Characteristics of Lower Respiratory Tract Escherichia Coli Isolates in Mechanically Ventilated Intensive Care Patients

Completed

• Conditions: Escherichia Coli; Diarrhea, Enteroaggregative; Mechanical Ventilation Complication; Escherichia Coli Infections; Nosocomial Pneumonia; Ventilator Associated Pneumonia; Escherichia Coli Pneumonia

• Registration Number: NCT03303937
• Lead Sponsor: Hôpital Louis Mourier

Brief Summary

Prospective, multicenter observational study to collect Escherichia coli (E. coli) isolates originating from mechanically ventilated intensive care unit (ICU) patients; in order to characterize phenotype and genotype of E. coli strains retrieved from the lower respiratory tract of ventilated patients.

Detailed Description

Prospective, observational, multiple center study performed in 14 ICUs in France to collect Escherichia coli (E. coli) isolates originating from mechanically ventilated intensive care unit (ICU) patients; in order to characterize phenotype and genotype of E. coli strains retrieved from the lower respiratory tract of ventilated patients. All E. coli isolates identified in the microbiology lab and retrieved from a lung specimen (either tracheal aspirate, bronchoalveolar lavage, or telescopic plugged catheter) originating from an ICU patient will be kept, and stored at -80°C in brain-heart infusion broth containing glycerol 20 %. They will be then centralized in the investigators' research unit for further analysis that includes determination of Antimicrobial susceptibility, E. coli phylotype , O-type, and virulence factor gene content.

These isolates will be compared to those of two previously published collections, one from the stools of community subjects, considered as commensal strains, the other from the blood of bacteraemia patients.

Study Timeline

• Study Start: 2012-03-27
• Primary Completion: 2015-06-10
• Study Completion: 2016-06-06
• Study First Submitted: 2017-09-25
• Status Verified: 2017-10
• Study First Submitted QC: 2017-10-05
• Last Update Submitted: 2017-10-05
• Study First Posted: 2017-10-06
• Last Update Posted: 2017-10-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 289

Inclusion Criteria

• adult, admitted to the intensive care unit
• under invasive mechanical ventilation
• presence of Escherichia coli in lower respiratory tract specimen

Exclusion Criteria

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
phylogenetic group determination	50 minutes	Quadruplex polymerase chain reaction (PCR) method was used to determine the E. coli phylogenetic group (A, B1, B2, C, D, E, F), or Escherichia clade I belonging

Secondary Outcome Measures

Name	Time	Method
presence of betalactamase	90 minutes	Detection of gene sequences coding for the CTX-M and TEM enzymes was performed by PCR with genomic DNA
antimicrobial susceptibility determination	24 hours	Antimicrobial susceptibility of each isolate was determined by disk-diffusion method according to the French Society of Microbiology. Resistance score was defined as the sum of inactive in vitro antimicrobial agents for each isolate
virulence factor (VF) gene content determination	90 minutes	Multiplex PCR was used to detect genes encoding for eleven frequently encountered extraintestinal VFs (S and F fimbriae (sfa/foc), pili associated with pyelonephritis (papC), P adhesin (papGII, papGIII), the ferric yersiniabactin uptake receptor (fyuA), iron transport (iroN), aerobactin (aer), conjugal transfer protein (traT), N-acetylglucosamine 2-epimerase protein (neuC), hemolysin (hlyC), and the cytotoxic necrotizing factor 1(cnf1)
O-type determination	50 minutes	polymerase chain reaction (PCR) method was used to search for the most anticipated serotypes in extra-intestinal infections : O1, O2a, O2b, O4, O6, O7, O12, O15, O16, O17, O18, O22, O25a, O25b, O45a, O75, O78