Severe Legionellosis Cases Admitted to Grenoble University Hospital, 2006-2011. (LEGIOGRE)

Molecular Epidemiology of Legionellosis in Grenoble Region

The study aimed at further describing the epidemiological, clinical, diagnostic and prognostic features in legionellosis cases admitted to Grenoble University Hospital during the 2006-2011period. The investigators also tested lower respiratory samples collected from these patients during their routine medical care, using a number of molecular tools allowing determination of the involved Legionella species, the bacterial load, and the presence of antibiotic resistant mutants. Our primary goal was to define biological markers that could predict severity and outcome of infection in legionellosis cases requiring hospitalization.

Study Overview

• Status: Completed
• Conditions: Legionnaires' Disease
• Intervention / Treatment: Biological: Real-time PCR testing of lower respiratory tract samples

Detailed Description

Patients admitted to Grenoble University Hospital between 2006 and 2011 for severe legionellosis were retrospectively included in the study.

Clinical, epidemiological, diagnostic and prognostic data of these patients were recorded retrospectively.

Lower respiratory samples collected from these patients on a routine basis for microbiological analysis, especially Legionella culture, were tested using traditional microbiological methods. The remaining part of these samples was stored at -80°C fur further molecular analyses.

The molecular tools developed by our bacteriology laboratory included the following: a real-time polymerase chain reaction (qPCR) test allowing detection and differentiation of L. pneumophila and other Legionella species; a qPCR test allowing determination of the Legionella DNA load in lower respiratory samples; a qPCR allowing detection of gyrA (the gene encoding subunit A of DNA gyrase) mutations that the investigators previously determined to be correlated with fluoroquinolones resistance in L. pneumophila; a high-throughput sequencing approach allowing confirmation of gyrA mutations and determination of the percentage of mutated alleles.

The microbiological data, especially those obtained with the developped molecular tools, were tentatively correlated with the severity and outcome of infection in our patients' cohort.

• Study Type: Observational
• Enrollment (Actual): 82

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

82 unrelated legionellosis cases 64 males, 18 females mean age: 55 years, range: 27-97 years severe legionellosis requiring hospitalization

Description

Inclusion Criteria:

• age higher than 18 years
• proven legionellosis case (positive culture and/or PCR and/or urinary antigen test)
• severe case requiring hospitalization

Exclusion Criteria:

• age under 18 years
• pregnant women

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Severe legionellosis cases; Patients admitted to Grenoble University Hospital for severe legionellosis between 2006 and 2011.	Biological: Real-time PCR testing of lower respiratory tract samples; qPCR and high-throughput DNA sequencing testing of lower respiratory tract samples collected routinely in patients with severe legionellosis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Legionella DNA load in lower respiratory tract samples	Real-time polymerase chain reaction (qPCR) dosages in lower respiratory tract samples collected on a routine basis all over the hospitalization duration	through study completion, an average of 1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluoroquinolones resistant gyrA mutants in lower respiratory tract samples	Real-time polymerase chain reaction (qPCR) and high-throughput DNA sequencing testing of lower respiratory tract samples collected on a routine basis all over the hospitalization duration	through study completion, an average of 1 year

Collaborators and Investigators

• Sponsor: University Hospital, Grenoble
• Investigators: Study Director: Hélène Sabbah-Guillaume, Director, Direction of Research and Medical Innovation (DRCI)

Study record dates

Study Major Dates

• Study Start: September 1, 2009
• Primary Completion (Actual): December 1, 2011
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: August 22, 2016
• First Submitted That Met QC Criteria: August 30, 2016
• First Posted (Estimate): August 31, 2016

Study Record Updates

• Last Update Posted (Estimate): August 31, 2016
• Last Update Submitted That Met QC Criteria: August 30, 2016
• Last Verified: August 1, 2016

More Information

Terms related to this study

• Keywords: Prognosis; Diagnosis; Legionnaires' disease; Legionella
• Additional Relevant MeSH Terms: Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Gram-Negative Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Legionnaires' Disease; Legionellosis
• Other Study ID Numbers: Grenobole University Hospital

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Biological data are available at the bacteriology laboratory. Clinical data are available at the participating medical wards.