Prognosis and Virulence Determination of Capsule and Endotoxin During Klebsiella Spp. Ventilator-associated Pneumonias

Fondation Hôpital Saint-Joseph1,000 enrolled

Overview

Ventilator-associated pneumonia is the leading cause of nosocomial infection in the ICU. The pathogens responsible are multiple, but enterobacteria constitute a major source of pathogens involved. Within this family, Klebsiella spp. and Escherichia coli are the two most frequent genera, with Klebsiella spp. often present in severe forms. The factors associated with the occurrence of Ventilator-associated pneumonia and its adverse course depend on host defenses and the virulence of the pathogen. The virulence of Klebsiella spp. depends on several structures, notably the presence of a capsule, the particularities of its lipopolysaccharide, its adhesins (type 3 fimbriae), its capacity to capture iron (siderophores). The objective of this work is to evaluate the role of these different virulence mechanisms in the evolution of Ventilator-associated pneumonia and the hospital prognosis.

Study Type

OBSERVATIONAL

Enrollment

1,000

Conditions

Ventilator-associated Pneumonia

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patient whose age is ≥ 18 years * Patient hospitalized in an intensive care unit * Patient with ventilator-associated Klebsiella spp. pneumonia * French-speaking patient Exclusion Criteria: * Patient with a severe psychiatric disorder * Patient under guardianship or curatorship * Patient deprived of liberty * Patient under court protection * Patient who objects to the use of his or her data for this research

Locations (1)

Outcomes

Primary Outcomes

Role of 2-hydroxymyristate within lipid A of lipopolysaccharide in the prognosis of mechanically ventilated pneumonia caused by Klebsiella spp.

This outcome corresponds to the prognostic value (prediction of clinical cure) of the studied virulence parameters (myristate hydroxylation, presence of fimbriae, expression of siderophores, expression of capsule) at D7 of effective antibiotic treatment, according to the virulence parameters of the pathogen, after adjustment on known prognostic factors. This value will be estimated by the adjusted HR, the improvement of the model fit, the number of patients who change classification (cured/not cured) after inclusion of this factor.

Time frame: Month 1

Secondary Outcomes

Effect of other virulence factors on the evolution of ventilator-associated pneumonia

This outcome corresponds to the prognostic value (accuracy of recurrence of pulmonary infection under mechanical ventilation with the same germ (Klebsiella spp.) during the stay in intensive care.