infection Control of ST1 Legionella pneumophila Using Genomic Approaches. Microorganisms 2024, 12, 857. Michel, C.; Echahidi, F.; Place, S.; Filippin, L.; Colombie, V.; Yin, N.; Martiny, D.; Vandenberg, O.; Piérard, D.; Hallin, M. From Investigating a Case of Cellulitis to Exploring Nosocomial Infection Control of ST1 Legionella pneumophila Using Genomic Approaches. Microorganisms 2024, 12, 857.

Abstract

Legionella pneumophila can cause a large panel of symptoms beside the classic pneumonia presentation. We present here a case of fatal nosocomial cellulitis in an immunocompromised patient followed, a year later, by a second case of legionnaires’ disease in the same ward. While the first one was easily assumed as nosocomial based on the date of symptoms onset, the other case needed to rely on clear typing results to be either assigned as nosocomial and related to the same environmental source as the first one, or community acquired. To untangle this specific question, we applied Core-genome MultiLocus Typing (MLST), whole-genome Single Nucleotide Polymorphism and whole-genome MLST methods to a collection of 36 Belgian and 41 international sequence-type 1 (ST1) isolates using both thresholds recommended in the literature and tailored threshold based on local epidemiological data. Based on the thresholds applied to cluster isolates together, the three methods gave different results and no firm conclusion about the nosocomial setting of the second case could been drawn. Our data highlight that despite promising results in the study of outbreaks and for large scale epidemiological investigations, NGS typing methods applied to ST1 outbreak investigation still need standardization regarding both wet-lab protocols and bioinformatics. A deeper evaluation of L. pneumophila evolutionary clock is also required to increase our understanding of genomic differences between isolates sampled during a clinical infection and in environment.

Keywords

Legionella pneumophila; Legionella pneumophila ST1; WGS; genomic typing; wgMLST; cgMLST; wgSNP; nosocomial; hygiene investigation

Subject

Public Health and Healthcare, Public Health and Health Services

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.